Institute of Parasitology, McGill University, Quebec, H9X3V9, Canada.
Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, Quebec, H3G 1Y6, Canada.
Sci Rep. 2019 Apr 11;9(1):5904. doi: 10.1038/s41598-019-42409-1.
RNA-binding proteins play a particularly important role in regulating gene expression in trypanosomes. A map of the network of protein complexes in Trypanosoma brucei uncovered an essential protein (Tb927.10.7910) that is postulated to be an RNA-binding protein implicated in the regulation of the mitochondrial post-transcriptional gene regulatory network by its association with proteins that participate in a multi-protein RNA editing complex. However, the mechanism by which this protein interacts with its multiple target transcripts remained unknown. Using sensitive database searches and experimental data, we identify Z-DNA-binding domains in T. brucei in the N- and C-terminal regions of Tb927.10.7910. RNA-binding studies of the wild-type protein, now referred to as RBP7910 (RNA binding protein 7910), and site-directed mutagenesis of residues important for the Z-DNA binding domains show that it preferentially interacts with RNA molecules containing poly(U) and poly(AU)-rich sequences. The interaction of RBP7910 with these regions may be involved in regulation of RNA editing of mitochondrial transcripts.
RNA 结合蛋白在调控锥虫基因表达中起着特别重要的作用。在布氏锥虫蛋白复合物网络图谱中发现了一种必需蛋白（Tb927.10.7910），该蛋白被推测为 RNA 结合蛋白，通过与参与多蛋白 RNA 编辑复合物的蛋白质结合，参与调控线粒体转录后基因调控网络。然而，该蛋白与多个靶标转录本相互作用的机制尚不清楚。利用敏感的数据库搜索和实验数据，我们在 Tb927.10.7910 的 N 端和 C 端区域鉴定出了布氏锥虫中的 Z-DNA 结合结构域。对野生型蛋白（现在称为 RBP7910，RNA 结合蛋白 7910）进行 RNA 结合研究和对 Z-DNA 结合结构域重要残基进行定点突变显示，它优先与含有聚（U）和富含聚（AU）序列的 RNA 分子相互作用。RBP7910 与这些区域的相互作用可能参与调控线粒体转录物的 RNA 编辑。
