Showing papers on "Transcription (biology) published in 1981"
TL;DR: The data indicate that, as a rare event, the ALV provirus integrates adjacent to the c-myc gene and that transcription, initiating from a viral promoter, causes enhanced expression of c- myc, leading to neoplastic transformation.
Abstract: Analyses of DNA and RNA from avian leukosis virus (ALV)-induced lymphomas have provided strong evidence that, in most tumours, ALV induces neoplastic disease by activating the c-myc gene, the cellular counterpart of the transforming gene of MC29 virus. The data indicate that, as a rare event, the ALV provirus integrates adjacent to the c-myc gene and that transcription, initiating from a viral promoter, causes enhanced expression of c-myc, leading to neoplastic transformation.
1,448 citations
TL;DR: To investigate the sequences necessary for proper initiation of transcription of SV40 early genes, several deletion mutants are constructed in the promoter region of the TATA box region.
Abstract: To investigate the sequences necessary for proper initiation of transcription of SV40 early genes, we have constructed several deletion mutants in the promoter region. The TATA box region is apparently involved in fixing initiation precisely within a narrow area, but is dispensable for gene expression, while the sequences located more than 150 base pairs upstream are indispensable.
1,140 citations
TL;DR: The results strongly suggest that the same two overlapping promoters, which were previously identified by in vitro transcription of gal DNA fragments, also control the expression of the galactose operon in intact cells.
970 citations
TL;DR: It is proposed that Tetrahymena pre-rRNA splicing occurs by a phosphoester transferase mechanism where the guanosine cofactor provides the free 3' hydroxyl necessary to initiate a series of three transfers that results in splicing of the pre- rRNA and cyclization of the excised IVS.
820 citations
TL;DR: The results indicate that little, if any, transcription from the adult or embryonic beta-globin genes is detectable in the heterologous red cell nuclei, even under conditions in which ribonucleic acid processing probably does not occur.
Abstract: We used recombinant chicken deoxyribonucleic acid clones containing embryonic and adult beta-globin genes and "runoff" endogenous nuclear transcription to investigate the expression of embryonic and adult beta-globin genes during hematopoiesis in the developing chicken embryo. Purified, cloned deoxyribonucleic acids were digested with various restriction enzymes, separated on agarose gels, blotted to nitrocellulose, and annealed with purified nuclear [32P]ribonucleic acid synthesized in vitro from embryonic or adult red cell nuclei. Transcription of the respective globin genes was assayed by hybridization of nuclear [32P]ribonucleic acid to specific restriction fragments containing adult or embryonic coding sequences. Our results indicate that little, if any, transcription from the adult or embryonic beta-globin genes is detectable in the heterologous red cell nuclei, even under conditions in which ribonucleic acid processing probably does not occur.
748 citations
TL;DR: It is shown that virions and purified viral cores contain a unique endonuclease that cleaves RNAs containing a 5' methylated cap structure preferentially at purine residues 10 to 14 nucleotides from the cap, generating fragments with 3'-terminal hydroxyl groups.
716 citations
TL;DR: The possibility that the 72 bp repeat region in SV40 may act as a bi-directional entry site for RNA polymerase B such that promoter sequences linked to the repeat are more efficiently utilised is discussed.
Abstract: By introduction of recombinant plasmids into monkey CV1 cells, we have unambiguously demonstrated that sequences entirely within the 72 bp repeat, which is located upstream of the SV40 early region, are crucial for T-antigen expression in vivo. We have also shown that a DNA fragment containing the 72 bp repeat, inserted directly before chicken conalbumin or adenovirus-2 major late promoter sequences in chimeric plasmids where these promoters replace that of the SV40 early genes, caused a dramatic increase in the expression of T-antigen in vivo. This effect was independent of the orientation of the 72 bp repeat, but was sensitive to its location within the plasmid, when the 72 bp repeat was separated from the promoter sequences, T-antigen expression was reduced. Insertion of the 72 bp repeat into equivalent plasmids containing no known eukaryotic promoter sequences (plasmids which were not detectably expressed in vivo) gave rise to a measurable, but smaller level of expression. The stimulation of expression by the 72 bp repeat is cis-acting : it required covalent linkage to the recombinant. We discuss the possibility that the 72 bp repeat region in SV40 may act as a bi-directional entry site for RNA polymerase B such that promoter sequences linked to the repeat are more efficiently utilised.
609 citations
TL;DR: The 2.9 Å resolution crystal structure of Escherichia coli catabolite gene activator protein (CAP) completed with cyclic AMP reveals two distinct structural domains separated by a cleft, suggesting that the CAP conversion of right- to left-handed DNA in a closed supercoil, is what activates transcription by RNA polymerase.
Abstract: The 2.9 A resolution crystal structure of Escherichia coli catabolite gene activator protein (CAP) complexed with cyclic AMP reveals two distinct structural domains separated by a cleft. The smaller carboxy-terminal domain is presumed to bind DNA while the amino-terminal domain is seen to bind cyclic AMP. Model building studies suggest that CAP binds to left-handed B-type DNA, contracting its major groove via two alpha-helices. It is possible that the CAP conversion of right- to left-handed DNA in a closed supercoil, is what activates transcription by RNA polymerase.
582 citations
TL;DR: Eight classes of human leukocyte interferon cDNA clones have been identified in a cDNA library prepared from a myeloblastoid cell line and nucleotide sequences demonstrate that the multiple human LeIFN genes code for a family of homologous, yet distinct proteins.
Abstract: Eight classes of human leukocyte interferon (LeIFN) cDNA clones have been identified in a cDNA library prepared from a myeloblastoid cell line. The nucleotide sequences demonstrate that the multiple human LeIFN genes code for a family of homologous, yet distinct proteins. One of the cDNA clones may have been derived from the transcription of a LeIFN pseudogene.
524 citations
TL;DR: A rapid and simple method for studying the transcription of cloned eucaryotic genes is developed, which involves transfecting SV40-transformed monkey cell lines (COS cells) with derivatives of the plasmid pBR322 that contain the SV40 viral replication origin but lack regions necessary for viral transcription (SV-ORI vectors).
500 citations
TL;DR: It appears that transcriptional events are primarily responsible for the synthesis of these, and perhaps most, tissue-specific moderately abundant mRNAs.
TL;DR: The introduction of a cloned rabbit DNA fragment containing the adult β-globin gene into the germ-line of mice is reported, and 24 mice derived from eggs microinjected with this DNA are analysed.
Abstract: The introduction of cloned foreign genes into cultured mammalian cells1–7 has been used to identify DNA sequences required for correct transcription in vivo8–10. It is not clear, however, to what extent these systems will be useful for an analysis of the sequences necessary for tissue-specific gene expression. A more appropriate approach for such an analysis might be the production of mice that contain a cloned foreign gene in all their cells, throughout development. This could be accomplished by the transfer of a cloned gene into germ-line cells, and the subsequent transmission of that gene to offspring. Previously, SV40 DNA sequences11 and a cloned HSV-1 thymidine kinase gene12 have been introduced into somatic tissues of mice by microinjection of the DNAs into blastocysts11 or eggs12, but germ-line transmission of these sequences has not been demonstrated. The only foreign DNA sequences which have been transferred into and transmitted by the mouse germ-line have been exogenous Moloney leukaemia virus genomes introduced by viral infection of early embryos13. We now report the introduction of a cloned rabbit DNA fragment containing the adult β-globin gene into the germ-line of mice. We have analysed 24 mice derived from eggs microinjected with this DNA. Nine mice contain the rabbit β-globin gene in liver DNA, and at least four males from this group transmit the gene to a fraction of their progeny.
TL;DR: In this paper, the DNA sequences required for termination of Xenopus 5S RNA synthesis in vitro were analyzed and it was shown that termination occurs within clusters of four or more consecutive T residues in the noncoding DNA strand sequence.
TL;DR: The complete nucleotide sequence of the thymidine kinase (ATP:thymidine 5' phosphotransferase, EC 2.7.1.21) gene of herpes simplex virus type 1 strain CL101 is determined from a plasmid clone of viral DNA derived by Enquist et al.
