| | |
Summary: Cystic Fibrosis Transmembrane
Conductance Regulator
STRUCTURE AND FUNCTION OF AN EPITHELIAL
CHLORIDE CHANNEL*
Myles H. Akabas
From the Center for Molecular Recognition,
Departments of Physiology & Cellular Biophysics
and Medicine, Columbia University,
New York, New York 10032
The cystic fibrosis transmembrane conductance regulator
(CFTR)1
forms a Cl channel that is an essential component of
epithelial Cl transport systems in many organs, including the
intestines, pancreas, lungs, sweat glands, and kidneys. In the
Cl secretory intestinal epithelium, Cl enters the cells
through a Na -K -2Cl cotransporter in the basolateral mem-
brane and exits through CFTR in the apical membrane; water
follows osmotically (1). Absorptive epithelia use similar trans-
porters and channels, but their polarized distribution between
the apical and basolateral membranes is usually reversed. A
|
