Replication fork collapse and genome instability in dCMP deaminase mutant

Sánchez, AranchaScripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA (författare)

Ribonucleotide reductase (RNR) and deoxycytidylate deaminase (dCMP deaminase) are pivotal allosteric enzymes required to maintain adequate pools of deoxyribonucleoside triphosphates (dNTPs) for DNA synthesis and repair. Whereas RNR inhibition slows DNA replication and activates checkpoint responses, the effect of dCMP deaminase deficiency is largely unknown. Here, we report that deleting the Schizosaccharomyces pombe dcd1(+) dCMP deaminase gene (SPBC2G2.13c) increases dCTP ∼30-fold and decreases dTTP ∼4-fold. In contrast to the robust growth of a Saccharomyces cerevisiae dcd1Δ mutant, fission yeast dcd1Δ cells delay cell cycle progression in early S phase and are sensitive to multiple DNA damaging agents, indicating impaired DNA replication and repair. DNA content profiling of dcd1Δcells differs from an RNR-deficient mutant. Dcd1 deficiency activates genome integrity checkpoints enforced by Rad3 (ATR), Cds1 (Chk2) and Chk1, and creates critical requirements for proteins involved in recovery from replication fork collapse, including the γH2AX-binding protein Brc1 and Mus81 Holliday junction resolvase. These effects correlate with increased nuclear foci of the single-stranded DNA binding protein RPA and the homologous recombination repair protein Rad52. Moreover, Brc1 suppresses spontaneous mutagenesis in dcd1Δ cells. We propose that replication forks stall and collapse in dcd1Δ cells, burdening DNA damage and checkpoint responses to maintain genome integrity.

Sharma, SushmaUmeå universitet,Institutionen för medicinsk kemi och biofysik(Swepub:umu)sush0003 (författare)
Rozenzhak, SophieScripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA (författare)
Roguev, AssenUniv Calif San Francisco, Dept Cellular & Mol Pharmacol, San Francisco, CA 94143 USA (författare)
Krogan, Nevan JUniv Calif San Francisco, Dept Cellular & Mol Pharmacol, San Francisco, CA 94143 USA (författare)
Chabes, AndreiUmeå universitet,Institutionen för medicinsk kemi och biofysik,Molekylär Infektionsmedicin, Sverige (MIMS)(Swepub:umu)anch0002 (författare)
Russell, PaulScripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA (författare)
Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USAInstitutionen för medicinsk kemi och biofysik (creator_code:org_t)

Ingår i:Molecular and Cellular BiologyWashington : American Society Microbiology32:21, s. 4445-44540270-73061098-5549

Av författaren/redakt...: Sánchez, Arancha; Sharma, Sushma; Rozenzhak, Sophi ...; Roguev, Assen; Krogan, Nevan J; Chabes, Andrei; visa fler...; Russell, Paul; visa färre...

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