Purification and characterization of the receptor for insulin-like growth factor I.
Purification and characterization of the receptor for insulin-like growth factor I.
复制标题
胰岛素样生长因子 I 受体的纯化和表征。
DOI：
10.1021/bi00367a032
复制
发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
Roth,RA
中科院分区：
文献类型：
--
作者：
Morgan,DO;Jarnagin,K;Roth,RA
斯坦福大学医学院药理学系，Stanford, California 94305，以及加州大学生理学和激素研究实验室系，San Francisco, California 94143 收稿日期：1986 年 3 月 25 日；修订稿于 1986 年 5 月 23 日收到摘要：通过单克隆抗受体抗体柱和麦芽凝集素柱的组合从大鼠肝细胞系 BRL-3A 中纯化胰岛素样生长因子 I (IGF-I) 的受体。在还原的十二烷基硫酸钠-聚丙烯酰胺凝胶上对这些受体制剂进行分析，产生了M、136K（亚基）以及Mr 85K和94K（β亚基）的蛋白质条带。这些受体制剂结合的 IGF-I 比胰岛素多 5 倍，并且未标记的 IGF-I 比胰岛素对两种标记配体的结合的抑制更有效。这些结果表明这些受体制剂主要含有IGF-I受体。人们发现这种高度纯化的受体制剂具有内在的激酶活性；低浓度的 IGF-I 刺激受体/3 亚基的自身磷酸化（0.4 nM IGF-I 的半最大刺激）。需要高出二十倍的胰岛素浓度才能产生相当水平的刺激。发现抑制胰岛素受体激酶的单克隆抗体能够抑制 IGF-I 受体激酶，其效力与抑制胰岛素受体的效力相同。相比之下，针对胰岛素受体其他部分的单克隆抗体只能很少识别 IGF-I 受体。对胰岛素和 IGF-I 受体的 V8 蛋白酶消化物的比较再次揭示了这两种受体结构的一些相似之处和一些差异。因此，IGF-I受体在结构、抗原性和功能上与胰岛素受体相似但不相同。 胰岛素样生长因子I (IGF-I)是一种多肽激素，其氨基酸序列与胰岛素原的氨基酸序列大约50%同源(Rinderknecht & Humbel, 1978)。高浓度的 IGF-I 还可以与胰岛素受体结合，并通过该受体引发生物反应，其效力约为胰岛素的 1%（Froesch 等，1985）。此外，各种细胞具有独特的 IGF-I 受体，其以高亲和力结合 IGF-I，以较弱的亲和力结合胰岛素 (Rechler & Nissley, 1985)。在体内，IGF-I 似乎是生长的主要调节剂，而胰岛素主要起到更急性代谢反应的调节剂的作用。然而，在细胞培养中，已经发现胰岛素通过其自身受体调节细胞生长，IGF-I 通过其独特受体调节急性代谢反应的例子（Froesch 等，1985；Rechler & Nissley，1985）。这
Department of Pharmacology, Stanford University School of Medicine, Stanford, California 94305, and Department of Physiology and Hormone Research Laboratory, University of California, San Francisco, California 94143 Received March 25, 1986; Revised Manuscript Received May 23, 1986 abstract: The receptor for insulin-like growth factor I (IGF-I) was purified from the rat liver cell line BRL-3A by a combination monoclonal anti-receptor antibody column and a wheat germ agglutinin column. Analyses of these receptor preparations on reduced sodium dodecyl sulfate-polyacrylamide gels yielded protein bands of M, 136K (a subunit) and Mr 85K and 94K (/? subunit). These receptor preparations bound 5 times more IGF-I than insulin, and the binding of both labeled ligands was more potently inhibited by unlabeled IGF-I than by insulin. These results indicate that these receptor preparations contained pre-dominantly the IGF-I receptor. This highly purified receptor preparation was found to possess an intrinsic kinase activity; autophosphorylation of the receptor/3 subunit was stimulated by low concentrations of IGF-I (half-maximal stimulation at 0.4 nM IGF-I). Twentyfold higher concentrations of insulin were required to give comparable levels of stimulation. Amonoclonal antibody that inhibits the insulin receptor kinase was found to inhibit the IGF-I receptor kinase with the same potency with which it inhibits the insulin receptor. In contrast, monoclonal antibodiesto other parts of the insulin receptor only poorly recognized the IGF-I receptor. A comparison of V8 protease digests of the insulin and IGF-I receptors again revealed some similarities and also some differences in the structures of these two receptors. Thus, the IGF-I receptor is structurally, antigenically, and functionally similar to but not identical with the insulin receptor.Insulin-like growth factor I (IGF-I) is a polypeptide hormone whose amino acid sequence is about 50% homologous to that of proinsulin (Rinderknecht & Humbel, 1978). IGF-I, at high concentrations, can also bind to the insulin receptor and elicit biological responses through this receptor with about 1% of the potency of insulin (Froesch et al., 1985). In addition, various cells have a distinct receptor for IGF-I which binds IGF-I with high affinity and insulin with a weaker affinity (Rechler & Nissley, 1985). In vivo, IGF-I appears to be a primary regulator of growth, whereas insulin primarily functions as a regulator of more acute metabolic responses. However, with cells inculture, examples have been found of insulin regulating cellular growth through its own receptor and IGF-I regulating acute metabolic responses through its distinct receptor (Froesch et al., 1985; Rechler & Nissley, 1985). The