title: Direct evidence of O-GlcNAcylation in the apicomplexan Toxoplasma gondii: a biochemical and bioinformatic study.
abstract: Toxoplasma gondii and Plasmodium falciparum are apicomplexan parasites responsible for serious diseases in humans. Many studies have focused on the post-translational modifications (PTMs) found in the two protists including phosphorylation, acetylation or SUMOylation but only a few of these are concerned with the nuclear and cytosolic-specific glycosylation O-GlcNAcylation. O-GlcNAcylation is a highly dynamic PTM-regulated by the ON and OFF enzymes: O-GlcNAc transferase and O-GlcNAcase-that can compete with phosphorylation but its function remains unclear. In this work, we directly prove the O-GlcNAcylation in T. gondii using antibodies specifically directed against the modification and we strongly suggest its occurrence in P. falciparum. We found that the inducible 70 kDa-Heat Shock Protein is O-GlcNAcylated, or associated with an O-GlcNAc-partner, in T. gondii. Using anti-OGT antibodies we were able to detect the expression of the glycosyltransferase in T. gondii cultured both in human foreskin fibroblast and in Vero cells and report its putative sequence. For the first time the presence of O-GlcNAcylation is unequivocally shown in T. gondii and suspected in P. falciparum. Since the O-GlcNAcylation is implicated in many biological fundamental processes this study opens a new research track in the knowledge of apicomplexans' life cycle and pathogenic potential.
authors.affiliation: Unit of Structural and Functional Glycobiology, CNRS-UMR 8576, IFR 147, Université de Lille 1, Cité Scientifique, Villeneuve d'Ascq, France.
authors.forename: Yobana
authors.initials: Y
authors.lastname: Perez-Cervera
authors.forename: Grégoire
authors.initials: G
authors.lastname: Harichaux
authors.forename: Jörg
authors.initials: J
authors.lastname: Schmidt
authors.forename: Françoise
authors.initials: F
authors.lastname: Debierre-Grockiego
authors.forename: Vanessa
authors.initials: V
authors.lastname: Dehennaut
authors.forename: Ulrike
authors.initials: U
authors.lastname: Bieker
authors.forename: Edwige
authors.initials: E
authors.lastname: Meurice
authors.forename: Tony
authors.initials: T
authors.lastname: Lefebvre
authors.forename: Ralph T
authors.initials: RT
authors.lastname: Schwarz
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D019295:Computational Biology; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010963:Plasmodium falciparum / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014122:Toxoplasma / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; D017351:N-Acetylglucosaminyltransferases; C449880:O-GlcNAc transferase; D000117:Acetylglucosamine