Skip to main content

Free Content In Vitro Binding and Phosphorylation of Insulin Receptor Substrate 1 by the Insulin Receptor: Role of Interactions Mediated by the Phosphotyrosine-Binding Domain and the Pleckstrin-Homology Domain

Download Article:

You have access to the full text article on a website external to ingentaconnect.

Please click here to view this article on Wiley Online Library.

You may be required to register and activate access on Wiley Online Library before you can obtain the full text. If you have any queries please visit Wiley Online Library

Abstract:

Insulin receptor substrate 1 (IRS-1) is a major substrate of the insulin receptor in most cells. The N terminus of IRS-1 contains a phosphotyrosine binding (PTB) domain and a pleckstrin homology (PH) domain, both of which have been identified as important for insulin-stimulated phosphorylation in intact cells. The PTB domain binds to a phosphorylated motif, NPEY(P)960, that is present in the juxtamembrane region of the insulin receptor. A direct interaction between the PH domain of IRS-1 and the receptor has not been demonstrated. In this study, we examine the role of the IRS-1 PTB and PH domains during IRS-1-receptor binding and IRS-1 phosphorylation in intact cells and in vitro. Abrogation of binding of the PTB domain to NPXY(P) by mutation of Tyr960 of the insulin receptor did not reduce the binding of phosphorylated IRS-1 to insulin receptors in intact cells, and had no effect on binding of insulin receptors to IRS-1 or on IRS-1 phosphorylation in vitro. We examined the phosphorylation and receptor binding of a mutant recombinant IRS-1 that lacks the N-terminal PH domain (PH-IRS-1). Although phosphorylation of _lratri;fPH-IRS-1 by wild-type or [Ala960]insulin receptors was similar to that of IRS-1, binding of insulin receptor to _lratri;PH-IRS-1 was markedly reduced relative to that to IRS-1. We conclude that stable association of IRS-1 with the insulin receptor is unaffected by disruption of PTB-domain–Tyr960 interactions but requires the IRS-1 PH domain, and that efficient phosphorylation of IRS-1 in intact cells correlates with the formation of stable receptor IRS-1 complexes.

Keywords: insulin action; insulin receptor; insulin-receptor substrate-1; pleckstrin-homology domain

Document Type: Research Article

DOI: http://dx.doi.org/10.1111/j.1432-1033.1997.t01-1-00091.x

Affiliations: Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, USA

Publication date: April 1, 1997

bsc/ejb/1997/00000245/00000001/art00011
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more