Insulin-induced tyrosine phosphorylation of Shc in liver, muscle and adipose tissue of insulin resistant rats

E. Verónica Páez-Espinosa, Eduardo M. Rocha, Lício A. Velloso, Antonio C. Boschero, Mário J.A. Saad

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Insulin stimulates rapid tyrosine phosphorylation of the protein Shc, which subsequently binds to Grb2, resulting in the activation of a complex mitogenic signaling network. In this study, we examined the levels of Shc protein, its phosphorylation state and Shc-Grb2 association in liver, muscle and adipose tissue before and after insulin administration in three animal models of insulin resistance (chronic dexamethasone treatment, 72-h starvation and aging). There were no differences in Shc protein expression between tissues from control and insulin resistant animals. In fasted hypoinsulinemic rats, there was a decrease in insulin-induced Shc phosphorylation in liver and adipose tissue. However, a significant increase in Shc phosphorylation was observed in liver and muscle from dexamethasone-treated hyperinsulinemic rats and in liver, muscle and adipose tissue of hyperinsulinemic 20-month-old rats. Alterations in Shc phosphorylation correlated well with the level of Shc-Grb2 association. These results indicate that Shc tyrosyl phosphorylation and Shc-Grb2 association are regulated in the different types of insulin resistance and that this regulation is apparently related to the animals' plasma insulin levels. The Shc-Grb2 association is directly related to the insulin-induced tyrosyl phosphorylation of Shc. Copyright (C) 1999 Elsevier Science Ireland Ltd.

Original languageEnglish
Pages (from-to)121-129
Number of pages9
JournalMolecular and Cellular Endocrinology
Volume156
Issue number1-2
DOIs
StatePublished - 25 Oct 1999
Externally publishedYes

Keywords

  • Diabetes
  • Fasting
  • Hyperinsulinemia
  • Hypoinsulinemia
  • p52Shc
  • Shc-Grb 2 association

Fingerprint

Dive into the research topics of 'Insulin-induced tyrosine phosphorylation of Shc in liver, muscle and adipose tissue of insulin resistant rats'. Together they form a unique fingerprint.

Cite this