Browse
Submit Data
Databases
API
Help

Dataset Information

14 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Inhibition of ribonucleic acid efflux from isolated SV40-3T3 cell nuclei by 3'-deoxyadenosine (cordycepin).

ABSTRACT: The effect of 3'-deoxyadenosine (cordycepin) on mRNA efflux from isolated SV40-3T3 cell nuclei has been studied and compared with its effect on the nucleoside triphosphatase activity in the isolated nuclear envelope. Inhibition of mRNA efflux occurs rapidly, but is dependent on the presence of ATP. Half-maximal inhibition occurs with 40 microM-cordycepin. The effect is not simulated by 2'-deoxyadenosine or by actinomycin D, and adenosine provides a substantial degree of protection against it. Cordycepin does not directly inhibit the nucleoside triphosphatase. The stimulation of this enzyme by poly(A) is not affected unless the poly(A) and cordycepin are incubated together with nuclear lysate in the presence of ATP; in this case the stimulation is significantly reduced. Possible interpretations of these results and their relevance for understanding the system in vivo for nucleo-cytoplasmic messenger transport are discussed.

SUBMITTER: Agutter PS

PROVIDER: S-EPMC1161062 | biostudies-other | 1979 May

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Modified messenger ribonucleic acid release from isolated hepatic nuclei after inhibition of polyadenylate formation.

Project description:Treatment of rats with Cordycepin (3'-deoxyadenosine), an inhibitor of nuclear poly(A) synthesis, selectively decreased the energy and cytosol-dependent release of a portion of the mRNA species from the isolated hepatic nuclei in a cell-free system by approximately 40%. An analysis of the differential binding of the transported mRNA containing poly(A) tracts to nitrocellulose filters, and to cellulose or poly(U)-Sepharose columns suggested that the poly(A) tracts in the mRNA transported from the isolated hepatic nuclei of Cordycepin-treated rats, are decreased in size. This size decrease was confirmed through an analysis of the average size of the poly(A) tracts, released from the messengers by ribonuclease activity, on sucrose density gradients.

| S-EPMC1166266 | biostudies-other

Ribonucleic acid synthesis in isolated rat liver nuclei under conditions of ribonucleic acid processing and transport.

Project description:A cell-free system is described which permits a significant and prolonged synthesis of RNA in isolated rat liver nuclei, under conditions previously demonstrated to support normal nuclear processing and transport of both rRNA and mRNA. The system contains cytosol but not (NH4)2SO4 or other non-physiological components. Evidence is presented for cytosol factors which stimulate ribosomal, and to a lesser degree, non-ribosomal RNA synthesis.

| S-EPMC1165430 | biostudies-other

Methylation of newly synthesized ribonucleic acid by isolated rat liver nuclei. Characterization of the ribonucleic acid synthesized by nuclei from starved animals.

Project description:1. Nuclei from rat liver incubated with S-adenosyl[methyl-(14)C]methionine incorporated radioactivity into RNA and into lipid and protein. 2. All of the labelled RNA was extracted from the nuclei with trichloroacetic acid at 90 degrees C. 3. The [(14)C]methyl-group incorporation into the hot-trichloroacetic acid extract was 30% inhibited by the addition of actinomycin D (100mug/mg of DNA) or by the omission of CTP, GTP and UTP. 4. Assuming that the main substrate for this triphosphate-dependent methylation was newly synthesized precursor rRNA containing one methyl group/30 uridylate residues, it was calculated that approx. 60% of the [(14)C]UMP incorporated under similar conditions represented precursor rRNA synthesis. 5. In agreement with this, low concentrations of actinomycin D (approx. 1mug/mg of DNA) sufficient to abolish the triphosphate-dependent incorporation of [(14)C]methyl group inhibited 68% of the [(14)C]UMP incorporation. 6. The incorporation of [(14)C]UMP by nuclei from starved animals decreased progressively with increasing periods of starvation, whereas the triphosphate-dependent [(14)C]methyl-group incorporation was not further decreased after 1 day of starvation. 7. This suggests that precursor rRNA synthesis decreased within 1 day whereas other species of RNA were affected only after longer periods of starvation.

| S-EPMC1177074 | biostudies-other

Characterization of the ribonucleic acid synthesized by isolated rat-liver nuclei.

