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Faculty of Science Depertment of Chemistry |
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Title |
Associate Professor |
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Laboratory Address |
坂戸市けやき台1-1 |
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Contact information |
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External Link |
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Akanuma Genki
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Degree 【 display / non-display 】
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修士（理学） ( 2004.03 立教大学 )
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博士（理学） ( 2007.03 立教大学 )
Research Areas 【 display / non-display 】
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Life Science / Genetics
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Life Science / Applied microbiology
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Life Science / Molecular biology
From School 【 display / non-display 】
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Rikkyo University Faculty of Science Graduated
- 2002.03
From Graduate School 【 display / non-display 】
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Rikkyo University Graduate School, Division of Natural Science Doctor's Course Completed
- 2007.03
Country：Japan
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Rikkyo University Graduate School, Division of Natural Science Master's Course Completed
- 2004.03
Country：Japan
Employment Record in Research 【 display / non-display 】
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Josai University Faculty of Science Depertment of Chemistry Associate Professor
2024.04
External Career 【 display / non-display 】
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学習院大学理学部生命科学科 助教
2019.10 - 2024.03
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Rikkyo University College of Science Department of Life Science Assistant Professor
2015.04 - 2019.09
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中央大学理工学部応用化学科 助教
2010.04 - 2015.03
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The University of Tokyo Special researcher of the Japan Society for the Promotion of Science
2007.04 - 2010.03
Professional Memberships 【 display / non-display 】
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日本遺伝学会
2021.09
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日本農芸化学会
2002.03
Qualification Acquired 【 display / non-display 】
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Junior High School Teacher Specialization License
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High School Teacher Specialization License
Papers 【 display / non-display 】
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RecN spatially and temporally controls RecA-mediated repair of DNA double-strand breaks. Reviewed International journal
Shunsuke Noda, Genki Akanuma, Kenji Keyamura, Takashi Hishida
The Journal of biological chemistry 299 ( 12 ) 105466 - 105466 2023.12
Language：English Publishing type：Research paper (scientific journal)
RecN, a bacterial structural maintenance of chromosomes-like protein, plays an important role in maintaining genomic integrity by facilitating the repair of DNA double-strand breaks (DSBs). However, how RecN-dependent chromosome dynamics are integrated with DSB repair remains unclear. Here, we investigated the dynamics of RecN in response to DNA damage by inducing RecN from the PBAD promoter at different time points. We found that mitomycin C (MMC)-treated ΔrecN cells exhibited nucleoid fragmentation and reduced cell survival; however, when RecN was induced with arabinose in MMC-exposed ΔrecN cells, it increased a level of cell viability to similar extent as WT cells. Furthermore, in MMC-treated ΔrecN cells, arabinose-induced RecN colocalized with RecA in nucleoid gaps between fragmented nucleoids and restored normal nucleoid structures. These results suggest that the aberrant nucleoid structures observed in MMC-treated ΔrecN cells do not represent catastrophic chromosome disruption but rather an interruption of the RecA-mediated process. Thus, RecN can resume DSB repair by stimulating RecA-mediated homologous recombination, even when chromosome integrity is compromised. Our data demonstrate that RecA-mediated presynapsis and synapsis are spatiotemporally separable, wherein RecN is involved in facilitating both processes presumably by orchestrating the dynamics of both RecA and chromosomes, highlighting the essential role of RecN in the repair of DSBs.
