scholarly journals Amino termini of histones H3 and H4 are required for a1-alpha2 repression in yeast.

1997 ◽  
Vol 17 (11) ◽  
pp. 6555-6562 ◽  
Author(s):  
L Huang ◽  
W Zhang ◽  
S Y Roth
Keyword(s):  
General Feature ◽  
Amino Terminus ◽  
Specific Gene ◽  
Alpha Cells ◽  
Histone H4 ◽  
Cell Type ◽  
A Cell ◽  
Cell Type Specific ◽  
Diploid Cells

The Saccharomyces cerevisiae alpha2 repressor controls two classes of cell-type-specific genes in yeast through association with different partners. alpha2-Mcm1 complexes repress a cell-specific gene expression in haploid alpha cells and diploid a/alpha cells, while a1-alpha2 complexes repress haploid-specific genes in diploid cells. In both cases, repression is mediated through Ssn6-Tu1 corepressor complexes that are recruited via direct interactions with alpha2. We have previously shown that nucleosomes are positioned adjacent to the alpha2-Mcm1 operator under conditions of repression and that Tupl interacts directly with histones H3 and H4. Here, we examine the role of chromatin in a1-alpha2 repression to determine if chromatin is a general feature of repression by Ssn6-Tup1. We find that mutations in the amino terminus of histone H4 cause a 4- to 11-fold derepression of a reporter gene under a1-alpha2 control, while truncation of the H3 amino terminus has a more modest (3-fold or less) effect. Strikingly, combination of the H3 truncation with an H4 mutation causes a 40-fold decrease in repression, clearly indicating a central role for these histones in a1-alpha2-mediated repression. However, in contrast to the ordered positioning of nucleosomes adjacent to the alpha2-Mcm1 operator, nucleosomes are not positioned adjacent to the a1-alpha2 operator in diploid cells. Our data indicate that chromatin is important to Ssn6-Tup1-mediated repression but that the degrees of chromatin organization directed by these proteins differ at different promoters.

scholarly journals Distinct CoREST complexes act in a cell-type-specific manner

2019 ◽  
Author(s):  
Igor Mačinković ◽  
Ina Theofel ◽  
Tim Hundertmark ◽  
Kristina Kovač ◽  
Stephan Awe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Germ Line ◽  
Protein Complexes ◽  
Specific Gene ◽  
S2 Cells ◽  
Cell Type ◽  
Specific Gene Expression ◽  
Genome Wide ◽  
A Cell ◽  
Cell Type Specific

Abstract CoREST has been identified as a subunit of several protein complexes that generate transcriptionally repressive chromatin structures during development. However, a comprehensive analysis of the CoREST interactome has not been carried out. We use proteomic approaches to define the interactomes of two dCoREST isoforms, dCoREST-L and dCoREST-M, in Drosophila. We identify three distinct histone deacetylase complexes built around a common dCoREST/dRPD3 core: A dLSD1/dCoREST complex, the LINT complex and a dG9a/dCoREST complex. The latter two complexes can incorporate both dCoREST isoforms. By contrast, the dLSD1/dCoREST complex exclusively assembles with the dCoREST-L isoform. Genome-wide studies show that the three dCoREST complexes associate with chromatin predominantly at promoters. Transcriptome analyses in S2 cells and testes reveal that different cell lineages utilize distinct dCoREST complexes to maintain cell-type-specific gene expression programmes: In macrophage-like S2 cells, LINT represses germ line-related genes whereas other dCoREST complexes are largely dispensable. By contrast, in testes, the dLSD1/dCoREST complex prevents transcription of germ line-inappropriate genes and is essential for spermatogenesis and fertility, whereas depletion of other dCoREST complexes has no effect. Our study uncovers three distinct dCoREST complexes that function in a lineage-restricted fashion to repress specific sets of genes thereby maintaining cell-type-specific gene expression programmes.

scholarly journals Inducible cell-specific mouse models for paired epigenetic and transcriptomic studies of microglia and astroglia

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Ana J. Chucair-Elliott ◽  
Sarah R. Ocañas ◽  
David R. Stanford ◽  
Victor A. Ansere ◽  
Kyla B. Buettner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Affinity Purification ◽  
Regulation Of Gene Expression ◽  
Cell Types ◽  
Tissue Level ◽  
Cell Phenotype ◽  
Specific Gene ◽  
Cell Type ◽  
A Cell ◽  
Cell Type Specific

AbstractEpigenetic regulation of gene expression occurs in a cell type-specific manner. Current cell-type specific neuroepigenetic studies rely on cell sorting methods that can alter cell phenotype and introduce potential confounds. Here we demonstrate and validate a Nuclear Tagging and Translating Ribosome Affinity Purification (NuTRAP) approach for temporally controlled labeling and isolation of ribosomes and nuclei, and thus RNA and DNA, from specific central nervous system cell types. Analysis of gene expression and DNA modifications in astrocytes or microglia from the same animal demonstrates differential usage of DNA methylation and hydroxymethylation in CpG and non-CpG contexts that corresponds to cell type-specific gene expression. Application of this approach in LPS treated mice uncovers microglia-specific transcriptome and epigenome changes in inflammatory pathways that cannot be detected with tissue-level analysis. The NuTRAP model and the validation approaches presented can be applied to any brain cell type for which a cell type-specific cre is available.

