scholarly journals The Hepatitis Delta Virus Large Antigen Is Farnesylated Both in Vitro and in Animal Cells

1996 ◽  
Vol 271 (9) ◽  
pp. 4569-4572 ◽  
Author(s):  
James C. Otto ◽  
Patrick J. Casey
Keyword(s):  
Hepatitis Delta Virus ◽  
Animal Cells ◽  
Hepatitis Delta ◽  
Delta Virus

scholarly journals Selection in vitro of Trans -Acting Genomic Human Hepatitis Delta Virus (HDV) Ribozymes

1996 ◽  
Vol 237 (3) ◽  
pp. 712-718 ◽  
Author(s):  
Fumiko Nishikawa ◽  
Junji Kawakami ◽  
Atsushi Chiba ◽  
Makoto Shirai ◽  
Penmetcha K. R. Kumar ◽  
...  
Keyword(s):  
Hepatitis Delta Virus ◽  
Hepatitis Delta ◽  
Human Hepatitis ◽  
Delta Virus

Farnesoid X receptor alpha ligands inhibit hepatitis delta virus replication in vitro independently of their effect on hepatitis B virus

2020 ◽  
Vol 73 ◽  
pp. S834-S835
Author(s):  
Benoît Lacombe ◽  
Julie Lucifora ◽  
Camille Ménard ◽  
Michelet Maud ◽  
Adrien Foca ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Virus Replication ◽  
Hepatitis Delta Virus ◽  
Farnesoid X Receptor ◽  
Hepatitis Delta ◽  
Receptor Alpha ◽  
B Virus ◽  
Delta Virus

scholarly journals Origin of Hepatitis Delta Virus mRNA

2000 ◽  
Vol 74 (16) ◽  
pp. 7204-7210 ◽  
Author(s):  
Severin Gudima ◽  
Shwu-Yuan Wu ◽  
Cheng-Ming Chiang ◽  
Gloria Moraleda ◽  
John Taylor
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Hepatitis Delta Virus ◽  
Rna Synthesis ◽  
Genome Replication ◽  
Rna Transcription ◽  
Hepatitis Delta ◽  
New Findings ◽  
Delta Virus

ABSTRACT Hepatitis delta virus (HDV) is unique relative to all known animal viruses, especially in terms of its ability to redirect host RNA polymerase(s) to transcribe its 1,679-nucleotide (nt) circular RNA genome. During replication there accumulates not only more molecules of the genome but also its exact complement, the antigenome. In addition, there are relatively smaller amounts of an 800-nt RNA of antigenomic polarity that is polyadenylated and considered to act as mRNA for translation of the single and essential HDV protein, the delta antigen. Characterization of this mRNA could provide insights into the in vivo mechanism of HDV RNA-directed RNA transcription and processing. Previously, we showed that the 5′ end of this RNA was located in the majority of species, at nt 1630. The present studies show that (i) at least some of this RNA, as extracted from the liver of an HDV-infected woodchuck, behaved as if it contained a 5′-cap structure; (ii) in the infected liver there were additional polyadenylated antigenomic HDV RNA species with 5′ ends located at least 202 nt and even 335 nt beyond the nt 1630 site, (iii) the 5′ end at nt 1630 was not detected in transfected cells, following DNA-directed HDV RNA transcription, in the absence of genome replication, and (iv) nevertheless, using in vitro transcription with purified human RNA polymerase II holoenzyme and genomic RNA template, we did not detect initiation of template-dependent RNA synthesis; we observed only low levels of 3′-end addition to the template. These new findings support the interpretation that the 5′ end detected at nt 1630 during HDV replication represents a specific site for the initiation of an RNA-directed RNA synthesis, which is then modified by capping.

scholarly journals Hepatitis Delta Virus Antigen Is Methylated at Arginine Residues, and Methylation Regulates Subcellular Localization and RNA Replication

2004 ◽  
Vol 78 (23) ◽  
pp. 13325-13334 ◽  
Author(s):  
Yi-Jia Li ◽  
Michael R. Stallcup ◽  
Michael M. C. Lai
Keyword(s):  
Subcellular Localization ◽  
Posttranslational Modification ◽  
Hepatitis Delta Virus ◽  
Rna Binding ◽  
Rna Replication ◽  
Genomic Rna ◽  
Hepatitis Delta ◽  
Arginine Residues ◽  
Delta Virus

