Publications

electron microscopy of host cells infected with tobacco etch virus. ii. fine structures of leaf cells before and after the appearance of external systems.		1964	14197607
cylindrical inclusions in the cytoplasm of leaf cells infected with tobacco etch virus.	combined tracings from electron micrographs of serial sections of leaf tissue infected with tobacco etch virus show that one type of cytoplasmic inclusion, when sectioned in different planes, can produce configurations which have been interpreted as being two distinct types of inclusion bodies.	1966	17780650
some properties of tobacco etch virus and its alkaline degradation products.		1966	4956897
electron microscopy of host cells infected with tobacco etch virus. 3. intranuclear modifications of leaves at an early stage of infection.		1966	5932835
physiology of tobacco etch virus-induced wilt of tabasco peppers.		1967	6017400
electron microscopy of host cells infected with tobacco etch virus. iv. tritiated uridine and leucine uptake of intracellular virus and intranuclear crystalline inclusions.		1967	6039962
electron microscopy of mixed infections with two plant viruses. i. intracellular interactions between tobacco mosaic virus and tobacco etch virus.		1967	6039964
electron microscopy of subtilisin-treated tobacco etch virus nuclear and cytoplasmic inclusions.		1968	5677120
tobacco etch virus cylindrical inclusions: antigenically unrelated to the causal virus.		1969	4891219
some of the chemical properties of the tobacco etch virus and its protein and nucleic acid components.		1970	5411195
partial purification of inclusions induced by tobacco etch virus and potato virus y.		1971	4107552
partial purification and some properties of tobacco etch virus induced intranuclear inclusions.		1974	4213287
ultrastructure of the crystalline inclusion induced by tobacco etch virus visualized by freeze-etching.		1974	4834848
experimental mixed infection with two tick-borne viruses and interferon-mediated interference.	tick-borne encephalitis virus (tev), a flavivirus, and lipovník virus (lv), a member of the kemerovo group and complex and possible member of the rioviridae, were used to infect chick embryo cell (cec) cultures. lv reproduction was inhibited by preinfection with tev, mainly in aged cultures. in young cec cultures, tev production was stimulated slightly and interferon was sometimes depressed by this superinfection; on the contrary, in aged cultures the superinfecting lv stimulated interferon also ...	1975	235191
suppression of an arenavirus by a togavirus in experimental acute double infection.	lymphocytic choriomeningitis virus (lcmv) and tick-borne encephalitis virus (tev) were inoculated in young and old chick embryo cell (cec) and in l-cell cultures at various multiplicities per cell, simultaneously or 17 hr apart. the yield of infective lcmv was inhibited in double infection, most in old cec with elevated interferon mechanisms, and least in l cells producing no interferon. in young cec, tev-induced interferon was stimulated by coinfecting lcmv; lcmv alone never has induced interfe ...	1978	30264
viral superinfection in cells carrying an arenavirus and/or a togavirus.	four lines of the same l-cell clone were transferred 60 times in parallel: uninfected cells, a line carrying lymphocytic choriomeningitis virus (lcmv), another one carrying tick-borne encephalitis virus (tev) and one carrying both viruses. in double persistency, lcm and tev were suppressed and stimulated, respectively. cell multiplication rates were comparable in all four lines. single lcmv persistence caused marked resistance of l cells to superinfecting viruses from various taxonomic groups, b ...	1978	35946
selective resistance to togaviral superinfection in mice with tolerant lymphocytic choriomeningitis virus infection.	mice infected neonatally with lymphocytic choriomeningitis virus (lcmv) developed partial and complete resitance to cerebral superinfection with tick-borne encephalitis virus (tev) in 10 and 20 days after birth, respectively. this resistance lasted at least till the age of 40 days. lcmv tolerant mice neither succumbed to tev infection, nor circulated tev in their blood. moderate, gradually decreasing tev titres were detected in the brains and tev-induced brain interferon was lower than in contro ...	1979	42297
the rna of tobacco etch virus contains poly(a).		1979	425327
translation of potyvirus rna in a rabbit reticulocyte lysate: reaction conditions and identification of capsid protein as one of the products of in vitro translation of tobacco etch and pepper mottle viral rnas.	rnas of pepper mottle virus (pemv) and tobacco etch virus (tev) were efficient messengers when translated in the rabbit reticulocyte lysate system. viral rna (39 s) isolated from sucrose density gradients stimulated [35s]methionine incorporation into products precipitated by trichloroacetic acid 15- to 20-fold over endogenous background levels. optimal reaction conditions for in vitro translation contained 2 mug rna/30 mul reaction assay, 0.8-1.0 mm magnesium ions, and 100-125 mm potassium ions. ...	1980	18631642
translation of potyvirus rna in a rabbit reticulocyte lysate: identification of nuclear inclusion proteins as products of tobacco etch virus rna translation and cylindrical inclusion protein as a product of the potyvirus genome.	the translations of tobacco etch virus (tev) rna and pepper mottle virus (pemv) rna in the mrna-dependent rabbit reticulocyte lysate produced products which comigrated with potyviral inclusion proteins on polyacrylamide gels. the tev rna translation products comigrating with the 49,000 and 54,000 molecular weight tev nuclear inclusion proteins were also immunoprecipitated by antisera specific to the nuclear inclusion proteins. the proteolytic peptide map of the comigrating in vitro translation p ...	1980	18631661
translation of potyvirus rna in a rabbit reticulocyte lysate: cell-free translation strategy and a genetic map of the potyviral genome.	the translations of tobacco etch virus (tev) rna and pepper mottle virus (pemv) in a rabbit reticulocyte lysate were analyzed to determine the effect of rna quality on template activity and to identify all the products of the potyviral genome. the size distribution of the in vitro translation products, as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page), was dependent on rna quality. full-length rna stimulated the cell-free synthesis primarily of a 87,000 (87k) mo ...	1980	18631662
in vitro translation of tobacco etch virus rna.	the wheat-embryo-derived cell-free system was optimized for translation of tobacco etch virus (tev) rna. when examined by polyacrylamide gel electrophoresis, the product of the tev rna stimulated system proved to be a single protein with a molecular weight of 40,000. this finding is different from results obtained when tev rna is used as a template in the rabbit reticulocyte lysate in vitro protein-synthesizing system.	1980	18631719
the rna of tobacco etch virus: further characterization and detection of protein linked to rna.	tev-rna was separated into poly(a)+ and poly(a)- rna by affinity chromatography. both classes of rna have similar base ratios. the poly(a) segment in the rna was shown to be located at the 3'-oh end by dihydroxyborylaminoethyl-cellulose chromatography. although the poly(a) was heterodisperse in length, ranging from about 200 to less than 33 amp residues, two size classes averaging about 150 and 30 amp residues, respectively, could be recognized. the presence of a genome-linked protein of molecul ...	1981	18635072
cell-free translation of tobacco vein mottling virus rna. ii. immunoprecipitation of products by antisera to cylindrical inclusion, nuclear inclusion, and helper component proteins.	the genomic rna of tobacco vein mottling virus (tvmv) was translated in a cell-free system derived from rabbit reticulocytes. antisera against tvmv coat protein, tvmv cylindrical inclusions, the helper component required for aphid transmission of tvmv, and the 49- and 54-kd nuclear inclusion proteins of tobacco etch virus (tev) were used to characterize the translational products. each of the five antisera precipitated a distinctive pattern of polypeptides. specificity of immunoprecipitation was ...	1983	18638869
detection and cell-free translation of subgenomic rnas of tobacco etch virus.	rna extracted from purified tobacco etch virus and virus-infected tissue was examined by the northern hybridization technique and found to contain several subgenomic-sized viral rna species in addition to the 3 x 10(6) mw genomic rna. of the 10 subgenomic-sized rnas detected (2.03, 1.24, 1.14, 1.01, 0.84, 0.62, 0.55, 0.46, 0.34, and 0.28 x 10(6) mw), 4 were found in both virion rna and infected tissue rna, 3 others only in virion rna, and 3 only in infected tissue rna. of the last three, two may ...	1983	18638889
helper components of two potyviruses are serologically distinct.	the specificity of antisera to helper component (hc) from tobacco vein mottling virus (tvmv)- or potato virus y (pvy)-infected tobacco plants was tested in immunoprecipitation and immunoabsorption chromatography experiments. treatment with the homologous antiserum abolished or drastically reduced the activity of either tvmv-hc or pvy-hc, as measured by their ability to effect aphid transmission of purified tobacco etch virus, while the heterologous antiserum had little or no effect on hc activit ...	1983	18638913
analysis of viral rna isolated from tobacco leaf tissue infected with tobacco etch virus.	total rna has been isolated from tobacco seedlings systemically infected with the potyvirus, tobacco etch virus (tev). analysis of this rna by agarose gel electrophoresis under denaturing conditions, in conjunction with gel hybridization using various virus-specific nucleic acid probes, revealed genomic length tev rna and eight zones of less-than-full-length rna. however, reconstitution experiments demonstrated that the zones were electrophoretic artifacts and not authentic subgenomic rnas. furt ...	1983	18639175
translation of soybean mosaic virus rna in vitro: evidence of protein processing.	the genomic rna of soybean mosaic virus (smv), a member of the potyvirus group of plant viruses, was translated in both the wheat germ and reticulocyte cell free systems to identify some viral encoded proteins and as an approach to determining the translational strategy of the virus. the rna was translated into the same specific set of 10 to 12 polypeptides in both in vitro systems. immunological tests and peptide analyses indicate that six translation products are related to smv coat protein, a ...	1984	18639801
immunoprecipitation analysis of potyviral in vitro translation products using antisera to helper component of tobacco vein mottling virus and potato virus y.	the serological relationships of the products of in vitro translation of the rna of various potyviruses were analyzed by using antisera to helper component (hc) from tobacco plants infected with either tobacco vein mottling virus (tvmv) or potato virus y (pvy). the pvy-hc antiserum immunoprecipitated a specific pvy-rna translation product; this product was not reactive with antisera to pvy-induced cylindrical inclusion protein or capsid protein or to the two tobacco etch virus nuclear inclusion ...	1984	18639815
isolation and partial characterization of the amorphous cytoplasmic inclusions associated with infections caused by two potyviruses.	the potyviruses pepper mottle (pemv) and watermelon mosaic virus-1, a strain of papaya ringspot (prsv-w), induce the formation of a second type of cytoplasmic inclusion in addition to cylindrical (pinwheel) inclusions. the conspicuous aggregates of electron-dense material with imperfect spherical shapes have been called amorphous inclusions (ai). the ai were isolated from extracts of infected tissue using a combination of clarification with triton x-100 and low-speed centrifugations through sucr ...	1985	18639842
topographic analysis of tobacco etch virus capsid protein epitopes.	monoclonal antibodies have been prepared, which react with capsid protein of an aphid-transmitted isolate of tobacco etch virus (tev). ten different monoclonal antibodies were characterized with reference to (1) antibody class, (2) reactivity with different plant virus antigens, (3) the spatial relationship between epitopes, and (4) whether these epitopes were located on the exterior surface of the virion. three monoclonal antibodies were specific for tev isolates. these monoclonal antibodies re ...	1985	18640514
biochemical analysis of the capsid protein gene and capsid protein of tobacco etch virus: n-terminal amino acids are located on the virion's surface.	the sequence of the 1491 nucleotides found at the 3' end of the genome of the highly aphid-transmissible (hat) isolate of tobacco etch virus (tev) has been determined. the nucleotide sequence of the capsid protein gene has been identified and compared with the corresponding region of the not-aphid-transmissible (nat) isolate of tev and with pepper mottle virus (pemv). the deduced amino acid sequences of the two tev capsid proteins displayed 98% homology and a 66% homology with pemv capsid protei ...	1985	18640560
sequence determination of the capsid protein gene and flanking regions of tobacco etch virus: evidence for synthesis and processing of a polyprotein in potyvirus genome expression.	the nucleotide sequence of the 3'-terminal portion of the tobacco etch virus (tev) genome was determined. the 2324-nucleotide sequence represented approximately one-fourth of the tev genome and included the capsid protein gene and flanking regions. an open reading frame of 2135 nucleotides and an untranslated region of 189 nucleotides adjacent to a polyadenylate tract were identified. the sequence began within an open reading frame, indicating that the initiation codon was upstream of the availa ...	1985	16593574
