Structural and functional versatility of NFAT

描述（由申请人提供）：拟议研究的长期目标是了解活化T细胞核因子（NFAT）传递常见钙信号以引发多种转录反应的分子机制。为了解决这个问题，将结合结构、生化和基于细胞的研究来分析NFAT和不同转录因子伴侣之间的相互作用。对于表征良好的NFAT复合物，将开发小肽抑制剂来进一步分析这些复合物在体内的功能。Aim 1的主要目标是建立NFAT/GATA相互作用的高分辨率结构模型。这种相互作用涉及许多重要的生理过程，如心脏肥大、igf诱导的心肌细胞肥大和T细胞发育。这些结构信息将为进一步分析NFAT/GATA协同作用的体内机制和功能提供基础。Aim 2的重点是描述NFAT和MEF2之间详细的蛋白-蛋白相互作用，以了解NFAT/MEF2协同作用在各种钙介导的生物反应中的机制和功能，如心脏肥厚，骨骼肌纤维转换T细胞分化和增殖。这些研究也将使我们能够表征DNA结合域之外的NFAT1的结构和功能。最后，Aim 3的目标将是开发小分子抑制剂来破坏NFAT和Fos-Jun之间的蛋白-蛋白相互作用。这些研究将测试相对较小的分子是否可以有效抑制NFAT和Fos-Jun之间的大蛋白界面。这些肽将成为分析细胞内NFAT/Fos-Jun相互作用功能的有用工具。总的来说，这三个具体目标从不同的角度解决了NFAT的结构和功能多功能性。这些研究将建立一个完整的分子模型，以了解钙调神经磷酸酶/NFAT途径如何从钙调神经磷酸酶节点下游分支，以及特定分支是否可以被突变或肽抑制剂选择性靶向。这些研究将进一步剖析钙调神经磷酸酶/NFAT通路的功能，并为开发用于治疗的化合物奠定基础。

DESCRIPTION (provided by applicant): The long-term goal of the proposed research is to understand the molecular mechanisms by which the nuclear factor of activated T cells (NFAT) transmits the common calcium signal to elicit diverse transcriptional responses. To address this question, a combination of structural, biochemical and cell-based studies will be used to analyze the interactions between NFAT and distinct transcription factor partners. For well-characterized NFAT complexes, small peptide inhibitors will be developed to further analyze the functions of these complexes in vivo. The main goal of Aim 1 is to establish the high-resolution structural model of the NFAT/GATA interaction. This interaction has been implicated in many important physiological processes, such as heart hypertrophy, IGF-induced myocyte hypertrophy and T cell development. This structural information will provide a foundation for further analyzing the mechanism and function of NFAT/GATA synergy in vivo. The focus of Aim 2 is to characterize the detailed protein-protein interactions between NFAT and MEF2 in an effort to understand the mechanism and functions of NFAT/MEF2 synergy in a variety of calcium-mediated biological responses, such as cardiac hypertrophy, skeletal muscle fiber switching T cell differentiation and proliferation. These studies will also allow us to characterize the structure and function of NFAT1 beyond the DNA binding domain. Finally, the goal of Aim 3 will be to develop small molecule inhibitors to disrupt the protein-protein interactions between NFAT and Fos-Jun. These studies will test whether relatively small molecules can effectively inhibit the large protein interface between NFAT and Fos-Jun. These peptides will be useful tools for analyzing the function of the NFAT/Fos-Jun interaction inside cells. Overall, the three Specific Aims address the structural and functional versatility of NFAT from different perspectives. These studies will establish an integrated molecular model for understanding how the calcineurin/NFAT pathway branches downstream from the calcineurin nodal point and whether a specific branch can be selectively targeted by mutations or peptide inhibitors. These studies will further dissect the function of the calcineurin/NFAT pathway and serve as a basis for developing compounds for therapeutic applications.