Fig. 6: Both exonuclease and helicase functions of WRN facilitate MiDAS.

a Experimental workflow for analyzing MiDAS in SW620 WRN-BdTAG cells following APH treatment in S-phase and degradation of WRN with AGB1 treatment for one hour at late G2 phase early M phase. b Western blot analysis of the expression of WRN at the end of G2 phase. Tubulin was used as loading control. This experiment was repeated independently with similar results at least three times. Representative immunofluorescence images (c) and quantification (d) of prometaphase cells (U2OS). e Experimental workflow for analyzing MiDAS in HCT116 WRN-BdTAG cells following APH treatment in S-phase and degradation of WRN with AGB1 treatment for one hour at late G2 phase early M phase. This batch of cells were also subject to transfection with plasmids expressing wild type (WT) or mutant WRN with inactivation of exonuclease function (WRN E84A), or helicase function (WRN K577M), or both (WRN E84A/K577M). Representative immunofluorescence images (f) and quantification (h) of prometaphase cells with MiDAS. g Western blot analysis of the expression of endogenous WRN and Myc-tag of exogenous expressed WRN-myc. Tubulin was used as loading control. This experiment was repeated independently with similar results at least three times. In all cases, ongoing MiDAS was labeled using EdU (red), and DNA was stained with DAPI (blue). Scale bars, 10 μm. In each quantification, data are presented as mean ± s.e.m. of at least 3 independent experiments. n = 150: 50 cells were analyzed in each condition in each replicate. In total, 150 cells were analyzed for each condition. Statistical p values were calculated with two-tailed non-parametric Mann–Whitney tests and indicated in quantification graphs. Source data are provided as a Source Data file.