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Hosaka Takeshi

Academic OrganizationAcademic Assembly School of Science and Technology Institute of AgricultureTEL
Education and Research OrganizationInterdisciplinary Cluster for Cutting Edge Research, Institute for Biomedical Sciences , Department of Interdisciplinary Genome Sciences and Cell MetabolismFAX
PositionAssociate ProfessorMail Address
AddressWeb site



Research Field
Applied Microbiology
Current Subject
Molecular physiological studies on actinomycetes for a fundamental understanding of antibiotics
Keywords:Antibiotics , Antibiotic resistance , Secondary metabolism , Actinomycetes
Exploitation of novel antimicrobial compounds from various microbial sources and its applications
Keywords:Microorganisms , Antimicrobial compounds
Fundamental and applied research in ribosome engineering
Keywords:Ribosomes , Ribosome engineering , Ribosomal mutations , Ribosome-targeting antibiotics
Academic Societies
Academic Societies
Japan society for Bioscience, Biotechnology and Agrochemistry
Thesociety for Actinomycetes Japan
American Society for Microbiology

Committee of Academic Societies
2020- , 日本放線菌学会 , 理事
Academic Background
Graduate School
Yamanashi University , 2001

山梨大学工学部化学生物工学科 , 1996

Ph.D. , Yamanashi University
2012 , The society for actinomycetes Japan Hamada Award
2005 , The Japan Society for Bioscience Biotechnology and Agrochemistry New Project Award (2005)
2003 , The Best Poster Award, The Society for Actinomycetes Japan (2003)
Research Career
Research Career
2019- , 信州大学 先鋭領域融合研究群 バイオメディカル研究所 生体分子イノベーション部門ユニット長
2016- , 大阪大学 生物工学国際交流センター 招聘准教授
2014- , 信州大学 先鋭領域融合研究群 バイオメデイカル研究所 准教授
2012- , Faculty of Agriculture, Associate Professor
2007-2012 , Tenure-Track Assistant Professor, International Young Researchers Empowerment Center, Shinshu University, Japan
2001-2007 , Postdoctoral Fellow, MicrobialFunction Laboratory, National Food Research Institute, Japan

Overseas Education
2018- , Visiting Researcher, Umeå University/Sweden


Books, Articles, etc.
Unique physiological and genetic features of ofloxacin-resistant Streptomyces mutants
Applied and Environmental Microbiology,88(3) 2022
Author:Hoshino K, Hamauzu R, Nakagawa H, Kodani S, Hosaka T

Lincomycin-induced secondary metabolism in Streptomyces lividans 66 with a mutation in the gene encoding the RNA polymerase beta subunit
Current Microbiology,77:2933-2939 2020(Aug. 28)
Author:Mukai K, Kobayashi M, Hoshino K, Maruyama T, Hayashi D, Hamauzu R, Hosaka T

A putative mechanism underlying secondary metabolite overproduction by Streptomyces strains with a 23S rRNA mutation conferring erythromycin resistance
Applied Microbiology and Biotechnology,104(5):2193-2203 2020(Jan. 10)
Author:Hoshino K, Imai Y, Mukai K, Hamauzu R, Ochi K, Hosaka T

Isolation and structure determination of a new cytotoxic peptide curacozole from Streptomyces curacoi based on genome mining
The Journal of Antibiotics,72:1-7 2019
Author:Kodani S, Kaweewan I, Komaki H, Hemmi H, Hoshino K, Hosaka T, Isokawa G, and Oyoshi T

A possible mechanism for lincomycin induction of secondary metabolism in Streptomyces coelicolor A3(2)
Antonie van Leeuwenhoek,111:705-716 2018
Author:Ishizuka M, Imai Y, Mukai K, Shimono K, Hamauzu R, Ochi K, Hosaka T

Combined Drug-Resistance Mutations Substantially Enhance Enzyme Production in Paenibacillus agaridevorans
Journal of Bacteriology,200:e00188-18 2018
Author:Funane K, Tanaka Y, Hosaka T, Murakami K, Miyazaki T, Shiwa Y, Gibu S, Inaoka T, Kasahara K, Fujita N, Yoshikawa H, Hiraga Y, Ochi K

生物工学会誌(大村智先生ノーベル賞受賞記念特集−微生物由来天然物の実用化と未来−),94:399-400 2016
Author:保坂 毅

Lincomycin at subinhibitory concentrations potentiates secondary metabolite production by Streptomyces spp.
Applied and Environmental Microbiology,81:3869-3879 2015
Author:Imai Y, Sato S, Tanaka Y, Ochi K, Hosaka T.

