scholarly journals HP1B is a euchromatic Drosophila HP1 homolog with links to metabolism

2018 ◽  
Author(s):  
Benjamin B. Mills ◽  
Andrew D. Thomas ◽  
Nicole C. Riddle
Keyword(s):  
Gene Expression ◽  
Genome Stability ◽  
Regulation Of Gene Expression ◽  
Activity Levels ◽  
Heterochromatin Protein 1 ◽  
Heterochromatin Protein ◽  
Regulation Of Metabolism ◽  
Animal Activity ◽  
Drosophila Homolog ◽  
Hp1 Proteins

ABSTRACTHeterochromatin Protein 1 (HP1) proteins are an important family of chromosomal proteins conserved among all major eukaryotic lineages. While HP1 proteins are best known for their role in heterochromatin, many HP1 proteins function in euchromatin as well. As a group, HP1 proteins carry out diverse functions, playing roles in the regulation of gene expression, genome stability, chromatin structure, and DNA repair. While the heterochromatic HP1 proteins are well studied, our knowledge of HP1 proteins with euchromatic distribution is lagging behind. We have created the first mutations in HP1B, a Drosophila HP1 protein with euchromatic function, and the Drosophila homolog most closely related to mammalian HP1α, HP1β, and HP1γ. We find that HP1B is a non-essential protein in Drosophila, with mutations affecting fertility and animal activity levels. In addition, animals lacking HP1B show altered food intake and higher body fat levels. Gene expression analysis of animals lacking HP1B demonstrates that genes with functions in various metabolic processes are affected primarily by HP1B loss. Our findings suggest that there is a link between the chromatin protein HP1B and the regulation of metabolism.

scholarly journals Alkyladenine DNA glycosylase associates with transcription elongation to coordinate DNA repair with gene expression

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nicola P. Montaldo ◽  
Diana L. Bordin ◽  
Alessandro Brambilla ◽  
Marcel Rösinger ◽  
Sarah L. Fordyce Martin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genome Stability ◽  
Genome Instability ◽  
Excision Repair ◽  
Regulation Of Gene Expression ◽  
Direct Interaction ◽  
Dna Glycosylase ◽  
Pol Ii ◽  
Naked Dna ◽  
Alkyladenine Dna Glycosylase

AbstractBase excision repair (BER) initiated by alkyladenine DNA glycosylase (AAG) is essential for removal of aberrantly methylated DNA bases. Genome instability and accumulation of aberrant bases accompany multiple diseases, including cancer and neurological disorders. While BER is well studied on naked DNA, it remains unclear how BER efficiently operates on chromatin. Here, we show that AAG binds to chromatin and forms complex with RNA polymerase (pol) II. This occurs through direct interaction with Elongator and results in transcriptional co-regulation. Importantly, at co-regulated genes, aberrantly methylated bases accumulate towards the 3′end in regions enriched for BER enzymes AAG and APE1, Elongator and active RNA pol II. Active transcription and functional Elongator are further crucial to ensure efficient BER, by promoting AAG and APE1 chromatin recruitment. Our findings provide insights into genome stability maintenance in actively transcribing chromatin and reveal roles of aberrantly methylated bases in regulation of gene expression.

scholarly journals Heterochromatin Protein 1 (HP1) Proteins Do Not Drive Pericentromeric Cohesin Enrichment in Human Cells

PLoS ONE ◽  
2009 ◽  
Vol 4 (4) ◽  
pp. e5118 ◽  
Author(s):  
Ángel Serrano ◽  
Miriam Rodríguez-Corsino ◽  
Ana Losada
Keyword(s):  
Human Cells ◽  
Heterochromatin Protein 1 ◽  
Heterochromatin Protein ◽  
Hp1 Proteins

scholarly journals Nuclear Functions of TOR: Impact on Transcription and the Epigenome

