Characterization of strychnine-sensitive glycine receptor in the intact frog retina: Modulation by protein kinases
Por:
Salceda R., Aguirre-Ramirez M.
Publicada:
1 ene 2005
Resumen:
We studied 3H-glycine and 3H-strychnine specific binding to glycine receptor (GlyR) in intact isolated frog retinas. To avoid glycine binding to glycine uptake sites, experiments were performed at low ligand concentrations in a sodium-free medium. The binding of both radiolabeled ligands was saturated. Scatchard analysis of bound glycine and strychnine revealed a K D of 2.5 and 2.0 ?M, respectively. Specific binding of glycine was displaced by ?-alanine, sarcosine, and strychnine. Strychnine binding was displaced 50% by glycine, and sarcosine. Properties of the strychnine-binding site in the GlyR were modified by sarcosine. Binding of both radioligands was considerably reduced by compounds that inhibit or activate adenylate cyclase and increased cAMP levels. A phorbol ester activator of PKC remarkably decreased glycine and strychnine binding. These results suggest modulation of GlyR in response to endogenous activation of protein kinases A and C, as well as protein phosphorylation modulating GlyR function in retina. © 2005 Springer Science+Business Media, Inc.
Filiaciones:
Salceda R.:
Instituto de Fisilogía Celular, Universidad Nacional Autonoma de México, Apdo. Postal 70-253, 04510 México D.F., Mexico
Aguirre-Ramirez M.:
Instituto de Fisilogía Celular, Universidad Nacional Autonoma de México, Apdo. Postal 70-253, 04510 México D.F., Mexico
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