Fig. 6. CaMKIV* alone can activate a MEF2-responsive promoter, in a fashion that depends on the MEF2 sites. P19 cells were co-transfected with 0.8 µg of HDAC4, MEF2C and CaMKIV* expression vectors individually and in combination, and with either a wild-type or mutated MEF2-responsive promoter (1.4 µg) as indicated. Cells were harvested 24 hours after transfection and CAT assays were used to measure the activity from the MEF2-responsive promoter. Error bars represent the standard error (+ s.e.); n=2-13.