IUGR increases chromatin-remodeling factor Brg1 expression and binding to GR exon 1.7 promoter in newborn male rat hippocampus

2015 ◽  
Vol 309 (2) ◽  
pp. R119-R127 ◽  
Author(s):  
Xingrao Ke ◽  
Robert A. McKnight ◽  
Lia E. Gracey Maniar ◽  
Ying Sun ◽  
Christopher W. Callaway ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Male Rat ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Mrna Variant ◽  
Active Transcription ◽  
Carboxy Terminal ◽  
Specificity Protein ◽  
Target Promoters ◽  
Rat Pup

Intrauterine growth restriction (IUGR) increases the risk for neurodevelopment delay and neuroendocrine reprogramming in both humans and rats. Neuroendocrine reprogramming involves the glucocorticoid receptor ( GR) gene that is epigenetically regulated in the hippocampus. Using a well-characterized rodent model, we have previously shown that IUGR increases GR exon 1.7 mRNA variant and total GR expressions in male rat pup hippocampus. Epigenetic regulation of GR transcription may involve chromatin remodeling of the GR gene. A key chromatin remodeler is Brahma-related gene-1( Brg1), a member of the ATP-dependent SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex. Brg1 regulates gene expression by affecting nucleosome repositioning and recruiting transcriptional components to target promoters. We hypothesized that IUGR would increase hippocampal Brg1 expression and binding to GR exon 1.7 promoter, as well as alter nucleosome positioning over GR promoters in newborn male pups. Further, we hypothesized that IUGR would lead to accumulation of specificity protein 1 ( Sp1) and RNA pol II at GR exon 1.7 promoter. Indeed, we found that IUGR increased Brg1 expression and binding to GR exon 1.7 promoter. We also found that increased Brg1 binding to GR exon 1.7 promoter was associated with accumulation of Sp1 and RNA pol II carboxy terminal domain pSer-5 (a marker of active transcription). Furthermore, the transcription start site of GR exon 1.7 was located within a nucleosome-depleted region. We speculate that changes in hippocampal Brg1 expression mediate GR expression and subsequently trigger neuroendocrine reprogramming in male IUGR rats.

Differing Domain-Specific Roles of KLF1 At the LCR and β-Globin Promoter.,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3189-3189
Author(s):  
Aurelie Desgardin ◽  
Valerie M. Jansen ◽  
Tatiana Abramova ◽  
Eun-Hee Shim ◽  
John M Cunningham
Keyword(s):  
Transcription Factors ◽  
Chromatin Remodeling ◽  
Globin Gene ◽  
Gene Promoter ◽  
Erythroid Cell ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Globin Promoter ◽  
Carboxy Terminal

Abstract Abstract 3189 Binding of the Krüppel-like Factor 1 (KLF1) to the β-globin gene promoter is required for developmental stage-specific chromatin remodeling and transcriptional initiation. Interaction with a long-range enhancer, the Locus Control Region (LCR) is also required for maximal gene expression. KLF1 binds the LCR, and has been described recently as a facilitator of the proximal clustering of the LCR with the β-globin gene promoter region. To elucidate the role(s) of KLF1 at the LCR and their relationship to β-globin gene activation, we evaluated KLF1-directed events across the β-globin locus using a 4-OH-Tamoxifen KLF-1 inducible erythroid cell line. KLF1 binding was maximal 1 hour post-induction at the LCR, whereas 2 hours elapsed prior to maximal occupancy at the β-globin promoter. The site-specific differential in factor occupancy is consistent with the notion that the LCR serves as a nucleating docking element for sequence-specific transcription factors as well as the RNA Pol-II complex. LCR occupancy by Pol-II, p45 NF-E2, GATA-1 and the SCL/LMO2/Ldb1 complex was KLF1-independent. In contrast, the occupancy of the β-globin promoter by Pol-II and erythroid-restricted factors was dependent on maximal KLF-1 binding. Interestingly, the SCL/LMO2/Ldb1 complex was recruited first, consistent with the idea that this complex is required for LCR/promoter interaction. Interestingly, we have identified a direct protein-protein interaction between the carboxy terminal (aa221–396) domain of KLF1 (Δ221KLF1) and Ldb1, the factor implicated as critical for distal regulatory loci interactions at the β-globin locus. To dissect these events in vivo, we took advantage of a novel KLF1 knock-in strain (Δ221KLF1). In these animals, the endogenous KLF1 gene is replaced with a carboxy-terminal domain (aa221–396) expression cassette, resulting in DNA binding of the mutant factor, with β-globin chromatin remodeling. However, Δ221KLF1 fetal liver erythroblasts fail to activate the KLF1-dependent gene network, and have the identical differentiation defect characteristic of KLF1-null erythroblasts. Chromatin remodeling at the β-globin failed to result in recruitment of GATA-1, NF-E2, or the SCL/LMO2/Ldb1 complex. In contrast, ChIP analyses of the LCR in Δ221KLF1 erythroblasts revealed rescue of RNA Pol-II, GATA-1 and the SCL/LMO2/Ldb1 complex occupancy to wild type levels. Structural studies, utilizing the chromosome conformation capture (3C) assay, revealed that an incomplete re-configuration of the locus in Δ221 KLF1 mice. In conclusion, the chromatin remodeling domain of KLF1 is sufficient to reconfigure the LCR. However, KLF1-dependent Ldb1 recruitment at the LCR is insufficient to promote adequate communication between the two regulatory elements of the β-globin gene. Preliminary data suggest that an adjacent domain (aa163–221) is sufficient to rescue β-globin transcription in vivo. Together, these domains (aa163–396) are sufficient to promote the appropriate loading of transcription factors at the β-globin promoter in conjunction with locus structural re-configuration. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Maize RAMOSA3 accumulates in nuclear condensates enriched in RNA POLYMERASE II isoforms during the establishment of axillary meristem determinacy.

