Figure 8. The E2 signal peptide is required for targeting of capsid protein to mitochondria.

A. Schematic of capsid constructs used for transfection experiments. RNA = RNA-binding domain; R = Arginine-rich motif; SP = E2 signal peptide. Numbers denote the amino acid residues of capsid protein. B. A549 cells were transfected with plasmids encoding capsid constructs and were then processed for indirect immunofluorescence after 40 hours. With the exception of transfectants expressing CapNT, all samples were stained with mouse anti-capsid and rabbit anti-cytochrome c to label mitochondria. Primary antibodies were detected with chicken anti-mouse Alexa594 and donkey anti-rabbit Alexa488. CapNT was detected using goat anti-RV serum and chicken anti-goat Alexa594. Nuclei were stained with DAPI. Scale bar  = 10 µm.