FIG. 5.

The PF/PN domain inhibits nuclear localization of ESX1 in transfected cells. A control plasmid (Vector) or pcDNA3-Esx1 plasmids encoding the indicated proteins were transfected into COS1 cells, and the ESX1 proteins were visualized by indirect immunofluorescence with anti-ESX1 antisera (α-Esx1) (A, C, E, G, I, and K), while cell nuclei were visualized by DAPI staining (B, D, F, H, J, and L). For each pair of images, arrows point to the same cell showing the anti-ESX1 antiserum staining (green) or the DAPI staining (blue). Note that ESX1 proteins containing the PF/PN domain [ESX1(1–382), ESX1(69–382), and ESX1(160–382)] are primarily cytoplasmic whereas those lacking this domain [ESX1(1–327) and ESX1(1–283)] are primarily nuclear. Bar, 25 μm.