ATR-CHK1-E2F3 signaling transactivates human ribonucleotide reductase small subunit M2 for DNA repair induced by the chemical carcinogen MNNG.

•The chemical carcinogen MNNG induces the upregulation of RRM2.•RRM2 translocates to the nucleus for DNA repair in response to MNNG.•The transcription of RRM2 is co-activated by E2F3 and NFY in response to MNNG.•E2F3 is phosphorylated and stabilized by the ATR–CHK1 pathway in response to MNNG.