Figure 2.

Class II Arf-positive puncta correspond to peripheral ERGIC that also contain GFP-GBF1. (A) NRK cells cotransfected with plasmids encoding p58-GFP and mCherry-tagged forms of either Arf1, Arf3, Arf4, or Arf5 as described in Materials and Methods. Images were acquired from live cells using a spinning disk confocal microscope as described in Materials and Methods. The upper row displays representative merged stills corresponding to a single confocal slice. Bottom rows show enlargement of the boxed area for single and merged images acquired from the mCherry and GFP channels. The majority of cells expressing Arf1 (91%), Arf3 (76%), Arf4 (100%), and Arf5 (100%) contain mCherry-positive puncta. Bar, 10 μm for full images and 2 μm for magnified images. (B) NRK cells stably expressing low levels of GFP-GBF1 (NRK-GFP-GBF1) were transfected with plasmids encoding mCherry-tagged forms of either Arf1, Arf3, Arf4, or Arf5 as described in Materials and Methods, and they were imaged as described for A. Bar, 10 μm for full image and 2 μm for magnified image.