DNA transposon MER81 carries two RELA motifs responsible for enhancer activity. (A) Genome browser view of an instance of a MER81-derived RELA-bound region. “−” and “+” denote basal and TNF stimulation, respectively. (B) Location of RELA motifs within the MER81 consensus sequence. Orange and gray represent RELA-bound and unbound instances determined by ChIP-seq, respectively. (C) Mean phastCons score for RELA-bound and unbound MER81 sequences. (D) Chromatin run-on sequencing signal (TeloHAEC ChRO-seq) at MER81-derived RELA sites before and after TNF stimulation. (E) Impact of CRISPR-Cas9 deletions of the RELA-bound MER81 element at the IFNGR2 and IFNAR1 locus. The plots show the qPCR-measured expression levels of IFNGR2 and IFNAR1 in wild-type and two MER81 knockout TeloHAEC lines (with/without TNF simulation for 45 min). One-sided t-test for comparisons that involve the same genotype (e.g., stimulated vs. unstimulated mutants) and unpaired one-sided t-test for ones that involve different genotypes. Error bars indicate standard error of the mean. Each biological replicate is shown with a unique shape in the figure.
