Modulation of O-GlcNAc glycosylation during Xenopus oocyte maturation.
O-linked N-acetylglucosamine (O-GlcNAc) glycosylation is a post-translational modification, which is believed antagonises phosphorylation. We have studied the O-GlcNAc level during Xenopus oocyte meiotic resumption, taking advantage of the high synchrony of this model which is dependent upon a burst of phosphorylation. Stimulation of immature stage VI oocytes using progesterone was followed by a 4.51 +/- 0.32 fold increase in the GlcNAc content, concomitantly to an increase in phosphorylation, notably on two cytoplasmic proteins of 66 and 97 kDa. The increase of O-GlcNAc for the 97 kDa protein, which we identified as beta-catenin was partly related to its accumulation during maturation, as was demonstrated by the use of the protein synthesis inhibitor--cycloheximide. Microinjection of free GlcNAc, which inhibits O-glycosylated proteins-lectins interactions, delayed the progesterone-induced maturation without affecting the O-GlcNAc content. Our results suggest that O-GlcNAc glycosylation could regulate protein-protein interactions required for the cell cycle kinetic.
Lefebvre
Tony
T
Unité Mixte de Recherches 8576 du CNRS, Glycobiologie Structurale et Fonctionnelle, IFR 118, USTL, Bâtiment C9, 59655 Villeneuve d'Ascq, France. tony.lefebvre@univ-lille1.fr
Baert
Frédéric
F
Bodart
Jean-François
JF
Flament
Stéphane
S
Michalski
Jean-Claude
JC
Vilain
Jean-Pierre
JP
D000117:Acetylglucosamine / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D003513:Cycloheximide / Q000378:metabolism; D006031:Glycosylation; D008540:Meiosis / Q000502:physiology*; D008845:Microinjections; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011374:Progesterone / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011500:Protein Synthesis Inhibitors / Q000378:metabolism; D014982:Xenopus laevis
D011500:Protein Synthesis Inhibitors; D011374:Progesterone; D003513:Cycloheximide; D000117:Acetylglucosamine