scholarly journals unc-37/Groucho and lsy-22/AES repress Wnt target genes in C. elegans asymmetric cell divisions

2022 ◽  
Author(s):  
Kimberly N. Bekas ◽  
Bryan T. Phillips
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Target Gene ◽  
Target Genes ◽  
Intermediate Cell ◽  
Beta Catenin ◽  
Cell Fate Decisions ◽  
C Elegans ◽  
Somatic Gonad ◽  
Seam Cell

Asymmetric cell division (ACD) is a fundamental mechanism of developmental cell fate specification and adult tissue homeostasis. In C. elegans, the Wnt/beta-catenin asymmetry (WβA) pathway regulates ACDs throughout embryonic and larval development. Under control of Wnt ligand-induced polarity, the transcription factor TCF/POP-1 functions with the coactivator beta-catenin/SYS-1 to activate gene expression in the signaled cell or, in absence of the coactivator, to repress Wnt target genes in the nascent unsignaled daughter cell. To date, a broad investigation of Groucho function in WβA is lacking and the function of the short Groucho AES homolog, lsy-22 has only been evaluated in C. elegans neuronal cell fate decisions. Further, there is conflicting evidence showing TCF utilizing Groucho-mediated repression may be either aided or repressed by addition of AES subfamily of Groucho proteins. Here we demonstrate a genetic interaction between Groucho repressors and TCF/POP-1 in ACDs in the somatic gonad, the seam hypodermal stem cell lineage and the early embryo. Specifically, in the somatic gonad lineage, the signaled cell fate increases after individual and double Groucho loss of function, representing the first demonstration of Groucho function in wild-type WβA ACD. Further, WβA target gene misexpression occurs at a higher rate than DTC fate changes, suggesting derepression generates an intermediate cell fate. In seam cell ACD, loss of Groucho unc-37 or Groucho-like lsy-22 in a pop-1(RNAi) hypomorphic background enhances a pop-1 seam cell expansion and target gene misregulation. Moreover, while POP-1 depletion in lsy-22 null mutants yielded an expected increase in seam cells we observed a surprising seam cell decrease in the unc-37 null subjected to POP-1 depletion. This phenotype may be due to UNC-37 regulation of pop-1 expression in this tissue since we find misregulation of POP-1 in unc-37 mutants. Lastly, Groucho functions in embryonic endoderm development since we observe ectopic endoderm target gene expression in lsy-22(ot244) heterozygotes and unc-37(tm4649) heterozygotes subjected to intermediate levels of hda-1(RNAi). Together, these data indicate Groucho repressor modulation of cell fate via regulation of POP-1/TCF repression is widespread in asymmetric cell fate decisions and suggests a novel role of LSY-22 as a bona fide TCF repressor. As AES Grouchos are well-conserved, our model of combinatorial TCF repression by both Gro/TLE and AES warrants further investigation. 

SUMOylated Non-canonical Polycomb PRC1.6 Complex as a Prerequisite for Recruitment of Transcription Factor RBPJ

2021 ◽  
Author(s):  
Małgorzata Sotomska ◽  
Robert Liefke ◽  
Francesca Ferrante ◽  
Heiko Schwederski ◽  
Franz Oswald ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Cell Fate ◽  
Target Gene ◽  
Target Genes ◽  
Adult Stem Cell ◽  
Notch Signalling ◽  
Cell Fate Decisions ◽  
Contact Points ◽  
Coactivator Complex

Abstract BackgroundNotch signaling controls cell fate decisions in many contexts during development and adult stem cell homeostasis and, when dysregulated, leads to carcinogenesis. The central transcription factor RBPJ assembles the Notch coactivator complex in the presence of Notch signalling, and represses Notch target gene expression in its absence.ResultsWe identified L3MBTL2 and additional members of the non-canonical polycomb repressive PRC1.6 complex in DNA-bound RBPJ associated complexes and demonstrate that L3MBTL2 directly interacts with RBPJ. Depletion of RBPJ does not affect occupancy of PRC1.6 components at Notch target genes. Conversely, absence of L3MBTL2 reduces RBPJ occupancy at enhancers of Notch target genes. Since L3MBTL2 and additional members of the PRC1.6 are known to be SUMOylated, we investigated whether RBPJ uses SUMO-moieties as contact points. Indeed, we found that RBPJ binds to SUMO2/3 and that this interaction depends on a defined SUMO-interaction motif. Furthermore, we show that pharmacological inhibition of SUMOylation reduces RBPJ occupancy at Notch target genes.ConclusionsWe propose that the PRC1.6 complex and its conjugated SUMO-modifications provide a scaffold that is recognized by RBPJ and promotes its recruitment to Notch target genes.

