Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “RNA, MESSENGER”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources
PubMed1975

Messenger RNA species synthesized in vitro by the virion-associated RNA polymerase of vesicular stomatitis virus.

The virion-associated RNA-dependent RNA polymerase of vesicular stomatitis virus (VSV) synthesizes in vitro two size classes of RNA products similar to those observed in VSV-infected cells. One RNA product sediments at 31S with an approximate molecular weight of 2.1 X 106. The smaller products consist of at least three classes of RNA sedimenting at 17S, 14.5S, and 12S with molecular weights of 0.7 X 106, 0.52 X 106, and 0.37 X 106, respectively. Hybridization experiments show that both the 31S and 12-18S RNA products are complementary to the genome RNA, and that each class is transcribed from different nucleotide sequences. From the molecular weights of the RNA species and the hybridization experiments, it seems that almost the entire VSV genome RNA is transcribed in vitro.

Animals↗
PubMed1975

Further evidence of transcriptional and translational control of histone messenger RNA during the HeLa S3 cycle.

Using a translational assay and new analytical procedures we have found that: -Histone mRNA can be detected both associated with polyribosomes and in the postribosomal supernatant of S phase HeLa S3 cells.-Inhibition of DNA replication by cytosine arabinoside treatment causes histone mRNA to completely disappear from polyribosomes, and little histone mRNA can be detected in the postribosomal supernatant of inhibited cells. These data indicate that histone mRNA does not accumulate in the cytoplasm after the inhibition of DNA replication. -Histone mRNA species cannot be detected in the postribosomal supernatant of G1 cells synchronized by selective detachment. This observation, together with the previous finding that histone mRNA is not present on G1 polyribosomes, is consistent with the idea of a transcriptional block in histone mRNA production and transport to the cytoplasm during G1.

Carbon Radioisotopes↗
PubMed1975

Methylated nucleotides block 5' terminus of HeLa cell messenger RNA.

Polyadenylylated [poly(A)+] mRNA from HeLa cells that were labeled with [3H-methyl]-methionine and 14C-uridine was isolated by poly(U)-Sepharose chromatography. The presence of approximately two methyl groups per 1000 nucleotides of poly(A)+ RNA was calculated from the 3H/14C ratios and known degrees of methylation of 18S and 28S ribosomal RNAs. All four 2'-O-methylribonucleosides, but only two base-methylated derivatives, 7-methylguanosine (7MeG) and 6-methyladenosine (6MeA), were identified. 6MeA was the major component accounting for approximately 50% of the total methyl-labeled ribonucleosides. 7MeG, comprising about 10% of the total, was present exclusively at the 5' terminus of the poly(A)+ RNA and could be removed by periodate oxidation and beta elimination. Evidence for a 5' to 5' linkage of 7MeG to adjacent 2'-O-methylribonucleosides through at least two and probably three phosphates to give structures of the type 7MeG5'ppp5pNMep- and 7MeG5'ppp5'NMepNmep- was presented. The previous finding of similar sequences of methylated nucleotides in mRNA synthesized in vitro by enzymes associated with virus cores indicates that blocked 5' termini may be a characteristic feature of mRNAs that function in eucaryotic cells.

Adenosine↗
PubMed1976

Topography of polyoma virus messenger RNA molecules.

The different species of polyoma virus-spedific RNA molecules present in the cytoplasm of 3T6 cells 30 hr after viral infection have been characterized by molecular hybridization between nonradioactive polyadenlated RNA, fractionated by sedimentation through sucrose-formamide density gradients, and the 32P-labeled separated strands of restriction endonuclease fragments of polyoma DNA. Two relatively abundant RNA molecules, sedimenting at 16S and at 19S, transcribed from the L strand of the viral DNA, as well as a minor 20S species transcribed from the E strand of the DNA, were detected. The most abundant viral transcript, the 16S RNA molecule, was estimated to be complementary to the 22% of the L-strand DNA extending from 47 to 25 map units. The less abundant 19S L DNA strand transcript included all the sequences present in the 16S RNA and mapped between 68 and 25 map units. The minor 20S RNA molecule was tentatively identified as a transcript of the E-strand DNA from the entire early region of the polyoma genome. These three viral RNA molecules together exhaust greater than 95% of the coding capacity of the viral DNA. A small region of the DNA (4-5%), including the origin of DNA replication, does not appear to determine sequences present among the major stable species of vital mRNA.

