Active, Recombinant Human NAE1 / UBA3 Complex

Background: NEDD8-activating enzyme (NAE; NEDD8 E1) initiates neddylation, a ubiquitin-like modification that regulates protein stability and signaling. This E1 is a heterodimer of NAE1 (APPBP1) and UBA3. It uses ATP to adenylate NEDD8’s C-terminus, forms a high-energy thioester with UBA3’s catalytic cysteine, then transfers NEDD8 to E2 enzymes UBE2M and UBE2F. These E2s conjugate NEDD8 to cullin scaffolds, activating cullin–RING ligases (CRLs) that ubiquitylate substrates controlling cell cycle, DNA damage responses, hypoxia, and metabolism. The Neddylation inhibitor pevonedistat (MLN4924) targets NAE, suppressing CRL function and inducing cytotoxicity.