Figure 1.

Regulation of lysine acetylation by histone deacetylases. Histone acetyltransferases (HATs) transfer acetyl groups from acetyl-CoA to ɛ-amines of lysine residues on a variety of proteins, and HDACs catalyze removal of these groups. HDACs are categorized into four distinct classes. Class II HDACs are further divided into two subclasses, IIa and IIb. Class III HDACs also are known as sirtuins. Current data based on genetic and pharmacological investigations suggests that class I HDACs promote pathological cardiac remodeling while class IIa and class III HDACs are protective. There is nothing known about the functions of class IIb and class IV HDACs in the heart.