FIG 4 .

Light-particle exocytosis. Cells were transduced to express mCherry-tagged Rab proteins, infected with PRV expressing gM-pHluorin and a cyan capsid tag, and imaged at 4.5 to 5 h after PRV infection. Exocytosis events corresponding to light particles were selected for analysis (see Fig. 1D). (A and B) Rab6a is associated with light particle exocytosis. (C and D) Rab8a is associated with light-particle exocytosis. (E and F) Rab11a is associated with light-particle exocytosis. (A, C, and E) Still images at the moment of exocytosis show colocalization between gM-pHluorin and indicated Rab protein (yellow arrowheads) but not a cyan capsid tag. All images are of a 7.2-µm area. (B, D, and F) Relative fluorescence (f/f₀) ensemble averages of gM-pHluorin (top, green lines) and indicated Rab protein (bottom, red lines) over a 60-s time course. Shaded areas represent standard deviations. (G) Particles in infected-cell supernatants were imaged to detect gM-pHluorin (green), red capsid tag, and immunofluorescence staining of CD63, a cellular exosome marker (blue). Images depict single representative particles. The percentage of particles in each category, out of a total of n = 1,627 particles, is indicated.