scholarly journals Locally acting transcription factors regulate p53-dependent cis-regulatory element activity

2020 ◽  
Vol 48 (8) ◽  
pp. 4195-4213 ◽  
Author(s):  
Allison N Catizone ◽  
Gizem Karsli Uzunbas ◽  
Petra Celadova ◽  
Sylvia Kuang ◽  
Daniel Bose ◽  
...  

Abstract The master tumor suppressor p53 controls transcription of a wide-ranging gene network involved in apoptosis, cell cycle arrest, DNA damage repair, and senescence. Recent studies revealed pervasive binding of p53 to cis-regulatory elements (CREs), which are non-coding segments of DNA that spatially and temporally control transcription through the combinatorial binding of local transcription factors. Although the role of p53 as a strong trans-activator of gene expression is well known, the co-regulatory factors and local sequences acting at p53-bound CREs are comparatively understudied. We designed and executed a massively parallel reporter assay (MPRA) to investigate the effect of transcription factor binding motifs and local sequence context on p53-bound CRE activity. Our data indicate that p53-bound CREs are both positively and negatively affected by alterations in local sequence context and changes to co-regulatory TF motifs. Our data suggest p53 has the flexibility to cooperate with a variety of transcription factors in order to regulate CRE activity. By utilizing different sets of co-factors across CREs, we hypothesize that global p53 activity is guarded against loss of any one regulatory partner, allowing for dynamic and redundant control of p53-mediated transcription.

2019 ◽  
Author(s):  
Allison N. Catizone ◽  
Gizem Karsli Uzunbas ◽  
Petra Celadova ◽  
Sylvia Kuang ◽  
Daniel Bose ◽  
...  

AbstractThe master tumor suppressor p53 controls transcription of a wide-ranging gene network involved in apoptosis, cell cycle arrest, DNA damage repair, and senescence. Recent studies revealed pervasive binding of p53 to cis-regulatory elements (CRE), which are non-coding segments of DNA that spatially and temporally control transcription through the combinatorial binding of local transcription factors (TFs). Although the role of p53 as a strong trans-activator of gene expression is well known, the co-regulatory factors and local sequences acting at p53-bound CREs are comparatively understudied. We designed and executed a massively parallel reporter assay (MPRA) to investigate the effect of transcription factor binding motifs and local sequence context on p53-bound CRE activity. Our data indicate that p53-bound CREs are both positively and negatively affected by alterations in local sequence context and changes to co-regulatory TF motifs. We identified a SP1/KLF family motif located in an intronic p53 CRE that is required for the endogenous expression of the p53-dependent gene CCNG1. We also identified ATF3 as a factor that co-regulates the expression of the p53-dependent gene GDF15 through binding with p53 in an upstream CRE. Loss of either p53 or ATF3 severely reduces CRE activity and alters endogenous GDF15 mRNA levels in the cell. Our data suggests that p53 has the flexibility to cooperate with a variety of transcription factors in order to regulate CRE activity. By utilizing different sets of co-factors across CREs, we hypothesize that p53 activity is guarded against loss of any one regulatory partner allowing for dynamic and redundant control of p53-mediated transcription.


2021 ◽  
pp. 1-13
Author(s):  
Francis Poulat

In vertebrates, gonadal sex determination is the process by which transcription factors drive the choice between the testicular and ovarian identity of undifferentiated somatic progenitors through activation of 2 different transcriptional programs. Studies in animal models suggest that sex determination always involves sex-specific transcription factors that activate or repress sex-specific genes. These transcription factors control their target genes by recognizing their regulatory elements in the non-coding genome and their binding motifs within their DNA sequence. In the last 20 years, the development of genomic approaches that allow identifying all the genomic targets of a transcription factor in eukaryotic cells gave the opportunity to globally understand the function of the nuclear proteins that control complex genetic programs. Here, the major transcription factors involved in male and female vertebrate sex determination and the genomic profiling data of mouse gonads that contributed to deciphering their transcriptional regulation role will be reviewed.


