Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/194459
Type: Artigo de periódico
Title: Insulin-induced Tyrosine Phosphorylation Of Shc In Liver, Muscle And Adipose Tissue Of Insulin Resistant Rats.
Author: Páez-Espinosa, E V
Rocha, E M
Velloso, L A
Boschero, A C
Saad, M J
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.
Subject: Adaptor Proteins, Signal Transducing
Adaptor Proteins, Vesicular Transport
Adipose Tissue
Animals
Blood Glucose
Dexamethasone
Eating
Fasting
Grb2 Adaptor Protein
Hydrocortisone
Hyperinsulinism
Insulin
Insulin Resistance
Liver
Male
Muscle, Skeletal
Phosphorylation
Proteins
Rats
Rats, Wistar
Receptor, Epidermal Growth Factor
Shc Signaling Adaptor Proteins
Src Homology Domains
Rights: fechado
Identifier DOI: 
Address: http://www.ncbi.nlm.nih.gov/pubmed/10612430
Date Issue: 1999
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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