Recherche - Observatoire océanologique de Banyuls sur mer
Laboratoire Arago

Since the discovery of nitric oxide (NO) as a signal molecule was awarded with Nobel Prize in 1998, the importance of this molecule has been recognized in multiple areas of biology, pharmacology and medicine. NO is a ubiquitous molecule present in all living organisms, whose synthesis is catalyzed by NO synthase enzymes (NOS). Yet, how and when nitric oxide synthase (NOS), the enzyme responsible for NO production, evolved across metazoan phylogeny is not fully understood. During evolution, a single Nos gene, observed in most invertebrate species, has given rise to three mammalian orthologues that differ in distribution, regulation and activity. Diversification of NO metabolism by enzyme specialization may have occurred through selective gains and losses of protein motifs. Protein domains and gene organization - i.e. intron positions and phases - of animal NOS is remarkably conserved in all lineages, even in fast-evolving species. With the aim to understand the evolutionary history of this important family of enzymes, we performed a detailed study of Nos genealogy by gene homology, protein domain conservation, phylogenetic reconstruction and synteny conservation. Moreover, we propose an evolutionary scenario of NOS family as the result of both whole genome duplications and lineage-specific gene duplications, even though with high degree of structural conservation which appears to have been preserved since the origin of metazoans.

Séminaire présenté par Salvatore D'ANIELLO, Stazione Zoologica Anton Dohrn, Italy.