scholarly journals The Open Reading Frame 3 Gene of Hepatitis E Virus Contains a cis-Reactive Element and Encodes a Protein Required for Infection of Macaques

2005 ◽  
Vol 79 (11) ◽  
pp. 6680-6689 ◽  
Author(s):  
Judith Graff ◽  
Hanh Nguyen ◽  
Claro Yu ◽  
William R. Elkins ◽  
Marisa St. Claire ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Phosphorylation Site ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reactive Element ◽  
Genome Replication ◽  
Null Mutant ◽  
Coding Region ◽  
Reading Frame ◽  
Orf3 Protein

ABSTRACT An infectious cDNA clone of hepatitis E virus was mutated in order to prevent synthesis of either open reading frame 2 (ORF2) protein or ORF3 protein. HuH-7 cells transfected with an ORF2-null mutant produced ORF3, and those transfected with an ORF3-null mutant produced ORF2. Silent mutations introduced into a highly conserved nucleotide sequence in the ORF3 coding region eliminated the synthesis of both ORF2 and ORF3 proteins, suggesting that it comprised a cis-reactive element. A mutant that was not able to produce ORF3 protein did not produce a detectable infection in rhesus macaques. However, a mutant that encoded an ORF3 protein lacking a phosphorylation site reported to be critical for function was able to replicate its genome in cell culture and to induce viremia and seroconversion in rhesus monkeys, suggesting that phosphorylation of ORF3 protein was not necessary for genome replication or for production of infectious virions.

scholarly journals Release of Genotype 1 Hepatitis E Virus from Cultured Hepatoma and Polarized Intestinal Cells Depends on Open Reading Frame 3 Protein and Requires an Intact PXXP Motif

2010 ◽  
Vol 84 (18) ◽  
pp. 9059-9069 ◽  
Author(s):  
Suzanne U. Emerson ◽  
Hanh T. Nguyen ◽  
Udana Torian ◽  
Danielle Burke ◽  
Ronald Engle ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Cultured Cells ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Intestinal Cells ◽  
Protein Accumulation ◽  
Genotype 1 ◽  
Virus Genotype ◽  
Reading Frame ◽  
Orf3 Protein

ABSTRACT Hepatitis E virus genotype 1 strain Sar55 replicated in subcloned Caco-2 intestinal cells and Huh7 hepatoma cells that had been transfected with in vitro transcribed viral genomes, and hepatitis E virions were released into the culture medium of both cell lines. Virus egress from cells depended on open reading frame 3 (ORF3) protein, and a proline-rich sequence in ORF3 was important for egress from cultured cells and for infection of macaques. Both intracellular ORF3 protein accumulation and virus release occurred at the apical membrane of polarized Caco-2 cells. ORF3 protein and lipids were intimately associated with virus particles produced in either cell line; ORF2 epitopes were masked in these particles and could not be immunoprecipitated with anti-ORF2.

scholarly journals Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1385
Author(s):  
Giulia Pezzoni ◽  
Lidia Stercoli ◽  
Eleonora Pegoiani ◽  
Emiliana Brocchi
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Recombinant Antigen ◽  
Open Reading Frame ◽  
Reading Frame ◽  
E Coli ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Open Reading Frame 2

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1–660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens’ immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394–608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394–608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461–544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

Hepatitis E virus open reading frame 3 protein interacts with porcine liver-specific plasminogen and α2-antiplasmin

2013 ◽  
Vol 86 (3) ◽  
pp. 487-495 ◽  
Author(s):  
Yan Zhou ◽  
Yansheng Geng ◽  
Jun Yang ◽  
Chenyan Zhao ◽  
Tim J. Harrison ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Porcine Liver ◽  
Reading Frame

scholarly journals Hepatitis E Virus (HEV) Open Reading Frame 2 Antigen Kinetics in Human-Liver Chimeric Mice and Its Impact on HEV Diagnosis

2019 ◽  
Vol 220 (5) ◽  
pp. 811-819 ◽  
Author(s):  
Ibrahim M Sayed ◽  
Lieven Verhoye ◽  
Claire Montpellier ◽  
Florence Abravanel ◽  
Jacques Izopet ◽  
...  
Keyword(s):  
Density Gradient ◽  
Hepatitis E Virus ◽  
Gradient Analysis ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Viral Rna ◽  
Humanized Mice ◽  
Molecular Diagnostic ◽  
Reading Frame ◽  
Open Reading Frame 2