complementary dna cloning and expression of the papaya ringspot potyvirus sequences encoding capsid protein and a nuclear inclusion-like protein in escherichia coli.	three cdna clones that express viral gene products in escherichia coli jm83 were derived from a watermelon mosaic virus-1 strain of papaya ringspot virus (prsv-w). dnas complementary to portions of the viral rna were inserted into the puc8 and puc9 plasmids, and the expressed polypeptides were fusion products with the amino terminus of beta-galactosidase. clones w1-77 and w2-1 expressed fusion products with apparent molecular weights of 40,000 (40k) and 14k, respectively, which were serologicall ...	1985	2998020
association of tobacco etch virus related rna with chloroplasts in extracts of infected plants.	the rna in various subcellular fractions of tobacco etch virus (tev) infected tissue was analyzed for the presence of complementary viral rna, and double-stranded viral rna by hybridization with 32p-labeled viral rna or cdna probes. although viral rna was detected in several cellular fractions, the complementary rna of full-length size was found exclusively associated with fractions containing chloroplasts. treatment of rnas with rnase before hybridization suggested that the virus-related comple ...	1986	3952987
construction of a recombinant vaccinia virus which expresses immunoreactive plant virus proteins.	a chimeric transcription unit was assembled consisting of a vaccinia virus promoter linked to a 2400 bp(3) double-stranded complementary dna (cdna) made to the 3' end of the genomic rna of the plant pathogen, tobacco etch virus (tev). marker rescue techniques were used to introduce virus recombinant genes into the vaccinia virus genome. the recombinant virus (designated wnat) was isolated, purified, and subjected to molecular genetic analyses. the ability of wnat to direct the expression of plan ...	1986	18640593
coat protein of potyviruses. 2. amino acid sequence of the coat protein of potato virus y.	the amino acid sequence of the coat protein of potato virus y (pvy), the type member of the potyvirus group, has been determined by protein sequencing techniques. the protein contains 267 amino acid residues with a calculated mol wt of 29,945. a comparison of the pvy coat protein sequence with those of tobacco etch virus (tev) and pepper mottle virus (pemv) predicted from nucleotide sequence data (r. f. allison, j. g. sorenson, m. e. kelly, f. b. armstrong, and w. g. dougherty, proc. natl. acad. ...	1986	18640638
the effect of helper component on the uptake and localization of potyviruses in myzus persicae.	125i-labeled virions were used to determine whether helper component (hc) affected the uptake or distribution of potyviruses in aphids. aphids were allowed to acquire purified, 125i-labeled tobacco etch virus or potato virus y mixed with hc or with inactivated hc. helper component had no effect upon uptake of labeled virus, as measured by gamma counting. autoradiography of freeze-sectioned aphids revealed, however, that in the presence of hc, label was associated with the maxillary stylets and w ...	1986	18640647
the nucleotide sequence of the coding region of tobacco etch virus genomic rna: evidence for the synthesis of a single polyprotein.	the complete nucleotide sequence of the tobacco etch virus (tev) rna genome has been determined excepting only the nucleotide(s) present at the extreme 5' terminus. the assembled tev genomic sequence is 9496 nucleotides in length followed by a polyadenylated tract ranging from 20 to 140 residues. a computer search of the sequence reveals the following. a 5' untranslated region, rich in adenosine and uridine, is present between nucleotides 1 and 144. a putative initiation codon, at nucleotides 14 ...	1986	18640649
potyviral proteins share amino acid sequence homology with picorna-, como-, and caulimoviral proteins.	the predicted amino acid sequences of the polyproteins of two potyviruses, tobacco vein mottling virus (tvmv) and tobacco etch virus (tev), were compared to each other, to proteins of other viruses, and to the national biomedical research foundation protein sequence bank. three potyviral proteins, the cylindrical inclusion and the two nuclear inclusion proteins, were found to be homologous to proteins considered to be involved in the replication and expression of picorna- and comovirus rna. a lo ...	1987	18644561
processing of the tobacco etch virus 49k protease requires autoproteolysis.	the final products encoded by the tobacco etch virus genome arise by proteolytic cleavage of a single large polyprotein precursor. processing of the polyprotein at several sites requires the activity of a viral protease of 49,000 molecular weight (49k). we have examined the excision of the 49k protease from polyproteins translated from defined rna transcripts. polyproteins containing an intact 49k protein were efficiently processed after synthesis in a rabbit reticulocyte lysate to yield the 49k ...	1987	18644573
small nuclear inclusion protein encoded by a plant potyvirus genome is a protease.	tobacco etch virus, a plant potyvirus, expresses its rna genome as a large polyprotein precursor which undergoes extensive proteolytic processing to yield seven or more mature products. two of these products, proteins with apparent molecular weights of 49,000 and 54,000 (49k and 54k proteins), aggregate in the form of crystalline inclusions within the nuclei of infected cells. cell-free translation of synthetic transcripts was used to map the genes for these two products on the viral genome and ...	1987	16789265
interaction of tobacco etch or tobacco vein mottling virus and ozone on biomass changes in burley tobacco.	burley tobacco is susceptible to several different types of virus diseases that suppress plant growth and development. two viruses, tobacco etch virus (tev) and tobacco vein mottling virus (tvmv), are particularly damaging to burley. burley tobacco cultivars resistant to these two viruses are currently being developed. some of these cultivars also show differential sensitivity to ozone (o3). recent field observations have suggested that burley tobacco infected with tev and tvmv was more sensitiv ...	1988	15092551
coat protein of potyviruses. 5. symptomatology, serology, and coat protein sequences of three strains of passionfruit woodiness virus.	three strains of passionfruit woodiness virus, tip blight (pwv-tb), severe (pwv-s) and mild (pwv-m), were compared on the basis of their biological, serological and coat protein structural properties. each of the strains could be distinguished on the basis of their reactions on selected test plant species but no differences were observed in the serological properties of the three pwv strains. molecular weight estimates on sds-page suggest the pwv coat protein contains 275 amino acid residues and ...	1988	3202695
