Freire Eden R, Sturm Nancy R, Campbell David A, de Melo Neto Osvaldo P
Department of Microbiology, Instituto Aggeu Magalhães, Fiocruz, Recife 50740-465, PE, Brazil.
Department of Microbiology, Immunology & Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA.
Pathogens. 2017 Oct 27;6(4):55. doi: 10.3390/pathogens6040055.
Trypanosomatid protozoa are unusual eukaryotes that are well known for having unusual ways of controlling their gene expression. The lack of a refined mode of transcriptional control in these organisms is compensated by several post-transcriptional control mechanisms, such as control of mRNA turnover and selection of mRNA for translation, that may modulate protein synthesis in response to several environmental conditions found in different hosts. In other eukaryotes, selection of mRNA for translation is mediated by the complex eIF4F, a heterotrimeric protein complex composed by the subunits eIF4E, eIF4G, and eIF4A, where the eIF4E binds to the 5'-cap structure of mature mRNAs. In this review, we present and discuss the characteristics of six trypanosomatid eIF4E homologs and their associated proteins that form multiple eIF4F complexes. The existence of multiple eIF4F complexes in trypanosomatids evokes exquisite mechanisms for differential mRNA recognition for translation.
锥虫类原生动物是一类独特的真核生物，以其控制基因表达的独特方式而闻名。这些生物缺乏精细的转录控制模式，但通过多种转录后控制机制得以弥补，例如对mRNA周转的控制以及对用于翻译的mRNA的选择，这些机制可能会根据在不同宿主中发现的多种环境条件来调节蛋白质合成。在其他真核生物中，用于翻译的mRNA的选择由复杂的eIF4F介导，eIF4F是一种由亚基eIF4E、eIF4G和eIF4A组成的异源三聚体蛋白复合物，其中eIF4E与成熟mRNA的5'-帽结构结合。在这篇综述中，我们展示并讨论了六种锥虫类eIF4E同源物及其相关蛋白的特征，这些蛋白形成了多个eIF4F复合物。锥虫类中多个eIF4F复合物的存在引发了用于差异mRNA识别以进行翻译的精妙机制。
