title: The arginine-rich domain of hepatitis B virus precore and core proteins contains a signal for nuclear transport.
abstract: Precore and core proteins are two related co-carboxy-terminal proteins of hepatitis B virus. Precore protein contains the entire sequence of core protein plus an amino-terminal extension of 29 amino acid residues. Both proteins can display a common antigenic determinant known as core antigen (HBcAg). Clinically, HBcAg is detected in the nucleus, cytoplasm, or both of hepatitis B virus-infected hepatocytes. In order to understand the mechanism that regulates nuclear transport of HBcAg, various portions of precore and core proteins were linked to a reporter protein, human alpha-globin, and expressed in mammalian cells. Our results indicate that the precore protein-specific sequence, although important for nuclear transport, does not contain a nuclear localization signal. Instead, a signal for nuclear transport is located near the carboxy termini of precore and core proteins in the arginine-rich domain. This signal is made up of a set of two direct PRRRRSQS repeats and is highly conserved among mammalian hepadnaviruses.
authors.affiliation: Department of Microbiology, University of Southern California, Los Angeles 90033-1054.
authors.forename: C T
authors.initials: CT
authors.lastname: Yeh
authors.forename: Y F
authors.initials: YF
authors.lastname: Liaw
authors.forename: J H
authors.initials: JH
authors.lastname: Ou
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine; D001483:Base Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics; D005455:Fluorescent Antibody Technique; D005914:Globins / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D014758:Viral Core Proteins / Q000235:genetics* / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D011498:Protein Precursors; D014758:Viral Core Proteins; D014760:Viral Fusion Proteins; D005914:Globins; D001120:Arginine