Abstract
It is speculated that the transmission of an insulin signal across the plasma membrane of cells occurs through activation of the tyrosine-specific receptor kinase, autophosphorylation of the receptor, and subsequent phosphorylation of unidentified substrates in the cell. In an attempt to identify possible substrates, we labeled intact rat fat cells with [32P]orthophosphate and used an antiphosphotyrosine antibody to identify proteins that become phosphorylated on tyrosine residues in an insulin-stimulated way. In the membrane fraction of the fat cells, we found, in addition to the 95-kDa beta-subunit of the receptor, a 46-kDa phosphoprotein that is phosphorylated exclusively on tyrosine residues. This protein is not immunoprecipitated by antibodies against different regions of the insulin receptor and its HPLC tryptic peptide map is different from the tryptic peptide map of the insulin receptor, suggesting that it is not derived from the receptor beta-subunit. Insulin stimulates the tyrosine phosphorylation of the 46-kDa protein within 150 sec in the intact cell 3- to 4-fold in a dose-dependent way at insulin concentrations between 0.5 nM and 100 nM. The insulin effect starts after 30 sec, is maximal at 150 sec, and declines to almost basal values by 5 min. Furthermore, the antiphosphotyrosine antibody precipitated at least five proteins in the soluble fraction of the fat cell. Insulin (0.5 nM, 100 nM) stimulated within 2 min the 32P incorporation into a 116-kDa band, a 62-kDa band, and three bands between 45 kDa and 50 kDa 2- to 10-fold. We suggest that the 46-kDa membrane protein and possibly also the soluble proteins are endogenous substrates of the receptor tyrosine kinase in fat cells and that their phosphorylation is an early step in insulin signal transmission.
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Ahmad Z., DePaoli-Roach A. A., Roach P. J. Purification and characterization of a rabbit liver calmodulin-dependent protein kinase able to phosphorylate glycogen synthase. J Biol Chem. 1982 Jul 25;257(14):8348–8355. [PubMed] [Google Scholar]
- Avruch J., Leone G. R., Martin D. B. Identification and subcellular distribution of adipocyte peptides and phosphopeptides. J Biol Chem. 1976 Mar 10;251(5):1505–1510. [PubMed] [Google Scholar]
- Avruch J., Nemenoff R. A., Blackshear P. J., Pierce M. W., Osathanondh R. Insulin-stimulated tyrosine phosphorylation of the insulin receptor in detergent extracts of human placental membranes. Comparison to epidermal growth factor-stimulated phosphorylation. J Biol Chem. 1982 Dec 25;257(24):15162–15166. [PubMed] [Google Scholar]
- Belsham G. J., Brownsey R. W., Denton R. M. Reversibility of the insulin-stimulated phosphorylation of ATP citrate lyase and a cytoplasmic protein of subunit Mr 22000 in adipose tissue. Biochem J. 1982 Apr 15;204(1):345–352. doi: 10.1042/bj2040345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Benjamin W. B., Clayton N. L. Action of insulin and catecholamines on the phosphorylation of proteins associated with the cytosol, membranes, and "fat cake" of rat fat cells. J Biol Chem. 1978 Mar 10;253(5):1700–1709. [PubMed] [Google Scholar]
- Grunberger G., Zick Y., Roth J., Gorden P. Protein kinase activity of the insulin receptor in human circulating and cultured mononuclear cells. Biochem Biophys Res Commun. 1983 Sep 15;115(2):560–566. doi: 10.1016/s0006-291x(83)80181-8. [DOI] [PubMed] [Google Scholar]
- Haring H. U., Kasuga M., White M. F., Crettaz M., Kahn C. R. Phosphorylation and dephosphorylation of the insulin receptor: evidence against an intrinsic phosphatase activity. Biochemistry. 1984 Jul 3;23(14):3298–3306. doi: 10.1021/bi00309a028. [DOI] [PubMed] [Google Scholar]
