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. 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. Although p53 was identified as a tumor suppressor protein more than 2 decades ago and is the most commonly mutated gene in human cancers (1Hollstein M. Sidransky D. Vogelstein B. Harris C.C. Science. 1991; 253: 49-53Crossref PubMed Scopus (7479) Google Scholar, 2Hollstein M. Rice K. Greenblatt M.S. Soussi T. Fuchs R. Sorlie T. Hovig E. Smith-Sorensen B. Montesano R. Harris C.C. Nucleic Acids Res. 1994; 22: 3551-3555PubMed Google Scholar, 3Lane D.P. Nature. 1992; 358: 15-16Crossref PubMed Scopus (4523) Google Scholar), mechanisms of its tumor suppressor function remain a challenge. The p53 protein is maintained at a very low level in unstressed cells and is rapidly stabilized and activated during periods of cellular stress, such as that induced by DNA damage, resulting in enhanced binding to promoters of specific target genes and their transcriptional activation (4Appella E. Anderson C.W. Eur. J. Biochem. 2001; 268: 2764-2772Crossref PubMed Scopus (916) Google Scholar, 5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar, 6Vogelstein B. Lane D. Levine A.J. Nature. 2000; 408: 307-310Crossref PubMed Scopus (5850) Google Scholar, 7Levine A.J. Cell. 1997; 88: 323-331Abstract Full Text Full Text PDF PubMed Scopus (6759) Google Scholar). DNA damage-induced post-translational modifications, such as phosphorylation, ubiquitination, and acetylation, have emerged as critical mediators of altered p53 protein stability (4Appella E. Anderson C.W. Eur. J. Biochem. 2001; 268: 2764-2772Crossref PubMed Scopus (916) Google Scholar, 8Bode A.M. Dong Z. Nat. Rev. Cancer. 2004; 4: 793-805Crossref PubMed Scopus (1028) Google Scholar). Acetylation of p53 provides a particularly important mechanism to control p53 stability as well as its activity (5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar, 9Oren M. J. Biol. Chem. 1999; 274: 36031-36034Abstract Full Text Full Text PDF PubMed Scopus (491) Google Scholar). Acetylation of p53 involves the recruitment of coactivator complexes containing histone acetyltransferases (HATs) 3The abbreviations used are: HAT, histone acetyltransferase; CREB, cAMP-response element-binding protein; CBP, CREB-binding protein; PCAF, p300/CBP-associated factor; hAda3, human Ada3; hGcn5, human Gcn5; GFP, green fluorescent protein; RT, reverse transcription; RNAi, RNA interference; HRP, horseradish peroxidase; shRNA, short hairpin RNA. to promoter-bound p53 function, a process that concurrently controls the level of histone acetylation and hence the accessibility of active promoters to general transcriptional machinery (10Barlev N.A. Liu L. Chehab N.H. Mansfield K. Harris K.G. Halazonetis T.D. Berger S.L. Mol. Cell. 2001; 8: 1243-1254Abstract Full Text Full Text PDF PubMed Scopus (598) Google Scholar, 11Espinosa J.M. Emerson B.M. Mol. Cell. 2001; 8: 57-69Abstract Full Text Full Text PDF PubMed Scopus (365) Google Scholar). Understanding the molecular mechanisms that promote stress-induced acetylation and consequent alterations in the activity of p53 is therefore of significant biological interest and extremely relevant to human cancer. Previous studies have identified a number of HATs that can acetylate p53 protein in vitro and appear to mediate p53 acetylation in vivo. These analyses have identified p300/CREB-binding protein (CBP) as well as p300/CBP-associated factor (PCAF) as p53-directed HATs (5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar, 12Gu W. Roeder R.G. Cell. 1997; 90: 595-606Abstract Full Text Full Text PDF PubMed Scopus (2189) Google Scholar, 13Ito A. Lai C.H. Zhao X. Saito S. Hamilton M.H. Appella E. Yao T.P. EMBO J. 2001; 20: 1331-1340Crossref PubMed Scopus (441) Google Scholar). Interestingly, different HATs may selectively acetylate specific sites in p53, resulting in distinct biological outcomes. For example, p300-dependent acetylation of Lys-370, -372, -373, -381, and -382 has been correlated with p53 stabilization and increased DNA binding (12Gu W. Roeder R.G. Cell. 1997; 90: 595-606Abstract Full Text Full Text PDF PubMed Scopus (2189) Google Scholar, 14Lohrum M.A. Woods D.B. Ludwig R.L. Balint E. Vousden K.H. Mol. Cell. Biol. 2001; 21: 8521-8532Crossref PubMed Scopus (195) Google Scholar, 15Luo J. Li M. Tang Y. Laszkowska M. Roeder R.G. Gu W. Proc. Natl. Acad. Sci. U. S. A. 2004; 101: 2259-2264Crossref PubMed Scopus (343) Google Scholar). Notably, analysis of knock-in