THE M(R)-35,000 BETA-ADRENERGIC-RECEPTOR MESSENGER-RNA-BINDING PROTEIN BINDS TRANSCRIPTS OF G-PROTEIN-LINKED RECEPTORS WHICH UNDERGO AGONIST-INDUCED DESTABILIZATION

The M(r) 35,000 beta-adrenergic receptor mRNA-binding protein, termed beta-ARB protein, is induced by beta-adrenergic agonists and binds to beta(2)-receptor mRNAs that display agonist-induced destabilization. Recently a cognate sequence in the mRNA was identified that provides for recognition by beta-ARE protein. In the present work we test the ability of the beta-ARB to discriminate among G-protein-linked receptor mRNAs that either do or do not display agonist-induced destabilization and test the predictive value of the presence of the cognate sequence to identify receptors displaying post-transcriptional regulation. Transcripts of beta(2)-, but not rat beta(1)-, rat beta(3)-, or human beta(3)-adrenergic receptors bind beta-ARB protein, linking agonist-induced destabilization of mRNA to transcripts with the cognate sequence. Scanning GeneBank for G-protein-linked receptor transcripts with the cognate sequence revealed several candidates, including the thrombin receptor. We demonstrate that the thrombin receptor mRNA is recognized by beta-ARB protein and like the beta(2)-receptor is regulated post-transcriptionally by agonist and cAMP. Thus, the domain of regulation by beta-ARB protein includes transcripts of G-protein-linked receptors other than beta(2)-adrenergic receptors.