2019年11月, 協和発酵バイオ賞（茨城テックプランター2019）, 藻バイオリファイナリー（藻によるモノづくり）
MoMo
国内学会・会議・シンポジウム等の賞

2004年, 農芸化学奨励賞

Alkane biosynthesis gene expression and its increased production in recombinant cyanobacteria.
Misato Nagao; Takato Ozaki; Hirofumi Fukuda; Yu Kanesaki; Munehiko Asayama, Microalgae such as cyanobacteria convert CO2 to compatible drop-in fuels, such as alkanes. However, the production yield is approximately 0.05-1.0% of the dry weight of natural algae. Here, we aimed to study the role of transcriptional expression, mRNA molecular structure and culture-dependent accumulation of alkanes from two cyanobacteria species. The transcription start sites of the alkane biosynthesis genes ado and aar were identified in the representative cyanobacteria strains Synechocystis sp. PCC 6803 and Limnothrix sp. SK1-2-1, which produce heptadecane and pentadecane, respectively. This characterisation revealed the potential promoters and unique mRNA structures of the ado and aar genes in these species. Transcripts from these genes were induced more in the nitrogen-depleted BG11 (BG11-N) culture than in the BG11 culture, although the biomass was reduced, and as such the amount of alkanes obtained per unit medium was greater for BG11 than for BG11-N. PCC 6803 transconjugants carrying alkane biosynthesis genes from PCC 6803 or SK1-2-1 showed an approximately 1.8- to 2.3-fold increase in heptadecane production compared to the control strain when grown on BG11 cultures without any nitrogen depletion. These results suggest that not only the enzymes ADO/AAR but also the intracellular production of fatty acyl-ACP substrates may be important for the mass production of target alkanes.
FEBS open bio, 2025年03月06日

ユニークな糸状性藍藻からのフィコシアノビリンの新規抽出法の開発と機能解析
Jinichi Aoki; Takashi Yarita; Morifumi Hasegawa; Munehiko Asayama, 責任著者, Elsevier BV
Journal of Biotechnology, 2024年11月

抗糖化活性を有するフィコシアニン産生糸状性藍藻の有効培養条件と安全性評価
Jinichi Aoki; Takato Ozaki; Runa Koshikawa; Daisaku Sasaki; Katsuyoshi Kitajima; Yuta Yoshida; Hiromi Nakajima; Munehiko Asayama, 責任著者, Elsevier BV
Journal of Biotechnology, 2024年08月

〔主要な業績〕Efficient pH and CO2 conditions for indoor and outdoor cultures of green alga Parachlorella
Akari Takagi; Misato Nagao; Yuya Uejima; Daisaku Sasaki; Munehiko Asayama, 筆頭著者, Frontiers
Frontiers in Bioengineering and Biotechnology, 2023年09月11日, ［査読有り］

Expression of candidate marker genes of sugar starvation is upregulated in growth-suppressed parthenocarpic cucumber fruit: Novel gene markers for sugar starvation in growth-suppressed cucumber fruit
Akio Tazuke; Tsuguki Kinoshita and Munehiko Asayama, Frontiers
Frontiers in Plant Science, 2023年08月18日, ［査読有り］

Enhanced supply of acetyl-CoA by exogenous pantothenate kinase promotes synthesis of poly(3-hydroxybutyrate)
Sho Ono; Kenta Abe; Mami Matsuda; Tomohisa Hasunuma; Tomoyasu Nishizawa; Munehiko Asayama; Hirofumi Nishihara; Shigeru Chohnan, Springer Nature
BMC Microbial Cell Factories, 2023年04月20日, ［査読有り］

〔主要な業績〕Regulation of RNase E during the UV-stress response in the cyanobacterium Synechocystis sp. PCC 6803
Watanabe S; Stazic D; Georg J; Ohtake S; Sakamaki Y; Numakura M; Asayama M; Chibazakura M; Wilde A; Steglich C; Hess WR:, Wiley
mLife, 2023年02月15日, ［査読有り］

〔主要な業績〕Coproduction of lipids and carotenoids by the novel green alga Coelastrella sp. depending on cultivation conditions
責任著者, 培養条件に依存した新奇緑藻コーラストレラ株による脂質とカロテノイドの共生産, ELSEVIER
Biotechnology Reports, 2022年10月24日, ［査読有り］

〔主要な業績〕Development of a method for phycocyanin recovery from filamentous cyanobacteria and evaluation of its stability and antioxidant capacity
Aoki J; Sasaki D; Asayama M, 責任著者, Elsevier
BMC Biotechnology, 2021年06月16日, ［査読有り］

Characteristics and function of an extracellular polysaccharide from a green alga Parachlorella
Sasaki, M; Takagi, A; Sasaki, D; Nakamura, A; Asayama M, 責任著者, Elsevier
Carbohydrate Polymers, 2021年02月, ［査読有り］

Enhancement of fatty acid biosynthesis by exogenous acetyl- CoA carboxylase and pantothenate kinase in Escherichia coli
Shusaku Satoh; Miho Ozaki; Saki Matsumoto; Takumi Nabatame; Moena Kaku; Takashi Shudo; Munehiko Asayama; Shigeru Chohnan, Enhancement of fatty acid biosynthesis, Springer
Biotechnology Letters, 2020年09月09日, ［査読有り］

Coproduction of lipids and extracellular polysaccharides from the novel green alga,Parachlorella sp. BX1.5 depending on cultivation conditions
Sasaki, M; Takagi, A; Ota, S; Kawano, S; Sasaki, D; Asayama M, 責任著者, ELSEVIER
Biotechnology Reports, 2020年02月, ［査読有り］

Biofuel production utilizing a dual-phase cultivation system with filamentous cyanobacteria
Jinichi Aoki; Toru Kawamata; Asuka Kodaka; Masayuki Minakawa; Nobukazu Imamura; Mikio Tsuzuki; Munehiko Asayama, Biomass yields and biofuel production were examined in a dual (solid and liquid)-phase cultivation system (DuPHA) with the unique filamentous cyanobacteria, Pseudanabaena sp. ABRG 5-3 and Limnothrix sp. SK1-2-1. Continuous circular cultivation was driven under the indoor closed (IC) or indoor opened (IO) conditions and provided biomass yields of approximately 8–27 g dry cell weight (DCW) floor m−2 d−1. Alkanes of heptadecane (C17H36) or pentadecane (C15H32) as liquid biofuels were also recovered from the lower liquid-phase, in which cyanobacteria were dropped from the upper solid-phase and continuously cultivated with a small amount of medium. After the main cultivation in DuPHA, the upper solid-phase of a cotton cloth on which cyanobacteria grew was dried and directly subjected to a combustion test. This resulted in the thermal power (kJ s−1) of the cloth with microalgae increasing approximately 20–50% higher than that of the cloth only, suggesting a possibility of using the solid phase with microalgae as solid biofuel., Elsevier B.V.
Journal of Biotechnology, 2018年08月20日, ［査読有り］

Flocculation and pentadecane production of a novel filamentous cyanobacterium Limnothrix sp. strain SK1-2-1
Takuya Sugawara; Mariko Chinzei; Setsuko Numano; Chifumi Kitazaki; Munehiko Asayama, Objective: A novel filamentous cyanobacterium, a photosynthesizing microorganism, was isolated from a river, and its unique features of flocculation and pentadecane production were characterized. Results: Microscopic observations and a phylogenetic analysis with 16S rDNA revealed that this strain was a Limnothrix species denoted as the SK1-2-1 strain. Auto cell-flocculation was observed when this strain was exposed to a two-step incubation involving a standing cultivation following a shaking preincubation. Flocculation was enhanced by blue light at a wavelength at 470 nm and irradiation for several hours to 1 day. Moreover, the strain exhibiting exponential cell growth may preferentially accumulate alkanes as pentadecane C15H32 alkane, which may be used as jet fuel, at a range of approximately 1% in the dry cell weight of flocculated cells. Conclusion: This is the first study on biofuel production using flocculated cells in which the specific manner of production may be regulated by cultivation conditions., Springer Netherlands
Biotechnology Letters, 2018年05月01日, ［査読有り］

Complete Genome Sequence of the Nonheterocystous Cyanobacterium Pseudanabaena sp. ABRG5-3.
Naoyuki Tajima; Yu Kanesaki; Shusei Sato; Hirofumi Yoshikawa; Fumito Maruyama; Ken Kurokawa; Hiroyuki Ohta; Tomoyasu Nishizawa; Munehiko Asayama; Naoki Sato, We report here the complete sequences of the main genome (4.8 Mb) and seven plasmids of the semifilamentous, nonheterocystous cyanobacterium Pseudanabaena sp. ABRG5-3, a strain isolated from a pond in Japan. These data are expected to enhance our understanding of the Pseudanabaena subclade near the root of cyanobacterial diversity.
Genome announcements, 2018年02月08日, ［査読有り］

The expression of a candidate cucumber fruit sugar starvation marker gene CsSEF1 is enhanced in malformed fruit induced by salinity
Akio Tazuke; Tsuguki Kinoshita; Munehiko Asayama, The cucumber (Cucumis sativus L.) gene Cucumis sativus Somatic Embryogenesis Zinc Finger 1 (CsSEF1) was suggested to be a good marker gene for sugar starvation in fruit. The expression of this gene in fruits is dramatically upregulated in plants that have suffered either complete defoliation or prolonged darkness. CsSEF1 was initially discovered as a gene that was upregulated during somatic embryogenesis. We examined the difference in fruit parts and the effect of pollination on the upregulation of CsSEF1 induced by defoliation treatment. The results indicated that the upregulation of CsSEF1 in fruit by defoliation is not dependent on the presence of developing embryos. The expression of CsSEF1 was upregulated in malformed fruit induced by salinity in which the development of placenta was arrested. Partial cutting of the distal part of the fruit showed that if placenta tissue remained there was no upregulation of CsSEF1, whereas when placenta tissue did not remain there was a marked upregulation of CsSEF1. These results could be consistently interpreted as showing that placenta tissue induced the transport of photoassimilates to the fruit and that without developing placenta tissue, pericarp tissue suffers from severe sugar starvation. This interpretation, in turn, enforces the view that CsSEF1 is a good marker gene of fruit sugar starvation., SPRINGER
PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS, 2017年07月, ［査読有り］

多彩な戦略で挑むシアノバクテリア由来の燃料生産 〜持続可能な第三世代バイオ, 燃料生産の最前線〜
日原由香子; 朝山宗彦; 蘆田弘樹; 天尾豊; 新井宗仁; 粟井光一郎; 得平茂樹; 小山; 内崇; 鞆達也; 成川礼; 蓮沼誠久; 増川一, 日本農芸化学会
化学と生物, 2017年, ［査読有り］, ［招待有り］

Actinophage R4 integrase-based site-specific chromosomal integration of non-replicative closed circular DNA
Takamasa Miura; Akito Nishizawa; Tomoyasu Nishizawa; Munehiko Asayama; Makoto Shirai, The actinophage R4 integrase (Sre)-based molecular genetic engineering system was developed for the chromosomal integration of multiple genes in Escherichia coli. A cloned DNA fragment containing two attP sites, green fluorescent protein (gfp) as a first transgene, and an antibiotic resistance gene as a selection marker was self-ligated to generate non-replicative closed circular DNA (nrccDNA) for integration. nrccDNA was introduced into attB-inserted E. coli cells harboring the plasmid expressing Sre by electroporation. The expressed Sre catalyzed site-specific integration between one of the two attP sites on nrccDNA and the attB site on the E. coli chromosome. The integration frequency was affected by the chromosomal location of the target site. A second nrccDNA containing two attB sites, lacZ encoding the alpha fragment of -galactosidase as a transgene, and another antibiotic resistance gene was integrated into the residual attP site on the gfp-integrated E. coli chromosome via one of the two attB sites according to reiterating site-specific recombination. The integrants clearly exhibited -galactosidase activity and green fluorescence, suggesting the simultaneous expression of multiple recombinant proteins in E. coli. The results of the present study showed that a step-by-step integration procedure using nrccDNA achieved the chromosomal integration of multiple genes., WILEY-BLACKWELL
JOURNAL OF BASIC MICROBIOLOGY, 2016年06月, ［査読有り］

Genetic engineering and metabolite profiling for overproduction of polyhydroxybutyrate in cyanobacteria
Sayaka Hondo; Masatoshi Takahashi; Takashi Osanai; Mami Matsuda; Tomohisa Hasunuma; Akio Tazuke; Yoichi Nakahira; Shigeru Chohnan; Morifumi Hasegawa; Munehiko Asayama, Genetic engineering and metabolite profiling for the overproduction of polyhydroxybutyrate (PHB), which is a carbon material in biodegradable plastics, were examined in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Transconjugants harboring cyanobacterial expression vectors that carried the pha genes for PHB biosynthesis were constructed. The overproduction of PHB by the engineering cells was confirmed through microscopic observations using Nile red, transmission electron microscopy (TEM), or nuclear magnetic resonance (NMR). We successfully recovered PHB from transconjugants prepared from nitrogen-depleted medium without sugar supplementation in which PHB reached approximately 7% (w/w) of the dry cell weight, showing a value of 12-fold higher productivity in the transconjugant than that in the control strain. We also measured the intracellular levels of acetyl-CoA, acetoacetyl-CoA, and 3-hydroxybutyryl-CoA (3HB-CoA), which are intermediate products for PHB. The results obtained indicated that these products were absent or at markedly low levels when cells were subjected to the steady-state growth phase of cultivation under nitrogen depletion for the overproduction of bioplastics. Based on these results, efficient factors were discussed for the overproduction of PHB in recombinant cyanobacteria. (C) 2015, The Society for Biotechnology, Japan. All rights reserved., SOC BIOSCIENCE BIOENGINEERING JAPAN
JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 2015年11月, ［査読有り］

Overproduction and easy recovery of biofuels from engineered cyanobacteria, autolyzing multicellular cells
Satomi Yoshida; Masatoshi Takahashi; Ayae Ikeda; Hirofumi Fukuda; Chifumi Kitazaki; Munehiko Asayama, The semi-filamentous multicellular cyanobacterium Limnothrix/Pseudanabaena sp. strain ABRG5-3 undergoes autolysis, which involves the accumulation of polyphosphate compounds and disintegration of thylakoid membranes in cells, as a unique feature that occurs due to growth conditions. In this study, the overexpression and easy recovery of alkane (a saturated hydrocarbon, C17H36) as a biofuel were examined in recombinants of the cyanobacteria ABRG5-3 and Synechocystis sp. strain PCC6803. The results obtained indicated that the accumulated mass of alkane accounted for similar to 50 or 60% of the dry weight of ABRG5-3 or PCC6803 recombinant cells, respectively. Furthermore, cultivating cells in liquid medium BG11 in which the nitrogen resource had been depleted promoted the production of alkane and cell lysis, resulting in the easy recovery of target products from the supernatant., OXFORD UNIV PRESS
JOURNAL OF BIOCHEMISTRY, 2015年06月, ［査読有り］

Expression of the BTB/POZ domain-containing protein At1g63850-like gene CsFDI1 is enhanced by sugar starvation in cucumber fruit
Akio Tazuke; Tsuguki Kinoshita; Munehiko Asayama, The cDNA of Cucumis sativus Fruit Defoliation Induced 1 (CsFDI1) was newly cloned using the subtraction method from a fruit of a defoliated cucumber (Cucumis sativus L. cv. Tokiwa) plant. An expression analysis of CsFDI1 in fruits and leaves was conducted along with those of the asparagine synthetase 1-like gene (AS) and Cucumis sativus Somatic Embryogenesis Zinc Finger 1 (CsSEF1), previously reported as control marker genes for sugar starvation. The transcript level of CsFDI1 and AS was relatively high, whereas that of CsSEF1 was very low under normal fruit development. The time course of the transcript levels of the three genes under prolonged darkness was compared with that of the fruit respiration rate and leaf starch concentration. The fruit respiration rate suggested that photoassimilate translocation to fruit ceased abruptly under prolonged darkness. The transcript level of CsFDI1, AS, and CsSEF1 increased in fruits, but the time course of the change was quite different in fruits and leaves under the condition of sugar starvation. The response of AS in leaves and CsSEF1 in fruits was close to all-or-none., SPRINGER HEIDELBERG
ACTA PHYSIOLOGIAE PLANTARUM, 2015年02月, ［査読有り］

