Showing papers on "RNA published in 1986"
TL;DR: In this paper, the authors describe a method to clone a functional gene for bacteriophage T7 RNA polymerase, which is useful for synthesizing large amounts of RNA in vivo or in vitro, and can produce a single RNA selectively from a complex mixture of DNAs.
Abstract: This application describes a means to clone a functional gene for bacteriophage T7 RNA polymerase. Active T7 RNA polymerase is produced from the cloned gene, and a plasmid has been constructed that can produce the active enzyme in large amounts. T7 RNA polymerase transcribes DNA very efficiently and is highly selective for a relatively long promoter sequence. This enzyme is useful for synthesizing large amounts of RNA in vivo or in vitro, and is capable of producing a single RNA selectively from a complex mixture of DNAs. The procedure used to obtain a clone of the R7 RNA polymerase gene can be applied to other T7-like phages to obtain clones that produce RNA polymerases having different promoter specificities, different bacterial hosts, or other desirable properties. T7 RNA polymerase is also used in a system for selective, high-level synthesis of RNAs and proteins in suitable host cells.
971 citations
TL;DR: It is concluded that four extra, reading frame-restoring nucleotides are added during or after transcription of the frameshift gene by an RNA-editing process.
785 citations
TL;DR: It is demonstrated that HTLV-III expression in lymph node and peripheral blood is very low in vivo and the lymph node hyperplasia observed in HT LV-III-associated lymphadenopathy is not directly due to proliferation of HTLV -III-infected lymphocytes.
Abstract: By using in situ hybridization methodology, we have directly examined primary lymph node and peripheral blood from patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex for the presence of human T-lymphotropic virus type III (HTLV-III) viral RNA. Mononuclear cell preparations were hybridized with a 35S-labeled HTLV-III-specific RNA probe and exposed to autoradiographic emulsion for 2 days. HTLV-III-infected cells expressing viral RNA were detected in approximately 86% (6/7) of lymph node and 50% (7/14) of peripheral blood samples studied. However, in all patient samples examined, labeled cells were observed at very low frequency (less than 0.01% of total mononuclear cells). The HTLV-III-infected cells exhibited morphological characteristics consistent with that of lymphocytes and expressed viral RNA at relatively low abundance (20-300 copies per cell). These results demonstrate that HTLV-III expression in lymph node and peripheral blood is very low in vivo. Furthermore, the lymph node hyperplasia observed in HTLV-III-associated lymphadenopathy is not directly due to proliferation of HTLV-III-infected lymphocytes.
700 citations
TL;DR: The E7 protein has been identified in CaSki cells and the prevalence of its mRNA suggests a possible function in progression to, or long-term maintenance of, the malignant state.
Abstract: Human papillomavirus type 16 DNA and RNA were characterized in the cervical cancer-derived CaSki cell line, which contains only integrated DNA, and in a cervical cancer, which contains predominantly plasmid DNA In both, a major RNA can code for the early open reading frame E7 and a minor one can code for E6 The cervical cancer, but not the CaSki cell line, contains a minor RNA that can code for an intact E2 protein, and this may relate to the continued presence of plasmid DNA The RNA mapping data suggest that the poly(A)+ RNA is transcribed from a minor fraction of the several hundred gene copies present, and in the cervical cancer these genomes appear to be integrated The E7 protein has been identified in CaSki cells and the prevalence of its mRNA suggests a possible function in progression to, or long-term maintenance of, the malignant state
666 citations
Patent•
09 Jul 1986TL;DR: In this article, the authors describe epithelial cells expressing foreign genetic material, which can be defined as DNA or RNA which does not occur in epithelium but is expressed in them at levels which are biologically significant.
Abstract: Epithelial cells expressing foreign genetic material are described. The foreign genetic material can be DNA or RNA which does not occur in epithelial cells; DNA or RNA which occurs in epithelial cells but is not expressed in them at levels which are biologically significant; DNA or RNA which occurs in epithelial and has been modified so that it is expressed in epithelial cells; and any DNA or RNA which can be modified to be expressed in epithelial cells, alone or in any combination thereof. In addition, epithelial cells of the present invention can express genetic material encoding a selectable marker by which cells expressing the foreign genetic material can be expressed.
641 citations
TL;DR: Analysis of transfected lymphoid and nonlymphoid cell lines suggests that tat-III-mediated trans-activation of viral gene expression is operative predominantly, if not exclusively, at a posttranscriptional level.
623 citations
TL;DR: Biochemical and electron microscopic data indicate that the human hepatitis δ viral agent contains a covalently closed circular and single-stranded RNA genome that has certain similarities with viroid-like agents from plants.
