MAP KINASE CASCADE SIGNAL TRANSMISSION AND SPECIFICITY

MAP 激酶级联信号传输和特异性

• 批准号: 6628839
• 负责人: LEE S BARDWELL
• 金额: $ 23.62万
• 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/6628839
• 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。错误或故障的信号通路是许多疾病，特别是癌症的分子病理学的基础。蛋白激酶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，但却产生不同的（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，但彼此之间保持适当的绝缘。在这种情况下，细胞对信号反应的特异性是如何维持的还不是很清楚，这是细胞生物学的一个基本问题。本研究提出了高亲和蛋白-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激酶，ERKs）和MAPK/ERK激酶（MEKs）之间信号传递特异性中的作用的实验。具体来说，在mek上发现了一个短的、进化上保守的基序（MAPK对接位点），在酵母中，该基序已被证明介导与同源MAPK的高亲和力结合。具体目的是确定人类MEK1和Mek2的对接位点是否与同源的人类MAPK结合，表征酵母和人类MEK和MAPK上介导这种高亲和力结合的氨基酸残基，并利用这些信息构建合适的突变体，以进一步了解MEK/MAPK对接的体内功能。在此过程中，我们将讨论关于高亲和蛋白激酶底物相互作用在蛋白激酶信号传导中的作用的两个（非排他的）假设：传递假设和特异性假设。不适当的MAPK激活，例如由众所周知的癌蛋白Ras和Raf引起的激活，足以使培养的哺乳动物细胞发生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级联中的信号传递和信号特异性的理解。更广泛地说，这项研究可以更好地理解蛋白激酶如何找到它们的靶标，提高我们预测靶标的能力，并可能最终提出基于蛋白激酶相互作用调节的新治疗方法。