Nicotinamide riboside kinase 1 (NRK1)

Nicotinamide riboside kinase 1 (NRK1) is a key enzyme in the salvage pathway of NAD+ biosynthesis, catalyzing the phosphorylation of nicotinamide riboside (NR) and nicotinic acid riboside (NaR) to form nicotinamide mononucleotide (NMN) and nicotinic acid mononucleotide, respectively[4][5][1]. This reaction is essential for utilizing NR and NMN supplements to raise cellular NAD+ levels, which are important for metabolic health, neuroprotection, and potentially longevity[2]. NRK1 is necessary and rate-limiting for the conversion of exogenous NR and NMN into intracellular NAD+, and its expression is critical for the efficacy of these precursors[2]. Deficiency or loss of function disrupts the utilization of NR and NMN, but not of other NAD+ precursors such as nicotinamide or nicotinic acid[2]. The enzyme is part of the uridine kinase family and shares structural similarity with Rossmann fold metabolite kinases[1][7]. Its biological importance is underscored in models of nerve damage, metabolic disease, and age-related decline[2].

Other names

NRK1NMRK1Nicotinamide riboside kinaseNicotinamide riboside kinase type 1

Catalyzes phosphorylation of NR and NaR to NMN and nicotinic acid mononucleotide, facilitating NAD+ synthesis enhancement