RbAp48 is essential for viability of vertebrate cells and plays a role in chromosome stability
RbAp48 is essential for viability of vertebrate cells and plays a role in chromosome stability
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RbAp48 对于脊椎动物细胞的活力至关重要，并在染色体稳定性中发挥作用
DOI：
10.1007/s10577-015-9510-8
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发表时间：
2016
影响因子：
2.6
通讯作者：
Tatsuo Fukagawa & Yasunari Takami
中科院分区：
文献类型：
--
作者：
Pasjan Satrimafitrah;Hirak Kumar Barman;Ahyar Ahmad;Hideki Nishitoh;Tatsuo Nakayama;Tatsuo Fukagawa & Yasunari Takami
组蛋白伴侣蛋白RbAp46/48是一个进化保守的WD40重复序列蛋白家族，参与多种染色质代谢过程，但其在体内的功能相关性尚不清楚。为了检验pRbAp48在鸡DT40细胞中的生物学作用，我们建立了一个四环素诱导的条件rbap48敲除细胞系统。RbAp48的缺失导致S期进展延迟，与DNA合成缓慢和新生核小体形成相关，随后在G2/M期积累，最终导致细胞死亡。在细胞死亡之前，这些细胞表现出异常的有丝分裂，如中期板上高度凝聚和异常的染色体排列，导致染色体错误分离。RbAp48的缺失也导致了异染色质蛋白1 （HP1）与中心周围异染色质的分离。此外，细胞中RbAp48的缺失导致乙酰化水平升高，甲基化水平略有下降，特别是在组蛋白H3的Lys-9残基上。这些结果表明RbAp48通过调控表观遗传标记在染色体稳定性中发挥重要作用，使异染色质结构得以合理组织。
RbAp46/48, histone chaperone, is a family of evolutionarily conserved WD40 repeat-containing proteins, which are involved in various chromatin-metabolizing processes, but their in vivo functional relevance is yet unclear. In order to examine the biological role of pRbAp48 in chicken DT40 cells, we generated a tetracycline-inducible system for conditionalRbAp48-knockout cells. Depletion of RbAp48 led to delayed S phase progression associated with slow DNA synthesis and nascent nucleosome formation, followed by accumulation in G2/M phase, finally leading to cell death. Prior to cell death, these cells exhibited aberrant mitosis such as highly condensed and abnormal chromosome alignment on the metaphase plate, leading to chromosome missegregation. Depletion of RbAp48 also caused dissociation of heterochromatin protein 1 (HP1) from pericentromeric heterochromatin. Furthermore, depletion of RbAp48 from cells led to elevated levels of acetylation and slightly decreased levels of methylation, specifically at Lys-9 residue of histone H3. These results suggest that RbAp48 plays an important role in chromosome stability for proper organization of heterochromatin structure through the regulation of epigenetic mark.