Control of cardiac-specific transcription by p300 through myocyte enhancer factor-2D.
The transcriptional integrator p300 regulates gene expression by interaction with sequence-specific DNA-binding proteins and local remodeling of chromatin. p300 is required for cardiac-specific gene transcription, but the molecular basis of this requirement is unknown. Here we report that the MADS (MCM-1, agamous, deficiens, serum response factor) box transcription factor myocyte enhancer factor-2D (MEF-2D) acts as the principal conduit for cardiac transcriptional activation by p300. p300 activation of the native 2130-base pair human skeletal alpha-actin promoter required a single hybrid MEF-2/GATA-4 DNA motif centered at -1256 base pairs. Maximal expression of the promoter in cultured myocytes and in vivo correlated with binding of both MEF-2 and p300, but not GATA-4, to this AT-rich motif. p300 and MEF-2 were coprecipitated from cardiac nuclear extracts by an oligomer containing this element. p300 was found exclusively in a complex with MEF-2D at this and related sites in other cardiac-restricted promoters. MEF-2D, but not other MEFs, significantly potentiated cardiac-specific transcription by p300. No physical or functional interaction was observed between p300 and other factors implicated in skeletal actin transcription, including GATA-4, TEF-1, or SRF. These results show that, in the intact cell, p300 interactions with its protein targets are highly selective and that MEF-2D is the preferred channel for p300-mediated transcriptional control in the heart.
Slepak
T I
TI
Department of Molecular and Cellular Pharmacology, University of Miami, Florida 33101, USA.
Webster
K A
KA
Zang
J
J
Prentice
H
H
O'Dowd
A
A
Hicks
M N
MN
Bishopric
N H
NH
D000199:Actins / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D019921:Biotinylation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050881:E1A-Associated p300 Protein; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D006801:Humans; D064326:MEF2 Transcription Factors; D008297:Male; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D018006:Myogenic Regulatory Factors; D009687:Nuclear Proteins / Q000378:metabolism*; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D017354:Point Mutation; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D000199:Actins; D004268:DNA-Binding Proteins; D064326:MEF2 Transcription Factors; D018006:Myogenic Regulatory Factors; D009687:Nuclear Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D004247:DNA; D050881:E1A-Associated p300 Protein; C494362:Ep300 protein, rat