Thy-1 mRNA destabilization by norepinephrine a 3' UTR cAMP responsive decay element and involves RNA binding proteins.
Thy-1 is a cell surface protein important in immunologic and neurologic processes, including T cell activation and proliferation, and neuronal outgrowth. In murine thymocytes, Thy-1 is downregulated in response to norepinephrine (NE) through posttranscriptional destabilization of its mRNA mediated by βAR/AC/cAMP/PKA signaling. In this study we investigated factors involved in NE/cAMP-mediated Thy-1 mRNA destabilization in S49 thymoma cells, and identified a region containing two copies of the AUUUA regulatory element (ARE), a motif commonly associated with mRNA decay, in the Thy-1 mRNA 3' UTR. Insertion of the Thy-1 ARE region into a reporter gene, resulted in cAMP induced destabilization of the reporter gene mRNA. RNA-protein binding studies revealed multiple Thy-1 ARE binding proteins, including AUF1, HuR, and TIAR. RNA silencing of HuR enhanced cAMP-mediated downregulation of Thy-1 mRNA, in contrast, silencing AUF1 had no effect. Immunoblotting revealed multiple proteins phosphorylated by PKA as a result of NE or cAMP signaling. These results reveal that the machinery of NE/cAMP modulation of Thy-1 mRNA decay involves a cAMP responsive ARE in its 3' UTR and multiple site specific ARE binding proteins. These findings add to our knowledge of Thy-1 mRNA regulation and provide insight into the regulation of ARE containing mRNAs, which impacts stress-related immunosuppression.
LaJevic
Melissa D
MD
Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60612, USA.
Koduvayur
Sujatha P
SP
Caffrey
Veronique
V
Cohen
Rhonna L
RL
Chambers
Donald A
DA
D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism; D015153:Blotting, Western; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D017930:Genes, Reporter; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009638:Norepinephrine / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D034622:RNA Interference; D020871:RNA Stability; D012333:RNA, Messenger; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics*; D018800:Thy-1 Antigens / Q000235:genetics* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology*; D014162:Transfection / Q000379:methods
D020413:3' Untranslated Regions; D000954:Antigens, Surface; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; C000630986:HNRNPD protein, human; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D; C000630987:Hnrpd protein, mouse; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D018800:Thy-1 Antigens; C489665:Tial1 protein, mouse; D000242:Cyclic AMP; D009638:Norepinephrine