DECBI - Departamento de Ciências Biológicas
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Navegando DECBI - Departamento de Ciências Biológicas por Autor "Abreu, Fabiano Carlos Pinto de"
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Item Characterization of export receptor exportins (XPOs) in the parasite Schistosoma mansoni.(2013) Abreu, Fabiano Carlos Pinto de; Pereira, Roberta Verciano; Oliveira, Victor Fernandes de; Gomes, Matheus de Souza; Passos, Liana Konovaloff Jannotti; Borges, William de Castro; Cota, Renata Guerra de SáSeveral proteins and different species of RNA that are produced in the nucleus are exported through the nuclear pore complexes, which require a family of conserved nuclear export receptors called exportins (XPOs). It has been reported that the XPOs (XPO1, XPO5, and XPOT) are directly involved in the transport processes of noncoding RNAs from the nucleus to the cytoplasm and/or from cytoplasm to the nucleus. All three genes are present in fungi, plants, and deuterostome metazoans. However, protostome metazoan species lack one of the three genes across evolution. In this report, we have demonstrated that all three XPO proteins are present in the parasite protostome Schistosoma mansoni . As this parasite has a complex life cycle presenting several stages in different hosts and environments, implying a differential gene regulation, we proposed a genomic analysis of XPOs to validate their annotation. The results showed the conservation of exportin family members and gene duplication events in S. mansoni .We performed quantitative RT-PCR, which revealed an upregulation of SmXPO1 in 24 h schistosomula (sixfold when compared with cercariae), and similar transcription levels were observed for SmXPO5 and SmXPOT in all the analyzed stages. These three XPO proteins have been identified for the first time in the protostome clade, which suggests a higher complexity in RNA transport in the parasite S. mansoni. Taken together, these results suggest that RNA transport by exportins might control cellular processes during cercariae, schistosomula, and adult worm development.Item In silico analysis and developmental expression of ubiquitin-conjugating enzymes in Schistosoma mansoni.(2015) Costa, Marcela Pereira; Oliveira, Victor Fernandes de; Pereira, Roberta Verciano; Abreu, Fabiano Carlos Pinto de; Passos, Liana Konovaloff Jannotti; Borges, William de Castro; Cota, Renata Guerra de SáUbiquitin-conjugating enzymes (Ub-E2) perform the second step of ubiquitination and, consequently, are essential for regulating proteolysis and for modulating protein function, interactions and trafficking. Previously, our group demonstrated the crucial role of ubiquitination and the Ubproteasome pathway during the Schistosoma mansoni life cycle. In the present investigation, we used a homology-based genome-wide bioinformatics approach to identify and molecularly characterise the Ub-E2 enzymes in S. mansoni. The putative functions were further investigated through molecular phylogenetic and expression profile analyses using cercariae, adult worms, eggs and mechanically transformed schistosomula (MTS) cultured in vitro for 3.5 h or 1 or 3 days. We identified, via in silico analysis, 17 Ub-E2 enzymes with conserved structural characteristics: the beta-sheet and the helix-2 form a central core bordered by helix-1 at one side and helix-3 and helix-4 at the other. The observed quantitative differences in the steady-state transcript levels between the cercariae and adult worms may contribute to the differential protein ubiquitination observed during the parasite’s life cycle. This study is the first to identify and characterise the E2 ubiquitin conjugation family in S. mansoni and provides fundamental information regarding their molecular phylogenetics and developmental expression during intra-mammalian stages.