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Gen Enomoto Assistant Professor |
From School 【 display / non-display 】
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The University of Tokyo Graduate School of Arts and Sciences Multi-Disciplinary Sciences Life Sciences Graduated
2013.04 - 2016.03
Country：Japan
Notes：PhD
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The University of Tokyo Graduate School of Arts and Sciences Multi-Disciplinary Sciences Life Sciences Graduated
2011.04 - 2013.03
Country：Japan
Notes：MS
Employment Record in Research 【 display / non-display 】
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Tokyo University of Agriculture Faculty of Applied Bio-Science Department of Agricultural Chemistry Assistant Professor
2024.04
External Career 【 display / non-display 】
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The University of Electro-Communications Graduate School of Informatics and Engineering Department of Engineering Science Japan Society for the Promotion of Science (JSPS) Restart Postdoctoral Research Fellow
2022.07 - 2024.03
Country：Japan
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Albert-Ludwigs-Universität Freiburg Institut für Biologie III Japan Society for the Promotion of Science (JSPS) Overseas Research Fellow
2020.07 - 2022.06
Country：Germany
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Albert-Ludwigs-Universität Freiburg Institut für Biologie III EMBO Long-Term Fellow
2018.02 - 2020.06
Country：Germany
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The University of Tokyo Graduate School of Arts and Sciences Assistant Professor
2016.04 - 2018.01
Country：Japan
Research Areas 【 display / non-display 】
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Life Science / Plant molecular biology and physiology
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Life Science / Applied microbiology
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Life Science / Molecular biology / 光生物学
Research Interests 【 display / non-display 】
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Applied Microbiology
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microbiology
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thermophile
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photobiology
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photoreceptor
Papers 【 display / non-display 】
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Evidence for an early green/red photocycle that precedes the diversification of GAF domain photoreceptor cyanobacteriochromes. Reviewed International coauthorship International journal
Nibedita Priyadarshini, Niklas Steube, Dennis Wiens, Rei Narikawa, Annegret Wilde, Georg K A Hochberg, Gen Enomoto
Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2023.02
Authorship：Last author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
Phytochromes are linear tetrapyrrole-binding photoreceptors in eukaryotes and bacteria, primarily responding to red and far-red light signals reversibly. Among the GAF domain-based phytochrome superfamily, cyanobacteria-specific cyanobacteriochromes show various optical properties covering the entire visible region. It is unknown what physiological demands drove the evolution of cyanobacteriochromes in cyanobacteria. Here, we utilize ancestral sequence reconstruction and biochemical verification to show that the resurrected ancestral cyanobacteriochrome proteins reversibly respond to green and red light signals. pH titration analyses indicate that the deprotonation of the bound phycocyanobilin chromophore is crucial to perceive green light. The ancestral cyanobacteriochromes show only modest thermal reversion to the green light-absorbing form, suggesting that they evolved to sense the incident green/red light ratio. Many cyanobacteria can utilize green light for photosynthesis using phycobilisome light-harvesting complexes. The green/red sensing cyanobacteriochromes may have allowed better acclimation to changing light environments by rearranging the absorption capacity of the phycobilisome through chromatic acclimation.
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Control of light-dependent behaviour in cyanobacteria by the second messenger cyclic di-GMP. Reviewed International coauthorship International journal
Gen Enomoto, Thomas Wallner, Annegret Wilde
microLife 4 uqad019 2023
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
Nucleotide-derived signalling molecules control a wide range of cellular processes in all organisms. The bacteria-specific cyclic dinucleotide c-di-GMP plays a crucial role in regulating motility-to-sessility transitions, cell cycle progression, and virulence. Cyanobacteria are phototrophic prokaryotes that perform oxygenic photosynthesis and are widespread microorganisms that colonize almost all habitats on Earth. In contrast to photosynthetic processes that are well understood, the behavioural responses of cyanobacteria have rarely been studied in detail. Analyses of cyanobacterial genomes have revealed that they encode a large number of proteins that are potentially involved in the synthesis and degradation of c-di-GMP. Recent studies have demonstrated that c-di-GMP coordinates many different aspects of the cyanobacterial lifestyle, mostly in a light-dependent manner. In this review, we focus on the current knowledge of light-regulated c-di-GMP signalling systems in cyanobacteria. Specifically, we highlight the progress made in understanding the most prominent behavioural responses of the model cyanobacterial strains Thermosynechococcus vulcanus and Synechocystis sp. PCC 6803. We discuss why and how cyanobacteria extract crucial information from their light environment to regulate ecophysiologically important cellular responses. Finally, we emphasize the questions that remain to be addressed.
