scholarly journals Cellular remodeling and JAK inhibition promote zygotic gene expression in the Ciona germline

2021 ◽  
Author(s):  
Naoyuki Ohta ◽  
Lionel Christiaen
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Cell Fate ◽  
Primordial Germ Cells ◽  
Transcription Control ◽  
Cell Fate Decisions ◽  
Fate Specification ◽  
Zygotic Transcription ◽  
General Inhibitor ◽  
Zygotic Gene

During development, remodeling of the cellular transcriptome and proteome underlies cell fate decisions and, in somatic lineages, transcription control is a major determinant of fateful biomolecular transitions. By contrast, early germline fate specification in numerous vertebrate and invertebrate species relies extensively on RNA-level regulation, exerted on asymmetrically inherited maternal supplies, with little-to-no zygotic transcription. However delayed, a maternal-to-zygotic transition is nevertheless poised to complete the deployment of pre-gametic programs in the germline. Here, we focused on early germline specification in the tunicate Ciona to study zygotic genome activation. We first demonstrate that a peculiar cellular remodeling event excludes localized postplasmic mRNAs, including Pem-1, which encodes the general inhibitor of transcription. Subsequently, zygotic transcription begins in Pem-1-negative primordial germ cells (PGCs), as revealed by histochemical detection of elongating RNA Polymerase II (RNAPII), and nascent transcripts from the Mef2 locus. Using PGC-specific Mef2 transcription as a read-out, we uncovered a provisional antagonism between JAK and MEK/BMPRI/GSK3 signaling, which controls the onset of zygotic gene expression, following cellular remodeling of PGC progenitor cells. We propose a 2-step model for the onset of zygotic transcription in the Ciona germline, which relies on successive cellular remodeling and JAK inhibition, and discuss the significance of germ plasm dislocation and remodeling in the context of developmental fate specification.

scholarly journals CDK12 is Necessary to Promote Epidermal Differentiation through Transcription Elongation

2021 ◽  
Author(s):  
George Sen ◽  
Jingting Li ◽  
Manisha Tiwari ◽  
Yifang Chen
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
Cell Fate ◽  
Target Genes ◽  
Skin Diseases ◽  
Transcription Elongation ◽  
The Body ◽  
Epidermal Differentiation ◽  
Transcription Control ◽  
Cell Fate Decisions

Proper differentiation of the epidermis is essential to prevent water loss and to protect the body from the outside environment. Perturbations in this process can lead to a variety of skin diseases that impacts 1 in 5 people. While transcription factors that control epidermal differentiation have been well characterized, other aspects of transcription control such as elongation are poorly understood. Here we show that of the two cyclin dependent kinases (CDK12 and CDK13), that are known to regulate transcription elongation, only CDK12 is necessary for epidermal differentiation. Depletion of CDK12 led to loss of differentiation gene expression and absence of skin barrier formation in regenerated human epidermis. CDK12 binds to genes that code for differentiation promoting transcription factors (GRHL3, KLF4, and OVOL1) and is necessary for their elongation. CDK12 is necessary for elongation by promoting Ser2 phosphorylation on the C-terminal domain of RNA polymerase II and the binding of the elongation factor SPT6 to target genes. Our results suggest that control of transcription elongation by CDK12 plays a prominent role in adult cell fate decisions.

scholarly journals GATA-targeted compounds modulate cardiac subtype cell differentiation in dual reporter stem cell line

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mika J. Välimäki ◽  
Robert S. Leigh ◽  
Sini M. Kinnunen ◽  
Alexander R. March ◽  
Ana Hernández de Sande ◽  
...  
Keyword(s):  
Gene Expression ◽  
Progenitor Cells ◽  
Cell Fate ◽  
Reporter Gene ◽  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Cell Fate Decisions ◽  
Dual Reporter ◽  
Gene Regulatory ◽  
Reporter Gene Assays

