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)

30 compounds with antipicorna virus activity were selected from 173 N,N'-disubstituted thiourea derivatives. The spectrum of antiviral activity was determined in vitro using entero, FMD, rhino and EMC viruses. Structure-activity relationships were studied. Several compounds produced marked activity against coxsackie viruses A and B infection of mice and FMD infection in mice and guinea pigs. N-Phenyl-N'-3-hydroxyphenyl-thiourea (PTU-23) inhibited poliovirus production by more than 99% without influencing the FL host cell. EMC virus was readily inhibited by PTU-23 in Kreb-II cells. Virus RNA synthesis was significantly reduced. Under the effect of PTU-23 the amount of 37S ssRNA extracted from EMC virus infected cells was considerably more reduced than that of the 20S ds RNA. PTU-23 did not influence the activity of virus-induced RNA polymerase in a cell-free system.
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PMID:Thiourea derivatives as specific inhibitors of picorna viruses. 23 63

Poliovirus infection leads to the appearance of a number of cytoplasmic vacuoles involved in the replication of virus genomes. To characterize the viral proteins involved in membrane proliferation different poliovirus proteins have been expressed in HeLa cells. Two recombinant vaccinia viruses have been obtained that express poliovirus protein 2C, one under the 5' untranslated (UTR) sequence of poliovirus and another under the leader region of EMC virus. Expression of 2C was very efficient in both cases, although better results were obtained when poliovirus 2C was expressed under the 5'UTR sequence of EMC virus. Transient expression of poliovirus proteins 2B, 2C or 2BC placed under a T7 promoter was analyzed using a recombinant vaccinia virus that contains the bacteriophage T7 RNA polymerase. The expression of 2C, or 2BC, contrary to 2B, was able to induce the proliferation of vacuoles morphologically similar to those found during poliovirus infection. These findings indicate that poliovirus protein 2C, in addition to its NTPase and RNA binding activities, is also endowed with the capacity to induce the formation of cytoplasmic vacuoles.
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PMID:Induction of membrane proliferation by poliovirus proteins 2C and 2BC. 781 52

Expression of bacteriophage T7 RNA polymerase in mammalian cells can efficiently drive the transcription of a foreign gene controlled by the T7 promoter (Elroy-Stein et al., Proc. Natl. Acad. Sci. USA. 86, 6126-6130, 1989). We have tested the hypothesis that purified T7 RNA polymerase can be co-delivered into mammalian cells together with a reporter gene (chloramphenicol acetyltransferase, CAT) controlled by the T7 promoter (pT7-EMC-CAT) using DC-chol cationic liposomes. Indeed, significant level of CAT activity was observed in human lung adenocarcinoma (A549-1) cells which had been incubated with a complex of T7 RNA polymerase, pT7-EMC-CAT DNA and DC-chol cationic liposomes. The expression was specific in that T3 RNA polymerase could not replace the T7 RNA polymerase, and that co-delivered T7 RNA polymerase did not enhance the expression of a CAT gene controlled by the SV40 early promoter. The system was optimized in terms of enzyme, DNA and liposome concentrations. Time course experiment indicated that the expression of the T7 system was about 8-10 hours sooner than the SV40 system, consistent with the notion that T7 RNA polymerase does not enter into the nucleus and the transcription takes place in the cytoplasm of the transfected cells. The expression of the T7 system was transient; it declined after 30 hours post transfection, probably due to turnover of the phage enzyme in the mammalian cells. The expression system described here should be useful for gene transfer experiments which require a fast but transient expression of a foreign gene. We have also compared our delivery system with a commercial reagent, Lipofectin, which has been used to deliver T3 or T7 RNA polymerase with a reporter plasmid encoding the T3 or T7 promoter.
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PMID:Cytoplasmic expression of a reporter gene by co-delivery of T7 RNA polymerase and T7 promoter sequence with cationic liposomes. 833 95

Poliovirus protease 2Apro has been efficiently expressed in HeLa and COS cells upon transfection with vector pTM1-2A and infection with the recombinant vaccinia virus bearing the T7 RNA polymerase. The expressed poliovirus protease localizes to the cytoplasm of the transfected cells, both in the endoplasmic reticulum and in vesicles scattered in the cytoplasm. Cleavage of p220, a component of initiation factor eIF-4F, selectively occurs from 5 h post-infection in transfected cells infected with the recombinant virus. This cleavage correlates in time with the profound inhibition observed in the synthesis of vaccinia virus proteins. A similar blockade of vesicular stomatitis virus translation takes place upon 2Apro expression. Finally, the synthesis of poliovirus protein 2C from a recombinant vaccinia virus that expresses this protein under the EMC untranslated leader region is not affected by the synthesis of 2Apro. These findings lend support to the idea that translation of capped mRNAs requires the integrity of p220, while this requirement is not observed when translation of a mRNA bearing a picornavirus leader region is assayed.
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PMID:Expression of poliovirus 2Apro in mammalian cells: effects on translation. 854 8