- Haring H. U., White M. F., Kahn C. R., Ahmad Z., DePaoli-Roach A. A., Roach P. J. Interaction of the insulin receptor kinase with serine/threonine kinases in vitro. J Cell Biochem. 1985;28(2):171–182. doi: 10.1002/jcb.240280209. [DOI] [PubMed] [Google Scholar]
- Haring H. U., White M. F., Kahn C. R., Kasuga M., Lauris V., Fleischmann R., Murray M., Pawelek J. Abnormality of insulin binding and receptor phosphorylation in an insulin-resistant melanoma cell line. J Cell Biol. 1984 Sep;99(3):900–908. doi: 10.1083/jcb.99.3.900. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Häring H. U., Biermann E., Kemmler W. Coupling of insulin binding and insulin action on glucose transport in fat cells. Am J Physiol. 1981 May;240(5):E556–E565. doi: 10.1152/ajpendo.1981.240.5.E556. [DOI] [PubMed] [Google Scholar]
- Häring H. U., Kasuga M., Kahn C. R. Insulin receptor phosphorylation in intact adipocytes and in a cell-free system. Biochem Biophys Res Commun. 1982 Oct 29;108(4):1538–1545. doi: 10.1016/s0006-291x(82)80082-x. [DOI] [PubMed] [Google Scholar]
- Häring H., Kirsch D., Obermaier B., Ermel B., Machicao F. Tumor-promoting phorbol esters increase the Km of the ATP-binding site of the insulin receptor kinase from rat adipocytes. J Biol Chem. 1986 Mar 15;261(8):3869–3875. [PubMed] [Google Scholar]
- Jacobs S., Sahyoun N. E., Saltiel A. R., Cuatrecasas P. Phorbol esters stimulate the phosphorylation of receptors for insulin and somatomedin C. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6211–6213. doi: 10.1073/pnas.80.20.6211. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Karnieli E., Zarnowski M. J., Hissin P. J., Simpson I. A., Salans L. B., Cushman S. W. Insulin-stimulated translocation of glucose transport systems in the isolated rat adipose cell. Time course, reversal, insulin concentration dependency, and relationship to glucose transport activity. J Biol Chem. 1981 May 25;256(10):4772–4777. [PubMed] [Google Scholar]
- Kasuga M., Fujita-Yamaguchi Y., Blithe D. L., Kahn C. R. Tyrosine-specific protein kinase activity is associated with the purified insulin receptor. Proc Natl Acad Sci U S A. 1983 Apr;80(8):2137–2141. doi: 10.1073/pnas.80.8.2137. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kasuga M., Karlsson F. A., Kahn C. R. Insulin stimulates the phosphorylation of the 95,000-dalton subunit of its own receptor. Science. 1982 Jan 8;215(4529):185–187. doi: 10.1126/science.7031900. [DOI] [PubMed] [Google Scholar]
- Kasuga M., Zick Y., Blith D. L., Karlsson F. A., Häring H. U., Kahn C. R. Insulin stimulation of phosphorylation of the beta subunit of the insulin receptor. Formation of both phosphoserine and phosphotyrosine. J Biol Chem. 1982 Sep 10;257(17):9891–9894. [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Lawrence J. C., Jr, Hiken J. F., Inkster M., Scott C. W., Mumby M. C. Insulin stimulates the generation of an adipocyte phosphoprotein that is isolated with a monoclonal antibody against the regulatory subunit of bovine heart cAMP-dependent protein kinase. Proc Natl Acad Sci U S A. 1986 Jun;83(11):3649–3653. doi: 10.1073/pnas.83.11.3649. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lienhard G. E., Kim H. H., Ransome K. J., Gorga J. C. Immunological identification of an insulin-responsive glucose transporter. Biochem Biophys Res Commun. 1982 Apr 14;105(3):1150–1156. doi: 10.1016/0006-291x(82)91090-7. [DOI] [PubMed] [Google Scholar]
- Machicao F., Urumow T., Wieland O. H. Evidence for phosphorylation of actin by the insulin receptor-associated protein kinase from human placenta. FEBS Lett. 1983 Oct 31;163(1):76–80. doi: 10.1016/0014-5793(83)81167-3. [DOI] [PubMed] [Google Scholar]
