Screen For Inhibitors of Parkin E3 Autoubiquition

描述（由申请人提供）：神经退行性疾病是维持不同人群健康和生活质量的主要挑战。在这一类的各种疾病中，帕金森病（PD）是发病率和预期寿命降低的主要原因，今天人们正在努力发现新的治疗方法。一种有希望的治疗干预方法是旨在增加帕金森氏症细胞水平的治疗，帕金森氏症是一种在模型系统中被发现可以拮抗神经退行性变的蛋白质，它与某些形式的帕金森病有遗传联系。目标的选择和验证可以被操纵来实现这种效果取决于与帕金调节相关的信息的增加。药物发现的一个新领域——通过泛素途径酶进行蛋白质稳态调节——最近被证明与抗神经退行性药物的研究有关。事实上，Parkin已被确定为一种环指E3泛素连接酶，它催化泛素化，随后诱导与神经变性相关的各种蛋白质的蛋白酶体降解。此外，它还能催化自身的泛素化。因此，选择性抑制剂的parkin自体泛素化是

DESCRIPTION (provided by applicant): Neurodegenerative disease represents a major challenge to the maintenance of health and quality of life in diverse segments of the population. Among the various diseases of this class, Parkinson's disease (PD) is a major cause of morbidity and diminished life expectancy, and there is today an intense effort to discover novel treatments. A promising approach for therapeutic intervention is treatment designed to increase the cellular level of parkin, a protein which has been found to antagonize neurodegeneration in model systems, and which is linked genetically with some forms of PD. The selection and validation of targets that can be manipulated to achieve this effect depends on an increasing amount of information relating to parkin regulation. A novel area for drug discovery -- protein homeostatic regulation via ubiquitin pathway enzymes -- has recently been demonstrated to have relevance to the search for anti-neurodegenerative drugs. Parkin has, in fact, been determined to be a RING-finger E3 ubiquitin ligase that catalyses ubiquitination and, subsequently, induces proteasomal degradation of various proteins associated with neurodegeneration. In addition, it catalyses its own ubiquitination. Thus, selective inhibitors of parkin autoubiquitination are hypothesized to have a neuroprotective effect. In Phase I, it is proposed to establish a yeast-based screening assay for inhibitors of parkin autoubiquitination and a selectivity counter screen for ubiquitination of alpha-synuclein, a parkin substrate. Essential components of the E3 system (parkin) will be cloned and expressed in S. cerevisiae, along with human parkin or alpha-synuclein linked to p53, and a reporter construct that monitors p53 activity (beta-galactosidase activation). The reconstructed E3 ligase function and reporter system will then be configured and validated as a high throughput screen for inhibitors of parkin autoubiquitination. Collections of plant and marine organism extracts and small molecules from the NCI and academic collaborators, will be screened for potent inhibitors of this activity. In Phase II, fractionation of active extracts will be guided by the assay to identify active principles. Novel pure compounds arising from this effort will be considered as development candidates for PD therapy. The modular assay construction format will permit evaluation of other E3s that are associated with a variety of diseases.