scholarly journals Erk signaling and chromatin remodeling in MMTV promoter activation by progestins

2009 ◽  
Vol 7 (1) ◽  
pp. nrs.07008 ◽  
Author(s):  
Guillermo P. Vicent ◽  
Roser Zaurin ◽  
Cecilia Ballaré ◽  
A. Silvina Nacht ◽  
Miguel Beato

Transcription from the mouse mammary tumor virus (MMTV) promoter can be induced by progestins. The progesterone receptor (PR) binds to a cluster of five hormone responsive elements (HREs) and activates the promoter by synergistic interactions with the ubiquitous transcription factor, nuclear factor 1 (NF1). Progesterone treatment of cells in culture leads to activation of the Src/Ras/Erk/Msk1 cascade. Selective inhibition of Erk, or its target kinase Msk1, interferes with chromatin remodeling and blocks MMTV activation. A complex of activated PR, Erk and Msk1 is recruited to promoter after 5 min of hormone treatment and phosphorylates histone H3 at serine 10. This modification promotes the displacement of HP1γ and subsequent chromatin remodeling. Progestin treatment leads to the recruitment of the BAF complex, which selectively displaces histones H2A and H2B from the nucleosome containing the HREs. The acetyltransferase PCAF is also required for induction of progesterone target genes and acetylates histone H3 at K14, an epigenetic mark, which interacts with Brg1 and Brm, anchoring the BAF complex to chromatin. In nucleosomes assembled on either MMTV or mouse rDNA promoter sequences, SWI/SNF displaces histones H2A and H2B from MMTV, but not from the rDNA nucleosome. Thus, the outcome of nucleosome remodeling by purified SWI/SNF depends on DNA sequence. The resultant H3/H4 tetramer particle is then the substrate for subsequent events in induction. Thus, initial activation of the MMTV promoter requires activation of several kinases and PCAF leading to phosphoacetylation of H3, and recruitment of BAF with subsequent removal of H2A/H2B.

2010 ◽  
Vol 24 (11) ◽  
pp. 2088-2098 ◽  
Author(s):  
Guillermo P. Vicent ◽  
A. Silvina Nacht ◽  
Roser Zaurín ◽  
Cecilia Ballaré ◽  
Jaime Clausell ◽  
...  

Abstract Steroid hormones regulate gene expression by interaction of their receptors with hormone-responsive elements on DNA or with other transcription factors, but they can also activate cytoplasmic signaling cascades. Rapid activation of Erk by progestins via an interaction of the progesterone receptor (PR) with the estrogen receptor is critical for transcriptional activation of the mouse mammary tumor virus (MMTV) promoter and other progesterone target genes. Erk activation leads to the phosphorylation of PR, activation of mitogen- and stress-activated protein kinase 1, and the recruitment of a complex of the three activated proteins and of P300/CBP-associated factor (PCAF) to a single nucleosome, resulting in the phosphoacetylation of histone H3 and the displacement of heterochromatin protein 1γ. Hormone-dependent gene expression requires ATP-dependent chromatin remodeling complexes. Two switch/sucrose nonfermentable-like complexes, Brahma-related gene 1-associated factor (BAF) and polybromo-BAF are present in breast cancer cells, but only BAF is recruited to the MMTV promoter and cooperates with PCAF during activation of hormone-responsive promoters. PCAF acetylates histone H3 at K14, an epigenetic mark recognized by BAF subunits, thus anchoring the complex to chromatin. BAF catalyzes localized displacement of histones H2A and H2B, facilitating access of nuclear factor 1 and additional PR complexes to the hidden hormone-responsive elements on the MMTV promoter. The linker histone H1 is a structural component of chromatin generally regarded as a general repressor of transcription. However, it contributes to a better regulation of the MMTV promoter by favoring a more homogeneous nucleosome positioning, thus reducing basal transcription and actually enhancing hormone induced transcription. During transcriptional activation, H1 is phosphorylated and displaced from the promoter. The kinase cyclin-dependent kinase 2 is activated after progesterone treatment and could catalyze progesterone-induced phosphorylation of histone H1 by chromatin remodeling complexes. The initial steps of gene induction by progestins involve changes in the chromatin organization of target promoters that require the activation of several kinase signaling pathways initiated by membrane anchored PR. Because these pathways also respond to other external signals, they serve to integrate the hormonal response in the global context of the cellular environment.


