Nicotinamide nucleotide transhydrogenase, mitochondrial (NNT) (NNT)

Nicotinamide nucleotide transhydrogenase (NNT) is an integral protein of the inner mitochondrial membrane that plays a critical role in maintaining cellular redox balance (UniProt P26358). It functions by coupling the translocation of a proton across the membrane with the reversible transfer of a hydride ion between NADH and NADP+, effectively using the mitochondrial proton motive force to generate high concentrations of NADPH (PubMed: 22634753). This NADPH is a vital cofactor for antioxidant enzymes like glutathione reductase and thioredoxin reductase, which protect the mitochondria from oxidative damage caused by reactive oxygen species (ROS). Clinically, mutations in the NNT gene are linked to Familial Glucocorticoid Deficiency (FGD) type 4, where the loss of NNT leads to increased ROS and apoptosis in adrenal cells (PubMed: 22634753). Additionally, NNT has been implicated in the metabolic adaptation of cancer cells and the progression of heart failure, making it a subject of interest for therapeutic intervention (PubMed: 25673692). While no FDA-approved drugs currently target NNT, it remains a significant focus for research into metabolic and mitochondrial-related disorders. The protein's ability to modulate the NADPH pool makes it a key player in both normal physiology and the pathophysiology of oxidative stress-related diseases. Understanding NNT's structural and functional properties is essential for developing strategies to mitigate mitochondrial dysfunction.

Other names

Mitochondrial nicotinamide nucleotide transhydrogenasePyridine nucleotide transhydrogenaseNAD(P) transhydrogenase, mitochondrial

Catalyzes the reversible transfer of a hydride ion between NADH and NADP+, coupled to the translocation of a proton across the inner mitochondrial membrane.