scholarly journals Delta-1 Activation of Notch-1 Signaling Results inHES-1 Transactivation

1998 ◽  
Vol 18 (12) ◽  
pp. 7423-7431 ◽  
Author(s):  
Sophie Jarriault ◽  
Odile Le Bail ◽  
Estelle Hirsinger ◽  
Olivier Pourquié ◽  
Frédérique Logeat ◽  
...  

ABSTRACT The Notch receptor is involved in many cell fate determination events in vertebrates and invertebrates. It has been shown inDrosophila melanogaster that Delta-dependent Notch signaling activates the transcription factor Suppressor of Hairless, leading to an increased expression of the Enhancer of Splitgenes. Genetic evidence has also implicated the kuzbaniangene, which encodes a disintegrin metalloprotease, in the Notch signaling pathway. By using a two-cell coculture assay, we show here that vertebrate Dl-1 activates the Notch-1 cascade. Consistent with previous data obtained with active forms of Notch-1 aHES-1-derived promoter construct is transactivated in cells expressing Notch-1 in response to Dl-1 stimulation. Impairing the proteolytic maturation of the full-length receptor leads to a decrease in HES-1 transactivation, further supporting the hypothesis that only mature processed Notch is expressed at the cell surface and activated by its ligand. Furthermore, we observed that Dl-1-inducedHES-1 transactivation was dependent both on Kuzbanian and RBP-J activities, consistent with the involvement of these two proteins in Notch signaling in Drosophila. We also observed that exposure of Notch-1-expressing cells to Dl-1 results in an increased level of endogenous HES-1 mRNA. Finally, coculture of Dl-1-expressing cells with myogenic C2 cells suppresses differentiation of C2 cells into myotubes, as previously demonstrated for Jagged-1 and Jagged-2, and also leads to an increased level of endogenousHES-1 mRNA. Thus, Dl-1 behaves as a functional ligand for Notch-1 and has the same ability to suppress cell differentiation as the Jagged proteins do.

Development ◽  
1999 ◽  
Vol 126 (17) ◽  
pp. 3925-3935 ◽  
Author(s):  
P. Beatus ◽  
J. Lundkvist ◽  
C. Oberg ◽  
U. Lendahl

The Notch signaling pathway is important for cellular differentiation. The current view is that the Notch receptor is cleaved intracellularly upon ligand activation. The intracellular Notch domain then translocates to the nucleus, binds to Suppressor of Hairless (RBP-Jk in mammals), and acts as a transactivator of Enhancer of Split (HES in mammals) gene expression. In this report we show that the Notch 3 intracellular domain (IC), in contrast to all other analysed Notch ICs, is a poor activator, and in fact acts as a repressor by blocking the ability of the Notch 1 IC to activate expression through the HES-1 and HES-5 promoters. We present a model in which Notch 3 IC interferes with Notch 1 IC-mediated activation at two levels. First, Notch 3 IC competes with Notch 1 IC for access to RBP-Jk and does not activate transcription when positioned close to a promoter. Second, Notch 3 IC appears to compete with Notch 1 IC for a common coactivator present in limiting amounts. In conclusion, this is the first example of a Notch IC that functions as a repressor in Enhancer of Split/HES upregulation, and shows that mammalian Notch receptors have acquired distinct functions during evolution.


2015 ◽  
Vol 112 (5) ◽  
pp. E402-E409 ◽  
Author(s):  
Marcelo Boareto ◽  
Mohit Kumar Jolly ◽  
Mingyang Lu ◽  
José N. Onuchic ◽  
Cecilia Clementi ◽  
...  

Notch signaling pathway mediates cell-fate determination during embryonic development, wound healing, and tumorigenesis. This pathway is activated when the ligand Delta or the ligand Jagged of one cell interacts with the Notch receptor of its neighboring cell, releasing the Notch Intracellular Domain (NICD) that activates many downstream target genes. NICD affects ligand production asymmetrically––it represses Delta, but activates Jagged. Although the dynamical role of Notch–Jagged signaling remains elusive, it is widely recognized that Notch–Delta signaling behaves as an intercellular toggle switch, giving rise to two distinct fates that neighboring cells adopt––Sender (high ligand, low receptor) and Receiver (low ligand, high receptor). Here, we devise a specific theoretical framework that incorporates both Delta and Jagged in Notch signaling circuit to explore the functional role of Jagged in cell-fate determination. We find that the asymmetric effect of NICD renders the circuit to behave as a three-way switch, giving rise to an additional state––a hybrid Sender/Receiver (medium ligand, medium receptor). This phenotype allows neighboring cells to both send and receive signals, thereby attaining similar fates. We also show that due to the asymmetric effect of the glycosyltransferase Fringe, different outcomes are generated depending on which ligand is dominant: Delta-mediated signaling drives neighboring cells to have an opposite fate; Jagged-mediated signaling drives the cell to maintain a similar fate to that of its neighbor. We elucidate the role of Jagged in cell-fate determination and discuss its possible implications in understanding tumor–stroma cross-talk, which frequently entails Notch–Jagged communication.