scholarly journals SUMOylated non-canonical polycomb PRC1.6 complex as a prerequisite for recruitment of transcription factor RBPJ

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Małgorzata Sotomska ◽  
Robert Liefke ◽  
Francesca Ferrante ◽  
Heiko Schwederski ◽  
Franz Oswald ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Notch Signaling ◽  
Cell Fate ◽  
Target Gene ◽  
Target Genes ◽  
Adult Stem Cell ◽  
Cell Fate Decisions ◽  
Contact Points ◽  
Coactivator Complex

Abstract Background Notch signaling controls cell fate decisions in many contexts during development and adult stem cell homeostasis and, when dysregulated, leads to carcinogenesis. The central transcription factor RBPJ assembles the Notch coactivator complex in the presence of Notch signaling, and represses Notch target gene expression in its absence. Results We identified L3MBTL2 and additional members of the non-canonical polycomb repressive PRC1.6 complex in DNA-bound RBPJ associated complexes and demonstrate that L3MBTL2 directly interacts with RBPJ. Depletion of RBPJ does not affect occupancy of PRC1.6 components at Notch target genes. Conversely, absence of L3MBTL2 reduces RBPJ occupancy at enhancers of Notch target genes. Since L3MBTL2 and additional members of the PRC1.6 are known to be SUMOylated, we investigated whether RBPJ uses SUMO-moieties as contact points. Indeed, we found that RBPJ binds to SUMO2/3 and that this interaction depends on a defined SUMO-interaction motif. Furthermore, we show that pharmacological inhibition of SUMOylation reduces RBPJ occupancy at Notch target genes. Conclusions We propose that the PRC1.6 complex and its conjugated SUMO-modifications provide a favorable environment for binding of RBPJ to Notch target genes.

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 hecd-1 Modulates Notch Activity in Caenorhabditis elegans

2015 ◽  
Vol 5 (3) ◽  
pp. 353-359 ◽  
Author(s):  
Yunting Chen ◽  
Iva Greenwald
Keyword(s):  
Quality Control ◽  
Caenorhabditis Elegans ◽  
Cell Fate ◽  
Germ Line ◽  
Notch Pathway ◽  
Cell Fate Decisions ◽  
Notch Activity ◽  
C Elegans ◽  
Somatic Gonad ◽  
Constitutively Active

Abstract Notch is a receptor that mediates cell–cell interactions that specify binary cell fate decisions in development and tissue homeostasis. Inappropriate Notch signaling is associated with cancer, and mutations in Notch pathway components have been associated with developmental diseases and syndromes. In Caenorhabditis elegans, suppressors of phenotypes associated with constitutively active LIN-12/Notch have identified many conserved core components and direct or indirect modulators. Here, we molecularly identify sel(ar584), originally isolated as a suppressor of a constitutively active allele of lin-12. We show that sel(ar584) is an allele of hecd-1, the ortholog of human HECDT1, a ubiquitin ligase that has been implicated in several different mammalian developmental events. We studied interactions of hecd-1 with lin-12 in the somatic gonad and with the other C. elegans Notch gene, glp-1, in the germ line. We found that hecd-1 acts as a positive modulator of lin-12/Notch activity in a somatic gonad context—the original basis for its isolation—but acts autonomously as a negative modulator of glp-1/Notch activity in the germ line. As the yeast ortholog of HECD-1, Ufd4p, has been shown to function in quality control, and C. elegans  HECD-1 has been shown to affect mitochondrial maintenance, we propose that the different genetic interactions between hecd-1 and Notch genes we observed in different cell contexts may reflect differences in quality control regulatory mechanisms or in cellular metabolism.

scholarly journals PQN-59 antagonizes microRNA-mediated repression and functions in stress granule formation during C. elegans development

2021 ◽  
Author(s):  
Christopher Martin Hammell ◽  
Colleen Carlston ◽  
Robin Weinmann ◽  
Natalia Stec ◽  
Simona Abbatemarco ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Intracellular Transport ◽  
Target Genes ◽  
Protein Translation ◽  
Transcriptional Level ◽  
Temporal Patterning ◽  
Granule Formation ◽  
C Elegans ◽  
Stable Pattern

