Regulation of Cl- and K+ channels in airway epithelium.
Stimulation of transepithelial Cl- secretion by the airway epithelium requires activation of channels at the two opposite sides of the cell: the apical and basolateral membranes. At the apical membrane, the Cl- channel is regulated by phosphorylation with PKA and PKC. At the basolateral membrane, the KCLIC channel is regulated by [Ca2+]c. Addition of a secretagogue that increases cellular levels of cAMP also causes release of Ca2+ from intracellular stores. The Ca2+ may then regulate basolateral membrane KCLIC channels. The cAMP-induced increase in [Ca2+]c and activation of the KCLIC channel is transient, however, whereas activation of the Cl- channel and stimulation of secretion is a more sustained response. Those results suggest that the presence of a second Ca2(+)-independent K+ channel located at the basolateral membrane, which is only expressed in cells grown on permeable supports.
McCann
J D
JD
Howard Hughes Medical Institute, Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242.
Welsh
M J
MJ
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System / Q000378:metabolism; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D009994:Osmolar Concentration; D015221:Potassium Channels / Q000378:metabolism*; D011494:Protein Kinases / Q000494:pharmacology; D013268:Stimulation, Chemical; D014132:Trachea / Q000378:metabolism*
D018118:Chloride Channels; D002712:Chlorides; D008565:Membrane Proteins; D015221:Potassium Channels; D011494:Protein Kinases; D002118:Calcium