Mitofusin 2026-10-20
A family of outer-mitochondrial-membrane proteins supporting GTP-dependent membrane fusion. Loss-and-rescue experiments establish a role beyond merely correlating protein abundance with network shape.[ref]
The mitochondrial fission-fusion cycle is continuous remodeling of a mitochondrial population by division and merger. In mammalian biological cells, mitofusins promote fusion of outer mitochondrial membranes, while OPA1 supports fusion of inner mitochondrial membranes. Fusion mixes matrix contents and permits functional complementation between mitochondria. Genetic disruption and rescue of mitofusins demonstrated their requirement for normal mitochondrial fusion.[ref]
Mitofusins Mfn1 and Mfn2 coordinately regulate mitochondrial fusion and are essential for embryonic development by Hsiuchen Chen and others. Abstract and Results: mitofusin loss, fragmented mitochondria and rescue
For fission, recruited Drp1 assembles at constrictions and uses GTP-dependent remodeling to help divide the organelle.[ref]
Dynamin-related protein Drp1 is required for mitochondrial division in mammalian cells by Elena Smirnova and others. Abstract and Results: Drp1 recruitment and division defects
The balance controls network shape, distribution and quality control. Division can help distribute mitochondria to daughter biological cells and segregate damaged portions for mitophagy; fusion can restore mixed contents. These are regulated competing events in a network, not an obligatory synchronized sequence that every mitochondrion completes on a fixed timetable.