Neuronal Gαi-GPCR targeting to primary cilia and impact on cAMP mediated transcription

项目摘要/摘要 纤毛疾病是一组疾病的集合，这些疾病的特征是基因突变损害了初级纤毛形态或 其症状包括发育障碍、肥胖、认知功能障碍和 人类的行为缺陷。初级纤毛是固定的细胞器，通常突出神经元胞体。 与核隔间相邻。越来越多的证据表明，细胞外刺激(即， 神经调节剂)通过G蛋白偶联受体(GPCRs)传递特殊信号 神经元初级纤毛影响转录变化和神经元活动。因此，确定如何 特异性靶向神经元睫状神经GPCRs，将导致神经和 神经精神疾病。该提案将侧重于确定所采用的选择性纤毛靶向机制 通过神经GαI偶联的GPCRs和纤毛GPCRs信号对基因转录的影响。 我们发现，在脑切片中，神经G-αI偶联的GPCRs，如Mu阿片受体，表达在 某些神经元群体的神经元初级纤毛，而不是其他神经元群体，这表明细胞和/或受体具有选择性 纤毛打靶机械。在特定的目标1中，我们剖析了纤毛靶向机制是否具有细胞特异性 和/或在三种不同的细胞类型中具有受体选择性。在特定目标2中，我们使用了基于蛋白质组学的方法 在细胞和脑中寻找与G-αI偶联GPCRs纤毛靶向相关的新蛋白 组织。在特定的目标3中，我们将评估睫状GαI偶联的GPCR环-AMP信号对 神经元转录。总的来说，这项提议将试图弄清纤毛背后的机制 神经元GPCRs的靶向性和睫状GPCRs的神经调节功能。

PROJECT SUMMARY / ABSTRACT Ciliopathies are a collection of diseases that feature genetic mutations that impair primary cilia morphology or function and are characterized by symptoms that include developmental disorders, obesity, cognitive and behavioral deficits in humans. Primary cilia are immotile organelles that protrude off neuronal soma often adjacent to the nuclear compartment. A growing body of evidence indicates that extracellular stimuli (i.e., neuromodulators) transmits specialized signaling through G protein-coupled receptors (GPCRs) located on neuronal primary cilia to influence transcriptional changes and neuronal activity. Thus, determining how to specifically target neuronal ciliary GPCRs, will lead to novel therapeutic approaches for neurological and neuropsychiatric diseases. This proposal will focus on identifying selective ciliary targeting mechanics employed by neural Gαi-coupled GPCRs and the impact of ciliary GPCR signaling on gene transcription. We found that in brain sections, neural Gαi-coupled GPCRs, such as the mu opioid receptor, are expressed in neuronal primary cilia of some neuronal populations but not others suggesting cell and/or receptor-selective ciliary targeting machinery. In Specific Aim 1, we dissect whether ciliary targeting mechanics are cell-specific and/or receptor-selective in three distinct cell types. In Specific Aim 2, we employ Proteomics-based approaches to identify novel GPCR-associated proteins involved in ciliary targeting of Gαi-coupled GPCRs in cells and brain tissue. In Specific Aim 3, we will evaluate the contribution of ciliary Gαi-coupled GPCR cyclic-AMP signaling to neuronal transcription. Collectively, this proposal will attempt to discern the mechanisms underlying ciliary targeting of neuronal GPCRs and the neuromodulatory function of ciliary GPCRs.