Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| the xxiiird phage/virus assembly meeting. | the xxiiird phage/virus assembly (pva) meeting returned to its birthplace in lake arrowhead, ca on september 8-13, 2013 (fig. 1). the original meeting occurred in 1968, organized by bob edgar (caltech, pasadena, ca usa), fred eiserling (university of california, los angeles, los angeles, ca usa) and bill wood (caltech, pasadena, ca usa). the organizers of the 2013 meeting were bill gelbart (university of california, los angeles, los angeles, ca usa) and jack johnson (scripps research institute, ... | 0 | 24498537 |
| antiphytoviral activity of 2,4 dioxo hexahydro triazine. | three treatments with 2,4 dioxo hexahydro triazine (dht) significantly reduced the concentration of potato virus x (pvx) in systemically infected tobacco plants. in hypersensitive plants dht caused a reduction in the number of local lesions produced by pvx. in systemic and hypersensitive hosts, treatment with dht resulted in a more or less marked reduction in the concentration of, and in the number of local lesions caused by, potato virus y (pvy), potato virus a (pva), tobacco mosaic virus (tmv) ... | 1979 | 42301 |
| some factors influencing purification of potato virus a (pva). | potato virus a (pva) was purified from mechanically infected plants nicotiana tabacum cv samsun by high speed centrifugation and subsequent isopycnic density gradient centrifugation in cscl gradient. from different procedures tested 0.05 mol/l phosphate buffer (pbs) ph 8 seemed optimal for virus purification and 0.1 mol/l borate buffer ph 8.0 for virus storage; other ph of pbs, tris and hepes buffers were less suitable. additives preventing virus aggregation were beneficial. the average yield ra ... | 1991 | 1688081 |
| monoclonal antibodies against potato virus a--competitive binding tests. | six mouse monoclonal antibodies (moabs) against potato virus a (pva) were tested. one of them (pva 534) reacted only with complete virions and was apparently specific for epitopes dependent on quaternary structure. moab pva 328 recognized the virus antigen only after its dissociation into subunits. moab pva 328 must have reacted with a cryptotope of the antigen. moab pva 151 and 290 appeared to be conformation independent and reacted with exposed regions on native virus particles as well as on t ... | 1992 | 1284864 |
| a new electron microscope positive staining method for viruses in suspension. | a new procedure for the positive staining of viruses in suspension, the tokuyasu staining procedure (tsp), was evaluated using a non-enveloped virus, rotavirus; an enveloped virus, rubella virus and two glutaraldehyde-treated enveloped viruses, human t cell lymphotropic virus type i (htlv-i) and human immunodeficiency virus type 1 (hiv-1) as models. the tsp involves an initial staining of the virus with uranyl acetate (ua) followed by thin embedding in a mixture of ua and polyvinyl alcohol (pva) ... | 1992 | 1378851 |
| nucleotide sequence of the 3'-terminal region of potato virus a rna. | the sequence of the 3'-terminal region of the genome of the potato virus a (pva) was obtained from two independent cdna clones. this sequence is 1383 nucleotides long and contains an open reading frame of 1178 nucleotides, ending with the translation termination codon taa and followed by untranslated region of 205 nucleotides. since the n-terminal amino acid of the coat protein of pva was blocked, the position of the putative coat protein cleavage site has been deduced by searching for consensus ... | 1992 | 1604933 |
| coat protein gene-mediated resistance to potato virus y in tobacco: examination of the resistance mechanisms--is the transgenic coat protein required for protection? | we transformed sr1 tobacco with a cdna fragment of the potato virus y strain n (pvyn) 605 genome which contained the 3' end of the nib polymerase gene, the coat protein (cp) coding sequence, and most of the viral 3' untranslated region. complete resistance to several pvy strains was obtained in plants of the r2 generation. the resistance to pvyn and pvyo strains was maintained when the plants were inoculated dually with the potato potyviruses v or a (pvv or pva). only partial resistance to pvyn ... | 1993 | 8324247 |
| cloning and nucleotide sequence of the capsid protein and the nuclear inclusion protein (nib) of potato virus a. | the sequence of the 3'-terminal 2597 nucleotides of potato virus a (pva) genome has been determined from cdna clones. an open reading frame was identified and potentially encodes a large polyprotein containing 789 amino acid residues. this large open reading frame was found to have a high similarity to the nuclear inclusion protein (nib) and the capsid protein (cp) genes of several potyviruses. the data suggest that the pva nib and cp are products arising from the maturation of the large polypro ... | 1993 | 8418789 |
| the nucleotide sequence of potato virus a genomic rna and its sequence similarities with other potyviruses. | the complete nucleotide sequence of potato virus a (pva) was obtained from six independent cdna clones. the rna genome of pva is 9565 nucleotides long and contains one open reading frame (orf) of 9177 bases encoding a large polyprotein of 3059 amino acids with a calculated m(r) of 340k. seven potential proteinase nia, one hc-pro and one p1 proteinase recognition sites were found in pva polyprotein by searching for cleavage site consensus sequences amongst the potyvirus group. the non-coding regi ... | 1994 | 8113771 |
| comparison of seven bio- and chemiluminescent reagents for in situ detection of antigens and nucleic acids. | bio- and chemiluminescence have proved sensitive enough to compete with chromogenic and radioisotopic tracers for in situ detection. however, they must also provide a discriminant morphological analysis of the specific signal. we have tested seven bio- or chemiluminescent reagents for tissue antigen and nucleic acid detection by immunocytochemistry (icc) or in situ hybridization (ish). they were based on luminescent detection of peroxidase, alkaline phosphatase, beta-galactosidase or xanthine ox ... | 1995 | 8533606 |
| functional mrna can be generated by rna polymerase iii. | eukaryotic cellular mrna is believed to be synthesized exclusively by rna polymerase ii (pol ii), whereas pol i produces long rrnas and pol iii produces 5s rrna, trna, and other small rnas. to determine whether this functional differentiation is obligatory, we examined the translational potential of an artificial pol iii transcript. the coding region of the human immunodeficiency virus type 1 tat gene was placed under the control of a strong pol iii promoter from the adenovirus type 2 va rnai ge ... | 1995 | 7791767 |
| infectious in vitro transcripts from cloned cdna of the potato a potyvirus. | a full-length cdna copy of potato virus a rna was constructed downstream from the bacteriophage t7 rna polymerase promoter. a single extra guanosine not present in pva rna was added to the 5'-end of the cdna. the capped in vitro transcripts from cloned cdna were infectious in the mesophyll protoplasts and intact plants of nicotiana tabacum. pva coat protein accumulated in transcript-inoculated tobacco protoplasts and infected systematically intact plants producing high pva titres according to th ... | 1996 | 8725109 |
| comparison of the nucleotide sequences of the 3'-terminal regions of one aphid and two non-aphid transmissible isolates of potato a potyvirus. | the sequences of the 3'-terminal 1145 nucleotides of two non-aphid transmissible (nat) isolates (ali and juliniere) and one aphid transmissible (at) isolate (rouge) of potato virus a (pva) rna were determined. those sequences contained the complete coding region of the coat protein (cp) followed by a 3'-nontranslated region (3'-ntr) of 225 (ali and juliniere) and 227 (rouge) nucleotides. the obtained sequences were compared to those of the 3'-regions of four published pva isolates and a virus de ... | 1996 | 8774682 |
