FIG. 1.

c-Jun/AP-1 regulates Ras-GRF1 expression in rat fibroblasts. (A) Two micrograms of total RNA from Rat1a-GFP control cells and Rat1a-c-Jun4 cells grown in suspension without (−) and with (+) doxycycline treatment for 3 days was used in Northern blots probing for Ras-GRF1 and c-Jun expression. 28S RNA was used as a loading control. (B) Northern blot analysis of time-dependent induction of Ras-GRF1 and stromelysin expression in response to doxycycline treatment of Rat1a-c-Jun4 cells. (C) Immunoblots showing doxycycline-induced p75-Ras-GRF1 protein expression in Rat1a-c-Jun4 cells. Tubulin was used as a control for loading. (D) Immunoblots of Ras-GRF1 expression in GFP- and c-Jun-expressing cells after 3 days of treatment with doxycycline.