scholarly journals miR-27 and miR-125 Distinctly Regulate Muscle-Enriched Transcription Factors in Cardiac and Skeletal Myocytes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Estefania Lozano-Velasco ◽  
Jennifer Galiano-Torres ◽  
Alvaro Jodar-Garcia ◽  
Amelia E. Aranega ◽  
Diego Franco
Keyword(s):  
Transcription Factors ◽  
Cardiac Development ◽  
Protein Translation ◽  
Cell Type ◽  
Atrial Cardiomyocytes ◽  
Skeletal Myocytes ◽  
Specific Manner ◽  
A Cell ◽  
Cell Type Specific

MicroRNAs are noncoding RNAs of approximately 22–24 nucleotides which are capable of interacting with the 3′ untranslated region of coding RNAs (mRNAs), leading to mRNA degradation and/or protein translation blockage. In recent years, differential microRNA expression in distinct cardiac development and disease contexts has been widely reported, yet the role of individual microRNAs in these settings remains largely unknown. We provide herein evidence of the role of miR-27 and miR-125 regulating distinct muscle-enriched transcription factors. Overexpression of miR-27 leads to impair expression ofMstnandMyocdin HL1 atrial cardiomyocytes but not in Sol8 skeletal muscle myoblasts, while overexpression of miR-125 resulted in selective upregulation ofMef2din HL1 atrial cardiomyocytes and downregulation in Sol8 cells. Taken together our data demonstrate that a single microRNA, that is, miR-27 or miR-125, can selectively upregulate and downregulate discrete number of target mRNAs in a cell-type specific manner.

scholarly journals Effect of Sequence-Directed Nucleosome Disruption on Cell-Type-Specific Repression by α2/Mcm1 in the Yeast Genome

2006 ◽  
Vol 5 (11) ◽  
pp. 1925-1933 ◽  
Author(s):  
Nobuyuki Morohashi ◽  
Yuichi Yamamoto ◽  
Shunsuke Kuwana ◽  
Wataru Morita ◽  
Heisaburo Shindo ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Nucleosome Positioning ◽  
Yeast Genome ◽  
Specific Gene ◽  
Cell Type ◽  
Chromatin Structural ◽  
A Cell ◽  
Cell Type Specific ◽  
Acting In Concert ◽  
Modest Effect

ABSTRACT In Saccharomyces cerevisiae, a-cell-specific genes are repressed in MATα cells by α2/Mcm1, acting in concert with the Ssn6-Tup1 corepressors and the Isw2 chromatin remodeling complex, and nucleosome positioning has been proposed as one mechanism of repression. However, prior studies showed that nucleosome positioning is not essential for repression by α2/Mcm1 in artificial reporter plasmids, and the importance of the nucleosome positioning remains questionable. We have tested the function of positioned nucleosomes through alteration of genomic chromatin at the a-cell-specific gene BAR1. We report here that a positioned nucleosome in the BAR1 promoter is disrupted in cis by the insertion of diverse DNA sequences such as poly(dA) · poly(dT) and poly(dC-dG) · poly(dC-dG), leading to inappropriate partial derepression of BAR1. Also, we show that isw2 mutation causes loss of nucleosome positioning in BAR1 in MATα cells as well as partial disruption of repression. Thus, nucleosome positioning is required for full repression, but loss of nucleosome positioning is not sufficient to relieve repression completely. Even though disruption of nucleosome positioning by the cis- and trans-acting modulators of chromatin has a modest effect on the level of transcription, it causes significant degradation of the α-mating pheromone in MATα cells, thereby affecting its cell type identity. Our results illustrate a useful paradigm for analysis of chromatin structural effects at genomic loci.

Targeted delivery of Chil3/Chil4 siRNA to alveolar macrophages using ternary complexes composed of HMG and oligoarginine micelles

Nanoscale ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 933-943 ◽  
Author(s):  
Moonhwan Choi ◽  
Haeyoon Jeong ◽  
Sol Kim ◽  
Minkyung Kim ◽  
Minhyung Lee ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Delivery System ◽  
Alveolar Macrophages ◽  
Targeted Delivery ◽  
Ternary Complexes ◽  
Specific Gene ◽  
Gene Delivery System ◽  
Cell Type ◽  
A Cell ◽  
Cell Type Specific

Cell-type-specific genes involved in disease can be effective therapeutic targets; therefore, the development of a cell-type-specific gene delivery system is essential.

scholarly journals Stress kinases in the modulation of metabolism and energy balance

2015 ◽  
Vol 55 (2) ◽  
pp. R11-R22 ◽  
Author(s):  
Elisa Manieri ◽  
Guadalupe Sabio
Keyword(s):  
Metabolic Stress ◽  
Cellular Responses ◽  
Cell Type ◽  
Global Pandemic ◽  
Increased Risk ◽  
Regulation Of Metabolism ◽  
A Cell ◽  
Cell Type Specific ◽  
Jnk Isoforms

