HEXIM1 OE results in redistribution of GATA1 occupancy. (A) Heat map of differential GATA1 occupancy in EV, HEXIM1 OE, and Y271A OE lines. (B) PC analysis plot based on GATA1 occupancy in EV, HEXIM1 OE, and Y271A OE cell lines. (C) Volcano plot of differential GATA1 occupancy in EV and HEXIM1 OE cells. (D) Motif analysis of GATA1 binding sites gained in HEXIM1 OE cells. (E) GATA1, Ser5, and total RNAPII occupancy at the β-globin locus in indicated cell lines. (F) Gene ontology terms enriched for genomic regions that gained GATA1 in HEXIM1 OE cells. (G) Genomic annotation of gained GATA1 binding sites. (H) Venn diagram showing overlap of GATA1 occupancy in HEXIM1 OE and EV lines (left), and chromatin accessibility at GATA1 sites gained in HEXIM1 OE lines (right). (I) Chromatin accessibility levels in WT HUDEP-2 cells at previously established and gained GATA1 sites (left) and H3K27ac occupancy in WT HUDEP-2 cells at previously established and gained GATA1 sites (right). (J) Heat maps showing chromatin accessibility and H3K27ac at gained and shared GATA1 sites in WT HUDEP-2 cells. (K) Quantification of chromatin accessibility (top) and H3K27ac occupancy (bottom) at shared and gained GATA1 sites. (L) Examples of RUNXT1, which gained GATA1 occupancy, chromatin accessibility, and RNAPII occupancy at the promoter region; and BCL11a, which lost both GATA1 and RNAPII occupancy at the well-established +55 enhancer region. (M) Venn diagrams showing the open chromatin regions in HUDEP-1 and HUDEP-2 cell lines. (N) GATA1 occupancy at the HUDEP-1 or HUDEP-2 only open chromatin regions in the EV, HEXIM1 OE, and Y271A OE cell lines. HBB, hemoglobin subunit beta; HBG, hemoglobin subunit gamma; UTR, untranslated region.