Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent

https://www.embopress.org/doi/10.15252/embj.2018101056

Dane M Wolf, Mayuko Segawa, Arun Kumar Kondadi, Ruchika Anand, Sean T Bailey, Andreas S Reichert, Alexander M van der Bliek, David B Shackelford, Marc Liesa, Orian S Shirihai

• It is often supposed that the inner mitochondrial membrane is at a uniform membrane potential (ΔΨm). 
• The authors develop an approach to evaluate ΔΨm at the level of individual cristae.
• The authors find the existence of heterogeneity in ΔΨm throughout the inner mitochondrial membrane, with individual cristae possessing different membrane potentials.
• Interventions causing acute depolarization to a particular crista may leave other cristae unchanged in their membrane potential.
• In other words, individual cristae seen to act as independent bioenergetic units, so that the failure of a specific one does not spread to the entire mitochondrion. Therefore, mitochondria should be thought of not as  electric wires, but as sets of batteries.
• The loss of this cristae compartmentalization, causing the spread of damage among regions of a mitochondrion, may be implied in pathological states. Several diseases are associated with structural perturbations in cristae. Restoring the heterogeneity of ΔΨm could represent a therapeutic avenue. 
• A fascinating area of future investigation would be to link cristae membrane heterogeneity to mitochondrial genetics.