AbstractBackgroundPharmacological modulation of cell fate decisions and developmental gene regulatory networks holds promise for the treatment of heart failure. Compounds that target tissue-specific transcription factors could overcome non-specific effects of small molecules and lead to the regeneration of heart muscle following myocardial infarction. Due to cellular heterogeneity in the heart, the activation of gene programs representing specific atrial and ventricular cardiomyocyte subtypes would be highly desirable. Chemical compounds that modulate atrial and ventricular cell fate could be used to improve subtype-specific differentiation of endogenous or exogenously delivered progenitor cells in order to promote cardiac regeneration.MethodsTranscription factor GATA4-targeted compounds that have previously shown in vivo efficacy in cardiac injury models were tested for stage-specific activation of atrial and ventricular reporter genes in differentiating pluripotent stem cells using a dual reporter assay. Chemically induced gene expression changes were characterized by qRT-PCR, global run-on sequencing (GRO-seq) and immunoblotting, and the network of cooperative proteins of GATA4 and NKX2-5 were further explored by the examination of the GATA4 and NKX2-5 interactome by BioID. Reporter gene assays were conducted to examine combinatorial effects of GATA-targeted compounds and bromodomain and extraterminal domain (BET) inhibition on chamber-specific gene expression.ResultsGATA4-targeted compounds 3i-1000 and 3i-1103 were identified as differential modulators of atrial and ventricular gene expression. More detailed structure-function analysis revealed a distinct subclass of GATA4/NKX2-5 inhibitory compounds with an acetyl lysine-like domain that contributed to ventricular cells (%Myl2-eGFP+). Additionally, BioID analysis indicated broad interaction between GATA4 and BET family of proteins, such as BRD4. This indicated the involvement of epigenetic modulators in the regulation of GATA-dependent transcription. In this line, reporter gene assays with combinatorial treatment of 3i-1000 and the BET bromodomain inhibitor (+)-JQ1 demonstrated the cooperative role of GATA4 and BRD4 in the modulation of chamber-specific cardiac gene expression.ConclusionsCollectively, these results indicate the potential for therapeutic alteration of cell fate decisions and pathological gene regulatory networks by GATA4-targeted compounds modulating chamber-specific transcriptional programs in multipotent cardiac progenitor cells and cardiomyocytes. The compound scaffolds described within this study could be used to develop regenerative strategies for myocardial regeneration.

scholarly journals Resolution of Cell Fate Decisions Revealed by Single-Cell Gene Expression Analysis from Zygote to Blastocyst

2010 ◽  
Vol 18 (4) ◽  
pp. 675-685 ◽  
Author(s):  
Guoji Guo ◽  
Mikael Huss ◽  
Guo Qing Tong ◽  
Chaoyang Wang ◽  
Li Li Sun ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Cell Fate ◽  
Expression Analysis ◽  
Gene Expression Analysis ◽  
Cell Fate Decisions ◽  
Cell Gene Expression ◽  
Cell Gene

scholarly journals Pluripotency factors select gene expression repertoire at Zygotic Genome Activation

2020 ◽  
Author(s):  
Meijiang Gao ◽  
Marina Veil ◽  
Marcus Rosenblatt ◽  
Anna Gebhard ◽  
Helge Hass ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Early Gene ◽  
Zebrafish Embryos ◽  
Fate Specification ◽  
Pluripotency Factors ◽  
Zygotic Transcription ◽  
Simultaneous Loss ◽  
Genome Activation ◽  
Zygotic Genome

AbstractAwakening of zygotic transcription in animal embryos relies on maternal pioneer transcription factors. The interplay of global and specific functions of these proteins remains poorly understood. Here, we analyzed nucleosome positioning, H3K27 acetylation, transcription, and gastrulation rates in zebrafish embryos lacking pluripotency factors Pou5f3 and Sox19b. We show that the bulk transcriptional onset does not require Sox19b and Pou5f3, but is sensitive to their balance. Pou5f3 docks H3K27ac on the enhancers of genes involved in gastrulation and ventral fate specification. Sox19b facilitates Pou5f3 access to one-third of these enhancers. The genes regulating mesendodermal and dorsal fates are primed for activation independently on Pou5f3 and Sox19b. Strikingly, the loss of either factor results in activation of silent enhancers; simultaneous loss of both leads to premature expression of differentiation genes. Our results uncover how independent activities of maternal Pou5f3 and Sox19b add up or antagonize to determine the early gene expression repertoire.

Serrate and Notch specify cell fates in the heart field by suppressing cardiomyogenesis

Development ◽  
2000 ◽  
Vol 127 (17) ◽  
pp. 3865-3876
Author(s):  
M.S. Rones ◽  
K.A. McLaughlin ◽  
M. Raffin ◽  
M. Mercola
Keyword(s):  
Gene Expression ◽  
Notch Signaling ◽  
Cell Fate ◽  
Notch Pathway ◽  
Cell Types ◽  
Myocardial Cell ◽  
Dominant Negative ◽  
Cell Fates ◽  
Cell Fate Decisions ◽  
Heart Field

