Functions as a histone acetyltransferase (HAT) to promote transcriptional activation . Has significant histone acetyltransferase activity with core histones (H3 and H4), and also with nucleosome core particles . Also acetylates non-histone proteins, such as ACLY, MAPRE1/EB1, PLK4, RRP9/U3-55K and TBX5 (   ). Inhibits cell-cycle progression and counteracts the mitogenic activity of the adenoviral oncoprotein E1A . Acts as a circadian transcriptional coactivator which enhances the activity of the circadian transcriptional activators: NPAS2-BMAL1 and CLOCK-BMAL1 heterodimers . Involved in heart and limb development by mediating acetylation of TBX5, acetylation regulating nucleocytoplasmic shuttling of TBX5 . Acts as a negative regulator of centrosome amplification by mediating acetylation of PLK4 . Acetylates RRP9/U3-55K, a core subunit of the U3 snoRNP complex, impairing pre-rRNA processing . Acetylates MAPRE1/EB1, promoting dynamic kinetochore-microtubule interactions in early mitosis . Also acetylates spermidine .
(Microbial infection) In case of HIV-1 infection, it is recruited by the viral protein Tat. Regulates Tat's transactivating activity and may help inducing chromatin remodeling of proviral genes.
Subcellular locations: Nucleus, Cytoplasm, Cytoskeleton, Microtubule organizing center, Centrosome, Cytoplasm
Mainly localizes to the nucleus. Also localizes to centrosomes in late G1 and around the G1/S transition, coinciding with the onset of centriole formation. Subcellular location may vary depending upon cell differentiation state. Cytoplasmic at the very stages of keratinocyte differentiation, becomes nuclear at later differentiation stages. Cytoplasmic in basal epithelial cells (undifferentiated cells) and nuclear in parabasal cells (differentiated cells) . Localizes to sites of DNA damage .
Ubiquitously expressed but most abundant in heart and skeletal muscle. Also expressed in the skin, in keratinocytes (at protein level) .