RGS9-2 Protein: Novel Partners and Functional Roles

RGS9-2 蛋白：新伙伴和功能作用

• 批准号: 7230223
• 负责人: MOHAMAD BOUHAMDAN
• 金额: $ 21.92万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7230223
• 关键词: Actinin; Address; Brain; C-terminal; Cells; Cerebral cortex; Co-Immunoprecipitations; Corpus striatum structure; Development; Disease; Exhibits; Family; Functional disorder; G-Protein Signaling Pathway; GTP-Binding Protein Regulators; GTP-Binding Proteins; Laboratories; Mediating; Molecular; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; Neuraxis; Neurons; Opioid; Parkinson Disease; Physiological; Proline-Rich Domain; Prosencephalon; Protein Binding Domain; Proteins; RGS Domain; RGS Proteins; Regulation; Research Personnel; Role; Signal Transduction; Techniques; Thinking; Time; To specify; Yeasts; desensitization; member; neuropsychiatry; novel; platelet protein P47; protein protein interaction; receptor; receptor function; yeast two hybrid system

DESCRIPTION (provided by applicant): RGS (Regulators of G protein Signaling) proteins modulate the information transduced into cells through G protein signaling pathways. Approximately thirty RGSs have been identified. All of these proteins contain a highly conserved RGS domain, but differ in the presence of additional protein-protein interaction motifs that are thought to specify interactions with signaling partners. The presence and arrangement of these motifs defines several distinct families of RGS proteins. RGS9-2 is a brain-specific member of a group of RGS proteins identifiable by the tandem arrangement of 4 protein- protein interaction domains, namely a Dishevelled egllO, pjeckstrin (DEP) domain, a G-gamma-like (GGL) domain, a Regulator of G protein signaling (RGS) domain, and a C-terminal proline-rich domain. This protein exhibits a remarkable distribution in the central nervous system, with very high levels of expression only in the striatum, and during development, also in the cerebral cortex. This distribution suggests a role for RGS9-2 in regulating specific aspects of G protein signaling in these regions, and hence a potential role in the pathophysiology of neuropsychiatric disorders. In fact, RGS9-2 has been shown to be increased in Parkinson's disease and to facilitate tolerance to opioids. Unfortunately, little is known at the present time about the specific function(s) of the RGS9-2 in the brain. In an effort to understand the role of RGS9-2 at a cellular/molecular level, our laboratory has focused on the identification of specific signaling partners for this protein. Using yeast two hybrid screen and co- immunoprecipitation techniques, we have identified a strong interaction between RGS9-2 and a-actinin-2. One of the best understood roles for a-actinin-2 is in the regulation of NMD A receptor desensitization. Consistent with a physiological role for the interaction between RGS9-2 and a-actinin-2, in preliminary studies we have uncovered a strong regulation of NMD A currents by RGS9-2. Combined, these results suggest a novel and potentially very exciting role for RGS9-2 in central forebrain neurons. In the present application, we propose to extend these preliminary observations by addressing these three questions: 1) what specific regions within RGS9-2 and a-actinin-2 are critical for their mutual interaction, 2) do RGS9-2 and a-actinin-2 colocalize in the brain, 3) does the interaction between RGS9-2 and a-actinin-2 have functional significance for NMDA receptor function. To answer these questions, we propose the following aims: Specific Aim 1. To identify the regions most critical in mediating the interaction ofRGS9-2 and a-actinin-2, and to determine the functional relevance of this interaction. Specific Aim 2. To assess the physical and functional interaction between RGS9-2 and a-actinin-2 in central neurons.

描述（由申请人提供）：RGS（G蛋白信号调节因子）蛋白调节通过G蛋白信号通路转导到细胞中的信息。已经确定了大约30个RGS。所有这些蛋白质都含有高度保守的RGS结构域，但不同之处在于存在额外的蛋白质-蛋白质相互作用基序，这些基序被认为指定与信号伴侣的相互作用。这些基序的存在和排列定义了几个不同的RGS蛋白家族。RGS 9 -2是一组RGS蛋白的脑特异性成员，其可通过4个蛋白质-蛋白质相互作用结构域的串联排列来鉴定，所述4个蛋白质-蛋白质相互作用结构域即Dishevelled egllO、pjeckstrin（DEP）结构域、G-γ样（GGL）结构域、G蛋白信号传导调节因子（RGS）结构域和C-末端富含脯氨酸的结构域。这种蛋白质在中枢神经系统中表现出显著的分布，仅在纹状体中具有非常高的表达水平，并且在发育期间，也在大脑皮层中。这种分布表明RGS 9 -2在这些区域中调节G蛋白信号传导的特定方面的作用，因此在神经精神疾病的病理生理学中具有潜在作用。事实上，研究表明，帕金森病患者的RGS 9 -2含量增加，并促进对阿片类药物的耐受性。不幸的是，目前对RGS 9 -2在大脑中的具体功能知之甚少。为了了解RGS 9 -2在细胞/分子水平上的作用，我们的实验室专注于鉴定这种蛋白质的特异性信号伴侣。使用酵母双杂交筛选和免疫共沉淀技术，我们已经鉴定了RGS 9 -2和α-辅肌动蛋白-2之间的强相互作用。α-辅肌动蛋白-2的最佳理解的作用之一是在NMDA受体脱敏的调节中。与RGS 9 -2和α-辅肌动蛋白-2之间相互作用的生理作用一致，在初步研究中，我们已经发现RGS 9 -2对NMDA电流的强烈调节。结合起来，这些结果表明RGS 9 -2在中央前脑神经元中的一种新的和潜在的非常令人兴奋的作用。在本申请中，我们提出通过解决这三个问题来扩展这些初步观察：1）RGS 9 -2和α-辅肌动蛋白-2内的哪些特定区域对于它们的相互作用是关键的，2）RGS 9 -2和α-辅肌动蛋白-2在脑中共定位吗，3）RGS 9 -2和α-辅肌动蛋白-2之间的相互作用对NMDA受体功能是否具有功能意义。为了回答这些问题，我们提出了以下目标：具体目标1。确定在调节RGS 9 -2和α-辅肌动蛋白-2相互作用中最关键的区域，并确定这种相互作用的功能相关性。具体目标2。评估RGS 9 -2和α-辅肌动蛋白-2在中枢神经元中的物理和功能相互作用。