2004 ◽  
Vol 379 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Sarita NEGI ◽  
Saurabh K. SINGH ◽  
Nirupma PATI ◽  
Vikas HANDA ◽  
Ruchi CHAUHAN ◽  
...  

The apo(a) [apolipoprotein(a)] gene is responsible for variations in plasma lipoprotein(a), high levels of which are a risk factor for atherosclerosis and myocardial infarction. The apo(a) promoter stimulates the expression of reporter genes in HepG2 cells, but not in HeLa cells. In the present study, we demonstrate that the 1.4 kb apo(a) promoter comprises two composite regulatory regions: a distal negative regulatory module (positions −1432 to −716) and a proximal tissue-specific module (−716 to −616). The distal negative regulatory module contains two strong negative regulatory regions [polymorphic PNR (pentanucleotide repeat region) and NREβ (negative regulatory element β)], which sandwich the postive regulatory region PREβ (positive regulatory element β). The PNR was shown to bind to transcription factors in a tissue-specific manner, whereas the ubiquitous transcription factors hepatocyte nuclear factor 3α and GATA binding protein 4 bound to NREβ to repress gene transcription. The proximal tissue-specific module contains two regulatory elements: an activating region (PREα) that activates transcription in HepG2 cells, and NREα, which is responsible for repressing the apo(a) gene in HeLa cells. NREα binds to a HeLa-specific repressor. These multiple regulatory elements might work co-operatively to finely regulate apo(a) gene expression. Although the tissue-specific module is required for apo(a) gene activation and repression in a tissue-specific manner, the combinatorial interplay of the distal and proximal regulators might define the complex pathway(s) of apo(a) gene regulation.


Author(s):  
Alexandra Maslova ◽  
Ricardo N. Ramirez ◽  
Ke Ma ◽  
Hugo Schmutz ◽  
Chendi Wang ◽  
...  

SUMMARYThe mammalian genome contains several million cis-regulatory elements, whose differential activity marked by open chromatin determines organogenesis and differentiation. This activity is itself embedded in the DNA sequence, decoded by sequence-specific transcription factors. Leveraging a granular ATAC-seq atlas of chromatin activity across 81 immune cell-types we show that a convolutional neural network (“AI-TAC”) can learn to infer cell-type-specific chromatin activity solely from the DNA sequence. AI-TAC does so by rediscovering, with astonishing precision, binding motifs for known regulators, and some unknown ones, mapping them with high concordance to positions validated by ChIP-seq data. AI-TAC also uncovers combinatorial influences, establishing a hierarchy of transcription factors (TFs) and their interactions involved in immunocyte specification, with intriguingly different strategies between lineages. Mouse-trained AI-TAC can parse human DNA, revealing a strikingly similar ranking of influential TFs. Thus, Deep Learning can reveal the regulatory syntax that drives the full differentiative complexity of the immune system.


2021 ◽  
Author(s):  
Jennifer A. Noble ◽  
Alex Seddon ◽  
Sahra Uygun ◽  
Steven E. Smith ◽  
Shin-Han Shiu ◽  
...  

Synergid cells in the micropylar end of the female gametophyte are required for critical cell-cell signaling interactions between the pollen tube and the ovule that precede double fertilization and seed formation in flowering plants. LORELEI (LRE) encodes a GPI-anchored protein that is expressed primarily in the synergid cells, and together with FERONIA, a receptor-like kinase, it controls pollen tube reception by the receptive synergid cell. Still, how LRE expression is controlled in synergid cells remains poorly characterized. We identified candidate cis-regulatory elements enriched in LRE and other synergid cell-expressed genes. One of the candidate motifs (TAATATCT) in the LRE promoter was an uncharacterized variant of the Evening Element motif that we named as the Short Evening Element-like (SEEL) motif. Deletion or point mutations in the SEEL motif of the LRE promoter resulted in decreased reporter expression in synergid cells, demonstrating that the SEEL motif is important for expression of LRE in synergid cells. Additionally, we found that LRE expression is decreased in the loss of function mutants of REVEILLE (RVE) transcription factors, which are clock genes known to bind the SEEL and other closely related motifs. We propose that RVE transcription factors regulate LRE expression in synergid cells by binding to the SEEL motif in the LRE promoter. Identification of a cis-regulatory element and transcription factors involved in the expression of LRE will serve as a foundation to characterize the gene regulatory networks in synergid cells and investigate the potential connection between circadian rhythm and fertilization.


