Metabotropic Glutamate Receptor 5 Is a Disulfide-linked Dimer

作者：Carmelo Romano, Wan-Lin Yang, Karen L. O’Malley · 发表于：Journal of Biological Chemistry · 年份：1996 · DOI：10.1074/jbc.271.45.28612 · 被引用次数：538 · 研究领域：Neuroscience and Neuropharmacology Research、Receptor Mechanisms and Signaling、Nicotinic Acetylcholine Receptors Study

The sequences of the metabotropic glutamate receptors (mGluRs) show little homology with other members of the G protein-coupled receptor family and exhibit several distinctive features, including a large N-terminal extracellular domain with 17 cysteines in conserved positions. Here we demonstrate that mGluR5, as well as other mGluRs, behave as species approximately twice as large as expected from their sequence, but reducing conditions cause a decrease to the predicted molecular mass. Co-immunoprecipitation experiments using wild type and epitope-tagged receptors demonstrate that this is due to specific, disulfide-dependent dimerization of the receptor. The intermolecular disulfide that mediates dimerization occurs in the extracellular domain, within about 17 kDa from the N terminus.