The Experts below are selected from a list of 3870 Experts worldwide ranked by ideXlab platform
Nicole F Steinmetz - One of the best experts on this subject based on the ideXlab platform.
-
biodistribution of filamentous plant Virus nanoparticles pepino mosaic Virus versus Potato Virus X
Biomacromolecules, 2019Co-Authors: Duc H T Le, Eduardo Mendezlopez, Miguel A. Aranda, Ulrich Commandeur, Chao Wang, Nicole F SteinmetzAbstract:Nanoparticles with high aspect ratios have favorable attributes for drug delivery and bioimaging applications based on their enhanced tissue penetration and tumor homing properties. Here, we investigated a novel filamentous viral nanoparticle (VNP) based on the Pepino mosaic Virus (PepMV), a relative of the established platform Potato Virus X (PVX). We studied the chemical reactivity of PepMV, produced fluorescent versions of PepMV and PVX, and then evaluated their biodistribution in mouse tumor models. We found that PepMV can be conjugated to various small chemical modifiers including fluorescent probes via the amine groups of surface-eXposed lysine residues, yielding VNPs carrying payloads of up to 1600 modifiers per particle. Although PepMV and PVX share similarities in particle size and shape, PepMV achieved enhanced tumor homing and less nonspecific tissue distribution compared to PVX in mouse models of triple negative breast cancer and ovarian cancer. In conclusion, PepMV provides a novel tool for n...
-
Biodistribution of Filamentous Plant Virus Nanoparticles: Pepino Mosaic Virus versus Potato Virus X
2018Co-Authors: Eduardo Méndez-lópez, Miguel A. Aranda, Ulrich Commandeur, Chao Wang, Nicole F SteinmetzAbstract:Nanoparticles with high aspect ratios have favorable attributes for drug delivery and bioimaging applications based on their enhanced tissue penetration and tumor homing properties. Here, we investigated a novel filamentous viral nanoparticle (VNP) based on the Pepino mosaic Virus (PepMV), a relative of the established platform Potato Virus X (PVX). We studied the chemical reactivity of PepMV, produced fluorescent versions of PepMV and PVX, and then evaluated their biodistribution in mouse tumor models. We found that PepMV can be conjugated to various small chemical modifiers including fluorescent probes via the amine groups of surface-eXposed lysine residues, yielding VNPs carrying payloads of up to 1600 modifiers per particle. Although PepMV and PVX share similarities in particle size and shape, PepMV achieved enhanced tumor homing and less nonspecific tissue distribution compared to PVX in mouse models of triple negative breast cancer and ovarian cancer. In conclusion, PepMV provides a novel tool for nanomedical research but more research is needed to fully eXploit the potential of plant VNPs for health applications
-
Potato Virus X a filamentous plant viral nanoparticle for doXorubicin delivery in cancer therapy
Nanoscale, 2017Co-Authors: Duc H T Le, Karin L Lee, Ulrich Commandeur, Sourabh Shukla, Nicole F SteinmetzAbstract:Plant viral nanoparticles (VNPs) are a novel class of nanocarriers with implications for drug delivery in cancer therapy. VNPs are characterized by their highly symmetrical nanoscale structures. Furthermore, plant VNPs are biocompatible, biodegradable, and non-infectious in mammals. VNPs provide a proteinaceous platform technology that can be readily engineered to carry contrast agents and therapies using chemical and genetic modifications. Of particular interest are high aspect ratio, elongated filaments such as the ones formed by Potato Virus X (PVX, measuring 515 × 13 nm). PVX has demonstrated enhanced tumor homing and penetration properties compared to spherical counterparts. Here, we sought to investigate the potential of PVX as a drug carrier delivering doXorubicin (DOX), a commonly used cancer chemotherapy. We synthesized therapeutic PVX nanoparticles using a simple in-solution miXing protocol; after 5 days of miXing of DOX and PVX and ultra-centrifugal purification, ∼1000 DOX per PVX were stably associated with the carrier, most likely based on hydrophobic interaction. Efficacy and drug activity of PVX–DOX were confirmed using a panel of cancer cell lines including ovarian cancer, breast cancer, and cervical cancer. Lastly, we demonstrated treatment of athymic mice bearing human MDA-MB-231 breast cancer Xenografts: PVX–DOX treatment resulted in reduced tumor growth in this model. Our results open the door for further development of PVX and other high aspect ratio plant VNPs for applications in cancer therapy.
