Using fluorometry and ion-sensitive microelectrodes to study the functional expression of heterologously-expressed ion channels and transporters in Xenopus oocytes.

摘要: Abstract The Xenopus laevis oocyte is a model system for the electrophysiological study of exogenous ion transporters. Three main reasons make suitable this purpose: (a) it has large cell size (∼1 mm diameter), (b) an established capacity to produce—from microinjected mRNAs or cRNAs—exogenous transporters with close-to-physiological post-translational modifications and actions, (c) its membranes contain endogenous ion-transport activities which are usually smaller in magnitude than exogenously-expressed expression as green fluorescent protein fusions allows fluorometric assay transporter yield living oocytes. Monitoring transporter-mediated movement ions such Cl−, H+ (and hence base equivalents like OH− HCO3−), K+, Na+ achieved by positioning tips ion-sensitive microelectrodes inside and/or at surface plasma membrane. use electrodes critical studying net ion-movements mediated electroneutral combined fluorometry electrophysiology expedites allowing measurement prior correlation relative transport rates.