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USF1 and hSET1A mediated epigenetic modifications regulate lineage differentiation and HoxB4 transcription.

Deng C, Li Y, Liang S, Cui K, Salz T, Yang H, Tang Z, Gallagher PG, Qiu Y, Roeder R, Zhao K, Bungert J, Huang S - PLoS Genet. (2013)

Bottom Line: Disruption of USF or hSET1A function by overexpression of a dominant-negative AUSF1 mutant or by RNA-interference-mediated knockdown, respectively, led to reduced expression of mesoderm markers and inhibition of lineage differentiation.We show that USF1 and hSET1A together regulate H3K4me3 modifications and transcription preinitiation complex assembly at the hematopoietic-associated HoxB4 gene during differentiation.Taken together, our findings reveal that the guided-recruitment of the hSET1A histone methyltransferase complex and its H3K4 methyltransferase activity by transcription regulator USF1 safeguards hematopoietic transcription programs and enhances mesoderm/hematopoietic differentiation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL, USA.

ABSTRACT
The interplay between polycomb and trithorax complexes has been implicated in embryonic stem cell (ESC) self-renewal and differentiation. It has been shown recently that WRD5 and Dpy-30, specific components of the SET1/MLL protein complexes, play important roles during ESC self-renewal and differentiation of neural lineages. However, not much is known about how and where specific trithorax complexes are targeted to genes involved in self-renewal or lineage-specification. Here, we report that the recruitment of the hSET1A histone H3K4 methyltransferase (HMT) complex by transcription factor USF1 is required for mesoderm specification and lineage differentiation. In undifferentiated ESCs, USF1 maintains hematopoietic stem/progenitor cell (HS/PC) associated bivalent chromatin domains and differentiation potential. Furthermore, USF1 directed recruitment of the hSET1A complex to the HoxB4 promoter governs the transcriptional activation of HoxB4 gene and regulates the formation of early hematopoietic cell populations. Disruption of USF or hSET1A function by overexpression of a dominant-negative AUSF1 mutant or by RNA-interference-mediated knockdown, respectively, led to reduced expression of mesoderm markers and inhibition of lineage differentiation. We show that USF1 and hSET1A together regulate H3K4me3 modifications and transcription preinitiation complex assembly at the hematopoietic-associated HoxB4 gene during differentiation. Finally, ectopic expression of USF1 in ESCs promotes mesoderm differentiation and enforces the endothelial-to-hematopoietic transition by inducing hematopoietic-associated transcription factors, HoxB4 and TAL1. Taken together, our findings reveal that the guided-recruitment of the hSET1A histone methyltransferase complex and its H3K4 methyltransferase activity by transcription regulator USF1 safeguards hematopoietic transcription programs and enhances mesoderm/hematopoietic differentiation.

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Recruitment of the hSET1A complex and H3K4me3 correlates with expression of the HoxB4 gene during hematopoiesis.(A) ChIP-seq and RNA-seq analyses of HoxB4 expression, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD34+ HSCs. (B) ChIP-seq and RNA-seq analyses of HoxB4 expression, hSET1A recruitment, RBBP5 binding, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD36+ Hematopoietic progenitors.
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pgen-1003524-g002: Recruitment of the hSET1A complex and H3K4me3 correlates with expression of the HoxB4 gene during hematopoiesis.(A) ChIP-seq and RNA-seq analyses of HoxB4 expression, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD34+ HSCs. (B) ChIP-seq and RNA-seq analyses of HoxB4 expression, hSET1A recruitment, RBBP5 binding, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD36+ Hematopoietic progenitors.

Mentions: The hSET1A complex is responsible for H3K4me3 patterns that mark transcriptionally active chromatin. Having implicated hSET1A in hematopoietic transcription of HoxB4 in K562 cells, we carried out un-biased ChIP-seq and RNA-seq analyses in human primary CD34+ HSCs and CD36+ progenitors to investigate whether targeting hSET1A and its HMT activity are critical for HoxB4 transcription during hematopoiesis. RNA-seq data revealed that HoxB4 was actively transcribed in both CD34+ and CD36+ cells (Figure 2A and B). Consistent with the transcription status of the HoxB4 gene in these cells, H3K4me3 and RNAPII were enriched around the transcription start site (TSS) of the HoxB4 gene compared to the IgG control which did not bind to the locus (Figure 2A and B). Furthermore, the hSET1A and RBBP5 components of the hSET1A complex were also associated with the TSS (Figure 2B), suggesting that recruitment of the hSET1A complex causes promoter H3K4 methylation and transcriptional activation of HoxB4 expression in hematopoietic cells. Moreover, the hSET1A complex, H3K4me3, and RNAPII were enriched in the highly transcribed β-actin gene but not in the silenced MyoD1 gene (Figure S2 and S3).


USF1 and hSET1A mediated epigenetic modifications regulate lineage differentiation and HoxB4 transcription.