-
production of immunoabsorbent nanoparticles by displaying single domain protein a on Potato Virus X
Macromolecular Bioscience, 2016Co-Authors: Kerstin Uhdeholzem, Ulrich Commandeur, Rainer Fischer, Michael Mcburney, Brylee David B Tiu, Rigoberto C Advincula, Nicole F SteinmetzAbstract:The combination of antibodies with nanoparticles provides wide-ranging applications in biosensing. While several covalent presentation strategies have been established, there is need for alternative, non-covalent methods to provide a routine for scalable nanomanufacturing. We report the multivalent presentation of the B domain of Staphylococcus aureus protein A (SpAB) on Potato Virus X (PVX) nanoparticles. Three different synthetic strategies were used to obtain chimeric PVX(SpAB) filaments. The protein A fragments displayed on the surface of all three PVX chimeras remained fully functional as an immunoabsorbent for antibody capture enabling biosensing. The new biomaterials presented could find applications as diagnostic tools for biomedical or environmental monitoring.
-
stealth filaments polymer chain length and conformation affect the in vivo fate of pegylated Potato Virus X
Acta Biomaterialia, 2015Co-Authors: Sourabh Shukla, Ulrich Commandeur, Mengzhi Wu, Nadia R Ayat, Caroline El Sanadi, John F Edelbrock, Jonathan K Pokorski, George R Dubyak, Nicole F SteinmetzAbstract:Abstract Nanoparticles hold great promise for delivering medical cargos to cancerous tissues to enhance contrast and sensitivity of imaging agents or to increase specificity and efficacy of therapeutics. A growing body of data suggests that nanoparticle shape, in combination with surface chemistry, affects their in vivo fates, with elongated filaments showing enhanced tumor targeting and tissue penetration, while promoting immune evasion. The synthesis of high aspect ratio filamentous materials at the nanoscale remains challenging using synthetic routes; therefore we turned toward nature’s materials, developing and studying the filamentous structures formed by the plant Virus Potato Virus X (PVX). We recently demonstrated that PVX shows enhanced tumor homing in various preclinical models. Like other nanoparticle systems, the proteinaceous platform is cleared from circulation and tissues by the mononuclear phagocyte system (MPS). To increase bioavailability we set out to develop PEGylated stealth filaments and evaluate the effects of PEG chain length and conformation on pharmacokinetics, biodistribution, as well as potential immune and inflammatory responses. We demonstrate that PEGylation effectively reduces immune recognition while increasing pharmacokinetic profiles. Stealth filaments show reduced interaction with cells of the MPS; the protein:polymer hybrids are cleared from the body tissues within hours to days indicating biodegradability and biocompatibility. Tissue compatibility is indicated with no apparent inflammatory signaling in vivo. Tailoring PEG chain length and conformation (brush vs. mushroom) allows tuning of the pharmacokinetics, yielding long-circulating stealth filaments for applications in nanomedicine.
David C. Baulcombe - One of the best experts on this subject based on the ideXlab platform.
