Figure 5.

Internalized Tac-furin is delivered to the TGN without accumulation into CI-MPR–labeled endosomes. (A–D) TRVb-1/TTF cells were incubated with Cy3–anti-Tac (red) for 5 min and chased for 20 or 40 min as indicated. Cy5-transferrin (Trfn, green in C and D) was present for the last 5 min of the chase. Cells were fixed, permeabilized, and labeled with polyclonal antibodies against CI-MPR followed by Alexa 488 goat anti–rabbit secondary antibodies (green in A and B). (E and F) TRVb-1 cells were incubated with rhodamine-dextrans (red) for 5 min and chased for 20 or 40 min as indicated. Cells were stained for CI-MPR (green) as in A–D. Z-series confocal projections (A–D) and epifluorescence micrographs (E and F) are shown. Pixels labeled with both fluorophores appear yellow. Bars, 10 μm.