INHIBITION BY GLUCOCORTICOIDS OF PIT 1 INDUCED ACTIVATION OF TRANSCRIPTION FROM RPR1 PROMOTER FRAGMENTS IN NON PITUITARY CELLS

Document Type : Original Article

Authors

Department of biochemistry faculty of medicine Alfateh University

Abstract

Bovine and rat prolactin gene promoter function by glucocorticoids. It was of interest, therefore to examine the possible inhibition by glucocorticoids of pit l induced activation of transcription from the 3'- rPrl promoter mutant generated for this study. The studies were carried out by co-transfection into glucocorticoids receptor (GR) deficient CV-1 cells both pin1 and (GR) expression vectors and the reporter CAT plasmids with upstream rPrl promoter fragments. The effect of glucocorticoids was examined by the Addition of dexamethasone (10-6 M) to the cultures immediately after transfection. In these studies glucocorticoids receptor (GR) deficient CV-l cells were used and the (GR) was expressed from an expression vector parker et al. (1994). However, in the case of prolactin promoter fragments (eg, - 1960/+ 38, -44/ -423, -190/-423 and – 75 /+ 38) decreased in pitl induced DAT gene expression was seen when the (GR) was expressed but it was evident even in the absence of glucocorticoids.