Possible regulation of CFTR-chloride channels by membrane-bound phosphatases in pancreatic duct cells.
We have studied CFTR-Cl- channels in non-CF CAPAN-1 and in CFTR-transfected CFPAC-PLJ-CFTR-6 epithelial cells from human pancreas. Theophylline and IBMX induced the opening of cell-attached CFTR-Cl- channels. Theophylline, IBMX and the alkaline phosphatase (AP) inhibitor levamisole enhanced the activity of excised channels and reduced by 70-75% the apical membrane-associated APs activity. Okadaic acid had no effect on APs and channel activities. A polyclonal anti-alkaline phosphatase antibody (which detected apical APs) reduced APs activity and activated quiescent excised chloride channels. These results suggest that CFTR channels may be regulated by membrane-bound phosphatases.
Becq
F
F
Laboratoire de Neurobiologie, CNRS, Marseille, France.
Fanjul
M
M
Merten
M
M
Figarella
C
C
Hollande
E
E
Gola
M
M
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000469:Alkaline Phosphatase / Q000502:physiology*; D001483:Base Sequence; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism; D003550:Cystic Fibrosis / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004277:DNA, Single-Stranded; D006801:Humans; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D008969:Molecular Sequence Data; D010179:Pancreas / Q000166:cytology / Q000201:enzymology* / Q000502:physiology; D013806:Theophylline / Q000494:pharmacology; D014407:Tumor Cells, Cultured
C505032:CFTR protein, human; D018118:Chloride Channels; D002712:Chlorides; D004277:DNA, Single-Stranded; D007473:Ion Channels; D008565:Membrane Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D013806:Theophylline; D000469:Alkaline Phosphatase; D015056:1-Methyl-3-isobutylxanthine