title: Identification of Toxoplasma TgPH1, a pleckstrin homology domain-containing protein that binds to the phosphoinositide PI(3,5)P2.
abstract: The phosphoinositide phosphatidylinositol-3,5-bisphosphate (PI(3,5)P2) plays crucial roles in the maintenance of lysosome/vacuole morphology, membrane trafficking and regulation of endolysosome-localized membrane channel activity. In Toxoplasma gondii, we previously reported that PI(3,5)P2 is essential for parasite survival by controlling homeostasis of the apicoplast, a particular organelle of algal origin. Here, by using a phosphoinositide pull-down assay, we identified TgPH1 in Toxoplasma a protein conserved in many apicomplexan parasites. TgPH1 binds specifically to PI(3,5)P2, shows punctate intracellular localization, but plays no vital role for tachyzoite growth in vitro. TgPH1 is a protein predominantly formed by a pleckstrin homology (PH) domain. So far, PH domains have been described to bind preferentially to bis- or trisphosphate phosphoinositides containing two adjacent phosphates (i.e. PI(3,4)P2, PI(4,5)P2, PI(3,4,5)P3). Therefore, our study reveals an unusual feature of TgPH1 which binds preferentially to PI(3,5)P2.
authors.affiliation: Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS, Université de Montpellier, Montpellier, France.
authors.forename: Wassim
authors.initials: W
authors.lastname: Daher
authors.affiliation: Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS, Université de Montpellier, Montpellier, France.
authors.forename: Juliette
authors.initials: J
authors.lastname: Morlon-Guyot
authors.affiliation: Plateforme de Protéomique et des Peptides Modifiés (P3M), Institut Pasteur de Lille, CNRS, Université de Lille, 59000 Lille, France.
authors.forename: Tchilabalo Dilezitoko
authors.initials: TD
authors.lastname: Alayi
authors.affiliation: Plateforme de Protéomique et des Peptides Modifiés (P3M), Institut Pasteur de Lille, CNRS, Université de Lille, 59000 Lille, France; Laboratory of Cellular and Molecular Biology of Toxoplasma, Center for Infection and Immunity of Lille, CNRS UMR8204, INSERM 1019, Université de Lille, Institut Pasteur de Lille, 59000, Lille, France.
authors.forename: Stan
authors.initials: S
authors.lastname: Tomavo
authors.affiliation: Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS, Université de Montpellier, Montpellier, France.
authors.forename: Kai
authors.initials: K
authors.lastname: Wengelnik
authors.affiliation: Dynamique des Interactions Membranaires Normales et Pathologiques, UMR5235 CNRS, Université de Montpellier, Montpellier, France. Electronic address: mylebrun@univ-montp2.fr.
authors.forename: Maryse
authors.initials: M
authors.lastname: Lebrun
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D017353:Gene Deletion; D015870:Gene Expression; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D000070539:Pleckstrin Homology Domains / Q000235:genetics; D011485:Protein Binding; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014122:Toxoplasma / Q000235:genetics / Q000378:metabolism*
chemical_list: D018129:Phosphatidylinositol Phosphates; D015800:Protozoan Proteins; C106336:phosphatidylinositol 3,5-diphosphate
keywords: Apicoplast; PI(3,5)P(2); Phosphoinositides; Pleckstrin Homology domain; Toxoplasma gondii