Yamamoto R, Shiba T, Tobe K, Shibasaki Y, Koshio O, Izumi T, Odawara M, Mikami Y, Matsuura N, Akanuma Y
Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
J Clin Endocrinol Metab. 1990 Apr;70(4):869-78. doi: 10.1210/jcem-70-4-869.
We report here a defect in tyrosine kinase activity of the insulin receptor from an insulin-resistant patient with acanthosis nigricans using cultured Ebstein-Barr virus (EBV)-transformed B-lymphocytes. As judged by affinity labeling and immunoblotting, the alpha- and beta-subunits of insulin receptors from the patient's lymphocytes exhibited the same mol wt as those from control subjects. Lectin-purified extracts from lymphocytes of the patient and the control subjects containing the same insulin-binding capacity were assayed for autophosphorylation and the ability to phosphorylate histone H2B. The degree of insulin-dependent autophosphorylation and the tyrosine kinase activity of the insulin receptor from the patient's lymphocytes were decreased to 15% and 13%, respectively, in a cell-free system. The insulin-dependent autophosphorylation of the insulin receptor was also impaired in intact EBV lymphocytes from the patient. Consistent with these results, we found that one of this patient's alleles had a mutation in which valine is substituted for Gly996, the third glycine in the conserved Gly-X-Gly-X-X-Gly motif in the kinase domain. Thus, it seems likely that the defect in tyrosine kinase activity of the insulin receptor cause the insulin resistance in this patient. The EBV lymphocyte can be a good system to detect genetically determined abnormalities in the insulin receptor.
我们在此报告，利用培养的爱泼斯坦 - 巴尔病毒（EBV）转化的B淋巴细胞，对一名患有黑棘皮病的胰岛素抵抗患者的胰岛素受体酪氨酸激酶活性缺陷进行了研究。通过亲和标记和免疫印迹判断，患者淋巴细胞胰岛素受体的α和β亚基与对照受试者的亚基具有相同的分子量。对来自患者和对照受试者淋巴细胞的凝集素纯化提取物进行了自磷酸化和磷酸化组蛋白H2B能力的检测，这些提取物具有相同的胰岛素结合能力。在无细胞系统中，患者淋巴细胞胰岛素受体的胰岛素依赖性自磷酸化程度和酪氨酸激酶活性分别降至15%和13%。在患者完整的EBV淋巴细胞中，胰岛素受体的胰岛素依赖性自磷酸化也受到损害。与这些结果一致，我们发现该患者的一个等位基因发生了突变，其中缬氨酸取代了激酶结构域中保守的Gly-X-Gly-X-X-Gly基序中的第三个甘氨酸（Gly996）。因此，胰岛素受体酪氨酸激酶活性缺陷似乎导致了该患者的胰岛素抵抗。EBV淋巴细胞可能是检测胰岛素受体遗传决定异常的良好系统。