Metabolomic analysis reveals rewiring of Synechocystis sp PCC 6803 primary metabolism by ntcA overexpression
Takashi Osanai; Akira Oikawa; Hiroko Iijima; Ayuko Kuwahara; Munehiko Asayama; Kan Tanaka; Masahiko Ikeuchi; Kazuki Saito; Masami Yokota Hirai, NtcA is a cAMP receptor protein-type transcription factor conserved among cyanobacteria and is essential for gene expression in response to nitrogen status. NtcA has been widely studied; however, no metabolomic analysis has been conducted using the ntcA mutant. Here, we generated a strain that overexpresses ntcA in Synechocystis sp. PCC 6803, named NOX10, and performed physiological, transcriptomic and metabolomic analyses. NOX10 grew faster than the wild-type strain under photoautotrophic conditions, but slower under light-activated heterotrophic conditions. Transcriptome analysis revealed that the expression of genes related to primary metabolism was altered by ntcA overexpression particularly under nitrogen-depleted conditions. Metabolomic analysis revealed that metabolite levels in sugar, purine/pyrimidine nucleotide, organic acid and amino acid metabolism were widely altered by ntcA overexpression. The protein levels of nitrogen-regulated transcriptional regulators were altered by ntcA overexpression during nitrogen starvation. These results demonstrate the alteration of primary metabolism by genetic engineering of NtcA, and they contribute to the current understanding of metabolic regulation of unicellular cyanobacteria., WILEY-BLACKWELL
ENVIRONMENTAL MICROBIOLOGY, 2014年10月, ［査読有り］

Construction of a stepwise gene integration system by transient expression of actinophage R4 integrase in cyanobacterium Synechocystis sp PCC 6803
Takamasa Miura; Akito Nishizawa; Tomoyasu Nishizawa; Munehiko Asayama; Hideo Takahashi; Makoto Shirai, The integrase of actinophage R4, which belongs to the large serine-recombinase family, catalyzes site-specific recombination between two distinct attachment site sequences of the phage (attP) and actinomycete Streptomyces parvulus 2297 chromosome (attB). We previously reported that R4 integrase (Sre) catalyzed site-specific recombination both in vivo and in vitro. In the present study, a Sre-based system was developed for the stepwise site-specific integration of multiple genes into the chromosome of cyanobacterium Synechocystis sp. PCC 6803 (hereafter PCC 6803). A transgene-integrated plasmid with two attP sites and a non-replicative sre-containing plasmid were co-introduced into attB-inserted PCC 6803 cells. The transiently expressed Sre catalyzed highly efficient site-specific integration between one of the two attP sites on the integration plasmid and the attB site on the chromosome of PCC 6803. A second transgene-integrated plasmid with an attB site was integrated into the residual attP site on the chromosome by repeating site-specific recombination. The transformation frequencies (%) of the first and second integrations were approximately 5.1 x 10(-5) and 8.2 x 10(-5), respectively. Furthermore, the expression of two transgenes was detected. This study is the first to apply the multiple gene site-specific integration system based on R4 integrase to cyanobacteria., SPRINGER HEIDELBERG
MOLECULAR GENETICS AND GENOMICS, 2014年08月, ［査読有り］

Role of prokaryotic type I and III pantothenate kinases in the coenzyme A biosynthetic pathway of Bacillus subtilis
Yuta Ogata; Hiroki Katoh; Munehiko Asayama; Shigeru Chohnan, kinases (CoaAs) catalyze the phosphorylation of pantothenate in the first step of the coenzyme A (CoA) biosynthetic pathway. These bacterial enzymes have been categorized into 3 types, the prokaryotic type I, II, and III CoaAs. Bacteria typically carry a single CoaA gene on their genome, but Bacillus subtilis possesses 2 proteins homologous to type I and III CoaAs, known as BsCoaA and BsCoaX, respectively. Both recombinant proteins exhibited the expected kinase activity and the characteristic properties of type I and III CoaAs, i.e., regulation by CoASH and acyl-CoAs in BsCoaA and the requirement of a monovalent cation in BsCoaX. Both gene disruptants appeared to grow in a manner similar to the wild-type strain. With the BsCoaX disruptant, the BsCoaA had the ability to completely fill the intracellular CoA pool, whereas the BsCoaA disruptant did not. These findings clearly indicate that these 2 CoaAs are employed together in the CoA biosynthetic pathway in B. subtilis and that the contribution of the type I CoaA (BsCoaA) to the formation of the intracellular CoA pool is larger than that of the type III CoaA (BsCoaX)., CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS
CANADIAN JOURNAL OF MICROBIOLOGY, 2014年05月, ［査読有り］

Expression of CsSEF1 gene encoding putative CCCH zinc finger protein is induced by defoliation and prolonged darkness in cucumber fruit
Tazuke A; Asayama M., To find a marker gene for photoassimilate limitation in cucumber fruit, genes induced in young fruit by total defoliation were cloned using the subtraction method. Almost every clone matched perfectly to a member of cucumber unigene ver. 3 of the Cucurbit Genomics Database. From the clones obtained, six genes were selected and the effect of defoliation on their expression was analyzed. In particular, expression of a gene that is highly homologous to the cucumber gene CsSEF1 (CAI30889) encoding putative CCCH zinc finger protein, which is reported to be induced at somatic embryogenesis in suspension culture, was enhanced by the treatment by about 50 times. The sequencing of the full-length cDNA and BLAST search in the Cucurbit Genomics Database indicated that our cloned gene is identical to CsSEF1. In control fruit, the expression of CsSEF1 did not change markedly in terms of development. By contrast, the expression of CsSEF1 was enhanced by prolonged darkness at the transcript level. This increase in the expression of CsSEF1 was temporally correlated with the decline in the fruit respiration rate. In mature leaves under prolonged darkness, enhanced expression was observed in the asparagine synthetase gene, but not in CsSEF1. These results suggest that the asparagine synthetase gene can be a good marker for sugar starvation and that CsSEF1 might be involved in the signal transduction pathway from photoassimilate limitation to growth cessation in cucumber fruit. © 2012 Springer-Verlag Berlin Heidelberg.
Planta, 2013年, ［査読有り］

Characterization of Lysis of Multicellular Cyanobacterium, Limnothrix/Pseudanabaena sp.,Strain ABRG5-3
Kitazaki C; Numano S; Takanezawa A; Nishizawa T; Shirai M; Asayama M., The cyanobacterium semi-filamentous multicellular strain ABRG5-3 undergoes cell lysis as a unique feature that occurs due to growth condition changes from normal cultivation with shaking to static cultivation without shaking in liquid culture (Nishizawa et al., 2010). Microscopic observation and energy dispersive X-ray spectrometer (EDX) analysis have revealed that lysis is involved in the accumulation of polyphosphate compounds and the disintegration of thylakoid membranes in cells. Static cultivation, dark or red light exposure, and temperature (22 to 42 degrees C) conditions were found to be effective factors for the induction of lysis. Moreover, stress induced by salts, osmotic pressure with sucrose, and the depletion of nitrogen or phosphate in cultures also induced ABRG5-3 cell lysis. Based on these results, we discuss lysis and its utilization in the biotechnology industry., TAYLOR & FRANCIS LTD
Bioscience, Biotechnology, and Biochemistry, 2013年, ［査読有り］

Overproduction and easy recovery of target gene products from cyanobacteria, photosynthesizing microorganisms
Munehiko Asayama, New cyanobacterial expression vectors, possessing an origin of replication that functions in a broad range of Gram-negative bacteria, were constructed. To inspect the shuttle vectors, the gene gfp was cloned downstream from the expression control element (ECE) originating from the regulatory region of the Microcystis aeruginosa gene psbA2 (for photosystem II D1 protein), and the vectors were introduced into three kinds of cyanobacteria (Synechocystis sp. PCC 6803, Synechococcus elongatus PCC 7942, and Limnothrix/Pseudanabaena sp. ABRG5-3) by conjugation. Multiple copy numbers of the expression vectors (in the range of 14-25 copies per cell) and a high expression of green fluorescent protein (GFP) at the RNA/protein level were observed in the cyanobacterial transconjugants. Importantly, GFP was observed in a supernatant from the autolysed transconjugants of ABRG5-3 and easily collected from the supernatant without centrifugation and/or further cell lysis. These results indicate the vectors together with the recombinant cells to be useful for overproducing and recovering target gene products from cyanobacteria., SPRINGER
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 2012年08月, ［査読有り］

In vivo and in vitro characterization of site-specific recombination of actinophage R4 integrase
Miura T; Hosaka Y; Yan-Zhuo Y; Nishizawa T; Asayama M; Takahashi H; Shirai M, The site-specific integrase of actinophage R4 belongs to the serine recombinase family. During the lysogenization process, it catalyzes site-specific recombination between the phage genome and the chromosome of Streptomyces parvulus 2297. An in vivo assay using Escherichia coli cells revealed that the minimum lengths of the recombination sites attB and attP are 50-bp and 49-bp, respectively, for efficient intramolecular recombination. The in vitro assay using overproduced R4 integrases as a hexahistidine (His(6))-glutathione-S-transferase (GST)-R4 integrase fusion protein, showed that the purified protein preparation retains the site-specific recombination activity which catalyzes the site-specific recombination between affP and attB in the intermolecular reaction. It also revealed that the inverted repeat within attP is essential for efficient in vitro intermolecular recombination. In addition, a gel shift assay showed that His(6)-GST-R4 integrase bound to the 50-bp attB and 49-bp attP specifically. Moreover, based on a detailed comparison analysis of amino acid sequences of serine integrases, we found the DNA binding region that is conserved in the serine recombinase containing the large C-terminal domain. Based on the results presented on this report, attachment sites needed in vitro and in vivo for site-specific recombination by the R4 integrase have been defined more precisely. This knowledge is useful for developing new genetic manipulation tools in the future., MICROBIOL RES FOUNDATION
Journal of General Applied Microbiolgy, 2011年, ［査読有り］

Characterization of the locus of genes encoding enzymes producing heptadepsipeptide micropeptin in the unicellular cyanobacterium Microcystis
Nishizawa T; Ueda A; Nakano T; Nishizawa A; Miura T; Asayama M; Fujii K; Harada K; Shirai M., The gene cluster involved in producing the cyclic heptadepsipeptide micropeptin was cloned from the genome of the unicellular cyanobacterium Microcystis aeruginosa K-139. Sequencing revealed four genes encoding non-ribosomal peptide synthetases (NRPSs) that are highly similar to the gene cluster involved in cyanopeptolins biosynthesis. According to predictions based on the non-ribosomal consensus code, the order of the mcnABCE NPRS modules was well consistent with that of the biosynthetic assembly of cyclic peptides. The biochemical analysis of a McnB(K-139) adenylation domain and the knock-out of mcnC in a micropeptin-producing strain, M. viridis S-70, revealed that the mcn gene clusters were responsible for the production of heptadepsipeptide micropeptins. A detailed comparison of nucleotide sequences also showed that the regions between the mcnC and mcnE genes of M. aeruginosa K-139 retained short stretches of DNA homologous to halogenase genes involved in the synthesis of halogenated cyclic peptides of the cyanopeptolin class including anabaenopeptilides. This suggests that the mcn clusters of M. aeruginosa K-139 have lost the halogenase genes during evolution. Finally, a comparative bioinformatics analysis of the congenial gene cluster for depsipetide biosynthesis suggested the diversification and propagation of the NRPS genes in cyanobacteria., OXFORD UNIV PRESS
Journal of Biochemistry, 2011年, ［査読有り］

Isolation and Molecular Characterization of a Multicellular Cyanobacterium, Limnothrix/Pseudanabaena sp. Strain ABRG5-3
Nishizawa T; Hanami T; Hirano E; Miura T; Watanabe Y; Takanezawa A; Komatsuzaki M; Ohta H; Shirai M; Asayama M, A cyanobacterium, semi-filamentous multicellular strain ABRG5-3, was isolated and its unique nature was characterized. This axenic strain formal colonies and was motile on an agarose plate. The 16S rRNA gene of ABRG5-3 exhibited similarities to those of the Limnothrix and Pseudanabaena strains, which are known as filamentous and nonheterocystous cyanobacteria. Peaks in absorbance for the accumulation of chlorophyll a, phycocyanin, and phycoerythrin were observed in the cell extract. Natural separation of the pigments occurred in the supernatant of the autolysed cells. The cell lysis was promoted by osmotic shocks and lysozyme treatments. Chlorophyll a and total DNA were abundantly recovered from the cells. Analysis of the restriction-modification system for genomic DNA revealed novel diversity. Moreover, we made a successful attempt to create antibiotic-resistant strains by conjugation with a foreign plasmid, which indicates that strain ABRG5-3 is transformable., TAYLOR & FRANCIS LTD
Bioscience, Biotechnology, and Biochemistry, 2010年, ［査読有り］

ChlH, the H subunit of the Mg-chelatase, is an anti-sigma factor for SigE in Synechocystis sp. PCC 6803
Osanai T; Imashimizu M; Seki A; Sato S; Tabata S; Imamura S; Asayama M; Ikeuchi M; Tanaka K, Although regulation of sigma factors has been intensively investigated, anti-sigma factors have not been identified in oxygenic photosynthetic organisms. A previous study suggested that the sigma factor, SigE, of the cyanobacterium Synechocystis sp. PCC 6803, a positive regulator of sugar catabolism, is posttranslationally activated by light-to-dark transition. In the present study, we found that the H subunit of Mg-chelatase ChlH interacts with sigma factor SigE by yeast two-hybrid screening, and immunoprecipitation analysis revealed that ChlH associates with SigE in a light-dependent manner in vivo. We also found that Mg(2+) promotes the interaction of SigE and ChlH and determines their localization in vitro. In vitro transcription analysis demonstrated that ChlH inhibits the transcription activity of SigE. Based on these results, we propose a model in which ChlH functions as an anti-sigma factor, transducing light signals to SigE in a process mediated by Mg(2+)., NATL ACAD SCIENCES
Proceedings of the National Academy of Sciences of the United State of America, 2009年, ［査読有り］

Genetic analysis of the microcystin biosynthesis gene cluster in Microcystis strains from four bodies of eutrophic water in Japan
Noguchi T; Shinohara A; Nishizawa A; Asayama M; Nakano T; Hasegawa M; Harada K; Nishizawa T; Shirai M, The highly conserved organization of microcystin biosynthesis (mcy) gene clusters, which includes nonribosomal peptide synthetase (NRPS) genes, polyketide synthase (PKS) genes, and fused NRPS-PKS genes, has been characterized in the genus Microcystis. In this study, a total of 135 cyanobacterial strains from four different geographical locations in Japan were isolated. Fourteen mcy-possessing (mcy(+)) strains were identified according to PCR amplification between two genes from domestic mcy(+) strains and the mcy gene's organization was classified into five types. Phylogenetic relationships of the 16S-23S internal transcribed spacer region indicated that the five types of mcy gene cluster structure classified into two groups of the genus Microcystis. HPLC of the isolated mcy(+) strain containing a partial deletion of mcyI (Delta mcyI) revealed that microcystin production disappeared. A transcriptional analysis of the Delta mcyI-strain and an assay of recombinant McyI dehydrogenase activity showed that McyI is responsible for microcystin biosynthesis. Based on patterns of the PCR amplicons and analyses of nucleotide sequences in the mcy gene cluster of Microcystis, we confirmed the presence of inserts at three specific loci, between mcyA and mcyD, and downstream of mcyC and mcyI. Our study is the first investigation of the mcy gene cluster structure in the genus Microcystis from environmental samples., MICROBIOL RES FOUNDATION
The Journal of General and Applied Microbiology, 2009年, ［査読有り］

