Deciphering the role of RNA in regulating CTCF's DNA binding affinity in leukemia cells.

BACKGROUND: CTCF, a highly studied transcription factor, is essential for chromatin interaction maintenance. Several independent studies report that CTCF interacts with RNAs in vitro and in cells. Yet continuous debates about the authenticity of the RNA-binding affinity of CTCF and its biological role remain in large part due to limited research techniques available, such as CLIP-seq. RESULT: Here, we investigate RNA's role in CTCF's transcription factor function through its chromatin occupancy. To systematically explore whether RNAs affect CTCF's ability to bind DNA, we perturb CTCF-RNA interactions by three independent approaches and examine CTCF genome occupancy by ChIP-seq. Although RNase A and triptolide treatment each affect a certain number of CTCF-binding peaks, few peaks overlap between treatment groups indicating the effect of RNA in regulating CTCF's DNA binding affinity is variable between loci. In addition, limited transcriptional or chromatin accessibility changes occur between cells expressing wild-type CTCF or CTCF lacking the RNA binding region. CONCLUSION: Our data provide a complementary approach and in silico evidence to consider the significance of RNA affecting CTCF's DNA binding affinity globally.