scholarly journals The N Terminus of Drosophila ESC Binds Directly to Histone H3 and Is Required for E(Z)-Dependent Trimethylation of H3 Lysine 27

2007 ◽  
Vol 27 (6) ◽  
pp. 2014-2026 ◽  
Author(s):  
Feng Tie ◽  
Carl A. Stratton ◽  
Rebeccah L. Kurzhals ◽  
Peter J. Harte
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Histone H3 ◽  
Polycomb Group ◽  
Set Domain ◽  
Chromatin Immunoprecipitation Assay ◽  
Polycomb Repressive Complex 2 ◽  
Polycomb Response Element ◽  
Evolutionarily Conserved ◽  
Hmtase Activity ◽  
And Function

ABSTRACT Polycomb group proteins mediate heritable transcriptional silencing and function through multiprotein complexes that methylate and ubiquitinate histones. The 600-kDa E(Z)/ESC complex, also known as Polycomb repressive complex 2 (PRC2), specifically methylates histone H3 lysine 27 (H3 K27) through the intrinsic histone methyltransferase (HMTase) activity of the E(Z) SET domain. By itself, E(Z) exhibits no detectable HMTase activity and requires ESC for methylation of H3 K27. The molecular basis for this requirement is unknown. ESC binds directly, via its C-terminal WD repeats (β-propeller domain), to E(Z). Here, we show that the N-terminal region of ESC that precedes its β-propeller domain interacts directly with histone H3, thereby physically linking E(Z) to its substrate. We show that when expressed in stable S2 cell lines, an N-terminally truncated ESC (FLAG-ESC61-425), like full-length ESC, is incorporated into complexes with E(Z) and binds to a Ubx Polycomb response element in a chromatin immunoprecipitation assay. However, incorporation of this N-terminally truncated ESC into E(Z) complexes prevents trimethylation of histone H3 by E(Z). We also show that a closely related Drosophila melanogaster paralog of ESC, ESC-like (ESCL), and the mammalian homolog of ESC, EED, also interact with histone H3 via their N termini, indicating that the interaction of ESC with histone H3 is evolutionarily conserved, reflecting its functional importance. Our data suggest that one of the roles of ESC (and ESCL and EED) in PRC2 complexes is to enable E(Z) to utilize histone H3 as a substrate by physically linking enzyme and substrate.

scholarly journals Subunit Contributions to Histone Methyltransferase Activities of Fly and Worm Polycomb Group Complexes

2005 ◽  
Vol 25 (16) ◽  
pp. 6857-6868 ◽  
Author(s):  
Carrie S. Ketel ◽  
Erica F. Andersen ◽  
Marcus L. Vargas ◽  
Jinkyo Suh ◽  
Susan Strome ◽  
...  
Keyword(s):  
Germ Line ◽  
Histone H3 ◽  
Polycomb Group ◽  
Missense Mutations ◽  
Set Domain ◽  
Multiple Partner ◽  
Global Methylation ◽  
Hmtase Activity ◽  
Surface Loops ◽  
Polycomb Group Complexes

ABSTRACT The ESC-E(Z) complex of Drosophila melanogaster Polycomb group (PcG) repressors is a histone H3 methyltransferase (HMTase). This complex silences fly Hox genes, and related HMTases control germ line development in worms, flowering in plants, and X inactivation in mammals. The fly complex contains a catalytic SET domain subunit, E(Z), plus three noncatalytic subunits, SU(Z)12, ESC, and NURF-55. The four-subunit complex is >1,000-fold more active than E(Z) alone. Here we show that ESC and SU(Z)12 play key roles in potentiating E(Z) HMTase activity. We also show that loss of ESC disrupts global methylation of histone H3-lysine 27 in fly embryos. Subunit mutations identify domains required for catalytic activity and/or binding to specific partners. We describe missense mutations in surface loops of ESC, in the CXC domain of E(Z), and in the conserved VEFS domain of SU(Z)12, which each disrupt HMTase activity but preserve complex assembly. Thus, the E(Z) SET domain requires multiple partner inputs to produce active HMTase. We also find that a recombinant worm complex containing the E(Z) homolog, MES-2, has robust HMTase activity, which depends upon both MES-6, an ESC homolog, and MES-3, a pioneer protein. Thus, although the fly and mammalian PcG complexes absolutely require SU(Z)12, the worm complex generates HMTase activity from a distinct partner set.

