Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| coat protein binding sites on rna 1 of alfalfa mosaic virus. | the largest genome segment, rna 1, of alfalfa mosaic virus forms complexes with viral coat protein. these complexes were subjected to digestion with ribonucleases t1 or a and filtered onto millipore filters. specific fragments were collected from the filters by phenol extraction. after electrophoretic separation in denaturing polyacrylamide gels, these fragments were sequenced. besides extracistronic fragments originating from the 3'-terminal region of rna 1, fragments were found originating fro ... | 1983 | 6404055 |
| structure of the 5'-terminal untranslated region of the genomic rnas from two strains of alfalfa mosaic virus. | we report the sequences of the 5'-terminal regions of the 3 alfalfa mosaic virus genomic rnas for the strasbourg strain (almv-s) and for a new isolate, almv-b; they are compared to similar data obtained by koper-zwarthoff et al. (nucleic acids res. 1980, 8, 5635-5647) for strain 425. the structure of these leaders is highly conserved in rnas 1 and 2. the length of the leader is 102, 100 and 101 nucleotides in rna1 for strains s, b and 425 respectively; 55 and 56 in rna2 for strains s and b respe ... | 1983 | 6856476 |
| complete nucleotide sequence of alfalfa mosaic virus rna3. | a full-length cdna clone of alfalfa mosaic virus (amv) rna3 was prepared and sequenced. the 2,037 base sequence contains two open reading frames of 903 and 666 nucleotides that code for a 32,400 dalton protein (32.4k protein) and the 24,380 dalton coat protein, respectively. a 5'-noncoding sequence of 240 bases preceeding the 32.4k protein contains homologous regions that may have a function in its translation. the intercistronic junction is 49 bases long, the last 36 bases representing the 5'-e ... | 1983 | 6856479 |
| inhibition of alfalfa mosaic virus rna and protein synthesis by actinomycin d and cycloheximide. | actinomycin d, added early after inoculation, reduces the production of infectious alfalfa mosaic virus in cowpea protoplasts by 90%. this reduction was associated with an inhibition of viral minus-strand and plus-strand rna synthesis, suggesting the involvement of host factors in these processes. coat protein production was less affected by the drug. addition of cycloheximide throughout the growth cycle resulted in an immediate cessation of coat protein production and an enhanced degradation of ... | 1983 | 6857995 |
| structure of a t = 1 aggregate of alfalfa mosaic virus coat protein seen at 4.5 a resolution. | a t = 1 empty aggregate of alfalfa mosaic virus coat protein had been crystallized in a hexagonal unit cell and its orientation was determined with the rotation function. a single heavy-atom derivative has now been prepared and the position of the two hg atoms per protein subunit were determined using a systematic patterson search procedure, given the particle orientation. phases, initially determined by single isomorphous replacement, were refined by six cycles of electron density averaging and ... | 1983 | 6876169 |
| sites of heavy atom substitution in alfalfa mosaic virus crystals. | 1983 | 6876170 | |
| complete nucleotide sequence of alfalfa mosaic virus rna 2. | double-stranded cdna of in vitro polyadenylated alfalfa mosaic virus (almv) rna 2 has been cloned and sequenced. the use of an oligodeoxyribonucleotide corresponding to the known sequence of the 5'-end of rna 2 to prime second-strand dna synthesis, enabled us to construct the complete primary structure of almv rna 2. the sequence of 2,593 nucleotides contains a long open reading frame for a protein of mr 89,753 starting at the first aug codon from the 5'-end. this coding region is flanked by a 5 ... | 1983 | 6304618 |
| identification of the leukemogenic protein of avian myeloblastosis virus and of its normal cellular homologue. | the genome of the replication-defective avian myeloblastosis virus (amv) contains an inserted cellular sequence (amv) that is part of the oncogene responsible for acute myeloblastic leukemia in chickens infected with amv. three antisera raised against distinct synthetic peptides predicted from the long open reading frame of amv specifically precipitated the same 48-kilodalton protein (p48amv) from leukemic myeloblasts but not from normal hematopoietic tissue, fibroblasts, or from fibroblasts inf ... | 1983 | 6304685 |
| the product of the retroviral transforming gene v-myb is a truncated version of the protein encoded by the cellular oncogene c-myb. | avian myeloblastosis virus (amv) is an oncogenic retrovirus that rapidly causes myeloblastic leukemia in chickens and transforms myeloid cells in culture. amv carries an oncogene, v-myb, that is derived from a cellular gene, c-myb, found in the genomes of vertebrate species. we constructed a plasmid vector that allows expression of a portion of the coding region for v-myb in a procaryotic host. we then used the myb-encoded protein produced in bacteria to immunize rabbits. the antisera obtained p ... | 1983 | 6305504 |
| the transforming gene of avian myeloblastosis virus (amv): nucleotide sequence analysis and identification of its translational product. | the genome of the avian myeloblastosis virus (amv) has undergone a sequence substitution in which a portion of the region normally coding for the env protein has been replaced by cellular sequences. we have determined the complete nucleotide sequence of this region. examination of the amv oncogenic sequence revealed an open reading frame starting with the initiation codon atg and terminating with the triplet tag within the acquired cellular sequences and terminating with the triplet tag at a poi ... | 1983 | 6305788 |
| tripartite structure of the avian erythroblastosis virus e26 transforming gene. | only two avian oncogenic viruses specifically cause acute leukaemias yet do not transform chicken fibroblasts in culture: e26, which causes erythroblastosis and a low level of concomitant myeloblastosis in chickens, and avian myeloblastosis virus (amv), which causes myeloblastosis exclusively. both viruses are replication-defective and share a sequence termed myb (also known as amv) which is unrelated to essential virion genes and is therefore thought to be part of the transforming onc genes of ... | 1983 | 6316155 |
| 5'-conformation of capped alfalfa mosaic virus ribonucleic acid 4 may reflect its independence of the cap structure or of cap-binding protein for efficient translation. | most eukaryotic mrnas are characterized by the presence of a 5'-terminal cap structure (m7gpppn), and removal of the cap or translation of capped mrnas in the presence of cap analogues (m7g) results in most cases in a significant decrease in the translational efficiency of the mrnas. one way of explaining the importance of the 5'-cap is that cap-binding proteins recognize the cap structure, destabilize the mrna secondary structure, and thus allow the 40s ribosomal subunit to bind to the mrna [so ... | 1983 | 6317016 |
| production and characterization of monoclonal antibodies against avian myeloblastosis virus. | hybridomas were prepared by fusion of mouse myeloma cell line sp2/0 with lymphocytes from mice immunized with avian myeloblastosis virus (amv). the specificity of each monoclonal antibody was characterized by radioimmunoassay (ria) using purified viral core proteins, immunoprecipitation of radioactively labeled virus (35s-methionine-labeled amv, 125j-labeled amv) and immunoblotting. one monoclonal antibody (ic11) which is of igg1 subclass, and two other monoclonal antibodies (if9 and ib8), both ... | 1983 | 6318135 |
