| comparative studies of the inhibitory properties of antibiotics on human immunodeficiency virus and avian myeloblastosis virus reverse transcriptases and cellular dna polymerases. | the inhibition of human immunodeficiency virus (hiv) reverse transcriptase by certain antibiotics and related compounds was studied in comparison with that of avian myeloblastosis virus (amv) reverse transcriptase and cellular dna polymerases alpha and beta. in general, compounds that inhibited hiv reverse transcriptase also inhibited amv reverse transcriptase. for example, 10 micrograms/ml of the isoquinoline quinones used in this study inhibited approximately 80% of the activity of reverse tra ... | 1989 | 2466028 |
| use of avian myeloblastosis virus reverse transcriptase at high temperature for sequence analysis of highly structured rna. | avian myeloblastosis virus reverse transcriptase (amv rt) is routinely used in the sequence analysis of rna and dna templates. we review the various methods for dealing with secondary structures that would otherwise result in premature termination or sequence compression. based on our experience in sequencing the 11-kb single-stranded rna genome of lymphocytic choriomeningitis virus, we have found that raising the reaction temperature above 47 degrees c is the simplest way to overcome template s ... | 1989 | 2473018 |
| intrinsic properties of reverse transcriptase in reverse transcription. associated rnase h is essentially regarded as an endonuclease. | the intrinsic properties of reverse transcriptase in reverse transcription were studied using a synthetic, partial ovalbumin mrna with a synthetic dna oligonucleotide annealed to the 3'-end of the rna as a model substrate. with or without concomitant cdna synthesis, the rnase h activity of avian myeloblastosis virus (amv)-reverse transcriptase cleaved the substrate at a site which would leave a hybrid of between 7 and 14 base pairs between the 3' termini of the rna and dna oligonucleotide. varia ... | 1989 | 2478553 |
| inhibition of reverse transcriptases by flavonoids. | selected naturally occurring flavonoids were shown to inhibit three reverse transcriptases (rt): avian myeloblastosis (amv) rt, rous-associated virus-2 (rav-2) rt and maloney murine leukemia virus (mmlv) rt when poly (ra)oligo(dt)12-18 or rabbit globin mrna were used as template. amentoflavone, scutellarein and quercetin were the most active compounds and their effect was concentration-dependent. the enzymes exhibited differential sensitivity to the inhibitory effects of the flavonoids. the comp ... | 1989 | 2480745 |
| a "zinc-finger"-type binding domain in tobacco streak virus coat protein. | tobacco streak virus (tsv) rna and alfalfa mosaic virus (aimv) rna will replicate only if a few copies of their coat proteins are bound to the rna. to understand this phenomenon experiments were performed to find unique features of the tsv and aimv subunits. atomic absorption analysis showed that tsv and aimv contained substantial quantities of zinc in native virions (approximately one zinc atom per four protein subunits in tsv and one zinc atom per two protein subunits in aimv), while other pla ... | 1989 | 2491924 |
| constitutive expression of pathogenesis-related proteins pr-1, grp, and pr-s in tobacco has no effect on virus infection. | samsun nn tobacco cells were transformed with chimeric genes for pathogenesis-related (pr) proteins derived from genomic (pr-1a, grp) or cdna (pr-s) clones under the transcriptional control of the cauliflower mosaic virus 35s promoter. regenerated plants were assayed by rna and protein gel blotting, and plants showing high specific expression of the inserted genes were selected for self-pollination and seed formation. inspection of second generation transformants showed that constitutive express ... | 1989 | 2535503 |
| effects of ph and ionic strength on precipitation of phytopathogenic viruses by polyethylene glycol. | the effects of ionic strength of the solution (changed by varying nacl concentrations or buffer molarity) on the precipitation with polyethylene glycol (peg) 6000 were studied on phytopathogenic viruses of different morphology: the isometric red clover mottle virus (rcmv), rod-shaped tobacco mosaic virus, flexuous potato virus x (pvx) and bacilliform alfalfa mosaic virus. with increasing nacl concentration or buffer molarity up to a certain level (0.1 mol/l), the efficiency of peg precipitation ... | 1989 | 2565676 |