Abstract: Biochemical and electron microscopic data indicate that the human hepatitis δ viral agent contains a covalently closed circular and single-stranded RNA genome that has certain similarities with viroid-like agents from plants. The sequence of the viral genome (1,678 nucleotides) has been determined and an open reading frame within the complementary strand has been shown to encode an antigen that binds specifically to antisera from patients with chronic hepatitis δ viral infections.
605 citations
TL;DR: Positive hybridisation signals, quantified by densitometry, were obtained with 9 of 17 samples from patients with histological evidence of active or healing myocarditis or dilated cardiomyopathy with inflammatory changes, and no Coxsackie-B-virus-specific sequences were detected in 4 samples from Patients in whom a viral aetiology was unlikely and the histological diagnosis was negative for myocardritis.
588 citations
TL;DR: Unexpectedly, the first AUG codon is required for efficient GCN4 expression under starvation conditions and appears to involve antagonism of the inhibitory effect of the 3' proximal AUGcodons since it is dispensable in the absence of these sequences.
556 citations
TL;DR: In vitro mutagenesis and genetic analysis demonstrate the existence of a third intron whose removal is required for transposase production and propose that this intron is only removed in the germline and that its removal is the sole basis for the Germline restriction of P element transposition.
553 citations
TL;DR: Evidence is presented for the in vitro autolytic processing of dimeric and trimeric forms of this satellite RNA of tobacco ringspot virus, which apparently is reversible to form dimeric RNA from monomeric RNA, and does not require an enzyme for its catalysis.
Abstract: Associated with some plant viruses are small satellite RNA's that depend on the plant virus to provide protective coat protein and presumably at least some of the proteins necessary for satellite RNA replication. Multimeric forms of the satellite RNA of tobacco ringspot virus are probable in vivo precursors of the monomeric satellite RNA. Evidence is presented for the in vitro autolytic processing of dimeric and trimeric forms of this satellite RNA. The reaction generates biologically active monomeric satellite RNA, apparently is reversible to form dimeric RNA from monomeric RNA, and does not require an enzyme for its catalysis.
TL;DR: Self-cleavage of both plus and minus RNA transcripts of the 247-residue avocado sunblotch viroid (ASBV), prepared from tandem dimeric cDNA clones, occurs specifically at two sites in each transcript to give monomeric plus andminus species.
Abstract: Self-cleavage of both plus and minus RNA transcripts of the 247-residue avocado sunblotch viroid (ASBV), prepared from tandem dimeric cDNA clones, occurs specifically at two sites in each transcript to give monomeric plus and minus species. The cleavage reaction occurs both during transcription and on incubation of purified transcripts at pH 8 and 37 degrees C in the presence of magnesium ions to give a 3'-terminal 2',3'-cyclic phosphate and a 5'-terminal hydroxyl group. Although the self-cleavage occurs at different sites in the ASBV molecule for the plus and minus species, very similar secondary structures with high sequence homology can be drawn at each site. The results are considered to provide further evidence that ASBV is replicated in vivo by a rolling circle mechanism involving non-enzymic cleavage of high molecular weight RNA precursors of ASBV.
TL;DR: Treating HOS cells in vitro with MNNG resulted in fusion of two chromosomally disparate loci, met and tpr, generating the active met oncogene, related to the tyrosine kinase gene family.
TL;DR: The shortened form of the self-splicing ribosomal RNA intervening sequence of Tetrahymena thermophila acts as an enzyme in vitro that can act as an RNA polymerase, differing from the protein enzyme in that it uses an internal rather than an external template.
Abstract: A shortened form of the self-splicing ribosomal RNA (rRNA) intervening sequence of Tetrahymena thermophila acts as an enzyme in vitro. The enzyme catalyzes the cleavage and rejoining of oligonucleotide substrates in a sequence-dependent manner with Km = 42 microM and kcat = 2 min-1. The reaction mechanism resembles that of rRNA precursor self-splicing. With pentacytidylic acid as the substrate, successive cleavage and rejoining reactions lead to the synthesis of polycytidylic acid. Thus, the RNA molecule can act as an RNA polymerase, differing from the protein enzyme in that it uses an internal rather than an external template. At pH 9, the same RNA enzyme has activity as a sequence-specific ribonuclease.
TL;DR: Detailed investigation of the higher-order structure of 16 S ribosomal RNA and extensive protection of conserved, unpaired adenines upon formation of 30 S subunits suggests that they play a special role in the assembly process, possibly providing signals for protein recognition.
TL;DR: The results strongly support a copy choice mechanism for RNA recombination, in which the viral RNA polymerase switches templates during negative strand synthesis.
