Molecular and Structural Biology Division, Central Drug Research Institute, CSIR, Uttar Pradesh, Lucknow, India.
J Cell Sci. 2010 Jun 15;123(Pt 12):2035-44. doi: 10.1242/jcs.064725. Epub 2010 May 25.
Actin-based myosin motors have a pivotal role in intracellular trafficking in eukaryotic cells. The parasitic protozoan organism Leishmania expresses a novel class of myosin, myosin XXI (Myo21), which is preferentially localized at the proximal region of the flagellum. However, its function in this organism remains largely unknown. Here, we show that Myo21 interacts with actin, and its expression is dependent of the growth stage. We further reveal that depletion of Myo21 levels results in impairment of the flagellar assembly and intracellular trafficking. These defects are, however, reversed by episomal complementation. Additionally, it is shown that deletion of the Myo21 gene leads to generation of ploidy, suggesting an essential role of Myo21 in survival of Leishmania cells. Together, these results indicate that actin-dependent trafficking activity of Myo21 is essentially required during assembly of the Leishmania flagellum.
基于肌动蛋白的肌球蛋白马达在真核细胞的细胞内运输中起着关键作用。寄生原生动物生物利什曼原虫表达了一类新型肌球蛋白，即肌球蛋白 XXI（Myo21），它优先定位于鞭毛的近端区域。然而，其在该生物体内的功能在很大程度上仍是未知的。在这里，我们表明 Myo21 与肌动蛋白相互作用，其表达依赖于生长阶段。我们进一步揭示，Myo21 水平的耗竭导致鞭毛组装和细胞内运输受损。然而，这些缺陷可以通过外源性互补得到逆转。此外，还表明 Myo21 基因的缺失会导致倍性的产生，这表明 Myo21 在利什曼虫细胞的存活中起着至关重要的作用。总之，这些结果表明，Myo21 的肌动蛋白依赖性运输活性在利什曼虫鞭毛的组装过程中是必不可少的。
