Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing [Capture-C]

ABSTRACT: HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing [Capture-C]

PROVIDER: PRJNA602343 | ENA |

REPOSITORIES: ENA

ACCESS DATA

Json Xml

Similar Datasets

HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing [Capture-C]

Project description:Through a CRISPR-Cas9 guided loss-of-function screen in human erythroid cells we identified transcription factor ATF4, a known HRI-regulated protein, as a novel γ-globin repressor. ATF4 binds to a BCL11A enhancer to augment promoter contacts, stimulates BCL11A transcription to repress γ-globin expression. Notably, mice deficient for HRI displayed normal Bcl11a levels, suggesting species selective regulation that we explain here by demonstrating that the analogous ATF4 motif at the murine Bcl11a enhancer is largely dispensable. This illustrates potential limits of commonly used murine models of globin gene regulation.

2020-04-17 | GSE143962 | GEO

HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing [ChIP-seq]

2020-04-17 | GSE143961 | GEO

HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing

Project description:HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing

| PRJNA602341 | ENA

HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing [ChIP-seq]

Project description:HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing [ChIP-seq]

| PRJNA602344 | ENA

HRI depletion cooperates with pharmacologic inducers to elevate fetal hemoglobin and reduce sickle cell formation

Project description:Increasing fetal hemoglobin (HbF) provides clinical benefit in patients with sickle cell disease (SCD). We recently identified heme-regulated inhibitor (HRI, EIF2AK1) as a novel HbF regulator. Since HRI is an erythroid-specific protein kinase it presents a potential target for pharmacologic intervention. We find that maximal HbF induction requires >80-85% HRI depletion. As it remains unclear whether this degree of HRI inhibition can be achieved pharmacologically, we explored whether HRI knockdown can be combined with pharmacologic HbF inducers to achieve greater HbF production and minimize potential adverse effects associated with treatments. Strongly cooperative HbF induction was observed when HRI depletion was combined with exposure to pomalidomide or the EHMT1/2 inhibitor UNC0638, but not hydroxyurea. Mechanistically, reduction in the levels of the HbF repressor BCL11A reflected the cooperativity of HRI loss and pomalidomide treatment, whereas UNC0638 did not modulate BCL11A levels. In conjunction with HRI loss, pomalidomide maintained its HbF inducing activity at 10-fold lower concentrations, at which condition there were minimal observed detrimental effects on erythroid cell maturation and viability as well as fewer alterations in the erythroid transcriptome. In sum, this study provides a foundation for the exploration of combining future small molecule HRI inhibitors with additional pharmacologic HbF inducers to maximize HbF production and preserve erythroid cell functionality for the treatment of SCD and other hemoglobinopathies.

2020-09-21 | GSE150341 | GEO

Domain-focused CRISPR-screen identifies HRI as a fetal hemoglobin regulator in human erythroid cells

Project description:Increasing fetal hemoglobin (HbF) levels in adult red blood cells provides clinical benefit to patients with sickle cell disease and some forms of beta-thalassemia. To identify potentially druggable HbF regulators in adult human erythroid cells, we employed a protein kinase-domain focused CRISPR/Cas9-based genetic screen with a newly optimized sgRNA scaffold. The screen uncovered the heme-regulated inhibitor HRI (also known as EIF2AK1), an erythroid-specific kinase that controls protein translation, as an HbF repressor. HRI depletion markedly increased HbF production in a specific manner and reduced sickling in cultured erythroid cells. Diminished expression of the HbF repressor BCL11A accounted in large part for the effects of HRI depletion. Taken together, these results suggest HRI as a potential therapeutic target for hemoglobinopathies.

2018-07-20 | GSE115687 | GEO

The HRI-regulated transcription factor ATF4 activates BCL11A transcription to silence fetal hemoglobin expression.

Project description: Not available

| S-EPMC7290097 | biostudies-literature

Let-7 miRNAs repress HIC2 to regulate BCL11A transcription and hemoglobin switching [Capture-C]

Project description:The fetal hemoglobin (HBG) regulator BCL11A is repressed by HIC2 to regulate hemoglobin switching. HIC2 itself is under developmental control, highly expressed in fetal tissues and decreased in adult cells, but the mechanism of this developmental regulation is unclear. Here, we demonstrate that HIC2 is developmentally controlled by miRNAs, and loss of global miRNA biogenesis through DICER1 depletion leads to upregulation of HIC2 and HBG. We subsequently identify the adult-expressed let-7 miRNA family as a repressor of HIC2 expression. Ectopic expression of let-7 in fetal-type cells repressed HIC2 levels, while let-7 inhibition in adult erythroblasts upregulated HIC2 levels. Let-7 regulates BCL11A and HBG through induction of HIC2 and reduction of GATA1 binding at the BCL11A erythroid enhancer. Finally, HIC2 depletion rescues BCL11A-mediated repression of fetal hemoglobin in let-7 inhibited cells. Together these data demonstrate a key miRNA-mediated mechanism for developmental regulation of BCL11A expression and fetal hemoglobin repression in adult erythroid cells.

2024-02-05 | GSE216194 | GEO

HIC2 represses BCL11A transcription to regulate hemoglobin switching during development (Capture-C)

Project description:The switch from fetal to adult hemoglobin production has been studied in great depth in part because of its relevance to the treatment of hemolobinopathies. Transcription factor BCL11A, which is essential for repression of the fetal beta-type globin (γ-globin) genes after birth, is largely controlled at the level of transcription but the mechanism of BCL11A developmental control is unknown. Here, using a CRISPR-Cas9 screen in human erythroblasts, we identify transcription factor HIC2 as a repressor of BCL11A transcription. HIC2 and BCL11A expression are anti-correlated in fetal and adult erythroblasts. Forced expression of HIC2 in adult erythroblasts silences BCL11A transcription and markedly induces γ-globin expression. HIC2 binds selectively to constituent erythroid developmental BCL11A enhancer to reduce chromatin accessibility and impair access by transcription factor GATA1, resulting in loss of enhancer activity and enhancer-promoter contacts. Conversely, loss of HIC2 in fetal erythroblasts increases enhancer accessibility, enables GATA1 binding and induces BCL11A transcription. HIC2 is unveiled as a critical evolutionarily conserved regulator of globin gene switching by imposing developmental control on the BCL11A gene.

2022-05-26 | GSE173583 | GEO

HRI activates ATF4 to promote BCL11A transcription and fetal hemoglobin silencing

Project description:This SuperSeries is composed of the SubSeries listed below.

2020-04-17 | GSE143963 | GEO