scholarly journals Glucocorticoid receptor wields chromatin interactions to tune transcription for cytoskeleton stabilization in podocytes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Hong Wang ◽  
Aiping Duan ◽  
Jing Zhang ◽  
Qi Wang ◽  
Yuexian Xing ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Glucocorticoid Receptor ◽  
Protective Effect ◽  
Histone Modification ◽  
Regulatory Networks ◽  
Target Gene ◽  
Regulatory Elements ◽  
Chromatin Interactions ◽  
Super Enhancer

AbstractElucidating transcription mediated by the glucocorticoid receptor (GR) is crucial for understanding the role of glucocorticoids (GCs) in the treatment of diseases. Podocyte is a useful model for studying GR regulation because GCs are the primary medication for podocytopathy. In this study, we integrated data from transcriptome, transcription factor binding, histone modification, and genome topology. Our data reveals that the GR binds and activates selective regulatory elements in podocyte. The 3D interactome captured by HiChIP facilitates the identification of remote targets of GR. We found that GR in podocyte is enriched at transcriptional interaction hubs and super-enhancers. We further demonstrate that the target gene of the top GR-associated super-enhancer is indispensable to the effective functioning of GC in podocyte. Our findings provided insights into the mechanisms underlying the protective effect of GCs on podocyte, and demonstrate the importance of considering transcriptional interactions in order to fine-map regulatory networks of GR.

scholarly journals Expression of miR159 Is Altered in Tomato Plants Undergoing Drought Stress

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 201 ◽  
Author(s):  
María José López-Galiano ◽  
Inmaculada García-Robles ◽  
Ana I. González-Hernández ◽  
Gemma Camañes ◽  
Begonya Vicedo ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Regulatory Networks ◽  
Crop Yields ◽  
Insect Pest ◽  
Regulatory Function ◽  
Myb Transcription Factor ◽  
Regulation Of Transcription ◽  
Tomato Plants

In a scenario of global climate change, water scarcity is a major threat for agriculture, severely limiting crop yields. Therefore, alternatives are urgently needed for improving plant adaptation to drought stress. Among them, gene expression reprogramming by microRNAs (miRNAs) might offer a biotechnologically sound strategy. Drought-responsive miRNAs have been reported in many plant species, and some of them are known to participate in complex regulatory networks via their regulation of transcription factors involved in water stress signaling. We explored the role of miR159 in the response of Solanum lycopersicum Mill. plants to drought stress by analyzing the expression of sly-miR159 and its target SlMYB transcription factor genes in tomato plants of cv. Ailsa Craig grown in deprived water conditions or in response to mechanical damage caused by the Colorado potato beetle, a devastating insect pest of Solanaceae plants. Results showed that sly-miR159 regulatory function in the tomato plants response to distinct stresses might be mediated by differential stress-specific MYB transcription factor targeting. sly-miR159 targeting of SlMYB33 transcription factor transcript correlated with accumulation of the osmoprotective compounds proline and putrescine, which promote drought tolerance. This highlights the potential role of sly-miR159 in tomato plants’ adaptation to water deficit conditions.

scholarly journals The first enhancer in an enhancer chain safeguards subsequent enhancer-promoter contacts from a distance

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Wei Song ◽  
Roded Sharan ◽  
Ivan Ovcharenko
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Target Gene ◽  
Regulatory Elements ◽  
Distal Enhancer ◽  
Human Genes ◽  
Multiple Cell ◽  
A Chain ◽  
Target Promoter

Abstract Background Robustness and evolutionary stability of gene expression in the human genome are established by an array of redundant enhancers. Results Using Hi-C data in multiple cell lines, we report a comprehensive map of promoters and active enhancers connected by chromatin contacts, spanning 9000 enhancer chains in 4 human cell lines associated with 2600 human genes. We find that the first enhancer in a chain that directly contacts the target promoter is commonly located at a greater genomic distance from the promoter than the second enhancer in a chain, 96 kb vs. 45 kb, respectively. The first enhancer also features higher similarity to the promoter in terms of tissue specificity and higher enrichment of loop factors, suggestive of a stable primary contact with the promoter. In contrast, a chain of enhancers which connects to the target promoter through a neutral DNA segment instead of an enhancer is associated with a significant decrease in target gene expression, suggesting an important role of the first enhancer in initiating transcription using the target promoter and bridging the promoter with other regulatory elements in the locus. Conclusions The widespread chained structure of gene enhancers in humans reveals that the primary, critical enhancer is distal, commonly located further away than other enhancers. This first, distal enhancer establishes contacts with multiple regulatory elements and safeguards a complex regulatory program of its target gene.

