Dissection of protein and RNA regions required for SPEN binding to XIST A-repeat RNA

Four XIST A-repeat units are sufficient for high-affinity SPEN_{RRM 1–4} binding. (A) Diagram of XIST RNA constructs containing various A-repeat sequence units from repeats 1 through 9 (solid rectangles), and U-rich linker or additional sequences (hashed rectangles). (B) Comparison of binding affinities for SPEN_{RRM 1–4} to all XIST RNA constructs, SRA, BARD1, or tRNA_Cys negative controls. Dark blue color indicates high-affinity binding of the RNA construct to SPEN_{RRM 1–4}. Light blue color indicates a significant decrease in SPEN–RNA binding compared to XIST_A-full transcript, n = 3–6. (*) P < 0.05, (**) P < 0.01, (***) P < 0.001. Data are the mean ± SEM.