1.1.4. Reovirus

Reoviruses (e.g., rotavirus) have non-enveloped capsids with a diameter of ~75 nm and contain RNA genomes. The exact entry of reoviruses is unclear, but it is likely to occur through endocytosis. After uptake, endosomal cathepsins are activated by a drop in pH. The outer capsid is then proteolytically processed and capsid protein σ3 is removed [34]. This uncovers the membrane lytic capsid protein μ1 and autoproteolytic processing renders it membrane-lytic [35,36]. The fully processed μ1 N-terminal peptides are then myristylated, released from the capsid and insert into the endosomal membrane, where they form size selective pores [37,38]. While these pores are too small (estimated to 4–9 nm) to permit reovirus translocation, it was suggested that endosome lysis could involve osmotic lysis [39,40].
