VTC Events Mediated by the Rab2 Complex

由 Rab2 Complex 主持的 VTC 活动

• 批准号: 6920350
• 负责人: ELLEN J TISDALE
• 金额: $ 24.82万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6920350
• 关键词: Golgi apparatus; SDS polyacrylamide gel electrophoresis; cell line; confocal scanning microscopy; endoplasmic reticulum; enzyme mechanism; glyceraldehyde 3 phosphate dehydrogenase; green fluorescent proteins; guanosinetriphosphatases; isozymes; mass spectrometry; metastasis; microtubules; neoplasm /cancer; pathologic process; protein binding; protein kinase C; protein localization; protein protein interaction; protein structure function; protein transport; proteomics; vesicle /vacuole

DESCRIPTION (provided by applicant): Our long-term goal is to understand the mechanism of protein sorting and recycling from vesicular tubular clusters (VTCs). VTCs function as transport complexes delivering cargo from the ER to the Golgi complex. Moreover, these structures are the first site of segregation of the anterograde and retrograde pathways and thereby perform a critical function. The small GTPase Rab2 plays an essential role in this trafficking step by promoting formation of retrograde-directed vesicles that carry recycling cargo back to the ER. Rab2- mediated vesicle formation requires atypical PKCi/X and GAPDH. In this application we propose to characterize Rab2 mechanistically and to establish the role of Rab2 in events associated with VTCs. The Specific Aims are: 1) to identify the protein components of the VTC subcompartment that binds Rab2, 2) to characterize the interaction between components of the Rab2 complex by mapping their reciprocal binding domains, and 3) elucidate the molecular mechanism of Rab2-dependent-retrograde vesicle budding from VTCs. The importance of investigating Rab2 function in secretion is underscored by the observation that elevated Rab2, PKC, and GAPDH expression correlates with high metastatic potential in various cancers. Since metastasis is a reflection of cytoskeletal reorganization and increased cell motility, it is noteworthy that Rab2 and its effectors influence microtubule dynamics. However, the precise function of Rab2, aPKCi/A, and GAPDH in the early secretory pathway and how these proteins contribute to the disease are unknown. The studies proposed in this application will develop a new and novel paradigm that couples Rab2-Apkc lA-GAPDH dysfunction with pathological consequences.

描述（由申请人提供）：我们的长期目标是了解蛋白质分选和从泡状小管簇（VTC）回收的机制。VTC作为转运复合体发挥功能，将货物从ER运送到高尔基复合体。此外，这些结构是顺行和逆行通路分离的第一个部位，从而执行关键功能。小GTTRab 2通过促进将再循环货物带回ER的逆行定向囊泡的形成，在该运输步骤中起着至关重要的作用。Rab 2介导的囊泡形成需要非典型PKCi/X和GAPDH。在这个应用程序中，我们提出的Rab 2的机械特性，并建立Rab 2在与VTC相关的事件中的作用。具体目标是：1）鉴定结合Rab 2的VTC亚室的蛋白组分，2）通过绘制Rab 2复合物组分之间的相互结合结构域来表征Rab 2复合物组分之间的相互作用，以及3）阐明Rab 2依赖性逆行囊泡从VTC出芽的分子机制。Rab 2、PKC和GAPDH表达升高与各种癌症的高转移潜能相关，这一观察结果强调了研究Rab 2在分泌中的功能的重要性。由于转移是细胞骨架重组和细胞运动性增加的反映，因此值得注意的是Rab 2及其效应物影响微管动力学。然而，Rab 2、aPKCi/A和GAPDH在早期分泌途径中的确切功能以及这些蛋白质如何促成疾病尚不清楚。本申请中提出的研究将开发一种将Rab 2-Apkc 1A-GAPDH功能障碍与病理后果相结合的新的和新颖的范例。