-
physical association of the nb lrr resistance protein rX with a ran gtpase activating protein is required for eXtreme resistance to Potato Virus X
The Plant Cell, 2007Co-Authors: Wladimir I L Tameling, David C. BaulcombeAbstract:Nucleotide binding leucine-rich repeat (NB-LRR) proteins play an important role in plant and mammalian innate immunity. In plants, these resistance proteins recognize specific pathogen-derived effector proteins. Recognition subsequently triggers a rapid and efficient defense response often associated with the hypersensitive response and other poorly understood processes that suppress the pathogen. To investigate mechanisms associated with the activation of disease resistance responses, we investigated proteins binding to the Potato (Solanum tuberosum) NB-LRR protein RX that confers eXtreme resistance to Potato Virus X (PVX) in Potato and Nicotiana benthamiana. By affinity purification eXperiments, we identified an endogenous N. benthamiana Ran GTPase-Activating Protein2 (RanGAP2) as an RX-associated protein in vivo. Further characterization confirmed the specificity of this interaction and showed that the association occurs through their N-terminal domains. By specific Virus-induced gene silencing of RanGAP2 in N. benthamiana carrying RX, we demonstrated that this interaction is required for eXtreme resistance to PVX and suggest that RanGAP2 is part of the RX signaling compleX. These results implicate RanGAP-mediated cellular mechanisms, including nucleocytoplasmic trafficking, in the activation of disease resistance.
-
an rna dependent rna polymerase prevents meristem invasion by Potato Virus X and is required for the activity but not the production of a systemic silencing signal
Plant Physiology, 2005Co-Authors: Frank Schwach, Fabian E Vaistij, Louise Jones, David C. BaulcombeAbstract:One of the functions of RNA silencing in plants is antiviral defense. A hallmark of RNA silencing is spreading of the silenced state through the plant. Little is known about the nature of the systemic silencing signal and the proteins required for its production, transport, and reception in plant tissues. Here, we show that the RNA-dependent RNA polymerase RDR6 in Nicotiana benthamiana is involved in defense against Potato Virus X at the level of systemic spreading and in eXclusion of the Virus from the apical growing point. It has no effect on primary replication and cell-to-cell movement of the Virus and does not contribute significantly to the formation of Virus-derived small interfering (si) RNA in a fully established Potato Virus X infection. In grafting eXperiments, the RDR6 homolog was required for the ability of a cell to respond to, but not to produce or translocate, the systemic silencing signal. Taking these findings together, we suggest a model of Virus defense in which RDR6 uses incoming silencing signal to generate double-stranded RNA precursors of secondary siRNA. According to this idea, the secondary siRNAs mediate RNA silencing as an immediate response that slows down the systemic spreading of the Virus into the growing point and newly emerging leaves.
-
size constraints for targeting post transcriptional gene silencing and for rna directed methylation in nicotiana benthamiana using a Potato Virus X vector
Plant Journal, 2001Co-Authors: Carole L Thomas, David C. Baulcombe, Louise Jones, Andrew J MauleAbstract:Using a recombinant Potato Virus X (PVX) vector, we investigated the relationship between the length of RNA sequence identity with a transgene and the ability to promote post-transcriptional gene silencing (PTGS) and transgene methylation. The lower size limit required for targeting reporter transgene mRNA de novo using PTGS was 23 nucleotides (nt) of complete identity, a size corresponding to that of small RNAs associated with PTGS in plants and RNA interference (RNAi) in animals. The size and sequence specificity were also eXplored for PTGS-associated transgene methylation and for the targeting of the vector RNA. The PTGS-competent short sequences resulted in similar patterns of methylation. In all cases, including specific sequences of 33 nt with or without symmetrical cytosine residues, the methylation was distributed throughout the transcribed region of the transgene. In contrast, short sequences lacking symmetrical cytosines were less efficient at promoting PTGS of the transgene mRNA. Short gfp sequences in the PVX vector provided as effective a target for the degradation of viral RNA as was found for PVX carrying the complete gfp cDNA. Short sequences were able to initiate PTGS of an endogenous gene, phyotene desaturase, although this occurred in the absence of DNA methylation. This eXperimental approach provides important insights into the relationship between short RNA sequences and PTGS.
-
cell to cell movement of the 25k protein of Potato Virus X is regulated by three other viral proteins
Molecular Plant-microbe Interactions, 2000Co-Authors: Yang Yang, David C. Baulcombe, Biao Ding, Jeanmarie VerchotAbstract:The 25K, 12K, and 8K proteins and coat protein (CP) of Potato Virus X (PVX) are required for Virus cell-to-cell movement. In this study, eXperiments were conducted to determine whether the PVX 25K protein moves cell to cell and to eXplore potential interactions between the PVX 25K, 12K, and 8K proteins and CP. The PVX 25K gene was fused to the green fluorescent protein (GFP) gene and inserted into plasmids adjacent to the cauliflower mosaic Virus 35S promoter. These plasmids were introduced by biolistic bombardment to transgenic tobacco eXpressing the PVX 12K, 8K, and CP genes. The GFP:25K fused proteins moved cell to cell on nontransgenic tobacco and tobacco eXpressing either the 12K or 8K proteins. However, the GFP:25K proteins did not move on transgenic tobacco eXpressing the combined 12K/8K genes or the CP gene. Thus, movement of the PVX 25K protein through plasmodesmata may be regulated by interactions with other PVX proteins.
-
Potato Virus X amplicons in arabidopsis mediate genetic and epigenetic gene silencing
The Plant Cell, 2000Co-Authors: Tamas Dalmay, Andrew J Hamilton, Elisabeth Mueller, David C. BaulcombeAbstract:Amplicon transgenes from Potato Virus X (PVX) are based on a modified version of the viral genome and are efficient activators of post-transcriptional gene silencing (PTGS). To determine whether PVX amplicons activate PTGS in Arabidopsis, we used constructs based on the genome of PVX carrying a green fluorescent protein (GFP) reporter gene. Our analysis of the transgene phenotype eXploited previous observations indicating that PTGS is associated with short 25-nucleotide RNA species, transgene methylation, and homology-dependent Virus resistance. We also used the ability of turnip mosaic Virus to suppress gene silencing as a means of dissecting stages of the mechanism. The results showed that a PVX:GFP amplicon induces weak PTGS and that this PTGS was enhanced in the presence of a GFP reporter gene. Our interpretation of these data is that the PTGS induced by the amplicon was genetically determined and equivalent to the initiation stage of the PTGS mechanism. The PTGS induced by the combined amplicon and reporter gene was equivalent to the maintenance stage and was associated with an epigenetic conversion of the transgene. The distinction between genetic and epigenetic PTGS eXplains the well-characterized effects of transgene dosage on PTGS that have been previously interpreted in terms of RNA eXpression thresholds.
Ulrich Commandeur - One of the best experts on this subject based on the ideXlab platform.
-
Analysis of Engineered Tobacco Mosaic Virus and Potato Virus X Nanoparticles as Carriers for Biocatalysts
'Frontiers Media SA', 2021Co-Authors: Juliane Schuphan, Ulrich CommandeurAbstract:Plant Virus nanoparticles are promising candidates for the development of novel materials, including nanocomposites and scaffolds/carriers for functional molecules such as enzymes. Their advantages for enzyme immobilization include a modular organization, a robust and programmable structure, and a simple, cost-effective production. However, the activity of many enzymes relies on posttranslational modification and most plant Viruses replicate in the cytoplasm, so functional enzymes cannot be displayed on the Virus surface by direct coat protein fusions. An alternative display system to present the Trichoderma reesei endoglucanase Cel12A on Potato Virus X (PVX) using SpyTag/SpyCatcher (ST/SC) technology was recently developed by the authors, which allows the carrier and enzyme to be produced separately before isopeptide conjugation. Although kinetic analysis clearly indicated efficient biocatalyst activity, the PVX carrier interfered with substrate binding. To overcome this, the suitability of tobacco mosaic Virus (TMV) was tested, which can also accommodate a larger number of ST peptides. We produced TMV particles displaying ST as a new platform for the immobilization of enzymes such as Cel12A, and compared its performance to the established PVX-ST platform in terms of catalytic efficiency. Although more enzyme molecules were immobilized on the TMV-ST particles, we found that the rigid scaffold and helical spacing significantly affected enzyme activity
-
biodistribution of filamentous plant Virus nanoparticles pepino mosaic Virus versus Potato Virus X
Biomacromolecules, 2019Co-Authors: Duc H T Le, Eduardo Mendezlopez, Miguel A. Aranda, Ulrich Commandeur, Chao Wang, Nicole F SteinmetzAbstract:Nanoparticles with high aspect ratios have favorable attributes for drug delivery and bioimaging applications based on their enhanced tissue penetration and tumor homing properties. Here, we investigated a novel filamentous viral nanoparticle (VNP) based on the Pepino mosaic Virus (PepMV), a relative of the established platform Potato Virus X (PVX). We studied the chemical reactivity of PepMV, produced fluorescent versions of PepMV and PVX, and then evaluated their biodistribution in mouse tumor models. We found that PepMV can be conjugated to various small chemical modifiers including fluorescent probes via the amine groups of surface-eXposed lysine residues, yielding VNPs carrying payloads of up to 1600 modifiers per particle. Although PepMV and PVX share similarities in particle size and shape, PepMV achieved enhanced tumor homing and less nonspecific tissue distribution compared to PVX in mouse models of triple negative breast cancer and ovarian cancer. In conclusion, PepMV provides a novel tool for n...
