A+U-rich instability elements differentially activate 5'-3' and 3'-5' mRNA decay.
The A+U-rich elements (or AREs) are cis-acting sequences that activate rapid mRNA decay, yet the overall polarity of this process is unknown. The current study describes an unbiased approach to this using the Invader RNA assay (Third Wave Technologies, Inc.) to quantify the decay of each of the three exons of human beta-globin mRNA without added instability elements or with the AREs from c-fos or granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA in the 3' untranslated region. Each of these genes under tetracycline operator control was stably transfected into cells, and beta-globin mRNA was quantified with exon-specific probes following transcription termination. There was little overall evidence for polarity in stable mRNA decay. Adding the c-fos ARE activated rapid and simultaneous decay from both ends of the mRNA. In contrast, the GM-CSF ARE activated decay primarily from the mRNA 5' end. These data were supported by reciprocal RNA interference knockdowns, and we present evidence that the 5'-3' and 3'-5' decay pathways are functionally linked.
Murray
Elizabeth L
EL
Department of Molecular and Cellular Biochemistry, The Ohio State University, 1645 Neil Ave., Columbus, OH 43210-1218, USA.
Schoenberg
Daniel R
DR
D000225:Adenine; D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D015152:Blotting, Northern; D005091:Exons / Q000235:genetics; D005914:Globins / Q000235:genetics; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D020871:RNA Stability / Q000235:genetics*; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics*; D038621:Regulatory Sequences, Ribonucleic Acid / Q000235:genetics*; D014498:Uracil
D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D038621:Regulatory Sequences, Ribonucleic Acid; D014498:Uracil; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D005914:Globins; D000225:Adenine