| monoclonal antipeptide antibodies: affinity and kinetic rate constants measured for the peptide and the cognate protein using a biosensor technology. | the interaction of antipeptide antibodies with the corresponding peptide and the cognate protein has been compared using a novel biosensor technology (biacore, pharmacia). the peptide corresponds to residues 110-135 of the coat protein of tobacco mosaic virus, known to encompass an alpha-helical region reactive with antiprotein antibodies. a panel of 33 monoclonal antibodies raised against the peptide was studied and the epitope recognized by these antibodies was determined by the pepscan method ... | 1993 | 7679185 |
| phosphorylation of tobacco mosaic virus cell-to-cell movement protein by a developmentally regulated plant cell wall-associated protein kinase. | in host plants, cell-to-cell spread of tobacco mosaic virus (tmv) presumably occurs through intercellular connections, the plasmodesmata. tmv movement is mediated by a specific virus-encoded single-strand nucleic acid-binding protein, p30. the mechanism by which p30 operates is largely unknown. here, we demonstrate that p30 expressed in transgenic plants is a phosphoprotein. we have developed an assay for in vitro phosphorylation of purified p30 by plant cell wall fractions and have localized th ... | 1993 | 7684009 |
| production of a monoclonal antibody reactive with poly(a) and its application in the isolation of poly(a)+ rna. | hybridoma cells producing antibody reactive with poly(a) were isolated following fusion of spleen cells from a balb/c mouse immunized with poly(a).poly(dt) and myeloma cells. the antibody was purified from ascitic fluid by the formation of immune complexes with poly(a). the antibody reacted with poly(a) and some homopolymers (poly(dt), poly(i) and poly(dc)) which was most probably due to its reaction with the ribose-phosphate part of the molecules, but not with cellular rnas and dna. poly(a) tai ... | 1993 | 7689620 |
| "rattlesnake" structure of a filamentous plant rna virus built of two capsid proteins. | elongated particles of simple rna viruses of plants are composed of an rna molecule coated with numerous identical capsid protein subunits to form a regular helical structure, of which tobacco mosaic virus is the archetype. filamentous particles of the closterovirus beet yellow virus (byv) reportedly contain approximately 4000 identical 22-kda (p22) capsid protein subunits. the byv genome encodes a 24-kda protein (p24) that is structurally related to the p22. we searched for the p24 in byv parti ... | 1995 | 7708667 |
| proteasomes (prosomes) inhibit the translation of tobacco mosaic virus rna by preventing the formation of initiation complexes. | proteasomes (prosomes) are large multiprotein complexes. they are involved in protein degradation of ubiquitin-conjugated proteins and in the generation of mhc class i peptides. we gave further evidence that they interfere with in vitro protein synthesis. proteasomes inhibit the translation of tobacco mosaic virus rna. analysis of cell-free systems by sucrose gradient centrifugation revealed that they prevent the formation of 80s initiation complexes but not the early phase of initiation. | 1994 | 7715610 |
| studies of coat protein-mediated resistance to tmv. i. the pm2 assembly defective mutant confers resistance to tmv. | tobacco mosaic virus mutant pm2 contains two amino acid changes in coat protein sequence relative to the sequence of the coat protein of tmv u1. this results in unstable infectivity, inability to cause normal systemic infection, and accumulation of elongated open helixes of coat protein. using site-directed mutagenesis we demonstrated that the characteristics of pm2 are due to the change of thr28-->ile, while the second change, glu95-->asp, had no apparent effect on virion structure or infectivi ... | 1995 | 7747421 |
| transposon tagging of tobacco mosaic virus resistance gene n: its possible role in the tmv-n-mediated signal transduction pathway. | plants can recognize and resist invading pathogens by signaling the induction of rapid defense responses. often these responses are mediated by single dominant resistance genes (r genes). the products of r genes have been postulated to recognize the pathogen and trigger rapid host defense responses. here we describe isolation of the classical resistance gene n of tobacco that mediates resistance to the well-characterized pathogen tobacco mosaic virus (tmv). the n gene was isolated by transposon ... | 1995 | 7753780 |
| use of arabidopsis thaliana defense-related mutants to dissect the plant response to pathogens. | the plant defense response to microbial pathogens had been studied primarily by using biochemical and physiological techniques. recently, several laboratories have developed a variety of pathosystems utilizing arabidopsis thaliana as a model host so that genetic analysis could also be used to study plant defense responses. utilizing a pathosystem that involves the infection of arabidopsis with pathogenic pseudomonads, we have cloned the arabidopsis disease-resistance gene rps2, which corresponds ... | 1995 | 7753782 |
| 2d exchange 31p nmr spectroscopy of bacteriophage m13 and tobacco mosaic virus. | two-dimensional (2d) exchange 31p nuclear magnetic resonance spectroscopy is used to study the slow overall motion of the rod-shaped viruses m13 and tobacco mosaic virus in concentrated gels. even for short mixing times, observed diagonal spectra differ remarkably from projection spectra and one-dimensional spectra. our model readily explains this to be a consequence of the t2e anisotropy caused by slow overall rotation of the viruses about their length axis. 2d exchange spectra recorded for 30% ... | 1995 | 7756532 |
| a new tobacco mosaic virus vector and its use for the systemic production of angiotensin-i-converting enzyme inhibitor in transgenic tobacco and tomato. | we have developed a new tobacco mosaic virus (tmv) rna vector and have used it initially to systemically produce an angiotensin-i-converting enzyme inhibitor peptide (acei) in tobacco and tomato plants. this vector incorporates a six base 3' context sequence, which permits readthrough of the stop codon for the tmv 130k protein gene, inserted between the stop codon for the coat protein (cp) gene and acei gene. in contrast to previous tmv rna vectors, the new vector produced both an intact cp and ... | 1993 | 7763916 |
| virus-induced gene expression for enzymes of ethylene biosynthesis in hypersensitively reacting tobacco. | a full-length cdna clone (cefe-26) encoding ethylene-forming enzyme (efe) was isolated from a cdna library, prepared from leaves of tobacco mosaic virus (tmv)-infected tobacco cultivar samsun nn. the cdna clone encodes a protein with 90% amino acid sequence similarity to established efes of tomato and other plants. by using cefe-26 cdna and the insert from cdna clone pacc13 (b. a. bailey, a. avni, n. li, a. k. mattoo, and j. d. anderson, plant physiol. 100:1615-1616, 1992) encoding tobacco 1-ami ... | 1995 | 7772800 |
| versatile vectors to study recoding: conservation of rules between yeast and mammalian cells. | in many viruses and transposons, expression of some genes requires alternative reading of the genetic code, also called recoding. such events depend on specific mrna sequences and can lead to read through of an in-frame stop codon or to +1 or -1 frameshifting. here, we addressed the issue of conservation of recoding rules between the yeast saccharomyces cerevisiae and mammalian cells by establishing a versatile vector that can be used to study recoding in both species. we first assessed this vec ... | 1995 | 7784210 |
