title: The Leishmania nicotinamidase is essential for NAD+ production and parasite proliferation.
abstract: NAD+ is a central cofactor that plays important roles in cellular metabolism and energy production in all living cells. Genomics-based reconstruction of NAD+ metabolism revealed that Leishmania protozoan parasites are NAD+ auxotrophs. Consequently, these parasites require assimilating NAD+ precursors (nicotinamide, nicotinic acid, nicotinamide riboside) from their host environment to synthesize NAD+ by a salvage pathway. Nicotinamidase is a key enzyme of this salvage pathway that catalyses conversion of nicotinamide (NAm) to nicotinic acid (Na), and that is absent in higher eukaryotes. We present here the biochemical and functional characterizations of the Leishmania infantum nicotinamidase (LiPNC1). Generation of Lipnc1 null mutants leads to a decrease in NAD+ content, associated with a metabolic shutdown-like phenotype with an extensive lag phase of growth. Both phenotypes could be rescued by an add-back construct or by addition of exogenous Na. In addition, Lipnc1 null mutants were unable to establish a sustained infection in a murine experimental model. Altogether, these results illustrate that NAD+ homeostasis is a fundamental component of Leishmania biology and virulence, and that NAm constitutes its main NAD+ source in the mammalian host. The crystal structure of LiPNC1 we solved allows now the design of rational inhibitors against this new promising therapeutic target.
authors.affiliation: MIVEGEC (UM1-CNRS 5290-IRD 224), Institut de Recherche pour le Développement (IRD), BP 64501, 34394 Montpellier Cedex 5, France.
authors.forename: E
authors.initials: E
authors.lastname: Gazanion
authors.forename: D
authors.initials: D
authors.lastname: Garcia
authors.forename: R
authors.initials: R
authors.lastname: Silvestre
authors.forename: C
authors.initials: C
authors.lastname: Gérard
authors.forename: J F
authors.initials: JF
authors.lastname: Guichou
authors.forename: G
authors.initials: G
authors.lastname: Labesse
authors.forename: M
authors.initials: M
authors.lastname: Seveno
authors.forename: A
authors.initials: A
authors.lastname: Cordeiro-Da-Silva
authors.forename: A
authors.initials: A
authors.lastname: Ouaissi
authors.forename: D
authors.initials: D
authors.lastname: Sereno
authors.forename: B
authors.initials: B
authors.lastname: Vergnes
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D006801:Humans; D018314:Leishmania infantum / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology* / Q000378:metabolism; D007898:Leishmaniasis, Visceral / Q000469:parasitology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009243:NAD / Q000096:biosynthesis*; D009535:Nicotinamidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D015800:Protozoan Proteins; D009243:NAD; D009535:Nicotinamidase