Ferredoxin--NADP(+) reductase (human mitochondrial) (FDXR)

**Ferredoxin--NADP(+) reductase (FDXR)** is a mitochondrial flavoprotein enzyme that catalyzes electron transfer from NADPH to mitochondrial ferredoxins, primarily FDX1 and FDX2[1][3][5]. This provides the reducing power necessary for mitochondrial cytochrome P450 enzymes involved in steroid hormone biosynthesis, heme production, and iron–sulfur (Fe-S) cluster assembly[1][3][5]. FDXR is also a transcriptional target of the p53 family and participates in cellular stress responses and apoptosis regulation[5]. Loss-of-function mutations in FDXR cause rare mitochondrial disorders, including sensorineural hearing loss and optic atrophy, due to disturbed Fe-S cluster biogenesis and iron metabolism[1][5].

Other names

Adrenodoxin reductase, NADPH:adrenodoxin oxidoreductase, mitochondrialADXRARADRANOAFerredoxin reductaseFerredoxin--NADP(+) reductaseadrenodoxin-NADP(+) reductaseMMDS9Bepididymis secretory sperm binding protein[4][5]

Drugs modulating this enzyme would be expected to alter mitochondrial steroidogenesis, iron–sulfur cluster assembly, or cause mitochondrial dysfunction via disrupted electron transport; Mechanisms would include inhibition or activation of electron transfer from NADPH to ferredoxin isoforms, thereby impacting downstream pathways[1][3][5]