microRNAs (miRNAs) are potent regulators of gene expression that function in a variety of developmental and physiological processes by dampening the expression of their target genes at a post-transcriptional level. In many gene regulatory networks (GRNs), miRNAs function in a switch-like manner whereby their expression and activity elicit a transition from one stable pattern of gene expression to a distinct, equally stable pattern required to define a nascent cell fate. While the importance of miRNAs that function in this capacity are clear, we have less of an understanding of the cellular factors and mechanisms that ensure the robustness of this form of regulatory bistability. In a screen to identify suppressors of temporal patterning phenotypes that result from ineffective miRNA-mediated target repression during  C. elegans  development, we identified  pqn-59,  an ortholog of human UBAP2L, as a novel factor that antagonizes the activities of multiple heterochronic miRNAs.  Specifically, we find that depletion of  pqn-59 can restore normal development in animals with reduced miRNA activity. Importantly, inactivation of  pqn-59  is not sufficient to bypass the requirement of these regulatory RNAs within the heterochronic GRN. The  pqn-59  gene encodes an abundant, cytoplasmically localized and unstructured protein that harbors three essential “prion-like” domains.  These domains exhibit LLPS properties  in vitro  and normally function to limit PQN-59 diffusion in the cytoplasm  in vivo . Like human UBAP2L, PQN-59’s localization becomes highly dynamic during stress conditions where it re-distributes to cytoplasmic stress granules and is important for their formation. Proteomic analysis of PQN-59 complexes from embryonic extracts indicates that PQN-59 and human UBAP2L interact with orthologous cellular components involved in RNA metabolism and promoting protein translation and that PQN-59 additionally interacts with proteins involved in transcription and intracellular transport. Finally, we demonstrate that  pqn-59  depletion results in the stabilization of several mature miRNAs (including those involved in temporal patterning) without altering steady-state pre-miRNAs levels indicating that PQN-59 may ensure the bistability of some GRNs that require miRNA functions by promoting miRNA turnover and, like UBAP2L, enhancing protein translation.

scholarly journals Gene expression profiling of epidermal cell types in C. elegans using Targeted-DamID

Development ◽  
2021 ◽  
Author(s):  
Dimitris Katsanos ◽  
Mar Ferrando-Marco ◽  
Iqrah Razzaq ◽  
Gabriel Aughey ◽  
Tony Southall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Epidermal Cell ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Cell Types ◽  
Specific Gene ◽  
C Elegans ◽  
Seam Cell ◽  
Developmental Progression

The epidermis of Caenorhabditis elegans is an essential tissue for survival as it contributes to the formation of the cuticle barrier, as well as facilitates developmental progression and animal growth. Most of the epidermis consists of the hyp7 hypodermal syncytium, the nuclei of which are largely generated by the seam cells that exhibit stem cell-like behaviour during development. How the seam cell progenitors differ transcriptionally from the differentiated hypodermis is poorly understood. Here, we introduce Targeted DamID (TaDa) in C. elegans as a method for identifying genes expressed within a tissue of interest without cell isolation. We show that TaDa signal enrichment profiles can be used to identify genes transcribed in the epidermis and use this method to resolve differences in gene expression between the seam cells and the hypodermis. We finally predict and functionally validate new transcription and chromatin factors acting in seam cell development. These findings provide insights into cell-type-specific gene expression profiles likely associated with epidermal cell fate patterning.

scholarly journals Highly multiplexed spatially resolved gene expression profiling of mouse organogenesis

2020 ◽  
Author(s):  
T. Lohoff ◽  
S. Ghazanfar ◽  
A. Missarova ◽  
N. Koulena ◽  
N. Pierson ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Resolution ◽  
Single Cell ◽  
Cell Fate ◽  
Target Genes ◽  
Single Cells ◽  
Spatial Context ◽  
Sequencing Data ◽  
Cell Fate Decisions ◽  
Spatially Resolved

AbstractTranscriptional and epigenetic profiling of single-cells has advanced our knowledge of the molecular bases of gastrulation and early organogenesis. However, current approaches rely on dissociating cells from tissues, thereby losing the crucial spatial context that is necessary for understanding cell and tissue interactions during development. Here, we apply an image-based single-cell transcriptomics method, seqFISH, to simultaneously and precisely detect mRNA molecules for 387 selected target genes in 8-12 somite stage mouse embryo tissue sections. By integrating spatial context and highly multiplexed transcriptional measurements with two single-cell transcriptome atlases we accurately characterize cell types across the embryo and demonstrate how spatially-resolved expression of genes not profiled by seqFISH can be imputed. We use this high-resolution spatial map to characterize fundamental steps in the patterning of the midbrain-hindbrain boundary and the developing gut tube. Our spatial atlas uncovers axes of resolution that are not apparent from single-cell RNA sequencing data – for example, in the gut tube we observe early dorsal-ventral separation of esophageal and tracheal progenitor populations. In sum, by computationally integrating high-resolution spatially-resolved gene expression maps with single-cell genomics data, we provide a powerful new approach for studying how and when cell fate decisions are made during early mammalian development.