| transforming ability of avian defective leukemia viruses in early embryogenesis. | the response to infection of chicken hemopoietic cells derived from the early stages of embryogenesis by avian myeloblastosis virus (amv) and avian erythroblastosis virus (aev) was investigated. it was found that erythroid progenitor cells were present in the blastoderm at a higher frequency than that of myeloid progenitor cells. these results correlate with the observation that target cells for aev were found to be more numerous than those for amv. therefore, blastoderm cells are of potential v ... | 1983 | 6297153 |
| complete nucleotide sequence of alfalfa mosaic virus rna 1. | double-stranded cdna of alfalfa mosaic virus (almv) rna 1 has been cloned and sequenced. from clones with overlapping inserts, and other sequence data, the complete primary sequence of the 3644 nucleotides of rna 1 was deduced: a long open reading frame for a protein of mr 125,685 is flanked by a 5'-terminal sequence of 100 nucleotides and a 3' noncoding region of 163 nucleotides, including the sequence of 145 nucleotides the three genomic rnas of almv have in common. the two uga-termination cod ... | 1983 | 6298738 |
| organization of chicken dna sequences homologous to the transforming gene of avian myeloblastosis virus. ii. isolation and characterization of lambda proto-amv dna recombinant clones from a library of leukemic chicken dna. | several lambda proto-amv recombinants isolated from a lambda charon 4a library of leukemic chicken dna were analyzed by using various restriction endonucleases and hybridization with specific probes representing different regions of the transforming gene of avian myeloblastosis virus. the position of 30 sites for 11 different restriction endonucleases was established in the proto-amv region of chicken dna. identical restriction endonuclease maps were obtained for the normal and leukemic dnas in ... | 1983 | 6300463 |
| the mechanism of inhibition of avian myeloblastosis virus reverse transcriptase by a dialdehyde derivative of atp. inactivation of essential sulfhydryl group function. | the dialdehyde derivative of atp inhibits dna synthesis by amv reverse transcriptase, while the polymerase-associated ribonuclease h activity is significantly resistant to this reagent. neither atp nor its dialcohol form effectively block dna synthesis, indicating that the aldehyde moiety is required for inhibition. the nature of the reactivity of dialdehyde-atp with amv reverse transcriptase has been examined and we find that: (a) inhibition is non-competitive with respect to substrate deoxynuc ... | 1983 | 6189518 |
| a higher affinity of amv reverse transcriptase for template-primers correlates with a lower rate of dna synthesis. | the kinetics of copying of poly (a)--oligo (dt) and poly (c)--oligo (dg) by reverse transcriptase from avian myeloblastosis virus have been studied, and binding affinity of enzyme for template-primer and primer alone have been determined separately. although the maximal rate of dna synthesis obtained with poly (c)-oligo (dg) is higher than that for poly (a)-oligo (dt), the binding affinity of the enzyme for poly (c)-oligo (dg) or oligo (dg) is considerably lower than that for poly (a)--oligo (dt ... | 1983 | 6193009 |
| the human dna locus related to the oncogene myb of avian myeloblastosis virus (amv): molecular cloning and structural characterization. | chicken and human cell dna contains sequences homologous to the avian myeloblastosis virus oncogene, v-myb. these cellular sequences, c-myb (human) and c-myb (chicken), were isolated from libraries of human or chicken cell dna fragments, generated by partial digestion with the restriction enzymes alui and haeiii, and compared. the chicken c-myb locus isolated from two distinct overlapping recombinant phages, contained five contiguous ecori fragments of 5.4, 1.1, 2.1, 2.2 and 9 kbp, accounting fo ... | 1983 | 6194989 |
| use of monoclonal antibodies against avian retroviral protein p19 for competitive radioimmunoassay and immunodiffusion. | monoclonal antibodies were used in competitive binding assays to investigate the arrangement of three epitopes on the protein p19 of avian myeloblastosis virus (amv). it was reasoned that if the epitopes recognized by two monoclonal antibodies are physically close, the binding of one antibody will sterically block the binding of the second; conversely no blocking will occur if the epitopes are sufficiently distant. the results of these competitive binding assays demonstrated the presence of two ... | 1983 | 6197663 |
| high-level expression of oncogenes in escherichia coli. | a plasmid, pjl6, was constructed that contains a unique cla i site 12 codons beyond the bacteriophage lambda cii gene initiation codon, as well as an adjacent unique hind iii site. these sites allowed us to fuse the sequences from the avian myelocytomatosis virus (mc29) v-myc gene, the avian myeloblastosis virus (amv) v-myb gene, and the harvey murine sarcoma virus (ha-musv) v-ras gene to the amino-terminal portion of the cii gene. transcription of the hybrid genes is controlled from the lambda ... | 1983 | 6101025 |
| competition between the rna 3 molecules of wildtype alfalfa mosaic virus and the temperature-sensitive mutant tbts 7(uv). | in mixed infections of wildtype (wt) alfalfa mosaic virus (amv) and a temperature-sensitive mutant tbts 7(uv), which carries a thermosensitive defect in the early function of the coat protein, the mutant symptoms were not found at 30°c. in the progeny from these mixed infections almost no mutant coat protein and no mutant rna 3 could be detected. even at 23°c there was some loss of mutant rna 3 and coat protein from the progeny of the mixed infections. analysis and comparison of mutant and wt ds ... | 1983 | 24318205 |
| age dependence of cowpea protoplasts for uptake of spermidine and infectibility by alfalfa mosaic virus. | cowpea protoplasts were prepared from plants of different ages and examined for their ability to take up polyamines and for their infectibility by alfalfa mosaic virus. a lag period of ∼20 h was necessary before the onset of rapid polyamine uptake; the occurrence of this rapid uptake depended on the age of the leaves used for protoplast preparation. the percentage of infection of cowpea protoplasts by alfalfa mosaic virus, and the amount of virus produced also depended on the age of the plants u ... | 1983 | 24318141 |
| an alfalfa mosaic virus rna 2 mutant, which does not induce a hypersensitive reaction in cowpea plants, is multiplied to a high concentration in cowpea protoplasts. | a mutant of alfalfa mosaic virus (amv), which in contrast to wild type (wt) can invade cowpea plants systemically, is replicated more efficiently in cowpea protoplasts than the wt. mutant preparations isolated from infected cowpea protoplasts contained a higher amount of middle component (m, containing rna 2) than wt preparations. both in cowpea plants and in cowpea protoplasts a wt phenotype is obtained upon addition of wt m to this mutant, suggesting a correlation between the type of plant rea ... | 1983 | 24318140 |
| flow cytometric analysis of tobacco and cowpea protoplasts infected in vivo and in vitro with alfalfa mosaic virus. | immunofluorescence flow cytometry was used to study the distribution of viral antigen in protoplast populations. protoplasts were isolated from healthy and alfalfa mosaic virus (amv) infected tobacco leaves (designated in vivo infected). furthermore isolated tobacco and cowpea protoplasts were infected in vitro with amv. the fitc-conjugated antibodies could penetrate formaldehyde fixed protoplasts. the flow cytometric measurements were rapid and reproducible. comparable immunofluorescence patter ... | 1983 | 24318100 |
