Chloride channels in the nuclear membrane
Chloride-selective ion channels were measured from isolated rat liver nuclei. Single ion channel currents were recorded in both “nuclear-attached” and in excised patches in the insideout configuration of the patch-clamp technique. Two types of chloride conductance were defined, a large conductance (150 pS;iCl.N) channel with complex kinetics and multiple substates, and a second smaller conductance (58 pS;ICl.n) channel sensitive to block by ATP. The channels were inhibited by pharmacological agents known to block chloride channels and were insensitive to internal and external changes in calcium and magnesium. Presumably the channels reside in the external membrane of the nuclear double membrane and may mediate charge balance in the release and uptake of calcium from the perinuclear space.
Key Wordsnuclear membrane ion channels chloride channels patch clamp nucleus
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- Nicotera, P., McConkey, D.J., Jones, D.P., Orrenius, S. 1989. ATP stimulates Ca2+ uptake and increases the free Ca2+ concentration in isolated rat liver nuclei.Proc. Natl. Acad. Sci. USA 86:452–457Google Scholar
- Paine, P.L., Horowitz, S.B. 1980. The movement of material between nucleus and cytoplasm.Cell Biol. 4:318–326Google Scholar
- Satoh, T., Ross, C.A., Villa, A., Supattapone, S., Pozzan, T., Snyder, S.H., Meldolesi, J. 1990. The inositol 1,4,5-trisphosphate receptor in cerebellar purkinje cells: Quantitative immunogold labeling reveals concentration in an ER subcompartment.J. Cell. Biol. 111:615–624CrossRefPubMedGoogle Scholar
- Tabcharani, J.A., Hanrahan, J.W. 1989. Inhibition of epithelial anion channels by HEPES and related buffer.J. Gen. Physiol. 94:34a Google Scholar
- White, M., Alwyn, M. 1990. Niflumic and flufenamic acids are potent, reversible blockers of Ca++-activated Cl-channels inXenopus oocytes.Mol. Pharmacol. 315:720–724Google Scholar