Full virus map of Brome Mosaic Virus (picked particles)
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ABSTRACT:
SUBMITTER: Zhao Wang
PROVIDER: EMPIAR-10011 | biostudies-other |
REPOSITORIES: biostudies-other
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Project description: Not available
| EMPIAR-10010 | biostudies-other
Project description:Brome mosaic virus complete genome sequencing
| PRJNA718423 | ENA
Project description:There is an increasing interest in the use of plant viruses as vehicles for anti-cancer therapy. In particular, the plant virus brome mosaic virus (BMV) and cowpea chlorotic mottle virus (CCMV) are novel potential nanocarriers for different therapies in nanomedicine. In this work, BMV and CCMV were loaded with a fluorophore and assayed on breast tumor cells. The viruses BMV and CCMV were internalized into breast tumor cells. Both viruses, BMV and CCMV, did not show cytotoxic effects on tumor cells in vitro. However, only BMV did not activate macrophages in vitro. This suggests that BMV is less immunogenic and may be a potential carrier for therapy delivery in tumor cells. Furthermore, BMV virus-like particles (VLPs) were efficiently loaded with small interfering RNA (siRNA) without packaging signal. The gene silencing was demonstrated by VLPs loaded with siGFP and tested on breast tumor cells that constitutively express the green fluorescent protein (GPF). After VLP-siGFP treatment, GFP expression was efficiently inhibited corroborating the cargo release inside tumor cells and the gene silencing. In addition, BMV VLP carring siAkt1 inhibited the tumor growth in mice. These results show the attractive potential of plant virus VLPs to deliver molecular therapy to tumor cells with low immunogenic response.
| S-EPMC7059527 | biostudies-literature
Project description:Viral particles are biological machines that have evolved to package, protect, and deliver the viral genome into the host via regulated conformational changes of virions. We have developed a procedure to modify lysine residues with S-methylthioacetimidate across the pH range from 5.5 to 8.5. Lysine residues that are not completely modified are involved in tertiary or quaternary structural interactions, and their extent of modification can be quantified as a function of pH. This procedure was applied to the pH-dependent structural transitions of brome mosaic virus (BMV). As the reaction pH increases from 5.5 to 8.5, the average number of modified lysine residues in the BMV capsid protein increases from 6 to 12, correlating well with the known pH-dependent swelling behavior of BMV virions. The extent of reaction of each of the capsid protein's lysine residues has been quantified at eight pH values using coupled liquid chromatography-tandem mass spectrometry. Each lysine can be assigned to one of three structural classes identified by inspection of the BMV virion crystal structure. Several lysine residues display reactivity that indicates their involvement in dynamic interactions that are not obvious in the crystal structure. The influence of several capsid protein mutants on the pH-dependent structural transition of BMV has also been investigated. Mutant H75Q exhibits an altered swelling transition accompanying solution pH increases. The H75Q capsids show increased reactivity at lysine residues 64 and 130, residues distal from the dimer interface occupied by H75, across the entire pH range.
| S-EPMC3468295 | biostudies-literature
Project description:Brome mosaic virus (BMV) is a representative member of positive-strand RNA viruses. The 1a replicase from BMV is a membrane protein of unknown structure with a methyltransferase N-terminal domain and a putative helicase activity in the C-terminal domain. In order to make a functional prediction of the helicase activity of the BMV 1a C-terminal domain, we have built a model of its structure. The use of fold recognition servers hinted at two different superfamilies of helicases [superfamily 1 (SF1) and superfamily 2 (SF2)] as putative templates for the C-terminal fragment of BMV 1a. A structural model of BMV 1a in SF2 was obtained by means of a fold recognition server (3D-PSSM). On the other hand, we used the helicase motifs described in the literature to construct a model of the structure of the BMV 1a C-terminal domain as a member of the SF1. The biological functionality and statistic potentials were used to discriminate between the two models. The results illustrate that the use of sequence profiles and patterns helps modeling. Accordingly, the C-terminal domain of BMV 1a is a potential member of the SF1 of helicases, and it can be modeled with the structure of a member of the UvrD family of helicases. The helicase mechanism was corroborated by the model and this supports the hypothesis that BMV 1a should have helicase activity.
| S-EPMC7187956 | biostudies-literature
Project description:An amended kinetic model for the self-assembly of empty capsids of brome mosaic virus is proposed. The model has been modified to account for a new feature in the assembly kinetics revealed by time-course light scattering experiments at higher temporal resolution than previously attempted. To be able to simulate the sharp takeoff from the initial lag phase to the growth phase in the kinetic curves, a monomer activation step was proposed.
| S-EPMC2753409 | biostudies-literature
Project description:UnlabelledThe four brome mosaic virus (BMV) RNAs (RNA1 to RNA4) are encapsidated in three distinct virions that have different disassembly rates in infection. The mechanism for the differential release of BMV RNAs from virions is unknown, since 180 copies of the same coat protein (CP) encapsidate each of the BMV genomic RNAs. Using mass spectrometry, we found that the BMV CP contains a complex pattern of posttranslational modifications. Treatment with phosphatase was found to not significantly affect the stability of the virions containing RNA1 but significantly impacted the stability of the virions that encapsidated BMV RNA2 and RNA3/4. Cryo-electron microscopy reconstruction revealed dramatic structural changes in the capsid and the encapsidated RNA. A phosphomimetic mutation in the flexible N-terminal arm of the CP increased BMV RNA replication and virion production. The degree of phosphorylation modulated the interaction of CP with the encapsidated RNA and the release of three of the BMV RNAs. UV cross-linking and immunoprecipitation methods coupled to high-throughput sequencing experiments showed that phosphorylation of the BMV CP can impact binding to RNAs in the virions, including sequences that contain regulatory motifs for BMV RNA gene expression and replication. Phosphatase-treated virions affected the timing of CP expression and viral RNA replication in plants. The degree of phosphorylation decreased when the plant hosts were grown at an elevated temperature. These results show that phosphorylation of the capsid modulates BMV infection.ImportanceHow icosahedral viruses regulate the release of viral RNA into the host is not well understood. The selective release of viral RNA can regulate the timing of replication and gene expression. Brome mosaic virus (BMV) is an RNA virus, and its three genomic RNAs are encapsidated in separate virions. Through proteomic, structural, and biochemical analyses, this work shows that posttranslational modifications, specifically, phosphorylation, on the capsid protein regulate the capsid-RNA interaction and the stability of the virions and affect viral gene expression. Mutational analysis confirmed that changes in modification affected virion stability and the timing of viral infection. The mechanism for modification of the virion has striking parallels to the mechanism of regulation of chromatin packaging by nucleosomes.
| S-EPMC4988143 | biostudies-literature
Project description:Incubation of tyrosine with the RNA from brome-mosaic-virus under conditions favourable for aminoacylation of tRNA resulted in binding of tyrosine to the viral RNA. Sucrose-density-gradient centrifugation showed that tyrosine binds to three and probably to all four of the viral RNA components. The bound amino acid was readily released in mild alkaline solutions. Of 20 amino acids tested, only tyrosine was found to bind. The maximum extent of binding observed was 0.58mol of tyrosine/mol of brome-mosaic-virus RNA.
| S-EPMC1174243 | biostudies-other
Project description:Wheat breeders are developing new virus-resistant varieties; however, it is assumed that only a few viruses or well-known viruses are present in the field. New sequencing technology is allowing for better determination of natural field virus populations. For three years, 2019-2021, Kansas wheat field surveys were conducted to determine the constituents of natural field virus populations using nanopore sequencing. During analysis, brome mosaic virus (BMV) was identified for the first time in Kansas but was in association with other wheat viruses. Brome mosaic virus was identified from 29 out of 47 different Kansas counties sampled and 44% of the total samples. BMV was found co-infected with wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) in 27.8% of the samples, with WSMV only (13.9%) and co-infected with WSMV + TriMV + High Plains wheat mosaic emaravirus (HPWMoV) (13.9%). RNA genomes of Kansas BMV isolates had 99.4 to 100% nucleotide and amino acid sequence identity, respectively, to each other. RNA2a possessed relatively high divergence (π = 0.01) compared to RNA1a and RNA3a (π = 0.004). Coding regions of all BMV RNAs were considered negative for purifying selection pressure as nonsynonymous and synonymous nucleotide ratio was less than one (dNs/dS >1). The identification of BMV in Kansas virus populations adds another layer of complexity to plant breeding. This work provides information to improve tools to aid in monitoring, detecting, and determining the variation within BMV.
| S-EPMC10022736 | biostudies-literature
Project description:Replication of viral RNA genomes requires the specific interaction between the replicase and the RNA template. Members of the Bromovirus and Cucumovirus genera have a tRNA-like structure at the 3' end of their genomic RNAs that interacts with the replicase and is required for minus-strand synthesis. In Brome mosaic virus (BMV), a stem-loop structure named C (SLC) is present within the tRNA-like region and is required for replicase binding and initiation of RNA synthesis in vitro. We have prepared an enriched replicase fraction from tobacco plants infected with the Fny isolate of Cucumber mosaic virus (Fny-CMV) that will direct synthesis from exogenously added templates. Using this replicase, we demonstrate that the SLC-like structure in Fny-CMV plays a role similar to that of BMV SLC in interacting with the CMV replicase. While the majority of CMV isolates have SLC-like elements similar to that of Fny-CMV, a second group displays sequence or structural features that are distinct but nonetheless recognized by Fny-CMV replicase for RNA synthesis. Both motifs have a 5'CA3' dinucleotide that is invariant in the CMV isolates examined, and mutational analysis indicates that these are critical for interaction with the replicase. In the context of the entire tRNA-like element, both CMV SLC-like motifs are recognized by the BMV replicase. However, neither motif can direct synthesis by the BMV replicase in the absence of other tRNA-like elements, indicating that other features of the CMV tRNA can induce promoter recognition by a heterologous replicase.
| S-EPMC110906 | biostudies-literature