HeLa cells were treated for 1 h with bafilomycin A1 followed by 2 h with bafilomycin A1 in full medium or in Hank’s balanced salt solution (HBSS). Immunoprecipitates obtained using TfR antibody were processed for immunoblot for ubiquitin. Histogram shows the amount of TfR ubiquitination normalized for TfR immunoprecipitated. Data are mean ± SD (n= 3; graphs represent means from three independent experiments). Two-tailed paired t test,**p< 0.01.
