Division of Stem Cell Regulation Research, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, 565-0871, Osaka, Japan.
Sci Rep. 2017 Sep 29;7(1):12462. doi: 10.1038/s41598-017-12772-y.
The Cys2/His2-type zinc finger protein Zfp296 has been implicated in stem cell pluripotency and tumor pathogenesis. However, its mechanisms remain elusive. Here, we demonstrated that a Zfp296 deficiency in mice impairs germ-cell development and embryonic growth. Zfp296 was intracellularly localized to heterochromatin in embryos. A GST-Zfp296 pull-down experiment using ES cell nuclear extract followed by LC-MS/MS showed that Zfp296 interacts with component proteins of heterochromatin (such as HP1, Dnmt1, Dnmt3b, and ATRX) and the NuRD complex. We focused on H3K9 methylation as a hallmark of heterochromatin, and found that Zfp296 overexpression in cultured cells reduces the Suv39h1-mediated H3K9 methylation. Consistent with this finding, in Zfp296 mouse embryos, we observed a global increase in H3K9 methylation in a developmental stage-dependent manner, and showed, by ChIP-qPCR, that the H3K9me3 levels at major satellite repeats were elevated in Zfp296 embryos. Our results demonstrate that Zfp296 is a component of heterochromatin that affects embryonic development by negatively regulating H3K9 methylation.
Cys2/His2 型锌指蛋白 Zfp296 被认为与干细胞多能性和肿瘤发病机制有关。然而，其机制仍不清楚。在这里，我们证明了小鼠中 Zfp296 的缺失会损害生殖细胞的发育和胚胎的生长。Zfp296 在胚胎内定位于异染色质。使用 ES 细胞核提取物进行 GST-Zfp296 下拉实验，然后进行 LC-MS/MS 分析表明，Zfp296 与异染色质的组成蛋白（如 HP1、Dnmt1、Dnmt3b 和 ATRX）和 NuRD 复合物相互作用。我们专注于 H3K9 甲基化为异染色质的标志，发现培养细胞中 Zfp296 的过表达降低了 Suv39h1 介导的 H3K9 甲基化。与这一发现一致的是，在 Zfp296 小鼠胚胎中，我们观察到 H3K9 甲基化在发育阶段依赖性的方式下在全基因组范围内增加，并通过 ChIP-qPCR 显示，Zfp296 胚胎中主要卫星重复序列的 H3K9me3 水平升高。我们的结果表明，Zfp296 是异染色质的一个组成部分，通过负调控 H3K9 甲基化来影响胚胎发育。