| monoclonal antibodies against potato virus a -- immunoblot analysis. | monoclonal antibodies (moabs) against potato virus a (pva) were examined in their reactivity with pva and its denatured capsid protein (pva-cp) bound to the nitrocellulose membrane. five moabs reacted with native pva, three of them also with pva-cp. one moab gave no reaction in dot-blot test. in polyacrylamide electrophoresis in the presence of sodium dodecyl sulphate (sds-page) pva-cp migrated as two major bands. in immunoblot analysis, two moabs reacted only with the slower band, one only with ... | 1996 | 9171457 |
| inheritance of resistance to potato viruses y and a in progeny obtained from potato cultivars containing gene ry:evidence for a new gene for extreme resistance to pva. | extreme resistance in cultivated potato (solanum tuberosum) to potato viruses y and a (pvy and pva) conditioned by the presence of ry genes introduced from solanum stoloniferum was described by cockerham (1970). cockerham detailed a number of genes which controlled a variety of reactions, including extreme resistance to both viruses (i.e. little or no visible reaction of plants and no viral replication following graft and manual inoculation) controlled by gene ry sto. in the present study, cvs ' ... | 1996 | 24162398 |
| the potential transmission of infectious agents by semen packaging during storage for artificial insemination. | plastic straws, of a type widely used for semen cryopreservation, sealed using three different methods, (pva powder, plastic spheres and plasticine modelling clay) were tested for leakage of low molecular weight dye (methylene blue), bacteria (escherichia coli) and virus (newcastle disease virus). leakage was found to be dependent on the method used to fill the straws. straws filled using a traditional 'dip and wipe' method and sealed with pva powder demonstrated a significant degree of methylen ... | 1997 | 9360772 |
| potato virus a detection by reverse transcription-polymerase chain reaction. | simple and reliable procedure for sample preparation and reverse transcription-polymerase chain reaction (rt-pcr) detection of potato virus a (pva) is described. pva-specific primers used in the rt-pcr defined a target sequence of 321 bp and did not produce amplification product(s) with potato virus y. | 1998 | 9770075 |
| vpg, coat protein and five non-structural proteins of potato a potyvirus bind rna in a sequence-unspecific manner. | the potato a potyvirus (pva)-encoded proteins p1, hc-pro, p3, ci, vpg, niapro, nib and coat protein (cp) were expressed as 6 x his-tagged recombinant proteins in escherichia coli and purified to homogeneity. rna binding was tested using purified proteins in northwestern and liquid assays. pva proteins except p3 bound to positive- and negative-sense transcripts prepared from the nontranslated 5'- and 3'-regions of pva genomic rna and to full-length transcripts of pva rna. rna binding by these pro ... | 1998 | 9880031 |
| biological, serological, and molecular differences among isolates of potato a potyvirus. | abstract sequences of the coat protein (cp) and 3'-end nontranslated region (3'ntr) of 13 isolates and the helper component proteinase (hc) of nine isolates of potato a potyvirus (pva) were determined and compared with the eight previously determined pva cp and 3'ntr sequences and one hc sequence. cp amino acid (aa), 3'ntr nucleotide, and hc aa sequence identities were 92.9, 93.4, and 94.8%, respectively. sequence data, serological tests, and the necrotic local lesions induced in the leaves of t ... | 1998 | 18944954 |
| electron microscopic observation of potato virus a using murine monoclonal antibodies. | six monoclonal antibodies (moabs) against potato virus a (pva) were prepared and used in enzyme-linked immunosorbent assay (elisa), immunoblot analysis and electron microscopic study of the virus. four moabs, 151, 290, 328 and 634, reacted with purified virus preparation in dot blot test and showed strong reaction also with virus coat protein (cp) denatured by sodium dodecyl sulphate (sds), while two moabs, 534 and 187, gave significantly weaker reaction with denatured cp than with purified viru ... | 1998 | 10358736 |
| biochemical and genetic evidence for interactions between potato a potyvirus-encoded proteins p1 and p3 and proteins of the putative replication complex. | interactions of the first and third proteins (p1 and p3) of the potato a potyvirus (pva) with the other six main proteins of pva were studied using escherichia coli-expressed recombinant proteins in two in vitro interaction assays and a genetic assay yeast two-hybrid system (yths). in overlay blotting and binding assays in liquid, p1 and p3 interacted with each other and with proteins of the putative replication complex of potyvirus: rna-helicase (ci), viral protein genome-linked (vpg), nia prot ... | 1999 | 10544078 |
| the 6k2 protein and the vpg of potato virus a are determinants of systemic infection in nicandra physaloides. | infection with the isolate pva-m of potato virus a (pva; genus potyvirus) is restricted to the inoculated leaves of nicandra physaloides (solanaceae), whereas the isolate pva-b11 infects plants systemically by 10 days post inoculation. resistance to systemic infection was shown to develop during plant growth. a recombinant virus (b11-m) in which a 1,208-nucleotide sequence of the full-length cdna clone of pva-b11 was replaced with the corresponding sequence from pva-m displayed a phenotype simil ... | 1999 | 10624016 |
| comparison of the complete sequences of five different isolates of potato virus a (pva), genus potyvirus. | the complete nucleotide (nt) and deduced amino acid (aa) sequences of isolates ali, u, her (from potato, solanum tuberosum) and tammv (from tamarillo, solanum betacea) of potato virus a (pva, genus potyvirus) were determined and compared with the previously reported sequence of pva isolate b11. most parts (proteins) of the polyprotein showed over 95% aa sequence similarity. the cylindrical inclusion (ci) protein and the 6k 1 protein were the most conserved proteins among the five isolates. tammv ... | 1999 | 10664389 |
| comparison of in-situ hybridization, direct and indirect in-situ pcr as well as tyramide signal amplification for the detection of hpv. | one hundred paraffin-embedded cervical biopsy specimens were tested for the presence of human papilloma virus (hpv) by in situ hybridization (ish), and by direct and indirect in situ pcr (is-pcr) in order to evaluate the efficiency of the different in situ methods in detecting hpv infection. ish was performed using either commercial dna probes or a cocktail of 5'-digoxigenin labeled oligoprimers. the same were used for ish during indirect is-pcr. to enhance the sensitivity of ish several polymer ... | 1999 | 10090569 |
| self-association and mapping of interaction domains of helper component-proteinase of potato a potyvirus. | potyviral helper component-proteinase (hc-pro) is a multifunctional protein involved in aphid transmission, long-distance movement, polyprotein processing, genome amplification and symptom expression. it has been proposed that the active form of hc-pro is a dimer and that coat protein (cp)-hc-pro interaction is required for aphid transmission. to test these proposed interactions between cp and hc-pro of potato a potyvirus (pva), the yeast two-hybrid system was used. hc-pro was shown to interact ... | 1999 | 10355758 |