| replication of temperature-sensitive mutants of alfalfa mosaic virus in protoplasts. | six mutants of alfalfa mosaic virus (aimv), previously found to have conditionally lethal defects when inoculated to tobacco leaf discs, were assayed for a temperature-sensitive (ts) phenotype in cowpea protoplasts. at 30 degrees the virus production of four mutants was less than 10% of that obtained at 25 degrees , whereas wild-type aimv multiplied with similar efficiencies at both temperatures. supplementation experiments performed in protoplasts with two mutants indicated the presence of muta ... | 1983 | 18638887 |
| time course of alfalfa mosaic virus rna and coat protein synthesis in cowpea protoplasts. | a study was made of the time course of the synthesis of viral plus-strand rna, minus-strand rna, and coat protein in alfalfa mosaic virus-infected cowpea protoplasts. the three genomic rnas were synthesized at different rates, as were their corresponding minus-strands. we conclude that viral rna synthesis is regulated both at the level of minus-strand production and the level of plus-strand production. the synthesis of subgenomic rna 4 was slower than that of its corresponding genomic rna (rna 3 ... | 1983 | 18638888 |
| a mutant of alfalfa mosaic virus with an unusual structure. | a spontaneous mutant of alfalfa mosaic virus (amv) with an altered structure is described. by analysis of pseudorecombinants the mutation(s) responsible for the altered structure were assigned to rna 3. by in vitro translation and serology it is shown that both proteins (35k protein and coat protein) encoded by rna 3 are changed. the mutation(s) present in rna 3 also have an effect on the ratio of the three genomic rnas, both in virion as well as in double-stranded rna preparations. compared to ... | 1983 | 18638937 |
| removal of the n-terminal part of alfalfa mosaic virus coat protein interferes with the specific binding to rna 1 and genome activation. | trypsinized coat protein of alfalfa mosaic virus lacking 25 amino acids at its n terminus still has the capability to form complexes with rna which are detectable by sedimentation in sucrose gradients. however, it does not protect specific sites on the rna against degradation by ribonuclease, as the native coat protein does (d. zuidema, m. f. a. bierhuizen, b. j. c. cornelissen, j. f. bol, and e. m. j. jaspars (1983) virology 125, 361-369.). the trypsinized coat protein has lost the capacity of ... | 1983 | 18639115 |
| virus protein synthesis in alfalfa mosaic virus infected alfalfa protoplasts. | four proteins unique to virus infection were synthesized in alfalfa mosaic virus-infected alfalfa mesophyll protoplasts. these proteins, p1, p2, p3, and coat protein comigrated on electrophoresis with the major in vitro translation products of rna 1, rna 2, rna 3, and rna 4, respectively. p1, p3, and coat protein were observed at 5 hr post inoculation; p2 was detected at 9 hr post inoculation. the three nonstructural proteins accumulated most rapidly early in infection until about 15 hr post ino ... | 1983 | 18639174 |
| altered balance of the synthesis of plus- and minus-strand rnas induced by rnas 1 and 2 of alfalfa mosaic virus in the absence of rna 3. | the synthesis of viral plus-strand and minus-strand rnas in cowpea protoplasts inoculated with mixtures of alfalfa mosaic virus nucleoproteins (b, m, tb, and ta) was analyzed by the northern blotting technique. a mixture of b, m, and tb induced the synthesis of plus-strand rnas 1, 2, 3, and 4 and three minus-strand rnas corresponding to rnas 1, 2, and 3, respectively. compared to this complete infection, a mixture of b and m induced the synthesis of a reduced amount of plus-strand rnas 1 and 2 a ... | 1983 | 18644274 |
| the use of elisa for detection of exogenous and endogenous avian leukosis viral antigens in basic breeding flocks. | an enzyme-linked immunosorbent assay (elisa) for avian leukosis/ sarcoma virus (alv) group-specific (gs) antigens was used to study the identification of hens which congenitally excrete exogenous alv. the sensitivity of this assay was compared with that of the phenotypic mixing test (pmt) and the direct complement fixation test (cft) by testing limiting dilutions of purified avian myeloblastosis virus (amv), embryo homogenates and albumens. about 0.4 ng/ml of purified amv protein could be detect ... | 1983 | 18766804 |
| comparative investigations on the coat protein binding sites of the genomic rnas of alfalfa mosaic and tobacco streak viruses. | the genomic rnas of alfalfa mosaic virus (aimv) and tobacco streak virus (tsv) form complexes with viral coat protein. these complexes were subjected to digestion with ribonuclease t1 and filtered onto millipore filters. it was shown that the major coat protein binding sites are located at the 3' ends of the genomic rna species of aimv and tsv in both heterologous and homologous rna-coat protein combinations. internal coat protein binding sites were found as well. although there is homology betw ... | 1984 | 18639816 |
| minimum requirements for specific binding of rna and coat protein of alfalfa mosaic virus. | coat protein-protected fragments of alfalfa mosaic virus rna (almv-rna) and tobacco streak virus rna (tsv-rna), which were isolated as described [d. zuidema, m. f. a. bierhuizen, b. j. c. cornelissen, j. f. bol, and e. m. j. jaspars (1983)virology, 125, 361-369], were tested for their ability to rebind almv coat protein in the presence of an excess of escherichia coli trna by means of a nitrocellulose filter retention assay. in order to obtain the minimum requirements for coat protein binding, a ... | 1984 | 18639820 |
| nonstructural alfalfa mosaic virus rna-coded proteins present in tobacco leaf tissue. | the proteins synthesized under the direction of alfalfa mosaic virus rnas in tobacco leaves have been examined under conditions of suppressed host protein synthesis. besides the coat protein we could detect a 22k (k = apparent molecular weight in thousands), a 35k, and a set of 54k proteins. the 22k protein is serologically related to the coat protein. the 35k protein comigrated with the 35k protein whose synthesis is directed by rna 3 in vitro the 54k proteins are serologically related to the 3 ... | 1984 | 18639831 |
| homology between the proteins encoded by tobacco mosaic virus and two tricornaviruses. | a comparison was made of the amino acid sequences of the proteins encoded by rnas 1 and 2 of alfalfa mosaic virus (a1mv) and brome mosaic virus (bmv), and the 126k and 183k proteins encoded by tobacco mosaic virus (tmv). three blocks of extensive homology of about 200 to 350 amino acids each were observed. two of these blocks are located in the a1mv and bmv rna 1 encoded proteins and the tmv encoded 126k protein; they are situated at the n-terminus and c-terminus, respectively. the third block i ... | 1984 | 24310571 |
| neoplastic transformation by e26 leukemia virus is mediated by a single protein containing domains of gag and myb genes. | the genome of avian leukemia virus e26 shares homology with v-myb, the oncogene of avian myeloblastosis virus, and encodes a protein with an mr of 135,000. analyses of tryptic oligopeptides show that this protein is related to the proteins encoded by gag (pr76gag) as well as v-myb (p45v-myb[amv] ) and c-myb (p75c-myb). we found no evidence for the existence of additional myb-related proteins or subgenomic species of myb-related rna in myeloblasts transformed by strain e26. | 1984 | 6199515 |
| targeted mutagenesis in vitro: lac repressor mutations generated using amv reverse transcriptase and dbrutp. | we have cloned the gene for the lac operon repressor (laci) of escherichia coli into the m13 related phage f1. mutagenesis of the laci gene was performed in vitro by filling dsdna molecules gapped over the laci gene with avian myeloblastosis virus (amv) reverse transcriptase. laci mutants are found at a frequency of 1 in 10(4) using a genetic screen in vivo. for two-thirds of the 60 mutants, lesions were identified within the first 400 bases of laci, by dideoxy sequencing. an unexpectedly wide r ... | 1984 | 6203097 |
