(B) Co-IPs using HA-tagged constructs expressed in HEK293 cells. As baits HA-tagged proteins were immunoprecipitated with anti-HA beads. IP samples and cell lysates were subjected to immunoblotting with α-HA, α-ERGIC-53, α-BET1, α-SEC22b, α-GOSR2 and α-GAPDH antibodies, respectively. 