Myeloid Translocation Gene (MTG)-16 Binds Intracellular Domains of Notch Receptors to Coordinate Notch-Dependent Cell Fate Specification.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 257-257
Author(s):  
Michael E Engel ◽  
Hong Nguyen ◽  
Jolene Mariotti ◽  
Aubrey A Hunt ◽  
Scott Hiebert
Keyword(s):  
Gene Expression ◽  
Notch Signaling ◽  
Cell Fate ◽  
Conflicts Of Interest ◽  
Intracellular Domain ◽  
Fate Specification ◽  
Notch Receptors ◽  
Notch Signal ◽  
Intracellular Domains ◽  
Signal Activation

Abstract Abstract 257 The Notch signaling pathway regulates gene expression programs to control the specification of cell fate in diverse tissues. In response to ligand binding, the intracellular domain of Notch receptors is cleaved by the γ-secretase complex and then translocates to the nucleus. There it binds the transcriptional repressor CSL, triggering its conversion to an activator of Notch target gene expression. The events that control this conversion are poorly understood. We show that the transcriptional co-repressor, MTG16, interacts with both CSL and the intracellular domains of Notch receptors. The MTG16 NHR3 domain contributes to CSL binding, while N-ICD binding sites lie within the PST1 and PST2 domains. The Notch intracellular domain disrupts the MTG16—CSL interaction, suggesting a pivotal role in regulating the Notch transcription complex. Using co-culture of Lin-/Sca-1+/c-Kit+ (LSK) cells on OP9-DL1 stromal cells, we show that ex vivo fate specification in response to Notch signal activation is altered in Mtg16 (−/−) hematopoietic progenitors. While Notch signal activation specifies lymphoid fate in Mtg16 (+/+) LSK cells, Mtg16 (−/−) LSK cells display cell surface marker expression reminiscent of myeloid differentiation. We used this lineage allocation assay to assess the contribution of MTG16 to cell fate determination. Lymphoid fate specification is restored by MTG16WT expression in Mtg16 (−/−) LSK cells. However, an MTG16 mutant deficient in N1-ICD binding is defective in this assay, suggesting this region is important to Notch-dependent lineage allocation. These data suggest that MTG family proteins interface with critical components of the Notch transcription complex and intimate a functional relationship between MTG proteins and Notch signaling in normal and malignant hematopoiesis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Myeloid Translocation Gene 16 (MTG16) Interacts with Notch Transcription Complex Components To Integrate Notch Signaling in Hematopoietic Cell Fate Specification

2010 ◽  
Vol 30 (7) ◽  
pp. 1852-1863 ◽  
Author(s):  
Michael E. Engel ◽  
Hong N. Nguyen ◽  
Jolene Mariotti ◽  
Aubrey Hunt ◽  
Scott W. Hiebert
Keyword(s):  
Gene Expression ◽  
Notch Signaling ◽  
Cell Fate ◽  
Ex Vivo ◽  
Notch Signaling Pathway ◽  
Notch Receptor ◽  
Intracellular Domain ◽  
Fate Specification ◽  
Dependent Cell ◽  
Critical Components

ABSTRACT The Notch signaling pathway regulates gene expression programs to influence the specification of cell fate in diverse tissues. In response to ligand binding, the intracellular domain of the Notch receptor is cleaved by the γ-secretase complex and then translocates to the nucleus. There, it binds the transcriptional repressor CSL, triggering its conversion to an activator of Notch target gene expression. The events that control this conversion are poorly understood. We show that the transcriptional corepressor, MTG16, interacts with both CSL and the intracellular domains of Notch receptors, suggesting a pivotal role in regulation of the Notch transcription complex. The Notch1 intracellular domain disrupts the MTG16-CSL interaction. Ex vivo fate specification in response to Notch signal activation is impaired in Mtg16 −/− hematopoietic progenitors, and restored by MTG16 expression. An MTG16 derivative lacking the binding site for the intracellular domain of Notch1 fails to restore Notch-dependent cell fate. These data suggest that MTG16 interfaces with critical components of the Notch transcription complex to affect Notch-dependent lineage allocation in hematopoiesis.

