Regulation of c-Raf-1 by Ras and Growth Factors

Ras 和生长因子对 c-Raf-1 的调节

• 批准号: 6561581
• 负责人: GURI TZIVION
• 金额: $ 26.19万
• 依托单位: TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6561581
• 关键词: SDS polyacrylamide gel electrophoresis; animal extract; antineoplastics; biological signal transduction; cell cycle proteins; cell transformation; chimeric proteins; gene deletion mutation; growth factor; growth inhibitors; guanine nucleotide binding protein; immunoprecipitation; mitogen activated protein kinase; phosphorylation; protein binding; protein protein interaction; protein structure function; protein transport; protooncogene; transfection; western blottings

DESCRIPTION (provided by applicant): The Ras-Raf-MAPK pathway regulates many physiological processes by transmitting signals from membrane-bound receptors to nuclear and cytoplasmic targets that coordinate cellular response to a variety of factors, such as growth, stress, survival and inflammation. Aberrations in this pathway result in abnormal growth and proliferation, and in many cases, cause malignant transformation. The high frequency of activating Ras mutations found in various human cancers, together with the well-documented role of Raf in numerous physiological processes, make the Ras-Raf-MAPK pathway a prime target for drug development for various cancers, inflammation and other aliments, c-Raf-1, a cellular protooncogene also found in transforming viruses, is the primary Ras effector for MAPK activation and is a major and indispensable part of the Ras-MAPK cascade. Although many laboratories have been studying Raf regulation, many aspects of this highly complex mechanism remain unknown. Published work by the applicant and preliminary results presented in this proposal help to unravel several of these aspects and provide a novel approach for inhibiting Raf activity. The objectives of the present application are to further the understanding of Raf regulation, focusing on specific roles of Ras and phosphorylation in Raf regulation, and to develop a useful in vivo Raf inhibitor based on a potent in vitro Raf inhibitor, described in this application. These objectives will be accomplished by pursuing the following three specific alms: 1. Characterize the role of Ras in the Raf-1 activation process. Attention will be given to distinguishing between the roles of Ras in recruiting Raf to the membrane and displacing 14-3-3, and to the role of Ras-Ras and Raf-Raf dimerization in the activation process. 2. Determine the role of Raf-1 S471 and T481 sites in Rat regulation and function. This aim will be accomplished by examining the regulation of S471 and T481 phosphorylation and by evaluating the functional significance of their substitution and phosphorylation. 3. Characterize the mechanism underlying Raf inhibition by the Raf-1 inhibitor peptide, and identify peptide-delivery methods allowing inhibition of cellular Raf-1 in vivo. The proposed study will enhance our understanding of Raf regulation by providing molecular details on the role of Ras and newly identified Raf phosphorylation sites in Raf activation. In addition, the proposed study offers the prospect for developing an in vivo Raf inhibitor, which in addition to being a highly useful research tool, would provide a basis for developing therapeutic agents for diseases involving excessive cell proliferation such as cancer and inflammation.

描述（由申请人提供）：RAS-RAF-MAPK途径通过将信号从膜结合的受体传输到核和细胞质靶靶标，从而调节许多生理过程，这些信号与各种因素（例如生长，压力，存活和炎症）相协调细胞反应。该途径中的像差导致异常生长和增殖，在许多情况下会导致恶性转化。 The high frequency of activating Ras mutations found in various human cancers, together with the well-documented role of Raf in numerous physiological processes, make the Ras-Raf-MAPK pathway a prime target for drug development for various cancers, inflammation and other aliments, c-Raf-1, a cellular protooncogene also found in transforming viruses, is the primary Ras effector for MAPK activation and is a major and indispensable part of the Ras-Mapk级联。尽管许多实验室一直在研究RAF调节，但这种高度复杂机制的许多方面仍然未知。申请人发表的工作和本提案中提出的初步结果有助于揭开这些方面的几个方面，并为抑制RAF活动提供了一种新颖的方法。本应用的目标是进一步了解RAF调节，重点介绍RAS和磷酸化在RAF调节中的特定作用，并根据本应用中描述的有效的体外RAF抑制剂开发有用的体内RAF抑制剂。这些目标将通过追求以下三个特定施舍来实现：1。表征RAS在RAF-1激活过程中的作用。将注意区分RAS在将RAF募集到膜上的作用和取代14-3-3，以及RAS-RAS和RAF-RAF二聚体在激活过程中的作用。 2。确定RAF-1 S471和T481位点在大鼠调节和功能中的作用。通过检查S471和T481磷酸化的调节以及评估其取代和磷酸化的功能意义，可以实现此目标。 3。表征RAF-1抑制剂肽的RAF抑制作用的机制，并鉴定肽 - 降低方法，允许在体内抑制细胞RAF-1。拟议的研究将通过提供有关RAS和新鉴定的RAF磷酸化位点在RAF激活中的作用的分子细节来增强我们对RAF调节的理解。此外，拟议的研究还提供了开发体内RAF抑制剂的前景，除了是一种非常有用的研究工具外，还将为开发涉及过度细胞增殖（例如癌症和炎症）的疾病的治疗剂提供基础。