title: Physical and functional interactions among AP-2 transcription factors, p300/CREB-binding protein, and CITED2.
abstract: The transcriptional co-activators and histone acetyltransferases p300/CREB-binding protein (CBP) interact with CITED2, a transcription factor AP-2 (TFAP2) co-activator. p300/CBP, CITED2, and TFAP2A are essential for normal neural tube and cardiac development. Here we show that p300 and CBP co-activate TFAP2A in the presence of CITED2. TFAP2A transcriptional activity was modestly impaired in p300(+/-) and CBP(+/-) mouse embryonic fibroblasts; this was rescued by ectopic expression of p300/CBP. p300, TFAP2A, and endogenous CITED2 could be co-immunoprecipitated from transfected U2-OS cells indicating that they can interact physically in vivo. CITED2 interacted with the dimerization domain of TFAP2C, which is highly conserved in TFAP2A/B. In mammalian two-hybrid experiments, full-length p300 and TFAP2A interacted only when CITED2 was co-transfected. N-terminal residues of TFAP2A, containing the transactivation domain, are both necessary and sufficient for interaction with p300, and this interaction was independent of CITED2. Consistent with this, N-terminal residues of TFAP2A were required for p300- and CITED2-dependent co-activation. A histone acetyltransferase-deficient p300 mutant (D1399Y) did not co-activate TFAP2A and did not affect the expression or cellular localization of TFAP2A or CITED2. In mammalian two-hybrid experiments p300D1399Y failed to interact with TFAP2A, explaining, at least in part, its failure to function as a co-activator. Our results suggest a model wherein interactions among TFAP2A, CITED2, and p300/CBP are necessary for TFAP2A-mediated transcriptional activation and for normal neural tube and cardiac development.
authors.affiliation: Department of Cardiovascular Medicine, Wellcome Trust Centre for Human Genetics, Henry Wellcome Building of Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
authors.forename: José
authors.initials: J
authors.lastname: Bragança
authors.forename: Jyrki J
authors.initials: JJ
authors.lastname: Eloranta
authors.forename: Simon D
authors.initials: SD
authors.lastname: Bamforth
authors.forename: J Claire
authors.initials: JC
authors.lastname: Ibbitt
authors.forename: Helen C
authors.initials: HC
authors.lastname: Hurst
authors.forename: Shoumo
authors.initials: S
authors.lastname: Bhattacharya
mesh_terms: D000818:Animals; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D019281:Dimerization; D050881:E1A-Associated p300 Protein; D051379:Mice; D009687:Nuclear Proteins / Q000737:chemistry / Q000502:physiology*; D011233:Precipitin Tests; D012097:Repressor Proteins; D013329:Structure-Activity Relationship; D015534:Trans-Activators / Q000737:chemistry / Q000502:physiology*; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D015533:Transcriptional Activation
chemical_list: C110087:Cited2 protein, mouse; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D004247:DNA; D050881:E1A-Associated p300 Protein; C494361:Ep300 protein, mouse