Linking proteasome activity to DNA repair through hHR23

描述（由申请人提供）：我们建议通过揭示连接这两种途径的蛋白质的结构和动力学来研究蛋白酶体在DNA修复中的作用机制。蛋白酶体是一种著名的蛋白质降解机制，核苷酸切除修复是修复紫外线损伤DNA的主要过程。最近有大量证据表明，蛋白酶体的活性对于通过hHR23蛋白家族（hHR23a和hHR23b）介导的核苷酸切除修复很重要。HHR23蛋白包含四个结构域，每个结构域与不同的结合伙伴相互作用。正在进行的研究表明，hHR23蛋白与蛋白酶体结合后会发生全局结构变化。本研究拟利用核磁共振波谱进一步研究hHR23a单独及与泛素-蛋白酶体通路组分的结构和动力学。核磁共振是研究分子运动和蛋白质相互作用的最佳方法，我们的发现已经建立了蛋白酶体如何通过hHR23蛋白在核苷酸切除修复中起作用的模型。基于我们的结构数据，我们设计了突变的结构，用功能分析在体内测试我们的模型。这项工作有望为hHR23与泛素-蛋白酶体途径相互作用的机制以及这种相互作用如何在核苷酸切除修复中发挥作用提供基础知识。

DESCRIPTION (provided by applicant): We propose to investigate the mechanism by which the proteasome functions in DNA repair by revealing the structure and dynamics of the proteins that are instrumental in linking these two pathways. The proteasome is a renowned protein degradation machinery and nucleotide excision repair is the major process responsible for repairing UV-damaged DNA. Much evidence has recently established that proteasome activity is important for nucleotide excision repair as mediated via the hHR23 family of proteins (hHR23a and hHR23b). HHR23 proteins contain four structured domains, each of which interacts with a different binding partner. Ongoing studies reveal that hHR23 proteins undergo global structural changes upon associating with the proteasome. The proposed research uses NMR spectroscopy to further investigate the structure and dynamics of hHR23a alone and with components of the ubiquitin-proteasome pathway. NMR is the best method for studying molecular motions and protein-protein interactions and our findings have resulted in a model for how the proteasome functions through hHR23 proteins in nucleotide excision repair. Based on our structural data, we design mutated constructs to test our model in vivo with functional assays. This work is expected to yield fundamental knowledge of the mechanism behind the hHR23 interaction with the ubiquitin-proteasome pathway and how this interaction functions in nucleotide excision repair.