scholarly journals Characterization of the Phosphorylated Forms and the Phosphorylated Residues of Hepatitis Delta Virus Delta Antigens

1999 ◽  
Vol 73 (12) ◽  
pp. 10540-10545 ◽  
Author(s):  
Jung-Jung Mu ◽  
Hui-Lin Wu ◽  
Bor-Luen Chiang ◽  
Ruo-Ping Chang ◽  
Ding-Shinn Chen ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Hepatitis Delta Virus ◽  
Biological Functions ◽  
Two Dimensional Gel Electrophoresis ◽  
Hepatitis Delta ◽  
Delta Antigen ◽  
Gradient Electrophoresis ◽  
Phosphoamino Acid Analysis ◽  
Delta Virus

ABSTRACT Hepatitis delta virus (HDV) replication requires both the cellular RNA polymerase and one virus-encoded protein, small delta antigen (S-HDAg). S-HDAg has been shown to be a phosphoprotein, but its phosphorylation status is not yet clear. In this study, we employed three methods to address this question. A special two-dimensional gel electrophoresis, namely, nonequilibrium pH gradient electrophoresis, was used to separate the very basic S-HDAg. By carefully adjusting the pH of solubilization solution, the ampholyte composition, and the appropriate electrophoresis time periods, we were able to clearly resolve S-HDAg into two phosphorylated isoforms and one unphosphorylated form. In contrast, the viral large delta antigen (L-HDAg) can only be separated into one phosphorylated and one unphosphorylated form. By metabolic 32P labeling, both immunoprecipitated S-HDAg and L-HDAg were found to incorporate radioactive phosphate. The extent of S-HDAg phosphorylation was increased upon 12-O-tetradecanoylphorbol-13-acetate treatment, while that of L-HDAg was not affected. Finally, phosphoamino acid analysis identified serine and threonine as the phospho residues in the labeled S-HDAg and only serine in the L-HDAg. Therefore, HDV S- and L-HDAgs differ in their phosphorylation patterns, which may account for their distinct biological functions.

scholarly journals Characterization of hepatitis delta antigen: specific binding to hepatitis delta virus RNA.

1990 ◽  
Vol 64 (9) ◽  
pp. 4051-4058 ◽  
Author(s):  
J H Lin ◽  
M F Chang ◽  
S C Baker ◽  
S Govindarajan ◽  
M M Lai
Keyword(s):  
Hepatitis Delta Virus ◽  
Specific Binding ◽  
Hepatitis Delta ◽  
Delta Antigen ◽  
Virus Rna ◽  
Hepatitis Delta Antigen ◽  
Delta Virus

scholarly journals Transcription of Hepatitis Delta Virus RNA by RNA Polymerase II

2007 ◽  
Vol 82 (3) ◽  
pp. 1118-1127 ◽  
Author(s):  
Jinhong Chang ◽  
Xingcao Nie ◽  
Ho Eun Chang ◽  
Ziying Han ◽  
John Taylor
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Hepatitis Delta Virus ◽  
Cell System ◽  
Hepatitis Delta ◽  
Pol Ii ◽  
Delta Antigen ◽  
Nuclear Extracts ◽  
Virus Rna ◽  
Delta Virus

ABSTRACT Previous studies have indicated that the replication of the RNA genome of hepatitis delta virus (HDV) involves redirection of RNA polymerase II (Pol II), a host enzyme that normally uses DNA as a template. However, there has been some controversy about whether in one part of this HDV RNA transcription, a polymerase other than Pol II is involved. The present study applied a recently described cell system (293-HDV) of tetracycline-inducible HDV RNA replication to provide new data regarding the involvement of host polymerases in HDV transcription. The data generated with a nuclear run-on assay demonstrated that synthesis not only of genomic RNA but also of its complement, the antigenome, could be inhibited by low concentrations of amanitin specific for Pol II transcription. Subsequent studies used immunoprecipitation and rate-zonal sedimentation of nuclear extracts together with double immunostaining of 293-HDV cells, in order to examine the associations between Pol II and HDV RNAs, as well as the small delta antigen, an HDV-encoded protein known to be essential for replication. Findings include evidence that HDV replication is somehow able to direct the available delta antigen to sites in the nucleoplasm, almost exclusively colocalized with Pol II in what others have described as transcription factories.

scholarly journals Characterization of Proteins Associated with Hepatitis Delta Virus

1987 ◽  
Vol 68 (11) ◽  
pp. 2953-2959 ◽  
Author(s):  
M. Roggendorf ◽  
C. Pahlke ◽  
B. Bohm ◽  
R. Rasshofer
Keyword(s):  
Hepatitis Delta Virus ◽  
Hepatitis Delta ◽  
Delta Virus

scholarly journals Hepatitis Delta Virus Minimal Substrates Competent for Editing by ADAR1 and ADAR2

2001 ◽  
Vol 75 (18) ◽  
pp. 8547-8555 ◽  
Author(s):  
Shuji Sato ◽  
Swee Kee Wong ◽  
David W. Lazinski
Keyword(s):  
Hepatitis Delta Virus ◽  
Cultured Cells ◽  
Reporter System ◽  
Editing Event ◽  
Hepatitis Delta ◽  
Reading Frame ◽  
Adenosine Deaminases ◽  
Delta Antigen ◽  
Amber Codon ◽  
Delta Virus

ABSTRACT A host-mediated RNA-editing event allows hepatitis delta virus (HDV) to express two essential proteins, the small delta antigen (HDAg-S) and the large delta antigen (HDAg-L), from a single open reading frame. One or several members of the ADAR (adenosine deaminases that act on RNA) family are thought to convert the adenosine to an inosine (I) within the HDAg-S amber codon in antigenomic RNA. As a consequence of replication, the UIG codon is converted to a UGG (tryptophan [W]) codon in the resulting HDAg-L message. Here, we used a novel reporter system to monitor the editing of the HDV amber/W site in the absence of replication. In cultured cells, we observed that both human ADAR1 (hADAR1) and hADAR2 were capable of editing the amber/W site with comparable efficiencies. We also defined the minimal HDV substrate required for hADAR1- and hADAR2-mediated editing. Only 24 nucleotides from the amber/W site were sufficient to enable efficient editing by hADAR1. Hence, the HDV amber/W site represents the smallest ADAR substrate yet identified. In contrast, the minimal substrate competent for hADAR2-mediated editing contained 66 nucleotides.