| potyvirus helper component-proteinase and coat protein (cp) have coordinated functions in virus-host interactions and the same cp motif affects virus transmission and accumulation. | amino acid differences between helper component-proteinase (hc-pro) and coat protein (cp) that are putatively associated with biological differences between isolates pva-b11 and pva-u of potato a potyvirus (pva) were studied using an infectious cdna clone of pva-b11. replacement of the entire cp gene of pva-b11 with the cp gene of pva-u reduced virus accumulation in tobacco 5-fold, to the level of pva-u. in contrast, four simultaneous amino acid substitutions made in pva-b11 hc-pro (according to ... | 1999 | 10355759 |
| one-step capillary isoelectric focusing for the separation of the recombinant human immunodeficiency virus envelope glycoprotein glycoforms. | one-step capillary isoelectric focusing was investigated as a rapid method to resolve the glycoforms of the heterogeneous recombinant human immunodeficiency virus (hiv) envelope glycoprotein (rgp 160smn/lai). the separation was performed in a poly(vinyl alcohol) (pva) coated capillary using a mixture of ampholyte of narrow and wide ph range. a combination of saccaharose and 3-(cyclohexylamino)-1-propanesulfonic acid was shown to be the most efficient additive to avoid protein precipitation which ... | 2000 | 10681015 |
| recessive and dominant genes interfere with the vascular transport of potato virus a in diploid potatoes. | resistance to potato virus a (pva) was examined in a diploid cross involving solanum tuberosum subsp. andigena as a resistance source. hypersensitive resistance (hr) to pva cosegregated with extreme resistance (er) to potato virus y conferred by the dominant gene ry(adg) on chromosome xi. hence, hr to pva was controlled by a novel, dominant resistance gene closely linked to ry(adg), or ry(adg) recognized both viruses but conferred a different type of resistance to each virus. the hr prevented sy ... | 2000 | 10755303 |
| complementation of the movement-deficient mutations in potato virus x: potyvirus coat protein mediates cell-to-cell trafficking of c-terminal truncation but not deletion mutant of potexvirus coat protein. | the cell-to-cell movement of the gus-tagged potato virus x (pvx) coat protein (cp) movement-deficient mutant was restored by potyviral cps of potato virus a (pva) and potato virus y (pvy) in nicotiana benthamiana leaves in transient cobombardment experiments. viral cell-to-cell movement of pvx cp mutant was complemented in nicotiana tabacum cv. sr1 transgenic plants expressing pvy cp: pvx rna and polymerase were detected in the pvx cp mutant-inoculated leaves of transgenic plants. these findings ... | 2000 | 10772977 |
| an ry-mediated resistance response in potato requires the intact active site of the nia proteinase from potato virus y. | ry confers extreme resistance to all strains of potato virus y (pvy). to identify the elicitor of the ry-mediated resistance against pvy in potato, we expressed each of the pvy-encoded proteins in leaves of pvy-resistant (ry) and -susceptible (ry) plants. for most of the proteins tested, there was no evident response. however, when the nia proteinase was expressed in leaves of ry plants, there was a hypersensitive response (hr). proteinase active site mutants failed to induce the ry-mediated res ... | 2000 | 10972891 |
| molecular characterization of potato virus v genomes from europe indicates limited spatiotemporal strain differentiation. | abstract because there were no previous reports on the molecular characterization of potato virus v (pvv, genus potyvirus, family potyviridae), the complete genomic sequence of pvv isolate dv42 was determined. the length of the single-stranded messenger-polarity rna genome was 9,851 nt (nucleotides), followed by a poly(a) tail. the genome contained a 5'-terminal nontranslated region (5'-ntr; 204 nt), a single open reading frame (nucleotides 205-9406; 3,067 amino acids), and a 3'-ntr that was unu ... | 2000 | 18944596 |
| differential accumulation of potato virus a and expression of pathogenesis-related genes in resistant potato cv. shepody upon graft inoculation. | abstract potato (solanum tuberosum l.) cv. shepody is highly resistant to potato virus a (pva), yielding no visible symptoms after rub inoculation. in 'shepody' rootstocks graft-inoculated by pva-infected scions from a susceptible host, we found a resistance consisting of traces of necrosis (necrotic streaks) in stems and chlorosis in newly emerged leaves. the response was temperature dependent, appearing at 15 to 18 degrees c but not at 28 to 31 degrees c. necrosis was also observed in tubers, ... | 2001 | 18944394 |
| phosphorylation down-regulates the rna binding function of the coat protein of potato virus a. | plant viruses encode movement proteins (mps) to facilitate transport of their genomes from infected into neighboring healthy cells through plasmodesmata. growing evidence suggests that specific phosphorylation events can regulate mp functions. the coat protein (cp) of potato virus a (pva; genus potyvirus) is a multifunctional protein involved both in virion assembly and virus movement. labeling of pva-infected tobacco leaves with [(33)p]orthophosphate demonstrated that pva cp is phosphorylated i ... | 2001 | 11152464 |
| a novel usage of random primers for multiplex rt-pcr detection of virus and viroid in aphids, leaves, and tubers. | a multiplex reverse transcription polymerase chain reaction (m-rt-pcr) was developed for the simultaneous detection of five potato viruses and a viroid. the synthesis of cdnas used for amplification was primed by hexanucleotides (random primers, rp). an rna extraction procedure employing dnase i, is routinely used to isolate potato viruses and viroid (potato virus s, pvs; potato leafroll virus, plrv; potato virus x, pvx; potato virus a and y, pva, pvy; and potato spindle tuber viroid, pstvd) fro ... | 2001 | 11164484 |
| identification of the genome-linked protein in virions of potato virus a, with comparison to other members in genus potyvirus. | viruses of the genus potyvirus, the largest genus of plant-infecting viruses, have a messenger-polarity ssrna genome encapsidated by approximately 2000 units of the viral coat protein (cp), resulting in filamentous virions. only few studies have examined potyvirus virions for the presence of other structural proteins. a protein linked covalently to the 5'-end of the genome has been identified in tobacco vein mottling virus (tvmv) and tobacco etch virus (tev). in tev, it is either the viral nia p ... | 2001 | 11172914 |
| towards a protein interaction map of potyviruses: protein interaction matrixes of two potyviruses based on the yeast two-hybrid system. | a map for the interactions of the major proteins from potato virus a (pva) and pea seed-borne mosaic virus (psbmv) (members of the genus potyvirus:, family potyviridae:) was generated using the yeast two-hybrid system (yths). interactions were readily detected with five pva protein combinations (hc-hc, hc-ci, vpg-vpg, nia-nib and cp-cp) and weak but reproducible interactions were detected for seven additional combinations (p1-ci, p3-nib, niapro-nib, vpg-nia, vpg-niapro, niapro-nia and nia-nia). ... | 2001 | 11257200 |
| potyviral helper-component proteinase expressed in transgenic plants enhances titers of potato leaf roll virus but does not alleviate its phloem limitation. | coinfection of nicotiana benthamiana with potato virus a (pva, a potyvirus) and potato leaf-roll virus (plrv, a luteovirus) induces a synergistic interaction manifested by enhanced titers of plrv. the helper component proteinase (hc-pro) of potyviruses is involved in viral vascular movement and suppression of an antiviral defense mechanism in plants. data of our study showed that accumulation of plrv in transgenic n. benthamiana expressing the pva hc-pro was enhanced on average by 4.5-fold, as c ... | 2001 | 11336553 |
