Tytuł:

New insights into the modulation of the mitochondrial large-conductance calcium-activated potassium channel : interaction with cytochrome c oxidase and carbon monoxide : PhD thesis

Twórca:

Rotko, Daria

Twórca instytucjonalny:

Instytut Biologii Doświadczalnej im. Marcelego Nenckiego PAN ; Universität Bonn

Współtwórca:

Szewczyk, Adam (1960- ) : Supervisor ; Kunz, Wolfram S. : Supervisor ; Kulawiak, Bogusz : Assistant supervisor

Wydawca:

Nencki Institute of Experimental Biology PAS

Miejsce wydania:

Warsaw

Data wydania/powstania:

2022

Opis:

165 pages : illustrations ; 30 cm ; Bibliography ; Summmary in Polish

Instytucja nadająca tytuł:

Instytut Biologii Doświadczalnej im. Marcelego Nenckiego PAN

Typ obiektu:

Thesis

Temat i słowa kluczowe:

BK channels ; Carbon monoxide ; Carbon monoxide releasing molecules ; Cytochrome c oxidase ; Mitochondria ; Potassium channels

Abstrakt:

The defining property of mitochondria – generation of mitochondrial membrane potential –interlinks the metabolic and signaling functions of this organelle. Mitochondrial large- conductance calcium-activated potassium channels (mitoBK) execute its fine regulation by allowing the controlled influx of potassium ions into the mitochondrial matrix. This functionendows them with unique properties, resulting in a cytoprotective phenomenon of mitoBKactivation in ischemia-reperfusion injury. The functional and structural interaction of mitoBKchannels with the electron transfer chain, and in particular, its terminal enzyme cytochrome c oxidase (COX), can be one of its molecular mechanisms.To investigate the interaction between the COX and mitoBK channels, different COX-deficientcellular models were employed. Specifically, human astrocytoma cells were depleted ofmitochondrial DNA (mtDNA) by the treatment with 2’,3’-dideoxycytidine. The comparison ofthe protein complexes formed by the mitoBK and COX in the mtDNA-depleted and WTastrocytoma cells identified the interaction of the pore-forming mitoBK subunit with the COX-containing complexes and respirasomes. Furthermore, downregulation of mitoBK-α subunits on both protein and mRNA levels occurred upon mtDNA-induced COX deficiency. Theanalysis of the retrograde signaling pathways induced by the mtDNA depletion in the mtDNA-depleted astrocytoma cells showed activation of the integrated stress response signaling.Human dermal fibroblasts with a mutation in the structural COX subunit – COX8A – were usedas another cellular model with a deficiency in COX. The organization of the electron transportchain was characterized in the COX8A-deficient fibroblasts and HEK293T cells with CRISPR/Cas9 induced mutations in COX8A and ensuing COX deficiency, identifying that theresidual COX was stabilized in the respirasomes. The decrease in the protein amount of mitoBKpore-forming subunit, as well as its protein complexes, was observed.To follow the systemic implications of this coupling, the effect of a gaseous transmitter carbonmonoxide (CO), putatively targeting both COX and mitoBK, was assessed in the patch-clampstudies. While direct application of CO-saturated solution has not exerted significantmodulation of the mitoBK channel activity, patch perfusion with CO-releasing moleculesinduced pleiotropic effects. Perfusion with heme and hemin inhibited mitoBK channels. Thesubsequent application of CO-saturated solution released this inhibition, activating mitoBKchannels in the presence of heme

Typ zasobu:

Text

Szczegółowy typ zasobu:

PhD Dissertations

Źródło:

IBD PAN, call no. 20057

Język:

eng

Język streszczenia:

pol

Digitalizacja:

Nencki Institute of Experimental Biology of the Polish Academy of Sciences

Lokalizacja oryginału:

Library of the Nencki Institute of Experimental Biology PAS

Dostęp:

Open