scholarly journals A signal peptide encoded within the precore region of hepatitis B virus directs the secretion of a heterogeneous population of e antigens in Xenopus oocytes.

1988 ◽  
Vol 85 (22) ◽  
pp. 8405-8409 ◽  
Author(s):  
D. N. Standring ◽  
J. H. Ou ◽  
F. R. Masiarz ◽  
W. J. Rutter
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Signal Peptide ◽  
Xenopus Oocytes ◽  
Heterogeneous Population ◽  
Precore Region ◽  
B Virus

Fulminant hepatitis B: Induction by hepatitis B virus mutants defective in the precore region and incapable of encoding E antigen

1991 ◽  
Vol 100 (4) ◽  
pp. 1087-1094 ◽  
Author(s):  
Yoshitane Kosaka ◽  
Kohjiro Takase ◽  
Mineo Kojima ◽  
Masaru Shimizu ◽  
Kyoichi Inoue ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Fulminant Hepatitis ◽  
Precore Region ◽  
B Virus

scholarly journals Biogenesis of hepatitis B virus e antigen is driven by translocon-associated protein complex and regulated by conserved cysteines in signal peptide

2021 ◽  
Author(s):  
Helena Zábranská ◽  
Aleš Zábranský ◽  
Barbora Lubyová ◽  
Jan Hodek ◽  
Alena Křenková ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Immune Responses ◽  
Signal Peptide ◽  
Protein Complex ◽  
Secretory Pathway ◽  
Virus Infectivity ◽  
Host Immune Responses ◽  
B Virus ◽  
Processing Product

Hepatitis B virus (HBV) uses e antigen (HBe), which is dispensable for virus infectivity, to modulate host immune responses and achieve viral persistence in human hepatocytes. The HBe precursor (p25) is directed to the endoplasmic reticulum (ER), where cleavage of the signal peptide (sp) gives rise to the first processing product, p22. P22 can be retro-translocated back to the cytosol or enter the secretory pathway and undergo a second cleavage event, resulting in secreted p17 (HBe). Here, we report that translocation of p25 to the ER is promoted by translocon-associated protein complex (TRAP). We found that p25 is not completely translocated into the ER; a fraction of p25 is phosphorylated and remains in the cytoplasm and nucleus. Within the p25 sp sequence, we identified three cysteine residues that control the efficiency of sp cleavage and contribute to proper subcellular distribution of the precore pool.

scholarly journals Hepatitis B Virus Mutants with Precore-Region Defects in Two Babies with Fulminant Hepatitis and Their Mothers Positive for Antibody to Hepatitis B e Antigen

1991 ◽  
Vol 29 (1) ◽  
pp. 5-9 ◽  
Author(s):  
Sousuke Terazawa ◽  
Mineo Kojima ◽  
Tatsuru Yamanaka ◽  
Shigeru Yotsumoto ◽  
Hiroaki Okamoto ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Fulminant Hepatitis ◽  
Hepatitis B E Antigen ◽  
Precore Region ◽  
B Virus

Mutations in the Precore Region of Hepatitis B Virus DNA in Patients with Fulminant and Severe Hepatitis

1991 ◽  
Vol 324 (24) ◽  
pp. 1699-1704 ◽  
Author(s):  
Masao Omata ◽  
Toshiki Ehata ◽  
Osamu Yokosuka ◽  
Kazuhiko Hosoda ◽  
Masao Ohto
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Severe Hepatitis ◽  
Hepatitis B Virus Dna ◽  
Precore Region ◽  
B Virus

scholarly journals Mutations in the basic core promotor and the precore region of hepatitis b virus and their selection in children with fulminant and chronic hepatitis B

Hepatology ◽  
1999 ◽  
Vol 29 (4) ◽  
pp. 1252-1258 ◽  
Author(s):  
Michael Friedt ◽  
Patrick Gerner ◽  
Ekkehart Lausch ◽  
Hubert Trübel ◽  
Bernhard Zabel ◽  
...  
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Chronic Hepatitis B ◽  
Precore Region ◽  
B Virus

scholarly journals Hepatitis B Virus of Genotype B with or without Recombination with Genotype C over the Precore Region plus the Core Gene

