A TRYPOMASTIGOTE SURFACE GLYCOPROTEIN REGULON INVOLVED IN TRYPANOSOMA CRUZI INFECTIVITY

SABALETTE, KARINA B; ROMANIUK, ALBERTINA; CASSOLA, ALEJANDRO; CAMPO VANINA A; DE GAUDENZI JAVIER G

PARANA

Congreso; 54th Annual Meeting Agentine Society for Biochemistry and Molecular Biology LIV Reunion Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2018

In the absence of transcription initiation regulation, organized subsets of Trypanosoma cruzi RNAs must bepost-transcriptionally co-regulated in response to extracellular signals. Hence regulons, functionally linkedmRNAs modulated by trans-acting factors, regain importance. The RNA-binding protein TcUBP1 binds a largevariety of transcripts including trans-sialidase/trans-sialidaselike (TcS) superfamily, a polymorphic group ofsurface glycoproteins preferentially expressed in the infective forms of the parasite. In vitro RNA-bindingassays showed that a 50-nt cis-element highly conserved in the 3?UTR of most TcS family members mediatesthe interaction with TcUBP1. When steady-state levels of these mRNAs were analyzed by qPCR in replicativenon-infective parasites ectopically expressing TcUBP1-GFP, an average of 12-fold increase was observed incomparison to non-induced and GFP induced controls. Moreover, FISH assays revealed that RNA localizationof TcS family transcripts change after induction of TcUBP1-GFP to a perinuclear localization, suggesting asubcellular distribution appropriate for RNA translation. Experiments are underway to quantitatively measurethese transcript levels in polysomal fractions of both induced and non-induced samples. Finally, cell derivedtrypomastigotes obtained from epimastigotes expressing TcUBP1-GFP showed a 2-fold increased infectivitycomparing to the non-induced controls. Altogether, our results point to a coordinately up-regulation effect ofTcS proteins as a response to induction of TcUBP1, thus reflecting a switch towards trypomastigote-formmRNA expression patterns.