ABSTRACT Hepatitis delta virus (HDV) contains a circular RNA which encodes a single protein, hepatitis delta antigen (HDAg). HDAg exists in two forms, a small form (S-HDAg) and a large form (L-HDAg). S-HDAg can transactivate HDV RNA replication. Recent studies have shown that posttranslational modifications, such as phosphorylation and acetylation, of S-HDAg can modulate HDV RNA replication. Here we show that S-HDAg can be methylated by protein arginine methyltransferase (PRMT1) in vitro and in vivo. The major methylation site is at arginine-13 (R13), which is in the RGGR motif of an RNA-binding domain. The methylation of S-HDAg is essential for HDV RNA replication, especially for replication of the antigenomic RNA strand to form the genomic RNA strand. An R13A mutation in S-HDAg inhibited HDV RNA replication. The presence of a methylation inhibitor, S-adenosyl-homocysteine, also inhibited HDV RNA replication. We further found that the methylation of S-HDAg affected its subcellular localization. Methylation-defective HDAg lost the ability to form a speckled structure in the nucleus and also permeated into the cytoplasm. These results thus revealed a novel posttranslational modification of HDAg and indicated its importance for HDV RNA replication. This and other results further showed that, unlike replication of the HDV genomic RNA strand, replication of the antigenomic RNA strand requires multiple types of posttranslational modification, including the phosphorylation and methylation of HDAg.

scholarly journals Role of N Glycosylation of Hepatitis B Virus Envelope Proteins in Morphogenesis and Infectivity of Hepatitis Delta Virus

2003 ◽  
Vol 77 (9) ◽  
pp. 5519-5523 ◽  
Author(s):  
Camille Sureau ◽  
Chantal Fournier-Wirth ◽  
Patrick Maurel
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Envelope Proteins ◽  
Virus Envelope ◽  
Hepatitis Delta ◽  
B Virus ◽  
L Proteins ◽  
Delta Virus

ABSTRACT Hepatitis delta virus (HDV) particles are coated with the large (L), middle (M), and small (S) hepatitis B virus envelope proteins. In the present study, we constructed glycosylation-defective envelope protein mutants and evaluated their capacity to assist in the maturation of infectious HDV in vitro. We observed that the removal of N-linked carbohydrates on the S, M, and L proteins was tolerated for the assembly of subviral hepatitis B virus (HBV) particles but was partially inhibitory for the formation of HDV virions. However, when assayed on primary cultures of human hepatocytes, virions coated with S, M, and L proteins lacking N-linked glycans were infectious. Furthermore, in the absence of M, HDV particles coated with nonglycosylated S and L proteins retained infectivity. These results indicate that carbohydrates on the HBV envelope proteins are not essential for the in vitro infectivity of HDV.

scholarly journals Characterization of the 5′ Ends for Polyadenylated RNAs Synthesized during the Replication of Hepatitis Delta Virus

1999 ◽  
Vol 73 (8) ◽  
pp. 6533-6539 ◽  
Author(s):  
Severin Gudima ◽  
Kate Dingle ◽  
Ting-Ting Wu ◽  
Gloria Moraleda ◽  
John Taylor
Keyword(s):  
Transcription Initiation ◽  
Hepatitis Delta Virus ◽  
Circular Rna ◽  
Genome Replication ◽  
Genomic Rna ◽  
Experimental Conditions ◽  
Hepatitis Delta ◽  
Polyadenylated Rnas ◽  
Delta Virus

ABSTRACT The genome of hepatitis delta virus (HDV) is a 1,679-nucleotide (nt) single-stranded circular RNA that is predicted to fold into an unbranched rodlike structure. During replication, two complementary RNAs are also detected: an exact complement, referred to as the antigenome, and an 800-nt polyadenylated RNA that could act as the mRNA for the delta antigen. We used a 5′ rapid amplification of cDNA ends procedure, followed by cloning and sequencing, to determine the 5′ ends of the polyadenylated RNAs produced during HDV genome replication following initiation under different experimental conditions. The analyzed RNAs were from the liver of an infected woodchuck and from a liver cell line at 6 days after transfection with either an HDV cDNA or ribonucleoprotein (RNP) complexes assembled in vitro with HDV genomic RNA and purified recombinant small delta protein. In all three situations the 5′ ends mapped specifically to nt 1630. In relationship to what is called the top end of the unbranched rodlike structure predicted for the genomic RNA template, this site is located 10 nt from the top, and in the middle of a 3-nt external bulge. Following transfection with RNP, such specific 5′ ends could be detected as early as 24 h. We next constructed a series of mutants of this predicted bulge region and of an adjacent 6-bp stem and the top 5-nt loop. Some of these mutations decreased the ability of the genome to undergo antigenomic RNA synthesis and accumulation and/or altered the location of the detected 5′ ends. The observed end located at nt 1630, and most of the novel 5′ ends, were consistent with transcription initiation events that preferentially used a purine. The present studies do not prove that the detected 5′ ends correspond to initiation sites and do not establish the hypothesis that there is a promoter element in the vicinity, but they do show that the location of the observed 5′ ends could be controlled by nucleotide sequences at and around nt 1630.

scholarly journals Hepatitis delta virus facilitates the selection of hepatitis B virus mutants in vivo and functionally impacts on their replicative capacity in vitro

