title: Biosynthesis of GDP-fucose and other sugar nucleotides in the blood stages of Plasmodium falciparum.
abstract: Carbohydrate structures play important roles in many biological processes, including cell adhesion, cell-cell communication, and host-pathogen interactions. Sugar nucleotides are activated forms of sugars used by the cell as donors for most glycosylation reactions. Using a liquid chromatography-tandem mass spectrometry-based method, we identified and quantified the pools of UDP-glucose, UDP-galactose, UDP-N-acetylglucosamine, GDP-mannose, and GDP-fucose in Plasmodium falciparum intraerythrocytic life stages. We assembled these data with the in silico functional reconstruction of the parasite metabolic pathways obtained from the P. falciparum annotated genome, exposing new active biosynthetic routes crucial for further glycosylation reactions. Fucose is a sugar present in glycoconjugates often associated with recognition and adhesion events. Thus, the GDP-fucose precursor is essential in a wide variety of organisms. P. falciparum presents homologues of GDP-mannose 4,6-dehydratase and GDP-L-fucose synthase enzymes that are active in vitro, indicating that most GDP-fucose is formed by a de novo pathway that involves the bioconversion of GDP-mannose. Homologues for enzymes involved in a fucose salvage pathway are apparently absent in the P. falciparum genome. This is in agreement with in vivo metabolic labeling experiments showing that fucose is not significantly incorporated by the parasite. Fluorescence microscopy of epitope-tagged versions of P. falciparum GDP-mannose 4,6-dehydratase and GDP-L-fucose synthase expressed in transgenic 3D7 parasites shows that these enzymes localize in the cytoplasm of P. falciparum during the intraerythrocytic developmental cycle. Although the function of fucose in the parasite is not known, the presence of GDP-fucose suggests that the metabolite may be used for further fucosylation reactions.
authors.affiliation: Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Sanz
authors.affiliation: College of Life Sciences, University of Dundee, Division of Biological Chemistry and Drug Discovery, Wellcome Trust Biocentre, Dundee DD15EH, Scotland, United Kingdom.
authors.forename: Giulia
authors.initials: G
authors.lastname: Bandini
authors.affiliation: Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Ospina
authors.affiliation: Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Bernabeu
authors.affiliation: College of Life Sciences, University of Dundee, Division of Biological Chemistry and Drug Discovery, Wellcome Trust Biocentre, Dundee DD15EH, Scotland, United Kingdom.
authors.forename: Karina
authors.initials: K
authors.lastname: Mariño
authors.affiliation: Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Fernández-Becerra
authors.affiliation: Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, CEK, 1a Planta, Rosselló 149-153, 08036, Barcelona, Spain. Electronic address: luis.izquierdo@cresib.cat.
authors.forename: Luis
authors.initials: L
authors.lastname: Izquierdo
mesh_terms: D002238:Carbohydrate Epimerases / Q000235:genetics / Q000378:metabolism; D016678:Genome / Q000502:physiology; D006154:Guanosine Diphosphate Fucose / Q000096:biosynthesis* / Q000235:genetics; D006155:Guanosine Diphosphate Mannose / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism; D010963:Plasmodium falciparum / Q000235:genetics / Q000378:metabolism*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D015800:Protozoan Proteins; D006154:Guanosine Diphosphate Fucose; D006155:Guanosine Diphosphate Mannose; D006836:Hydro-Lyases; C044971:GDPmannose 4,6-dehydratase; D002238:Carbohydrate Epimerases
keywords: FS; Fucose; GMD; Glycobiology; Malaria; Metabolism; Parasite Metabolism; Plasmodium; Sugar Nucleotides