2021 ◽  
Author(s):  
Edgar Demesa-Arevalo ◽  
Maria Jazmin Abraham-Juarez ◽  
Xiaosa Xu ◽  
Madelaine Bartlett ◽  
David Jackson
Keyword(s):  
Rna Polymerase Ii ◽  
Chromatin Remodeling ◽  
Transcriptional Response ◽  
Mrna Processing ◽  
Nuclear Speckles ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Imaging Processing ◽  
Whole Mount ◽  
Double Immunolabeling

Maize meristem determinacy is regulated by Trehalose-6-Phosphate Phosphatase (TPP) metabolic enzymes RAMOSA3 and TPP4. However, this function is independent of their enzymatic activity, suggesting they have an unpredicted, or moonlighting function. Using whole-mount double immunolabeling and imaging processing, we investigated the co-localization of RA3 nuclear speckles with markers for transcription, chromatin state and splicing. We find evidence for RA3 co-localization with RNA POL II, a transcription marker, and not with markers for promoter chromatin remodeling or mRNA processing, suggesting a function of nuclear RA3 in mediating a transcriptional response during meristem determinacy.

scholarly journals The yeast prefoldin-like URI-orthologue Bud27 associates with the RSC nucleosome remodeler and modulates transcription

2014 ◽  
Vol 42 (15) ◽  
pp. 9666-9676 ◽  
Author(s):  
María Carmen Mirón-García ◽  
Ana Isabel Garrido-Godino ◽  
Verónica Martínez-Fernández ◽  
Antonio Fernández-Pevida ◽  
Abel Cuevas-Bermúdez ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Molecular Chaperones ◽  
Protein Complexes ◽  
Rna Polymerases ◽  
Dependent Manner ◽  
Rna Pol Ii ◽  
Present Evidence ◽  
Pol Ii ◽  
Chromatin Remodeling Complex

Abstract Bud27, the yeast orthologue of human URI/RMP, is a member of the prefoldin-like family of ATP-independent molecular chaperones. It has recently been shown to mediate the assembly of the three RNA polymerases in an Rpb5-dependent manner. In this work, we present evidence of Bud27 modulating RNA pol II transcription elongation. We show that Bud27 associates with RNA pol II phosphorylated forms (CTD-Ser5P and CTD-Ser2P), and that its absence affects RNA pol II occupancy of transcribed genes. We also reveal that Bud27 associates in vivo with the Sth1 component of the chromatin remodeling complex RSC and mediates its association with RNA pol II. Our data suggest that Bud27, in addition of contributing to Rpb5 folding within the RNA polymerases, also participates in the correct assembly of other chromatin-associated protein complexes, such as RSC, thereby modulating their activity.

scholarly journals TheESS1Prolyl Isomerase and Its SuppressorBYE1Interact With RNA Pol II to Inhibit Transcription Elongation inSaccharomyces cerevisiae

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 1687-1702 ◽  
Author(s):  
Xiaoyun Wu ◽  
Anne Rossettini ◽  
Steven D Hanes
Keyword(s):  
Rna Polymerase Ii ◽  
Conformational Changes ◽  
Protein Complexes ◽  
Transcription Elongation ◽  
Negative Regulator ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Multicopy Suppressors ◽  
Carboxy Terminal

