Telomere replication poses unique challenges. Here, the authors show that TRF1 prevents telomere fragility by promoting replication fork reversal, a process dependent on RNA:DNA hybrids and necessary for TFIIH-mediated restart of leading strand synthesis. When fork reversal is impaired, PrimPol serves as a compensatory mechanism.
- Mélina Vaurs
- Eloïse Claude
- Anabelle Decottignies
