The 27,000 daltons stress proteins are phosphorylated by protein kinase C during the tumor promoter-mediated growth inhibition of human mammary carcinoma cells

Détails

ID Serval
serval:BIB_A1733BDBF10C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
The 27,000 daltons stress proteins are phosphorylated by protein kinase C during the tumor promoter-mediated growth inhibition of human mammary carcinoma cells
Périodique
Biochemical and Biophysical Research Communications
Auteur(s)
Regazzi  R., Eppenberger  U., Fabbro  D.
ISSN
0006-291X (Print)
Statut éditorial
Publié
Date de publication
04/1988
Volume
152
Numéro
1
Pages
62-8
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Apr 15
Résumé
Phorbol-12-myristate-13-acetate (PMA) inhibited growth of human mammary carcinoma cell lines and increased mainly the phosphorylation of two cytosolic phosphoproteins (pp) of 27 kD with isoelectric points of 5.5 (pp27a) and 5.0 (pp27b). The time course of pp27 phosphorylation closely paralleled the rapid PMA-induced subcellular redistribution of protein kinase C (PKC) activity and its subsequent down regulation. Addition of phospholipase C and fetal calf serum to intact cells or purified PKC to a cell free system enhanced the phosphorylation of both pp27 suggesting that the two polypeptides are specific substrates for PKC. Exposure of human mammary carcinoma cells to stress inducers such as arsenite or cadmium increased the 32P incorporation of both pp27 to an extent comparable to PMA. The increased phosphorus content following stress was rather due to a higher rate of synthesis of both pp27 than to a higher phosphorylation state of these polypeptides as determined by [3H]-leucine labeling. These results indicate that the major substrates of PKC, phosphorylated during the PMA-induced growth inhibition of human mammary carcinoma cells, are members of the stress protein family, suggesting a new possible function for these proteins.
Mots-clé
Breast Neoplasms Cell Line Cell Membrane/enzymology Cytosol/enzymology Electrophoresis, Polyacrylamide Gel Female Heat-Shock Proteins/*metabolism Humans Molecular Weight Phosphorylation Protein Kinase C/*metabolism Tetradecanoylphorbol Acetate/*pharmacology
Pubmed
Web of science
Création de la notice
24/01/2008 15:30
Dernière modification de la notice
03/03/2018 20:07
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