NAD^+ biosynthetic pathway

NAD^+ biosynthesis comprises multiple metabolic pathways in cells that generate nicotinamide adenine dinucleotide (NAD^+), a pivotal coenzyme for redox reactions and signaling. NAD^+ can be produced via the de novo pathway (from tryptophan, via intermediates like quinolinic acid and enzymes such as QPRT, NMNAT, NADSYN), or via salvage pathways (from nicotinamide, nicotinic acid, nicotinamide riboside, catalyzed by NAMPT, NAPRT, NMRK). These biosynthetic processes are essential for cellular metabolism, energy production, DNA repair, and regulation of cell survival and death. Disruption or targeting of NAD^+ biosynthesis enzymes (not the pathway as a whole) is under clinical investigation for cancer and other age-related diseases, since cancer cells depend heavily on NAD^+ supply for survival. "NAD^+ biosynthesis" does not correspond to a single, well-defined molecular target suitable for drug targeting but to an ensemble of key enzymes—such as NAMPT, NMNAT, QPRT, NADSYN—which individually may serve as therapeutic targets. For structured target definitions, one should specify the enzyme (e.g., "Nicotinamide phosphoribosyltransferase (NAMPT)") rather than the pathway itself.

Other names

NAD synthesisNAD biosynthetic pathwayNAD^+ productionNAD^+ metabolic pathway

Inhibition of NAD^+ biosynthetic enzymes (e.g., NAMPT inhibition reduces NAD^+ production; PARP inhibition modulates NAD^+ consumption in DNA repair and apoptosis)