MID51 Recombinant Rabbit mAb (S-3570-28)

MID51 (Mitochondrial Dynamics Protein of 51 kDa), also known as MIEF1 (Mitochondrial Elongation Factor 1) or SMCR7L, is a unique outer mitochondrial membrane (OMM) protein that plays a pivotal and somewhat paradoxical role in regulating mitochondrial dynamics by primarily promoting mitochondrial fusion and inhibiting fission. Unlike the canonical fission mediator Drp1 (Dynamin-related protein 1), which MID51 physically recruits to the mitochondrial surface, MID51 acts as a dominant-negative regulator that sequesters Drp1 into inactive spiral structures, thereby preventing Drp1 from executing membrane constriction and division. Structurally, MID51 contains an N-terminal transmembrane domain anchoring it to the OMM and a C-terminal nucleotidyltransferase-like domain that, despite retaining the structural fold, has lost catalytic activity and instead functions as a protein-protein interaction hub essential for Drp1 binding. Beyond its role in maintaining elongated mitochondrial networks crucial for cellular energy homeostasis and stress resistance, MID51 is implicated in various physiological and pathological processes, including cardiomyocyte function, neuronal development, and viral immune evasion (e.g., by hepatitis C virus), where its dysregulation can lead to fragmented mitochondria, impaired bioenergetics, and increased susceptibility to apoptosis.