title: Prostaglandin A2-mediated stabilization of p21 mRNA through an ERK-dependent pathway requiring the RNA-binding protein HuR.
abstract: Treatment with the stress agent prostaglandin A2 (PGA2) induces expression of the cyclin-dependent kinase inhibitor p21. Here, we present evidence that p21 expression increases through PGA2-triggered stabilization of the p21 mRNA and further show that these events require the mitogen-activated protein (MAP) kinase ERK. Binding experiments using either endogenous p21 mRNA or in vitro-labeled p21 transcripts revealed a specific PGA2-dependent association of the p21 mRNA with the RNA-binding protein HuR. Interestingly, although inhibition of the ERK pathway did not prevent the PGA2-triggered increase in cytoplasmic HuR, it did impair the formation of endogenous and in vitro [HuR-p21 mRNA] complexes and further prevented the PGA2-mediated stabilization of the p21 mRNA, suggesting that ERK-mediated events were required for binding HuR to the p21 mRNA and preventing its decay. RNA interference-based knockdown of HuR abundance further served to demonstrate the contribution of HuR-mediated p21 mRNA stabilization toward enhancing p21 expression after PGA2 treatment. Collectively, our results indicate that PGA2 stabilizes the p21 mRNA through an ERK-independent increase in cytoplasmic HuR levels and an ERK-dependent association of HuR with the p21 mRNA.
authors.affiliation: Laboratory of Cellular and Molecular Biology, NIA, National Institutes of Health, Baltimore, MD 21224, USA.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Yang
authors.forename: Wengong
authors.initials: W
authors.lastname: Wang
authors.forename: Jinshui
authors.initials: J
authors.lastname: Fan
authors.forename: Ashish
authors.initials: A
authors.lastname: Lal
authors.forename: Dongmei
authors.initials: D
authors.lastname: Yang
authors.forename: Heping
authors.initials: H
authors.lastname: Cheng
authors.forename: Myriam
authors.initials: M
authors.lastname: Gorospe
mesh_terms: D020413:3' Untranslated Regions; D000954:Antigens, Surface / Q000737:chemistry*; D001710:Biotin / Q000737:chemistry; D015152:Blotting, Northern; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D003432:Cross-Linking Reagents / Q000494:pharmacology; D050759:Cyclin-Dependent Kinase Inhibitor p21; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D047468:Immunoprecipitation; D007700:Kinetics; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D011454:Prostaglandins A / Q000378:metabolism*; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D014466:Ultraviolet Rays
chemical_list: D020413:3' Untranslated Regions; D000954:Antigens, Surface; C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D003432:Cross-Linking Reagents; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018076:DNA, Complementary; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; D004791:Enzyme Inhibitors; D011454:Prostaglandins A; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D003609:Dactinomycin; D001710:Biotin; D048052:Mitogen-Activated Protein Kinase 3; C100008:prostaglandin A2; D002118:Calcium