title: Structural correlates of rotavirus cell entry.
abstract: Cell entry by non-enveloped viruses requires translocation into the cytosol of a macromolecular complex--for double-strand RNA viruses, a complete subviral particle. We have used live-cell fluorescence imaging to follow rotavirus entry and penetration into the cytosol of its ∼ 700 Å inner capsid particle ("double-layered particle", DLP). We label with distinct fluorescent tags the DLP and each of the two outer-layer proteins and track the fates of each species as the particles bind and enter BSC-1 cells. Virions attach to their glycolipid receptors in the host cell membrane and rapidly become inaccessible to externally added agents; most particles that release their DLP into the cytosol have done so by ∼ 10 minutes, as detected by rapid diffusional motion of the DLP away from residual outer-layer proteins. Electron microscopy shows images of particles at various stages of engulfment into tightly fitting membrane invaginations, consistent with the interpretation that rotavirus particles drive their own uptake. Electron cryotomography of membrane-bound virions also shows closely wrapped membrane. Combined with high resolution structural information about the viral components, these observations suggest a molecular model for membrane disruption and DLP penetration.
authors.affiliation: Laboratory of Molecular Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Aliaa H
authors.initials: AH
authors.lastname: Abdelhakim
authors.affiliation: Laboratory of Molecular Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Eric N
authors.initials: EN
authors.lastname: Salgado
authors.affiliation: Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts, United States of America.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Fu
authors.affiliation: Program in Cellular and Molecular Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Mithun
authors.initials: M
authors.lastname: Pasham
authors.affiliation: Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts, United States of America.
authors.forename: Daniela
authors.initials: D
authors.lastname: Nicastro
authors.affiliation: Program in Cellular and Molecular Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Tomas
authors.initials: T
authors.lastname: Kirchhausen
authors.affiliation: Laboratory of Molecular Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America; Howard Hughes Medical Institute, Boston, Massachusetts, United States of America.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Harrison
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D002478:Cells, Cultured; D002522:Chlorocebus aethiops / Q000821:virology; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000821:virology; D008854:Microscopy, Electron; D009154:Mutation / Q000235:genetics; D012401:Rotavirus / Q000737:chemistry* / Q000502:physiology; D014771:Virion; D019065:Virus Assembly / Q000502:physiology*; D053586:Virus Internalization
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; C060339:VP4 protein, Rotavirus; C050779:VP7 protein, Rotavirus