FIGURE 1: L3MBTL2 links RNF8 and RNF168 in the DNA double strand break response. The protein kinase ATM phosphorylates L3MBTL2, which recruits it to the DNA lesion by promoting the interaction between MDC1 and L3MBTL2. L3MBTL2 is subsequently ubiquitinated by RNF8, which acts as a docking site for RNF168, thereby recruiting the ubiquitin ligase to the damage site. RNF168, in turn, ubiquitinates H2A-type histones to amplify the DNA damage response and recruit downstream DNA repair proteins for proper DSB signaling.