scholarly journals Molecular Determinants for Subcellular Localization of the Severe Acute Respiratory Syndrome Coronavirus Open Reading Frame 3b Protein

2009 ◽  
Vol 83 (13) ◽  
pp. 6631-6640 ◽  
Author(s):  
Eric C. Freundt ◽  
Li Yu ◽  
Elizabeth Park ◽  
Michael J. Lenardo ◽  
Xiao-Ning Xu
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Nuclear Export ◽  
Cellular Localization ◽  
Intracellular Localization ◽  
Open Reading Frame ◽  
Type I ◽  
Accessory Gene ◽  
Reading Frame ◽  
Mitochondrial Antiviral Signaling ◽  
Α Helix

ABSTRACT Viruses such as hepatitis C and the severe acute respiratory syndrome coronavirus (SARS-CoV) encode proteins that are distributed between mitochondria and the nucleus, but little is known about the factors that control partitioning between these sites. SARS-CoV encodes a unique accessory gene called open reading frame (ORF) 3b that, like other unique accessory genes in SARS-CoV, likely contributes to viral pathogenicity. The ORF 3b protein is 154 amino acids and is predicted to express from the second ORF in subgenomic RNA3. In this report, we have characterized the molecular components that regulate intracellular localization of the ORF 3b protein. We demonstrate unique shuttling behavior of ORF 3b, whereby the protein initially accumulates in the nucleus and subsequently translocates to mitochondria. Following nuclear localization, ORF 3b traffics to the outer membrane of mitochondria via a predicted amphipathic α-helix. Additionally, ORF 3b contains a consensus nuclear export sequence, and we demonstrate that nuclear export and thus mitochondrial translocation are dependent on a leptomycin B-sensitive nuclear export mechanism. We further show that ORF 3b inhibits induction of type I interferon induced by retinoic acid-induced gene 1 and the mitochondrial antiviral signaling protein. Our observations provide insights into the cellular localization of ORF 3b that may enhance our understanding of the mechanisms by which ORF 3b contributes to SARS-CoV pathogenesis. The findings reported here reveal that for multilocalized proteins, consideration of the spatiotemporal distribution may be crucial for understanding viral protein behavior and function.

scholarly journals Human Cytomegalovirus Open Reading Frame TRL11/IRL11 Encodes an Immunoglobulin G Fc-Binding Protein

2001 ◽  
Vol 75 (22) ◽  
pp. 11218-11221 ◽  
Author(s):  
Brendan N. Lilley ◽  
Hidde L. Ploegh ◽  
Rebecca S. Tirabassi
Keyword(s):  
Human Cytomegalovirus ◽  
Immunoglobulin G ◽  
Binding Protein ◽  
Fc Receptors ◽  
Binding Activity ◽  
Open Reading Frame ◽  
Membrane Glycoprotein ◽  
Type I ◽  
Reading Frame

ABSTRACT Several herpesviruses encode Fc receptors that may play a role in preventing antibody-mediated clearance of the virus in vivo. Human cytomegalovirus (HCMV) induces an Fc-binding activity in cells upon infection, but the gene that encodes this Fc-binding protein has not been identified. Here, we demonstrate that the HCMV AD169 open reading frame TRL11 and its identical copy, IRL11, encode a type I membrane glycoprotein that possesses IgG Fc-binding capabilities.

scholarly journals Divergent degeneration of creA antitoxin genes from minimal CRISPRs and the convergent strategy of tRNA-sequestering CreT toxins

2021 ◽  
Vol 49 (18) ◽  
pp. 10677-10688
Author(s):  
Feiyue Cheng ◽  
Rui Wang ◽  
Haiying Yu ◽  
Chao Liu ◽  
Jun Yang ◽  
...  
Keyword(s):  
Adaptive Immunity ◽  
Deep Sequencing ◽  
Small Rnas ◽  
Transfer Rna ◽  
Open Reading Frame ◽  
Type I ◽  
Essential Information ◽  
Reading Frame ◽  
Crea Gene

