caa a22 4500 469078650 CHVBK 20180323132943.0 cr unu---uuuuu 170328e19921101xx s 000 0 eng 10.1007/BF00168999 doi (NATIONALLICENCE)springer-10.1007/BF00168999 G protein-mediated receptor-receptor interaction: studies with chemotactic receptors in membranes of human leukemia (HL 60) cells [Elektronische Daten] [Thomas Wieland, Peter Gierschik, Karl Jakobs] Summary: Differentiated human leukemia (HL 60) cells contain high numbers of receptors for the chemotactic factors, N-formylmethionyl-leucyl-phenylalanine (fMet-Leu-Phe) and complement component 5a (C5a), both coupled to pertussis toxin-sensitive guanine nucleotide-binding regulatory proteins (G proteins). Agonist activation of either receptor stimulated binding of the GTP analog, guanosine 5′-[γ-thio]triphosphate (GTP[S]), to membrane G proteins and by a similar extent in a non-additive manner. The possible interaction of the two receptors was studied by measuring agonist binding to one receptor in the presence of the other receptor agonist. fMet-Leu-Phe and C5a had no effects on [125I]C5a and fMet-Leu-[3H]Phe receptor binding, respectively, when studied in the absence of regulatory ligands. Similarly, the inhibitory effects of NaCl and GDP on agonist receptor binding were not altered in the presence of the other receptor agonist. In contrast, in the presence of the GTP analogs, GTP[S] and guanosine 5′-[β,γ-imino] triphosphate, fMet-Leu-Phe and C5a reduced the binding of [125I]C5a and fMet-Leu-[3H]Phe, respectively, in a concentration-dependent manner. The potencies of the GTP analogs to inhibit binding of [125I]C5a and fMet-Leu-[3H]Phe was increased about 3-fold by fMet-Leu-Phe and C5a, respectively. The data presented suggest that fMet-Leu-Phe and C5a receptors share the same G protein pool in membranes of HL 60 cells and that activation of these G proteins by one of the two receptors decreases the availability of G proteins for the other receptor. Springer-Verlag, 1992 Formyl peptide receptor nationallicence Complement 5a receptor nationallicence G protein nationallicence (HL 60 cells) nationallicence Wieland Thomas Institut für Pharmakologie der Universität GH Essen, Hufelandstrasse 55, W-4300, Essen, Federal Republic of Germany aut Gierschik Peter Pharmakologisches Institut der Universität Heidelberg, W-6900, Heidelberg, Federal Republic of Germany aut Jakobs Karl Institut für Pharmakologie der Universität GH Essen, Hufelandstrasse 55, W-4300, Essen, Federal Republic of Germany aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/5(1992-11-01), 475-481 0028-1298 346:5<475 1992 346 210 https://doi.org/10.1007/BF00168999 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00168999 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wieland Thomas Institut für Pharmakologie der Universität GH Essen, Hufelandstrasse 55, W-4300, Essen, Federal Republic of Germany aut NATIONALLICENCE 700 1- Gierschik Peter Pharmakologisches Institut der Universität Heidelberg, W-6900, Heidelberg, Federal Republic of Germany aut NATIONALLICENCE 700 1- Jakobs Karl Institut für Pharmakologie der Universität GH Essen, Hufelandstrasse 55, W-4300, Essen, Federal Republic of Germany aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/5(1992-11-01), 475-481 0028-1298 346:5<475 1992 346 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer