HTS for Inhibitors of BAP1,BRCA:Deubiquinating(RMI)

描述(申请人提供)：携带乳腺癌易感基因BRCA1突变的个人容易患早发性乳腺癌和卵巢癌，这是西方社会最常见的一些恶性肿瘤。BRCA1的这种突变几乎在所有遗传性乳腺癌和卵巢癌家族中都存在，而在仅患有乳腺癌的家族中约有一半。在BRCA1携带者的肿瘤中检测到影响野生型BRCA1等位基因的杂合性缺失(LOH)，表明BRCA1是一种肿瘤抑制基因。BRCA1在乳腺癌中的作用是复杂的；到目前为止，已经鉴定出100多个独特的、自然发生的BRCA1种系突变。BRCA1的研究对乳腺癌研究具有重要意义，阐明其生化功能的尝试包括确定其蛋白质伙伴，如BAP1。BAP1是脱泛素酶(DUB)家族的一员。这些是蛋白质酶，可以逆转泛素与蛋白质的结合，被蛋白酶体降解或对泛素化作出反应而重新定位。泛素的结合在细胞周期调节、染色质结构、DNA修复和基因组稳定性、转录、病毒致病、免疫反应和蛋白质质量控制等诸多调控途径中发挥着重要作用。脱泛素酶至少在某些病理条件下可能是有用的药物靶点。除了神经元UCH-L1，没有DUB是系统筛查的目标。我们已经开发出了以负担得起的成本生产大量非专利Dub底物的方法，并选择首先将我们的努力集中在与BRCA1肿瘤抑制因子相关的Dub上。我们已经开始优化筛选条件，并表明该方法适用于384井格式。我们将对可用的NIH化合物文库进行常规的高通量药物筛选，以确定DUB作用的抑制剂和激活剂。这一筛选将产生有用的BAP1功能的分子探针，并有助于阐明BAP1在BRCA1介导的事件中的作用。

DESCRIPTION (provided by applicant): Individuals who carry mutations in the breast cancer susceptibility gene, BRCA1, are predisposed to early onset breast and ovarian cancer, some of the most common malignancies in Western societies. Such mutations in BRCA1 account for almost all families with inherited breast and ovarian cancer and for approximately half of families with breast cancer only. The detection of loss-of-heterozygosity (LOH) affecting the wild-type BRCA1 allele in tumors from BRCA1 carriers implies that BRCA1 is a tumor suppressor. The involvement of BRCA1 in breast cancer is complex; to date, more than 100 unique, naturally occurring BRCA1 germline mutations have been identified. The study of BRCA1 has important implications for breast cancer research and attempts to elucidate its biochemical function have included identifying its protein partners, such as BAP1. BAP1 is a member of the UCH family of deubiquitinating enzymes (DUB). These are proteases that reverse the conjugation of ubiquitin to proteins targeted for degradation by the proteasome or relocalization in response to ubiquitination. The conjugation of ubiquitin has been shown to be important in control of many regulatory pathways including; cell cycle regulation, chromatin structure, DNA repair and genome stability, transcription, viral pathogenesis, immune response, and protein quality control. Deubiquitinating enzymes are likely to be useful drug targets in at least some pathological conditions. With the exception of neuronal UCH-L1, no DUB has been the target of a systematic screen. We have developed the means to produce significant amounts of a generic DUB substrate at affordable costs and have chosen to focus our efforts first on a DUB associated with the BRCA1 tumor suppressor. We have begun to optimize the screening conditions and have shown that the assay is adaptable to the 384 well format. We will mount a conventional high throughput drug screen of available NIH compound libraries to identify inhibitors and activators of DUB action. This screen will result in useful molecular probes of BAP1 function and help to clarify the role of BAP1 in BRCA1 mediated events.