Molecular Endocrinology, Vol 8, 1139-1146, Copyright © 1994 by Endocrine Society

ARTICLES

Insulin-like growth factor-1-mediated association of p85 phosphatidylinositol 3-kinase with pp 185: requirement of SH2 domains for in vivo interaction

D Altschuler, K Yamamoto and EG Lapetina
Division of Cell Biology, Burroughs Wellcome Company, Research Triangle Park, North Carolina 27709.

Insulin-like growth factor-I (IGF-1) stimulates the production of 3- phosphoinositides and increases the phosphatidylinositol 3-kinase activity that is immunoprecipitated by antiphosphotyrosine antibodies, a small portion of which are also associated with the IGF-1 receptor. In vitro reconstitution experiments showed that p85 associates with high affinity to the IGF-1 receptor and this interaction is mediated through the p85 SH2 groups. Moreover, in vitro, p85 is a substrate for the IGF-1 receptor tyrosine kinase activity. In this study, we analyzed the in vivo association of p85 with tyrosyl- phosphorylated proteins and its tyrosyl phosphorylation state, in response to IGF-1. After stimulation with IGF-1, the major tyrosylphosphorylated protein that was associated with p85 was a 185-kilodalton protein, identified as IRS- 1. Only a small fraction of p85 was associated with the IGF-1 receptor. In contrast, the PDGF receptor was the major protein associated with p85 upon stimulation. Neither ligand stimulated the tyrosyl phosphorylation of p85 in vivo. In order to determine whether the SH2 domains of p85 were involved in its association with p185 in vivo after IGF-1 stimulation, different SH2-constructs of p85 were expressed in COS-1 cells. After stimulation with IGF-1, the expressed SH2 proteins were immunoprecipitated with specific antibodies, and associated p185 was detected on Western blots. These results show that both the p85 N- SH2 and N+C-SH2 associate with IRS-1 after IGF-1 stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				S. D. Hester, D. C. Wolf, S. Nesnow, and S.-F. Thai Transcriptional Profiles in Liver from Rats Treated with Tumorigenic and Non-tumorigenic Triazole Conazole Fungicides: Propiconazole, Triadimefon, and Myclobutanil Toxicol Pathol, December 1, 2006; 34(7): 879 - 894. [Abstract] [Full Text] [PDF]

				R. X-D Song, P. Fan, W. Yue, Y. Chen, and R. J Santen Role of receptor complexes in the extranuclear actions of estrogen receptor {alpha} in breast cancer Endocr. Relat. Cancer, December 1, 2006; 13(Supplement_1): S3 - S13. [Abstract] [Full Text] [PDF]

				R. X.-D. Song and R. J. Santen Membrane Initiated Estrogen Signaling in Breast Cancer Biol Reprod, July 1, 2006; 75(1): 9 - 16. [Abstract] [Full Text] [PDF]

				C. A. Molloy, F. E. B. May, and B. R. Westley Insulin Receptor Substrate-1 Expression Is Regulated by Estrogen in the MCF-7 Human Breast Cancer Cell Line J. Biol. Chem., April 21, 2000; 275(17): 12565 - 12571. [Abstract] [Full Text] [PDF]

				A. Vogt, A. S. Wang, C. S. Johnson, J. P. Fabisiak, P. Wipf, and J. S. Lazo In Vivo Antitumor Activity and Induction of Insulin-Like Growth Factor-1-Resistant Apoptosis by SC-alpha alpha delta 9 J. Pharmacol. Exp. Ther., February 1, 2000; 292(2): 530 - 537. [Abstract] [Full Text]

				B. Valentinis, G. Romano, F. Peruzzi, A. Morrione, M. Prisco, S. Soddu, B. Cristofanelli, A. Sacchi, and R. Baserga Growth and Differentiation Signals by the Insulin-like Growth Factor 1 Receptor in Hemopoietic Cells Are Mediated through Different Pathways J. Biol. Chem., April 30, 1999; 274(18): 12423 - 12430. [Abstract] [Full Text] [PDF]

				B. Kim, H.-L. Cheng, B. Margolis, and E. L. Feldman Insulin Receptor Substrate 2 And Shc Play Different Roles In Insulin-like Growth Factor I Signaling J. Biol. Chem., December 18, 1998; 273(51): 34543 - 34550. [Abstract] [Full Text] [PDF]

				V. A. Blakesley, A. P. Koval, B. S. Stannard, A. Scrimgeour, and D. LeRoith Replacement of Tyrosine 1251 in the Carboxyl Terminus of the Insulin-like Growth Factor-I Receptor Disrupts the Actin Cytoskeleton and Inhibits Proliferation and Anchorage-independent Growth J. Biol. Chem., July 17, 1998; 273(29): 18411 - 18422. [Abstract] [Full Text] [PDF]

				I. Mothe, L. Delahaye, C. Filloux, S. Pons, M. F. White, and E. Van Obberghen Interaction of Wild Type and Dominant-Negative p55PIK Regulatory Subunit of Phosphatidylinositol 3-Kinase with Insulin-Like Growth Factor-1 Signaling Proteins Mol. Endocrinol., December 1, 1997; 11(13): 1911 - 1923. [Abstract] [Full Text] [PDF]