Notch signaling mediates numerous developmental cell fate decisions in organisms ranging from flies to humans, resulting in the generation of multiple cell types from equipotential precursors. In this paper, we present evidence that activation of Notch by its ligand Serrate apportions myogenic and non-myogenic cell fates within the early Xenopus heart field. The crescent-shaped field of heart mesoderm is specified initially as cardiomyogenic. While the ventral region of the field forms the myocardial tube, the dorsolateral portions lose myogenic potency and form the dorsal mesocardium and pericardial roof (Raffin, M., Leong, L. M., Rones, M. S., Sparrow, D., Mohun, T. and Mercola, M. (2000) Dev. Biol., 218, 326–340). The local interactions that establish or maintain the distinct myocardial and non-myocardial domains have never been described. Here we show that Xenopus Notch1 (Xotch) and Serrate1 are expressed in overlapping patterns in the early heart field. Conditional activation or inhibition of the Notch pathway with inducible dominant negative or active forms of the RBP-J/Suppressor of Hairless [Su(H)] transcription factor indicated that activation of Notch feeds back on Serrate1 gene expression to localize transcripts more dorsolaterally than those of Notch1, with overlap in the region of the developing mesocardium. Moreover, Notch pathway activation decreased myocardial gene expression and increased expression of a marker of the mesocardium and pericardial roof, whereas inhibition of Notch signaling had the opposite effect. Activation or inhibition of Notch also regulated contribution of individual cells to the myocardium. Importantly, expression of Nkx2. 5 and Gata4 remained largely unaffected, indicating that Notch signaling functions downstream of heart field specification. We conclude that Notch signaling through Su(H) suppresses cardiomyogenesis and that this activity is essential for the correct specification of myocardial and non-myocardial cell fates.

scholarly journals Maximal STAT5-Induced Proliferation and Self-Renewal at Intermediate STAT5 Activity Levels

2008 ◽  
Vol 28 (21) ◽  
pp. 6668-6680 ◽  
Author(s):  
Albertus T. J. Wierenga ◽  
Edo Vellenga ◽  
Jan Jacob Schuringa
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Target Genes ◽  
Expression Patterns ◽  
Activity Levels ◽  
Dependent Manner ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions

ABSTRACT The level of transcription factor activity critically regulates cell fate decisions, such as hematopoietic stem cell (HSC) self-renewal and differentiation. We introduced STAT5A transcriptional activity into human HSCs/progenitor cells in a dose-dependent manner by overexpression of a tamoxifen-inducible STAT5A(1*6)-estrogen receptor fusion protein. Induction of STAT5A activity in CD34+ cells resulted in impaired myelopoiesis and induction of erythropoiesis, which was most pronounced at the highest STAT5A transactivation levels. In contrast, intermediate STAT5A activity levels resulted in the most pronounced proliferative advantage of CD34+ cells. This coincided with increased cobblestone area-forming cell and long-term-culture-initiating cell frequencies, which were predominantly elevated at intermediate STAT5A activity levels but not at high STAT5A levels. Self-renewal of progenitors was addressed by serial replating of CFU, and only progenitors containing intermediate STAT5A activity levels contained self-renewal capacity. By extensive gene expression profiling we could identify gene expression patterns of STAT5 target genes that predominantly associated with a self-renewal and long-term expansion phenotype versus those that identified a predominant differentiation phenotype.

scholarly journals C/EBPα determines hematopoietic cell fate in multipotential progenitor cells by inhibiting erythroid differentiation and inducing myeloid differentiation

Blood ◽  
2006 ◽  
Vol 107 (11) ◽  
pp. 4308-4316 ◽  
Author(s):  
Hyung Chan Suh ◽  
John Gooya ◽  
Katie Renn ◽  
Alan D. Friedman ◽  
Peter F. Johnson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Hematopoietic Cell ◽  
Myeloid Differentiation ◽  
Specific Gene ◽  
Erythroid Progenitors ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions ◽  
Conditional Expression ◽  
Murine Erythroleukemia

AbstractC/EBPα is an essential transcription factor required for myeloid differentiation. While C/EBPα can act as a cell fate switch to promote granulocyte differentiation in bipotential granulocyte-macrophage progenitors (GMPs), its role in regulating cell fate decisions in more primitive progenitors is not known. We found increased numbers of erythroid progenitors and erythroid cells in C/EBPα–/– fetal liver (FL). Also, enforced expression of C/EBPα in hematopoietic stem cells resulted in a loss of erythroid progenitors and an increase in myeloid cells by inhibition of erythroid development and inducing myeloid differentiation. Conditional expression of C/EBPα in murine erythroleukemia (MEL) cells induced myeloid-specific genes, while inhibiting erythroid-specific gene expression including erythropoietin receptor (EpoR), which suggests a novel mechanism to determine hematopoietic cell fate. Thus, C/EBPα functions in hematopoietic cell fate decisions by the dual actions of inhibiting erythroid and inducing myeloid gene expression in multipotential progenitors.

