A BRCA 1‐interacting lnc RNA regulates homologous recombination

Long non‐coding RNA s (lnc RNA s) are important players in diverse biological processes. Upon DNA damage, cells activate a complex signaling cascade referred to as the DNA damage response ( DDR ). Using a microarray screen, we identify here a novel lnc RNA , DDSR 1 ( DNA damage‐sensitive RNA 1), which is induced upon DNA damage. DDSR 1 induction is triggered in an ATM ‐ NF ‐ κB pathway‐dependent manner by several DNA double‐strand break ( DSB ) agents. Loss of DDSR 1 impairs cell proliferation and DDR signaling and reduces DNA repair capacity by homologous recombination ( HR ). The HR defect in the absence of DDSR 1 is marked by aberrant accumulation of BRCA 1 and RAP 80 at DSB sites. In line with a role in regulating HR , DDSR 1 interacts with BRCA 1 and hn RNPUL 1, an RNA ‐binding protein involved in DNA end resection. Our results suggest a role for the lnc RNA DDSR 1 in modulating DNA repair by HR .