Identification Of New Proteins Involved In Small Rna Pathway In Platyhelminth Parasites

MALDONADO, L.; FOX, A.; MACCHIAROLI, N.; FONTENLA, S.; CUCHER, M.; TORT, J.; ROSENZVIT, M.; KAMENETZKY, L.

Congreso; 4º Congreso Argentino de Bioinformática y Biología Computacional.; 2013

P { margin-bottom: 0.21cm; direction: ltr; color: rgb(0, 0, 0); }P.western { font-family: "Times New Roman",serif; font-size: 12pt; }P.cjk { font-family: "DejaVu Sans","Arial Unicode MS"; font-size: 12pt; }P.ctl { font-family: "Lohit Hindi","Arial Unicode MS"; font-size: 12pt; } In bilaterial animals, such as humans, flies and worms, hundreds of small RNAs, some conserved throughout bilaterial evolution, collectively regulate gene expression. In addition to microRNAs (miRNAs), other bilaterial small RNAs known as Piwi-interactig RNAs (piRNAs) seem to protect the genome regulating transposon expression. Interestingly, platyhelminth parasites seem to lack bona fide Piwi proteins. With the aim to identify the small RNA pathway proteins in platelminth parasites we searched for Argonaute, Piwi, Dicer, Pasha and Drosha proteins in the recently generated Echinococcus genomes and transcriptomes. We found Argonaute, Dicer, Pasha and Drosha orthologs expressed in both E. granulosus and E. multilocularis species. Interestingly, phylogenetic analysis showed new Argonaute/Piwi- like proteins divergent from classical Argonaute or Piwi proteins described so far. We confirmed the presence of these new proteins by RT-qPCR from protoscolex, the human infective stage.In order to determine conserved domains, and the possible interaction between miRNA and protein Piwi domain, we have also modeled the Argonaute/Piwi-like proteins by comparative modeling with Swissmodel server and Pymol software. Conclusion. Computational analysis including phylogenetic and protein structure studies suggested the existence of new Argonaute/Piwi-like proteins in Echinococcus spp. containing conserved structural domain with human Argonaute 2. These results suggest those proteins could bind small RNAs and could be functional. References. Elad Elkayam, Claus-D. Kuhn, Ante Tocilj, Astrid D. Haase, Emily M. Greene, Gregory J. Hannon, and Leemor Joshua-Tor: The Structure of Human Argonaute-2 in Complex with miR-20a. Cell. 2012 July 6; 150(1): 100?110. Nicole T. Schirle and Ian J. MacRae: The Crystal Structure of Human Argonaute2. Science. 2012 May 25; 336(6084): 1037?1040.