The E3 ligase adaptor molecule SPOP regulates fetal hemoglobin levels in adult erythroid cells.
Xianjiang LanEugene KhandrosPeng HuangScott A PeslakSaurabh K BhardwajJeremy D GrevetOsheiza AbdulmalikHongxin WangCheryl A KellerBelinda M GiardineJosue BaezaEmily R DuffnerOsama El DemerdashXiaoli S WuChristopher R VakocBenjamin A GarciaRoss Cameron HardisonJunwei ShiGerd A BlobelPublished in: Blood advances (2020)
Reactivation of fetal hemoglobin (HbF) production benefits patients with sickle cell disease and β-thalassemia. To identify new HbF regulators that might be amenable to pharmacologic control, we screened a protein domain-focused CRISPR-Cas9 library targeting chromatin regulators, including BTB domain-containing proteins. Speckle-type POZ protein (SPOP), a substrate adaptor of the CUL3 ubiquitin ligase complex, emerged as a novel HbF repressor. Depletion of SPOP or overexpression of a dominant negative version significantly raised fetal globin messenger RNA and protein levels with minimal detrimental effects on normal erythroid maturation, as determined by transcriptome and proteome analyses. SPOP controls HbF expression independently of the major transcriptional HbF repressors BCL11A and LRF. Finally, pharmacologic HbF inducers cooperate with SPOP depletion during HbF upregulation. Our study implicates SPOP and the CUL3 ubiquitin ligase system in controlling HbF production in human erythroid cells and may offer new therapeutic strategies for the treatment of β-hemoglobinopathies.
Keyphrases
- transcription factor
- induced apoptosis
- crispr cas
- gene expression
- poor prognosis
- amino acid
- protein protein
- cell cycle arrest
- binding protein
- cell proliferation
- endothelial cells
- dna damage
- newly diagnosed
- small molecule
- genome editing
- long non coding rna
- drug delivery
- prognostic factors
- young adults
- cancer therapy
- dna methylation
- sickle cell disease
- pi k akt
- induced pluripotent stem cells
- pluripotent stem cells