mice with a missense (K317R) mutation suggests a negative regulatory role of the PCAF-dependent Lys-317 (human p53 Lys-320) acetylation site in p53 (16Chao C. Wu Z. Mazur S.J. Borges H. Rossi M. Lin T. Wang J.Y. Anderson C.W. Appella E. Xu Y. Mol. Cell. Biol. 2006; 26: 6859-6869Crossref PubMed Scopus (91) Google Scholar). Thus, cellular factors that facilitate HAT-dependent p53 acetylation are of substantial interest in our understanding of p53 as a tumor suppressor. We and others have recently identified human Ada3 (alteration/deficiency in activation) as a novel p53-binding protein (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar, T. T. R. EMBO J. 2001; 20: PubMed Scopus Google Scholar, M. A. Meng G. Gao G. D. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). Ada3 is the homologue of the yeast essential component of the transcriptional coactivator of and control a B. Berger S. J. L. Mol. Cell. Biol. PubMed Scopus Google Scholar). Notably, yeast and each required for the transcriptional activity of a human p53 to in yeast R. Halazonetis T.D. Berger S.L. 1997; PubMed Scopus Google Scholar). mammalian overexpression of hAda3 increased p53 levels (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google and enhanced the transcriptional activation of p53 target genes (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar, T. T. R. EMBO J. 2001; 20: PubMed Scopus Google Scholar). of mammalian cell identified hAda3 as a component of complexes that include and T. X. R.L. T. J. Y. Cell. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar). hAda3 is in a number of such as that include and E. A. A.M. Roeder R.G. Mol. Biol. 2001; 21: PubMed Scopus Google Scholar). studies have that hAda3 with T. T. R. EMBO J. 2001; 20: PubMed Scopus Google Scholar). the of Ada3 to interact with transcriptional activation studies that Ada3 may a role to complexes to p53 and p53 acetylation, and activity. we used inducible hAda3 knockdown of endogenous hAda3, and a p53 mutant in acetylation to demonstrate essential role of hAda3 in p53 acetylation, and transcriptional activation following DNA damage. and a human cell was in with a human cells was in as R. Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar). of has been (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar). of was using to the p53 and p53 was and was and cells in and with the expression using The was of the cells in and and of cell for and to with the of by the expression with cells using the M. A. Meng G. Gao G. D. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, G. Zhao Y. A. Zeng M. G. Gao R. H. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). cells with and for in containing cells cells in a with was by (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google the and sites of cells cells with for of cell to by with of used in are as The in the cells with hAda3 as M. A. Meng G. Gao G. D. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, G. Zhao Y. A. Zeng M. G. Gao R. H. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). cells in for and expression of endogenous hAda3 was in the cell using using in our (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar). The inducible by the in the as by the cells used to the inducible cells the with and with of protein and of protein for at For 2 of was with 2 of for 2 with of protein protein to the and for at The with the binding and the by the with the for at and the with the by and with cells with p53, and expression as in the using cells with for and cell with containing and to with and to using RNA and RNA was using The was with of RNA using the following p53 and reverse and reverse and and reverse The products of the p53 of cells with p53 in with cells and and of cells of was to the and cells at the cell and and by analysis was using for of to DNA cells hAda3 to of with cells at of and as and for p53, p53, hAda3 with and others have (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar, T. T. R. EMBO J. 2001; 20: PubMed Scopus Google that expression of hAda3 and p53 hAda3 with Here, we by hAda3 and endogenous p53 in cells with and hAda3 by by with a of cell with by with and of hAda3 as well as endogenous hAda3 with endogenous p53 was in and the increased upon and These results and our of of hAda3 with hAda3 the of to p53, and that overexpression of hAda3 and p53 transcriptional activity (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar, T. T. R. EMBO J. 2001; 20: PubMed Scopus Google Scholar). we that overexpression of hAda3 increased the levels of a p53 protein (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google hAda3 a endogenous p53, we a of human cell for expression of of in cell was and hAda3 levels elevated in cells by for a increase in the level of endogenous p53 protein was in p53 levels was upon of the cell with the control These our results with p53 (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google and demonstrate that of the cellular hAda3 protein levels the level of the endogenous p53 hAda3 the of p53 the of the regulated p53 protein in the cells M. J. Biol. Chem. 1999; 274: 36031-36034Abstract Full Text Full Text PDF PubMed Scopus (491) Google Scholar), that hAda3-dependent increase in p53 levels may a post-translational we to of hAda3 expression p53 For cells with by for for of protein and analysis of p53 Although to the and increased p53 protein analysis that p53 levels to levels of the gene used as a control and the increase in the level of protein, a transcriptional target of p53, was by increase in levels These that the of p53 protein upon hAda3 overexpression is to to a to the hAda3-dependent increase in p53 levels increase in the stability of p53 protein, we the of p53 protein following of protein For cells with p53 expression with expression The cells in the of and p53 levels by of cellular at by to the in the overexpression of in a of p53 with cells hAda3 The of the p53 protein increased in cells Ada3 overexpression to more than in cells with hAda3 overexpression with the of p53 our that hAda3 overexpression p53 protein levels by promoting its hAda3 the of p53 protein is and is by the J.M. Res. Google Scholar), and is known to a role in process Y. R. A. M. Nature. 1997; PubMed Scopus Google Scholar, M.H. Vousden K.H. Nature. 1997; PubMed Scopus Google Scholar). have that that with and p53 p53 Y. S. Wu L. G. Wang H. Y. J. Y. W. Wu M. Mol. Biol. 2006; 26: PubMed Scopus Google Scholar, H. Mol. Cell. 2006; 22: Full Text Full Text PDF PubMed Scopus Google Scholar). Thus, we increase in p53 p53 For cells with p53, and of with and with by with to The was for p53, of and enhanced p53 as with p53 and Notably, of hAda3 the of p53 in a with and is of used in with the These results demonstrate that hAda3 stabilizes p53 by its hAda3 the of p53 of p53 is by post-translational with protein and a number of modifications, such as acetylation and (4Appella E. Anderson C.W. Eur. J. Biochem. 2001; 268: 2764-2772Crossref PubMed Scopus (916) Google Scholar, 5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar). Acetylation of can stability by as well as by and (5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar, 12Gu W. Roeder R.G. Cell. 1997; 90: 595-606Abstract Full Text Full Text PDF PubMed Scopus (2189) Google Scholar, 15Luo J. Li M. Tang Y. Laszkowska M. Roeder R.G. Gu W. Proc. Natl. Acad. Sci. U. S. A. 2004; 101: 2259-2264Crossref PubMed Scopus (343) Google Scholar, M. J. Gu W. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). hAda3 has been demonstrated to complexes containing such as and T. X. R.L. T. J. Y. Cell. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar, S.L. Biol. 1999; PubMed Scopus Google Scholar), with the of yeast Ada3 to histone activity S.L. Biol. 1999; PubMed Scopus Google Scholar, R. Berger S.L. EMBO J. 1997; PubMed Scopus Google Scholar, R. W. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), we that hAda3 may p53 by promoting its acetylation. cells with p53 with each was in each was used as a control the was to for to DNA damage, and cell for and p53 levels using as well as p53 levels increased upon and Notably, p53 levels in cells hAda3, and levels increased upon the increase in p53 the increase in p53 levels and the of the in using These results show that overexpression of hAda3 acetylation of p53 in a significant Acetylation of p53 for hAda3-dependent studies have a number of p53 that as sites for acetylation by the HAT, and (4Appella E. Anderson C.W. Eur. J. Biochem. 2001; 268: 2764-2772Crossref PubMed Scopus (916) Google Scholar, 12Gu W. Roeder R.G. Cell. 1997; 90: 595-606Abstract Full Text Full Text PDF PubMed Scopus (2189) Google Scholar, D. J. Nature. 1997; PubMed Scopus Google Scholar). Notably, has been to acetylate p53 Lys-370, and and missense mutations of in a mutant that is by J. D. A. Gu W. Nature. 