Mouse Models And LRRK2 Kinase Substrates for Park8-Parkinson's Disease

描述(申请人提供)：新发现的LRRK2是一种家族性显性迟发性帕金森病的疾病基因，编码一种激酶。目前还没有可用于PARKS的小鼠模型；LRRK2激酶底物尚不清楚；对LRRK2在帕金森病中的正常功能和致病作用知之甚少。在这个最适合R21机制的早期探索阶段，我们已经建立了LRRK2小鼠模型，现在建议对其进行表征，并利用这些新的小鼠模型来鉴定LRRK2底物。LRRK2基因突变已被确定为家族性帕金森病以及散发性帕金森病中最常见的突变。所有PARKS突变都是导致显性表型的错义突变，表明突变蛋白的“功能获得”或“多动”机制在发病中起作用。因此，转基因(非基因敲除)小鼠模型适合用于公园建模。我们的中心假设是，PARTS的病理是由突变的LRRK2过度磷酸化其底物引起的。为了验证这一假设，我们培育了携带野生型序列或在人类细菌人工染色体(BAG)中存在突变的转基因LRRK2小鼠。具体目的1：分析LRRK2转基因小鼠运动功能、黑质神经元病理和多巴胺产生与释放的进行性行为缺陷。具体目的2：使用我们的新小鼠模型，以候选和无偏见的方法鉴定LRRK2激酶的底物。意义：PARKS的小鼠模型将成为机械研究和未来治疗药物测试的关键工具。鉴定LRRK2底物很重要，因为激酶通路和组分是高度“可用药”的靶标。LRRK2的研究也很可能影响散发性帕金森病的研究，因为PARKS突变G2019S被发现在散发性帕金森病中也非常普遍。

DESCRIPTION (provided by applicant): The newly identified LRRK2, a disease gene of familial dominant late-onset ParkS, encodes a kinase. No mouse models are available for ParkS; no LRRK2 kinase substrates are known; and little is known about LRRK2 normal functions and pathogenic roles in Parkinson's disease. In this early exploratory phase of research which is most suitable for R21 mechanism, we have established LRRK2 mouse models and now propose to characterize them, and utilize these new mouse models to identify LRRK2 substrates. Mutations in LRRK2 have been identified as the most prevalent ones in familial Parkinson's disease, as well as in sporadic PD unexpectedly. All ParkS mutations are missense mutations that cause a dominant phenotype, indicating a "gain of function" or "hyperactivity" mechanism of mutant proteins for pathogenesis. Therefore, transgenic (not knockout) mouse models are appropriate for modeling ParkS. Our CENTRAL HYPOTHESIS is that ParkS pathology is caused by hyperactivity of the mutant LRRK2 to hyper-phosphorylate its substrates. To test this hypothesis, we have generated transgenic LRRK2 mice that carry wild type sequence or ParkS mutations in HUMAN bacterial artificial chromosome (BAG). SPECIFIC AIM 1: to analyze the phenotypes of the LRRK2 transgenic mice for progressive behavioral deficits in motor function and in niagrostriatal pathways, neuronal pathology in substantia nigra, and dopamine production and release. SPECIFIC AIM 2: to use our new mouse models to identify substrates of LRRK2 kinase with both candidate and non-biased approaches. SIGNIFICANCE: Mouse models for ParkS will be critical tools for mechanistic studies and future therapeutic drug testing. The identification of LRRK2 substrates is important because kinase pathways and components are highly "drug-able" targets. The study of LRRK2 is also very likely to impact sporadic PD research, because ParkS mutation G2019S was discovered to be also highly prevalent in sporadic PD.