title: Region-specific initiation of mouse mammary tumor virus RNA synthesis by endogenous RNA polymerase II in preparations of cell nuclei.
abstract: Adenosine 5'-O-(2-thiotriphosphate) (ATP beta S) and guanosine 5'-O-(2-thiotriphosphate) (GTP beta S) were used to demonstrate initiation of mouse mammary tumor virus (MMTV) RNA in preparations of whole nuclei from control and glucocorticoid-treated MMTV-infected rat hepatoma tissue culture cells. RNA chains initiated in the cell-free reaction retain a thiol group at the 5' end and can be separated from thiol-free RNA chains by chromatography on mercury-Sepharose. The abundance of MMTV sequences was determined by nucleic acid hybridization with filter-bound DNA representing four different regions of the MMTV genome. About six times more MMTV RNA is initiated with GTP beta S than with ATP beta S. Most of the cell-free initiation of MMTV RNA occurs within or very near a 380-nucleotide section of the proviral long terminal repeat that is the presumptive site of transcription initiation in vivo. The sensitivity of MMTV RNA initiation and synthesis to alpha-amanitin and actinomycin D are characteristic of DNA-directed transcription by RNA polymerase II. Nuclei from glucocorticoid-treated cells initiate approximately 10 times more MMTV RNA than nuclei from control cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000031:analogs & derivatives*; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D008114:Liver Neoplasms, Experimental; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D012319:RNA Polymerase II / Q000378:metabolism*; D012367:RNA, Viral / Q000235:genetics*; D051381:Rats; D013873:Thionucleotides / Q000494:pharmacology; D014158:Transcription, Genetic
chemical_list: D012367:RNA, Viral; D013873:Thionucleotides; C034883:guanosine 5'-O-(2-thiotriphosphate); D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D012319:RNA Polymerase II; D012321:DNA-Directed RNA Polymerases