Characterization of the complex family of middle repetitive VIPER elements of T. cruzi.

ROBLEDO, GERMÁN; SYRIANI, EMILIO; BEN DOV, CLAUDIA; VAZQUEZ, MARTIN; LEVIN, MARIANO J.

Congreso; XXXVII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB).; 2001

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB).

The Vestigial IntersPersEd Retroelement, VIPER; is a non-LTR retrotransposon of Trypanosoma cruzi. This is 2,359 bp long fragment that has been isolated the landaZapII genomic library. VIPER 5- and 3-end consist of the first 182 bp and last 226 bp of SIRE (Short Interspersed Repetitive Element) respectively. Both SIRE moieties are connected by a 1,924 bp long fragment that carries a unique ORF encoding 230 amino acids long protein. The last 15 C-terminal amino acids derive from codons specified by SIRE region II. The amino acid sequence of this protein share significant homology whit the RT-RNAse H genes of different retroelement. Two independent messengers, called SEXII and N5 were obtained from T. cruzi cDNA library using VIPER element as a probe. The nucleotide sequence of both messengers confirmed the amino acid sequence deduced from the VIPER ORF. However, the complete sequence of the functional RT-RNAsaH of VIPER has not yet been obtained. The spliced leader (SL) of 39 pb preceding all the messengers of tripanosomatides and sequences of the 3-end of VIPER have been used to drive primers to perform RT-PCR in an attempt to clone it. The products of different RT-PCRs demonstrate the complex pattern of expression of VIPER, and predict the existence of several VIPER related functional mRNAs in T. cruzi epimastigotes.