| 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 |
| identification of two translational products for c-myb. | the c-myb gene is the normal cellular homolog of v-myb, the oncogenic component of avian myeloblastosis virus (amv). the c-myb gene has previously been shown to code for a single protein species of about 75 kd. however, accumulating evidence indicates that this gene could code for multiple mrnas as a result of differential splicing. this was first detected in the abpl-2 tumor line and was later shown to occur in normal cells. to test if indeed these differentially spliced mrnas code for a new pr ... | 1989 | 2674850 |
| [synthesis of 2',3',-dideoxy-3'-fluoradenosine and -guanosine, their 5'-triphosphates and a study of 2',3'-dideoxy-3'-fluoronucleoside- 5'-triphosphates as substrates for dna-polymerases]. | potential antiviral and antitumour nucleosides, 3'-fluoro-2', 3'-dideoxy-adenosine and -guanosine, have been synthesized by the chemical transglycosylation reaction using 5'-o-acetyl-3'-fluoro-2', 3'-dideoxy-thymidine and -uridine as donors of the carbohydrate fragment and persilylated 6-n-benzoyladenine and 2-n-palmitoylguanine as acceptors, respectively. 5'-triphosphates of 3'-fluoro-2', 3'-dideoxy-thymidine, -cytidine, -adenosine, and -guanosine (dntp(3'f] were synthesized and tested as termi ... | 1989 | 2675851 |
| competitive multiplication of rna3 species of different strains of alfalfa mosaic virus. | competition between rna3 from alfalfa mosaic virus (almv) strain s (rna3-s), strain b (rna3-b) and strain 425l (rna3-l) was studied. the identification of the rna3 species multiplying in infected leaves was possible since the rna3 5' non-coding leader sequences in strains s, b and 425l differ in length. rna3 present in total rna from infected tobacco leaves was detected, and strains were identified from the length of the cdna reverse-transcribed from rna primed with a specific oligonucleotide. i ... | 1989 | 2732703 |
| biological properties of streptonigrin derivatives. iii. in vitro and in vivo antiviral and antitumor activities. | antitumor antibiotic streptonigrin (stn-cooh) is a potent inhibitor of avian myeloblastosis virus (amv) and human immunodeficiency virus reverse transcriptases. the carboxyl group at 2'-position of stn-cooh was modified to give esters, hydrazide, amides and amino acid derivatives for biological studies. against amv reverse transcriptase, the hydrazide, amides and amino acid derivatives showed inhibitory activity, which compared favorably to that of stn-cooh, with the id50 values ranging 2-8 micr ... | 1989 | 2737955 |
| alfalfa mosaic virus temperature-sensitive mutants. v. the nucleotide sequence of tbts 7 rna 3 shows limited nucleotide changes and evidence for heterologous recombination. | nucleotide sequence determination of the coat protein cistron of the alfalfa mosaic virus (aimv) temperature-sensitive mutant, tbts 7 (uv) revealed a small number of point mutations of which only one results in the replacement of an amino acid: the asparagine residue at position 126 is replaced by an aspartate residue. rna transcribed in vitro from a tbts 7 cdna 4 clone directed the production in vitro of a polypeptide which shows the same altered electrophoretic mobility in sds-polyacrylamide g ... | 1989 | 2763460 |
| preparation of soluble, biologically active alfalfa mosaic virus coat protein and its cacl2-induced degradation. | a method for the preparation of soluble protein from five biologically distinct alfalfa mosaic virus (amv) isolates is described. highly purified amv was dissociated with 1 m cacl2 in 10 mm sodium acetate, ph 6.0, and the precipitated rna was removed by centrifugation. the protein was dialysed against 10 mm sodium acetate, ph 6.0, containing 0.1 m cacl2. if the salt concentration was reduced further, proteins from some amv isolates precipitated. proteins prepared by this method were shown to be ... | 1989 | 2778029 |
| selective inhibition of proteins synthesized from different mrna species in reticulocyte lysates containing l-pyrroline-5-carboxylic acid. | l-pyrroline-5-carboxylic acid is a naturally occurring nonprotein amino acid present in human plasma that changes concentrations with diet. l-pyrroline-5-carboxylic acid inhibited net synthesis of globin in untreated reticulocyte lysates in a dose dependent manner. this inhibition was greater than that observed with equimolar gssg or nadp+ and was prevented by a nadph generating system. l-pyrroline-5-carboxylic acid also inhibited net synthesis of proteins from brome mosaic and alfalfa mosaic vi ... | 1988 | 2827672 |
| 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 |
| studies on the mechanism of translational enhancement by the 5'-leader sequence of tobacco mosaic virus rna. | translation of foreign mrnas is enhanced by a cis-acting derivative (omega') of the 5'-leader sequence (omega) of tobacco mosaic virus rna (vulgare strain). to explain this effect we have conducted several experiments in vitro. 1. the presence of various 5'-terminal sequences, including omega', did not significantly increase the half-lives of chloramphenicol acetyltransferase (cat) or neomycin phosphotransferase (nptii) mrnas in wheat-germ extract. also, a long leader sequence, unrelated to omeg ... | 1988 | 2841127 |
| a point mutation in the dna binding domain of the v-myb oncogene of e26 virus confers temperature sensitivity for transformation of myelomonocytic cells. | we have molecularly cloned a mutant of the v-myb, ets-containing e26 avian leukemia virus which is temperature sensitive for the transformation of myeloid cells. cells infected with this mutant, ts21e26, are immature at 37 degrees c and can be induced to differentiate into resting, macrophage-like cells when shifted to 42 degrees c. the sequence of ts21e26 reveals a single relevant nucleotide alteration resulting in a threonine to arginine change in the highly conserved, putative dna binding v-m ... | 1988 | 2852341 |
| 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 |
| 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 |
| characterization of a virus-specific proteolytic activity processing the gag precursor of the simian sarcoma-associated virus. | the proteolytic processing of the gag precursor polypeptide pr65gag of simian sarcoma-associated virus (ssav) has been studied in vivo and in vitro. in ssav-infected cells (i.e., in vivo) proteins of 52 and 38 kda and the viral protein p30 could be immunoprecipitated with anti-p30 serum. this cleavage pattern is only in part imitated by in vitro cleavage of the isolated pr65gag with avian myeloblastosis virus (amv) protease p15. however, in vitro incubation of isolated pr65gag with detergent-dis ... | 1987 | 3027976 |
| dihydrothymidine and thymidine glycol triphosphates as substrates for dna polymerases: differential recognition of thymine c5-c6 bond saturation and sequence specificity of incorporation. | the ability of dihydrothymidine (dhdttp) and thymidine glycol (dttp-gly) 5'-triphosphates to serve as substrates for different dna polymerases was investigated. dhdttp but not dttp-gly was used as a substrate by e. coli dna polymerase i (pol i). within the detection limit of the assay used, neither t4 dna polymerase nor avian myeloblastosis virus (amv) reverse transcriptase used dhdttp or dttp-gly as substrates. the ability of dhdttp and dttp-gly to undergo enzyme-catalyzed turnover to the monop ... | 1988 | 3060857 |
| 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 |
| 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 |
| a centrifugation method for separation of plant viral genomic and subgenomic rnas. | using alfalfa mosaic virus (amv) as a model, a simple method for separating plant viral genomic rnas from their subgenomic counterparts was established. the method relies on sucrose gradient fractionation under carefully selected conditions of centrifugation and fraction collection. the rna components are recovered in nearly quantitative yield and have full biological activity as measured by infectivity of the reconstituted rnas in suitable protoplasts and plant hosts. the individual rnas, on th ... | 1988 | 3181424 |