TL;DR: Results indicate that the strategy of generating antisense RNA to inhibit gene expression may be useful in delineating the function of protooncogenes.
Abstract: Antisense RNA complementary to c-fos mRNA was produced in mouse 3T3 cells by gene transfer techniques. Transcriptional units were constructed consisting of a steroid-inducible mouse mammary tumor virus (MMTV) promoter, mouse or human 5' c-fos gene fragments in either the sense (5' to 3') or antisense (3' to 5') orientation, and splice and poly(A) signals from the human beta-globin gene. A gene that confers neomycin resistance was included in the vectors to allow isolation of stable transformants. Dexamethasone caused a marked induction of hybrid MMTV-fos-globin RNA. Induction of the hybrid transcript containing antisense c-fos RNA decreased colony formation following DNA transfer and inhibited the proliferation of cells into which the antisense transcriptional unit had been integrated. In contrast, colony formation and cell proliferation were not inhibited by induction of hybrid RNA containing c-fos RNA sequences in the sense orientation. These results indicate that the strategy of generating antisense RNA to inhibit gene expression may be useful in delineating the function of protooncogenes. The c-fos gene product appears to have a required role in normal cell division.
TL;DR: It is concluded that trnas splicing is the physiological process by which mature mRNA molecules are synthesized in trypanosomes.
TL;DR: The antibody and an alkaline phosphatase-labeled second antibody were used in an immunodetection method for measurement of hybrids formed between immobilized DNA probes of various lengths and 23 S ribosomal RNA, the colorimetric response of this assay increased linearly with the amount of hybrid formed.
Patent•
17 Mar 1986
TL;DR: In this article, a fragment, synthetic or natural, DNA or RNA, may be attached to a non-radiological label such as a fluorescent compound, a luminescent compound or a color reflective compound, by a linker.
Abstract: A fragment, synthetic or natural, DNA or RNA, may be attached to a non-radiological label such as a fluorescent compound, a luminescent compound or a color reflective compound, by a linker. The linker is an aminoalkylphosphoramide. The linker may contain a number of methyl units selected to adjust the mobility of the arrangement of the tagged fragment in a polyacrylamide gel during electro-phoresis. A unique color may be attached to each for the four bases. The color coded bases may be separated in a single lane of the ployacrylamide gel. Because the mobility of each arrangement has been adjusted the normal one base spacing will be produced. The sequence of the target may be read directly by manually observing the color sequence or by an automatic reader. The tagging of natural fragments may be used to tag a preselected gene, in the application of Southern and Northern bloting diagnostic procedures, as a diagnostic tool to hunt/detect selected DNA and to label probes to detect ribosonal RNA of pathogens.
TL;DR: The results point to a therapeutic potential of the complementary oligodeoxynucleotide ("hybridization competition" or "hybridon") approach in the treatment of patients with AIDS and AIDS-related complex.
Abstract: The possibility of using oligodeoxynucleotides complementary to viral RNA or proviral DNA to inhibit the replication of human T-cell lymphotropic virus type III (HTLV-III) [the etiological agent of acquired immunodeficiency syndrome (AIDS)] in cultured human cells was addressed by studying the association of 32P-labeled oligodeoxynucleotides with mammalian cellular components. The results indicated that exogenous oligodeoxynucleotides at 20 microM became associated with the membrane/cytosol fractions of the cell in amounts approximating 1.5 microM. Oligodeoxynucleotides complementary to a region close to the tRNALys primer binding site on HTLV-III RNA and others complementary to HTLV-III mRNA donor or acceptor splice sites inhibited viral replication (assayed as reverse transcriptase) and gene expression (assayed as virus-encoded proteins p15 and p24) by as much as 95%. Use of control (random) oligodeoxynucleotides suggests that the antiviral effects were specific. Although these results pertain to HTLV-III-infected cells in tissue culture, rather than to AIDS patients, they nevertheless point to a therapeutic potential of the complementary oligodeoxynucleotide ("hybridization competition" or "hybridon") approach in the treatment of patients with AIDS and AIDS-related complex.
TL;DR: Two cDNAs are identified which predict distinct peptide precursors of 153 and 195 amino acids, confirming the hypothesis that at least two IGF-I mRNAs are generated by alternative RNA processing of the primary gene transcript.
TL;DR: It is concluded that all classes of genes become competent for activation during cycle 10, and that subsequent activation is differentially suppressed by functions associated with nuclear division.
TL;DR: Results show that the class II intron products are similar to those of nuclear pre-mRNA splicing, particularly the spliced exons and broken form of the lariat.
