Identification of a newSchistosoma mansoniSMYB1 partner: putative roles in RNA metabolism

Abstract

SMYB1 is a Schistosoma mansoni protein highly similar to members of the Y-box binding protein family. Similar to other homologues, SMYB1 is able to bind double- and single-stranded DNA, as well as RNA molecules. The characterization of proteins involved in the regulation of gene expression in S. mansoni is of great importance for the understanding of molecular events that control morphological and physiological changes in this parasite. Here we demonstrate that SMYB1 is located in the cytoplasm of cells from different life-cycle stages of S. mansoni, suggesting that this protein is probably acting in mRNA metabolism in the cytoplasm and corroborating previous findings from our group that showed its ability to bind RNA. Protein-protein interactions are important events in all biological processes, since most proteins execute their functions through large supramolecular structures. Yeast two-hybrid screenings using SMYB1 as bait identified a partner in S. mansoni similar to the SmD3 protein of Drosophila melanogaster (SmRNP), which is important in the assembly of small nuclear ribonucleoprotein complexes. Also, pull-down assays were conducted using immobilized GST-SMYB1 proteins and confirmed the SMYB1-SmRNP interaction. The interaction of SMYB1 with a protein involved in mRNA processing suggests that it may act in processes such as turnover, transport and stabilization of RNA molecules.

rSJYB1 inhibits collagen type I protein expression in hepatic stellate cells via down‐regulating activity of collagen α1 (I) promoter

“…A schistosome YB1 protein SMYB1 was earlier identified by Franco et al who isolated from an Schistosoma mansoni ( S mansoni ) adult worm library using the expressed sequence tag strategy . SMYB1 has been verified the ability to bind DNA and RNA like other Y‐box proteins and may act in the process of RNA metabolism . Furthermore, mice immunized with the recombinant SMYB1 (rSMYB1) were detected the high levels of specific anti‐rSMYB1 antibodies in their sera .…”

Evaluation of the Schistosoma mansoni Y-box-binding protein (SMYB1) potential as a vaccine candidate against schistosomiasis

“…We also showed the presence of SMYB1 near the tegument in adult worms proposing an action on the translational regulation of tegument proteins (Rocha et al, 2013). Intrinsically disordered proteins have recently been characterized as the prevalent type of RNA and protein chaperones (Tompa and Csermely, 2004).…”

“…Although the exact function of the SMYB1 protein in this parasite has not been determined, results presented by Valadão et al (2002) and Rocha et al (2013) suggested that, while SMYB1 may not act directly as a transcription factor, this protein may be necessary for the regulation of S. mansoni gene expression. These studies suggest that SMYB1 can function in the turnover, transport, and stabilization of RNA molecules, acting as RNA chaperones (Valadão et al, 2002; de Oliveira et al, 2004; Rocha et al, 2013). Although intracellular proteins are not usually the first choice of immunogens for vaccination, several extracellular S. mansoni proteins have been previously tested with moderate success.…”

“…Due to the similarity between SMYB1 and Y-box proteins from other organisms, and the importance of these proteins in the control of gene expression, our group conducted several studies to characterize the SMYB1 protein. We reported that (i) the protein binds to double- or single-stranded DNA oligonucleotides, with a preference for sequences containing the CCAATT motif, (ii) the protein is expressed in all stages of the parasite life cycle, (iii) SMYB1 interacts with proteins involved in mRNA processing, and (iv) SMYB1 has a cytoplasmic localization (Franco et al, 1997; Valadão et al, 2002; de Oliveira et al, 2004; Rocha et al, 2013). Although the exact function of the SMYB1 protein in this parasite has not been determined, results presented by Valadão et al (2002) and Rocha et al (2013) suggested that, while SMYB1 may not act directly as a transcription factor, this protein may be necessary for the regulation of S. mansoni gene expression.…”

“…We reported that (i) the protein binds to double- or single-stranded DNA oligonucleotides, with a preference for sequences containing the CCAATT motif, (ii) the protein is expressed in all stages of the parasite life cycle, (iii) SMYB1 interacts with proteins involved in mRNA processing, and (iv) SMYB1 has a cytoplasmic localization (Franco et al, 1997; Valadão et al, 2002; de Oliveira et al, 2004; Rocha et al, 2013). Although the exact function of the SMYB1 protein in this parasite has not been determined, results presented by Valadão et al (2002) and Rocha et al (2013) suggested that, while SMYB1 may not act directly as a transcription factor, this protein may be necessary for the regulation of S. mansoni gene expression. These studies suggest that SMYB1 can function in the turnover, transport, and stabilization of RNA molecules, acting as RNA chaperones (Valadão et al, 2002; de Oliveira et al, 2004; Rocha et al, 2013).…”