Wilden P A, Broadway D
Department of Pharmacology, University of Missouri-Columbia, School of Medicine 65212, USA.
J Cell Biochem. 1995 Jul;58(3):279-91. doi: 10.1002/jcb.240580303.
To analyze the mechanism of action of the insulinomimetic agents H2O2, vanadate, and pervanadate (H2O2 and vanadate), CHO cells or CHO cells that overexpress wild-type or mutant insulin receptor and/or the insulin receptor substrate (IRS-1) were used. H2O2 or vanadate treatment alone had little or no effect on tyrosine phosphorylation of cellular proteins; however, pervanadate treatment dramatically enhanced tyrosine phosphorylation of a number of proteins including the insulin receptor and IRS-1. However, the insulin receptor and IRS-1 coimmunoprecipitate from insulin-treated but not from pervanadate-treated cells. Pervanadate-induced tyrosine phosphorylation of the insulin receptor led to an increase in insulin receptor tyrosine kinase activity toward IRS-1 in vivo and IRS-1 peptides in vitro equal to that induced by insulin treatment. Pervanadate-enhanced phosphorylation of IRS-1 led to a fifteenfold increase in IRS-1-associated phosphatidylinositol (PtdIns) 3-kinase activity. However, insulin receptor-associated PtdIns 3-kinase activity from pervanadate-treated cells was not detectable, while insulin receptor-associated PtdIns 3-kinase activity from insulin-treated cells was 20% of the IRS-1-associated activity. Thus, pervanadate but not H2O2 or vanadate alone under these conditions mimics many of insulin actions, but pervanadate treatment does not induce insulin receptor/IRS-1 association.
为分析类胰岛素剂过氧化氢（H₂O₂）、钒酸盐和过氧钒酸盐（H₂O₂与钒酸盐）的作用机制，使用了CHO细胞或过表达野生型或突变型胰岛素受体和/或胰岛素受体底物（IRS-1）的CHO细胞。单独用H₂O₂或钒酸盐处理对细胞蛋白的酪氨酸磷酸化几乎没有影响；然而，过氧钒酸盐处理显著增强了包括胰岛素受体和IRS-1在内的多种蛋白的酪氨酸磷酸化。但是，胰岛素受体和IRS-1可从胰岛素处理的细胞中共免疫沉淀，却不能从过氧钒酸盐处理的细胞中共免疫沉淀。过氧钒酸盐诱导的胰岛素受体酪氨酸磷酸化导致体内胰岛素受体对IRS-1以及体外对IRS-1肽的酪氨酸激酶活性增加，与胰岛素处理诱导的活性相当。过氧钒酸盐增强的IRS-1磷酸化导致与IRS-1相关的磷脂酰肌醇（PtdIns）3-激酶活性增加了15倍。然而，过氧钒酸盐处理的细胞中未检测到与胰岛素受体相关的PtdIns 3-激酶活性，而胰岛素处理的细胞中与胰岛素受体相关的PtdIns 3-激酶活性是与IRS-1相关活性的20%。因此，在这些条件下，过氧钒酸盐而非单独的H₂O₂或钒酸盐模拟了许多胰岛素的作用，但过氧钒酸盐处理不会诱导胰岛素受体/IRS-1结合。
