Fig. 4: Loss of FTO enhances PARP1 function.
a Live imaging of WT or FTO HeLa KO cells expressing GFP-PARP1 following UVA micro-irradiation. Scale bar, 5 μm. b, c Average (b) and normalized (c) traces showing relative changes in GFP-PARP1 fluorescence intensity at the site of DNA damage over time. Solid and dashed lines indicate means and SEM, respectively. d, e Quantification of the time-constant (τ) of fluorescence recovery after photobleaching (d) and the peak fluorescent intensity (e) of GFP-PARP1 at DNA damage sites (WT, N = 24; KO.1, N = 19; KO.2, N = 17). Data were analyzed using one-way ANOVA with Dunnett’s multiple comparison test. f UVC-induced global PARylation in WT or FTO KO HeLa cells. g Quantification of total PAR levels. Data were normalized to the 1 min timepoint of the WT group (N = 7 per group) and analyzed using two-way ANOVA with Holm-Šídák’s multiple comparison test (*WT vs KO.1 and # WT vs KO.2). h Recombinant Flag-PARP1 (indicated by the asterisk) was incubated with or without NAD + , Olaparib and His-FTO for 30 min at 30 °C. i Quantification of the levels of PARP1 auto-PARylation (arrowhead in h). Data were normalized to the no FTO group (N = 5 per group) and analyzed using a two-tailed paired t-test. j UVC-induced PARP1 auto-PARylation in WT or FTO KO HeLa cells. The high molecular weight smear of PARylated PARP1 was eliminated in the Olaparib-treated cells. k Quantification of the levels of PARP1 auto-PARylation in cells. Data were normalized to the 1 min timepoint of the WT group (N = 7 per group) and analyzed using two-way ANOVA with Holm-Šídák’s multiple comparison test (*WT vs KO.1 and # WT vs KO.2). All data are represented as mean ± SEM. Source data are provided as a Source Data file.
