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Showing papers on "Transcription (biology) published in 1972"



Book ChapterDOI
TL;DR: It is hard to imagine that eukaryotes, being presented with such a superb mechanism for controlling DNA transcription, would totally discard it and opt for something different, but several observations suggest that higher organisms may have picked up a number of fundamental genetic tricks from their lowly predecessors.
Abstract: Biochemical and genetic studies have produced a vast fund of knowledge concerning gene action and regulation in prokaryotes In these organisms the DNA is exposed rather nakedly to the world, protected primarily by the cell membrane In eukaryotes the DNA seems far better shielded, being enmeshed in histone and nonhistone proteins and sequestered behind both the cell and the nuclear membrane These differences have led to a considerable degree of caution in the application of this knowledge of prokaryotes to problems of gene regulation in eukaryotes, and rightly so There are, however, several observations which suggest that higher organisms may have picked up a number of fundamental genetic tricks from their lowly predecessors It has frequently been suggested that eukaryotes must do things differently from prokaryotes, until proven otherwise It may be prudent to reverse this line of thought and suggest that they do things the came until proven different The following similarities suggest this (1) T he basic genetic dogmas concerning DNA replication, transcription, andlation are similar, (2) The genetic code is the same (3) Both systems appear to make use of cyclic AMP as a basic mediator for, humoral or diffusible, signals (4) In both systems DNA synthesis may be controlled at membranes (5) Both make use of different types of RNA polymerase and RNA polymerase cofactors (6) Recent studies of polylysine binding to chromatin suggest the eukaryotic DNA may not be so thoroughly enmeshed in Protein as once thought (7) The visualization of genes in action by electron microscopic techniques intimates that genes are spaced and read in a similar manner And finally, (8) merely because the clustering of related genes is unusual in higher organisms is no reason in itself to totally discard the promoter-operator-repressor concept as a way of regulating single structural genes This system has provided an immense amount of data concerning the manner in which proteins interact with specific DNA sequences to control the attachment and utilization of RNA polymerase It is hard to imagine that eukaryotes, being presented with such a superb mechanism for controlling DNA transcription, would totally discard it and opt for something different It is far more likely that they would build on to this solid foundation

257 citations


Journal ArticleDOI
10 Nov 1972-Nature
TL;DR: It is shown that mRNA decay is not responsible for protein synthesis decay in actinomycin, and therefore, mRNA appears quite stable after the administration of act inomycin.
Abstract: SYNTHESIS of proteins from the mRNA in eukaryotic cells differs from prokaryotes in two important ways. In the mammalian cell, the translation of mRNA in the cytoplasm is remote from the transcription in the nucleus, whereas in bacteria these two processes occur almost simultaneously1,2. Bacterial protein synthesis ceases within several minutes of inhibition of RNA transcription with actinomycin3; hence, the mRNA is short-lived. In metazoan eukaryotic cells, a similar experiment indicates that protein synthesis is not immediately affected by inhibition of transcription. Thus the mRNA is much more stable—of the order of several hours4. In a few specialized systems, the lifetime of mRNA can be deduced by observing the decay of protein synthesis after RNA synthesis has ceased. The messenger for haemoglobin in the reticulocyte5 and for silk fibroin in the silkworm6 are examples of stable messenger molecules with a lifetime of several days. The measurement of messenger lifetime in cells with active RNA metabolism is more difficult. In the experimental approach mentioned above, new RNA synthesis was blocked with actinomycin and the subsequent decay of protein synthesis measured. Under these conditions, protein synthesis generally decreased with a 2.5 to 3 h half-life in a wide variety of systems4,7–9. Interpreting the decay of protein synthesis as due to a concomitant degradation of mRNA assumes that the availability of messenger molecules is limiting in protein synthesis. Here, we shall show that mRNA decay is not responsible for protein synthesis decay in actinomycin. Rather, mRNA appears quite stable after the administration of actinomycin. The subsequent decay of protein synthesis appears to be due to a failure in the initiation of translation.

