Regulation of MEF2 transcriptional activity by calcineurin/mAKAP complexes

► Calcineurin regulates MEF2 activity in striated muscle. ► mAKAP is a calcineurin scaffold in striated muscle. ► The mAKAP/calcineurin interaction can be disrupted using a competitive binding peptide. ► Disruption of the interaction prevents differentiation-induced MEF2 gene transcription in C2C12 cells. ► Disruption of the interaction also prevents induction of cardiac hypertrophy in neonatal cardiac myocytes.