Placzek Silja, Vanzan Ludovica, Deluz Cédric, Suter David M
Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Cell Rep. 2025 Apr 22;44(4):115486. doi: 10.1016/j.celrep.2025.115486. Epub 2025 Mar 27.
Cell identity maintenance faces many challenges during mitosis, as most DNA-binding proteins are evicted from DNA and transcription is virtually abolished. How cells maintain their identity through division and faithfully re-initiate gene expression during mitotic exit is unclear. Here, we develop a novel reporter system enabling cell cycle synchronization-free separation of pluripotent stem cells in temporal bins of <30 min during mitotic exit. This allows us to quantify genome-wide reactivation of transcription, sequential changes in chromatin accessibility and transcription factor footprints, and re-binding of the pluripotency transcription factors OCT4, SOX2, and NANOG (OSN). We find that transcriptional activity progressively ramps up after mitosis and that OSN rapidly reoccupy the genome during the anaphase-telophase transition. We also demonstrate transcription factor-specific, dynamic relocation patterns and a hierarchical reorganization of the OSN binding landscape governed by OCT4 and SOX2. Our study sheds light on the dynamic orchestration of transcriptional reactivation after mitosis.
在有丝分裂过程中，细胞身份维持面临诸多挑战，因为大多数DNA结合蛋白会从DNA上被驱逐，转录实际上也会停止。细胞如何在分裂过程中维持其身份，并在有丝分裂退出时忠实地重新启动基因表达尚不清楚。在此，我们开发了一种新型报告系统，能够在有丝分裂退出期间以小于30分钟的时间间隔对多能干细胞进行无细胞周期同步分离。这使我们能够量化全基因组转录的重新激活、染色质可及性和转录因子足迹的顺序变化，以及多能性转录因子OCT4、SOX2和NANOG（OSN）的重新结合。我们发现，有丝分裂后转录活性逐渐增强，并且OSN在后期-末期转换期间迅速重新占据基因组。我们还证明了转录因子特异性的动态重新定位模式以及由OCT4和SOX2控制的OSN结合图谱的分层重组。我们的研究揭示了有丝分裂后转录重新激活的动态调控机制。
