KAT2B
Description
The KAT2B (lysine acetyltransferase 2B) is a protein-coding gene located on chromosome 3.
PCAF, also known as K(lysine) acetyltransferase 2B (KAT2B), is a human gene and transcriptional coactivator associated with p53. It has separate acetyltransferase and E3 ubiquitin ligase domains, as well as a bromodomain for interaction with other proteins. PCAF also possesses sites for its own acetylation and ubiquitination. PCAF associates with p300/CBP, and competes with E1A for binding sites in p300/CBP. It has histone acetyl transferase activity with core histones and nucleosome core particles, indicating a direct role in transcriptional regulation. The acetyltransferase activity and cellular location of PCAF are regulated through acetylation of PCAF itself. Acetylation leads to nuclear migration and enhanced acetyltransferase activity. PCAF interacts with and is deacetylated by HDAC3, leading to reduced PCAF acetyltransferase activity and cytoplasmic localization. PCAF forms complexes with numerous proteins that guide its activity.
The human gene KAT2B, also known as PCAF, functions as a histone acetyltransferase (HAT) to promote transcriptional activation. It exhibits significant HAT activity with core histones (H3 and H4) and nucleosome core particles, displaying a strong preference for acetylation of H3 at 'Lys-9' (H3K9ac). In addition to histones, KAT2B acetylates non-histone proteins, including ACLY, MAPRE1/EB1, PLK4, RRP9/U3-55K, and TBX5. This gene plays a role in inhibiting cell-cycle progression, counteracting the mitogenic activity of the adenoviral oncoprotein E1A, and acting as a circadian transcriptional coactivator, enhancing the activity of circadian transcriptional activators like NPAS2-BMAL1 and CLOCK-BMAL1 heterodimers. KAT2B is involved in heart and limb development by mediating acetylation of TBX5, regulating its nucleocytoplasmic shuttling. Furthermore, it acts as a negative regulator of centrosome amplification by mediating acetylation of PLK4. Acetylating RRP9/U3-55K, a core subunit of the U3 snoRNP complex, impairs pre-rRNA processing, while acetylating MAPRE1/EB1 promotes dynamic kinetochore-microtubule interactions during early mitosis. KAT2B also acetylates spermidine.
KAT2B is also known as CAF, P/CAF, PCAF.
