scholarly journals Chromatin profiling of the repetitive and non-repetitive genome of the human fungal pathogen Candida albicans

2018 ◽  
Author(s):  
Robert Jordan Price ◽  
Esther Weindling ◽  
Judith Berman ◽  
Alessia Buscaino
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Histone Modifications ◽  
Chromatin Structure ◽  
Fungal Pathogen ◽  
Genome Stability ◽  
Regulation Of Gene Expression ◽  
Rdna Locus ◽  
Genome Wide ◽  
Chromatin Profiling

ABSTRACTBackgroundEukaryotic genomes are packaged into chromatin structures with pivotal roles in regulating all DNA-associated processes. Post-translational modifications of histone proteins modulate chromatin structure leading to rapid, reversible regulation of gene expression and genome stability which are key steps in environmental adaptation. Candida albicans is the leading fungal pathogen in humans, and can rapidly adapt and thrive in diverse host niches. The contribution of chromatin to C. albicans biology is largely unexplored.ResultsHere, we harnessed genome-wide sequencing approaches to generate the first comprehensive chromatin profiling of histone modifications (H3K4me3, H3K9Ac, H4K16Ac and γ-H2A) across the C. albicans genome and relate it to gene expression. We demonstrate that gene-rich non-repetitive regions are packaged in canonical euchromatin associated with histone modifications that mirror their transcriptional activity. In contrast, repetitive regions are assembled into distinct chromatin states: subtelomeric regions and the rDNA locus are assembled into canonical heterochromatin, while Major Repeat Sequences and transposons are packaged in chromatin bearing features of euchromatin and heterochromatin. Genome-wide mapping of γH2A, a marker of genome instability, allowed the identification of potential recombination-prone genomic sites. Finally, we present the first quantitative chromatin profiling in C. albicans to delineate the role of the chromatin modifiers Sir2 and Set1 in controlling chromatin structure and gene expression.ConclusionsThis study presents the first genome-wide chromatin profiling of histone modifications associated with the C. albicans genome. These epigenomic maps provide an invaluable resource to understand the contribution of chromatin to C. albicans biology.

scholarly journals Chromatin Profiling of the Repetitive and Nonrepetitive Genomes of the Human Fungal Pathogen Candida albicans

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Robert Jordan Price ◽  
Esther Weindling ◽  
Judith Berman ◽  
Alessia Buscaino
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Histone Modifications ◽  
Chromatin Structure ◽  
Fungal Pathogen ◽  
Histone H3 ◽  
Content Type ◽  
Chromatin States ◽  
Genome Wide ◽  
Chromatin Profiling

ABSTRACT Eukaryotic genomes are packaged into chromatin structures that play pivotal roles in regulating all DNA-associated processes. Histone posttranslational modifications modulate chromatin structure and function, leading to rapid regulation of gene expression and genome stability, key steps in environmental adaptation. Candida albicans, a prevalent fungal pathogen in humans, can rapidly adapt and thrive in diverse host niches. The contribution of chromatin to C. albicans biology is largely unexplored. Here, we generated the first comprehensive chromatin profile of histone modifications (histone H3 trimethylated on lysine 4 [H3K4me3], histone H3 acetylated on lysine 9 [H3K9Ac], acetylated lysine 16 on histone H4 [H4K16Ac], and γH2A) across the C. albicans genome and investigated its relationship to gene expression by harnessing genome-wide sequencing approaches. We demonstrated that gene-rich nonrepetitive regions are packaged into canonical euchromatin in association with histone modifications that mirror their transcriptional activity. In contrast, repetitive regions are assembled into distinct chromatin states; subtelomeric regions and the ribosomal DNA (rDNA) locus are assembled into heterochromatin, while major repeat sequences and transposons are packaged in chromatin that bears features of euchromatin and heterochromatin. Genome-wide mapping of γH2A, a marker of genome instability, identified potential recombination-prone genomic loci. Finally, we present the first quantitative chromatin profiling in C. albicans to delineate the role of the chromatin modifiers Sir2 and Set1 in controlling chromatin structure and gene expression. This report presents the first genome-wide chromatin profiling of histone modifications associated with the C. albicans genome. These epigenomic maps provide an invaluable resource to understand the contribution of chromatin to C. albicans biology and identify aspects of C. albicans chromatin organization that differ from that of other yeasts. IMPORTANCE The fungus Candida albicans is an opportunistic pathogen that normally lives on the human body without causing any harm. However, C. albicans is also a dangerous pathogen responsible for millions of infections annually. C. albicans is such a successful pathogen because it can adapt to and thrive in different environments. Chemical modifications of chromatin, the structure that packages DNA into cells, can allow environmental adaptation by regulating gene expression and genome organization. Surprisingly, the contribution of chromatin modification to C. albicans biology is still largely unknown. For the first time, we analyzed C. albicans chromatin modifications on a genome-wide basis. We demonstrate that specific chromatin states are associated with distinct regions of the C. albicans genome and identify the roles of the chromatin modifiers Sir2 and Set1 in shaping C. albicans chromatin and gene expression.

