Physical and Functional Interactions among AP-2 Transcription Factors, p300/CREB-binding Protein, and CITED2

• Published in: The Journal of biological chemistry Vol. 278; no. 18; pp. 16021 - 16029
• Main Authors: Bragança, José, Eloranta, Jyrki J., Bamforth, Simon D., Ibbitt, J. Claire, Hurst, Helen C., Bhattacharya, Shoumo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 02.05.2003; American Society for Biochemistry and Molecular Biology
• Subjects: Animals; Dimerization; DNA - metabolism; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - physiology; E1A-Associated p300 Protein; Mice; Nuclear Proteins - chemistry; Nuclear Proteins - physiology; Precipitin Tests; Repressor Proteins; Structure-Activity Relationship; Trans-Activators - chemistry; Trans-Activators - physiology; Transcription Factor AP-2; Transcription Factors - chemistry; Transcription Factors - physiology; Transcriptional Activation
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M208144200

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.