Cells were UV-irradiated (50 mJ/cm2) and total RNA, or whole cell protein extracts were prepared at the indicated times post irradiation. A, c-Jun and C, c-Fos mRNA levels were quantified by real-time RT-PCR, normalized to mRNA for 36B4, which encodes a ribosomal protein, used as an internal control. B, c-Jun and D, c-Fos protein levels were determined by Western analysis. Insets show representative Western blots. Bar heights indicate means ± SEM fold change relative to levels in non-irradiated control cells (CTRL). *p<0.05 vs. CTRL. N=3-5.