a viral cleavage site cassette: identification of amino acid sequences required for tobacco etch virus polyprotein processing.	mature viral-encoded proteins of tobacco etch virus (tev) arise by proteolytic processing of a large precursor. the proteinase responsible for most of these cleavages is a viral-encoded 49-kda protein. all known or predicted cleavage sites in the tev polyprotein are flanked by the conserved sequence motif glu-xaa-xaa-tyr-xaa-gln-ser or gly, with the scissile bond located between the gln-ser or gly dipeptide. by using cell-free systems to manipulate and express cloned cdna sequences, a 25-amino a ...	1988	3285343
mutational analysis of tobacco etch virus polyprotein processing: cis and trans proteolytic activities of polyproteins containing the 49-kilodalton proteinase.	the genome of tobacco etch virus contains a single open reading frame with the potential to encode a 346-kilodalton (kda) polyprotein. the large polyprotein is cleaved at several positions by a tobacco etch virus genome-encoded, 49-kda proteinase. the locations of the 49-kda proteinase-mediated cleavage sites flanking the 71-kda cytoplasmic pinwheel inclusion protein, 6-kda protein, 49-kda proteinase, and 58-kda putative polymerase have been determined by using cell-free expression, proteolytic ...	1988	3286889
mapping of the tobacco vein mottling virus vpg cistron.	the location of the cistron encoding the genome-linked protein (vpg) in the potyvirus tobacco vein mottling virus (tvmv) was investigated. precipitation of 125i-labeled vpg with anti-tobacco etch virus 49k nuclear inclusion protein antiserum (which reacts with the nia nuclear inclusion protein of tvmv) indicated that the tvmv vpg is immunologically related to nia. lysyl residues were found to be present at positions 2, 11, and 16 of the amino-terminal region of the vpg. a search of the tvmv poly ...	1988	3354210
biochemical and mutational analysis of a plant virus polyprotein cleavage site.	the rna genome of tobacco etch virus (tev) is organized as a single translational unit coding for a 346,000 (346 kd) mol. wt (mr) polyprotein. the 346 kd mr polyprotein is cleaved by a 49 kd mr virus-encoded proteinase at five different sites between the dipeptides gln-ser or gln-gly. these cleavage sites or gene product boundaries are defined by the heptapeptide sequence...glu-xaa-xaa-tyr-xaa-gln-ser or gly.... we have used the 54 kd mr nuclear inclusion protein/30 kd mr capsid protein junction ...	1988	3409865
antibody-mediated activation of sindbis virus.	the biological activity of an anti-sindbis monoclonal antibody (mcab 49) has been explored. the antibody recognizes an epitope on the e2 glycoprotein of sindbis virus and, in the presence of complement (c'), neutralizes virus infectivity. in the absence of c', reaction of the antibody with our laboratory strain of sindbis, sb, increased the number of plaque-forming units (pfu) detected on baby hamster kidney (bhk) cells rather than neutralizing virus infectivity. the elevated titers of sb approa ...	1988	3413988
characterization of the catalytic residues of the tobacco etch virus 49-kda proteinase.	the 49-kda proteinase of tobacco etch virus (tev) cleaves the polyprotein derived from the tev genomic rna at five locations. molecular genetic and biochemical analyses of the 49-kda tev proteinase were performed to test its homology to the cellular trypsin-like serine proteases. a cdna fragment, containing the tev 49-kda proteinase gene and flanking sequences, was expressed in a cell-free transcription/translation system and resulted in the formation of a polyprotein precursor that underwent ra ...	1989	2475971
a second proteinase encoded by a plant potyvirus genome.	the rna genome of tobacco etch virus (tev) encodes a large polyprotein precursor that is processed to mature proteins by virus-specific proteinases. cleavage sites located within the carboxyl-terminal two-thirds of the polyprotein are processed by a tev-encoded 49 kd proteinase, while the enzyme(s) responsible for cleaving the remaining sites has not been found. in this study, a second tev-encoded proteinase has been identified based on cell-free expression of defined rna transcripts. the bounda ...	1989	2656254
artificial cleavage site recognized by plum pox potyvirus protease in escherichia coli.	a synthetic plum pox virus (ppv) nib-cp cleavage site was recognized by a ppv protease in an in vivo escherichia coli expression system. the presence of the natural nib-cp cleavage site did not affect processing at the artificial one. however, although both the proteases and the cleavage sites of ppv and tobacco etch virus show high sequence homology, a similar cassette from the tobacco etch virus nib-cp junction was not efficiently recognized by the ppv protease.	1989	2657098
molecular genetic analysis of a plant virus polyprotein cleavage site: a model.	the rna genome of tobacco etch virus (tev) is expressed as a polyprotein which is co- and post-translationally processed by viral encoded proteinases. the tev 49,000 dalton (49-kda) proteinase cleaves the polyprotein at five positions each defined by the seven amino acid consensus sequence, (formula; see text) one of the cleavage sites, the 58-kda nuclear inclusion/30-kda capsid protein junction was altered by site-directed mutagenesis and the effects of these alterations on cleavage were determ ...	1989	2669323
molecular cloning, sequencing and expression in escherichia coli of the bean yellow mosaic virus coat protein gene.	the sequence of 1015 nucleotides from the 3' poly(a) tract of the potyvirus bean yellow mosaic virus (bymv) rna has been determined from two cdna clones. this sequence contained a single long open reading frame (orf) starting upstream of the cloned region. the orf was expressed as a fusion protein in escherichia coli, and the product was detected by antibodies specific for the coat protein of bymv. the predicted length of the coat protein gene was 822 nucleotides, corresponding to a 273 amino ac ...	1989	2671258
molecular genetic and biochemical evidence for the involvement of the heptapeptide cleavage sequence in determining the reaction profile at two tobacco etch virus cleavage sites in cell-free assays.	potyviruses express their genetic information from a genome length rna as a single polyprotein, which is post-translationally processed by at least two different viral-encoded proteolytic activities. since regulation of the expression of individual genes is not likely to occur at the transcriptional level, we sought to determine if post-translational regulation of gene expression was possible via differential proteolytic processing. modulating the rate of cleavage at different gene product junct ...	1989	2672562
