Metazoan Ribosome Inactivating Protein encoding genes acquired by Horizontal Gene Transfer

LAPADULA WJ; MARCET P; MASCOTTI ML; SÁNCHEZ-PUERTA MV; JURI AYUB M

Scientific Reports

Nature Publishing Group

Año: 2017

2045-2322

Ribosomeinactivating proteins (RIPs) are RNA N-glycosidasesthat depurinate a specific adenine residue in the conserved sarcin/ricin loop of28S rRNA. These enzymes are widely distributed among plants and their presencehas also been confirmed in several bacterial species. Recently, we reported forthe first time in silico evidence of RIPencoding genes in metazoans, in two closely related species of insects: Aedes aegypti and Culex quinquefasciatus. Here, we have experimentally confirmed thepresence of these genes in mosquitoes and attempted to unveil theirevolutionary history. A detailed study was conducted, including evaluation oftaxonomic distribution, phylogenetic inferences and microsynteny analyses,indicating that mosquito RIP genes derived from a single Horizontal GeneTransfer (HGT) event, probably from a cyanobacterial donor species. Moreover, evolutionary analyses showthat, after the HGT event, these genes evolved under purifying selection, stronglysuggesting they play functional roles in these organisms.