Fig. 4.

The reovirus cell entry pathway. (a) Following attachment to cell-surface carbohydrate (α-linked sialic acid for serotype 3 reoviruses) and JAM-A, reovirus virions enter cells by receptor-mediated endocytosis. (b) Within the endocytic compartment, the viral outer capsid undergoes acid-dependent proteolysis. (c) The first disassembly intermediate is the ISVP, which is characterized by loss of σ3 and cleavage of μ1C into particle-associated fragments δ and φ. (d) The ISVP then undergoes further conformational changes to form the ISVP*. The ISVP* is characterized by conformational rearrangements of the μ1 fragments to expose hydrophobic residues, release of μ1N, and loss of attachment protein σ1. (e) The μ1 cleavage fragments mediate penetration through the endosomal membrane, releasing the transcriptionally active core into the cytoplasm