2020 ◽  
Author(s):  
Christina B. Azodi ◽  
John P. Lloyd ◽  
Shin-Han Shiu

ABSTRACTPlants respond to their environment by dynamically modulating gene expression. A powerful approach for understanding how these responses are regulated is to integrate information about cis-regulatory elements (CREs) into models called cis-regulatory codes. Transcriptional response to combined stress is typically not the sum of the responses to the individual stresses. However, cis-regulatory codes underlying combined stress response have not been established. Here we modeled transcriptional response to single and combined heat and drought stress in Arabidopsis thaliana. We grouped genes by their pattern of response (independent, antagonistic, synergistic) and trained machine learning models to predict their response using putative CREs (pCREs) as features (median F-measure = 0.64). We then developed a deep learning approach to integrate additional omics information (sequence conservation, chromatin accessibility, histone modification) into our models, improving performance by 6.2%. While pCREs important for predicting independent and antagonistic responses tended to resemble binding motifs of transcription factors associated with heat and/or drought stress, important synergistic pCREs resembled binding motifs of transcription factors not known to be associated with stress. These findings demonstrate how in silico approaches can improve our understanding of the complex codes regulating response to combined stress and help us identify prime targets for future characterization.


Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4571-4580 ◽  
Author(s):  
Lydia Teboul ◽  
Juliette Hadchouel ◽  
Philippe Daubas ◽  
Dennis Summerbell ◽  
Margaret Buckingham ◽  
...  

Vertebrate myogenesis is controlled by four transcription factors known as the myogenic regulatory factors (MRFs): Myf5, Mrf4, myogenin and MyoD. During mouse development Myf5 is the first MRF to be expressed and it acts by integrating multiple developmental signals to initiate myogenesis. Numerous discrete regulatory elements are involved in the activation and maintenance of Myf5 gene expression in the various muscle precursor populations, reflecting the diversity of the signals that control myogenesis. Here we focus on the enhancer that recapitulates the first phase of Myf5 expression in the epaxial domain of the somite, in order to identify the subset of cells that first transcribes the gene and therefore gain insight into molecular, cellular and anatomical facets of early myogenesis. Deletion of this enhancer from a YAC reporter construct that recapitulates the Myf5 expression pattern demonstrates that this regulatory element is necessary for expression in the early epaxial somite but in no other site of myogenesis. Importantly, Myf5 is subsequently expressed in the epaxial myotome under the control of other elements located far upstream of the gene. Our data suggest that the inductive signals that control Myf5 expression switch rapidly from those that impinge on the early epaxial enhancer to those that impinge on the other enhancers that act later in the epaxial somite, indicating that there are significant changes in either the signalling environment or the responsiveness of the cells along the rostrocaudal axis. We propose that the first phase of Myf5 epaxial expression, driven by the early epaxial enhancer in the dermomyotome, is necessary for early myotome formation, while the subsequent phases are associated with cytodifferentiation within the myotome.


Author(s):  
Can Sönmezer ◽  
Rozemarijn Kleinendorst ◽  
Dilek Imanci ◽  
Laura Villacorta ◽  
Dirk Schübeler ◽  
...  