Disruption of a gene encoding C(4)-dicarboxylate transporter-like protein increases ozone sensitivity through deregulation of the stomatal response in Arabidopsis thaliana
Shoko Saji; Srinivas Bathula; Akihiro Kubo; Masanori Tamaoki; Machi Kanna; Mitsuko Aono; Nobuyoshi Nakajima; Tatsuro Nakaji; Tomomi Takeda; Munehiko Asayama; Hikaru Saji, To understand better the plant response to ozone, we isolated and characterized an ozone-sensitive (ozs1) mutant strain from a set of T-DNA-tagged Arabidopsis thaliana ecotype Columbia. The mutant plants show enhanced sensitivity to ozone, desiccation and sulfur dioxide, but have normal sensitivity to hydrogen peroxide, low temperature and high light levels. The T-DNA was inserted at a single locus which is linked to ozone sensitivity. Identification of the genomic sequences flanking the T-DNA insertion revealed disruption of a gene encoding a transporter-like protein of the tellurite resistance/C(4)-dicarboxylate transporter family. Plants with either of two different T-DNA insertions in this gene were also sensitive to ozone, and these plants failed to complement ozs1. Transpiration levels, stomatal conductance levels and the size of stomatal apertures were greater in ozs1 mutant plants than in the wild type. The stomatal apertures of ozs1 mutant plants responded to light fluctuations but were always larger than those of the wild-type plants under the same conditions. The stomata of the mutant and wild-type plants responded similarly to stimuli such as light, abscisic acid, high concentrations of carbon dioxide and ozone. These results suggest that OZS1 helps to close stomata, being not involved in the responses to these signals., OXFORD UNIV PRESS
PLANT AND CELL PHYSIOLOGY, 2008年01月, ［査読有り］

Stringent promoter recognition and autoregulation by the group 3 σ factor SigF in the cyanobacterium Synechocystis sp. PCC 6803.
Asayama M; Imamura S, The cyanobacteirum Synechocystis sp. strain PCC 6803 possesses nine species of the sigma (sigma)-factor gene for RNA polymerase (RNAP). Here, we identify and characterize the novel-type promoter recognized by a group 3 sigma-factor, SigF. SigF autoregulates its own transcription and recognizes the promoter of pilA1 that acts in pilus formation and motility in PCC 6803. The pilA1 promoter (PpilA1-54) was recognized only by SigF and not by other -factors in PCC 6803. No PpilA1-54 activity was observed in Escherichia coli cells that possess RpoF (sigma(28)) for fragellin and motility. Studies of in vitro transcription for PpilA1-54 identified the region from 39 to 7 including an AG-rich stretch and a core promoter with TAGGC (32 region) and GGTAA (12 region) as important for transcription. We also confirmed the unique PpilA1-54 architecture and further identified two novel promoters, recognized by SigF, for genes encoding periplasmic and phytochrome-like phototaxis proteins. These results and a phylogenetic analysis suggest that the PCC 6803 SigF is distinct from the E. coli RpoF or RpoD (sigma(70)) type and constitutes a novel eubacterial group 3 sigma-factor. We discuss a model case of stringent promoter recognition by SigF. Promoter types of PCC 6803 genes are also summarized., OXFORD UNIV PRESS
Nucleic Acids Research, 2008年, ［査読有り］

Two novel nuclear genes, SIG5 and SIG6, encoding potential plastid sigma factors of RNA polymerase in rice: tissue-specific and light-responsive transcription　　　　　　　　　　　　　　　
Kubota Y; Miyao A; Hirochika H; Tozawa Y; Yasuda H; Tsunoyama Y; Niwa Y; Imamura S; Shirai M; Asayama M
Plant and Cell Physiology, 2007年, ［査読有り］

Interference expression at levels of the transcript and protein among group 1, 2, and 3 sigma factor genes in a cyanobacterium
Matsui M; Yoshimura T; Wakabayashi Y; Imamura S; Tanaka K; Tanahashi H; Asayama M; Shirai M, The sigma (sigma) factor is a subunit for the RNA polymerase (RNAP) holoenzyme and can confer promoter selectivity at a target gene. On the inactivation of all group 2 and 3 sigma factor genes, expression at the level of the transcript and protein was examined under continuous white light at an exponential phase in a unicellular cyanobacterium, Synechocystis sp. strain PCC 6803. It was found that interference expression exists among group 1, 2, and 3 sigma factor genes. Authentic echoes of the expression did not always reflect correlations between the transcript and protein levels. Linkages for the expression network of the sigma factors were summarized and unique properties discussed., JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE
Microbes and Environments, 2007年, ［査読有り］

Cloning and Characterization of a new hetero-gene cluster of nonribomal peptide synthetase and polyketide synthase from the cyanobacterium Microcystis aeruginosa K-139
Nishizawa A; Arshad AB; Nishizawa T; Asayama M; Fujii K; Nakano T; Harada K; Shirai M, Two nonribosomal peptide synthetase genes responsible for the biosynthesis of microcystin and micropeptin in Microcystis aeruginosa K-139 have been identified. A new nonribosomal peptide synthetase gene, psm3, was identified in M. aeruginosa K-139. The gene is a cluster extending 30 kb and comprising 13 bidirectionally transcribed open reading frames arranged in two putative operons. psm3 encodes four adenylation proteins, one polyketide synthase, and several unique proteins, especially Psm3L consisting of halogenase, acyl-CoA binding protein-like protein, and acyl carrier protein. Alignment of the binding pocket of the adenylation domain and an ATIR-PPi exchange analysis using a recombinant protein with the adenylation domain of Psm3B showed that Psm3G and Psm3B activate aspartic acid and tyrosine, respectively. Although disruption of psm3 did not reveal the product produced by Psm3, we identified microviridin B and aeruginosin K139 in the cells of M. aeruginosa K-139. The above-mentioned results indicated that M. aeruginosa possesses at least five nonribosomal peptide synthetase gene clusters., MICROBIOL RES FOUNDATION
Journal of General Applied Microbiolgy, 2007年, ［査読有り］

Cooperation of group 2 σ factors, SigD and SigE for light-induced transcription in the cyanobacterium Synechocystis sp. PCC 6803
Yoshimura T; Imamura S; Tanaka K; Shirai M; Asayama M, A light-inducible sigma factor of RNA polymerase, SigD, can contributes to the light-induced transcription of psbA in the cyanobacterium Synechocystis sp. PCC 6803. Here, another light-induced sigma F factor, SigE, was characterized together with SigD. Results indicated that SigE also contributes to light-induced transcription on the cpcBACD, psbA, petBD and psaAB promoters whose potential sequences are of the Escherichia coli sigma(70)-type. SigD and SigE interfere with each other's expression. A rhythmic expression, in which the periodic peak of SigE exhibits a 24-h interval according to the upcoming night, was observed at the protein level. The cooperation of group 2 a factors, SigD and SigE, for light-induced transcription was discussed. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV
FEBS Letters, 2007年, ［査読有り］

The NMR structure of the domain II of a chloroplastic NifU-like protein OsNifU1A.
Kumeta H; Ogura K; Asayama M; Katoh S; Katoh E; Teshima K; Inagaki F., NifU-like proteins are a highly conserved protein that serves as the scaffold for assembly of Fe-S clusters. Chloroplastic NifU-like proteins have tandem NifU like domains, named domain I and domain II. Although the amino acid sequences of these domains are very similar to each other, the predicted functional region for the Fe-S cluster assembly, the CXXC motif, exists only in domain I. The structure of the domain II of chloroplastic NifU-like protein OsNifU1A has an alpha-beta sandwich structure containing two alpha helices located on one side of the beta-sheet. The electrostatic surface potential of OsNifU1A domain II is predominantly positively charged. Chloroplastic NifU-like proteins are targeted to ferredoxin for transferring the Fe-S cluster. The ferredoxin presents an overall negatively charged surface, which may evoke an electrostatic association with OsNifU1A domain II., SPRINGER
Journal of Biomolecular NMR, 2007年, ［査読有り］

Dark-induced mRNA instability involves RNase E/G-type endoribonuclease cleavage at the AU-box and SD sequences in cyanobacteria.
Horie Y; Ito Y; Ono M; Moriwaki N; Kato H; Hamakubo Y; Amano T; Wachi M; Shirai M; Asayama M., Light-responsive gene expression is crucial to photosynthesizing organisms. Here, we studied functions of cis-elements (AU-box and SD sequences) and a trans-acting factor (ribonuclease, RNase) in light-responsive expression in cyanobacteria. The results indicated that AU-rich nucleotides with an AU-box, UAAAUAAA, just upstream from an SD confer instability on the mRNA under darkness. An RNase E/G homologue, Slr1129, of the cyanobacterium Synechocystis sp. strain PCC 6803 was purified and confirmed capable of endoribonucleolytic cleavage at the AU- (or AG)-rich sequences in vitro. The cleavage depends on the primary target sequence and secondary structure of the mRNA. Complementation tests using Escherichia coli rne/rng mutants showed that Slr1129 fulfilled the functions of both the RNase E and RNase G. An analysis of systematic mutations in the AU-box and SD sequences showed that the cis-elements also affect significantly mRNA stability in light-responsive genes. These results strongly suggested that dark-induced mRNA instability involves RNase E/G-type cleavage at the AU-box and SD sequences in cyanobacteria. The mechanical impact and a possible common mechanism with RNases for light-responsive gene expression are discussed., SPRINGER
Molecular Genomics and Genetics, 2007年, ［査読有り］

The cooperative role of OsCnfU-1A Domain I and Domain II in the iron sulphur cluster transfer process as revealed by NMR
Saio T; Kumeta H; Ogura K; Yokochi M; Asayama M; Katoh S; Katoh E; Teshima K; Inagaki F., OsCnfU-1A is a chloroplast-type Nfu-like protein that consists of tandem repeats sharing high sequence homology. Domain I of this protein, but not domain II, has a C-X-X-C motif that is thought to assemble an iron-sulphur cluster. Herein we report the solution structure of OsCnfU-1A domain I (73-153). Although OsCnfU-1A domain I is structurally similar to OsCnfLJ-1A domain II (154-226), the electrostatic surface potential of the 2 domains differs. Domain I has an acidic surface, whereas that of domain II is predominantly basic. Chemical shift perturbation studies on OsCnfu1A domain I and domain II with ferredoxin revealed negligible chemical shift changes in domain I, whereas much larger chemical shift changes were observed in domain II. The residues with larger chemical shift changes were located on the basic surface of domain II. Considering that ferredoxin is predominantly negatively charged, we propose the following hypothesis: First, an iron-sulphur cluster is assembled on domain I. Next, domain II interacts with the ferredoxin, thus tethering domain I close to the ferredoxin. Finally, domain I transfers the iron-sulphur cluster to the ferredoxin. Thus, domain II facilitates the efficient transfer of the iron-sulphur cluster from domain I to the ferredoxin., OXFORD UNIV PRESS
Journal of Biochemistry, 2007年, ［査読有り］

Diversity within the microcystin biosynthetic gene clusters among the genus Microcystis
Nishizawa T; Nishizawa A; Asayama M; Harada K; Shirai M., The principle organization of microcystin biosynthesis (mcy) gene clusters is characterized in three genera among the microcystin-producing cyanobacteria. To examine the conservation of the mcy gene clusters among the genus Microcystis, internal non-coding regions of the cluster in 21 strains including M. aeruginosa, M. viridis, and M. wesenbergii, were amplified by PCR using specific primer sets and sequenced. PCR-based analysis revealed a completely conserved organization of the bidirectional cluster structure, mcyABC and mcyDEFGHIJ, among all toxic and some microcystin-negative strains. Furthermore, all mcy gene clusters were flanked by a gene with homology to dnaN adjacent to mcyJ and by umal with no-homology to any known genes at the 3'-end of mcyC. Transposase homolog genes were observed in a non-coding region between dnaN and mcyJ in three rnicrocystin-producing Microcystis strains. Sequence analysis of a region adjacent to umal in mcy-negative strains revealed two types of gene constitution, dnaN-umal and the hypothetical protein gene-umal. PCR-based analyses can be used to assess the identification of microcystin-producer strains in Microcystis spp., JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE
Microbes and Environments, 2007年, ［査読有り］

Growth phase-dependent activation of nitrogen-related genes by a control network of group 1 and group 2 sigma factors in a cyanobacterium.　　　　　　　　　　　　　　　
Imamura S; Tanaka K; Shirai M; Asayama M
The Journal of Biological Chemistry, 2006年, ［査読有り］

Nitrogen induction of sugar catabolic gene expression in Synechocystis sp. PCC 6803
Osanai T; Imamura S; Asayama M; Shirai M; Suzuki I; Murata N; Tanaka K, Nitrogen starvation requires cells to change their transcriptome in order to cope with this essential nutrient limitation. Here, using microarray analysis, we investigated changes in transcript profiles following nitrogen depletion in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Results revealed that genes for sugar catabolic pathways including glycolysis, oxidative pentose phosphate (OPP) pathway, and glycogen catabolism were induced by nitrogen depletion, and activities of glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD), two key enzymes of the OPP pathway, were demonstrated to increase under this condition. We recently showed that a group 2 sigma factor SigE, which is under the control of the global nitrogen regulator NtcA, positively regulated these sugar catabolic pathways. However, increases of transcript levels of these sugar catabolic genes under nitrogen starvation were still observed even in a sigE-deficient mutant, indicating the involvement of other regulatory element(s) in addition to SigE. Since these nitrogen activations were abolished in an ntcA mutant, and since these genes were not directly included in the NtcA regulon, we suggested that sugar catabolic genes were induced by nitrogen depletion under complex and redundant regulations including SigE and other unknown factor(s) under the control of NtcA., OXFORD UNIV PRESS
DNA Research, 2006年, ［査読有り］

Refolding and purification of recombinant OsNifU1A domain II that was expressed by Escherichia coli.
Katoh S; Murata K; Kubota Y; Kumeta H; Ogura K; Inagaki F; Asayama M; Katoh; E, OsNifU1A is a NitU-like rice (Oryza sativa) protein, discovered recently. Its amino acid sequence is very homologous to the sequence of cyanobacterial CnfU and to the sequences of NifU C-terminal domains. Based on its sequence, OsNifU1A is probably a modular structure consisting of two CnfU-Iike domains, with domain I (formed by residues Leu73 to Gly153) and domain II (formed by residues Leu154 to Ser226). Domain I have a conserved Cys-X-X-Cys motif, which may function as an iron-sulfur cluster assembly scaffold. Domain II lacks a Cys-X-X-Cys motif and therefore, cannot function analogously. Other NifU-like proteins, with sequences homologous to OsNifU1A domain II, have been identified during plant genomic projects; however, the biological roles of these domains remain unknown. We successfully constructed an Escherichia coli expression system for OsNifU1A domain II that enabled us to synthesize and purify milligram quantities of protein for use in structural and functional studies. Using the Gateway system, we built DNA sequences corresponding to two OsNifLJ1A domain II fusion proteins. One construct has a (H'S)6 sequence upstream of the OsNifU1A domain II sequence; the other has an upstream thioredoxin-(HiS)(6) sequence. Recombinant OsNifU1A domain II fusion proteins were extracted from E coli inclusion bodies by dissolving them in 6 M guanidine-HCI. About 36% of the total (HiS)(6)/ OsNifU1A domain II fusion protein initially present remained soluble after guanidine-HCI was completely removed by step-wise dialysis; whereas, recovery of soluble Trx-(H'S)6 fusion protein was about 60% of the total cell lysate. About 2 mg of N-15-labeled OsNifUlA domain II was purified for NMR spectral studies. Examination of the OsNifUlA domain II H-1-N-15 HSQC NMR spectrum indicated that the purified protein was monomeric and correctly folded. Therefore, we established an efficient procedure for synthesis and purification of N-15-labeled OsNifUlA domain II in quantities sufficient for heteronuclear NMR solution structure studies. (c) 2005 Elsevier Inc. All rights reserved., ACADEMIC PRESS INC ELSEVIER SCIENCE
Protein Expression and Purification, 2005年

