Responsible for the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4). Histone deacetylation plays an important role in transcriptional regulation, cell cycle progression and developmental events. Histone deacetylases act via the formation of large multiprotein complexes (By similarity). May play a role in the regulation of the timing of gene expression during the development and in the definition aspects of the phenotype that mediate social behavior in genetically heterogeneous groups. H2O + N(6)-acetyl-L-lysyl-[histone] = acetate + L-lysyl-[histone] Its activity is inhibited by trichostatin A (TSA), a well known histone deacetylase inhibitor. Cytosolic activity is refractory to inhibition by TSA, while the nuclear activity is inhibited completely. Expressed throughout growth and development. Develop normally but when mixed with wild type cells they sporulate less efficiently than the wild type. Do not show major alterations in gross histone acetylation levels. Belongs to the histone deacetylase family. HD type 1 subfamily.