title: An essential role of human Ada3 in p53 acetylation.
abstract: The p53 tumor suppressor protein functions as a critical component of genotoxic stress response by regulating the expression of effector gene products that control the fate of a cell following DNA damage. Unstressed cells maintain p53 at low levels through regulated degradation, and p53 levels and activity are rapidly elevated upon genotoxic stress. Biochemical mechanisms that control the levels and activity of p53 are therefore of great interest. We and others have recently identified hAda3 (human homologue of yeast alteration/deficiency in activation 3) as a p53-interacting protein and enhancer of p53 activity. Here, we show that endogenous levels of p53 and Ada3 interact with each other, and by using inducible overexpression and short hairpin RNA-mediated knockdown strategies we demonstrate that hAda3 stabilizes p53 protein by promoting its acetylation. Use of a p53 mutant with mutations of known p300/CREB-binding protein acetylation sites demonstrated that hAda3-dependent acetylation is required for increase in p53 stability and target gene induction. Importantly, we demonstrate that endogenous hAda3 is essential for DNA damage-induced acetylation and stabilization of p53 as well as p53 target gene induction. Overall, our results establish hAda3, a component of coactivator complexes that include histone acetyltransferase p300/CREB-binding protein, as a critical mediator of acetylation-dependent stabilization and activation of p53 upon genotoxic stress in mammalian cells.
authors.affiliation: Division of Cancer Biology, Evanston Northwestern Healthcare Research Institute, IL 60201, USA.
authors.forename: Alo
authors.initials: A
authors.lastname: Nag
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Germaniuk-Kurowska
authors.forename: Manjari
authors.initials: M
authors.lastname: Dimri
authors.forename: Michael A
authors.initials: MA
authors.lastname: Sassack
authors.forename: Channabasavaiah Basavaraju
authors.initials: CB
authors.lastname: Gurumurthy
authors.forename: Qingshen
authors.initials: Q
authors.lastname: Gao
authors.forename: Goberdhan
authors.initials: G
authors.lastname: Dimri
authors.forename: Hamid
authors.initials: H
authors.lastname: Band
authors.forename: Vimla
authors.initials: V
authors.lastname: Band
mesh_terms: D000107:Acetylation; D050882:CREB-Binding Protein / Q000737:chemistry; D045744:Cell Line, Tumor; D004249:DNA Damage; D005786:Gene Expression Regulation; D016158:Genes, p53; D006801:Humans; D009154:Mutation; D034622:RNA Interference; D012190:Retroviridae / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors / Q000502:physiology*; D015533:Transcriptional Activation; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000378:metabolism*; D025801:Ubiquitin / Q000737:chemistry / Q000378:metabolism
chemical_list: C444103:TADA3 protein, human; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D025801:Ubiquitin; D050882:CREB-Binding Protein