Obesity is a new global pandemic, with growing incidence and prevalence. This disease is associated with increased risk of several pathologies, including diabetes, cardiovascular diseases, and cancer. The mechanisms underlying obesity-associated metabolic changes are the focus of efforts to identify new therapies. Stress-activated protein kinases (SAPK), including cJun N-terminal kinases (JNKs) and p38, are required for cellular responses to metabolic stress and therefore might contribute to the pathogenesis of obesity. Tissue-specific knockout models support a cell-type-specific role for JNK isoforms, in particular JNK1, highlighting its importance in cell homeostasis and organ crosstalk. However, more efforts are needed to elucidate the specific roles of other JNK isoforms and p38 family members in metabolism and obesity. This review provides an overview of the role of SAPKs in the regulation of metabolism.

scholarly journals Genetic Deletion of SEPT7 Reveals a Cell Type-Specific Role of Septins in Microtubule Destabilization for the Completion of Cytokinesis

PLoS Genetics ◽  
2014 ◽  
Vol 10 (8) ◽  
pp. e1004558 ◽  
Author(s):  
Manoj B. Menon ◽  
Akihiro Sawada ◽  
Anuhar Chaturvedi ◽  
Pooja Mishra ◽  
Karin Schuster-Gossler ◽  
...  
Keyword(s):  
Specific Role ◽  
Cell Type ◽  
A Cell ◽  
Cell Type Specific ◽  
Genetic Deletion

scholarly journals Inducible cell-specific mouse models for paired epigenetic and transcriptomic studies of microglia and astroglia

2019 ◽  
Author(s):  
Ana J. Chucair-Elliott ◽  
Sarah R. Ocañas ◽  
David R. Stanford ◽  
Victor A. Ansere ◽  
Kyla B. Buettner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Regulation Of Gene Expression ◽  
Cell Types ◽  
Tissue Level ◽  
Cell Phenotype ◽  
Specific Gene ◽  
Cell Type ◽  
Current Cell ◽  
A Cell ◽  
Cell Type Specific

AbstractEpigenetic regulation of gene expression occurs in a cell type-specific manner. Current cell-type specific neuroepigenetic studies rely on cell sorting methods that can alter cell phenotype and introduce potential confounds. Here we demonstrate and validate a Nuclear Tagging and Translating Ribosome Affinity Purification (NuTRAP) approach for temporally controlled labeling and isolation of ribosomes and nuclei, and thus RNA and DNA, from specific CNS cell types. Paired analysis of the transcriptome and DNA modifications in astrocytes and microglia demonstrates differential usage of DNA methylation and hydroxymethylation in CG and non-CG contexts that corresponds to cell type-specific gene expression. Application of this approach in LPS treated mice uncovers microglia-specific transcriptome and epigenome changes in inflammatory pathways that cannot be detected with tissue-level analysis. The NuTRAP model and the validation approaches presented can be applied to any CNS cell type for which a cell type-specific cre is available.

scholarly journals Functional interaction of c-Ets-1 and GHF-1/Pit-1 mediates Ras activation of pituitary-specific gene expression: mapping of the essential c-Ets-1 domain.

1995 ◽  
Vol 15 (5) ◽  
pp. 2849-2857 ◽  
Author(s):  
A P Bradford ◽  
K E Conrad ◽  
C Wasylyk ◽  
B Wasylyk ◽  
A Gutierrez-Hartmann
Keyword(s):  
Transcription Factor ◽  
Molecular Mechanism ◽  
Specific Gene ◽  
Ras Signaling ◽  
Cell Type ◽  
Functional Interaction ◽  
Amino Terminal ◽  
Ras Activation ◽  
A Cell ◽  
Cell Type Specific

The mechanism by which activation of common signal transduction pathways can elicit cell-specific responses remains an important question in biology. To elucidate the molecular mechanism by which the Ras signaling pathway activates a cell-type-specific gene, we have used the pituitary-specific rat prolactin (rPRL) promoter as a target of oncogenic Ras and Raf in GH4 rat pituitary cells. Here we show that expression of either c-Ets-1 or the POU homeo-domain transcription factor GHF-1/Pit-1 enhance the Ras/Raf activation of the rPRL promoter and that coexpression of the two transcription factors results in an even greater synergistic Ras response. By contrast, the related GHF-1-dependent rat growth hormone promoter fails to respond to Ras or Raf, indicating that GHF-1 alone is insufficient to mediate the Ras/Raf effect. Using amino-terminal truncations of c-Ets-1, we have mapped the c-Ets-1 region required to mediate the optimal Ras response to a 40-amino-acid segment which contains a putative mitogen-activated protein kinase site. Finally, dominant-negative Ets and GHF constructs block Ras activation of the rPRL promoter, and each blocks the synergistic activation mediated by the other partner protein, further corroborating that a functional interaction between c-Ets-1 and GHF-1 is required for an optimal Ras response. Thus, the functional interaction of a pituitary-specific transcription factor, GHF-1, with a widely expressed nuclear proto-oncogene product, c-Ets-1, provides one important molecular mechanism by which the general Ras signaling cascade can be interpreted in a cell-type-specific manner.

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