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Natsuki Sugaya, Shion Tanaka, Kenji Keyamura, Shunsuke Noda, Genki Akanuma, Takashi Hishida
Genes & Genetic Systems 2023
Publishing type：Research paper (scientific journal) Publisher：Genetics Society of Japan
DOI： 10.1266/ggs.23-00013
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Diploid-associated adaptation to chronic low-dose UV irradiation requires homologous recombination in Saccharomyces cerevisiae. Reviewed International journal
Mana Shibata, Kenji Keyamura, Takuya Shioiri, Shunsuke Noda, Genki Akanuma, Takashi Hishida
Genetics 222 ( 1 ) 2022.08
Language：English Publishing type：Research paper (scientific journal)
Ultraviolet-induced DNA lesions impede DNA replication and transcription and are therefore a potential source of genome instability. Here, we performed serial transfer experiments on nucleotide excision repair-deficient (rad14Δ) yeast cells in the presence of chronic low-dose ultraviolet irradiation, focusing on the mechanisms underlying adaptive responses to chronic low-dose ultraviolet irradiation. Our results show that the entire haploid rad14Δ population rapidly becomes diploid during chronic low-dose ultraviolet exposure, and the evolved diploid rad14Δ cells were more chronic low-dose ultraviolet-resistant than haploid cells. Strikingly, single-stranded DNA, but not pyrimidine dimer, accumulation is associated with diploid-dependent fitness in response to chronic low-dose ultraviolet stress, suggesting that efficient repair of single-stranded DNA tracts is beneficial for chronic low-dose ultraviolet tolerance. Consistent with this hypothesis, homologous recombination is essential for the rapid evolutionary adaptation of diploidy, and rad14Δ cells lacking Rad51 recombinase, a key player in homologous recombination, exhibited abnormal cell morphology characterized by multiple RPA-yellow fluorescent protein foci after chronic low-dose ultraviolet exposure. Furthermore, interhomolog recombination is increased in chronic low-dose ultraviolet-exposed rad14Δ diploids, which causes frequent loss of heterozygosity. Thus, our results highlight the importance of homologous recombination in the survival and genomic stability of cells with unrepaired lesions.
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Diverse relationships between metal ions and the ribosome. Reviewed International journal
Genki Akanuma
Bioscience, biotechnology, and biochemistry 85 ( 7 ) 1582 - 1593 2021.06
Authorship：Lead author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
The ribosome requires metal ions for structural stability and translational activity. These metal ions are important for stabilizing the secondary structure of ribosomal RNA, binding of ribosomal proteins to the ribosome, and for interaction of ribosomal subunits. In this review, various relationships between ribosomes and metal ions, especially Mg2+ and Zn2+, are presented. Mg2+ regulates gene expression by modulating the translational stability and synthesis of ribosomes, which in turn contribute to the cellular homeostasis of Mg2+. In addition, Mg2+ can partly complement the function of ribosomal proteins. Conversely, a reduction in the cellular concentration of Zn2+ induces replacement of ribosomal proteins, which mobilizes free-Zn2+ in the cell and represses translation activity. Evolutional relationships between these metal ions and the ribosome are also discussed.
DOI： 10.1093/bbb/zbab070
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Evolution of Ribosomal Protein S14 Demonstrated by the Reconstruction of Chimeric Ribosomes in Bacillus subtilis. Reviewed International journal
Genki Akanuma, Fujio Kawamura, Satoru Watanabe, Masaki Watanabe, Fumiya Okawa, Yousuke Natori, Hideaki Nanamiya, Kei Asai, Taku Chibazakura, Hirofumi Yoshikawa, Akiko Soma, Takashi Hishida, Yasuyuki Kato-Yamada
Journal of bacteriology 203 ( 10 ) 2021.04
Authorship：Lead author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
Ribosomal protein S14 can be classified into three types. The first, the C+ type has a Zn2+ binding motif and is ancestral. The second and third are the C- short and C- long types, neither of which contain a Zn2+ binding motif and which are ca. 90 residues and 100 residues in length, respectively. In the present study, the C+ type S14 from Bacillus subtilis ribosomes (S14BsC+) were completely replaced by the heterologous C- long type of S14 from Escherichia coli (S14Ec) or Synechococcus elongatus (S14Se). Surprisingly, S14Ec and S14Se were incorporated fully into 70S ribosomes in B. subtilis However, the growth rates as well as the sporulation efficiency of the mutants harboring heterologous S14 were significantly decreased. In these mutants, the polysome fraction was decreased and the 30S and 50S subunits accumulated unusually, indicating that cellular translational activity of these mutants was decreased. In vitro analysis showed a reduction in the translational activity of the 70S ribosome fraction purified from these mutants. The abundance of ribosomal proteins S2 and S3 in the 30S fraction in these mutants was reduced while that of S14 was not significantly decreased. It seems likely that binding of heterologous S14 changes the structure of the 30S subunit, which causes a decrease in the assembly efficiency of S2 and S3, which are located near the binding site of S14. Moreover, we found that S3 from S. elongatus cannot function in B. subtilis unless S14Se is present.IMPORTANCE S14, an essential ribosomal protein, may have evolved to adapt bacteria to zinc-limited environments by replacement of a zinc-binding motif with a zinc-independent sequence. It was expected that the bacterial ribosome would be tolerant to replacement of S14 because of the previous prediction that the spread of C- type S14 involved horizontal gene transfer. In this study, we completely replaced the C+ type of S14 in B. subtilis ribosome with the heterologous C- long type of S14 and characterized the resulting chimeric ribosomes. Our results suggest that the B. subtilis ribosome is permissive for the replacement of S14, but coevolution of S3 might be required to utilize the C- long type of S14 more effectively.
