Fig. 4. The effect of overexpression of SARA and Rab5 mutants on surface TfR distribution. HEK cells transfected with GFP-SARA (A,B), Rab5Q79L (C,D), Rab5S34N (E,F) and both GFP-SARA and Rab5S34N (G,H) were fixed. Without permeabilization, the cells were labeled for surface TfR using an antibody recognizing the extracellular domain of TfR (B3/25), followed by Alexa594 anti-mouse IgG (B,D,F,H). Cells overexpressing GFP-SARA and Rab5Q79L, but not Rab5S34N, appear to have reduced surface TfR labeling (^*). In contrast, cells double-transfected with GFP-SARA and Rab5S34N have similar levels of surface TfR compared with the neighboring cells (^*). Bar, 10 µm.