| structural features of fungal beta-d-glucans for the efficient inhibition of the initiation of virus infection on nicotiana tabacum. | glucans of fungal origin have been shown to inhibit the early stages of infection of nicotiana by numerous viruses of different taxonomic groups. several glucans were isolated from the cell walls of phytophthora parasitica, phytophthora megasperma f. sp. glycinea (pmg) and fusarium oxysporum, and their antiviral activity compared on tobacco leaves inoculated with tobacco mosaic virus. these polysaccharides consist of a mixture of (1-->3)(1-->6)-beta-d-glucans with m(r) varying from 1.1 x 10(3) t ... | 1995 | 7786491 |
| a long-lived batch reaction system of cell-free protein synthesis. | several reaction conditions of cell-free protein synthesis such as temperatures, buffers, trnas, and creatine phosphate were intensively investigated and optimized to prolong protein synthesis and make it more efficiently in a batch system. as a result of these modifications, the protein synthesis reaction continued for 10 h so that about 30 micrograms of dihydrofolate reductase (dhfr) protein derived from escherichia coli was synthesized in 1 ml of reaction mixture. in this improved system, tra ... | 1995 | 7793634 |
| molecular characterization of a novel tobacco pathogenesis-related (pr) protein: a new plant chitinase/lysozyme. | a new pr (pathogenesis-related) protein was isolated from tobacco leaves (nicotiana tabacum cv. samsun nn), reacting hypersensitively to tobacco mosaic virus (tmv), by zinc chelate chromatography and was therefore named pz. its reactivity toward several lectins indicated the presence of bound sugar residues. from the amino acid sequence of tryptic peptides, oligonucleotide primers were derived which allowed the synthesis of pz cdna by pcr. using this cdna as probe, near full-length clones were i ... | 1994 | 7816033 |
| phenylalanine ammonia-lyase in tobacco. molecular cloning and gene expression during the hypersensitive reaction to tobacco mosaic virus and the response to a fungal elicitor. | a tobacco (nicotiana tabacum l. cv samsun nn) cdna clone coding the enzyme phenylalanine ammonia-lyase (pal) was isolated from a cdna library made from polyadenylated rna purified from tobacco mosaic virus (tmv)-infected leaves. southern analysis indicated that, in tobacco, pal is encoded by a small family of two to four unclustered genes. northern analysis showed that pal genes are weakly expressed under normal physiological conditions, they are moderately and transiently expressed after woundi ... | 1994 | 7824656 |
| a defective movement protein of tmv in transgenic plants confers resistance to multiple viruses whereas the functional analog increases susceptibility. | transgenic tobacco plants that express a gene encoding a defective mutant of the tobacco mosaic virus (tmv) movement protein which are known to be resistant to several tobamoviruses were inoculated with viruses from different taxonomic groups to determine the breadth of resistance. there were significant delays in the time of appearance of disease symptoms and/or there was reduced systemic accumulation of virus in upper leaves of plants inoculated with tobacco rattle tobravirus, tobacco ringspot ... | 1995 | 7831786 |
| sequence analysis and gene content of potato mop-top virus rna 3: further evidence of heterogeneity in the genome organization of furoviruses. | the complete sequence of the 2315 nucleotides in rna 3 of potato mop-top furovirus (pmtv) isolate t was obtained by analysis of cdna clones and by direct rna sequencing. the sequence contains an open reading frame for the coat protein (20k) terminated by an amber codon, followed by an in-phase coding region for an additional 47k. pmtv therefore resembles soil-borne wheat mosaic (sbwmv) and beet necrotic yellow vein (bnyvv) viruses (two other fungus-transmitted viruses with rod-shaped particles) ... | 1995 | 7831829 |
| site-directed mutagenesis confirms the involvement of carboxylate groups in the disassembly of tobacco mosaic virus. | electrostatic repulsion between carboxylate groups across subunit interfaces has for many years been recognized as important in the disassembly of simple plant viruses. in the coat protein of tobacco mosaic virus (tmv), the amino acids glu50 and asp77 have been proposed as examples of such carboxylate groups. site-directed mutagenesis has been used to replace these amino acids by gln and asn, respectively. increased virion stability, together with reduced infectivity and reduced capacity for lon ... | 1995 | 7831832 |
| identification of the cauliflower mosaic virus movement protein rna-binding domain. | the in vitro rna-binding activity of the movement protein (p1) of cauliflower mosaic virus was studied after its expression in escherichia coli, purification, and uv-crosslinking to a radioactive probe. it was found that insoluble p1 aggregates were involved in rna-binding activity. a series of deletion mutants were used to identify a domain within p1 required for binding activity. the rna-binding domain is located between amino acids 120 and 197 and includes the region of homology between p1 an ... | 1995 | 7856089 |
| photoelectron imaging of viruses and dna: evaluation of substrates by unidirectional low angle shadowing and photoemission current measurements. | photoelectron imaging (photoelectron emission microscopy, pem or peem) is a promising high resolution surface-sensitive technique for biophysical studies. at present, image quality is often limited by the underlying substrate. for photoelectron imaging, the substrate must be electrically conductive, low in electron emission, and relatively flat. a number of conductive substrate materials with relatively low electron emission were examined for surface roughness. low angle, unidirectional shadowin ... | 1994 | 7858141 |
| a single nucleotide change in the coat protein gene of tobacco mosaic virus is involved in the induction of severe chlorosis. | ysi/1 is a mutant of the common strain (u1) of tobacco mosaic virus (tmv) which induces a severe yellow mosaic in nicotiana tabacum instead of the light green/dark green mosaic induced by its parental u1 virus. although there was less coat protein (cp) in whole leaf extracts of ysi/1-infected leaves than in u1-infected leaves, severalfold more cp was found in the chloroplasts, most of which was associated with the thylakoids. sequencing the cp genes of both viruses showed the presence of nucleot ... | 1995 | 7871732 |
| serine/threonine protein phosphatase is required for tobacco mosaic virus-mediated programmed cell death. | a major gap in our understanding of host response to virus infection is how the molecular signals are passed within infected cells. tobacco mosaic virus-mediated programmed cell death in genotype nn tobaccos was used to evaluate the hypothesis that these molecular signals are transduced via reversible-protein phosphorylation. nicotiana tabacum l. (genotype nn) confers a hypersensitive response at the site of virus infection when incubated at a permissive temperature. activation of serine/threoni ... | 1995 | 7886949 |
| replicase-mediated resistance to alfalfa mosaic virus. | tobacco plants transformed with the p1 and p2 replicase genes of alfalfa mosaic virus (aimv) have been shown to produce functional replicase proteins, permitting their infection with aimv inocula lacking the genome segments encoding p1 and p2, respectively. to see whether expression of a mutant p2 protein would interfere with the assembly of a functional replicase complex, tobacco plants were transformed with modified p2 genes. when plants were transformed with a p2 gene encoding an n-terminally ... | 1995 | 7886950 |
