Molecular characteristics of the apical recycling system

顶端回收系统的分子特征

• 批准号: 7667796
• 负责人: JAMES Richard GOLDENRING
• 金额: $ 29.94万
• 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/7667796
• 关键词: Address; Apical; Back; Be++ element; Beryllium; Binding; Cell membrane; Characteristics; Complex; Digestive System Disorders; Environment; Epithelial Cells; Family; Gastric Parietal Cells; Glean; H(+)-K(+)-Exchanging ATPase; Human; Ion Channel; Ion Pumps; Mediating; Membrane; Membrane Proteins; Molecular; Molecular Motors; Monomeric GTP-Binding Proteins; Motor; Movement; Myosin ATPase; National Institute of Diabetes and Digestive and Kidney Diseases; Organelles; Pattern; Population; Process; Proteins; Proteome; Proteomics; Recycling; Regulation; Research; Role; Signal Transduction; Specificity; Surface; System; Vesicle; apical membrane; base; genetic regulatory protein; insight; novel; polarized cell; protein complex; protein transport; rab11 protein; receptor; response; trafficking

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取决于它们在顶部表面上的质膜蛋白的表达和表现。离子泵，离子通道和受体的阵列在很大程度上受到了这些蛋白质成分的运输和回收，这些蛋白质成分专门针对顶端极。回收过程的大部分特异性通过含RAB11A的顶端回收系统进行调节。回收由Rab11相互作用蛋白（RAB11-FIPS）的家族调节，该家族根据其与Rab11a的相互作用而旨在回收囊泡。此外，货物通过回收系统的移动向根顶膜的移动需要分子运动肌球蛋白VB，该肌球蛋白VB也与RAB11A相互作用。我们假设涉及RAB11A及其效应子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，与回收系统机械以及通过该动态细胞器的货物相关的蛋白质不容易预测。我们以前已经通过免疫共透明从人壁细胞中制备了高度纯化的回收囊泡，并开始对微管膜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范围，我们将追求两个具体的目的：首先，我们将确定由人类胃顶细胞制备的免疫共透明回收囊泡群体的新成分，并将确定它们在调节上皮细胞中再利用的作用。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运动复合物的组成部分，并确定复合成分之间相互作用的结构基础。这些研究应提供有关顶端回收系统组件的功能相关性的一般见解，包括货物，调节蛋白质复合物和信号系统。