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. R ecently a cognate sequence in the mRNA was identified that provides fo r recognition by beta-ARE protein. In the present work we test the abi lity of the beta-ARB to discriminate among G-protein-linked receptor m RNAs 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. Tran scripts of beta(2)-, but not rat beta(1)-, rat beta(3)-, or human beta (3)-adrenergic receptors bind beta-ARB protein, linking agonist-induce d destabilization of mRNA to transcripts with the cognate sequence. Sc anning GeneBank for G-protein-linked receptor transcripts with the cog nate sequence revealed several candidates, including the thrombin rece ptor. We demonstrate that the thrombin receptor mRNA is recognized by beta-ARB protein and like the beta(2)-receptor is regulated post-trans criptionally by agonist and cAMP. Thus, the domain of regulation by be ta-ARB protein includes transcripts of G-protein-linked receptors othe r than beta(2)-adrenergic receptors.