title: G protein-mediated ion channel activation.
abstract: Guanine nucleotide binding proteins couple a wide variety of receptors to ion channels via both "direct" or membrane-delimited and "indirect" second messenger-mediated pathways. This tutorial summarizes current approaches to defining the mechanisms of guanine nucleotide binding protein-mediated ion channel activation. Two well-characterized ion channels in the heart, namely, the beta-adrenergic receptor-activated calcium channel and the muscarinic receptor-activated potassium channel, are used to illustrate the criteria that can distinguish between direct and indirect guanine nucleotide binding protein-transduced pathways.
authors.affiliation: Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Md. 21205.
authors.forename: G E
authors.initials: GE
authors.lastname: Breitwieser
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology*; D006801:Humans; D007473:Ion Channels / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism; D015221:Potassium Channels / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D011976:Receptors, Muscarinic / Q000502:physiology
chemical_list: D015220:Calcium Channels; D007473:Ion Channels; D015221:Potassium Channels; D011943:Receptors, Adrenergic, beta; D011976:Receptors, Muscarinic; D019204:GTP-Binding Proteins