AbstractTranscription by RNA polymerase II (pol II) requires the ordered binding of distinct protein complexes to catalyze initiation, elongation, termination, and coupled mRNA processing events. One or more proteins from each complex are known to bind pol II via the carboxy-terminal domain (CTD) of the largest subunit, Rpb1. How binding is coordinated is not known, but it might involve conformational changes in the CTD induced by the Ess1 peptidyl-prolyl cis/trans isomerase. Here, we examined the role of ESS1 in transcription by studying one of its multicopy suppressors, BYE1. We found that Bye1 is a negative regulator of transcription elongation. This led to the finding that Ess1 also inhibits elongation; Ess1 opposes elongation factors Dst1 and Spt4/5, and overexpression of ESS1 makes cells more sensitive to the elongation inhibitor 6-AU. In reporter gene assays, ess1 mutations reduce the ability of elongation-arrest sites to stall polymerase. We also show that Ess1 acts positively in transcription termination, independent of its role in elongation. We propose that Ess1-induced conformational changes attenuate pol II elongation and help coordinate the ordered assembly of protein complexes on the CTD. In this way, Ess1 might regulate the transition between multiple steps of transcription.

scholarly journals GSK3β-SCFFBXW7 mediated phosphorylation and ubiquitination of IRF1 are required for its transcription-dependent turnover

2018 ◽  
Author(s):  
Alexander J. Garvin ◽  
Ahmed H.A. Khalaf ◽  
Alessandro Rettino ◽  
Jerome Xicluna ◽  
Laura Butler ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Lines ◽  
Target Genes ◽  
Glycogen Synthase ◽  
Ubiquitin Proteasome System ◽  
Receptor Protein ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Ubiquitin E3 Ligase ◽  
Target Promoters

ABSTRACTIRF1 (Interferon Regulatory Factor-1) is the prototype of the IRF family of DNA binding transcription factors. IRF1 protein expression is regulated by transient up-regulation in response to external stimuli followed by rapid degradation via the ubiquitin-proteasome system. Here we report that DNA bound IRF1 turnover is promoted by GSK3β (Glycogen Synthase Kinase 3β) via phosphorylation of the T181 residue which generates a phosphodegron for the SCF (Skp-Cul-Fbox) ubiquitin E3-ligase receptor protein Fbxw7α (F-box/WD40 7). This regulated turnover is essential for IRF1 activity, as mutation of T181 results in an improperly stabilised protein that accumulates at target promoters but fails to induce RNA-Pol-II elongation and subsequent transcription of target genes. Consequently, the anti-proliferative activity of IRF1 is lost in cell lines expressing T181A mutant. Further, cell lines with dysfunctional Fbxw7 are less sensitive to IRF1 overexpression, suggesting an important co-activator function for this ligase complex. As T181 phosphorylation requires both DNA binding and RNA-Pol-II elongation, we propose that this event acts to clear “spent” molecules of IRF1 from transcriptionally engaged target promoters.

scholarly journals TATA-binding protein is limiting for both TATA-containing and TATA-lacking RNA polymerase III promoters in Drosophila cells.

1996 ◽  
Vol 16 (12) ◽  
pp. 6909-6916 ◽  
Author(s):  
A Trivedi ◽  
A Vilalta ◽  
S Gopalan ◽  
D L Johnson
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Tata Binding Protein ◽  
Gene Promoters ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Pol Iii ◽  
Carboxy Terminal ◽  
Drosophila Cells ◽  
U6 Rna

We have investigated the role of the TATA-binding protein (TBP) in modulating RNA polymerase (Pol) III gene activity. Epitope-tagged TBP (e-TBP) was both transiently and stably transfected in Drosophila Schneider S-2 cells to increase the total cellular level of TBP. Analysis of the transcripts synthesized from cotransfected tRNA and U6 RNA genes revealed that both types of RNA Pol III promoters were substantially stimulated by an increase in e-TBP in a dose-dependent manner. Furthermore, a TBP-dependent increase in the levels of endogenous tRNA transcripts was produced in the stable line induced to express the e-TBP. We further determined whether the ability of increased TBP to induce RNA Pol III gene expression was due to a direct effect of increased TBP complexes on RNA Pol III gene promoters or an indirect consequence of enhanced expression of RNA Pol II genes. A TBP expression plasmid (e-TBP332), containing a mutation within the highly conserved carboxy-terminal domain, was both transiently and stably transfected into S-2 cells. e-TBP332 augmented the transcription from two RNA Pol II gene promoters indistinguishably from that observed when e-TBP was expressed. In contrast, e-TBP332 was completely defective in its ability to stimulate either the tRNA or U6 RNA gene promoters. In addition, increasing levels of a truncated TBP protein containing only the carboxy-terminal region failed to induce either the tRNA or U6 RNA gene promoter, whereas it retained its ability to stimulate an RNA Pol II promoter. Thus, the TBP-dependent increase in RNA Pol II gene activity is not sufficient for enhanced RNA Pol III gene transcription; rather, a direct effect on RNA Pol III promoters is required. Furthermore, these results provide the first direct evidence that the amino-terminal region of TBP is important for the formation or function of TBP-containing complexes utilized by TATA-less and TATA-containing RNA Pol III promoters. Together, these studies demonstrate that TBP is limiting for the expression of both classes of RNA Pol III promoters in Drosophila cells and implicate an important role for TBP in regulating RNA Pol III gene expression.

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