Prinzipien der transmembranaeren Signalumsetzung bei der Wirkung von Hormonen und Neurotransmittern [Principles of transmembranous signal transduction in the action of hormones and neurotransmitters]

Item Type:	Article
Title:	Prinzipien der transmembranaeren Signalumsetzung bei der Wirkung von Hormonen und Neurotransmittern [Principles of transmembranous signal transduction in the action of hormones and neurotransmitters]
Creators Name:	Schultz, G. and Rosenthal, W.
Abstract:	In the membranous signal transduction process, hormone-binding to receptors causes receptor interaction with signal-transducing components; these components transfer the stimulus to effector systems, which generate intracellular signals. Several guanine nucleotide-binding proteins (N- or G-proteins) have been identified as membranous signal-transducing components. Two N-proteins are involved in the hormonal regulation of adenylate cyclase activity, one of which being stimulatory (Ns), the other one being inhibitory (Ni). Ns, Ni and a third N-protein, No, whose function is unknown, occur ubiquitously. On the other hand, transducin, an N-protein, which functionally couples light-activated rhodopsin to a cGMP phosphodiesterase, is specific for the retina. In addition to their established role as transducers regulating adenylate cyclase and retinal cGMP phosphodiesterase, N-proteins proteins may be involved in two mechanisms by which the cytoplasmic calcium concentration is elevated, i.e. hormonal stimulation of a phospholipase C catalyzing phosphatidyl-inositol 4,5-diphosphate hydrolysis (Pi response) and hormone-induced opening of receptor-operated calcium channels; the membrane-bound forms of cAMP phosphodiesterase and guanylate cyclase, stimulated by insulin and atrial natriuretic factor, respectively, are also likely to be regulated via N-proteins. Guanine nucleotide-binding proteins appear to play a universal role in transmembranous signalling processes, controlling effector systems (i.e. enzymes and ion channels) that regulate cytoplasmic concentrations of intracellular messengers such as cyclic AMP, cyclic GMP and calcium.
Keywords:	Adenylate Cyclase, Calcium, Cyclic GMP, GTP-Binding Proteins, Hormones, Membrane Potentials, Neurotransmitter Agents, Peptides, Cell Surface Receptors, Neurotransmitter Receptors, Animals
Source:	Arzneimittelforschung
ISSN:	0004-4172
Publisher:	Editio Cantor
Volume:	35
Number:	12A
Page Range:	1879-1885
Date:	1985
PubMed:	View item in PubMed

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