Gene activation requires the cooperative activity of multiple transcription factors at cis-regulatory elements. Yet, most transcription factors have short residence time, questioning the requirement of their physical co-occupancy on DNA to achieve cooperativity. Here, we advance Single Molecule Footprinting to detect individual molecular interactions of transcription factors and nucleosomes with DNA at mouse cis-regulatory elements. We apply this strategy to quantify the simultaneous binding of multiple transcription factors on single DNA molecules. Analysis of the binary occupancy patterns at thousands of motif combinations reveals that for most types of transcription factors high DNA co-occupancy can occur in absence of direct physical interaction, at sites of competition with nucleosomes. Perturbation of pairwise interactions demonstrates the function of molecular co-occupancy for binding cooperativity. These findings elucidate the binding cooperativity mechanism used by transcription factors in absence of strict organisation of their binding motifs, a characteristic feature of most of enhancers.


2018 ◽  
Author(s):  
Francesco N. Carelli ◽  
Angélica Liechti ◽  
Jean Halbert ◽  
Maria Warnefors ◽  
Henrik Kaessmann

ABSTRACTThe spatiotemporal control of gene expression exerted by promoters and enhancers is central for organismal development, physiology and behaviour. These two types of regulatory elements have long been distinguished from each other based on their function, but recent work highlighted common architectural and functional features. It also suggested that inheritable alterations in the epigenetic and sequence context of regulatory elements might underlie evolutionary changes of their principal activity, which could result in changes in the transcriptional profile of genes under their control or even facilitate the birth of new genes. Here, based on integrated cross-mammalian analyses of DNase hypersensitivity, chromatin modification and transcriptional data, we provide support for this hypothesis by detecting 449 regulatory elements with signatures of activity turnover in sister species from the primate and rodent lineages (termed “P/E” elements). Through the comparison with outgroup species, we defined the directionality of turnover events, which revealed that most instances represent transformations of ancestral enhancers into promoters, leading to the emergence of species-specific transcribed loci or 5’ exons. Notably, P/E elements have distinct GC sequence compositions and stabilizing 5’ splicing (U1) regulatory motif patterns, which may predispose them to functional repurposing during evolution. Moreover, we trace changes in the U1 and polyadenylation signal densities and distributions that accompanied and likely drove the evolutionary activity switches. Overall, our work suggests rather widespread evolutionary remodelling of regulatory element functions. Functional repurposing thus represents a notable mechanism that likely facilitated regulatory innovation and the origination of new genes and exons during mammalian evolution.


2017 ◽  
Vol 131 (16) ◽  
pp. 2161-2182 ◽  
Author(s):  
Rocio Rojo ◽  
Clare Pridans ◽  
David Langlais ◽  
David A. Hume

The proliferation, differentiation, and survival of cells of the macrophage lineage depends upon signals from the macrophage colony-stimulating factor (CSF) receptor (CSF1R). CSF1R is expressed by embryonic macrophages and induced early in adult hematopoiesis, upon commitment of multipotent progenitors to the myeloid lineage. Transcriptional activation of CSF1R requires interaction between members of the E26 transformation-specific family of transcription factors (Ets) (notably PU.1), C/EBP, RUNX, AP-1/ATF, interferon regulatory factor (IRF), STAT, KLF, REL, FUS/TLS (fused in sarcoma/ranslocated in liposarcoma) families, and conserved regulatory elements within the mouse and human CSF1R locus. One element, the Fms-intronic regulatory element (FIRE), within intron 2, is conserved functionally across all the amniotes. Lineage commitment in multipotent progenitors also requires down-regulation of specific transcription factors such as MYB, FLI1, basic leucine zipper transcriptional factor ATF-like (BATF3), GATA-1, and PAX5 that contribute to differentiation of alternative lineages and repress CSF1R transcription. Many of these transcription factors regulate each other, interact at the protein level, and are themselves downstream targets of CSF1R signaling. Control of CSF1R transcription involves feed–forward and feedback signaling in which CSF1R is both a target and a participant; and dysregulation of CSF1R expression and/or function is associated with numerous pathological conditions. In this review, we describe the regulatory network behind CSF1R expression during differentiation and development of cells of the mononuclear phagocyte system.


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