Sequence and structure of the catalytic RNA of hepatitis delta virus genomic RNA

1992 ◽  
Vol 223 (1) ◽  
pp. 233-245 ◽  
Author(s):  
Huey-Nan Wu ◽  
Yueh-Ju Wang ◽  
Chien-Fu Hung ◽  
Han-Jung Lee ◽  
Michael M.C. Lai
Keyword(s):  
Hepatitis Delta Virus ◽  
Catalytic Rna ◽  
Genomic Rna ◽  
Hepatitis Delta ◽  
Delta Virus

scholarly journals The Large Delta Antigen of Hepatitis Delta Virus Potently Inhibits Genomic but Not Antigenomic RNA Synthesis: a Mechanism Enabling Initiation of Viral Replication

2000 ◽  
Vol 74 (16) ◽  
pp. 7375-7380 ◽  
Author(s):  
Lucy E. Modahl ◽  
Michael M. C. Lai
Keyword(s):  
Life Cycle ◽  
Hepatitis Delta Virus ◽  
Rna Synthesis ◽  
Rna Replication ◽  
Dominant Negative ◽  
Genomic Rna ◽  
Inhibitory Effects ◽  
Hepatitis Delta ◽  
Artificial Dna ◽  
Delta Virus

ABSTRACT Hepatitis delta virus (HDV) contains two types of hepatitis delta antigens (HDAg) in the virion. The small form (S-HDAg) is required for HDV RNA replication, whereas the large form (L-HDAg) potently inhibits it by a dominant-negative inhibitory mechanism. The sequential appearance of these two forms in the infected cells regulates HDV RNA synthesis during the viral life cycle. However, the presence of almost equal amounts of S-HDAg and L-HDAg in the virion raised a puzzling question concerning how HDV can escape the inhibitory effects of L-HDAg and initiate RNA replication after infection. In this study, we examined the inhibitory effects of L-HDAg on the synthesis of various HDV RNA species. Using an HDV RNA-based transfection approach devoid of any artificial DNA intermediates, we showed that a small amount of L-HDAg is sufficient to inhibit HDV genomic RNA synthesis from the antigenomic RNA template. However, the synthesis of antigenomic RNA, including both the 1.7-kb HDV RNA and the 0.8-kb HDAg mRNA, from the genomic-sense RNA was surprisingly resistant to inhibition by L-HDAg. The synthesis of these RNAs was inhibited only when L-HDAg was in vast excess over S-HDAg. These results explain why HDV genomic RNA can initiate replication after infection even though the incoming viral genome is complexed with equal amounts of L-HDAg and S-HDAg. These results also suggest that the mechanisms of synthesis of genomic versus antigenomic RNA are different. This study thus resolves a puzzling question about the early events of the HDV life cycle.

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 Self-cleavage of a 71 nucleotide-long ribozyme derived from hepatitis delta virus genomic RNA

1991 ◽  
Vol 19 (23) ◽  
pp. 6519-6525 ◽  
Author(s):  
Gilbert Thill ◽  
Marta Blumenfeld ◽  
Franck Lescure ◽  
Marc Vasseur
Keyword(s):  
Hepatitis Delta Virus ◽  
Genomic Rna ◽  
Hepatitis Delta ◽  
Delta Virus

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.

RNA conformational requirements of self-cleavage of hepatitis delta virus RNA

1990 ◽  
Vol 10 (10) ◽  
pp. 5575-5579
Author(s):  
H N Wu ◽  
M M Lai
Keyword(s):  
Hepatitis Delta Virus ◽  
High Efficiency ◽  
Catalytic Rna ◽  
Heat Denaturation ◽  
Active Conformation ◽  
Hepatitis Delta ◽  
Rna Molecules ◽  
Virus Rna ◽  
Delta Virus

Hepatitis delta virus (HDV) RNA subfragments undergo self-cleavage at varying efficiencies. We have developed a procedure of using repeated cycles of heat denaturation and renaturation of RNA to achieve a high efficiency of cleavage. This effect can also be achieved by gradual denaturation of RNA with heat or formamide. These results suggest that only a subpopulation of the catalytic RNA molecules assumes the active conformation required for self-cleavage. This procedure could be of general use for detecting catalytic RNA activities.

scholarly journals Efficient Site-Specific Nonribozyme Opening of Hepatitis Delta Virus Genomic RNA in Infected Livers

2000 ◽  
Vol 74 (21) ◽  
pp. 9889-9894 ◽  
Author(s):  
Jinhong Chang ◽  
Gloria Moraleda ◽  
Severin Gudima ◽  
John Taylor
Keyword(s):  
Cleavage Site ◽  
Hepatitis Delta Virus ◽  
Unit Length ◽  
Genomic Rna ◽  
Hepatitis Delta ◽  
Site Specific ◽  
Endonucleolytic Cleavage ◽  
Rna Ligation ◽  
Delta Virus

ABSTRACT Examination of the 1,679-nucleotide (nt) unit-length hepatitis delta virus (HDV) RNAs in the livers of two HDV-infected woodchucks showed that 96% of the antigenomic RNA but only 50% of the genomic RNA was circular. We subsequently found that at least half of the linear unit-length genomic RNA was open at a unique location. Using a modified form of RNA ligation-mediated amplification of cDNA ends, we showed that the 5′ end was located at nt 1212. Like the previously described ribozyme cleavage site at nt 686, the new site produced a 5′-OH. Nevertheless, we showed that this novel site was not produced by activity of the HDV genomic ribozyme. We speculate that the 5′ end at nt 1212 reflects a preferred site of posttranscriptional endonucleolytic cleavage of genomic RNA.

scholarly journals Transcription of Subgenomic mRNA of Hepatitis Delta Virus Requires a Modified Hepatitis Delta Antigen That Is Distinct from Antigenomic RNA Synthesis

2008 ◽  
Vol 82 (19) ◽  
pp. 9409-9416 ◽  
Author(s):  
Chung-Hsin Tseng ◽  
King-Song Jeng ◽  
Michael M. C. Lai
Keyword(s):  
Hepatitis Delta Virus ◽  
Rna Synthesis ◽  
Nuclear Bodies ◽  
Genomic Rna ◽  
Mrna Transcription ◽  
Hepatitis Delta ◽  
Qrt Pcr ◽  
Delta Antigen ◽  
Hepatitis Delta Antigen ◽  
Delta Virus

ABSTRACT Hepatitis delta virus (HDV) contains a viroid-like, 1.7-kb circular RNA genome, which replicates via a double-rolling-circle model. However, the exact mechanism involved in HDV genome RNA replication and subgenomic mRNA transcription is still unclear. Our previous studies have shown that the replications of genomic and antigenomic HDV RNA strands have different sensitivities to α-amanitin and are associated with different nuclear bodies, suggesting that these two strands are synthesized in different transcription machineries in the cells. In this study, we developed a unique quantitative reverse transcription-PCR (qRT-PCR) procedure for detection of various HDV RNA species from an RNA transfection system. Using this qRT-PCR procedure and a series of HDV mutants, we demonstrated that Arg-13 methylation, Lys-72 acetylation, and Ser-177 phosphorylation of small hepatitis delta antigen (S-HDAg) are important for HDV mRNA transcription. In addition, these three S-HDAg modifications are dispensable for antigenomic RNA synthesis but are required for genomic RNA synthesis. Furthermore, the three RNA species had different sensitivities to acetylation and deacetylation inhibitors, showing that the metabolic requirements for the synthesis of HDV antigenomic RNA are different from those for the synthesis of genomic RNA and mRNA. In sum, our data support the hypothesis that the cellular machinery involved in the synthesis of HDV antigenomic RNA is different from that of genomic RNA synthesis and mRNA transcription, even though the antigenomic RNA and the mRNA are made from the same RNA template. We propose that acetylation and deacetylation of HDAg may provide a molecular switch for the synthesis of the different HDV RNA species.

scholarly journals Relevance of a Full-Length Genomic RNA Standard and a Thermal-Shock Step for Optimal Hepatitis Delta Virus Quantification

2014 ◽  
Vol 52 (9) ◽  
pp. 3334-3338 ◽  
Author(s):  
Maria Homs ◽  
Katja Giersch ◽  
Maria Blasi ◽  
Marc Lütgehetmann ◽  
Maria Buti ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Hepatitis Delta Virus ◽  
Full Length ◽  
Genomic Rna ◽  
Hepatitis Delta ◽  
Virus Quantification ◽  
Delta Virus
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