REGULATING EXPRESSION AND FUNCTION OF G-PROTEIN-LINKED RECEPTORS

G-protein-linked receptors constitute a populous family of heptahelica l, membrane-localized receptors for hormones, drugs and neurotransmitt ers that activate a diverse and smaller subset of effectors, including adenylylcyclases, phospholipases and various ion channels. The expres sion and functional status of G-protein-linked receptors is highly reg ulated. Expression is controlled largely by activation or repression o f the genes encoding the receptors, balanced by post-transcriptional m echanisms such as destabilization of receptor mRNA. Agonist-induced do wn-regulation of receptors involves both transcriptional and post-tran scriptional controls. Gene structure reveals details of promoters as w ell as determinants for mRNA stability. Post-translational regulation of G-protein-linked receptors is dominated by protein phosphorylation. G-protein-linked receptors are substrates not only for protein kinase A, protein kinase C and receptor-specific kinases, but also for growt h factor receptors with intrinsic tyrosine kinase activity. Recent adv ances in the study of beta-adrenergic receptors (beta ARs) illuminate new dynamic features of receptor regulation, central to our understand ing of neurobiology. Copyright (C) 1996 Elsevier Science Ltd