| proto-oncogene expression in chicken leukemic cells induced by avian myeloblastosis virus. | sixteen proto-oncogenes which have generated retroviral oncogenes were tested for their expression in chicken leukemic cells induced by avian myeloblastosis virus (amv) and five were found to be expressed (c-ets, c-fps, c-mht, c-myc, and c-rel). the size of the c-fps transcript (4.0 kb) was not in good agreement with the size (approximately 3.0 kb) previously reported but was uniform in the leukemic cells from 10 different chickens. the size of the other proto-oncogene transcripts appeared norma ... | 1988 | 3226723 |
| in vitro transcription and translational efficiency of chimeric sp6 messenger rnas devoid of 5' vector nucleotides. | a plasmid containing the bacteriophage sp6 promoter, designated phsto, permits in vitro transcription of rnas devoid of vector-derived nucleotides. this vector has been characterized for relative transcriptional activity using constructs which alter the conserved nucleotides extending beyond the sp6 transcriptional initiation site. sp6 polymerase efficiently transcribes cdna inserts which contain a guanosine (g) nucleotide at position +1 relative to the sp6 promoter; however, inserts with an ade ... | 1988 | 3260027 |
| evidence that the 5'-untranslated leader of mrna affects the requirement for wheat germ initiation factors 4a, 4f, and 4g. | the efficiency of translation of alfalfa mosaic virus (amv) rna 4, barley alpha-amylase (b alpha a) mrna, and two chimeric mrnas, amv 4-b alpha a and b alpha a-amv 4 (in which the 5' leader sequences of the two mrnas were interchanged), was measured in an s30 extract from wheat germ and a fractionated system from wheat germ in which translation could be made dependent upon initiation factor (eif) 3, 4a, 4f, or 4g. in the s30 system, amv rna 4 and the chimeric mrna amv 4-b alpha a are translated ... | 1988 | 3260235 |
| 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 |
| expression of alfalfa mosaic virus cdna1 and 2 in transgenic tobacco plants. | chimeric genes composed of dna complementary to alfalfa mosaic virus (aimv) rnas 1 or 2, the camv 35 s promoter, and the nos polyadenylation signal were transferred to the genome of nicotiana tabacum cv. samsun nn by means of the agrobacterium tumefaciens transformation system. transformants contained intact copies of the viral genes and accumulated transcripts of approximately the size predicted from the cloning procedure. using antisera raised against synthetic peptides corresponding to the c- ... | 1988 | 3354206 |
| pharmacokinetics and chemotherapeutic efficacy of adriamycin encapsulated in immunoliposomes against avian myeloblastosis virus infection. | immunoliposomes were prepared using rabbit anti-amv gp80 igg for the targeted chemotherapy of avian myeloblastosis virus infection. adriamycin was encapsulated into immunoliposomes and used for in vivo studies. comparative pharmacokinetics of free drug, drug encapsulated in free liposomes and of drug encapsulated in immunoliposomes in the virus-infected cells revealed that (i) the drug encapsulated in liposomes was cleared from the plasma slowly, and (ii) the drug encapsulated in immunoliposomes ... | 1988 | 3366852 |
| transgenic tobacco expressing tobacco streak virus or mutated alfalfa mosaic virus coat protein does not cross-protect against alfalfa mosaic virus infection. | transgenic tobacco plants expressing the coat protein (cp) genes of tobacco streak virus (tsv) and alfalfa mosaic virus (aimv) were used in studies on cross-protection and genome activation. plants expressing the tsv cp gene were highly resistant to infection with tsv nucleoproteins but were susceptible to infection with aimv nucleoproteins. moreover, these plants could be infected with a mixture of aimv rnas 1, 2, and 3 in contrast to the nontransformed control plants. this demonstrates that th ... | 1988 | 3369086 |