| complete nucleotide sequence of rna 3 from alfalfa mosaic virus, strain s. | we report the sequence of rna 3 from strain s of alfalfa mosaic virus (2,055 nucleotides). this rna codes for a 32.4 kd protein (p3) and for the 24 kd coat protein (p4). the largest part of the sequence was established using rna sequencing methods. the completion of the sequence in the region coding for p3 was achieved with cloned cdna synthesized after priming at internal sites of rna 3. comparison of the rna sequences coding p3 and p4 proteins in strain s with those reported in the literature ... | 1984 | 6205697 |
| assessment of mutagenic efficiency of two carcinogen-modified nucleosides, 1,n6-ethenodeoxyadenosine and o4-methyldeoxythymidine, using polymerases of varying fidelity. | terminal deoxynucleotidyl transferase (tdt) was used to prepare copolymers of da and 1,n6-ethenodeoxyadenosine (epsilon da). when used as templates for escherichia coli dna polymerase i (pol i) and compared with poly (da), normal dttp incorporation was not significantly affected by the presence of 7% epsilon da. dgtp misincorporation was only slightly increased and occurred about once for every 500 epsilon da residues. the error-prone polymerase from avian myeloblastosis virus (amv reverse trans ... | 1984 | 6205783 |
| computer-aided nucleic acid secondary structure modeling incorporating enzymatic digestion data. | we present a computer-aided method for determining nucleic acid secondary structure. the method utilizes a program which has the capability to filter matrix diagonal data on the basis of diagonal length, stabilization energy, and chemical and enzymatic data. the program also allows the user to assign selected regions of the structure as uniquely single-stranded or paired, and to filter out "trade-off" structures on the basis of such pairing. in order to demonstrate the utility of the program we ... | 1984 | 6320093 |
| candidate products of avian myeloblastosis virus oncogene region produced by in vitro translation of genomic rna. | avian myeloblastosis virus (amv) genomic rna was translated in vitro to identify the amv transforming gene (myb) product(s). full-length rna yielded, in addition to the expected pr76gag, a gag-related product of 92,000 daltons which did not appear to be a gag-oncogene fusion protein. subgenomic amv rna in vitro translation, nonstructural products (specific for amv) were of 54,000, 49,000 and 34,000 daltons. based on their sizes and similar peptide maps for the smaller two proteins, it is propose ... | 1984 | 6321391 |
| regional assignment of human protooncogene c-myb to 6q21----qter. | using human-mouse somatic cell hybrids containing different parts of chromosome 6 and a dna probe of the oncogene (v-myb) of avian myeloblastosis virus (amv), we regionally mapped by southern blot techniques the human cellular myb (c-myb) protooncogene to 6q21----qter. | 1984 | 6322357 |
| chromosomal localization of the human proto-oncogene c-ets. | e26 is an acute leukaemia avian retrovirus which induces myeloblastosis and erythroblastosis in vivo and transforms erythroblasts and myeloblasts in vitro. it contains the oncogene v-myb (ref. 4), first described for avian myeloblastosis virus (amv), as well as a second specific nucleotide sequence, v-ets located 3' to v-myb (refs 5,6). we have reported that v-ets has a cellular counterpart (c-ets) in chicken and human dna. now, using two independent methods--hybridization with human c-ets probe ... | 1984 | 6462246 |
| la crosse virions contain a primer-stimulated rna polymerase and a methylated cap-dependent endonuclease. | purified la crosse virions in vitro were found to transcribe their negative polarity (-)rna genomes. this polymerase activity was stimulated by oligonucleotides such as (a)ng, cap analogs such as m7gpppam, and natural mrnas such as alfalfa mosaic virus rna 4. for (a)ng- and alfalfa mosaic virus rna 4-stimulated reactions, evidence is presented that these rnas stimulate activity by acting as primers for viral transcription. the cap analogs appear to stimulate activity via an alternative mechanism ... | 1984 | 6481853 |
| complete nucleotide sequence of tobacco streak virus rna 3. | double-stranded cdna of in vitro polyadenylated tobacco streak virus (tsv) rna 3 has been cloned and sequenced. the complete primary structure of 2,205 nucleotides reveals two open reading frames flanked by a leader sequence of 210 bases, an intercistronic region of 123 nucleotides and a 3'-extracistronic sequence of 288 nucleotides. the 5'-terminal open reading frame codes for a mr 31,742 protein, which probably corresponds to the only in vitro translation product of tsv rna 3. the 3'-terminal ... | 1984 | 6546793 |
| nucleotide sequence of cucumber-mosaic-virus rna 2 reveals a translation product significantly homologous to corresponding proteins of other viruses. | the nucleotide sequence of the 3035 residues of rna 2 (mr 1.03 x 10(6) ) of the q strain of cucumber mosaic virus (cmv) was determined by sequencing m13 clones of the rna 2 cdna and by dideoxy sequencing using primers prepared either from m13 clones or by chemical synthesis. a single long open reading frame starts at the second aug from the 5' end of rna 2 and encodes 839 amino acids (mr 94333). this frame has flanking regions of 92 nucleotides at the 5' terminus and 423 nucleotides at the 3' te ... | 1984 | 6547906 |
| striking similarities in amino acid sequence among nonstructural proteins encoded by rna viruses that have dissimilar genomic organization. | the plant viruses alfalfa mosaic virus (amv) and brome mosaic virus (bmv) each divide their genetic information among three rnas while tobacco mosaic virus (tmv) contains a single genomic rna. amino acid sequence comparisons suggest that the single proteins encoded by amv rna 1 and bmv rna 1 and by amv rna 2 and bmv rna 2 are related to the nh2-terminal two-thirds and the cooh-terminal one-third, respectively, of the largest protein encoded by tmv. separating these two domains in the tmv rna seq ... | 1984 | 6611550 |
| subcellular localization of proteins encoded by oncogenes of avian myeloblastosis virus and avian leukemia virus e26 and by chicken c-myb gene. | analysis of the subcellular location of the proteins encoded by the oncogenes of avian myeloblastosis virus and avian leukemia virus e26 ( p45v -myb and p135gag -myb-ets, respectively) and by the chicken c-myb gene ( p75c -myb) shows that all three proteins are located in the nucleus. in amv-infected (but not transformed) chicken fibroblasts p45v -myb also resides in the nucleus, indicating that a nuclear location of p45v -myb in these cells is not sufficient to achieve transformation. in amv-tr ... | 1984 | 6327074 |
| in vitro translation of fractionated rna isolated from chicken leukaemic plasma virus (amv). a 76k pol-related polypeptide. | the 60s rna was isolated from amv-chicken leukaemic plasma virus. it was poly(a) selected, sized on sucrose gradients, and each fraction of rna translated in vitro in the rabbit reticulocyte lysate. it was shown by immunoprecipitation and peptide mapping that p76gag was translated from genome-length rna, a 76k pol-related polypeptide from 24-26s rna and a 34k protein, not related to any virion proteins, from 14s rna. the possible relationship of these in vitro translated proteins to known genome ... | 1984 | 6083884 |
