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Updated: Jul 5, 2026

Simultaneous Measurement of Mitochondrial Calcium and Mitochondrial Membrane Potential in Live Cells by Fluorescent Microscopy
Published on: January 24, 2017
Mitochondrial creatine kinase and mitochondrial outer membrane porin show a direct interaction that is modulated by
U Schlattner1, M Dolder, T Wallimann
1Institute of Cell Biology, Swiss Federal Institute of Technology (ETH), Hönggerberg HPM, CH-8093 Zürich, Switzerland. schlattn@cell.biol.ethz.ch
Abstract:
Mitochondrial creatine kinase (MtCK) co-localizes with mitochondrial porin (voltage-dependent anion channel) and adenine nucleotide translocator in mitochondrial contact sites. A specific, direct protein-protein interaction between MtCK and mitochondrial porin was demonstrated using surface plasmon resonance spectroscopy. This interaction was independent of the immobilized binding partner (porin reconstituted in liposomes or MtCK) or the analyzed isoform (chicken sarcomeric MtCK or human ubiquitous MtCK, human recombinant porin, or purified bovine porin). Increased ionic strength reduced the binding of MtCK to porin, suggesting predominantly ionic interactions. By contrast, micromolar concentrations of Ca(2+) increased the amount of bound MtCK, indicating a physiological regulation of complex formation. No interaction of MtCK with reconstituted adenine nucleotide translocator was detectable in our experimental setup. The relevance of these findings for structure and function of mitochondrial contact sites is discussed.
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