Molecular Mechanism of Membrane Dynamics during Autophagy

自噬过程中膜动力学的分子机制

• 批准号: 15002012
• 负责人: OHSUMI Yoshinori
• 金额: $ 312.83万
• 依托单位: National Institute for Basic Biology (2004-2007)Okazaki National Research Institutes (2003)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Specially Promoted Research
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15002012/
• 关键词: autophagy; protein degradation; vacuole; lysosome; ATG; ubiqutin-like protein; autophagosome; nutrient starvation; Atg; 酵母; 膜形成

Recently autophagy is getting a hot field in cell biology. There appeared many papers showing physiological significance of autophagy in many important aspects in mammals. However, molecular mechanism of autophagy is still remained to be uncovered. This research project aimed to understand the dynamics of membrane during autophgy at molecular level. For 4 years of the research period, we could obtain the following progress.Total 18 Atg proteins are essential for autophagosome formation and consist five functional units. We systematically studied localization of each Atg proteins in every atg mutant and proposed hierarchy of Atg proteins for autophagosome formation. Furthermore auophagy-specific Atg protein complex (Atg17-Atg29-Atg31) was found to be basal for PAS formation for autophagosome.Two conjugation systems are essential for autophagy. In vitro reconstitution of Atg12 conjugation and Atg8 lipidation was established using purified yeast and plant proteins. We succeeded to show Atg8-PE causes membrane tethering and hemifusion of PE-containing liposome. Also we showed that Atg12-Atg5 conjugate catalytically stimulate the Atg8 lipidation reaction like E3 enzyme.Localization of autophagy-specific PI3-kinase was determined by Atg14 and PI3 kinase activity and its product PI3P are required for autophagosome formation.In collaboration with Dr. Inagaki's group we succeeded to obtain crystal structures of LC3, Atg3, Atg4B, Atg4b-LC3 complex, Atg5/Atg16 complex, and Ape1.It was shown that autophagy is essential for maintenance of amino acid levels for protein synthesis during nitrogen starvation.

自噬是近年来细胞生物学研究的热点。近年来，已有大量文献报道了自噬在哺乳动物中的重要生理意义。然而，自噬的分子机制仍有待进一步研究。本研究旨在从分子水平了解自噬过程中细胞膜的动态变化。经过4年的研究，我们获得了如下进展：自噬体形成所必需的Atg蛋白共有18个，由5个功能单位组成。我们系统地研究了每一个Atg蛋白在每一个Atg突变体中的定位，并提出了自噬体形成的Atg蛋白的层次结构。自噬特异性的Atg蛋白复合物（Atg 17-Atg 29-Atg 31）是PAS自噬体形成的基础。使用纯化的酵母和植物蛋白建立了Atg 12缀合和Atg 8脂化的体外重建。我们成功地表明Atg 8-PE引起含PE脂质体的膜束缚和半融合。我们还发现Atg 12-Atg 5偶联物像E3酶一样催化Atg 8脂化反应。自噬特异性PI 3-激酶的定位由Atg 14决定，PI 3激酶活性及其产物PI 3 P是自噬体形成所必需的。与Inagaki博士的小组合作，我们成功地获得了LC 3，Atg 3，Atg 4 B，Atg 4 b-LC 3复合物，Atg 5/Atg 16复合物，研究表明，自噬对维持氮饥饿时蛋白质合成所需的氨基酸水平是必不可少的。

项目成果

Role of the Apgl2 conjugation system in mammalian autophagy.

Apgl2 缀合系统在哺乳动物自噬中的作用。

• 发表时间: 2003
• 期刊: Int. J. Biochem. Cell Biol 35
• 作者: Mizushima;N.
• 通讯作者: N.

Promotion of tumorigenesis by heterozygous disruption of the beclin 1 autophagy gene.

• DOI: 10.1172/jci20039
• 发表时间: 2003-12
• 期刊: The Journal of clinical investigation
• 作者: X. Qu;Jie Yu;G. Bhagat;Norihiko Furuya;H. Hibshoosh;A. Troxel;J. Rosen;E. Eskelinen;N. Mizushima

Assortment of phosphatidylinositol 3-kinase complexes-Atg14p directs association of complex I to the pre-autophagosomal structure in Saccharomyces cerevisiae

• DOI: 10.1091/mbc.e05-09-0841
• 发表时间: 2006-04-01
• 期刊: MOLECULAR BIOLOGY OF THE CELL
• 影响因子: 3.3
• 作者: Obara, K;Sekito, T;Ohsumi, Y
• 通讯作者: Ohsumi, Y

In vivo and in vitro reconstitution of Atg8 conjugation essential for autophagy

• DOI: 10.1074/jbc.m405860200
• 发表时间: 2004-09-24
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Ichimura, Y;Imamura, Y;Ohsumi, Y
• 通讯作者: Ohsumi, Y

Processing of ATG8s, ubiquitin-like proteins, and their deconjugation by ATG4s are essential for plant autophagv.

ATG8、泛素样蛋白的加工以及 ATG4 对其的解结合对于植物自噬至关重要。

• 发表时间: 2004
• 期刊: Plant Cell 16
• 作者: Yoshimoto;K.
• 通讯作者: K.