Nucleolin functions in nucleolus formation and chromosome congression
Nucleolin functions in nucleolus formation and chromosome congression
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DOI：
10.1242/jcs.008771
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发表时间：
2007-06-15
影响因子：
4
通讯作者：
Fukui, Kiichi
中科院分区：
文献类型：
--
作者：
Ma, Nan;Matsunaga, Sachihiro;Fukui, Kiichi
有丝分裂期间，每条染色体周围都有一个复杂的结构，称为染色体外围。尽管已证明几种蛋白质定位于染色体外围，但它们在有丝分裂期间的功能仍不清楚。在这里，我们结合使用高分辨率显微镜和 RNA 干扰介导的损耗来研究核仁蛋白（一种位于染色体外围的核仁蛋白）在间期和有丝分裂中的功能。在有丝分裂期间，核仁素位于外围区域，包括染色体外着丝粒附近。用对 CDC2 磷酸化核仁素特异的抗体进行染色表明，核仁素也与从前期到后期的纺锤体极相关。核仁素耗尽导致间期核仁解体。此外，核仁素耗尽的细胞显示出细胞周期延长，染色体错位和纺锤体组织缺陷。错位的染色体显示着丝粒-微管连接，着丝粒拉伸减少。综上所述，我们的结果表明核仁素是核仁形成所必需的，并且还参与染色体大会和纺锤体形成。
A complex structure, designated the chromosome periphery, surrounds each chromosome during mitosis. Although several proteins have been shown to localize to the chromosome periphery, their functions during mitosis remain unclear. Here, we used a combination of high-resolution microscopy and RNA-interference-mediated depletion to study the functions of nucleolin, a nucleolar protein localized at the chromosome periphery, in interphase and mitosis. During mitosis, nucleolin was localized in the peripheral region including the vicinity of the outer kinetochore of chromosomes. Staining with an antibody specific for nucleolin phosphorylated by CDC2 revealed that nucleolin was also associated with the spindle poles from prometaphase to anaphase. Nucleolin depletion resulted in disorganization of the nucleoli at interphase. Furthermore, nucleolin-depleted cells showed a prolonged cell cycle with misaligned chromosomes and defects in spindle organization. The misaligned chromosomes showed syntelic kinetochore-microtubule attachments with reduced centromere stretching. Taken together, our results indicate that nucleolin is required for nucleolus formation, and is also involved in chromosome congression and spindle formation.