Conformational allocation of mitofusin 2 in neuronal mitochondrial dynamics: Mechanisms and therapeutic targeting.

Abstract

Neurons must sustain functional mitochondria far from the cell body. Mitofusin 2 (MFN2), a dynamin-like large guanosine triphosphatase (GTPase), coordinates outer mitochondrial membrane remodeling with axonal transport, bioenergetic support, inter-organelle communication, and stress-responsive quality control. Studying these activities separately obscures how disruption of one protein produces diverse neuronal phenotypes. We propose a testable conformational-allocation framework in which molecular state distributions and transition kinetics bias MFN2 participation across cellular outputs. Integrating structural and functional evidence, we distinguish experimentally resolved mechanisms from working models. Variants associated with Charcot-Marie-Tooth disease type 2A (CMT2A) are compared by the molecular step or functional output affected. Fusion loss alone does not capture this mechanistic diversity. Structure-guided docking supports local compatibility at a shallow, conformationally conditional C-terminal surface, without establishing native accessibility, affinity, or therapeutic response. CMT2A provides the strongest context for intervention, combining causal genetics, direct mitofusin engagement studies, and multiscale rescue. Amyotrophic lateral sclerosis (ALS) provides secondary preclinical evidence, whereas Alzheimer's and Parkinson's diseases remain exploratory. The mitofusin pathway is chemically tractable, but paralog selectivity and state-dependent target engagement remain unresolved. A state- and variant-informed strategy may better match intervention to the affected output than indiscriminate enhancement of fusion.