Fig. 1.

Suppression of myocardin transcriptional activity by p65. Luciferase reporters controlled by SM22 and ANF were transfected into COS7 cells (a) or rat neonatal cardiomyocytes (b) and cotransfected with expression plasmids for myocardin (0.1 μg) and increasing amounts of p65 (COS7: 0.01, 0.05, 0.1, and 0.2 μg; cardiomyocytes: 0.02 and 0.1 μg). p65 protein assayed by Western blot. (c) COS7 cells were cotransfected with the indicated deleted CArG box within either the SM22 or ANF promoter. (d and e) COS7 cells (d) or cardiomyocytes (e) treated with TNF-α (10 ng/ml for 6 h) or cotransfected with an IκBα superrepressor. Values are the fold increase of luciferase activity relative to activation of the reporter alone of at least three experiments. Student's t test: P < 0.05, myocardin alone vs. myocardin plus p65, TNF-α, or IκBα-SR.