As the powerhouses of the cell, mitochondria host various supramolecular protein complexes. Delineating the structural basis of these protein complexes is essential to improve our understanding of how mitochondria function and generate energy. In
a study published in
Molecular & Cellular Proteomics,
Albert Heck and a team of investigators at
Utrecht University in the Netherlands, in collaboration with the National Institutes of Health, aimed to discover the organization and interactions of proteins in the mitochondria of mouse hearts.
“We were most curious about the organization of protein molecules within mitochondria, because proteins are the molecular building blocks that make the mitochondrial energy factory work,” Heck said. “It was already known which proteins are involved in energy generation, but it is still not fully understood how these building blocks come together within intact mitochondria.”
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Going a step further to validate their map, the investigators soaked the mitochondria in a high-salt solution to disrupt the protein supercomplexes. They showed, using the same cross-linking technique, that these “dysfunctional” mitochondria displayed a very different protein interaction network. “These data show that protein organization and mitochondria function are two sides of the same coin,” said co-author Philip Lössl. “We believe that our protein maps will help us understand the organization principles that allow mitochondria to work as molecular powerhouses.”