scholarly journals Divergent Antiviral Mechanisms of Two Viperin Homeologs in a Recurrent Polyploid Fish

2021 ◽  
Vol 12 ◽  
Author(s):  
Cheng-Yan Mou ◽  
Shun Li ◽  
Long-Feng Lu ◽  
Yang Wang ◽  
Peng Yu ◽  
...  
Keyword(s):  
Crucian Carp ◽  
Expression Patterns ◽  
Protein A ◽  
Open Reading Frame ◽  
Gibel Carp ◽  
Duplicated Genes ◽  
Reading Frame ◽  
Screening Analysis ◽  
Α Helix ◽  
Shed Light

Polyploidy and subsequent diploidization provide genomic opportunities for evolutionary innovations and adaptation. The researches on duplicated gene evolutionary fates in recurrent polyploids have seriously lagged behind that in paleopolyploids with diploidized genomes. Moreover, the antiviral mechanisms of Viperin remain largely unclear in fish. Here, we elaborate the distinct antiviral mechanisms of two viperin homeologs (Cgviperin-A and Cgviperin-B) in auto-allo-hexaploid gibel carp (Carassius gibelio). First, Cgviperin-A and Cgviperin-B showed differential and biased expression patterns in gibel carp adult tissues. Subsequently, using co-immunoprecipitation (Co-IP) screening analysis, both CgViperin-A and CgViperin-B were found to interact with crucian carp (C. auratus) herpesvirus (CaHV) open reading frame 46 right (ORF46R) protein, a negative herpesvirus regulator of host interferon (IFN) production, and to promote the proteasomal degradation of ORF46R via decreasing K63-linked ubiquitination. Additionally, CgViperin-B also mediated ORF46R degradation through autophagosome pathway, which was absent in CgViperin-A. Moreover, we found that the N-terminal α-helix domain was necessary for the localization of CgViperin-A and CgViperin-B at the endoplasmic reticulum (ER), and the C-terminal domain of CgViperin-A and CgViperin-B was indispensable for the interaction with degradation of ORF46R. Therefore, the current findings clarify the divergent antiviral mechanisms of the duplicated viperin homeologs in a recurrent polyploid fish, which will shed light on the evolution of teleost duplicated genes.

Evolutionarily conserved regions in Caenorhabditis transposable elements deduced by sequence comparison

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Shiv S. Prasad ◽  
Linda J. Harris ◽  
David L. Baillie ◽  
Ann M. Rose
Keyword(s):  
Amino Acid ◽  
Transposable Element ◽  
Sequence Comparison ◽  
Horizontal Transmission ◽  
Protein A ◽  
Open Reading Frame ◽  
Single Open Reading Frame ◽  
Major Open Reading Frame ◽  
Reading Frame ◽  
Caenorhabditis Species

In this paper we present the sequence of an intact Caenorhabditis briggsae transposable element, Tcb2. Tcb2 is 1606 base pairs in length and contains 80 base pair imperfect terminal repeats and a single open reading frame. We have identified blocks of T-rich repeats in the regions 150–200 and 1421–1476 of this element which are conserved in the Caenorhabditis elegans element Tc1. The sequence conservation of these regions in elements from different Caenorhabditis species suggests that they are of functional importance. A single open reading frame corresponding to the major open reading frame of Tc1 is conserved among Tc1, Tcb1, and Tcb2. Comparison of the first 550 nucleotides of the sequence among the three elements has allowed the evaluation of a model proposing an extension of the major open reading frame. Our data support the suggestion that Tc1 is capable of producing a 335 amino acid protein. A comparison of the sequence coding for the amino and carboxy termini of the 273 amino acid transposase from Caenorhabditis Tc1-like elements and Drosophila HB1 showed different amounts of divergence for each of these regions, indicating that the two functional domains have undergone different amounts of selection. Our data are not compatible with the proposal that Tc1-related sequences have been acquired via horizontal transmission. The divergence of Tc1 from the two C. briggsae elements, Tcb1 and Tcb2, indicated that all three elements have been diverging from each other for approximately the same amount of time as the genomes of the two species.Key words: Caenorhabditis, transposable element, sequence comparison.

scholarly journals Identification and Characterization of alcR, a Gene Encoding an AraC-Like Regulator of Alcaligin Siderophore Biosynthesis and Transport in Bordetella pertussis andBordetella bronchiseptica

1998 ◽  
Vol 180 (4) ◽  
pp. 862-870 ◽  
Author(s):  
Fiona C. Beaumont ◽  
Ho Young Kang ◽  
Timothy J. Brickman ◽  
Sandra K. Armstrong
Keyword(s):  
Bordetella Pertussis ◽  
Transcription Initiation ◽  
Expression System ◽  
Protein A ◽  
Initiation Site ◽  
Open Reading Frame ◽  
Growth Defect ◽  
Nucleotide Sequencing ◽  
Reading Frame ◽  
Siderophore Biosynthesis

