Multifunctional Role of ATM/Tel1 Kinase in Genome Stability: From the DNA Damage Response to Telomere Maintenance

Figure 1

Description of the relevant proteins recruited to DNA double-strand break. In undamaged cells, ATM is an inactive multimer. After DSBs, ATM is recruited to the site of damage by the MRN complex, triggering its autophosphorylation, monomerization, and subsequent activation. Adjacent to the site of damage, the first target of ATM is the histone H2AX, followed by the phosphorylation of MDC1 and the recruitment of the ubiquitin ligase RNF8. RNF8 binding causes H2AX ubiquitylation, facilitating the association of BRCA1 and, ultimately 53BP1, that is required for ATM retention at the site of damage.