Abstract
Adenine-uridine rich elements (AREs) play an important role in modulating mRNA stability, being the target site of many ARE-binding proteins (AUBPs) that are involved in the decay process. Three 26-mer 2′-O-methyl oligoribonucleotides (ORNs) homologous to the core region of ARE of bcl2 mRNA have been studied for decoy-aptamer activity in UV cross-linking assays. Sense-oriented ORNs competed with the ARE motif for the interaction with both destabilizing and stabilizing AUBPs in cell-free systems and in cell lines. Moreover, ORNs induced mRNA stabilization and up-regulated both Bcl2 mRNA and protein levels in the cells. Bcl2 ORNs stabilized other ARE-containing transcripts and up-regulated their expression. These results indicate that Bcl2 ORNs compete for AUBP-ARE interactions independently of ARE class and suggest that in the cell, the default labile status of ARE-containing mRNAs depends on the combined interaction of such transcripts with destabilizing AUBPs.
Footnotes
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This work was sponsored by grants from Ministero dell'Istruzione, dell'Università e della Ricerca-Consiglio Nazionale delle Ricerche and Istituto Superiore Sanità, Rome, Italy.
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A.B. and L.G. contributed equally to this work.
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ABBREVIATIONS: ARE, adenine-uridine rich element; AUBP, adenine-uridine binding protein; ORN, oligoribonucleotide; UTR, untranslated region; b-ARE, bcl2 adenine-uridine rich element; b-RNA, 3′-untranslated region of Bcl2 RNA; HEK, human embryonic kidney; degORNs, 2′-O-methyl-degenerated oligoribonucleotide; DRB, 5,6-dichloro-1-β-d-ribofuranosyl-benzimidazole; GST, glutathione transferase; RT-PCR, reverse transcription polymerase chain reaction; MoAb, monoclonal antibody; IGFR, insulin-like growth factor-I receptor; nt, nucleotide MKK6, mitogen-activated protein kinase kinase 6; Rluc, Renilla reniformis luciferase.
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The online version of this article (available at http://molpharm.aspetjournals.org) contains supplemental material. - Received July 30, 2006.
- Accepted October 31, 2006.
- The American Society for Pharmacology and Experimental Therapeutics
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