2004 ◽  
Vol 24 (7) ◽  
pp. 3036-3047 ◽  
Author(s):  
Sergey Belikov ◽  
Carolina Åstrand ◽  
Per-Henrik Holmqvist ◽  
Örjan Wrange

ABSTRACT Mouse mammary tumor virus (MMTV) promoter-driven transcription is induced by glucocorticoid hormone via binding of the glucocorticoid receptor (GR). The MMTV promoter also harbors a binding site for nuclear factor 1 (NF1). NF1 and GR were expressed in Xenopus oocytes; this revealed GR-NF1 cooperativity both in terms of DNA binding and chromatin remodeling but not transcription. A fraction of NF1 sites were occupied in a hormone-dependent fashion, but a significant and NF1 concentration-dependent fraction were constitutively bound. Activation of the MMTV promoter resulted in an ∼50-fold increase in the NF1 accessibility for its DNA site. The hormone-dependent component of NF1 binding was dissociated by addition of a GR antagonist; however, the antagonist RU486, which supports partial GR-DNA binding, also maintained partial NF1 binding. Hence GR-NF1 cooperativity is independent of agonist-driven chromatin remodeling. NF1 induced the formation of a micrococcal-nuclease-resistant protein-DNA complex containing the DNA segment from −185 to −55, the MMTV enhanceosome. Coexpression of NF1 and Oct1 resulted in a significant stimulation of hormone-induced MMTV transcription and also in increased basal transcription. We propose that hormone-independent NF1 binding may be involved in maintaining transcriptional competence and establishment of tissue-specific gene networks.


2002 ◽  
Vol 22 (18) ◽  
pp. 6471-6479 ◽  
Author(s):  
Hong Liu ◽  
Hyeog Kang ◽  
Rui Liu ◽  
Xin Chen ◽  
Keji Zhao

ABSTRACT The mammalian SWI/SNF-like chromatin-remodeling BAF complex plays several important roles in controlling cell proliferation and differentiation. Interferons (IFNs) are key mediators of cellular antiviral and antiproliferative activities. In this report, we demonstrate that the BAF complex is required for the maximal induction of a subset of IFN target genes by alpha IFN (IFN-α). The BAF complex is constitutively associated with the IFITM3 promoter in vivo and facilitates the chromatin remodeling of the promoter upon IFN-α induction. Furthermore, we show that the ubiquitous transcription activator Sp1 interacts with the BAF complex in vivo and augments the BAF-mediated activation of the IFITM3 promoter. Sp1 binds constitutively to the IFITM3 promoter in the absence of the BAF complex, suggesting that it may recruit and/or stabilize the BAF complex binding to the IFITM3 promoter. Our results bring new mechanistic insights into the antiproliferative effects of the chromatin-remodeling BAF complex.


2003 ◽  
Vol 23 (23) ◽  
pp. 8829-8845 ◽  
Author(s):  
Sungpil Yoon ◽  
Hongfang Qiu ◽  
Mark J. Swanson ◽  
Alan G. Hinnebusch

ABSTRACT The nucleosome remodeling complex SWI/SNF is a coactivator for yeast transcriptional activator Gcn4p. We provide strong evidence that Gcn4p recruits the entire SWI/SNF complex to its target genes ARG1 and SNZ1 but that SWI/SNF is dispensable for Gcn4p binding to these promoters. It was shown previously that Snf2p/Swi2p, Snf5p, and Swi1p interact directly with Gcn4p in vitro. However, we found that Snf2p is not required for recruitment of SWI/SNF by Gcn4p nor can Snf2p be recruited independently of other SWI/SNF subunits in vivo. Snf5p was not recruited as an isolated subunit but was required with Snf6p and Swi3p for optimal recruitment of other SWI/SNF subunits. The results suggest that Snf2p, Snf5p, and Swi1p are recruited only as subunits of intact SWI/SNF, a model consistent with the idea that Gcn4p makes multiple contacts with SWI/SNF in vivo. Interestingly, Swp73p is necessary for efficient SWI/SNF recruitment at SNZ1 but not at ARG1, indicating distinct subunit requirements for SWI/SNF recruitment at different genes. Optimal recruitment of SWI/SNF by Gcn4p also requires specific subunits of SRB mediator (Gal11p, Med2p, and Rox3p) and SAGA (Ada1p and Ada5p) but is independent of the histone acetyltransferase in SAGA, Gcn5p. We suggest that SWI/SNF recruitment is enhanced by cooperative interactions with subunits of SRB mediator and SAGA recruited by Gcn4p to the same promoter but is insensitive to histone H3 acetylation by Gcn5p.


