Krüppel-like Factor 4 activates HBG gene expression in primary erythroid cells

Inderdeep S. Kalra, Md M. Alam, Pankaj K. Choudhary, Betty Sue Pace

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The SP1/Krüppel-like Factor (SP1/KLF) family of transcription factors plays a role in diverse cellular processes, including proliferation, differentiation and control of gene transcription. The discovery of KLF1 (EKLF), a key regulator of HBB (β-globin) gene expression, expanded our understanding of the role of KLFs in erythropoiesis. In this study, we investigated a mechanism of HBG (γ-globin) regulation by KLF4 siRNA-mediated gene silencing and enforced expression of KLF4 in K562 cells substantiated the ability of KLF4 to positively regulate endogenous HBG gene transcription. The physiological significance of this finding was confirmed in primary erythroid cells, where KLF4 knockdown at day 11 significantly attenuated HBG mRNA levels and enforced expression at day 28 stimulated the silenced HBG genes. In vitro binding characterization using the γ-CACCC and β-CACCC probes demonstrated KLF4 preferentially binds the endogenous γ-CACCC, while CREB binding protein (CREBBP) binding was not selective. Co-immunoprecipitation studies confirmed protein-protein interaction between KLF4 and CREBBP. Furthermore, sequential chromatin immunoprecipitation assays showed co-localization of both factors in the γ-CACCC region. Subsequent luciferase reporter studies demonstrated that KLF4 trans-activated HBG promoter activity and that CREBBP enforced expression resulted in gene repression. Our data supports a model of antagonistic interaction of KLF4/CREBBP trans-factors in HBG regulation.

Original languageEnglish (US)
Pages (from-to)248-259
Number of pages12
JournalBritish Journal of Haematology
Volume154
Issue number2
DOIs
StatePublished - Jul 1 2011
Externally publishedYes

Fingerprint

CREB-Binding Protein
Erythroid Cells
Gene Expression
Globins
Genes
K562 Cells
Chromatin Immunoprecipitation
Erythropoiesis
Gene Silencing
Luciferases
Immunoprecipitation
Protein Binding
Small Interfering RNA
Proteins
Transcription Factors
Messenger RNA

Keywords

  • CREB binding protein
  • Erythroid cells
  • HBG
  • Krüppel-like Factor 12
  • Krüppel-like Factor 4

ASJC Scopus subject areas

  • Hematology

Cite this

Krüppel-like Factor 4 activates HBG gene expression in primary erythroid cells. / Kalra, Inderdeep S.; Alam, Md M.; Choudhary, Pankaj K.; Pace, Betty Sue.

In: British Journal of Haematology, Vol. 154, No. 2, 01.07.2011, p. 248-259.

Research output: Contribution to journalArticle

Kalra, Inderdeep S. ; Alam, Md M. ; Choudhary, Pankaj K. ; Pace, Betty Sue. / Krüppel-like Factor 4 activates HBG gene expression in primary erythroid cells. In: British Journal of Haematology. 2011 ; Vol. 154, No. 2. pp. 248-259.
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