scholarly journals CREAM: Clustering of genomic REgions Analysis Method

2017 ◽  
Author(s):  
Seyed Ali Madani Tonekaboni ◽  
Parisa Mazrooei ◽  
Victor Kofia ◽  
Benjamin Haibe-Kains ◽  
Mathieu Lupien
Keyword(s):  
Expression Profiles ◽  
Gene Expression Profiles ◽  
R Package ◽  
Regulatory Elements ◽  
Specific Gene ◽  
Analysis Method ◽  
Chromatin Interactions ◽  
Super Enhancer ◽  
Highly Expressed Genes ◽  
Genomic Regions

ABSTRACTCellular identity relies on cell type-specific gene expression profiles controlled by cis-regulatory elements (CREs), such as promoters, enhancers and anchors of chromatin interactions. CREs are unevenly distributed across the genome, giving rise to distinct subsets such as individual CREs and Clusters Of cis-Regulatory Elements (COREs), also known as super-enhancers. Identifying COREs is a challenge due to technical and biological features that entail variability in the distribution of distances between CREs within a given dataset. To address this issue, we developed a new unsupervised machine learning approach termed Clustering of genomic REgions Analysis Method (CREAM) that outperforms the Ranking Of Super Enhancer (ROSE) approach. Specifically CREAM identified COREs are enriched in CREs strongly bound by master transcription factors according to ChIP-seq signal intensity, are proximal to highly expressed genes, are preferentially found near genes essential for cell growth and are more predictive of cell identity. Moreover, we show that CREAM enables subtyping primary prostate tumor samples according to their CORE distribution across the genome. We further show that COREs are enriched compared to individual CREs at TAD boundaries and these are preferentially bound by CTCF and factors of the cohesin complex (e.g.: RAD21 and SMC3). Finally, using CREAM against transcription factor ChIP-seq reveals CTCF and cohesin-specific COREs preferentially at TAD boundaries compared to intra-TADs. CREAM is available as an open source R package (https://CRAN.R-project.org/package=CREAM) to identify COREs from cis-regulatory annotation datasets from any biological samples.

scholarly journals Multivalency regulates activity in an intrinsically disordered transcription factor

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Sarah Clark ◽  
Janette B Myers ◽  
Ashleigh King ◽  
Radovan Fiala ◽  
Jiri Novacek ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Target Gene ◽  
Intrinsic Disorder ◽  
Negative Cooperativity ◽  
Intrinsically Disordered ◽  
Main Target ◽  
Recognition Motifs ◽  
Cellular Transcription

The transcription factor ASCIZ (ATMIN, ZNF822) has an unusually high number of recognition motifs for the product of its main target gene, the hub protein LC8 (DYNLL1). Using a combination of biophysical methods, structural analysis by NMR and electron microscopy, and cellular transcription assays, we developed a model that proposes a concerted role of intrinsic disorder and multiple LC8 binding events in regulating LC8 transcription. We demonstrate that the long intrinsically disordered C-terminal domain of ASCIZ binds LC8 to form a dynamic ensemble of complexes with a gradient of transcriptional activity that is inversely proportional to LC8 occupancy. The preference for low occupancy complexes at saturating LC8 concentrations with both human and Drosophila ASCIZ indicates that negative cooperativity is an important feature of ASCIZ-LC8 interactions. The prevalence of intrinsic disorder and multivalency among transcription factors suggests that formation of heterogeneous, dynamic complexes is a widespread mechanism for tuning transcriptional regulation.

