Identification of novel bradyzoite-specific Toxoplasma gondii genes with domains for protein-protein interactions by suppression subtractive hybridization

Mol Biochem Parasitol. 2008 Feb;157(2):228-32. doi: 10.1016/j.molbiopara.2007.10.005. Epub 2007 Oct 24.


By using suppression subtractive hybridization we identified five so far uncharacterized stage specific genes in Toxoplasma gondii, which are induced during tachyzoite-to-bradyzoite differentiation. The mRNA level of a putative zinc-finger protein was increased 23-fold in bradyzoites, while the remaining four genes displayed induction levels >100-fold. Two of these genes predict proteins with domains for protein-protein interactions. One protein (ANK1) contains both, a TPR-domain and an ankyrin motif, which consists of seven repeats. ANK1 was shown by epitope tagging experiments to be localized in the cytosol. In a fraction of parasites, the myc-tagged fusion protein was additionally localized in the nucleus, which is in agreement with the presence of a bipartite nuclear targeting sequence in ANK1. The identification of bradyzoite-specific proteins with TPR- and ankyrin-domains supports the concept that during stage conversion a variety of proteins which are involved in protein-protein interactions are induced, thereby assisting the rebuilding of the proteome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Ankyrins / analysis
  • Ankyrins / genetics*
  • Cell Nucleus / chemistry
  • Cytosol / chemistry
  • DNA, Protozoan / chemistry
  • DNA, Protozoan / genetics
  • Gene Expression Regulation
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Nucleic Acid Hybridization / methods*
  • Protein Binding
  • Protein Structure, Tertiary
  • Protozoan Proteins / analysis
  • Protozoan Proteins / genetics*
  • Sequence Analysis, DNA
  • Toxoplasma / chemistry
  • Toxoplasma / genetics*


  • Ankyrins
  • DNA, Protozoan
  • Protozoan Proteins

Associated data

  • GENBANK/DQ512717