Updated project metadata.
Reactivation of fetal hemoglobin expression by down-regulation of BCL11A is a promising treatment of -hemoglobinopathies. A detailed understanding of BCL11A-mediated repression of -globin gene (HBG1/2) transcription is lacking, as studies to date used perturbations by shRNA or CRISPR/Cas9 gene editing. We leveraged the dTAG PROTAC platform to acutely deplete BCL11A protein in erythroid cells and examined consequences by PRO-seq, proteomics, chromatin accessibility, and histone profiling. Among ≤ 31 genes repressed by BCL11A, HBG1/2 and HBZ show the most abundant and progressive changes in transcription and chromatin accessibility upon BCL11A loss. Transcriptional changes at HBG1/2 were detected in < 2h. Robust HBG1/2 reactivation upon acute BCL11A-depletion occurred without loss of promoter 5methylcytosine (5mC). Using targeted protein degradation, we establish a hierarchy of gene reactivation at BCL11A targets, in which nascent transcription is followed by increased chromatin accessibility, and both are uncoupled from promoter DNA methylation at the HBG1/2 loci