– Nicotinate-Nucleotide Pyrophosphorylase (QPRT) belongs to the nadC/modD family. QPRT plays an improtant role in catabolism of quinolinate which acts as a potent endogenous exitotoxin to neurons. In addition, QPRT serves as an an intermediate in the Tryptophan-Nicotinamide Adenine Dinucleotide pathway. QPRT participates in some pathways including Cofactor biosynthesis, NAD(+) biosynthesis and the Nicotinate D-Ribonucleotide from Quinolinate. In addition, QPRT is involved in the catabolism of Quinolinic Acid (QA). The activity toward QA is slightly repressed by phosphoribosylpyrophosphate (PRPP) in both a competitive and a non-competitive manner.