Figure 7.

ARF1 effectors demonstrate different sensitivities to BFA. A, Time-lapse confocal micrographs demonstrate the effect of BFA treatment on a live tobacco epidermal cell coexpressing YFP-GDAP1 and ɛCOP-YFP. Representative images are shown with the time in seconds indicated in the top right corner. The first image in the sequence (labeled 0.0) was taken after a 45-min pretreatment with latrunculin B and a subsequent incubation of 3.5 min with BFA. The images indicate that ɛCOP-YFP fluorescence is released from the Golgi, whereas CFP-GDAP1 remains on punctate structures. Scale bar = 5 μm. The fluorescence of the Golgi relative to that of the cytosol was measured for both GDAP1-CFP and ɛCOP-YFP in each frame of the time lapse with (B) and without (C) BFA treatment. The RPSF is given as a percentage of the ratio between fluorescence intensity values (arbitrary units) measured in the punctate structure and the sum of intensity values for the cytosol and punctate structure (see “Materials and Methods”).