Human RIT1 was tagged with HA tag + N or C terminal ubiquitin (HA-Ubiqutin-RIT1 and HA-RIT1-Ubiqutin) and compared with empty vector (EV) or S35N/M90I RIT1 mutant (HA-RIT1 S35N/M90I). The constructs were expressed in human 293T cells and affinity purified using HA beads. RIT1 interacting proteins were compared by quantifying MS1 extracted chromatograms of peptides identified in conventional target-decoy database search.