| further implications for the evolutionary relationships between tripartite plant viruses based on cucumber mosaic virus rna 3. | the nucleotide sequence of the rna 3 of the q-strain of cucumber mosaic virus (q-cmv) has been reinvestigated and supporting partial amino acid sequence data obtained for the coat protein. corrections to the previously published sequence of rna 3 [a. r. gould and r. h. symons (1982) eur. j. biochem. 126, 217-226] result in changes to the size and composition of the putative 3a and coat proteins. analysis of the nucleotide sequence revealed a 14-nucleotide sequence present in the intercistronic r ... | 1988 | 3388769 |
| 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 |
| 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 |
| 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 |
| the in vivo behaviour of twenty-four strains of alfalfa mosaic virus. | | 1970 | 4098410 |
| studies on alfalfa mosaic virus. iv. an unusual strain. | | 1970 | 4099064 |
| surface-active agents for isolation of the core component of avian myeloblastosis virus. | sixty-one surface-active agents were evaluated in a procedure designed to assess their ability to remove the envelope from the core component of avian myeloblastosis virus (amv). the procedure consisted of centrifugation of intact amv through a series of sucrose gradients each containing an upper layer of agent at one of eight concentrations between 0.01 and 10%. the effectiveness of an agent in producing amv cores was indicated by (i) the appearance of light-scattering bands in the region of co ... | 1972 | 4112071 |
| the uncoating of alfalfa mosaic virus by its own rna. | | 1972 | 4113242 |
| evidence for a ph-induced structural change of alfalfa mosaic virus. | | 1972 | 4117934 |
| serological analysis of the deoxyribonucleic acid polymerase of avian oncornaviruses. i. preparation and characterization of monospecific antiserum with purified deoxyribonucleic acid polymerase. | monospecific antiserum was prepared against purified deoxyribonucleic acid (dna) polymerase from avian myeloblastosis virus (amv). immunodiffusion assay with purified dna polymerase revealed that the anti-dna polymerase serum formed one precipitation band, whereas no reaction with any of the seven major structural proteins of amv was observed. the antiserum also demonstrated enzyme-neutralizing antibody activity that was associated with the immunoglobulin g fraction. there was no difference in t ... | 1972 | 4117965 |
| serological analysis of the deoxyribonucleic acid polymerase of avian oncornaviruses. ii. comparison of avian deoxyribonucleic acid polymerases. | monospecific antiserum prepared against the isolated deoxyribonucleic acid (dna) polymerase of avian myeloblastosis virus (amv) neutralized the endogenous ribonucleic acid-instructed dna polymerase activity of detergent-disrupted virus. the viral polymerase was serologically unrelated to the seven major structural polypeptides of amv. furthermore, the viral enzyme was distinguished from normal cellular dna polymerases by serological criteria; thus, antiserum against the viral enzyme neutralized ... | 1972 | 4117966 |
| outer membrane of avian myeloblastosis virus. | guinea pigs immunized intracerebrally with avian myeloblastosis virus (amv) produced antiserum which reacted with intact virus particles in complement fixation. the antigen in question appeared to be located on the surface of the virion and could be distinguished from the type-specific virus envelope and the group-specific internal antigens of chicken leukosis-sarcoma viruses (chilsv). the material could be isolated by sequential treatments of amv with bromelin, tween 20, and freeze-thawing, and ... | 1973 | 4128385 |
| detection of naturally occurring antibodies to rna-dependent dna polymerase of murine leukemia virus in kidney eluates of akr mice. | specific antibodies to the rna-dependent dna polymerase (reverse transcriptase) of murine type c viruses have been isolated from the renal glomeruli of both leukemic and nonleukemic akr mice where they presumably had been deposited as immune complexes. the antibodies were shown to have sedimentation coefficients of 26s to 28s and 5s to 7s on sucrose rate zonal centrifugation. inactivation with monospecific antisera to various mouse immunoglobulins identified antibodies as being in both immunoglo ... | 1974 | 4129792 |