| [the primary structure of a vaccine strain of tobacco mosaic virus v-69]. | a random set of cdna fragments were synthesized on genomic rna of tmv vaccine strain v-69, using random primers and reverse transcriptase. following synthesis of double-stranded cdna, they were cloned into the puc-19 plasmid; and 28 clones were sequenced (insert size 100-500 bp). high nucleotide sequence homology of v-69 (more than 95%) was shown only with tomato strain tmv-l [1]. sequenced clones represent 54% of the genome (50% of the replicase gene, 98% of the transport protein gene, and 60% ... | 1994 | 7890152 |
| the product of the tobacco mosaic virus resistance gene n: similarity to toll and the interleukin-1 receptor. | the products of plant disease resistance genes are postulated to recognize invading pathogens and rapidly trigger host defense responses. here we describe isolation of the resistance gene n of tobacco that mediates resistance to the viral pathogen tobacco mosaic virus (tmv). the n gene was isolated by transposon tagging using the maize activator transposon. a genomic dna fragment containing the n gene conferred tmv resistance to tmv susceptible tobacco. sequence analysis of the n gene shows that ... | 1994 | 7923359 |
| similarities between the secondary structure of satellite tobacco mosaic virus and tobamovirus rnas. | the secondary structure of satellite tobacco mosaic virus (stmv) rna was predicted using computer simulations of rna folding. the analogies of structural elements in the 3' end untranslated regions (3'-utr) of tobamoviral rnas were analysed. in addition to the trna-like structure and pseudoknot stalk, which are found in all known rnas of tobamoviruses and stmv, another region of stable consecutive pseudoknots was predicted in the 3'-utr of stmv rna. a similar pattern of repeated structural units ... | 1994 | 7931178 |
| disruption of virus movement confers broad-spectrum resistance against systemic infection by plant viruses with a triple gene block. | white clover mosaic virus strain o (wclmv-o), species of the potexvirus genus, contains a set of three partially overlapping genes (the triple gene block) that encodes nonvirion proteins of 26 kda, 13 kda, and 7 kda. these proteins are necessary for cell-to-cell movement in plants but not for replication. the wclmv-o 13-kda gene was mutated (to 13*) in a region of the gene that is conserved in all viruses known to possess triple-gene-block proteins. all 10 13* transgenic lines of nicotiana benth ... | 1994 | 7937946 |
| characterization of accumulation of tobacco pr-5 proteins by ief-immunoblot analysis. | accumulation of group 5 pathogenesis-related (pr) proteins in tobacco was characterized by immunological analysis combined with isoelectric focusing. this method clearly distinguished 3 subclasses of pr-5 proteins; basic (osmotin), neutral (osmotin-like protein: olp) and acidic (pr-s). a high accumulation of pr-5 proteins was detected only in root tissues in which neutral osmotin-like protein was mainly accumulated, in addition to a small amount of osmotin. immunohistochemical analysis revealed ... | 1994 | 7952963 |
| space microbiology--lethality, mutagenicity and cytological effects of terrestrial microorganisms by irradiation of cosmic proton under simulated space condition. | we have been discussing in connection with a space quarantine. the subject is not merely an academic problem, but it contains a fundamental problem which avoid the contamination of other planets by terrestrial microflora. the space environments in the solar system were simulated by using an apparatus of cryostat (low temperature of 110-310k, high vacuum of 1 x 10(-8) torr) and proton irradiation from the van de graaff generator. after exposure to a barrage of protons corresponding to about 250 y ... | 1993 | 7967372 |
| influence of heterologous tobamovirus movement protein and chimeric-movement protein genes on cell-to-cell and long-distance movement. | sunn-hemp mosaic tobamovirus (shmv) moves slowly from cell to cell in nicotiana tabacum cv. xanthi, but fails to move long distance. to determine the role of the shmv movement protein (mp) in cell-to-cell and long-distance movement in tobacco, the shmv mp gene was inserted into a tmv-cdna clone that had approximately the 5'-half of the endogenous mp gene deleted. rna transcripts inoculated onto tobacco induced systemic infections by 8 days postinoculation. sequence analysis of the mp genes from ... | 1994 | 7975216 |
| self-assembling process of cylindrical virus coat proteins as observed by synchrotron small-angle x-ray scattering. | the self-assembly process of cucumber green mottle mosaic virus (cgmmv) protein and tobacco mosaic virus (tmv) protein was examined by the thermodynamic analysis of small-angle x-ray scattering (saxs) data. each polymerization step of the coat proteins was assumed to be specified by a single equilibrium constant, and the equilibrium constant was evaluated by fitting the size and shape of the constituents observed by saxs to those calculated from an assumed polymerization scheme. the logarithmic ... | 1994 | 7982882 |
| [cloning transport protein genes for two strains of tobacco mosaic virus and their expression in escherichia coli cells]. | recombinant constructs expressing fusion (his)6 movement proteins of two strains (cruciferous and vulgare) of tobacco mosaic virus were generated by cloning the pcr-amplified fragments into the pqe-9 vector. the movement proteins containing n-terminal (his)6 affinity tags were purified on a metal chelate adsorbent. | 1994 | 7993379 |
| nucleotide sequence analysis of a cdna clone encoding the 34k movement protein gene of odontoglossum ringspot virus, orsv-cy, the korean isolate. | the partial nucleotide sequence of the 3'-terminal region of the korean isolate of odontoglossum ringspot tobamovirus (orsv-cy) from cool-growing cymbidium was determined. the sequence contained a full length open reading frame (orf) coding for the viral cell-to-cell movement protein (mp). the orf was located upstream of the coat protein gene and 105 nucleotides longer than that of tobacco mosaic virus (tmv). the orf predicts a polypeptide chain of 303 amino acids with a molecular weight of 3357 ... | 1994 | 8000012 |
| a new class of tobacco chitinases homologous to bacterial exo-chitinases displays antifungal activity. | a novel chitinase gene of tobacco was isolated and characterized by dna sequence analysis of a genomic clone and a cdna clone. comparative sequence analysis of both clones showed an identity of 94%. the proteins encoded by these sequences do not correspond to any of the previously characterized plant chitinases of classes i-iv and are designated as class v chitinases. comparison of the chitinase class v peptide sequence with sequences in the swiss protein databank revealed significant sequence s ... | 1994 | 8012401 |
| the immobilized movement proteins of two tobamoviruses form stable ribonucleoprotein complexes with full-length viral genomic rna. | the movement proteins of two tobamoviruses (tobacco mosaic virus, tmv, common strain u1 and cruciferous tmv strain) containing amino-terminal hexahistidine affinity tags were overexpressed in escherichia coli and purified by metal chelate affinity chromatography. purified recombinant proteins were immobilized to a ni(2+)-chelate adsorbent and their ability to interact with full-length genomic tmv rna was tested. here we report that binding of viral rna to hexahistidine fusion movement proteins r ... | 1994 | 8013637 |
| developmental, hormonal, and pathogenesis-related regulation of the tobacco class i beta-1,3-glucanase b promoter. | the class i beta-1,3-glucanases are antifungal vacuolar proteins implicated in plant defense that show developmental, hormonal, and pathogenesis-related regulation. the tobacco enzymes are encoded by a small gene family with members derived from ancestors related to the present-day species nicotiana sylvestris and n. tomentosiformis. we studied the expression in transgenic tobacco plants of a chimeric beta-glucuronidase (gus) reporter gene fused to 1.6 kb of upstream sequence of the tobacco clas ... | 1994 | 8018877 |