The Genetics of Evolutionary Novelties

2014 ◽  
Author(s):  
Günter P. Wagner
Keyword(s):  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Regulatory Elements ◽  
Complex Problem ◽  
Micro Rnas ◽  
Sex Comb ◽  
Gene Regulatory ◽  
Transcription Factor Proteins ◽  
Evolutionary Novelties

This chapter examines the molecular genetics of evolutionary novelties. In particular, it investigates which molecular mechanisms might be involved in the origination of novel gene regulatory networks (and, thus, character identity networks) and what these mechanisms imply for the origin of novel characters. The chapter begins with a discussion of the complex problem of the evolution of transcriptional regulation by focusing on the evolution of cis-regulatory elements (CREs) and the evolution of transcription factor proteins. It then asks whether novel pigment spots, such as the Drosophila wing spots, are novelties. It also explores an evolutionary novelty known as sex comb and the role of transposable elements in the origin of novel CREs. Finally, it considers the role of gene duplications, the evolution of micro-RNAs (miRNAs), and the possibility of a mechanistic difference between adaptation and innovation.

scholarly journals Genome-wide analysis of cis-regulatory changes in the metabolic adaptation of cavefish

2020 ◽  
Author(s):  
Jaya Krishnan ◽  
Chris W. Seidel ◽  
Ning Zhang ◽  
Jake VanCampen ◽  
Robert Peuß ◽  
...  
Keyword(s):  
Regulatory Networks ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Metabolic Adaptation ◽  
Enhancer Activity ◽  
Genome Wide ◽  
Cave Environment

AbstractChanges in cis-regulatory elements play important roles in adaptation and phenotypic evolution. However, their contribution to metabolic adaptation of organisms is less understood. Here we have utilized a unique vertebrate model, Astyanax mexicanus, different morphotypes of which survive in nutrient-rich surface and nutrient-deprived cave water to uncover gene regulatory networks in metabolic adaptation. We performed genome-wide epigenetic profiling in the liver tissue of one surface and two independently derived cave populations. We find that many cis-regulatory elements differ in their epigenetic status/chromatin accessibility between surface fish and cavefish, while the two independently derived cave populations have evolved remarkably similar regulatory signatures. These differentially accessible regions are associated with genes of key pathways related to lipid metabolism, circadian rhythm and immune system that are known to be altered in cavefish. Using in vitro and in vivo functional testing of the candidate cis-regulatory elements, we find that genetic changes within them cause quantitative expression differences. We characterized one cis-regulatory element in the hpdb gene and found a genomic deletion in cavefish that abolishes binding of the transcriptional repressor IRF2 in vitro and derepresses enhancer activity in reporter assays. Genetic experiments further validated a cis-mediated role of the enhancer and suggest a role of this deletion in the upregulation of hpdb in wild cavefish populations. Selection of this mutation in multiple independent cave populations supports its importance in the adaptation to the cave environment, providing novel molecular insights into the evolutionary trade-off between loss of pigmentation and adaptation to a food-deprived cave environment.

scholarly journals apterous A specifies dorsal wing patterns and sexual traits in butterflies

2017 ◽  
Author(s):  
Anupama Prakash ◽  
Antónia Monteiro
Keyword(s):  
Transcription Factor ◽  
Regulatory Networks ◽  
Sexually Dimorphic ◽  
Color Patterns ◽  
Bicyclus Anynana ◽  
Sexual Ornaments ◽  
Wing Patterns ◽  
Specific Factors ◽  
Different Color

AbstractButterflies have evolved different color patterns on their dorsal and ventral wing surfaces to serve different signaling functions, yet the developmental mechanisms controlling surface-specific patterning are still unknown. Here, we mutate both copies of the transcription factor apterous in Bicyclus anynana butterflies using CRISPR/Cas9 and show that apterous A functions both as a repressor and modifier of ventral wing color patterns, as well as a promoter of dorsal sexual ornaments in males. We propose that the surface-specific diversification of wing patterns in butterflies proceeded via the co-option of apterous A into various gene regulatory networks involved in the differentiation of discrete wing traits. Further, interactions between apterous and sex-specific factors such as doublesex may have contributed to the origin of sexually dimorphic surface-specific patterns. Finally, we discuss the evolution of eyespot pattern diversity in the family Nymphalidae within the context of developmental constraints due to apterous regulation.Significance statementButterflies have evolved different wing patterns on their dorsal and ventral wing surfaces that serve different signaling functions. We identify the transcription factor, apterous A, as a key regulator of this surface-specific differentiation in butterflies. We also show a role for apterous A in restricting the developmental origin of a novel trait, eyespots, to just the ventral wing surface. Dorsal-ventral differentiation of tissues is not just restricted to butterfly wings but occurs in many other organs and organisms from arthropods to humans. Thus, we believe that our work will be of interest to a diverse group of biologists and layman alike interested in the role of development in shaping biodiversity.

