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

描述（由申请人提供）：新鉴定的LRRK 2是家族性显性迟发型ParkS的疾病基因，编码一种激酶。没有小鼠模型可用于ParkS;没有LRRK 2激酶底物是已知的;并且对LRRK 2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机制的早期探索研究阶段，我们建立了LRRK 2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LRRK 2底物。LRRK 2突变已被确定为家族性帕金森病中最常见的突变，以及意外地在散发性PD中。所有ParkS突变都是错义突变，导致显性表型，表明突变蛋白的发病机制是“功能获得”或“过度活跃”机制。因此，转基因（非敲除）小鼠模型适用于ParkS建模。我们的中心假设是ParkS病理是由突变型LRRK 2过度磷酸化其底物的过度活性引起的。为了验证这一假设，我们已经产生了转基因LRRK 2小鼠，其在人类细菌人工染色体（BAG）中携带野生型序列或Parks突变。具体目标1：分析LRRK 2转基因小鼠在运动功能和黑质纹状体通路中的进行性行为缺陷、黑质中的神经元病理以及多巴胺产生和释放的表型。具体目标2：使用我们的新小鼠模型，以候选和非偏倚方法鉴定LRRK 2激酶的底物。意义：Parks的小鼠模型将是机制研究和未来治疗药物测试的关键工具。LRRK 2底物的鉴定是重要的，因为激酶途径和组分是高度“可药物化”的靶标。LRRK 2的研究也很可能影响散发性PD研究，因为ParkS突变G2019 S被发现在散发性PD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.