Abstract Background Hepatitis E virus infection (HEV) is an emerging problem in developed countries. Diagnosis of HEV infection is based on the detection of HEV-specific antibodies, viral RNA, and/or antigen (Ag). Humanized mice were previously reported as a model for the study of HEV infection, but published data were focused on the quantification of viral RNA. However, the kinetics of HEV Ag expression during infection remains poorly understood. Methods Plasma specimens and suspensions of fecal specimens from HEV-infected and ribavirin-treated humanized mice were analyzed using HEV antigen–specific enzyme-linked immunosorbent assay, reverse transcription–quantitative polymerase chain reaction analysis, density gradient analysis, and Western blotting. Result Open reading frame 2 (ORF2) Ag was detected in both plasma and stool from HEV-infected mice, and levels increased over time. Contrary to HEV RNA, ORF2 Ag levels were higher in mouse plasma than in stool. Interestingly, ORF2 was detected in plasma from mice that tested negative for HEV RNA in plasma but positive for HEV RNA in stool and was detected after viral clearance in mice that were treated with ribavirin. Plasma density gradient analysis revealed the presence of the noninfectious glycosylated form of ORF2. Conclusion ORF2 Ag can be used as a marker of active HEV infection and for assessment of the effect of antiviral therapy, especially when fecal samples are not available or molecular diagnostic tests are not accessible.

Primary structure of open reading frame 2 and 3 of the hepatitis E virus isolated from Morocco

1999 ◽  
Vol 57 (2) ◽  
pp. 126-133 ◽  
Author(s):  
Jihong Meng ◽  
Mian-er Cong ◽  
Xing Dai ◽  
Jacques Pillot ◽  
Michael A. Purdy ◽  
...  
Keyword(s):  
Primary Structure ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Open Reading Frame 2

scholarly journals The Hepatitis E Virus Open Reading Frame 3 Protein Activates ERK through Binding and Inhibition of the MAPK Phosphatase

2004 ◽  
Vol 279 (27) ◽  
pp. 28345-28357 ◽  
Author(s):  
Anindita Kar-Roy ◽  
Hasan Korkaya ◽  
Ruchi Oberoi ◽  
Sunil Kumar Lal ◽  
Shahid Jameel
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Mapk Phosphatase

scholarly journals RNA 5′-Triphosphatase Activity of the Hepatitis E Virus Helicase Domain

2010 ◽  
Vol 84 (18) ◽  
pp. 9637-9641 ◽  
Author(s):  
Yogesh A. Karpe ◽  
Kavita S. Lole
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Helicase Domain ◽  
Reading Frame ◽  
Essential Step ◽  
Positive Sense ◽  
Rna Triphosphatase ◽  
Rna Duplexes ◽  
Open Reading Frame 1

ABSTRACT Hepatitis E virus (HEV) has a positive-sense RNA genome with a 5′-m7G cap. HEV open reading frame 1 (ORF1) encodes a polyprotein with multiple enzyme domains required for replication. HEV helicase is a nucleoside triphosphatase (NTPase) with the ability to unwind RNA duplexes in the 5′-to-3′ direction. When incubated with 5′-[γ-32P]RNA and 5′-[α-32P]RNA, HEV helicase released 32P only from 5′-[γ-32P]RNA, showing specificity for the γ-β-triphosphate bond. Removal of γ-phosphate from the 5′ end of the primary transcripts (pppRNA to ppRNA) by RNA triphosphatase is an essential step during cap formation. It is suggested that HEV employs the helicase to mediate the first step of 5′ cap synthesis.

Cloning, sequencing, and expression of the hepatitis E virus (HEV) nonstructural open reading frame 1 (ORF1)

2000 ◽  
Vol 60 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Israrul Haque Ansari ◽  
Santosh Kumar Nanda ◽  
Hemlata Durgapal ◽  
Shipra Agrawal ◽  
Sujit Kumar Mohanty ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Sequencing And Expression ◽  
Open Reading Frame 1
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