Assembly of polycystin complexes

描述（由申请方提供）：约0.1%的世界人口受常染色体显性遗传性多囊肾病（ADPKD）影响，这是人类最常见的遗传病之一。这种疾病是由两种多囊蛋白PKD 1和TRPP 2突变引起的。PKD 1是一种质膜受体，可能参与细胞-细胞和细胞-基质相互作用。TRPP 2是存在于内质网以及质膜上的Ca 2+可渗透的非选择性阳离子通道。在肾细胞中，它们形成细胞表面复合物，其可作为机械敏感性Ca 2+传导离子通道，其可通过肾小管中的流体流动来调节。TRPP 2和PKD 1的关联至少部分地由两种蛋白质的胞质C末端中的卷曲螺旋结构域介导。TRPP 3与TRPP 2相关但不同，也形成Ca 2+可渗透的非选择性阳离子通道，其基因在小鼠中的缺失与致命的肾缺陷有关。其胞质C末端也含有卷曲螺旋结构域。最近，研究发现TRPP 3与PKD 1样蛋白PKD 1 L3结合形成舌头酸味受体。我们的长期目标是了解多囊蛋白的功能和调节的结构，分子和细胞机制。近期的目标是研究TRPP 2/PKD 1和TRPP 3/PKD 1 L3复合物的组装和化学计量。我们建议解决这两个复合物的推定卷曲螺旋结构域的晶体结构，确定两个复合物在细胞中的亚基化学计量，调查的重要性，卷曲螺旋结构域的相互作用，在组装的两个复合物和PKD 1的TRPP 2活性的调节和PKD 1 L3的TRPP 3活性的调节。我们还提出了测试的假设，PKD 1和PKD 1 L3直接参与形成通道孔的TRPP 2/PKD 1复合物和TRPP 3/PKD 1 L3复合物，分别。本研究将加深我们对多囊蛋白功能的分子基础的理解。公共卫生相关性：常染色体显性遗传性多囊肾病（ADPKD）是人类最常见的遗传性疾病之一，由肾细胞中多囊蛋白复合物突变引起。这项研究的目的是了解这些复合物是如何形成的，以及它们是如何发挥作用的。

DESCRIPTION (provided by applicant): Approximately 0.1% of the world population is affected by autosomal dominant polycystic kidney disease (ADPKD), which is one of the most common genetic diseases in humans. This disease is caused by mutations in two polycystin proteins, PKD1 and TRPP2. PKD1 is a plasma membrane receptor probably involved in cell-cell and cell-matrix interactions. TRPP2 is a Ca2+permeable nonselective cation channel present in the endoplasmic reticulum as well as on the plasma membrane. In kidney cells, they form a cell surface complex that may function as a mechanosensitive Ca2+conducting ion channel that can be regulated by fluid flow in the kidney tubule. The association of TRPP2 and PKD1 is mediated, at least in part, by a coiled coil domain in the cytoplasmic C terminus of both proteins. TRPP3, related to but distinct from TRPP2, also forms a Ca2+permeable nonselective cation channel, and deletion of its gene in mice is linked to fatal kidney defects. Its cytoplasmic C terminus also contains a coiled coil domain. Recently, it has been found that TRPP3 associates with a PKD1-like protein named PKD1L3 to form the receptors for sour taste in the tongue. Our long-term objective is to understand the structural, molecular and cellular mechanisms of the function and regulation of polycystins. The immediate goal is to investigate the assembly and stoichiometry of the TRPP2/PKD1 and TRPP3/PKD1L3 complexes. We propose to solve the crystal structure of the putative coiled coil domain of both complexes, determine the subunit stoichiometry of both complexes in cells, investigate the importance of the coiled coil domain interaction in the assembly of both complexes and in the PKD1 regulation of TRPP2 activity and PKD1L3 regulation of TRPP3 activity. We also propose to test the hypothesis that PKD1 and PKD1L3 directly participate to form the channel pore in the TRPP2/PKD1 complex and the TRPP3/PKD1L3 complex, respectively. This research will enhance our understanding of the molecular basis of polycystin function. PUBLIC HEALTH RELEVANCE: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic diseases in humans and is caused by mutations of polycystin complexes in kidney cells. The goal of this research is to understand how these complexes are formed and how they function.