Characterization of a strain-specific monoclonal antibody to hepatitis delta virus antigen

2000 ◽  
Vol 87 (1-2) ◽  
pp. 53-62 ◽  
Author(s):  
Sheng-Chieh Hsu ◽  
Ho-Pi Lin ◽  
Jaw-Ching Wu ◽  
Kai-Liang Ko ◽  
I-Jane Sheen ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Hepatitis Delta Virus ◽  
Virus Antigen ◽  
Specific Monoclonal Antibody ◽  
Hepatitis Delta ◽  
Delta Virus

scholarly journals Large Hepatitis Delta Antigen Is Not a Suppressor of Hepatitis Delta Virus RNA Synthesis once RNA Replication Is Established

2002 ◽  
Vol 76 (19) ◽  
pp. 9910-9919 ◽  
Author(s):  
Thomas B. Macnaughton ◽  
Michael M. C. Lai
Keyword(s):  
Hepatitis Delta Virus ◽  
Rna Synthesis ◽  
State Level ◽  
Rna Replication ◽  
Replication Cycle ◽  
Steady State Level ◽  
Hepatitis Delta ◽  
Delta Antigen ◽  
Hepatitis Delta Antigen ◽  
Delta Virus

ABSTRACT Moderation of hepatitis delta virus (HDV) replication is a likely prerequisite in the establishment of chronic infections and is thought to be mediated by the intracellular accumulation of large hepatitis delta antigen (L-HDAg). The regulatory role of this protein was suggested from several studies showing that cotransfection of plasmid cDNAs expressing both L-HDAg and HDV RNA results in a potent inhibition of HDV RNA replication. However, since this approach differs significantly from natural HDV infections, where HDV RNA replication is initiated from an RNA template, and L-HDAg appears only late in the replication cycle, it remains unclear whether L-HDAg can modulate HDV RNA replication in the natural HDV replication cycle. In this study, we investigated the effect of L-HDAg, produced as a result of the natural HDV RNA editing event, on HDV RNA replication. The results showed that following cDNA-free HDV RNA transfection, a steady-state level of RNA was established at 3 to 4 days posttransfection. The same level of HDV RNA was reached when a mutant HDV genome unable to make L-HDAg was used, suggesting that L-HDAg did not play a role. The rates of HDV RNA synthesis, as measured by metabolic labeling experiments, were identical at 4 and 8 days posttransfection and in the wild type and the L-HDAg-deficient mutant. We further examined the effect of overexpression of L-HDAg at various stages of the HDV replication cycle, showing that HDV RNA synthesis was resistant to L-HDAg when it was overexpressed 3 days after HDV RNA replication had initiated. Finally, we showed that, contrary to conventional thinking, L-HDAg alone, at a certain molar ratio with HDV RNA, can initiate HDV RNA replication. Thus, L-HDAg does not inherently inhibit HDV RNA synthesis. Taken together, these results indicated that L-HDAg affects neither the rate of HDV RNA synthesis nor the final steady-state level of HDV RNA and that L-HDAg is unlikely to act as an inhibitor of HDV RNA replication in the natural HDV replication cycle.

scholarly journals Arginine-Rich Motifs Are Not Required for Hepatitis Delta Virus RNA Binding Activity of the Hepatitis Delta Antigen

2013 ◽  
Vol 87 (15) ◽  
pp. 8665-8674 ◽  
Author(s):  
L. H. Daigh ◽  
B. L. Griffin ◽  
A. Soroush ◽  
M. R. Mamedov ◽  
J. L. Casey
Keyword(s):  
Hepatitis Delta Virus ◽  
Rna Binding ◽  
Binding Activity ◽  
Hepatitis Delta ◽  
Delta Antigen ◽  
Virus Rna ◽  
Hepatitis Delta Antigen ◽  
Delta Virus

scholarly journals A divergent hepatitis D-like agent in birds

2018 ◽  
Author(s):  
Michelle Wille ◽  
Hans J. Netter ◽  
Margaret Littlejohn ◽  
Lilly Yuen ◽  
Mang Shi ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Amino Acid Similarity ◽  
Hepatitis Delta ◽  
Hepatitis D ◽  
Delta Antigen ◽  
B Virus ◽  
Severe Liver Disease ◽  
Delta Virus

AbstractHepatitis 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 subviral agents.ImportanceHepatitis delta virus (HDV) is currently only found in humans, and coinfections of HDV and Hepatitis B virus (HBV) in humans result in severe liver disease. There are a number of hypotheses for the origin of HDV, although a key component of all is that HDV only exists in humans. Here, we describe a novel deltavirus-like agent identified in wild birds. Although this agent is genetically divergent, it exhibits important similarities to HDV, such as the presence of ribosymes and self-complementarity. The discovery of an avian HDV-like agent challenges our understanding of both the origin and the co-evolutionary relationships of subviral agents with helper viruses.

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