caa a22 4500 477101089 CHVBK 20200916193757.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/BF00262642 doi (NATIONALLICENCE)springer-10.1007/BF00262642 Guanosine triphosphate-binding proteins on the plasmalemma of spinach leaf cells [Elektronische Daten] [Pierre Crespi, Pierre-François Perroud, Hubert Greppin] The molecular mechanism of light perception through phytochrome is not well understood. This red-light photosensor has been implicated in various physiological processes, including the photoinduction of flowering. A few recent studies have shown that phytochrome initiates signal transduction chains via guanosine triphosphate (GTP)-binding proteins (G-proteins). We show here by different approaches that G-proteins exist in spinach (Spinacia oleracea L. cv. Nobel). Binding of GTP on the plasmalemma has been partially characterized and its possible regulation by red light examined by in-vitro assays. These experiments indicate a clear regulation of GTP binding by red light and also by Mastoparan. At least three G-proteins or protein subunits were found to be associated with the plasmalemma of leaf cells. The use of an antibody raised against an animal Gβ subunit confirmed the presence of heterotrimeric G-proteins. Separation of a crude membrane extract by free-flow electrophoresis also showed that some G-proteins could exist on the tonoplast. Springer-Verlag, 1996 Guanosine triphosphate binding protein (G-protein) nationallicence Light nationallicence Plasmalemma nationallicence Spinacia nationallicence FFE : free flow electrophoresis nationallicence G-protein : GTP-binding protein nationallicence PLC : phospholipase C nationallicence Crespi Pierre Laboratoire de Biochimie et Physiologie Végétales, Université de Genève, Place de l'Université 3, CH-1211, Genève 4, Switzerland aut Perroud Pierre-François Laboratoire de Biochimie et Physiologie Végétales, Université de Genève, Place de l'Université 3, CH-1211, Genève 4, Switzerland aut Greppin Hubert Laboratoire de Biochimie et Physiologie Végétales, Université de Genève, Place de l'Université 3, CH-1211, Genève 4, Switzerland aut Planta Springer-Verlag 198/4(1996-04-01), 557-562 0032-0935 198:4<557 1996 198 425 https://doi.org/10.1007/BF00262642 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00262642 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Crespi Pierre Laboratoire de Biochimie et Physiologie Végétales, Université de Genève, Place de l'Université 3, CH-1211, Genève 4, Switzerland aut NATIONALLICENCE 700 1- Perroud Pierre-François Laboratoire de Biochimie et Physiologie Végétales, Université de Genève, Place de l'Université 3, CH-1211, Genève 4, Switzerland aut NATIONALLICENCE 700 1- Greppin Hubert Laboratoire de Biochimie et Physiologie Végétales, Université de Genève, Place de l'Université 3, CH-1211, Genève 4, Switzerland aut NATIONALLICENCE 773 0- Planta Springer-Verlag 198/4(1996-04-01), 557-562 0032-0935 198:4<557 1996 198 425