The Sof domain in the DCAF13 C-terminal was essential for its interaction with NPM1. (A) Network of DCAF13-interacting proteins in EL-4 T cells identified by LC–MS/MS. Subgrouping into ribosomal proteins (blue) and other proteins (red). The sizes of bubbles correspond to fold enrichment. A red dashed box is used to highlight the location of NPM1. (B) Co-IP of Flag-DCAF13-FL, Flag-DCAF13-Nter, Flag-DCAF13-Inter, and Flag-DCAF13-Cter to roughly map out its C-terminal charging the interaction with NPM1. (C and D) Co-IP of Flag-NPM1-FL, Flag-NPM1-Nter, and Flag-NPM1-Cter to roughly map out its N-terminal charging the interaction with DCAF13 (down; D). IF for cellular colocalization between Flag-DCAF13-FL, Flag-DCAF13-1-417aa, Flag-DCAF13-1-391aa, and Flag-DCAF13-1-370aa with NPM1. Scale bar, 10 μm. (E) The rescue of proliferation defect in CD4 T cells caused by DCAF13 deletion by ectopic expressing DCAF13-FL and DCAF13(1–417) mutations in tamoxifen-treated ERT2 Cre⁺Dcaf13^fl/fl T cells (regarded as DCAF13 KO). The percentages of individual peaks were quantified by FlowJo V10 software. (F) NPM1 protein expression levels in CD4 Cre⁻Dcaf13^fl/fl (WT) and CD4 Cre⁺Dcaf13^fl/fl (cKO) CD4⁺or CD8⁺ T cells. The gray values of bands were quantified with ImageJ. (G) PTEN and SUV39H1 protein expression levels in CD4 Cre⁻Dcaf13^fl/fl (WT) and CD4 Cre⁺Dcaf13^fl/fl (cKO) T cells. The gray values of bands were quantified with ImageJ. Source data are available for this figure: SourceData FS4.