Regulated Proteolysis in RAS Signal Transduction

RAS 信号转导中的调节蛋白水解

基本信息

批准号：
7053409
负责人：
Amy H. Tang
金额：
$ 23.77万
依托单位：
MAYO CLINIC ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-05-01 至 2009-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7053409
关键词：
Drosophilidae apoptosis biological signal transduction carcinogenesis cell differentiation cell proliferation developmental genetics gene expression genetic screening glutathione transferase guanine nucleotide binding protein monoclonal antibody pancreas neoplasms phenotype proteolysis protooncogene

项目摘要

DESCRIPTION (provided by applicant): The RAS signaling pathway controls cell growth, survival and death in all multicellular organisms. Deregulation of RAS proto-oncogenes is found in approximately 30% of human cancer. Thus an important goal in cancer biology is to understand the molecular mechanisms underlying normal and aberrant RAS signals. Drosophila R7 photoreceptor cell fate specification is a genetically tractable model in which to study RAS signal transduction. In this system, we have shown that RAS activation directs a ubiquitin-mediated proteolysis pathway mediated by SEVEN-IN-ABSENTIA (SINA). SINA encodes a member of a highly conserved family of E3 ubiquitin ligases and has been implicated in neuronal differentiation, apoptosis, stress response, tumor suppression, beta-catenin, APC and p53 signaling in vertebrates. The substrate specificity of ubiquitin-mediated proteolysis is primarily determined by the E3 ligases, and the focus of our proposal is the SINA E3 ligase, an essential downstream component of RAS signaling pathway in Drosophila. The objectives of this research proposal are (1) to determine the developmental roles and regulation of SINA E3 family-dependent proteolysis in RAS signaling using Drosophila as a model organism, (2) to identify new SINA pathway components and determine their function in regulated proteolysis in RAS signal transduction, and (3) to investigate the roles of the mammalian SINA homologues (SIAHs) in RAS-mediated oncogenesis and to elucidate how the SIAH-dependent proteolysis promotes cell growth, differentiation and apoptosis during animal development and human cancers. Our central hypothesis is that the SINA-dependent proteolysis plays an important role in development. We will test this hypothesis by examining sina loss-of function phenotypes, by identifying new SINA pathway components by genetic screens and biochemical purification, and by determining their functions by a combination of genetic, molecular and biochemical analyses. We will also test the hypothesis that SIHA is required for RAS signal transduction during oncogenesis. We have detected enhanced expression of SINA in rapidly dividing cells during normal mammalian development and in human carcinomas, suggesting that SINA may be required for RAS-mediated cell proliferation in carcinogenesis. We propose to identify the function and regulation of SINA proteins in Drosophila, and apply what we have learned to human pancreatic cancer cells. Since many known SINA substrates have a demonstrated role in oncogenesis, it is likely that the proposed research will identify novels targets for anticancer therapies and contribute to our understanding of cancer biology.

描述（由申请人提供）：RAS 信号通路控制所有多细胞生物体中的细胞生长、存活和死亡。大约 30% 的人类癌症中发现了 RAS 原癌基因的失调。因此，癌症生物学的一个重要目标是了解正常和异常 RAS 信号背后的分子机制。果蝇 R7 感光细胞命运规范是一种遗传易处理的模型，用于研究 RAS 信号转导。在该系统中，我们发现 RAS 激活指导由 SEVEN-IN-ABSENTIA (SINA) 介导的泛素介导的蛋白水解途径。 SINA 编码高度保守的 E3 泛素连接酶家族的成员，与脊椎动物的神经元分化、细胞凋亡、应激反应、肿瘤抑制、β-连环蛋白、APC 和 p53 信号传导有关。泛素介导的蛋白水解的底物特异性主要由E3连接酶决定，我们的研究重点是SINA E3连接酶，它是果蝇RAS信号通路的重要下游成分。本研究计划的目标是 (1) 使用果蝇作为模型生物，确定 SINA E3 家族依赖性蛋白水解在 RAS 信号传导中的发育作用和调节，(2) 识别新的 SINA 通路成分并确定其在调节蛋白水解中的功能(3) 研究哺乳动物 SINA 同源物 (SIAH) 在 RAS 介导的肿瘤发生中的作用，并阐明 SIAH 依赖性如何蛋白水解促进动物发育和人类癌症过程中的细胞生长、分化和凋亡。我们的中心假设是 SINA 依赖性蛋白水解在发育中发挥重要作用。我们将通过检查 sina 功能丧失表型，通过遗传筛选和生化纯化鉴定新的 SINA 途径成分，并通过遗传、分子和生化分析相结合确定其功能来检验这一假设。我们还将检验肿瘤发生过程中 RAS 信号转导需要 SIHA 的假设。我们在正常哺乳动物发育过程中和人类癌症中的快速分裂细胞中检测到 SINA 的表达增强，这表明 SINA 可能是癌发生过程中 RAS 介导的细胞增殖所必需的。我们建议确定果蝇中 SINA 蛋白的功能和调节，并将我们所学到的知识应用于人类胰腺癌细胞。由于许多已知的 SINA 底物已被证明在肿瘤发生中发挥作用，因此拟议的研究很可能将确定抗癌治疗的新靶点，并有助于我们对癌症生物学的理解。