autocatalytic processing of the potyvirus helper component proteinase in escherichia coli and in vitro.	the virus-encoded proteins of tobacco etch virus (tev), a plant potyvirus, arise by proteolytic processing of a large polyprotein precursor. the tev genome codes for two proteinases, a 49-kilodalton proteinase and helper component proteinase (hc-pro), which cleave the polyprotein at specific sites. the only known cleavage event catalyzed by hc-pro occurs at the hc-pro carboxyl terminus. the proteolytic activity of hc-pro was analyzed by expression of the enzyme in bacterial and cell-free systems ...	1989	2674480
generation and characterization of monoclonal antibodies reactive with the 49-kda proteinase of tobacco etch virus.	monoclonal antibodies (mcabs) were generated against two tobacco etch virus (tev)-encoded nonstructural proteins, the 49-kilodalton (kda) proteinase and the 58-kda putative rna-dependent rna polymerase. this process was facilitated by the fact that these two tev nonstructural proteins cocrystallize in the nuclei of virus-infected cells to form nuclear inclusion (ni) bodies which can be purified readily. the anti-ni mcabs were shown by western blot analysis to be specific for either the tev 49-kd ...	1989	2688299
identification of essential residues in potyvirus proteinase hc-pro by site-directed mutagenesis.	two virus-encoded proteinases are responsible for proteolysis of potyvirus polyproteins. one of these, hc-pro, is a multifunctional protein that autolytically cleaves at its carboxyl-terminus (j.c. carrington et al., 1989, embo j. 8, 365-370). to identify the class of proteinase to which hc-pro belongs, tobacco etch virus (tev) hc-pro mutants containing single amino acid substitutions at serine, cysteine, aspartic acid, and histidine positions were synthesized by in vitro transcription and trans ...	1989	2688301
nucleotide sequence of the 3'-terminal region of potato virus yn rna.	the sequence of the 3'-terminal 1611 nucleotides of the genome of the tobacco veinal necrosis strain of potato virus y (pvyn) was determined. the sequence revealed an open reading frame of 1285 nucleotides, of which the start was not identified, and an untranslated region of 316 nucleotides upstream of a poly(a) tract. comparison of the open reading frame with the amino-terminal sequence of the viral coat protein enabled mapping of the start of the coat protein at amino acid -267, and indicated ...	1989	2732687
the complete nucleotide sequence of plum pox virus rna.	the complete nucleotide sequence of the rna of an aphid non-transmissible plum pox virus (ppv-nat) isolate has been determined from five overlapping cdna clones. cdna prepared by primer extension was used to determine the 5' terminus. the assembled rna is 9741 nucleotides in length, excluding a 3' terminal poly(a) sequence. one large open reading frame starts at nucleotide positions 36 to 38 and is terminated with an uag codon at positions 9522 to 9524. the putative start codon is located at pos ...	1989	2732699
nucleotide sequence of potato virus y (n strain) genomic rna.	the complete nucleotide sequence of the genomic rna of the potyvirus potato virus y strain n (pvyn) was obtained from cloned cdnas. this sequence is 9704 nucleotides long and can encode a polyprotein of 3063 amino acids. the positions of the cleavage sites at the n terminus of the capsid and cytoplasmic inclusion proteins have been determined. other putative protein cleavage sites have been deduced by searching for consensus sequences and by analogy with the polyprotein of the tobacco vein mottl ...	1989	2732709
the complete nucleotide sequence of plum pox potyvirus rna.	the complete nucleotide sequence of the plum pox virus (ppv) rna genome has been determined. the rna sequence is 9786 nucleotides in length, excluding the 3'-terminal poly(a) tail. an aug triplet at position 147-149 was assigned as the initiation codon for the translation of the genome size viral polyprotein which would consist of 3140 amino acid residues. the nucleotide sequence of the non-coding regions and the predicted amino acid sequence of the polyprotein of ppv were compared with those pr ...	1989	2773595
the genome-linked protein and 5' end rna sequence of plum pox potyvirus.	the infectivity of plum pox potyvirus (ppv) rna was decreased by treatment with proteases. ribonuclease digestion of iodinated ppv rna yielded material which had an electrophoretic mobility corresponding to mr 22,000. this protein presumably corresponds to the protease-sensitive structure needed for infectivity. a protein-linked rnase t1-resistant oligonucleotide, 38 nucleotides long, was sequenced and shown to correspond to the 5' terminus of the rna by sequence comparison to the rnas of two ot ...	1989	2794981
the establishment of rat hybridoma cell lines secreting mcab against strains of potato virus y and analysis of its stability.	the rat splenocytes immunized with potato virus y (pvyn) and ratmyeloma (ir983) were fused by peg (m. w.1450). three kinds of stable hybridoma cell lines secreting specific monoclonal antibodies (mcabs) were derived. one kind of the cell lines producing mcabs reacts to pvyn specifically. another reacts to pvyo specifically. the third one reacts to both of the two strains. tested by the methods of sandwich-elisa and indirect-elisa, all kinds of mcabs did not react to seven plant viruses: tobacco ...	1990	2104212
nuclear transport of plant potyviral proteins.	we have used immunoblotting, immunocytochemical, and gene fusion methods to examine the differential subcellular partitioning of tobacco etch potyvirus proteins that are potentially associated with rna replication. from the earliest timepoints at which viral proteins could be detected, proteins nla (49-kilodalton proteinase) and nlb (58-kilodalton polymerase) were localized primarily in the nucleus, whereas the 71-kilodalton cylindrical inclusion protein was identified in the cytoplasm. the nla ...	1990	2136629
determination of polyprotein processing sites by amino terminal sequencing of nonstructural proteins encoded by plum pox potyvirus.	nonstructural proteins of plum pox potyvirus were partially purified following a procedure described for the isolation of tobacco etch virus nuclear inclusion proteins. plum pox virus proteins with electrophoretic mobilities corresponding to 49, 59 and 68 kda reacted with antibodies against the 49 kda and 54 kda components of the nuclear inclusions and the 70 kda component of the cylindrical inclusions of tobacco etch virus, respectively. further purification by size exclusion high performance l ...	1990	2138835
expression of potyviral polyproteins in transgenic plants reveals three proteolytic activities required for complete processing.	all proteins encoded by the plant potyvirus, tobacco etch virus (tev), arise by proteolytic processing of a single polyprotein. two virus-encoded proteinases (nia and hc-pro) that catalyze most of the proteolytic events have been characterized previously. the two proteins that are derived from the n-terminal 87 kd region of the viral polyprotein are a 35 kd protein and hc-pro (52 kd). it is demonstrated in this study that a third proteolytic activity is required to process the junction between t ...	1990	2184028
