Swelling-activated chloride and potassium conductance in primary cultures of mouse proximal tubules. Implication of KCNE1 protein

J Membr Biol. 2003 Jun 1;193(3):153-70. doi: 10.1007/s00232-003-2014-z.


Volume-sensitive chloride and potassium currents were studied, using the whole-cell clamp technique, in cultured wild-type mouse proximal convoluted tubule (PCT) epithelial cells and compared with those measured in PCT cells from null mutant kcne1 -/- mice. In wild-type PCT cells in primary culture, a Cl- conductance activated by cell swelling was identified. The initial current exhibited an outwardly rectifying current-voltage (I-V) relationship, whereas steady-state current showed decay at depolarized membrane potentials. The ion selectivity was I- > Br- > Cl- > > gluconate. This conductance was sensitive to 1 mM 4,4'-Diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), 0.1 mM 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and 1 mM diphenylamine-2-carboxylate (DPC). Osmotic stress also activated K+ currents. These currents are time-independent, activated at depolarized potentials, and inhibited by 0.5 mM quinidine, 5 mM barium, and 10 microM clofilium but are insensitive to 1 mM tetraethylammonium (TEA), 10 nM charybdotoxin (CTX), and 10 microM 293B. In contrast, the null mutation of kcne1 completely impaired volume-sensitive chloride and potassium currents in PCT. The transitory transfection of kcne1 restores both Cl- and K+ swelling-activated currents, confirming the implication of KCNE1 protein in the cell-volume regulation in PCT cells in primary cultures.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Cell Size
  • Cells, Cultured
  • Chloride Channels / drug effects
  • Chloride Channels / physiology
  • Chlorine / metabolism*
  • Electric Conductivity
  • Hypotonic Solutions / pharmacology
  • Kidney Tubules, Proximal / cytology*
  • Kidney Tubules, Proximal / drug effects
  • Kidney Tubules, Proximal / physiology*
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology*
  • Mice
  • Mice, Knockout
  • Osmosis / drug effects
  • Osmosis / physiology
  • Osmotic Pressure / drug effects
  • Potassium / metabolism*
  • Potassium Channels / deficiency
  • Potassium Channels / drug effects
  • Potassium Channels / physiology*
  • Potassium Channels, Voltage-Gated*


  • Chloride Channels
  • Hypotonic Solutions
  • Potassium Channels
  • Potassium Channels, Voltage-Gated
  • potassium channel protein I(sk)
  • Chlorine
  • Potassium