| Project/Area Number |
10480202
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cell biology
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| Research Institution | Okazaki National Research Institutes |
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Principal Investigator |
OHSUMI Yoshinori Okazaki Natl. Res. Inst. NIBB Professor, 基礎生物学研究所, 教授 (30114416)
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| Co-Investigator(Kenkyū-buntansha) |
KAMADA Yoshiaki Okazaki Natl. Res. Inst. NIBB Research Associate, 基礎生物学研究所, 助手 (20291891)
NODA Takeshi Okazaki Natl. Res. Inst. NIBB Research Associate, 基礎生物学研究所, 助手 (00290908)
YOSHIMORI Tamotsu Okazaki Natl. Res. Inst. NIBB Associate Professor, 基礎生物学研究所, 助教授 (60191649)
OHSUMI Mariko Teikyou Univ. of Sci. & Tech., Faculty of Science & Engineering Associate Professor, 理工学部, 助教授 (40168927)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥14,800,000 (Direct Cost: ¥14,800,000)
Fiscal Year 1999: ¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 1998: ¥9,300,000 (Direct Cost: ¥9,300,000)
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| Keywords | Autophagy / yeast / Protein conjugation / autophagosome / Apg8 / Apg5 / Apg12 / Apg10 / オートファジー / 酵母 / 液胞 / 自食作用 / タンパク質分解 / タンパク質結合反応 / 栄養飢餓 |
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| Research Abstract |
We discovered autophagy in yeast and defined the whole process., then isolated a set of autophagy-deficient mutants, and have cloned most of APG genes essential for autophagy. We are now characterizing these gene products. We found a novel protein conjugation system required for autophagy. The C-terminal Gly of Apg12 is bound to Lys residue of Apg5 via an isopeptide bond. This conjugation reaction is distinct from but quite similar to ubiquitination. Apg10 functions as an E2 conjugating enzyme by showing thioester bond between Apg12 and Apg10. In a two-hybrid screen with Apg12 as a bait, we identified Apg16. We noticed that the Apg16 is bound to preferentially to Apg12-Apg5 conjugate. Apg16 forms an homo-oligomer via the coiled coil domain. Hence, this hetero-oligomeric large protein complex may play a role in autophagic process.
Apg8 is up-regulated upon starvation. Indirect immunofluorescence study showed that intracellular localization of Apg8 drastically changes. Upon starvation, Apg8 appears adjacent to the vacuole, which represents autophagosome or its intermediate and finally autophagic bodies. According to EM analysis, Apg8 is mostly enriched on the intermediate of autophagosome. Thus, Apg8 could be a useful tracer for membrane flow in autophagosome formation. Formation process of autophagosome is accompanied with multiple fusion of small precursor structures to the intermediate structure.
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