Class I and IIb histone deacetylase (HDAC)

Class I and IIb histone deacetylases are subgroups of the histone deacetylase enzyme family involved in the removal of acetyl groups from lysine residues of histone and non-histone proteins. This enzymatic deacetylation promotes chromatin condensation, transcriptional repression, and regulation of numerous cellular processes, including gene expression, cell cycle progression, and apoptosis. Class I HDACs (HDAC1, HDAC2, HDAC3, HDAC8) are predominantly nuclear and strongly associated with the regulation of gene expression and cell proliferation, while class IIb HDACs (HDAC6, HDAC10) are mainly cytoplasmic and regulate processes such as α-tubulin deacetylation and protein trafficking. Dysregulation of these enzymes contributes to diverse diseases, notably cancer and neurodegenerative disorders. Selective HDAC inhibitors have been developed and approved as anticancer agents, though their clinical use is associated with notable toxicities due to widespread actions on both histone and non-histone proteins.

Other names

Histone deacetylases (general)HDAC1HDAC2HDAC3HDAC8 (Class I)HDAC6HDAC10 (Class IIb)zinc-dependent histone deacetylase

Inhibition of histone deacetylase activity, leading to increased acetylation of lysine residues on histone and non-histone proteins; Promotes chromatin relaxation and activation of gene transcription; Induction of cell cycle arrest and apoptosis in cancer cells; Modulation of protein acetylation affecting cell motility, protein aggregation, and immune synapse formation (notably for HDAC6)