Histone deacetylase class I and IIb isoform (HDAC (Class I/IIb))

Histone deacetylase class I/IIb isoforms are members of the histone deacetylase (HDAC) enzyme family that regulate chromatin structure and gene expression by removing acetyl groups from lysine residues on histone and non-histone proteins[4][3][6]. Class I HDACs (HDAC1, HDAC2, HDAC3, HDAC8) are primarily nuclear and essential for cell proliferation, apoptosis, and cellular differentiation[2][5][6]. Class IIb HDACs (HDAC6, HDAC10) are mainly cytoplasmic and regulate processes involving the cytoskeleton and protein degradation[3][5]. Both classes are zinc-dependent enzymes with key roles in cellular homeostasis, and their dysregulation has been implicated in cancer, neurodegenerative disorders, and other diseases[3][5]. HDAC inhibitors are in clinical use or development for several malignancies, but the broad substrate specificity and functional overlap of isoforms pose therapeutic and safety challenges[2][3][5].

Other names

HDACs (Class I: HDAC1, HDAC2, HDAC3, HDAC8; Class IIb: HDAC6, HDAC10)Histone deacetylase enzymes

Inhibition of lysine deacetylation on histones and non-histone substrates, leading to hyperacetylation Modulation of chromatin structure, promoting gene expression of tumor suppressors or pro-apoptotic factors Interference with non-histone protein function through acetylation regulation