AJP - Endo Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab 266: E486-E494, 1994;
0193-1849/94 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lamphere, L.
Right arrow Articles by Lienhard, G. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lamphere, L.
Right arrow Articles by Lienhard, G. E.

AJP - Endocrinology and Metabolism, Vol 266, Issue 3 E486-E494, Copyright © 1994 by American Physiological Society

ARTICLES

Activation of PI 3-kinase in 3T3-L1 adipocytes by association with insulin receptor substrate-1

L. Lamphere, C. L. Carpenter, Z. F. Sheng, R. G. Kallen and G. E. Lienhard
Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755.

Insulin treatment of adipocytes causes the rapid phosphorylation of the insulin receptor substrate-1 (IRS-1) on tyrosine. The phosphotyrosine [Tyr(P)] form of IRS-1 then complexes with the enzyme phosphatidylinositol (PI) 3-kinase. In this study, we have investigated the effect of this association on PI 3-kinase activity in 3T3-L1 adipocytes. Insulin stimulated cytosolic PI 3-kinase activity about sevenfold. This stimulation was maximal after 1 min of exposure of cells to insulin, persisted for at least 1 h, and occurred over the range of insulin concentrations that saturate its receptor. By means of immunoprecipitation of IRS-1, it was shown that virtually all of the enhanced activity was due to PI 3-kinase complexed with IRS-1. Moreover, the purified Tyr(P) form of IRS-1, either isolated from 3T3-L1 adipocytes or obtained by phosphorylation of the recombinant protein with the insulin receptor, markedly stimulated the activity of purified rat liver PI 3-kinase. These results show that the association of Tyr(P) IRS-1 with PI 3-kinase activates the enzyme and thereby can explain the elevation of PI 3,4-bisphosphate and PI 3,4,5-trisphosphate in vivo observed upon treatment of adipocytes with insulin.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
A. R. Sedaghat, A. Sherman, and M. J. Quon
A mathematical model of metabolic insulin signaling pathways
Am J Physiol Endocrinol Metab, November 1, 2002; 283(5): E1084 - E1101.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
S. F. Hausdorff, D. C. Fingar, K. Morioka, L. A. Garza, E. L. Whiteman, S. A. Summers, and M. J. Birnbaum
Identification of Wortmannin-sensitive Targets in 3T3-L1 Adipocytes. DISSOCIATION OF INSULIN-STIMULATED GLUCOSE UPTAKE AND GLUT4 TRANSLOCATION
J. Biol. Chem., August 27, 1999; 274(35): 24677 - 24684.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
E. U. Frevert, C. Bjorbak, C. L. Venable, S. R. Keller, and B. B. Kahn
Targeting of Constitutively Active Phosphoinositide 3-Kinase to GLUT4-containing Vesicles in 3T3-L1 Adipocytes
J. Biol. Chem., September 25, 1998; 273(39): 25480 - 25487.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
V. R. Fantin, J. D. Sparling, J. W. Slot, S. R. Keller, G. E. Lienhard, and B. E. Lavan
Characterization of Insulin Receptor Substrate 4 in Human Embryonic Kidney 293 Cells
J. Biol. Chem., April 24, 1998; 273(17): 10726 - 10732.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online