Positive regulation of sugar catabolic pathways in the cyanobacterium Synechocystis sp. PCC 6803 by the Group 2 σ factor SigE.
Osanai T; Kanesaki Y; Nakano T; Takahashi H; Asayama M; Shirai M; Kanehisa M; Suzuki I; Murata N; Tanaka K, The sigE gene of Synechocystis sp. PCC 6803 encodes a group 2 sigma factor for RNA polymerase and has been proposed to function in transcriptional regulation of nitrogen metabolism. By using microarray and Northern analyses, we demonstrated that the abundance of transcripts derived from genes important for glycolysis, the oxidative pentose phosphate pathway, and glycogen catabolism is reduced in a sigE mutant of Synechocystis maintained under the normal growth condition. Furthermore, the activities of the two key enzymes of the oxidative pentose phosphate pathway, glucose- 6- phosphate dehydrogenase and 6- phophogluconate dehydrogenase, encoded by the zwf and gnd genes were also reduced in the sigE mutant. The dark enhancements in both enzyme activity and transcript abundance apparent in the wild type were eliminated by the mutation. In addition, the sigE mutant showed a reduced rate of glucose uptake and an increased intracellular level of glycogen. Moreover, it was unable to proliferate under the light- activated heterotrophic growth conditions. These results indicate that SigE functions in the transcriptional activation of sugar catabolic pathways in Synechocystis sp. PCC 6803., AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
The Journal of Biological Chemistry, 2005年

Heat shock protein 90 inhibitor 17-allylamino-17-demethoxygeldanamycin potentiates the radiation response of tumor cells grown as monolayer cultures and spheroids by inducing apoptosis.
Machida M; Nakajima S; Shikano N; Nishio J; Okada S; Asayama M; Shirai M; Kubota N, Activation of the PI3K-Akt pathway is known to induce tumor radioresistance. In the current study, we examined the ability of 17AAG, which decreases the levels of Hsp90 client proteins including components of the PI3K-Akt pathway, to sensitize radioresistant human squamous cell carcinoma cells to X-irradiation. Human squamous cell carcinoma cell lines (SQ20B, SCC61 and SCC13) were incubated for 16 h at 37 degrees C in medium containing 17AAG. Radiation sensitivity was determined by clonogenic assays, and protein levels were examined by western blotting. Apoptosis was determined in monolayer cells by AO/EB double staining and in spheroids using the TdT-mediated dUTP nick end labeling assay. 17AAG (0.2 mu M) enhanced the radiosensitivity more effectively in radioresistant SQ20B and SCC13 cells than in radiosensitive SCC61 cells. However, in all three cell lines, 17AAG increased radiation-induced apoptosis by reducing the expression of EGFR and ErbB-2 and inhibiting the phosphorylation of Akt. Furthermore, 17AAG (1 mu M) sensitized SQ20B spheroids to radiation, and inhibition of Akt activation by 17AAG increased radiation-induced apoptosis in spheroids. The findings suggest that 17AAG effectively sensitizes radioresistant cells to radiation by inhibiting the PI3K-Akt pathway. Targeting the PI3K-Akt pathway with 17AAG could be a useful strategy for radiosensitization of carcinomas., BLACKWELL PUBLISHING
Cancer Science, 2005年

SigC, the group 2 sigma factor of RNA polymerase, contributes to the late-stage expression and,nitrogen promoter recognition in the cyanobacterium Synechocystis sp. strain PCC 6803.
Asayama M; Imamura S; Yoshihara S; Miyazaki A; Yoshida N; Sazuka T; Kaneko T; Ohara O; Tabata S; Tanaka K; Takahashi H; Shirai M, We examined the role of SigC (Sll0184), a sigma factor of RNA polymerase (RNAP), in a unicellular cyanobacterium, Synechocystis sp. strain PCC 6803. On the inactivation of sigC, which is an Escherichia coli rpoD homolog, cells were viable but had a low survival rate in the stationary phase of growth under normal physiological conditions, indicating that SigC is a group 2 type sigma factor. In analyses of transcript and protein levels using the sigC knockout strain, it was found that expression of glnB, a nitrogen key regulatory gene, is controlled by SigC in the stationary phase. Primer extension revealed that the glnB nitrogen promoter (P2) was specifically recognized by SigC in the stationary phase under conditions of nitrogen starvation. In vitro studies with purified enzymes indicated effective transcription, on supercoiled DNA templates, from P2 by SigC-RNAP with NtcA which is an activator for nitrogen gene transcription. DNase I footprinting also indicated binding and related sites of NtcA and/or RNAP with SigC on the nitrogen promoter. The unique promoter architecture and the mechanism of transcription by RNAP with SigC are also discussed., TAYLOR & FRANCIS LTD
Bioscience, Biotechnology, and Biochemistry, 2004年

光合成微生物の光誘導性遺伝子発現調節機構：転写・後転写に関与するシス配列とトランス因子　　　　　　　　　　　　　　　
朝山宗彦
日本農芸化学会誌（２００４年度農芸化学奨励賞受賞総説）, 2004年, ［招待有り］

In vitro transcription analysis by reconstituted cyanobacterial RNA polymerase: roles of group 1 and 2 sigma factors and a core subunit, RpoC2.　　　　　　　　　　　　　　　
Imamura S; Asayama M; Shirai M
Genes to Cells, 2004年

Purification, characterization, and gene expression of all sigma factors of RNA polymerase in a cyanobacterium.
Imamura S; Yoshihara S; Nakano S; Shiozaki N; Yamada A; Tanaka K; Takahashi H; Asayama M; Shirai M, The expression of RNA polymerase (RNAP) sigma factor genes and proteins was characterized as a first step toward understanding their functions in a unicellular cyanobacterium Synechocystis sp. PCC 6803, which can perform photosynthesis. All nine sigma factors (group 1, SigA; group 2, SigB to SigE; and group 3, SigF to SigI) and each RNAP core subunit (RpoA, RpoB, RpoC1 and RpoC2) were overproduced and purified from Escherichia coli cells, then polyclonal antibodies were prepared. Western blot and primer extension analyses revealed that the intracellular levels of group 1 and 2 sigma factors ranged from 0.9 fmol to 9.3 fmol per micro-gram of the total protein under conditions of steady-state growth, and that growth phase-dependent or constitutive transcripts were observed. Interestingly, no group 3 sigma factor proteins were detected under normal physiological conditions whereas their transcripts were robust, implying a possible regulation of translational attenuation and/or protein instability. Phylogenetic analysis also revealed that group 3 sigma factor homologues of cyanobacteria are conserved with evolutionary or functionary divergence among them. In vitro and in vivo results indicated significant evidence of high-light responsive SigD expression and its promoter recognition of the photosynthesis gene, psbA. On the other hand, autoregulated sigB transcription, a dramatically increased SigB expression upon the exposure of cells to heat-shock, and specific promoter recognition by SigB with redundancy of other sigma factors on the heat-shock hspA promoter were observed. These findings clearly indicated that SigB is a heat-shock responsive sigma factor. The unique promoter architecture and expression of the relevant sigma factor gene are also discussed herein. (C) 2003 Elsevier Science Ltd. All rights reserved., ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD
Journal of Molecular Biolology, 2003年

Light-responsive psbA transription requires the -35 hexamer in the promoter and its proximal upstream element, UPE, in cyanobacteria.
Ito Y; Asayama M; Shirai M, We characterized the function of the -35 hexamer in the promoter and an element just upstream, UPE, in the expression in a unicellular cyanobacterium, Microcystis aeruginosa K-81, of the light-responsive gene psbA2, which encodes a reaction center key protein for photosynthesis. A series of mutants with mutations at the -35 hexamer (-35 to -30) and a novel conserved upstream element (UPE: -45 to -36, +1 referring to the transcription start point) were constructed. Expression of the mutants was examined in vivo and in vitro by analyses using a beta-galactosidase assay, primer extension, and a DNA-mobility shift assay with RNA polymerases. Results indicated that the -35 hexamer and its proximal UPE act as effective cis-elements for the light-responsive and/or basal transcription, respectively. A model of the 5'-upstream region with cis- and possible trans-acting factors is presented for the psbA regulatory system., TAYLOR & FRANCIS LTD
Bioscience, Biotechnology, and Biochemistry, 2003年

Two-distinct curved DNAs upstream of the light-responsive psbA gene in a cyanobacterium.
Agrawal GK; Asayama M; Shirai M, A functional intrinsic DNA curvature, CIT, and potential DNA-binding factors for the basal transcription of psbA2 have been reported in a cyanobacterium, Microcystis aeruginosa K-81 (Asayama et al., Nucleic Acids Res., 30, 4658-4666 (2002)). In this article, we found another novel curved DNA, which was induced by RNA polymerases binding to the promoter region. Circular permutation analyses showed that the curved center of RNA polymerase-induced DNA bending (RIB) lies at approximately the + 10 site, referring to the transcription start point as + 1, in the RNA polymerase-DNA complex. Regions containing the curved center of RIB and CIT contributed to the basal transcription in vivo and in vitro. These results indicate that the region upstream of K-81 psbA2 has two distinct curved DNAs, CIT (sequence-directed type) and RIB (protein-induced type)., TAYLOR & FRANCIS LTD
Bioscience, Biotechnology, and Biochemistry, 2003年

Antagonistic dark-/light-induced SigB/SigD, group 2 sigma factors, expression through redox potential and their roles in cyanobacteria.　　　　　　　　　　　　　　　
Imamura S; Asayama M; Hiroyuki Takahashi; Tanaka K; Takahashi H; Shirai M
FEBS Letters, 2003年

The 5'-upstream cis-sequences of cyanobacterial psbA: analysis of their roles in basal, light-dependent and circadian rhythmic transcription.
Shibato J; Agrawal GK; Kato H; Asayama M; Shirai M, Transcription of the psbA2 gene in the unicellular photosynthetic cyanobacterium Microcystis aeruginosa K-81 is modulated by light and follows a circadian rhythm. In this study, we further characterized psbA transcription using a series of 5'-upstream deletions and mutant promoters which were tested in both photosynthetic and non-photosynthetic bacteria. Specific psbA2 transcripts were obtained from a minimal promoter sequence (-38/+14) with Escherichia coli RNA polymerases (RNAPs) both in vivo and in vitro, indicating the presence of a common regulatory mechanism for basal transcription. A DNase I footprinting assay showed that the E. coli RNAP, which is structurally similar to that of cyanobacteria, specifically binds to a large segment (from -115 to +23) of the sequence upstream of psbA2. In cyanobacteria, the -10 sequence (TAGTAT), but not the -35 motif (TTTACA), is essential for basal transcription by homologous and heterologous RNAPs that contain the major sigma factor. Each of the conserved thymidine nucleotides at positions -12 and -7 (underlined above) was essential, and both an insertion and a deletion in the spacer region of the promoter caused reductions in transcription. RNAP was able to bind to a mutant promoter lacking the -10 sequence, though this did not actually lead to transcription. Interestingly, a high level of arrhythmic circadian transcription was observed in mutants lacking the -35 region. In contrast, a mutation in the AU-box mutation, which controls the stability of the psbA2 mRNA, did not affect the circadian pattern of transcription. These findings demonstrate that light-dependent psbA2 expression is controlled at the transcriptional and post-transcriptional levels, whereas the circadian pattern of expression is regulated at the transcriptional level., SPRINGER-VERLAG
Molecular Genetics and Genomics, 2002年

The curved DNA structure in the 5'-upstream region of the light-responsive genes: its universality, binding factor and function for cyanobacterial psbA transcription.
Asayama M; Kato H; Shibato J; Shirai M; Ohyama T, A unique DNA curvature, the CIT, has been found in the 5'-upstream region of the psbA2 gene, which exhibits basal, light-responsive and circadian rhythmic transcription, in a unicellular photosynthetic cyanobacterium, Microcystis aeruginosa K-81. In this study, we report the universality of curvatures found in 5'-upstream regions in the psbA family and the function of the curvature in gene expression. Intrinsic curvatures were identified within 1000 bp upstream from the psbA genes in another cyanobacterium, a red alga and in plants (monocot and dicot). Mutagenized curvatures were constructed and confirmed to have disrupted architecture by gel electrophoresis and atomic force microscopy. Relatively small amounts but light-responsive transcripts of psbA2 were observed in cyanobacterial transformants harboring the mutagenized curvature under light/dark and light/high-light conditions. This shows that the curvature is important for basal transcription. In vitro primer extension and DNA mobility shift assay revealed that factors which might bind to the region upstream from the bending center contribute to the effective basal transcription of psbA2., OXFORD UNIV PRESS
Nucleic Acids Research, 2002年

Cyclic heptapeptide microcystin biosynthesis requires the glutamate racemase.
Nishizawa T; Asayama M; Shirai M, It was demonstrated previously that the operon consisting of the nonribosomal peptide synthetase (NRPS) gene coupled with the polyketide synthase (PKS) gene involved in cyclic heptapeptide microcystin synthesis includes two different D-amino acid synthetase genes, an epimerization domain at the 3' end of module 2, and the racemase gene mcyF, To determine the role of mcyF in microcystin synthesis, gene-disruption and complementation analyses were carried out. Insertional mutagenesis in the mcyF gene, generated by homologous recombination, abolished only microcystin synthesis, but did not influence cell growth, Furthermore, McyF supported D-Glu-independent growth of a strain of Escherichia coli defective in D-Glu synthesis, It is concluded that mcyF is the glutamic acid racemase gene involved in the synthesis of D-Glu residues in the microcystin molecule. This is the first report of the racemase in prokaryotic NRPS., SOC GENERAL MICROBIOLOGY
Microbiology, 2001年

An AU-box motif upstream of the SD-seqence of light-dependent psbA transcripts confers mRNA instability under darkness in cyanobacteria.
Agrawal GK; Kato H; Asayama M; Shirai M, The psbA2 gene of a unicellular cyanobacterium, Microcystis aeruginosa K-81, encodes a D1 protein homolog in the reaction center of photosynthetic Photosystem II. The expression of the psbA2 transcript has been shown to be light-dependent as assessed under light and dark (12/12 h) cycling conditions. We aligned the 5'-untranslated leader regions (UTRs) of psbAs from different photosynthetic organisms and identified a conserved sequence, UAAAUAAA or the 'AU-box', just upstream of the SD sequences. To clarify the role of 5'-upstream cis-elements containing the AU-box for light-dependent expression of psbA2 a series of deletion and point mutations in the region were introduced into the genome of heterologous cyanobacterium Synechococcus sp. strain PCC 7942, and psbA2 expression was examined, A clear pattern of light-dependent expression was observed in recombinant cyanobacteria carrying the K-81 psbA2-38/+36 region (which includes the minimal promoter element and a light-dependent cis-element with the AU-box), +1 indicating the transcription start site. A constitutive pattern of expression, in which the transcripts remained almost stable under dark conditions, was obtained in cells harboring the -38/+14 region (the minimal element), indicating that the +14/+36 region with the AU-box is important for the observed light-dependent expression. Point mutations analyses within the AU-box also revealed that changes in number, direction and identity (as assayed by adenine/uridine nucleotide substitutions) influenced the light-dependent pattern of expression, The level of psbA2 transcripts increased markedly in CG- or deletion-box mutants in the dark, strongly indicating that the AU- (AT-) box acts as a negative cis-element, Furthermore, characterization of transcript accumulation in cells treated with rifampicin suggests that psbA2 5'-mRNA is unstable in the dark, supporting the view that the light-dependent expression is controlled at the post-transcriptional level. We discuss various mechanisms that may lead to altered mRNA stability such as the binding of factor(s) or ribosomes to the 5'-UTR and possible roles of the AU-box motif and the SD sequence., OXFORD UNIV PRESS
Nucleic Acids Research, 2001年

