ACTIVATION OF HAPTOGLOBIN GENE-EXPRESSION BY CAMP INVOLVES CCAAT ENHANCER-BINDING PROTEIN ISOFORMS IN INTESTINAL EPITHELIAL-CELLS/

Citation
N. Pelletier et al., ACTIVATION OF HAPTOGLOBIN GENE-EXPRESSION BY CAMP INVOLVES CCAAT ENHANCER-BINDING PROTEIN ISOFORMS IN INTESTINAL EPITHELIAL-CELLS/, FEBS letters, 439(3), 1998, pp. 275-280
Citations number
47
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology,"Cell Biology",Biophysics
Journal title
ISSN journal
0014-5793
Volume
439
Issue
3
Year of publication
1998
Pages
275 - 280
Database
ISI
SICI code
0014-5793(1998)439:3<275:AOHGBC>2.0.ZU;2-I
Abstract
CCAAT/enhancer-binding protein (C/EBP) isoforms are expressed in roden t intestine and in the rat intestinal epithelial cell line IEC-6 but t heir role remains to be determined. Treatment of IEC-6 cells with the adenylate cyclase activator forskolin led to coordinate induction of C /EBP isoforms alpha, beta and delta at the mRNA and protein levels. Tr ansient transfection assays showed that their expression is controlled at the transcriptional level, Forskolin treatment induced haptoglobin mRNA levels. Electrophoretic mobility shift and supershift assays dem onstrated an increase in DNA-binding activities of the three C/EBP iso forms to the haptoA and haptoC C/EBP DNA-binding sites of the proximal haptoglobin promoter, Site-specific mutations of both sites led to a decrease in transcriptional induction by forskolin, suggesting that C/ EBP isoforms are involved in the cAMP-dependent regulation of the acut e-phase protein gene haptoglobin in intestinal epithelial cells. (C) 1 998 Federation of European Biochemical Societies.