Figure 3

GFP-R-Ras colocalizes with Rab11, but not Rab5- or Rab4-positive endosomal compartments. Cos7 cells were transfected with GFP-R-Ras-(wt), -(38V), or -(41A) and then fixed and stained with antibodies against: (A-F) Rab11; (G-I) Rab5; or (J-L) Rab4. The largest vesicle compartments in 85% of -(wt) and 92% of -(38V) transfected cells were positive for Rab11 (arrows, for -(wt) n = 13 cells and -(38V), n = 12), but not Rab5 or Rab4 (<5%, n = 15 each). Intracellular GFP-R-Ras localized to smaller compartments and PM fluorescence lacked correlation with Rab fluorescence. Scale bar is 20 μm. (D-F) Insets of cells shown in A-C are shown at 3× zoom to highlight features.