UBA3 Gene - Function, Mutations, and Role in Cancer | NEDD8 Activating Enzyme

UBA3 encodes the catalytic subunit of the NEDD8-activating enzyme (NAE), which is essential for neddylation, a process that conjugates the ubiquitin-like protein NEDD8 to target proteins such as cullins. Neddylation regulates the activity of cullin-RING ubiquitin ligases (CRLs) and thereby controls the degradation of numerous cellular proteins involved in cell cycle progression, signal transduction, and transcription. UBA3 forms a heterodimer with NAE1 (APPBP1) to activate NEDD8. The gene is located on chromosome 3p14.1, a region frequently altered in cancer. UBA3 is the molecular target of the investigational drug pevonedistat (MLN4924), which blocks neddylation and induces cancer cell death.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Neddylation pathway (Reactome R-HSA-8951664)

• Cullin-RING ubiquitin ligase regulation (KEGG hsa04120)

• Ubiquitin mediated proteolysis (KEGG hsa04120)

UBA3 (also known as NAE1 beta subunit) is a 463-amino acid protein that forms the catalytic core of the NEDD8-activating enzyme (NAE). It contains an adenylation domain and a catalytic cysteine residue (Cys216) that forms a thioester intermediate with NEDD8. The protein is predominantly cytoplasmic but can shuttle to the nucleus. UBA3 is essential for cell viability and is overexpressed in multiple cancers, making it a validated drug target. The inhibitor pevonedistat binds to the NEDD8-UBA3 complex, blocking neddylation and leading to CRL inactivation, accumulation of CRL substrates (e.g., p27, NRF2), and apoptosis in cancer cells.