An assessment of human insulin receptor phosphorylation and exogenous kinase activity following deletion of 69 residues from the carboxyl-terminus of the receptor beta-subunit.
An assessment of human insulin receptor phosphorylation and exogenous kinase activity following deletion of 69 residues from the carboxyl-terminus of the receptor beta-subunit.
复制标题
删除受体 β 亚基羧基末端 69 个残基后，评估人胰岛素受体磷酸化和外源激酶活性。
DOI：
10.1016/0006-291x(92)92353-y
复制
发表时间：
1992
影响因子：
3.1
通讯作者：
Ellis,L
中科院分区：
文献类型：
--
作者：
Tavaré,JM;Ramos,P;Ellis,L
突变的人胰岛素受体羧基末端缺失69个氨基酸(前受体残基1287-1355)，在瞬时转染的COS细胞中以稳定蛋白的形式表达。我们发现，在完整的细胞中，该突变对核心酪氨酸1158、1163和1163的磷酸化依赖于胰岛素。正如预期的那样，该突变体中没有羧基末端的β亚单位磷酸化位点(丝氨酸1305/6、酪氨酸132834和苏氨酸1348)。然而，两种主要的胰岛素刺激丝氨酸磷酸肽仍然存在。在完整细胞中，胰岛素仅通过截断的受体∼1.9倍刺激外源底物磷酸化(参见这些细胞中野生型受体的∼1.9倍)，这是∼基础胰岛素非依赖性激酶活性增加4.8倍的结果。
A mutant human insulin receptor with a carboxyl-terminal deletion of 69 amino acids (proreceptor residues 1287–1355) is expressed as a stable protein in transiently transfected COS cells. We find that in intact cells this mutant is phosphorylated in an insulin-dependent manner on core tyrosines 1158, 1163 and 1163. As expected, the carboxyl-terminal β-subunit phosphorylation sites (serines 1305/6, tyrosines 1328 34 and threonine 1348) are absent from this mutant. However, the two major insulin-stimulated serine phosphopeptides remain. In intact cells, insulin stimulates exogenous substrate phosphorylation by the truncated receptor only∼ 1.9-fold (cf.∼ 1.9-fold for the wild-type receptor in these cells), a consequence of a∼ 4.8-fold elevation in basal insulin-independent kinase activity.