scholarly journals Coupling of DNA Replication and Negative Feedback Controls Gene Expression for Cell-Fate Decisions

iScience ◽  
2018 ◽  
Vol 6 ◽  
pp. 1-12 ◽  
Author(s):  
Qiuyan Shao ◽  
Michael G. Cortes ◽  
Jimmy T. Trinh ◽  
Jingwen Guan ◽  
Gábor Balázsi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Replication ◽  
Cell Fate ◽  
Negative Feedback ◽  
Feedback Controls ◽  
Cell Fate Decisions

scholarly journals Focal adhesion kinase protein regulates Wnt3a gene expression to control cell fate specification in the developing neural plate

2011 ◽  
Vol 22 (13) ◽  
pp. 2409-2421 ◽  
Author(s):  
Yuri Fonar ◽  
Yoni E. Gutkovich ◽  
Heather Root ◽  
Anastasia Malyarova ◽  
Emil Aamar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Wnt Signaling ◽  
Focal Adhesion Kinase ◽  
Cell Fate ◽  
Focal Adhesion ◽  
Control Cell ◽  
Focal Adhesions ◽  
Neural Plate ◽  
Cell Fate Specification ◽  
Fate Specification

Focal adhesion kinase (FAK) is a cytoplasmic tyrosine kinase protein localized to regions called focal adhesions, which are contact points between cells and the extracellular matrix. FAK protein acts as a scaffold to transfer adhesion-dependent and growth factor signals into the cell. Increased FAK expression is linked to aggressive metastatic and invasive tumors. However, little is known about its normal embryonic function. FAK protein knockdown during early Xenopus laevis development anteriorizes the embryo. Morphant embryos express increased levels of anterior neural markers, with reciprocally reduced posterior neural marker expression. Posterior neural plate folding and convergence-extension is also inhibited. This anteriorized phenotype resembles that of embryos knocked down zygotically for canonical Wnt signaling. FAK and Wnt3a genes are both expressed in the neural plate, and Wnt3a expression is FAK dependent. Ectopic Wnt expression rescues this FAK morphant anteriorized phenotype. Wnt3a thus acts downstream of FAK to balance anterior–posterior cell fate specification in the developing neural plate. Wnt3a gene expression is also FAK dependent in human breast cancer cells, suggesting that this FAK–Wnt linkage is highly conserved. This unique observation connects the FAK- and Wnt-signaling pathways, both of which act to promote cancer when aberrantly activated in mammalian cells.

scholarly journals Cdk8 Kinase Module: A Mediator of Life and Death Decisions in Times of Stress

2021 ◽  
Vol 9 (10) ◽  
pp. 2152
Author(s):  
Brittany Friedson ◽  
Katrina F. Cooper
Keyword(s):  
Cell Death ◽  
Rna Polymerase Ii ◽  
Cell Fate ◽  
Ubiquitin Proteasome System ◽  
Mitochondrial Morphology ◽  
Atp Production ◽  
Cell Fate Decisions ◽  
Regulated Cell Death ◽  
Cyclin C ◽  
Convergence Point

The Cdk8 kinase module (CKM) of the multi-subunit mediator complex plays an essential role in cell fate decisions in response to different environmental cues. In the budding yeast S. cerevisiae, the CKM consists of four conserved subunits (cyclin C and its cognate cyclin-dependent kinase Cdk8, Med13, and Med12) and predominantly negatively regulates a subset of stress responsive genes (SRG’s). Derepression of these SRG’s is accomplished by disassociating the CKM from the mediator, thus allowing RNA polymerase II-directed transcription. In response to cell death stimuli, cyclin C translocates to the mitochondria where it induces mitochondrial hyper-fission and promotes regulated cell death (RCD). The nuclear release of cyclin C requires Med13 destruction by the ubiquitin-proteasome system (UPS). In contrast, to protect the cell from RCD following SRG induction induced by nutrient deprivation, cyclin C is rapidly destroyed by the UPS before it reaches the cytoplasm. This enables a survival response by two mechanisms: increased ATP production by retaining reticular mitochondrial morphology and relieving CKM-mediated repression on autophagy genes. Intriguingly, nitrogen starvation also stimulates Med13 destruction but through a different mechanism. Rather than destruction via the UPS, Med13 proteolysis occurs in the vacuole (yeast lysosome) via a newly identified Snx4-assisted autophagy pathway. Taken together, these findings reveal that the CKM regulates cell fate decisions by both transcriptional and non-transcriptional mechanisms, placing it at a convergence point between cell death and cell survival pathways.

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