scholarly journals Hfq-assisted RsmA regulation is central to Pseudomonas aeruginosa biofilm polysaccharide PEL expression

2018 ◽  
Author(s):  
Yasuhiko Irie ◽  
Victoriia Murina ◽  
Vasili Hauryliuk ◽  
Victoria Shingler
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transcription Factor ◽  
Family Member ◽  
Mrna Stability ◽  
Rna Binding ◽  
Transcriptional Regulator ◽  
Regulatory Elements ◽  
Polysaccharide Biosynthesis ◽  
Chaperone Protein

ABSTRACTExpression of biofilm-associated genes is controlled by multiple regulatory elements, allowing bacteria to appropriately switch between sessile and motile lifestyles. In Pseudomonas aeruginosa, the post-transcriptional regulator RsmA has been implicated in the control of various genes including those related to biofilms, but much of the evidence for these links is limited to transcriptomic and phenotypic studies. RsmA binds to target mRNAs to modulate translation by affecting ribosomal access and/or mRNA stability. Here we trace a global regulatory role of RsmA to the inhibition of Vfr – a transcription factor that controls a transcriptional regulator FleQ. FleQ directly controls biofilm-associated genes that encode the PEL polysaccharide biosynthesis machinery. Furthermore, we show that RsmA cannot bind vfr mRNA alone, but requires the RNA chaperone protein Hfq. This is the first example where a RsmA protein family member is demonstrated to require another protein for RNA binding.

scholarly journals Expression Pattern, Regulation, and Biological Role of Runt Domain Transcription Factor, run, in Caenorhabditis elegans

2002 ◽  
Vol 22 (2) ◽  
pp. 547-554 ◽  
Author(s):  
Seunghee Nam ◽  
Yun-Hye Jin ◽  
Qing-Lin Li ◽  
Kwang-Youl Lee ◽  
Goo-Bo Jeong ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Caenorhabditis Elegans ◽  
Essential Role ◽  
Regulatory Elements ◽  
Intestinal Cells ◽  
Human Leukemia ◽  
Runt Domain ◽  
C Elegans ◽  
Intron Region

ABSTRACT The Caenorhabditis elegans run gene encodes a Runt domain factor. Runx1, Runx2, and Runx3 are the three known mammalian homologs of run. Runx1, which plays an essential role in hematopoiesis, has been identified at the breakpoint of chromosome translocations that are responsible for human leukemia. Runx2 plays an essential role in osteogenesis, and inactivation of one allele of Runx2 is responsible for the human disease cleidocranial dysplasia. To understand the role of run in C. elegans, we used transgenic run::GFP reporter constructs and a double-stranded RNA-mediated interference method. The expression of run was detected as early as the bean stage exclusively in the nuclei of seam hypodermal cells and lasted until the L3 stage. At the larval stage, expression of run was additionally detected in intestinal cells. The regulatory elements responsible for the postembryonic hypodermal seam cells and intestinal cells were separately located within a 7.2-kb-long intron region. This is the first report demonstrating that an intron region is essential for stage-specific and cell type-specific expression of a C. elegans gene. RNA interference analysis targeting the run gene resulted in an early larva-lethal phenotype, with apparent malformation of the hypodermis and intestine. These results suggest that run is involved in the development of a functional hypodermis and gut in C. elegans. The highly conserved role of the Runt domain transcription factor in gut development during evolution from nematodes to mammals is discussed.

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