PubMed Journals: Nucleic Acids Res
Source: PMID: 9016641
⇦ ⇨ Nucleic Acids Res. 1997 Feb 15;25(4):877-82.
Phosphorylation of ATF-1 enhances its DNA
binding and transcription of the Na,K-ATPase
alpha 1 subunit gene promoter.
Kobayashi M(1), Shimomura A, Hagiwara M,
(1) Department of Biology, Jichi Medical
School, Tochigi, Japan.
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.
PMCID: PMC146500 PMID: 9016641 [Indexed