-
Small, Smaller, Nano: New Applications for Potato Virus X in Nanotechnology
Frontiers Media S.A., 2019Co-Authors: Juliane Röder, Christina Dickmeis, Ulrich CommandeurAbstract:Nanotechnology is an eXpanding interdisciplinary field concerning the development and application of nanostructured materials derived from inorganic compounds or organic polymers and peptides. Among these latter materials, proteinaceous plant Virus nanoparticles have emerged as a key platform for the introduction of tailored functionalities by genetic engineering and conjugation chemistry. Tobacco mosaic Virus and Cowpea mosaic Virus have already been developed for bioimaging, vaccination and electronics applications, but the fleXible and filamentous Potato Virus X (PVX) has received comparatively little attention. The filamentous structure of PVX particles allows them to carry large payloads, which are advantageous for applications such as biomedical imaging in which multi-functional scaffolds with a high aspect ratio are required. In this conteXt, PVX achieves superior tumor homing and retention properties compared to spherical nanoparticles. Because PVX is a protein-based nanoparticle, its unique functional properties are combined with enhanced biocompatibility, making it much more suitable for biomedical applications than synthetic nanomaterials. Moreover, PVX nanoparticles have very low toXicity in vivo, and superior pharmacokinetic profiles. This review focuses on the production of PVX nanoparticles engineered using chemical and/or biological techniques, and describes current and future opportunities and challenges for the application of PVX nanoparticles in medicine, diagnostics, materials science, and biocatalysis
-
Biodistribution of Filamentous Plant Virus Nanoparticles: Pepino Mosaic Virus versus Potato Virus X
2018Co-Authors: Eduardo Méndez-lópez, Miguel A. Aranda, Ulrich Commandeur, Chao Wang, Nicole F SteinmetzAbstract:Nanoparticles with high aspect ratios have favorable attributes for drug delivery and bioimaging applications based on their enhanced tissue penetration and tumor homing properties. Here, we investigated a novel filamentous viral nanoparticle (VNP) based on the Pepino mosaic Virus (PepMV), a relative of the established platform Potato Virus X (PVX). We studied the chemical reactivity of PepMV, produced fluorescent versions of PepMV and PVX, and then evaluated their biodistribution in mouse tumor models. We found that PepMV can be conjugated to various small chemical modifiers including fluorescent probes via the amine groups of surface-eXposed lysine residues, yielding VNPs carrying payloads of up to 1600 modifiers per particle. Although PepMV and PVX share similarities in particle size and shape, PepMV achieved enhanced tumor homing and less nonspecific tissue distribution compared to PVX in mouse models of triple negative breast cancer and ovarian cancer. In conclusion, PepMV provides a novel tool for nanomedical research but more research is needed to fully eXploit the potential of plant VNPs for health applications
-
Systemic Infection of Nicotiana benthamiana with Potato Virus X Nanoparticles Presenting a Fluorescent iLOV Polypeptide Fused Directly to the Coat Protein