New strategies for drug discovery: activation of silent or weakly expressed microbial gene clusters
Applied Microbiology and Biotechnology,97:87-98 2013
Author:Ochi K. and Hosaka T.

Heterologous expression of plant RelA/SpoT homolog results in increased stresstolerance inSaccharomyces cerevisiae by accumulating the bacterial alarmone ppGpp
Microbiology,158:2213 - 2224 2012
Author:Ochi K., Nishizawa T., Inaoka T., Yamada Y., Hashimoto K., Hosaka T., Okamoto S., Ozeki, Y.

Development of the ability to produce secondary metabolites in Streptomyces through the acquisition of erythromycin resistance
J. Antibiot.,65:323–326 2012
Author:Imai Y., Fujiwara T., Ochi K., and Hosaka, T.

Rare earth elements activate the secondary metabolite-biosynthesis gene clusters in Streptomyces coelicolor A3(2)
J Antibiot,63:477-481 2010
Author:Tanaka, Y., Hosaka T., and Ochi, K.

Antibacterial discovery in actinomycetes strains with mutations in RNA polymerase or ribosomal protein S12
Nature Biotechnology,27(5):462-464 2009
Author:Hosaka T., Ohnishi-Kameyama M., Muramatsu H., Murakami K., Tsurumi Y., Kodani S., Yoshida M., Fujie A., and Ochi K..

Bacterialalarmone, guanosine 5'-diphosphate 3'-diphosphate (ppGpp), predominantly binds the beta' subunit of plastid-encoded plastid RNA polymerasein chloroplasts.
Chembiochem,10:1227-1233 2009
Author:Sato M., Takahashi K, Ochiai Y, Hosaka T, Ochi K, Nabeta K

Dramatic activation of antibiotic production in Streptomyces coelicolor by cumulative drug resistance mutations
Appl Environ Microbiol,74:2834-2840 2008
Author:Wang G., Hosaka T., and Ochi K.

Mutations in rsmG, encoding a16S rRNA methyltransferase, result in low-level streptomycin resistance and antibiotic overproduction in Streptomyces coelicolor A3(2)
J Bacteriol,189:3876-3883 2007
Author:Nishimura, K., Hosaka T., Tokuyama S., Okamoto S., and Ochi K.

Identification of the RsmG methyltransferase target as 16S rRNA nucleotide G527 and characterization of Bacillus subtilis rsmG mutants
J Bacteriol,189:6068-6073 2007
Author:Nishimura K., Johansen SK., Inaoka T., Hosaka T., Tokuyama S., Tahara Y., Okamoto S., Kawamura F., Douthwaite S., and Ochi K. .

Improvement of alpha-amylase production by modulation of ribosomal component protein S12 in Bacillus subtilis 168
Appl Environ Microbiol,72:71-77 2006
Author:Kurosawa, K., T. Hosaka, N. Tamehiro, T. Inaoka and K. Ochi

EshA accentuates ppGpp accumulation andis conditionally required for antibiotic production in Streptomyces coelicolor A3(2)
J Bacteriol,188:4952-4961 2006
Author:Saito, N., J. Xu, T. Hosaka, S. Okamoto, H.Aoki, M. J. Bibb and K. Ochi.