Deng C, Li Y, Liang S, Cui K, Salz T, Yang H, Tang Z, Gallagher PG, Qiu Y, Roeder R, Zhao K, Bungert J, Huang S - PLoS Genet. (2013)

Recruitment of the hSET1A complex and H3K4me3 correlates with expression of the HoxB4 gene during hematopoiesis.(A) ChIP-seq and RNA-seq analyses of HoxB4 expression, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD34+ HSCs. (B) ChIP-seq and RNA-seq analyses of HoxB4 expression, hSET1A recruitment, RBBP5 binding, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD36+ Hematopoietic progenitors.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675019&req=5

pgen-1003524-g002: Recruitment of the hSET1A complex and H3K4me3 correlates with expression of the HoxB4 gene during hematopoiesis.(A) ChIP-seq and RNA-seq analyses of HoxB4 expression, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD34+ HSCs. (B) ChIP-seq and RNA-seq analyses of HoxB4 expression, hSET1A recruitment, RBBP5 binding, H3K4me3 enrichment, and RNAPII loading at the anterior HoxB locus in CD36+ Hematopoietic progenitors.
Mentions: The hSET1A complex is responsible for H3K4me3 patterns that mark transcriptionally active chromatin. Having implicated hSET1A in hematopoietic transcription of HoxB4 in K562 cells, we carried out un-biased ChIP-seq and RNA-seq analyses in human primary CD34+ HSCs and CD36+ progenitors to investigate whether targeting hSET1A and its HMT activity are critical for HoxB4 transcription during hematopoiesis. RNA-seq data revealed that HoxB4 was actively transcribed in both CD34+ and CD36+ cells (Figure 2A and B). Consistent with the transcription status of the HoxB4 gene in these cells, H3K4me3 and RNAPII were enriched around the transcription start site (TSS) of the HoxB4 gene compared to the IgG control which did not bind to the locus (Figure 2A and B). Furthermore, the hSET1A and RBBP5 components of the hSET1A complex were also associated with the TSS (Figure 2B), suggesting that recruitment of the hSET1A complex causes promoter H3K4 methylation and transcriptional activation of HoxB4 expression in hematopoietic cells. Moreover, the hSET1A complex, H3K4me3, and RNAPII were enriched in the highly transcribed β-actin gene but not in the silenced MyoD1 gene (Figure S2 and S3).

Bottom Line: Disruption of USF or hSET1A function by overexpression of a dominant-negative AUSF1 mutant or by RNA-interference-mediated knockdown, respectively, led to reduced expression of mesoderm markers and inhibition of lineage differentiation.We show that USF1 and hSET1A together regulate H3K4me3 modifications and transcription preinitiation complex assembly at the hematopoietic-associated HoxB4 gene during differentiation.Taken together, our findings reveal that the guided-recruitment of the hSET1A histone methyltransferase complex and its H3K4 methyltransferase activity by transcription regulator USF1 safeguards hematopoietic transcription programs and enhances mesoderm/hematopoietic differentiation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL, USA.

ABSTRACT
The interplay between polycomb and trithorax complexes has been implicated in embryonic stem cell (ESC) self-renewal and differentiation. It has been shown recently that WRD5 and Dpy-30, specific components of the SET1/MLL protein complexes, play important roles during ESC self-renewal and differentiation of neural lineages. However, not much is known about how and where specific trithorax complexes are targeted to genes involved in self-renewal or lineage-specification. Here, we report that the recruitment of the hSET1A histone H3K4 methyltransferase (HMT) complex by transcription factor USF1 is required for mesoderm specification and lineage differentiation. In undifferentiated ESCs, USF1 maintains hematopoietic stem/progenitor cell (HS/PC) associated bivalent chromatin domains and differentiation potential. Furthermore, USF1 directed recruitment of the hSET1A complex to the HoxB4 promoter governs the transcriptional activation of HoxB4 gene and regulates the formation of early hematopoietic cell populations. Disruption of USF or hSET1A function by overexpression of a dominant-negative AUSF1 mutant or by RNA-interference-mediated knockdown, respectively, led to reduced expression of mesoderm markers and inhibition of lineage differentiation. We show that USF1 and hSET1A together regulate H3K4me3 modifications and transcription preinitiation complex assembly at the hematopoietic-associated HoxB4 gene during differentiation. Finally, ectopic expression of USF1 in ESCs promotes mesoderm differentiation and enforces the endothelial-to-hematopoietic transition by inducing hematopoietic-associated transcription factors, HoxB4 and TAL1. Taken together, our findings reveal that the guided-recruitment of the hSET1A histone methyltransferase complex and its H3K4 methyltransferase activity by transcription regulator USF1 safeguards hematopoietic transcription programs and enhances mesoderm/hematopoietic differentiation.

Show MeSH
Related in: MedlinePlus