Hindawi Limited, 2018Co-Authors: Juliane Röder, Rainer Fischer, Christina Dickmeis, Ulrich CommandeurAbstract:Plant Virus-based nanoparticles can be produced in plants on a large scale and are easily modified to introduce new functions, making them suitable for applications such as vaccination and drug delivery, tissue engineering, and in vivo imaging. The latter is often achieved using green fluorescent protein and its derivatives, but the monovalent fluorescent protein iLOV is smaller and more robust. Here, we fused the iLOV polypeptide to the N-terminus of the Potato Virus X (PVX) coat protein, directly or via the Foot-and-mouth disease Virus 2A sequence, for eXpression in Nicotiana benthamiana. Direct fusion of the iLOV polypeptide did not prevent the assembly or systemic spread of the Virus and we verified the presence of fusion proteins and iLOV hybrid Virus particles in leaf eXtracts. Compared to wild-type PVX virions, the PVX particles displaying the iLOV peptide showed an atypical, intertwined morphology. Our results confirm that a direct fusion of the iLOV fluorescent protein to filamentous PVX nanoparticles offers a promising tool for imaging applications
Duc H T Le - One of the best experts on this subject based on the ideXlab platform.
-
biodistribution of filamentous plant Virus nanoparticles pepino mosaic Virus versus Potato Virus X
Biomacromolecules, 2019Co-Authors: Duc H T Le, Eduardo Mendezlopez, Miguel A. Aranda, Ulrich Commandeur, Chao Wang, Nicole F SteinmetzAbstract:Nanoparticles with high aspect ratios have favorable attributes for drug delivery and bioimaging applications based on their enhanced tissue penetration and tumor homing properties. Here, we investigated a novel filamentous viral nanoparticle (VNP) based on the Pepino mosaic Virus (PepMV), a relative of the established platform Potato Virus X (PVX). We studied the chemical reactivity of PepMV, produced fluorescent versions of PepMV and PVX, and then evaluated their biodistribution in mouse tumor models. We found that PepMV can be conjugated to various small chemical modifiers including fluorescent probes via the amine groups of surface-eXposed lysine residues, yielding VNPs carrying payloads of up to 1600 modifiers per particle. Although PepMV and PVX share similarities in particle size and shape, PepMV achieved enhanced tumor homing and less nonspecific tissue distribution compared to PVX in mouse models of triple negative breast cancer and ovarian cancer. In conclusion, PepMV provides a novel tool for n...
-
Potato Virus X a filamentous plant viral nanoparticle for doXorubicin delivery in cancer therapy
Nanoscale, 2017Co-Authors: Duc H T Le, Karin L Lee, Ulrich Commandeur, Sourabh Shukla, Nicole F SteinmetzAbstract:Plant viral nanoparticles (VNPs) are a novel class of nanocarriers with implications for drug delivery in cancer therapy. VNPs are characterized by their highly symmetrical nanoscale structures. Furthermore, plant VNPs are biocompatible, biodegradable, and non-infectious in mammals. VNPs provide a proteinaceous platform technology that can be readily engineered to carry contrast agents and therapies using chemical and genetic modifications. Of particular interest are high aspect ratio, elongated filaments such as the ones formed by Potato Virus X (PVX, measuring 515 × 13 nm). PVX has demonstrated enhanced tumor homing and penetration properties compared to spherical counterparts. Here, we sought to investigate the potential of PVX as a drug carrier delivering doXorubicin (DOX), a commonly used cancer chemotherapy. We synthesized therapeutic PVX nanoparticles using a simple in-solution miXing protocol; after 5 days of miXing of DOX and PVX and ultra-centrifugal purification, ∼1000 DOX per PVX were stably associated with the carrier, most likely based on hydrophobic interaction. Efficacy and drug activity of PVX–DOX were confirmed using a panel of cancer cell lines including ovarian cancer, breast cancer, and cervical cancer. Lastly, we demonstrated treatment of athymic mice bearing human MDA-MB-231 breast cancer Xenografts: PVX–DOX treatment resulted in reduced tumor growth in this model. Our results open the door for further development of PVX and other high aspect ratio plant VNPs for applications in cancer therapy.
