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Direct Promoter Repression by BCL11A Controls the Fetal to Adult Hemoglobin Switch

ABSTRACT: Fetal hemoglobin (HbF) level is genetically controlled and modifies severity of adult hemoglobin (HbA) disorders. Common genetic variation affects expression of BCL11A, a critical regulator of HbF silencing. Current models suggest that BCL11A acts at a distance from the gamma-globin genes via long-distance chromosomal interactions. Here we use a functional cellular assay and protein-binding microarray to establish a requirement for a zinc-finger cluster of BCL11A for globin repression, and identify a preferred DNA recognition sequence (TGACCA). The motif is present in embryonic and fetal-expressed globin promoters, and duplicated in gamma-globin promoters, yet only the distal motif is mutated in alleles of individuals with hereditary persistence of hemoglobin. Using CUT&RUN to map protein binding sites, we detected BCL11A occupancy preferentially at the distal motif, and validated its absence in HbF-expressing, promoter-edited erythroid cells. Taken together, our findings reveal that direct gamma-globin gene promoter repression by BCL11A underlies hemoglobin switching.

ORGANISM(S): Homo sapiens

PROVIDER: GSE104676 | GEO | 2018/03/30

REPOSITORIES: GEO

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Transcription factor competition at the γ-globin promoters controls hemoglobin switching [CUT&RUN]

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