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Thermosynechococcus switches the direction of phototaxis by a c-di-GMP-dependent process with high spatial resolution. Reviewed International coauthorship International journal
Daisuke Nakane, Gen Enomoto, Heike Bähre, Yuu Hirose, Annegret Wilde, Takayuki Nishizaka
eLife 11 2022.05
Authorship：Lead author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
Many cyanobacteria, which use light as an energy source via photosynthesis, show directional movement towards or away from a light source. However, the molecular and cell biological mechanisms for switching the direction of movement remain unclear. Here, we visualized type IV pilus-dependent cell movement in the rod-shaped thermophilic cyanobacterium Thermosynechococcus vulcanus using optical microscopy at physiological temperature and light conditions. Positive and negative phototaxis were controlled on a short time scale of 1 min. The cells smoothly moved over solid surfaces towards green light, but the direction was switched to backward movement when we applied additional blue light illumination. The switching was mediated by three photoreceptors, SesA, SesB, and SesC, which have cyanobacteriochrome photosensory domains and synthesis/degradation activity of the bacterial second messenger cyclic dimeric GMP (c-di-GMP). Our results suggest that the decision-making process for directional switching in phototaxis involves light-dependent changes in the cellular concentration of c-di-GMP. Direct visualization of type IV pilus filaments revealed that rod-shaped cells can move perpendicular to the light vector, indicating that the polarity can be controlled not only by pole-to-pole regulation but also within-a-pole regulation. This study provides insights into previously undescribed rapid bacterial polarity regulation via second messenger signalling with high spatial resolution.
DOI： 10.7554/eLife.73405
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Kaisei Maeda, Yukiko Okuda, Gen Enomoto, Satoru Watanabe, Masahiko Ikeuchi
eLife 10 2021.06
Publishing type：Research paper (scientific journal) Publisher：eLife Sciences Publications, Ltd
Extracellularpolysaccharides of bacteria contribute to biofilm formation, stress tolerance, and infectivity. Cyanobacteria, the oxygenic photoautotrophic bacteria, uniquely produce sulfated extracellular polysaccharides among bacteria to support phototrophic biofilms. In addition, sulfated polysaccharides of cyanobacteria and other organisms have been focused as beneficial biomaterial. However, very little is known about their biosynthesis machinery and function in cyanobacteria. Here, we found that the model cyanobacterium, <italic>Synechocystis</italic> sp. strain PCC 6803, formed bloom-like cell aggregates embedded in sulfated extracellular polysaccharides (designated as synechan) and identified whole set of genes responsible for synechan biosynthesis and its transcriptional regulation, thereby suggesting a model for the synechan biosynthesis apparatus. Because similar genes are found in many cyanobacterial genomes with wide variation, our findings may lead elucidation of various sulfated polysaccharides, their functions, and their potential application in biotechnology.
DOI： 10.7554/elife.66538
Other Link： https://cdn.elifesciences.org/articles/66538/elife-66538-v1.xml
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Evolution-inspired design of multicolored photoswitches from a single cyanobacteriochrome scaffold. Reviewed International coauthorship International journal
Keiji Fushimi, Masumi Hasegawa, Takeru Ito, Nathan C Rockwell, Gen Enomoto, Ni-Ni -Win, J Clark Lagarias, Masahiko Ikeuchi, Rei Narikawa
Proceedings of the National Academy of Sciences of the United States of America 117 ( 27 ) 15573 - 15580 2020.07
Language：English Publishing type：Research paper (scientific journal)
Cyanobacteriochromes (CBCRs) are small, bistable linear tetrapyrrole (bilin)-binding light sensors which are typically found as modular components in multidomain cyanobacterial signaling proteins. The CBCR family has been categorized into many lineages that roughly correlate with their spectral diversity, but CBCRs possessing a conserved DXCF motif are found in multiple lineages. DXCF CBCRs typically possess two conserved Cys residues: a first Cys that remains ligated to the bilin chromophore and a second Cys found in the DXCF motif. The second Cys often forms a second thioether linkage, providing a mechanism to sense blue and violet light. DXCF CBCRs have been described with blue/green, blue/orange, blue/teal, and green/teal photocycles, and the molecular basis for some of this spectral diversity has been well established. We here characterize AM1_1499g1, an atypical DXCF CBCR that lacks the second cysteine residue and exhibits an orange/green photocycle. Based on prior studies of CBCR spectral tuning, we have successfully engineered seven AM1_1499g1 variants that exhibit robust yellow/teal, green/teal, blue/teal, orange/yellow, yellow/green, green/green, and blue/green photocycles. The remarkable spectral diversity generated by modification of a single CBCR provides a good template for multiplexing synthetic photobiology systems within the same cellular context, thereby bypassing the time-consuming empirical optimization process needed for multiple probes with different protein scaffolds.
