Transcription factor EKLF (KLF1) recruitment of the histone chaperone HIRA is essential for β-globin gene expression

Abstract

The binding of chromatin-associated proteins and incorporation of histone variants correlates with alterations in gene expression. These changes have been particularly well analyzed at the mammalian β-globin locus, where transcription factors such as erythroid Krüppel-like factor (EKLF), which is also known as Krüppel-like factor 1 (KLF1), play a coordinating role in establishing the proper chromatin structure and inducing high-level expression of adult β-globin. We had previously shown that EKLF preferentially interacts with histone H3 and that the H3.3 variant is differentially recruited to the β-globin promoter. We now find that a novel interaction between EKLF and the histone cell cycle regulation defective homolog A (HIRA) histone chaperone accounts for these effects. HIRA is not only critical for β-globin expression but is also required for activation of the erythropoietic regulators EKLF and GATA binding protein 1 (GATA1). Our results provide a mechanism by which transcription factor-directed recruitment of a generally expressed histone chaperone can lead to tissue-restricted changes in chromatin components, structure, and transcription at specific genomic sites during differentiation.

Neomorphic effects of the neonatal anemia (Nan-Eklf) mutation contribute to deficits throughout development

“…4B, left), Nan/Nan EBs are defective in generating late ( primitive or definitive) erythroid cells, as judged by the absence of Ter119 expression in these cells at day 6 or day 7 (Fig. 4B, left), which attains normal levels (Lohmann and Bieker, 2008;Soni et al, 2014) in the wild-type EBs.…”

“…Quantitative gel shifts were performed using GST-tagged EKLF zinc fingers (Bieker and Southwood, 1995), purified as previously described (Soni et al, 2014) and incubated with 32 P-labeled DNA oligonucleotide probes in 25 mM HEPES ( pH 7.5), 16 mM KCl, 50 mM NaCl, 2 µM ZnCl 2 , 0.6 mM β-mercaptoethanol and 8% glycerol for 30 min on ice at various concentrations (see figures and legends). A 10-fold molar excess of polydeoxyinosinic-deoxycytidylic acid (dIdC, Sigma-Aldrich) relative to the DNA probe was used to reduce non-specific binding.…”

The DEK Oncoprotein Is a Critical Component of the EKLF/KLF1 Enhancer in Erythroid Cells

“…Therefore, we focused on isolating proteins that interact with the particularly strong enhancer element located within EHS1. Using a biochemical affinity purification approach, we have identified transduction of 25 ϫ 10 4 murine erythroleukemic cells were carried out as described previously (33), followed by selection in 1 g/ml puromycin (Sigma). After 4 days, samples were prepared for mRNA and protein analysis.…”

“…Transfections, extractions, coprecipitation, and Western blot analyses were performed as described previously (33,45,46) using pFLag-Smad5 and pHA-DEK.…”

MicroRNA 200a inhibits erythroid differentiation by targeting PDCD4 and THRB

“…The regulation of erythroid differentiation has been examined previously, and multiple factors were found to be involved in the regulation of erythropoiesis (Tsiftsoglou et al, 2009). GATA1 (Zheng et al, 2006;Yu et al, 2009;Mancini et al, 2012;Ross et al, 2012;Zhu et al, 2013) and KLF1 (Zhou et al, 2010;Yien & Bieker, 2013;Soni et al, 2014) are essential transcriptional factors for erythropoiesis that aid in the regulation of globin, haem synthetase, erythroid and non-erythroid genes. Chromatin conformation was also found to have a role in regulating globin gene expression (Chang et al, 2012).…”