EPIDERMAL GROWTH FACTOR MISLOCATION IN ARPKD

产品描述：上皮细胞极性的形成是胚胎发育和器官发生的基本过程。极化的上皮细胞在宿主和外部环境之间形成了一个物理屏障，对体内平衡至关重要。这种类型的细胞通过积极调节脂质和蛋白质的膜分布以及每个表面特有的膜下细胞骨架来维持不同的顶侧和基底侧膜结构域。顶端质膜通常含有器官特异性功能所需的蛋白质。例如，在排列在肾小管段内腔的上皮细胞中，许多顶端膜蛋白介导吸收。基底外侧质膜包含执行基本细胞机制所需的大多数“管家”蛋白质，包括生长调节分子如EGF受体。该项目的长期目标是了解导致多囊肾疾病的不同基因如何使EGF受体错误定位于起源于集合管的肾囊肿中的顶端质膜。我们还希望了解如何顶端EGF受体的错误定位有助于病理生理学在这一组遗传多样性疾病，强调常染色体隐性遗传病。这项申请有两个广泛的具体目标。第一个特定目的旨在确定是否有位于顶端质膜和信号输出的EGF受体的配体诱导的贩运之间的功能连接，使用新开发的条件永生化集合小管细胞系。这个目标的一个长期目标是确定EGF受体信号通路从心尖表面可能参与多囊肾病的病理生理。第二个具体目标旨在定义和理解蛋白质相互作用的内在基序介导的EGF受体胞膜结构域重要的调节内吞转运和/或信号转导。这一目标将通过三种互补的实验方法来实现，使用从结构研究和体外结合研究中获得的信息来操纵和分析体内蛋白质-蛋白质相互作用。这些研究的一个长期目标是确定新的治疗靶点，以控制异常贩运和信号传导的EGF受体错误定位到顶端质膜在囊性病变。该项目是一个在EGF受体运输和信号传导方面具有广泛经验的细胞生物学家和一个在结构-功能研究方面具有丰富经验的结构生物学家之间的合作。

Description: (Taken directly from the application) The formation of epithelial cell polarity is a fundamental process in embryonic development and organogenesis. Polarized epithelia form a physical barrier between the host and external environment essential for homeostasis. Cells of this type maintain distinct apical and basolateral membrane domains by actively regulating the membrane distribution of lipids and proteins as well as the submembraneous cytoskeleton unique to each surface. The apical plasma membrane usually contains proteins required for organ-specific functions. In epithelial cells, which line the lumen of kidney tubule segments, for example, many apical membrane proteins mediate absorption. The basolateral plasma membrane contains most of the "house-keeping" proteins necessary for executing basic cellular mechanisms, including growth regulatory molecules like the EGF receptor. A long-term goal of this project is to understand how different genes which cause polycystic kidney disease allow the EGF receptor to mislocalize to the apical plasma membrane in renal cysts originating in collecting tubules. We also wish to learn how apical EGF receptor mislocalization contributes to pathophysiology in this genetically diverse set of diseases, with an emphasis on autosomal recessive disease. This application has two broad Specific Aims. The first Specific Aim seeks to determine whether there is functional connection between ligand-induced trafficking of EGF receptors located at the apical plasma membrane and signaling output, using newly-developed conditionally immortalized collecting tubule cell lines. A long-term goal of this aim is to identify EGF receptor signaling pathways initiated from the apical surface which may be involved in polycystic kidney disease pathophysiology. The second Specific Aim seeks to define and understand protein interactions mediated by intrinsic motifs in the EGF receptor juxtamembrane domain important for regulating endocytic transport and/or signal transduction. This aim will be achieved with three complementary experimental approaches, using information gained from structural studies and in vitro binding studies to manipulate and analyze protein-protein interactions in vivo. A long-term goal of these studies is to identify novel therapeutic targets to control abnormal trafficking and signaling by EGF receptors mislocalized to the apical plasma membrane in cystic lesions. This project is a collaboration between a cell biologist with broad experience in EGF receptor trafficking and signaling, and a structural biologist experienced in structure-function studies.