Figure 6.

 ATF-2 and p300 cooperate to transactivate DRE-mediated transcription in F9 cells. F9 cells that had been stably transfected with 5 μg of 3× DRE/tk–CAT (lanes 1–4,9–11,15–22) or tk–CAT (lanes 5–8,12–14) were cotransfected with various amounts of pCMV–ATF-2 (lanes 2–4,6–8), pCMV–ATF-2 Δ(amino acids 112–350) (lanes 18–20), pACT–p300 (lanes 9–11,12–14), or pACT–p300 Δ(amino acids 963–1571) (lanes 15–17) and 5 μg (lanes 9–11,15–17), 8 μg (lanes 12–14) of pCMV–ATF-2, or 2 μg of pRSV–LacZ (lanes 1–22). The cells were incubated for 72 hr and CAT assays were performed with extracts in which the amount of protein had been normalized by the activity of β-galactosidase. The percent conversion of CAT to its acetylated forms is indicated. (Lane 1) DRE/tk–CAT only; (lanes 2–4,6–8,18–20) 1.0, 4.0, and 8.0 μg of pCMV–ATF-2 or pCMV–ATF-2 Δ(amino acids 112–350), respectively; (lane 5) tk–CAT only; (lanes 9–17) 1.0, 4.0, and 8.0 μg of pACT–p300 or pACT–p300 Δ(amino acids 963–1571), respectively. (Lane 21) treatment with 3 × 10⁻⁷ m RA; (lane 22) transfection with pCMV–E1A (4 μg).