title: Functional study of hepatitis delta virus large antigen in packaging and replication inhibition: role of the amino-terminal leucine zipper.
abstract: The large hepatitis delta antigen (HDAg) has been found to be essential for the assembly of the hepatitis delta virion. Furthermore, in a cotransfection experiment, the large HDAg itself, without the hepatitis delta virus (HDV) genome and small HDAg, could be packaged into hepatitis B surface antigen (HBsAg) particles. By deletion analysis, it was shown that the amino-terminal leucine zipper domain was dispensable for packaging. The large HDAg could also help in copackaging of the small HDAg into HBsAg particles without the need for HDV RNA. This process was probably mediated through direct interaction of the two HDAgs as a mutated large HDAg whose leucine zipper domain was deleted such that it could not help in copackaging of the small HDAg. This mutated large HDAg did not suppress HDV replication, suggesting that this effect is probably also via protein interaction. These results indicated that functional domains of the large HDAg responsible for packaging with HBsAg particles and for the trans-negative effect on HDV replication can be separated.
authors.affiliation: Graduate Institute of Clinical Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei.
authors.forename: P J
authors.initials: PJ
authors.lastname: Chen
authors.forename: F L
authors.initials: FL
authors.lastname: Chang
authors.forename: C J
authors.initials: CJ
authors.lastname: Wang
authors.forename: C J
authors.initials: CJ
authors.lastname: Lin
authors.forename: S Y
authors.initials: SY
authors.lastname: Sung
authors.forename: D S
authors.initials: DS
authors.lastname: Chen
mesh_terms: D000956:Antigens, Viral / Q000378:metabolism*; D001483:Base Sequence; D004252:DNA Mutational Analysis; D003673:Defective Viruses / Q000378:metabolism*; D006514:Hepatitis B Surface Antigens / Q000378:metabolism; D003699:Hepatitis D / Q000378:metabolism*; D003698:Hepatitis Delta Virus / Q000254:growth & development*; D035923:Hepatitis delta Antigens; D006801:Humans; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D013329:Structure-Activity Relationship; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D006514:Hepatitis B Surface Antigens; D035923:Hepatitis delta Antigens; C442244:hepatitis delta virus large antigen