Polyketide synthase gene coupled to the peptide synthetase module involved in the biosynthesis of the cyclic heptapeptide Microcystin.
Nishizawa T; Ueda A; Asayama M; Fujii K; Harada K; Ochi K; Shirai M, The peptide synthetase gene operon, which consists of mcyA, mcyB, anti mcyC, for the activation and incorporation of the five amino acid constituents of microcystin has been identified [T. Nishizawa et al. (1999) J. Biochem. 126, 52-529]. By sequencing an additional 34 kb of DNA from microcystin-producing Microcystis aeruginosa K-139, we identified the residual microcystin synthetase gene operon, which consists of mcyD, mcyE, mcyF,and mcyG, in the opposite orientation to the mcyABC operon. McyD consisted of two polyketide synthase modules, and McyE contained a polyketide synthase module at the N-terminus and a peptide synthetase module at the C-terminus. McyF was found to exhibit similarity to amino acid racemase, McyG consisted of a peptide synthetase module at the N-terminus and a polyketide synthase at the C-terminus, The microcystin synthetase gene cluster was conserved in another microcystin-producing strain, Microcystis sp, S-70, which produces Microcystin-LR, -RR, and -YR. Insertional mutagenesis of mcyA, mcyD, or mcyE in Microcystis sp, S-70 abolished microcystin production. In conclusion, the mcyDEFG operon is presumed to be responsible for 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid (Adda) biosynthesis, and the incorporation of Adda and glutamic acid into the microcystin molecule., JAPANESE BIOCHEMICAL SOC
Journal of Biochemistry, 2000年

An intrinsic DNA curvature found in the cyanobacterium Microcystis aeruginosa K-81 affects the promoter activity sigma factor.
Asayama M; Hayasaka Y; Kabasawa M; Shirai M; Ohyama T, The rpoD1 gene in the unicellular cyanobacterium Microcystis aeruginosa K-81 encodes a principal sigma factor of RNA polymerase and is transcribed under light and dark conditions to produce multiple monocistronic transcripts. In the 5'-upstream region from rpoD1 Promoter 2, which has a sequence of Escherichia coli type, we found a sequence-directed DNA curvature with an AT-rich sequence. Insertions of 2 to 21 base pairs introduced into the curved center changed a gross geometry of the original curved DNA structure. The rpoD1 promoter activities assayed in vivo by using transcriptional lacZ fusions were correlated with the change in the gross geometry in not only a cyanobacterium but also E. coli. In addition, RNA polymerase binding to the rpoD1 promoter region and the efficiency of the mRNA synthesis from the rpoD1 Promoter 2 were also affected in vitro by the change in the geometry. These results suggest that the tertiary structure of the curved DNA is important for the rpoD1 transcription. The deletion of the center region of the curvature resulted in a considerable reduction of the transcription from Promoter 2 in the cyanobacterium. This report demonstrates that a curved DNA plays a significant role in transcription in cyanobacteria, and that this functional curvature is located in the 5'-upstream region from the rpoD gene, which encodes a principal sigma factor in eubacteria., OXFORD UNIV PRESS
Journal of Biochemistry, 1999年

Light-dependent and rhythmic psbA transcripts in homologous/heterologous cyanobacterial cells.
Agrawal GK; Asayama M; Shirai M, The psbA2 gene exhibits light-dependent and rhythmic expression in a unicellular cyanobacterium, Microcystis aeruginosa (Synechocystis) K-81. To further understand the psbA2 expression, biological analyses were performed in homologous and heterologous cyanobacterial cells. The results of the experiments using the K-81 cells revealed that (i) the light-dependent expression appeared on transcriptional and/or post-transcriptional level(s) under light/dark cycles, (ii) circadian-rhythmic transcripts were also observed under the control of an endogenous clock. To assess whether light-dependent and rhythmic psbA2 expression occurs in heterologous cyanobacterium, Synechococcus sp. strain PCC 7942, the K-81 psbA2 5'-upstream region of which the promoter and its around sequences share with those of PCC 7942 psbAII, was fused to the bacterial lacZ reporter gene, introduced into the genome of PCC 7942 and the psbA2 transcripts were directly investigated by primer extension. The K-81 psbA2 specific transcripts were also light-dependent and rhythmic in PCC 7942, strongly demonstrating that a common regulatory mechanism exists per se for the psbA2 expression in both strains. Furthermore, psbA2 expression in the recombinant PCC 7942 strain, AG400 in which the region from -404 to +111 of psbA2 is fused to lacZ, exhibited clear rhythmicity, while very little or no rhythmicity was observed in AG429 (-38 to +14, the only promoter region), suggesting that the region(s) around the promoter was essentially required for clear rhythmic expression. (C) 1999 Academic Press., ACADEMIC PRESS INC
Biochemical and Biophysical Research Communications, 1999年

Genetic analysis of the peptide synthetase genes for a cyclic heptapeptide microcystin in Microcystis spp.
Nishizawa T; Asayama M; Fujii K; Harada K; Shirai M, Peptide-synthetase-encoding DNA fragments were isolated by a PCR-based approach from the chromosome of Microcystis aeruginosa K-139, which produces cyclic heptapeptides, 7-desmethylmicrocystin-LR and 3,7-didesmethylmicrocystin-LR. Three open reading frames (mcyA, mcyB, mcyC) encoding microcystin synthetases were identified in the gene cluster. Sequence analysis indicated that McyA (315 kDa) consists of two modules with an N-methylation domain attached to the first and an epimerization domain attached to the second; McyB (242 kDa) has two modules, and McyC (147 kDa) contains one module with a putative C-terminal thioesterase domain. Conserved amino acid sequence motifs for ATP binding, ATP hydrolysis, adenylate formation, and 4'-phosphspantetheine attachment were identified by sequence comparison with authentic peptide synthetase. Insertion mutations in mcyA, generated by homologous recombination, abolished the production of both microcystins in ill. aeruginosa K-139, Primer extension analysis demonstrated light-dependent mcy expression. Southern hybridization and partial DNA sequencing analyses of six microcystin-producing and two non-producing Microcystis strains suggested that the microcystin-producing strains contain the mcy gene and the non-producing strains can be divided into two groups, those possessing no mcy genes and those with mcy genes., JAPANESE BIOCHEMICAL SOC
Journal of Biochemistry, 1999年

Specific recognition of the cyanobacterial psbA promoter by RNA polymerases containing principal sigma factors.
Shibato J; Asayama M; Shirai M, The psbA2 gene of a unicellular cyanobacterium, Microcystis aeruginosa K-81, encodes a D1 protein homolog in the reaction center of photosynthetic Photosystem II. To clarify the promoter recognition by a sigma factor of RNA polymerase, in vivo and in vitro analyses were performed for the photosynthetic gene. Although the specific transcript from the psbA2 promoter, whose sequence is of Escherichia coli consensus type, was observed in both cyanobacterium K-81 and E. coli cells, the expression was light-dependent in K-81 whereas it was constitutive in E, coli under the conditions of light and darkness (L/D). The specific psbA2-dependent transcripts were also detected in vitro by RNA polymerases containing the principal sigma factors, E. coli sigma(70) and K-81 sigma(A1) (constitutively exists in K-81 grown under L/D cycles). Furthermore, a series of promoter fragments were constructed to confirm minimal cis elements for the in vitro psbA2 transcription. A -80 to +6 or -38 to +46 region, the sequences of which consisted of a core promoter (-38 to +6), was identified as the potential minimal cis element using the RNA polymerase fraction (*E sigma(A1)) containing sigma(A1) partially purified from K-81. These results suggest that the pshA2 transcription with the minimal sequence was induced by the RNA polymerase (E sigma(A1)) containing the principal sigma factor, sigma(A1), under both light and dark conditions in K-81. (C) 1998 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV
Biochimica et Biophysica Acta, 1998年

Translational attenuation of the Bacillus subtilis spo0B cistron by an RNA structure encompassing the initiation region.
Asayama M; Saito K; Kobayashi Y, The spoOB gene, which exists as an operon with the obg gene, is required to initiate sporulation (stage 0) of Bacillus subtilis. This gene encodes a phosphotransferase in the multicomponent phosphorelay system. We here report the novel finding that a spoOB 5'-terminal. SLR (stem-loop structure sequestering ribosome binding sequence; ACUCCUAA-X-16-UUG-GGAGU, Delta G = -8.71 kcal/mol) attenuated spoOB translation, The spoOB gene was efficiently transcribed but SpoOB protein was not overproduced in Escherichia coli when spoOB was induced using expression vectors carrying the SLR-spoOB region under control of the tac promoter. Deletion of the SLR from the vectors resulted in overexpression of spoOB. Therefore, to characterize expression of spoOB with a SLR in B. subtilits we constructed transcriptional and translational lacZ fusions combined with the spoOB 5'-terminal region with a deleted or mutagenized SLR. these constructs were subsequently introduced into B.subtilis as multiple and single copies, then beta-galactosidase activities were measured. The possible SLR also functioned as a negative cis element in B.subtilis. Furthermore, B.subtilis strain 1S16 (spoOB136) lysogenized phi CDOB-S and -W, harboring spoOB with mutagenized SLRs that were more (Delta G = -14.0 kcal/mol) and less-stable (Delta G = -1.31 kcal/mol) compared with the wild-type, exhibited-null and wild-type sporulation respectively. These results indicate that the spoOB 5'-SLR affects spoOB gene expression for sporulation but that low expression of spoOB through the wild-type SLR was sufficient to initiate sporulation in B.subtilis., OXFORD UNIV PRESS
Nucleic Acids Research, 1998年

A new sigma factor homolog in a oyanobacterium: Cloning, sequencing, and light-responsive transcripts of rpoD2 from Microcystis aeruginosa K-81.
Asayama M; Suzuki A; Nozawa S; Yamada A; Tanaka K; Takahashi H; Aida T; Shirai M, We isolated an rpoD2 gene encoding the potential sigma factor of RNA polymerase from the cyanobacterium Microcystis aeruginosa K-81, which can perform photosynthesis. The deduced amino acid sequence of RpoDZ (sigma(A2)) exhibits extensive homology to other eubacterial RpoD proteins. This gene possessed multiple 5'-end transcripts, expressed specifically under light (P-L), dark (P-D), or constitutively light/dark (P-C) conditions during exponential cell growth. (C) 1997 Elsevier Science B.V., ELSEVIER SCIENCE BV
Biochimica et Biophysica Acta, 1997年

A novel genetic organization : the leuA-rpoD1 locus in the cyanobacterium Microcystis aeruginosa K-81.
Asayama M; Kabasawa M; Shirai M, We cloned and sequenced the region upstream of rpoD1, which encodes a principal sigma factor in the cyanobacterium Microcystis aeruginosa K-81. An open reading frame (orf1, 1599 bp) was discovered, the deduced amino-acid sequence of which (533 aa, 58, 016 Da) exhibits homology to another bacterial leuA gene product, 2-isopropylmalate synthase. The leuA (orf1) gene specifically complemented an E. coli leuA mutant. The 5'-upstream region of leuA did not contain possible leader peptide or stem-loop structures for attenuation. These findings indicate that the genetic structure of the leuA-rpoD1 locus in M. aeruginosa K-81 significantly differs from those of known leuA and rpoD loci found in other bacteria., ELSEVIER SCIENCE BV
Biochimica et Biophysica Acta, 1997年

A novel bend of DNA CIT: Changeable bending-center sites of an intrinsic curvature under temperature conditions.
Agrawal GK; Asayama M; Shirai M, We found a novel DNA curvature, which has changeable bending-center sites of an intrinsic curvature under temperature conditions (CIT) in the cyanobacterium strain Microcystis aeruginosa K-81. Circular permutation analyses (CPA) for CIT under different temperature conditions (4-50 degrees C) revealed that the changeable bending-center sites are located in the 5'-upstream region (-141 to -184) of the psbA2 gene, encoding the Dl protein homolog for photosynthesis. The nucleotide sequence around the bending center contains several dT (deoxy thymine) tracts, which seem to be a pivotal determinant for CIT., ELSEVIER SCIENCE BV
FEMS Microbiology Letters, 1997年

Highly repetitive seguences and characteristics of genomic DNA in unicellular cyanobacterial strains.
Asayama M; Kabasawa M; Takahashi I; Aida T; Shirai; M, Microcystis aeruginosa (Synechocystis) is a unicellular cyanobacterium that performs oxygenic photosynthesis. We found two novel sets of repetitive sequences, A (REP-A) and B (REP-B), on the M. aeruginosa K-81 genomic DNA, which consisted of distinct motifs of tandem repeated sequences located in the up- and downstream regions of the orf1 structural gene, respectively. Genomic Southern hybridization revealed multicopies of REP-A and -B on the genome. Furthermore, genomic Southern blots of cyanobacteria species with the REP-A and -B probes revealed that different hybridization signals appeared on the genomic DNAs of all 12 Microcystis strains, but no signal appeared on those of Synechocystis sp. PCC 6803, Synechococcus sp. PCC 7942, and Anabaena sp. PCC 7120., ELSEVIER SCIENCE BV
FEMS Microbiology Letters, 1996年

The sre gene (ORF469) encodes a site-specific recombinase responsible for integration of the R4 phage genome
Matsuura M; Noguchi T; Yamaguchi D; Aida T; Asayama M; Takahashi H; Shirai M, The sre gene (ORF469) of the R4 phage encodes a protein similar to the resolvase-DNA invertase family proteins. Insertional gene disruption of sre prevented a lysogen from entering the lytic cycle, implying that Sre protein is a site-specific recombinase needed for excision of the R 4 prophage genome (M. Matsuura, T. Noguchi, T. Aida, M. Asayama, H. Takahashi, and M. Shirai, J. Gen, Appl, Microbiol, 41:53-61, 1995). To determine whether this sre gene is also necessary for the integration reaction, we studied its function by integration plasmid analysis. When deletions, frameshifts, and site directed mutations that caused an amino acid substitution of Ser-17 for Ala were introduced into the sre structural gene, transformation effciency of Streptogyces parvulus 2297 with these plasmid DNAs was severely reduced. However, an adenine insertion just before the possible initiation codon of the sre gene did not significantly decrease the efficiency. These data suggest that the Sre protein is a site-specific recombinase responsible for integration of the R4 phage genome., AMER SOC MICROBIOLOGY
Journal of Bacteriology, 1996年

Cloning, sequencing and characterization of the gene encoding a principal sigma factor homolog from the cyanobacterium Microcystis aeruginosa K-81.
Asayama M; Tanaka K; Takahashi H; Sato A; Aida T; Shirai M, We cloned and sequenced the rpoD1 gene of Microcystis aeruginosa K-81, a unicellular colony-forming cyanobacterium that can perform photosynthesis involving light-responsive gene expression. The deduced amino acid sequence of RpoD1 exhibited extensive homology to the other eubacterial principal sigma factors. Primer extension and Western blot analyses revealed that the rpoD1 gene, which encodes a principle sigma factor homolog, had two transcription start points, P1 and P2. These transcripts, and the corresponding protein, constitutively appeared in M. aeruginosa, irrespective of light or dark conditions., ELSEVIER SCIENCE BV
Gene, 1996年

