Fig. 4: YY1–G4 interaction and dimerization of YY1 promote long-range DNA looping.
From: YY1 interacts with guanine quadruplexes to regulate DNA looping and gene expression
a, A schematic diagram showing the design of CRISPR–Cas9-based editing of an endogenous G4-forming sequence. PAM, protospacer adjacent motif. HA, homology arm. b,c, BG4 ChIP (b) and YY1 ChIP (c) enrichments of the site were substantially attenuated after mutation of the G4 sequence. d, YY1-mediated DNA looping was disrupted by mutation of the G4 sequence. Shown are the HiChIP–qPCR quantification results of YY1-mediated DNA looping in HEK293T cells with or without mutation of G4 sequence. e, A schematic diagram depicting the truncated YY1 protein that is defective in dimerization. aa, amino acid. f, ChIP enrichments for YY1, YY1∆231–290 and GST-YY1∆231–290 at sites 1 and 2. Sites 1 and 2 are the same sites as described in Extended Data Fig. 5. g, HiChIP–qPCR quantification results of YY1, YY1∆231–290- and GST-YY1∆231–290-mediated DNA looping. The data represent mean ± s.e.m. of results obtained from three independent experiments. The P values were calculated by using two-tailed Student’s t-test: **P < 0.01; ***P < 0.001; P = 0.0012 in b; P = 0.0015 in c; P = 0.0011 in d; P = 0.000031 and 0.0013 for YY1 and GST-YY1∆231–290, respectively, for site 1, and P = 0.0000034 and P = 0.0047 for YY1 and GST-YY1∆231–290, respectively, for site 2 in g.
