Figure 5.

The Dilysine Motif Confers ER Localization to Membrane-Bound GFP in Tobacco BY-2 Cells.

(A) KKRY fusion. A projection of four 1-μm-thick sections through the cortex reveals that GFP fluorescence is localized in the ER.

(B) Lower magnification views of same cells depicted in (A). At the top, a projection through the first 25 μm shows cortical ER and some transvacuolar strands. At the bottom, a projection through the next 17 μm of optical sections clearly illustrates the fluorescence extending from the nuclear envelope through transvacuolar strands to the cortical ER.

(C) NNRY fusion. Using identical image acquisition and processing settings as in (B), virtually no fluorescence was attributable to the GFP. The same autofluorescent material was observed in nontransformed controls (data not shown). This is a 42-μm-thick projection, which is equal to the total depth shown in (B).

Bar in (A) = 10 μm; bar in (C) = 25 μm for (B) and (C).