Molecular characteristics of the apical recycling system

顶端回收系统的分子特征

• 批准号: 7141109
• 负责人: JAMES Richard GOLDENRING
• 金额: $ 23.27万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7141109
• 关键词: SDS polyacrylamide gel electrophoresis; apical membrane; biological transport; cellular polarity; gastric mucosa; gastrointestinal epithelium; guanine nucleotide binding protein; human tissue; immunocytochemistry; mass spectrometry; myosins; protein protein interaction; protein structure function; proteomics; transport proteins; vesicle /vacuole; western blottings

DESCRIPTION (provided by applicant): The interaction of polarized epithelial cells with the external environment is determined by their expression and presentation of plasma membrane proteins at their apical surfaces. The array of ion pumps, ion channels and receptors is regulated to a great extent by the trafficking and recycling of these protein constituents specifically to the apical pole. Much of the specificity of the recycling process is regulated through the Rab11a-containing apical recycling system. Recycling is regulated by a family of Rab11 interacting proteins (Rab11-FIPs) that are targeted to recycling vesicles based on their interaction with Rab11a. In addition, movement of cargoes through and out of the recycling system back to the apical membrane requires the molecular motor myosin Vb, which also interacts with Rab11a. We have hypothesized that multi-protein complexes involving Rab11a and its effectors regulate the trafficking of cargoes through the apical recycling system. Because of the complexity of the trafficking system, the proteins associated with recycling system machinery as well as the cargoes passing through this dynamic organelle are not readily predictable. We have previously prepared highly purified populations of recycling vesicles from human parietal cells by immunoisolation and begun a proteomic examination of tubulovesicle-associated proteins. To address the spectrum of trafficking regulation through the recycling system, we will pursue two specific aims: First, we will identify novel components of immunoisolated recycling vesicle populations prepared from human gastric parietal cells and will determine their roles in regulating recycling in epithelial cells. Second we will identify the components of putative multiprotein myosin Vb motor complexes associated with recycling vesicles and determine the structural basis of interactions among complex constituents. These studies should provide general insights into the functional relevance of components of the apical recycling system, including cargoes, regulatory protein complexes and signaling systems.

描述（由申请人提供）：极化上皮细胞与外部环境的相互作用由它们的表达和质膜蛋白在其顶端表面的呈现决定。离子泵、离子通道和受体的阵列在很大程度上通过这些蛋白质成分特异地到达顶极的运输和再循环来调节。回收过程的大部分特异性是通过含有 Rab11a 的顶端回收系统来调节的。回收受到 Rab11 相互作用蛋白 (Rab11-FIP) 家族的调节，这些蛋白根据与 Rab11a 的相互作用来回收囊泡。此外，货物通过和离开回收系统返回顶膜的运动需要分子马达肌球蛋白 Vb，它也与 Rab11a 相互作用。我们假设涉及 Rab11a 及其效应器的多蛋白复合物通过顶端回收系统调节货物的运输。由于运输系统的复杂性，与回收系统机械相关的蛋白质以及通过该动态细胞器的货物不容易预测。我们之前通过免疫分离从人壁细胞中制备了高度纯化的回收囊泡群，并开始对管泡相关蛋白进行蛋白质组学检查。为了通过回收系统解决运输调节的问题，我们将追求两个具体目标：首先，我们将鉴定由人胃壁细胞制备的免疫分离回收囊泡群的新成分，并确定它们在调节上皮细胞回收中的作用。其次，我们将确定与回收囊泡相关的假定多蛋白肌球蛋白 Vb 运动复合物的成分，并确定复杂成分之间相互作用的结构基础。这些研究应该提供对顶端回收系统组件的功能相关性的一般见解，包括货物、调节蛋白复合物和信号系统。