The cDNA sequences of viral GPs and GFP were cloned into pCAGGs plasmids with a C-terminal Twin-Strep-tag (WSHPQFEKGGGSGGGSGGSAWSHPQFEK). pLX304 plasmids encoding V5-tagged RPN1, RPN2, OSTC, DDOST, and pGRN were obtained from a purchased public genome-scale lentiviral expression library of human ORFs (74) . pcDNA3.1(-) plasmids encoding 6ϫHis-tagged MAGT1, Flag-tagged TUSC3, and Strep-tagged SHBG were constructed manually by PCR and an In-Fusion HD cloning kit (TaKaRa).