Cristae membranes are the hallmark feature of mitochondria, giving them their distinctive appearance in electron microscopy images. Cristae are home to the respiratory complexes that generate ATP, which makes us think of mitochondria as the "powerhouse of the cell" (among their multitude of other jobs!).
Despite it being such a fundamental question how cristae are made, there is still a lot we don't understand. The key protein complex that contributes to cristae organization, MICOS, was only discovered about 10-15 years ago. MICOS is highly conserved and plays a crucial role in stabilizing cristae junctions, the sites of cristae invaginations. However, we think that MICOS likely plays additional roles through its interactions inside of mitochondria.
We are interested in the mechanisms that control MICOS positioning within mitochondria and how MICOS senses and responds to cellular metabolic needs to dynamically organize cristae membranes and mitochondrial functions. We recently found that a key factor in contributing to cristae organization comes from outside the organelle, as we found MICOS assemblies are positioned near sites where mitochondria contact the endoplasmic reticulum. Check out this work here!