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

U Chung1, T Igarashi, T Nishishita

  • 1Fourth Department of Internal Medicine, University of Tokyo School of Medicine, Bunkyo-ku, Tokyo 112, Japan.

The Journal of Biological Chemistry
|April 12, 1996
PubMed

Insights

Extracellular calcium (Ca2+e) regulates gene expression via the Ku antigen and REF1 protein. Their specific interaction enables sequence-specific DNA binding, uncovering a novel mechanism for gene regulation.

Area of Science:

  • Molecular Biology
  • Gene Regulation
  • Biochemistry

Background:

  • Extracellular calcium (Ca2+e) negatively regulates genes like the human parathyroid hormone gene through specific DNA-binding proteins.
  • The Ku antigen is known to mediate this Ca2+e-dependent gene regulation by interacting with the REF1 protein.
  • The mechanism behind the Ku antigen's sequence-specific DNA binding has remained unclear.

Purpose of the Study:

  • To elucidate the mechanism by which the Ku antigen achieves sequence-specific DNA binding.
  • To understand the role of the interaction between Ku antigen and REF1 in gene regulation.

Main Methods:

  • Investigated the interaction between the Ku antigen and REF1 protein.
  • Analyzed the DNA-binding properties of the Ku antigen-REF1 complex.

Main Results:

  • Demonstrated that the specific binding of the Ku antigen to REF1 is crucial for its DNA-binding activity.
  • Identified a novel sequence specificity mediated by the Ku antigen-REF1 complex.
  • Showed that this complex formation leads to the regulation of gene expression.

Conclusions:

  • The interaction between Ku antigen and REF1 confers sequence-specific DNA binding to the Ku antigen.
  • This novel mechanism provides new insights into calcium-mediated gene regulation.

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