HMG Domain Containing SSRP1 Is Required for DNA Demethylation and Genomic Imprinting in Arabidopsis
HMG Domain Containing SSRP1 Is Required for DNA Demethylation and Genomic Imprinting in Arabidopsis
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DOI：
10.1016/j.devcel.2011.08.013
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发表时间：
2011-09-13
影响因子：
11.8
通讯作者：
Kinoshita, Tetsu
中科院分区：
文献类型：
--
作者：
Ikeda, Yoko;Kinoshita, Yuki;Kinoshita, Tetsu
在拟南芥中，DEMETER（DME）DNA脱甲基酶有助于中央细胞基因组表观遗传状态的重编程。然而，活性DNA去甲基化过程的其他方面仍然难以捉摸。在这里，我们表明，拟南芥SSRP 1，被称为HMG结构域的FACT组蛋白伴侣的组成部分，是必需的DNA去甲基化和激活和抑制的许多父母印记基因在中央细胞。虽然DNA甲基化的丧失释放了印迹FWA-GFP的沉默，但双ssrp 1 -3; met 1 -3突变体令人惊讶地在中央细胞中显示出对母体FWA-GFP的有限激活，并且仅在胚乳中的几次核分裂后才完全激活。这种行为与dme-1; met 1双突变体相反，其中met 1对FWA-GFP的低甲基化抑制了dme-1的DNA去甲基化缺陷。我们建议，主动DNA去甲基化DME需要SSRP 1功能，通过一个明显不同的过程，从直接的DNA甲基化控制。
In Arabidopsis, DEMETER (DME) DNA demethylase contributes to reprogramming of the epigenetic state of the genome in the central cell. However, other aspects of the active DNA demethylation processes remain elusive. Here we show that Arabidopsis SSRP1, known as an HMG domain-containing component of FACT histone chaperone, is required for DNA demethylation and for activation and repression of many parentally imprinted genes in the central cell. Although loss of DNA methylation releases silencing of the imprinted FWA-GFP, double ssrp1-3;met1-3 mutants surprisingly showed limited activation of maternal FWA-GFP in the central cell, and only became fully active after several nuclear divisions in the endosperm. This behavior was in contrast to the dme-1;met1 double mutant in which hypomethylation of FWA-GFP by met1 suppressed the DNA demethylation defect of dme-1. We propose that active DNA demethylation by DME requires SSRP1 function through a distinctly different process from direct DNA methylation control.