Figure 6. The lumenal domain of TGN46 is necessary and sufficient for its CARTS-mediated export from the trans-Golgi network (TGN).

(A) HeLa cells co-expressing the different indicated proteins (green and magenta channels) were fixed, processed for immunostaining when required, and the localization of those proteins was monitored by fluorescence confocal microscopy. Insets correspond to zoom-in areas of the dashed, white boxed areas. Scale bars are 10 µm. (B) Percentage of transport carriers containing each of the cargoes described on the x-axis that are also positive for pancreatic adenocarcinoma upregulated factor (PAUF; CARTS, empty circles) or VSVG (VSVG carriers, gray circles), as measured from confocal micrographs in (A). Results are from at least 10 cells from each of n = 3 independent experiments (individual values shown, with mean ± stdev; ***p ≤ 0.001; ****p ≤ 0.0001).

Figure 6—figure supplement 1. The lumenal domain of TGN46 is necessary and sufficient for its CARTS-mediated export from the trans-Golgi network (TGN).

(A) Fluorescence microscopy images obtained from a characteristic fluorescence loss in photobleaching (FLIP) experiment assessing the export rate of the denoted proteins from the perinuclear area in HeLa cells. Time from the beginning of the FLIP experiments is indicated, and the area enclosed by the white lines shown in the left images denotes the photobleached area. Scale bars are 10 µm. (B–D) Residence time in the perinuclear area measured as the half time of the FLIP curves. Results are from 7 to 12 cells from n = 3 independent experiments (individual values shown, with mean ± stdev; ns, p > 0.05; **p ≤ 0.01; ****p ≤ 0.0001). In (B), unpaired two-tailed t test (ns, p > 0.05).