Neural Precursor Cell Expressed, Developmentally Down Regulated 8 (NEDD8)

NEDD8 is activated by an E1-like complex, consisting of beta-amyloid precursor protein-binding protein-1 (APPBP1) and UBA3, and then linked to the E2-like enzyme, UBC12. Nedd8 conjugation negatively regulates contractility of the microfilament-rich cell cortex during pronuclear migration and during cytokinesis.

Human NEDD8 and ubiquitin share 60% amino acid sequence identity. By Western blot analysis of human cell line lysates, NEDD8 migrated as a 6-kD protein. Immunofluorescence studies showed that NEDD8 is expressed primarily in the nucleus. As with ubiquitin and sentrin, NEDD8 is conjugated to other cellular proteins after its C-terminal tail is processed. Northern blot analysis detected NEDD8 expression predominantly in heart and skeletal muscle.