| structural studies of avian myeloblastosis virus: comparison of polypeptides in virion and core component by dodecyl sulfate-polyacrylamide gel electrophoresis. | two different systems of dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) in separate laboratories detected analogous patterns of dye bands in virions of avian myeloblastosis virus (amv). at least 11 of the dye bands co-migrated with the major polypeptides reported in rous sarcoma virus. particles with the morphology of the amv core component, obtained after exposure of amv to the nonionic surfactant sterox sl, contained major polypeptides p12, p27, p60, p64, p91, and p98. the polyp ... | 1974 | 4129794 |
| dna polymerase in virions of a reptilian type c virus. | a study was made of the dna polymerase of reptilian type c virus isolated from russell's viper spleen cells. simultaneous detection experiments demonstrated the presence of 70s rna and rna-dependent dna polymerase activity in reptilian type c virions. the endogenous activity was dependent on the addition of all four deoxynucleotide triphosphates and demonstrated an absolute requirement for a divalent cation. the reptilian viral dna polymerase elutes from phosphocellulose at 0.22 m salt. in this ... | 1974 | 4129837 |
| the quaternary structure of alfalfa mosaic virus. | | 1974 | 4137292 |
| the effect of inhibitors of protein biosynthesis on the infectivity of alfalfa mosaic virus: role of coat protein. | | 1974 | 4274500 |
| [inhibition of the multiplication of the myeloblastosis virus (amv) in vitro by guanidine]. | | 1965 | 4285130 |
| avian myeloblastosis virus (amv) biosynthesis in chick embryo cells: studies of the particles released by trypsin from the infected cells. | | 1966 | 4287875 |
| [heterotransmission of avian myeloblastoma virus (amv) to the hamster]. | | 1969 | 4306857 |
| [demonstration of virus particles of amv type in a transplantable hamster tumor: hp]. | | 1969 | 4318901 |
| [resistance of german chicken lines against avian myeloblastosis virus (amv)]. | | 1973 | 4354748 |
| subunits of oncornavirus high-molecular-weight rna. i. stepwise conversion of 60 s amv (avian myeloblastosis virus) rna to subunits. | | 1973 | 4354929 |
| subunits of oncornavirus high-molecular-weight rna. ii. detection of double-stranded-regions in 60s amv (avian myeloblastosis virus) rna. | | 1973 | 4356817 |
| on influence of aflatoxin b1 on the physical properties of the avian myeloblastosis virus bai strain a (amv) and on the biosynthesis of viral nucleic acids. | | 1974 | 4371293 |
| alfalfa mosaic virus in lucerne plants and its transmission by aphids in the course of the vegetation period. | | 1971 | 4399140 |
| efficiency of alfalfa mosaic virus transmission by aphids in relation to the level of virus in plants. | | 1971 | 4399142 |
| the biological function and mutual dependence of bottom component and top component a of alfalfa mosaic virus. | | 1968 | 4967833 |
| alfalfa mosaic virus: comparative investigation of top component a and bottom component by means of fingerprinting and immunological techniques. | | 1968 | 4972584 |
| three nucleoprotein components of alfalfa mosaic virus necessary for infectivity. | | 1970 | 4985557 |
| alfalfa mosaic virus. | | 1969 | 5001896 |
| electron microscopy of replicative form and single-stranded rna of alfalfa mosaic virus. | | 1972 | 5049079 |
| effect of avian myeloblastosis virus in the japanese quail. | moscovici, carlo (university of colorado medical center, denver), and e. h. macintyre. effect of avian myeloblastosis virus in the japanese quail. j. bacteriol. 92:1141-1149. 1966.-avian myeloblastosis virus (amv) induced a spectrum of neoplasms in japanese quail (coturnix coturnix japonica) which was similar to that observed in the chicken, with one exception: the total absence of acute myeloblastic leukemia in quail. studies in vivo as well as in vitro suggested that the cause for this differe ... | 1966 | 4288797 |
| in vivo replacement of the helper virus in bryan's strain of rous sarcoma virus by amv and rpl12 viruses. | | 1966 | 4288867 |
| [homology between the genome of avian myeloblastosis virus (amv) and the cellular genome]. | | 1966 | 4291018 |