scholarly journals Multivariable regulation of gene expression plasticity in metazoans

2019 ◽  
Author(s):  
Long Xiao ◽  
Zhiguang Zhao ◽  
Fei He ◽  
Zhuo Du
Keyword(s):  
Gene Expression ◽  
Histone Modifications ◽  
Regulation Of Gene Expression ◽  
Rapid Change ◽  
High Plasticity ◽  
Expression Levels ◽  
Genome Wide ◽  
Expression Potential ◽  
Highly Correlated

ABSTRACTAn important capacity of genes is the rapid change of expression levels to cope with environment, known as expression plasticity. Elucidating the genomic mechanisms determining expression plasticity is critical for understanding the molecular basis of phenotypic plasticity, fitness, and adaptation. In this study, we systematically quantified genome-wide gene expression plasticity in four metazoan species by integrating changes of expression levels under a large number of genetic and environmental conditions. From this, we demonstrated that expression plasticity measures a distinct feature of gene expression that is orthogonal to other well-studies features including gene expression potential and tissue specificity/broadness. Expression plasticity is conserved across species with important physiological implications. The magnitude of expression plasticity is highly correlated with gene function and genes with high plasticity are implicated in disease susceptibility. Genome-wide analysis identified many conserved promoter cis-elements, trans-acting factors (such as CFCF), and gene body histone modifications (H3K36me3, H3K79me2, and H4K20me1) that are significantly associated with expression plasticity. Analysis of expression changes in perturbation experiments further validated a causal role of specific transcription factors and histone modifications. Collectively, this work reveals general properties, physiological implications, and multivariable regulation of gene expression plasticity in metazoans, extending the mechanistic understanding of gene regulation.

scholarly journals Chromatin is an ancient innovation conserved between Archaea and Eukarya

eLife ◽  
2012 ◽  
Vol 1 ◽  
Author(s):  
Ron Ammar ◽  
Dax Torti ◽  
Kyle Tsui ◽  
Marinella Gebbia ◽  
Tanja Durbic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chromatin Structure ◽  
Nucleosome Occupancy ◽  
Regulation Of Gene Expression ◽  
Haloferax Volcanii ◽  
Dna Compaction ◽  
Genome Wide ◽  
Eukaryotic Chromatin ◽  
Transcriptional Start Sites

The eukaryotic nucleosome is the fundamental unit of chromatin, comprising a protein octamer that wraps ∼147 bp of DNA and has essential roles in DNA compaction, replication and gene expression. Nucleosomes and chromatin have historically been considered to be unique to eukaryotes, yet studies of select archaea have identified homologs of histone proteins that assemble into tetrameric nucleosomes. Here we report the first archaeal genome-wide nucleosome occupancy map, as observed in the halophile Haloferax volcanii. Nucleosome occupancy was compared with gene expression by compiling a comprehensive transcriptome of Hfx. volcanii. We found that archaeal transcripts possess hallmarks of eukaryotic chromatin structure: nucleosome-depleted regions at transcriptional start sites and conserved −1 and +1 promoter nucleosomes. Our observations demonstrate that histones and chromatin architecture evolved before the divergence of Archaea and Eukarya, suggesting that the fundamental role of chromatin in the regulation of gene expression is ancient.

