title: Disclosing the essentiality of ribose-5-phosphate isomerase B in Trypanosomatids.
abstract: Ribose-5-phosphate isomerase (RPI) belongs to the non-oxidative branch of the pentose phosphate pathway, catalysing the inter-conversion of D-ribose-5-phosphate and D-ribulose-5-phosphate. Trypanosomatids encode a type B RPI, whereas humans have a structurally unrelated type A, making RPIB worthy of exploration as a potential drug target. Null mutant generation in Leishmania infantum was only possible when an episomal copy of RPIB gene was provided, and the latter was retained both in vitro and in vivo in the absence of drug pressure. This suggests the gene is essential for parasite survival. Importantly, the inability to remove the second allele of RPIB gene in sKO mutants complemented with an episomal copy of RPIB carrying a mutation that abolishes isomerase activity suggests the essentiality is due to its metabolic function. In vitro, sKO promastigotes exhibited no defect in growth, metacyclogenesis or macrophage infection, however, an impairment in intracellular amastigotes' replication was observed. Additionally, mice infected with sKO mutants rescued by RPIB complementation had a reduced parasite burden in the liver. Likewise, Trypanosoma brucei is resistant to complete RPIB gene removal and mice infected with sKO mutants showed prolonged survival upon infection. Taken together our results genetically validate RPIB as a potential drug target in trypanosomatids.
authors.affiliation: Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Faria
authors.affiliation: Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
authors.forename: Inês
authors.initials: I
authors.lastname: Loureiro
authors.affiliation: Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Santarém
authors.affiliation: Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Cecílio
authors.affiliation: Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.|Protein Crystallography Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal.
authors.forename: Sandra
authors.initials: S
authors.lastname: Macedo-Ribeiro
authors.affiliation: Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Tavares
authors.affiliation: Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal.|Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.|Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Portugal.
authors.forename: Anabela
authors.initials: A
authors.lastname: Cordeiro-da-Silva
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology; D004195:Disease Models, Animal; D017353:Gene Deletion; D015870:Gene Expression; D020043:Genes, Essential; D005816:Genetic Complementation Test; D006801:Humans; D018314:Leishmania infantum / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D007898:Leishmaniasis, Visceral / Q000469:parasitology; D008018:Life Cycle Stages / Q000187:drug effects / Q000235:genetics*; D008099:Liver / Q000469:parasitology; D051379:Mice; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D011760:Pyrrolidinones / Q000494:pharmacology; D012267:Ribosemonophosphates / Q000378:metabolism; D012274:Ribulosephosphates / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014346:Trypanosoma brucei brucei / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D014353:Trypanosomiasis, African / Q000469:parasitology
chemical_list: D000981:Antiprotozoal Agents; D015800:Protozoan Proteins; D011760:Pyrrolidinones; D012267:Ribosemonophosphates; D012274:Ribulosephosphates; C420726:blasticidin A; C031524:ribulose 5-phosphate; C031626:ribose-5-phosphate; D019747:Aldose-Ketose Isomerases; C022548:ribosephosphate isomerase