Abstract: We have determined the complete nucleotide sequence of the thymidine kinase (ATP:thymidine 5' phosphotransferase, EC 2.7.1.21) gene of herpes simplex virus type 1 strain CL101 from a plasmid clone of viral DNA derived by Enquist et al. [Enquist, L. W., Vande Woude, G. F., Wagner, M., Smiley, J. R. & Summers, W. C. (1979) Gene 7, 335-342]. A cDNA copy of the 5' end of thymidine kinase mRNA was also analyzed to locate the transcribed sequences. The transcribed portion of the gene is approximately 1300 nucleotides in length and appears to contain no intervening sequences. There is an untranslated region of 107 nucleotides at the 5' end of the mRNA followed by an open reading frame of 1128 nucleotides. The gene is thus capable of coding for a protein of 376 amino acids. Sequences similar to those thought to be involved in control of transcription and translation of a variety of eukaryotic and viral genes such as a "Hogness box" and A-A-T-A-A-A polyadenylylation signals are also present in the herpesvirus thymidine kinase gene.
TL;DR: A DNA segment close to the 5' end of the chicken adult beta-globin gene contains a hypersensitive site for nuclease action, which is in fact an accessible region which extends from approximately 60 to approximately 260 base pairs 5' from the start of mRNA transcription.
TL;DR: Observations indicate that the 72-base-pair repeated sequences form an essential element in the early viral transcriptional promoter and explain the inability of such a deleted genome to complement an early temperature-sensitive mutant of SV40, tsA, as well as the failure to replicate its DNA.
Abstract: On the late side of the simian virus 40 (SV40) DNA replication origin are several sets of tandem repeated sequences, the largest of which is 72 base pairs long. The role of these sequences was examined through construction of deletion mutants of SV40. A mutant from which one of the 72-base-pair repeated units was removed is viable upon transfection of monkey kidney cells with viral DNA. Extension of this deletion into the second repeated unit, however, leads to nonviability, as recognized by the absence of early transcription and of tumor antigen production. These observations indicate that the 72-base-pair repeated sequences form an essential element in the early viral transcriptional promoter and explain the inability of such a deleted genome to complement an early temperature-sensitive mutant of SV40, tsA, as well as the failure to replicate its DNA. In a parallel experiment it was found that the extended deletion mutant was also unable to complement a late temperature-sensitive mutant of SV40, tsB. This suggests that the extended mutant is also defective in DNA replication or late transcription (or both).
TL;DR: A recombinant plasmid has been constructed for the expression of inserted DNA sequences coding for polypeptide chains using the simian virus 40 early promoter and splicing and polyadenylylation signals from the rabbit beta-globin gene.
Abstract: A recombinant plasmid has been constructed for the expression of inserted DNA sequences coding for polypeptide chains using the simian virus 40 early promoter and splicing and polyadenylylation signals from the rabbit beta-globin gene. The coding regions for two prokaryotic methotrexate-resistant dihydrofolate reductases were introduced into the expression vector. When mouse fibroblasts were exposed to these recombinant plasmids, it was possible to select methotrexate-resistant clones that had integrated the plasmids and produced a chimeric RNA coding for the prokaryotic enzyme.
TL;DR: Experiments with recombinant plasmids show the region that determines the specificity of response to RNA I to be greater than 300 base pairs upstream of the origin of DNA replication, which indicates the inhibition of primer formation by RNA I is incompatibility specific.
Abstract: Transcription of ColE1 DNA by RNA polymerase in vitro starts at two sites in a region required for maintenance of the plasmid. Certain transcripts that start at one of the sites can be cleaved by RNase H and then act as primers for DNA replication. Transcription from the other site produces a RNA approximately 108 nucleotides long (species I or RNA I). Transcripts analogous to the primer and RNA I of ColE1 are produced when p15A or small derivatives of two other ColE1-compatible plasmids, CloDF13 and RSF1030, are used as template. If purified RNA I is added to the transcription reaction containing RNase H, formation of primer is inhibited. Each RNA I can inhibit primer formation by the plasmid that specifies it but has no effect on primer formation by heterologous templates. Thus, the inhibition of primer formation by RNA I is incompatibility specific. Because RNA I does not inhibit initiation or propagation of transcription or the processing of preformed precursors, the step that is sensitive to inhibition is probably formation of the hybrid between the primer precursor and the template. This hybrid is the required substrate for RNase H. Experiments with recombinant plasmids show the region that determines the specificity of response to RNA I to be greater than 300 base pairs upstream of the origin of DNA replication.
