Control of Epithelial Polarity

上皮极性的控制

基本信息

批准号：
8082094
负责人：
Keith E Mostov
金额：
$ 38.63万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-07-01 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8082094
关键词：
3-Dimensional Abbreviations Adhesives Annexins Apical Basement membrane Binding Canis familiaris Cell Line Cell membrane Cells Cellular biology Charge Collagen Cyst Data Development Enzymes Epithelial Epithelial Cells Extracellular Matrix Face Gel Hepatocyte Growth Factor Image Ions Kidney Life Lipids MDCK cell Membrane Mesenchymal Microscopy Modeling Molecular Molecular Models Movement Nephrons Organ PH Domain PTEN gene Phosphatidylinositol 4,5-Diphosphate Phosphatidylinositols Phospholipase D Phosphoric Monoester Hydrolases Phosphotransferases Polycystic Kidney Diseases Polymeric Immunoglobulin Receptors Positioning Attribute Protein Isoforms Proteins RNA Interference Recruitment Activity Role Scaffolding Protein Signal Transduction Surface Testing Thin Layer Chromatography Tight Junctions Tube Work base cellular imaging inhibitor/antagonist innovation inorganic phosphate inositol 4,5-bisphosphate inositol 4-phosphate inositol-1,4,5-trisphosphate 5-phosphatase matrigel molecular modeling monolayer phosphatidylinositol 3,4,5-triphosphate podocalyxin prevent protein transport research study sialomucin sialomucins sodium-hydrogen exchanger regulatory factor src Homology Region 2 Domain

项目摘要

DESCRIPTION (provided by applicant): Many internal organs, such as the kidney, consist of hollow tubules and spheres lined by a layer of polarized epithelial cells. These cells have an apical plasma membrane domain facing the central lumen and a basolateral plasma membrane facing the underlying basement membrane. These two plasma membrane domains have completely different protein and lipid compositions, and trafficking of proteins and lipids to these distinct membrane surfaces is vital. We have found that the signaling lipid phosphatidyl inositol 3,4,5- trisphosphate (PIP3) is found only at the basolateral plasma membrane and is a key determinant of the identity and formation of this surface. In contrast phosphatidyl inositol 4,5-bisphosphate (PIP2) is concentrated at the apical plasma membrane, where it is a main determinant of this surface. We will test the hypothesis that PIP2 and PIP3 control the development of epithelial polarity, using live cell imaging. We will test the hypothesis that PIP3 is synthesized at the basolateral plasma membrane by a specific isoform(s) of phosphatidyl inositiol 3- kinase. We will test the respective roles of the lipid phosphatases PTEN and SHIP1/2 in preventing PIP3 from accumulating at the apical plasma membrane. We will test the hypothesis that gp135/podocalyxin and proteins with which it interacts are directly involved in formation of the apical surface. Gp135 is a negatively charged, transmembrane sialomucin, which binds via a PDZ motif at its C-terminus to the scaffolding protein NHERF1. We will mislocalize gp135 to the basolateral surface and see if NHERF1 and other proteins follow. Much of the PIP2 at the plasma membrane is synthesized by phosphatidyl inositol 4- phosphate 5-kinase (PI5K). The isoform PI5K1beta is found at the apical plasma membrane and interacts with NHERF1. We will test the involvement of PI5K1beta (as well as the alpha and gamma isoforms) in formation of the apical plasma membrane. We will also test if PTEN is recruited to the apical plasma membrane by its interaction with NHERF. Together, these experiments will help us understand the molecular mechanism of apical plasma membrane and lumen formation. PUBLIC HEALTH RELEVANCE: Many organs consist largely of hollow tubes, lined by a layer of epithelial cells. The epithelial cells have specialized surfaces facing either the central lumen of the tube or other cells. We will analyze how the epithelial cells form these specialized surfaces and organize themselves spatially.

描述（由申请人提供）：许多内脏器官，例如肾脏，由空心小管和球体组成，内衬一层极化上皮细胞。这些细胞具有面向中央腔的顶端质膜域和面向下面的基底膜的基底外侧质膜。这两个质膜结构域具有完全不同的蛋白质和脂质组成，将蛋白质和脂质运输到这些不同的膜表面至关重要。我们发现信号脂质磷脂酰肌醇 3,4,5-三磷酸 (PIP3) 仅存在于基底外侧质膜上，并且是该表面的身份和形成的关键决定因素。相比之下，磷脂酰肌醇 4,5-二磷酸 (PIP2) 集中在顶端质膜上，它是该表面的主要决定因素。我们将使用活细胞成像检验 PIP2 和 PIP3 控制上皮极性发展的假设。我们将检验以下假设：PIP3 是由磷脂酰肌醇 3-激酶的特定亚型在基底外侧质膜合成的。我们将测试脂质磷酸酶 PTEN 和 SHIP1/2 在防止 PIP3 在顶端质膜积聚中各自的作用。我们将检验 gp135/podocalyxin 及其相互作用的蛋白质直接参与顶端表面形成的假设。 Gp135 是一种带负电荷的跨膜唾液酸粘蛋白，通过其 C 末端的 PDZ 基序与支架蛋白 NHERF1 结合。我们将 gp135 错误定位到基底外侧表面，看看 NHERF1 和其他蛋白质是否会跟随。质膜上的大部分 PIP2 由磷脂酰肌醇 4-磷酸 5-激酶 (PI5K) 合成。同种型 PI5K1beta 存在于顶端质膜并与 NHERF1 相互作用。我们将测试 PI5K1beta（以及 α 和 γ 同工型）在顶端质膜形成中的参与情况。我们还将测试 PTEN 是否通过与 NHERF 的相互作用被招募到顶端质膜。总之，这些实验将帮助我们了解顶端质膜和管腔形成的分子机制。公共卫生相关性：许多器官主要由空心管组成，内衬一层上皮细胞。上皮细胞具有面向管的中央腔或其他细胞的特殊表面。我们将分析上皮细胞如何形成这些特殊的表面并在空间上组织自身。