| incorporation of precursors into ribonucleic acid, protein, glycoprotein, and lipoprotein of avian myeloblastosis virions. | freshly explanted leukemic myeloblasts produce avian myeloblastosis virus (amv) at a constant rate without any obvious cytopathic effect; therefore, subviral components are continually synthesized at a steady rate. the incorporation of various radioactive precursors into virions was monitored by determination of radioactivity in purified virus after density equilibrium sedimentation in preformed sucrose gradients. the kinetics of incorporation of (3)h-uridine have shown that there is an average ... | 1969 | 4311791 |
| an improved adenosine triphosphatase assay for physical particles of avian myeloblastosis virus (amv). | | 1969 | 4311838 |
| dna complementary to viral rna in leukemic cells induced by avian myeloblastosis virus. | nucleic acid hybridization studies were made between 71s-amv-rna and dna from leukemic myeloblasts and from normal chicken cells. there was homology between the viral rna and chicken cell dna and to a greater extent between viral rna and leukemic cell dna. leukemic cell dna hybridized approximately twice as much viral rna as did normal chicken dna. thermal melting studies showed that the viral rna bound to normal and leukemic cell dna consists of long polynucleotides (t(m) = 87 degrees and 92 de ... | 1970 | 4317913 |
| mechanism of carcinogenesis by rna tumor viruses. 3. formation of rna, dna complex and duplex dna molecules by the dna polymerase (s) of avian myeloblastosis virus. | dna polymerase activity can be unmasked in avian myeloblastosis virus (amv) by treatment with the nonionic detergent nonidet p-40. two products are formed: (1) rna.dna hybrid molecules and (2) duplex dna molecules. the kinetics of dttp incorporation into dna are biphasic: an initial rapid reaction for 4 min at 37 degrees c with a minimal polymerization rate of 10-20 nucleotides per see, and a second reaction at about half the initial rate. viral rna.dna complexes are detected as early as 30 sec ... | 1970 | 4322024 |
| distribution of deoxyribonucleic acid complementary to the ribonucleic acid of avian myeloblastosis virus in tissues of normal and tumor-bearing chickens. | (3)h-labeled 70s ribonucleic acid (rna) from purified avian myeloblastosis virus (amv) was used as a probe in deoxyribonucleic acid (dna)-rna hybridization experiments to detect the presence of dna complementary to the amv genome in various tissues from noninfected normal chickens and from chickens infected with amv. there was a remarkable constancy in the average cellular concentration of virus-specific dna found in every tissue from the same uninfected chicken, and even in different chickens f ... | 1972 | 4344249 |
| quantitative determination and location of newly synthesized virus-specific ribonucleic acid in chicken cells infected with rous sarcoma virus. | a sensitive and quantitative nucleic acid hybridization assay for the detection of radioactively labeled avian tumor virus-specific rna in infected chicken cells has been developed. in our experiments we made use of the fact that dna synthesized by virions of avian myeloblastosis virus in the presence of actinomycin d (amv dna) is complementary to at least 35% of the sequences of 70s rna from the schmidt-ruppin strain (srv) of rous sarcoma virus. annealing of radioactive rna (either srv rna or r ... | 1973 | 4350719 |
| chromatographic analyses of isoaccepting trnas from avian myeloblastosis virus. | avian myeloblastosis virus (amv) 4s rna was tested for amino acid acceptor activity for 18 of the 20 amino acids. a nonrandom distribution of viral trnas was found compared with trna from normal liver or from amv-infected leukemic myeloblasts, confirming previous reports. methionine and proline trnas were considerably enriched, whereas glutamic acid, glutamine, serine, tyrosine, and valine trnas were markedly depleted in amv relative to homologous cellular trnas. the seven amv trnas with the gre ... | 1973 | 4355849 |
