Small Molecule Probes for Elucidating LRRK2 Kinase Functions

描述（由申请人提供）：神经变性疾病，包括阿尔茨海默氏病、帕金森氏病、亨廷顿氏病、肌萎缩侧索硬化症（ALS）和多发性硬化症，折磨着大部分人群。这些病症中的许多还对治疗性干预具有很强的抗性，主要是由于难以鉴定提供疾病改变作用的可生物修饰的分子靶标。然而，最近的研究已经确定了富含亮氨酸的重复激酶2基因（LRRK2）的突变，在最常见的家族形式和一些散发形式的帕金森病（PD）。LRRK2是由多个结构域组成的大蛋白，包括激酶和GT3结构域。研究还表明，LRRK2的激酶活性在最常见的PD相关突变G2019S和一些其他突变中升高。此外，增加的激酶活性与升高的神经元毒性相关，表明LRRK2的功能获得机制。该建议的目的是将从高通量筛选鉴定的命中物开发成更有用的探针以阐明LRRK2的作用。本提案的具体目的是对LRRK2激酶抑制剂的三种不同结构系列进行构效关系（SAR）研究和优化，对LRRK2激酶抑制剂进行酶表征，并开发功能性细胞测定法，以确认LRRK2激酶抑制剂的细胞活性。尽管PD患者的亚群携带LRRK2突变，但在散发性和家族性病例中均发现了LRRK2突变，并且良好的探针化合物可能导致在理解蛋白质的功能和疾病的病理学方面取得重大突破。

DESCRIPTION (provided by applicant): Neurodegenerative diseases, including Alzheimer's, Parkinson's, Huntington's diseases, amyotrophic lateral sclerosis (ALS) and multiple sclerosis, afflict a large portion of the population. Many of these conditions also have been very resistant to therapeutic intervention primarily due to difficulties identifying pharmacologically modifiable molecular targets that provide disease altering effects. However, recent studies have identified mutations in the leucine-rich repeat kinase2 gene (LRRK2) in the most common familial forms and some sporadic forms of Parkinson's disease (PD). LRRK2 is a large protein comprised of multiple domains, including kinase and GTPase domains. Studies have also demonstrated that LRRK2's kinase activity is elevated in the most common PD-associated mutation G2019S and some other mutations. Furthermore, the increased kinase activity correlates with elevated neuronal toxicity, suggesting a gain-of-function mechanism of LRRK2. The purpose of this proposal is to develop hits identified from high throughput screening into more useful probes to elucidate the role of LRRK2. The specific aims of this proposal are to conduct structure- activity relationship (SAR) studies and optimization of three distinct structure series of LRRK2 kinase inhibitors, to conduct enzymatic characterization of the LRRK2 kinase inhibitors and to develop functional cell-based assays to confirm cell-based activity of LRRK2 kinase inhibitors. Even though subsets of PD patients carry mutations in LRRK2, it is found in both sporadic and familial cases and good probe compounds could lead to significant breakthroughs in understanding the function of the protein and the pathology of the disease.