Nadk Recombinant Rabbit mAb (S-4113-65)

NADK is the sole key enzyme responsible for the de novo synthesis of NADP+ in organisms, catalyzing the phosphorylation of NAD+ to generate NADP+. NADPH, as a reducing equivalent, is crucial for maintaining intracellular redox balance and anabolic metabolism. Human NADK consists of 446 amino acids with a molecular weight of approximately 49 kDa and exists as a homotetramer in its active form. Its activity is finely regulated: the N-terminus contains an inhibitory regulatory domain. Upon activation of the PI3K-Akt signaling pathway, Akt can phosphorylate three serine sites (Ser44/46/48) within this domain, relieving autoinhibition and thereby activating the enzyme to accelerate NADP+ production. In addition, NADK has multiple transcript isoforms, among which isoform 3 exhibits constitutively high activity due to the deletion of the N-terminal regulatory region. In melanoma metastasis, tumor cells upregulate isoform 3 transcriptionally through NRF2 to enhance antioxidant capacity and counteract oxidative stress during the metastatic process. In mitochondria, its homologous isoform MNADK (NADK2) independently regulates intramitochondrial NADP(H) levels, and its loss of function is closely associated with metabolic diseases such as type 2 diabetes and non-alcoholic fatty liver disease.