Seems to be involved in regulation of DNA repair correlated to non-homologous double strand breaks (DSBs) repair. In vitro, involved in rapid but not in slow DSB repair mechanism. Required for effective immune responses that involve activation of DNA damage responses (PubMed:24207055). Interacts with SNI1. By genotoxic stress and by DNA damage (PubMed:15165187). Negatively regulated by the key immune regulator SNI1 (PubMed:24207055). Suppressor of sni1 mutation symptoms including the accumulation of DNA damage leading to a constitutively activated DNA damage responses (DDR) and increased basal expression of pathogenesis-related (PR) genes. Belongs to the rad17/RAD24 family.