ATP-activated chloride channel inhibited by an antibody to P glycoprotein.
In this report, we present the characteristics of a Cl- channel found in lens fiber cells. The single channel has a conductance of 17 pS, a linear current-voltage curve, is activated by ATP or strong depolarization and is blocked by verapamil, quinidine, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, 5-nitro-2-(3- phenylpropylamino)benzoate, dideoxyforskolin, and tamoxifen. These properties are similar to those reported for a volume-activated Cl- channel associated with the multidrug resistance (MDR) gene product, P glycoprotein (24). Confirming this connection, we demonstrate that our lens Cl- channel is inhibited by an antibody to P glycoprotein. The data we present here may, therefore, be the first characterization of the single channel activity of the Cl- channel associated with P glycoprotein.
Zhang
J J
JJ
Department of Physiology, University of Wales, Cardiff, United Kingdom.
Jacob
T J
TJ
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000276:immunology*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D000906:Antibodies / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D018118:Chloride Channels / Q000037:antagonists & inhibitors* / Q000187:drug effects* / Q000502:physiology; D004594:Electrophysiology; D007908:Lens, Crystalline / Q000378:metabolism*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000906:Antibodies; D018118:Chloride Channels; D000255:Adenosine Triphosphate; D002118:Calcium