In human and rat lung membranes [35s]GTPγS binding is a tool for pharmacological characterization of G protein-coupled devucleotide receptors
| Autor: | H J Schäfer, Georg Reiser, Gundula Streubel, Tobias Welte, Werner Laubinger |
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| Rok vydání: | 1999 |
| Předmět: |
P2Y receptor
G protein GTPgammaS Receptors Cell Surface Biology Sulfur Radioisotopes General Biochemistry Genetics and Molecular Biology Radioligand Assay chemistry.chemical_compound Species Specificity GTP-Binding Proteins Animals Humans General Pharmacology Toxicology and Pharmaceutics Receptor Lung G protein-coupled receptor G protein-coupled receptor kinase Membranes Receptors Purinergic P2 General Medicine Fluid transport Rats chemistry Biochemistry Guanosine 5'-O-(3-Thiotriphosphate) Ap4A |
| Zdroj: | Life Sciences. 65:PL183-PL190 |
| ISSN: | 0024-3205 |
| Popis: | The P2Y receptor family is activated by extracellular nucleotides such as ATP and UTP. P2Y receptors regulate physiological functions in numerous cell types. In lung, the P2Y2 receptor subtype plays a role in controlling Cl- and fluid transport. Besides ATP or UTP, also diadenosine tetraphosphate (Ap4A), a stable nucleotide, seems to be of physiological importance. In membrane preparations from human and rat lung we applied several diadenosine polyphosphates to investigate whether they act as agonists for G protein-coupled receptors. We assessed this by determining the stimulation of [35S]GTPgammaS binding. Stimulation of [35S]GTPgammaS binding to G proteins has already been successfully applied to elucidate agonist binding to various G protein-coupled receptors. Ap(n)A (n = 2 to 6) enhanced [35S]GTPgammaS binding similarly in human and rat lung membranes, an indication of the existence of G protein-coupled receptor binding sites specific for diadenosine polyphosphates. Moreover, in both human and rat lung membranes comparable pharmacological properties were found for a diadenosine polyphosphate ([3H]Ap4A) binding site. The affinity for Ap2A, Ap3A, Ap4A, Ap5A, and Ap6A was also comparable. 8-Diazido-Ap4A and ATP were less potent, whereas the pyrimidine nucleotide UTP showed hardly any affinity. Thus, we present evidence that different diadenosine polyphosphates bind to a common G protein-coupled receptor binding site in membranes derived either from human or rat lung. |
| Databáze: | OpenAIRE |
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