O-GlcNAcylation is a key modulator of skeletal muscle sarcomeric morphometry associated to modulation of protein-protein interactions
Résumé
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.
Mots clés
Mesh:Actinin/metabolism
Mesh:Muscle Contraction/physiology
Mesh:Myofibrils/metabolism
Mesh:Protein Interaction Maps/drug effects
Mesh:Protein Interaction Maps/physiology*
Mesh:Protein Processing
Mesh:Post-Translational/drug effects
Mesh:Post-Translational/physiology
Mesh:Proteome/metabolism
Mesh:Pyrans/pharmacology
Mesh:Sarcomeres/metabolism*
Mesh:Thiazoles/pharmacology
Mesh:Cell Line
Mesh:Crystallins/metabolism
Mesh:Desmin/metabolism
Mesh:Mice
Mesh:Microfilament Proteins/metabolism
Mesh:Animals
Mesh:Acylation/physiology*
Mesh:Acylation/drug effects
Mesh:Muscle Contraction/drug effects
Mesh:Muscle Fibers
Mesh:Skeletal/metabolism
Mesh:Muscle
Mesh:Skeletal/drug effects
Mesh:Skeletal/metabolism*
O-GlcNAcylation
Skeletal muscle cells
Sarcomere structure
alpha B-crystallin
Desmin
Protein-protein interactions
Domaines
Sciences du Vivant [q-bio]Origine | Fichiers produits par l'(les) auteur(s) |
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