Structural analysis of the human LRRK2

点击翻译按钮获取中文摘要

PROJECT SUMMARY Parkinson’s Disease (PD) is the second most common neurodegenerative disease, featured by movement disorders. PD affects nearly one million Americans and ten million people worldwide. While aging is the major risk factor, PD can also be caused by genetic mutations. More than ten PD-associated genes have been identified, and LRRK2 mutations are the most common cause of both familial and sporadic PD cases. LRRK2 gene encodes the leucine-rich repeat kinase 2 (LRRK2), a large multidomain protein with both kinase and GTPase activities; most of the LRRK2 disease mutations show increased kinase activity. Therefore, inhibiting LRRK2 kinase activity holds great potential for treating PD, and numerous pharmaceutical companies are making tremendous efforts to develop specific inhibitors. Our previous work has revealed the first cryo-EM structures of full-length human LRRK2, providing the atomic architecture of this 286-kDa kinase in an inactive conformation. Here we propose to further investigate the working mechanism of LRRK2 by combining cutting- edge structural biology techniques such as single-particle cryoEM with biochemical, biophysical and cell biology approaches. We hypothesize that understanding the structural basis of the LRRK2 recruitment, activation and substrate recognition could provide novel directions for the development of allosteric inhibitors. In this proposal, the working mechanism of LRRK2 will be dissected at atomic details by addressing the following fundamental questions. i) How do Rab GTPases recruit LRRK2? ii) What is the active conformation of LRRK2? and iii) how does LRRK2 specifically recognize its substrates? The successful outcome of this proposal will provide a molecular picture of the LRRK2 recruitment, activation and substrate recognition processes in atomic details and, therefore, could serve as the conceptual framework for designing allosteric LRRK2 inhibitors to treat PD.