| coat protein gene-mediated resistance to potato virus a in transgenic plants is suppressed following infection with another potyvirus. | high levels of resistance to potato virus a (pva, genus potyvirus), indicated by absence of detectable infection in inoculated leaves, were attained in nicotiana benthamiana transformed with a construct expressing the pva 5'-untranslated region fused with the coat protein (cp)-encoding sequence. low steady-state levels of the transgene transcripts were detected. resistance was pva-specific and did not protect the plants against infection with potato virus y (pvy, genus potyvirus). consequently, ... | 2001 | 11514739 |
| in situ spatial organization of potato virus a coat protein subunits as assessed by tritium bombardment. | potato virus a (pva) particles were bombarded with thermally activated tritium atoms, and the intramolecular distribution of the label in the amino acids of the coat protein was determined to assess their in situ steric accessibility. this method revealed that the n-terminal 15 amino acids of the pva coat protein and a region comprising amino acids 27 to 50 are the most accessible at the particle surface to labeling with tritium atoms. a model of the spatial arrangement of the pva coat protein p ... | 2001 | 11559802 |
| a mosaic disease of senna hirsuta induced by a potyvirus in nigeria. | a virus inducing mosaic and severe leaf malformation, isolated from senna hirsuta in nigeria, was studied. the virus had a rather narrow host range, infecting a few species in caesalpinaceae, chenopodiaceae and fabaceae families. the virus was widespread in southern nigeria with prevalence ranging from 74% to 86.4% in some locations. it was transmitted mechanically and in a non-persistent manner by myzuspersicae, aphis craccivora and a. spiraecola. there was no evidence of transmission by seeds. ... | 2001 | 11719985 |
| viral genome-linked protein (vpg) controls accumulation and phloem-loading of a potyvirus in inoculated potato leaves. | the viral protein covalently linked to the 5' end of the plus-sense, single-stranded rna genome of potyviruses (genus potyvirus) can be an avirulence determinant in incompatible potyvirus-host combinations in which the resistance prevents systemic virus infection. the mechanism is not well known. this study shows that virus strain-specific resistance to systemic infection with potato virus a (pva) in solanum commersonii is overcome by a single amino acid (aa) substitution, his118tyr, in the vira ... | 2002 | 11878318 |
| analysis of putative interactions between potyviral replication proteins and plant retinoblastoma proteins. | sequence comparisons suggest that the rna-dependent rna polymerase (nib) of potyviruses and bymoviruses, as well as the viral polymerase of potexviruses may contain a putative retinoblastoma protein (prb) binding motif. the possibility that the potyviral nib may function in the nucleus through interactions with plant prb-related (rbr) proteins, and the modifications of the cell cycle was investigated by a combination of mutagenesis of the nib and yeast two-hybrid system (yths). mutation of a hig ... | 2002 | 11930964 |
| functional genomics on potato virus a: virus genome-wide map of sites essential for virus propagation. | transposition-based in vitro insertional mutagenesis strategies provide promising new approaches for functional characterization of any cloned gene or genome region. we have extended the methodology and scope of such analysis to a complete viral genome. to map genome regions both essential and nonessential for potato virus a propagation, we generated a genomic 15-bp insertion mutant library utilizing the efficient in vitro dna transposition reaction of phage mu. we then determined the proficienc ... | 2002 | 11932242 |
| proteolytic processing of potyviral proteins and polyprotein processing intermediates in insect and plant cells. | processing of the polyprotein encoded by potato virus a (pva; genus potyvirus) was studied using expression of the complete pva polyprotein or its mutants from recombinant baculoviruses in insect cells. the time-course of polyprotein processing by the main viral proteinase (niapro) was examined with the pulse-chase method. the sites at the p3/6k1, ci-6k2 and vpg/niapro junctions were processed slowly, in contrast to other proteolytic cleavage sites which were processed at a high rate. the ci-6k2 ... | 2002 | 11961277 |
| enhanced enzyme-linked immunosorbent assay for detection of antibodies to virus-like particles of human papillomavirus. | measurement of antibodies to human papillomavirus (hpv) is complicated by many factors. although enzyme-linked immunosorbent assays (elisas) that use virus-like particles (vlps) have proved useful, the assays have, in general, had moderate sensitivities and low signal-to-noise ratios. to enhance the performance of the assay, a systematic investigation was undertaken to examine key variables used in elisas for the detection of antibodies to vlps of hpv. incorporation of two vinyl polymers, polyvi ... | 2002 | 11980956 |
| mapping of viral genomic regions important in cross-protection between strains of a potyvirus. | cross-protection was tested between potato and tobacco strains of potato virus a, a member of the genus potyvirus (pva), in tobacco plants. cross-protection was effective only at the initiation of infection. the potato strains provided only weak cross-protection against the tobacco strain, whereas the tobacco strain provided strong cross-protection against potato strains. the tamarillo strain (tammv) showed cross-protection phenotypes mostly resembling those of the potato strains. chimera of the ... | 2002 | 12118884 |
| silencing of a viral rna silencing suppressor in transgenic plants. | high expression levels of the helper component proteinase (hc(pro)), a known virus suppressor of rna silencing, were attained in nicotiana benthamiana transformed with the hc(pro) cistron of potato virus a (pva, genus potyvirus). no spontaneous silencing of the hc(pro) transgene was observed, in contrast to the pva coat protein (cp)-encoding transgene in other transgenic lines. hc(pro)-transgenic plants were initially susceptible to pva and were systemically infected by 14 days post-inoculation ... | 2002 | 12185289 |
| molecular characterization and expression analysis of 1-aminocyclopropane-1-carboxylate oxidase homologs from potato under abiotic and biotic stresses. | in this work, we report cloning of two full-length 1-aminocyclopropane-1-carboxylate oxidase (aco) cdnas (aco1 and aco2) from potato (solanum tuberosum) and their expression in potato tissues. the sequence data indicate that the two cdnas share a high degree of homology with each other, and with known aco genes from other plant species, including monocots and dicots. however, these potato genes lack homology at the 5' and 3' ends, despite similarities in their open reading frames and encoded ami ... | 2002 | 12416623 |
| detection of the potyviral genome-linked protein vpg in virions and its phosphorylation by host kinases. | the multifunctional genome-linked protein (vpg) of potato virus a (pva; genus potyvirus) was found to be phosphorylated as a part of the virus particle by a cellular kinase activity from tobacco. immunoprecipitation, immunolabeling, and immunoelectron microscopy experiments showed that vpg is exposed at one end of the virion and it is accessible to protein-protein interactions. substitution ser185leu at the c-proximal part of vpg reduces accumulation of pva in inoculated leaves of the wild potat ... | 2002 | 12438596 |
