NADH:ubiquinone oxidoreductase subunit A13 (NDUFA13)

NADH:ubiquinone oxidoreductase subunit A13 (NDUFA13) is an accessory subunit of Complex I (NADH dehydrogenase), the largest multicomponent enzyme of the mitochondrial electron transport chain[1][2][3]. Localized to the inner mitochondrial membrane, it participates in the transfer of electrons from NADH to ubiquinone, a process coupled to proton translocation supporting ATP synthesis. Although not directly catalytically active, NDUFA13 is essential for the assembly, structural stability, and full activity of Complex I; its depletion leads to impaired electron flow and energy failure. Beyond this metabolic role, NDUFA13 (GRIM-19) also acts as a cell death regulatory protein, mediating apoptotic responses to interferon and retinoic acid and serving as a tumor suppressor through negative regulation of STAT3—an oncogenic transcription factor[2][3]. Mutations cause early-onset mitochondrial disease with neurodevelopmental defects, optic atrophy, and features overlapping Leigh syndrome[2]. There are no drugs targeting NDUFA13 specifically; however, complex I inhibitors affect the functional outcome of the pathway. NDUFA13 loss-of-function is embryonic lethal in animal models, underscoring its essential biological functions[2].

Other names

NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 13Cell death regulatory protein GRIM-19GRIM19CI-B16.6Complex I-B16.6B16.6CDA016CGI-39MC1DN28

Complex I inhibitors block electron transfer from NADH to ubiquinone, reducing ATP production and affecting cell survival especially in rapidly proliferating or energy-demanding cells. Modulation of apoptosis or STAT3 activity via protein–protein interactions, not via classical small molecule inhibition[2][3].