Metaxin-2

Metaxin-2 (MTX2) is a 263-amino acid protein involved in the transport of proteins into mitochondria (UniProt: O75431). It plays a role in mitochondrial protein import, a fundamental process for organellar biogenesis and function. The protein is associated with Mandibuloacral dysplasia progeroid syndrome (MDPS), an autosomal recessive disorder characterized by growth retardation, craniofacial dysmorphic features, musculoskeletal abnormalities, and lipodystrophy, among other features (UniProt: O75431).

In the context of Alzheimer's Disease, Metaxin-2 is downregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The mean log2 fold-change is −0.456, indicating a modest but consistent reduction in protein levels (Chaparral AD proteomics). This downregulation was observed in a TMT-labeled proteomic analysis of four subcellular fractions from human post-mortem brain. The reduced expression of this mitochondrial import factor may reflect impaired mitochondrial protein homeostasis in AD neuropathology.