Mitogen-induced expression of the primary response gene cMG1 in a rat intestinal epithelial cell-line (RIE-1).

cMG1 is a primary response gene first identified in a rat intestinal epithelial (RIE-1) cell-line [(1990) Oncogene 5, 1081-1083]. A number of mitogens, including epidermal growth factor (EGF), angiotensin II (AII), serum and insulin rapidly induced 2- to 6-fold increases of cMG1 mRNA in RIE-1 cells, while transforming growth factor-beta caused a small reduction. Cyclic AMP-elevating agents blocked the increase of cMG1 mRNA induced by EGF. The AII-stimulated increase of cMG1 mRNA was blocked by the depletion of protein kinase C, whereas the EGF-stimulated increase was not affected, indicating that protein kinase C-dependent and -independent signalling pathways stimulate cMG1 expression.