O-GlcNAcylation is a key modulator of skeletal muscle sarcomeric morphometry associated to modulation of protein-protein interactions.
The sarcomere structure of skeletal muscle is determined through multiple protein-protein interactions within an intricate sarcomeric cytoskeleton network. The molecular mechanisms involved in the regulation of this sarcomeric organization, essential to muscle function, remain unclear. O-GlcNAcylation, a post-translational modification modifying several key structural proteins and previously described as a modulator of the contractile activity, was never considered to date in the sarcomeric organization.



C2C12 skeletal myotubes were treated with Thiamet-G (OGA inhibitor) in order to increase the global O-GlcNAcylation level.



Our data clearly showed a modulation of the O-GlcNAc level more sensitive and dynamic in the myofilament-enriched fraction than total proteome. This fine O-GlcNAc level modulation was closely related to changes of the sarcomeric morphometry. Indeed, the dark-band and M-line widths increased, while the I-band width and the sarcomere length decreased according to the myofilament O-GlcNAc level. Some structural proteins of the sarcomere such as desmin, αB-crystallin, α-actinin, moesin and filamin-C have been identified within modulated protein complexes through O-GlcNAc level variations. Their interactions seemed to be changed, especially for desmin and αB-crystallin.



For the first time, our findings clearly demonstrate that O-GlcNAcylation, through dynamic regulations of the structural interactome, could be an important modulator of the sarcomeric structure and may provide new insights in the understanding of molecular mechanisms of neuromuscular diseases characterized by a disorganization of the sarcomeric structure.



In the present study, we demonstrated a role of O-GlcNAcylation in the sarcomeric structure modulation.
Univ.Lille, EA7369-URePSSS, Unité de Recherche Pluridisciplinaire Sport, Santé, Société, Equipe « Activité Physique, Muscle, Santé », F-59000 Lille, France.
Matthias
M
Lambert
BiCeL (BioImaging Center of Lille - Campus Lille 1), Univ.Lille, FR3688 CNRS FRABio, F-59000 Lille, France.
Elodie
E
Richard
Laboratoire de la Barrière Hémato-Encéphalique (LBHE), EA2465, Université d'Artois, Faculté Jean Perrin, 62307 Lens, France.
Sophie
S
Duban-Deweer
PAGés (Plateforme d'Analyses des Glycoconjugués), Univ.Lille, CNRS, UMR 8576, UGSF, Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France.
Frederic
F
Krzewinski
Univ.Lille, EA7369-URePSSS, Unité de Recherche Pluridisciplinaire Sport, Santé, Société, Equipe « Activité Physique, Muscle, Santé », F-59000 Lille, France.
Barbara
B
Deracinois
Univ.Lille, EA7369-URePSSS, Unité de Recherche Pluridisciplinaire Sport, Santé, Société, Equipe « Activité Physique, Muscle, Santé », F-59000 Lille, France.
Erwan
E
Dupont
Univ.Lille, EA7369-URePSSS, Unité de Recherche Pluridisciplinaire Sport, Santé, Société, Equipe « Activité Physique, Muscle, Santé », F-59000 Lille, France.
Bruno
B
Bastide
Univ.Lille, EA7369-URePSSS, Unité de Recherche Pluridisciplinaire Sport, Santé, Société, Equipe « Activité Physique, Muscle, Santé », F-59000 Lille, France. Electronic address: caroline.cieniewski-bernard@univ-lille1.fr.
Caroline
C
Cieniewski-Bernard
D000185:Actinin / Q000378:metabolism; D000215:Acylation / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002460:Cell Line; D003459:Crystallins / Q000378:metabolism; D003893:Desmin / Q000378:metabolism; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009210:Myofibrils / Q000378:metabolism; D060066:Protein Interaction Maps / Q000187:drug effects / Q000502:physiology*; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000502:physiology; D020543:Proteome / Q000378:metabolism; D011714:Pyrans / Q000494:pharmacology; D012518:Sarcomeres / Q000378:metabolism*; D013844:Thiazoles / Q000494:pharmacology
D003459:Crystallins; D003893:Desmin; D008840:Microfilament Proteins; D020543:Proteome; D011714:Pyrans; D013844:Thiazoles; C572247:thiamet G; D000185:Actinin; C071058:moesin
Desmin; O-GlcNAcylation; Protein–protein interactions; Sarcomere structure; Skeletal muscle cells; αB-crystallin