Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Department of Physics, University of Maryland, College Park, MD 20742, USA.
Sci Adv. 2022 Apr;8(13):eabj8360. doi: 10.1126/sciadv.abj8360. Epub 2022 Mar 30.
The cohesin complex is central to chromatin looping, but mechanisms by which these long-range chromatin interactions are formed and persist remain unclear. We demonstrate that interactions between a transcription factor (TF) and the cohesin loader NIPBL regulate enhancer-dependent gene activity. Using mass spectrometry, genome mapping, and single-molecule tracking methods, we demonstrate that the glucocorticoid (GC) receptor (GR) interacts with NIPBL and the cohesin complex at the chromatin level, promoting loop extrusion and long-range gene regulation. Real-time single-molecule experiments show that loss of cohesin markedly diminishes the concentration of TF molecules at specific nuclear confinement sites, increasing TF local concentration and promoting gene regulation. Last, patient-derived acute myeloid leukemia cells harboring cohesin mutations exhibit a reduced response to GCs, suggesting that the GR-NIPBL-cohesin interaction is defective in these patients, resulting in poor response to GC treatment.
黏合蛋白复合体是染色质环化的核心,但这些长距离染色质相互作用形成和持续的机制仍不清楚。我们证明,转录因子 (TF) 和黏合蛋白加载器 NIPBL 之间的相互作用调节增强子依赖性基因活性。通过使用质谱、基因组作图和单分子跟踪方法,我们证明糖皮质激素 (GC) 受体 (GR) 在染色质水平与 NIPBL 和黏合蛋白复合物相互作用,促进环伸出和长距离基因调控。实时单分子实验表明,丧失黏合蛋白会显著降低特定核限制位点处 TF 分子的浓度,从而增加 TF 的局部浓度并促进基因调控。最后,携带黏合蛋白突变的患者来源的急性髓系白血病细胞对 GCs 的反应降低,表明这些患者的 GR-NIPBL-黏合蛋白相互作用有缺陷,导致对 GC 治疗的反应不佳。