NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 5, mitochondrial

NDUFB5 encodes an accessory subunit of mitochondrial Complex I (NADH dehydrogenase), a key component of the electron transport chain. Though not directly catalytic, it supports Complex I's transfer of electrons from NADH to ubiquinone in oxidative phosphorylation (UniProt: O43674).

The protein is expressed in mitochondrial membranes throughout tissues and plays a housekeeping role in cellular energy metabolism. UniProt records no primary disease associations for NDUFB5, though mitochondrial dysfunction is implicated in various neurodegenerative conditions (UniProt: O43674).

NDUFB5 shows reduced abundance in Alzheimer's disease. Proteomics analysis of post-mortem AD brain tissue versus age-matched controls detected a mean log2 fold-change of −0.66, indicating down-regulation in the examined subcellular fraction (Chaparral AD proteomics). This decrease is consistent with bioenergetic stress and impaired mitochondrial function noted in AD pathology, though the functional consequence of reduced Complex I accessory subunit levels remains to be clarified.