Abstract Aside from providing adaptive immunity, type I CRISPR-Cas was recently unearthed to employ a noncanonical RNA guide (CreA) to transcriptionally repress an RNA toxin (CreT). Here, we report that, for most archaeal and bacterial CreTA modules, the creA gene actually carries two flanking ‘CRISPR repeats’, which are, however, highly divergent and degenerated. By deep sequencing, we show that the two repeats give rise to an 8-nt 5′ handle and a 22-nt 3′ handle, respectively, i.e., the conserved elements of a canonical CRISPR RNA, indicating they both retained critical nucleotides for Cas6 processing during divergent degeneration. We also uncovered a minimal CreT toxin that sequesters the rare transfer RNA for isoleucine, tRNAIleCAU, with a six-codon open reading frame containing two consecutive AUA codons. To fully relieve its toxicity, both tRNAIleCAU overexpression and supply of extra agmatine (modifies the wobble base of tRNAIleCAU to decipher AUA codons) are required. By replacing AUA to AGA/AGG codons, we reprogrammed this toxin to sequester rare arginine tRNAs. These data provide essential information on CreTA origin and for future CreTA prediction, and enrich the knowledge of tRNA-sequestering small RNAs that are employed by CRISPR-Cas to get addictive to the host.

scholarly journals The Major Open Reading Frame of the β2.7 Transcript of Human Cytomegalovirus: In Vitro Expression of a Protein Posttranscriptionally Regulated by the 5′ Region

1998 ◽  
Vol 72 (10) ◽  
pp. 8425-8429 ◽  
Author(s):  
Giovanna Bergamini ◽  
Marko Reschke ◽  
Maria Concetta Battista ◽  
Maria Cristina Boccuni ◽  
Fabio Campanini ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Cytomegalovirus Infection ◽  
Intracellular Localization ◽  
Protein Product ◽  
Transient Transfection ◽  
Open Reading Frame ◽  
Major Open Reading Frame ◽  
Reading Frame ◽  
Human Cytomegalovirus Infection

ABSTRACT β2.7 is the major early transcript produced during human cytomegalovirus infection. This abundantly expressed RNA is polysome associated, but no protein product has ever been detected. In this study, a stable peptide of 24 kDa was produced in vitro from the major open reading frame (ORF), TRL4. Following transient transfection, the intracellular localization was nucleolar and the expression was posttranscriptionally inhibited by the 5′ sequence of the transcript, which harbors two short upstream ORFs.

scholarly journals Bioinformatics Analysis Identifies a Small ORF in the Genome of Fish Nidoviruses of Genus Oncotshavirus Predicted to Encode a Novel Integral Protein

2021 ◽  
Vol 12 (4) ◽  
pp. 753-764
Author(s):  
Frederick Kibenge ◽  
Ashley McKibbon ◽  
Molly Kibenge ◽  
Yingwei Wang
Keyword(s):  
Bioinformatics Analysis ◽  
Signal Sequence ◽  
Open Reading Frame ◽  
Type I ◽  
Structural Protein ◽  
Genome Sequence Analysis ◽  
Reading Frame ◽  
The Third ◽  
E Protein ◽  
Small Open Reading Frame

Genome sequence analysis of Atlantic salmon bafinivirus (ASBV) revealed a small open reading frame (ORF) predicted to encode a Type I membrane protein with an N-terminal cleaved signal sequence (110 aa), likely an envelope (E) protein. Bioinformatic analyses showed that the predicted protein is strikingly similar to the coronavirus E protein in structure. This is the first report to identify a putative E protein ORF in the genome of members of the Oncotshavirus genus (subfamily Piscavirinae, family Tobaniviridae, order Nidovirales) and, if expressed would be the third family (after Coronaviridae and Arteriviridae) within the order to have the E protein as a major structural protein.

scholarly journals Epstein-Barr Virus BamHI-A Rightward Transcript-Encoded RPMS Protein Interacts with the CBF1-Associated Corepressor CIR To Negatively Regulate the Activity of EBNA2 and NotchIC

2001 ◽  
Vol 75 (6) ◽  
pp. 2946-2956 ◽  
Author(s):  
Jinxia Zhang ◽  
Honglin Chen ◽  
Gerry Weinmaster ◽  
S. Diane Hayward
Keyword(s):  
Cell Lines ◽  
Epstein Barr Virus ◽  
Intracellular Localization ◽  
Open Reading Frame ◽  
Negative Regulator ◽  
Reading Frame ◽  
Barr Virus ◽  
Corepressor Complex ◽  
Epstein Barr ◽  
Two Hybrid