a novel human immunodeficiency virus type 1 protein, tev, shares sequences with tat, env, and rev proteins.	we have characterized a novel 28-kilodalton protein, p28tev, detected in human immunodeficiency virus type 1-infected cells. tev is recognized by both tat and rev monospecific antibodies. tev is initiated at the tat aug and contains the first exon of tat at its amino terminus, a small portion of env in the middle, and the second exon of rev at its carboxy terminus. a cdna clone producing tev was cloned and expressed in human cells. sequence analysis revealed that the tev mrna is generated by spl ...	1990	2186172
the vpg of tobacco etch virus rna is the 49-kda proteinase or the n-terminal 24-kda part of the proteinase.	preparations of tobacco etch virus (tev) rna which were purified by sucrose gradient centrifugation, digested with rnase, and analyzed by sds-polyacrylamide gel electrophoresis contained proteins of 49, 32, and 24 kda. the 49- and 24-kda proteins reacted with polyclonal antiserum to the tev 49-kda proteinase while the 32-kda protein reacted with anti-tev serum. further purification of the rna by centrifugation through cscl removed the coat protein (32 kda), but not the 49- and 24-kda proteins. t ...	1990	2202147
sphere-linked immunodiagnostic assay (slida): an electron microscopic method for detecting specific antibodies.	we have developed a sensitive method, sphere-linked immunodiagnostic assay, using specific antigens covalently bonded to microspheres for the detection of antibodies in serum. in this method, specific antigens, such as the capsid proteins of tobacco mosaic virus and tobacco etch virus, were independently, covalently bonded to plastic micropheres of 0.5 microns or 0.9 microns in diameter. the antigen-linked spheres were then exposed to normal serum or serum containing specific antibody, followed ...	1990	2223076
different sites of interaction for rev, tev, and rex proteins within the rev-responsive element of human immunodeficiency virus type 1.	we have analyzed the action of the rev and tev proteins of human immunodeficiency virus type 1 (hiv-1) and of the rex protein of human t-cell leukemia virus type i (htlv-i) on a series of rev-responsive element (rre) mutants. the minimum continuous rre region necessary and sufficient for rev function was determined to be 204 nucleotides. interestingly, this region was not sufficient for tev or rex function. these proteins require additional sequences, which may stabilize the structure of the rre ...	1990	2243384
mutational analysis of plum pox potyvirus polyprotein processing by the nia protease in escherichia coli.	a binary escherichia coli expression system has been used to study the pathway for proteolytic processing of the plum pox potyvirus (ppv) polyprotein. trans cleavage at the carboxyl end of the cylindrical inclusion protein occurred, although with lower efficiency than that at the large nuclear inclusion protein-capsid protein junction. no trans cleavage at the carboxyl end of the small nuclear inclusion protein (nia) was detected. the proteolytic activities at different cleavage sites of several ...	1990	2273380
cap-independent enhancement of translation by a plant potyvirus 5' nontranslated region.	the rna genome of tobacco etch virus (tev), a plant potyvirus, functions as an mrna for synthesis of a 346-kilodalton polyprotein that undergoes extensive proteolytic processing. the rna lacks a normal 5' cap structure at its terminus, which suggests that the mechanism of translational initiation differs from that of a normal cellular mrna. we have identified a translation-enhancing activity associated with the 144-nucleotide, 5' nontranslated region (ntr) of the tev genome. when fused to a repo ...	1990	2319646
protection against detrimental effects of potyvirus infection in transgenic tobacco plants expressing the papaya ringspot virus coat protein gene.	we obtained transgenic tobacco plants expressing the papaya ringspot virus (prv) coat protein (cp) gene by transformation via agrobacterium tumefaciens. expression was effectively monitored by enzyme-linked immunosorbent assays (elisa) of crude tissue extracts. subcloned plants derived from eight original ro transformants were inoculated with potyviruses: tobacco etch (tev), potato virus y (pvy), and pepper mottle (pemv). plants that accumulated detectable levels of the prv cp showed significant ...	1991	1367635
post-translational processing of the tobacco etch virus 49-kda small nuclear inclusion polyprotein: identification of an internal cleavage site and delimitation of vpg and proteinase domains.	the 49,000-dalton (49-kda) small nuclear inclusion (ni) protein of tobacco etch virus (tev) has two distinct functions associated with it. an n-terminal segment is covalently attached to the genomic length rna and likely involved in rna replication, while the c-terminal half is associated with a proteolytic activity critical for genome expression. the junction delineating these two proteins has not been identified. we have analyzed naturally occurring cleavage products of tev ni proteins and hav ...	1991	1853555
the complete nucleotide sequence of pea seed-borne mosaic virus rna.	the complete nucleotide sequence of the rna genome of pea seed-borne mosaic virus (psbmv) was determined from cloned cdna and by direct sequencing of viral rna. the psbmv genomic sequence was determined to be 9924 nucleotides in length excluding the poly(a) tract. the rna contained an open reading frame (orf) of 9618 nucleotides with the potential to encode a polyprotein with a calculated mr of 364000 (364k). the orf was flanked by a 5' untranslated leader sequence of 143 nucleotides and a 3' un ...	1991	1940858
in vitro cleavage at or near the n-terminus of the helper component protein in the tobacco vein mottling virus polyprotein.	translation of tobacco vein mottling virus (tvmv) rna in a wheat germ system resulted in two products that were not observed in a rabbit reticulocyte system. one of these was the n-terminal protein, based on its being the most abundant product and its migration on sds-page at about 34 kda. the second product was similar or identical to helper component (hc) isolated from tvmv-infected plants, based on co-migration with hc on sds-page and immunoprecipitation with anti-hc antibodies. the n-terminu ...	1991	1962446
