The ability of mitochondria to complete critical functions such as ATP generation and lipid metabolism is a product of their iconic structure. It has also long been understood that aberrances in the folds of mitochondrial cristae are associated with numerous, severe, life-limiting human conditions. Despite their clear importance to human health, the molecular processes dictating their formation and also wider mitochondrial architecture are poorly understood. Stephan et al. recently increased our knowledge in this area by using CRISPR-Cas9 to knock out individual genes of the human MICOS (mitochondrial contact site and cristae organising system) along with super-resolution microscopy techniques to capture images of the structure of single mitochondria. They discovered that individual proteins within the MICOS are associated with specific aspects of crista formation, with each one playing a role in tightly co-ordinated organisation. Interestingly, they also found that crista precursors are first formed prior to remodelling by the MICOS complex.

As a result of these experiments, they propose a new model for mitochondrial crista formation in higher eukaryotes distinct from that in lower eukaryotes. This advancement in knowledge moves us towards a better grasp of the genetic and physical interactions that give rise to the unique energy-generating organelles inside our cells.

Read the full article in EMBO Journal doi:10.15252/embj.2019104105