scholarly journals Selective regulation of Notch ligands during angiogenesis is mediated by vimentin

2017 ◽  
Vol 114 (23) ◽  
pp. E4574-E4581 ◽  
Author(s):  
Daniel Antfolk ◽  
Marika Sjöqvist ◽  
Fang Cheng ◽  
Kimmo Isoniemi ◽  
Camille L. Duran ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Placental Tissue ◽  
Intermediate Filament Protein ◽  
Vascular Integrity ◽  
Notch Receptors ◽  
Fringe Proteins ◽  
Filament Protein ◽  
Intracellular Domains ◽  
Signal Activation ◽  
Notch Activation

Notch signaling is a key regulator of angiogenesis, in which sprouting is regulated by an equilibrium between inhibitory Dll4-Notch signaling and promoting Jagged-Notch signaling. Whereas Fringe proteins modify Notch receptors and strengthen their activation by Dll4 ligands, other mechanisms balancing Jagged and Dll4 signaling are yet to be described. The intermediate filament protein vimentin, which has been previously shown to affect vascular integrity and regenerative signaling, is here shown to regulate ligand-specific Notch signaling. Vimentin interacts with Jagged, impedes basal recycling endocytosis of ligands, but is required for efficient receptor ligand transendocytosis and Notch activation upon receptor binding. Analyses of Notch signal activation by using chimeric ligands with swapped intracellular domains (ICDs), demonstrated that the Jagged ICD binds to vimentin and contributes to signaling strength. Vimentin also suppresses expression of Fringe proteins, whereas depletion of vimentin enhances Fringe levels to promote Dll4 signaling. In line with these data, the vasculature in vimentin knockout (VimKO) embryos and placental tissue is underdeveloped with reduced branching. Disrupted angiogenesis in aortic rings from VimKO mice and in endothelial 3D sprouting assays can be rescued by reactivating Notch signaling by recombinant Jagged ligands. Taken together, we reveal a function of vimentin and demonstrate that vimentin regulates Notch ligand signaling activities during angiogenesis.

scholarly journals SEL-10 Is an Inhibitor of Notch Signaling That Targets Notch for Ubiquitin-Mediated Protein Degradation

2001 ◽  
Vol 21 (21) ◽  
pp. 7403-7415 ◽  
Author(s):  
Guangyu Wu ◽  
Svetlana Lyapina ◽  
Indranil Das ◽  
Jinhe Li ◽  
Mark Gurney ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Protein Degradation ◽  
Notch Receptor ◽  
Dominant Negative ◽  
Intracellular Domain ◽  
Notch Receptors ◽  
Intracellular Domains ◽  
Wd40 Repeats ◽  
In Cells

ABSTRACT Notch receptors and their ligands play important roles in both normal animal development and pathogenesis. We show here that the F-box/WD40 repeat protein SEL-10 negatively regulates Notch receptor activity by targeting the intracellular domain of Notch receptors for ubiquitin-mediated protein degradation. Blocking of endogenous SEL-10 activity was done by expression of a dominant-negative form containing only the WD40 repeats. In the case of Notch1, this block leads to an increase in Notch signaling stimulated by either an activated form of the Notch1 receptor or Jagged1-induced signaling through Notch1. Expression of dominant-negative SEL-10 leads to stabilization of the intracellular domain of Notch1. The Notch4 intracellular domain bound to SEL-10, but its activity was not increased as a result of dominant-negative SEL-10 expression. SEL-10 bound Notch4 via the WD40 repeats and bound preferentially to a phosphorylated form of Notch4 in cells. We mapped the region of Notch4 essential for SEL-10 binding to the C-terminal region downstream of the ankyrin repeats. When this C-terminal fragment of Notch4 was expressed in cells, it was highly labile but could be stabilized by the expression of dominant-negative SEL-10. Ubiquitination of Notch1 and Notch4 intracellular domains in vitro was dependent on SEL-10. Although SEL-10 interacts with the intracellular domains of both Notch1 and Notch4, these proteins respond differently to interference with SEL-10 function. Thus, SEL-10 functions to promote the ubiquitination of Notch proteins; however, the fates of these proteins may differ.