| avian myeloblastosis virus and e26 virus oncogene products are nuclear proteins. | the defective acute leukemia viruses avian myeloblastosis virus (amv) and e26 virus each contain an inserted cellular sequence related to the same highly conserved cellular gene, proto-amv. the oncogenes of these two retroviruses differ from this cellular proto-oncogene in gene structure, transcript structure, and gene product. the product of the amv oncogene (myb) is a 48,000 mr protein, p48myb, encoded by a transduced segment (amv) of proto-amv flanked by short helper-virus-derived terminal se ... | 1984 | 6087315 |
| functional characterization of eukaryotic mrna cap binding protein complex: effects on translation of capped and naturally uncapped rnas. | we examined the effects of a eukaryotic mrna cap binding protein (cbp) complex purified by cap analogue affinity chromatography [edery, i., humebelin, m., darveau, a., lee, k.a. w., milburn, s., hershey, j.w.b., trachsel, h., & sonenberg, n. (1983) j. biol. chem. 258, 11398 11403], on translation of several capped and naturally uncapped mrnas in extracts prepared from poliovirus-infected or mock-infected hela cells. the cbp complex has activity that restores capped mrna (globin, tobacco mosaic v ... | 1984 | 6089873 |
| avian erythroblastosis virus e26: nucleotide sequence of the tripartite onc gene and of the ltr, and analysis of the cellular prototype of the viral ets sequence. | an intact 5.7-kb provirus of the avian erythroblastosis virus e26 has been molecularly cloned for comparisons with avian myeloblastosis virus (amv) and other avian tumor viruses. e26 and amv transform hemopoietic cells exclusively. both cause myeloblastosis, but e26 also causes erythroblastosis. sequence analysis of the proviral dna showed that: the tripartite transforming gene of e26 forms a contiguous reading frame of 1046 codons, including 272 gag, 283 mybe, and 491 ets codons. no subgenomic ... | 1984 | 6097027 |
| avian monocytic leukemia cells release fibroblast growth factor: implications to associated myelofibrosis. | the marrow of chicks with leukemia induced by avian 'myeloblastosis' virus (amv) exhibited a 5-10-fold increase in the number of fibroblast colony-forming cells (cfu-f). the increased cfu-f correlated with a mild fibrosis which can be seen in the marrow of these animals. fibroblast proliferation likely was not simply due to the presence of leukemic cells because addition of formaldehyde-fixed peripheral leukemic cells failed to initiate cfu-f growth. conditioned medium (cm) from day-4 cultures o ... | 1985 | 3866125 |
| induction of colony-stimulating factor from quiescent fibroblasts by avian macrophages and monocytic leukemic cells. | confluent, quiescent chick embryo fibroblasts maintained in protein-free medium released csf(s) active on granulocyte and monocyte progenitors and on monocytic leukemia cells induced by avian 'myeloblastosis' virus (amv) when exposed to formaldehyde-fixed amv leukemic cells. the csf was assayed under serum-free conditions. of several normal cell types tested including populations enriched for blast cells, only macrophages exhibited this capacity. | 1985 | 3935882 |
| sindbis virus proteins nsp1 and nsp2 contain homology to nonstructural proteins from several rna plant viruses. | although the genetic organization of tobacco mosaic virus (tmv) differs considerably from that of the tripartite viruses (alfalfa mosaic virus [almv] and brome mosaic virus [bmv]), all of these rna plant viruses share three domains of homology among their nonstructural proteins. one such domain, common to the almv and bmv 2a proteins and the readthrough portion of tmv p183, is also homologous to the readthrough protein nsp4 of sindbis virus (haseloff et al., proc. natl. acad. sci. u.s.a. 81:4358 ... | 1985 | 3968720 |
| influence of template primary and secondary structure on the rate and fidelity of dna synthesis. | high resolution gel electrophoresis was used to monitor the successive addition of dnmp residues onto the 3'-oh ends of discrete 5'-32p-primers, during dna synthesis on natural templates. resulting autoradiographic banding patterns revealed considerable variation in the relative rates of incorporation at different positions along the template. the pattern of "pause sites" along the template was unique for each of three different dna polymerases (polymerase i (the "large fragment" form of escheri ... | 1985 | 3972819 |
| translational discrimination between the four rnas of alfalfa mosaic virus. a quantitative evaluation. | in an attempt to relate the translational characteristics of alfalfa mosaic virus (a1mv) rnas to their structure [ravelonandro et al. (1983) nucleic acids res. 11, 2815-2826; gehrke et al. (1983) biochemistry 22, 5157-5164] we measured the relative affinities (discrimination ratios) of these rnas for the initiation complex, in the wheat germ extract and in the nuclease-treated reticulocyte lysate, using a competition method designed by brendler et al. [(1981) j. biol. chem. 256, 11747-11754]. as ... | 1985 | 3979386 |
| nucleotide sequence of cucumber mosaic virus rna. 1. presence of a sequence complementary to part of the viral satellite rna and homologies with other viral rnas. | the nucleotide sequence of the 3389 residues of rna 1 (mr 1.15 x 10(6) of the q strain of cucumber mosaic virus (cmv) was determined, completing the primary structure of the cmv genome (8617 nucleotides). cmv rna 1 was sequenced by the dideoxy-chain-termination method using m13 clones carrying rna 1 sequences as well as synthetic oligonucleotide primers on rna 1 as a template. at the 5' end of the rna there are 97 noncoding residues between the cap structure and the first aug (98-100), which is ... | 1985 | 4018086 |
| human leukocyte interferon does not inhibit alfalfa mosaic virus in protoplasts or tobacco tissue. | enzyme-linked immunosorbent assays and local lesion infectivity assays showed that recombinant leukocyte interferons, rifn-alpha a and rifn-alpha d, did not reproducibly affect the accumulation of alfalfa mosaic virus in tobacco leaf discs or in tobacco or alfalfa protoplasts when applied within 1 hr after inoculation with virus. | 1985 | 4060586 |
| 2'-fluoro-2'-deoxypolynucleotides as templates and inhibitors for rna- and dna-dependent dna polymerases. | poly(2'-fluoro-2'-deoxyadenylic acid) (poly(dafl)) and poly(2'-deoxycytidylic acid) (poly(dcfl)) were tested as templates in dna synthesis reactions catalyzed by xenopus laevis oocytes dna polymerase alpha, mouse cell dna polymerase gamma and avian myeloblastis virus (amv) reverse transcriptase. poly(dafl).(dt)12 can fully substitute for poly(ra).(dt)12 as template with dna polymerase gamma, to 50% with reverse transcriptase, but was poorly recognized by dna polymerase alpha. dna synthesis by re ... | 1985 | 2578820 |
| formycin 3' end modified trnatrp. recognition by avian myeloblastosis virus reverse transcriptase and primer function. | primer trnatrp has been modified at the 3' end by adenosine analogues: 2'deoxyadenosine, 3'deoxyadenosine, 3' amino-3' deoxyadenosine and formycin. aminoacylation of modified trnatrp with cognate aminoacyl-trna synthetase and primer function for dna synthesis catalyzed by amv reverse transcriptase have been studied. the trnatrp was able to accept tryptophan but did not initiate the dna synthesis directed by 35s amv rna. recognition of modified trnatrp by amv reverse transcriptase was not affecte ... | 1985 | 2412559 |
| ribosomes are stalled during in vitro translation of alfalfa mosaic virus rna 1. | in the presence of plant trnas the full-length translation product of alfalfa mosaic virus rna 1 is produced in rabbit reticulocytes only at low mrna concentration. at higher mrna concentration translation is restricted to the 5' half of rna 1. at high mrna concentration the full-length product can be formed when additional plant trna and glutamine are supplied to the translation mixture. in contrast, in the presence of yeast or calf liver trna the translation pattern of alfalfa mosaic virus rna ... | 1985 | 2414104 |
