FUNCTION OF P130 CAS IN CELL SURVIVAL

P130 CAS 在细胞存活中的功能

• 批准号: 2883932
• 负责人: QIANG YU
• 金额: $ 24.87万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2883932
• 关键词: apoptosis; biological signal transduction; cell adhesion; cell cell interaction; cell growth regulation; cell transformation; chimeric proteins; extracellular matrix proteins; growth factor; immunoprecipitation; phosphoproteins; phosphorylation; polymerase chain reaction; protein structure function; protein tyrosine phosphatase; site directed mutagenesis; tissue /cell culture; transfection; western blottings; yeast two hybrid system

The goal of the proposed research plan is to investigate an unexplored and important function of p130Cas in cellular physiology, i.e., its role in regulating cell death and survival. p130Cas, originally identified as a major tyrosine-phosphorylated protein in v-Crk or v-Src transformed cells, is a multifunctional cell signal assembly protein. It contains multiple structure motifs and interact with a number of signaling molecules, such as Crk, Src, and FAK. Consistent with its structural characteristics, p130Cas has been found to be functionally involved in cell transformation, adhesion, migration and actin organization. It is essential for normal animal development. Mutant mice lacking p130Cas die in utero showing marked systemic congestion and growth retardation. Function of p130Cas in cell death/survival regulation, however, has not been studied. During the course of our study on regulation of protein tyrosine phosphorylation and cell growth, we found p130Cas to be a key player in tyrosine phosphatase LAR-induced apoptosis. LAR dephosphorylates and destabilizes the p130Cas protein. The down regulation of p130Cas by LAR leads to activation of a caspase pathway and induces apoptosis. Restoring p130Cas protein level alleviates the LAR-induced apoptosis. These data suggest a new function of p130Cas in regulating cell death/survival and a new mechanism by which the p130Cas protein is regulated. The present proposal is designed to investigate the function and mechanism of p130Cas in regulating cell death/survival. We will use a combination of biochemical, molecular, and cell biological techniques to identify specific signaling molecules and signal transduction pathways, through which p130Cas transduces cell death/survival signals. We will investigate the physiological relevance of p130Cas-mediated cell death by examining the regulation and function of p130Cas during anoikis, a form of cell death caused by detachment of epithelial and endothelial cells from their substratum, and in growth factor deprivation induced cell death, in both of which protein tyrosine phosphorylation/dephosphorylation play a critical role. Finally, the new mechanism regulating p130Cas protein level will also be investigated. The proposed study will increase our knowledge on function and mechanism of p130Cas, shed light on our general understanding of signal transduction, regulation of cell death/survival, and cell growth, and help designing therapeutic reagents to induce/prevent apoptosis in treating human diseases.

拟议研究计划的目标是研究 p130Cas 在细胞生理学中未经探索的重要功能，即其在调节细胞死亡和存活中的作用。 p130Cas 最初被鉴定为 v-Crk 或 v-Src 转化细胞中的主要酪氨酸磷酸化蛋白，是一种多功能细胞信号组装蛋白。它包含多个结构基序并与许多信号分子相互作用，例如 Crk、Src 和 FAK。 与其结构特征一致，p130Cas被发现在功能上参与细胞转化、粘附、迁移和肌动蛋白组织。 它对于动物的正常发育至关重要。缺乏 p130Cas 的突变小鼠在子宫内死亡，表现出明显的全身充血和生长迟缓。 然而，p130Cas 在细胞死亡/生存调节中的功能尚未被研究。在我们对蛋白质酪氨酸磷酸化和细胞生长调节的研究过程中，我们发现 p130Cas 在酪氨酸磷酸酶 LAR 诱导的细胞凋亡中发挥着关键作用。 LAR 使 p130Cas 蛋白去磷酸化并不稳定。 LAR 对 p130Cas 的下调导致 caspase 途径激活并诱导细胞凋亡。 恢复 p130Cas 蛋白水平可减轻 LAR 诱导的细胞凋亡。这些数据表明p130Cas在调节细胞死亡/存活方面的新功能以及p130Cas蛋白调节的新机制。本提案旨在研究p130Cas在调节细胞死亡/存活中的功能和机制。 我们将结合生化、分子和细胞生物学技术来鉴定特定的信号分子和信号转导途径，p130Cas 通过这些分子和信号转导途径转导细胞死亡/生存信号。 我们将通过检查 p130Cas 在失巢过程中的调节和功能来研究 p130Cas 介导的细胞死亡的生理相关性，失巢凋亡是一种由上皮细胞和内皮细胞从其基质脱离引起的细胞死亡形式，以及生长因子剥夺诱导的细胞死亡，在这两种过程中，蛋白质酪氨酸磷酸化/去磷酸化都发挥着关键作用。 最后，还将研究调节p130Cas蛋白水平的新机制。 这项研究将增加我们对p130Cas功能和机制的了解，阐明我们对信号转导、细胞死亡/生存调节和细胞生长的一般理解，并有助于设计治疗人类疾病中诱导/预防细胞凋亡的治疗试剂。