Defect of receptor-cyclase coupling protein in psudohypoparathyroidism.
Defect of receptor-cyclase coupling protein in psudohypoparathyroidism.
复制标题
假性甲状旁腺功能减退症中受体环化酶偶联蛋白的缺陷。
DOI：
10.1097/00006254-198102000-00017
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
H. Bourne
中科院分区：
文献类型：
--
作者：
Z. Farfel;A. Brickman;H. Kaslow;H. Bourne
激素敏感性腺苷酸环化酶含有一种最近发现的蛋白质成分，该成分是激素和鸟嘌呤核苷酸刺激环AMP合成所必需的;该成分可能将膜受体与环化酶偶联。我们研究了这种蛋白质（称为“N”）在红细胞膜的患者假性甲状旁腺功能减退症，使用蛋白质的生化活性和其敏感性的放射性标记的存在下，[32 P]NAD和霍乱毒素的测定。通过这两种检测，蛋白质的活性降低了40%至50%，在红细胞的5个10例I型pseudopathyroidosis相比，与正常和甲状旁腺功能减退的主题和一个患者与II型pseudopathyroidosis。如果其他组织中N蛋白的活性降低，这种缺陷可能会导致假性甲状旁腺功能减退症的靶器官对甲状旁腺激素和其他通过环AMP起作用的激素产生抵抗。5例I型假性甲状旁腺功能减退症患者的红细胞，都在一个家庭，没有表现出缺陷的N蛋白的活性，这个家庭的生化缺陷仍然不确定。
Hormone-sensitive adenylate cyclase contains a recently discovered protein component that is required for stimulation of cyclic AMP synthesis by hormones and guanine nucleotides; the component presumably couples the membrane receptor to the cyclase. We studied this protein (termed "N") in erythrocyte membranes of patients with pseudohypoparathyroidism, using assays of the protein's biochemical activity and of its susceptibility to radiolabeling in the presence of [32P]NAD and cholera toxin. By both assays, the protein's activity was reduced by 40 to 50 per cent in erythrocytes of five of 10 patients with Type I pseudohypoparathyroidism as compared with those of normal and hypoparathyroid subjects and one patient with Type II pseudohypoparathyroidism. If activity of the N protein is reduced in other tissues, this deficiency could cause the resistance of target organs in pseudohypoparathyroidism to parathyroid hormone and other hormones that work via cyclic AMP. Erythrocytes of five patients with Type I pseudohypoparathyroidism, all in one family, showed no defect in activity of the N protein; the biochemical defect of this family remains undefined.