title: Incorporation of 6-thioguanosine and 4-thiouridine into RNA. Application to isolation of newly synthesised RNA by affinity chromatography.
abstract: Isolation of newly synthesised RNA can be achieved by treatment of cells in culture with 6-thioguanosine or 4-thiouridine followed by separation of thiol-containing RNA by affinity chromatography on mercurated cellulose columns. After short periods of treatment with 6-thioguanosine the proportion of RNA retained on mercurated cellulose is the same for both poly(A)-containing and poly(A)-free RNA, indicating similar incorporation of the drug into mRNA and rRNA. However, after longer periods of exposure, the cytotoxic effect of 6-thioguanosine results in diminished incorporation of radioactive uridine into RNA and of radioactive leucine into protein; this suggests that synthesis of both RNA and protein are impaired. On the other hand, even after long exposure to high concentrations of 4-thiouridine, the syntheses of RNA and protein are not significantly affected. Proteins synthesised after treatment of cells with 6-thioguanosine are less stable than proteins synthesised after treatment of cells with 4-thiouridine.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D006224:Cricetinae; D006151:Guanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D011061:Poly A / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D012313:RNA / Q000302:isolation & purification / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism; D013872:Thionucleosides / Q000378:metabolism*; D013891:Thiouridine / Q000378:metabolism*; D014529:Uridine / Q000378:metabolism
chemical_list: D011506:Proteins; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D013872:Thionucleosides; D006151:Guanosine; D013891:Thiouridine; D011061:Poly A; D012313:RNA; C005783:6-thioguanosine; D007930:Leucine; D014529:Uridine