J G Atabekov - One of the best experts on this subject based on the ideXlab platform.
-
RESEARCH ARTICLES Characteristics of Artificial Virus-like Particles Assembled in vitro from Potato Virus X Coat Protein and Foreign Viral
2016Co-Authors: M. V. Arkhipenko, N P Rodionova, O V Karpova, E. K. Petrova, N. A. Nikitin, A. D. Protopopova, E. V. Dubrovin, I. V. Yaminskii, J G AtabekovAbstract:Copyright © 2011 Park-media, Ltd. This is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Potato Virus X (PVX) and some other poteXViruses can be reconstituted in vitro from viral coat protein (CP) and RNA. PVX CP is capable of forming viral ribonucleoprotein compleXes (vRNP) not only with homologous, but also with foreign RNAs. This paper presents the structure and properties of vRNP assembled in vitro upon incubation of PVX CP and RNAs of various plant and animal Viruses belonging to different taXo-nomic groups. We have shown that the morphology and translational properties of vRNPs containing foreign (heterologous) RNA are identical to those of homological vRNP (PVX RNA – PVX CP). Our data suggest that the assembly of the “miXed ” vRNP in vitro could be started at the 5’-proXimal region of the RNA, producing a helical structure of vRNPs with foreign nucleic acids. The formation of heterologous vRNP in vitro with PVX CP appears not to require a specific 5 ’ end RNA nucleotide sequence, and the PVX CP seems to be able to pack foreign genetic material of various sizes and compositions into artificial Virus-like particles. KEYWORDS plant Viruses; RNA; viral ribonucleoproteins; translation activation. ABBREVIATIONS PVX – Potato Virus X; CP – coat protein; vRNP – viral ribonucleoprotein; MP – movement protein; BMV – Brome mosaic Virus; PAMV – Potato aucuba mosaic Virus; TMV – Tobacco mosaic Virus; NMV – Narcissus mosaic Virus; AltMV – Altenathera mosaic Virus
-
the 5 proXimal region of Potato Virus X rna involves the potential cap dependent conformational element for encapsidation
Biochimie, 2015Co-Authors: E. K. Petrova, O V Karpova, A. D. Protopopova, Nikolai Nikitin, E A Trifonova, J G AtabekovAbstract:Abstract Filamentous helical Potato Virus X (PVX) can be regarded as one of the well-studied Viruses. Nevertheless, some aspects of the PVX assembly remained obscure. Previously, we have shown that the presence of a cap structure at the 5′ end of PVX RNA is indispensable for assembly of viral ribonucleoprotein (vRNP) particles varying in length. Here, most significantly, removal of the cap structure from previously capped PVX RNA did not affect the efficiency of decapped RNA molecules to be assembled into vRNP. This result provided evidence that the cap structure by itself does not act as a signal for initiation of vRNP assembly. These observations allowed to presume that the capping triggers some spatial changes in the 5'-proXimal site of PVX RNA creating a “conformational encapsidation signal for vRNP assembly”, which is capable of triggering vRNP assembly in the absence of cap structure. Apparently, during capping the 5'-proXimal segment of PVX RNA acquires a unique conformation which is stable to be retained even after cap removal.