The rpoD1 gene produdt is a principal sigma factor of RNA polymerase in Microcystis aeruginosa K-81.
Asayama M; Suzuki H; Sato A; Aida T; Tanaka K; Takahashi H; Shirai M, We performed molecular characterization of the RpoD1 protein encoded by the rpoD1 gene isolated from a cyanobacterium, Microystis aeruginosa K-81, The deduced amino acid sequence (416 aa, 48,871 Da) of RpoD1 exhibited extensive similarity to those of proteins of the eubacterial RpoD family (Escherichia coli sigma(70) homologs), We overproduced and purified RpoD1 (54 kDa) from E, coli, Biological and biochemical analyses suggested that RpoD1 has a function homologous to that of E, coli sigma(70) as follows: (i) the RpoD1 protein complemented an rpoD mutant of E, coli strain YN543 (rpoD285) and (ii) the heterologous RNA polymerase holoenzyme reconstituted from the E, coli core enzyme and recombinant RpoD1 was specifically transcribed from E, coli promoters, Furthermore, Western blot analysis with antiserum against Synechococcus sp, strain PCC 7942 RpoD1 (a principal sigma factor of the sigma(70) type) indicated that M. aeruginosa K-81 RpoD1 (sigma(A1)) is the principal sigma factor, which is a major component of the sigma subunit on exponential cell growth., JAPAN BIOCHEMICAL SOC
Journal of Biochemistry, 1996年

Light-responsive and rhythmic gene expression of psbA2 in cyanobacterium Microcystis aeruginosa K-81.
Sato M; Shibato J; Aida T; Asayama M; Shirai M, We cloned, sequenced and characterized the psbA2 gene of the cyanobacterium Microcystis aeruginosa K-81 strain. The deduced amino acid sequence of PsbA2 exhibited extensive similarity to the D1 protein, which is known to be a core protein in the reaction center of the photosynthetic Photosystem II in cyanobacteria. The N-terminal amino acid sequence of PsbA2 also showed that this protein is a Form II type of D1 protein, as defined for Synechococcus sp. strain PCC 7942. The psbA2 gene was transcribed as a 1.2kb monocistron, and the potential promoter had an Escherichia coli consensus sequence. The light-responsive psbA2 message exhibited rhythmicity under conditions of constant darkness after prior entrainment to light and dark cycles., MICROBIOL RES FOUNDATION
Journal of General Applied Microbiology, 1996年

A new set of PCR primers for specific detection of the gene encoding the principal sigma factor in cyanobacteria.
Asayama M; Yamada A; Tanaka K; Takahashi H; Shirai; M, MICROBIOL RES FOUNDATION
Journal of General Applied Microbiology, 1996年

Restriction barrier composed of an extracellular nuclease and restriction endonuclease in the unicellular cyanobacterium Microcystis sp.
Takahashi I; Hayano D; Asayama M; Masahiro F; Watahiki M; Shirai M, The unicellular cyanobacterium Microcystis aeruginosa K-81 has two types of restriction barrier, an extracellular nuclease and sequence-specific endonucleases. The nuclease was detected in the culture supernatant and it was easily released from the cells by washing with water or buffer containing Triton X-100. This nuclease was identified as a polypeptide of about 28 kDa that digested covalently closed circular and linear double-stranded DNAs, including chromosomal DNA from M. aeruginosa K-81. Among another 13 Microcystis strains examined, 3 produced an extracellular nuclease. Furthermore, M. aeruginosa K-81 contained two sequence-specific endonucleases, MaeK81I and MaeK81IL, which were isoschizomers of SplI and San96I, respectively., ELSEVIER SCIENCE BV
FEMS Microbiology Letters, 1996年

Dimer form of phosphorylated Sp0A, a transcriptionl regulator, stimulates the spo0F transcription at the initiation of sporulation in Bacillus subtilis.
Asayama M; Yamamoto A; Kobayashi Y, The SpoOA protein of Bacillus subtilis is a transcriptional regulator that shows extensive homology to the regulator proteins in bacterial two-component regulatory systems. Phosphorylation of SpoOA is absolutely necessary for the initiation of sporulation. We now show that phospho-SpoOA is a dimer, binds specifically to the spoOF promoter region, and stimulates the transcription from the P2 promoter recognized by sigma(H)-RNA polymerase. Biochemical and biological analyses suggest that phospho-SpoOA interacts directly with the ''OA-like box'' sequence (TGTCGTA) located in the spoOF promoter region. Phosphorylation of SpoOA enhanced its affinity to the OA-like box. Evidence is also presented that the spoOF promoter region contains a static bend having two sets of oligo(dA-dT) tracts. It was demonstrated that the bending region overlaps with the recognition site for the phospho-SpoOA., ACADEMIC PRESS (LONDON) LTD
Journal of Molecular Biology, 1995年

A gene essential for the site-specific excision of actinophae R4 genome from the chromosome of a lysogen.
Matsuura M; Noguchi T; Aida T; Asayama M; Takahashi H; Shirai M, An open reading frame (ORF469) was found near the attP core site of the actinophage R4 which encoded a 469-amino acid polypeptide. A gene disruption experiment suggested that the ORF469 gene was essential for site-specific excision of the prophage R4 genome from its host chromosome. The predicted amino acid sequence of the protein showed a similarity to a resolvase of Tn2501 and SpoIVCA of Bacillus subtilis., MICROBIOL RES FOUNDATION
The Journal of General and Applied Microbiology, 1995年

Signal transduction and sporulation in Bacillus subtilis: Auto phosphorylation of SpoOA, a sporulation initiation gene product.
Asayama M; Kobayashi Y, Spo0A is a positive/negative transcriptional regulator that plays a very important role in sporulation initiation in Bacillus subtilis. The N-terminal amino acid sequence of Spo0A is homologous to that of regulator proteins of the two-component regulatory systems involved in signal transduction in bacteria. Phosphorylation of Spo0A through a phosphorelay has been reported recently. In this study, we found that Spo0A is autophosphorylated in the presence of ATP and that an autophosphorylation-deficient Spo0A mutant is completely defective in initiating sporulation. These results suggest that Spo0A autophosphorylation is an essential event in the signal transduction process that controls sporulation in B. subtilis., SPRINGER VERLAG
Molecular General Genetics, 1993年

Signal transduction and sporulation in Bacillus subtilis: Heterologous phosphorylation of SpoOA, a sporulation initiation gene product.
Asayama M; Kobayashi Y, Spo0A is both a positive and a negative transcriptional regulator which plays a very important role in sporulation initiation in Bacillus subtilis. Its N-terminal amino acid sequence is homologous to that of regulator proteins of the two-component regulatory systems involved in signal transduction in bacteria. Phosphorylation of Spo0A through phosphorelay has been reported by Burbulys et al. (1991). In this study, we found that (i) Spo0A is phosphorylated effectively with phospho-EnvZ* (N-terminal truncated EnvZ), which is a heterologous osmotic sensor protein in Escherichia coli, and (ii) a phosphorylation deficient mutant of Spo0A protein is completely defective in initiating sporulation. These results suggest that Spo0A phosphorylation may be an essential event in signal transduction of sporulation in B. subtilis and the signal transduction mechanism has a common feature in Gram-positive and Gram-negative bacteria., JAPANESE BIOCHEMICAL SOC
Journal of Biochemistry, 1993年

Characteristics of DNA and multiple rpoD homologs of Microcystis (Synechocytis) strain.
Sakamoto T; Shirai M; Asayama M; Aida T; Sato A; Tanaka K; Takahashi H; Nakano M, The base compositions of DNAs from nine Microcystis strains, as determined by high-performance liquid chromatography, were 41 to 42 mol% G+C. Chromosomal DNAs derived from these strains were found to be extremely resistant to many restriction endonucleases, and a restriction analysis revealed the presence of a dam-like methylase or both dam- and dcm-like methylases in all of the strains examined. Genomic Southern hybridization in which a synthetic oligonucleotide probe (rpoD probe) was used showed that members of the genus Microcystis might have multiple rpoD homologs, and the hybridization signal patterns observed with the DNAs of Microcystis aeruginosa strains were different from each other., AMER SOC MICROBIOLOGY
International Journal of Systematic Bacteriology, 1993年

Sigma Factors for Cyanobacterial Transcription
Imamura S; Asayama M
Gene Regulation and Systems Biology, 2009年, ［査読有り］, ［招待有り］

Natural product biosynthetic gene cluster from cyanobacteria. “Photosynthesis: Theory and Applications in Energy, Biotechnology and Nanotechnology”
Nishizawa T; Asayama M; Shirai M
Nova Science Publishers, Inc., 2008年, ［査読有り］, ［招待有り］

Regulatory system for light-responsive gene expression in photosynthesizing bacteria: cis-elements and trans-acting factors in transcription and post-transcription.
Asayama M
Bioscience, Biotechnology, and Biochemistry, 2006年, ［査読有り］, ［招待有り］

Establishment of in vitro transcription analysis with reconstituted RNA polymerase and roles of sigma factors in the cyanobacterium Synechocystis sp strain PCC 6803
S Imamura; M Asayama; M Shirai
PLANT AND CELL PHYSIOLOGY, 2005年

光誘導性の遺伝子発現
朝山宗彦
生物工学会誌, 1998年, ［招待有り］

富栄養化した湖沼に発生するアオコの毒性
白井 誠; 朝山宗彦
モダンメディア, 1996年

Gene structure and characterization of rpoD and psbA in cyanobacteria.
Asayama M; Iijima O; Shirai M; Sato A; Aida, T; Nakano, M
Research in Photosynthesis, 1993年

〔主要な業績〕有用藻による商品化を目指したモノづくり　　　　　　　　　　　　　　　
朝山 宗彦; 佐々木 大作, 共著
日本農芸化学会 https://www.jsbba.or.jp/info/news/news_20220112.html, 2021年12月15日, ［査読有り］

多彩な戦略で挑むシアノバクテリア由来の燃料生産 〜持続可能な第三世代バイオ燃料生産の最前線〜　　　　　　　　　　　　　　　
日原由香子; 朝山宗彦; 蘆田弘樹; 天尾豊; 新井宗仁; 粟井光一郎; 得平茂樹; 小山内崇; 鞆達也; 成川礼; 蓮沼誠久; 増川一, 共著
日本農芸化学会, 2017年01月20日

Natural product biosynthetic gene cluster from cyanobacteria. In "Photosynthesis: Theory and Applications in Energy, Biotechnology and Nanotechnology"　　　　　　　　　　　　　　　
Nishizawa T; Asayama M; Shirai M, 共著
Nova Science Publishers, Inc. (New York), 2009年

Curved DNA and Prokaryotic promoters: A Mechanism for Activation of Transcription. (CAPTER 3) In "DNA Conformation and Transcription"　　　　　　　　　　　　　　　
Asayama M; Ohyama T, 共著
Springer (New York) & Landes Bioscience (Texas), 2005年

Coexistence of cyanobacteria and aqueous rhizobia, co-culturing for developmental biorefinery　　　　　　　　　　　　　　　
Nanako MACHIDA; Akari TAKAGI; Munehiko ASAYAMA
The 18th International Student Conference in Ibaraki, 2022年12月03日, Ibaraki University
20221203, 20221203

Effect of microalgae-derived extracts on animal cell growth　　　　　　　　　　　　　　　
Misato NAGAO; Munehiko ASAYAMA; Takeshi OHKUBO
The 18th International Student Conference in Ibaraki, 2022年12月03日, Ibaraki University
20221203, 20221203

〔主要な業績〕Production development and characteristic analysis of phycocyanobilin derived from filamentous cyanobacteria　　　　　　　　　　　　　　　
青木 仁一、鎗田 孝、長谷川 守、朝山 宗彦
第45回日本分子生物学会年会2022, 2022年12月02日, 日本分子生物学会
20221130, 20221202

〔主要な業績〕Cultivation condition for lipid and EPS production in green algae　　　　　　　　　　　　　　　
石田 怜也、朝山 宗彦
第45回日本分子生物学会年会2022, 2022年12月02日, 日本分子生物学会年会
20221130, 20221202

〔主要な業績〕【茨城大学プレスリリース】緑藻から脂質と色素を同時に高効率生産する培養技術を開発〜有用物質生産に弾み〜細胞から抽出した緑色素・赤色素エキスの作用も解明　　　　　　　　　　　　　　　
朝山 宗彦
【茨城大学プレスリリース】, 2022年11月30日, 茨城大学
20221130

新奇緑藻由来の抗酸化・抗炎症能を有する赤色/緑色エキス　　　　　　　　　　　　　　　
斉藤 瑞季、朝山 宗彦
第14回三大学交流セミナー2022, 2022年09月26日, ［招待有り］
20220926, 20220926

〔主要な業績〕緑藻コーラストレラによる脂質とカロテノイドの共生産　　　　　　　　　　　　　　　
斉藤 瑞季、渡邉 明花、佐々木 美月、大窪 まどか、鎗田 孝、白岩雅和、朝山宗彦
日本農芸化学会 関東支部 2022年度大会, 2022年08月27日, 日本農芸化学会 関東支部
20220827, 20220827

〔主要な業績〕【採択PJ報告書2021】有用藻による商品化を目指したモノづくりhttps://www.jsbba.or.jp/info/news/news_20220112.html （p28-35）
朝山 宗彦、佐々木大作
【日本農芸化学会】第１回中小企業産学・産官連携研究報告書 2021, 2021年12月15日, 日本農芸化学会, ［招待有り］
2021

〔主要な業績〕藻によるモノづくり　　　　　　　　　　　　　　　
佐々木大作、朝山宗彦、髙木明香莉
第6回 BRAVE 2020 大会, 2020年10月17日, ［招待有り］
20201017, 20201017

〔主要な業績〕藻産業の技術革新の基盤を作るバイオファイナリー　　　　　　　　　　　　　　　
朝山宗彦、髙木明香莉、佐々木大作
第7回 アグリテックグランプリ 2020年度大会, 2020年09月26日, ［招待有り］
20200926, 20200926

〔主要な業績〕藻によるモノづくり 〜探索・遺伝子・物質生産〜　　　　　　　　　　　　　　　
朝山 宗彦
日本農芸化学会 2019年度大会, 2020年03月28日, ［招待有り］
20200328, 20200328

〔主要な業績〕A new manufacturing method for phycocyanin from novel filamentous, cyanobacteria　　　　　　　　　　　　　　　
AOKI Jinichi、ASAYAMA Munehiko
2019年12月04日
20191203, 20191206

〔主要な業績〕藻によるモノづくりで未来を創造する藻類カンパニー　　　　　　　　　　　　　　　
佐々木大作、佐々木智子、朝山宗彦
第１４回広島県信用金庫合同 ビジネスフェア, 2019年11月13日, ［招待有り］
20191113, 20191113

〔主要な業績〕藻バイオリファイナリー（藻によるモノづくり）　　　　　　　　　　　　　　　
髙木明香莉、佐々木大作、朝山宗彦
第3回茨城テックプランター2019, 2019年11月09日, ［招待有り］
20191109, 20191109

〔主要な業績〕有用油脂生産藻の特性分析と環境ストレス耐性評価　　　　　　　　　　　　　　　
髙木明香莉、佐々木美月、朝山宗彦
第71回日本生物工学会年会2019, 2019年09月16日, ［招待有り］
20190916, 20190918

〔主要な業績〕藻によるモノづくりで未来を創造する藻類カンパニー　　　　　　　　　　　　　　　
佐々木大作、佐々木智子、朝山宗彦
Class A主催 コンベンション2019, 2019年09月08日, ［招待有り］
20190908, 20190908

〔主要な業績〕糸状性ラン藻 Pseudanabaena 株シグマ因子 SigBの特徴と発現解析　　　　　　　　　　　　　　　
渡邉明花、菅原卓也、鎭西真理子、兼崎友、中平洋一、朝山宗彦
日本農芸化学会 関東支部2019年度大会, 2019年09月07日
20190907, 20190907

〔主要な業績〕緑藻パラクロレラ新素材によるバイオリファイナリーの新展開　　　　　　　　　　　　　　　
佐々木美月、髙木明香莉、中村彰宏、佐々木 大作、朝山宗彦
日本農芸化学会 関東支部2019年度大会, 2019年09月07日
20190907, 20190907

〔主要な業績〕藻由来油脂と多糖の新素材 (藻バイオリファイナリーの可能性)　　　　　　　　　　　　　　　
朝山 宗彦
JST主催イノベーションJapan 2019〜大学見本市〜, 2019年08月29日, ［招待有り］
20190829, 20190830

〔主要な業績〕油と糖の共生産藻などによる機能性バイオ　　　　　　　　　　　　　　　
朝山宗彦
第7回機能性バイオミニシンポジウム ,〜藻類バイオとOPERAの新たな展開に向けて〜 JST_OPERAプロジェクト主催, 2019年07月04日, ［招待有り］
20190704, 20190704

〔主要な業績〕Production and Extraction of Useful Substances from Filamentous Cyanobacteria, Grown in Dual-Phase Cultivation System　　　　　　　　　　　　　　　
AOKI Jinichi; KWAMATA Toru; KODAKA Asuka; MINAKAWA Masayuki; IMAMURA Nobukazu; TSUZUKI Mikio; ASAYAMA Munehiko
第41回日本分子生物学会年会2018, 2018年11月29日
20181128, 20181130

〔主要な業績〕新奇糸状性シアノバクテリアのSigB相同性因子の発現と機能解析　　　　　　　　　　　　　　　
菅原卓也、鎭西真理子、中平洋一、兼崎友、吉川博文、朝山宗彦
第41回日本分子生物学会年会2018, 2018年11月29日
20181128, 20181130

〔主要な業績〕屋外培養可能な新奇微細藻類による有用油脂の生産　　　　　　　　　　　　　　　
佐々木美月、福田寛史、佐々木智子、佐々木 大作、朝山宗彦
日本生物工学会年会, 2018年09月06日
20180905, 20180907

〔主要な業績〕藻由来油脂と多糖の新素材 (藻バイオリファイナリーの可能性)　　　　　　　　　　　　　　　
JST主催イノベーションJapan 2019〜大学見本市〜, 2018年08月29日, ［招待有り］
20180829, 20180830

微細藻類研究の魅力 〜探索・遺伝子・物質生産〜　　　　　　　　　　　　　　　
朝山宗彦
一般講演, 2017年11月10日, 東京都立目黒高校, ［招待有り］

屋外培養可能な新奇微細藻による有用油脂生産　　　　　　　　　　　　　　　
佐々木美月、福田寛史、朝山宗彦、佐々木智子、佐々木大作
日本農芸化学会関東支部大会2017, 2017年10月02日, 日本農芸化学会

自己凝集藻によるジェット燃料の製造法
朝山宗彦
JST主催新技術説明会2017, 2017年09月26日, JST, ［招待有り］

二相培養による糸状性シアノバクテリアからの有用物質の生産と抽出　　　　　　　　　　　　　　　
青木仁一、川又透、小高明日香、皆川真之、岡田克彦、今村信和、都筑幹夫、朝山宗彦
第69回日本生物工学会年会2017, 2017年09月12日, 日本生物工学会

新奇糸状性シアノバクテリアのSigB相同性因子の特徴付けと発現解析　　　　　　　　　　　　　　　
菅原卓也、鎭西真理子、川又透、田島直幸、兼崎友、中平洋一、吉川博文、佐藤直樹、; 朝山宗彦
第69回日本生物工学会年会2017, 2017年09月12日, 日本生物工学会

シアノバクテリアにおけるドロップイン燃料生産性強化に向けた遺伝子改変技術の開発　　　　　　　　　　　　　　　
金子太樹、山根里佳、櫻井大貴、福田寛史、朝山宗彦、中平洋一
第39回日本分子生物学会年会2016, 2016年12月02日, 日本分子生物学会

シアノバクテリアのアルカンと脂質生産に与える栄養源欠乏培地の影響　　　　　　　　　　　　　　　
福田寛史、中平洋一、長谷川守文、宮口右二、朝山宗彦
第39回日本分子生物学会年会2016, 2016年12月02日

微細藻類研究の魅力 〜探索・遺伝子・物質生産〜　　　　　　　　　　　　　　　
朝山宗彦
一般講演, 2016年11月25日, ［招待有り］

溶菌藻によるバイオ燃料等有用物質の生産 〜天然藻でフィコシアニン＆組換藻でアルカン〜　　　　　　　　　　　　　　　
朝山宗彦
イノベーションJapan 2016 大学見本市, 2016年08月26日, JST, ［招待有り］

シアノバクテリア由来RNA polymeraseの枯草菌での発現とその解析　　　　　　　　　　　　　　　
高橋宏樹、白川文教、渡辺智、朝山宗彦、今村壮輔、兼崎友、吉川博文、浅井計
日本農芸化学会2016年度大会, 2016年03月29日

Genetic Engineering for the Overproduction of Polyhydroxybutyrate in Cyanobacteria　　　　　　　　　　　　　　　
Hondo S; Takahashi M; Osanai T; Matsuda M; Hasunuma T; Tazuke A; Nakahira Y; Chohnan S; Hasegawa M; Asayama M
The 2015 International Chemical Congress of Pacific Basin Societies (Pacifichem 2015), 2015年12月19日, 日本化学会（協賛）

Overproduction of Alkane as Biofuel from an Engineered Cyanobacteirum under Heterotrophic Culture Condition　　　　　　　　　　　　　　　
Fukuda H; Yoshida S; Takahashi M; Ikeda A; Kitazaki C; Asayama M
The 2015 International Chemical Congress of Pacific Basin Societies (Pacifichem 2015), 2015年12月19日, 日本化学会（協賛）

固相支持体を用いた微細藻類の高密度培養法の開発　　　　　　　　　　　　　　　
青木仁一、川又透、小高明日香、皆川真之、岡田克彦、今村信和、都筑幹夫、; 朝山宗彦
日本農芸化学会関東支部大会2015, 2015年09月26日, 日本農芸化学会

新奇 Microcystis 属シアノバクテリアの特徴付け　　　　　　　　　　　　　　　
鎭西真理子、本堂彩花、菅原将太、西澤智康、白井誠、朝山宗彦
日本農芸化学会関東支部大会2015, 2015年09月26日, 日本農芸化学会

藻類バイオプラスチックPHB高生産株の創生と特徴付け　　　　　　　　　　　　　　　
本堂彩花、高橋正俊、小山内崇、松田真実、蓮沼誠久、長谷川守文、中平洋一、; 朝山宗彦
第37回日本分子生物学会2014, 2014年11月27日, 日本分子生物学会

藻類バイオ燃料アルカン高生産株の創生と簡便回収技術開発　　　　　　　　　　　　　　　
吉田聡美、高橋正俊、池田絢江、福田寛史、北﨑千富美、朝山宗彦
第37回日本分子生物学会2014, 2014年11月27日, 日本分子生物学会

微細藻によるバイオ燃料等有用物質生産と利用の新技術　　　　　　　　　　　　　　　
朝山宗彦
JST主催サイエンスアゴラ2014, 2014年11月07日, JST, ［招待有り］

藻バイオ燃料生産の新技術　　　　　　　　　　　　　　　
朝山宗彦
国立大学法人茨城大学農学部遺伝子実験施設 実験講座, 2014年10月26日, 茨城大学

固相支持体を用いた微細藻類の高密度培養　　　　　　　　　　　　　　　
川又透、小高明日香、皆川真之、岡田克彦、今村信和、都筑幹夫、朝山宗彦
日本農芸化学会 関東支部大会2014, 2014年10月18日, 日本農芸化学会

藻類バイオ燃料アルカン高生産株の特徴付けと油回収法の検証　　　　　　　　　　　　　　　
福田寛史、吉田聡美、高橋正俊、池田絢江、北﨑千富美、朝山宗彦
日本農芸化学会関東支部大会2014, 2014年10月18日, 日本農芸化学会

組換え藻によるバイオ燃料等生産と回収の新技術　　　　　　　　　　　　　　　
朝山宗彦
藻類バイオ燃料生産の新技術セミナー, 2014年06月19日, 株式会社 技術情報センター

固相表面を利用した微細藻類の屋外通年培養系　　　　　　　　　　　　　　　
佐藤諒、有賀理沙、白武拓磨、今村信和、朝山宗彦、岡田克彦、都筑幹夫
第16回 マリンバイオテクノロジー学会2014, 2014年05月31日, マリンバイオテクノロジー学会

Limnothrix sp. ABRG5-3株のゲノム配列解読　　　　　　　　　　　　　　　
田島直幸、兼崎友、佐藤修正、吉川博文、丸山史人、黒川顕、太田啓之、田畑哲之、; 高根澤陽、西澤智康、朝山宗彦、佐藤直樹
第5回 日本光合成学会年会2014, 2014年05月30日, 日本光合成学会

Limnothrix sp. ABRG5-3株のゲノム配列決定とシアノバクテリアの中での系統関係　　　　　　　　　　　　　　　
田島直幸、兼崎友、佐藤修正、吉川博文、丸山史人、黒川顕、太田啓之、田畑哲之、; 高根澤陽、西澤智康、朝山宗彦、佐藤直樹
第55回日本植物生理学会年会2014, 2014年03月19日, 日本植物生理学会

Limnothrix sp. ABRG5-3株ゲノム配列決定とシアノバクテリアの中での系統関係　　　　　　　　　　　　　　　
田島直幸、兼崎友、佐藤修正、吉川博文、丸山史人、黒川顕、太田啓之、田畑哲之、高根澤陽、西澤智康、朝山宗彦、佐藤直樹
ラン藻の分子生物学2013, 2013年11月23日

新奇シアノバクテリアの自己溶菌とポリリン酸蓄積　　　　　　　　　　　　　　　
北﨑千富美、沼野節子、高根澤陽、西澤智康、白井誠、朝山宗彦
日本農芸化学会 関東支部大会2013, 2013年11月22日, 日本農芸化学会

藻類バイオプラスチックPHB高増産株の創成　　　　　　　　　　　　　　　
本堂彩花、高橋正俊、沼野節子、北﨑千富美、長谷川守、朝山宗彦
日本農芸化学会 関東支部大会2013, 2013年11月22日, 日本農芸化学会

溶ける藻　　　　　　　　　　　　　　　
朝山宗彦
さきがけ成果報告会（一般公開）, 2013年11月19日, JST

Cyanobacterial Autolysis and its Utilization for Easy Recovery of Target Gene Product　　　　　　　　　　　　　　　
ASAYAMA Munehiko
1st Korea-Japan Microalgae Symposium (KJMS 2013), 2013年10月10日, JST and KAIST, ［招待有り］

「藻類バイオマスの利用」Algal Biomass for Future　　　　　　　　　　　　　　　
朝山宗彦
平成２４年度 第２回「環境・エネルギー」セミナー （二酸化炭素を資源と捉え、その循環を考える）, 2013年02月22日, 中国産業創造センター, ［招待有り］

藻の秘密 〜遺伝子、形態、バイオ燃料生産まで〜　　　　　　　　　　　　　　　
朝山宗彦
東京工業大学 第１０回バイオテンプレート研究セミナー, 2012年12月07日, 東京工業大学, ［招待有り］

身近な生き物 藻の秘密 〜遺伝子発現からバイオ燃料生産まで〜　　　　　　　　　　　　　　　
朝山宗彦
茨城大学農学部-産業技術総合研究所 相互研究発表会, 2012年11月28日, ［招待有り］

自己溶菌藻と発現ベクターを組み合せた有用物質の生産・回収による排気 CO2ガス再利用資源化のための基盤技術創成　　　　　　　　　　　　　　　
朝山宗彦
JST主催福島復興パネル展示, 2012年11月07日, JST, ［招待有り］

自己溶菌藻と発現ベクターを組み合せた有用物質の生産・回収による排気,CO2ガス再利用資源化のための基盤技術創成　　　　　　　　　　　　　　　
朝山宗彦
JST主催福島復興パネル展示, 2012年11月07日, JST, ［招待有り］

Overproduction and Easy Recovery of Target Gene Products from Autolysed Cyanobacteria, Photosynthesizing Microorganisms　　　　　　　　　　　　　　　
Asayama M; Yoshida S; Hondo S; Minakawa M; Numano S; Kitazaki C; Takahashi M
生物工学会９０周年記念大会国際シンポジウム2012, 2012年10月24日

Overproduction and Easy Recovery of Target Gene Products from Cyanobacteria, Photosynthesizing Microorganisms　　　　　　　　　　　　　　　
Asayama M; Takanezawa A; Takahashi M; Numano S; Kitazaki C; Nishizawa T; Shirai M
The 112nd General Meeting of American Society for Microbiology, San Francisco (USA), 2012年06月18日

Characterization of Prokaryotic Type I and III Pantothenate Kinases from Bacillus subtilis　　　　　　　　　　　　　　　
Ogata Y; Asayama M; Tokutake Y; Chohnan S
The 112nd General Meeting of American Society for Microbiology, San Francisco (USA), 2012年06月18日

Novel Biosynthetic Gene Cluster Encoding NRPS, PKS I and PKS III in Cyanobacterium Microcystis　　　　　　　　　　　　　　　
Shirai M; Yamazaki Y; Futamura A; Li C; Takanezawa A; Nishizawa A; Nishizawa T; Harada K-i; Asayama M
The 112nd General Meeting of American Society for Microbiology, San Francisco (USA), 2012年06月17日

溶ける藻を利用したバイオ燃料等の大量生産と回収方法　　　　　　　　　　　　　　　
首都圏北部４大学発新技術説明会 (JST東京別館ホール・市ヶ谷), 2012年06月12日

Expression Vector, Overproduction, and Easy Recovery of Target Gene Products from Cyanobacteria, Photosynthesizing Microorganisms　　　　　　　　　　　　　　　
Munehiko Asayama; Setsuko Numano; Chifumi Kitazaki
日本化学会第92春季年会 JST さきがけ四領域国際シンポジウム (慶応義塾大学日吉キャンパス), 2012年03月27日

糸状性シアノバクテリア Limnothrix/Pseudanabaena sp. ABRG5-3株の分子特徴付け　　　　　　　　　　　　　　　
第３４回日本分子生物学会年会2011 (パシフィコ横浜), 2011年12月14日

新奇糸状性シアノバクテリアABRG5-3株の特徴付け　　　　　　　　　　　　　　　
高根澤陽、西澤智康、花見知世、朝山宗彦、原田健一、白井誠
第２７回日本微生物生態学会2011 (京都大学農学部), 2011年10月09日

Characterization of Site-Specific Recombination of Actinophage R4 Integrase　　　　　　　　　　　　　　　
Miura T; Nishizawa T; Asayama M; Takahashi H; Shirai M
The 111th General Meeting of American Society for Microbiology, New Orleans (USA), 2011年05月22日

シアノバクテリア藻発現ベクターのバイオ産業利用に向けた評価　　　　　　　　　　　　　　　
朝山宗彦、白井誠
第３３回日本分子生物学会年会／第８３回日本生化学会合同大会2010 (神戸ポートアイランド), 2010年12月09日

新奇糸状性シアノバクテリアABRG5-3株の遺伝学及び生理学的特徴づけ　　　　　　　　　　　　　　　
高根澤陽、西澤智康、花見知世、平野恵理子、三浦隆匡、渡辺優子、原田賢一、朝山宗彦、白井誠
第３３回日本分子生物学会年会／第８３回日本生化学会合同大会2010 (神戸ポートアイランド), 2010年12月09日

放線菌糸ファージR4の部位特異的組換え機構の解析と遺伝子導入システムの開発　　　　　　　　　　　　　　　
三浦隆匡、西澤明人、朝山宗彦、高橋秀夫、白井誠
第３３回日本分子生物学会年会／第８３回日本生化学会合同大会2010 (神戸ポートアイランド), 2010年12月08日

モデル光合成微生物における転写と転写後レベルでの遺伝子発現制御　　　　　　　　　　　　　　　
朝山宗彦
第９回微生物研究会 2010 (法政大学), 2010年06月26日

Isolation and Molecular Characterization of a Multicellular Cyanobacterium for Biotech Industry　　　　　　　　　　　　　　　
Nishizawa T; Hanami T; Hirano E; Takanezawa A; Watanabe Y; Miura T; Ohta H; Shirai M; Asayama M
International Symposium of Microalgal Biotechnology, Tokyo (Japan), 2010年05月31日

Isolation and Molecular Characterization of a Multicellular Cyanobacterium, Limnothrix/Pseudanabaena sp. strain ABRG5-3　　　　　　　　　　　　　　　
Takanezawa A; Nishizawa T; Hanami T; Hirano E; Watanabe Y; Miura T; Asayama M; Shirai M
The 110th General Meeting of American Society for Microbiology, San Diego (USA), 2010年05月25日

In Vivo and In Vitro Analysis of Site-Specific Recombination System Based on Actinophage R4 Integrase for Application of Genetic Engineering　　　　　　　　　　　　　　　
Miura T; Nishizawa A; Asayama M; Takahashi H; Shirai M
The 110th General Meeting of American Society for Microbiology, San Diego (USA), 2010年05月24日

Analysis of Genes Around the Site-specific Recombinase Gene in Actinophase R4　　　　　　　　　　　　　　　
Nonetsu A; Miura T; Sano N; Harada C; Nishizawa T; Asayama M; Takahashi H; Shirai M
The 110th General Meeting of American Society for Microbiology, San Diego (USA), 2010年05月24日

半糸状性有用藍藻ABRG5-3の特徴付けと宿主発現ベクター系の構築　　　　　　　　　　　　　　　
朝山宗彦、西澤智康、花見知世、平野恵理子、高根澤陽、太田寛行、白井誠
平成21年度日本農芸化学会大会2010（東京大学), 2010年03月28日

霞ヶ浦に発生したアオコの微生物群集構造解析　　　　　　　　　　　　　　　
西澤智康、二渡弘貴、朝山宗彦、原田健一、白井誠
第３４回日本藻類学会2010（筑波大学), 2010年03月19日

シアノバクテリア Microcystis 属におけるホスホパンテテイントトランスフェラーゼの遺伝・生化学的解析　　　　　　　　　　　　　　　
渡辺優子、西澤明人、西澤智康、朝山宗彦、原田健一、白井誠
第３２回日本分子生物学会年会 2009 (パシフィコ横浜), 2009年12月12日

高効率プロモーターを有する藻発現ベクターの構築と利用　　　　　　　　　　　　　　　
朝山宗彦、平野恵理子、花見知世、堀江良尚、西澤智康、白井誠
第３２回日本分子生物学会年会 2009 (パシフィコ横浜), 2009年12月10日

シアノバクテリア Microcystis aeruginosa の生産する aeruginosin 生合成遺伝子の遺伝学的解析　　　　　　　　　　　　　　　
大崎賢一、山本真弓、三浦隆一、西澤明人、原田健一、中野知世、朝山宗彦、白井誠
第３２回日本分子生物学会年会 2009 (パシフィコ横浜), 2009年12月09日

放線菌R4ファージの部位特異的組換え機構の解析と遺伝子導入システムの開発　　　　　　　　　　　　　　　
三浦隆匡、西澤明人、朝山宗彦、高橋秀夫、白井誠
第３２回日本分子生物学会年会 2009 (パシフィコ横浜), 2009年12月09日

アクチノファージR4の部位特異的組換え酵素遺伝子周辺遺伝子の解析　　　　　　　　　　　　　　　
米津篤人、三浦隆匡、佐野夏枝、原田千津子、西澤智康、朝山宗彦、高橋秀夫、白井誠
第３２回日本分子生物学会年会 2009 (パシフィコ横浜), 2009年12月09日

Construction and Utilization of Cyanobacterial Expression Vector　　　　　　　　　　　　　　　
朝山宗彦、平野恵理子、花見知世、堀江良尚、西澤智康、白井 誠
ラン藻の分子生物学 2009（かずさアカデミヤホール), 2009年12月05日

霞ヶ浦に発生した毒素生産性シアノバクテリア Microcystis の遺伝学的解析　　　　　　　　　　　　　　　
二渡弘貴、西澤智康、野口貴彦、原田健一、朝山宗彦、白井誠
第２５回日本微生物生態学会 2009（広島大学), 2009年11月21日

多細胞棒状シアノバクテリアABRG5-3株の単離と分子遺伝学的解析　　　　　　　　　　　　　　　
西澤智康、花見智世、三浦隆匡、渡部優子、高根澤陽、太田寛行、白井誠、朝山宗彦
日本農芸化学会関東支部 2009年度大会 (玉川大学), 2009年10月31日

「シグマ因子とRNaseE 相互作用因子」〜転写・転写後調節のこれまでのまとめと今後〜　　　　　　　　　　　　　　　
朝山宗彦
ラン藻ゲノム交流会 2009 (東京大学), 2009年07月04日

シアノバクテリア Microcystis 属におけるホスホパンテテイントトランスフェラーゼの遺伝・生化学的解析　　　　　　　　　　　　　　　
渡辺優子、西澤明人、西澤智康、朝山宗彦、原田健一、白井誠
第３１回日本分子生物学会・第８１回日本生化学会 合同大会 2008（神戸ポートアイランド）, 2008年12月10日

放線菌R4ファージの部位特異的組換え機構の解析と遺伝子組込みシステムの開発　　　　　　　　　　　　　　　
三浦隆匡、西澤明人、朝山宗彦、高橋秀夫、白井誠
第３１回日本分子生物学会・第８１回日本生化学会 合同大会 2008（神戸ポートアイランド）, 2008年12月10日

シアノバクテリアのグループ３型シグマ因子 SigF の自己制御と厳密な新規プロモーター認識能　　　　　　　　　　　　　　　
朝山宗彦、今村壮輔
第３１回日本分子生物学会・第８１回日本生化学会 合同大会 2008（神戸ポートアイランド）, 2008年12月09日

山間水域より分離した新規光合成微生物の性格付け　　　　　　　　　　　　　　　
西澤智康、花見智世、三浦隆匡、渡部優子、小松崎将一、太田寛行、白井誠、朝山宗彦
日本農芸化学会関東支部 2008年度大会（山梨大学）, 2008年10月11日

シロイヌナズナのオゾン感受性突然変異体 ozs1 の生理学的解析　　　　　　　　　　　　　　　
佐治章子、久保明弘、玉置雅紀、青野光子、中嶋信美、中路達郎、武田知己、; 朝山宗彦、佐治光
第４９回日本植物生理学会年会（札幌）, 2008年03月20日

放線菌R4ファージの部位特異的組換え機構を利用した大腸菌・ラン藻ゲノムへの遺伝子導入法の開発　　　　　　　　　　　　　　　
三浦隆匡、西澤明人、朝山宗彦、高橋秀夫、白井誠
第３０回日本分子生物学会・第８０回日本生化学会 合同大会 2007（パシフィコ横浜）, 2007年12月14日

Interference Expression at Levels of the Transcript and Protein among Group 1, 2, and 3 Sigma Factor Genes in a Cyanobacterium　　　　　　　　　　　　　　　
朝山宗彦; 松井雅恵; 吉村功; 若林裕子; 今村壮輔; 田中寛; 高橋秀夫; 白井誠
第３０回日本分子生物学会・第８０回日本生化学会 合同大会 2007（パシフィコ横浜）, 2007年12月12日

Interference Expression at Levels of the Transcript and Protein,among Group 1, 2, and 3 Sigma Factor Genes in a Cyanobacterium　　　　　　　　　　　　　　　
朝山宗彦、松井雅恵、吉村功、若林裕子、今村壮輔、田中寛、高橋秀夫、白井誠
第３０回日本分子生物学会・第８０回日本生化学会 合同大会 2007（パシフィコ横浜）, 2007年12月12日

シアノバクテリアにおける新規なポリケチド合成遺伝子の解析　　　　　　　　　　　　　　　
李晨瑤、西澤明人、西澤智康、朝山宗彦、原田健一、白井誠
第３０回日本分子生物学会・第８０回日本生化学会 合同大会 2007（パシフィコ横浜）, 2007年12月11日

Microcystis aeruginosa K-139における phosphopantetheinly transferase (PPTase) の同定と機能解析　　　　　　　　　　　　　　　
渡辺優子、西澤明人、西澤智康、朝山宗彦、白井誠
第３０回日本分子生物学会・第８０回日本生化学会 合同大会 2007（パシフィコ横浜）, 2007年12月11日

シアノバクテリアにおける新規二次代謝産物合成遺伝子の解析　　　　　　　　　　　　　　　
李 晨瑶、西澤明人、西澤智康、朝山宗彦、白井 誠
ラン藻の分子生物学 2007 (カズサDNA研究所), 2007年12月03日

放線菌R4ファージの部位特異的組換え機構を利用したラン藻ゲノムへの 遺伝子導入と発現　　　　　　　　　　　　　　　
三浦 隆匡; 西澤 明人; 朝山 宗彦; 高橋 秀夫; 白井 誠
ラン藻の分子生物学 2007（カズサDNA研究所）, 2007年12月03日

放線菌R4ファージの部位特異的組換え機構を利用したラン藻ゲノムへの,遺伝子導入と発現　　　　　　　　　　　　　　　
三浦 隆匡、西澤 明人、朝山 宗彦、高橋 秀夫 、白井 誠
ラン藻の分子生物学 2007（カズサDNA研究所）, 2007年12月03日

新規光合成微生物の単離と分離菌の性格付け　　　　　　　　　　　　　　　
西澤智康、小松崎将一、太田寛行、白井誠、朝山宗彦
日本農芸化学会関東支部 2007年度大会（宇都宮大学）, 2007年11月10日

Development of Gene Integration System Using a Site-specific Recombinase of Actinophage R4 in E. coli and Cyanobacteria　　　　　　　　　　　　　　　
三浦隆匡; 西澤明人; 西澤智康; 朝山宗彦; 高橋秀夫; 白井誠
第２３回微生物生態学会（松山）, 2007年09月15日

Development of Gene Integration System Using a Site-specific,Recombinase of Actinophage R4 in E. coli and Cyanobacteria　　　　　　　　　　　　　　　
三浦隆匡、西澤明人、西澤智康、朝山宗彦、高橋秀夫、白井誠
第２３回微生物生態学会（松山）, 2007年09月15日

シロイヌナズナのオゾン感受性 ozs1 突然変異体の気孔応答　　　　　　　　　　　　　　　
佐治章子、久保明弘、玉置雅紀、青野光子、中嶋信美、朝山宗彦、佐治光
第４８回大気環境学会年会（岡山）, 2007年09月05日

Development of gene integration system using a site-specific recombinase of actinophage R4 in E. coli and Cyanobacteria.　　　　　　　　　　　　　　　
Miura T; Nishizawa A; Nishizawa T; Asayama M; Takahashi H; Shirai M
The 107th General Meeting of the American Society for Microbiology, Toronto (CANADA), 2007年05月

Analysis of a Novel Hetero-gene Cluster of NRPS and PKS for Secondary Metabolite.　　　　　　　　　　　　　　　
Li C; Nishizawa A; Nishizawa T; Asayama M; Harada K; Shirai M
The 107th General Meeting of American Society for Microbiology, Toronto (CANADA), 2007年05月

Microcystis 株におけるミクロキスチン合成遺伝子構成の保存性　　　　　　　　　　　　　　　
西澤智康、西澤明人、野口貴彦、原田健一、朝山宗彦、白井誠
第２２回日本微生物生態学会年会（東京大学）, 2006年10月27日, 東京大学

Ribonuclease Cleavage at the AU-box Sequence Causes to mRNA Instability of Light-responsive Genes in Cyanobacteria.　　　　　　　　　　　　　　　
Horie Y; Ito Y; Shirai M; Asayama M
The 20th IUBMB International Congress of Biochemistry and Molecular Biology, Kyoto (Japan), 2006年06月18日

In vitro transcription system of rice plastids.　　　　　　　　　　　　　　　
Kubota Y; Imamura S; Shirai M; Asayama M
The 20th IUBMB International Congress of Biochemistry and Molecular Biology, Kyoto (Japan), 2006年06月18日

Biochemical characterization of McyG including a loading module for microcystin biosynthesis.　　　　　　　　　　　　　　　
Nishizawa A; Nishizawa T; Asayama M; Shirai M
The 106th General Meeting of the American Society for Microbiology, Orlando (USA), 2006年05月

Analysis of biosynthesis gene for secondary metabolites in cyanobacteria.　　　　　　　　　　　　　　　
Ri C; Nishizawa A; Nishizawa T; Asayama M; Harada K; Shirai M
The 106th General Meeting of the American Society for Microbiology, Orlando (USA), 2006年05月

Genetic engineering using a site-specific recombination function of actinophage R4.　　　　　　　　　　　　　　　
Miura T; Nishizawa A; Nishizawa T; Asayama M; Takahashi H; Shirai M
The 106th General Meeting of the American Society for Microbiology, Orlando (USA), 2006年05月

藍藻毒ミクロキスチン合成遺伝子の発現調節機構に関する研　　　　　　　　　　　　　　　
大森昌、西澤明人、朝山宗彦、白井誠
平成１５年度日本農芸化学会大会（京都女子大学）, 2006年03月26日

イネ葉緑体 in vitro 転写系の構築　　　　　　　　　　　　　　　
久保田芳樹、白井誠、朝山宗彦
第４７回日本植物生理学会年会（筑波大学）, 2006年03月19日

Nitrogen control of sugar catabolic gene expression in Synechocystis sp. PCC 6803　　　　　　　　　　　　　　　
Osanai T; Imamura S; Asayama M; Shirai M; Kanehisa M; Suzuki I; Murata N; Tanaka K
第４７回日本植物生理学会年会（筑波大学）, 2006年03月19日

DNA microarray analysis of sigma factor in the cyanobacterium Synechocystis sp. PCC 6803.　　　　　　　　　　　　　　　
Azuma M; Kanesaki Y; Osanai T; Asayama M; Shirai M; Kanehisa M; Murata N; Suzuki I; Kanehisa M; Tanaka K
第４７回日本植物生理学会年会（筑波大学）, 2006年03月19日

Nitrogen control of sugar catabolic gene expression in,Synechocystis sp. PCC 6803　　　　　　　　　　　　　　　
Osanai T; Imamura S; Asayama M; Shirai M; Kanehisa M; Suzuki I; Murata N; Tanaka K.
第４７回日本植物生理学会年会（筑波大学）, 2006年03月19日

DNA microarray analysis of sigma factor in the cyanobacterium,Synechocystis sp. PCC 6803.　　　　　　　　　　　　　　　
Azuma M; Kanesaki Y; Osanai T; Asayama M; Shirai M; Kanehisa M; Murata N; Suzuki I; Kanehisa M; Tanaka K.
第４７回日本植物生理学会年会（筑波大学）, 2006年03月19日

〔主要な業績〕バイオテクノロジー入門　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕食生命科学入門　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕大学入門ゼミ　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕分子生物学　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕微生物学実験 II （分子生物学実験）　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕食生命科学演習　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕遺伝子制御学　　　　　　　　　　　　　　　
茨城大学

卒業論文（プレゼンテーション演習）　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕卒業論文　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕分子植物化学特論　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕遺伝子制御学特論　　　　　　　　　　　　　　　
茨城大学

修士論文（特別演習）　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕修士論文（専攻研究）　　　　　　　　　　　　　　　
茨城大学

〔主要な業績〕細胞工学特論　　　　　　　　　　　　　　　
東京農工大学大学院連合農学科

〔主要な業績〕博士論文　　　　　　　　　　　　　　　
東京農工大学大学院連合農学科

2012年, 日本生物工学会

1993年, 米国微生物学会

1993年, 日本植物生理学会

1988年, 日本分子生物学会

1988年, 日本農芸化学会