2022 Fiscal Year Final Research Report
Cellular responses to chronic heat stress in yeast
| Project/Area Number |
20K06620
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 44010:Cell biology-related
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| Research Institution | Shizuoka University |
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Principal Investigator |
Kimura Yoko 静岡大学, 農学部, 教授 (80291152)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 熱ストレス / 酵母 / 液胞 / 形態変化 / 陥入 / 相分離 |
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| Outline of Final Research Achievements |
In yeast exposed to chronically high temperatures, vacuolar membranes get deformed and invaginations are formed. In this study, we showed that phase-separation of vacuolar membrane occurred after heat stress leading to the formation of the invagination. In addition, Atg8 and Hfl1, a vacuolar membrane-localized Atg8-binding protein, were found to suppress the excess vacuolar invaginations after heat stress. At that time, Hfl1 formed foci at the neck of the invaginations in wild-type cells, whereas it was efficiently degraded in the vacuole in the atg8 mutant. Interestingly, a combined mutation with the vacuole BAR domain protein Ivy1 led to vacuoles in hfl1 ivy1 and atg8ivy1 mutants having constitutively invaginated structures; moreover, these mutants showed stress-sensitive phenotypes.
Our findings suggest that vacuolar invaginations result from the combination of changes in the physiochemical properties of the vacuolar membrane and other cellular factors.
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| Free Research Field |
分子細胞生物学
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| Academic Significance and Societal Importance of the Research Achievements |
熱ストレスによる液胞膜の陥入形成の亢進、及び陥入を制御する分子の同定は申請者らによるオリジナルな発見である。液胞膜陥入は熱ストレス時の液胞膜の膜面積の急激な増加に応じて、そのまま液胞の体積を増やさないようにする細胞の制御機構の可能性があるが、細胞内因子によって制御されていることを申請者のグループが初めて明らかにした。
また通常では液胞が球状の形態をとるのは、エネルギー的に球状が最も安定であるからと考えられるが、恒常的に陥入形成している変異株の取得により、細胞には液胞を積極的に球状に保つ機能がある可能性や、さらに、液胞の形態変化は生命活動を制御する機構の一つである仮説も発展的に考えられた。
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