NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 9, mitochondrial (NDUFA9)

NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 9, mitochondrial (NDUFA9) is an accessory subunit of Complex I (NADH:ubiquinone oxidoreductase) in the mitochondrial inner membrane[1][2][3][5]. Complex I is responsible for transferring electrons from NADH to ubiquinone (coenzyme Q), driving proton translocation and ATP production during oxidative phosphorylation[1][2][3][5]. NDUFA9 is crucial for proper assembly of Complex I but is not directly involved in catalysis; instead, it contributes to the structural stability of the enzyme complex[2][5]. Mutations or altered expression of NDUFA9 have been associated with severe mitochondrial disorders such as Leigh syndrome and mitochondrial complex I deficiency, presenting mainly with neurological symptoms[1][2]. Drugs such as rotenone and metformin can interact with the overall Complex I, impacting functions in which NDUFA9 is critical[5].

Other names

NDUFA9CI-39kCI-39kDComplex I-39kDCOQ11SDR22E1NDUFS2LMC1DN26Short chain dehydrogenase/reductase family 22E, member 1NADH:ubiquinone oxidoreductase subunit A9

Inhibition of electron transfer via Complex I (inhibitors such as rotenone block the NDUFA9-containing complex, reducing ATP synthesis and increasing reactive oxygen species generation). Modulation of mitochondrial oxidative phosphorylation (e.g., by metformin).