Regulation of expression and function of muscarinic receptors.
Regulation of expression and function of muscarinic receptors.
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毒蕈碱受体表达和功能的调节。
DOI：
10.1016/0024-3205(93)90298-h
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发表时间：
1993
期刊：
影响因子：
6.1
通讯作者：
Nathanson,NM
中科院分区：
文献类型：
--
作者：
Habecker,BA;Tietje,KM;vanKoppen,CJ;Creason,SA;Goldman,PS;Migeon,JC;Parenteau,LA;Nathanson,NM
已用几种不同的系统研究了M胆碱受体的表达和功能的调节。通过定点突变去除糖基化位点，然后在稳定表达的细胞中表达，研究了m2受体的糖基化作用。结果表明，糖基化不是细胞表面受体的合成和出现所必需的，也不是受体偶联到腺苷环化酶活性抑制所必需的。定点突变也被用来证明M2受体羧基末端结构域中的单个半胱氨酸不是受体功能所必需的，因此不太可能建立一个模型，表明该半胱氨酸在受体功能中需要棕榈酰化。利用分子克隆技术对鸡胚胎心脏中表达的M受体进行鉴定。初步鉴定了两个基因，它们在鸡心脏中表达，分别对应于鸡的M2和M4受体。利用聚合酶链式反应鉴定低丰度的mRNAs的实验表明，至少有一个附加受体基因在鸡的心脏中表达。在细胞培养中，M受体的激活降低了编码cm2和cm4受体的mRNA水平。这可能是由于mAChR介导的腺酰环化酶抑制和mAChR介导的磷脂酶C刺激导致的基因转录减少所致。阐明调控M胆碱型乙酰胆碱受体(MAChR)表达和功能的因素对于理解胆碱能传递的机制具有明显的重要意义。在这一章中，我们将介绍野生型和突变型M受体的表达和功能，鸡心脏表达的mAChR的分子特征，以及M受体激活对mAChR基因表达的调控。
The regulation of expression and function of the muscarinic acetylcholine receptor has been studied using several different systems. The role of glycosylation of the m2 receptor was examined by removal of glycosylation sites using site-directed mutagenesis followed by expression in stably transfected cells. The results demonstrated that glycosylation was not required for the synthesis and appearance of the receptors on the cell surface or for the coupling of the receptors to inhibition of adenylyl cyclase activity. Site-directed mutagenesis also was used to demonstrate that the single cysteine in the carboxy terminal domain of the m2 receptor was not required for receptor function, thus rendering unlikely a model suggesting a requirement for palmitoylation of this cysteine in receptor function. The muscarinic receptors expressed in embryonic chick heart were identified by molecular cloning. Two genes were initially identified which are expressed in chick heart and correspond to the chick m2 and m4 receptors. Experiments using the polymerase chain reaction to identify low abundance mRNAs indicate that at least one addition receptor gene is expressed in chick heart. In cell culture, activation of the muscarinic receptors decreases the levels of mRNA encoding the cm2 and cm4 receptors. This probably results from decreased gene transcription due to both mAChR-mediated inhibition of adenylyl cyclase and mAChR-mediated stimulation of phospholipase C.The elucidation of the factors which regulate the expression and function of muscarinic acetylcholine receptors (mAChR) is of obvious importance in understanding the mechanisms underlying cholinergic transmission. In this chapter, we will describe studies on the expression and function of wild type and mutant muscarinic receptors, the molecular characterization of mAChR expressed in chick heart, and the regulation of mAChR gene expression in response to muscarinic receptor activation.