Replication-coupled chromatin assembly cooperates with ATR/CHK1 signaling to suppress DNA damage and premature MMB-dependent mitotic transcription
- 1University of Wuerzburg
Abstract
Faithful genome duplication requires coordination of DNA replication, chromatin assembly, and checkpoint signaling to prevent inappropriate mitotic progression. Using a targeted siRNA screen for factors modulating CHK1 inhibitor-induced DNA damage and premature mitotic entry, we identified replication-coupled chromatin assembly as a determinant of checkpoint dependence. Acute depletion of the CAF-1 subunit CHAF1A modestly delayed S-phase progression but caused little DNA damage, whereas inhibition of CHK1 or ATR triggered extensive DNA damage, premature mitotic entry, and loss of viability. Transcriptomic analyses revealed that CHK1 inhibition induced a transcriptional response enriched for B-MYB/Myb-MuvB (MMB) target genes in CHAF1A-deficient cells. Notably, induction of these genes occurred without corresponding increases in promoter accessibility, suggesting that enhanced MMB-dependent transcription is largely independent of widespread promoter opening. B-MYB depletion attenuated MMB target-gene induction, premature mitotic entry, and DNA damage. Depletion of ASF1 and NAP1L1 similarly enhanced checkpoint inhibitor sensitivity, indicating that increased dependence on ATR-CHK1 signaling is a broader consequence of impaired histone chaperone function. Together, our findings establish a functional link between replication-coupled chromatin assembly, ATR-CHK1 signaling, and MMB-dependent mitotic transcription.
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BibTeX
@misc{murugan2026replicationcoupled,
title = {{Replication-coupled chromatin assembly cooperates with ATR/CHK1 signaling to suppress DNA damage and premature MMB-dependent mitotic transcription}},
author = {D. B. Murugan and D. Gertzmann and M. Ramic and N. Greim and A. Boura and K. M. Auweiler and L. Damaschke and C. Schuelein-Voelk and C. P. Ade and M. Eilers and S. Gaubatz},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.27.754407},
url = {https://www.biorxiv.org/content/10.64898/2026.09.27.754407v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Replication-coupled chromatin assembly cooperates with ATR/CHK1 signaling to suppress DNA damage and premature MMB-dependent mitotic transcription
AU - D. B. Murugan
AU - D. Gertzmann
AU - M. Ramic
AU - N. Greim
AU - A. Boura
AU - K. M. Auweiler
AU - L. Damaschke
AU - C. Schuelein-Voelk
AU - C. P. Ade
AU - M. Eilers
AU - S. Gaubatz
PY - 2026
DA - 2026/09/27
PB - bioRxiv
DO - 10.64898/2026.09.27.754407
UR - https://www.biorxiv.org/content/10.64898/2026.09.27.754407v1
AB - Faithful genome duplication requires coordination of DNA replication, chromatin assembly, and checkpoint signaling to prevent inappropriate mitotic progression. Using a targeted siRNA screen for factors modulating CHK1 inhibitor-induced DNA damage and premature mitotic entry, we identified replication-coupled chromatin assembly as a determinant of checkpoint dependence. Acute depletion of the CAF-1 subunit CHAF1A modestly delayed S-phase progression but caused little DNA damage, whereas inhibition of CHK1 or ATR triggered extensive DNA damage, premature mitotic entry, and loss of viability. Transcriptomic analyses revealed that CHK1 inhibition induced a transcriptional response enriched for B-MYB/Myb-MuvB (MMB) target genes in CHAF1A-deficient cells. Notably, induction of these genes occurred without corresponding increases in promoter accessibility, suggesting that enhanced MMB-dependent transcription is largely independent of widespread promoter opening. B-MYB depletion attenuated MMB target-gene induction, premature mitotic entry, and DNA damage. Depletion of ASF1 and NAP1L1 similarly enhanced checkpoint inhibitor sensitivity, indicating that increased dependence on ATR-CHK1 signaling is a broader consequence of impaired histone chaperone function. Together, our findings establish a functional link between replication-coupled chromatin assembly, ATR-CHK1 signaling, and MMB-dependent mitotic transcription.
ER -