Ca2+-activated K channel of the BK-type in the inner mitochondrial membrane of a human glioma cell line
D Siemen, C Loupatatzis, J Borecky, E Gulbins… - Biochemical and …, 1999 - Elsevier
D Siemen, C Loupatatzis, J Borecky, E Gulbins, F Lang
Biochemical and biophysical research communications, 1999•ElsevierA single channel current was recorded from mitoplasts (ie, inner mitochondrial membrane)
of the human glioma cell line LN229 using patch-clamp techniques in the mitoplast-attached
mode. We frequently found a 295±18 pS channel that showed a straighti-Erelation in the
range±60 mV in 150 mM KCl solutions on either side of the mitoplast. If KCl in the bath was
exchanged against NaCl, outward currents were undetectable, indicating potassium
selectivity. Channel activity determined as open probability increased with increasing Ca2+ …
of the human glioma cell line LN229 using patch-clamp techniques in the mitoplast-attached
mode. We frequently found a 295±18 pS channel that showed a straighti-Erelation in the
range±60 mV in 150 mM KCl solutions on either side of the mitoplast. If KCl in the bath was
exchanged against NaCl, outward currents were undetectable, indicating potassium
selectivity. Channel activity determined as open probability increased with increasing Ca2+ …
A single channel current was recorded from mitoplasts (i.e., inner mitochondrial membrane) of the human glioma cell line LN229 using patch-clamp techniques in the mitoplast-attached mode. We frequently found a 295 ± 18 pS channel that showed a straighti-Erelation in the range ±60 mV in 150 mM KCl solutions on either side of the mitoplast. If KCl in the bath was exchanged against NaCl, outward currents were undetectable, indicating potassium selectivity. Channel activity determined as open probability increased with increasing Ca2+concentrations (EC50= 0.9 μM at 60 mV). Open probability was voltage dependent. Ane-fold increase of time spent in the open state was induced by a depolarization of 10.5 mV. Open probability was decreased by charybdotoxin concentration and voltage dependently (EC50= 1.4 nM). In conclusion, we show for the first time that the inner mitochondrial membrane in human glioma cells contains a calcium-dependent K channel of the BK-type.
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