For western blot analysis, the following commercial primary antibodies were used to probe for calnexin (SPA-860, rabbit polyclonal; StressGen), calreticulin (SPA-602, rabbit polyclonal; StressGen), Erp29 (67675-1-IG, mouse monoclonal; Proteintech), ERp57 (23886, mouse monoclonal; Santa Cruz), GAPDH (MA5 15738, mouse monoclonal; Thermo Fisher Scientific), GFP (66002-1-IG, mouse monoclonal; Proteintech), Glucosidase1/MOGS (17859-1-AP, rabbit polyclonal; Proteintech), Glucosidase 2/PRKCSH (12148-1-AP, rabbit polyclonal; Proteintech), GRP78/BiP (AF4846, goat polyclonal; R&D), GRP94 (SPA-850, rat monoclonal; StressGen), Malectin (26655-1-AP, rabbit polyclonal; Proteintech), Nixin (H00148066-B01P, mouse polyclonal; Novus Bio), and UGGT1/UGCGL1 (14170-1-AP, rabbit polyclonal; Proteintech). Homemade rabbit antisera for Tmp21 was previously described (Satpute-Krishnan et al., 2014). The following secondary antibodies were used: HRP-conjugated goat IgG antibody (HAF109; R&D), HRP-conjugated goat anti-mouse IgG (H+L) Superclonal Secondary antibody (A28177; Thermo Fisher Scientific), HRP-conjugated goat anti-rabbit IgG (H+L) Superclonal Secondary antibody (A27036; Thermo Fisher Scientific).

For steady-state chases, homemade rabbit antisera for GFP and RFP, which were gifts from Dr. Jennifer Lippincott-Schwartz, HHMI Janelia Research Campus, Ashburn, VA, were used as previously described (Satpute-Krishnan et al., 2014).

For immunofluorescence of calnexin, anti-calnexin primary (AB22595; Abcam, rabbit polyclonal) and Cy5-conjugated goat anti-rabbit IgG (111-175-003; Jackson ImmunoResearch) were used.

For lectin blotting of N-linked glycosylated proteins, HRP-conjugated wheat germ agglutinin was used per the manufacturer’s instructions (L3892; Sigma-Aldrich).

For antibody uptake imaging experiments, we used Alexa Fluor 647-conjugated rabbit anti-GFP antibody (A-31852; Thermo Fisher Scientific).