- Oesch B., Westaway D., Wälchli M., McKinley M. P., Kent S. B., Aebersold R., Barry R. A., Tempst P., Teplow D. B., Hood L. E. A cellular gene encodes scrapie PrP 27-30 protein. Cell. 1985 Apr;40(4):735–746. doi: 10.1016/0092-8674(85)90333-2. [DOI] [PubMed] [Google Scholar]
- Pang D. T., Sharma B. R., Shafer J. A. Purification of the catalytically active phosphorylated form of insulin receptor kinase by affinity chromatography with O-phosphotyrosyl-binding antibodies. Arch Biochem Biophys. 1985 Oct;242(1):176–186. doi: 10.1016/0003-9861(85)90491-6. [DOI] [PubMed] [Google Scholar]
- Petruzzelli L. M., Ganguly S., Smith C. J., Cobb M. H., Rubin C. S., Rosen O. M. Insulin activates a tyrosine-specific protein kinase in extracts of 3T3-L1 adipocytes and human placenta. Proc Natl Acad Sci U S A. 1982 Nov;79(22):6792–6796. doi: 10.1073/pnas.79.22.6792. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rees-Jones R. W., Taylor S. I. An endogenous substrate for the insulin receptor-associated tyrosine kinase. J Biol Chem. 1985 Apr 10;260(7):4461–4467. [PubMed] [Google Scholar]
- Sadoul J. L., Peyron J. F., Ballotti R., Debant A., Fehlmann M., Van Obberghen E. Identification of a cellular 110 000-Da protein substrate for the insulin-receptor kinase. Biochem J. 1985 May 1;227(3):887–892. doi: 10.1042/bj2270887. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Takayama S., White M. F., Lauris V., Kahn C. R. Phorbol esters modulate insulin receptor phosphorylation and insulin action in cultured hepatoma cells. Proc Natl Acad Sci U S A. 1984 Dec;81(24):7797–7801. doi: 10.1073/pnas.81.24.7797. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ullrich A., Bell J. R., Chen E. Y., Herrera R., Petruzzelli L. M., Dull T. J., Gray A., Coussens L., Liao Y. C., Tsubokawa M. Human insulin receptor and its relationship to the tyrosine kinase family of oncogenes. 1985 Feb 28-Mar 6Nature. 313(6005):756–761. doi: 10.1038/313756a0. [DOI] [PubMed] [Google Scholar]
- Van Obberghen E., Kowalski A. Phosphorylation of the hepatic insulin receptor: stimulating effect of insulin on intact cells and in a cell-free system. FEBS Lett. 1982 Jul 5;143(2):179–182. doi: 10.1016/0014-5793(82)80094-x. [DOI] [PubMed] [Google Scholar]
- Van Obberghen E., Rossi B., Kowalski A., Gazzano H., Ponzio G. Receptor-mediated phosphorylation of the hepatic insulin receptor: evidence that the Mr 95,000 receptor subunit is its own kinase. Proc Natl Acad Sci U S A. 1983 Feb;80(4):945–949. doi: 10.1073/pnas.80.4.945. [DOI] [PMC free article] [PubMed] [Google Scholar]
- White M. F., Haring H. U., Kasuga M., Kahn C. R. Kinetic properties and sites of autophosphorylation of the partially purified insulin receptor from hepatoma cells. J Biol Chem. 1984 Jan 10;259(1):255–264. [PubMed] [Google Scholar]
- White M. F., Takayama S., Kahn C. R. Differences in the sites of phosphorylation of the insulin receptor in vivo and in vitro. J Biol Chem. 1985 Aug 5;260(16):9470–9478. [PubMed] [Google Scholar]
- Yu K. T., Czech M. P. Tyrosine phosphorylation of the insulin receptor beta subunit activates the receptor-associated tyrosine kinase activity. J Biol Chem. 1984 Apr 25;259(8):5277–5286. [PubMed] [Google Scholar]
- Zick Y., Kasuga M., Kahn C. R., Roth J. Characterization of insulin-mediated phosphorylation of the insulin receptor in a cell-free system. J Biol Chem. 1983 Jan 10;258(1):75–80. [PubMed] [Google Scholar]
- Zick Y., Rees-Jones R. W., Taylor S. I., Gorden P., Roth J. The role of antireceptor antibodies in stimulating phosphorylation of the insulin receptor. J Biol Chem. 1984 Apr 10;259(7):4396–4400. [PubMed] [Google Scholar]




