The polycomb group protein PCGF6 mediates germline gene silencing by recruiting histone-modifying proteins to target gene promoters
The polycomb group protein PCGF6 mediates germline gene silencing by recruiting histone-modifying proteins to target gene promoters
复制标题
多梳蛋白 PCGF6 通过招募组蛋白修饰蛋白至靶基因启动子来介导种系基因沉默
DOI：
10.1074/jbc.ra119.012121
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发表时间：
2020-07-10
影响因子：
4.8
通讯作者：
Qin, Jinzhong
中科院分区：
文献类型：
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作者：
Liu, Mengjie;Zhu, Yaru;Qin, Jinzhong
Polycomb group（PcG）蛋白是通过协调发育基因表达程序来维持谱系保真度所必需的。先前已报道Polycomb group ring finger 6（PCGF 6）通过非典型的polycomb抑制复合物PRC1.6抑制谱系特异性基因的表达，特别是小鼠胚胎干细胞（ESCs）中生殖细胞相关基因的表达。然而，这种抑制的分子机制在很大程度上仍然未知。在这里，使用RNA-Seq，实时RT-PCR，免疫组织化学，免疫沉淀和ChIP分析，我们证明了PCGF 6在胚胎发育中起着至关重要的作用，在纯合子PCGF 6（Pcgf 6 −/−）缺陷小鼠中的部分渗透胚胎致死率表明。我们还发现，存活的Pcgf 6缺陷小鼠表现出生育能力下降。使用Pcgf 6缺陷型小鼠，我们观察到体细胞组织中Pcgf 6的消融强烈地去抑制生殖细胞相关基因。我们进一步提供证据表明，这些基因是胚胎干细胞中PCGF 6的直接靶点，并且内源性PCGF 6与组蛋白修饰蛋白G9 A组蛋白甲基转移酶（G9 A）/G9 a样蛋白（GLP）和组蛋白脱乙酰酶1/2（HDAC 1/2）共定位在生殖细胞相关基因的启动子上。此外，这些蛋白质与其靶基因的结合与组蛋白3的Lys-9的甲基化和这些基因的组蛋白乙酰化状态相关。此外，G9 A/GLP和HDAC 1/2向靶启动子的募集依赖于PCGF 6的结合。我们的研究结果表明，PCGF 6在保护谱系决定和防止生殖细胞相关基因的异常表达方面具有关键作用。
Polycomb group (PcG) proteins are essential for maintenance of lineage fidelity by coordinating developmental gene expression programs. Polycomb group ring finger 6 (PCGF6) has been previously reported to repress expression of lineage-specific genes, especially germ cell–related genes in mouse embryonic stem cells (ESCs) via the noncanonical polycomb repressive complex PRC1.6. However, the molecular mechanism of this repression remains largely unknown. Here, using RNA-Seq, real-time RT-PCR, immunohistochemistry, immunoprecipitation, and ChIP analyses, we demonstrate that PCGF6 plays an essential role in embryonic development, indicated by the partially penetrant embryonic lethality in homozygous PCGF6 (Pcgf6−/−)-deficient mice. We also found that surviving Pcgf6-deficient mice exhibit reduced fertility. Using the Pcgf6-deficient mice, we observed that ablation of Pcgf6 in somatic tissues robustly derepresses germ cell–related genes. We further provide evidence that these genes are direct targets of PCGF6 in ESCs and that endogenous PCGF6 co-localizes with the histone-modifying proteins G9A histone methyltransferase (G9A)/G9a-like protein (GLP) and histone deacetylase 1/2 (HDAC1/2) on the promoters of the germ cell–related genes. Moreover, the binding of these proteins to their target genes correlated with methylation of Lys-9 of histone 3 and with the status of histone acetylation at these genes. Moreover, the recruitment of G9A/GLP and HDAC1/2 to target promoters depended on the binding of PCGF6. Our findings indicate that PCGF6 has a critical role in safeguarding lineage decisions and in preventing aberrant expression of germ cell–related genes.