Kuhse J, Laube B, Magalei D, Betz H
Department of Neurochemistry, Max-Planck-Institute for Brain Research, Frankfurt, Federal Republic of Germany.
Neuron. 1993 Dec;11(6):1049-56. doi: 10.1016/0896-6273(93)90218-g.
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.
抑制性甘氨酸受体（GlyR）是一种由两种类型（α和β）的跨膜亚基组成的五聚体蛋白。α2亚基的低亲和力突变体与α1和β亚基在非洲爪蟾卵母细胞中共表达表明，由α1和α2多肽组装而成的GlyR含有可变的亚基比例，而α/β异源寡聚体具有不变的（3:2）化学计量比。对不同α/β嵌合构建体的分析表明，这种组装行为的差异是由受体亚基的N端细胞外区域介导的。α和β亚基之间不同残基的替换确定了决定亚基化学计量比的序列基序组合。
