title: Trichomonas vaginalis Repair of Iron Centres Proteins: The Different Role of Two Paralogs.
abstract: Trichomonas vaginalis, the causative parasite of one of the most prevalent sexually transmitted diseases is, so far, the only protozoan encoding two putative Repair of Iron Centres (RIC) proteins. Homologs of these proteins have been shown to protect bacteria from the chemical stress imposed by mammalian immunity. In this work, the biochemical and functional characterisation of the T. vaginalis RICs revealed that the two proteins have different properties. Expression of ric1 is induced by nitrosative stress but not by hydrogen peroxide, while ric2 transcription remained unaltered under similar conditions. T. vaginalis RIC1 contains a di-iron centre, but RIC2 apparently does not. Only RIC1 resembles bacterial RICs on spectroscopic profiling and repairing ability of oxidatively-damaged iron-sulfur clusters. Unexpectedly, RIC2 was found to bind DNA plasmid and T. vaginalis genomic DNA, a function proposed to be related with its leucine zipper domain. The two proteins also differ in their cellular localization: RIC1 is expressed in the cytoplasm only, and RIC2 occurs both in the nucleus and cytoplasm. Therefore, we concluded that the two RIC paralogs have different roles in T. vaginalis, with RIC2 showing an unprecedented DNA binding ability when compared with all other until now studied RICs.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República (EAN), 2780-157 Oeiras, Portugal.
authors.forename: Lígia S
authors.initials: LS
authors.lastname: Nobre
authors.affiliation: University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Centre d'Infection et d'Immunité de Lille, 1 rue du Professeur Calmette, BP 245, 59019 Lille Cedex, France.
authors.forename: Dionigia
authors.initials: D
authors.lastname: Meloni
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República (EAN), 2780-157 Oeiras, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Teixeira
authors.affiliation: University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Centre d'Infection et d'Immunité de Lille, 1 rue du Professeur Calmette, BP 245, 59019 Lille Cedex, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Viscogliosi
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República (EAN), 2780-157 Oeiras, Portugal. Electronic address: lst@itqb.unl.pt.
authors.forename: Lígia M
authors.initials: LM
authors.lastname: Saraiva
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D004247:DNA / Q000378:metabolism; D020869:Gene Expression Profiling; D007501:Iron / Q000378:metabolism; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013057:Spectrum Analysis; D014158:Transcription, Genetic; D014246:Trichomonas vaginalis / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; D004247:DNA; D007501:Iron
keywords: RIC; Trichomonas vaginalis; YtfE; iron-sulfur repair; leucine zipper; nitrosative stress.