Fig. 2: PARP1 is required for the early recruitment of RECQL4 to sites of DNA damage. | Experimental & Molecular Medicine

Fig. 2: PARP1 is required for the early recruitment of RECQL4 to sites of DNA damage.

From: RECQL4 requires PARP1 for recruitment to DNA damage, and PARG dePARylation facilitates its associated role in end joining

Fig. 2

a, RECQL4 recruitment to laser-induced DNA damage. GFP-tagged RECQL4 was transiently transfected into U2OS cells (WT or PARP1 KO) for 24 h. The cells were targeted with a 21% laser to induce DSBs. The cells were imaged at the indicated time points to observe the recruitment of the proteins to the damaged DNA. The recruitment kinetics of cells from three independent experiments were quantified for GFP–RECQL4. b, RECQL4, showing the same type of cells (U2OS) that were pretreated for 3 h with 5 µM olaparib and then targeted with the 21% laser to induce DSBs. c, GFP-tagged BLM was transiently transfected into U2OS cells (WT or PARP1 KO) for 24 h. The cells were targeted with a 21% laser to induce DSBs. The cells were imaged at the indicated time points to observe the recruitment of the proteins to the damaged DNA. The recruitment kinetics of cells from three independent experiments were quantified for GFP–BLM. d, GFP–BLM image showing the same type of cells (U2OS) that were pretreated for 3 h with 5 µM olaparib and then targeted with the 21% laser to induce DSBs. In a–d, the lower graphics represent the relative signal intensities at the laser line calculated using volocity software and plotted versus time. The white arrow indicates the laser striking area. The error bars represent the s.e.m. Two-way analysis of variance (ANOVA) was performed to assess significant differences (*P < 0.05, **P < 0.01 and ***P < 0.001). e, Proportional increase in RECQL4–γH2AX foci in response to etoposide dosage. U2OS cells, including WT, PARP1 KO and PARG-expressing cells, were treated with either dimethylsulfoxide (DMSO) or specified concentrations of etoposide for 2 h. PLA staining was subsequently performed with anti-RECQL4 and anti-γH2AX antibodies. The graph shows the number of PLA foci per cell under various treatment conditions. Statistical analysis was conducted using two-way ANOVA to evaluate significant differences (*P < 0.05, **P < 0.01 and ****P < 0.0001).

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