Project description:1. Isolated rat-liver nuclei incorporated [(14)C]UMP into RNA when incubated in the presence of Mg(2+) and all four ribonucleoside triphosphates. The addition of bentonite to the system diminished the breakdown of the newly synthesized RNA. 2. AMP and CMP were incorporated in the absence of the other added triphosphates, and in the presence of deoxyribonuclease. 3. RNA synthesized in the presence of Mg(2+) contained a high proportion of CMP and GMP, and sedimented in the regions of ribosomal RNA and of heavier molecules. About 1% of this RNA hybridized with homologous DNA, and hybrid formation was more effectively inhibited by nuclear RNA than by ribosomal RNA. 4. RNA synthesized in the presence of Mn(2+) plus ammonium sulphate had a composition intermediate between that of ribosomal RNA and of DNA, and about 4% of this RNA formed hybrids with DNA. 5. Less than 2% of the newly synthesized RNA was capable of forming ribonuclease- and deoxyribonuclease-resistant complexes. 6. It was concluded that the newly synthesized RNA arose as a result of an asymmetric process and included both ribosomal and DNA-like species.

| S-EPMC1270224 | biostudies-other

Nature of the facilitated messenger ribonucleic acid transport from isolated nuclei.

Project description:Cytoplasmic macromolecules were previously identified which regulate both qualitatively and quantitatively the release of messenger-like RNA from isolated nuclei. These macromolecules are now shown to be denatured at 45-50 degrees C and their synthesis is sensitive to pactamycin or cycloheximide. The putative regulatory proteins are essentially quantitatively precipitated with high specificity from the cytosol by streptomycin at a concentration 10-fold higher than that used to precipitate RNA. The nuclear concentration-dependence of RNA transport from successive samples of nuclei strongly suggests that the regulatory factors are recycled. Quantitative changes in the sequences transported at various dilutions of the cytosol suggest that not all the different classes of the putative regulatory macromolecules are present in an effective concentration at any one dilution.

| S-EPMC1172718 | biostudies-other

Decreased ribonucleic acid synthesis in isolated rat liver nuclei during starvation.

Project description:1. Isolated nuclei from starved rats showed a lowered incorporation of [(14)C]UMP into RNA. 2. The Mg(2+)-dependent incorporation was decreased by 30% after 1 day of starvation, but incorporation in the presence of Mn(2+) and ammonium sulphate decreased only after longer periods of starvation. 3. RNA synthesis by nuclei in the presence of excess of added RNA polymerase was unchanged after 1 day of starvation and was inhibited by 20% after 4 days. 4. The capacity of nuclei to bind actinomycin D was unchanged after 1 day and was decreased by 20% after 4 days of starvation.

| S-EPMC1179608 | biostudies-other

The loss of rapidly labelled ribonucleic acid from isolated HeLa cell nuclei.

Project description:1. The loss of nucleic acids and protein from isolated HeLa-cell nuclei was studied. During 4hr. incubation at 37 degrees DNA was conserved, but appreciable amounts of RNA and protein were lost. 2. Two classes of nuclear RNA were distinguished: at least 75% of the RNA was lost from the nuclei relatively slowly through degradation to acid-soluble fragments; the rest of the RNA was lost much more rapidly, not only through degradation to acid-soluble fragments but also through diffusion of RNA out of the nuclei into the incubation medium. 3. The RNA that was preferentially lost was the fraction of nuclear RNA that was rapidly labelled when intact HeLa cells were grown in a medium containing radioactive precursors of RNA. 4. The RNA appearing in the incubation medium was apparently partially degraded and had a sedimentation coefficient of about that of transfer RNA. 5. Both the degradation of RNA and the loss of RNA from the nuclei were sensitive to bivalent cations. Low concentrations of Mg(2+) and Mn(2+) greatly increased the rate of degradation of the rapidly labelled RNA to acid-soluble fragments, and produced a corresponding decrease in the amount of RNA diffusing into the medium. At higher concentrations they suppressed both degradation and diffusion of RNA. The cations Ca(2+), Cu(2+), Zn(2+) and Ni(2+) all progressively inhibited both forms of loss of RNA. 6. Salts of univalent cations produced appreciable effects only at ionic strengths of about 0.2, when degradation to acid-soluble fragments was preferentially inhibited. 7. Both ADP and ATP inhibited loss of RNA at about 30mm. 8. It was concluded that the diffusion of rapidly labelled RNA out of the isolated nuclei was not related to the movement of RNA from nucleus to cytoplasm in vivo, but reflected the ease with which the rapidly labelled RNA detached from the chromatin and the permeability of the membranes of isolated nuclei.

