Through the activity of SIRT1, NAD plays a vital role in a variety of biological processes. Although studies in mammals have shown that nicotinic acid (NA) is a better precursor than nicotinamide (Nam) for increasing tissue NAD levels, the molecular details of NA-based NAD production are still unknown. Partly due to lack of feedback inhibition of NAPRT but not NamPRT by NAD, NA elevates NAD levels through NAPRT function and, thus, protects the cells against stress.
NAPRT Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)