NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 7

NDUFB7 (NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 7) is an accessory subunit of mitochondrial Complex I (NADH dehydrogenase), the first enzyme complex of the electron transport chain. Though structurally part of the Complex I assembly, NDUFB7 does not directly participate in catalysis but supports the enzyme's function in transferring electrons from NADH to ubiquinone (UniProt: P17568).

NDUFB7 is expressed in mitochondria-rich tissues throughout the body. Genetic variants in NDUFB7 cause mitochondrial complex I deficiency, nuclear type 39 (MC1DN39), a severe autosomal recessive disorder presenting with intrauterine growth retardation, cardiomyopathy, lactic acidosis, encephalopathy, and fatal Complex I dysfunction (UniProt: P17568).

In Alzheimer's disease, NDUFB7 protein is significantly upregulated in post-mortem AD brain tissue relative to age-matched controls (mean log2 fold-change: +1.52, Chaparral AD proteomics). This elevation was detected across subcellular fractions from a TMT-labeled differential proteomic analysis, suggesting altered mitochondrial respiratory chain composition or compensatory upregulation of Complex I assembly in AD pathology.