The nuclear import of proteins in eukaryotic cells is a fundamental biological process. While it has been analysed to different extents in model eukaryotic organisms, this event has rarely been studied in the early divergent protozoa of the order Kinetoplastida. The work presented here represents an overview of nuclear import in these important species of human pathogens. Initially, an in silico study of classical nuclear localization signals within the published nuclear proteomes of Trypanosoma brucei and Trypanosoma cruzi was carried out. The basic amino acids that comprise the monopartite and bipartite classical nuclear localization signals (cNLS) in trypanosomal proteins are similar to the consensus sequences observed for the nuclear proteins of yeasts, animals and plants. In addition, a summarized description of published studies that experimentally address the NLS of nuclear proteins in trypanosomatids is presented, and the clear occurrence of non-classical NLS (NLS that lack the consensus motifs of basic amino acids) in the analysed reports indicate a complex scenario for the types of receptors in these species. In general, the information presented here agrees with the hypothetical appearance of mechanisms for the recognition of nuclear proteins in early eukaryotic evolution.

真核细胞中蛋白质的核输入是一个基本的生物学过程。尽管已经在模型真核生物中对它进行了不同程度的分析，但很少在动塑料体阶的原生动物原生动物中研究此事件。本文介绍的工作概述了这些重要人类病原体物种中的核输入。最初，对已发表的布鲁氏锥虫和克氏锥虫的核蛋白质组中经典核定位信号进行了计算机模拟研究进行了。包含在锥虫蛋白中的单部分和双部分经典核定位信号（cNLS）的碱性氨基酸类似于针对酵母，动物和植物的核蛋白观察到的共有序列。此外，还提供了已发表的研究的概述性描述，该研究通过实验方法解决了锥虫病中核蛋白的NLS，并且分析报告中非经典NLS（缺少碱性氨基酸共有基序的NLS）的清楚出现表明存在复杂的这些物种的受体类型的情景。通常，此处提供的信息与在真核生物早期进化中识别核蛋白的机制的假想外观一致。