title: Evidence for de novo sphingolipid biosynthesis in Toxoplasma gondii.
abstract: Glycolipids are important components of cellular membranes involved in various biological functions. In this report, we describe the identification of the de novo synthesis of glycosphingolipids by Toxoplasma gondii tachyzoites. Parasite-specific glycolipids were identified by metabolic labelling of parasites with tritiated serine and galactose. These glycolipids were characterised as sphingolipids based on the labelling protocol and their insensitivity towards alkaline treatment. Synthesis of parasite glycosphingolipids were inhibited by threo-phenyl-2-palmitoylamino-3-morpholino-1-propanol and L-cycloserine, two well-established inhibitors of de novo sphingolipid biosynthesis. The identified glycolipids were insensitive towards treatment with endoglycoceramidase II indicating that they might belong to globo-type glycosphingolipids. Taken together, we provide evidence for the first time that T. gondii is capable of synthesising glycosphingolipids de novo.
authors.affiliation: Medizinisches Zentrum für Hygiene und Medizinische Mikrobiologie, Philipps-Universität Marburg, Robert-Koch Strasse 17, 35037, Marburg, Germany.
authors.forename: Nahid
authors.initials: N
authors.lastname: Azzouz
authors.forename: Beatrice
authors.initials: B
authors.lastname: Rauscher
authors.forename: Peter
authors.initials: P
authors.lastname: Gerold
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Cesbron-Delauw
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Dubremetz
authors.forename: Ralph T
authors.initials: RT
authors.lastname: Schwarz
mesh_terms: D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D002518:Ceramides / Q000096:biosynthesis; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D003523:Cycloserine / Q000494:pharmacology; D005690:Galactose / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013107:Sphingolipids / Q000096:biosynthesis* / Q000302:isolation & purification; D014122:Toxoplasma / Q000378:metabolism*; D014316:Tritium / Q000378:metabolism
chemical_list: D000963:Antimetabolites; D002518:Ceramides; D013107:Sphingolipids; D014316:Tritium; D012694:Serine; D003523:Cycloserine; D006026:Glycoside Hydrolases; C050427:endoglycoceramidase; D005690:Galactose