title: A single aquaporin gene encodes a water/glycerol/urea facilitator in Toxoplasma gondii with similarity to plant tonoplast intrinsic proteins.
abstract: We describe a single aquaporin gene in Toxoplasma gondii which, surprisingly, has only 28% sequence similarity to the aquaglyceroporin of another apicomplexan parasite, Plasmodium falciparum. Sequence comparisons showed 47% similarity to water-specific plant aquaporins and the conservation of typical pore-forming residues. We established that the Toxoplasma aquaporin protein is a bifunctional membrane pore with intermediate water and high glycerol permeability. Furthermore, we identified hydroxyurea, an antineoplastic agent with inhibitory effects on parasite proliferation, as a permeant of this channel.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Tübingen, Morgenstelle 8, D-72076, Tübingen, Germany.
authors.forename: Slavica
authors.initials: S
authors.lastname: Pavlovic-Djuranovic
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Schultz
authors.forename: Eric
authors.initials: E
authors.lastname: Beitz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020346:Aquaporins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D005990:Glycerol / Q000378:metabolism*; D006918:Hydroxyurea / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D010539:Permeability; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D018272:Porins / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014122:Toxoplasma / Q000235:genetics* / Q000378:metabolism; D014508:Urea / Q000378:metabolism*; D014867:Water / Q000378:metabolism*; D014981:Xenopus
chemical_list: D020346:Aquaporins; D008565:Membrane Proteins; C449801:PfAQP protein, Plasmodium falciparum; D010940:Plant Proteins; D018272:Porins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C077491:tonoplast intrinsic protein, plant; D014867:Water; D014508:Urea; D005990:Glycerol; D006918:Hydroxyurea