Protein samples were run on 12% SDS-PAGE. After electroblotting on PVDF membrane (Millipore), Western analysis was performed using rabbit anti-CNIH-2 (1∶1000; [26]), mouse anti-calnexin (1∶1000, Abcam), rabbit anti-GluA1 (1∶1000, Millipore), mouse anti-GluA2 (1∶1000, Millipore) followed by goat anti-mouse or anti-rabbit secondary antibodies conjugated to horseradish peroxidase (1∶15000, Santa Cruz). Blots were finally developed with ECL plus (GE Healthcare).