Subtype-specific assembly of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor subunits is mediated by their n-terminal domains.
Glutamate receptors (GluR) are oligomeric protein complexes formed by the assembly of four or perhaps five subunits. The rules that govern the selectivity of this process are not well understood. Here, we expressed combinations of subunits from two related GluR subfamilies in COS7 cells, the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainate receptors. By co-immunoprecipitation experiments, we assessed the ability of AMPA receptor subunits to assemble into multimeric complexes. Subunits GluR1-4 associated with indistinguishable efficiency with each other, whereas the kainate receptor subunits GluR6 and 7 showed a much lower degree of association with GluR1. Using chimeric receptors and truncation fragments of subunits, we show that this assembly specificity is determined by N-terminal regions of these subunits and that the most N-terminal domain of GluR2 together with a membrane anchor efficiently associates with GluR1.
Leuschner
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WD
Max-Planck-Institut für Entwicklungsbiologie, Abteilung Biochemie, Spemannstrasse 35, D-72076 Tübingen, Germany.
Hoch
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D000818:Animals; D000918:Antibody Specificity; D001665:Binding Sites; D019556:COS Cells; D002451:Cell Compartmentation; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D018091:Receptors, AMPA / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D018092:Kainic Acid Receptors / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D010446:Peptide Fragments; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D011993:Recombinant Fusion Proteins; C104723:glutamate receptor ionotropic, AMPA 3; C104724:glutamate receptor ionotropic, AMPA 4; C104722:glutamate receptor ionotropic, AMPA 2