Identification of possible cargo and interactor proteins of KDELR

To investigate possible cargo and interactor proteins of KDELR isoforms 1, 2, and 3, HEK293T cells were transfected with BioID2-fused KDELR and cultured in DMEM containing 2 µM biotin. Biotinylated proteins were recovered from the cell lysates using streptavidin beads and visualized by silver staining. Biotinylated proteins were identified by mass analysis.