Mechanistic perspective of mitochondrial fusion: Tubulation vs. fragmentation

► Mitochondrial fusion key mediators are conserved DRPs called mitofusins and OPA1/Mgm1. ► Mammalian cell-free mitochondrial fusion assays can now be used in disease models. ► Recent data allow to propose new mechanisms for both OM and IM fusion. ► Tubulation and fragmentation: opposite processes requiring similar proteolytic events.