Reconstitution and Phosphorylation of Chloride Channels from Airway Epithelium Membranes

• Published in: Science (American Association for the Advancement of Science) Vol. 242; no. 4884; pp. 1441 - 1444
• Main Authors: Valdivia, Hector H., Dubinsky, William P., Coronado, Roberto
• Format: Journal Article
• Language: English
• Published: Washington, DC The American Association for the Advancement of Science 09.12.1988; American Association for the Advancement of Science
• Subjects: Air breathing; Animals; Anions; Biological and medical sciences; Cattle; Cell Membrane - physiology; chloride; Chloride Channels; Chlorides; Chlorides - isolation & purification; Chlorides - metabolism; Chlorides - physiology; Cocktails; Cystic fibrosis; Electric Conductivity; Electric potential; Epithelium; Fundamental and applied biological sciences. Psychology; Ion channels; Ion Channels - physiology; Membrane Potentials; Membrane proteins; Membrane Proteins - isolation & purification; Membrane Proteins - metabolism; Membrane Proteins - physiology; Phosphorylation; reconstitution; Respiratory system: anatomy, metabolism, gas exchange, ventilatory mechanics, respiratory hemodynamics; Secretion; Trachea; Trachea - physiology; Ungulates; Vertebrates: respiratory system; Phosphorylation; Secretion; Electrophysiology; Ox; Permeability; Respiratory system; Inorganic element; Apical membrane; Respiratory tract; Vertebrata; Mammalia; Chlorides; Artiodactyla; Membrane channel; Trachea; Ungulata
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.2462280

Airway epithelial chloride secretion is controlled by the apical-membrane chloride permeability. Purified apical-membrane vesicles from bovine tracheal epithelium have now been shown to contain functional chloride channels by using the planar-bilayer technique. Three types of chloride channels were observed; a voltage-dependent, calcium-independent, 71-picoSiemen (in 150 mM NaCl) channel accounted for more than 80 percent of the vesicular chloride conductance and was under strict control of phosphorylation. The channel underwent a fast rundown in less than 2 to 3 minutes of recording, and reactivation required in situ exposure to a phosphorylating ``cocktail'' containing the catalytic subunit of the adenosine 3$^{\prime}$,5$^{\prime}$-monophosphate (cAMP)-dependent protein kinase. Mean open time and open probability were increased after phosporylation, whereas slope conductance remained unchanged. Thus, metabolic control of tracheal chloride single channels can now be studied in vitro.