The ProteoSeine Lab contributed to the publication of a new article inNature Communications:
Abstract:
Meiotic progression relies on maintaining a precise balance between cyclin B/CDK1 activity and the phosphatase PP2A-B55. The latter is negatively regulated by the Greatwall kinase (Gwl). In maturing Xenopus oocytes, we show that the loss of Gwl and the subsequent hyperactivation of PP2A-B55 prevents phosphorylation of key proteins involved in spindle formation, chromosome condensation and spindle migration as well as the phosphorylation of Wee1/Myt1 and the APC/C complex. As a consequence, in these oocytes bipolar spindles cannot be formed and migrate to the cortex and chromosomes are partially decondensed preventing meiotic I progression. The APC/C remains inactive impairing cyclin B3 degradation and ultimately preventing Erp1 accumulation. Finally, the c-Mos-MAPK-Rsk1/2 pathway fails to activate due to the absence of c-Mos as a consequence of its improper degradation. Overall, our findings reveal a crucial role of Gwl in the coordination and progression of meiotic divisions.
Roque S, Ben Choug C, Khodja CH, Vigneron S, Legros V, Chevreux G, Lacroix B, Castro A, Lorca T. Greatwall depletion from Xenopus oocytes reveals a key role of the cyclin B/CDK1-PP2A-B55 balance in the coordination of meiotic events. Nat Commun. 2026 May 13. doi: 10.1038/s41467-026-73011-5. Epub ahead of print. PMID: 42129183.