| 研究課題/領域番号 |
20H00476
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| 研究種目 |
基盤研究(A)
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| 配分区分 | 補助金 |
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| 応募区分 | 一般 |
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| 審査区分 |
中区分45:個体レベルから集団レベルの生物学と人類学およびその関連分野
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| 研究機関 | 岡山大学 |
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研究代表者 |
ROBINSON ROBERT 岡山大学, 異分野基礎科学研究所, 客員教授 (60814118)
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| 研究分担者 |
千住 洋介 岡山大学, 異分野基礎科学研究所, 研究准教授 (90536848)
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| 研究期間 (年度) |
2020-04-01 – 2025-03-31
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| 研究課題ステータス |
交付 (2024年度)
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| 配分額 *注記 |
45,760千円 (直接経費: 35,200千円、間接経費: 10,560千円)
2024年度: 6,500千円 (直接経費: 5,000千円、間接経費: 1,500千円)
2023年度: 6,500千円 (直接経費: 5,000千円、間接経費: 1,500千円)
2022年度: 6,500千円 (直接経費: 5,000千円、間接経費: 1,500千円)
2021年度: 6,500千円 (直接経費: 5,000千円、間接経費: 1,500千円)
2020年度: 19,760千円 (直接経費: 15,200千円、間接経費: 4,560千円)
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| キーワード | Eukaryogenesis / Cytoskeleton / Asgard Archaea / Evolution / Roadblock proteins / Rab GTPases / Endoplasmic Reticulum / Sec61 / Actin / Asgard archaea / cytoskeleton / Tubulin / Small GTPases / Asgard / Structure / Gelsolin / evolution / archaea / structural biology / metagenomics |
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| 研究開始時の研究の概要 |
The origin of the eukaryotic cell is controversial. Metagenomics sequencing has revealed that Asgard archaea genomes contain potential homologs to eukaryotic genes. We will structurally characterize the Asgard eukaryotic-like protein homologs using X-ray crystallography and cryo-electron microscopy.
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| 研究実績の概要 |
We have analyzed the structures of Asgard archaea small GTPases, roadblock proteins and TRAPP proteins. The GTPase structure is similar to Rab GTPases, which in eukaryotes control the trafficking of vesicles between internal membranes. Asgard archaea do not possess internal membranes. However, the Asgard Rabs do not possess the C-terminal modification sites, which are needed to locate to discrete eukaryotic membranes. Thus, Rab proteins evolved their membrane specificity after proto-eukaryotes separated from Asgard archaea. The roadblock and TRAPP structures are also very similar between eukaryotes and Asgard archaea. However, Asgard form homodimers, whereas eukaryotes form heterodimers, indicating gene duplication and diversification were an important processes for eukaryotic evolution.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
Over the past year we have made several unexpected discoveries through expressing Asgard archaea proteins in mammalian cells. Several Asgard protein classes localize to the same regions of the eukaryotic cell as their eukaryotic counterparts. In particular, some proteins localize to eukaryotic internal membranes, which do not exist in Asgard archaea. These data have given us a new insight that the properties of existing pre-eukaryotic machines shaped the process of eukaryogenesis, since their fundamental properties remain intact during 2 billion years of evolution. This insight has advanced our understanding beyond what we proposed at the beginning of the project. Based on this understanding, we expect to make outstanding progress in the last year of our project.
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| 今後の研究の推進方策 |
We have achieved most of the aims listed in our proposal. In our final year we will: 1)Carry out mass spectrometry analysis of Asgard proteins against mammalian extracts to look for protein interactions that have been maintained over 2 billion years of evolution; 2) Conduct further structural and biochemical analyses of Asgard gelsolin proteins; 3) Carry out biochemical analyses of Asgard membrane remodeling proteins.
Challenges: One major challenge is that publication costs have increased dramatically during the lifetime of this grant.
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