p38alpha stabilizes interleukin-6 mRNA via multiple AU-rich elements.
AU-rich elements (AREs) in the 3'-untranslated region (UTR) of unstable mRNA dictate their degradation or mediate translational repression. Cell signaling through p38alpha MAPK is necessary for post-transcriptional regulation of many pro-inflammatory cytokines. Here, the cis-acting elements of interleukin-6 (IL-6) 3'-UTR mRNA that required p38alpha signaling for mRNA stability and translation were identified. Using mouse embryonic fibroblasts (MEFs) derived from p38alpha(+/+) and p38alpha(-/-) mice, we observed that p38alpha is obligatory for the IL-1-induced IL-6 biosynthesis. IL-6 mRNA stability is promoted by p38alpha via 3'-UTR. To understand the mechanism of cis-elements regulated by p38alpha at post-transcriptional level, truncation of 3'-UTR and the full-length 3'-UTR with individual AUUUA motif mutation placed in gene reporter system was employed. Mutation-based screen performed in p38alpha(+/+) and p38alpha(-/-) mouse embryonic fibroblast cells revealed that ARE1, ARE2, and ARE5 in IL-6 3'-UTR were targeted by p38alpha, and truncation-based screen showed that IL-6 3'-UTR-(56-173) was targeted by p38alpha to stable mRNA. RNA secondary structure analysis indicated that modulated reporter gene expression was consistent with predicted secondary structure changes.
Zhao
Wenpu
W
Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, Michigan 48109-1078, USA.
Liu
Min
M
Kirkwood
Keith L
KL
D020413:3' Untranslated Regions / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology / Q000201:enzymology*; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology*; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D048308:Mitogen-Activated Protein Kinase 14 / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects / Q000502:physiology*; D020871:RNA Stability / Q000187:drug effects / Q000502:physiology*
D020413:3' Untranslated Regions; D007375:Interleukin-1; D015850:Interleukin-6; D048308:Mitogen-Activated Protein Kinase 14