FIG 12.

Working model for cellular sites of EBOV and SARS CoV entry. We propose that Ebola and SARS enter the cytoplasm later than other “late-penetrating viruses” (e.g., influenza and LCMV), through NPC1⁺ endolysosomes (LE/Lys). We further propose that they do so to access high levels of endosomal cathepsins (and, for EBOV, to bind to NPC1). Text in green boxes indicates markers of the respective organelles (pink circles). Viruses known to exit each organelle are indicated above. While one study showed that influenza enters through transitional endosomes (40), others refer to influenza and LCMV as entering through LE (15, 26). H⁺ indicates protons, and Cat indicates cathepsins. Lines and text below the organelles indicate GFP-tagged markers used in Fig. 11 and Movies S1 to S3 in the supplemental material.