TL;DR: Electron microscopic analysis of in vitro transcriptional complexes of pBR322 and pACYC184 revealed five and six major transcriptional units, respectively, in these two plasmid vectors, which permit a more predictable utilization of these cloning vehicles and also allow the reinterpretation of earlier cloning results.
Abstract: Electron microscopic analysis of in vitro transcriptional complexes of pBR322 and pACYC184 revealed five and six major transcriptional units, respectively, in these two plasmid vectors. These units are transcribed with various efficiencies, depending upon the individual promoter strengths, which differ in pBR322 up to 10-fold. A most interesting signal arrangement was found at the beginning of the tetracycline resistance region, where two partially overlapping promoters (P1 and P2) initiate transcription crosswise in opposite directions. Whereas P2 is known to promote tetracycline resistance and to be inactivated by HindIII cleavage, P1 is able to transcribe DNA integrated at that site and probably contributes to the expression of the beta-lactamase gene in pBR322. In pACYC184, besides P1, P2, and the cat (chloramphenicol resistance) promoter (P5), two initiation sites (P3 and P4) were mapped in a region that appears to be part of insertion sequence 1. The maps of transcription signals permit a more predictable utilization of these cloning vehicles and also allow the reinterpretation of earlier cloning results.
TL;DR: The bacteriophage λ regulatory protein, cII, has been purified and shown to activate positively RNA transcription from the two phage promoters which coordinately regulate phage lysogenic development.
Abstract: The bacteriophage lambda regulatory protein, cII, has been purified and shown to activate positively RNA transcription from the two phage promoters which coordinately regulate phage lysogenic development. To obtain this protein, the cII gene was cloned into a plasmid vector carrying the strong, regulatable lambda phage promoter PL such that it was overproduced to levels approaching 5% of cellular protein.
TL;DR: Analysis of the process of partial transcription termination (attenuation), which results in nonequimolar synthesis of vesicular stomatitis virus (VSV) mRNAs during sequential transcription, shows that transcription appears to be discontinuous, with significant pauses occurring at or near the intergenic regions.
TL;DR: The present understanding of negative-strand RNA virus replication is summarized and the replicative event leading to the generation of defective interfering (DI) particles is examined.
TL;DR: It is shown that VAII RNA as well as VAI RNA and the EBERs exist in ribonucleoprotein complexes which are precipitable by anti-La antibodies associated with systemic lupus erythematosus.
Abstract: The nucleotide sequence of the region of the Epstein-Barr virus genome that specifies two small ribonucleic acids (RNAs), EBER 1 and EBER 2, has been determined. Both of these RNAs are encoded by the right-hand 1,000 base pairs of the EcoRI J fragment of EBV deoxyribonucleic acid. EBER 1 is 166 (167) nucleotides long and EBER 2 is 172 +/- 1 nucleotides long; the heterogeneity resides at the 3' termini. The EBER genes are separated by 161 base pairs and are transcribed from the same deoxyribonucleic acid strand. In vitro, both EBER genes can be transcribed by RNA polymerase III; sequences homologous to previously identified RNA polymerase III intragenic transcription control regions are present. Striking similarities are therefore apparent both between the EBERs and the two adenovirus-associated RNAs, VAI and VAII, and between the regions of the two viral genomes that specify these small RNAs. We have shown that VAII RNA as well as VAI RNA and the EBERs exist in ribonucleoprotein complexes which are precipitable by anti-La antibodies associated with systemic lupus erythematosus. Finally, we have demonstrated that the binding of protein(s) from uninfected cells confers antigenicity on each of the four virus-encoded small RNAs.
