MAP KINASE CASCADE SIGNAL TRANSMISSION AND SPECIFICITY

MAP 激酶级联信号传输和特异性

• 批准号: 6695621
• 负责人: LEE S BARDWELL
• 金额: $ 24.2万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6695621
• 关键词: biochemical evolution; biological signal transduction; enzyme activity; enzyme mechanism; fungal genetics; mitogen activated protein kinase; mutant; protein protein interaction; yeasts

Signal transduction networks are a crucial part of the circuitry by which a cell regulates its growth and developmental program and its response to its environment. Faulty or malfunctioning signaling pathways underlie the molecular pathology of many diseases, particularly cancer. Protein kinase cases are central components of many signaling pathways. Often, the transmission of different upstream signals involves common protein kinases, yet elicits distinct (and appropriate) outcomes. On the other hand, distinct pathways may contain highly similar protein kinase cascades, yet remain appropriately insulated from one another. How specificity form cellular to signal response is maintained in such cases is not well understood, and a fundamental problem in cell biology. This proposal presents experiments that address the role of a high-affinity protein-protein interactions in the specificity of signal transmission between mitogen-activated protein kinases (MAPKs, also called extracellular-signal regulated kinases, or ERKs) and MAPK/ERK kinases (MEKs). Specifically, a short, evolutionarily conserved motif ( the MAPK docking site) has been identified on MEKs that, in yeast, has been shown to mediate high-affinity binding to the cognate MAPKs. Specific aims are to determine if the docking sites of human MEK1 and Mek2 bind to the cognate human MAPKs, to characterize the amino acid residues on the yeast and human MEKs and MAPKs that mediate this high-affinity binding, and to use this information to construct appropriate mutants to learn more about the in vivo functions of MEK/MAPK docking. In so doing, we will address two (non-exclusive) hypotheses about the role of high-affinity protein-kinase substrate interactions in protein kinase signaling the transmission hypothesis and the specificity hypothesis. Inappropriate MAPK activation, such as that evoked by the well known oncoproteins Ras and Raf, is sufficient for the neoplastic transformation of cultured mammalian cells and consequent tumorigenesis. The research proposed herein should improve our understanding of the signal transmission and signal specificity in MAPK cascades. More generally, this research could lead to better understanding of how protein kinases find their targets, improve our ability to predict targets, and may ultimately suggest novel approaches to therapy based upon the modulation of protein kinase interactions.

信号转导网络是细胞调节其生长和发育程序及其对环境反应的电路的重要组成部分。故障或故障信号通路是许多疾病，特别是癌症的分子病理学基础。蛋白激酶是许多信号通路的核心组成部分。通常，不同上游信号的传递涉及共同的蛋白激酶，但产生不同的（和适当的）结果。另一方面，不同的途径可能包含高度相似的蛋白激酶级联，但仍然适当地彼此绝缘。在这种情况下，细胞对信号反应的特异性是如何维持的还没有很好的理解，这是细胞生物学中的一个基本问题。本提案提出了解决高亲和力蛋白质-蛋白质相互作用在有丝分裂原活化蛋白激酶（MAPK，也称为细胞外信号调节激酶或ERK）和MAPK/ERK激酶（MEK）之间的信号传递特异性中的作用的实验。具体而言，已经在MEK上鉴定了短的进化上保守的基序（MAPK对接位点），其在酵母中已经显示介导与同源MAPK的高亲和力结合。具体目标是确定人MEK 1和Mek 2的对接位点是否与同源人MAPK结合，表征酵母和人MEK和MAPK上介导这种高亲和力结合的氨基酸残基，并使用此信息构建适当的突变体以了解更多关于MEK/MAPK对接的体内功能。在这样做的时候，我们将解决两个（非排他性的）假说的作用，高亲和力蛋白激酶底物相互作用的蛋白激酶信号传导的传输假说和特异性假说。不适当的MAPK活化，如由众所周知的癌蛋白Ras和Raf引起的活化，足以使培养的哺乳动物细胞发生肿瘤转化并随后发生肿瘤。本文提出的研究将提高我们对MAPK级联信号传递和信号特异性的理解。更一般地说，这项研究可以更好地了解蛋白激酶如何找到其靶点，提高我们预测靶点的能力，并最终可能提出基于调节蛋白激酶相互作用的新型治疗方法。