Physiological analysis of the stringent response elicited in an extreme thermophilic bacterium, Thermus thermophilus
J Bacteriol,188:7111-7122 2006
Author:Kasai, K., T. Nishizawa, K. Takahashi, T. Hosaka, H. Aoki and K. Ochi

Increased expression of ribosome recycling factor is responsible for the enhanced protein synthesis during the late growth phase in an antibiotic-overproducing Streptomyces coelicolor ribosomal rpsL mutant
Mol Microbiol,61:883-897 2006
Author:Hosaka, T., J. Xu, and K. Ochi

Effects of Escherichia coli ribosomal protein S12 mutations on cell-free protein synthesis
Eur J Biochem,271:1127-1134 2004
Author:Chumpolkulwong, N., C. Hori-Takemoto, T. Hosaka, T. Inaoka, T. Kigawa, M. Shirouzu, K. Ochi and S. Yokoyama

The novel mutation K87E in ribosomal protein S12 enhances protein synthesis activity during the late growth phase in Escherichia coli
Mol Genet Genomics,271:317-324 2004
Author:Hosaka, T., N. Tamehiro, N. Chumpolkulwong, C. Hori-Takemoto, M. Shirouzu, S. Yokoyama and K.Ochi

Structural basis for transcription regulation by alarmone ppGpp
Cell,117:299-310 2004
Author:Artsimovitch, I., V. Patlan, S. Sekine, M. N. Vassylyeva, T. Hosaka, K. Ochi, S. Yokoyama and D. G. Vassylyev

Ribosome engineering and secondary metabolite production
Adv Appl Microbiol,56:155-184 2004
Author:Ochi, K., S. Okamoto, Y. Tozawa, T. Inaoka, T. Hosaka, J. Xu and K. Kurosawa

Enhanced expression of S-adenosylmethionine synthetase causes overproduction of actinorhodin in Streptomyces coelicolor A3(2)
J Bacteriol,185:601-609 2003
Author:Okamoto, S., A. Lezhava, T. Hosaka, Y. Okamoto-Hosoya and K. Ochi

Innovative approach for improvement of an antibiotic-overproducing industrial strain of Streptomyces albus
Appl Environ Microbiol,69:6412-6417 2003
Author:Tamehiro, N., T. Hosaka, J. Xu, H. Hu, N. Otake and K. Ochi

An aberrant protein synthesis activity is linked with antibiotic overproduction in rpsL mutants of Streptomyces coelicolor A3(2)
Microbiology,149:3299-309 2003
Author:Okamoto-Hosoya, Y., T. Hosaka and K. Ochi

Acetylacetoin synthase as a marker enzyme for detecting the 2,3-butanediol cycle
J Biosci Bioeng,93:248-251 2002
Author:Ui, S., T. Hosaka, K. Mizutani, T. Ohtsuki and A. Mimura

Characterization of the NADH-linked acetylacetoin reductase/2,3-butanediol dehydrogenase gene from Bacillus cereus YUF-4
J Biosci Bioeng,91:539-544 2001
Author:Hosaka, T., S. Ui, T. Ohtsuki, A. Mimura, M. Ohkuma and T. Kudo

Separation and properties of two acetylacetoin reductases from Bacillus cereus YUF-4
Biosci Biotechnol Biochem,63:199-201 1999
Author:Hosaka, T., S. Ui and A. Mimura

Discovery of a new mechanism of 2,3-butanediol stereoisomer formation Bacillus cereus YUF-4
J Biosci Bioeng,85:79-83 1998
Author:Ui, S., T. Hosaka, K. Watanabe, and A. Mimura

Purification andproperties of acetylacetoin synthase from Bacillus sp. YUF-4
Biosci Biotechnol Biochem,62:795-797 1998
Author:Ui, S., T. Hosaka, K. Mizutani and A. Mimura

Molecular physiological studies on actinomycetes for a fundamental understanding of antibiotics
第93回日本細菌学会総会シンポジウム 2020(Feb. 19)

微生物ウィーク2019 2019(Jul. 25)

Analysis of mechanisms for antibiotic induction of secondary metabolism
18th International Symposium on the Biology of Actinomycetes (JEJU/KOREA) 2017

第68回日本生物工学会大会シンポジウム 2016
Presenter:保坂 毅 (Invited)

第10回ゲノム微生物学会年会シンポジウム 2016
Presenter:保坂 毅(Invited)