scholarly journals The Roles of the Histone Protein Modifier EZH2 in the Uterus and Placenta

Epigenomes ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 20
Author(s):  
Ana M. Mesa ◽  
Cheryl S. Rosenfeld ◽  
Geetu Tuteja ◽  
Theresa I. Medrano ◽  
Paul S. Cooke
Keyword(s):  
Critical Role ◽  
Histone H3 ◽  
Gene Promoter ◽  
Epigenetic Changes ◽  
Promoter Regions ◽  
Polycomb Repressive Complex 2 ◽  
Gene Sets ◽  
Ezh2 Expression ◽  
And Function ◽  
Transcription Enhancer

Epigenetic modifications regulate normal physiological, as well as pathological processes in various organs, including the uterus and placenta. Both organs undergo dramatic and rapid restructuring that depends upon precise orchestration of events. Epigenetic changes that alter transcription and translation of gene-sets regulate such responses. Histone modifications alter the chromatin structure, thereby affecting transcription factor access to gene promoter regions. Binding of histones to DNA is regulated by addition or removal of subunit methyl and other groups, which can inhibit or stimulate transcription. Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of polycomb repressive complex 2 (PRC2) that catalyzes tri-methylation of histone H3 at Lys 27 (H3K27me3) and subsequently suppresses transcription of genes bound by such histones. Uterine EZH2 expression exerts a critical role in development and function of this organ with deletion of this gene resulting in uterine hyperplasia and expression of cancer-associated transcripts. Elucidating the roles of EZH2 in uterus and placenta is essential as EZH2 dysregulation is associated with several uterine and placental pathologies. Herein, we discuss EZH2 functions in uterus and placenta, emphasizing its physiological and pathological importance.

scholarly journals Phylogenetic profiling suggests early origin of the core subunits of Polycomb Repressive Complex 2 (PRC2)

2021 ◽  
Author(s):  
Abdoallah Sharaf ◽  
Mallika Vijayanathan ◽  
Miroslav Obornik ◽  
iva Mozgova
Keyword(s):  
Developmental Regulation ◽  
Structural Diversity ◽  
Polycomb Group ◽  
Catalytic Subunit ◽  
Set Domain ◽  
Polycomb Repressive Complex ◽  
Polycomb Repressive Complex 2 ◽  
Domains Of Life ◽  
Domain Protein ◽  
Phylogenetic Profiling

Polycomb Repressive Complex 2 (PRC2) is involved in establishing transcriptionally silent chromatin states through its ability to methylate lysine 27 of histone H3 by the catalytic subunit Enhancer of zeste [E(z)]. Polycomb group (PcG) proteins play a crucial role in the maintenance of cell identity and in developmental regulation. Previously, the diversity of PRC2 subunits within some eukaryotic lineages has been reported and its presence in early eukaryotic evolution has been hypothesized. So far however, systematic survey of the presence of PRC2 subunits in species of all eukaryotic lineages is missing. Here, we report the diversity of PRC2 core subunit proteins in different eukaryotic supergroups with emphasis on the early-diverged lineages and explore the molecular evolution of PRC2 subunits by phylogenetics. In detail, we investigate the SET-domain protein sequences and their evolution across the four domains of life and particularly focus on the structural diversity of the SET-domain subfamily containing E(z), the catalytic subunit of PRC2. We show that PRC2 subunits are already present in early eukaryotic lineages, strengthening the support for PRC2 emergence prior to diversification of eukaryotes. We identify a common presence of E(z) and ESC, suggesting that Su(z)12 may have emerged later and/or may be dispensable from the evolutionarily conserved functional core of PRC2. Furthermore, our results broaden our understanding of the E(z) evolution within the SET-domain protein family, suggesting possibilities of function evolution. Through this, we shed light on a possible emerging point of the PRC2 and the evolution of its function in eukaryotes.

scholarly journals Polycomb Complex 2 Is Required for E-cadherin Repression by the Snail1 Transcription Factor