Regulation of osteoclast development by Notch signaling directed to osteoclast precursors and through stromal cells

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2227-2234 ◽  
Author(s):  
Takayuki Yamada ◽  
Hidetoshi Yamazaki ◽  
Toshiyuki Yamane ◽  
Miya Yoshino ◽  
Hiromi Okuyama ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Notch Signaling ◽  
Cell Fate ◽  
Stromal Cells ◽  
Bone Marrow Cells ◽  
Notch Signaling Pathway ◽  
Osteoclast Precursors ◽  
Notch Receptors ◽  
Macrophage Colony

Osteoclasts are derived from hematopoietic precursor cells belonging to the monocyte/macrophage lineage. Osteoclast development has been reported to be regulated by several molecules such as macrophage colony-stimulating factor (M-CSF), receptor activator of nuclear factor (NF)-κB ligand (RANKL), and a decoy receptor of RANKL, osteoprotegerin (OPG). Recently, it was demonstrated that the Notch signaling pathway regulates myeloid differentiation and antagonizes cell fate determination, however, the effect of Notch signaling on the osteoclast lineage has not been reported. In this study, we examined the effect of signaling via Notch receptors on the differentiation into osteoclasts by using cells from the bone marrow, spleen, and peritoneal cavity, and a cloned macrophagelike cell line. Osteoclastogenesis was inhibited by an immobilized Notch ligand, Delta-1. The dish-adherent bone marrow cells precultured with M-CSF expressed both Mac-1 and M-CSF receptors, c-Fms; osteoclastogenesis of these cells was efficiently inhibited. The immobilized Delta-1 also down-regulated the surface c-Fms expression, while the c-Fms gene expression was not changed. Genes for Notch receptors and Notch ligands are expressed in not only hematopoietic cells but also stromal cells that support osteoclast development. Constitutively active Notch1-transfected stromal cells showed increased expression of RANKL and OPG genes, and strong inhibition of M-CSF gene expression, resulting in reduction of their ability to support osteoclast development. Taken together, these findings indicate that Notch signaling affects both osteoclast precursors and stromal cells and thereby negatively regulates osteoclastogenesis.

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 Scabrous overexpression in the eye affects R3/R4 cell fate specification and inhibits notch signaling

2015 ◽  
Vol 245 (2) ◽  
pp. 166-174 ◽  
Author(s):  
Verónica Muñoz-Soriano ◽  
Diego Santos ◽  
Fabrice C. Durupt ◽  
Sandra Casani ◽  
Nuria Paricio
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Cell Fate Specification ◽  
Fate Specification

The Interaction of the Wnt and Notch Pathways Modulates NK vs. T Cell Commitment.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 765-765
Author(s):  
Keisuke Aoyama ◽  
Barbara Varnum-Finney ◽  
Randall T. Moon ◽  
Irwin D. Bernstein
Keyword(s):  
T Cell ◽  
Wnt Signaling ◽  
Notch Signaling ◽  
Nk Cells ◽  
Cell Fate ◽  
Stem Cell Differentiation ◽  
Precursor Cells ◽  
Intracellular Domain ◽  
Hes1 Expression ◽  
Cell Commitment

