Histone deacetylase class I isoforms (HDAC1, HDAC2, HDAC3, HDAC8)

Class I histone deacetylases are a group of zinc-dependent enzymes comprising HDAC1, HDAC2, HDAC3, and HDAC8, which catalyze the removal of acetyl groups from lysine residues in histones and other proteins, thereby modulating chromatin structure and repressing gene transcription. These enzymes play critical roles in cell cycle regulation, differentiation, apoptosis, and tissue development, and their dysregulation has been implicated in cancer, cardiovascular, and neurodegenerative diseases. Numerous small molecule inhibitors targeting class I HDACs—either pan, class-specific, or isoform-specific—have demonstrated therapeutic potential, although specificity and safety remain important challenges. Class I HDAC isoforms are validated therapeutic targets and are the focus of ongoing drug development for applications in oncology, cardiovascular disease, and other indications.

Other names

HDAC1, HDAC2, HDAC3, HDAC8Class I HDACsZn^2+-dependent histone deacetylases (classical HDACs)

Inhibition of deacetylase activity: Results in increased acetylation of histones and non-histone proteins, leading to chromatin relaxation, derepression of gene transcription, induction of cell cycle arrest, and apoptosis Isoform-specific inhibition: Allows selective modulation of particular cellular processes and reduces off-target effects