2016 ◽  
Vol 22 (1) ◽  
pp. 98.e1-98.e6 ◽  
Author(s):  
E. Shirvani-Dastgerdi ◽  
M.R. Pourkarim ◽  
U. Herbers ◽  
S. Amini-Bavil-Olyaee ◽  
E. Yagmur ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis Delta Virus ◽  
Replicative Capacity ◽  
Hepatitis Delta ◽  
B Virus ◽  
Selection Of ◽  
Delta Virus

scholarly journals Susceptibility of Human Hepatitis Delta Virus RNAs to Small Interfering RNA Action

2003 ◽  
Vol 77 (17) ◽  
pp. 9728-9731 ◽  
Author(s):  
Jinhong Chang ◽  
John M. Taylor
Keyword(s):  
Hepatitis Delta Virus ◽  
Detectable Effect ◽  
Genome Replication ◽  
Small Interfering Rnas ◽  
Animal Cells ◽  
Rna Sequences ◽  
Hepatitis Delta ◽  
Ability To Act ◽  
Huh7 Cells ◽  
Delta Virus

ABSTRACT In animal cells, small interfering RNAs (siRNA), when exogenously provided, have been reported to be capable of inhibiting replication of several different viruses. In preliminary studies, siRNA species were designed and tested for their ability to act on the protein expressed in Huh7 cells transfected with DNA-directed mRNA constructs containing hepatitis delta virus (HDV) target sequences. The aim was to achieve siRNA specific for each of the three RNAs of HDV replication: (i) the 1,679-nucleotide circular RNA genome, (ii) its exact complement, the antigenome, and (iii) the less abundant polyadenylated mRNA for the small delta protein. Many of the 16 siRNA tested gave >80% inhibition in this assay. Next, these three classes of siRNA were tested for their ability to act during HDV genome replication. It was found that only siRNA targeted against HDV mRNA sequences could interfere with HDV genome replication. In contrast, siRNA targeted against genomic and antigenomic RNA sequences had no detectable effect on the accumulation of these RNAs. Reconstruction experiments with nonreplicating HDV RNA sequences support the interpretation that neither the potential for intramolecular rod-like RNA folding nor the presence of the delta protein conferred resistance to siRNA. In terms of replicating HDV RNAs, it is considered more likely that the genomic and antigenomic RNAs are resistant because their location within the nucleus makes them inaccessible to siRNA-mediated degradation.

scholarly journals Nucleic acid polymers are active against Hepatitis Delta Virus infection in vitro.

2017 ◽  
pp. JVI.01416-17 ◽  
Author(s):  
Frauke Beilstein ◽  
Matthieu Blanchet ◽  
Andrew Vaillant ◽  
Camille Sureau
Keyword(s):  
Nucleic Acid ◽  
Viral Entry ◽  
Hepatitis Delta Virus ◽  
Immune Escape ◽  
Envelope Proteins ◽  
Infection Model ◽  
Hepatitis Delta ◽  
Hdv Infection ◽  
Delta Virus

In this study, an in vitro infection model for the hepatitis delta virus (HDV) was used to evaluate the antiviral effects of phosphorothioate nucleic acid polymers (NAPs) and investigate their mechanism of action. The results show that NAPs inhibit HDV infection at less than 4 micromolar concentrations in cultures of differentiated human hepatoma cells. NAPs were shown to be active at viral entry, but inactive post entry on HDV RNA replication. Inhibition was independent of the NAPs nucleotide sequence, but dependent on both size and amphipathicity of the polymer. NAPs antiviral activity was effective against HDV virions bearing the main hepatitis B virus (HBV) immune escape substitutions (D144A and G145R) and was pangenomic with regard to HBV envelope proteins. Furthermore, similar to immobilized heparin, immobilized NAPs could bind HDV particles suggesting that entry inhibition was due, at least in part, to preventing attachment of the virus to cell surface glycosaminoglycans. The results document NAPs as a novel class of antiviral compounds that can prevent HDV propagation.IMPORTANCEHDV infection causes the most severe form of viral hepatitis in humans and one of the most difficult to cure. Currently, treatments are limited to long-term administration of interferon at high doses, which provide only partial efficacy. There is thus an urgent need for innovative approaches to identify new antiviral against HDV. The significance of our study is in demonstrating that nucleic acid polymers (NAPs) are active against HDV by targeting the envelope of HDV virions. In an in vitro infection assay, NAPs activity was recorded at less than 4 micromolar concentrations in the absence of cell toxicity. Furthermore, the fact that NAPs could block HDV at viral entry, suggest their potential to control the spread of HDV in a chronically HBV-infected liver. In addition, NAPs anti-HDV activity was pangenomic with regard to HBV envelope proteins and not circumvented by HBsAg substitutions associated with HBV immune escape.

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