| S-EPMC1187643 | biostudies-other

Inhibition by alpha-amanitin of ribonucleic acid polymerase solubilized from rat liver nuclei.

Project description:1. alpha-Amanitin inhibits in vitro the RNA polymerase solubilized from isolated rat liver nuclei. 2. In contrast with previous observations with whole nuclei, the inhibition occurs approximately to the same extent in the presence and in the absence of ammonium sulphate. 3. Evidence is presented that the toxin acts by interacting with the enzyme itself and not with DNA or other components.

| S-EPMC1185343 | biostudies-other

Messenger ribonucleic acid of cerebral nuclei.

Project description:1. RNA was isolated from crude nuclear preparations and from ribosomes derived from rat brain and liver. Nuclear RNA was obtained by lysis of the nuclei with sodium dodecyl sulphate, followed by denaturation and removal of DNA and protein with hot phenol. 2. Base composition analyses indicated that the cerebral nuclear RNA preparation contained a higher proportion of non-ribosomal RNA than the analogous hepatic preparation. 3. Sucrose-density-gradient analyses revealed a heterogeneous profile for each nuclear RNA preparation, with two major peaks possessing the sedimentation properties of ribosomal RNA (18s and 28s). 4. Template activities of both preparations were widely distributed through the sucrose density gradients. 5. The cerebral nuclear RNA preparation was more active than the hepatic nuclear RNA preparation in promoting amino acid incorporation in cell-free systems from Escherichia coli and rat brain. 6. Cerebral nuclear RNA stimulated amino acid incorporation in a cerebral ribosomal system even in the presence of an excess of purified E. coli transfer RNA. 7. It is concluded that a significant proportion of cerebral nuclear RNA has the characteristics of messenger RNA.

| S-EPMC1198432 | biostudies-other

Age-associated changes in initiation of ribonucleic acid synthesis in isolated rat liver nuclei.

Project description:Initiation of RNA synthesis was studied in an attempt to determine a possible molecular mechanism for age-related biochemical and physiological changes. Initiation of RNA synthesis was determined by incorporation of [gamma-32 P]ATP and of [gamma-32P]GTP into an acid-insoluble product by intact nuclei isolated from livers of Sprague-Dawley CD-strain rats of various ages. When the rats were grouped into young (0.75-9 months) and old (12-30 months) rats, a significant decrease (P less than or equal to 0.001) in incorporation of initiating nucleotides was observed. The rat population was divided into five age groups (0.75-3 months, 4-9 months, 12-18 months, 19-23 months and 30 months) for further analysis of the effect of age on the initiation of RNA synthesis. Analysis of data from these groups indicated a significant trend for an age-related decrease in RNA-synthesis initiation (correlation coefficient = 0.94). Long-term hypophysectomy coupled with minimal hormone-replacement therapy was shown to have a significant effect on the reversal of the age-related decrease in initiation of RNA synthesis. It was observed that initiation of RNA synthesis in nuclei from 19-month-old rats, hypophysectomized at 12 months of age, was closest to that in 3-month-old intact rats and was not significantly different from that in liver nuclei of 0.75-9-month-old intact rats.

| S-EPMC1162536 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data