SCCRO5 interacts with components of the neddylation pathway. A, Western blot analysis of the products of GST-SCCRO, GST-SCCRO5, and selected GST-SCCRO5 mutants after pull-down assays from HeLa lysates probed with the indicated antibodies, which shows that, like SCCRO, SCCRO5 binds to CAND1, Cul1, Cul2, Cul3, and ROC1. Mutations in the PONY domain (SCCRO5_D225N and SCCRO5_E226A), but not the N-terminal NLS (SCCRO5_Δ1-46), result in loss of binding. The dividing line between lane 1 and lane 2 indicates the position of omitted lanes from the same gel. B, Western blot analysis of Ubc12 after GST and GST-SCCRO5 pull-down assays on products from a thioester reaction (lane 1), which shows preferential binding to Ubc12~Nedd8, even in the presence of excess free Ubc12. C, Western blot analysis of Ubc12 after pull-down assays on products of thioester reaction, which shows that GST-SCCRO5 and PONY and NLS mutants bind equally to Ubc12~Nedd8.