ABSTRACT The Epstein-Barr virus (EBV) BamHI-A rightward transcripts (BARTs) are expressed in all EBV-associated tumors as well as in latently infected B cells in vivo and cultured B-cell lines. One of the BART family transcripts contains an open reading frame, RPMS1, that encodes a nuclear protein termed RPMS. Reverse transcription-PCR analysis revealed that BART transcripts with the splicing pattern that generates the RPMS1 open reading frame are commonly expressed in EBV-positive lymphoblastoid cell lines and are also detected in Hodgkin's disease tissues. Experiments undertaken to determine the function of RPMS revealed that RPMS interacts with both CBF1 and components of the CBF1-associated corepressor complex. RPMS interaction with CBF1 was demonstrated in a glutathione S-transferase (GST) affinity assay and by the ability of RPMS to alter the intracellular localization of a mutant CBF1. A Gal4-RPMS fusion protein mediated transcriptional repression, suggesting an additional interaction between RPMS and corepressor proteins. GST affinity assays revealed interaction between RPMS and the corepressor Sin3A and CIR. The RPMS-CIR interaction was further substantiated in mammalian two-hybrid, coimmunoprecipitation, and colocalization experiments. RPMS has been shown to interfere with NotchIC and EBNA2 activation of CBF1-containing promoters in reporter assays. Consistent with this function, immunofluorescence assays performed on cotransfected cells showed that there was colocalization of RPMS with NotchIC and with EBNA2 in intranuclear punctate speckles. The effect of RPMS on NotchIC function was further examined in a muscle cell differentiation assay where RPMS was found to partially reverse NotchIC-mediated inhibition of differentiation. The mechanism of RPMS action was examined in cotransfection and mammalian two-hybrid assays. The results revealed that RPMS blocked relief of CBF1-mediated repression and interfered with SKIP-CIR interactions. We conclude that RPMS acts as a negative regulator of EBNA2 and Notch activity through its interactions with the CBF1-associated corepressor complex.

scholarly journals Caprine MAVS Is a RIG-I Interacting Type I Interferon Inducer Downregulated by Peste des Petits Ruminants Virus Infection

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 409
Author(s):  
Qiuhong Miao ◽  
Ruibing Qi ◽  
Chunchun Meng ◽  
Jie Zhu ◽  
Aoxing Tang ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
Type I Interferon ◽  
Intracellular Localization ◽  
Vital Role ◽  
Type I ◽  
Mrna Levels ◽  
Peste Des Petits Ruminants ◽  
Type I Ifn ◽  
Interferon Inducer ◽  
Mitochondrial Antiviral Signaling

The mitochondrial antiviral-signaling protein (MAVS, also known as VISA, IPS-1, or CARDIF) plays an essential role in the type I interferon (IFN) response and in retinoic acid-inducible gene I (RIG-I) mediated antiviral innate immunity in mammals. In this study, the caprine MAVS gene (caMAVS, 1566 bp) was identified and cloned. The caMAVS shares the highest amino acid similarity (98.1%) with the predicted sheep MAVS. Confocal microscopy analysis of partial deletion mutants of caMAVS revealed that the transmembrane and the so-called Non-Characterized domains are indispensable for intracellular localization to mitochondria. Overexpression of caMAVS in caprine endometrial epithelial cells up-regulated the mRNA levels of caprine interferon-stimulated genes. We concluded that caprine MAVS mediates the activation of the type I IFN pathway. We further demonstrated that both the CARD-like domain and the transmembrane domain of caMAVS were essential for the activation of the IFN-β promotor. The interaction between caMAVS and caprine RIG-I and the vital role of the CARD and NC domain in this interaction was demonstrated by co-immunoprecipitation. Upon infection with the Peste des Petits Ruminants Virus (PPRV, genus Morbillivirus), the level of MAVS was greatly reduced. This reduction was prevented by the addition of the proteasome inhibitor MG132. Moreover, we found that viral protein V could interact and colocalize with MAVS. Together, we identified caMAVS as a RIG-I interactive protein involved in the activation of type I IFN pathways in caprine cells and as a target for PPRV immune evasion.

Sign in / Sign up

Export Citation Format

Share Document