title: Endocytic tubules regulated by Rab GTPases 5 and 11 are used for envelopment of herpes simplex virus.
abstract: Enveloped viruses employ diverse and complex strategies for wrapping at cellular membranes, many of which are poorly understood. Here, an ultrastructural study of herpes simplex virus 1 (HSV1)-infected cells revealed envelopment in tubular membranes. These tubules were labelled by the fluid phase marker horseradish peroxidase (HRP), and were observed to wrap capsids as early as 2 min after HRP addition, indicating that the envelope had recently cycled from the cell surface. Consistent with this, capsids did not colocalise with either the trans-Golgi network marker TGN46 or late endosomal markers, but showed coincidence with the transferrin receptor. Virus glycoproteins were retrieved from the plasma membrane (PM) to label wrapping capsids, a process that was dependent on both dynamin and Rab5. Combined depletion of Rab5 and Rab11 reduced virus yield to <1%, resulting in aberrant localisation of capsids. These results suggest that endocytosis from the PM into endocytic tubules provides the main source of membrane for HSV1, and reveal a new mechanism for virus exploitation of the endocytic pathway.
authors.affiliation: Section of Virology, Faculty of Medicine, Imperial College London, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Hollinshead
authors.forename: Helen L
authors.initials: HL
authors.lastname: Johns
authors.forename: Charlotte L
authors.initials: CL
authors.lastname: Sayers
authors.forename: Claudia
authors.initials: C
authors.lastname: Gonzalez-Lopez
authors.forename: Geoffrey L
authors.initials: GL
authors.lastname: Smith
authors.forename: Gillian
authors.initials: G
authors.lastname: Elliott
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002213:Capsid / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004705:Endocytosis / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000821:virology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000378:metabolism; D006367:HeLa Cells; D006561:Herpes Simplex / Q000378:metabolism / Q000821:virology; D018259:Herpesvirus 1, Human / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D051907:Lysosomal Membrane Proteins / Q000378:metabolism; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000378:metabolism; D019065:Virus Assembly / Q000502:physiology*; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020696:rab5 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism / Q000821:virology; D000099193:rab11 GTP-Binding Proteins; D052118:Lysosomal-Associated Membrane Protein 1
chemical_list: D006023:Glycoproteins; D006735:Horseradish Peroxidase; D051907:Lysosomal Membrane Proteins; D014759:Viral Envelope Proteins; D020691:rab GTP-Binding Proteins; D020696:rab5 GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C489116:LAMP1 protein, human; D052118:Lysosomal-Associated Membrane Protein 1