Cellular distribution of the human IFITM proteins.

<p>C-terminal domain HA-tagged IFITM1, IFITM2, IFITM3 and control A549 cell lines were stained intact, or following permeabilisation, with an anti-HA antibody and a secondary anti-rat Alexa-488 antibody. A) Permeabilised A549 cells show no specific staining. B-D) IFITM1-HA, IFITM2-HA and IFITM3-HA have distinct cellular distributions in permeabilised cells. E) Intact A549 cells (no detergent treatment) show no specific staining. F) Intact IFITM1-HA cells show positive cell surface HA staining. G) Intact IFITM2-HA cells show no detectable HA staining. H) Although the majority of intact IFITM3-HA cells show no anti-HA labelling, a minority (<1%) show low-level positive staining. Nuclei were labelled with Hoechst. All images are maximum projections of 0.25 µm optical sections taken through the depth of the cells using a confocal microscope. All images were taken using the same microscope settings and the levels adjusted uniformly. Scale bar represents 15 µm.