Fig. 5: SUMO-SIM interaction between PIDD1 and RAIDD DDs sustains nascent PIDD1/RAIDD complexes.

a, b ClustalW alignment of human (Hs), mouse (Mm), xenopus (Xl), and zebrafish (Dr) RAIDD homologs with GPS- SUMO and JASSA -predicted SUMO-interacting domains (SIM) boxed in red and green, respectively (probability scores also indicated) (a), with conserved putative SIMs boxed in black on AlphaFold2 RAIDD model (b). Caspase recruitment domain (CARD) and DD underlined in orange and blue, respectively. (c-d) RAIDD^—/— C2.Pro-BiFC HeLa cells were transfected with indicated VSV-RAIDD variants, treated with or without MMC and Go6976 (5 μM each) and imaged at 24 h. At least 40 cells per sample were scored in each of n = 3 independent experiments. Representative images (c) were quantified (d), with data expressed as means +/− SD. ***p < 0.001, two-tailed Student’s t-test. e RAIDD^—/— HeLa cells transfected with indicated VSV-RAIDD variants, and treated with or without MMC and Go6976 (1 μM each) were harvested at 24 h, immunoprecipitated with anti-VSV antibodies and analyzed by western blot. f SV40-transformed MEF of indicated genotypes treated with MMC and Go6976 (1 μM each) were harvested at indicated time points and analyzed by western blot. g PIDD1^—/— HeLa cells transfected with indicated siRNA and cotransfected with indicated FLAG-PIDD1 variants were harvested at 24 h, immunoprecipitated with anti-FLAG antibody and analyzed by western blot. h, i PIDD1^—/— HeLa cells transfected with indicated FLAG-PIDD1 variants, were treated MMC and Go6976 (1 μM each), harvested at indicated time points, immunoprecipitated with anti-FLAG antibody and analyzed by western blot. Cells in (e–i) were TdR-synchronized as described in Supplementary Tables 1A (f) and 1B (e, g–i). Source data are provided as a Source data file.