Exchange of guanine nucleotide between GTP-binding proteins that regulate neuronal adenylate cyclase.
- 1 August 1986
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 83 (15) , 5439-5443
- https://doi.org/10.1073/pnas.83.15.5439
Abstract
GTP-binding proteins have been demonstrated to stimulate and inhibit rat brain adenylate cyclase without the prior addition of hormone. Exposure of rat cerebral cortex membranes to hydrolysis-resistant GTP analogs results in inhibition (or stimulation) of adenylate cyclase, which persists subsequent to buffer washing. The hydrolysis-resistant GTP photoaffinity probe P3-(4-azidoanilido)-P1-5'' GTP (AAGTP) can promote a similar perisistent inhibition of adenylate cyclase, and, after removal of unbound AAGTP and subsequent UV photolysis, AAGTP is covalently linked to the 40-kDa inhibitory GTP binding protein, GNi (inhibitory guanine nucleotide binding regulatory subunit of adenylate cyclase). Under conditions where the persistent inhibition of adenylate cyclase is overcome by subsequent incubation with 5''-guanylyl imidodiphosphate or NaF, AAGTP bound to the 40-kDa GNi protein is diminished while that bound to the 42-kDa stimulatory GTP-binding protein (GNs). This protein does not appear to be a byproduct of proteolysis as demonstrated by Staphylococcus aureus V8 protease digestion experiments, and it is not a substrate for ADP-ribosylation by bacterial toxins. The sum of the AAGTP bound by the GNi and GNs proteins is constant, and the transfer of nonphotoactivated AAGTP to GNs from GNi is stable to buffer washing. Furthermore, this alteration in the AAGTP-labeling pattern corresponds to the shift in adenylate cyclase from inhibition to stimulation. These data raise the possibility that hydrolysis-resistant GTP analogs might be exchanged directly between the GNi and GNs and that there exists some interaction between those proteins in the regulation of adenylate cyclase activity.Keywords
This publication has 28 references indexed in Scilit:
- Antibodies against the carboxyl-terminal 5-kDa peptide of the alpha subunit of transducin crossreact with the 40-kDa but not the 39-kDa guanine nucleotide binding protein from brain.Proceedings of the National Academy of Sciences, 1985
- Photoaffinity Identification of Colchicine‐Solubilized Regulatory Subunit from Rat Brain Adenylate CyclaseJournal of Neurochemistry, 1984
- Reconstitution of catecholamine-stimulated guanosine triphosphatase activityBiochemistry, 1983
- Formation of a Persistent Inhibitory State of Brain Adenylate Cyclase by GTP AnalogsJournal of Neurochemistry, 1983
- Role of Cytoskeletal Organization in the Regulation of Adenylate Cyclase-Cyclic Adenosine Monophosphate by HormonesEndocrine Reviews, 1983
- A minor component of the binding of [3H]guanyl-5'-yl imidodiphosphate to cardiac membranes associated with the activation of adenylate cyclase.Journal of Biological Chemistry, 1981
- Partial purification and characterization of a macromolecule which enhances fluoride activation of adenylate cyclase.Proceedings of the National Academy of Sciences, 1980
- Agonist-promoted coupling of the beta-adrenergic receptor with the guanine nucleotide regulatory protein of the adenylate cyclase system.Proceedings of the National Academy of Sciences, 1980
- A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye BindingAnalytical Biochemistry, 1976
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970