2000; 408: PubMed Scopus Google Scholar). Thus, we used mutant to acetylation was required for hAda3-dependent p53 cells with mutant p53 with and cell using for and levels of to the increase in the level of p53 hAda3 was the level of mutant p53 protein with to the of the was by the overexpression of hAda3 the that of stabilization of mutant p53 may to its to to hAda3, we analyses of the cell in of demonstrated hAda3 with the and mutant p53 These results demonstrate that acetylation of p53, a is a for hAda3-dependent stabilization of is well known that DNA damage-induced increase in p53 activity involves a (5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar, T.P. Mol. Biol. Cell. PubMed Scopus Google Scholar). to the role of hAda3 of p53, p53 was in cells with of cell for the levels of hAda3, p53, and p53 by in hAda3 induced of p53 in a that hAda3 the p53 at the of hAda3 the of using hAda3 overexpression analyses in the of and endogenous p53 the that endogenous hAda3 a role in we used a of the cell with p53 to the expression of endogenous These cells with a distinct with a the cells with with to the and cell by with the that of cells with the levels of hAda3 and that p53 levels of cells with hAda3 in substantial in Ada3 protein we a in the levels of endogenous p53 protein in cells hAda3 was induced These results that endogenous hAda3 is required for the stability of p53 hAda3 for Acetylation of the important role of p53 during DNA we to the role of endogenous hAda3 in p53 acetylation upon DNA damage. We the levels of and p53 in cells with hAda3 knockdown to DNA damage. For we of the cell in the hAda3 a control by The cells used in show in Ada3 levels and levels of p53 protein These cells to different analysis of cell demonstrated that hAda3 the in a in hAda3 protein levels Notably, with specific for and in p53 that the DNA damage-induced increase in p53 acetylation as well as p53 protein levels in the hAda3 knockdown cells as with the control cells analysis demonstrated the levels of p53 target in hAda3 cells as with control that hAda3-dependent acetylation and stabilization of p53 is required for the activity of p53 as a transcriptional we to hAda3 has the levels of cells with of expression analysis of the cell that the level by expression of hAda3 that expression is p53 results demonstrate that hAda3 essential role in p53 acetylation and stabilization of endogenous p53 protein and its consequent activation as a The p53 gene is the most gene in human cancers and is mutated in of cancers (1Hollstein M. Sidransky D. Vogelstein B. Harris C.C. Science. 1991; 253: 49-53Crossref PubMed Scopus (7479) Google Scholar, 2Hollstein M. Rice K. Greenblatt M.S. Soussi T. Fuchs R. Sorlie T. Hovig E. Smith-Sorensen B. Montesano R. Harris C.C. Nucleic Acids Res. 1994; 22: 3551-3555PubMed Google Scholar, 3Lane D.P. Nature. 1992; 358: 15-16Crossref PubMed Scopus (4523) Google Scholar). The p53 protein is a factor that activated in response to of cellular stress, such as DNA damage, and in p53 the of genes to cell more to DNA 2004; PubMed Scopus Google Scholar, S. Vousden K.H. Mol. Sci. 1999; PubMed Scopus Google Scholar). in the activation of cellular involves the stabilization and activation of the DNA binding activity of have emerged as mechanisms in (4Appella E. Anderson C.W. Eur. J. Biochem. 2001; 268: 2764-2772Crossref PubMed Scopus (916) Google Scholar). factors that control the post-translational of p53 and hence its have therefore important in understanding the of Here, we demonstrate a critical role of hAda3 in DNA damage-induced stabilization and activation of We that hAda3-dependent of p53 stability and activity is by acetylation of Ada3 was identified as a component of the yeast coactivator that protein in with a protein R. W. S. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). Ada3 with the activation of transcriptional as a component in the recruitment of and its activity to transcriptional to specific promoters S.L. Biol. 1999; PubMed Scopus Google Scholar, A. R. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar, A. D. A. Berger S.L. Mol. Cell. Biol. 1999; PubMed Scopus Google Scholar). studies of Ada3 and in have demonstrated that complexes that can the yeast For example, mammalian cells appear to a that include Y. 1997; PubMed Scopus Google Scholar). distinct in and studies in demonstrate that are essential for of distinct functions T. L. Z. S. A. L. J. Mol. Cell. Biol. PubMed Scopus Google Scholar). Ada3 has been as component of complexes in and a role of Ada3 in coactivator functions of Ada3 emerged as a binding of the human (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar, M. A. Meng G. Gao G. D. