Active, Recombinant Human FBXO31 / SKP1 Complex

Background: FBXO31 (F-box only protein 31) is an F-box protein that functions as a substrate-recognition subunit of the SCF (SKP1–CUL1–F-box) E3 ubiquitin ligase complex. It contains an F-box domain that binds SKP1 and multiple substrate-interacting motifs, allowing it to target specific proteins for ubiquitylation and proteasomal degradation. Biologically, FBXO31 has been implicated in cell-cycle regulation, particularly the G1/S and G2/M transitions, through degradation of key regulators such as cyclin D1. In response to oxidative stress, FBXO31 selectively tags proteins with C‑terminal amidation for ubiquitylation, thereby targeting them for proteasomal degradation. Targeted Protein Degradation (TPD) approaches have recently attempted to mimic the C-terminal amide degron as a means of developing bivalent degraders.