2008 ◽  
Vol 182 (6) ◽  
pp. 1113-1125 ◽  
Author(s):  
An-Chi Tien ◽  
Akhila Rajan ◽  
Karen L. Schulze ◽  
Hyung Don Ryoo ◽  
Melih Acar ◽  
...  

Notch-mediated cell–cell communication regulates numerous developmental processes and cell fate decisions. Through a mosaic genetic screen in Drosophila melanogaster, we identified a role in Notch signaling for a conserved thiol oxidase, endoplasmic reticulum (ER) oxidoreductin 1–like (Ero1L). Although Ero1L is reported to play a widespread role in protein folding in yeast, in flies Ero1L mutant clones show specific defects in lateral inhibition and inductive signaling, two characteristic processes regulated by Notch signaling. Ero1L mutant cells accumulate high levels of Notch protein in the ER and induce the unfolded protein response, suggesting that Notch is misfolded and fails to be exported from the ER. Biochemical assays demonstrate that Ero1L is required for formation of disulfide bonds of three Lin12-Notch repeats (LNRs) present in the extracellular domain of Notch. These LNRs are unique to the Notch family of proteins. Therefore, we have uncovered an unexpected requirement for Ero1L in the maturation of the Notch receptor.


2019 ◽  
Vol 14 (7) ◽  
pp. 583-590 ◽  
Author(s):  
Shao-jie Liang ◽  
Xiang-guang Li ◽  
Xiu-qi Wang

: The intestine serves mainly as a place for digestion and absorption and functions as an immune and endocrine organ. Intestinal stem cells (ISCs) play critical roles in the maintenance of intestinal homeostasis and regeneration, and a complex of signaling pathways is involved in these processes. The Notch signaling pathway is induced via distinct cell-to-cell connections, which are activated through the binding of the Notch ligand on the surface of niche cells to the Notch receptor on ISCs. Numerous studies have shown the central importance of Notch signaling in the proliferation and differentiation of ISCs. Here, we summarize the latest research progress on the crucial functions of Notch signaling in maintaining homeostasis and determining the cell fate of ISCs. Furthermore, the challenges of Notch signaling in colon cancer therapy strategies are also discussed. Several important questions regarding Notch regulation of ISCs are proposed.


2010 ◽  
Vol 30 (7) ◽  
pp. 1852-1863 ◽  
Author(s):  
Michael E. Engel ◽  
Hong N. Nguyen ◽  
Jolene Mariotti ◽  
Aubrey Hunt ◽  
Scott W. Hiebert

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jingxia Xu ◽  
Thomas Gridley

The Notch signaling pathway is an evolutionarily conserved intercellular signaling mechanism that is required for embryonic development, cell fate specification, and stem cell maintenance. Discovered and studied initially in Drosophila melanogaster, the Notch pathway is conserved and functionally active throughout the animal kingdom. In this paper, we summarize the biochemical mechanisms of Notch signaling and describe its role in regulating one particular developmental pathway, oogenesis in Drosophila.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4287-4287
Author(s):  
Maria D. Cappellini ◽  
Ilaria V. Libani ◽  
Elisabetta Calzavara ◽  
Luisa Ronzoni ◽  
Raffaella Chiaramonte ◽  
...  

Abstract Hematopoiesis involves highly regulated proliferation and differentiation during which a small number of multipotent stem cells give rise to differentiated progenies. In several developmental systems stem cells fate is influenced by soluble molecules acting via cell-cell interaction, including those mediate by the Notch receptor family. Members of Notch family transmembrane receptors are found on primitive hematopoietic precursors, suggesting a role for Notch signaling in mammalian blood cells development. Notch signaling regulates cell fate controlling asymmetric cell division during stem/progenitor cell differentiation. A previous study on K562 cell line showed that Notch signaling inhibits erythroid/megakaryocytic development by suppressing GATA-1 activity. Furthermore there are evidences that Notch is expressed in early murine erythroid precursors. Probably Notch signaling in these uncommittted precursors may lead to enhanced survival, preserving multilineage potential. The role of Notch pathway during human adult erytropiesis has not been described. The aim of this study is to investigate the modulation of Notch activity during “in vitro” human erythropiesis. Human CD34+ from perpheral blood of normal adult subjects were differentiate “in vitro” for two weeks by the addiction of IL-3, SCF and Epo. This method of colture reproduces all stages of adult erythropoiesis. We analized the modulation of the expression of Notch-1, of its effector Hes-1 and of several erythoid specific genes, at different stages of differentiation using real time PCR. Our analysis shows that Hes-1 expression, which indicates the activation of Notch-1 pathway, is very high in the early steps of differentiation (BFU-E, CFU-E) while in the late stages rapidly decreases to undetectable levels. The Notch-1 gene expression doesn’t seem to be modulated way, but we didn’t invstigate the protein levels yet. These data suggest that Notch pathway is involved in the early stages of erythroid differentiation where it may enhance erythroid progenitors survival up to CFU-E, as hypothisized in mouse model, preventing them from apoptotic stimuli and promoting their proliferation. Involvement of Notch-1 signaling in preventing erythroid progenitors from apoptosis during erythroid differentiation could be important in some erythropoietic disorders such as b-Thalassemia syndromes or diserythropoietic anemias.


