Research Paper Volume 10, Issue 10 pp 2585—2605

H3K9me3 and H4K20me3 represent the epigenetic landscape for 53BP1 binding to DNA lesions

Figure 3. The nuclear distribution pattern of 53BP1 protein. (A) Recruitment of 53BP1 to locally micro-irradiated chromatin in (a) Suv39h1/h2 wt and (b) Suv39h1/h2 dn fibroblasts. Quantification using LAS AF software in panel (b) shows that the level of the 53BP1 protein at UVA-irradiated ROIs was reduced in Suv39h1/h2 dn MEFs. For statistical analysis, the Student’s t-test was used; the difference in the protein levels is statistically significant at P≤0.05. (B) An average number of 53BP1-positive foci was significantly increased in γ-irradiated Suv39h1/h2 wt MEFs compared with those in the non-irradiated wt counterpart. In Suv39h1/h2 dn MEFs, γ-irradiation did not significantly change a number of 53BP1-positive repair foci. Student’s t-test was used for statistical analysis, and statistical significance was defined as P≤0.05. The distribution of 53BP1 in (C) in (a) non-irradiated and (b) γ-irradiated wild-type MEFs and (D) (a) non-irradiated and (b) γ-irradiated Suv39h1/h2 dn MEFs. Scale bars represent 10 µm.