Pak Protein Kinases in Transformation & Survival

Pak 蛋白激酶的转化

• 批准号: 6621216
• 负责人: JEFFREY M FIELD
• 金额: $ 36.74万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6621216
• 关键词: 3T3 cells; G protein; actins; apoptosis; biological signal transduction; cell free system; cell transformation; enzyme mechanism; gene expression; genetic mapping; guanine nucleotide binding protein; mitogen activated protein kinase; molecular site; neoplasm /cancer genetics; oncogenes; phosphatidylinositol 3 kinase; phosphorylation; point mutation; protease inhibitor; protein kinase; protooncogene; serine proteinases; western blottings

DESCRIPTION (provided by applicant): Our long-term goals are to understand how signaling pathways regulated by oncogenes interact with each other to transform cells. Ras is one of the most common proto-oncogenes found mutated in tumors. When Ras transforms cells, it alters several basic properties of the cell by modifying key transcription factors to promote cell proliferation, rearranging the actin cytoskeleton to stimulate invasion and inhibiting apoptosis to promote survival. Thus, studying the signals from oncogenes to their multiple targets may provide insights into how tumor growth is coordinated. Many effects of Ras, both proliferative and cytoskeletal, are regulated through the coordinated actions of the Rho family of G proteins, including members such as, Rac, Rho and Cdc42. However, the signals beyond these small G proteins that mediate Ras transformation remain to be elucidated. Rac and Cdc42 bind several proteins, including members of a highly conserved family of protein kinases known as Paks. The Pak kinases are candidates for downstream effectors that regulate both transcription and the cytoskeleton. Our preliminary results demonstrate, for the first time, a direct link between Pak and cell transformation. We found that Ras transformation can be inhibited by expression of specific Pak mutants. This type of mutation, usually called a dominant negative mutation, provides a powerful tool to explore the role of Pak in Ras transformation. Furthermore, we traced a signal from Ras through Pak to the downstream kinase, Erk. We also developed several assay systems showing for the first time that Ras activates Pak through a linear pathway requiring PT 3-kinase and a small G protein (Rac or Cdc42). Unexpectedly, one of the key intermediates is the Akt proto-oncogene, which transduces cell survival signals through Pak to a cell survival factor called Bad. This signal inhibits apoptosis. Together, these data demonstrated a new Ras signaling pathway and provided the first evidence for transformation signals through a specific effector of the Rho family. This proposal aims to build on our earlier work by tracing the signals step by step from Ras to Pak and linking Pak to another oncogene, Abl. We hypothesize that Pak is a convergence point for Ras and Abl to transduce signals to transformation and survival pathways. We will: (1) Determine the signals from Ras to Pak. (2) Determine the role of Pak in cell survival signals through Bad. (3) Determine the role of the RasPak module in signaling by the Abl oncogene.

描述（由申请人提供）：我们的长期目标是了解如何 由致癌基因调节的信号通路相互相互作用以转化 细胞。 RAS是发现在肿瘤中突变的最常见的原始癌基因之一。 当Ras转换细胞时，它会通过 修改关键转录因子以促进细胞增殖，重新排列 肌动蛋白细胞骨架以刺激侵袭并抑制凋亡 促进生存。因此，研究从致癌基因到其多重的信号 目标可以提供有关肿瘤生长如何协调的见解。许多效果 Ras的增殖和细胞骨架，都通过 Rho g蛋白家族的协调行动，包括成员，例如 RAC，RHO和CDC42。但是，超出这些小g蛋白的信号 介导的RAS转化仍有待阐明。 RAC和CDC42绑定了几个 蛋白质，包括高度保守的蛋白激酶家族的成员 被称为paks。 PAK激酶是下游效应子的候选者 调节转录和细胞骨架。我们的初步结果 首次证明PAK与细胞之间的直接联系 转型。我们发现RAS转化可以被表达抑制 特定的PAK突变体。这种类型的突变，通常称为主要 负突变为探索PAK在RAS中的作用提供了强大的工具 转型。此外，我们从RAS到PAK追踪了一个信号 下游激酶，ERK。我们还开发了几个显示的测定系统 首次通过需要PT的线性途径激活PAK 3-激酶和小G蛋白（RAC或CDC42）。出乎意料的是，其中之一 中间体是Akt原型癌基因，它传递了细胞存活信号 通过PAK到达称为Bad的细胞生存因子。该信号抑制 凋亡。这些数据一起证明了一个新的RAS信号通路， 提供了通过特定的转换信号的第一个证据 Rho家族的效果因子。该建议旨在以我们早期的工作为基础 从RAS到PAK逐步跟踪信号，然后将PAK链接到另一个 癌基因，abl。我们假设PAK是RA和ABL的收敛点 将信号转换为转化和生存途径。我们将：（1） 确定从RAS到PAK的信号。 （2）确定PAK在细胞中的作用 生存信号通过坏处。 （3）确定Raspak模块在 ABL致癌基因发出信号。