Low-conductance chloride channels in IEC-6 and CF nasal cells expressing CFTR
| Autor: | J. Bijman, W. Dalemans, M. Kansen, J. Keulemans, E. Verbeek, A. Hoogeveen, H. De Jonge, M. Wilke, D. Dreyer, J. P. Lecocq, al. et |
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| Rok vydání: | 1993 |
| Předmět: |
Pulmonary and Respiratory Medicine
medicine.medical_specialty Cell Membrane Permeability Physiology Protein subunit Cell Cystic Fibrosis Transmembrane Conductance Regulator Biology Transfection digestive system Ion Channels Membrane Potentials Adenosine Triphosphate Nasal Polyps Chlorides Physiology (medical) Internal medicine Tumor Cells Cultured medicine Humans RNA Messenger Patch clamp Intestinal Mucosa Fibroblast Protein kinase A Cells Cultured Colforsin Membrane Proteins DNA DNA Neoplasm Cell Biology Molecular biology Adenosine digestive system diseases Gene Expression Regulation Neoplastic Intestines medicine.anatomical_structure Endocrinology Gene Expression Regulation Cell culture Chloride channel medicine.drug |
| Zdroj: | American Journal of Physiology-Lung Cellular and Molecular Physiology. 264:L229-L235 |
| ISSN: | 1522-1504 1040-0605 |
| Popis: | The properties of the cystic fibrosis gene product (CFTR) were studied by expression of cloned cDNA in different cell systems. Infection of both simian fibroblast (Vero) cells and immortalized CF nasal polyp cells (NCF3A) with a vaccinia virus encoding CFTR induced forskolin-induced Cl- permeability and low-conductance (8 pS) Cl- channels. By stable transfection of the rat intestinal crypt-derived cell line IEC-6 we have isolated a clone, IEC-CF7, which expresses CFTR mRNA and antigen. IEC-CF7 cells, but not IEC-6, display forskolin-induced Cl- permeability and multiple linear low-conductance (+/- 8 pS) Cl- channels in cell-attached membrane patches. In excised patches of IEC-CF7 cells, low-conductance Cl- channels could be activated by addition of the catalytic subunit of the adenosine 3',5'-cyclic monophosphate-dependent protein kinase A (PKA) plus ATP. During bath fluid replacement studies, the activated low-conductance channel remained active in the absence of ATP at room temperature and showed saturation kinetics. Rectifying (32 pS) Cl- channels were not observed in either IEC-6 cells or IEC-CF7 cells, indicating that there is no relation between CFTR expression and the incidence of this channel. Our data strongly support the conclusion that CFTR can act as a low-conductance Cl- channel, gated by PKA. The IEC-6-derived cell line IEC-CF7 may prove to be a useful model in the study of CFTR function because of the absence of 32-pS Cl- channel activity and its potential for differentiation. |
| Databáze: | OpenAIRE |
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