Investigation of the synergistic role of PLK2 and alpha-synuclein in the regulation of neuronal homeostasis and functions

最新进展：α-突触核蛋白(-syn)是一种定位于中枢神经系统突触前终末的小分子可溶性蛋白。虽然这种蛋白在大脑中大量表达(占总胞浆蛋白的1%)，但其确切的生理功能仍不清楚。在过去的十年里，人们对磷酸化在调节体内正常功能中的作用越来越感兴趣。在这种背景下，我们最近的工作确定Polo-like kinase(Plks)是在体外和体内负责-syn磷酸化的主要激酶。此外，我们还报道了PLK家族成员PLK2通过自噬降解途径调节-SYN的选择性清除。然而，PLK2介导的SYN清除的分子机制以及这两种蛋白确切的协同生理作用仍不清楚。 目的：该研究计划的具体目的是：1)破译SYN/PLK2相互作用的分子机制；2)研究这一通路在神经元功能调节中的作用，重点是控制突触内环境的稳定。 研究方法：本研究计划基于多学科方法，结合组织学和生化分析、使用哺乳动物细胞和原代神经元培养的细胞分析以及活体动物模型。 影响：拟议研究计划的5年成果是：1)确定-syn及其天然激酶PLK2的新的生理功能，阐明突触可塑性和动态平衡的新分子机制；2)通过发展体内方法的特殊专业知识，培训分子和细胞生物学研究生。

Recent Progress: Alpha-synuclein (-syn) is a small soluble protein localized at presynaptic terminals in the central nervous system. Although this protein is abundantly expressed in the brain (1% of total cytosolic protein), its exact physiological functions remain unknown. In the past decade, there has been an increasing interest for the role of phosphorylation in the regulation of -syn normal function in vivo. In this context, our recent work identified Polo-like kinases (Plks) as the main kinases responsible for -syn phosphorylation in vitro and in vivo. Moreover, we reported that Plk2, a member of Plk family, regulates -syn selective clearance via the autophagy degradation pathway. However, the molecular mechanisms underlying Plk2-mediated -syn clearance and the exact synergistic physiological role of these two proteins remain unknown. Objective: The specific aims of the proposed research program are 1) to decipher the molecular mechanisms underlying -syn/Plk2 interaction and 2) to investigate the role of this pathway in the regulation of neuronal functions, with a focus in the control of the synaptic homeostasis. Methodology: This research program is based on a multidisciplinary approach combining histological and biochemical analysis, cell-based assays using mammalian cells and primary neuronal culture, as well as in vivo animal models. Impact: The 5-year deliverables of the proposed research program are 1) to identify new physiological functions of -syn and its natural kinase Plk2 and to shed light onto new molecular mechanisms underlying synaptic plasticity and homeostasis and 2) to train graduate students in molecular and cellular biology by developing a particular expertise in in vivo approaches.