Physical interaction between calcineurin and Cav3.2 T‐type Ca 2 + channel modulates their functions

Ca v 3.2 T‐type Ca 2+ channel is required for the activation of calcineurin/NFAT signaling in cardiac hypertrophy. We aimed to investigate how Ca v 3.2 and calcineurin interact. We found that Ca 2+ and calmodulin modulate the Ca v 3.2/calcineurin interaction. Calcineurin binding to Ca v 3.2 decreases the enzyme's phosphatase activity and diminishes the channel's current density. Phenylephrine‐induced hypertrophy in neonatal cardiac myocytes is reduced by a cell‐permeable peptide with the calcineurin binding site sequence. These data suggest that Ca v 3.2 regulates calcineurin/NFAT pathway through both the Ca 2+ influx and calcineurin binding. Our findings unveiled a reciprocal regulation of Ca 2+ signaling which contributes to our understanding of cardiac hypertrophy.