O-GlcNAc level variations are associated with the development of skeletal muscle atrophy.
O-linked N-acetylglucosaminylation (O-GlcNAc) is a regulatory posttranslational modification of nucleocytoplasmic proteins, which consists of the attachment of N-acetylglucosamine to serine or threonine residues of a protein. This glycosylation is a ubiquitous posttranslational modification, which probably plays important roles in many aspects of protein function. Our laboratory has previously reported that, in skeletal muscle, proteins of the glycolytic pathway and energetic metabolism and contractile proteins were O-GlcNAc modified (Cieniewski-Bernard C, Bastide B, Lefebvre T, Lemoine J, Mounier Y, and Michalski JC. Mol Cell Proteomics 3: 577-585, 2004). O-GlcNAc has been recently demonstrated to play a role in modulating cellular function in response to nutrition and also in stress conditions. Therefore, we have investigated here the implication of the glycosylation/deglycosylation process in the development of atrophy in rat skeletal muscle after hindlimb unloading. The high O-GlcNAc level found in control soleus [compared with control extensor digitorum longus (EDL)] becomes lower in atrophied soleus. On the opposite side, the low rate of O-GlcNAc in control EDL reaches higher levels in EDL, not atrophied after hindlimb unloading. These variations in O-GlcNAc level are correlated with a variation of the O-GlcNAc process enzyme activities and could be associated with a differential expression of heat shock proteins. Our results suggest that O-GlcNAc variations could control the muscle protein homeostasis and be implicated in the regulation of muscular atrophy.
Cieniewski-Bernard
Caroline
C
Unité Mixte de Recherche Centre National de la Recherche Scientifique 8576, Glycobiologie Structurale et Fonctionnelle, Institut Fédératif de Recherche 118, France.
Mounier
Yvonne
Y
Michalski
Jean-Claude
JC
Bastide
Bruno
B
D000117:Acetylglucosamine / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D015971:Gene Expression Regulation, Enzymologic; D006031:Glycosylation; D006360:Heat-Shock Proteins / Q000032:analysis / Q000502:physiology; D019417:Hindlimb Suspension / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D009133:Muscular Atrophy / Q000473:pathology / Q000503:physiopathology*; D017351:N-Acetylglucosaminyltransferases / Q000032:analysis / Q000235:genetics / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
D006360:Heat-Shock Proteins; D017351:N-Acetylglucosaminyltransferases; C063057:UDP-N-acetylglucosamine-peptide beta-N-acetylglucosaminyltransferase; D000117:Acetylglucosamine