| rna-dna covalent bonds between the rna primers and the dna products formed by rna tumor virus dna polymerase. | initiation of dna synthesis by endogenous rna primer molecules was studied with three different rna tumor viruses. the influence of the method of virus disruption on the observed rna-dna bonds was ascertained. ether disrupted virions of both murine leukemia virus (mulv) and the b77 strain of avian sarcoma virus (b77 virus) have rc-dc and ra-da covalent linkages between rna primers and newly synthesized dna. none of the 14 other possible bonds were formed. ether-disrupted virions of avian myelobl ... | 1973 | 4357517 |
| integrated state of oncornavirus dna in normal chicken cells and in cells transformed by avian myeloblastosis virus. | the covalent linkage of oncornavirus-specific dna to chicken dna was investigated in normal chicken embryo fibroblasts (cef) and in virus-producing leukemic cells transformed by avian myeloblastosis virus (amv). the virus-specific sequences present in cellular dna fractionated by different methods were detected by dna-rna hybridization by using 70s amv rna as a probe. in cef and in leukemic cells, the viral dna appeared to be present only in the nucleus. after cesium chloride-ethidium bromide de ... | 1973 | 4359950 |
| limited proteolysis of alfalfa mosaic virus: influence on the structural and biological function of the coat protein. | | 1974 | 4362543 |
| presence in leukemic cells of avian myeloblastosis virus-specific dna sequences absent in normal chicken cells. | (3)h-labeled 35s rna from purified avian myeloblastosis virus (amv) was exhaustively hybridized with an excess of normal chicken dna to remove all viral rna sequences which are complementary to dna from uninfected cells. the [(3)h]rna which failed to hybridize was isolated by hydroxylapatite column chromatography which separates dna-rna hybrids from single-stranded [(3)h]rna. the residual rna hybridized to leukemic chicken dna but did not rehybridize with normal chicken dna. this demonstrates co ... | 1974 | 4365719 |
| transfection of chicken embryo cells with dna extracted from avian virus-producing neoplastic cells. | dna isolated from avian virus-producing leukemic myeloblasts induced the production of viruses, but not morphological transformation, in cultivated chicken fibroblasts. the recovered virus had the same biological characteristics as the original avian myeloblastosis virus (amv) and produced myeloblastosis and nephroblastomas when injected into chickens. neutralization experiments with chicken anti-amv-bai strain a sera showed an antigenic community between the dna-transfected virus and the origin ... | 1974 | 4369392 |
| effect of chemically modified 70s rna from avian myeloblastosis virus (amv) upon the activity of amv dna polymerase. | adenine residues of 70s avian myeloblastosis virus (amv) rna are modified when reacted with chloroacetaldehyde. this modification introduces characteristic fluorescent epsilon-adenosine (epsilona) probes which were used to monitor the reaction. under suitable conditions, modified 70s(epsilona) rna was maintained intact and was inactive as a template for the amv dna polymerase. furthermore, it inhibited the reaction catalyzed by amv polymerase when 70s rna was used as template-primer and had no e ... | 1974 | 4372390 |
| mechanistic independence of avian myeloblastosis virus dna polymerase and ribonuclease h. | differential inhibition conditions were established for the dna polymerase and rnase h activities of avian myeloblastosis virus (amv) with ether-disrupted amv and a purified enzyme preparation. the rnase h activity of ether-disrupted amv with (ra)(n).(dt)(n) and (ra)(n).(dt)(11) as substrates was inhibited 80 to 100% by preincubation with naf at a final reaction concentration of 27 to 30 mm. under these conditions, the dna polymerase activity was inhibited only 0 to 20%. similar inhibitions were ... | 1974 | 4372408 |
| alfalfa mosaic virus hybrids constructed by exchanging nucleoprotein components. | | 1972 | 4627343 |
| function of top component a rna in the initiation of infection by alfalfa mosaic virus. | | 1973 | 4684580 |
| electric permittivity of alfalfa mosaic virus in aqueous solutions. | | 1973 | 4687139 |
| replication of alfalfa mosaic virus rnas. | | 1974 | 4821703 |