title: Role of GDP in formyl-peptide-receptor-induced activation of guanine-nucleotide-binding proteins in membranes of HL 60 cells.
abstract: Membranes of myeloid differentiated human leukemia (HL 60) cells contain receptors for the chemotactic peptide, fMet-Leu-Phe (fMet, N-formylmethionine), interacting with pertussis-toxin-sensitive guanine-nucleotide-binding proteins (G proteins). Agonist activation of the receptors increases binding of the GTP analog, guanosine 5'-[gamma-thio]triphosphate (GTP[S]), to membrane G proteins, at 30 degrees C only in the presence of exogenous GDP. In contrast, at 0 degrees C fMet-Leu-Phe stimulated binding of GTP[S] to G proteins maximally without addition of GDP. Under conditions resulting in marked degradation of membrane-bound GDP, control binding of GTP[S] measured at 0 degrees C was significantly increased, whereas the extent of agonist-stimulated binding was reduced. Furthermore, there was a rapid spontaneous release of membrane-bound GDP at 30 degrees C, but not at 0 degrees C. The data suggest that in intact membranes of HL 60 cells G proteins are initially in a GDP-liganded form, which state allows the receptor-induced exchange of bound GDP for GTP[S] at low temperature. In contrast, at or near physiological temperature, bound GDP is rapidly released (and degraded), resulting in unligated G proteins to which GTP[S] will bind independently of agonist-activated receptors.
authors.affiliation: Institut für Pharmakologie Universität GH Essen, Federal Republic of Germany.
authors.forename: T
authors.initials: T
authors.lastname: Wieland
authors.forename: J
authors.initials: J
authors.lastname: Kreiss
authors.forename: P
authors.initials: P
authors.lastname: Gierschik
authors.forename: K H
authors.initials: KH
authors.lastname: Jakobs
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000502:physiology*; D006801:Humans; D007951:Leukemia, Myeloid / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000378:metabolism*; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic / Q000378:metabolism*; D013696:Temperature; D014407:Tumor Cells, Cultured
chemical_list: D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D009240:N-Formylmethionine Leucyl-Phenylalanine; D000469:Alkaline Phosphatase; D019204:GTP-Binding Proteins