Correction: Feline Calicivirus Can Tolerate Gross Changes of Its Minor Capsid Protein Expression Levels Induced by Changing Translation Reinitiation Frequency or Use of a Separate VP2-Coding mRNA
Ontology highlight
ABSTRACT:
SUBMITTER:
PROVIDER: S-EPMC4143369 | biostudies-literature | 2014 Jan
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The third open reading frame (ORF3) located at the 3' end of the genomic RNA of feline calicivirus (FCV) encodes a small (12.2-kDa) minor structural protein of 106 amino acids designated VP2. Point mutations and deletions were introduced into an infectious FCV cDNA clone in order to evaluate the functional importance of ORF3 and its encoded protein, VP2. Deletion of the entire ORF3 sequence was lethal for the virus, and evidence was found for strong selective pressure to produce the VP2 protein. Extended deletions in the 5' end and small deletions in the 3' end of ORF3, as well as the introduction of stop codons into the ORF3 sequence, were tolerated by the viral replication machinery, but infectious virus could not be recovered. Infectious virus particles could be rescued from a full-length FCV cDNA clone encoding a nonfunctional VP2 when VP2 was provided in trans from a eukaryotic expression plasmid. Our data indicate that VP2, a protein apparently unique to the caliciviruses, is essential for productive replication that results in the synthesis and maturation of infectious virions and that the ORF3 nucleotide sequence itself overlaps a cis-acting RNA signal at the genomic 3' end.
| S-EPMC1061574 | biostudies-literature
Project description:Feline calicivirus Genome sequencing and assembly
| PRJNA902118 | ENA
Project description:Feline calicivirus Genome sequencing and assembly
| PRJNA728105 | ENA
Project description:The major capsid protein of norovirus VP1 assembles to form an icosahedral viral particle. Despite evidence that the Norwalk virus (NV) minor structural protein VP2 is present in infectious virions, the available crystallographic and electron cryomicroscopy structures of NV have not revealed the location of VP2. In this study, we determined that VP1 associates with VP2 at the interior surface of the capsid, specifically with the shell (S) domain of VP1. We mapped the interaction site to amino acid 52 of VP1, an isoleucine located within a sequence motif IDPWI in the S domain that is highly conserved across norovirus genogroups. Mutation of this isoleucine abrogated VP2 incorporation into virus-like particles without affecting the ability for VP1 to dimerize and form particles. The highly basic nature of VP2 and its location interior to the viral particle are consistent with its potential role in assisting capsid assembly and genome encapsidation.
| S-EPMC3624303 | biostudies-literature
Project description:Possible mechanisms that lead to inactivation of feline calicivirus (FCV) by cold atmospheric-pressure plasma (CAP) generated in 99% argon-1% O2 admixture were studied. We evaluated the impact of CAP exposure on the FCV viral capsid protein and RNA employing several cultural, molecular, proteomic and morphologic characteristics techniques. In the case of long exposure (2 min) to CAP, the reactive species of CAP strongly oxidized the major domains of the viral capsid protein (VP1) leading to disintegration of a majority of viral capsids. In the case of short exposure (15 s), some of the virus particles retained their capsid structure undamaged but failed to infect the host cells in vitro. In the latter virus particles, CAP exposure led to the oxidation of specific amino acids located in functional peptide residues in the P2 subdomain of the protrusion (P) domain, the dimeric interface region of VP1 dimers, and the movable hinge region linking the S and P domains. These regions of the capsid are known to play an essential role in the attachment and entry of the virus to the host cell. These observations suggest that the oxidative effect of CAP species inactivates the virus by hindering virus attachment and entry into the host cell. Furthermore, we found that the oxidative impact of plasma species led to oxidation and damage of viral RNA once it becomes unpacked due to capsid destruction. The latter effect most likely plays a secondary role in virus inactivation since the intact FCV genome is infectious even after damage to the capsid.
| S-EPMC5864060 | biostudies-literature
Project description:The sequence of the 3'-terminal 2,486 bases of the feline calicivirus (FCV) genome was determined. This region of the FCV genome, from which the 2.4-kb subgenomic RNA is derived, contained two open reading frames. The larger open reading frame, found in the 5' end of the subgenomic mRNA, contained 2,004 bases encoding a polypeptide of 73,467 Da. The smaller open reading frame, encoded in the 3' end of the mRNA, was composed of 318 bases, encoding a polypeptide of 12,185 Da. The AUG initiation codon of the second open reading frame overlapped the UGA termination codon of the first, with the sequence AUGA. The nucleotide sequence of the region containing this overlap resembles the -1 frameshift sequences of the retroviruses. The 5' end of the 2.4-kb subgenomic RNA was mapped by primer extension analysis. There were two apparent transcription initiation points, both of which were 5' to the AUG initiation codon of the large open reading frame. Transcription from these sites yielded RNA transcripts with 5' nontranslated leader regions of 17 and 18 bases. The total length of the 2.4-kb subgenomic RNA was 2,375 bases (from the 5'-most start site) excluding the poly(A) tail. Edman degradation of the purified capsid protein of FCV showed that the capsid protein was encoded by the large open reading frame. Western immunoblot analysis of FCV-infected cells using a feline anti-FCV antiserum demonstrated that translation of the capsid protein was detectable at 3 h postinfection and continued to accumulate until 8 h postinfection, the last time examined.
| S-EPMC249032 | biostudies-other
Project description:Feline calicivirus (FCV), a member of the Caliciviridae, produces its major structural protein as a precursor polyprotein from a subgenomic-sized mRNA. In this study, we show that the proteinase responsible for processing this precursor into the mature capsid protein is encoded by the viral genome at the 3'-terminal portion of open reading frame 1 (ORF1). Protein expression studies of either the entire or partial ORF1 indicate that the proteinase is active when expressed either in in vitro translation or in bacterial cells. Site-directed mutagenesis was used to characterize the proteinase Glu-Ala cleavage site in the capsid precursor, utilizing an in vitro cleavage assay in which mutant precursor proteins translated from cDNA clones were used as substrates for trans cleavage by the proteinase. In general, amino acid substitutions in the P1 position (Glu) of the cleavage site were less well tolerated by the proteinase than those in the P1' position (Ala). The precursor cleavage site mutations were introduced into an infectious cDNA clone of the FCV genome, and transfection of RNA derived from these clones into feline kidney cells showed that efficient cleavage of the capsid precursor by the virus-encoded proteinase is a critical determinant in the growth of the virus.
| S-EPMC109753 | biostudies-literature
Project description:The leader of the capsid (LC) protein is exclusive to the Vesivirus genus, and it is needed for successful feline calicivirus (FCV) replication, as well as an efficient apoptosis induction through the mitochondrial pathway. In this work, we aimed to determine if the LC protein from the FCV is a viroporin. Although lacking in a transmembrane domain or an amphipathic helix, the LC protein from the FCV is toxic when expressed in bacteria and it oligomerizes through disulfide bonds, which are both key characteristics of viroporins. An electron microscopy analysis of LC-expressing E. coli cells suggest that the protein induces osmotic stress. Moreover, we found that the previously studied C40A LC mutant, that fails to induce apoptosis and that hinders the replication cycle, also oligomerizes but it has a reduced toxicity and fails to induce osmotic stress in bacteria. We propose that the LC protein is a viroporin that acts as a disulfide bond-dependent antimicrobial peptide, similar to the Ebola virus delta peptide.
| S-EPMC8955107 | biostudies-literature
Project description:Reinitiation is a strategy used by viruses to express several cistrons from one mRNA. Although extremely weak after translation of long open reading frames (ORFs) on cellular mRNAs, reinitiation occurs efficiently on subgenomic bicistronic calicivirus mRNAs, enabling synthesis of minor capsid proteins. The process is governed by a short element upstream of the restart AUG, designated "termination upstream ribosomal binding site" (TURBS). It contains the conserved Motif 1 complementary to h26 of 18S rRNA, displayed in the loop of a hairpin formed by species-specific Motifs 2/2(∗). To determine the advantages conferred on reinitiation by TURBS, we reconstituted this process in vitro on two model bicistronic calicivirus mRNAs. We found that post-termination ribosomal tethering of mRNA by TURBS allows reinitiation by post-termination 80S ribosomes and diminishes dependence on eukaryotic initiation factor 3 (eIF3) of reinitiation by recycled 40S subunits, which can be mediated either by eIFs 2/1/1A or by Ligatin following ABCE1-dependent or -independent splitting of post-termination complexes.
| S-EPMC4521216 | biostudies-literature