P2X7 purinoceptor expression in Xenopus oocytes is not sufficient to produce a pore-forming P2Z-like phenotype.
The purinergic rP2X7 receptor expressed in a number of heterologous systems not only functions as a cation channel but also gives rise to a P2Z-like response, i.e. a reversible membrane permeabilization that allows the passage of molecules with molecular masses of > or = 300 Da. We investigated the properties of rP2X7 receptors expressed in Xenopus oocytes. In two-electrode voltage-clamp experiments, ATP or BzATP caused inward currents that were abolished or greatly diminished when NMDG+ or choline replaced Na+ as the principal external cation. In fluorescent dye experiments, BzATP application did not result in entry of the fluorophore YO-PRO-1(2+). Thus, rP2X7 expression in Xenopus oocytes does not by itself give rise to the pore-forming P2Z phenotype, suggesting that ancillary factors are involved.
Petrou
S
S
Department of Physiology, University of Massachusetts Medical School, Worcester 01655-0127, USA.
Ugur
M
M
Drummond
R M
RM
Singer
J J
JJ
Walsh
J V
JV
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001583:Benzoxazoles; D002463:Cell Membrane Permeability; D004594:Electrophysiology; D005456:Fluorescent Dyes / Q000378:metabolism; D015870:Gene Expression; D007473:Ion Channels / Q000378:metabolism*; D008536:Meglumine / Q000378:metabolism; D008845:Microinjections; D009865:Oocytes; D018408:Patch-Clamp Techniques; D010641:Phenotype; D011806:Quinolinium Compounds; D018075:RNA, Complementary / Q000235:genetics; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism*; D058486:Receptors, Purinergic P2X7; D011994:Recombinant Proteins / Q000378:metabolism; D014981:Xenopus
D001583:Benzoxazoles; D005456:Fluorescent Dyes; D007473:Ion Channels; D011806:Quinolinium Compounds; D018075:RNA, Complementary; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7; D011994:Recombinant Proteins; C089813:YO-PRO 1; C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D008536:Meglumine; D000255:Adenosine Triphosphate