第5回遺伝研研究会 2015
Presenter:保坂 毅(Invited)

Ribosome-targeting antibiotics at subinhibitory concentrations potentiate secondary metabolite production by streptomycetes
Society for Industrial Microbiology and Biotechnology Annual Meeting 2015
Presenter:Hosaka T(Invited)

Activation of the potential to produce secondary metabolites in actinomycetes by modulating the RNA polymerase and/or ribosome
ISIM2014 (Dalian/China) 2014
Presenter:Hosaka T (Invited)

Lincomycin at subinhibitory concentrations activates the potential of Streptomyces strains to produce secondary metabolites
17th International Symposium on the Biology of Actinomycetes [ISBA’17](Aydin/Turkey) 2014
Presenter:Imai Y., Sato S., Tanaka Y., Ochi K., and Hosaka T.

Activation of secondary metabolite production in Streptomyces spp. by exposure to subinhibitory concentrations of lincomycin.
IUMS2014 [XIVth International Congress of Bacteriology and Applied Microbiology] 2014
Presenter:Imai Y., Sato S., Tanaka Y., Ochi K., and Hosaka T.

山梨大学学術研究会 2010
Presenter:保坂毅 (invited)

平成 21 年度科学交流フォーラム 第 11 回静岡ライフサイエンスシンポジウム 2010
Presenter:保坂毅 (invited)

放線菌の潜在的な抗生物質生産力を活性化するRNA ポリメラーゼ変異とリボソーム変異
日本農芸化学会中部支部 第 157 回例会 若手シンポジウム 2009
Presenter:保坂毅 (invited)

Activation of silent genes in Streptomyces sp. 631689 by generating a spontaneous gentamicin-resistant mutant
15th International Symposium on the Biology of Actinomycetes 2009
Presenter:Hosaka, T., T. Fujiwara, Y. Imai, K. Sen and K. Ochi

The impact of “ribosome engineering” on antibiotic discovery
Japan-UK Workshop 2008 (Genomics of Antibiotic-producing Actinomycete: Implicationsand Applications) 2008
Presenter:Hosaka T (invited)

バイオサイエンスとインダストリー,74:516-518 2016
Author:保坂 毅,今井 優

日本放線菌学会誌,28(2):9-14 2014
Author:保坂 毅

信州大学農学部紀要,48:9-15 2012(Mar. 27)
Author:保坂毅, 今井優, 藤原達也

2010 年度日本放線菌学会大会感想記
日本放線菌学会誌,24(2):17-18 2010

化学と生物,42:636-638 2004
Author:保坂毅, 為広紀正, 越智幸三

月刊バイオインダストリー,24(10):59-66 2007
Author:保坂毅, 王国君, 岡本晋, 越智幸三

農林水産技術研究ジャーナル,33(3):22-25 2010

バイオサイエンスとインダストリー,67(8):413-417 2009

月刊アグリバイオ 2018(Nov. 30)

S12 リボソームタンパク質に変異を有する大腸菌細胞抽出液及びそれを用いる無細胞系によるタンパク質の製造方法
Research Grants
Grants‐in‐aid for Scientific Research(Research Representative)
2014 - 2016 , リボソーム攻撃性抗生物質の活用による糸状菌の潜在的二次代謝能活性化技術の確立 , 挑戦的萌芽研究
2013 - 2015 , 放線菌の転写・翻訳系改変による潜在能力活性化機構の解明と二次代謝産物発掘への応用 , 若手研究(A)
2009 - 2011 , 薬剤耐性付与による放線菌からのRNAポリメラーゼ変異株の分離と新抗生物質の探索 , 若手研究 (B)

Scholarship donation
2009 , 放線菌の潜在遺伝子を覚醒させる薬剤耐性変異を活用した抗生物質探索技術の開発 (ホクト生物科学振興財団研究奨励金)
2005 , 微生物の潜在機能誘発メカニズムと有用天然物の効率的生産を目指した「リボゾーム工学」技術の活用 (日本農芸化学会研究資金)