title: Heterogeneity in control of mRNA stability by AU-rich elements.
abstract: AU-rich elements (AREs), located in the 3'-untranslated region of unstable cytokine and chemokine mRNAs, promote rapid decay of otherwise stable mRNAs and may mediate selective mRNA stabilization in response to stimulation with interleukin-1 (IL-1). AREs vary considerably, however, in both size and sequence context. To assess the heterogeneity involved in control of mRNA stability by ARE motifs, human mRNA sequences from IL-1alpha-stimulated HEK293 cells and T98G cells were screened for either instability or stability using both cDNA (950 ARE containing sequences) and Affymetrix oligonucleotide (U95Av2 GeneChip) array analysis. Although ARE-containing mRNAs exhibited a broad range of stability, IL-1alpha promoted stability in a subset of mRNAs that were unstable when transcriptionally induced by tumor necrosis factor alpha. Stabilization of granulocyte/macrophage-colony stimulating factor and IL-8 mRNAs by IL-1alpha was achieved only after 2 h of stimulation, required ongoing protein synthesis, and depended on the activation of p38 MAPK. In contrast, stabilization of Gro3 mRNA in response to IL-1alpha was achieved immediately and was insensitive to inhibitors of protein synthesis and p38 MAPK activation. In concert, these findings demonstrate that ARE sequences are functionally heterogeneous; only a subset of unstable mRNAs is sensitive to stabilization by IL-1alpha. Moreover, IL-1alpha promotes stabilization of unstable mRNAs through distinct mechanistic pathways that distinguish between specific mRNA sequences.
authors.affiliation: Departments of Immunology and Cancer Biology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Tebo
authors.forename: Sandy
authors.initials: S
authors.lastname: Der
authors.forename: Mathias
authors.initials: M
authors.lastname: Frevel
authors.forename: Khalid S A
authors.initials: KS
authors.lastname: Khabar
authors.forename: Bryan R G
authors.initials: BR
authors.lastname: Williams
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Hamilton
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D018740:Genetic Heterogeneity; D005909:Glioblastoma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D016209:Interleukin-8 / Q000235:genetics; D007668:Kidney / Q000166:cytology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D020871:RNA Stability / Q000187:drug effects / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D020413:3' Untranslated Regions; D007375:Interleukin-1; D016209:Interleukin-8; D012333:RNA, Messenger; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases