Figure 4.

Inhibition of secGFP Transport by an AtRab1b Mutant.

(A) Low-magnification images of GFP fluorescence in epidermal cells of leaves infiltrated with strains carrying secGFP, GFP-HDEL, or secGFP plus either wild-type or mutant AtRab1b as indicated. AtRab1b(N121I) causes accumulation of secGFP in the ER. This is visible as a reticulate network when the optical section passes through the cytoplasm underlying the periclinal cell walls; in most cells, however, the section passes through the anticlinal walls, and the network in the underlying cortical cytoplasm is not resolved.

(B) High-resolution images of the intracellular accumulation of secGFP and GFP-HDEL. The distribution of secGFP accumulating in the presence of AtRab1b(N121I) resembles that of GFP-HDEL. In each case, the optical sections pass through a portion of the cortical cytoplasm beneath the periclinal cell walls.

for all images; for both images.