| cap accessibility correlates with the initiation efficiency of alfalfa mosaic virus rnas. | the rate of cap removal from the alfalfa mosaic virus (a1mv) rnas with tobacco acid pyrophosphatase (tap) depends on the rna species. at 37 degrees c and in the absence of divalent cation, rna 3 reacts more slowly than the other three, which are decapped at similar rates. in the presence of magnesium, at 25 degrees c, tap also discriminates against rna 1. thus the order of reactivity with tap largely mimics the hierarchy of initiation efficiencies of the a1mv rnas (godefroy-colburn et al., prece ... | 1985 | 2983983 |
| dna-binding activity is associated with purified myb proteins from amv and e26 viruses and is temperature-sensitive for e26 ts mutants. | oncogene protein products from avian myeloblastosis virus, p48v-myb, and from avian leukemia virus e26, p135gag-myb-ets, are located predominantly in the nucleus of nonproducer bone marrow cell clones, as revealed by indirect immunofluorescence. both oncogene proteins were purified by immunoaffinity chromatography using monoclonal antibodies against p19 and immunoglobulins specific for myb, which was expressed in bacteria for antibody production. the purified proteins bind to dna in vitro. in co ... | 1985 | 2985272 |
| transformation of brown leghorn chicken embryo fibroblasts by avian myeloblastosis virus proviral dna. | brown leghorn chicken embryo fibroblasts were transfected with a mixture of avian myeloblastosis virus (amv) and myeloblastosis-associated virus type 1 (mav1) proviral dna purified from lambda-charon 4a recombinant clones. a transformed cell line (t1am) able to grow without anchorage in semisolid medium was obtained. the presence of both proviral amv and mav sequences was detected in t1am dna by hybridization with v-myb- and mav1-specific probes. altered amv and mav1 proviral genomes were found ... | 1985 | 2989555 |
| sites of recombination between the transforming gene of avian myeloblastosis virus and its helper virus. | the sites of recombination between the transforming gene of avian myeloblastosis virus (amv) and its natural helper myeloblastosis-associated virus (mav) have been determined. in amv, the cellular sequence substituting for the viral envelope (env) gene gives rise to a different carboxyl terminus of the dna polymerase. the 5'-recombination site coincides with the rna splice acceptor site for the production of env mrna in mav-infected cells. the 3'-recombination site reveals that the last 11 amino ... | 1985 | 2992154 |
| detection and localization of the v-myb(amv) gene products of avian myeloblastosis virus by a synthetic peptide antiserum. | an antiserum made against a synthetic peptide from an internal region of the predicted amino acid sequence of the avian myeloblastosis virus (amv) transforming v-myb(amv) gene identified two products, p46v-myb(amv) and p32v-myb(amv), which were localized in the nucleus of amv-transformed myeloblasts. we propose that these proteins are the in vivo products of the v-myb(amv) gene and thus the transforming protein(s) of amv. | 1985 | 2999319 |
| plant-virus-based vectors for gene transfer will be of limited use because of the high error frequency during viral rna synthesis. | the error frequency during the rna replication of alfalfa mosaic virus (amv) was calculated to be significantly higher than 10(-5). it may be expected that rna synthesis in general will have low fidelity compared to dna synthesis. the low fidelity of rna replication will severely restrict the usefulness of vectors for genetic engineering which are based on rna viruses, viroids or dna viruses which are replicated via an rna intermediate (e.g. caulimoviruses). spontaneous mutants selected by host ... | 1985 | 24310884 |
| synthesis of double-stranded complementary dna from poly(a)(+)mrna. | the use of avian myeloblastosis virus reverse transcriptase (amv rtase) to produce dna copies of mrna templates is a common and well-documented method (1-3). briefly, the method involves synthesis of a complementary dna strand to the mrna from a short double-stranded region, usually provided by using an oligo(dt) primer on poly(a)(+)rna. the enzyme does not always produce full length transcripts, but all the complementary strands are finished off with a short hairpin loop. this provides a ready- ... | 1985 | 21374188 |
| specificity of rna and coat protein interaction in alfalfa mosaic virus and related viruses. | well-defined coat protein binding sites were found to be present on the genomic rnas of almv and tsv. in view of the regulatory importance of these sites in virus multiplication, the possibility that nonrelated proteins also were able to interact with these sites was investigated. the coat proteins of tsv, bmv, cmv, and sbmv recognize specific sites on almv rna 1. the significance of these sites in virus multiplication is discussed. no specific binding sites were found with tmv coat protein or t ... | 1985 | 18639837 |
| alfalfa mosaic virus temperature-sensitive mutants. i. mutants defective in viral rna and protein synthesis. | the replication in cowpea protoplasts of temperature-sensitive (ts) mutants of alfalfa mosaic virus (aimv) was studied at the permissive (25 degrees) and the restrictive (30 degrees) temperature. using the northern blot hybridization technique, it was shown that at the restrictive temperature two rna 1 mutants, bts 03 and bts 04, and two rna 2 mutants, mts 03 and mts 04, were all defective in the synthesis of viral minus-strand rna, whereas the synthesis of the plus-strand genomic rnas 1, 2, and ... | 1985 | 18639838 |
| alfalfa mosaic virus temperature-sensitive mutants. ii. early functions encoded by rnas 1 and 2. | mutants bts 03 and mts 04 of alfalfa mosaic virus (aimv) have temperature-sensitive mutations in genomic rnas 1 and 2, respectively. these mutants are defective in the production of viral minus-strand rna, coat protein, and infectious virus when assayed in cowpea protoplasts at the nonpermissive temperature (30 degrees). to determine the temperature-sensitive step in the replication cycle, mutant-infected protoplasts were shifted from an incubation temperature of 25 degrees (permissive temperatu ... | 1985 | 18639839 |
| human interferon does not protect cowpea plant cell protoplasts against infection with alfalfa mosaic virus. | orchansky et al. (p. orchansky, m. rubenstein, and i. sela), proc. natl. acad. sci. usa 79, 2278-2280, 1982) reported that natural and recombinant human interferon (huifn), e.g., huifn-beta and -alpha subspecies gamma3, protects plant cells from infection with a plant virus (tobacco mosaic virus). for their study they used tobacco leaf discs as well as tobacco protoplasts. it is now reported that recombinant huifn-beta and huifn-alpha2 do not significantly decrease alfalfa mosaic virus increase ... | 1985 | 18639858 |
| expression of alfalfa mosaic virus rna 4 cdna transcripts in vitro and in vivo. | copies of alfalfa mosaic virus (amv) rna 4 synthesized by transcription in vitro were shown to be biologically active in protoplasts when inoculated together with a mixture of amv rnas 1, 2, and 3. a 5' cap was essential for activity, whereas 15 nonviral nucleotides at the 5' end of the rna transcripts did not detectably affect activity. transcripts that terminated 65 nucleotides from the 3' end of the coding region and transcripts that lacked all or part of the 3'-noncoding region were effectiv ... | 1985 | 18640556 |
