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Insights into the Regulation of mRNA Processing of Polycistronic Transcripts Mediated by DRBD 4/ PTB 2, a Trypanosome Homolog of the Polypyrimidine Tract‐Binding Protein
Author(s) -
De Gaudenzi Javier G.,
Jäger Adriana V.,
Izcovich Ronan,
Campo Vanina A.
Publication year - 2016
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/jeu.12288
Subject(s) - biology , rna splicing , rna binding protein , polyadenylation , polypyrimidine tract , polypyrimidine tract binding protein , messenger rna , intron , trans splicing , rna , poly(a) binding protein , untranslated region , three prime untranslated region , gene expression , microbiology and biotechnology , heterogeneous ribonucleoprotein particle , gene , translation (biology) , genetics
Trypanosomes regulate gene expression mostly by posttranscriptional mechanisms, including control of mRNA turnover and translation efficiency. This regulation is carried out via certain elements located at the 3′‐untranslated regions of mRNA s, which are recognized by RNA ‐binding proteins. In trypanosomes, trans‐splicing is of central importance to control mRNA maturation. We have previously shown that Tc DRBD 4/ PTB 2, a trypanosome homolog of the human polypyrimidine tract‐binding protein splicing regulator, interacts with the intergenic region of one specific dicistronic transcript, referred to as Tc UBP (and encoding for Tc UBP 1 and Tc UBP 2, two closely kinetoplastid‐specific proteins). In this work, a survey of Tc UBP RNA processing revealed certain Tc DRBD 4/ PTB 2‐regulatory elements within its intercistronic region, which are likely to influence the trans‐splicing rate of monocistronic‐derived transcripts. Furthermore, Tc DRBD 4/ PTB 2 overexpression in epimastigote cells notably decreased both UBP 1 and UBP 2 protein expression. This type of posttranscriptional gene regulatory mechanism could be extended to other transcripts as well, as we identified several other RNA precursor molecules that specifically bind to Tc DRBD 4/ PTB 2. Altogether, these findings support a model in which Tc DRBD 4/ PTB 2‐containing ribonucleoprotein complexes can prevent trans‐splicing. This could represent another stage of gene expression regulation mediated by the masking of trans‐splicing/polyadenylation signals.