Jensen Christina L, Chen Liang-Fu, Swigut Tomek, Crocker Olivia J, Yao David, Bassik Mike C, Ferrell James E, Boettiger Alistair N, Wysocka Joanna
bioRxiv. 2024 Jul 19:2024.07.19.604327. doi: 10.1101/2024.07.19.604327.
While critical for tuning the timing and level of transcription, enhancer communication with distal promoters is not well understood. Here we bypass the need for sequence-specific transcription factors and recruit activators directly using CARGO-VPR, an approach for targeting dCas9-VPR using a multiplexed array of RNA guides. We show that this approach achieves effective activator recruitment to arbitrary genomic sites, even those inaccessible by single dCas9. We utilize CARGO-VPR across the locus in mESCs, where neither gene is expressed. We demonstrate that while activator recruitment to any tested region results in transcriptional induction of at least one gene, the expression level strongly depends on the genomic distance between the promoter and activator recruitment site. However, the expression-distance relationship for each gene scales distinctly in a manner not attributable to differences in 3D contact frequency, promoter DNA sequence or presence of the repressive chromatin marks at the locus.
虽然增强子与远端启动子之间的通讯对于调节转录的时间和水平至关重要,但目前人们对此还了解甚少。在这里,我们绕过了对序列特异性转录因子的需求,直接使用CARGO-VPR招募激活因子,CARGO-VPR是一种利用RNA引导物的多重阵列靶向dCas9-VPR的方法。我们表明,这种方法能够将激活因子有效地招募到任意基因组位点,即使是单个dCas9无法到达的位点。我们在小鼠胚胎干细胞的整个基因座上使用CARGO-VPR,该基因座上的两个基因均未表达。我们证明,虽然将激活因子招募到任何测试区域都会导致至少一个基因的转录诱导,但表达水平强烈依赖于启动子与激活因子招募位点之间的基因组距离。然而,每个基因的表达-距离关系以一种与3D接触频率、启动子DNA序列或该基因座上抑制性染色质标记的存在差异无关的方式明显不同。