TL;DR: The addition of polyethylene glycol to filter-bound nucleic acid hybridization greatly increases the hybridization rate and is easier to manipulate and less expensive than dextran sulfate.
TL;DR: The primary objective in reviewing these bifunctional viral mRNAs and the mechanisms that underlie their misbehavior is to call attention to certain cellular m RNAs that may also be able to produce two proteins.
TL;DR: The VAI RNA of adenovirus is a small, RNA polymerase III-transcribed species required for efficient translation of host cell and viral mRNAs late after infection and can be reproduced in extracts of interferon-treated cells.
TL;DR: The main theme of this review is the discontinuous synthesis of mRNAs in trypanosomes, which was discovered in the unicellular eukaryote Trypanosoma brucei and is probably a general feature of the order of Kinetoplastida, to which several other major human pathogens belong.
Abstract: The main theme of this review is the discontinuous synthesis of mRNAs in trypanosomes. This novel process was discovered in the unicellular eukaryote Trypanosoma brucei, but it is probably a general feature of the order of Kinetoplastida, to which several other major human pathogens belong. Discontinuous RNA synthesis involves a sequence of 35 nucleotides (nt) found at the 5' end of all trypanosome mRNAs analyzed. The 35-nt sequence is encoded in arrays of 1.35-kb repeats that are clustered in the genome. The primary transcript of the 1.35-kb repeat is an RNA of 140 nt that carries the 35-nt sequence at its 5' end. The 35-nt sequence is transferred from the 140-nt precursor to pre-mRNAs made elsewhere in the genome. The process has not yet been reconstructed in vitro, and whether transfer involves priming of pre-mRNA synthesis, RNA-RNA ligation followed by splicing, trans-splicing, or more than one of these mechanisms, is still unknown. Circumstantial evidence makes priming the least likely of these alternatives. Why it is advantageous to trypanosomes to make their mRNAs in such an unusual fashion is unclear. As yet, there is no evidence for discontinuous synthesis of mRNAs in organisms other than kinetoplastid flagellates. The mini-exon sequence was first found in mRNAs for Variant-specific Surface Glycoproteins (VSGs), and the control of the synthesis of these proteins is a second theme of this review. Silent VSG genes may be activated by their duplicative transposition to a telomeric expression site. The transposition process looks like a gene conversion, mediated by short blocks of sequence homology. Activation of the transposed gene is due to its insertion into an active transcription unit, i.e. to promoter addition. Telomeric VSG genes can also be activated without duplication. This can occur by a reciprocal translocation in which a silent telomeric gene exchanges position with a gene residing in an active expression site. A VSG gene may also be activated without detectable translocation, however, by the transcriptional activation of the silent expression site in which it is located. How this occurs is still unknown, because the transcription units are so long that the promoter for pre-mRNA synthesis has not yet been reached by chromosome walking. A simple mechanism in which a mobile promoter moves between telomeres has been rendered unlikely by the demonstration that two telomeric transcription units can be simultaneously active when one of them is interrupted by a large DNA insertion.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: The ability to make infectious poliov virus RNA efficiently from cloned DNA makes it possible to apply techniques of in vitro mutagenesis to the analysis of poliovirus functions and the construction of novel and perhaps useful derivatives of pol Giovirus.
Abstract: Plasmids containing the entire cDNA sequence of poliovirus type 1 (Mahoney strain) under control of a promoter for T7 RNA polymerase have been constructed. Purified T7 RNA polymerase efficiently transcribes the entire poliovirus cDNA in either direction to produce full-length poliovirus RNA [(+)RNA] or its complement [(-)RNA]. The (+)RNA produced initially had 60 nucleotides on the 5' side of the poliovirus RNA sequence, including a string of 18 consecutive guanine residues generated in the original cloning and an additional 626 nucleotides of pBR322 sequence beyond the poly(A) tract at the 3' end. Such RNA, while much more infectious than the plasmid DNA, is only about 0.1% as infectious as RNA isolated from the virus. Subsequently, a T7 promoter was placed only 2 base pairs ahead of the poliovirus sequence, so that T7 RNA polymerase synthesizes poliovirus RNA with only 2 additional guanine residues at the 5' end and no more than seven nucleotides past the poly(A) tract at the 3' end. Such RNA has much higher specific infectivity, about 5% that of RNA isolated from the virus. The ability to make infectious poliovirus RNA efficiently from cloned DNA makes it possible to apply techniques of in vitro mutagenesis to the analysis of poliovirus functions and the construction of novel and perhaps useful derivatives of poliovirus. A source of variant RNAs should also allow detailed study of the synthesis and processing of poliovirus proteins in vitro.