title: p300 protein as a coactivator of GATA-5 in the transcription of cardiac-restricted atrial natriuretic factor gene.
abstract: A cellular target of adenovirus E1A oncoprotein, p300 is a transcriptional coactivator and a negative regulator of cellular proliferation. A previous study suggests that the p300 family is also involved in cell type-specific transcription in cardiac myocytes. However, nothing is known about which cardiac transcription factor(s) interact with and transactivate through these proteins. The transcription factors GATA-4/5/6 have been implicated as key regulators of cardiogenesis, and they participate in the transcription of many cardiac-specific genes. Here we show that E1A represses the GATA-5-dependent transactivation of a promoter derived from the cardiac-restricted atrial natriuretic factor gene. This repression is correlated with the interaction of E1A with p300, indicating that p300 participates in GATA-5-dependent transactivation. E1A markedly down-regulates endogenous atrial natriuretic factor expression, as well as disrupts the interaction between p300 and GATA-5. A small fragment of p300 containing the carboxyl-terminal cysteine/histidine-rich domain, sufficient to interact with GATA-5, prevents transcriptional activation by GATA-5 as a dominant-negative mutant. Consistent with its role as a coactivator, p300 markedly potentiates GATA-5-activated transcription. These results implicate p300 as an important component of myocardial cell differentiation and provide an insight into the relationship between mechanisms that mediate cell type-specific transcription and cell cycle regulation during cardiogenesis.
authors.affiliation: Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, 54 Kawara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kakita
authors.forename: K
authors.initials: K
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Morimoto
authors.forename: S
authors.initials: S
authors.lastname: Kaburagi
authors.forename: H
authors.initials: H
authors.lastname: Wada
authors.forename: S
authors.initials: S
authors.lastname: Sasayama
mesh_terms: D016475:3T3 Cells; D017500:Adenovirus E1A Proteins / Q000235:genetics; D000818:Animals; D000831:Animals, Newborn; D009320:Atrial Natriuretic Factor / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D019556:COS Cells; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D050881:E1A-Associated p300 Protein; D050992:GATA5 Transcription Factor; D005786:Gene Expression Regulation; D051379:Mice; D009154:Mutation; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D017500:Adenovirus E1A Proteins; D004268:DNA-Binding Proteins; D050992:GATA5 Transcription Factor; C494756:Gata5 protein, mouse; C494757:Gata5 protein, rat; D009687:Nuclear Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D009320:Atrial Natriuretic Factor; D050881:E1A-Associated p300 Protein; C494361:Ep300 protein, mouse; C494362:Ep300 protein, rat