Genome-Wide Epigenetics in Myeloid Leukemias.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. sci-35-sci-35
Author(s):  
Maria Eugenia Figueroa ◽  
John Greally ◽  
Ruud Delwel ◽  
Ari M. Melnick
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Chromatin Structure ◽  
Target Genes ◽  
Regulation Of Gene Expression ◽  
Promoter Hypermethylation ◽  
Genetic Alterations ◽  
Genome Wide ◽  
Myeloid Leukemias ◽  
Covalent Modifications

Abstract While the role of genetic alterations in cancer is well-recognized, epigenetic deregulation has only recently been identified as a hallmark of malignant transformation. The term “epigenetic” refers to a heritable regulation of gene expression that is not dependent on changes in the DNA sequence. These epigenetic modifications – including but not limited to DNA methylation and covalent modifications of histone tails – play a crucial role in determining chromatin structure and gene expression. Abnormal epigenetic regulation can lead to aberrant chromatin structure and deregulation of transcriptional activity. Epigenetic lesions can affect cancer-related genes, such as CDKN2B, CDKN2A, RB, and BRCA1, and it is not rare for epigenetic lesions to accompany genetic mutations of these and other genes, suggesting that epigenetic deregulation can form a part of the multi-step process of oncogenesis. An alteration in the distribution of DNA methylation has been demonstrated in AML as well as in other malignancies. Generally, intergenic DNA methylation is reported to decrease and promoter methylation to increase. Hypomethylation of DNA can lead to genomic instability and further increase the number of genetic lesions, while promoter hypermethylation has been associated with aberrant silencing of tumor suppressor genes. Altered levels of acetylation at specific histone residues were also shown to be associated with aberrant chromatin structure and gene deregulation in AML. Several oncogenic transcription factors and fusion proteins, such as PML-RARalpha, and AML1-ETO, can introduce aberrant epigenetic programming in myeloid cells through recruitment of epigenetic modifying enzymes to their target genes. However, the emerging field of epigenomic profiling has yielded evidence that epigenetic deregulation in AML is more profound and cannot always be linked to the presence of a given fusion protein. The mechanisms leading to genome-wide epigenetic deregulation still remain largely unidentified, although environmental factors and aging can contribute to this process. Current epigenetic profiling studies have revealed that DNA methylation or histone modification patterns can identify biologically distinct forms of AML that may not be readily identified through other methods. New data suggest that specific DNA methylation profiles may be associated with response to therapeutic agents, including epigenetic-targeted drugs. Numerous epigenetic candidate biomarkers have been recently described in both myeloid and lymphoid malignancies. Integrative analysis of DNA methylation, histone modifications, and gene expression may synergize to identify in far greater depth than single platform studies differences in gene regulation among leukemias. Overall, the emerging field of epigenomics provide a new opportunity to more accurately identify biological variation and therapeutically target acute myeloid leukemias.

scholarly journals Multivariable regulation of gene expression plasticity in metazoans

Open Biology ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 190150 ◽  
Author(s):  
Long Xiao ◽  
Zhiguang Zhao ◽  
Fei He ◽  
Zhuo Du
Keyword(s):  
Gene Expression ◽  
Histone Modifications ◽  
Tissue Specificity ◽  
Regulation Of Gene Expression ◽  
Rapid Change ◽  
High Plasticity ◽  
Expression Levels ◽  
Genome Wide ◽  
Highly Correlated

