Fig. 5. Inhibition of TIVAMP-GFP and Cb-GFP transport to the plasma membrane in cells expressing syntaxin 1. HeLa cells were transfected with either TIVAMP-GFP or Cb-GFP alone (upper panels) or co-transfected with syntaxin 1 (lower panels), as indicated. 24 hours after transfection cells were incubated with anti-GFP antibodies for 1 hour at 37°C and processed for immunofluorescence. Note that when expressed alone, TIVAMP-GFP and Cb-GFP displayed their typical staining patterns and efficiently took up the anti-GFP antibody from the medium. However, when co-expressed together with syntaxin 1, TIVAMP-GFP and Cb-GFP were both retained in the ER and their expression at the plasma membrane and endocytosis was inhibited. Bar, 6 µm.