a temporal study of the expression of the capsid, cytoplasmic inclusion and nuclear inclusion proteins of tobacco etch potyvirus in infected plants.	young leaves of tobacco, systemically infected by tobacco etch potyvirus (tev), were examined for the presence and distribution of four virus encoded proteins [capsid, cytoplasmic inclusion (ci) and two nuclear inclusion (ni) proteins] at various time periods after inoculation of expanded leaves of the plants. the analyses were carried out by elisa and by immunogold electron microscopy of thin sections of the leaves. all four proteins were detected simultaneously in the systemic leaves for the f ...	1991	2005427
proteolytic activity of plum pox virus-tobacco etch virus chimeric nia proteases.	plasmids encoding chimeric nia-type proteases made of sequences from the potyviruses plum pox virus (ppv) and tobacco etch virus (tev) have been constructed. their proteolytic activity on the large nuclear inclusion protein (nib)-capsid protein (cp) junction of each virus was assayed in escherichia coli cells. the amino half of the protease seemed to be involved neither in the enzymatic catalysis nor in substrate recognition. in spite of the large homology among the ppv and tev nia-type protease ...	1991	2015911
substrate recognition by the nia proteinase of two potyviruses involves multiple domains: characterization using genetically engineered hybrid proteinase molecules.	the proteolytic activity associated with the small nuclear inclusion protein (nia proteinase) of tobacco etch virus (tev), a potyvirus, catalyzes several cleavages at sites within the polyprotein derived from the tev rna genome. the homologous proteinase of tobacco vein mottling virus (tvmv), a closely related potyvirus, cleaves at similar, yet distinct, recognition sites. we examined these proteinases, in a cell-free cleavage system, in an attempt to define the biochemical basis of substrate sp ...	1991	2024462
direct selection for sequences encoding proteases of known specificity.	we have developed a simple genetic selection that could be used to isolate eukaryotic cdnas encoding proteases that cleave within a defined amino acid sequence. the selection was developed by using the transcription factor gal4 from saccharomyces cerevisiae as a selectable marker, a cloned protease from tobacco etch virus (tev), and an 18-amino acid tev protease target sequence. in yeast, tev protease cleaves its target even when the target is fused to internal regions of the gal4 protein. this ...	1991	2052595
the complete nucleotide sequence of pepper mottle virus genomic rna: comparison of the encoded polyprotein with those of other sequenced potyviruses.	the complete nucleotide sequence of a pepper mottle virus isolate from california (pepmov c) has been determined from cloned viral cdnas. the pepmov c genomic rna is 9640 nucleotides excluding the poly(a) tail and contains a long open reading frame starting at nucleotide 168 and potentially encoding a polyprotein of 3068 amino acids. comparison of the pepmov c presumptive polyprotein with those of other sequenced members of the potyvirus group, including tobacco etch virus (tev), tobacco vein mo ...	1992	1413501
tagging of plant potyvirus replication and movement by insertion of beta-glucuronidase into the viral polyprotein.	infectious rna transcripts were generated from full-length cdna clones of the tobacco etch potyvirus genome containing an insertion of the bacterial beta-glucuronidase (gus) gene between the polyprotein-coding sequences for the n-terminal 35-kda proteinase and the helper component-proteinase. the recombinant virus was able to spread systemically in plants and accumulated to a level comparable with wild-type tobacco etch potyvirus. proteolytic processing mediated by the 35-kda proteinase and help ...	1992	1438210
biological variants of tobacco etch virus that induce morphologically distinct nuclear inclusions.	the presence of distinctive nuclear inclusions has been used for many years as a diagnostic character for tobacco etch virus (tev). cytological examinations of isolates of tev in both weeds and solanaceous crops from areas widely separated geographically have demonstrated the presence of a variety of nuclear inclusions that vary considerably in form. such inclusions can, in many cases, be related to differences in symptom expression. it is suggested that distinctive nuclear inclusions may be use ...	1992	1450742
is pepper mottle virus a strain of potato virus y?	on the basis of serological properties and host plant reactions pepper mottle virus (pepmov) has been classified as a potyvirus related to, but distinct from, other pepper-infecting potyviruses, potato virus y (pvy) and tobacco etch virus (tev). recent amino acid and nucleotide sequence data show that pepmov is more closely related to pvy than previously assumed. pepmov shows a high degree of homology to various pvy strains in both the coat protein and the 3' non-translated sequences, while unre ...	1992	1450759
a nuclear localization signal and the c-terminal omega sequence in the agrobacterium tumefaciens vird2 endonuclease are important for tumor formation.	the t-dna portion of the agrobacterium tumefaciens tumor-inducing (ti) plasmid integrates into plant nuclear dna. direct repeats define the t-dna ends; transfer begins when the vird2 endonuclease produces a site-specific nick in the right-hand border repeat and attaches to the 5' end of the nicked strand. subsequent events generate linear single-stranded vird2-bound dna molecules that include the entire t-dna (t-strands). vird2 protein contains a nuclear localization signal (nls) near the c term ...	1992	1465407
coat protein properties suggest that azuki bean mosaic virus, blackeye cowpea mosaic virus, peanut stripe virus, and three isolates from soybean are all strains of the same potyvirus.	the interrelationship of a number of potyviruses infecting legumes has been investigated by comparing molecular properties of their coat proteins. comparison of the coat proteins by the techniques of amino acid analysis and page was inadequate to distinguish strains from distinct potyviruses. however, high-performance liquid chromatographic peptide profiles of tryptic digests of coat proteins of these legume-infecting potyviruses enabled such assignments to be made. these data indicate that amin ...	1992	1500273
regulation of nuclear transport of a plant potyvirus protein by autoproteolysis.	the nia proteinase encoded by tobacco etch potyvirus catalyzes six processing events, three of which occur by an autoproteolytic mechanism. autoproteolysis is necessary to cleave the boundaries of both nia and the 6-kda protein, which is located adjacent to the n terminus of nia in the viral polyprotein. as a consequence, nia may exist in a free form or in a transient polyprotein form containing the 6-kda protein. while the majority of nia molecules localize to the nuclei of infected cells, a fr ...	1992	1501298