2020 ◽  
Vol 21 (3) ◽  
pp. 762 ◽  
Author(s):  
Dominika M. Gratkowska-Zmuda ◽  
Szymon Kubala ◽  
Elzbieta Sarnowska ◽  
Pawel Cwiek ◽  
Paulina Oksinska ◽  
...  

SWI/SNF ATP-dependent chromatin remodeling complexes (CRCs) play important roles in the regulation of transcription, cell cycle, DNA replication, repair, and hormone signaling in eukaryotes. The core of SWI/SNF CRCs composed of a SWI2/SNF2 type ATPase, a SNF5 and two of SWI3 subunits is sufficient for execution of nucleosome remodeling in vitro. The Arabidopsis genome encodes four SWI2/SNF2 ATPases, four SWI3, a single SNF5 and two SWP73 subunits. Genes of the core SWI/SNF components have critical but not fully overlapping roles during plant growth, embryogenesis, and sporophyte development. Here we show that the Arabidopsis swi3c mutant exhibits a phenotypic reversion when grown at lower temperature resulting in partial restoration of its embryo, root development and fertility defects. Our data indicates that the swi3c mutation alters the expression of several genes engaged in low temperature responses. The location of SWI3C-containing SWI/SNF CRCs on the ICE1, MYB15 and CBF1 target genes depends on the temperature conditions, and the swi3c mutation thus also influences the transcription of several cold-responsive (COR) genes. These findings, together with genetic analysis of swi3c/ice1 double mutant and enhanced freezing tolerance of swi3c plants illustrate that SWI/SNF CRCs contribute to fine-tuning of plant growth responses to different temperature regimes.


2004 ◽  
Vol 24 (10) ◽  
pp. 4476-4486 ◽  
Author(s):  
Kairong Cui ◽  
Prafullakumar Tailor ◽  
Hong Liu ◽  
Xin Chen ◽  
Keiko Ozato ◽  
...  

ABSTRACT The elicitation of cellular antiviral activities is dependent on the rapid transcriptional activation of interferon (IFN) target genes. It is not clear how the interferon target promoters, which are organized into chromatin structures in cells, rapidly respond to interferon or viral stimulation. In this report, we show that alpha IFN (IFN-α) treatment of HeLa cells induced hundreds of genes. The induction of the majority of these genes was inhibited when one critical subunit of the chromatin-remodeling SWI/SNF-like BAF complexes, BAF47, was knocked down via RNA interference. Inhibition of BAF47 blocked the cellular response to viral infection and impaired cellular antiviral activity by inhibiting many IFN- and virus-inducible genes. We show that the BAF complex was required to mediate both the basal-level expression and the rapid induction of the antiviral genes. Further analyses indicated that the BAF complex primed some IFN target promoters by utilizing ATP-derived energy to maintain the chromatin in a constitutively open conformation, allowing faster and more potent induction after IFN-α treatment. We propose that constitutive binding of the BAF complex is an important mechanism for the IFN-inducible promoters to respond rapidly to IFN and virus stimulation.


2018 ◽  
Vol 115 (32) ◽  
pp. 8173-8178 ◽  
Author(s):  
Jian Sima ◽  
Zhijiang Yan ◽  
Yaohui Chen ◽  
Elin Lehrmann ◽  
Yongqing Zhang ◽  
...  

Ectodysplasin A (Eda) signaling activates NF-κB during skin appendage formation, but how Eda controls specific gene transcription remains unclear. Here, we find that Eda triggers the formation of an NF-κB–associated SWI/SNF (BAF) complex in which p50/RelB recruits a linker protein, Tfg, that interacts with BAF45d in the BAF complex. We further reveal that Tfg is initially induced by Eda-mediated RelB activation and then bridges RelB and BAF for subsequent gene regulation. The BAF component BAF250a is particularly up-regulated in skin appendages, and epidermal knockout of BAF250a impairs skin appendage development, resulting in phenotypes similar to those of Eda-deficient mouse models. Transcription profiling identifies several target genes regulated by Eda, RelB, and BAF. Notably, RelB and the BAF complex are indispensable for transcription of Eda target genes, and both BAF complex and Eda signaling are required to open chromatin of Eda targets. Our studies thus suggest that Eda initiates a signaling cascade and recruits a BAF complex to specific gene loci to facilitate transcription during organogenesis.


