Armadillo repeat-containing X-linked protein 3

ARMCX3 (armadillo repeat-containing X-linked protein 3) is a 379-amino acid protein that regulates mitochondrial aggregation, transport, and distribution in neuronal axons (UniProt: Q9UH62). It functions as a bridge linking mitochondria to the TRAK2-kinesin motor complex through interactions with Miro and TRAK2, with its activity modulated by protein degradation pathways involving PCK and WNT1 signaling. The protein also enhances SOX10-mediated transcriptional activation of neuronal acetylcholine receptor genes.

ARMCX3 is localized to mitochondrial and axonal compartments in neurons, reflecting its specialized role in mitochondrial dynamics—a process critical for neuronal energy metabolism and axonal function. No disease associations are documented in UniProt curated records.

In Alzheimer's disease, ARMCX3 shows ambiguous regulation across subcellular fractions in post-mortem brain tissue compared to age-matched controls (Chaparral AD proteomics). Analysis of TMT-labeled proteomics across four subcellular fractions (P2, P3, S2, S3) yielded a mean log2 fold-change of −0.20, indicating negligible overall change. The directional ambiguity suggests differential abundance depending on subcellular localization or AD-affected tissue microregions.