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 641 ◽  
Author(s):  
R. Nicholas Laribee ◽  
Ronit Weisman
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Protein Kinase ◽  
Neurological Disorders ◽  
Regulation Of Gene Expression ◽  
Clinical Implications ◽  
Biological Processes ◽  
The Core ◽  
Regulation Of Metabolism ◽  
Pharmacological Target

The target of rapamycin (TOR) protein kinase is at the core of growth factor- and nutrient-dependent signaling pathways that are well-known for their regulation of metabolism, growth, and proliferation. However, TOR is also involved in the regulation of gene expression, genomic and epigenomic stability. TOR affects nuclear functions indirectly through its activity in the cytoplasm, but also directly through active nuclear TOR pools. The mechanisms by which TOR regulates its nuclear functions are less well-understood compared with its cytoplasmic activities. TOR is an important pharmacological target for several diseases, including cancer, metabolic and neurological disorders. Thus, studies of the nuclear functions of TOR are important for our understanding of basic biological processes, as well as for clinical implications.

scholarly journals Pericentromeric Heterochromatin Domains Are Maintained without Accumulation of HP1

2007 ◽  
Vol 18 (4) ◽  
pp. 1464-1471 ◽  
Author(s):  
Julio Mateos-Langerak ◽  
Maartje C. Brink ◽  
Martijn S. Luijsterburg ◽  
Ineke van der Kraan ◽  
Roel van Driel ◽  
...  
Keyword(s):  
Histone H3 ◽  
Dominant Negative ◽  
Pericentromeric Heterochromatin ◽  
Heterochromatin Protein 1 ◽  
Dapi Staining ◽  
Heterochromatin Protein ◽  
3T3 Fibroblasts ◽  
Heterochromatin Structure ◽  
Hp1 Proteins

The heterochromatin protein 1 (HP1) family is thought to be an important structural component of heterochromatin. HP1 proteins bind via their chromodomain to nucleosomes methylated at lysine 9 of histone H3 (H3K9me). To investigate the role of HP1 in maintaining heterochromatin structure, we used a dominant negative approach by expressing truncated HP1α or HP1β proteins lacking a functional chromodomain. Expression of these truncated HP1 proteins individually or in combination resulted in a strong reduction of the accumulation of HP1α, HP1β, and HP1γ in pericentromeric heterochromatin domains in mouse 3T3 fibroblasts. The expression levels of HP1 did not change. The apparent displacement of HP1α, HP1β, and HP1γ from pericentromeric heterochromatin did not result in visible changes in the structure of pericentromeric heterochromatin domains, as visualized by DAPI staining and immunofluorescent labeling of H3K9me. Our results show that the accumulation of HP1α, HP1β, and HP1γ at pericentromeric heterochromatin domains is not required to maintain DAPI-stained pericentromeric heterochromatin domains and the methylated state of histone H3 at lysine 9 in such heterochromatin domains.

scholarly journals Epigenetic Regulation of Myogenic Gene Expression by Heterochromatin Protein 1 Alpha

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e58319 ◽  
Author(s):  
Patima Sdek ◽  
Kyohei Oyama ◽  
Ekaterini Angelis ◽  
Shing S. Chan ◽  
Katja Schenke-Layland ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epigenetic Regulation ◽  
Heterochromatin Protein 1 ◽  
Heterochromatin Protein

scholarly journals Heterochromatin protein 1 is recruited to various types of DNA damage

2009 ◽  
Vol 185 (4) ◽  
pp. 577-586 ◽  
Author(s):  
Martijn S. Luijsterburg ◽  
Christoffel Dinant ◽  
Hannes Lans ◽  
Jan Stap ◽  
Elzbieta Wiernasz ◽  
...  
Keyword(s):  
Dna Damage ◽  
Uv Light ◽  
High Sensitivity ◽  
Heterochromatin Protein 1 ◽  
Heterochromatin Protein ◽  
Strand Breaks ◽  
Essential Components ◽  
Associated Proteins ◽  
Chromo Shadow Domain ◽  
Hp1 Proteins

