FBXO31 is a substrate adapter for the SCF-type ubiquitin ligase complex SCF/FBXO31 which ubiquitylates C-terminal amide-bearing proteins (CTAPs), thereby triggering their proteasomal degradation in human cells. Immunoprecipitation followed by MS (IP-MS) was performed on HA-tagged cDNA-expressed variants of FBXO31 from HEK293T cells to identify putative clients.