| artifacts are responsible for the translational activity of polyribosome preparations isolated from alfalfa mosaic virus-infected tobacco leaves. | we observed that polyribosome preparations isolated from alfalfa mosaic virus (a1mv)-infected tobacco leaves were contaminated with virion-derived material which could not be removed completely by sucrose gradient centrifugation or by magnesium ion precipitation. upon incubation of polyribosome preparations with s 100 extracts from reticulocyte lysates, viral-encoded proteins were produced. aurintricarboxylic acid (ata), an inhibitor of initiation of translation, was used to inhibit de novo tran ... | 1985 | 18640561 |
| application of monoclonal antibodies in the avian leukosis virus gs-antigen elisa. | five hybridoma cell lines which secrete antibodies to avian leukosis/ sarcoma (alv) group-specific (gs) antigens (gag gene products) have been established. the hybrid cells resulted from fusion of p3/x63-ag8.653 myeloma cells with splenocytes of balb/c mice which had been immunised with purified avian myeloblastosis virus (amv). screening of supernatant fluids was performed by an indirect double antibody sandwich enzyme-linked immunosorbent assay (idas-elisa) and the immunoelectroblotting techni ... | 1985 | 18766897 |
| swelling of isometric and of bacilliform plant virus nucleocapsids is required for virus-specific protein synthesis in vitro. | encapsidated rna of cowpea chlorotic mottle virus (ccmv), brome mosaic virus (bmv), alfalfa mosaic virus, and southern bean mosaic virus can act as templates for protein synthesis when preswollen virions are added to a wheat germ extract, or when unswollen virions swell in the extract. encapsidated rna of turnip yellow mosaic virus, whose particles are unlikely to swell under the conditions used here, did not act as a template. ccmv and bmv, swollen in the extract, gave relatively more rna 1 and ... | 1986 | 18640565 |
| alfalfa mosaic virus temperature-sensitive mutants. iii. mutants with a putative defect in cell-to-cell transport. | forty-five mutants of alfalfa mosaic virus with a temperature-sensitive (ts) replication in tobacco leaf discs were assayed in cowpea protoplasts at 25 and 30 degrees . the extent of replication of 9 mutants at 30 degrees was less than 10% of that at 25 degrees, whereas the replication of 14 mutants was not affected at 30 degrees. twenty-two mutants showed an intermediate ts behavior. several mutants with a non-ts phenotype in cowpea protoplasts were also found to be non-ts in their replication ... | 1986 | 18640651 |
| variable repeats and poly (a)-stretches in the leader sequence of alfalfa mosaic virus rna 3. | the complete nucleotide sequence of rna 3 of the l strain of alfalfa mosaic virus (almv) was deduced and the 5'-terminal sequence of rna 3 of the s-strain was revised. a comparison of the rna sequences of almv strains l, s, and m showed that a sequence of 27 to 30 nucleotides is repeated two times in the 5' noncoding regions of all strains. in addition, sequences of 56 and 75 nucleotides are duplicated in the leaders of strain s and l, respectively. an a-rich sequence of 10 nucleotides, present ... | 1986 | 18640652 |
| biologically active transcripts of cloned dna of the coat protein messenger of two plant viruses. | to initiate infection, a mixture of the three genomic rnas of alfalfa mosaic virus (aimv) has to be supplemented with a small amount of coat protein or rna 4, the subgenomic messenger for coat protein. the possibility to replace rna 4 in the inoculum by in vitro synthesized transcripts of a cloned dna copy of the coat protein cistron was investigated using the sp6 transcription system. transcripts with or without the cap structure m(7)g(5')ppp(5')g were both translated in vitro in viral coat pro ... | 1986 | 24307327 |
| studies of the human c-myb gene and its product in human acute leukemias. | the myb gene is the transforming oncogene of the avian myeloblastosis virus (amv); its normal cellular homolog, c-myb, is conserved across a broad span of evolution. in humans, c-myb is expressed in malignant hematopoietic cell lines and in primary hematopoietic tumors. partial complementary dna clones were generated from blast cells of patients with acute myelogenous leukemia. the sequences of the clones were compared to the c-myb of other species, as well as the v-myb of amv. in addition, the ... | 1986 | 3014652 |
| characterization of monoclonal antibodies to avian leukosis viruses. | hybridoma cell lines secreting monoclonal antibody (mca) to avian leukosis virus (alv) structural proteins p27 and p19 have been established. in an indirect enzyme-linked immunosorbent assay (elisa), mca 6al20 (igg1 isotype) reacted with rpl-40 (alv subgroup a), avian myeloblastosis virus (amv) (a mixture of subgroups a and b), rous-associated virus (rav)-2 (subgroup b), and carr-zilber strain of rous sarcoma virus (cz-rsv) (subgroup d) but not with prague strain of rsv (prc-rsv) (subgroup c) or ... | 1986 | 3015099 |
| expression of molecular clones of v-myb in avian and mammalian cells independently of transformation. | we demonstrated that molecular clones of the v-myb oncogene of avian myeloblastosis virus (amv) can direct the synthesis of p48v-myb both in avian and mammalian cells which are not targets for transformation by amv. to accomplish this, we constructed dominantly selectable avian leukosis virus derivatives which efficiently coexpress the protein products of the tn5 neo gene and the v-myb oncogene. the use of chemically transformed qt6 quail cells for proviral dna transfection or retroviral infecti ... | 1986 | 3016296 |
| structure of the protein encoded by the chicken proto-oncogene c-myb. | the retroviral oncogene v-myb arose by transduction of the chicken proto-oncogene c-myb. we isolated and sequenced cdna that represents the entire coding domain of chicken c-myb. by transcribing the cdna into mrna in vitro and then translating the rna, we were able to document the integrity of the cdna and to identify the codon responsible for initiation of translation from c-myb. two different alleles of v-myb are extant, one in the genome of avian myeloblastosis virus (amv) and the other in th ... | 1986 | 3025608 |
| antibodies to the evolutionarily conserved amino-terminal region of the v-myb-encoded protein detect the c-myb protein in widely divergent metazoan species. | antibodies directed against a bacterial fusion protein that contains the domain encoded by the highly evolutionarily conserved 5' one-third of the v-myb oncogene of avian myeloblastosis virus (amv) detect the protein products of various members of the myb gene family. immunoprecipitation or immunoblot analyses with these antibodies yielded the following information. first, the products of the v-myb oncogenes of amv (p48v-myb) and of e26 virus (p135gag-myb-ets) contain this highly conserved amino ... | 1986 | 3088565 |
| fluorescence studies on the coat protein of alfalfa mosaic virus. | the intrinsic luminescence of different forms of the alfalfa mosaic virus (amv) strain 425 coat protein has been studied, both statically and time resolved. it was found that the emission of the protein (mr 24,250), which contains two tryptophans at positions 54 and 190 and four tyrosines, is completely dominated by tryptophan fluorescence. the high fluorescence quantum yield indicates that both tryptophans are emitting. surprisingly, the fluorescence decay is found to be strictly exponential, w ... | 1986 | 3271050 |
| nucleotide sequence of chicken c-myb complementary dna and implications for myb oncogene activation. | avian myeloblastosis virus (amv), like other acute transforming viruses, arose by recombination between its helper virus and host cellular sequences. the latter sequences, termed v-myb, are responsible for the oncogenic properties of the virus. amv causes acute myeloblastic leukaemia in chickens and transforms a specific class of haematopoietic cells in vitro, but does not induce morphological transformation of cultured fibroblasts, suggesting that only a restricted target-cell population is res ... | 1986 | 3753748 |