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, G. Zhao Y. A. Zeng M. G. Gao R. H. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar), the that the function of Ada3 during Thus, we have our understanding the of human we and others have that hAda3 with p53 and that hAda3 overexpression the transcriptional activity of p53 (17Kumar A. Zhao Y. Meng G. Zeng M. Srinivasan S. Delmolino L.M. Gao G. H. Mol. Biol. 22: PubMed Scopus Google Scholar, T. T. R. EMBO J. 2001; 20: PubMed Scopus Google Scholar). the of and the by hAda3 p53 function have and establish hAda3 as a relevant and of p53 stability and activity the of p53 acetylation. the function of to coactivator has been in the of through histone acetylation. have demonstrated that in transcriptional factors are by acetylation. acetylation of p53 provides a mechanism to control its activity. has been demonstrated that DNA and stress rapidly p53 acetylation a number of and and PCAF, have been as in the acetylation process (5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar, 12Gu W. Roeder R.G. Cell. 1997; 90: 595-606Abstract Full Text Full Text PDF PubMed Scopus (2189) Google Scholar, L. R. Halazonetis T.D. Berger S.L. Mol. Biol. 1999; PubMed Scopus Google Scholar), their role as well as the role of and HATs has been Importantly, mutation of p53 sites identified as acetylation sites DNA damage-induced activation of p53 J. D. A. Gu W. Nature. 2000; 408: PubMed Scopus Google Scholar). mutations of acetylation sites in the the role of acetylation in of DNA response in (16Chao C. Wu Z. Mazur S.J. Borges H. Rossi M. Lin T. Wang J.Y. Anderson C.W. Appella E. Xu Y. Mol. Cell. Biol. 2006; 26: 6859-6869Crossref PubMed Scopus (91) Google Scholar). Thus, our that hAda3 a role in acetylation-dependent stabilization and activity of p53 a significant in understanding the mechanisms that control p53 Notably, analyses using human p53 to that yeast and required for in the yeast R. Halazonetis T.D. Berger S.L. 1997; PubMed Scopus Google Scholar). These that the role of Ada3 to histone acetylation machinery for acetylation of factors and the factors may analyses in the of transcriptional as well as studies in is the HAT-dependent acetylation are by mechanism for acetylation-dependent of p53 is its of in interact with p53 and target for degradation, low p53 levels in unstressed cells. in that hAda3 with the of p53, to the p53 stabilization of has been to promote of p53, its M.A. Woods D.B. Ludwig R.L. Balint E. Vousden K.H. Mol. Cell. Biol. 2001; 21: 8521-8532Crossref PubMed Scopus (195) Google Scholar). DNA and resulting in stabilization of p53 and of its and for binding to target is that and for binding to the transcriptional activation of p53 R. T. J. Biol. Chem. 1999; 274: Full Text Full Text PDF PubMed Scopus Google Scholar), a and acetylation. We that Ada3 with p53 provides a mechanism as well as HATs are to p53 for its acetylation-dependent that a mutant p53 that acetylation sites is stabilized by Ada3 is with of ubiquitination, acetylation a role in promoting activity of p53 by promoting and by mechanisms (5Sakaguchi K. Herrera J.E. Saito S. Miki T. Bustin M. Vassilev A. Anderson C.W. Appella E. Genes Dev. 1998; 12: 2831-2841Crossref PubMed Scopus (1025) Google Scholar, J. D. A. Gu W. Nature. 2000; 408: PubMed Scopus Google Scholar). The of acetylation of p53 histone acetylation at promoters is important that in The substantial of of p53 acetylation, and target gene by Ada3 knockdown a important of protein in machinery to role for Ada3 a role of a that is Ada3 for with p53 the that most p53-directed HATs and are known to in with and studies that Ada3 and may in a T. T. R. EMBO J. 2001; 20: PubMed Scopus Google Scholar, T. X. R.L. T. J. Y. Cell. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar, E. A. A.M. Roeder R.G. Mol. Biol. 2001; 21: PubMed Scopus Google Scholar). These are with the that Ada3 may the HATs Previous studies of a with p53 D. J. Nature. 1997; PubMed Scopus Google studies using the that may to p53 analyses and of cells and mice in Ada3 to These studies are in our our of hAda3 as a critical of p53 acetylation, and activity provides a p53 studies of the of coactivator complexes as well as biological analyses of in and p53-directed HATs the as well as the biological of p53 We Vogelstein of for p53 and Gu for the mutant p53