Abstract The Wnt and Notch signaling pathways have critical roles in cell fate decisions. However, the interaction of these pathways is poorly understood. Using highly purified Wnt3a and immobilized Notch ligand, Delta1ext-IgG, we investigated the mechanisms involved in Wnt and Notch signaling interactions during hematopoietic stem cell differentiation. When CD34+CD38- cord blood stem cells were cultured for 2 to 3 weeks with five growth factors (SCF 300ng/ml, Flt-3L 300ng/ml, TPO 100ng/ml, IL-6 100ng/ml, and IL-3 10ng/ml), most precursor cells lost CD34 expression and differentiated into mature cells, most of which were monocytes. However, as we previously reported, when cells were cultured with Delta1ext-IgG, we found an increased percentage of lymphoid progenitors (CD34+CD7+) and more mature lymphoid precursors (CD34-CD7+) in the cell population. The addition of purified Wnt3a (100ng/ml) alone without Delta1ext-IgG did not significantly change the percentage of CD7+ cells (1% vs. 3%). However, when both Wnt3a and Delta1ext-IgG were added, we saw an increased percentage of CD7+ cells (11% with Delta1ext-IgG alone to 27% with both) (Fig. 1A). Wnt3a also enhanced gene expression of CD3ε and preTα induced by Delta1ext-IgG. These results suggest that Wnt3a enhances the effect of Notch signaling on T-cell lineage development. To test the role of endogenous Wnt signaling, we added Dickkopf1, an inhibitor of Wnt signaling. When CD34+CD38- cells were cultured with Dickkopf1 (300ng/ml) alone for a 2 week, the percentage and number of CD56+ NK cells was unaffected. However, when cultured with Dickkopf1 and Delta1ext-IgG, the percentage and number of CD56+ NK precursor cells were increased (2% with Delta1ext-IgG alone vs. 17% with Dickkopf1 and Delta1ext-IgG; 0.2 ×105 vs. 1.5×105, p<0.01) (Fig. 1B). This result shows that decreased endogenous Wnt signaling enhances the generation of NK cells in the presence of Notch signaling. To address whether Wnt signaling affects Notch signaling by modulating protein levels, we assessed the amount of activated Notch1 intracellular domain with or without Wnt 3a by Western blot (Fig. 2A). After stimulation for 24 h, Wnt3a increased the amount of activated Notch1 intracellular domain induced by Delta1ext-IgG. Wnt3a also enhanced the expression of a primary target gene of Notch signaling, Hes1, determined by quantitative RT-PCR (Fig. 2B). In contrast, Dickkopf1 reduced Delta1ext-IgG-induced Hes1 expression. These results suggest that Wnt signaling directly modulates Notch signaling. Thus, these studies suggest that Wnt signaling is a key factor in cell fate determination at the point of NK/T cell commitment that is mediated via an interaction with Notch signaling. These studies also suggest that Wnt directly regulates Notch signaling by modulating protein turnover. Fig. 1, Fig. 2 Fig. 1, Fig. 2.

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 RBP-Jκ-Dependent Notch Signaling Is Dispensable for Mouse Early Embryonic Development

2006 ◽  
Vol 26 (13) ◽  
pp. 4769-4774 ◽  
Author(s):  
Céline Souilhol ◽  
Sarah Cormier ◽  
Kenji Tanigaki ◽  
Charles Babinet ◽  
Michel Cohen-Tannoudji
Keyword(s):  
Embryonic Development ◽  
Notch Signaling ◽  
Signaling Pathway ◽  
Cell Fate ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Preimplantation Embryos ◽  
Cell Fate Specification ◽  
Fate Specification ◽  
Evolutionarily Conserved

ABSTRACT The Notch signaling pathway is an evolutionarily conserved signaling system which has been shown to be essential in cell fate specification and in numerous aspects of embryonic development in all metazoans thus far studied. We recently demonstrated that several components of the Notch signaling pathway, including the four Notch receptors and their five ligands known in mammals, are expressed in mouse oocytes, in mouse preimplantation embryos, or both. This suggested a possible implication of the Notch pathway in the first cell fate specification of the dividing mouse embryo, which results in the formation of the blastocyst. To address this issue directly, we generated zygotes in which both the maternal and the zygotic expression of Rbpsuh, a key element of the core Notch signaling pathway, were abrogated. We find that such zygotes give rise to blastocysts which implant and develop normally. Nevertheless, after gastrulation, these embryos die around midgestation, similarly to Rbpsuh-null mutants. This demonstrates that the RBP-Jκ-dependent pathway, otherwise called the canonical Notch pathway, is dispensable for blastocyst morphogenesis and the establishment of the three germ layers, ectoderm, endoderm, and mesoderm. These results are discussed in the light of recent observations which have challenged this conclusion.

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