INHIBITION OF PRE-MESSENGER RNA SPLICING BY 5-FLUOROURIDINE, 5-CHLOROURIDINE, AND 5-BROMOURIDINE

  • 15 November 1989
    • journal article
    • research article
    • Vol. 264  (32) , 19185-19191
Abstract
Pre-mRNA transcripts of the human .beta.-globin gene containing 5-fluoro-, 5-chloro- and 5-bromouridine were tested for splicing in vitro. Pre-mRNA containing 5-fluorouridine was spliced accurately and efficiently in the nuclear extract from HeLa cells, whereas 5-chloro-, and 5-bromouridine containing transcripts were not spliced. Analysis of the splicing reactions by electrophoresis on nondenaturing polyacrylamide gels showed that the latter two transcripts were unable to form active splicing complexes. Treatment of HeLa cell cultures with 5-fluorouridine decreased the splicing activity of the nuclear extracts in a dose- and time-dependent fashion. The decrease in splicing activity of these extracts appears to be due in part to a decreased level of U-2 small nuclear RNA and the corresponding ribonucleoprotein particle, U2-snRNP.