Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two maxima of optic density were observed at zones of gravity 1.27 g/ml and 1.15-1.16 g/ml by sedimentation equilibrium in sucrose gradient of cultural fluid, obtained from the transplantable cells of the HEP-2 strain and concentrated by ultracentrifugation. These fractions thus isolated were tested for presence of RNA- and DNA-dependent DNA-polymerase. The structures with the density of 1.15-1.16 g/ml were identified with the oncornaviruses on the basis of characteristics flotating density, presence of RNA-dependent DNA-polymerase. Analyses of products of RNA- and DNA-dependent polymerases reaction, flotating density of oncornaviral nucleotides in sucrose and CsCl gradients are presented. The optimal conditions for reverse-transcriptase reaction of virions of D type viruses are characterized.
 ...
PMID:[Further study of spontaneous virus production using transplantable HEp-2 cells as a model]. 7 26

We investigated the nature of temperature sensitivity of the HEP strain of rabies virus. After initial incubation for appropriate period (more than 12 hr) at the permissive temperature (36-37 degrees), incubation temperature of the rabies virus infected cultures was shifted to a nonpermissive temperature (39.5-40.5 degrees). Upon the upshift, virion production was ceased, but the rate of viral RNA synthesis was greatly increased and reached almost 10 times that of 36 degrees-infection within 8-10 hr, and then the activity quickly decreased together with the onset of accelerated CPE. Little or no 42S genome-sized RNA was produced at the elevated temperature, and almost all RNAs produced in large amounts seemed to be viral mRNAs and were shown to be functional in t he cell-free translation system. Consistent with these observations, the viral ribonucleoprotein complex isolated from the temperature-upshifted culture was associated with relatively large amounts of small sized RNAs, which might reflect their increased transcriptive activity. These observations suggest that the viral RNA polymerase itself is not temperature-sensitive and the temperature-induced defect may reside in the regulatory factor which plays a role in turning on the synthesis of viral genome-sized RNA.
 ...
PMID:Temperature-sensitivity of the replication of rabies virus (HEP-flury strain) in BHK-21 cells. I. Alteration of viral RNA synthesis at the elevated temperature. 173 1

Synthesis of virus-specific RNAs in human HEP-2 and L-41 cells chronically infected with measles virus was studied in comparison with synthesis of viral RNA in acutely infected L-41 cells. The RNA, a component of RNP isolated from chronically infected cells, was shown to be represented mainly by "minus" chains and to contain 23-25% "plus"-RNA. It was demonstrated by blotting hybridization that 1 species of genomic RNA with a molecular weight of 5 megadaltons was synthesized in acute infection whereas in chronically infected cells a small amount of subgenomic RNAs was additionally detected in RNP. The level of virus genome transcription in chronically infected cells was 7-8 fold lower than that in acute infection. The RNA-transcriptase activity of RNP isolated from chronically infected HEP-2 and L-41 cells was also lower than RNP activity from acutely infected L-41 cells. The observed features of virus-specific RNA synthesis in chronically infected cells seem to be likely to play a role in the maintenance of virus persistence.
 ...
PMID:[RNA analysis of the measles virus in a human cell culture of the chronic infection]. 242 50

To investigate the RNA polymerase of rabies virus, we cloned a cDNA of the catalytic subunit (called L protein because of its large molecular size) of the HEP-Flury strain, an avirulent strain obtained by high frequencies of serial embryonated hen egg passages. Nucleotide sequencing showed that the cDNA encodes a long polypeptide of 2,127 amino acids (Mr. 242,938). A comparison of the deduced amino acid sequence with that of other strains (PV and SAD B19) indicated that the sequence was highly conserved, except for several amino acid substitutions which were accumulated in some limited regions. A fragment of the cDNA was used for expression in Escherichia coli (E. coli) to prepare the L antigen for raising the antibodies in rabbits. Immunoprecipitation studies with the rabbit antiserum showed that the polypeptides produced in the L cDNA-transfected COS-7 cells displayed almost the same electrophoretic mobility as that of authentic L protein. Immunofluorescence studies indicated that both L and P (another subunit of RNA polymerase) proteins displayed colocalized distribution with the nucleocapsid antigen (N) in the cytoplasmic inclusion bodies, where envelope proteins (G and M) were absent. On the other hand, expression of the L protein alone did not cause inclusion body-like granular distribution, suggesting that the inclusion body-like accumulation depends on certain interaction(s) with other viral gene products, probably with the ribonucleoproteins comprising the inclusion bodies.
 ...
PMID:Studies on rabies virus RNA polymerase: 1. cDNA cloning of the catalytic subunit (L protein) of avirulent HEP-flury strain and its expression in animal cells. 971 1

Viral vectors that can infect neurons transsynaptically and can strongly express foreign genes are useful for investigating the organization of neural circuits. We previously developed a propagation-competent rabies virus (RV) vector based on a highly attenuated HEP-Flury strain (rHEP5.0-CVSG), which selectively infects neurons and propagates between synaptically connected neurons in a retrograde direction. Its relatively low level of transgene expression, however, makes immunostaining necessary to visualize the morphological features of infected neurons. To increase the transgene expression level of this RV vector, in this study we focused on two viral proteins: the large protein (L) and matrix protein (M). We first attempted to enhance the expression of L, which is a viral RNA polymerase, by deleting the extra transcription unit and shortening the intergenic region between the G and L genes. This viral vector (rHEP5.0-GctL) showed increased transgene expression level with efficient transsynaptic transport. We next constructed an RV vector with a rearranged gene order (rHEP5.0-GML) with the aim to suppress the expression of M, which plays a regulatory role in virus RNA synthesis. Although this vector showed high transgene expression level, the efficiency of transsynaptic transport was low. To further evaluate the usability of rHEP5.0-GctL as a transsynaptic tracer, we inserted a fluorescent timer as a transgene, which changes the color of its fluorescence from blue to red over time. This viral vector enabled us the differentiation of primary infected neurons from secondary infected neurons in terms of the fluorescence wavelength. We expect this propagation-competent RV vector to be useful for elucidating the complex organization of the central nervous system.
 ...
PMID:Increased transgene expression level of rabies virus vector for transsynaptic tracing. 2870 Jun 57