Get the balance right: mitofusins roles in health and disease.

Mitochondria are highly dynamic organelles exhibiting an elaborate morphology and fine structure. Fusion and fission processes contribute to the maintenance and dynamics of mitochondrial morphology. The Mitofusins, a class of evolutionary conserved GTPases of the mitochondrial outer membrane, are essential for the controlled fusion of mitochondrial membranes. Genetic and biochemical data propose a model in which functional domains, such as the GTPase domain and the C-terminally located coiled coil structure, act in an orchestrated manner to coordinate the tethering and mitochondrial outer membrane fusion. In addition, recent reports shed new light on the physiological importance of Mitofusin function suggesting a role in mitochondrial metabolism, apoptosis as well as cellular signalling. Mutations identified in the human Mfn2 gene from patients with the peripheral neuropathy Charcot-Marie-Tooth Type 2A invoke a direct correlation between mitochondrial morphology and function.