ATAC-seq reveals GATA-1- and heme-dependent chromatin targeting in erythroid cells.

CRISPR/Cas9-mediated ablation of two Alas2 intronic cis-elements in G1E-ER-GATA1 cells strongly reduced GATA-1-induced Alas2 transcription, heme biosynthesis, and GATA-1 regulation of other vital constituents of the erythroid cell transcriptome. Bypassing Alas2 function in Alas2 cis-element-mutant (double mutant) cells by providing its catalytic product 5-aminolevulinic acid (5-ALA) rescued heme biosynthesis and a subset of GATA-1-dependent genetic network. Using the same system, we discovered a GATA-1- and heme-dependent circuit that regulates chromatin accessibility during erythroid maturation. G1E-ER-GATA1 WT and double mutant cells were examined. Untreated WT, beta-estradiol-treated WT, untreated double mutant, beta-estradiol-treated double mutant and beta-estradiol/5-ALA-treated double mutant cells were subject to ATAC-seq.