| polyclonal antibodies to a recombinant coat protein of potato virus a. | specific mouse antibodies against a recombinant coat protein (cp) of potato virus a (pva) were produced. the pva cp gene was cloned in an expression vector pmpm4omega. after expression in escherichia coli the presence of the expressed cp was proved by western blot analysis using polyclonal and monoclonal antibodies (mabs). the expressed cp was purified by centrifugation in cscl density gradient or on a sucrose cushion. the production of virus-like particles (vlps) was proved by electron microsco ... | 2002 | 12580376 |
| detection of potato viruses using microarray technology: towards a generic method for plant viral disease diagnosis. | currently, most diagnostic methodology is geared towards detection of a very specific target species and often a number of assays need to be run in parallel to reach a result. the generic methods that are available for virus testing tends to give identification to the genus level only. the method described in this paper addresses this problem by exploiting a technology that has potential to test for a large number of targets in a single assay. using the array constructed, the method was able to ... | 2003 | 12609685 |
| two potato proteins, including a novel ring finger protein (hip1), interact with the potyviral multifunctional protein hcpro. | potyviral helper-component proteinase (hcpro) is a multifunctional protein exerting its cellular functions in interaction with putative host proteins. in this study, cellular protein partners of the hcpro encoded by potato virus a (pva) (genus potyvirus) were screened in a potato leaf cdna library using a yeast two-hybrid system. two cellular proteins were obtained that interact specifically with pva hcpro in yeast and in the two in vitro binding assays used. both proteins are encoded by single- ... | 2003 | 12744511 |
| dna microarray: parallel detection of potato viruses. | dna microarray assay has become a useful tool for gene expression studies. less frequent is its application to detection of viruses or diagnostics of virus diseases. here we show design of a microscope slide-based microarray assay for simultaneous identification of several potato viruses. different primer pairs were designed or adopted to obtain specific amplicons from six potato viruses: potato virus a (pva), potato virus s (pvs), potato virus x (pvx), potato virus y (pvy), potato mop-top virus ... | 2003 | 12828343 |
| molecular resolution of a complex of potyviruses infecting solanaceous crops at the centre of origin in peru. | peru is a centre of origin and domestication of the potato, pepper and tomato (family solanaceae). many potyviruses (genus potyvirus) that infect these crops were described 20-30 years ago. however, definitive classification of these viruses as distinct species remains unresolved for several reasons, including their close serological relationships, similar symptomatology in test plants and lack of genomic sequence data. using samples collected from peru, we have determined the complete genomic s ... | 2003 | 12917478 |
| phosphorylation of the potyvirus capsid protein by protein kinase ck2 and its relevance for virus infection. | we reported previously that the capsid protein (cp) of potato virus a (pva) is phosphorylated both in virus-infected plants and in vitro. in this study, an enzyme that phosphorylates pva cp was identified as the protein kinase ck2. the alpha-catalytic subunit of ck2 (ck2alpha) was purified from tobacco and characterized using in-gel kinase assays and liquid chromatography-tandem mass spectrometry. the tobacco ck2alpha gene was cloned and expressed in bacterial cells. specific antibodies were rai ... | 2003 | 12953115 |
| localization of a potyvirus and the viral genome-linked protein in wild potato leaves at an early stage of systemic infection. | the upper noninoculated 'sink' leaves of the wild potato species, solanum commersonii, were studied for distribution of potato virus a (pva) at an early stage of systemic infection. viral rna was detected by in situ hybridization, and five viral proteins were localized using immunohistochemical staining in leaf sections. initial systemic infection foci were found at the vicinity of major and minor veins. in these infection foci, the viral coat protein, cylindrical inclusion protein, and helper c ... | 2003 | 12580279 |
| in vitro recombinants of two nearly identical potyviral isolates express novel virulence and symptom phenotypes in plants. | six novel chimeric viruses were constructed by sequentially exchanging segments of the viral genomes between the infectious cdna clone (ppva-b11) of potato virus a (isolate pva-b11) and pufl, an almost identical infectious cdna of pva (isolate u) made in this study. the infectious in vitro transcripts of pufl and ppva-b11 caused similar severe mosaic and leaf malformation phenotypes in systemically infected leaves of nicotiana benthamiana. in contrast, one chimera induced a unique phenotype of y ... | 2004 | 14993660 |
| mutations in potato virus y genome-linked protein determine virulence toward recessive resistances in capsicum annuum and lycopersicon hirsutum. | the recessive resistance genes pot-1 and pvr2 in lycopersicon hirsutum and capsicum annuum, respectively, control potato virus y (pvy) accumulation in the inoculated leaves. infectious cdna molecules from two pvy isolates differing in their virulence toward these resistances were obtained using two different strategies. chimeras constructed with these cdna clones showed that a single nucleotide change corresponding to an amino acid substitution (arg119his) in the central part of the viral protei ... | 2004 | 15000399 |
| potyviral 6k2 protein long-distance movement and symptom-induction functions are independent and host-specific. | deletion of various portions, or insertion of six histidine residues (6xhis) into various positions of the membrane-bound 6k2 protein (53 amino acids) of potato virus a (pva, genus potyvirus), inhibited systemic infection in nicotiana tabacum and n. benthamiana plants. however, a spontaneous mutation (gly2cys) that occurred in 6k2 adjacent to the 6xhis insert placed between ser1 and gly2 enabled systemic infection in a single n. benthamiana plant. no symptoms were observed, but virus titers were ... | 2004 | 15141954 |
| uridylylation of the potyvirus vpg by viral replicase nib correlates with the nucleotide binding capacity of vpg. | poty- and picornaviruses share similar genome organizations and polyprotein processing strategies. by analogy to picornaviruses it has been proposed that the genome-linked protein vpg may serve as a primer for genome replication of potyviruses. the multifunctional vpg of potato virus a (pva; genus potyvirus) was found to be uridylylated by nib, the rna polymerase of pva. the nucleotidylation activity of nib is more efficient in the presence of mn(2+) than mg(2+) and does not require an rna templ ... | 2004 | 15218030 |
| from orfeomes to protein interaction maps in viruses. | although cloned viral orfeomes are particularly well suited for genome-wide interaction mapping due to the limited size of viral genomes, only a few such studies have been published. here, we summarize virus interaction mapping projects involving vaccinia virus, hepatitis c virus (hcv), potato virus a (pva), pea seed-borne mosaic virus (psbmv), and bacteriophage t7, as well as some projects in progress. the studies reported suggest that virus-specific coding and replication strategies must be ta ... | 2004 | 15489322 |
| [investigation of helical plant virus ribonucleoprotein structures with the help of tritium planigraphy and theoretical modeling]. | the results of the studies of helical plant virus structures by tritium planigraphy (tp) method are discussed. tp method is based on bombardment of macromolecular objects with a stream of tritium atoms, followed by analysis of tritium label distribution along the macromolecule. by combining the tp data with the results of theoretical predictions of the protein structure, it turned out to be possible to propose a model of the coat protein structure in the virions of potato virus x (the type membe ... | 2004 | 15554196 |
