GSE113747
An essential role for dNTP homeostasis following CDKinduced [Pu-seq]
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 MBFinduced  expression of Cdc22, the catalytic subunit of ribonucleotide reductase  (RNR). Disrupting dNTP synthesis following Wee1 inactivation, through loss  of Set2-dependent H3K36 tri-methylation, results in further dNTP depletion  due to reduced RNR expression, leading to replication catastrophe and cell  death. This lethality can be rescued by increasing dNTP levels. Similarly, we  find loss of the DNA integrity checkpoint results in synthetic lethality with  Wee1 inactivation, which is also associated with replication collapse through  critically low dNTP levels. Together, these findings support a 'dNTP supply  and demand' model in which maintaining dNTP homeostasis is essential in  preventing replication catastrophe in response to CDK-induced replication  stress. Overall design: We mapped ribonucleotide-incorporation by the mutated DNA polymerase delta and epsilon at single-nucleotide resolution and used the data for finding location and efficiency of replication origins by subsequent informatics analysis. Please note that processed data was generated from both delta and epsilon mutant together and is linked to the corresponding delta mutant sample records.