Fisk John C, Read Laurie K
Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
Eukaryot Cell. 2011 Aug;10(8):1013-22. doi: 10.1128/EC.05103-11. Epub 2011 Jun 17.
Protozoa constitute the earliest branch of the eukaryotic lineage, and several groups of protozoans are serious parasites of humans and other animals. Better understanding of biochemical pathways that are either in common with or divergent from those of higher eukaryotes is integral in the defense against these parasites. In yeast and humans, the posttranslational methylation of arginine residues in proteins affects myriad cellular processes, including transcription, RNA processing, DNA replication and repair, and signal transduction. The protein arginine methyltransferases (PRMTs) that catalyze these reactions, which are unique to the eukaryotic kingdom of organisms, first become evident in protozoa. In this review, we focus on the current understanding of arginine methylation in multiple species of parasitic protozoa, including Trichomonas, Entamoeba, Toxoplasma, Plasmodium, and Trypanosoma spp., and discuss how arginine methylation may play important and unique roles in each type of parasite. We mine available genomic and transcriptomic data to inventory the families of PRMTs in different parasites and the changes in their abundance during the life cycle. We further review the limited functional studies on the roles of arginine methylation in parasites, including epigenetic regulation in Apicomplexa and RNA processing in trypanosomes. Interestingly, each of the parasites considered herein has significantly differing sets of PRMTs, and we speculate on the importance of this diversity in aspects of parasite biology, such as differentiation and antigenic variation.
原生动物构成了真核生物谱系的最早分支，几类原生动物是人类和其他动物的严重寄生虫。更好地理解与高等真核生物相同或不同的生化途径，对于抵御这些寄生虫至关重要。在酵母和人类中，蛋白质中精氨酸残基的翻译后甲基化影响众多细胞过程，包括转录、RNA加工、DNA复制和修复以及信号转导。催化这些反应的蛋白质精氨酸甲基转移酶（PRMTs）是真核生物界所特有的，最早在原生动物中显现出来。在这篇综述中，我们聚焦于目前对多种寄生原生动物（包括毛滴虫、溶组织内阿米巴、弓形虫、疟原虫和锥虫属）中精氨酸甲基化的理解，并讨论精氨酸甲基化在每种寄生虫中可能如何发挥重要且独特的作用。我们挖掘现有的基因组和转录组数据，以梳理不同寄生虫中PRMTs家族及其在生命周期中的丰度变化。我们还进一步综述了关于精氨酸甲基化在寄生虫中作用的有限功能研究，包括顶复门中的表观遗传调控和锥虫中的RNA加工。有趣的是，本文所考虑的每种寄生虫都有显著不同的PRMTs组合，我们推测这种多样性在寄生虫生物学的各个方面（如分化和抗原变异）的重要性。