| experimental and natural weed host-virus relations. | weeds, as alternative hosts of plant viruses and nutrient plants of virus vectors play important role in virus ecology and epidemiology. the aim of our study was to discover new weed-virus relations. therefore some weed species were mechanically inoculated with 28 viruses (strains or isolates) maintained in our glasshouse. different weed species with and without visible symptoms were collected from agro-, water ecosystems and wastelands of hungary between 1997 and 2003. virus infections were eva ... | 2004 | 15759395 |
| a viral protein suppresses sirna-directed interference in tobacco mosaic virus infection. | plant viruses encode suppressors of post-transcriptional gene silencing (ptgs), an adaptive defense response that limits virus replication and its spread in plants. the helper component proteinase (hc-pro) of the potato virus a (pva, genus potyvirus) suppresses ptgs of silenced transgenes. here, the effect of hc-pro on sirna-directed interference in the tobacco mosaic virus (tmv) was examined by using a transient agrobacterium tumefaciens-based delivery system in intact tissues. it was shown tha ... | 2005 | 15806291 |
| oligonucleotide-based microarray: a new improvement in microarray detection of plant viruses. | microarrays are one of the new emerging methods in plant virology currently being developed by various laboratories. in this study, a new approach is described on the detection of plant viruses using short synthetic single-stranded oligomers (40 nt) instead of pcr products as capture probes. a microchip detecting potato viruses, pva, pvs, pvm, pvx, pvy and plrv, in both single and mixed infections was developed and tested. the chip was also designed to distinguish between the main strains of pvy ... | 2005 | 15927276 |
| a novel insertion site inside the potyvirus p1 cistron allows expression of heterologous proteins and suggests some p1 functions. | the p1 cistron encodes the first and most variable part of the polyprotein of potyviruses. a site tolerant to a pentapeptide insertion at the n-terminus of potato virus a p1 (genome res. 12, 584-594) was used to express heterologous proteins (insertions up to 783 nucleotides) with or without flanking new proteolytic sites. aequorea victoria green fluorescent protein (gfp) accumulated to high levels when proteolytically released from p1 and showed strong fluorescence in leaves systemically infect ... | 2005 | 16112702 |
| coat proteins of two filamentous plant viruses display ntpase activity in vitro. | coat proteins (cps) of plant viruses are involved in different stages of the viral life cycle such as virion assembly, replication, movement, vector transmission, and regulation of host defense responses. here, we report that the cps of two filamentous rna viruses, potato virus x (pvx, potexvirus) and potato virus a (pva, potyvirus) exhibit an enzyme activity. the cp isolated from pvx virions possesses atp-binding and atpase activities. recombinant pvx and pva cps produced in escherichia coli sh ... | 2005 | 16115626 |
| dna vaccines based on chimeric potyvirus-like particles carrying hpv16 e7 peptide (aa 44-60). | vaccine strategies for the treatment of human papillomavirus-induced cervical cancer are based mainly on the human papillomavirus 16 e7 (hpv16 e7) oncoprotein. the immunogenicity of the e7 gene has been enhanced by its fusion to many different genes. here, we linked a short sequence coding for the e7 peptide (aa 44-60) containing immunodominant epitopes for b and t cells to the 3' end of the gene coding for the whole coat protein (cp) of the poty-virus, potato virus a (pva), and its deleted form ... | 2005 | 16142370 |
| hepatic arterial chemoembolization for hepatocellular carcinoma: comparison of survival rates with different embolic agents. | the optimal embolic agent for transhepatic arterial chemoembolization (tace) for hepatocellular carcinoma (hcc) has not been identified. this study reports outcomes of tace for hcc with gelfoam powder and polyvinyl alcohol (pva). | 2005 | 16371533 |
| an unusual structure at one end of potato potyvirus particles. | the particles of potato virus y (pvy) and potato virus a (pva) potyviruses are helically constructed filaments that are thought to contain a single type of coat protein subunit. examination of negatively stained virions by electron microscopy reveals flexuous rod-shaped particles with no obvious terminal structures. it is known that some helically constructed rod-shaped virus particles incorporate additional minor protein components, which form stable complexes that mediate particle disassembly, ... | 2006 | 16414068 |
| a potyvirus-based gene vector allows producing active human s-comt and animal gfp, but not human sorcin, in vector-infected plants. | potato virus a (pva), a potyvirus with a (+)ssrna genome translated to a large polyprotein, was engineered and used as a gene vector for expression of heterologous proteins in plants. foreign genes including jellyfish gfp (aequorea victoria) encoding the green fluorescent protein (gfp, 27 kda) and the genes of human origin (homo sapiens) encoding a soluble resistance-related calcium-binding protein (sorcin, 22 kda) and the catechol-o-methyltransferase (s-comt; 25 kda) were cloned between the cis ... | 2006 | 16431010 |
| detection of transgene copy number by analysis of the t1 generation of tobacco plants with introduced p3 gene of potato virus a. | real-time pcr, namely the deltadeltact method was used to determine the relative copy number of potato virus a (pva) p3 gene in the genome of the t1 generation of 18 transgenic tobacco lines. these results were compared with segregation ratios of kanamycin (km)-resistant phenotype in t1 plants of each line and were found to be, in general, concordant. all the five lines with the mendelian segregation ratio of 3:1 carried one gene copy. in 12 of 13 lines with uneven segregation more inserted gene ... | 2006 | 16808332 |
| expression of a part of the potato virus a non-structural protein p3 in escherichia coli for the purpose of antibody preparation and p3 immunodetection in plant material. | the n-terminal part of the potato virus a (pva) p3 protein was cloned into two e. coli fusion expression systems. an overexpression of the p3 fragment fused with thioredoxin was observed between 2 and 21 h after induction. the protein formed insoluble inclusions. decreasing the cultivation temperature did not enhance its solubility. to obtain antigen for antibody preparation, inclusions were concentrated and purified by sucrose gradient centrifugation, and subjected to sds-polyacrylamide gel ele ... | 2006 | 16876262 |
| p1- and vpg-transgenic plants show similar resistance to potato virus a and may compromise long distance movement of the virus in plant sections expressing rna silencing-based resistance. | nicotiana benthamiana was transformed with p1 or vpg cistron of potato virus a (pva, genus potyvirus). for both transgenes, t1 progeny displayed (i) resistance to pva infection, (ii) susceptibility, or (iii) systemic infection followed by recovery of new leaves from pva infection (rc), regardless of the transgene. in rc plants, fully recovered leaves contained no detectable pva rna, were highly resistant to challenge inoculation with pva, and had barely detectable steady-state levels of transgen ... | 2006 | 16298007 |
