Selective Targeting of G Protein beta gamma Subunits with Small Molecules

描述(申请人提供)：G蛋白23亚基在G蛋白偶联受体(GPCR)介导的信号转导中起核心作用。它们在受体介导的激活过程中扮演辅助因子的角色，并在向下游靶点的信号传递中发挥直接作用。在许多系统中积累了大量的数据，表明超过23个信号会导致病理后果，操纵23个亚单位信号可能是心力衰竭和其他疾病的有效治疗策略。我们开发了一种新的靶向策略，通过使用小分子选择性地阻断G蛋白23亚单位与功能蛋白伙伴的结合作用，选择性地操纵G蛋白23亚单位信号通路。在我们的初步数据中，我们证明了这些化合物在心力衰竭、炎症和吗啡依赖止痛的动物模型中是有效的。在拟议的实验中，我们将探索这23种结合化合物的结合和选择性的基本机制。在具体目标1中，实验将表征化合物对广泛范围的G23目标的选择性，并开发预测化合物选择性的新方法。具体目标2将结合生物物理配基相互作用方法、诱变和X射线结晶学来详细了解选择性的机理。特定的目标3将利用来自特定的目标2的信息来改进我们的计算筛选方法，以允许更有效地鉴定可能具有独特作用机制的化合物。具体目标4将把我们的知识应用于中性粒细胞功能中的GPCR信号转导。这些实验的成功完成将导致对一系列新的靶向G23信号的分子的作用机制的彻底理解，这些分子在剖析GPCR刺激信号的作用机制方面具有潜在的用途，并为新的治疗方法提供基础。G蛋白偶联受体是一类主要的跨膜受体，负责识别一大类不同的配体。在这里，我们建议研究我们实验室发现的G蛋白23亚基的选择性小分子抑制剂，它们可以用来抑制多个GPCRs，并改变现有的GPCR靶向药物的作用。 公共卫生相关性：这些实验的结果将有助于验证这一替代方法，以修改GPCRs下游的信号通路，最终可能导致新疗法的开发。

DESCRIPTION (provided by applicant): G proteins 23 subunits play a central role in G-protein coupled receptor (GPCR)- mediated signal transduction. They act as cofactors in the receptor-mediated activation process as well as playing direct roles in signal transfer to downstream targets. Considerable data has accumulated in number of systems that excess 23 signaling has pathological consequences and that manipulation of 23 subunit signaling could be an effective therapeutic strategy in heart failure as well as other diseases. We have developed a novel targeting strategy for selective manipulation of G protein 23 subunit signaling pathways by selectively blocking 23-subunit binding interactions with functional protein partners using small molecules. In our preliminary data we demonstrate these compounds are efficacious in animal models of heart failure, inflammation and morphine-dependent analgesia. In the proposed experiments we will explore the fundamental mechanisms underlying binding and selectivity of these 23 binding compounds. In Specific aim 1 the experiments will characterize the selectivity of compounds for a broad range of G23 targets and develop new assays for predicting compound selectivity. Specific aim 2 will combine biophysical ligand interaction methods, mutagenesis and x-ray crystallography to develop a detailed understanding of the mechanisms for selectivity. Specific aim3 will exploit the information from specific aim 2 to refine our computational screening approach to allow for more efficient compound identification that may have unique mechanisms of action. Specific aim 4 will apply our knowledge of selectivity to GPCR signaling in neutrophil functions. Successful completion of the proposed experiments will lead to a thorough understanding of a the mechanism of action of a new family of molecules that target G23 signaling that have potential uses in dissecting the mechanisms of action of GPCR stimulated signaling and providing the basis for novel therapeutic approaches. G protein coupled receptors (GPCRs) are a major class of transmembrane receptors responsible for recognition of a large class of diverse ligands. Here we propose investigation of selective small molecule inhibitors of G protein 23 subunits identified in our laboratory which could be used to inhibit multiple GPCRs and modify actions of existing GPCR directed pharmaceuticals. Public Health Relevance: Results of these experiments will help to validate this alternate approach to modification of signaling pathways downstream of GPCRs that could ultimately lead to development of novel therapeutics.