Responsible for the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4) (By similarity). Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression and developmental events (By similarity). Histone deacetylases act via the formation of large multiprotein complexes (By similarity). Involved in transduction of sensory signals, together with egl-4, kin-29 and mef-2; binding to transcription factor mef-2 enables negative modulation of chemoreceptor gene expression in chemosensory neurons (PubMed:17170704, PubMed:18832350). May be involved in muscle development (By similarity). H2O + N(6)-acetyl-L-lysyl-[histone] = acetate + L-lysyl-[histone] Interacts with mef-2. Expressed in body-wall muscle cells, hypodermal seam cells and neuronal cells including sensory amphid neuronal processes, the nerve ring, ventral nerve cords and motor neuronal commissures. Phosphorylated by serine/threonine-protein kinase kin-29 at Ser-251; the phosphorylation inhibits repression of transcription by mef-2 (PubMed:17170704). May be phosphorylated by either cyclic-AMP dependent or cyclic-GMP dependent protein kinases (PubMed:18832350). Belongs to the histone deacetylase family. HD type 2 subfamily.