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R C Herman

Publications and source records attributed to R C Herman.

30 records · Page 2Linked to original sources
PubMed1981

Vesicular stomatitis virus RNA polymerase can read through the boundary between the leader and N genes in vitro.

Triphosphorylated in vitro transcripts of vesicular stomatitis virus were selected by mercury-Sepharose chromatography using adenosine-5'-O-(3-thiotriphosphate) as an affinity probe. Numerous RNAs ranging from less than 47 up to several hundred nucleotides in length were detected. Some of these contain the leader RNA covalently linked to transcripts of the N gene. A comparison of the published genomic sequences at the estimated termination sites of several of these RNAs reveals some homology with the sequence present at both the end of the leader and polymerase genes.

Base Sequence↗
PubMed1981

Aberrant glycoprotein mRNA synthesized by the internal deletion mutant of vesicular stomatitis virus.

The internal deletion mutant (DI-LT) derived from the heat-resistant strain of vesicular stomatitis virus synthesized an aberrant polyadenylated mRNA in vivo and in vitro. No normal glycoprotein message could be detected among the in vivo transcription products. The abnormal RNA contained a transcript of the partially deleted polymerase gene covalently linked to the 3' end of the glycoprotein message. The polyadenylate is located at the 3' end of the molecule and is most probably encoded by the remnant polymerase gene polyadenylation signal. This aberrant RNA may be synthesized because of either a failure to terminate transcription at the end of the glycoprotein gene or an inability to process an abnormal polycistronic precursor.

Animals↗
PubMed1981

Phase II studies of dianhydrogalactitol-based combination chemotherapy for recurrent brain tumors.

The drug combinations of dianhydrogalactitol and VP-16 and dianhydrogalactitol, VP-16, and triazinate were used in patients with primary brain tumors, principally astrocytoma, recurrent following cranial irradiation. Tumor regressions were noted in 40% of patients treated with the 2-drug regimen and in 33% of patients treated with the 3-drug regimens. Regression were noted in all grades of tumor. Poor performance score on the patients' part did not seem to effect regression rates. Myelosuppression was the principal toxicity encountered. Dianhydrogalactitol-based combination chemotherapy seems as active as nitrosourea therapy and presents an alternative to nitrosourea therapy.

Adolescent↗
PubMed1980

Polycistronic vesicular stomatitis virus RNA transcripts.

A procedure to enrich for the sequences present at the junction between the linked messages in the polycistronic RNAs symthesized in vitro by vesicular stomatitis virus (VSV) is described. Analyses of these sequences show that they contain a precise transcript of both the intercistronic dinucleotide and the pentanucleotide 5'--C-U-G-U-U--3', common to the 5'-end of all VSV cistrons, covalently linked to the 3'-side of the intervening poly(A). The data strongly suggest that the VSV transcriptase polyadenylylates the mRNAs and can then resume direct and precise transcription of the genome-without reinitiation and without skipping nucleotides.

Base Sequence↗
PubMed1980

Defective interfering particle generated by internal deletion of the vesicular stomatitis virus genome.

The genome structure of the long, truncated defective interfering particle derived from the heat-resistant strain of vesicular stomatitis virus has been examined. Stocks of this defective interfering particle are shown to contain several different species having information primarily from the 3' half of the vesicular stomatitis virus genome; the proportions of these components vary depending on the passage history of the stock. The two most abundant types have been identified and characterized. One has complementary 5' and 3' termini and consequently appears as a circular molecule when examined by electron microscopy. The other cannot circularize and remains linear. The circular forms are consistently 8 to 10% longer than the linear molecules. Rapid sequencing analyses reveal that both forms retain the 5' parental viral terminal sequence, but only the linear form retains the parental 3'-terminal sequence which is the complement of the 5' end. Hybridization experiments and electron microscopic analyses indicate that the linear form has retained 320 to 350 nucleotides of the 5' parental sequence and was probably generated by an internal deletion of the vesicular stomatitis virus genome.

Base Sequence↗
PubMed1980

Site on the vesicular stomatitis virus genome specifying polyadenylation and the end of the L gene mRNA.

