Towards small molecule modulators of RGS proteins

描述(申请人提供)：神经递质信号通常涉及G蛋白偶联受体(GPCRs)的激活。神经递质受体信号的调节是改善精神分裂症和抑郁症等疾病认知病理的关键治疗工具。“G蛋白信号调节蛋白”(RGS)蛋白是GPCR信号的关键组成部分，它作为GTP酶加速蛋白或GA亚基的“间隙”，极大地提高其固有的GTP水解性。为了促进RGS蛋白作为认知病理学药物发现靶点的应用，本研究计划的具体目的是描绘RGS-box间隙活性的变构调节的结构决定因素，并通过计算方法识别RGS-box间隙活性的小分子抑制剂和激活剂。对RGS-box序列的统计耦合分析和应用于已知RGS-box结构的位点识别算法将指导来自商业和公共化合物库的化合物的电子对接。在这些筛选中确定的化合物“HITS”的活性将通过基于荧光和表面等离子体共振的RGS-box Ga结合和Ga-GAP活性的体外分析来评估。经过验证的RGS-box GAP活性调节剂随后将在受体/G蛋白/效应器功能的细胞分析中进行评估，包括依赖于受体的异三聚体稳态GTP酶活性和磷脂酶C活性的激活。这些努力应该确定RGS蛋白作用的小分子调节剂的原理证明，这将建立RGS蛋白作为治疗干预的有效目标，在未来的中枢神经系统疾病的药物治疗中。

DESCRIPTION (provided by applicant): Neurotransmitter signaling often involves activation of G protein-coupled receptors (GPCRs). Modulation of neurotransmitter receptor signaling is a key therapeutic tool in ameliorating the cognitive pathologies of diseases such as schizophrenia and depression. "Regulator of G-protein signaling" (RGS) proteins are key components of GPCR signaling that act as GTPase-accelerating proteins or "GAPs" for Ga subunits, dramatically increasing their intrinsic GTP hydrolysis activity. In order to advance the utility of RGS proteins as drug discovery targets for cognitive pathologies, the specific aims of this research proposal are to delineate the structural determinants of allosteric modulation of RGS-box GAP activity and to identify small molecule inhibitors and activators of RGS-box GAP activity by computational approaches. Statistical coupling analyses of RGS-box sequences and site identification algorithms applied to known RGS-box structures will guide in silico docking of compounds from commercial and public compound libraries. The activity of compound "hits" identified in these screens will be evaluated using fluorescence- and surface plasmon resonance-based in vitro assays of RGS-box Ga-binding and Ga-GAP activities. Verified modulators of RGS-box GAP activity will then be evaluated in cellular assays of receptor/G-protein/effector function, including receptor-dependent activation of heterotrimer steady-state GTPase activity and of phospholipase C activity. These pursuits should identify proof-of-principle small molecule modulators of RGS protein action that will establish RGS proteins as valid targets for therapeutic intervention in future pharmacotherapy of CNS disorders.