Opposing Roles of Calcium and Intracellular ATP on Gating of the Purinergic P2X2 Receptor Channel.

ABSTRACT: P2X2 receptors (P2X2R) exhibit a slow desensitization during the initial ATP application and a progressive, calcium-dependent increase in rates of desensitization during repetitive stimulation. This pattern is observed in whole-cell recordings from cells expressing recombinant and native P2X2R. However, desensitization is not observed in perforated-patched cells and in two-electrode voltage clamped oocytes. Addition of ATP, but not ATPγS or GTP, in the pipette solution also abolishes progressive desensitization, whereas intracellular injection of apyrase facilitates receptor desensitization. Experiments with injection of alkaline phosphatase or addition of staurosporine and ATP in the intracellular solution suggest a role for a phosphorylation-dephosphorylation in receptor desensitization.

SUBMITTER: Rokic MB 

PROVIDER: S-EPMC5979340 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature