SITE-DIRECTED MUTAGENESIS OF THE CONSERVED N-GLYCOSYLATION SITE ON THE NICOTINIC ACETYLCHOLINE-RECEPTOR SUBUNITS
SITE-DIRECTED MUTAGENESIS OF THE CONSERVED N-GLYCOSYLATION SITE ON THE NICOTINIC ACETYLCHOLINE-RECEPTOR SUBUNITS
复制标题
DOI：
10.1016/0169-328x(91)90016-q
复制
发表时间：
1991-08-01
期刊：
影响因子：
--
通讯作者：
SUMIKAWA, K
中科院分区：
文献类型：
--
作者：
GEHLE, VM;SUMIKAWA, K
通过在非洲爪哇卵母细胞中表达定点突变的亚基，研究了电鱼乙酰胆碱受体(AChR)各亚基上保守的N-糖基化位点在该受体的生物发生和功能中的作用。不同的突变亚基引起不同的影响。最显著的影响是突变的伽马亚基，当它与阿尔法、贝塔和德尔塔亚基共表达时，导致所有亚基的降解。其他亚基的N-糖基化似乎有助于亚基的稳定性和/或受体有效地插入质膜，但不是组装所必需的。含有突变的α-亚基的AChRs在质膜上形成功能离子通道，其活性可被α-银环蛇毒素(α-BuTX)阻断。因此，在保守的N-糖基化位点上附着碳水化合物部分并不是形成ACh和α-BuTX结合位点的绝对要求。
The role of the conserved N-glycosylation site on each subunit of the Torpedo acetylcholine receptor (AChR) in the biogenesis and function of the receptor was examined by expressing site-directed mutant subunits in Xenopus oocytes. Different mutant subunits caused different effects. The most striking effect was seen with the mutant gamma-subunit which, when co-expressed with alpha, beta, and delta-subunits, caused degradation of all the subunits. N-Glycosylation of the other subunits appears to contribute to stability of the subunits and/or efficient insertion of the receptor into the plasma membrane, but is not required for assembly. The AChRs containing the mutant alpha-subunit formed functional ion channels in the plasma membrane and their activity could be blocked by alpha-bungarotoxin (alpha-BuTX). Thus, attachment of a carbohydrate moiety at the conserved N-glycosylation site is not an absolute requirement for the formation of ACh and alpha-BuTX binding sites.