Molecular mechanisms of polarized endocytic traffic in epithelial cells

上皮细胞极化内吞运输的分子机制

• 批准号: 8629137
• 负责人: Rytis Prekeris
• 金额: $ 14.83万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8629137
• 关键词: Address; Apical; Architecture; Atrophic; Binding; Binding Proteins; Cell Polarity; Cell membrane; Cells; Cellular biology; Complex; Cytomegalovirus Infections; Data; Defect; Disease; Drug Targeting; Endosomes; Ensure; Epithelial; Epithelial Cells; Epithelial cyst; Family; Funding; Gastrointestinal Diseases; Goals; Grant; Guanosine Triphosphate Phosphohydrolases; In Vitro; Individual; Intestines; KRP protein; Kidney; Kidney Diseases; Kinesin; Laboratories; Lead; Lipids; MDCK cell; Maintenance; Mediating; Membrane Protein Traffic; Modeling; Molecular; Morphogenesis; Nephrogenic Diabetes Insipidus; Organ; Phosphorylation; Phosphotransferases; Play; Polycystic Kidney Diseases; Principal Investigator; Process; Proteins; Publishing; Pulmonary Cystic Fibrosis; Recruitment Activity; Regulation; Role; Route; Site; Sorting - Cell Movement; Staging; Structure; Syndrome; System; Testing; Tight Junctions; Tissues; Transmembrane Transport; Vertebral column; Work; Zebrafish; apical membrane; base; cellular microvillus; design; in vivo; in vivo Model; insight; member; monolayer; nexin; novel; novel therapeutic intervention; polarized cell; protein complex; protein transport; public health relevance; rab GTP-Binding Proteins; scaffold; tissue culture; trafficking

Project Summary Epithelial tissues consist from polarized cells that are capable of selectively transporting substances across epithelial monolayer. This selective transport is achieved by the partitioning of the plasma membrane into distinct domains: apical and basolateral, with both of these plasma membrane compartments having distinct lipid and protein compositions. In addition to polarity at a single-cell level, individual polarized epithelial cells are organized around central apical lumen. Since the fidelity of trans-epithelial protein transport and epithelial tissue organization is crucial to a variety of epithelial functions, epithelial cells have developed complicated mechanisms to ensure correct cell and tissue polarization. Rab11 GTPases are the members of small monomeric GTPase super-family that have been implicated in regulating endocytic membrane transport. Rab GTPase work by recruiting various effector proteins to the distinct cellular compartments. Thus, deciphering the roles of these effector proteins is a key step in understanding the function of epithelial cell. During the last decade, several Rab11-binding proteins have been identified, which include Rab11 family interacting proteins, also known as FIPs. Work from several laboratories, including ours, has shown that FIP5 member of FIP family regulate polarized protein transport, as well as microvilli and apical lumen formation in epithelial cells. Furthermore, we have shown that FIP5 acts as a scaffolding factor by binding to and activating sorting nexin 18, kinesin II and cingulin. Based on recently published results and on our preliminary data, we propose the following hypotheses. First, FIP5/Cingulin complex mediates apical endosome targeting to the site of apical lumen formation, and that this complex is regulated by GSK3¿ kinase. Second, FIP5-dependent endocytic transport of Rap2A mediates microvilli formation in polarized epithelial cells. Thus, the main goal of this proposal is to identify and characterize the roles of FIP5 and its interacting proteins in mediating epithelial polarization. I propose three different aims designed to test these hypotheses in vitro and in vivo. In the aim #1 we will analyze the role of FIP5 and cingulin interaction in regulating apical protein transport during apical lumen formation. In the aim #2 we will characterize the role of FIP5 and its binding proteins during microvilli formation. Finally, in aim #3 we will test the role of FIP5-dependent endocytic transport during epithelial tissue morphogenesis using zebrafish intestinal tract formation model. Completion of this project will provide a novel insight in understanding the molecular machinery and regulation of epithelial cell polarization and apical lumen formation during epithelial tissue morphogenesis and remodeling.

项目摘要 上皮组织由能够选择性运输物质的偏振细胞组成 跨上皮单层。这种选择性运输是通过分配等离子体来实现的 膜变成不同的域：顶部和基底外侧，这两种质膜 具有不同脂质和蛋白质组成的隔室。除了单细胞的极性 水平，单个偏振上皮细胞周围是顶端腔周围的。自从忠诚 跨上皮蛋白的转运和上皮组织组织对各种上皮至关重要 功能，上皮细胞已开发出复杂的机制，以确保细胞和组织正确 极化。 Rab11 GTPases是小型单体GTPase超级家庭的成员 实施用于调节内吞膜运输。 Rab GTPase通过招聘各种 效应子蛋白到不同的细胞室。那，破译了这些效应子的角色 蛋白质是理解上皮细胞功能的关键步骤。在过去的十年中，有几个 已经确定了Rab11结合蛋白，其中包括Rab11家族相互作用的蛋白 称为fip。来自包括我们在内的几个实验室的工作表明，FIP5的FIP成员 家族调节极化蛋白的转运，以及微绒毛和顶腔形成 上皮细胞。此外，我们已经证明FIP5通过与和 激活排序Nexin 18，驱动蛋白II和cingulin。基于最近发布的结果和我们的 初步数据，我们提出以下假设。首先，FIP5/Cingulin复合物培养了顶端 内体靶向顶端管腔形成部位，并且该复合物受到GSK3的调节 激酶。其次，RAP2A的FIP5依赖性内吞转运介导了微绒毛形成 极化上皮细胞。这是该提案的主要目标是识别和表征角色 FIP5及其相互作用的蛋白质在介导上皮极化中的相互作用。 我提出了三个不同的目标，旨在在体外和体内检验这些假设。目的 ＃1我们将分析FIP5和金属蛋白相互作用在控制顶蛋白转运中的作用 在根尖管腔形成期间。在目标2中，我们将表征FIP5及其绑定的作用 微绒毛形成过程中的蛋白质。最后，在AIM＃3中，我们将测试依赖FIP5的作用 斑马鱼肠道形成在上皮组织形态发生过程中的内吞传递 模型。该项目的完成将提供一个新颖的见解，以了解分子 上皮上皮细胞极化和上皮腔的机械和调节 组织形态发生和重塑。