|Detection of Human Mitofusin 1 by Western Blot. Western blot shows mitochondrial extracts of HeLa human cervical epithelial carcinoma cell line (20 µg/lane) and Raji human Burkitt's lymphoma cell line (2.5 µg/lane). PVDF membrane was probed with 1 µg/mL of Sheep Anti-Human Mitofusin 1 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF7880) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for Mitofusin 1 at approximately 85 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.|
MFN-1 (Mitofusin 1; also Fzo/"fuzzy onions" homolog and Transmembrane GTPase MFN-1) is an 80-90 kDa mitochondrial member of the dynamin family of molecules. It is ubiquitously expressed, and found in the outer mitochondrial membrane. MFN-1 apparently mediates the fusion of individual mitochondria with each other through trans-interactions with adjacent mitochondrial MFN-1 and/or MFN-2. Pertubations with this process result in both a general overall fragmentation of mitochondria, and in cell-specific effects such as a reduction in oxidative phosphorylation or an imbalance in the generation of ROS. MFN-1 has two key domains. One is a coiled-coil region that mediates MFN-1:MFN-1/2 binding, and a second is a GTPase domain whose cleavage of GTP is necessary for membrane fusion. Human MFN-1 is a 741 amino acid (aa) two transmembrane protein that contains a cytoplasmic N- and C-terminus. The cytoplasmic N-terminus (aa 1-584) contains the GTPase domain (aa 82-286) while the cytoplasmic C-terminus possesses a critical coiled-coil motif (aa 679-734). MFN-1 is known to form oligomers, either with itself or MFN-2, and to undergo ubiquitination by MARCH5. Multiple splice variants are reported to occur. One is cytosolic and contains a four aa substitution for aa 367-741. Three others show a deletion of aa 444-554, aa 326-408 and an alternative start site at Met387, respectively. Over aa 1-77, human and mouse MFN-1 share 88% aa sequence identity. Full-length human MFN-1 and MFN-2 share 61% aa sequence identity.