title: Transmembrane region of N-methyl-D-aspartate receptor (NMDAR) subunit is required for receptor subunit assembly.
abstract: N-Methyl-D-aspartate receptors (NMDARs), one of three main classes of ionotropic glutamate receptors, play major roles in synaptic plasticity, synaptogenesis, and excitotoxicity. Unlike non-NMDA receptors, NMDARs are thought to comprise obligatory heterotetrameric complexes mainly composed of GluN1 and GluN2 subunits. When expressed alone in heterogenous cells, such as HEK293 cells, most of the NMDAR subunits can neither leave the endoplasmic reticulum (ER) nor be expressed in the cell membrane because of the ER retention signals. Only when NMDARs are heteromerically assembled can the ER retention signals be masked and NMDARs be expressed in the surface membrane. However, the mechanisms underlying NMDAR assembly remain poorly understood. To identify regions in subunits that mediate this assembly, we made a series of truncated or chimeric cDNA constructs. Using FRET measurement in living cells combined with immunostaining and coimmunoprecipitation analysis, we examined the assembly-determining domains of NMDAR subunits. Our results indicate that the transmembrane region of subunits is necessary for the assembly of NMDAR subunits, both for the homodimer and the heteromer.
authors.affiliation: Department of Neurobiology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.
authors.forename: Jing-yuan
authors.initials: JY
authors.lastname: Cao
authors.forename: Shuang
authors.initials: S
authors.lastname: Qiu
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Jie-jie
authors.initials: JJ
authors.lastname: Wang
authors.forename: Xiao-min
authors.initials: XM
authors.lastname: Zhang
authors.forename: Jian-hong
authors.initials: JH
authors.lastname: Luo
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D019281:Dimerization; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D010957:Plasmids; D016194:Receptors, N-Methyl-D-Aspartate / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D016194:Receptors, N-Methyl-D-Aspartate