Cell Line↗
PubMed1976

Elevated dihydrofolate reductase messenger RNA levels in methotrexate-resistant BHK cells.

Polysomal RNA from cultured sublines of baby hamster kidney (BHK) cells directed protein synthesis in an in vitro system derived from wheat germ extract. One product of the in vitro synthesis was dihydrofolate reductase (DHFR), as confirmed by methotrexate-substituted Sepharose affinity chromatography followed by SDS-polyacrylamide slab gel electrophoresis and autoradiography of the proteins labeled with 35S-methionine. The DHFR synthesized in vitro comigrates in the gel with authentic BHK DHFR, indicating that the molecular weights and structures of the in vivo and in vitro enzymes are probably the same. Polysomal RNA obtained from the methotrexate-resistant BHK subline (A5), which possesses some 140 times higher DHFR levels than the methotrexate-sensitive parents subline (B1), directed the synthesis of approximately 70 times more DHFR per unit of total in vitro synthesized protein than did B1 polysomal RNA. Assuming then that the rates of translation of A5 and B1 DHFR mRNAs in the wheat germ cell-free system are the same, our results show that a major part of the high DHFR levels observed in A5 cells is due to the presence of elevated quantities of DHFR mRNA.

Cell Line↗
PubMed1977

An amazing sequence arrangement at the 5' ends of adenovirus 2 messenger RNA.

The 5' terminal sequences of several adenovirus 2 (Ad2) mRNAs, isolated late in infection, are complementary to sequences within the Ad2 genome which are remote from the DNA from which the main coding sequence of each mRNA is transcribed. This has been observed by forming RNA displacement loops (R loops) between Ad2 DNA and unfractionated polysomal RNA from infected cells. The 5' terminal sequences of mRNAs in R loops, variously located between positions 36 and 92, form complex secondary hybrids with single-stranded DNA from restriction endonuclease fragments containing sequences to the left of position 36 on the Ad2 genome. The structures visualized in the electron microscope show that short sequences coded at map positions 16.6, 19.6 and 26.6 on the R strand are joined to form a leader sequence of 150-200 nucleotides at the 5' end of many late mRNAs. A late mRNA which maps to the left of position 16.6 shows a different pattern of second site hybridization. It contains sequences from 4.9-6.0 linked directly to those from 9.6-10.9. These findings imply a new mechanism for the biosynthesis of Ad2 mRNA in mammalian cells.

Adenoviruses, Human↗
PubMed1977

The gene and messenger RNA for adenovirus polypeptide IX.

A small RNA species, distinct from the VA RNAs, has been identified in HeLa cells infected with adenovirus type 2. The RNA, which has been purified using a novel screening procedure, is polyadenylated, sediments at 9S and has an estimated length of 550 nucleotides. In a cell-free translation system, the 9S RNA directs the synthesis of virion polypeptide IX, molecular weight 12,000 daltons. The location of its gene has been established by hybridization of the RNA to fragments of viral DNA produced by cleavage with restriction endonucleases: it spans position 10.0 on the r strand of the viral genome. These results unexpectedly place the gene for a "late" protein within a region of the genome which is transcribed early during infection

Adenoviruses, Human↗
PubMed1980

Expression of a subgenomic retroviral messenger RNA.

When mRNA for avian retroviral envolope glycoprotein (env) was injected into cells transformed by env-deficient Bryan Rous sarcoma virus, the env deficiency of the injected cells was complemented to allow the release of transforming virus for up to 40 hr. When virus spread within the injected culture was allowed to occur, a second phase of transforming virus production by the injected culture began approximately 2 days following injection, continued for many days and often increased to titers well above those seen soon after injection. The requirement for virus spread, along with the genetic properties of virus released long after injection, supported the hypothesis that the second phase of virus production resulted when injected env mRNA was packaged into virus released by injected cells. When this virus infected other cells within the culture the env mRNA was reverse-transcribed to form a subgenomic, proviral-like molecule able to direct the synthesis of env mRNA. Accordingly, it was shown tht neither DNA nor full genomic viral RNA contaminating injected mRNA preparations could account for the results. Evidence that an mRNA can be reverse-transcribed into an active, proviral-like molecule may be of importance in the relationship between retroviruses and their hosts.

Animals↗