Structural and molecular determinants regulating mGluR5 surface expression
Structural and molecular determinants regulating mGluR5 surface expression
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DOI：
10.1016/j.neuropharm.2016.04.037
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发表时间：
2017-03-15
影响因子：
4.7
通讯作者：
Roche, Katherine W.
中科院分区：
文献类型：
--
作者：
Chang, Kai;Roche, Katherine W.
G蛋白偶联受体（GPCRs）转运至细胞膜是其发挥生物学功能的关键过程。代谢型谷氨酸受体（mGluRs; mGluR 1 -8）在整个CNS中表达，并且对于调节突触传递和可塑性是重要的。I组mGluR，包括mGluR 1和mGluR 5，具有长的细胞内C-末端尾，其含有多个蛋白结合结构域和用于磷酸化和ER保留的位点。我们现在已经调查了一些mGluR 5贩运到质膜的结构决定因素，通过研究一系列的截断和配体结合突变体。我们还利用mGluR 5的胞外结构域（ECD）之间的二聚体形成，并设计了一个基于ECD的表面结合试验，以评估含有各种截短或点突变的mGluR 5的二聚化和表面表达。我们发现，C末端是不是必不可少的mGluR 5表面表达。相比之下，第7跨膜结构域（TM 7）在异源细胞和神经元的表面表达中发挥着关键作用。此外，阻断配体结合的mGluR 5的ECD内的配体结合突变（Y 64 A/T174 A）损害神经元中mGluR 5的表面表达和二聚化。整个7 TM结构域和mGluR 5的C-末端尾的完整性对于稳定与ECD的二聚化也是重要的。因此，多个结构域调节二聚化和mGluR 5的运输。这篇文章是题为“代谢型谷氨酸受体，5年”的特刊的一部分。(C)2016由Elsevier Ltd.出版
Trafficking of G protein-coupled receptors (GPCRs) to the plasma membrane is a pivotal process to fulfill their biological functions. Metabotropic glutamate receptors (mGluRs; mGluR1-8) are expressed throughout the CNS and are important for modulating synaptic transmission and plasticity. Group I mGluRs, including mGluR1 and mGluR5, have long intracellular C-terminal tails containing multiple protein binding domains and sites for phosphorylation and ER retention. We have now investigated some of the structural determinants for mGluR5 trafficking to the plasma membrane by studying a series of truncations and ligand binding mutants. We also take advantage of dimer formation between the extracellular domain (ECD) of mGluR5 and design an ECD based surface-binding assay to evaluate dimerization and surface expression of mGluR5 containing various truncations or point mutations. We found that the C terminus is not essential for mGluR5 surface expression. In contrast, the 7th trans membrane domain (TM7) plays a critical role in its surface expression in both heterologous cells and neurons. Furthermore, a ligand binding mutation within the ECD of mGluR5 (Y64A/T174A) that blocks ligand binding impairs both surface expression and dimerization of mGluR5 in neurons. The integrity of both the whole 7TM domain and the C- terminal tail of mGluR5 are also important for stabilizing dimerization with the ECD. Thus multiple domains regulate dimerization and trafficking of mGluR5.This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'. (C) 2016 Published by Elsevier Ltd.