Regulation of Polarized Traffic by PI-Metabolizing Enz

PI-代谢酶对极化流量的调节

• 批准号: 7654709
• 负责人: Ora A Weisz
• 金额: $ 34.39万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-15 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7654709
• 关键词: Abbreviations; Actins; Acute; Adaptor Signaling Protein; Adenoviruses; Affect; Affinity Chromatography; Agonist; Apical; Argipressin; Binding; Blood Circulation; Canis familiaris; Catabolism; Cell membrane; Cell physiology; Cell surface; Cells; Clathrin; Complex; Data; Disabled Persons; Duct (organ) structure; EGF gene; Endocytosis; Endoplasmic Reticulum; Endosomes; Enzymes; Epidermal Growth Factor; Epithelial; Epithelial Cells; Epithelium; Excision; Face; G-Protein-Coupled Receptors; Glutathione S-Transferase; Glycoproteins; Goals; Grant; Hydrolysis; Hypertension; Individual; Inositol; Ion Channel; Ion Transport; Ions; Kidney; Kidney Diseases; Kinetics; Laboratories; Lipids; Low-Density Lipoproteins; Maintenance; Mediating; Membrane; Membrane Protein Traffic; Membrane Proteins; Metabolism; Molecular Weight; Mus; N-terminal; Neurons; Parathyroid Hormones; Pathway interactions; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phospholipase C; Phospholipase D; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiological; Pik-off; Play; Polymeric Immunoglobulin Receptors; Process; Prostaglandins E; Protein Isoforms; Proteins; Proteinuria; Recycling; Regulation; Renal tubule structure; Research; Role; Signal Transduction; Site; Sodium Channel; Sorting - Cell Movement; Stress; Surface; TFAP2A gene; Testing; Transferrin; Ubiquitin; Urine; Vesicular stomatitis Indiana virus; Water; Wiskott-Aldrich Syndrome; actin-related protein 3; apical membrane; basolateral membrane; coated pit; epsin; human CCR10 protein; human PTH protein; hypercholesterolemia; inorganic phosphate; kidney cell; overexpression; phosphatidylinositol 3,4,5-triphosphate; platelet protein P47; polarized cell; protein complex; public health relevance; receptor; receptor internalization; response; trafficking

DESCRIPTION (provided by applicant): The maintenance of polarized plasma membrane domains with distinct protein and lipid compositions is critical for efficient renal cell function. The distribution of receptors and ion transporters in these cells is regulated in part by the rate at which these proteins are internalized from the apical and basolateral cell surfaces. The mechanisms that underlie cargo recruitment to clathrin coated pits where this process is initiated are poorly understood. Localized synthesis of phosphatidylinositol 4,5-bisphosphate (PIP2) at endocytic sites plays multiple roles in endocytosis, and modulation of surface PIP2 levels in nonpolarized cells can differentially affect the internalization of distinct proteins. The central hypothesis of this proposal is that apical and basolateral PIP2 metabolism in renal epithelial cells is independently regulated to selectively modulate clathrin-dependent endocytosis from these domains. Consistent with this idea, that the three isoforms of PI5-kinase (the enzymes that generate cell surface PIP2) are differentially localized in polarized renal epithelial cells. The specific aims of our proposal are to determine whether apical and basolateral pools of PIP2 are independently modulated in renal epithelial cells; to examine how changes in PIP2 levels upon agonist stimulation of G protein coupled receptors affect endocytosis from polarized membrane domains; and to determine how the apically localized PI5-kinase mPI5KI1 regulates apical endocytosis. The results of our studies have important implications for our understanding of how polarized cells compartmentalize PI synthesis and catabolism and for how this process is affected during normal signaling and in renal disease. PUBLIC HEALTH RELEVANCE: The surface of kidney cells is segregated into distinct domains with unique protein and lipid compositions that face the urine and the bloodstream. This asymmetric distribution of surface components is essential for kidney cells to properly reabsorb water, ions, and metabolites from the forming urine. These processes are controlled by receptors and ion transporters whose delivery to and removal from the cell surface is regulated by numerous cellular factors. Our goal is to understand how kidney cells differentially regulate the removal of these proteins from the surface, and how these mechanisms are selectively adjusted during the response to specific physiological signals. The results of our research will provide new information about how the trafficking of kidney proteins is regulated under normal conditions and under conditions of physiological stress.

描述（由申请人提供）：具有不同蛋白质和脂质组成的极化质膜结构域的维护对于有效的肾细胞功能至关重要。这些细胞中受体和离子转运蛋白的分布部分受受体和基底外侧细胞表面内部化的速率调节。知识渊博的货物覆盖坑的货物招募的机制是不了解的。磷脂酰肌醇4,5-双磷酸（PIP2）在内吞位点的局部合成在内吞作用中起多种作用，非极化细胞中表面PIP2水平的调节可以差异地影响不同蛋白质的内在化。该提议的中心假设是，肾上皮细胞中的顶端和基底外侧PIP2代谢被独立调节以选择性地调节这些结构域的网状蛋白依赖性内吞作用。与这个想法一致的是，PI5-激酶的三种同工型（产生细胞表面PIP2的酶）在极化的肾上皮细胞中差异化。我们建议的具体目的是确定PIP2的顶端和基底外侧池是否在肾上皮细胞中独立调节。为了检查G蛋白偶联受体的激动剂刺激对PIP2水平的变化如何影响偏光膜结构域的内吞作用；并确定顶尖定位的PI5-激酶MPI5KI1如何调节根尖内吞作用。我们的研究结果对我们了解对极化细胞的理解如何使PI合成和分解代谢以及在正常信号传导和肾脏疾病中如何影响该过程。公共卫生相关性：肾细胞的表面被隔离为具有独特蛋白质和脂质组成的不同结构域，面临尿液和血液。表面成分的这种不对称分布对于肾细胞从形成的尿液中正确吸收水，离子和代谢产物至关重要。这些过程由受体和离子转运蛋白控制，其从细胞表面递送和去除受许多细胞因子调节。我们的目标是了解肾细胞如何差异化调节这些蛋白质从表面上的去除，以及如何在对特定生理信号的响应中选择性调整这些机制。我们的研究结果将提供有关在正常情况和生理压力条件下如何调节肾脏蛋白的运输方式的新信息。