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: 8361544
• 负责人: Zhenyu Yue
• 金额: $ 0.13万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8361544
• 关键词: 1-Phosphatidylinositol 3-Kinase; Autophagocytosis; Autophagosome; Binding Proteins; Biochemical; Biochemistry; Cell Death; Cellular biology; Complex; Development; Endocytosis; Funding; Genetic; Grant; Lipids; Manuscripts; Mediating; Membrane; Mus; National Center for Research Resources; Nature; Nerve Degeneration; Pathway interactions; Phosphotransferases; Play; Principal Investigator; Proteins; Publishing; Regulation; Research; Research Infrastructure; Resources; Role; Source; Structure; Tissues; Tumor Suppression; United States National Institutes of Health; Vacuole; Vesicle; Vps34 Phosphatidylinositol 3 Kinase; Work; cost; in vivo; macromolecule; novel; protein complex; trafficking

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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.)

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 Beclin 1是一种哺乳动物自噬蛋白，在发育、肿瘤抑制、神经退行性变和细胞死亡中发挥重要作用。Beclin 1与Vps 34/磷脂酰肌醇（PtdIns）3-激酶（III类PI-3 K）形成复合物，其介导多种囊泡运输途径，包括内吞作用和自噬。然而，Beclin 1-Vps 34/PtdIns 3 K复合物在自噬调控中的确切作用仍有待阐明。通过结合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Beclin 1复合物特异性相关的蛋白质组分。生物化学分析揭示了一个大的体内Beclin 1复合物，包含已知的蛋白Vps 34/PtdIns 3 K，p150/Vps 15和UVRAG，以及新的蛋白BISC和BIRC。新蛋白的表征表明，BISC和BIRC以相反的方式调节Vps 34/PtdIns 3 K活性。BISC和BIRC对脂质激酶活性的这种相反作用与它们对自噬的不同调节相关：BISC正调节自噬，而BIRC参与自噬的负控制。此外，我们发现Beclin 1和BISC协同促进与Atg 5/Atg 12相关的双膜空泡的形成，而BIRC的强制表达导致异常的晚期内体/溶酶体结构（独立于Beclin 1）和自噬体成熟受损。 我们的研究表明，通过形成不同的蛋白质复合物，Beclin 1及其结合蛋白协调了Vps 34/PtdIns 3 K在多个步骤中调节自噬的精确功能。描述这项工作的手稿已出版（18。 Y. Zhong，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.）