The 5'-terminal nucleotide sequence from positions 50 to 130 of vesicular stomatitis virus RNA was determined indirectly by using a defective interfering particle RNA which contains covalently linked genomic minus and antigenomic plus sense RNAs. The last 18 nucleotides of the L gene coding for in the viral polymerase were identified and isolated by specific duplex formation between 5' terminally labeled oligonucleotides from a small single-stranded defective interfering particle RNA and L gene mRNA. The L gene ends at position 60 from the 5' terminus of the vesicular stomatitis genome. The data demonstrated that the first seven adenine residues in the polyadenylic acid tail of L gene mRNA may be coded for in the genome and suggested that the viral transcriptase itself may carry out polyadenylation, possibly by chattering at the uridine-rich sequence at the end of the L gene. Analysis of the 5'-terminal sequence of vesicular stomatitis virus genomic RNA revealed that it might fold into a complex secondary structure with possibly 62% of the bases paired.

Base Sequence↗
PubMed1979

Analysis of the message-sequence content of the pulse-labeled poly(A)+ heterogeneous nuclear RNA from HeLa cells by cDNA-excess hybridizations.

The message-sequence content of pulse-labeled poly(A)+ HeLa heterogenous nuclear RNA (hnRNA) has been examined by hybridizations to an excess of message cDNA. Control experiments show that the message cDNA accurately reflects the sequence distribution of the complex mixture of poly(A)+ messages present in the HeLa cytoplasm. Pulse-labeled poly(A)+ molecules in both the lamina-associated and shnRNA fractions contain message sequences, and approximately 65% of the poly(A)-adjacent hnRNA sequences are homologous to the 3' ends of mRNA. The majority of the pulse-labeled hnRNA molecules contain abundant message sequences. By use of these techniques it is also shown that some pulse-labeled polyadenylated message sequences are still synthesized in the presence of the adenosine analogue 5,6-dichloro-beta-D-ribofuranosylbenzimidazole under conditions where little or no new cytoplasmic mRNA is produced.

Base Sequence↗
PubMed1978

Intervening polyadenylate sequences in RNA transcripts of vesicular stomatitis virus.

Purified and partially resolved vesicular stomatitis virus (VSV) messenger RNA has been annealed to the VSV genomic RNA and visualized in the electron microscope under conditions in which duplex regions have a wider image width than single-stranded RNA. The locations of the intercistronic boundaries between the messages have been mapped on the VSV genome. The contour of the double-stranded regions is occasionally interrupted by looped-out single-stranded RNA. The loops are comprised of post transcriptionally synthesized polyadenylate. Most of these structures are found at the intercistronic boundaries and covalently bridge adjacent message sequences. In this paper, we discuss the possible significance of these loops.

Chromosome Mapping↗
PubMed1976

Message and non-message sequences adjacent to poly(A) in steady state heterogeneous nuclear RNA of HeLa cells.

Highly purified steady state heterogeneous nuclear RNA from HeLa cells has been prepared by a new procedure. Detergent-washed nuclei are disrupted in 0.4 M ammonium sulfate, which also disociated contamination polysomes. The hnRNA remains bound to chromatin, which can be pelleted by gentle centrifugation. Ribonuclease inhibitors permit the preparation of very high molecular weight nuclear RNA. The hnRNA was cleaved with alkali. The poly(A)-containing fragments were separated from those containing oligo(A), and a cDNA copy was prepared. Hybridization of this nuclear cDNA to cytoplasmic mRNA showed that the scarce (complex) message sequences make up a larger proportion of nuclear RNA than of cytoplasmic RNA. In addition, at least 30% of the poly(A)-adjacent sequences in nuclear RNA have no apparent counterparts in the cytoplasm. cDNA prepared from hnRNA sedimenting faster than 45S under denaturing conditions gives similar results, showing the presence of both message and non-message sequences in very large transcripts. cDNA complementary to mRNA was separated into the abundant and scarce sequences, and hybridized separately to the poly(A)-adjacent sequences in nuclear RNA. The hybridization of the abundant sequence cDNA was used to set an upper limit on possible cytoplasmic contamination. Hybridization of the scarce cytoplasmic sequences are represented in nuclear RNA approximately once per cell.

Cell Nucleus↗
PubMed1974

In vivo repair of the single-strand interruptions contained in bacteriophage T5 DNA.

Bacteriophage T5 is known to contain several unique single-strand interruptions in only one strand of the duplex DNA. Analysis of labeled parental phage DNA from infected Escherichia coli shows that these nicks are repaired in vivo to yield intact double-stranded molecules. Sealing begins at about 6 min after infection and is independent of DNA replication. Repair may be an ordered process that starts at a unique end of the molecule.

Autoradiography↗