Enables identical protein binding activity. Involved in several processes, including cellular response to decreased oxygen levels; regulation of mitochondrion organization; and response to glucocorticoid. Located in mitochondrial inner membrane and mitochondrial outer membrane. Biomarker of several diseases, including adult respiratory distress syndrome; dental fluorosis; kidney failure (multiple); pulmonary hypertension; and status epilepticus. Orthologous to human MFN1 (mitofusin 1). [provided by Alliance of Genome Resources, Apr 2022]