Misc 【 display / non-display 】
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海洋性シアノバクテリアAcaryochloris marinaが青色光光量感知機能をもつ意義
長谷川万純, 長谷川万純, 伏見圭司, 及川雄貴, 榎本元, 池内昌彦, 吉澤晋, 成川礼
日本微生物生態学会大会(Web) 2017 2017
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クロロフィルdを持つシアノバクテリアAcaryochloris marinaの光受容体シアノバクテリオクロムの解析
成川礼, 伏見圭司, 榎本元, 池内昌彦
日本植物学会大会研究発表記録 79th 2015
Honours, Awards and Prizes 【 display / non-display 】
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The First National High School Memorial Award
2016.03 The University of Tokyo, Graduate School of Arts and Sciences
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Encouragement Award
2013.03 The University of Tokyo, Graduate School of Arts and Sciences
Scientific Research Funds Acquisition Results 【 display / non-display 】
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細胞の短軸方向の極性制御を実現するタンパク質の同定
Grant number：24K08659 2024.04 - 2027.03
日本学術振興会 科学研究費助成事業 基盤研究(C)
榎本 元
Grant amount：\4550000 （ Direct Cost: \3500000 、 Indirect Cost：\1050000 ）
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Live-imaging analysis to reveal spatiotemporal dynamics of cyanobacterial light signaling
Grant number：22KJ1374 2023.03 - 2026.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows
Grant amount：\4550000 （ Direct Cost: \3500000 、 Indirect Cost：\1050000 ）
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c-di-GMP signaling network underpinning lifestyle transitions in response to incident light color
Grant number：17K15244 2017.04 - 2019.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B) Grant-in-Aid for Young Scientists (B)
Enomoto Gen
Grant amount：\4290000 （ Direct Cost: \3300000 、 Indirect Cost：\990000 ）
I previously reported that cyclic dimeric GMP (c-di-GMP) signaling governs light color-specific induction of cell aggregation of a thermophilic cyanobacterium. In this study, I aim to reveal the whole c-di-GMP signaling network, focusing on how various proteins work together in a cell. Phenotypic analyses of gene disruption mutants and systematic gene expression analyses led to the identification of Tlr1612 as the main repressor of cell aggregation. I also discovered that heterogeneity of c-di-GMP levels may be induced in a cell aggregate under natural light conditions.
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シアノバクテリオクロムによるｃ－ｄｉ－ＧＭＰシグナル伝達機構の解明
Grant number：13J08415 2013.04 - 2016.03
日本学術振興会 科学研究費助成事業 特別研究員奨励費 特別研究員奨励費
榎本 元
Grant amount：\3000000 （ Direct Cost: \3000000 ）
前年度において当初の研究実施計画をほぼ完遂し、本年度にその結果をProceedings of the National Academy of Sciences of the United States of America誌に発表した。
解析対象である三つの光受容体は協調して、c-di-GMP というセカンドメッセンジャーを介したシグナル伝達を行い、好熱性シアノバクテリアが示す細胞凝集を照射光波長依存的に制御している。本研究にさらに深い考察を与えるため、細胞凝集における最も重要なトリガーであるSesAの定量的解析を行った。SesAが示すc-di-GMP合成活性は、青色光照射下での活性化状態であっても、産物であるc-di-GMPによってその活性が阻害されることがわかった。
c-di-GMP受容体であるセルロース合成酵素Tll0007のc-di-GMPに対する親和性を測定すると、その親和性は低く、SesAが合成するc-di-GMPはTll0007を活性化するのに量が足りないことが示唆された。他のc-di-GMP合成酵素が、SesAとTll0007を仲介する増幅因子として機能する可能性を考え、網羅的な遺伝子破壊株を作製して増幅因子を探索した。増幅因子としてのc-di-GMP合成酵素は発見できなかったが、細胞凝集を抑制するのに必要な因子を同定した。現在は、この抑制因子の「抑制」が増幅因子として機能する可能性を検証している。
上記で示唆したようにc-di-GMPシグナル伝達が二段階に分かれていることは、細胞凝集という固着性への転換が、運動性の抑制、細胞外多糖生産など、多段階で進む反応であることを反映していると予想される。本研究は、バクテリアが固着性へ転換するという普遍的かつ複雑な生体プロセスを支える分子機構の解明に大きく貢献できることが期待される。
Other External Funds 【 display / non-display 】
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始原的生物時計における光入力の役割の解明
Grant number：Y-2024-2-012 2024.04 - 2026.03
公益財団法人 発酵研究所 若手研究者助成
Grant amount：\3000000
Teaching Experience 【 display / non-display 】
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Introductory course in life science experiments
2016.04 - 2018.01 Institution：The University of Tokyo
Committee Memberships 【 display / non-display 】
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The Japanese Society of Photosynthetic Research for Young Researchers organizer
2017.04 - 2020.03
Committee type：Academic society
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The Japanese Society of Photosynthetic Research for Young Researchers president
2017.04 - 2017.12
Committee type：Academic society