Effect of mutations in the small envelope protein of hepatitis B virus on assembly and secretion of hepatitis delta virus.
The gene coding for the small (S) envelope protein of hepatitis B virus was mutated to identify sequences important for the envelopment of the nucleocapsid during morphogenesis of hepatitis delta virus (HDV) virions. This study was focused on a domain of the S protein that is exposed in the cytoplasm during synthesis and thereby represented a good candidate for interaction with the viral nucleocapsid during virion assembly. The mutations consisted of deletion/insertions spanning the entire cytosolic domain of S between amino acid residues 24 and 80. Although the expression of mutants clustered between residues 59 and 80 could not be obtained, we demonstrated that a large part of the cytosolic loop, from residues 29-47 and 49-59, does not contain motifs essential for production of hepatitis B virus subviral particles or HDV virions. However, deletion of residues 24-28 led to the synthesis of S protein mutant, which was competent for secretion of subviral particles but deficient for production of HDV. We concluded that the sequence between Arg-24 and Ile-28 located at the carboxyl boundary of the transmembrane signal I for S contains residue or residues important for HDV particle assembly.
Jenna
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Laboratoire de Virologie, Institut de Biologie, 2 Boulevard Henri IV, Montpellier, 34060, France.
Sureau
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D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002500:Centrifugation, Isopycnic; D002586:Cesium; D002712:Chlorides; D006514:Hepatitis B Surface Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006515:Hepatitis B virus / Q000235:genetics / Q000378:metabolism*; D003698:Hepatitis Delta Virus / Q000302:isolation & purification / Q000502:physiology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011233:Precipitin Tests; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012367:RNA, Viral / Q000032:analysis; D017384:Sequence Deletion; D014162:Transfection; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019065:Virus Assembly
D002712:Chlorides; D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; D012367:RNA, Viral; D014759:Viral Envelope Proteins; C050806:presurface protein 1, hepatitis B surface antigen; C050807:presurface protein 2, hepatitis B surface antigen; D002586:Cesium; C028019:cesium chloride