Structure and functional mechanisms of molecular chaperones and protein kinases

项目摘要 我们的实验室工作在两个主要方向：第一，确定结构和动态基础， 大型蛋白质机器的功能和组装;第二， 调节蛋白质活性和变构相互作用的内部蛋白质动力学。我们建议使用 NMR光谱法，连同其他生物化学和生物物理技术，以确定在 原子分辨率支持两个重要蛋白质家族功能的机制： 分子伴侣和蛋白激酶。 分子伴侣是维持细胞中功能蛋白质组的核心， 天然蛋白质聚集和错误折叠，并协助其折叠。我们的实验室报告说 第一个高分辨率的分子伴侣结构与未折叠蛋白质的复合物。我们 将确定重要的分子伴侣的结构，如Hsp 40，Hsp 70和Hsp 90， 与客户蛋白质的复合物。我们希望解决不同的伴侣如何参与非本地 蛋白质以及不同的分子伴侣结构如何改变活性。 Src和BRAF在由人类基因编码的超过500种蛋白激酶中占有突出的位置。 基因组Src是约30种细胞质酪氨酸激酶的原型激酶，其中一半（Src， Frk、Abl、Tec和Csk家族）共享由SH 3、SH 2 和激酶结构域。因此，Src已经作为理解变构如何 相互作用调节激酶的活性。BRAF是RAF激酶的成员，并且是 ERK信号通路是人类最重要、研究最多的信号通路之一， 癌的BRAF基因在大约8%的人类肿瘤中发生突变， 据报道，A环、P环和DFG基序引起过度活跃的激酶。我们将使用核磁共振 光谱学来表征瞬时填充的构象状态，目的是揭示 人类激酶组中的新调控机制。

PROJECT SUMMARY Our lab works on two main directions: first, the determination of the structural and dynamic basis for the function and assembly of large protein machineries; and second, the determination of the role of internal protein dynamics in regulating protein activity and allosteric interactions. We propose to use NMR spectroscopy, together with other biochemical and biophysical techniques, to determine at the atomic resolution the mechanisms underpinning the function of two important protein families: molecular chaperones and protein kinases. Molecular chaperones are central to maintaining a functional proteome in the cell by rescuing non- native proteins from aggregation and misfolding and assisting with their folding. Our lab reported the first ever high resolution structures of molecular chaperones in complex with unfolded proteins. We will determine the structures of important chaperones such as the Hsp40, Hsp70 and Hsp90 in complex with client proteins. We wish to address how different chaperones engage non-native proteins and how distinct chaperone architectures may alter activity. Src and BRAF hold a prominent place among the over 500 protein kinases encoded by the human genome. Src is the archetypical kinase of the ~30 cytoplasmic tyrosine kinases, half of which (Src, Frk, Abl, Tec and Csk families) share the same core domain architecture consisting of an SH3, SH2 and kinase domain. As such, Src has served as the prototype for understanding how allosteric interactions regulate the activity of kinases. BRAF is a member of RAF kinases and is a part of the ERK signaling pathway, one of the most important and best studied signaling pathways in human cancers. The BRAF gene is mutated in approximately 8% of human tumors with substitutions in the A-loop, the P-loop and the DFG motif reported to give rise to a hyperactive kinase. We will use NMR spectroscopy to characterize transiently populated conformational states, with the goal of uncovering novel regulatory mechanisms in the human kinome.