HDAC3 and cardiac hypertrophy: Myofibril growth during cardiac hypertrophy is regulated by phosphorylation and acetylation of the actin-capping protein CapZβ1, and phenylephrine (PE) treatment of cardiomyocytes reduces HDAC3 binding to myofibrils, which leads to the phosphorylation of CapZβ1 at the serine 204 site and acetylation of CapZβ1 at the lysine 199 site [51].