Abstract DNA-repair proteins have been found to localize to the centrosomes and defects in these proteins cause centrosome over-duplication. Centrobin is a centriole-associated protein that is required for centriole duplication. In the present study, we investigated a possible role of centrobin in DNA damage response. Centrobin was phosphorylated in response to UV radiation and its phosphorylated form was detected only in the detergent / DNase 1-resistant fraction. UV-induced phosphorylation of centrobin was significantly decreased by ATR inhibition, but not by ATM inhibition. In addition, centrobin-depleted cells showed reduced survival rate after UV exposure compared with control cells. Moreover, centrobin knockdown in DR-GFP/U2OS cells had a significant reduction in DNA repair efficiency of homologous recombination (HR) and this defect was recovered by expression of wild-type centrobin, but not by a mutant form of centrobin. Taken together, these results suggest that centrobin may play a critical role in DDR and that ATR dependent phosphorylation of centrobin may be at least partially responsible for this function. Citation Format: Na-mi Ryu, Jin Ki Jung, Seok Won Jang, Jung Min Kim. Centrobin is involved in the cellular response to DNA damage [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3494.