DOI： 10.1128/JB.00599-20
Misc 【 display / non-display 】
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Regulatory C-terminal domain of the ε subunit in FoF1 ATP synthase is important to maintain cellular membrane potential by activating ATP-dependent H+ pumping in Bacillus subtilis
Kato-Yamada Y, Akanuma G, Tagana T, Sawada M, Suzuki S, Shimada T, Tanaka K, Kawamura F
Biochimica et Biophysica Acta - Bioenergetics 1859 e78 2018.08
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Stearyl alcohol, one of the most effective lipase-super-inducers, not only induces the expression of virulence related genes but also induces the production of polyester in Ralstonia sp NT80
Ishizuka M, Akanuma G, Yoshizawa R, Nagakura M, Shiwa Y, Watanabe S, Yoshikawa H, Ushio K
FEBS Journal 282 195 2015.06
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Characterization of group I introns in bacterial flagellin gene and homing endonuclease from thermophilic Bacillus sp Kps3
Ishizuka M, Umano W, Ishibashi N, Hayakawa J, Akanuma G
FEBS Journal 281 678 2014.06
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A study of rpsN and yhzA genes, coding for two types of S14 ribosomal protein in Bacillus subtilis
Yousuke Natori, Genki Akanuma, Hideaki Nanamiya, Fujio Kawamura
GENES & GENETIC SYSTEMS 81 ( 6 ) 442 - 442 2006.12
Language：English Publishing type：Research paper, summary (international conference) Publisher：GENETICS SOC JAPAN
Awards 【 display / non-display 】
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農芸化学奨励賞
2020 日本農芸化学会 枯草菌リボソームの新たな機能に関する研究
赤沼元気
Scientific Research Funds Acquisition Results 【 display / non-display 】
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グアニン四重鎖DNAの適切な複製に必要なMgs1機能の解明
Grant number：23K05014 2023.04 - 2026.03
日本学術振興会 科学研究費助成事業 基盤研究(C)
赤沼 元気
Grant amount：\4810000 （ Direct Cost: \3700000 、 Indirect Cost：\1110000 ）
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慢性的DNA損傷ストレス耐性におけるリボソームの役割
Grant number：20K05790 2020.04 - 2023.03
日本学術振興会 科学研究費助成事業 基盤研究(C)
赤沼 元気
Grant amount：\4160000 （ Direct Cost: \3200000 、 Indirect Cost：\960000 ）
本年度は主に、染色体異数化によるリボソームタンパク質遺伝子欠損株の増殖速度回復と、DNA損傷ストレス耐性低下に関する解析を行った。
リボソームタンパク質L42B欠損株以外にも、6種のリボソームタンパク質欠損株について、染色体異数化による増殖速度回復が見られるかを検討し、全てのサプレッサー変異株でパラログ遺伝子がコードされている染色体の倍加を確認した。これらの株では、DNA損傷剤や複製阻害剤への感受性増加が認められたが、感受性増加の程度は株によって大きく異なっており、増加した染色体とパラログ遺伝子の種類によってDNA損傷ストレス耐性への影響は変化すると考えられた。
出芽酵母は通常１倍体として増殖するが、２倍体化することで環境に適応する例が知られている。L42B欠損株でも2倍体化によりパラログ遺伝子が2コピーとなるため、増殖速度の回復が予想されるが、L42B欠損株から細胞増殖速度が回復した２倍体は得られていない。そこで、２倍体細胞のL42BとL42Aの遺伝子コピー数を制限した株を作製して調査した。L42A遺伝子のみ２コピー保持する2倍体株の増殖速度は１倍体のL42B欠損株とほとんど変わらず、80Sやpolysomeの含有量の増加も認められなかった。恐らく2コピーのL42A遺伝子では2倍体細胞に十分な量のリボソームタンパク質を供給できないことが原因と考えられる。
L42B欠損株のサプレッサー変異株ではDNA損傷ストレス耐性が低下するが、この表現型を抑圧する変異株の単離を試みた。サプレッサー変異株からMMS耐性株を選択し、そこから異数性が解消された株を除いた。これらの株のゲノム塩基配列を次世代シーケンサーで解析したところ、多くの変異がリボソーム合成や翻訳に関わる遺伝子から検出された。今回の結果は細胞の翻訳活性低下がタンパク質の不均衡解消に一定の効果があることを示すものである。 -
