The hierarchical structure of the perichromosomal layer comprises Ki67, ribosomal RNAs, and nucleolar proteins
The hierarchical structure of the perichromosomal layer comprises Ki67, ribosomal RNAs, and nucleolar proteins
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DOI：
10.1016/j.bbrc.2017.09.092
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发表时间：
2017-11-18
影响因子：
3.1
通讯作者：
Kimura, Keiji
中科院分区：
文献类型：
--
作者：
Hayashi, Yuki;Kato, Kazashi;Kimura, Keiji
染色体周层（PCL）是一种围绕有丝分裂染色体的结构，存在于动物和植物细胞中。它由多种蛋白质和rna组成，主要来源于核仁。提出了PCL的几个功能；然而，有丝分裂过程中PCL组织的机制尚不清楚。据报道，几种核核蛋白在PCL上的定位依赖于核糖体前rna和增殖标记物Ki67， Ki67是PCL定位的主要蛋白。在这里，我们证明，尽管从PCL中去除核糖体前rna会导致PCL中几种核仁蛋白的脱位，但它不会影响Ki67的定位。相反，Ki67缺失导致核糖体前rna和核仁蛋白与PCL分离，这表明Ki67是核糖体前rna在PCL积累所必需的，其中有几种核仁蛋白与之相关。鉴于这些发现，我们提出了一个PCL组织模型，该模型包括三个基本层：支架蛋白Ki67，用于连锁的前核糖体rna和外核仁蛋白。(C) 2017爱思唯尔公司版权所有。
The perichromosomal layer (PCL) is a structure that surrounds mitotic chromosomes, found in both animal and plant cells. It comprises various proteins and RNAs, mainly derived from the nucleolus. Several functions for the PCL have been suggested; however, the mechanism of PCL organization during mitosis remains unclear. The localization of several nucleolar proteins to the PCL is reportedly dependent on pre-ribosomal RNAs and the marker of proliferation, Ki67, which is a major PCL-localized protein. Here we demonstrate that, although the removal of pre-ribosomal RNAs from the PCL causes PCL delocalization of several nucleolar proteins, it does not affect the localization of Ki67. Conversely, Ki67 depletion results in the dissociation of both pre-ribosomal RNAs and nucleolar proteins from the PCL, which indicates that Ki67 is required for the PCL accumulation of pre-ribosomal RNAs, to which several nucleolar proteins are associated. Given these findings, we propose a model for PCL organization that comprises three essential layers: the scaffolding protein Ki67, pre-ribosomal RNAs for linkage, and outer nucleolar proteins. (C) 2017 Elsevier Inc. All rights reserved.