ADA3 (Transcriptional adapter 3-like, STAF54) is a 432 amino acid protein encoded by the human gene TADA3L. ADA3 is a ubiquitously expressed nuclear protein that functions as a component of the PCAF (p300/CBP-associated factor) complex. The PCAF complex is capable of efficiently acetylating histones in a nucleosomal context. The PCAF complex is the human homolog of the yeast SAGA complex. ADA3 interacts with the E6 gene and is a target of E6-induced degradation. ADA3 binds selectively to the high-risk HPV E6 proteins and immortalization-competent E6 mutants. ADA3 functions as a coactivator for p53-mediated transactivation by stabilizing p53 protein.
