Identification of a novel human nicotinamide mononucleotide adenylyltransferase

Biochem Biophys Res Commun. 2002 Oct 4;297(4):835-40. doi: 10.1016/s0006-291x(02)02285-4.


The enzyme nicotinamide mononucleotide adenylyltransferase is an ubiquitous enzyme catalyzing an essential step in NAD (NADP) biosynthetic pathway. In human cells, the nuclear enzyme, which we will now call NMNAT-1, has been the only known enzyme of this type for over 10 years. Here we describe the cloning and expression of a human cDNA encoding a novel 34.4kDa protein, that shares significant homology with the 31.9kDa NMNAT-1. We propose to call this enzyme NMNAT-2. Purified recombinant NMNAT-2 is endowed with NMN and nicotinic acid mononucleotide adenylyltransferase activities, but differs from NMNAT-1 with regard to chromosomal and cellular localization, tissue-specificity of expression, and molecular properties, supporting the idea that the two enzymes might play distinct physiological roles in NAD homeostasis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cell Nucleus / enzymology*
  • Cloning, Molecular
  • DNA / genetics
  • DNA Primers
  • Humans
  • Kinetics
  • Molecular Sequence Data
  • NAD / biosynthesis
  • NADP / biosynthesis
  • Nicotinamide-Nucleotide Adenylyltransferase / genetics*
  • Nicotinamide-Nucleotide Adenylyltransferase / isolation & purification
  • Nicotinamide-Nucleotide Adenylyltransferase / metabolism
  • Polymerase Chain Reaction
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae / enzymology
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • DNA Primers
  • Recombinant Proteins
  • NAD
  • NADP
  • DNA
  • NMNAT1 protein, human
  • NMNAT2 protein, human
  • NMNAT3 protein, human
  • Nicotinamide-Nucleotide Adenylyltransferase