title: A 43-nucleotide U-rich element in 3'-untranslated region of large number of Trypanosoma cruzi transcripts is important for mRNA abundance in intracellular amastigotes.
abstract: Trypanosoma cruzi, the agent of Chagas disease, does not seem to control gene expression through regulation of transcription initiation and makes use of post-transcriptional mechanisms. We report here a 43-nt U-rich RNA element located in the 3'-untranslated region (3'-UTR) of a large number of T. cruzi mRNAs that is important for mRNA abundance in the intracellular amastigote stage of the parasite. Whole genome scan analysis, differential display RT-PCR, Northern blot, and RT-PCR analyses were used to determine the transcript levels of more than 900 U-rich-containing mRNAs of large gene families as well as single and low copy number genes. Our results indicate that the 43-nt U-rich mRNA element is preferentially present in amastigotes. The cis-element of a protein kinase 3'-UTR but not its mutated version promoted the expression of the green fluorescent protein reporter gene in amastigotes. The regulatory cis-element, but not its mutated version, was also shown to interact with the trypanosome-specific RNA-binding protein (RBP) TcUBP1 but not with other related RBPs. Co-immunoprecipitation experiments of TcUBP1-containing ribonucleoprotein complexes formed in vivo validated the interaction with representative endogenous RNAs having the element. These results suggest that this 43-nt U-rich element together with other yet unidentified sequences might be involved in the modulation of abundance and/or translation of subsets of transcripts in the amastigote stage.
authors.affiliation: Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: Zhu-Hong
authors.initials: ZH
authors.lastname: Li
authors.forename: Javier G
authors.initials: JG
authors.lastname: De Gaudenzi
authors.forename: Vanina E
authors.initials: VE
authors.lastname: Alvarez
authors.forename: Nicolás
authors.initials: N
authors.lastname: Mendiondo
authors.forename: Haiming
authors.initials: H
authors.lastname: Wang
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Kissinger
authors.forename: Alberto C
authors.initials: AC
authors.lastname: Frasch
authors.forename: Roberto
authors.initials: R
authors.lastname: Docampo
mesh_terms: D020413:3' Untranslated Regions / Q000502:physiology*; D018503:Genome, Protozoan / Q000502:physiology*; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000502:physiology*
chemical_list: D020413:3' Untranslated Regions; D016053:RNA, Protozoan; D016601:RNA-Binding Proteins; C500732:UBP1 protein, Trypanosoma cruzi