2002 ◽  
Vol 76 (12) ◽  
pp. 5985-5992 ◽  
Author(s):  
Fuminaka Sugauchi ◽  
Etsuro Orito ◽  
Takafumi Ichida ◽  
Hideaki Kato ◽  
Hiroshi Sakugawa ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Gene ◽  
Entire Genome ◽  
Amino Acid Homology ◽  
The Core ◽  
Dna Database ◽  
Precore Region ◽  
B Virus ◽  
Genotype C

ABSTRACT The entire nucleotide sequences of 70 hepatitis B virus (HBV) isolates of genotype B (HBV/B), including 38 newly determined and 32 retrieved from the international DNA database (DDBJ/EMBL/GenBank), were compared phylogenetically. Two subgroups of HBV/B were identified based on sequence divergence in the precore region plus the core gene, one with the recombination with genotype C and the other without it. The analysis over the entire genome of HBV/B by the SimPlot program located the recombination with genotype C in the precore region plus the core gene spanning nucleotide positions from 1740 to 1838 to 2443 to 2485. Within this genomic area, HBV/B strains with the recombination had higher nucleotide and amino acid homology to genotype C than those without the recombination (96.9 versus 91.1% in nucleotides and 97.0 versus 92.9% in amino acids). There were 29 HBV/B strains without the recombination, and they were all recovered from carriers in Japan. The remaining 41 HBV/B isolates having the recombination with genotype C were from carriers in China (12 strains), Hong Kong (3 strains), Indonesia (4 strains), Japan (3 strains), Taiwan (4 strains), Thailand (3 strains), and Vietnam (12 strains). Due to the frequency of the distribution of HBV/B without the recombination (29 of 32 isolates, or 91%) and the fact that it was exclusive to Japan, it was provisionally classified into the Bj (j standing for Japan) subgroup, and HBV/B with the recombination was classified into the Ba (a for Asia) subgroup. Virological differences between HBV/Bj and HBV/Ba may be reflected in the severity of clinical disease in the patients infected with HBV of genotype B, which seems to be under strong geographic influences in Asia.

scholarly journals Point Mutations Upstream of Hepatitis B Virus Core Gene Affect DNA Replication at the Step of Core Protein Expression

2006 ◽  
Vol 80 (2) ◽  
pp. 587-595 ◽  
Author(s):  
Michael Guarnieri ◽  
Kyun-Hwan Kim ◽  
Genie Bang ◽  
Jisu Li ◽  
Yonghong Zhou ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Protein Expression ◽  
Core Protein ◽  
Core Gene ◽  
Genome Replication ◽  
The Core ◽  
Precore Region ◽  
B Virus ◽  
Genotype A

ABSTRACT The pregenomic RNA directs replication of the hepatitis B virus (HBV) genome by serving both as the messenger for core protein and polymerase and as the genome precursor following its packaging into the core particle. RNA packaging is mediated by a stem-loop structure present at its 5′ end designated the ε signal, which includes the core gene initiator AUG. The precore RNA has a slightly extended 5′ end to cover the entire precore region and, consequently, directs the translation of a precore/core protein, which is secreted as e antigen (HBeAg) following removal of precore-derived signal peptide and the carboxyl terminus. A naturally occurring G1862T mutation upstream of the core AUG affects the bulge of the ε signal and generates a “forbidden” residue at the −3 position of the signal peptide cleavage site. Transfection of this and other mutants into human hepatoma cells failed to prove their inhibition of HBeAg secretion but rather revealed great impairment of genome replication. This replication defect was associated with reduced expression of core protein and could be overcome by a G1899A covariation, or by nonsense or frameshift mutation in the precore region. All these mutations antagonized the G1862T mutation on core protein expression. Cotransfection of the G1862T mutant with a replication-deficient HBV genome that provides core protein in trans also restored genome replication. Consistent with our findings in cell culture, HBV genotype A found in African/Asian patients has T1862 and is associated with much lower viremia titers than the European subgroup of genotype A.

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