Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Estado de México, CP 54090, Mexico.
Biomed Res Int. 2018 Oct 10;2018:1641839. doi: 10.1155/2018/1641839. eCollection 2018.
Nucleogenesis is the cellular event responsible for the formation of the new nucleoli at the end of mitosis. This process depends on the synthesis and processing of ribosomal RNA (rRNA) and, in some eukaryotes, the transfer of nucleolar material contained in prenucleolar bodies (PNBs) to active transcription sites. The lack of a comprehensive description of the nucleolus throughout the cell cycle of the human pathogen prompted us to analyze the distribution of nucleolar protein 56 (Nop56) during interphase and mitosis in the promastigote stage of the parasite. By analysis we show that the orthologue of Nop56 in (LmNop56) contains the three characteristic Nop56 domains and that its predicted three-dimensional structure is also conserved. Fluorescence microscopy observations indicate that the nucleolar localization of LmNop56 is similar, but not identical, to that of the nucleolar protein Elp3b. Notably, unlike other nucleolar proteins, LmNop56 remains associated with the nucleolus in nonproliferative cells. Moreover, epifluorescent images indicate the preservation of the nucleolar structure throughout the closed nuclear division. Experiments performed with the related parasite show that nucleolar division is carried out by an analogous mechanism.
核发生是负责有丝分裂末期新核仁形成的细胞事件。这个过程依赖于核糖体 RNA(rRNA)的合成和加工，在一些真核生物中，还依赖于包含在核仁前体 (PNB) 中的核仁物质转移到活跃的转录位点。由于缺乏对人类病原体整个细胞周期的核仁的全面描述，我们促使我们分析核仁蛋白 56（Nop56）在寄生虫的前鞭毛体阶段的间期中和有丝分裂中的分布。通过分析，我们表明在（LmNop56）中的 Nop56 的同源物含有三个特征 Nop56 结构域，并且其预测的三维结构也是保守的。荧光显微镜观察表明，LmNop56 的核仁定位与核仁蛋白 Elp3b 的定位相似，但不完全相同。值得注意的是，与其他核仁蛋白不同，LmNop56 仍然与非增殖细胞中的核仁相关联。此外，荧光显微镜图像表明核仁结构在整个封闭核分裂过程中得到保留。与相关寄生虫进行的实验表明，核仁分裂是通过类似的机制进行的。
