title: A common mechanism of stage-regulated gene expression in Leishmania mediated by a conserved 3'-untranslated region element.
abstract: Developmental regulation of mRNA levels in trypanosomatid protozoa is determined post-transcriptionally and often involves sequences located in the 3'-untranslated regions (3'-UTR) of the mRNAs. We have previously identified a developmentally regulated gene family in Leishmania encoding the amastin surface proteins and showed that stage-specific accumulation of the amastin mRNA is mediated by sequences within the 3'-UTR. Here we identified a 450-nt region within the amastin 3'-UTR that can confer amastigote-specific gene expression by a novel mechanism that increases mRNA translation without an increase in mRNA stability. Remarkably, this 450-nt 3'-UTR element is highly conserved among a large number of Leishmania mRNAs in several Leishmania species. Here we show that several of these mRNAs are differentially expressed in the intracellular amastigote stage of the parasite and that the 450-nt conserved element in their 3'-UTRs is responsible for stage-specific gene regulation. We propose that the 450-nt conserved element, which is unlike any other regulatory element identified thus far, is part of a common mechanism of stage-regulated gene expression in Leishmania that regulates mRNA translation in response to intracellular stresses.
authors.affiliation: Centre de Recherche en Infectiologie du Centre de Recherche du Centre Hospitalier de Université Laval, Québec G1V 4G2, Canada.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Boucher
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Carole
authors.initials: C
authors.lastname: Dumas
authors.forename: Marthe
authors.initials: M
authors.lastname: Dube
authors.forename: Denis
authors.initials: D
authors.lastname: Sereno
authors.forename: Marie
authors.initials: M
authors.lastname: Breton
authors.forename: Barbara
authors.initials: B
authors.lastname: Papadopoulou
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D004247:DNA / Q000378:metabolism; D017353:Gene Deletion; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D007700:Kinetics; D007891:Leishmania / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
chemical_list: D020413:3' Untranslated Regions; D012333:RNA, Messenger; D004247:DNA