Mechanism of activation and modulation in human GABA(B) receptor

总结 抑制性神经递质GABA在大脑中产生缓慢和长期的抑制作用， 代谢型GABAB受体的活化。GABAB信号传导中的缺陷与以下因素有关： 各种神经和情绪障碍，包括痉挛、癫痫、成瘾和焦虑。GABAB 受体是C类G蛋白偶联受体（GPCR）家族的成员，其通常 作为二聚体起作用并具有大的胞外结构域。基本问题依然存在 关于这些C类受体的激活和调节的分子机制。 GABAB受体是GABAB 1和GABAB 2亚基的异源二聚体，并受GABAB 1和GABAB 2亚基的调节。 含钾通道四聚化结构域（KCTD）蛋白辅助亚基。我们 开发全长GABAB受体、其辅助亚基及其复合物的结构模型 G蛋白。根据我们的结构分析，我们将确定分子之间的关联 GABAB受体和KCTD，描述了在多种细胞中全长GABAB受体的构象， 功能状态，并表征GABAB受体和G proteins.总之，这些研究将促进我们对GABA作用的分子基础的理解 在大脑中，导致治疗神经系统疾病的新疗法的发展。

Summary The inhibitory neurotransmitter GABA produces slow and prolonged inhibition in the brain through activation of metabotropic GABAB receptors. Defects in GABAB signaling have been implicated in various neurological and mood disorders including spasticity, epilepsy, addiction and anxiety. GABAB receptor is a member of the class C G protein-coupled receptor (GPCR) family, which typically functions as a dimer and possesses large extracellular domains. Fundamental questions remain concerning the molecular mechanisms underlying activation and modulation of these class C receptors. The GABAB receptor is a heterodimer of GABAB1 and GABAB2 subunits and is modulated by the potassium channel tetramerization domain-containing (KCTD) protein auxiliary subunits. We are developing structural models for full-length GABAB receptor, its auxiliary subunits and their complexes with G-protein. Based on our structural analysis, we will determine the molecular association between GABAB receptor and KCTD, describe the conformations of full-length GABAB receptor in multiple functional states, and characterize the allosteric interaction between the GABAB receptor and G proteins. Together, these studies will advance our understanding of the molecular basis of GABA action in the brain, leading to the development of novel therapeutics for treating neurological diseases.