HDAC4 is a 140 kD class II histone deacetylase similar to the yeast HDA1 protein. This nuclear protein operates in concert with histone acetyltransferases to control core histone acetylation in highly conserved lysine residues. HDAC activity has been associated with transcriptional repression and nucleosomal condensation. HDAC4 uses active nuclear export to shuttle between the nucleus and the cytoplasm. HDAC4 is modified by phosphorylation by CaM kinase I or IV. HDAC4 has been reported to interact with 14-3-3 in the cytoplasm and MEF2A, HDAC3, NcoR and SMRT in the nucleus. The Poly6077 antibody has been shown to be useful for the detection of human (Western blotting and immunofluorescence) and mouse (Western blotting; immunofluorescence not tested) HDAC4 protein.