DNA damage response

53BP1 (p53 binding protein 1) was originally thought to be an enhancer for p53 transcriptional, but later studies have demonstrated that it is actually a substrate for ataxia telangiectasia mutated (ATM). 53BP1 is a classic late DNA damage response (DDR) marker that is present during the cell cycle phases of telophase and cytokinesis (within mitotic mammalian cells).

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.