The interaction between Ku antigen and REF1 protein mediates negative gene regulation by extracellular calcium

  • J Biol Chem. 1996 Apr 12;271(15):8593-8. doi: 10.1074/jbc.271.15.8593.
U Chung  1 ,  T Igarashi ,  T Nishishita ,  H Iwanari ,  A Iwamatsu ,  A Suwa ,  T Mimori ,  K Hata ,  S Ebisu ,  E Ogata ,  T Fujita ,  T Okazaki
Affiliations
  • 1. Fourth Department of Internal Medicine, University of Tokyo School of Medicine, Bunkyo-ku, Tokyo 112, Japan.
PMID: 8621488 DOI: 10.1074/jbc.271.15.8593
Abstract

Through the specific binding of a negative calcium-responsive element to its binding protein in response to extracellular CA (Ca2+e), negative calcium-responsive element-bearing genes, such as the human parathyroid hormone gene, are negatively regulated by Ca2+e. The Ku antigen mediated negative gene regulation by Ca2+e by interacting with a redox factor protein, REF1. Although sequence-nonspecific DNA binding activity of the Ku antigen has been well characterized, the mechanism of its sequence-specific DNA binding remained obscure. Here, we report that the specific binding of the Ku antigen to another protein, REF1, leads to DNA-protein complex formation with a novel sequence specificity and thereby regulates gene expression.