title: Reconstructing eukaryotic NAD metabolism.
abstract: In addition to its well-known role as a coenzyme in oxidation-reduction reactions, the distinct role of NAD as a precursor for molecules involved in cell regulation has been clearly established. The involvement of NAD in these regulatory processes is based on its ability to function as a donor of ADP-ribose; NAD synthesis is therefore required to avoid depletion of the intracellular pool. The rising interest in the biosynthetic routes leading to NAD formation and the highly conserved nature of the enzymes involved prompted us to reconstruct the NAD biosynthetic routes operating in distinct eukaryotic organisms. The evidence obtained from biochemical and computational analysis provides a good example of how complex metabolic pathways may evolve. In particular, it is proposed that the development of several NAD biosynthetic routes during evolution has led to partial functional redundancy, allowing a given pathway to freely acquire novel functions unrelated to NAD biosynthesis.
authors.affiliation: Laboratoire de Physiologie Animale, Université Libre de Bruxelles, Belgium.
authors.forename: Anthony
authors.initials: A
authors.lastname: Rongvaux
authors.forename: Fabienne
authors.initials: F
authors.lastname: Andris
authors.forename: Frédéric
authors.initials: F
authors.lastname: Van Gool
authors.forename: Oberdan
authors.initials: O
authors.lastname: Leo
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000818:Animals; D005057:Eukaryotic Cells; D006801:Humans; D009243:NAD / Q000096:biosynthesis / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism
chemical_list: D009243:NAD; D000246:Adenosine Diphosphate Ribose; D014364:Tryptophan