The Proteolytic Cleavage of Polycystin-1: How and Why

Polycystin-1 的蛋白水解裂解：如何以及为何

• 批准号: 7989311
• 负责人: Feng Qian
• 金额: $ 9.99万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-03 至 2010-12-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7989311
• 关键词: Affect; Age; Animal Model; Atomic Force Microscopy; Autosomal Dominant Polycystic Kidney; Biochemical; Biological; Biological Models; Cells; Cleaved cell; Cyst; Development; Disease; Distal; Duct (organ) structure; Embryonic Development; End stage renal failure; Extracellular Domain; G-Protein-Coupled Receptors; Grant; Human; In Vitro; Inborn Genetic Diseases; Kidney; Kidney Diseases; Lead; MDCK cell; Methods; Modeling; Mus; Mutation; Nephrons; PKD1 gene; Patients; Play; Property; Proteins; Reaction; Role; Site; Structure; System; Testing; Tissues; Tubular formation; United States; cell type; effective therapy; in vivo; insight; mouse model; novel; polycystic kidney disease 1 protein; postnatal; prevent; public health relevance; trafficking

DESCRIPTION (provided by applicant): Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common inherited disorders in humans, affecting one in a thousand people in the United States. Patients develop multiple cysts in both kidneys. The cysts progressively result in the destruction of the normal kidney structure and eventually lead to end-stage renal failure in approximately 50% of the patients by the age of 60. There are currently no cures for the disease. ADPKD is caused primarily by mutations of the PKD1 gene, which encodes polycystin-1 (PC1) protein. Therefore understanding of the normal structure and function of PC1 will be critical for the development of effective therapies. We have previously discovered that PC1 is proteolytically cleaved at the G-protein coupled receptor proteolytic site (GPS) in virtually all cell types and tissues in vivo. This reaction, the GPS cleavage, generates a number of previously unrecognized PC1 products. Defective GPS cleavage of PC1 has been found in a subset of ADPKD patients. We hypothesized that GPS cleavage is essential for the complete function of PC1 in the kidney. We have recently demonstrated using a novel mouse model that GPS cleavage of PC1 is essential for proper structure and function of the distal nephron segments in the kidney, but is apparently not required for that of the proximal segments and for embryonic development. We now propose that the cleavage products of PC1 are critically required for the structural integrity of distal segments of the nephron in the kidney. This grant aims at understanding the mechanism by which GPS cleavage regulates the important function of PC1 in the kidney. We propose the studies in three complementary Specific Aims using a combination of biochemical, biophysical, cell-biological methods and animal models. Specific Aim 1 will analyze structure and function of PC1 products generated by GPS cleavage in an in vitro MDCK model system. This study will likely establish basic principles of GPS functioning. Specific Aim 2 then looks at the role of the PC1 cleavage products in primary cells and finally in mice. Specific Aim 3 examines the reason why the proximal segments do not require GPS cleavage. The proposed studies will likely yield important insights into the function of PC1 in normal and disease states of the kidney. PUBLIC HEALTH RELEVANCE Polycystin-1 is the protein that when defective causes a complicated kidney disease known as autosomal dominant polycystic kidney disease, which at this point has no cure. This study aims to understand Polycystin-1, the reasons it becomes defective, and the ways to prevent it.

描述（由申请人提供）：常染色体显性多囊性肾脏疾病（ADPKD）是人类最常见的遗传性疾病之一，影响了美国一千人。患者在两个肾脏中都会出现多个囊肿。囊肿逐渐导致正常肾脏结构的破坏，并最终导致大约50％的患者到60岁。目前尚无治疗这种疾病。 ADPKD主要是由PKD1基因的突变引起的，该基因编码Polycystin-1（PC1）蛋白。因此，对PC1的正常结构和功能的理解对于开发有效疗法至关重要。我们以前已经发现，PC1在体内几乎所有细胞类型和组织中的G蛋白偶联受体蛋白水解位点（GPS）上蛋白水解裂解。该反应是GPS的裂解，产生了许多先前未识别的PC1产品。在ADPKD患者的一部分中发现了PC1的GPS裂解缺陷。我们假设GPS裂解对于PC1在肾脏中的完整功能至关重要。我们最近使用一种新的小鼠模型证明了PC1的GPS裂解对于肾脏远端肾小管片段的适当结构和功能至关重要，但显然对于近端片段和胚胎发育而言并不是必需的。现在，我们建议PC1的裂解产物至关重要，这对于肾脏中肾单位远端段的结构完整性至关重要。该赠款旨在了解GPS裂解调节PC1在肾脏中的重要功能的机制。我们通过生化，生物物理，细胞生物学方法和动物模型的组合提出了三个互补特定目的的研究。具体目标1将分析由GPS裂解在体外MDCK模型系统中产生的PC1产品的结构和功能。这项研究可能会建立GPS功能的基本原理。然后，特定的目标2探讨了PC1切割产物在原代细胞和小鼠中的作用。具体目标3研究了近端段不需要GPS裂解的原因。拟议的研究可能会产生对PC1在肾脏正常和疾病状态的功能的重要见解。 公共卫生相关性 Polycystin-1是一种蛋白质，当缺陷引起复杂的肾脏疾病时，称为常染色体显性多囊肾脏疾病，此时尚无治愈。这项研究旨在了解多囊蛋白-1，原因有缺陷以及预防它的方法。