胚胎干细胞中关于p53对转录调控的三维空间网络的研究

Tumor suppressor p53 as a transcription factor is critical in regulating the differentiation and apoptosis of embryonic stem cells (ESCs).We have made progress in genome-wide analysis of the p53 transcriptional network in mouse ESCs in recent years. To obtain a more comprehensive understanding of the three-dimensional chromatin interaction network bound by p53, we propose to map the chromatin interaction between p53 and two regulatory DNA elements, promoters and enhancers, by using chromatin interaction analysis by paired-end tag sequencing (ChIA-PET). Meanwhile, we propose to screen out p53-interacting proteins using a chip-based proteomic approach, chromatin immunoprecipitation with high-resolution mass spectrometry (ChIP-MS) and explore roles of the protein interactors involved in p53-regulated transcription. Based upon the integrative analysis of genomic and proteomic data sets, we will focus on the molecular mechanism underlying p53-mediated repression through recruiting protein interactors and interfering the promoter-enhancer interactions.

抑癌基因p53作为转录因子在胚胎干细胞（embryonic stem cells, ESCs）的分化和凋亡过程中发挥重要作用。近年来我们已在全基因组水平对p53在ESCs中的线性转录调控网络进行了逐步的揭示。为了进一步研究p53的全基因组三维空间转录调控网络，本研究拟采用ChIA-PET （Chromatin Interaction Analysis using Paired-End Tag sequencing），揭示p53与启动子和增强子的空间互作图谱；同时，我们还将结合ChIP-MS（ChIP-Mass Spectrometry）技术，在蛋白质组水平筛选与p53互作的蛋白因子，并研究参与p53转录调控的蛋白及其作用机制。通过结合基因组和蛋白质组的分析结果，我们将着重对p53通过募集相关蛋白因子、阻断启动子-增强子之间的相互作用从而对下游基因进行转录抑制的分子机制进行探索。