Heterochromatin protein 1 (HP1) family members are chromatin-associated proteins involved in transcription, replication, and chromatin organization. We show that HP1 isoforms HP1-α, HP1-β, and HP1-γ are recruited to ultraviolet (UV)-induced DNA damage and double-strand breaks (DSBs) in human cells. This response to DNA damage requires the chromo shadow domain of HP1 and is independent of H3K9 trimethylation and proteins that detect UV damage and DSBs. Loss of HP1 results in high sensitivity to UV light and ionizing radiation in the nematode Caenorhabditis elegans, indicating that HP1 proteins are essential components of DNA damage response (DDR) systems. Analysis of single and double HP1 mutants in nematodes suggests that HP1 homologues have both unique and overlapping functions in the DDR. Our results show that HP1 proteins are important for DNA repair and may function to reorganize chromatin in response to damage.

scholarly journals Dynamics of DNA Methylation and Its Functions in Plant Growth and Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Suresh Kumar ◽  
Trilochan Mohapatra
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Genome Stability ◽  
De Novo ◽  
Developmental Process ◽  
Global Climate ◽  
Regulation Of Gene Expression ◽  
Biotic Stresses ◽  
Epigenome Editing ◽  
Dna Base

Epigenetic modifications in DNA bases and histone proteins play important roles in the regulation of gene expression and genome stability. Chemical modification of DNA base (e.g., addition of a methyl group at the fifth carbon of cytosine residue) switches on/off the gene expression during developmental process and environmental stresses. The dynamics of DNA base methylation depends mainly on the activities of the writer/eraser guided by non-coding RNA (ncRNA) and regulated by the developmental/environmental cues. De novo DNA methylation and active demethylation activities control the methylation level and regulate the gene expression. Identification of ncRNA involved in de novo DNA methylation, increased DNA methylation proteins guiding DNA demethylase, and methylation monitoring sequence that helps maintaining a balance between DNA methylation and demethylation is the recent developments that may resolve some of the enigmas. Such discoveries provide a better understanding of the dynamics/functions of DNA base methylation and epigenetic regulation of growth, development, and stress tolerance in crop plants. Identification of epigenetic pathways in animals, their existence/orthologs in plants, and functional validation might improve future strategies for epigenome editing toward climate-resilient, sustainable agriculture in this era of global climate change. The present review discusses the dynamics of DNA methylation (cytosine/adenine) in plants, its functions in regulating gene expression under abiotic/biotic stresses, developmental processes, and genome stability.

scholarly journals “Alkyladenine DNA glycosylase associates with transcription elongation to coordinate DNA repair with gene expression”

2019 ◽  
Author(s):  
Nicola P. Montaldo ◽  
Diana L. Bordin ◽  
Alessandro Brambilla ◽  
Marcel Rösinger ◽  
Sarah L. Fordyce Martin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genome Stability ◽  
Genome Instability ◽  
Excision Repair ◽  
Regulation Of Gene Expression ◽  
Direct Interaction ◽  
Dna Glycosylase ◽  
Pol Ii ◽  
Naked Dna ◽  
Alkyladenine Dna Glycosylase

AbstractBase excision repair (BER) initiated by alkyladenine DNA glycosylase (AAG; aka MPG) is essential for removal of aberrantly methylated DNA bases. Genome instability and accumulation of aberrant bases accompany multiple diseases including cancer and neurological disorders. While BER is well studied on naked DNA, it remains unclear how BER efficiently operates on chromatin. Here we show that AAG binds to chromatin and forms complex with active RNA polymerase (pol) II. This occurs through direct interaction with Elongator and results in transcriptional co-regulation. Importantly, at co-regulated genes aberrantly methylated bases accumulate towards 3’end, in regions enriched for BER enzymes AAG and APE1, Elongator and active RNA pol II. Active transcription and functional Elongator are further crucial to ensure efficient BER, by promoting AAG and APE1 chromatin recruitment. Our findings provide novel insights to maintaining genome stability in actively transcribing chromatin, and reveal roles of aberrantly methylated bases in regulation of gene expression.

