Fig. 2

CGGBP1 and CTCF interact variously in different cell types and subcellular fractions. a Reciprocal co-IPs confirmed interaction between CGGBP1 and CTCF in human foreskin fibroblast. b Reciprocal co-IPs in human dermal fibroblast showed a different pattern of CGGBP1–CTCF interaction. CGGBP1 and CTCF co-IP was positive only when the cells were stimulated after 48 h of starvation. The interaction between CTCF and CGGBP1 was stoichiometrically different in these cells as the pull-down of CGGBP1 with CTCF antibody was much weaker than that of CTCF using CGGBP1 antibody. c CGGBP1–CTCF interaction was confirmed in HEK-293T cells by reciprocal co-IPs. d CGGBP1 and CTCF co-IP assays were performed in cytoplasmic and nuclear fractions of HEK-293T cells separately. CTCF–CGGBP1 pull-downs showed presence of a major protein–protein complex and a minor protein-DNA–protein complex. The purity of nuclear and cytoplasmic fractions was ascertained by using histone H3 (H3K4me3 and H3K27me3) and GAPDH, respectively as markers (Additional file 2: Figure S3)