Selective Targeting of G Protein beta gamma Subunits with Small Molecules

描述（由申请人提供）：G蛋白23个亚基在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作为辅助因子，并在向下游靶标的信号传递中发挥直接作用。在许多系统中积累的大量数据表明，过量的23信号传导具有病理后果，并且操纵23亚基信号传导可能是心力衰竭以及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23-亚基与功能蛋白伴侣的结合相互作用，选择性地操纵G蛋白23亚基信号通路。在我们的初步数据中，我们证明这些化合物对心力衰竭，炎症和吗啡依赖性镇痛的动物模型有效。在我们提出的实验中，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的G23靶标的选择性，并开发新的预测化合物选择性的分析方法。具体目标2将结合生物物理配体相互作用方法，诱变和x射线晶体学，以详细了解选择性机制。Specific aim3将利用来自Specific aim 2的信息来改进我们的计算筛选方法，以允许更有效的化合物鉴定，这些化合物可能具有独特的作用机制。具体目标4将应用我们的知识选择性GPCR信号在中性粒细胞功能。该实验的成功完成将导致对靶向G23信号的新分子家族的作用机制的透彻理解，这对剖析GPCR刺激信号的作用机制具有潜在的用途，并为新的治疗方法提供基础。G蛋白偶联受体（gpcr）是一类主要的跨膜受体，负责识别一类不同的配体。在这里，我们建议研究我们实验室鉴定的G蛋白23亚基的选择性小分子抑制剂，这些抑制剂可用于抑制多种GPCR和修饰现有GPCR导向药物的作用。

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.