2.7 Co-immunoprecipitation (Co-IP) assay
2×106 293T cells were seeded in 10 cm culture dishes and transfected 12 h later. Forty-eight hours post-transfection, the cells were lysed with RIPA buffer and cleared by centrifugation. The supernatants were collected and incubated with anti-FLAG antibody-conjugated magnetic beads (Sigma) overnight at 4°C. Then, the beads were collected with a magnetic rack, repeatedly washed, and used for the WB assay.