TL;DR: The structures of the aberrant proviruses and the absence of normal viral RNA in some tumors indicate that expression of viral genes is not required for maintenance of the tumor phenotype, in at least some cases, the mechanism of oncogenesis may involve stimulation of transcription of flanking cellular sequences by a viral promoter.
TL;DR: Activated glucocorticoid receptor protein, purified to 40-60% homogeneity from rat liver extracts, binds selectively in vitro to a cloned fragment of murine mammary tumor virus (MTV) DNA, consistent with the notion that steroid receptors may modulate rates of transcription by recognizing specific DNA sequences within or near the regulated genes.
Abstract: Activated glucocorticoid receptor protein, purified to 40-60% homogeneity from rat liver extracts, binds selectively in vitro to a cloned fragment of murine mammary tumor virus (MTV) DNA. The DNA fragment tested contains about half of the sequences present in intact MTV DNA, and its rate of transcription, like that of the intact viral element, is strongly stimulated by glucocorticoids when it is introduced into the genome of a receptor-containing cell. In contrast, the receptor fails to bind selectively to DNA restriction fragments from E. coli plasmids pBR322 and RSF2124 or from bacteriophages lambda and T4. Preliminary experiments to localize regions within MTV DNA responsible for selective binding have revealed thus far one subfragment that fails to bind the receptor and one selectively bound subfragment that maps far downstream from the 5' terminus of the normal RNA transcript. These studies are consistent with the notion that steroid receptors may modulate rates of transcription by recognizing specific DNA sequences within or near the regulated genes.
TL;DR: Pancreatic amylase messenger RNA progressively decreases in rats rendered diabetic with streptozotocin, and insulin reverses this effect, inducing a selective decrease in amyl enzyme messenger RNA in the pancreas.
Abstract: Pancreatic amylase messenger RNA progressively decreases in rats rendered diabetic with streptozotocin. Insulin reverses this effect, inducing a selective decrease in amylase messenger RNA in the pancreas. Parotid amylase messenger RNA is not significantly affected by either diabetes or insulin.
TL;DR: The results suggest the necessity for an endonucleolytic cleavage of a primary transcript followed by polyadenylation in the process of creating the 3′ end of this cellular mRNA, as has previously been demonstrated for every virus mRNA so far studied.
TL;DR: The extension of the active chromosomal domain beyond the most stable nuclear transcript suggests that transcription may proceed beyond the 3' ends of both alpha A and alpha D and the sharp boundaries of this subdomain suggest that specific DNA sequences may establish its borders.
TL;DR: The transcriptional activity of a kb † region of Saccharomyces DNA centered on three galactose-inducible sequences has been examined and suggests the presence of a promoter for the transcription of the GAL1 gene, an adjacent promoter forthe transcription of GAL10 and/or both GAL8 and GAL7, and a third promoters for theGAL7 gene.
TL;DR: Based on the studies of the E. coli top mutants, it appears that the supX gene, which was originally studied in Salmonella typhimurium, is likely to be the structural gene for DNA topoisomerase I, which has a more rapid rate of induction and a higher level of catabolite-sensitive enzymes including tryptophanase and beta-galactosidase.
Abstract: Mutations in top, the structural gene for Escherichia coli DNA topoisomerase I, have been identified and mapped at 28 min on the chromosome, near cysB. Strains carrying deletions of the top gene are viable. The top mutations, however, do exert pleiotropic effects on transcription and transposition. Mutants lacking DNA topoisomerase I have a more rapid rate of induction and a higher level of catabolite-sensitive enzymes including tryptophanase and beta-galactosidase. This general activation of transcription by top mutations can be attributed to an increase in the negative superhelicity of the DNA in vivo when the topoisomerase activity is abolished. The frequency of transposition of Tn5, a transposon carrying kanamycin resistance, is decreased by a factor of 40 or more in top mutants. A direct or indirect role of the topoisomerase in transposition is discussed. The transposition frequency of Tn3, however, is not dependent on top. Based on the studies of the E. coli top mutants, it appears that the supX gene, which was originally studied in Salmonella typhimurium [Dubnau, E. & Margolin, P. (1972) Mol. Gen. Genet. 117, 91-112] is likely to be the structural gene for DNA topoisomerase I.