Department of Cytophysiology, University of Łódź, Pomorska 141/143, 90-236 Łódź, Poland.
Micron. 2012 Aug;43(8):870-5. doi: 10.1016/j.micron.2012.02.016. Epub 2012 Mar 23.
Nucleolin and its homologues are multifunctional proteins which reside mainly in nucleoli of yeast, animal and plant cells. Hence, they are generally implicated in many stages of ribosome biosynthesis. In this study nucleolin was identified in root meristematic cell nucleoli of soybean plants subjected to chilling stress, recovered after chilling and under control conditions with the use of the immunogold electron microscopy technique. Soybean nucleoli exhibited various metabolic activities under these conditions (Stępiński, 2004). Current studies showed that the level of nucleolin, expressed as a number of gold grains per μm(2), varied in particular subnucleolar regions in the soybean root meristematic cell nucleoli. Labeling density changed in these regions when plants were subjected to the given treatment. Most abundantly this protein was present in dense fibrillar component (DFC) around fibrillar centers (FCs) in the nucleoli of recovered plants, while in the nucleoli of stressed plants this region contained the lowest level of nucleolin. It can be supposed that nucleolin participates in ribosome biogenesis and its level is correlated with metabolic activity of soybean nucleoli - the more active nucleoli, the higher level of nucleolin and vice versa.
核仁素及其同源物是多功能蛋白质，主要存在于酵母、动物和植物细胞的核仁中。因此，它们通常参与核糖体生物合成的许多阶段。在这项研究中，使用免疫金电子显微镜技术，在经历冷胁迫、冷胁迫后恢复以及对照条件下的大豆植物根分生细胞核仁中鉴定出核仁素。在这些条件下，大豆核仁表现出各种代谢活性（Stępiński，2004）。目前的研究表明，核仁素的水平（表示为每 μm(2)的金颗粒数）在大豆根分生细胞核仁的特定亚核仁区中有所不同。当植物受到特定处理时，这些区域的标记密度会发生变化。在恢复植物的核仁中，该蛋白在纤维中心（FC）周围的密集纤维成分（DFC）中最为丰富，而在受胁迫植物的核仁中，该区域的核仁素含量最低。可以假设核仁素参与核糖体生物发生，其水平与大豆核仁的代谢活性相关——核仁越活跃，核仁素水平越高，反之亦然。
