Characterization of insulin receptor substrate 4 in human embryonic kidney 293 cells

92Citations
Citations of this article
40Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

We recently cloned IRS-4, a new member of the insulin receptor substrate (IRS) family. In this study we have characterized IRS-4 in human embryonic kidney 293 cells, where it was originally discovered. IRS-4 was the predominant insulin-elicited phosphotyrosine protein in these cells. Subcellular fractionation revealed that about 50% of IRS-4 was located in cellular membranes, and immunofluorescence indicated that IRS-4 was concentrated at the plasma membrane. Immunoelectron microscopy conclusively established that a large portion of the IRS-4 was located at the cytoplasmic surface of the plasma membrane in both the unstimulated and insulin-treated states. IRS-4 was found to be associated with two src homology 2 (SH2) domain-containing proteins, phosphatidylinositol 3-kinase and Grb2, the adaptor to the guanine nucleotide exchange factor for Ras. On the other hand, no significant association was detected with two other SH2 domain proteins, the SH2-containing protein tyrosine phosphatase 2 and phospholipase Cγ. Insulin-like growth factor I acting through its receptor was as effective as insulin in eliciting tyrosine phosphorylation of IRS-4, but interleukin 4 and epidermal growth factor were ineffective.

Cite

CITATION STYLE

APA

Fantin, V. R., Sparling, J. D., Slot, J. W., Keller, S. R., Lienhard, G. E., & Lavan, B. E. (1998). Characterization of insulin receptor substrate 4 in human embryonic kidney 293 cells. Journal of Biological Chemistry, 273(17), 10726–10732. https://doi.org/10.1074/jbc.273.17.10726

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free