Fig. 3. GBF1 co-precipitates with ARF1 and ARF4 in vivo. HeLa cells were incubated with or without 5 µg/ml BFA for 45 minutes. Cell lysates were immunoprecipitated using antibodies against GBF1 and Rab8, and the immunoprecipitates (IPs) were analysed by western blotting with antibodies specific for ARF isoforms. ARF1 and ARF4 co-immunoprecipitate with GBF1 in the presence of BFA.