Chromatin assembly factor 1 ensures the stable maintenance of silent chromatin states in Arabidopsis
Chromatin assembly factor 1 ensures the stable maintenance of silent chromatin states in Arabidopsis
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DOI：
10.1111/j.1365-2443.2006.00928.x
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发表时间：
2006-02-01
期刊：
影响因子：
2.1
通讯作者：
Shibahara, K
中科院分区：
文献类型：
--
作者：
Ono, T;Kaya, H;Shibahara, K
新合成的DNA通过预先存在的和新生的组蛋白的沉积快速组装成成熟的核小体，并且该过程的某些部分由染色质组装因子1（CAF-1）促进。拟南芥中CAF-1的功能丧失突变体，fasciata（fas），表现出多种形态异常和分生组织中基因表达的独特缺陷。为了阐明CAF-1在维持高等真核生物染色质状态中的意义，我们研究了Fas突变体中各种基因的转录基因沉默（TGS）。在这里，我们发现内源性CACTA转座子的TGS在Fas中以随机方式释放。其他内源性沉默基因，一个转座子AtMu 1和一个假设的基因T5L23.26在异染色质旋钮，也被转录激活，和激活的三个不同的沉默基因座在不同的染色体位点发生非伴随彼此。此外，沉默的β-葡萄糖醛酸酶（GUS）转基因的TGS也在Fas中随机去阻遏。我们的结论是，CAF-1确保表观遗传状态的稳定遗传，通过生长和发育在拟南芥。
Newly synthesized DNA is rapidly assembled into mature nucleosomes by the deposition of pre-existing and nascent histones, and some parts of this process are facilitated by chromatin assembly factor 1 (CAF-1). Loss-of-function mutants of CAF-1 in Arabidopsis, fasciata (fas), show a variety of morphological abnormalities and unique defects in gene expression in the meristems. In order to clarify the implications of CAF-1 in the maintenance of chromatin states in higher eukaryotes, we investigated transcriptional gene silencing (TGS) of various genes in fas mutants. Here, we show that TGS of endogenous CACTA transposons was released in a stochastic manner in fas. Other endogenous silent genes, a transposon AtMu1 and a hypothetical gene T5L23.26 at a heterochromatin knob, were also transcriptionally activated, and the activation of the three different silent loci at different chromosomal sites occurred non-concomitantly with each other. Furthermore, TGS of the silent beta-glucuronidase (GUS) transgene was also de-repressed randomly in fas. We conclude that CAF-1 ensures the stable inheritance of epigenetic states through growth and development in Arabidopsis.