HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, Y. Articles by Cooper, G. J.S. Search for Related Content PubMed PubMed Citation Articles by Wang, Y. Articles by Cooper, G. J.S. Social Bookmarking                What's this?

Alteration in Phosphorylation of P20 Is Associated With Insulin Resistance

¹ School of Biological Sciences, University of Auckland, Auckland, New Zealand
² Garvan Institute of Medical Research, Sydney, Australia
³ Department of Medicine, School of Medicine, University of Auckland, Auckland, New Zealand

We have recently identified a small phosphoprotein, P20, as a common intracellular target for insulin and several of its antagonists, including amylin, epinephrine, and calcitonin gene-related peptide. These hormones elicit phosphorylation of P20 at its different sites, producing three phosphorylated isoforms: S1 with an isoelectric point (pI) value of 6.0, S2 with a pI value of 5.9, and S3 with a pI value of 5.6 (FEBS Letters 457:149–152 and 462:25–30, 1999). In the current study, we showed that P20 is one of the most abundant phosphoproteins in rat extensor digitorum longus (EDL) muscle. Insulin and amylin antagonize each other’s actions in the phosphorylation of this protein in rat EDL muscle. Insulin inhibits amylin-evoked phosphorylation of S2 and S3, whereas amylin decreases insulin-induced phosphorylation of S1. In rats made insulin resistant by dexamethasone treatment, levels of the phosphoisoforms S2 and S3, which were barely detectable in healthy rats in the absence of hormone stimulation, were significantly increased. Moreover, the ability of insulin to inhibit amylin-evoked phosphorylation of these two isoforms was greatly attenuated. These results suggested that alterations in the phosphorylation of P20 might be associated with insulin resistance and that P20 could serve as a useful marker to dissect the cellular mechanisms of this disease.

CiteULike

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				G.-C. Fan, X. Ren, J. Qian, Q. Yuan, P. Nicolaou, Y. Wang, W. K. Jones, G. Chu, and E. G. Kranias Novel Cardioprotective Role of a Small Heat-Shock Protein, Hsp20, Against Ischemia/Reperfusion Injury Circulation, April 12, 2005; 111(14): 1792 - 1799. [Abstract] [Full Text] [PDF]

				G.-C. Fan, G. Chu, B. Mitton, Q. Song, Q. Yuan, and E. G. Kranias Small Heat-Shock Protein Hsp20 Phosphorylation Inhibits {beta}-Agonist-Induced Cardiac Apoptosis Circ. Res., June 11, 2004; 94(11): 1474 - 1482. [Abstract] [Full Text] [PDF]

				G. Chu, G. F. Egnaczyk, W. Zhao, S.-H. Jo, G.-C. Fan, J. E. Maggio, R.-P. Xiao, and E. G. Kranias Phosphoproteome Analysis of Cardiomyocytes Subjected to {beta}-Adrenergic Stimulation: Identification and Characterization of a Cardiac Heat Shock Protein p20 Circ. Res., February 6, 2004; 94(2): 184 - 193. [Abstract] [Full Text] [PDF]

				Y. Wang, A. Xu, C. Knight, L. Y. Xu, and G. J. S. Cooper Hydroxylation and Glycosylation of the Four Conserved Lysine Residues in the Collagenous Domain of Adiponectin. POTENTIAL ROLE IN THE MODULATION OF ITS INSULIN-SENSITIZING ACTIVITY J. Biol. Chem., May 24, 2002; 277(22): 19521 - 19529. [Abstract] [Full Text] [PDF]