Development ◽  
2000 ◽  
Vol 127 (2) ◽  
pp. 291-306 ◽  
Author(s):  
E.C. Lai ◽  
R. Bodner ◽  
J. Kavaler ◽  
G. Freschi ◽  
J.W. Posakony

Cell-cell signaling through the Notch receptor is a principal mechanism underlying cell fate specification in a variety of developmental processes in metazoans, such as neurogenesis. In this report we describe our investigation of seven members of a novel gene family in Drosophila with important connections to Notch signaling. These genes all encode small proteins containing predicted basic amphipathic (α)-helical domains in their amino-terminal regions, as described originally for Bearded; accordingly, we refer to them as Bearded family genes. Five members of the Bearded family are located in a newly discovered gene complex, the Bearded Complex; two others reside in the previously identified Enhancer of split Complex. All members of this family contain, in their proximal upstream regions, at least one high-affinity binding site for the Notch-activated transcription factor Suppressor of Hairless, suggesting that all are directly regulated by the Notch pathway. Consistent with this, we show that Bearded family genes are expressed in a variety of territories in imaginal tissue that correspond to sites of active Notch signaling. We demonstrate that overexpression of any family member antagonizes the activity of the Notch pathway in multiple cell fate decisions during adult sensory organ development. These results suggest that Bearded family genes encode a novel class of effectors or modulators of Notch signaling.


2006 ◽  
Vol 173 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Elliott J. Hagedorn ◽  
Jennifer L. Bayraktar ◽  
Vasundhara R. Kandachar ◽  
Ting Bai ◽  
Dane M. Englert ◽  
...  

We have isolated mutations in the Drosophila melanogaster homologue of auxilin, a J-domain–containing protein known to cooperate with Hsc70 in the disassembly of clathrin coats from clathrin-coated vesicles in vitro. Consistent with this biochemical role, animals with reduced auxilin function exhibit genetic interactions with Hsc70 and clathrin. Interestingly, the auxilin mutations interact specifically with Notch and disrupt several Notch-mediated processes. Genetic evidence places auxilin function in the signal-sending cells, upstream of Notch receptor activation, suggesting that the relevant cargo for this auxilin-mediated endocytosis is the Notch ligand Delta. Indeed, the localization of Delta protein is disrupted in auxilin mutant tissues. Thus, our data suggest that auxilin is an integral component of the Notch signaling pathway, participating in the ubiquitin-dependent endocytosis of Delta. Furthermore, the fact that auxilin is required for Notch signaling suggests that ligand endocytosis in the signal-sending cells needs to proceed past coat disassembly to activate Notch.


2005 ◽  
Vol 25 (21) ◽  
pp. 9503-9508 ◽  
Author(s):  
Shaolin Shi ◽  
Mark Stahl ◽  
Linchao Lu ◽  
Pamela Stanley

ABSTRACT The canonical Notch signaling pathway mediated by Delta- and Jagged-like Notch ligands determines a variety of cell fates in metazoa. In Caenorhabditis elegans and sea urchins, canonical Notch signaling is essential for different cell fate specifications during early embryogenesis or the formation of endoderm, mesoderm, or ectoderm germ layers. Transcripts of Notch signaling pathway genes are present during mouse blastogenesis, suggesting that the canonical Notch signaling pathway may also function in early mammalian development. To test this directly, we used conditional deletion in oocytes carrying a ZP3Cre recombinase transgene to generate mouse embryos lacking both maternal and zygotic protein O-fucosyltransferase 1, a cell-autonomous and essential component of canonical Notch receptor signaling. Homozygous mutant embryos derived from eggs lacking Pofut1 gene transcripts developed indistinguishably from the wild type until approximately embryonic day 8.0, a postgastrulation stage after the formation of the three germ layers. Thus, in contrast to the case with C. elegans and sea urchins, canonical Notch signaling is not required in mammals for earliest cell fate specifications or for formation of the three germ layers. The use of canonical Notch signaling for early cell fate specifications by lower organisms may represent co-option of a regulatory pathway originally used later in development by all metazoa.


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