HDAC1 antibody [HDAC1-21]

Chromatin is composed of basic repeating units called nucleosomes, which are 146 bp of DNA wound around a histone octamer composed of two each of the core histones H2A, H2B, H3 and H4. Reversible acetylation of highly conserved lysine residues in N-terminal tail domains of core histones plays an important role in transcriptional regulation, cell cycle progression and developmental events. Several histone acetyltransferases (HATs) catalyze the acetylation reaction (GCN5, PCAF, p300/CBP, TAFII250, P/CAF, SRC-1 BRCA-2). Acetylation of the core histones is generally considered to be associated with gene activation, probably through maintenance of the unfolded structure of transcribing nucleosomes. Histone acetylation is a dynamic process whose levels are determined by the net activities of HATs and the competing enzymes histone deacetylases (HDACs). Both activities are associated with the nuclear matrix. Six or seven different mammalian HDACs have been described. HDACs are similar to the yeast Rpd3 protein, while HDACs are similar to the yeast Hda1 protein. Histone deacetylase activities are often, but not always, associated with transcriptional repression and nucleosomal condensations. HDAC1 and 2 are the catalytic subunits of different multiprotein regulatory complexes. The components of such complexes include: corepressors such as mSin3, N-CoR, SMRT, associated proteins such as SAP18, SAP30, RbAp46, RbAp48, c-Ski oncogenic protein, a protein involved in DNA methylation, and more.