Insights & Perspectives Mitochondria: Starving to reach quorum? Insight into the physiological purpose of mitochondrial fusion

Why might mitochondria fuse?Mammalian mitochondria continuouslyundergo fusion in vivo, a processaccomplished by an elaborate machin-ery of energy-dependant GTPaseproteins. These proteins are extensivelypost-translationally regulated and thefusion process involves actively mergingboth inner and outer mitochondrialmembranes to shape extensive net-works. Executing this energeticallycostly process must hold an essentialphysiological function. Recent reportsdemonstrate that cells with fusion-incompetent mitochondria fail to thrive,especially under challenging con-ditions. Bacteria, the ancestors of mito-chondria, also undergo life-promotingnetworking under challenging con-ditions. Here, we consider evolutionar-ily conserved behavioral similaritiesamong mitochondria and their bacterialcounterparts, as well as recent excitingdiscoveries in mitochondrial dynamics.We propose that the hunger of mito-chondria to undergo fusion results ininterconnected mitochondrial networksthat establish a life-sustaining unityand coherence within cells, allowingthem to thrive in times of energetichardship.