caa a22 4500 477120148 CHVBK 20180405111634.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/BF00227881 doi (NATIONALLICENCE)springer-10.1007/BF00227881 Phosphotransfer reactions as a means of G protein activation [Elektronische Daten] [Lucia Piacentini, Feraydoon Niroomand] Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) serve to transduce information from agonist-bound receptors to effector enzymes or ion channels. Current models of G protein activation-deactivation indicate that the oligomeric GDP-bound form must undergo release of GDP, bind GTP and undergo subunit dissociation, in order to be in active form (GTP bound α subunits and free βγ dimers) and to regulate effectors. The effect of receptor occupation by an agonist is generally accepted to be promotion of guanine nucleotide exchange thus allowing activation of the G protein. Recent studies indicate that transphosphorylation leading to the formation of GTP from GDP and ATP in the close vicinity, or even at the G protein, catalysed by membrane-associated nucleoside diphosphate kinase, may further activate G proteins. This activation is demonstrated by a decreased affinity of G protein-coupled receptors for agonists and an increased response of G protein coupled effectors. In addition, a phosphorylation of G protein β subunits and consequent phosphate transfer reaction resulting in G protein activation has also been demonstrated. Finally, endogenously formed GTP was preferentially effective in activating some G proteins compared to exogenous GTR The aim of this report is to present an overview of the evidence to date for a transphosphorylation as a means of G protein activation (see also refs [1 and 2] for reviews). (Mol Cell Biochem 157: 593, 1996) Kluwer Academic Publishers, 1996 nucleoside diphosphate kinase nationallicence G proteins nationallicence phosphate transfer reactions nationallicence Piacentini Lucia Innere Medizin III- Kardiologie, Universitat Heidelberg, D-69115, Heidelberg, Germany aut Niroomand Feraydoon Innere Medizin III- Kardiologie, Universitat Heidelberg, D-69115, Heidelberg, Germany aut Molecular and Cellular Biochemistry Kluwer Academic Publishers 157/1-2(1996-04-01), 59-63 0300-8177 157:1-2<59 1996 157 11010 https://doi.org/10.1007/BF00227881 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00227881 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Piacentini Lucia Innere Medizin III- Kardiologie, Universitat Heidelberg, D-69115, Heidelberg, Germany aut NATIONALLICENCE 700 1- Niroomand Feraydoon Innere Medizin III- Kardiologie, Universitat Heidelberg, D-69115, Heidelberg, Germany aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers 157/1-2(1996-04-01), 59-63 0300-8177 157:1-2<59 1996 157 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer