RRC ID 31014
著者 Lilly PJ, Devreotes PN.
タイトル Chemoattractant and GTP gamma S-mediated stimulation of adenylyl cyclase in Dictyostelium requires translocation of CRAC to membranes.
ジャーナル J Cell Biol
Abstract We have previously reported that activation of adenylyl cyclase by chemoattractant receptors in Dictyostelium requires, in addition to a heterotrimeric G-protein, a cytosolic protein, designated CRAC (Lilly, P., and P. N. Devreotes. 1994. J. Biol. Chem. 269:14123-14129; Insall, R. H., A. Kuspa, P. J. Lilly, G. Schaulsky, L. R. Levin, W. F. Loomis, and P. N. Devreotes. 1994. J. Cell Biol. 126:1537-1545). In this report, we show that in intact cells, chemoattractants promote translocation of CRAC from the cytosolic to the membrane fraction. However, CRAC is not required at the time of receptor stimulation; it can be added to lysates of activated cells. Treatment of membranes with guanine nucleotides creates binding sites for CRAC. These binding sites can be generated in mutants lacking each of the components of the pathway except the beta-subunit, suggesting that free or "activated" beta gamma-subunits may be a part of the binding site. This hypothesis is consistent with previous observations that CRAC contains a pleckstrin homology domain and that the beta gamma-subunits likely mediate activation of adenylyl cyclase in this system. Thus, CRAC may serve as an adapter, linking the G-protein beta gamma-subunits to activation of the enzyme. GTP gamma S cannot generate CRAC-binding sites when the adenylyl cyclase pathway has been adapted by prior chemoattractant stimulation, suggesting that this is a point of downstream adaptation.
巻・号 129(6)
ページ 1659-65
公開日 1995-6-1
DOI 10.1083/jcb.129.6.1659
PMID 7790361
PMC PMC2291171
MeSH Adenylyl Cyclases / metabolism* Animals Cell Membrane / drug effects Cell Membrane / metabolism Chemotactic Factors / pharmacology* Cyclic AMP / pharmacology* Dictyostelium / drug effects Dictyostelium / physiology* Fungal Proteins / metabolism* GTP-Binding Proteins / metabolism Guanosine 5'-O-(3-Thiotriphosphate) / pharmacology* Kinetics Macromolecular Substances Protozoan Proteins* Time Factors
IF 8.811
引用数 62
WOS 分野 CELL BIOLOGY
リソース情報
細胞性粘菌 S90405