Elucidation of molecular mechanism of super-induced secretion of lipase and construction of useful protein mass production system
Grant number：18K05414 2018.04 - 2023.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
Grant amount：\4290000 （ Direct Cost: \3300000 、 Indirect Cost：\990000 ）
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Investigation of the relationship between intracellular Mg2+ concentration and ribosomes
Grant number：17K15253 2017.04 - 2020.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
Akanuma Genki
Grant amount：\4290000 （ Direct Cost: \3300000 、 Indirect Cost：\990000 ）
We investigated the influence of the change of intracellular Mg2+ concentration on the ribosomes. Excess Mg2+ reduced the cellular translational activity and induced the transcription of rRNA. When decreasing the intracellular Mg2+ concentration, the amount of 70S ribosome was significantly decreased. These results suggest that the ribosomes which can chelate 25% of Mg2+ in the cell are involved in the Mg2+ homeostasis.
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The regulatory mechanisms of the induction of lipase expression and polyester production by stearyl alcohol
Grant number：26450101 2014.04 - 2017.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
AKANUMA Genki
Grant amount：\5070000 （ Direct Cost: \3900000 、 Indirect Cost：\1170000 ）
The transcriptional factor which activates the transcription of gene encoding lipase was determined. Moreover, we found the alcohol dehydrogenase which plays important role for induction of lipase expression by stearyl alcohol. The EliA, a secretory protein, is essential for the lipase-producing bacterium to respond to stearyl alcohol.
Other External Funds 【 display / non-display 】
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原始的リボソームの構築と進化の考察
2022.04 - 2024.03
公益財団法人発酵研究所 公益財団法人発酵研究所平成22年度一般研究助成
赤沼元気
Authorship：principal_investigator
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2013
産学が連携した研究開発成果の展開 研究成果展開事業 研究成果最適展開支援プログラム(A-STEP) 探索タイプ
赤沼 元気
リパーゼ発現誘導促進タンパク質EliAを高発現させることで、Ralstonia sp. NT80株においてステアリルアルコールによるリパーゼ生産誘導時間を12時間短縮させることに成功した。さらに、リパーゼの工業生産に利用されているBurkholderia glumaeにおいて、生産誘導までの時間、誘導効率ともに一般的な誘導剤であるオリーブオイルよりもステアリルアルコールが優れたリパーゼ誘導剤であることを見出した。また、ステアリルアルコールによるリパーゼ誘導時には、リパーゼの比活性を向上させる因子も同時に発現誘導されていることをin vitroで証明した。EliAのより安定かつ恒常的な発現系構築と、リパーゼ比活性向上因子の同定が今後の課題として残されているが、技術移転を目指した研究開発へのステップアップの可能性が示されたと言える。
Past of Cooperative Research 【 display / non-display 】
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原始的リボソームの作製と進化の考察
2020.04 - 2025.07
公益財団法人大隅基礎科学創成財団 微生物機能探究コンソーシアム活動費
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リボソームプロファイルの取得
2019.04 - 2023.03
三菱商事ライフサイエンス