Genetic factors controlling white gene expression of the transposon AR4-24 at a telomere in Drosophila melanogaster

Genome ◽  
2002 ◽  
Vol 45 (6) ◽  
pp. 1025-1034 ◽  
Author(s):  
M L Balasov
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Genetic Factors ◽  
Position Effect ◽  
Position Effect Variegation ◽  
Heterochromatin Protein 1 ◽  
Heterochromatin Protein ◽  
Effect Variegation ◽  
Restricted Pattern

The position effect of the AR 4-24 P[white, rosy] transposon was studied at cytological position 60F. Three copies of the transposon (within ~50-kb region) resulted in a spatially restricted pattern of white variegation. This pattern was modified by temperature and by removal of the Y chromosome, suggesting that it was due to classical heterochromatin-induced position effect variegation (PEV). In contrast with classical PEV, extra dose of the heterochromatin protein 1 (HP1) suppressed white variegation and one dose enhanced it. The effect of Pc-G, trx-G, and other PEV suppressors was also tested. It was found that E(Pc)1, TrlR85, and mutations of Su(z)2C relieve AR 4-24- silencing and z1 enhances it. To explain the results obtained with these modifiers, it is proposed that PEV and telomeric position effect can counteract each other at this particular cytological site.Key words: position effect variegation, heterochromatin protein 1, Drosophila melanogaster.

scholarly journals Biliverdin Reductase, a Novel Regulator for Induction of Activating Transcription Factor-2 and Heme Oxygenase-1

2004 ◽  
Vol 279 (19) ◽  
pp. 19916-19923 ◽  
Author(s):  
Anatoliy Kravets ◽  
Zhenbo Hu ◽  
Tihomir Miralem ◽  
Michael D. Torno ◽  
Mahin D. Maines
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Mapk Pathway ◽  
Regulation Of Gene Expression ◽  
Bzip Transcription Factor ◽  
Heme Oxygenase 1 ◽  
Activity Levels ◽  
Mobility Shift ◽  
Unlabeled Probe

Biliverdin IXα reductase (BVR) catalyzes reduction of the HO activity product, biliverdin, to bilirubin. hBVR is a serine/threonine kinase that contains a bZip domain. Presently, regulation of gene expression by hBVR was examined. 293A cells were infected with adenovirusdoxycycline (Ad-Dox)-inducible hBVR cDNA. High level expression of hBVR was determined at mRNA, protein, and activity levels 8 h after induction. Cell signal transduction microarray analysis of cells infected with expression or with the control Ad-inverted (INV)-hBVR vector identifiedATF-2among several up-regulated genes. ATF-2 is a bZip transcription factor for activation of cAMP response element (CRE) and a dimeric partner to c-junin MAPK pathway that regulates the stress protein, HO-1, expression. Northern and Western blot analyses showed increases of ∼10-fold in ATF-2 mRNA and protein at 16 and 24 h after Dox addition. Ad-INV-hBVR did not effect ATF-2 expression. In hBVR-infected cells, levels of HO-1 mRNA and protein were increased.In vitrotranslated hBVR and nuclear extract containing hBVR in gel mobility-shift assay bound to AP-1 sites in theATF-2promoter region and to an oligonucleotide containing the CRE site. Both bindings could be competed out by excess unlabeled probe; in the presence of hBVR antibody, they displayed shifted bands. Co-transfection of hBVR withATF-2or c-junpromoters caused a severalfold increase in luciferase activity. hBVR modulation ofATF-2andHO-1expression suggests it has a potential role in regulation of AP-1 and cAMP-regulated genes and a role in cell signaling. We propose that increased expression of the protein can be used to alter the gene expression profile in the cell.

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