MAP KINASE CASCADE SIGNAL TRANSMISSION AND SPECIFICITY

MAP 激酶级联信号传输和特异性

• 批准号: 6498707
• 负责人: LEE S BARDWELL
• 金额: $ 23万
• 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/6498707
• 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发育程序和对环境的反应的电路的关键部分。信号通路故障或失灵是许多疾病，特别是癌症的分子病理基础。蛋白激酶案例是许多信号通路的中心组成部分。通常，不同上游信号的传递涉及共同的蛋白激酶，但会产生不同的(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，但仍保持适当的相互隔离。在这种情况下，细胞对信号反应的特异性如何保持还不是很清楚，这是细胞生物学中的一个基本问题。本研究旨在探讨高亲和力蛋白-蛋白相互作用在丝裂原活化蛋白激酶(MAPKs，也称为细胞外信号调节蛋白激酶，ERKs)和MAPK/ERK激酶(MEKs)之间信号传递的特异性中的作用。具体地说，在酵母中发现了一个在进化上保守的短基序(MAPK对接位点)，在酵母中，它被证明介导了与同源MAPK的高亲和力结合。其具体目的是确定人MEK1和MEK2的对接位点是否与同源的人MAPK结合，鉴定酵母和人MEK上的氨基酸残基以及介导这种高亲和力结合的MAPK，并利用这些信息构建合适的突变体，以更多地了解MEK/MAPK对接的体内功能。在此过程中，我们将提出两个(非排他性的)假说，即高亲和力蛋白-激酶底物相互作用在蛋白激酶信号传递假说和特异性假说中的作用。不适当的MAPK激活，如众所周知的癌蛋白RAS和Raf所引起的激活，足以促进培养的哺乳动物细胞的肿瘤转化和随后的肿瘤发生。本文提出的研究将提高我们对MAPK级联反应中信号传递和信号特异性的理解。更广泛地说，这项研究可能会更好地理解蛋白激酶是如何找到靶点的，提高我们预测靶点的能力，并最终可能提出基于蛋白激酶相互作用调节的新的治疗方法。