Western blot analysis from HEK 293 WT and NEDP1 KO cells of the components of the NEDD8 conjugation/de-conjugation pathway shows that similar levels of NEDD8 pathway components are present in both WT and NEDP1 KO cells. Apart from UBA3, there is no detectable amount of NEDD8-modified enzymes in whole-cell lysates from NEDP1 KO cells. 