DISTINCT REGULATION OF AUTOPHAGIC ACTIVITY BY TWO NOVEL PROTEINS

两种新型蛋白质对自噬活性的独特调节

• 批准号: 8169173
• 负责人: Zhenyu Yue
• 金额: $ 0.35万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8169173
• 关键词: 1-Phosphatidylinositol 3-Kinase; Autophagocytosis; Autophagosome; Binding Proteins; Biochemical; Biochemistry; Cell Death; Cellular biology; Complex; Computer Retrieval of Information on Scientific Projects Database; Development; Endocytosis; Funding; Genetic; Grant; Institution; Lipids; Manuscripts; Mediating; Membrane; Mus; Nature; Nerve Degeneration; Pathway interactions; Phosphatidylinositols; Phosphotransferases; Play; Proteins; Publishing; Regulation; Research; Research Personnel; Resources; Role; Source; Structure; Tissues; Tumor Suppression; United States National Institutes of Health; Vacuole; Vesicle; Work; in vivo; novel; protein complex; trafficking

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Beclin 1 is a mammalian autophagy protein which was shown to play an important role in development, tumor suppression, neurodegeneration and cell death. Beclin 1 forms a complex with Vps34/phosphatidylinositol (PtdIns) 3-kinase (class III PI-3K), which mediates multiple vesicle trafficking pathways including endocytosis and autophagy. However, the precise role of Beclin 1-Vps34/PtdIns3K complex in the regulation of autophagy remains to be elucidated. Through a study that combines mouse genetics and biochemistry, we uncover several protein components that associate specifically with Beclin 1 complexes in mouse tissues. The biochemical analysis reveals a large in vivo Beclin 1 complex containing the known proteins Vps34/PtdIns3K, p150/Vps15 and UVRAG, as well as novel proteins BISC and BIRC. Characterization of the novel proteins suggests that BISC and BIRC modulate Vps34/PtdIns3K activity in opposite manner. This opposing effect of BISC and BIRC on the lipid kinase activity is correlated with their distinct regulation of autophagy: BISC positively regulates autophagy, whereas BIRC is involved in negative control of autophagy. Moreover, we find that Beclin 1 and BISC synergistically promote formation of double membrane vacuoles which are associated with Atg5/Atg12, while forced expression of BIRC results in aberrant late endosomal/lysosomal structures (independent of Beclin 1) and impaired autophagosome maturation. Our study suggests that, by forming distinct protein complexes, Beclin 1 and its binding proteins orchestrate the precise function of Vps34/PtdIns3K in regulating autophagy at multiple steps. A manuscript describing this work has been published (18. Y. Zhong, Q.J. Wang, X. Li, B.T. Chait, N. Heintz, Z. Yue "Distinct regulation of autophagic activity by Atg14L and Rubicon associated with Beclin 1-phosphatidylinositol-3-kinase complex" Nature Cell Biology. 11 (2009) 468-76.)

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 Beclin 1是一种哺乳动物自噬蛋白，在发育、肿瘤抑制、神经退变和细胞死亡等过程中发挥重要作用。Beclin 1与Vps34/磷脂酰肌醇(PtdIns)3-激酶(III类PI-3K)形成复合体，介导多种囊泡运输途径，包括内吞和自噬。然而，Beclin 1-Vps34/PtdIns3K复合体在自噬调控中的确切作用仍有待阐明。通过一项结合了小鼠遗传学和生物化学的研究，我们发现了几种与小鼠组织中的Beclin 1复合体特异相关的蛋白质成分。生化分析显示，在体内存在一个大的Beclin 1复合体，其中包含已知的蛋白质Vps34/PtdIns3K、P150/Vps15和UVRAG，以及新的蛋白质BISC和BIRC。对新蛋白的表征表明，BISC和BIRC以相反的方式调节Vps34/PtdIns3K的活性。BISC和BIRC对脂激酶活性的相反作用与它们对自噬的不同调控有关：BISC正向调节自噬，而BIRC参与负向自噬控制。此外，我们发现Beclin 1和BISC协同促进与ATG5/Atg12相关的双膜空泡的形成，而强迫表达BIRC会导致异常的晚期内噬/溶酶体结构(独立于Beclin 1)和自噬体成熟受阻。我们的研究表明，通过形成不同的蛋白质复合体，Beclin 1及其结合蛋白在多个步骤中协调Vps34/PtdIns3K在调节自噬中的精确功能。描述这项工作的手稿已经出版(18.Y.Chung，Q.J.Wang，X.Li，B.T.Chait，N.Heintz，Z.Yue)《自然细胞生物学》。11(2009)468-76。)