| three tetrahymena trna(gln) isoacceptors as tools for studying unorthodox codon recognition and codon context effects during protein synthesis in vitro. | three glutamine trna isoacceptors are known in tetrahymena thermophila. one of these has the anticodon umug which reads the two normal glutamine codons caa and cag, whereas the two others with cua and umua anticodons recognize uag and uaa, respectively, which serve as termination codons in other organisms. we have employed these trna(gln)-isoacceptors as tools for studying unconventional base interactions in a mrna- and trna-dependent wheat germ extract. we demonstrate here (i) that trna(gln)umu ... | 1994 | 8029002 |
| satellite tobacco mosaic virus sequence variants with only five nucleotide differences can interfere with each other in a cross protection-like phenomenon in plants. | the type strain of satellite tobacco mosaic virus (stmv) contains two major variants, designated type 5 (t5) and type 6 (t6), which can be easily distinguished by rnase protection analyses. clones containing cdna of representative t5 and t6 stmv genomes have only five single-base differences in the entire 1059-nucleotide genome, and rna transcribed from each clone is highly infectious when inoculated onto tobacco plants. the different rnase protection assay patterns can be used as genetic marker ... | 1994 | 8030213 |
| principles and background for the construction of transgenic plants displaying multiple virus resistance. | we investigated the possibility of reconstructing the 2'-5' oligoadenylate (2-5a) pathway into the plant kingdom to achieve multiple virus resistance. differently phosphorylated 2-5a trimers and tetramers inhibited tmv rna translation in cell-free systems. in wheat germ extracts the most potent inhibitors were nonphosphorylated forms of 2-5a. triphosphorylated forms of 2-5a were deposphorylated and hydrolysed in plant extracts. since we could not detect homologous dna to mammalian 2-5a synthetas ... | 1994 | 8032271 |
| structural studies of viruses by electron cryomicroscopy. | electron cryomicroscopy is a unique biophysical technique for studying molecular structures of viruses which are difficult to analyze by x-ray diffraction. the structural information derived from the low resolution reconstructions of viruses has so far been useful to understand various functional properties of the viruses such as antibody neutralization, receptor binding and assembly. electron cryomicroscopy has enabled the visualization of the four core alpha helices of the coat protein in toba ... | 1994 | 8032281 |
| adaptation of positive-strand rna viruses to plants. | the vast majority of positive-strand rna viruses (more than 500 species) are adapted to infection of plant hosts. genome sequence comparisons of these plant rna viruses have revealed that most of them are genetically related to animal cell-infecting counterparts; this led to the concept of "superfamilies". comparison of genetic maps of representative plant and animal viruses belonging to the same superfamily (e.g. cowpea mosaic virus [cpmv] versus picornaviruses and tobacco mosaic virus versus a ... | 1994 | 8032285 |
| analysis of 31p mas nmr spectra and transversal relaxation of bacteriophage m13 and tobacco mosaic virus. | phosphorus magic angle spinning nuclear magnetic resonance (nmr) spectra and transversal relaxation of m13 and tmv are analyzed by use of a model, which includes both local backbone motions of the encapsulated nucleic acid molecules and overall rotational diffusion of the rod-shaped virions about their length axis. backbone motions influence the sideband intensities by causing a fast restricted reorientation of the phosphodiesters. to evaluate their influence on the observed sideband patterns, w ... | 1994 | 8038391 |
| correlation between the activities of five ribosome-inactivating proteins in depurination of tobacco ribosomes and inhibition of tobacco mosaic virus infection. | the rrna depurination activities of five ribosome-inactivating proteins (rips) were compared in vitro using yeast and tobacco leaf ribosomes as substrates. all of the rips (pokeweed antiviral protein (pap), dianthin 32, tritin, barley rip and ricin a-chain) were active on yeast ribosomes. pap and dianthin 32 were highly active and ricin a-chain weakly active on tobacco ribosomes, whereas tritin and barley rip were inactive. pap and dianthin 32 were highly effective in inhibiting the formation of ... | 1994 | 8054989 |
| [study of the process of thermal aggregation of several representative tobamovirus coat proteins]. | the role of the specific region of the tobacco mosaic virus (tmv) coat protein (cp) molecule (called "70a degree-region") in the regulation of ordered and unordered cp aggregation was investigated. cps of the wild type tmv (strain u1), of temperature sensitive mutant with two amino acid substitutions in the "70a degree-region", and of cucumber virus 3 which is related to tmv but has a completely different structure in the "70a degree-region" were used. with the help of two different tests the pr ... | 1994 | 8065382 |
| a histidine accepting trna-like fold at the 3'-end of satellite tobacco mosaic virus rna. | a model of secondary structure is proposed for the 3'-terminal sequence of the satellite tobacco mosaic virus (stmv) rna on the basis of phylogenetic comparisons with tobacco mosaic virus (tmv) genomic rna. sequence homologies and compensatory base changes found between the two related viral rnas imply that the 3'-end of stmv rna folds into a trna-like domain similar to that found in the tmv rna. accordingly, functional assays showed that stmv rna can be aminoacylated in vitro with histidine by ... | 1994 | 8065897 |
| immunosorbent electron microscopic studies on a tobamovirus causing brinjal necrotic mosaic. | serological relationships of brinjal necrotic mosaic virus (bnmv), a strain of tobacco mosaic virus (tmv) causing necrotic mosaic disease of brinjal in india to other tmv strains was investigated by immunosorbent electron microscopy (isem). the intensity of trapping and decoration revealed a close relationship of bnmv to tmv-d, tmv-u1 and tmv-wu1 strains, and a distant relationship to tmv-a1 and tmv-p11 strains. there was a negligible relationship to tmv-p14, tomato mosaic virus (tomv) and cucum ... | 1994 | 8067314 |
| pyrimidine tract binding protein strongly stimulates in vitro encephalomyocarditis virus rna translation at the level of preinitiation complex formation. | cellular protein p57/58, now known to be identical to polypyrimidine tract binding protein (ptb), has earlier been shown to specifically bind to the internal ribosome entry sites (ires) of encephalomyocarditis virus (emcv) and some other picornaviral rnas. to elucidate its relevance to the internal initiation, the effect of cloned purified ptb on emcv ires directed translation was studied in cytoplasmic extracts of krebs-2 ascites carcinoma cells partially depleted of endogenous ptb. addition of ... | 1994 | 8082784 |
| structure-function relationship between tobacco mosaic virus coat protein and hypersensitivity in nicotiana sylvestris. | alterations in the structure of the tobacco mosaic virus (tmv) coat protein affect the elicitation of the n' gene hypersensitive response (hr) in nicotiana sylvestris. to investigate this structure-function relationship, amino acid substitutions with predicted structural effects were created throughout the known structure of the tmv coat protein. substitutions that resulted in the elicitation of the hr resided within and would predictably interfere with interface regions located between adjacent ... | 1994 | 8089836 |
