Fig. 6. Calcineurin and CaMKIV act synergistically to enhance the transactivating function of MEF2. Luciferase reporter plasmids controlled by the myoglobin or desMEF2 enhancers were cotransfected into C2C12 cells with expression plasmids encoding either constitutively active calcineurin A subunit or CaMKIV. Data are presented as in Figure 1, and represent results of three or more independent experiments.