Dicer is essential for formation of the heterochromatin structure in vertebrate cells
Dicer is essential for formation of the heterochromatin structure in vertebrate cells
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DOI：
10.1038/ncb1155
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发表时间：
2004-08-01
影响因子：
21.3
通讯作者：
Oshimura, M
中科院分区：
文献类型：
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作者：
Fukagawa, T;Nogami, M;Oshimura, M
RNA干扰是一种进化上保守的基因沉默途径，其中核酸酶Dicer将双链RNA切割成小的干扰RNA 1。脊椎动物细胞中RNAi相关通路的生物学功能尚未完全了解。在这里，我们报告了一个有条件的功能丧失Dicer突变体的鸡-人杂交DT 40细胞系，包含人类21号染色体的一代。我们发现，Dicer的丧失导致细胞死亡，异常有丝分裂细胞的积累，显示过早的姐妹染色单体分离。在Dicer缺陷细胞中检测到由人着丝粒重复DNA组成的α-卫星序列转录物的异常积累。免疫细胞化学分析显示，两个异染色质蛋白，Rad 21 cohesin蛋白和BubR 1检查点蛋白的定位异常，但核心动粒蛋白，如着丝粒蛋白（CENP）-A和-C的定位是正常的。我们的结论是，Dicer相关的RNA干扰机制参与了高等脊椎动物细胞异染色质结构的形成。
RNA interference is an evolutionarily conserved gene-silencing pathway in which the nuclease Dicer cleaves double-stranded RNA into small interfering RNAs1. The biological function of the RNAi-related pathway in vertebrate cells is not fully understood. Here, we report the generation of a conditional loss-of-function Dicer mutant in a chicken-human hybrid DT40 cell line that contains human chromosome 21. We show that loss of Dicer results in cell death with the accumulation of abnormal mitotic cells that show premature sister chromatid separation. Aberrant accumulation of transcripts from alpha-satellite sequences, which consist of human centromeric repeat DNAs, was detected in Dicer-deficient cells. Immunocytochemical analysis revealed abnormalities in the localization of two heterochromatin proteins, Rad21 cohesin protein and BubR1 checkpoint protein, but the localization of core kinetochore proteins such as centromere protein (CENP)-A and -C was normal. We conclude that Dicer-related RNA interference machinery is involved in the formation of the heterochromatin structure in higher vertebrate cells.