Characterization of TRPC6 mutations in inherited FSGS

描述（由申请人提供）：局灶节段性肾小球硬化（FSGS）是一种多种疾病状态下可见的肾脏病变，在终末期肾病患者中占有重要地位。几种遗传形式的FSGS已被描述。迄今为止发现的突变涉及足细胞中表达的蛋白质，对遗传性FSGS的研究进一步加深了我们对足细胞如何帮助维持过滤屏障以防止蛋白质溢出到尿液中的理解。最近，钙通道TRPC6的突变被确定为导致常染色体显性形式的FSGS。已经发现突变涉及TRPC6蛋白的几个不同区域，但它们如何影响TRPC6的功能尚不清楚。我们提出了几种研究方法来描述细胞和体外系统中的这些突变，包括对蛋白质稳定性、定位、磷酸化和通道活性的可能影响。此外，我们计划评估这些突变通道与其他TRPC家族成员聚合的能力，以及与足细胞狭缝隔膜的关键成分结合的能力。这些研究将进一步开辟新的研究路线，了解TRPC6功能如何对足细胞正常功能至关重要。

DESCRIPTION (provided by applicant): Focal segmental glomerular sclerosis (FSGS) is a kidney lesion seen in a number of disease states, and contributes significantly to the population of patients with end-stage renal disease. Several inherited forms of FSGS have been described. Mutations identified to date involve proteins expressed in the podocyte, and studies of inherited FSGS have furthered our understanding of how podocytes help maintain the filtration barrier that prevents protein from spilling into the urine. Recently, mutations in TRPC6, a calcium channel, have been identified as causing an autosomal dominant form of FSGS. Mutations have been found to involve several different areas of the TRPC6 protein, yet how they might affect TRPC6 function is unclear. We propose several lines of investigation to characterize these mutations in cell based and in vitro systems, including possible effects on protein stability, localization, phosphorylation, and channel activity. In addition, we plan to assess the ability of these mutant channels to multimerize with other TRPC family members as well as bind to key components of the podocyte slit diaphragm. These studies will further open new lines of investigation into how TRPC6 function is crucial for proper podocyte function.