Fiche publication
Date publication
février 2025
Journal
Nature communications
Auteurs
Membres identifiés du Cancéropôle Est :
Pr FAIVRE Laurence
,
Pr VABRES Pierre
,
Mr DUFFOURD Yannis
,
Pr KUENTZ Paul
Tous les auteurs :
El Masri R, Iannuzzo A, Kuentz P, Tacine R, Vincent M, Barbarot S, Morice-Picard F, Boralevi F, Oillarburu N, Mazereeuw-Hautier J, Duffourd Y, Faivre L, Sorlin A, Vabres P, Delon J
Lien Pubmed
Résumé
The genetic bases of mosaic pigmentation disorders have increasingly been identified, but these conditions remain poorly characterised, and their pathophysiology is unclear. Here, we report in four unrelated patients that a recurrent postzygotic mutation in GNA13 is responsible for a recognizable syndrome with hypomelanosis of Ito associated with developmental anomalies. GNA13 encodes Gα, a subunit of αβγ heterotrimeric G proteins coupled to specific transmembrane receptors known as G-protein coupled receptors. In-depth functional investigations revealed that this R200K mutation provides a gain of function to Gα. Mechanistically, we show that this variant hyperactivates the RHOA/ROCK signalling pathway that consequently increases actin polymerisation and myosin light chains phosphorylation, and promotes melanocytes rounding. Our results also indicate that R200K Gα hyperactivates the YAP signalling pathway. All these changes appear to affect cell migration and adhesion but not the proliferation. Our results suggest that hypopigmentation can result from a defect in melanosome transfer to keratinocytes due to cell shape alterations. These findings highlight the interaction between heterotrimeric G proteins and the RHOA pathway, and their role in melanocyte function.
Mots clés
Humans, Melanocytes, metabolism, rhoA GTP-Binding Protein, metabolism, Female, Signal Transduction, Male, GTP-Binding Protein alpha Subunits, G12-G13, metabolism, rho-Associated Kinases, metabolism, Hypopigmentation, genetics, Mosaicism, Cell Movement, genetics, Mutation, Up-Regulation, Child, Keratinocytes, metabolism, Child, Preschool
Référence
Nat Commun. 2025 02 18;16(1):1751
