The short apical membrane half-life of rescued {Delta}F508-cystic fibrosis transmembrane conductance regulator (CFTR) results from accelerated endocytosis of {Delta}F508-CFTR in polarized human airway epithelial cells.
The most common mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene in individuals with cystic fibrosis, DeltaF508, causes retention of DeltaF508-CFTR in the endoplasmic reticulum and leads to the absence of CFTR Cl(-) channels in the apical plasma membrane. Rescue of DeltaF508-CFTR by reduced temperature or chemical means reveals that the DeltaF508 mutation reduces the half-life of DeltaF508-CFTR in the apical plasma membrane. Because DeltaF508-CFTR retains some Cl(-) channel activity, increased expression of DeltaF508-CFTR in the apical membrane could serve as a potential therapeutic approach for cystic fibrosis. However, little is known about the mechanisms responsible for the short apical membrane half-life of DeltaF508-CFTR in polarized human airway epithelial cells. Accordingly, the goal of this study was to determine the cellular defects in the trafficking of rescued DeltaF508-CFTR that lead to the decreased apical membrane half-life of DeltaF508-CFTR in polarized human airway epithelial cells. We report that in polarized human airway epithelial cells (CFBE41o-) the DeltaF508 mutation increased endocytosis of CFTR from the apical membrane without causing a global endocytic defect or affecting the endocytic recycling of CFTR in the Rab11a-specific apical recycling compartment.
Swiatecka-Urban
Agnieszka
A
Department of Physiology, Dartmouth Medical School, Hanover, New Hampshire 03755, USA. Agnieszka.Swiatecka-Urban@Dartmouth.edu
Brown
Andrea
A
Moreau-Marquis
Sophie
S
Renuka
Janhavi
J
Coutermarsh
Bonita
B
Barnaby
Roxanna
R
Karlson
Katherine H
KH
Flotte
Terence R
TR
Fukuda
Mitsunori
M
Langford
George M
GM
Stanton
Bruce A
BA
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity; D002478:Cells, Cultured; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D004847:Epithelial Cells / Q000378:metabolism*; D006207:Half-Life; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D009154:Mutation; D009363:Neoplasm Proteins / Q000378:metabolism; D010957:Plasmids; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000494:pharmacology; D020545:Respiratory Mucosa / Q000166:cytology / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000099193:rab11 GTP-Binding Proteins
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C116614:ABCG2 protein, human; C093349:cystic fibrosis transmembrane conductance regulator delta F508