Figure 1.

(A) TfR is constitutively degraded by lysosomes in MEF cells. MEF cells were treated with DMSO (left part), 50 µg/ml cycloheximide (middle part) for 4 h or 100 nM bafilomycin A1 (bafilomycin; right part) for 9 h. The cells were fixed and immunostained with anti-TfR antibody. Note that TfR signals in cycloheximide-treated and bafilomycin-treated cells were weaker and stronger, respectively, than those in control cells. (B) Rab11 and Rab12 differently regulate the trafficking of TfR protein from recycling endosomes. MEF cells transfected with control siRNA (si-Control; left part), Rab11B siRNA (si-Rab11; middle part) or Rab12 siRNA (si-Rab12; right part) were immunostained with anti-TfR antibody. Note that TfR signals in Rab11B-knockdown and Rab12-knockdown cells were weaker and stronger, respectively, than those in control cells. Scale bar, 20 µm.