2021 ◽  
Author(s):  
Anne Helness ◽  
Jennifer Fraszczak ◽  
Charles Joly-Beauparlant ◽  
Halil Bagci ◽  
Christian Trahan ◽  
...  

Abstract GFI1 is a SNAG-domain, DNA binding transcriptional repressor which controls myeloid differentiation, in particular the formation of neutrophils. Here we show that GFI1 interacts with the chromodomain helicase CHD4 and other components of the “Nucleosome remodeling and deacetylase” (NuRD) complex. In granulo-monocytic precursors, GFI1, CHD4 or GFI1/CHD4 complexes occupy sites of open chromatin enriched for histone marks associated with active transcription suggesting that GFI1 recruits the NuRD complex to target genes that are regulated by active or bivalent promoters and active enhancers. Our data also show that GFI1 and GFI1/CHD4 complexes occupy promoters of different sets of genes that are either enriched for IRF1 or SPI-1 consensus sites, respectively. During neutrophil differentiation, overall chromatin closure and depletion of H3K4me2 occurs at different degrees depending on whether GFI1, CHD4 or both are present, indicating that GFI1 affects the chromatin remodeling activity of the NuRD complex. Moreover, GFI1/CHD4 complexes regulate chromatin openness and histone modifications differentially to enable regulation of target genes affecting the signaling pathways of the immune response or nucleosome organization or cellular metabolic processes.


Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 502 ◽  
Author(s):  
Ryan E. Hillmer ◽  
Brian A. Link

Hippo signaling controls cellular processes that ultimately impact organogenesis and homeostasis. Consequently, disease states including cancer can emerge when signaling is deregulated. The major pathway transducers Yap and Taz require cofactors to impart transcriptional control over target genes. Research into Yap/Taz-mediated epigenetic modifications has revealed their association with chromatin-remodeling complex proteins as a means of altering chromatin structure, therefore affecting accessibility and activity of target genes. Specifically, Yap/Taz have been found to associate with factors of the GAGA, Ncoa6, Mediator, Switch/sucrose nonfermentable (SWI/SNF), and Nucleosome Remodeling and Deacetylase (NuRD) chromatin-remodeling complexes to alter the accessibility of target genes. This review highlights the different mechanisms by which Yap/Taz collaborate with other factors to modify DNA packing at specific loci to either activate or repress target gene transcription.


2000 ◽  
Vol 14 (7) ◽  
pp. 956-971 ◽  
Author(s):  
Catharine L. Smith ◽  
Ronald G. Wolford ◽  
Tara B. O’Neill ◽  
Gordon L. Hager

Abstract Activated steroid receptors induce chromatin remodeling events in the promoters of some target genes. We previously reported that transiently expressed progesterone receptor (PR) cannot activate mouse mammary tumor virus (MMTV) promoter when it adopts the form of ordered chromatin. However, when expressed continuously, the PR acquires this ability. In this study we explored whether this gain of function occurs through alterations in nucleoprotein structure at the MMTV promoter or through changes in receptor status. We observed no major structural differences at the MMTV promoter in the presence of constitutively expressed PR and found its mechanism of activation to be very similar to that of the glucocorticoid receptor (GR). However, a systematic comparison of the functional behavior of the transiently and constitutively expressed PR elucidated significant differences. The transiently expressed PR is activated in the absence of ligand by cAMP and by components in FBS and has significantly increased sensitivity to progestins. In contrast, the constitutively expressed PR is refractory to activation by cAMP and serum and has normal sensitivity to its ligand. In addition, while the PR is localized to the nucleus in both cases, a significant fraction of the transiently expressed PR is tightly bound to the nucleus even in the absence of ligand, while the majority of constitutively expressed PR is not. These results strongly suggest that the PR undergoes processing in the cell subsequent to its initial expression and that this processing is important for various aspects of its function, including its ability to productively interact with target genes that require chromatin remodeling for activation.


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