2008 ◽  
Vol 28 (15) ◽  
pp. 4772-4781 ◽  
Author(s):  
Nicolás Herranz ◽  
Diego Pasini ◽  
Víctor M. Díaz ◽  
Clara Francí ◽  
Arantxa Gutierrez ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Epithelial Mesenchymal Transition ◽  
Es Cells ◽  
Histone H3 ◽  
Embryonic Stem ◽  
Cdh1 Gene ◽  
Mesenchymal Transition ◽  
Polycomb Repressive Complex 2 ◽  
Polycomb Complex ◽  
E Cadherin

ABSTRACT The transcriptional factor Snail1 is a repressor of E-cadherin (CDH1) gene expression essential for triggering epithelial-mesenchymal transition. Snail1 represses CDH1, directly binding its promoter and inducing the synthesis of the Zeb1 repressor. In this article, we show that repression of CDH1 by Snail1, but not by Zeb1, is dependent on the activity of Polycomb repressive complex 2 (PRC2). Embryonic stem (ES) cells null for Suz12, one of the components of PRC2, show higher levels of Cdh1 mRNA than control ES cells. In tumor cells, interference of PRC2 activity prevents the ability of Snail1 to downregulate CDH1 and partially derepresses CDH1. Chromatin immunoprecipitation assays demonstrated that Snail1 increases the binding of Suz12 to the CDH1 promoter and the trimethylation of lysine 27 in histone H3. Moreover, Snail1 interacts with Suz12 and Ezh2, as shown by coimmunoprecipitation experiments. In conclusion, these results demonstrate that Snail1 recruits PRC2 to the CDH1 promoter and requires the activity of this complex to repress E-cadherin expression.

scholarly journals Arabidopsis S2Lb links AtCOMPASS-like and SDG2 activity in histone H3 Lys-4 trimethylation independently from histone H2B monoubiquitination

2019 ◽  
Author(s):  
Anne-Sophie Fiorucci ◽  
Clara Bourbousse ◽  
Lorenzo Concia ◽  
Martin Rougée ◽  
Anne-Flore Deton-Cabanillas ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Arabidopsis Thaliana ◽  
Histone H3 ◽  
Set Domain ◽  
Histone H2b ◽  
High Molecular Weight Complex ◽  
Genomic Distribution ◽  
Histone Methyltransferases ◽  
Evolutionarily Conserved ◽  
Large Repertoire

AbstractThe functional determinants of histone H3 Lys-4 trimethylation (H3K4me3), their potential dependency on histone H2B monoubiquitination (H2Bub) and their contribution to defining transcriptional regimes are poorly defined in plant systems. Unlike inS. cerevisiae, where a single SET1 protein catalyzes H3 Lys-4 trimethylation as part of COMPASS (COMPlex of proteins ASsociated with Set1), inArabidopsis thalianathis activity involves multiple histone methyltransferases (HMTs). Among these, the plant-specific SDG2 (SET DOMAIN GROUP2) has a prominent role. We report that SDG2 co-regulates hundreds of genes with SWD2-like b (S2Lb), a plant ortholog of the Swd2 axillary subunit of yeast COMPASS. S2Lb co-purifies with the AtCOMPASS core subunit WDR5 from a high-molecular weight complex, and both S2Lb and SDG2 directly influence H3K4me3 enrichment over highly transcribed genes.S2Lbknockout triggers pleiotropic developmental phenotypes at the vegetative and reproductive stages, including reduced fertility and seed dormancy. Notwithstanding,s2lbseedlings display little transcriptomic defects as compared to the large repertoire of genes targeted by S2Lb, SDG2 or H3 Lys-4 trimethylation, suggesting that H3K4me3 enrichment is important for optimal gene induction during cellular transitions rather than for determining on/off transcriptional status. Moreover, unlike in budding yeast, most of the S2Lb and H3K4me3 genomic distribution does not rely on a trans-histone crosstalk with histone H2B monoubiquitination. Collectively, this study unveils that the evolutionarily conserved COMPASS-like complex has been coopted by the plant-specific SDG2 HMT and mediates H3K4me3 deposition through an H2Bub-independent pathway in Arabidopsis.

