Small RNAs: Emerging key players in DNA double-strand break repair

DNA double-strand break (DSB) is the most deleterious form of DNA damage and poses great threat to genome stability. Eukaryotes have evolved complex mechanisms to repair DSBs through coordinated actions of protein sensors, transducers, and effectors. DSB-induced small RNAs (diRNAs) or Dicer/Drosha-dependent RNAs (DDRNAs) have been recently discovered in plants and vertebrates, adding an unsuspected RNA component into the DSB repair pathway. DiRNAs/DDRNAs control DNA damage response (DDR) activation by affecting DDR foci formation and cell cycle checkpoint enforcement and are required for efficient DSB repair. Here, we summarize the findings of diRNAs/DDRNAs and discuss the possible mechanisms through which they act to facilitate DSB repair.