Agonist-mediated destabilization of human beta1-adrenergic receptor mRNA: role of the 3' untranslated translated region.
For proto-oncogenes and cytokines, regulation of gene expression at the level of mRNA stability is well established. In contrast, there is comparatively limited knowledge regarding this mechanism of regulation for G-protein-coupled receptors. To explore this process further, the human beta1-adrenergic receptor (AR) was stably expressed in tsAF8 cells. Treatment with beta-agonist decreased the half-life of beta1-AR mRNA by approximately 50%. Removal of the 3'UTR from the beta1-AR (coding region only) dramatically stabilized mRNA. Additionally, in a chimeric mRNA, the beta1-AR 3'UTR was able to target the normally highly stable beta-globin mRNA for accelerated decay. However, the chimera did not undergo agonist-mediated destabilization indicating that the 3'UTR may be "necessary but not sufficient" for agonist-mediated mRNA destabilization. Inhibition of translation significantly stabilized beta1-AR mRNA (approximately 2-fold); however, pretreatment of cells with beta-agonist prior to translational arrest produced the same degree of mRNA destabilization indicating that agonist-mediated destabilization may be independent of the translation process. Conversely, translational inhibition simultaneous with beta-agonist exposure abrogated agonist-mediated destabilization indicating a dependence on de novo protein synthesis.
Mitchusson
K D
KD
Department of Medicine, Division of Cardiology, University of Colorado Health Sciences Center, Denver, 80262, USA.
Blaxall
B C
BC
Pende
A
A
Port
J D
JD
D020413:3' Untranslated Regions; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D004355:Drug Stability; D006207:Half-Life; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics*; D014162:Transfection
D020413:3' Untranslated Regions; D000318:Adrenergic beta-Agonists; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D018342:Receptors, Adrenergic, beta-1; D003513:Cycloheximide; D007545:Isoproterenol