Murray Angus, Fu Christine, Habibi Golareh, McMaster W Robert
Immunity and Infection Research Centre, Vancouver Coastal Health Research Institute, and the Department of Medical Genetics, University of British Columbia, Jack Bell Research Centre, 451-2660 Oak Street, Vancouver, BC, Canada V6H 3Z6.
Mol Biochem Parasitol. 2007 Jun;153(2):125-32. doi: 10.1016/j.molbiopara.2007.02.010. Epub 2007 Mar 1.
Protozoan parasites of the genus Leishmania have a digenetic lifecycle, alternating between the promastigote and amastigote stages. The extracellular promastigote resides within a sandfly vector, while the obligate intracellular amastigote stage replicates in the phagolysosome of mammalian host macrophages. Adaptation to and survival within these vastly differently environments is accompanied by differential expression of a subset of genes, which is regulated post-transcriptionally via cis-acting elements in 3' untranslated region (3'UTR) or intercistronic sequences. It was reported previously that Leishmania mexicana A600-4 mRNA transcript abundance was eight-fold higher in the amastigotes. In this study, chimeric luciferase:A600-4 3'UTR reporter constructs were integrated at the A600 chromosome locus to identify regulatory regions of the A600-4 3'UTR sequence. Evidence is provided for distinct 3'UTR elements that function to stabilize the A600-4 mRNA transcript in the amastigote stage and to regulate translation efficiency, respectively.
利什曼原虫属的原生动物寄生虫具有双相生命周期，在前鞭毛体和无鞭毛体阶段之间交替。胞外前鞭毛体存在于白蛉载体中，而专性细胞内无鞭毛体阶段在哺乳动物宿主巨噬细胞的吞噬溶酶体中复制。适应并在这些差异极大的环境中生存伴随着一组基因的差异表达，这些基因通过3'非翻译区（3'UTR）或基因间序列中的顺式作用元件进行转录后调控。先前有报道称，墨西哥利什曼原虫A600-4 mRNA转录本丰度在无鞭毛体中高八倍。在本研究中，嵌合荧光素酶:A600-4 3'UTR报告构建体被整合到A600染色体位点，以鉴定A600-4 3'UTR序列的调控区域。研究提供了证据，证明不同的3'UTR元件分别在无鞭毛体阶段稳定A600-4 mRNA转录本并调节翻译效率。
