title: The middle hepatitis B virus envelope protein is not necessary for infectivity of hepatitis delta virus.
abstract: The hepatitis delta virus (HDV) envelope contains the large (L), middle (M), and small (S) surface proteins encoded by coinfecting hepatitis B virus. Although HDV-like particles can be assembled with only the S protein in the envelope, the L protein is essential for infectivity in vitro (C. Sureau, B. Guerra, and R. Lanford, J. Virol. 67:366-372, 1993). Here, we demonstrate that the M protein, previously described as carrying a site for binding to polymerized human albumin, is not necessary for infectivity. HDV-like particles coated with the S plus L or the S plus M plus L proteins are infectious in primary cultures of chimpanzee hepatocytes. We conclude that the S and L proteins serve two essential functions in the HDV replication cycle; the S protein ensures the export of the HDV genome from an infected cell by forming a particle, and the L protein ensures its import into a human hepatocyte.
authors.affiliation: Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, Texas 78228.
authors.forename: C
authors.initials: C
authors.lastname: Sureau
authors.forename: B
authors.initials: B
authors.lastname: Guerra
authors.forename: H
authors.initials: H
authors.lastname: Lee
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D006515:Hepatitis B virus / Q000235:genetics; D003699:Hepatitis D / Q000209:etiology / Q000382:microbiology; D003698:Hepatitis Delta Virus / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D008099:Liver / Q000378:metabolism / Q000382:microbiology; D002679:Pan troglodytes; D012367:RNA, Viral / Q000235:genetics; D014759:Viral Envelope Proteins / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: C096362:L protein, hepatitis B virus; D012367:RNA, Viral; D014759:Viral Envelope Proteins