Biophysical Society Thematic Meeting| Padova 2019

Quantitative Aspects of Membrane Fusion and Fission

Poster Abstracts

57-POS Board 57 MITOCHONDRIA SHAPE CHANGES AND THE INNER MEMBRANE-LOCATED MECHANOSENSOR, MITO(BK CA ) - A HYPOTHESIS Agnieszka Walewska 1 ; Piotr Koprowski 1 ; Adam Szewczyk 1 ; 1 Nencki Institute of Experimental Biology, Laboratory of Intracellular Ion Channels, Warsaw, Mazowieckie, Poland In our studies, we recorded by patch-clamp technique the single-channel activity of mitochondrial large-conductance calcium-activated potassium channels (mitoBK Ca ) residing in the inner membrane of mitochondria of the human glioma U-87 MG cells. We have found that subpopulation of mitoBK Ca channels was mechanosensitive and application of hydrostatic pressure to the recording pipette resulted in increased open probability due to longer open times. However, not all mitoBK Ca channels were mechanosensitive possibly due to the expression of different splice variants of BK Ca . Our finding indicated to possible engagement of the mitoBK Ca channel in mitochondrial dynamics in which changes in membrane tension and shape might play a role. Here, we hypothesize that mechanical forces that might arise during remodeling and volume changes of cristae, mitochondria fusion and fission could impact local tension within the inner mitochondrial membrane. This, in turn, can modulate the activity of mitoBK Ca and provide regulation of ion flow to modulate mitochondrial membrane potential or/and volume.This work was supported by the Polish National Science Center, grant no. 2017/26/M/NZ3/00727.

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