| expression of tobacco mosaic virus coat protein and assembly of pseudovirus particles in escherichia coli. | the bidirectional self-assembly of tobacco mosaic virus (tmv, common or u1 strain) has been studied extensively in vitro. foreign single-stranded rna molecules containing the tmv origin-of-assembly sequence (oas, 75-432 nt in length) are also packaged by tmv coat protein (cp) in vitro to form helical pseudovirus particles. to study virus assembly in vivo requires an easily manipulated model system, independent of replication in plants. the tmv assembly machinery also provides a convenient means ... | 1994 | 8090770 |
| cdna cloning and gene expression analysis of the microbial proteinase inhibitor of tobacco. | tobacco mosaic virus-infected tobacco (nicotiana tabacum var. samsun nn) leaves produce a serine proteinase inhibitor that has evolved a specificity for microbial proteinases. we have isolated two closely related cdnas that were shown to encode two active inhibitors. southern analysis of genomic dna, comparison of deduced amino acid sequences, and characterization of the two separated proteins suggest that the two genes of tobacco are homologous originating from each parent. amino acid sequences ... | 1993 | 8102364 |
| self-assembly of a double-helical complex of sodium. | spontaneous self-organization of helical and multiple-helical molecular structures occurs on several levels in living organisms. key examples are alpha-helical polypeptides, double-helical nucleic acids and helical protein structures, including f-actin, microtubules and the protein sheath of the tobacco mosaic virus. although the self-assembly of double-helical transition-metal complexes bears some resemblance to the molecular organization of double-stranded dna, selection between monohelical, d ... | 1994 | 8107802 |
| direct functional assay for tobacco mosaic virus cell-to-cell movement protein and identification of a domain involved in increasing plasmodesmal permeability. | plasmodesmata are cytoplasmic bridges between plant cells thought to generally allow only the passage of small molecules and metabolites. however, large structures such as plant viruses also move from cell to cell via plasmodesmata. in tobacco mosaic virus (tmv) infection a viral movement protein (tmv-mp) mediates viral spread. here, a microinjection assay is used to monitor the dynamics of tmv-mp function directly in wild-type plants. the results indicate that tmv-mp interacts with an endogenou ... | 1994 | 8108427 |
| a novel pathogen- and wound-inducible tobacco (nicotiana tabacum) protein with antifungal activity. | a novel pathogen- and wound-inducible antifungal protein of 20 kd was purified from tobacco (nicotiana tabacum) samsun nn leaves inoculated with tobacco mosaic virus (tmv). the protein, designated cbp20, was purified by chitin-affinity chromatography and gel filtration. in vitro assays demonstrated that cbp20 exhibits antifungal activity toward trichoderma viride and fusarium solani by causing lysis of the germ tubes and/or growth inhibition. in addition it was shown that cbp20 acts synergistica ... | 1994 | 8115541 |
| the upstream region of the gene for the pathogenesis-related protein 1a from tobacco responds to environmental as well as to developmental signals in transgenic plants. | pathogenesis-related proteins (pr proteins) are a heterogeneous group of proteins which are induced in plants by diverse stimuli, e.g. pr proteins are elicited by pathogen attack in the course of the hypersensitive defense reaction of the plant. to examine the regulation of these genes, the 5'-flanking region of the tobacco (nicotiana tabacum cv. wisconsin 38) pr-1a gene up to position -1533 was isolated from genomic dna by the polymerase chain reaction. two chimeric gene constructs containing 1 ... | 1994 | 8119292 |
| molecular dynamics in refinement against fiber diffraction data. | the molecular dynamics (md) method has been adapted for refinement of the structures of helical macromolecular aggregates aginst x-ray fiber diffraction data. to test the effectiveness of the method, refinements of the tobacco mosaic virus structure were carried out against a set of simulated fiber diffraction intensities using the md method as well as the conventional restrained least-squares (rls) method. the md refinement converged to a very low r factor and produced a structure with generall ... | 1993 | 8129880 |
| the "erf" clone corresponds to tryptophanyl-trna synthetase, not mammalian release factor. | to study the similarity between a putative cloned mammalian release factor (rf) and tryptophanyl-trna synthetase (trs), a recombinant rabbit rf fusion protein was expressed from prokaryotic expression vectors. purified fractions of the fusion proteins were tested for trs and rf activities. addition of the fusion protein to a trs assay increased the binding of tryptophan to trna(trp). however, in an assay for rf activity, the addition of the fusion protein resulted in release of only 1-3% of form ... | 1994 | 8146190 |
| the structure of viral coat protein and its in disease. | because the structure of the tobacco mosaic virus capsid protein is known, mutations that alter the phenotype of the virus-plant interaction can be correlated with structural changes in this protein. these mutations affect the disease symptoms caused by the virus and recognition of the virus by a plant resistance gene product. recognition-host interaction is analogous to the gene-for-gene interactions of bacteria and fungi. | 1993 | 8162410 |
| specificity of replicase-mediated resistance to cucumber mosaic virus. | plants transformed with a nucleotide sequence coding for a truncated rna 2 replicase gene of the subgroup i strain of cucumber mosaic virus, fny-cmv, are resistant to cucumber mosaic disease. two resistant lines representing independent transformations in the original study have been propagated, and their progeny have been examined. resistance to fny-cmv was genetically integrated and was retained in the r4 generation. fourteen subgroup i cmv strains, 6 strains uncharacterized as to subgroup, an ... | 1994 | 8184532 |
| the role of the 3'-untranslated region of non-polyadenylated plant viral mrnas in regulating translational efficiency. | tobacco mosaic virus (tmv) is a positive-sense rna virus in which the single genomic rna functions as a messenger rna. it is a member of a class of plant viral rnas that are the only known non-polyadenylated mrnas in plants. the 3'-untranslated region (utr) of tmv genomic rna is the functional equivalent of a poly(a) tail in that it increases mrna stability and regulates translational efficiency. to determine whether the 3'-utr of other non-polyadenylated plant viral mrnas regulate translation, ... | 1994 | 8194747 |
| structure determination of cucumber green mottle mosaic virus by x-ray fiber diffraction. significance for the evolution of tobamoviruses. | cucumber green mottle mosaic virus (cgmmv) is a rod-shaped virus of the tobacco mosaic virus (tmv) group. the structure of cucumber green mottle mosaic virus has been determined by fiber diffraction methods at 3.4 a resolution, and refined by molecular dynamics methods to an r factor of 0.093. disassembly of tmv is driven by the mutual repulsion of intersubunit carboxyl-carboxylate pairs, but one of these pairs is not conserved in cgmmv. an alternative pair, located about 5 a from the site of th ... | 1994 | 8201619 |
