Assembly of the inhibitory glycine receptor: identification of amino acid sequence motifs governing subunit stoichiometry.
The inhibitory glycine receptor (GlyR) is a pentameric protein composed of two types (alpha and beta) of membrane-spanning subunits. Coexpression in Xenopus oocytes of a low affinity mutant of the alpha 2 subunit with the alpha 1 and beta subunits indicated that GlyRs assembled from alpha 1 and alpha 2 polypeptides contain variable subunit ratios, whereas alpha/beta hetero-oligomers have an invariant (3:2) stoichiometry. Analysis of different alpha/beta chimeric constructs revealed that this difference in assembly behavior is mediated by the N-terminal extracellular regions of the receptor subunits. Substitution of residues diverging between the alpha and beta subunits identified combinations of sequence motifs determining subunit stoichiometry.
Kuhse
J
J
Department of Neurochemistry, Max-Planck-Institute for Brain Research, Frankfurt, Federal Republic of Germany.
Laube
B
B
Magalei
D
D
Betz
H
H
D000595:Amino Acid Sequence; D000818:Animals; D017931:DNA Primers; D005260:Female; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008564:Membrane Potentials / Q000502:physiology; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009865:Oocytes / Q000502:physiology; D016133:Polymerase Chain Reaction; D018075:RNA, Complementary / Q000378:metabolism; D051381:Rats; D018009:Receptors, Glycine / Q000096:biosynthesis* / Q000378:metabolism / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D014981:Xenopus
D017931:DNA Primers; D046911:Macromolecular Substances; D018075:RNA, Complementary; D018009:Receptors, Glycine; D011993:Recombinant Fusion Proteins