Tet1 and hydroxymethylcytosine in transcription and DNA methylation fidelity (ChIP/DIP-Seq data)

We analyzed the genome-wide binding of Tet1 in control (shScr) and Tet1 knockdown (shTet1) mouse ES cells using two different Tet1 antibodies (Tet1-C and Tet1-N). Furthermore, we generated genome-wide mapping of hydroxymethyl cytosine (hmC) and methyl cytosine (mC). We find that hmC, in contrast to mC, is also found at transcription start sites (TSSs), and that there is a significant overlap between Tet1 binding and hmC positive regions. Surprisingly, our results also suggest, that Tet1 has a role in transcriptional repression. We showed that Tet1 associates with Sin3A co-repressor complex, and by performing ChIP-sequencing of Sin3A, we find co-localisation of Tet1 and Sin3a throughout the genome Examination of Tet1 and Sin3A binding as well as hmC and mC localization in mouse ES cells

本研究针对对照（shScr）与Tet1敲低（shTet1）的小鼠胚胎干细胞（mouse ES cells），采用两种特异性Tet1抗体（Tet1-C与Tet1-N）分析了Tet1的全基因组结合特征。此外，我们还完成了羟甲基胞嘧啶（hydroxymethyl cytosine, hmC）与甲基胞嘧啶（methyl cytosine, mC）的全基因组定位分析。研究结果显示，与甲基胞嘧啶（mC）不同，羟甲基胞嘧啶（hmC）同样富集于转录起始位点（transcription start sites, TSSs）区域，且Tet1结合区域与hmC阳性区域存在显著重叠。出乎意料的是，本研究还发现Tet1在转录抑制过程中发挥调控作用。我们证实Tet1可与Sin3A共抑制复合物（Sin3A co-repressor complex）相互结合；通过对Sin3A进行染色质免疫共沉淀测序（ChIP-sequencing），我们发现Tet1与Sin3A在全基因组范围内存在共定位现象。本研究同时对小鼠胚胎干细胞中Tet1与Sin3A的结合特征以及hmC和mC的定位情况开展了系统检测。