| [incidence and altitudinal distribution of 13 virus cultures in solanum tuberosum (solanaceae) from costa rica]. | a survey was conducted in 30 fields located at three different altitudes in cartago, costa rica's main potato producing area. twenty plants were sampled per farm, for a total of 600 samples with 200 samples per altitude. elisa was used with commercial reagents to independently test for pvx, pvy, pvm, pva, pvs, plrv, pmtv, pamv, pvv, pvt, aplv, apmov and trsv. the presence of the following viruses was determined: pvx (77 %), pamv (62 %), plrv (42 %), trsv (42 %), pvt (39 %), pvv (37 %), pmtv (31% ... | 2006 | 18457151 |
| vpg of potato virus a alone does not suppress rna silencing but affects virulence of a heterologous virus. | the viral genome-linked protein (vpg) is a well-known virulence factor in potyviruses (genus potyvirus), including potato virus a (pva). its ability to suppress onset and signalling of transgene-mediated rna silencing and accumulation of small interfering rna (sirna) was studied using cross-protection and agrobacterium infiltration assays and green fluorescent protein (gfp) and pva vpg protein-expressing transgenic nicotiana benthamiana plants. n. benthamiana plants were also transformed with a ... | 2007 | 16927117 |
| simultaneous detection of potato viruses, plrv, pva, pvx and pvy from dormant potato tubers by taqman real-time rt-pcr. | the requirements of sprouting dormant potato tubers for biological or serological assays or rna extraction for nucleic acid and pcr assays add to the cost of virus screening. recently, cheaper, reliable and more rapid methods for the screening of potato tuber-seed pieces for viruses have been developed that do not require sprouted tubers for indexing, including taqman real-time rt-pcr. although the assays are often designed for minimal time and reagent use, they still require a time-consuming an ... | 2007 | 17276522 |
| highly sensitive fluorescent-labeled probes and glass slide hybridization for the detection of plant rna viruses and a viroid. | in this study, a modified method of the conventional rna dot-blot hybridization was established, by replacing (32)p labels with cy5 labels and replacing nylon membranes with positive-charged glass slides, for detecting plant rna viruses and a viroid. the modified rna dot-blot hybridization method was named glass slide hybridization. the optimum efficiency of rna binding onto the surfaces of activated glass slide was achieved using aminosilane-coated glass slide as a solid matrix and 5xsaline sod ... | 2007 | 17492129 |
| potyvirus-induced gene silencing: the dynamic process of systemic silencing and silencing suppression. | potato virus a (pva; genus potyvirus) was used for virus-induced gene silencing in a model system that included transgenic nicotiana benthamiana (line 16c) expressing the gfp transgene for green fluorescent protein (gfp) and chimeric pva (pva-gfp) carrying gfp in the p1-encoding region. infection of the 16c plants with pva-gfp in five experiments resulted in a reproducible pattern of systemic gfp transgene silencing, despite the presence of the strong silencing-suppressor protein, hc-pro, produc ... | 2007 | 17622640 |
| human and avian influenza viruses target different cells in the lower respiratory tract of humans and other mammals. | viral attachment to the host cell is critical for tissue and species specificity of virus infections. recently, pattern of viral attachment (pva) in human respiratory tract was determined for highly pathogenic avian influenza virus of subtype h5n1. however, pva of human influenza viruses and other avian influenza viruses in either humans or experimental animals is unknown. therefore, we compared pva of two human influenza viruses (h1n1 and h3n2) and two low pathogenic avian influenza viruses (h5 ... | 2007 | 17717141 |
| [modified model of potato virus x coat protein structure]. | we propose the modified model of the structure of coat protein (cp) subunits in filamentous virions of potato virus x (pvx). the model is similar to the one proposed by us in 2001 for the cp of another helical plant virus (potato virus a) belonging to other (potyvirus) group. in this model the pvx cp molecule consist of two main domains--a bundle of four alpha-helices located close to the virion long axis and a so-called rnp-fold (or abcd-fold) located near the virion surface. basing on this mod ... | 2007 | 17936992 |
| no recombination detected in artificial potyvirus mixed infections and between potyvirus derived transgenes and heterologous challenging potyviruses. | risk-assessment studies of virus-resistant transgenic plants (vrtps) focussing on recombination of a plant virus with a transgenic sequence of a different virus should include a comparison of recombination frequencies between viruses in double-infected non-transgenic plants with those observed in singly infected transgenic plants to estimate recombination incidence in vrtps. in this study, the occurrence of recombination events was investigated in non-transgenic plants double-infected with two d ... | 2007 | 18001687 |
| cylindrical inclusion protein of potato virus a is associated with a subpopulation of particles isolated from infected plants. | potato virus a (pva) particles were purified by centrifugation through a 30 % sucrose cushion and the pellet (p1) was resuspended and sedimented through a 5-40 % sucrose gradient. the gradient separation resulted in two different virus particle populations: a virus fraction (f) that formed a band in the gradient and one that formed a pellet (p2) at the bottom of the gradient. all three preparations contained infectious particles that retained their integrity when visualized by electron microscop ... | 2008 | 18272775 |
| transient expression of hpv16 e7 peptide (aa 44-60) and hpv16 l2 peptide (aa 108-120) on chimeric potyvirus-like particles using potato virus x-based vector. | the optimized expression of recombinant potato virus a coat protein (acp) carrying two different epitopes from human papillomavirus type 16 (hpv16) was developed. epitope derived from minor capsid protein l2 was expressed as n-terminal fusion with acp while an epitope derived from e7 oncoprotein was fused to its c-terminus. the construct was cloned into potato x potexvirus (pvx) based vector and transiently expressed in plants using agrobacterium tumefaciens mediated inoculation. to increase the ... | 2008 | 17980618 |
| purification of viral genome-linked protein vpg from potato virus a-infected plants reveals several post-translationally modified forms of the protein. | in order to be able to analyse post-translational modifications and protein interactions of viral genome-linked protein vpg taking place during potato virus a (pva) infection, an affinity tag-based purification system was developed by inserting a sequence encoding a six-histidine and haemagglutinin (hisha) tag to the 3' end of the vpg coding sequence within the infectious cdna clone of pva. the engineered virus was fully functional and the hisha tag-encoding sequence remained stable in the pva g ... | 2008 | 18474568 |
| [one-step cytometric bead array for rapid detection of potato virus a]. | based on immunoassay, we developed a method to detect potato virus a (pva) using one-step cytometric bead array (cba). | 2008 | 18479067 |
| three heterologous proteins simultaneously expressed from a chimeric potyvirus: infectivity, stability and the correlation of genome and virion lengths. | three heterologous proteins were simultaneously expressed from a chimeric potyvirus potato virus a (pva) in nicotiana benthamiana. the genes for green fluorescent protein of aequoria victoriae ("g"; 714 nucleotides, nt), luciferase of renilla reniformis ("l", 933 nt) and beta-glucuronidase of escherichia coli ("u", 1806 nt) were inserted into the engineered cloning sites at the n-terminus of the p1 domain, the junction of p1 and helper component protein (hc-pro), and the junction of the viral re ... | 2008 | 18511144 |