ABSTRACT A Bordetella bronchiseptica iron transport mutant was isolated following an enrichment procedure based on streptonigrin resistance. The mutant displayed a growth defect on iron-restricted medium containing ferric alcaligin as the sole iron source. In addition to the apparent inability to acquire iron from the siderophore, the mutant failed to produce alcaligin as well as two known iron-regulated proteins, one of which is the AlcC alcaligin biosynthesis protein. A 1.6-kb KpnI-PstI Bordetella pertussis DNA fragment mapping downstream of the alcaligin biosynthesis genes alcABC restored both siderophore biosynthesis and expression of the iron-regulated proteins to the mutant. Nucleotide sequencing of this complementing 1.6-kb region identified an open reading frame predicted to encode a protein with strong similarity to members of the AraC family of transcriptional regulators, for which we propose the gene designation alcR. Primer extension analysis localized an iron-regulated transcription initiation site upstream of the alcR open reading frame and adjacent to sequences homologous to the consensus Fur repressor binding site. The AlcR protein was produced by using an Escherichia coli expression system and visualized in electrophoretic gels. In-frame alcR deletion mutants of B. pertussisand B. bronchiseptica were constructed, and the defined mutants exhibited the alcR mutant phenotype, characterized by the inability to produce and transport alcaligin and express the two iron-repressed proteins. The cloned alcR gene provided intrans restored these siderophore system activities to the mutants. Together, these results indicate that AlcR is involved in the regulation of Bordetella alcaligin biosynthesis and transport genes and is required for their full expression.

Identification of envelope protein ORF10 of channel catfish herpesvirus

2012 ◽  
Vol 58 (3) ◽  
pp. 271-277
Author(s):  
Yulin Liu ◽  
Junfa Yuan ◽  
Weimin Wang ◽  
Xiaoxuan Chen ◽  
Rong Tang ◽  
...  
Keyword(s):  
Channel Catfish ◽  
Envelope Protein ◽  
Viral Protein ◽  
Protein A ◽  
Neutralization Assay ◽  
Open Reading Frame ◽  
Viral Pathogen ◽  
Ovary Cells ◽  
Viral Neutralization ◽  
Reading Frame

Channel catfish virus (CCV) is a viral pathogen of fry and fingerling channel catfish and can cause significant commercial loss. Previous studies have shown that the CCV virion contains at least 25 predicted structural proteins, including viral protein 10, which is encoded by the orf10 gene of the CCV. In this paper, the orf10 gene was expressed in Escherichia coli and used to produce a specific antibody. Western blot analysis confirmed that open reading frame 10 is an envelope protein. A viral neutralization assay demonstrated that open reading frame 10 antiserum was able to inhibit CCV infection of channel catfish ovary cells, suggesting that viral protein 10 is likely to play an important role in the CCV infection of channel catfish ovary cells.

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 An Ascovirus-Encoded RNase III Autoregulates Its Expression and Suppresses RNA Interference-Mediated Gene Silencing

2010 ◽  
Vol 84 (7) ◽  
pp. 3624-3630 ◽  
Author(s):  
Mazhar Hussain ◽  
Alexander M. Abraham ◽  
Sassan Asgari
Keyword(s):  
Rna Interference ◽  
Gene Silencing ◽  
Defense Mechanism ◽  
Expression System ◽  
Expression Patterns ◽  
Open Reading Frame ◽  
Green Fluorescent Protein Gene ◽  
Virus Species ◽  
Rnase Iii ◽  
Reading Frame

ABSTRACT RNase III proteins play vital roles in processing of several types of RNA molecules and gene silencing. Recently, it has been discovered that some plant and animal viruses encode RNase III-like proteins as well. Genome sequencing of four virus species belonging to the Ascoviridae family has revealed sequence conservation of an RNase III open reading frame among the viruses. These have not been explored in ascoviruses, and therefore their role in host-virus interaction is unknown. Here, we confirmed expression of Heliothis virescens ascovirus (HvAV-3e) open reading frame 27 (orf27) that encodes an RNase III-like protein after infection and demonstrated dsRNA specific endoribonuclease activity of the encoded protein. Analysis of the expression patterns of orf27 in virus-infected insect cells and a bacterial expression system revealed autoregulation of this protein over time. Moreover, HvAV-3e RNase III was found essential for virus DNA replication and infection using RNA interference (RNAi)-mediated gene silencing. In addition, using green fluorescent protein gene as a marker, we provide evidence that RNase III is involved in the suppression of gene silencing. To our knowledge, this is the first insect virus-encoded RNase III described and shown to suppress host cell RNAi defense mechanism.

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