| plant viral leaders influence expression of a reporter gene in tobacco. | in order to optimise expression of a foreign protein in transgenic plants we investigated the potential benefits of including a viral untranslated leader sequence within a plant transformation vector. a variety of 5 leaders, including the tobacco mosaic virus (tmv) leader sequence and 31 nucleotides of the cauliflower mosaic virus (camv) 35s rna leader, were compared. viral leader constructs employing the 35s promoter and the reporter beta-glucuronidase (gus) were tested by electroporation into ... | 1993 | 8219060 |
| pathogen, salicylic acid and developmental dependent expression of a beta-1,3-glucanase/gus gene fusion in transgenic tobacco plants. | the 5' flanking region of a gene encoding an acidic beta-1,3-glucanase from nicotiana tabacum was isolated and characterized. a chimeric gene composed of 1759 bp of the promoter sequence from the pr-2 gene was fused to the beta-glucuronidase (gus) coding region and used to transform tobacco. transcriptional activation of the pr-2 promoter was investigated in response to inoculation with tobacco mosaic virus (tmv), after treatment of leaves with salicylic acid (sa), and in specific tissues during ... | 1993 | 8220491 |
| measurement of kinetic binding constants of viral antibodies using a new biosensor technology. | association (ka) and dissociation (kd) rate constants of three monoclonal antibodies raised against tobacco mosaic virus were determined using a biosensor technique based on surface plasmon resonance (biacore, pharmacia). dissociation rates were constant over the 4-400 nm antibody concentration range whereas apparent association rates decreased over this range probably due to an increased saturation level of the antigen. affinity constants k calculated from the ratio of ka/kd were in reasonable ... | 1993 | 8228284 |
| on the relationship between x-bodies and symptom development in plants infected with different tobamoviruses. | the relationship between systemic mosaic symptoms and the occurrence of viral 126-kda protein in x-bodies was studied in tobacco infected with the tobacco mild green mosaic virus (tmgmv) strains u2, u5, and ribgrass mosaic virus (rmv) strain hr, and in other plant species infected with tobacco mosaic virus (tmv) strain w u 1. strains u2, u5, and hr coded for proteins of 126, 126, and 130 kda, respectively, but these were not recognized by antisera against the corresponding protein from w u 1. on ... | 1993 | 8240005 |
| colloidal gold particles as an incompressible atomic force microscope imaging standard for assessing the compressibility of biomolecules. | colloidal gold particles have multiple uses as three-dimensional atomic force microscopy imaging standards because they are incompressible, monodisperse, and spherical. the spherical nature of the particles can be exploited to characterize scanning tip geometry. as uniform spheres, colloidal gold particles may be used to calibrate the vertical dimensions of atomic force microscopy at the nanometer level. the monodisperse and incompressible nature of the gold can be used to characterize the verti ... | 1993 | 8241414 |
| broad resistance to tobamoviruses is mediated by a modified tobacco mosaic virus replicase transgene. | tobacco plants made transgenic to express the wild type tobacco mosaic virus (tmv) 183-kda replicase gene were not resistant to tmv. however, transgenic plants containing essentially the same sequences, but with an additional insertion that would terminate translation in the middle of the 183-kda gene, were highly resistant to systemic infection by tmv and other tobamoviruses. the 1.4-kbp insertion in the replicase open reading frame (orf) of the resistant plants was shown by dna sequencing to b ... | 1993 | 8274774 |
| developments in the understanding of the particle structure of tobraviruses. | particles of tobraviruses resemble those of tobacco mosaic tobramovirus (tmv) in having helical symmetry and in being rod-shaped. however, isolated tobravirus coat protein and tmv coat protein respond to changes in the ionic strength and ph of the solute in contrasting ways. the types of aggregate formed in solutions of coat protein also differ which may be related to differences in the apparent mechanism of reconstitution of virus particles from isolated protein and rna. the amino acid sequence ... | 1993 | 8286435 |
| a novel open reading frame in tobacco mosaic virus genome coding for a putative small, positively charged protein. | from sequence comparisons between the tobramovirus genomes an open reading frame (orf-x) potentially encoding a small, positively charged protein (33- to 45-amino-acids long) was found to overlap the immediate 3' and 5' sides of the transport protein gene and coat protein gene, respectively. in vitro translation of the monocistronic artificial transcripts generated with t7 rna polymerase yielded a protein of m(r) 4000 (p4) and an unexpected trypsin-sensitive complex of m(r) 54,000 that was resis ... | 1993 | 8286438 |
| detection of antiviral and antitumoral fractions of chenopodium amaranticolor leaf extract. | based on the fact that chenopodium amaranticolor extracts showed inhibitory activity against tobacco mosaic virus (tmv) and ehrlich tumour (ea), tests were carried out to investigate whether the antiviral and antitumoral activity were caused by the same compounds. when the extract was purified by cm sephadex c-25 column, after precipitation with 90% ammonium sulphate, twenty active fractions against tmv and two pools of fractions active against ea were obtained. only one fraction with high absor ... | 1993 | 8302201 |
| coat protein-mediated resistance in transgenic tobacco expressing the tobacco mosaic virus coat protein from tissue-specific promoters. | coat protein-mediated resistance (cp-mr) was studied in transgenic nicotiana tabacum 'xanthi nn' and 'xanthi nn' that express chimeric tobacco mosaic virus (tmv) coat protein (cp) gene constructs using two different tissue-specific promoters. the phaseolus vulgaris pal2 promoter leads to gene expression in the upper leaf epidermis and the xylem, while the rolc promoter from agrobacterium rhizogenes leads to gene expression in pholem and leaf hair tip cells. tissue-specific gene expression was ve ... | 1993 | 8324249 |
| genetic engineering of potyvirus resistance using constructs derived from the zucchini yellow mosaic virus coat protein gene. | three versions of the zucchini yellow mosaic virus (zymv) coat protein gene were engineered for expression in plants: the full-length coat protein sequence, the conserved core portion of the gene, and an antisense version. these constructs were introduced into muskmelon (cucumis melo) and tobacco plants (nicotiana tabacum) via agrobacterium tumefaciens-mediated transformation; gene expression was verified by northern and western analysis. transgenic r0 and r1 muskmelon plants expressing the full ... | 1993 | 8324251 |
| tobamovirus helper specificity of satellite tobacco mosaic virus involves a domain near the 5' end of the satellite genome. | the molecular basis of the interactions between plant virus satellites and their helper viruses is not understood. the features of the satellite tobacco mosaic virus (stmv) genome that determine tobamovirus helper specificity were investigated using two independent strategies. the first tested the possible significance of regions of nearly identical sequence within the 3'-terminal 150 bases of the genomes of stmv and its natural helper virus, tobacco mild green mosaic virus (tmgmv). a chimeric s ... | 1993 | 8336115 |
| capsid protein gene sequences of four tobacco mosaic virus strains defective for virus assembly. | | 1993 | 8341610 |
