Application(s): enzyme kinetics, inhibitor screening, and selectivity profiling · Source: N-terminal GST-tagged protein from baculovirus expression system · M_r: 75.2 kDa · Histone deacetylases (HDACs) catalyze the deacetylation of core histones, resulting in tightening of nucleosomal integrity, restriction of the access of transcription factors, and suppression of transcription. HDACs also play important roles in mediating nuclear receptor functions by forming co-repressor complexes with nuclear receptors in the absence of ligands. They are also involved in mediating other transcription regulatory pathways by associating with transcription factors, such as E2F, TFIIE, TFIIF, NF-kB, p300, Stat3, p53, and the retinoblastoma (Rb) protein.¹ HDAC4 is a Class IIa HDAC which is homologous to yeast Hda 1 and is larger in size than the other 2 classes of HDACs. Class IIa HDACs contain a highly conserved C-terminal deacetylase catalytic domain (~420 amino acids) and an N-terminal domain with no similarity to HDACs in other classes.^1,2 Class II HDACs can shuttle between the nucleus and cytoplasm, suggesting potential extranuclear functions by regulating the acetylation status of nonhistone substrates. By modifying chromatin structure and other nonhistone proteins, HDACs play important roles in controlling complex biological events, including cell development, differentiation, programmed cell death, angiogenesis, and inflammation. Considering these major roles, it is conceivable that dysregulation of HDACs and subsequent imbalance of acetylation and deacetylation may be involved in the pathogenesis of various diseases, including cancer and inflammatory diseases.

1 Lin, H., Chen, C., Lin, S., et al. Targeting histone deacetylase in cancer therapy. Med Res Rev 26(4) 397-413 (2006).

2 Huang, L. Targeting histone deacetylases for the treatment of cancer and inflammatory diseases. J Cell Physiol 39.1 611-616 (2006).

Lin, H., Chen, C., Lin, S., et al. Targeting histone deacetylase in cancer therapy. Med Res Rev 26(4) 397-413 (2006).

Huang, L. Targeting histone deacetylases for the treatment of cancer and inflammatory diseases. J Cell Physiol 39.1 611-616 (2006).