RNF8

The 53BP1 (p53 binding protein 1) was initially believed to be a p53 transcriptional enhancing partner, but it has now been established as an ataxia telangiectasia mutated (ATM) substrate. As a late DNA damage response (DDR) marker, 53BP1 appears during the telophase and cytokinesis phase of mitotic mammalian cells¹.