Fig. 5. Antibodies against Bet3 inhibit in vitro transport of VSV-G from the ER to the Golgi apparatus. Semi-intact NRK cells were incubated in the presence of cytosol and ATP on ice (lane 1) or at 32°C for 60 minutes (lanes 2-12). Increasing amounts of anti-Bet3 antibodies were added as indicated (lanes 4-9). Control assays were supplemented with 2 µg of antibody against GS28 (lane 3), 2 µg anti-Bet3 antibodies pre-incubated with 2 µg of GST-Bet3 (lane 10), 2 µg heat-inactivated anti-Bet3 antibodies (lane 11), or 2 µg GST-Bet3 alone (lane 12), respectively. Transport was measured by monitoring the percentage of conversion of the total pool of VSV-G from the endo-H-sensitive to the endo-H-resistant Golgi form (A). The transport was quantified (B).