Identification of novel bradyzoite-specific Toxoplasma gondii genes with domains for protein-protein interactions by suppression subtractive hybridization.
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.
Institute of Medical Microbiology, University of Göttingen, Kreuzbergring 57, Göttingen, Germany.
Johannes
J
Friesen
Tobias
T
Fleige
Uwe
U
Gross
Wolfgang
W
Bohne
D000595:Amino Acid Sequence; D000818:Animals; D017487:Ankyrins / Q000032:analysis / Q000235:genetics*; D002467:Cell Nucleus / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D005786:Gene Expression Regulation; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization / Q000379:methods*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000032:analysis / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014122:Toxoplasma / Q000737:chemistry / Q000235:genetics*
D017487:Ankyrins; D016054:DNA, Protozoan; D015800:Protozoan Proteins