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Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent
Author(s) -
Wolf Dane M,
Segawa Mayuko,
Kondadi Arun Kumar,
Anand Ruchika,
Bailey Sean T,
Reichert Andreas S,
Bliek Alexander M,
Shackelford David B,
Liesa Marc,
Shirihai Orian S
Publication year - 2019
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.2018101056
Subject(s) - biology , mitochondrion , membrane potential , microbiology and biotechnology , biophysics
The mitochondrial membrane potential (ΔΨ m ) is the main driver of oxidative phosphorylation (OXPHOS). The inner mitochondrial membrane (IMM), consisting of cristae and inner boundary membranes (IBM), is considered to carry a uniform ΔΨ m . However, sequestration of OXPHOS components in cristae membranes necessitates a re‐examination of the equipotential representation of the IMM. We developed an approach to monitor ΔΨ m at the resolution of individual cristae. We found that the IMM was divided into segments with distinct ΔΨ m , corresponding to cristae and IBM. ΔΨ m was higher at cristae compared to IBM. Treatment with oligomycin increased, whereas FCCP decreased, ΔΨ m heterogeneity along the IMM. Impairment of cristae structure through deletion of MICOS‐complex components or Opa1 diminished this intramitochondrial heterogeneity of ΔΨ m . Lastly, we determined that different cristae within the individual mitochondrion can have disparate membrane potentials and that interventions causing acute depolarization may affect some cristae while sparing others. Altogether, our data support a new model in which cristae within the same mitochondrion behave as independent bioenergetic units, preventing the failure of specific cristae from spreading dysfunction to the rest.