Functional expression of insulin receptor substrate-1 is required for insulin-stimulated mitogenic signaling

• Published in: The Journal of biological chemistry 1993-10, Vol.268 (30), p.22231-22234
• Main Authors: Waters, S.B., Yamauchi, K, Pessin, J.E.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Biological and medical sciences; Cell Division - drug effects; Cell physiology; CHO Cells; Clone Cells; Cricetinae; Fundamental and applied biological sciences. Psychology; Gene Expression; Insulin - pharmacology; Insulin Receptor Substrate Proteins; Kinetics; Luciferases - biosynthesis; Luciferases - metabolism; Mitogens - pharmacology; Molecular and cellular biology; Molecular Sequence Data; Phosphatidylinositol 3-Kinases; Phosphoproteins - biosynthesis; Phosphoproteins - metabolism; Phosphotransferases (Alcohol Group Acceptor) - metabolism; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - metabolism; RNA, Antisense - biosynthesis; Signal transduction; Signal Transduction - drug effects; Transcription, Genetic - drug effects; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)41513-X

To examine the role of the insulin receptor substrate-1 (IRS-1) in mediating insulin biological responsiveness, we generated Chinese hamster ovary cell lines expressing antisense IRS-1 RNA. These cells displayed morphological alterations as well as markedly reduced growth rates compared to the parental cells. Furthermore, the antisense IRS-1 cell lines had decreased insulin-stimulated IRS-1 tyrosine phosphorylation, reduced phosphatidylinositol 3-kinase activation, and decreased thymidine incorporation relative to the parental cell line. Insulin-dependent transcriptional regulation of a serum response element/luciferase reporter construct (SRE-Luc) was also reduced in the antisense IRS-1-expressing cell lines. However, co-transfection with a plasmid directing the expression of rat IRS-1 fully restored insulin-stimulated SRE-Luc activity in the IRS-1 antisense cell lines. Thus, the inhibition in insulin signaling was a specific effect of decreased IRS-1 tyrosine phosphorylation. Taken together, these data demonstrate that insulin regulation of mitogenic signaling requires the functional expression of IRS-1 and documents its central importance in the insulin intracellular signaling pathway.