Phosphorylation of ATF-1 enhances its DNA binding and transcription of the Na,K-ATPase alpha 1 subunit gene promoter.
Transcriptional activity of both ATF-1 and CREB is enhanced by protein phosphorylation. While enhancement has been attributed to an increase in binding affinity for a co-activator (CBP), induction of the DNA binding activity by phosphorylation is an open question. Using the Na,K-ATPase alpha1 subunit gene promoter, which has an asymmetrical ATF/CRE site, we analyzed the effect of phosphorylation on DNA binding activity of the ATF-1-CREB heterodimer. Dephosphorylation of the heterodimer in nuclear extracts reduced binding to the ATF/CRE site. Phosphorylation of ATF-1 at Ser63 enhanced its binding to the ATF/CRE site in both the homodimeric and heterodimeric forms. Transcription of the Na,K-ATPase alpha 1 subunit gene promoter was also stimulated by phosphorylated ATF-1 in vitro.
Kobayashi
M
M
Department of Biology, Jichi Medical School, Tochigi, Japan.
Shimomura
A
A
Hagiwara
M
M
Kawakami
K
K
D051697:Activating Transcription Factor 1; D000595:Amino Acid Sequence; D000818:Animals; D001482:Base Composition; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D012694:Serine / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D051697:Activating Transcription Factor 1; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D012694:Serine; D000254:Sodium-Potassium-Exchanging ATPase