Multigene TcTASV family: characterization of the subfamilies TcTASV-B and TcTASV-W in different T. cruzi strains.

RIZZI, M; MASIP, Y; TEKIEL, V

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias.; 2017

SAIB-SAP-SAIC-SAi, etc

MULTIGENE TcTASV FAMILY: CHARACTERIZATION OF THE SUBFAMILIES TcTASV-B AND TcTASV-W IN DIFFERENT T.cruzi STRAINS. TcTASV is a Trypanosoma cruzi multigene family comprising about ~40 members and without orthologs in other trypanosomatids. All protein products of the TcTASV family have conserved amino¬ and carboxy¬-termini, and a central variable core that allows partitioning TcTASV into four subfamilies: A, B, C and W. TcTASV-A and TcTASV-C subfamilies are the most numerous and were already characterized by our group (García, et al 2010; Bernabó et al 2013; Floridia et al 2016) but little is known about the less numerous TcTASV-B (2-10 genes) and TcTASV-W (2-4 genes) subfamilies. Our own previous results on sequences of the TcTASV family (Garcia et al, 2010) and the detailed inspection of more recently sequenced T. cruzi genomes, showed TcTASV-B genes in DTU-VI but not in DTU-I strains. This analysis was expanded here for a higher number of strains, by PCR and sequencing. On the other hand, we identified TcTASV-W genes in DTU-I, II, V and VI, by PCR and sequencing. TcTASV-B proteins are detected in trypomastigotes and extracellular amastigotes, while TcTASV-W is only expressed in trypomastigotes. Signals for surface localization and GPI anchoring are predicted in silico for both subfamilies. We determined that TcTASV-B is attached to the parasite membrane by a GPI anchor (but is not spontaneously secreted) in trypomastigotes, while TcTASV-W is not secreted nor attached to the parasite membrane by GPI, at least in the studied conditions. TcTASV-B is observed -by fluorescence microscopy- as discrete points on the membrane of both trypomastigotes and extracellular amastigotes. Interestingly, TcTASV-B and TcTASV-W proteins have divergent carboxy-termini domains that could explain the differences in protein location. Our final goal is to define which sequences determine the differential expression, traffic, cellular localization and, eventually, the function of the different TcTASV subfamilies. Supported by PICT 2014-1151; PIP-2015-186.