| potato virus a genome-linked protein vpg is an intrinsically disordered molten globule-like protein with a hydrophobic core. | genome-linked protein vpg of potato virus a (pva; genus potyvirus) has essential functions in all critical steps of pva infection, i.e. replication, movement, and virulence. structural features of the recombinant pva vpg were investigated with the aim to create an outline for structure-function relationships. circular dichroism data of pva vpg revealed a distinct near-uv spectrum indicating that the environment around its aromatic residues is structured but rather flexible, and a far-uv spectrum ... | 2008 | 18533220 |
| control of nuclear and nucleolar localization of nuclear inclusion protein a of picorna-like potato virus a in nicotiana species. | the multifunctional nuclear inclusion protein a (nia) of potyviruses (genus potyvirus; potyviridae) accumulates in the nucleus of virus-infected cells for unknown reasons. in this study, two regions in the viral genome-linked protein (vpg) domain of nia in potato virus a (pva) were found to constitute nuclear and nucleolar localization signals (nls) in plant cells (nicotiana spp). amino acid substitutions in both nls i (residues 4 to 9) and nls ii (residues 41 to 50) prevented nuclear localizati ... | 2009 | 19700632 |
| interaction of a potyviral vpg with anionic phospholipid vesicles. | the viral genome-linked protein (vpg) of potato virus a (pva) is a multifunctional protein that belongs to a class of intrinsically disordered proteins. typically, this type of protein gains a more stable structure upon interactions or posttranslational modifications. in a membrane lipid strip overlay binding assay, pva vpg was found to bind phosphatidylserine (ps), but not phosphatidylcholine (pc). according to circular dichroism spectroscopy, the secondary structure of pva vpg was stabilized u ... | 2009 | 19800647 |
| renilla luciferase-based quantitation of potato virus a infection initiated with agrobacterium infiltration of n. benthamiana leaves. | a quantitation method based on the sensitive detection of renilla luciferase (rluc) activity was developed and optimized for potato virus a (pva; genus potyviridae) gene expression. this system is based on infections initiated by agrobacterium infiltration and subsequent detection of the translation of pva::rluc rna, which is enhanced by viral replication, first within the cells infected initially and later by translation and replication within new cells after spread of the virus. firefly lucife ... | 2010 | 20026122 |
| hsp70 and its cochaperone cpip promote potyvirus infection in nicotiana benthamiana by regulating viral coat protein functions. | this study demonstrates that heat shock protein 70 (hsp70) together with its cochaperone cpip regulates the function of a potyviral coat protein (cp), which in turn can interfere with viral gene expression. hsp70 was copurified as a component of a membrane-associated viral ribonucleoprotein complex from potato virus a-infected plants. downregulation of hsp70 caused a cp-mediated defect associated with replication. when pva cp was expressed in trans, it interfered with viral gene expression and r ... | 2010 | 20154150 |
| handygun: an improved custom-designed, non-vacuum gene gun suitable for virus inoculation. | particle bombardment with a non-vacuum gene gun is an efficient method for transfection of plant cells with cloned viruses and initiation of virus infection. the handygun developed in this study is an improved version of a non-vacuum gene gun. bombardment parameters were studied by inoculating an infectious, 35s promoter-driven cdna of potato virus a (pva; potyvirus) to the potato clone 'a6', nicotiana benthamiana and n. tabacum as plasmid dna coated on microprojectiles (gold particles). the lar ... | 2010 | 20188761 |
| huge extrahepatic portal vein aneurysm as a late complication of liver transplantation. | a 60-year-old male underwent orthotopic liver transplantation because of hepatitis c virus related cirrhosis. after 12 d, the patient underwent re-transplantation due to primary graft non function. one year later the patient developed a thrombosis of the main portal vein needing a surgical revision. after 11 years the patient was operated on because of a clinical picture of intestinal occlusion. as an incidental finding, a large aneurysm of the main portal vein was diagnosed. the incidence of in ... | 2010 | 21160997 |
| structural flexibility allows the functional diversity of potyvirus genome-linked protein vpg. | several viral genome-linked proteins (vpgs) of plant viruses are intrinsically disordered and undergo folding transitions in the presence of partners. this property has been postulated to be one of the factors that enable the functional diversity of the protein. we created a homology model of potato virus a vpg and positioned the known functions and structural properties of potyviral vpgs on the novel structural model. the model suggests an elongated structure with a hydrophobic core composed of ... | 2010 | 21177813 |
| helper component proteinase of genus potyvirus is an interaction partner of translation initiation factors eif(iso)4e and eif4e that contains a 4e binding motif. | the multifunctional helper component proteinase (hcpro) of potyviruses (genus potyvirus; potyviridae) shows self-interaction and interacts with other potyviral and host plant proteins. host proteins that are pivotal to potyvirus infection include the eukaryotic translation initiation factor eif4e and the isoform eif(iso)4e, which interact with viral genome-linked protein (vpg). here we show that hcpro of potato virus a (pva) interacts with both eif4e and eif(iso)4e, with interactions with eif(is ... | 2011 | 21525344 |
| potyviral vpg enhances viral rna translation and inhibits reporter mrna translation in planta. | viral protein genome-linked (vpg) plays a central role in several stages of potyvirus infection. this study sought to answer questions about the role of potato virus a (pva; genus potyvirus) vpg in viral and host rna expression. when expressed in nicotiana benthamiana leaves in trans, a dual role of vpg in translation is observed. it repressed the expression of monocistronic luciferase (luc) mrna and simultaneously induced a significant upregulation in the expression of both replicating and nonr ... | 2011 | 21697470 |
| Resistance to multiple viruses in transgenic tobacco expressing fused, tandem repeat, virus-derived double-stranded RNAs. | Transgenic tobacco plants expressing fused, tandem, inverted-repeat, double-stranded RNAs derived either from the three viruses [potato virus Y (PVY), potato virus A (PVA), and potato leafroll virus (PLRV)] or the five viruses [PVY, PVA, PLRV as well as tobacco rattle virus (TRV), and potato mop-top virus (PMTV)] were generated in this study to examine whether resistance could be achieved against these three viruses or five viruses, respectively, in the same plant. The transgenic lines were engi ... | 2011 | 21853332 |
| [preparation and identification of a recombinant hepatitis c virus (hcv) based on sindbis virus vector]. | to construct the recombinant virus-like particles containing hcv envelope glycoprotein e1e2 based on sindbis virus vector. | 2012 | 23002557 |
| distribution patterns of influenza virus receptors and viral attachment patterns in the respiratory and intestinal tracts of seven avian species. | this study assessed the presence of sialic acid α-2,3 and α-2,6 linked glycan receptors in seven avian species. the respiratory and intestinal tracts of the chicken, common quail, red-legged partridge, turkey, golden pheasant, ostrich, and mallard were tested by means of lectin histochemistry, using the lectins maackia amurensis agglutinin ii and sambucus nigra agglutinin, which show affinity for α-2,3 and α-2,6 receptors, respectively. additionally, the pattern of virus attachment (pva) was eva ... | 2012 | 22489675 |