| anti-sense regions in satellite rna of cucumber mosaic virus form stable complexes with the viral coat protein gene. | the interaction in vitro of the rna of the q-strain of cucumber mosaic virus (cmv) with its satellite rna (sat-rna) has been studied. in hybridisation reactions containing 30% formamide at 45 degrees, sat-rna binds to cmv rna 3 and 4 but not to cmv rna 1 and 2 or rna from tobacco mosaic virus and alfalfa mosaic virus. the viral coat protein gene present in rna 3 and 4 contains the site of binding but this region does not contain complementary sequences of any significant length to the sat-rna se ... | 1986 | 2422629 |
| transforming potential of the v-myb oncogene from avian myeloblastosis virus: alterations in the oncogene product may reveal a new target specificity. | transfection of brown leghorn chicken embryo fibroblasts by dna containing v-myb sequences cloned either in a complete amv proviral dna or in a retroviral derived vector has led to the isolation of two kinds of transformed cells. a characterization of the proviral sequences retained and expressed in these transformed cells revealed that they contained either new or altered v-myb-related rna species. the experiments presented in this paper also show that both types of transformants expressed trun ... | 1986 | 2427128 |
| misincorporation by amv reverse transcriptase shows strong dependence on the combination of template and substrate nucleotides. | we have carried out a systematic investigation of the efficiency of misincorporation by avian myeloblastosis virus reverse transcriptase with all possible combinations of dntp substrate, template nucleotide, and the nucleotide at the 3' terminus of the primer. a series of synthetic oligonucleotide primers were annealed to single stranded m13 dna templates, and a single dntp was misincorporated at the primer 3' end using amv reverse transcriptase. the proportion and pattern of misincorporation an ... | 1986 | 2429257 |
| nucleoside 5'-triphosphates modified at sugar residues as substrates for calf thymus terminal deoxynucleotidyl transferase and for amv reverse transcriptase. | terminal deoxynucleotidyl transferase from calf thymus and rna-directed dna polymerase (reverse transcriptase) from the avian myeloblastosis virus catalyze the incorporation of 3'-amino-2',3'-dideoxynucleoside 5'-triphosphates, as well as some of their 3'-derivatives, 3'-amino-3'-deoxyarabinonucleoside 5'-triphosphates and some other nucleoside 5'-triphosphates modified at sugar residues. after incorporation of the appropriate 5'-mononucleotide residue into the dna, further chain elongation is b ... | 1986 | 2429703 |
| direct identification of small sequence changes in chromosomal dna. | dideoxynucleotide chain termination sequencing has been applied directly to genomic dna templates by annealing radiolabeled oligodeoxynucleotide primers to unique sites in total yeast dna and extending with avian myoblastosis virus (amv) reverse transcriptase. the technique is used here to confirm the introduction of selectively altered trna genes into the saccharomyces cerevisiae genome by gene replacement. | 1986 | 2429900 |
| synthesis and application of derivatizable oligonucleotides. | to investigate protein-dna interactions, we have synthesized a versatile phthalimide-protected 5-(3-aminopropyl)-2'-deoxyuridine nucleoside probe. the modified residue was incorporated into deoxyoligonucleotides by automated synthesis. the standard oligonucleotide workup also exposed the pendent amino group, which was found to react with either fluorescent labelling agents or, as detailed below, a photoactivatable cross-linking agent. in the dark, a strand with a photolabile group adjacent to th ... | 1987 | 2442728 |
| rna complementary to alfalfa mosaic virus rna 4 is not translated in vitro. | cdna of the subgenomic messenger rna (rna 4) of alfalfa mosaic virus was ligated in both orientations into plasmids containing the bacteriophage sp 6 promoter. upon transcription in vitro these plasmids yielded synthetic full-length complementary rna and messenger-sense rna. the complementary rna contained an open reading frame of 417 nucleotides; the messenger-sense rna encodes the virus coat protein. no translation products from the complementary rna were detected in a wheat germ translation s ... | 1987 | 2444555 |
| enhanced translation of chimaeric messenger rnas containing a plant viral untranslated leader sequence. | eukaryotic messenger rnas are translated with unequal efficiencies in vivo and in vitro and the molecular basis of this phenomenon is not understood. as an approach to understanding the role of the 5' untranslated leader sequence in regulating mrna translational efficiency, chimaeric mrnas have been generated by joining a heterologous leader to complementary dna (cdna) sequences, followed by in vitro transcription using sp6 rna polymerase and in vitro protein synthesis. we used the untranslated ... | 1987 | 3492677 |
| in vitro synthesis and processing of a bean pathogenesis-related (pr4) protein. | when bean plants (phaseolus vulgaris var. saxa) are treated with mercuric chloride or infected with alfalfa mosaic virus, they produce pathogenesis-related (pr) proteins. we report here that functional mrna encoding bean pr4 protein is only present when synthesis of this protein has been induced. treatment with mercuric chloride results in a rapid induction of functional bean pr4 mrna (within 2-3 h), whereas in virus-infected plants this mrna can only be detected the second day following the inf ... | 1987 | 3609026 |
| [tumors of the brain vascular plexuses caused by the avian myeloblastosis virus]. | a series of experiments on the induction of tumours in the central nervous system with the help of avian myeloblastosis virus was carried out. 142 highly sensitive and inbred chickens, 1 or 2 days of age, were used. the intracerebral virus dose was 0.01-0.02 ml. the titer was 10(9)--10(12) pfu/ml. 25 tumours of choroid plexus were induced during the experiments, 3 tumours developed in the control after intravenous inoculation. out of 33 chickens highly sensitive to amv tumours of choroid plexus ... | 1987 | 3620686 |
| the dynamical structure of the rna in alfalfa mosaic virus studied by 31p-nuclear magnetic resonance. | the structure of the viral rna in alfalfa mosaic virus (almv) was investigated by means of 31p-nuclear magnetic resonance (nmr). it was found that the 31p-nmr line width of almv top a particles is significantly smaller than that of the larger bottom particles. at low temperatures, the totational correlation time of the 31p nuclei essentially equals the tumbling rate of the virus particle, indicating that the rna is contained rigidly inside the virion. at more elevated temperatures, the nmr line ... | 1987 | 3117550 |
| immunoblotting with polyclonal and monoclonal antibody to avian myeloblastosis protein p27: studies of liver proteins in chickens with erythroblastosis. | an antigen detected by complement fixation with polyclonal antibody to avian myeloblastosis virus (amv) antigen p27, appears in the livers of chickens inoculated with avian erythroblastosis virus (aev). it can be demonstrated at the 30,000 dalton (30k) molecular weight level by western immunoblotting of electropherograms of aev infected liver extracts. the 30k protein reacted strongly with this polyclonal antibody but only weakly with a monoclonal antibody to the same viral antigen and possible ... | 1987 | 2836998 |