Association between frequency of amino acid changes in core region of hepatitis B virus (HBV) and the presence of precore mutation in Japanese HBV carriers

1997 ◽  
Vol 32 (5) ◽  
pp. 611-622 ◽  
Author(s):  
Tatsunobu Karasawa ◽  
Takuji Shirasawa ◽  
Yasuhiko Okawa ◽  
Akira Kuramoto ◽  
Noritomo Shimada ◽  
...  
1993 ◽  
Vol 268 (2) ◽  
pp. 1332-1337
Author(s):  
F. Schödel ◽  
D. Peterson ◽  
J. Zheng ◽  
J.E. Jones ◽  
J.L. Hughes ◽  
...  

1986 ◽  
Vol 6 (5) ◽  
pp. 1393-1400
Author(s):  
M J Roossinck ◽  
S Jameel ◽  
S H Loukin ◽  
A Siddiqui

We studied the expression of the core region of the hepatitis B virus genome in mammalian cells with recombinant plasmid vectors. Stably transformed rat fibroblast cell lines were established by transfection with vectors containing subgenomic and genome-length hepatitis B virus DNA, followed by G418 selection. The RNA transcripts directed by the core region were characterized by Northern blot hybridization and S1 nuclease mapping. Using the chloramphenicol acetyltransferase gene expression system, the promoter activity located upstream of the core open reading frame was confirmed. The synthesis of core and e polypeptides was studied with a commercial radioimmunoassay. These studies show that partial deletion of the precore sequences abolished secretion of the e antigen, but there was pronounced synthesis of the core antigen in transfected cells.


2016 ◽  
Vol 22 (17) ◽  
pp. 4287 ◽  
Author(s):  
Hong Kim ◽  
Seoung-Ae Lee ◽  
Seung Yeon Do ◽  
Bum-Joon Kim

2016 ◽  
Vol 10 (3) ◽  
pp. 553-559 ◽  
Author(s):  
Akira Sato ◽  
Toshiya Ishii ◽  
Fumiaki Sano ◽  
Takayuki Yamada ◽  
Hideaki Takahashi ◽  
...  

De novo hepatitis B is associated with a high risk of hepatic failure often resulting in fatal fulminant hepatitis even when nucleotide analogues are administered. A 77-year-old female developed de novo hepatitis B after R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) treatment for diffuse large B-cell lymphoma. Hepatitis B virus (HBV) isolated from the patient was of genotype Bj, with a precore mutation (G1896A) exhibiting an extremely high viral load at the onset of hepatitis. She showed markedly high levels of transaminase with mild jaundice on admission and rapid decrease of prothrombin activity after admission. Although acute liver failure was averted by the administration of entecavir and corticosteroid pulse therapy, liver volume decreased to 860 ml, and marked hypoalbuminemia accompanying massive ascites occurred 2 months after the onset of hepatitis and persisted for 3 months with high levels of HBV DNA and mild abnormal alanine aminotransferase levels. Frequent infusions of albumin solution, nutrition support, and alleviation therapy showed limited effect. However, overall improvement along with HBV DNA reduction was observed after increasing the dose of entecavir and completion of prednisolone that was administered with a minimum dose for adrenal insufficiency. An immediate and sufficient suppression of virus replication with potent antiviral therapy is critical, particularly in patients infected with HBV precore mutation (G1896A) and/or Bj genotype, which may have a high viral replication and direct hepatocellular damage.


Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 720 ◽  
Author(s):  
Michelle Wille ◽  
Hans Netter ◽  
Margaret Littlejohn ◽  
Lilly Yuen ◽  
Mang Shi ◽  
...  

Hepatitis delta virus (HDV) is currently only found in humans and is a satellite virus that depends on hepatitis B virus (HBV) envelope proteins for assembly, release, and entry. Using meta-transcriptomics, we identified the genome of a novel HDV-like agent in ducks. Sequence analysis revealed secondary structures that were shared with HDV, including self-complementarity and ribozyme features. The predicted viral protein shares 32% amino acid similarity to the small delta antigen of HDV and comprises a divergent phylogenetic lineage. The discovery of an avian HDV-like agent has important implications for the understanding of the origins of HDV and sub-viral agents.


1998 ◽  
Vol 18 (2) ◽  
pp. 978-988 ◽  
Author(s):  
Brian K. Meyer ◽  
Marilyn G. Pray-Grant ◽  
John P. Vanden Heuvel ◽  
Gary H. Perdew

ABSTRACT Prior to ligand activation, the unactivated aryl hydrocarbon receptor (AhR) exists in a heterotetrameric 9S core complex consisting of the AhR ligand-binding subunit, a dimer of hsp90, and an unknown subunit. Here we report the purification of an ∼38-kDa protein (p38) from COS-1 cell cytosol that is a member of this complex by coprecipitation with a FLAG-tagged AhR. Internal amino acid sequence information was obtained, and p38 was identified as the hepatitis B virus X-associated protein 2 (XAP2). The simian ortholog of XAP2 was cloned from a COS-1 cDNA library; it codes for a 330-amino-acid protein containing regions of homology to the immunophilins FKBP12 and FKBP52. A tetratricopeptide repeat (TPR) domain in the carboxy-terminal region of XAP2 was similar to the third and fourth TPR domains of human FKBP52 and the Saccharomyces cerevisiae transcriptional modulator SSN6, respectively. Polyclonal antibodies raised against XAP2 recognized p38 in the unliganded AhR complex in COS-1 and Hepa 1c1c7 cells. It was ubiquitously expressed in murine tissues at the protein and mRNA levels. It was not required for the assembly of an AhR-hsp90 complex in vitro. Additionally, XAP2 did not directly associate with hsp90 upon in vitro translation, but was present in a 9S form when cotranslated in vitro with murine AhR. XAP2 enhanced the ability of endogenous murine and human AhR complexes to activate a dioxin-responsive element–luciferase reporter twofold, following transient expression of XAP2 in Hepa 1c1c7 and HeLa cells.


1989 ◽  
Vol 9 (10) ◽  
pp. 4459-4466 ◽  
Author(s):  
K Kuroki ◽  
R Russnak ◽  
D Ganem

The preS1 surface glycoprotein of hepatitis B virus is targeted to the endoplasmic reticulum (ER) and is retained in this organelle when expressed in the absence of other viral gene products. The protein is also acylated at its N terminus with myristic acid. Sequences responsible for its ER retention have been identified through examination of mutants bearing lesions in the preS1 coding region. These studies reveal that such sequences map to the N terminus of the molecule, between residues 6 and 19. Molecules in which this region was present remained in the ER; those in which it had been deleted were secreted from the cell. Although all deletions which allowed efficient secretion also impaired acylation of the polypeptide, myristylation alone was not sufficient for ER retention: point mutations which eliminated myristylation did not lead to secretion. These data indicate that an essential element for ER retention resides in a 14-amino-acid sequence that is unrelated to previously described ER retention signals.


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