Activation of androgen receptor function by a novel nuclear protein kinase

Mol Biol Cell. 1998 Sep;9(9):2527-43. doi: 10.1091/mbc.9.9.2527.


Androgen receptor (AR) belongs to the nuclear receptor superfamily and mediates the biological actions of male sex steroids. In this work, we have characterized a novel 130-kDa Ser/Thr protein kinase ANPK that interacts with the zinc finger region of AR in vivo and in vitro. The catalytic kinase domain of ANPK shares considerable sequence similarity with the minibrain gene product, a protein kinase suggested to contribute to learning defects associated with Down syndrome. However, the rest of ANPK sequence, including the AR-interacting interface, exhibits no apparent homology with other proteins. ANPK is a nuclear protein that is widely expressed in mammalian tissues. Its overexpression enhances AR-dependent transcription in various cell lines. In addition to the zinc finger region, ligand-binding domain and activation function AF1 of AR are needed, as the activity of AR mutants devoid of these domains was not influenced by ANPK. The receptor protein does not appear to be a substrate for ANPK in vitro, and overexpression of ANPK does not increase the extent of AR phosphorylation in vivo. In view of this, it is likely that ANPK-mediated activation of AR function is exerted through modification of AR-associated proteins, such as coregulatory factors, and/or through stabilization of the receptor protein against degradation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • CHO Cells
  • COS Cells
  • Cell Line
  • Cell Nucleus / enzymology
  • Cricetinae
  • DNA, Complementary
  • Gene Expression
  • Humans
  • Male
  • Molecular Sequence Data
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • PC12 Cells
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Rats
  • Receptors, Androgen / metabolism*
  • Saccharomyces cerevisiae
  • Sequence Homology, Amino Acid
  • Transcriptional Activation


  • DNA, Complementary
  • Hipk3 protein, rat
  • Nuclear Proteins
  • Receptors, Androgen
  • Protein-Serine-Threonine Kinases

Associated data

  • GENBANK/AF036959