| effects of the tom1 mutation of arabidopsis thaliana on the multiplication of tobacco mosaic virus rna in protoplasts. | for the multiplication of rna viruses, specific host factors are considered essential, but as of yet little is known about this aspect of virus multiplication. to identify such host factors, we previously isolated pd114, a mutant of arabidopsis thaliana, in which the accumulation of the coat protein of tobacco mosaic virus (tmv) in uninoculated leaves of an infected plant was reduced to low levels. the causal mutation, designated tom1, was single, nuclear, and recessive. here, we demonstrate tha ... | 1993 | 8350399 |
| a phylogenetically conserved sequence within viral 3' untranslated rna pseudoknots regulates translation. | both the 68-base 5' leader (omega) and the 205-base 3' untranslated region (utr) of tobacco mosaic virus (tmv) promote efficient translation. a 35-base region within omega is necessary and sufficient for the regulation. within the 3' utr, a 52-base region, composed of two rna pseudoknots, is required for regulation. these pseudoknots are phylogenetically conserved among seven viruses from two different viral groups and one satellite virus. the pseudoknots contained significant conservation at th ... | 1993 | 8355685 |
| plants transformed with a cistron of a potato virus y protease (nia) are resistant to virus infection. | an oligonucleotide carrying signals for translation initiation in plants was engineered upstream to a cdna clone containing nucleotides 5812-7260 of the potato virus y (pvy) genome. this fragment contains all but the first 100 5' terminal bases of the cistron encoding one of the pvy proteases (nia) as well as the first 251 bases of the next cistron (nib). nicotiana tabacum cv. sr1 plants were transformed with this fragment. the presence of the nia sequences in transformed plants was determined b ... | 1993 | 8356047 |
| [effect of synthesizing molecules of double-stranded rna in transgenic tobacco plants on resistance to tobacco mosaic virus]. | | 1993 | 8358319 |
| purification of pvyo and its soluble antigen by physico chemical means. | potato virus yo was purified by centrifugation of infected and minced plant tissue in the virus extraction rotor. as the initial seeding material was heavily contaminated with tobacco mosaic virus (tmv) this virus was isolated and antibody was elicited in chickens. the chicken antibody (igy) against tmv was used for removing this extraneous virus from the original pvyo seeding material prior to propagating pvyo in tobacco plants, cv glutinosa. | 1993 | 8367403 |
| a theoretical study of rotational diffusion models for rod-shaped viruses. the influence of motion on 31p nuclear magnetic resonance lineshapes and transversal relaxation. | information about the interaction between nucleic acids and coat proteins in intact virus particles may be obtained by studying the restricted backbone dynamics of the incapsulated nucleic acids using 31p nuclear magnetic resonance (nmr) spectroscopy. in this article, simulations are carried out to investigate how reorientation of a rod-shaped virus particle as a whole and isolated nucleic acid motions within the virion influence the 31p nmr lineshape and transversal relaxation dominated by the ... | 1993 | 8369411 |
| analysis of 31p nuclear magnetic resonance lineshapes and transversal relaxation of bacteriophage m13 and tobacco mosaic virus. | the experimentally observed 31p lineshapes and transversal relaxation of 15% (wt/wt) m13, 30% m13, and 30% tobacco mosaic virus (tmv) are compared with lineshapes and relaxation curves that are simulated for various types of rotational diffusion using the models discussed previously (magusin, p. c. m. m., and m. a. hemminga. 1993. biophys. j. 64:1851-1860). it is found that isotropic diffusion cannot explain the observed lineshape effects. a rigid rod diffusion model is only successful in descri ... | 1993 | 8369412 |
| la autoantigen enhances and corrects aberrant translation of poliovirus rna in reticulocyte lysate. | translation initiation on poliovirus rna occurs by internal binding of ribosomes to a sequence within the 5' untranslated region. we have previously characterized a hela cell protein, p52, that binds to a fragment of the poliovirus 5' untranslated region (k. meerovitch, j. pelletier, and n. sonenberg, genes dev. 3:1026-1034, 1989). here we report the purification of the hela p52. protein microsequencing identified p52 as la autoantigen. the la protein is a human antigen that is recognized by ant ... | 1993 | 8389906 |
| chicken igy-fc antibody elicited in a rabbit as first coat on frosted glass beads in immunoassays. | the observation of esteves and binaghi that the fc moieties of mammalian igg are antigenically similar but antigenically unrelated to the fc fraction of chicken igg (igy) was usefully applied in enzyme linked immuno-sorbent assay (elisa). in this communication its use in elisa of two plant viruses viz. tobacco mosaic virus (common strain) and grape vine a virus is illustrated. frosted glass beads were used as reagent carriers and the reactions were conducted in the wells of multi-titre plates. | 1993 | 8406625 |
| two amino acid substitutions in the tomato mosaic virus 30-kilodalton movement protein confer the ability to overcome the tm-2(2) resistance gene in the tomato. | the tm-2(2) resistance gene is used in most commercial tomato cultivars for protection against infection with tobacco mosaic virus and its close relative tomato mosaic virus (tomv). to study the mechanism of this resistance gene, cdna clones encompassing the complete genome of a tomv strain (tomv-2(2)) that was able to break the tm-2(2) resistance were generated. chimeric full-length viral cdna clones were constructed under the control of the cauliflower mosaic virus 35s rna promoter, combining ... | 1993 | 8411345 |
| hiv-1 proteinase as structural model of intercellular transport proteins of plant viruses. | intracellular movement of viral infections of plants requires a virus-encoded protein. alignment of amino acid sequences of central conserved regions of such proteins produced a sequence profile that resembled that of lentiviral proteinases. the known three-dimensional structure of the proteinase encoded by the human immunodeficiency virus-1 (hiv-1) may serve as a model for the three-dimensional structure of the central region of the plant viral proteins. secondary structures predicted for the p ... | 1993 | 8412221 |
| physiological compensation in antisense transformants: specific induction of an "ersatz" glucan endo-1,3-beta-glucosidase in plants infected with necrotizing viruses. | plant class i glucan endo-1,3-beta-glucosidases (beta-1,3-glucanase; 1,3-beta-d-glucan glucanohydrolase, ec 3.2.1.39) have been implicated in development and defense against pathogen attack. nevertheless, beta-1,3-glucanase deficiencies generated by antisense transformation of nicotiana sylvestris and tobacco have little biological effect. we report here that another beta-1,3-glucanase activity is induced in these deficient mutants after infection with necrotizing viruses. induction of class i b ... | 1993 | 8415609 |
| double-helical rna in satellite tobacco mosaic virus. | satellite tobacco mosaic virus (stmv) is the spherical satellite to an obligatory rod-shaped helper tobacco mosaic virus (tmv), which is required for replication. stmv has 60 protein subunits of m(r) 17,500 on a t = 1 icosahedral capsid containing a single-stranded rna genome of 1,059 bases. stmv appears similar to another virus, stnv, but is approximately 20 per cent smaller. it shows no amino-acid homology or immunological cross-reactivity with either stnv or its host tmv. here we report the x ... | 1993 | 8421525 |
