CHARACTERIZATION OF THE HEPATIC INSULIN-RECEPTOR UNDERGOING INTERNALIZATION THROUGH CLATHRIN-COATED VESICLES AND ENDOSOMES

Citation
M. Jose et al., CHARACTERIZATION OF THE HEPATIC INSULIN-RECEPTOR UNDERGOING INTERNALIZATION THROUGH CLATHRIN-COATED VESICLES AND ENDOSOMES, FEBS letters, 334(3), 1993, pp. 286-288
Citations number
10
Categorie Soggetti
Biophysics,Biology
Journal title
ISSN journal
00145793
Volume
334
Issue
3
Year of publication
1993
Pages
286 - 288
Database
ISI
SICI code
0014-5793(1993)334:3<286:COTHIU>2.0.ZU;2-L
Abstract
Administration of insulin to rats caused a transient increase in the a mount of hepatic insulin receptor present in clathrin-coated vesicles and endosomes. However, the total 'in vitro' insulin stimulated tyrosi ne kinase activity of the receptor present in endosomes did not vary w hen expressed per mg of protein and decreased when expressed per beta- subunit content. A decrease in the endogenous phospho tyrosine content of the receptor beta-subunit was observed in endosomes in response to insulin. This indicates that a fraction of the internalized receptor is dephosphorylated in endosomes, which renders it unable to become st imulated by insulin 'in vitro'.