E2F activity determines mitosis versus whole-genome duplication in G2-arrested cells

Abstract While mitogenic signaling is known to regulate cell-cycle entry during the G1 phase, its function in the G2 phase remains elusive. Here we show that mitogenic signaling controls whether G2-arrested cells proceed through mitosis or undergo whole-genome duplication. Although mitogenic signali...

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Bibliographic Details
Main Authors: Kibum Kim, Jessica Armand, Sungsoo Kim, Hee Won Yang
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-62061-w
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Summary:Abstract While mitogenic signaling is known to regulate cell-cycle entry during the G1 phase, its function in the G2 phase remains elusive. Here we show that mitogenic signaling controls whether G2-arrested cells proceed through mitosis or undergo whole-genome duplication. Although mitogenic signaling is not required for the G2/M transition under normal conditions, it modulates E2F transcriptional activity via c-Myc. When G2 arrest occurs due to CDK4/6 and CDK2 suppression, E2F activity levels determine the status of APC/C inactivation and the CDK2-Rb feedback loop. Upon release from G2 arrest, cells maintaining APC/C inactivation promptly induce CDK2 activation and FoxM1 phosphorylation, driving mitotic entry. Conversely, APC/C reactivation degrades cyclin A and abolishes the CDK2-Rb loop, necessitating CDK4/6 activation for cell-cycle re-entry. This regulatory mechanism mirrors the G1-phase process, resulting in whole-genome duplication. In cancer cells, this process promotes genome instability and oncogene amplification, contributing to aggressive behavior. These findings reveal a previously unrecognized mitogen-dependent checkpoint that governs cell fate in the G2 phase.
ISSN:2041-1723