POLYCYSTIN G PROTEIN SIGNAL TRANSDUCTION

多囊蛋白 G 信号转导

• 批准号: 6195476
• 负责人: james p calvert
• 金额: $ 15.5万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-30 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6195476
• 关键词: G protein; biological signal transduction; genetically modified animals; laboratory mouse; membrane proteins; phenotype; polycystic kidney; protein protein interaction; protein structure function; receptor coupling; site directed mutagenesis

Description: (Taken directly from the application) Mutations in the PKD 1 gene cause 80-90% of the cases of polycystic kidney disease. These mutations give rise to cyst growth and enlargement, ultimately leading to the development of polycystic kidneys and to extrarenal manifestations of the disease, including Ever and pancreatic cysts, cerebral and aortic aneurysms, and heart valve defects. However, the function of the normal PKD 1 gene is not known and thus it is not understood how mutations in the PKD1 gene give rise to the disease pathogenesis associated with PKD. As such, it will be important to understand the biochemical and cellular functions of the PKD1 gene in order to gain insight into the aberrant mechanisms that occur upon initiation of the disease, and to design therapeutic interventions to treat or slow disease progression. The PKD 1 gene encodes an approximately 400 kDa protein, polycystin-1, that has been hypothesized function as a plasm membrane receptor. Sequence analysis has revealed that the C-terminal cytosolic domain of polycystin-1 has a number of conserved motifs that suggest that it functions by mediating signal transduction. This idea is supported by our new preliminary evidence that demonstrates that the C-terminal tail of polycystin-1 binds and activates heterotrimeric G-proteins; in vitro, and that it can be phosphorylated both in vitro and in vivo. If it can be confirmed that polycystin-1 directly interacts with heterotrimeric G-proteins, polycystin will be placed in the mainstream of a number of possible signal transduction pathways. Our general hypothesis is that polycystin-1 functions as a G-protein coupled receptor. This hypothesis will be tested by the following Specific Aims: Aim 1. Amino acid residues required for the in vitro binding interaction between polycystin-1 and heterotrimeric G-proteins will be determined. Aim 2. The potential for polycystin-1 to engage in heterotrimeric G-protein coupled signal transduction will be determined. Aim 3. The potential for polycystin-1 to interact with regulators of heterotrimeric G-protein coupled receptors will be determined. Aim 4. The importance of the conserved G-protein activation domain will be tested in transgenic mice.

说明：（直接取自应用）PKD 1基因突变导致80-90%的多囊肾病病例。这些突变引起囊肿生长和扩大，最终导致多囊肾的发展和疾病的肾外表现，包括Ever和胰腺囊肿，脑动脉瘤和主动脉瘤以及心脏瓣膜缺陷。然而，正常PKD 1基因的功能尚不清楚，因此不了解PKD 1基因中的突变如何引起与PKD相关的疾病发病机制。因此，了解PKD 1基因的生物化学和细胞功能，以深入了解疾病发生时的异常机制，并设计治疗干预措施以治疗或减缓疾病进展将是重要的。PKD 1基因编码一个分子量约为400 kDa的蛋白质，即多囊蛋白-1（polycystin-1），被认为是一种质膜受体。序列分析表明，多囊蛋白-1的C-末端胞质结构域具有许多保守的基序，表明它的功能是通过介导信号转导。这一想法得到了我们新的初步证据的支持，这些证据表明多囊蛋白-1的C末端尾部在体外结合并激活异源三聚体G蛋白，并且它可以在体外和体内被磷酸化。如果能够证实多囊蛋白-1直接与异源三聚体G蛋白相互作用，多囊蛋白将被置于许多可能的信号转导途径的主流。我们的一般假设是，多囊蛋白-1的功能作为一个G蛋白偶联受体。这一假设将通过以下具体目标进行检验：目标1。将确定多囊蛋白-1和异源三聚体G蛋白之间的体外结合相互作用所需的氨基酸残基。目标2.将确定多囊蛋白-1参与异源三聚体G蛋白偶联信号转导的潜力。目标3.将确定多囊蛋白-1与异源三聚体G蛋白偶联受体的调节剂相互作用的潜力。目标4。将在转基因小鼠中测试保守的G蛋白激活结构域的重要性。