cross-reactive potential of monoclonal antibodies raised against proteolysed tobacco etch virus.	monoclonal antibodies (mab) capable of reacting with different potyviruses were obtained by immunizing mice with proteolysed tobacco etch virus. the mab were not equally effective in all elisa formats and some were specific for different conformational states of the viral coat protein. the mab also detected antigenic differences between purified virus particles and viral antigen in infected plant sap. in an elisa format using antigen-coated plates, 5 different potyviruses (out of 7 viruses teste ...	1992	1518965
mutational analysis of the tobacco etch potyviral 35-kda proteinase: identification of essential residues and requirements for autoproteolysis.	the tobacco etch potyvirus (tev) polyprotein is processed by three virus-encoded proteinases, termed nla, hc-pro, and the 35-kda proteinase. the 35-kda proteinase is derived from the amino-terminal region of the polyprotein. analysis of polyproteins containing beta-glucuronidase fused to the expected carboxy terminus of the 35-kda proteinase confirmed the previously identified tyr304-ser305 dipeptide as the cleavage site between the 35-kda proteinase and hc-pro. the 35-kda proteinase of tev was ...	1992	1529535
effects of antisense oligodeoxynucleotide hybridization on in vitro translation of potato virus y rna.	potato virus y (pvy), a potyvirus, has an rna genome containing 9704 nucleotides of which 185 belong to the 5' nontranslated region (ntr). contrary to most eukaryotic mrnas that have a cap structure, the potyvirus rna has a genome-linked protein (vpg). in order to understand the mechanisms of pvy rna translation initiation, hybrid-arrest translation was used to localize sequences involved in binding of proteins and/or ribosomes. the 5' ntr was fused to the beta-glucuronidase (gus) reporter gene. ...	1992	1549909
the complete nucleotide sequence of rna 1 of a german isolate of barley yellow mosaic virus and its comparison with a japanese isolate.	the nucleotide sequence of rna 1 of a german isolate of barley yellow mosaic virus has been determined and compared with a japanese isolate of the same virus. the sequence identity is 93.6% at the nucleotide level and 96% at the amino acid level. similar values have been found for the polyproteins of the rna 2 of both isolates (95%). both isolates show an rna 1-encoded protein arrangement similar to that of potyviruses such as tobacco etch virus. in contrast, the polyproteins of the small rnas ( ...	1992	1588327
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
the 5' untranslated region from pea seedborne mosaic potyvirus rna as a translational enhancer in pea and tobacco protoplasts.	we have exploited the transient expression of foreign genes introduced into plant protoplasts to investigate the effect of the pea seedborne mosaic potyvirus (psbmv) 5' untranslated region (5'utr) on the level of gene expression in pea and tobacco protoplasts. the plant viral 5'utrs were found to increase translation significantly in comparison to a plasmid containing no 5'utr of viral origin. the enhancement effect of the 5'utrs of psbmv and tobacco etch potyvirus (tev) was found to be similar ...	1992	1607015
pathogen-derived resistance to a potyvirus: immune and resistant phenotypes in transgenic tobacco expressing altered forms of a potyvirus coat protein nucleotide sequence.	transgenic nicotiana tabacum 'burley 49' plants containing one of six different forms of the tobacco etch virus (tev) coat protein (cp) nucleotide sequence have been generated. in whole plant studies, r1 and r2 progeny were inoculated mechanically with tev, and the appearance and severity of symptoms were recorded. symptom phenotype was altered, ranging from near wild type susceptibility to apparent immunity. protoplasts derived from wild type and transgenic burley 49 plant lines were transfecte ...	1992	1617197
autocatalytic activity of the tobacco etch virus nia proteinase in viral and foreign protein sequences.	the small nuclear inclusion (nia) protein of the tobacco etch virus (tev) is synthesized initially as part of a genome-derived high m(r) precursor. the nia protein releases itself from this genome-derived precursor by self-cleavage, or an autocatalytic processing event. cleavage between specific glutamine-glycine dipeptides at the n and c termini generates the 430 amino acid or 49,000 m(r) (49k) nia protein. the requirements of this autocatalytic release, or cis cleavage, were examined by constr ...	1992	1634873
untranslatable transcripts of the tobacco etch virus coat protein gene sequence can interfere with tobacco etch virus replication in transgenic plants and protoplasts.	transgenic tobacco plants which express untranslatable sense or antisense forms of the tobacco etch virus potyvirus (tev) coat protein (cp) gene sequence have been generated. one of seven transgenic plant lines expressing a cp gene antisense transcript showed an attenuation of symptoms when inoculated with tev. three of ten transgenic plant lines expressing untranslatable sense transcripts did not develop symptoms when inoculated with tev. these lines were resistant to either aphid or mechanical ...	1992	1641986
cleavage profiles of tobacco etch virus (tev)-derived substrates mediated by precursor and processed forms of the tev nia proteinase.	nucleotide sequences coding for proteins containing the tobacco etch virus (tev) nia proteinase were generated by polymerase chain reaction amplification and/or site-directed mutagenesis. these coding regions contained sequences for the proteinase alone or as part of higher mr precursors. following transcription and translation of these sequences in a cell-free system, the various polyproteins, all containing an active small nuclear inclusion protein (nia) proteinase, were used to process a tev ...	1992	1730935
characterization of the potyviral hc-pro autoproteolytic cleavage site.	the helper component-proteinase (hc-pro) encoded by potyviruses functions to cleave the viral polyprotein by an autoproteolytic mechanism at the hc-pro c-terminus. this protein belongs to a group of viral cysteine-type proteinases and has been shown previously to catalyze proteolysis between a gly-gly dipeptide. the amino acid sequence requirements surrounding the hc-pro c-terminal cleavage site of the tobacco etch virus polyprotein have been investigated using site-directed mutagenesis and in v ...	1992	1736533
induction of a highly specific antiviral state in transgenic plants: implications for regulation of gene expression and virus resistance.	transgenic tobacco plants expressing either a full-length form of the tobacco etch virus (tev) coat protein or a form truncated at the n terminus of the tev coat protein were initially susceptible to tev infection, and typical systemic symptoms developed. however, 3 to 5 weeks after a tev infection was established, transgenic plants "recovered" from the tev infection, and new stem and leaf tissue emerged symptom and virus free. a tev-resistant state was induced in the recovered tissue. the resis ...	1993	12271055