scholarly journals Comparative Analysis of Chromatin Binding by Sex Comb on Midleg (SCM) and Other Polycomb Group Repressors at a Drosophila Hox Gene

2010 ◽  
Vol 30 (11) ◽  
pp. 2584-2593 ◽  
Author(s):  
Liangjun Wang ◽  
Neal Jahren ◽  
Ellen L. Miller ◽  
Carrie S. Ketel ◽  
Daniel R. Mallin ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Polycomb Group ◽  
S2 Cells ◽  
Chromatin Binding ◽  
Hox Gene ◽  
Functional Relationships ◽  
Polycomb Response Element ◽  
Sex Comb ◽  
Polycomb Repressive Complex 1

ABSTRACT Sex Comb on Midleg (SCM) is a transcriptional repressor in the Polycomb group (PcG), but its molecular role in PcG silencing is not known. Although SCM can interact with Polycomb repressive complex 1 (PRC1) in vitro, biochemical studies have indicated that SCM is not a core constituent of PRC1 or PRC2. Nevertheless, SCM is just as critical for Drosophila Hox gene silencing as canonical subunits of these well-characterized PcG complexes. To address functional relationships between SCM and other PcG components, we have performed chromatin immunoprecipitation studies using cultured Drosophila Schneider line 2 (S2) cells and larval imaginal discs. We find that SCM associates with a Polycomb response element (PRE) upstream of the Ubx gene which also binds PRC1, PRC2, and the DNA-binding PcG protein Pleiohomeotic (PHO). However, SCM is retained at this Ubx PRE despite genetic disruption or knockdown of PHO, PRC1, or PRC2, suggesting that SCM chromatin targeting does not require prior association of these other PcG components. Chromatin immunoprecipitations (IPs) to test the consequences of SCM genetic disruption or knockdown revealed that PHO association is unaffected, but reduced levels of PRE-bound PRC2 and PRC1 were observed. We discuss these results in light of current models for recruitment of PcG complexes to chromatin targets.

scholarly journals Structure, Activity and Function of the NSD3 Protein Lysine Methyltransferase

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 726
Author(s):  
Philipp Rathert
Keyword(s):  
Current Knowledge ◽  
Histone H3 ◽  
Set Domain ◽  
Histone Methyltransferases ◽  
Structure Activity ◽  
Lysine Methyltransferase ◽  
Active Transcription ◽  
Biochemical Mechanisms ◽  
And Function ◽  
Tumor Types

NSD3 is one of six H3K36-specific lysine methyltransferases in metazoans, and the methylation of H3K36 is associated with active transcription. NSD3 is a member of the nuclear receptor-binding SET domain (NSD) family of histone methyltransferases together with NSD1 and NSD2, which generate mono- and dimethylated lysine on histone H3. NSD3 is mutated and hyperactive in some human cancers, but the biochemical mechanisms underlying such dysregulation are barely understood. In this review, the current knowledge of NSD3 is systematically reviewed. Finally, the molecular and functional characteristics of NSD3 in different tumor types according to the current research are summarized.

Chromatin modulation and gene regulation in plants: insight about PRC1 function

2018 ◽  
Vol 46 (4) ◽  
pp. 957-966 ◽  
Author(s):  
Qiannan Wang ◽  
Wen-Hui Shen
Keyword(s):  
Current Knowledge ◽  
Protein Complexes ◽  
Histone H3 ◽  
Short Review ◽  
Polycomb Group ◽  
Trithorax Group ◽  
The Core ◽  
Evolutionarily Conserved ◽  
Trithorax Group Proteins ◽  
Polycomb Repressive Complex 1

In plant and metazoan, Polycomb Group (PcG) proteins play key roles in regulating developmental processes by repression of gene expression. PcG proteins function as multi-protein complexes; among them the best characterized ones are Polycomb Repressive Complex 1 (PRC1) and PRC2. PRC2 catalyzes histone H3 lysine 27 trimethylation (H3K27me3), and PRC1 can bind H3K27me3 and catalyzes H2A monoubiquitination. While the PRC2 components and molecular functions are evolutionarily conserved, varied PRC1 complexes are found and they show high divergences between animals and plants. In addition to the core subunits, an exponentially increasing number of PRC1-associated factors have been identified in Arabidopsis thaliana. Recent studies have also unraveled cross-component interactions and intertwined roles of PRC1 and PRC2 in chromatin modulation. In addition, complexities of interactions and functions between PcG and Trithorax Group proteins have been observed. This short review summarizes up current knowledge to provide insight about repressive functional mechanism of PRC1 and its interplay with other factors.

