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.
Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, Michigan 48109-1078, USA.
Wenpu
W
Zhao
Min
M
Liu
Keith L
KL
Kirkwood
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