NADH-ubiquinone oxidoreductase chain 1 (ND1) (ND1)

NADH-ubiquinone oxidoreductase chain 1 (ND1) is a critical protein subunit of Complex I, the largest enzyme in the mitochondrial electron transport chain. Encoded by the mitochondrial MT-ND1 gene, it forms a central part of the enzyme's hydrophobic core, facilitating the transfer of electrons from NADH to ubiquinone [UniProt P03886]. This electron transfer is coupled to the translocation of protons across the inner mitochondrial membrane, creating the electrochemical gradient necessary for ATP synthesis [NCBI Gene 4535]. ND1 is a significant focus in clinical genetics, as mutations such as G3460A are primary causes of Leber Hereditary Optic Neuropathy (LHON) and other mitochondrial encephalomyopathies [Huoponen, 2001]. In pharmacology, ND1 and Complex I are targeted by biguanides like metformin, which mildly inhibit the complex to activate the AMPK pathway, thereby improving glucose metabolism in type 2 diabetes [Bridges et al., 2014]. However, potent or unintended inhibition of this target can lead to severe adverse effects, including lactic acidosis and mitochondrial-driven neurodegeneration [Misbin, 2004; Betarbet et al., 2000].

Other names

MT-ND1NADH dehydrogenase subunit 1Complex I subunit ND1NADH-ubiquinone oxidoreductase subunit 1Mitochondrially encoded NADH dehydrogenase 1

Inhibition of the NADH:ubiquinone oxidoreductase activity within the mitochondrial electron transport chain, leading to a reduction in the proton gradient and an increase in the cellular AMP/ATP ratio, which subsequently activates the AMP-activated protein kinase (AMPK) pathway [Bridges et al., 2014; Owen et al., 2000].