LIN-12 protein expression and localization during vulval development in C. elegans

Development ◽  
1998 ◽  
Vol 125 (16) ◽  
pp. 3101-3109 ◽  
Author(s):  
D. Levitan ◽  
I. Greenwald
Keyword(s):  
Cell Fate ◽  
Feedback Mechanism ◽  
Precursor Cell ◽  
Vulval Development ◽  
Ras Pathway ◽  
Cell Fate Decisions ◽  
C Elegans ◽  
Somatic Gonad ◽  
Multiple Cell ◽  
Vulval Precursor Cell

We have used a LIN-12::GFP fusion protein to examine LIN-12 accumulation during cell fate decisions important for vulval development. During the naturally variable anchor cell (AC)/ventral uterine precursor cell (VU) decision of the somatic gonad, a transcription-based feedback mechanism biases two equivalent cells so that one becomes the AC while the other becomes a VU. LIN-12::GFP accumulation reflects lin-12 transcription: LIN-12::GFP is initially present in both cells, but disappears from the presumptive AC and becomes restricted to the presumptive VU. During vulval precursor cell (VPC) fate determination, six equipotential cells uniformly transcribe lin-12 and have invariant fates that are specified by multiple cell-cell interactions. The pattern of LIN-12::GFP accumulation in VPCs and in the VPC lineages is dynamic and does not always reflect lin-12 transcription. In particular, LIN-12::GFP is expressed initially in all six VPCs, but appears to be reduced specifically in P6.p as a consequence of the activation of the Ras pathway by an EGF-like inductive signal from the AC. We propose that downregulation of LIN-12 stability or translation in response to inductive signalling helps impose a bias on lateral signalling and contributes to the invariant pattern of VPC fates.

Translational control in the C. elegans hermaphrodite germ line

Genome ◽  
2010 ◽  
Vol 53 (2) ◽  
pp. 83-102 ◽  
Author(s):  
Hilary Racher ◽  
Dave Hansen
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Translational Control ◽  
Translational Regulation ◽  
Developmental Stages ◽  
Germ Line ◽  
Control Of Gene Expression ◽  
Cell Fate Decisions ◽  
C Elegans ◽  
Mrna Targets

The formation of a fully developed gamete from an undifferentiated germ cell requires progression through numerous developmental stages and cell fate decisions. The precise timing and level of gene expression guides cells through these stages. Translational regulation is highly utilized in the germ line of many species, including Caenorhabditis elegans , to regulate gene expression and ensure the proper formation of gametes. In this review, we discuss some of the developmental stages and cell fate decisions involved in the formation of functional gametes in the C. elegans germ line in which translational control has been implicated. These stages include the mitosis versus meiosis decision, the sperm/oocyte decision, and gamete maturation. We also discuss some of the techniques used to identify mRNA targets; the identification of these targets is necessary to clearly understand the role each RNA-binding protein plays in these decisions. Relatively few mRNA targets have been identified, thus providing a major focus for future research. Finally, we propose some reasons why translational control may be utilized so heavily in the germ line. Given that many species have this substantial reliance on translational regulation for the control of gene expression in the germ line, an understanding of translational regulation in the C. elegans germ line is likely to increase our understanding of gamete formation in general.

scholarly journals PRMT6 activates cyclin D1 expression in conjunction with the transcription factor LEF1

Oncogenesis ◽  
2021 ◽  
Vol 10 (5) ◽  
Author(s):  
Lucas Schneider ◽  
Stefanie Herkt ◽  
Lei Wang ◽  
Christine Feld ◽  
Josephine Wesely ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Transcription Factors ◽  
Cyclin D1 ◽  
Cell Fate ◽  
Target Genes ◽  
Specific Gene ◽  
Cell Fate Decisions ◽  
Rational Development ◽  
Differentiation And Proliferation

AbstractThe establishment of cell type specific gene expression by transcription factors and their epigenetic cofactors is central for cell fate decisions. Protein arginine methyltransferase 6 (PRMT6) is an epigenetic regulator of gene expression mainly through methylating arginines at histone H3. This way it influences cellular differentiation and proliferation. PRMT6 lacks DNA-binding capability but is recruited by transcription factors to regulate gene expression. However, currently only a limited number of transcription factors have been identified, which facilitate recruitment of PRMT6 to key cell cycle related target genes. Here, we show that LEF1 contributes to the recruitment of PRMT6 to the central cell cycle regulator CCND1 (Cyclin D1). We identified LEF1 as an interaction partner of PRMT6. Knockdown of LEF1 or PRMT6 reduces CCND1 expression. This is in line with our observation that knockdown of PRMT6 increases the number of cells in G1 phase of the cell cycle and decreases proliferation. These results improve the understanding of PRMT6 activity in cell cycle regulation. We expect that these insights will foster the rational development and usage of specific PRMT6 inhibitors for cancer therapy.

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