title: Dichlorobenzimidazole-riboside inhibition of nuclear RNA accumulation initiated with gamma-thio analogues of ATP and GTP.
abstract: The gamma-thio analogues of ATP and GTP, ATP[S] and GTP[S], have been used as affinity probes to measure RNA synthesis initiated in vitro in L cell nuclei. 5,6-Dichlororibofuranosylbenzimidazole was found to inhibit total RNA synthesis in vitro and the amount bound by mercury-affinity chromatography. Initiation in vitro was also shown by [35S]ATP[S] and [35S]GTP[S] incorporation in RNA molecules with a larger size distribution. Although 66% of RNA molecules labeled with [35S]GTP[S] and 74% of those labeled with [35S]ATP[S] were 3-12 S n size, the remainder of the label was recovered in RNA molecules larger than 12 S and a significant portion in RNA larger tha 18 S. The specificity of the initiation process seems to be indicated by the finding of molecules of the size of pre-tRNA on gel electrophoresis which were labeled with [35S]GTP[S] but not [35S]ATP[S] under our experimental conditions. 5,6-Dichlororibofuranosylbenzimidazole severely inhibited the incorporation of [35S]GTP[S] and [35S]AT[[S] by all size classes, indicating that it can decrease accumulation of RNA initiated in vitro in the L cell nuclear system.
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000345:Affinity Labels / Q000494:pharmacology*; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D007739:L Cells / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D012313:RNA / Q000302:isolation & purification; D012263:Ribonucleosides / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D000345:Affinity Labels; D012263:Ribonucleosides; D013873:Thionucleotides; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D004004:Dichlororibofuranosylbenzimidazole; C022570:adenosine 5'-O-(2-thiotriphosphate); D012313:RNA; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate