TY - JOUR
T1 - Signal Transduction in Dictyostelium fgd A Mutants with a Defective Interaction between Surface cAMP Receptors and a GTP-binding Regulatory Protein
AU - Kesbeke, Fanja
AU - Snaar-Jagalska, B. Ewa
AU - van Haastert, Peter J. M.
N1 - Relation: http://www.rug.nl/gbb/
date_submitted:2007
Rights: University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute
PY - 1988
Y1 - 1988
N2 - Transmembrane signal transduction was investigated in four Dictyostelium discoideum mutants that belong to the fgd A complementation group. The results show the following. (a) Cell surface cAMP receptors are present in fgd A mutants, but cAMP does not induce any of the intracellular responses, including the activation of adenylate or guanylate cyclase and chemotaxis. (b) cAMP induces down-regulation and the covalent modification (presumably phosphorylation) of the cAMP receptor. (c) The inhibitory effects of GTPγS and GDPβS on cAMP binding are reduced; the stimulatory effect of cAMP on GTPγS binding is lost in fgd A mutants. (d) Basal high-affinity GTPase activity is reduced 40% and the stimulatory effect of cAMP is decreased from 40% in wild type to 30% in fgd A. (e) GTP-mediated stimulation and inhibition of adenylate cyclase is normal in mutant membranes. The results suggest a defective interaction between cell surface cAMP receptors and a specific G-protein in fgd A mutants. This interaction appears to be essential for nearly all signal transduction pathways in Dictyostelium discoideum.
AB - Transmembrane signal transduction was investigated in four Dictyostelium discoideum mutants that belong to the fgd A complementation group. The results show the following. (a) Cell surface cAMP receptors are present in fgd A mutants, but cAMP does not induce any of the intracellular responses, including the activation of adenylate or guanylate cyclase and chemotaxis. (b) cAMP induces down-regulation and the covalent modification (presumably phosphorylation) of the cAMP receptor. (c) The inhibitory effects of GTPγS and GDPβS on cAMP binding are reduced; the stimulatory effect of cAMP on GTPγS binding is lost in fgd A mutants. (d) Basal high-affinity GTPase activity is reduced 40% and the stimulatory effect of cAMP is decreased from 40% in wild type to 30% in fgd A. (e) GTP-mediated stimulation and inhibition of adenylate cyclase is normal in mutant membranes. The results suggest a defective interaction between cell surface cAMP receptors and a specific G-protein in fgd A mutants. This interaction appears to be essential for nearly all signal transduction pathways in Dictyostelium discoideum.
U2 - 10.1083/jcb.107.2.521
DO - 10.1083/jcb.107.2.521
M3 - Article
VL - 107
JO - The Journal of Cell Biology
JF - The Journal of Cell Biology
SN - 0021-9525
IS - 2
ER -