206 citations


Journal ArticleDOI
TL;DR: A human cervical tumor, free of detectable infectious herpes simplex 2 virus, contained a fragment comprising 39% of herpes viral DNA, which is considerably less than that transcribed in productively infected cells.
Abstract: A human cervical tumor, free of detectable infectious herpes simplex 2 virus, contained a fragment comprising 39% of herpes viral DNA. Renaturation kinetics indicate that an average of 1 to 3.5 DNA fragments of herpes simplex virus are present per cell, depending on the ploidy of the cells in this particular tumor. Virus-specific sequences were found linked to highly repetitive sequences of host DNA, which reassociated under conditions designed to preclude reassociation of viral sequences. The tumor also contained RNA transcripts complementary to 5% of the viral DNA. The fraction of viral DNA template transcribed in the cervical tumor is considerably less than that transcribed in productively infected cells (50%).

205 citations


Journal ArticleDOI
09 Feb 1972-Nature
TL;DR: The following two articles describe successful syntheses in vitro of DNA copies of various mammalian globin mRNAs, using reverse transcriptase from avian myoblastosis virus, using poly(dT) sequences at their 3′-ends.
Abstract: The following two articles describe successful syntheses in vitro of DNA copies of various mammalian globin mRNAs, using reverse transcriptase from avian myoblastosis virus. Short stretches of poly(dT) greatly enhance this effect, presumably because they prime correct initiation of reverse transcription of these mRNAs by pairing with known poly (A) sequences at their 3′-ends.

202 citations


Journal ArticleDOI
TL;DR: Asymmetric RNA was synthesized in vitro from SV40 component I DNA using Escherichia coli DNA-dependent RNA polymerase and hybridized to RNA extracted at different stages of lytic infection and to RNA from transformed cells.

169 citations


Journal ArticleDOI
25 Aug 1972-Nature
TL;DR: This simple theory provides a function for non-histone proteins and an explanation for the large size of eukaryotic genomes, repetitive sequences in DNA, HnRNA and “processing” of nuclear RNA.
Abstract: This simple theory provides a function for non-histone proteins and an explanation for the large size of eukaryotic genomes, repetitive sequences in DNA, HnRNA and “processing” of nuclear RNA.

162 citations



Journal ArticleDOI
TL;DR: It is concluded that the RNA of defective T particles does not serve a transcriptive function and probably interferes through the replicative mechanism for virion RNA synthesis.
Abstract: Exposure of vesicular stomatitis virus-infected Chinese hamster ovary cells to cycloheximide results in the complete transcription of virion ribonucleic acid (RNA) into only 28S and 13 to 15S viral-specific RNA species. These RNA are identical to viral messenger RNA by the following criteria: size, single-strandedness, complementarity to virion RNA, and formation of messenger ribonucleoproteins. This transcription represents the intracellular enzymatic activity of the virion-associated polymerase and is shown to be dependent on input multiplicity. Intracellular transcription differs from in vitro polymerase activity in having a temperature optimum of 34 to 37 C and in synthesizing 28S as well as 13 to 15S messenger RNA species. Addition of interfering quantities of defective T particles to these cycloheximide-treated cells, either an hour before or at the same time as standard B particles of vesicular stomatitis virus, does not alter the rate of transcription nor does it change the sucrose gradient pattern of the viral RNA species. From these results it is concluded that the RNA of defective T particles does not serve a transcriptive function and probably interferes through the replicative mechanism for virion RNA synthesis.

142 citations


Journal ArticleDOI
07 Jun 1972-Nature
TL;DR: In this article, a technique consisting of hybridizing DNA from the cells concerned with the complementary RNA (cRNA) obtained by the transcription of EB virus DNA in vitro with E. coli RNA polymerase was proposed.
Abstract: DURING the past two years, work in this and other laboratories has demonstrated viral genomes characteristic of Epstein–Barr (EB) virus in cell lines and biopsy cells derived from Burkitt lymphomas1–4, and anaplastic carcinomas of the nasopharynx5. Our technique consists of hybridizing DNA from the cells concerned with the complementary RNA (cRNA) obtained by the transcription of EB virus DNA in vitro with E. coli RNA polymerase. We have now applied the technique to various lymphoblastoid cell lines which lack virus particle and structural viral antigens and found that they all seem to carry EB virus genomes. DNA from human umbilical cord leucocytes, however, seems to be free of such genomes.

134 citations


Journal ArticleDOI
TL;DR: It is concluded that dihydrotestosterone stimulates some aspect of mRNA transcription, maturation, or transport to the cytoplasm as well as the rate of RNA polymerase initiation on genes activated by estrogen.

Journal ArticleDOI
TL;DR: Heterogeneous nuclear RNA from HeLa cells contains double-stranded regions that arise by base pairing of complementary sequences that exist as parts of the same molecule (intramolecular base pairing).
Abstract: Heterogeneous nuclear RNA from HeLa cells contains double-stranded regions that arise by base pairing of complementary sequences that exist as parts of the same molecule (intramolecular base pairing). When denatured, the RNA sequences that form the double-stranded regions hybridize rapidly to HeLa cell DNA, suggesting that they are transcribed from reiterated sites in the genome. The messenger RNA does not contain the same class or amount of double-stranded RNA regions found in heterogeneous nuclear RNA.

Journal ArticleDOI
TL;DR: The purified reovirus with chymotrypsin in the presence of 0.15 M NaCl converts virions to infectious subviral particles (SVP(i)), which have an active ribonucleic acid (RNA) polymerase and are similar in composition to the partially uncoated virions which have been isolated from infected L cells.
Abstract: Digestion of purified reovirus with chymotrypsin in the presence of 0.15 M NaCl converts virions to infectious subviral particles (SVP(i)). The SVP(i) have an active ribonucleic acid (RNA) polymerase and are similar in composition to the partially uncoated virions which have been isolated from infected L cells. SVP(i) have a buoyant density of 1.40 g/ml in CsCl and sediment at 420S as compared to 1.37 g/ml and 630S for virions. They consist of 30% less protein and include the polypeptides of the inner structural layer, lambda(1), lambda(2), and sigma(3), and a polypeptide derived by cleavage of mu(2), a constituent of the outer shell. The genome RNA is retained within SVP(i), but more than 60% of the "adenine-rich," single-stranded RNA is released by the proteolytic treatment. Infection of L cells with SVP(i) or virions results in the transcription of all 10 genome segments. In cycloheximide-treated SVP(i)-infected cells, transcription occurs predominantly from one medium and two small genome segments, the same pattern of early messenger RNA (mRNA) observed in virion-infected cells. In contrast, SVP(i) incubated in vitro synthesize mRNA corresponding to all genome segments.

Journal ArticleDOI
TL;DR: The properties of the ribonucleic acid (RNA) polymerase activity which transcribes the major portion of the adenovirus genome were studied and its product is high-molecular-weight heterogeneous RNA.
Abstract: The properties of the ribonucleic acid (RNA) polymerase activity which transcribes the major portion of the adenovirus genome were studied. Nuclei were prepared from infected cells and incubated in vitro. Virus-specific RNA was determined by hybridization to adenovirus deoxyribonucleic acid (DNA). Adenovirus DNA is transcribed principally by an activity which resembles closely polymerase II of the host cell. This activity is inhibited by α-amanitine and stimulated by (NH4)2SO4. Its product is high-molecular-weight heterogeneous RNA. The polymerase activity measured early in infection (3 to 5 hr) resembles that found late in infection (16 to 18 hr).

Journal ArticleDOI
TL;DR: It is proposed that the function of the CAP/cyclic AMP complex is to bind to a site in the promoter, thus stimulating the initiation by RNA polymerase at the normally weak initiation site.

Journal ArticleDOI
TL;DR: A procedure has been developed for the sequential removal and purification of the glycoprotein and membrane protein of vesicular stomatitis virus (VSV), neither of these proteins exhibited transcriptase activity.
Abstract: A procedure has been developed for the sequential removal and purification of the glycoprotein and membrane protein of vesicular stomatitis virus (VSV). Neither of these proteins exhibited transcriptase activity. All of the activity was recovered in the ribonucleic acid (RNA)-ribonucleoprotein complex of VSV, which also has four other minor proteins associated with it. During transcription of 41% of the RNA of a virus preparation, no dissociation of the ribonucleoprotein from the viral RNA was observed.

Journal ArticleDOI
TL;DR: The ratio of ATP- to GTP-initiated T7 RNA chains is not altered by variations in the number of enzyme molecules added per DNA, nor by alterations in the ionic conditions employed for RNA synthesis, which suggests that RNA chain initiation sites are chosen randomly through binding of RNA polymerase to tight (class A) binding sites on T7 DNA.

Journal ArticleDOI
TL;DR: It can be shown that enzyme C does not emanate from a mitochondrial source and is different from both nuclear enzymes A and B by a number of suitable criteria, and functional tests show that the enzyme found in the cytoplasm is not identical to either of the nuclear enzymes a and B.

Journal ArticleDOI
TL;DR: Results indicate that mutation to alpha-amanitin resistance involves a change of a structural gene, and at least some of these mutants contain an altered form of DNA-dependent RNA polymerase II.
Abstract: Mutants of Chinese hamster ovary cells that are resistant to α-amanitin can be isolated. At least some of these mutants contain an altered form of DNA-dependent RNA polymerase II, as indicated by its resistance to α-amanitin. These results indicate that mutation to α-amanitin resistance involves a change of a structural gene.

Journal ArticleDOI
TL;DR: It is confirmed that some mRNA's reach the polyribosomes with little or no delay after the completion of their transcription, and this rapid processing may be a unique property of the histone messages.

Journal ArticleDOI
TL;DR: Data suggest that there is turnover of 16 + 23 s rRNA at slow growth rates in addition to the metabolic control affecting the rate of RNA synthesis which acts on the frequency with which transcription is initiated.

Journal ArticleDOI
TL;DR: Four peaks of DNA-directed RNA polymerase activity are resolved by salt gradient elution of a sonicated yeast cell extract on DEAE-Sephadex, finding that all enzymes are more active with Mn(++) than with Mg(++) as divalent ion.
Abstract: Four peaks of DNA-directed RNA polymerase activity are resolved by salt gradient elution of a sonicated yeast cell extract on DEAE-Sephadex. The enzymes, which are named IA, IB, II, and III in order of elution, all appear to come from cell nuclei. Only enzyme II is sensitive to α-amanitin. All enzymes are more active with Mn++ than with Mg++ as divalent ion. Enzymes IB and II have salt optima in the range 0.05-0.10 M (NH4)2SO4, whereas enzyme III is maximally active at 0.20-0.25 M (NH4)2SO4. With optimal salt concentration and saturating DNA, the template preference ratio, activity on native calfthymus DNA divided by activity on denatured calf-thymus DNA, is 2.2 for IB, 0.4 for II, and 3.5 for III. None of the yeast polymerases was inhibited by rifamycin SV. Rifamycin AF/013 effectively inhibited polymerases IB, II, and III.

Journal ArticleDOI
25 Oct 1972-Nature
TL;DR: Tyrothricin specifically inhibits RNA synthesis in growing cultures of Bacillus brevis as well as purified RNA polymerase, suggesting that the peptide antibiotic may function in the regulation of gene transcription during the transition from vegetative growth to sporulation.
Abstract: Tyrothricin specifically inhibits RNA synthesis in growing cultures of Bacillus brevis as well as purified RNA polymerase. This suggests that the peptide antibiotic may function in the regulation of gene transcription during the transition from vegetative growth to sporulation.

Journal ArticleDOI
TL;DR: It is raised the possibility that bidirectional transcription of cro has a regulatory function in phage λ, the gene that codes for phage repressor.
Abstract: There are two promoters for transcription of gene cI in phage λ, the gene that codes for phage repressor. The promoters, called pre and prm, are located on the distal (pre) and proximal (prm) sides of gene cro, which itself is adjacent to cI. Since cI and cro are transcribed in opposite directions, cI transcription initiating at pre gives rise to an antisense transcript of cro, while cI transcription initiating at prm does not. Pre, active after infection of a sensitive cell, is stimulated by products of phage genes cII and cIII, and may be located at the site defined by the mutant cY. Prm is active in an established lysogen. These conclusions are based on measurements of the rates of synthesis of antisense cro RNA, cI RNA, and repressor protein in infected and lysogenic cells. To measure antisense RNA, an assay based on the formation of nuclease-resistant, double-stranded RNA, specific to the cro region, was developed. These results raise the possibility that bidirectional transcription of cro has a regulatory function in phage λ.

Journal ArticleDOI
20 Dec 1972-Nature
TL;DR: A very high molecular weight RNA molecule is transcribed from a defined chromosome region, the Balbiani ring 2 in Chironomus tentans salivary glands, which supports the concept of the chromomere as a unit of transcription.
Abstract: A very high molecular weight RNA molecule is transcribed from a defined chromosome region, the Balbiani ring 2 in Chironomus tentans salivary glands. This supports the concept of the chromomere as a unit of transcription.

Journal ArticleDOI
TL;DR: Newly replicated adenovirus 2 deoxyribonucleic acid (DNA) can be isolated from the nucleus of HeLa cells by a gentle lysis procedure as a fairly homogeneous complex with a sedimentation of 73S and the synthesis of virus-specific RNA by the isolated nuclei is strongly inhibited by low doses of alpha-amanitine.
Abstract: Newly replicated adenovirus 2 deoxyribonucleic acid (DNA) can be isolated from the nucleus of HeLa cells by a gentle lysis procedure as a fairly homogeneous complex with a sedimentation of 73S. The viral DNA complex can be prepared completely free from host cell DNA. The viral complex is slightly active in ribonucleic acid (RNA) synthesis in vitro. Treatment of the complex with Pronase and sodium dodecyl sulfate converts the DNA to a form which sediments at 43S. Nuclei isolated from adeno-infected cells synthesize high-molecular-weight virus-specific RNA in vitro. Optimal RNA synthesis requires a divalent cation, preferentially manganese, and relatively high salt concentrations. The synthesis of virus-specific RNA by the isolated nuclei is strongly inhibited by low doses of alpha-amanitine. The latter experimental result is discussed in terms of the polymerase used to transcribe the adenovirus DNA in vivo.

Journal ArticleDOI
TL;DR: It is concluded that such non-histone protein fractions are capable of differentially augmenting transcription in vitro from DNA sequences of chromatin.

Journal ArticleDOI
TL;DR: The metabolism of f2c histone in non-dividing avian red blood cells may be an example of a more general phenomenon for other histones (particularly f 1 histones) in other tissues, and that the important feature which relates histones to the over-all potential of chromatin for transcription is not the static level of histone but rather the dynamic state of its synthesis and its release from DNA.

Journal ArticleDOI
TL;DR: The fidelity of initiation of T7 RNA synthesis is governed not only through regulation of the sites on T7 DNA at which binding of RNA polymerase can occur, but also by what appear to be rigid structural requirements for RNA chain initiation byRNA polymerase once it has been bound.

Journal ArticleDOI
TL;DR: Observations indicate that late in infection of monkey cells, SV40 DNA is transcribed symmetrically over a considerable portion of its length, and that subsequently some sequences from one or both of the RNA strands are degraded.
Abstract: Rapidly labeled RNA was extracted from monkey cells after infection with Simian Virus 40 (SV40) and exposure to short pulses of [5-3H]uridine late in infection. When this RNA was self-annealed, it became resistant to digestion with ribonuclease. The fraction of RNA that resisted the ribonuclease treatment decreased with increased labeling time, or when a short pulse of radioactivity was followed by incubation with unlabeled uridine and actinomycin D. The RNase-resistant RNA was isolated by chromatography on Sephadex G-100 and shown to be double-stranded by its susceptibility to ribonuclease as a function of salt concentration and temperature. This behavior was not due to RNA-DNA hybrid formation, since deoxyribonuclease had no effect upon the double-stranded molecules, even after their denaturation. The relation of the double-stranded RNA to SV40 was demonstrated by the hybridization of about 50% (corrected value, >90%) of the separated RNA strands with component I of SV40 DNA from plaque-purified virus. After self-annealing in formamide at low temperature, about 10% of the rapidly labeled, viral RNA sedimented at 13 S. This value corresponds in size to about 60% of the SV40 DNA. These observations indicate that late in infection of monkey cells, SV40 DNA is transcribed symmetrically over a considerable portion of its length, and that subsequently some sequences from one or both of the RNA strands are degraded.