| the tobamovirus capsid protein functions as a host-specific determinant of long-distance movement. | the tobamoviruses, tobacco mosaic virus (tmv) and odontoglossum ringspot virus (orsv), differ in the range of plant species that each can systemically infect. both viruses systemically infect nicotiana benthamiana similarly, but differ in the ability to systemically infect tobacco (n. tabacum). orsv is confined to the inoculated leaves of n. tabacum, whereas tmv causes a rapid systemic infection. genetic chimeras were created to identify viral genes involved in specific interactions in long-dist ... | 1993 | 8438560 |
| analysis of regulatory elements involved in stress-induced and organ-specific expression of tobacco acidic and basic beta-1,3-glucanase genes. | infection of tobacco by tobacco mosaic virus (tmv) induces coordinate expression of genes encoding acidic and basic beta-1,3-glucanase isoforms. these genes are differentially expressed in response to other treatments. salicylate treatment induces acidic glucanase mrna to a higher level than basic glucanase mrna. ethylene treatment and wounding strongly induce the basic glucanase genes but have little effect on genes encoding the acidic isoforms. furthermore, the basic glucanase genes are consti ... | 1993 | 8443340 |
| genomic position affects the expression of tobacco mosaic virus movement and coat protein genes. | alterations in the genomic position of the tobacco mosaic virus (tmv) genes encoding the 30-kda cell-to-cell movement protein or the coat protein greatly affected their expression. higher production of 30-kda protein was correlated with increased proximity of the gene to the viral 3' terminus. a mutant placing the 30-kda open reading frame 207 nucleotides nearer the 3' terminus produced at least 4 times the wild-type tmv 30-kda protein level, while a mutant placing the 30-kda open reading frame ... | 1993 | 8446627 |
| extracellular targeting of the vacuolar tobacco proteins ap24, chitinase and beta-1,3-glucanase in transgenic plants. | the nicotiana tabacum ap24 gene encoding a protein with antifungal activity toward phytophthora infestans has been characterized. analysis of cdna clones revealed that at least three ap24-like genes are induced in tobacco upon infection with tobacco mosaic virus. amino acid sequencing of the purified protein showed that ap24 is synthesized as a preproprotein from which an amino-terminal signal peptide and a carboxyl-terminal propeptide (ctpp) are cleaved off during post-translational processing. ... | 1993 | 8448358 |
| circadian expression and induction by wounding of tobacco genes for cysteine proteinase. | two sets of clones were isolated from a tobacco cdna library, utilizing as a probe a pcr fragment obtained from tomato cdna using a degenerate primer based on the sequence of tomato systemin. contrary to expectation, the clones did not correspond to tobacco homologues of tomato pro-systemin. however, the cdnas encoded two highly similar proteins with extensive structural homology to cysteine proteinases from a wide range of plant and animal species. northern blot analyses showed that in unstress ... | 1993 | 8448366 |
| regulation of pathogenesis-related protein-1a gene expression in tobacco. | pathogenesis-related protein-1a (pr-1a) is a protein of unknown function that is strongly induced during the onset of systemic acquired resistance (sar) in tobacco. the expression of pr-1a is under complex regulation that is controlled at least partially by the rate of transcription. in this study, we demonstrated that 661 bp of 5' flanking dna was sufficient to impart tobacco mosaic virus and salicylic acid inducibility to a reporter gene. the pr-1a promoter did not respond significantly to tre ... | 1993 | 8453300 |
| transient gene expression of foreign genes in preheated protoplasts: stimulation of expression of transfected genes lacking heat shock elements. | transfection of preheated petunia protoplasts with several biologically active dna constructs resulted in a significantly higher gene expression than that observed in transfected unheated protoplasts. it was observed with supercoiled, linearized and single-stranded dna structures that stimulation of transient gene expression in preheated protoplasts was neither dependent on the reporter gene nor on the regulatory elements used. heat treatment at 42 degrees c also increased expression in protopla ... | 1993 | 8467078 |
| rnase protection analyses show high genetic diversity among field isolates of satellite tobacco mosaic virus. | fifteen field isolates of satellite tobacco mosaic virus (stmv) were collected from wild nicotiana glauca plants within a 20-km2 area in southern california. analyses of the entire length of the satellite genomic rna of each isolate by rnase protection assays showed that there were 10 different genotypes within the 15 isolates, including some with regions of extreme divergence from the stmv type strain. this indicates a very high level of genetic diversity between natural stmv populations. isola ... | 1993 | 8480428 |
| predicting protein diffusion coefficients. | diffusion coefficients for proteins in water are predicted. the numerical method developed is general enough to be applied to a wide range of protein surface shapes, from rodlike to globular. results are presented for lysozyme and tobacco mosaic virus, and they are compared with actual data and with predictions made by less general methods. | 1993 | 8483901 |
| tobacco proteinase inhibitor i genes are locally, but not systemically induced by stress. | a cdna library of tobacco mosaic virus (tmv)-infected tobacco was screened with polymerase chain reaction products obtained using a degenerate primer corresponding to proteinase inhibitor i (pi-i) of tomato and potato. the resulting clones encoded two highly similar, putative tobacco pi-i proteins, indicating that both genes identified in tobacco are probably expressed. the tobacco pi-i's were approximately 50% identical to wound-inducible potato and tomato pi-i and 80% identical to an ethylene- ... | 1993 | 8490144 |
| inhibition of in vitro cotranslational disassembly of tobacco mosaic virus by monoclonal antibodies to the viral coat protein. | it has been shown by others that translation of tobacco mosaic virus (tmv) rna may begin before uncoating of particles is complete. we provide evidence that this cotranslational disassembly can be inhibited by incubating tmv treated at ph 8 with certain monoclonal antibodies (mabs) specific for tmv coat protein. the most efficient inhibition was achieved by incubation with some anti-metatope mabs known to bind to the tmv extremity that becomes disassembled first and contains the 5' end of the rn ... | 1993 | 8492095 |
| wild-type coat protein gene of tobacco mosaic virus mutant ni 2519. | tobacco mosaic virus mutant ni 2519 has a selected temperature-sensitive defect in the spreading of local lesions, and additional reported defects in virus assembly and in host range. here we show that the temperature-sensitive local lesion-spreading defect (which maps in the assembly origin within the gene encoding protein p30) is probably independent of mutations in the pseudoassembly origin or of host range defects resulting from other mutations in the coat protein. one new host range mutant ... | 1993 | 8492096 |
| tobacco mosaic virus infection of transgenic nicotiana tabacum plants is inhibited by antisense constructs directed at the 5' region of viral rna. | antisense (as) versions of two 51-nucleotide (nt) sequences near the 5' end of tobacco mosaic virus (tmv) rna have been shown to inhibit in vitro translation of the adjacent gene that encodes both the 126- and 183-kda proteins. these dna fragments have been cloned into the binary vector, pmon530, such that either the nopaline synthase (nos) promoter or cauliflower mosaic virus (camv) 35s rna promoter is used to drive synthesis of the corresponding sense and as rnas. transgenic nicotiana tabacum ... | 1993 | 8500765 |