Fig 5.

Blocking Arf6 function disrupts MuSK endocytosis. COS-7 cells were transiently transfected with SBP-MuSK and Arf6-GFP. MuSK was labelled with DyLight 649-conjugated streptavidin (blue) at 4 °C followed by incubation at 37 °C for 60 min. After cell fixation, actin was stained with rhodamine-labeled phalloidin (red). Cells were exposed to different treatments: cytochalasin D, myristoylated Arf6 peptide (myr-Arf6), wortmannin, aluminum fluoride (AlF) or co-transfection with the constitutively active mutant Arf6 Q67L. Dimethylsulfoxide treatment was used as a control. MuSK accumulates in cell protrusions close to the cell membrane. Magnified structures demonstrating colocalization (arrows) are shown as insets. Scale bar = 25 μm.