Figure 3. The formation of MYH foci induced at oxidatively damaged telomeres is dependent on SIRT6. (A and C), GFP-MYH does not form foci at sites with DsRed-TRF1 in undamaged control MEF and sirt6 KO MEF cells, respectively. (B and D), Damage response of GFP-MYH to the sites of KR-TRF1 after light activation in control and sirt6 KO MEF cells, respectively. GFP-MYH foci were not found at the sites of KR-TRF1 in sirt6 KO cells. (E), Analyses of about 20 cells in each (A–D) group indicated that approximately 70% of GFP-MYH foci colocalized with telomeres in control cells, in contrast, less than 10% of GFP-MYH foci colocalized with telomeres in sirt6 KO cells. (F–J), GFP-hSIRT6 foci formation at telomeres in control HEK-293T and MYH KO HEK-293T human cells. Experiments were performed similarly to (A–E) except using GFP-hSIRT6 and different cells. After ROS induction by activating the KR protein, about 70% of GFP-SIRT6 foci are colocalized with KR-TRF1 in both HEK-293T and MYH KO cells (J).