An important capacity of genes is the rapid change of expression levels to cope with the environment, known as expression responsiveness or plasticity. Elucidating the genomic mechanisms determining expression plasticity is critical for understanding the molecular basis of phenotypic plasticity, fitness and adaptation. In this study, we systematically quantified gene expression plasticity in four metazoan species by integrating changes of expression levels under a large number of genetic and environmental conditions. From this, we demonstrated that expression plasticity measures a distinct feature of gene expression that is orthogonal to other well-studied features, including gene expression level and tissue specificity/broadness. Expression plasticity is conserved across species with important physiological implications. The magnitude of expression plasticity is highly correlated with gene function and genes with high plasticity are implicated in disease susceptibility. Genome-wide analysis identified many conserved promoter cis -elements, trans -acting factors (such as CTCF), and gene body histone modifications (H3K36me3, H3K79me2 and H4K20me1) that are significantly associated with expression plasticity. Analysis of expression changes in perturbation experiments further validated a causal role of specific transcription factors and histone modifications. Collectively, this work reveals the general properties, physiological implications and multivariable regulation of gene expression plasticity in metazoans, extending the mechanistic understanding of gene regulation.

scholarly journals Genome‐wide gene expression dynamics of the fungal pathogen D othistroma septosporum throughout its infection cycle of the gymnosperm host P inus radiata

2015 ◽  
Vol 17 (2) ◽  
pp. 210-224 ◽  
Author(s):  
Rosie E. Bradshaw ◽  
Yanan Guo ◽  
Andre D. Sim ◽  
M. Shahjahan Kabir ◽  
Pranav Chettri ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fungal Pathogen ◽  
Infection Cycle ◽  
Genome Wide ◽  
Gene Expression Dynamics ◽  
Genome Wide Gene Expression

scholarly journals Genome-wide H3K9 Acetylation Level Increases with Age-Dependent Senescence of Flag Leaf in Rice (Oryza sativa)

2021 ◽  
Author(s):  
Yu Zhang ◽  
Yanyun Li ◽  
Yuanyuan Zhang ◽  
Zeyu Zhang ◽  
Deyu Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Oryza Sativa ◽  
Leaf Senescence ◽  
Epigenetic Modification ◽  
Flag Leaf ◽  
Regulation Of Gene Expression ◽  
Leaf Aging ◽  
Genome Wide ◽  
Age Dependent ◽  
H3k9 Acetylation

Flag leaf senescence is an important biological process that drives the remobilization of nutrients to the growing organs of rice. Leaf senescence is controlled by genetic information via gene expression and epigenetic modification, but the precise mechanism is as of yet unclear. Here, we analyzed genome-wide acetylated lysine residue 9 of histone H3 (H3K9ac) enrichment by chromatin immunoprecipitation-sequencing (ChIP-seq) and examined its association with transcriptomes by RNA-seq during flag leaf aging in rice (Oryza sativa). We found that genome-wide H3K9 acetylation levels increased with age-dependent senescence in rice flag leaf, and there was a positive correlation between the density and breadth of H3K9ac and gene expression and transcript elongation. A set of 1,249 up-regulated, differentially expressed genes (DEGs) and 996 down-regulated DEGs showing a strong relationship between temporal changes in gene expression and gain/loss of H3K9ac was observed during rice flag leaf aging. We produced a landscape of H3K9 acetylation- modified gene expression targets that includes known senescence-associated genes, metabolism-related genes, as well as miRNA biosynthesis- related genes. Our findings reveal a complex regulatory network of metabolism- and senescence-related pathways mediated by H3K9ac and also elucidate patterns of H3K9ac-mediated regulation of gene expression during flag leaf aging in rice.

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 Integration of Long-Term-Memory-Related Synaptic Plasticity Involves Bidirectional Regulation of Gene Expression and Chromatin Structure

Cell ◽  
2002 ◽  
Vol 111 (4) ◽  
pp. 483-493 ◽  
Author(s):  
Zhonghui Guan ◽  
Maurizio Giustetto ◽  
Stavros Lomvardas ◽  
Joung-Hun Kim ◽  
Maria Concetta Miniaci ◽  
...  
Keyword(s):  
Gene Expression ◽  
Synaptic Plasticity ◽  
Chromatin Structure ◽  
Regulation Of Gene Expression ◽  
Long Term Memory ◽  
Term Memory ◽  
Bidirectional Regulation
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