scholarly journals Multiple Myeloma-Related WHSC1/MMSET Isoform RE-IIBP Is a Histone Methyltransferase with Transcriptional Repression Activity

2008 ◽  
Vol 28 (6) ◽  
pp. 2023-2034 ◽  
Author(s):  
Ji-Young Kim ◽  
Hae Jin Kee ◽  
Nak-Won Choe ◽  
Sung-Mi Kim ◽  
Gwang-Hyeon Eom ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Transcriptional Repression ◽  
Histone H3 ◽  
Histone Methyltransferase ◽  
Set Domain ◽  
Interleukin 5 ◽  
Hmtase Activity ◽  
Critical Residues ◽  
Tumor Types

ABSTRACT Histone methylation is crucial for transcriptional regulation and chromatin remodeling. It has been suggested that the SET domain containing protein RE-IIBP (interleukin-5 [IL-5] response element II binding protein) may perform a function in the carcinogenesis of certain tumor types, including myeloma. However, the pathogenic role of RE-IIBP in these diseases remains to be clearly elucidated. In this study, we have conducted an investigation into the relationship between the histone-methylating activity of RE-IIBP and transcriptional regulation. Here, we report that RE-IIBP is up-regulated in the blood cells of leukemia patients, and we characterized the histone H3 lysine 27 (H3-K27) methyltransferase activity of RE-IIBP. Point mutant analysis revealed that SET domain cysteine 483 and arginine 477 are critical residues for the histone methyltransferase (HMTase) activity of RE-IIBP. RE-IIBP also represses basal transcription via histone deacetylase (HDAC) recruitment, which may be mediated by H3-K27 methylation. In the chromatin immunoprecipitation assays, we showed that RE-IIBP overexpression induces histone H3-K27 methylation, HDAC recruitment, and histone H3 hypoacetylation on the IL-5 promoter and represses expression. Conversely, short hairpin RNA-mediated knockdown of RE-IIBP reduces histone H3-K27 methylation and HDAC occupancy around the IL-5 promoter. These data illustrate the important regulatory role of RE-IIBP in transcriptional regulation, thereby pointing to the important role of HMTase activity in carcinogenesis.

scholarly journals Sir2 Represses Endogenous Polymerase II Transcription Units in the Ribosomal DNA Nontranscribed Spacer

2006 ◽  
Vol 17 (9) ◽  
pp. 3848-3859 ◽  
Author(s):  
Chonghua Li ◽  
John E. Mueller ◽  
Mary Bryk
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Chromatin Immunoprecipitation ◽  
Histone H3 ◽  
Total Histone ◽  
Nontranscribed Spacer ◽  
Naturally Occurring ◽  
Histone Modifying Enzymes ◽  
And Function ◽  
Rna Polymerase Ii Transcription

Silencing at the rDNA, HM loci, and telomeres in Saccharomyces cerevisiae requires histone-modifying enzymes to create chromatin domains that are refractory to recombination and RNA polymerase II transcription machineries. To explore how the silencing factor Sir2 regulates the composition and function of chromatin at the rDNA, the association of histones and RNA polymerase II with the rDNA was measured by chromatin immunoprecipitation. We found that Sir2 regulates not only the levels of K4-methylated histone H3 at the rDNA but also the levels of total histone H3 and RNA polymerase II. Furthermore, our results demonstrate that the ability of Sir2 to limit methylated histones at the rDNA requires its deacetylase activity. In sir2Δ cells, high levels of K4-trimethylated H3 at the rDNA nontranscribed spacer are associated with the expression of transcription units in the nontranscribed spacer by RNA polymerase II and with previously undetected alterations in chromatin structure. Together, these data suggest a model where the deacetylase activity of Sir2 prevents euchromatinization of the rDNA and silences naturally occurring intergenic transcription units whose expression has been associated with disruption of cohesion complexes and repeat amplification at the rDNA.

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