Histone deacetylases

Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from the lysine residues of both histone and nonhistone proteins.  In humans, there are 18 HDAC enzymes divided into four classes: the Class I Rpd3-like proteins (HDAC1, HDAC2, HDAC3, and HDAC8); the Class II Hda1-like proteins (HDAC4, HDAC5, HDAC6, HDAC7, HDAC9, and HDAC10); the Class III Sir2-like proteins (SIRT1, SIRT2, SIRT3, SIRT4, SIRT5, SIRT6, and SIRT7); and the Class IV protein (HDAC11).   Histone deacetylases act as erasers of epigenetic acetylation marks on lysine residues in histones and removal of these groups allows tighter packing of chromatin, leading to transcriptional repression.  Other biological functions of HDACS include metabolism, angiogenesis, DNA damage response, cell cycle, apoptosis, protein degradation and immunity.  Dysregulated HDAC activity is present in cancer cells and tumour tissues and HDAC inhibitors are approved for clinical use as anti-cancer therapeutics.

Further reading

Haberland et al (2009) The many roles of histone deacetylases in development and physiology: implications for disease and therapy. Nat Rev Genet. 10(1) 32 PMID: 19065135

Seto and Yoshida (2014) Erasers of histone acetylation: the histone deacetylase enzymes. Cold Spring Harb Perspect Biol. 6(4) a018713 PMID: 24691964

Li et al (2020) The Roles of Histone Deacetylases and Their Inhibitors in Cancer Therapy. Front Cell Dev Biol. 8 576946 PMID: 33117804