Fig. 2: MAD2L2 dimerization is needed for MAD2L2-mediated control of NHEJ at deprotected telomeres and MAD2L2-mediated class switch recombination.

a Experimental approach to address telomere deprotection induced NHEJ. b Schematic overview of the experimental setup used in c–e. c Chromosomal fusions in TRF2ts MEFs transduced with indicated shRNAs and expression constructs (n = 3 independent experiments, mean ± s.e.m., a minimum of 1500 chromosomes were counted per condition, per experiment). One-way ANOVA with Dunnett’s multiple comparisons test (**p = 0.0046; ***p = 0.0002). d Representative images of metaphases counted in c. Scale bar, 10 μm. e Survival assay of TRF2ts MEFs used in c–d Cells were cultured at 32 °C to exclude toxicity of the infected cells, or at 39 °C for 12 days to induce telomere deprotection. Cells were returned to 32 °C for the indicated times, and stained to assess survival. Plates are representative of n = 2 independent biological duplicates, the second biological duplicate is shown in Supplementary Fig. 1e, f. f CSR defect in Mad2l2^−/− cells is rescued after complementation with WT MAD2L2 and 1xMut but not with 3xMut. Bars represent mean ± s.e.m., two-sided Wilcoxon–Mann –Whitney test. n = 3 independent experiments with one WT clone and two Mad2l2^−/− clones, ns p = 0.6752 (-vs. EV) and p = 0.8340 (-vs. 3xMut); *p = 0.0119. CIT: anti-CD40, IL-4 and TGF-β. g Quantification of Igh breaks and translocations in metaphases of the indicated WT and Mad2l2^−/− CH12F3 cells. Horizontal bars represent means, two-sided Fisher’s exact test; n = 200 metaphases (WT), n = 400 (Mad2l2^−/−), n = 384 (Mad2l2^−/− + EV), n = 400 (Mad2l2^−/− + WT), n = 400 (Mad2l2^−/− + 1xMut), n = 357 (Mad2l2^−/− + 3xMut) from one experiment (WT) or two independent experiments (Mad2l2^−/−), ns p = 0.9798 (-vs. EV) and p = 0.9721 (-vs. 3xMut); *p = 0.0146 (-vs. WT) and p = 0.0126 (-vs. 1xMut). h Representative images of Igh breaks in aberrant metaphases in Mad2l2^−/− CH12F3 cells, as quantified in g. Scale bars, 5 μm. Significance; ns, not significant (p ≥ 0.05); *p < 0.05, **p < 0.01, ***p < 0.001. Source data are provided as a Source Data file.