Modulation of O-GlcNAc glycosylation during Xenopus oocyte maturation

✍ Scribed by Tony Lefebvre; Frédéric Baert; Jean-François Bodart; Stéphane Flament; Jean-Claude Michalski; Jean-Pierre Vilain

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 417 KB
• Volume: 93
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.20242

✦ Synopsis

Abstract

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 β‐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. © 2004 Wiley‐Liss, Inc.