Essential transmembrane GTPase, which mediates mitochondrial fusion. Fusion of mitochondria occurs in many cell types and constitutes an important step in mitochondria morphology, which is balanced between fusion and fission. MFN1 acts independently of the cytoskeleton. Overexpression induces the formation of mitochondrial networks.
Forms homomultimers and heteromultimers with MFN2. Multimerization, which is probably mediated by the coiled coil region, may play an essential role in mitochondrion fusion (By similarity). Participates in a high molecular weight multiprotein complex.