-
the role of the 5 cap structure in viral ribonucleoproteins assembly from Potato Virus X coat protein and rnas
Biochimie, 2013Co-Authors: E. K. Petrova, O V Karpova, M. V. Arkhipenko, A. D. Protopopova, Nikolai Nikitin, I V Yaminsky, J G AtabekovAbstract:The Potato Virus X (PVX) virion can be reconstituted in vitro from the Virus coat protein (CP) and RNA; heterologous RNAs may be used as well. In our recent study, structure and properties of cognate and heterologous viral ribonucleoproteins (vRNPs) were demonstrated to be similar to those of native virions. The assembly was found to be initiated at the 5' terminus of an RNA and was not dependent on RNA sequence. The aim of the present study was to search for a signal or an essential structural element that directs packaging of viral genetic material into vRNPs. vRNPs were formed by incubation of the PVX CP with heterologous capped RNAs, their functional fragments lacking the cap structure, as well as the capped and uncapped transcripts corresponding to the 5'-terminal region of the genomic PVX RNA. EXperimental data show that the presence of the cap structure at the 5' end of a nucleic acid is an important condition for vRNP assembly from RNA and CP. Presumably, the 5'-cap affects conformational state of the RNA region responsible for the efficient interaction with CP and creates conformational encapsidation signal for vRNP assembly.
-
characteristics of artificial Virus like particles assembled in vitro from Potato Virus X coat protein and foreign viral rnas
Acta Naturae, 2011Co-Authors: M. V. Arkhipenko, N P Rodionova, O V Karpova, E. K. Petrova, A. D. Protopopova, E. V. Dubrovin, I. V. Yaminskii, Nikolai Nikitin, J G AtabekovAbstract:Potato Virus X (PVX) and some other poteXViruses can be reconstitutedin vitrofrom viral coat protein (CP) and RNA. PVX CP is capable of forming viral ribonucleoprotein compleXes (vRNP) not only with homologous, but also with foreign RNAs. This paper presents the structure and properties of vRNP assembledin vitroupon incubation of PVX CP and RNAs of various plant and animal Viruses belonging to different taXonomic groups. We have shown that the morphology and translational properties of vRNPs containing foreign (heterologous) RNA are identical to those of homological vRNP (PVX RNA - PVX CP). Our data suggest that the assembly of the "miXed" vRNPin vitrocould be started at the 5'-proXimal region of the RNA, producing a helical structure of vRNPs with foreign nucleic acids. The formation of heterologous vRNPin vitrowith PVX CP appears not to require a specific 5' end RNA nucleotide sequence, and the PVX CP seems to be able to pack foreign genetic material of various sizes and compositions into artificial Virus-like particles.
-
Potato Virus X rna mediated assembly of single tailed ternary coat protein rna movement protein compleXes
Journal of General Virology, 2006Co-Authors: O V Karpova, N P Rodionova, Yu V Poljakov, M. V. Arkhipenko, I V Yaminsky, O V Zayakina, Eugene V Sheval, O I Kiselyova, J G AtabekovAbstract:Different models have been proposed for the nature of the poteXVirus transport form that moves from cell to cell over the infected plant: (i) genomic RNA moves as native virions; or (ii) in vitro-assembled non-virion ribonucleoprotein (RNP) compleXes consisting of viral RNA, coat protein (CP) and movement protein (MP), termed TGBp1, serve as the transport form in vivo. As the structure of these RNPs has not been elucidated, the products assembled in vitro from Potato Virus X (PVX) RNA, CP and TGBp1 were characterized. The compleXes appeared as single-tailed particles (STPs) with a helical, head-like structure composed of CP subunits located at the 5'-proXimal region of PVX RNA; the TGBp1 was bound to the terminal CP molecules of the head. Remarkably, no particular non-virion RNP compleXes were observed. These data suggest that the CP-RNA interactions resulting in head formation prevailed over TGBp1-RNA binding upon STP assembly from RNA, CP and TGBp1. STPs could be assembled from the 5' end of PVX RNA and CP in the absence of TGBp1. The translational ability of STPs was characterized in a cell-free translation system. STPs lacking TGBp1 were entirely non-translatable; however, they were rendered translatable by binding of TGBp1 to the end of the head. It is suggested that the RNA-mediated assembly of STPs proceeds via two steps. Firstly, non-translatable CP-RNA STPs are produced, due to encapsidation of the 5'-terminal region. Secondly, the TGBp1 molecules bind to the end of a polar head, resulting in conversion of the STPs into a translatable form.