CK2-dependent C-terminal phosphorylation at T300 directs the nuclear transport of TSPY protein

Biochem Biophys Res Commun. 2006 Mar 10;341(2):343-50. doi: 10.1016/j.bbrc.2005.12.190. Epub 2006 Jan 19.


TSPY (testis-specific protein, Y-encoded) is a member of the greater SET/NAP family of molecules with various functions, e.g., in chromatin remodeling, regulation of gene expression, and has been implicated to play a role in the malignant development of gonadoblastoma, testicular and prostate cancer. Here we demonstrate that the C-terminus has a functional role for the nucleo-cytoplasmatic shuttling of the TSPY protein. Using various combinations of in vitro mutagenesis and enhanced green fluorescent protein reporter gene-expression experiments we were able to show that while the deletion of C-terminus leads to a decreased stability and enhanced degradation of the protein, the selective mutation of a C-terminal CK2 phosphorylation site (T300) prevents the TSPY protein from entering the nucleus. We conclude that phosphorylation of the (T300) residue is a necessary and functional prerequisite for TSPY's transport into the nucleus reminding of comparable data from a related Drosophila molecule, NAP1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Casein Kinase II / metabolism
  • Casein Kinase II / physiology*
  • Cell Cycle Proteins / metabolism*
  • Cell Cycle Proteins / physiology
  • Cell Line
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Chromatin / metabolism
  • Cytoplasm / metabolism
  • DNA Mutational Analysis
  • DNA Primers / chemistry
  • Drosophila
  • Gene Deletion
  • Gene Expression Regulation
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Immunoblotting
  • Molecular Sequence Data
  • Mutagenesis
  • Mutation
  • Mutation, Missense
  • Phosphorylation
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / chemistry
  • Time Factors


  • Cell Cycle Proteins
  • Chromatin
  • DNA Primers
  • Recombinant Fusion Proteins
  • TSPY1 protein, human
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Casein Kinase II