LATS kinase-mediated selective disruption of CTCF genomic binding. LATS kinase-mediated selective disruption of CTCF genomic binding

We identified CTCF as a substrate of the LATS kinases. Under cellular stress conditions that activated LATS, CTCF was phosphorylated in a LATS-dependent manner and lost DNA-binding activity. LATS signaling target genes resided in CTCF-mediated insulated neighborhoods and depended on such chromatin organization to sustain their expression. Genome-wide CTCF DNA-binding profiling revealed that metabolic stress reduced CTCF occupancy specifically at a small subset of CTCF-binding sites that encompassed many LATS target genes and were most significantly associated with LATS signaling. Dissociation of CTCF from LATS target genes disrupted corresponding CTCF-mediated chromatin domains and downregulated LATS target gene expression. Overall design: CTCF ChIP-seq for WT and Glucose free medium treatment in MCF7 breast cancer cells

本研究将CCCTC结合因子（CTCF）鉴定为LATS激酶（LATS kinases）的底物。在激活LATS的细胞应激条件下，CTCF会以LATS依赖的方式发生磷酸化，并丧失DNA结合活性。LATS信号通路的靶基因位于CTCF介导的绝缘结构域（insulated neighborhoods）中，且依赖此类染色质组织以维持自身表达水平。全基因组CTCF DNA结合谱分析结果显示，代谢应激可特异性降低CTCF在一小部分CTCF结合位点上的结合占有率；这些位点涵盖大量LATS靶基因，且与LATS信号通路最为显著相关。CTCF从LATS靶基因位点解离后，会破坏相应的CTCF介导的染色质结构域，并下调LATS靶基因的表达。实验整体设计：对MCF7乳腺癌细胞分别进行野生型培养及无糖培养基处理，随后开展CTCF染色质免疫共沉淀测序（ChIP-seq）实验。