Plant HP1 protein ADCP1 links multivalent H3K9 methylation readout to heterochromatin formation
Plant HP1 protein ADCP1 links multivalent H3K9 methylation readout to heterochromatin formation
复制标题
植物 HP1 蛋白 ADCP1 将多价 H3K9 甲基化读数与异染色质形成联系起来
DOI：
10.1038/s41422-018-0104-9
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发表时间：
2019-01-01
期刊：
影响因子：
44.1
通讯作者：
Li, Haitao
中科院分区：
文献类型：
--
作者：
Zhao, Shuai;Cheng, Lingling;Li, Haitao
异染色质蛋白1（HP1）通过其保守的染色质结构域识别组蛋白H3赖氨酸9甲基化（H3K9me）并维持从裂殖酵母到哺乳动物的异染色质。然而，在拟南芥中，Like Heterochromatin Protein 1（LHP 1）与H3K27me3在全基因组范围内识别并共定位，是Polycomb蛋白的功能同源物。这就提出了一个问题，即植物中是否存在真正的HP1同源物。在这里，我们报告的发现，ADCP1，植物特异性的三重串联蛋白，作为一个多价H3K9me阅读器在拟南芥，并建立ADCP1是必不可少的异染色质形成和转座子沉默通过调节H3K9和DNA甲基化水平。结构研究揭示了ADCP1的串联引物对H3K9me特异性识别的分子基础。类似于人HP1α和蝇HP1a，ADCP1介导异染色质相分离。我们的研究结果表明，尽管其独特的结构域组合物，ADCP1收敛地演变为一个HP1等效蛋白在植物中调节异染色质的形成。
Heterochromatin Protein 1 (HP1) recognizes histone H3 lysine 9 methylation (H3K9me) through its conserved chromodomain and maintains heterochromatin from fission yeast to mammals. However, inArabidopsis, Like Heterochromatin Protein 1 (LHP1) recognizes and colocalizes genome-wide with H3K27me3, and is the functional homolog of Polycomb protein. This raises the question whether genuine HP1 homologs exist in plants. Here, we report on the discovery of ADCP1, a plant-specific triple tandem Agenet protein, as a multivalent H3K9me reader inArabidopsis, and establish that ADCP1 is essential for heterochromatin formation and transposon silencing through modulating H3K9 and DNA methylation levels. Structural studies revealed the molecular basis underlying H3K9me-specific recognition by tandem Agenet of ADCP1. Similar to human HP1α and fly HP1a, ADCP1 mediates heterochromatin phase separation. Our results demonstrate that despite its distinct domain compositions, ADCP1 convergently evolves as an HP1-equivalent protein in plants to regulate heterochromatin formation.