EPIDERMAL GROWTH FACTOR MISLOCATION IN ARPKD

描述：(直接取自应用)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道物理屏障，这是动态平衡所必需的。这种类型的细胞通过主动调节膜脂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端和基侧膜域。顶端质膜通常含有器官特异性功能所需的蛋白质。例如，在排列在肾小管节段管腔的上皮细胞中，许多顶膜蛋白介导吸收。基侧质膜含有执行基本细胞机制所需的大多数“看家”蛋白质，包括EGF受体等生长调节分子。该项目的一个长期目标是了解导致多囊肾病的不同基因如何允许EGF受体错误定位于起源于集合管的肾囊肿的顶端质膜。我们还希望了解顶端EGF受体错误定位如何在这组遗传多样性的疾病中起到病理生理学作用，重点是常染色体隐性遗传病。这个应用程序有两个广泛的具体目标。第一个具体目的是利用新开发的条件永生化收集小管细胞系，确定位于顶端质膜的EGF受体的配体诱导的转运与信号输出之间是否存在功能联系。这一目标的一个长期目标是确定EGF受体信号通路起始于心尖表面，这可能参与多囊肾病的病理生理。第二个特定的目的是定义和理解EGF受体膜旁区域中的内在基序介导的蛋白质相互作用，这些基序对于调节细胞内转运和/或信号转导非常重要。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。这些研究的长期目标是确定新的治疗靶点，以控制囊性病变中错误定位于顶端质膜的EGF受体的异常运输和信号传递。这个项目是一位在EGF受体运输和信号传递方面拥有丰富经验的细胞生物学家和一位在结构功能研究方面经验丰富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.