ATF4 regulates BCL11A in a species-selective manner. (A) Venn diagrams of the ATF4 ChIP-seq peaks in G1E-ER4 cells and the most enriched ATF4 binding motif. (B) ATF4 binding profile at mouse Bcl11a +55 enhancer. The sgRNA targeting the mouse ATF4 consensus motif is underlined, and the PAM sequence is shown in bold. (C) Representative ATF4 ChIP-seq track of the murine Bcl11a locus. The region orthologous to the human BCL11A +55 enhancer is highlighted in purple. ATAC-seq was obtained from ENCODE (ENCSR428BSK), and H3K27ac was obtained from published data.42 (D) Bcl11a (left) and Hbb-bh1 (right) mRNA levels in indicated cells. Note: the loss of function of Bcl11a by the sgRNA targeting exon 2 did not diminish transcript levels but depleted Bcl11a protein levels. Results are shown as mean ± standard deviation (n = 3). (E) Model depicting HRI and ATF4 regulation of BCL11A and γ-globin levels. **P < .01 by Student t test. n.s., not significant.