An essential role for dNTP homeostasis following CDK-induced replication stress

Pai, C.-C.; Hsu, K.-F.; Durley, S. C.; Keszthelyi, A.; Kearsey, S.; Rallis, C.; Folkes, L. K.; Deegan, R.; Wilkins, S. E.; Pfister, S. X.; Leon, N. D.; Schofield, C. J.; Bahler, J.; Carr, A. M.; Humphrey, T.

doi:10.1101/395715

bioRxiv · 10.1101/395715

An essential role for dNTP homeostasis following CDK-induced replication stress

Pai, C.-C.·Hsu, K.-F.·Durley, S. C.·Keszthelyi, A.·Kearsey, S.·Rallis, C.·Folkes, L. K.·Deegan, R.·Wilkins, S. E.·Pfister, S. X.·Leon, N. D.·Schofield, C. J.·Bahler, J.·Carr, A. M.·Humphrey, T.

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Abstract

Replication stress is a common feature of cancer cells, and thus a potentially important therapeutic target. Here we show that CDK-induced replication stress is synthetic lethal with mutations disrupting dNTP homeostasis in fission yeast. Wee1 inactivation leads to increased dNTP demand and replication stress through CDK-induced firing of dormant replication origins. Subsequent dNTP depletion leads to inefficient DNA replication, Mus81-dependent DNA damage, and to genome instability. Cells respond to this replication stress by increasing dNTP supply through Set2-dependent MBF-induced expression of Cdc22, the catalytic subunit of ribonucleotide reductase (RNR). Disrupting dNTP synthesis following Wee1 inactivation, through abrogating Set2-dependent H3K36 tri-methylation or DNA integrity checkpoint inactivation results in critically low dNTP levels, replication collapse and cell death, which can be rescued by increasing dNTP levels. These findings support a dNTP supply and demand model in which maintaining dNTP homeostasis is essential to prevent replication catastrophe in response to CDK-induced replication stress.

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Pai, C.-C., Hsu, K.-F., Durley, S. C., Keszthelyi, A., Kearsey, S., Rallis, C., Folkes, L. K., Deegan, R., Wilkins, S. E., Pfister, S. X., Leon, N. D., Schofield, C. J., Bahler, J., Carr, A. M., Humphrey, T.. 2018-09-03. An essential role for dNTP homeostasis following CDK-induced replication stress. https://doi.org/10.1101/395715

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