Mammalian beta-polymerase promoter: phosphorylation of ATF/CRE-binding protein and regulation of DNA binding

Nucleic Acids Res. 1991 Jun 25;19(12):3369-75. doi: 10.1093/nar/19.12.3369.


The gene for the mammalian DNA repair enzyme DNA polymerase beta (beta-pol) is constitutively expressed in most cells, but is regulated in a tissue-specific fashion and can be induced in response to some types of DNA damaging agents. The promoter for the human beta-pol gene has been characterized and found to be TATA-less, but it does have multiple GC boxes and one ATF/CRE-binding site located within 50 residues 5' of the major mRNA start site. The ATF/CRE-binding site has been found to be essential for activity of the cloned promoter. We report that a bovine testes DNA-binding protein with specificity for the beta-pol promoter ATF/CRE-binding site is phosphorylated in vivo and contains several phosphorylation sites. Sequence specific DNA-binding by the purified protein is reduced when the natural protein is dephosphorylated or when it is hyperphosphorylated by protein kinase A (cKA) in vitro. These results suggest the possibility that phosphorylation systems may change binding of this ATF/CRE-binding protein to the beta-pol promoter and in turn modulate the promoter. Possible correlation of the results with transient expression activity of the cloned beta-pol promoter fusion gene was obtained in 293 cells. Cotransfection with a cKA expression plasmid to elevate phosphorylation was found to strongly reduce promoter activity.

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Cattle
  • Cell Line
  • Cyclic AMP Response Element-Binding Protein
  • DNA / metabolism
  • DNA Polymerase I / genetics*
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism*
  • Kinetics
  • Male
  • Molecular Sequence Data
  • Phosphorylation
  • Promoter Regions, Genetic*
  • Testis / metabolism


  • Cyclic AMP Response Element-Binding Protein
  • DNA-Binding Proteins
  • DNA
  • DNA Polymerase I