Fig. 8: SUMO-ID identifies interactors of SUMOylated SALL1.

a WB of HEK293FT stable cell lines for TRIPZ-MYC-C-SUMO1nc/SUMO2nc transfected with FLAG-N-SALL1^WT or the SUMO site mutant FLAG-NTurboID¹⁹⁴-SALL1^ΔSUMO. Cells were treated or not with 1 μg/mL of doxycycline for 24 h and 50 μM of biotin at indicated time points. Efficient SALL1 SUMO-ID biotinylating activity was detected for SUMO1nc and SUMO2nc (black arrowhead). Dots indicate endogenous carboxylases that are biotinylated constitutively by the cell. Results are representative of two independent transfection experiments on the same stable cell lines. Source data are provided in the Source Data file. b Confocal microscopy of U2OS stable cell line for TRIPZ-MYC-C-SUMO2nc transfected with FLAG-N-SALL1^WT or the SUMO site mutant FLAG-N-SALL1^ΔSUMO. Cells were treated or not with 1 μg/mL of doxycycline for 24 h and 50 μM of biotin for 4 h. Nuclei are stained with DAPI (blue) and biotinylated material with fluorescent streptavidin (Strep, magenta). BirA antibody shows N-SALL1 staining (green). Black and white panels show the single green and magenta channels. Nuclear colocalization of FLAG-N-SALL1^WT and streptavidin signal was observed. Images are representative of three independent transfection experiments performed on cover slips on the same stable cell line. Scale bar: 10 μm. c Volcano plot of LC-MS analysis comparing streptavidin pull-downs of HEK293FT TRIPZ-MYC-C-SUMO2nc stable cell line transfected with FLAG-N-SALL1^WT or the SUMO site mutant FLAG-N-SALL1^ΔSUMO. Cells were treated with 1 μg/mL of doxycycline for 24 h and 50 μM of biotin for 4 h. Potential interactors of SUMOylated SALL1 are depicted. Statistical analyses were performed by two-sided Student’s t test. Data are provided as Supplementary Data 5. d Western blot validations of SUMOylated SALL1 interactors found in c. NuRD complex proteins GATAD2B, MTA2 and RBBP4 were confirmed. Black arrowheads point to SUMOylated SALL1 signal. Dots indicate endogenous carboxylases that are biotinylated constitutively by the cell. Dotted lines indicate different exposures of the same blot. Data are representative of three independent transfection experiments. IN input, St PD streptavidin pull-down. Source data are provided in the Source Data file. e STRING network analysis of the SALL1 SUMO-ID list and MCODE clustering identifies the NuRD complex as a highly interconnected subcluster. Gene ontology analysis also identified the NuRD complex as an enriched term. Color, transparency and size of the nodes were discretely mapped to the Log2 enrichment value as described. The border line type was discretely mapped to the p value as described. Data are provided as Supplementary Data 6. Molecular weight markers are shown to the left of the blots in kDa in a and d.