Coordination of membrane traffic through rab GEF and GAP cascades

通过 rab GEF 和 GAP 级联协调膜运输

• 批准号: 9381420
• 负责人: PETER Jay NOVICK
• 金额: $ 38.75万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9381420
• 关键词: AGFG1 gene; Address; Alleles; Alpha Cell; Binding; Biochemical; Biological Assay; Cell membrane; Cell physiology; Cell-Free System; Cells; Clinical; Complex; Defect; Diabetes Mellitus; Disease; Docking; Endocytic Vesicle; Event; Feedback; GTP Binding; GTPase-Activating Proteins; Glass; Goals; Golgi Apparatus; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Homologous Gene; Host Defense; Human; Hydrolysis; Immobilization; In Vitro; Individual; Kinetics; Lead; Leg; Link; Malignant Neoplasms; Mammalian Cell; Membrane; Membrane Protein Traffic; Modification; Motor; Myosin Type V; Nerve Degeneration; Organelles; Pathway interactions; Phenotype; Proteins; Recruitment Activity; Recycling; Regulation; Regulatory Element; Regulatory Pathway; Reporting; Role; SNAP receptor; Secretory Vesicles; Series; Site; Specific qualifier value; System; Testing; Time; Total Internal Reflection Fluorescent; Vesicle; Vesicle Transport Pathway; Yeasts; countercurrent chromatography; experimental study; flexibility; human disease; in vivo; member; novel; pathogen; rab GTP-Binding Proteins; response; retinal rods

Project Summary Rabs constitute the largest branch of the Ras GTPase superfamily, with ten members in yeast and more then 60 in mammalian cells. They serve as key nodes in the regulation of membrane traffic, each typically controlling several different aspects of a specific stage of membrane traffic by recruiting diverse effector proteins such as cytoskeletal motors, vesicle tethering proteins and regulators of SNARE complex assembly. Rabs are activated by specific guanine nucleotide exchange factors (GEFs) that catalyze the displacement of GDP and binding of GTP and are inactivated by GTPase activating proteins (GAPs) that stimulate the slow intrinsic rate of GTP hydrolysis. We have proposed that adjacent Rabs on a traffic pathway are networked to one another through their regulators. The postulated effect of these counter-current cascades is a programmed series of abrupt Rab conversions that lead to changes in the functional identity of the membrane as it flows along a pathway. Rabs are also thought to define the anterograde versus retrograde directionality of vesicular transport. In addition, Rab GEF-effector interactions are believed to generate positive feedback loops that promote vesicle maturation. While the roles of individual elements of the regulatory network have been examined, these proposals have not yet been tested at a more global, integrated level. We propose three specific aims that will address important aspects of the Rab regulatory network: 1. We will test the effects of rewiring a Rab regulatory circuit to evaluate its role in establishing organelle identity and pursue a novel inhibitory role for a coiled-coil vesicle tether that has emerged from these studies 2. We will directly test the role of Rabs in the control of the directionality of membrane traffic 3. We will determine the role of a Rab GEF-effector interaction in secretory vesicle maturation

项目摘要 RABS构成Ras GTPase超级家族的最大分支，有十名酵母中的成员，然后 在哺乳动物细胞中60。它们是膜流量调节的关键节点 通过招募多样的效应器来控制特定膜流量的特定阶段的几个不同方面 蛋白质，例如细胞骨架电动机，囊泡绑扎蛋白和SNARE复合物组件的调节剂。 Rabs被特定的鸟嘌呤核苷酸交换因子（GEF）激活，该因子催化了位移 GDP和GTP的结合，并被GTPase激活蛋白（GAP）灭活，刺激慢速 GTP水解的内在速率。我们提出，交通路径上的相邻RAB被网络与 通过他们的监管机构彼此。这些反电流级联反应的假设效果是一个编程 一系列突然的RAB转换会导致膜的功能身份变化。 沿着一条小路。 Rabs还被认为定义了囊泡的顺行与逆行方向性 运输。此外，据信RAB GEF效应器相互作用会产生积极的反馈回路 促进囊泡成熟。虽然监管网络的各个要素的作用已经 经过检查，这些建议尚未在更全球的集成级别上进行测试。我们提出了三个 具体目的将解决RAB监管网络的重要方面： 1。我们将测试重新布线调节电路以评估其在建立细胞器中的作用的效果 身份并追求从这些研究中出现的卷曲螺旋囊状系绳的新型抑制作用 2。我们将直接测试RAB在控制膜交通方向性中的作用 3。我们将确定RAB GEF效应器相互作用在分泌囊泡成熟中的作用