The third intracellular loop of the alpha_(1B)-adrenergic receptor:structural features as derived by NMR and MD calculations

摘要

The adrenergic receptors(AR)which mediate the functional effects of catecholamines are members of the G protein-coupled receptors(GPCR)superfamily.All GPCR sequences share the presence of seven hydrophobic regions forming a bundle of transmembrane helical domains(TMD)connected by alternating intracellular(i)and extracellular(e)loops.While ligand binding involves the extracellular portion and the TMD,the cytosolic regions mediate the interaction of these receptors with a number of signaling and regulatory proteins.