A novel voltage-gated potassium channel in hippocampal mitochondria

• Autorzy: Kowalczyk J.E. , Bednarczyk P. , Beresewicz M. , Dolowy K. , Szewczyk A. , Zablocka B.
• Języki publikacji: EN

Abstrakty

EN

Transient cerebral ischemia is known to induce endogenous adaptive mechanisms such as the activation of mitochondrial ATP-sensitive potassium channels or calcium-sensitive largeconductance potassium channels that can prevent or delay neuronal injury. In this study a single channel activity was measured after patch-clamp of the mitoplasts isolated from control gerbil hippocampus. In 70% of the all patches, a potassium selective current was recorded with mean conductance 109 ± 6 pS in symmetrical 150 mM KCl solution. Patch-clamp single channel studies protein showed properties of the voltage-gated potassium channel (Kv channel): it was blocked by negative voltage and margatoxin (MgTx) a specifi c Kv1.3 inhibitor. The inhibition by MgTx was no reversed. The channel was not affected by the other Kv1.3 channel blocker agitoxin-2 at nanomolar range. Additionally, we showed that ATP/Mg2+ complex and low or high concentration of Ca2+ ions have no effects on observed activity of ion channel. Mitochondrial localization of Kv1.3 was verifi ed by western blots using antibodies recognizing peptides located in N- or C-terminal of plasma membrane Kv1.3 protein. N-terminal specifi c antibodies recognized proteins with molecular masses around 95, 62 and 40 kDa in plasma membrane and 60 kDa in mitochondria while C-terminal specifi c antibodies recognized 40 kDa protein in mitochondria. Mitochondrial localization of Kv1.3 protein was also shown by immunohistochemistry. We conclude that gerbil hippocampus mitochondria contain voltagegated potassium channel (mitoKv) with properties similar to the surface membrane Kv1.3 channel which can play an important regulatory role for protection with respect of ischemia-reperfusion phenomena. Supported by Polish Mitochondrial Network MitoNet.pl

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2009
• Tom: 69
• Numer: 1
• Opis fizyczny: p.98

Twórcy

autor

Kowalczyk J.E.

• Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland

autor

Bednarczyk P.

• Department of Biophysics, Warsaw University of Life Sciences, Warsaw, Poland
• Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology Polish Academy of Sciences Warsaw, Poland

autor

Beresewicz M.

• Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland

autor

Dolowy K.

• Department of Biophysics, Warsaw University of Life Sciences, Warsaw, Poland

autor

Szewczyk A.

• Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology Polish Academy of Sciences Warsaw, Poland

autor

Zablocka B.

• Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland