Voltage-gated potassium channel in hippocampus mitochondria

• Autorzy: Bednarczyk P. , Kowalczyk J.E. , 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 regulated or Ca2+ regulated large conductance potassium channels that can prevent or delay neuronal injury. However, molecular mechanism of this effect remains unclear. In this study, a single channel activity was measured with patch-clamp of the mitoplasts isolated from gerbil hippocampus. In 70% of the all patches, a potassium selective current with properties of the voltage-gated potassium channel (Kv type channel) was recorded with mean conductance 109 ± 6 pS in symmetrical 150 mM KCl solution. Detected channel was blocked by negative voltage and margatoxin (MgTx) a specific Kv1.3 channel inhibitor. The inhibition by MgTx was irreversible. We observed that ATP/Mg2+ complex or Ca2+ ions had no effects on observed activity of ion channel. Additionally, we showed that agitoxin-2 (AgTx-2), potent inhibitor of the voltage-gated potassium channels, was without effect on channel activity. This observation suggests that mitochondrial voltage-gated potassium channel can represent different molecular structure without affinity to AgTx-2 in compare to surface membrane channels. Also, Western blot analysis of mitochondria isolated from gerbil hippocampus and immunohistochemistry on gerbil brain sections confirm the expression of Kv1.3 protein in mitochondria. All together, we conclude that gerbil hippocampal mitochondria contain voltage-gated potassium channel (mitoKv1.3 channel) with properties similar to the surface membrane Kv1.3 channel which can influence function of mitochondria in physiological and pathological conditions. This study was supported by the grant from the Ministry of Science and Higher Education (P-N/31/2006) and Polish Mitochondrial Network MitoNet.pl. P.B. would like to acknowledge to prof. Detlef Siemen for teaching patch-clamp and more discussion during postdoc in Magdeburg supported by EMBO (2006) and DAAD (2008).

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2011
• Tom: 71
• Numer: 1
• Opis fizyczny: p.161-162

Twórcy

autor

Bednarczyk P.

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

autor

Kowalczyk J.E.

• Molecular Biology Unit, Mossakowski Medical Research Centre, 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.

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

autor

Szewczyk A.

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

autor

Zablocka B.

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