Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Notch pathway”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,207 records · Page 67Linked to original sources
PubMed2006

Comparative integromics on BMP/GDF family.

WNT, Notch, FGF, Hedgehog and BMP signaling pathways network together during embryogenesis, tissue regeneration, and carcinogenesis. BMP2, BMP3, BMP4, BMP5, BMP6, BMP7, BMP8A, BMP8B, BMP10, BMP15, AMH, GDF1, GDF2, GDF3, GDF5, GDF6, GDF7, GDF8, GDF9, GDF10, GDF11, and GDF15 are BMP/GDF family genes within the human genome; however, transcriptional regulation of BMP/GDF family members by the canonical WNT signaling pathway remains unclear. We searched for the TCF/LEF-binding site within the promoter region of BMP/GDF family genes by using bioinformatics and human intelligence. Because four TCF/LEF-binding sites were identified within human GDF10 promoter, comparative genomics analyses on GDF10 orthologs were further performed. Chimpanzee GDF10 gene, encoding a 477-amino-acid protein, was identified within NW_112875.1 genome sequence. AY412135.1 was not the correct coding sequence for chimpanzee GDF10. Chimpanzee GDF10 showed 99.2%, 83.2% and 47.4% total amino-acid identity with human GDF10, mouse Gdf10 and human BMP3, respectively. RASGEF1A-GDF10-PRKG1 locus at human chromosome 10q11 and BMP3-PRKG2-RASGEF1B locus at human chromosome 4q21 were paralogous regions with insertions/deletions and recombination. Human GDF10 mRNA was expressed in fetal cochlea, fetal lung, testis, retina, pineal gland, other neural tissues, head and neck tumors, while mouse Gdf10 mRNA was expressed in fetal liver, inner ear, cerebellum, other neural tissues, prostate and blood vessels. Four TCF/LEF-binding sites in human GDF10 promoter were conserved in chimpanzee GDF10 promoter, but not in the mouse Gdf10 promoter; however, another TCF/LEF-binding site occurred in mouse Gdf10 promoter. Four bHLH-binding sites in human GDF10 promoter were conserved in chimpanzee GDF10 promoter, but only one in mouse Gdf10 promoter. Primate GDF10 promoters were divergent from mouse Gdf10 promoter. Because GDF10 was characterized as a potential target of canonical WNT signaling pathway in neural tissues, GDF10 is one of the targets of systems medicine, especially in the field of regenerative medicine.

Amino Acid Sequence↗
PubMed1998

Cell-cell signaling during neurogenesis: some answers and many questions.

Development of a multicellular organism requires that cells communicate with each other in order to regulate their growth, organize into tissues and coordinate their function. This cell-cell communication is mediated by signals cells receive (or send) between each other and from the environment. The signaling can be a short range remote signaling (through secreted signaling molecules), contact signaling (via plasma membrane bound molecules, gap junctions) or a long range signaling (through hormones). In this article, I have reviewed the recent advances on the role of cell-cell signaling in the development of the embryonic nervous system of the fruitfly Drosophila melanogaster and discussed some of the open questions raised by these studies. It discusses the contributions of the neurogenic genes Notch and Delta and the signaling pathways controlled by wingless, patched and hedgehog in neuroblast formation, neuroblast identity specification and neuroblast lineage elaboration.

Animals↗
PubMed2004

Two zebrafish Notch-dependent hairy/Enhancer-of-split-related genes, her6 and her4, are required to maintain the coordination of cyclic gene expression in the presomitic mesoderm.

Alterations of the Delta/Notch signalling pathway cause multiple morphogenetic abnormalities in somitogenesis, including defects in intersomitic boundary formation and failure in maintenance of somite regularity. Notch signalling has been implicated in establishing the anteroposterior polarity within maturing somites and in regulating the activity of a molecular segmentation clock operating in the presomitic mesoderm. The pleiotropy of Notch signalling obscures the roles of this pathway in different steps of somitogenesis. One possibility is that distinct Notch effectors mediate different aspects of Notch signalling. In this study, we focus on two zebrafish Notch-dependent hairy/Enhancer-of-split-related transcription factors, Her6 and Her4, which are expressed at the transition zone between presomitic mesoderm and the segmented somites. The results of overexpression/gain-of-function and of morpholino-mediated loss-of-function experiments show that Her6 and Her4 are Notch signalling effectors that feedback on the clock and take part in the maintenance of cyclic gene expression coordination among adjacent cells in the presomitic mesoderm.

Animals↗
PubMed2004

Developmental regulation of Notch signaling genes in the embryonic pituitary: Prop1 deficiency affects Notch2 expression.

Normal development of the pituitary gland requires coordination between the maintenance of a progenitor cell pool and the selection of progenitor cells for differentiation. As Notch signaling controls progenitor cell differentiation in many embryonic tissues, we investigated the involvement of this important developmental pathway in the embryonic pituitary. We report that expression of Notch signaling genes is spatially and temporally regulated in pituitary embryogenesis and implicate Notch2 in the differentiation of several cell lineages. Notch2, Notch3, and Dll1 are initially expressed by most cells within the pituitary primordium and become restricted to a subset of the progenitor cell pool as differentiated pituitary cells begin to appear. Mutations in the transcription factor Prop1 interfere with pituitary growth and cell specification, although the mechanism is unknown. Notch2 expression is nearly absent in the developing pituitaries of Prop1 mutant mice, but unaltered in some other panhypopituitary mutants, revealing that Prop1 is directly or indirectly required for normal Notch2 expression. Transgenic overexpression of Prop1 is not sufficient for enhancement of endogenous Notch2 expression, indicating that there are multiple inputs into this pathway. Dll3 is expressed only in the presumptive corticotrope and melanotrope cells. Analysis of Dll3 null mutants indicates that Dll3 is not required for specification of these two cell types, although there may be functional overlap with Dll1. The spatial and temporal expression patterns of Notch signaling genes in the pituitary suggest overlapping roles in pituitary growth and cell specification.

Animals↗
PubMed1999

Wingless modulates the effects of dominant negative notch molecules in the developing wing of Drosophila.

The development and patterning of the wing in Drosophila relies on a sequence of cell interactions molecularly driven by a number of ligands and receptors. Genetic analysis indicates that a receptor encoded by the Notch gene and a signal encoded by the wingless gene play a number of interdependent roles in this process and display very strong functional interactions. At certain times and places, during wing development, the expression of wingless requires Notch activity and that of its ligands Delta and Serrate. This has led to the proposal that all the interactions between Notch and wingless can be understood in terms of this regulatory relationship. Here we have tested this proposal by analysing interactions between Delta- and Serrate-activated Notch signalling and Wingless signalling during wing development and patterning. We find that the cell death caused by expressing dominant negative Notch molecules during wing development cannot be rescued by coexpressing Nintra. This suggests that the dominant negative Notch molecules cannot only disrupt Delta and Serrate signalling but can also disrupt signalling through another pathway. One possibility is the Wingless signalling pathway as the cell death caused by expressing dominant negative Notch molecules can be rescued by activating Wingless signalling. Furthermore, we observe that the outcome of the interactions between Notch and Wingless signalling differs when we activate Wingless signalling by expressing either Wingless itself or an activated form of the Armadillo. For example, the effect of expressing the activated form of Armadillo with a dominant negative Notch on the patterning of sense organ precursors in the wing resembles the effects of expressing Wingless alone. This result suggests that signalling activated by Wingless leads to two effects, a reduction of Notch signalling and an activation of Armadillo.

Animals↗
PubMedDate not supplied

Alzheimer's disease linking neurodegeneration with neurodevelopment.

An association has recently been suggested between several of the genes and proteins that play a central role in early neuronal development, particularly in neuronal migration and axon elongation, and Alzheimer's disease (AD). This paper reviews the work of several investigators who have hypothesised the involvement of three pathways known to be active participants in neuronal maturation (those involving Notch, Reelin, and Wnt intracellular signalling) and also in the neurodegenerative events underlying AD. The choice of these intracellular pathways is based on the observation that there exist several points of convergence among these systems and amyloid precursor protein processing and neurofibrillary tangle formation. Pharmacological manipulation of the Notch/Wnt/Reelin intracellular signalling pathways may thus represent a novel approach to the regulation of neurodegenerative processes in AD.

Alzheimer Disease↗
PubMed2003

A Notch so simple influence on T cell development.

T cell precursors undergo a series of developmental choices that progressively narrow their ability to give rise to different cell lineages. Evidence accumulated in the last few years suggests that Notch occupies a central place among the signal transduction pathways that regulate many of these choices, including the T/B, alphabeta/gammadelta and CD4/CD8 lineage decisions. Nevertheless the mechanisms by which Notch exerts its effects are not well understood, and in some cases the physiologic role is unclear. In this review we try to present succinctly the experiments and highlight the areas of controversy.

Animals↗
PubMed2001

Modulation of the Ras/MAPK signalling pathway by the redox function of selenoproteins in Drosophila melanogaster.

Modulation of reactive oxygen species (ROS) plays a key role in signal transduction pathways. Selenoproteins act controlling the redox balance of the cell. We have studied how the alteration of the redox balance caused by patufet (selD(ptuf)), a null mutation in the Drosophila melanogaster selenophosphate synthetase 1 (sps1) gene, which codes for the SelD enzyme of the selenoprotein biosynthesis, affects the Ras/MAPK signalling pathway. The selD(ptuf) mutation dominantly suppresses the phenotypes in the eye and the wing caused by hyperactivation of the Ras/MAPK cassette and the activated forms of the Drosophila EGF receptor (DER) and Sevenless (Sev) receptor tyrosine kinases (RTKs), which signal in the eye and wing, respectively. No dominant interaction is observed with sensitized conditions in the Wnt, Notch, Insulin-Pi3K, and DPP signalling pathways. Our current hypothesis is that selenoproteins selectively modulate the Ras/MAPK signalling pathway through their antioxidant function. This is further supported by the fact that a selenoprotein-independent increase in ROS caused by the catalase amorphic Cat(n1) allele also reduces Ras/MAPK signalling. Here, we present the first evidence for the role of intracellular redox environment in signalling pathways in Drosophila as a whole organism.

Alleles↗
PubMed2005

Mutations in rugose promote cell type-specific apoptosis in the Drosophila eye.

RUGOSE (RG): encodes an A kinase anchor protein and was isolated as a genetic interactor of the Notch and epidermal growth factor receptor (EGFR) pathways during eye development in Drosophila. rg mutants display a small, rough eye phenotype primarily caused by the loss of cone cells. Here we show that the basis of this phenotype is cell type-specific apoptosis rather than transformation and hence can be rescued by reduction of proapoptotic signals. Moreover, a nearly complete rescue is observed by an increased Notch signal suggesting an antiapoptotic function of Notch in this developmental context. Cone cell loss in rg mutants is accompanied by enhanced Jun N-terminal kinase activity and, concomitantly, by a reduction of EGFR signalling activity. Together, these findings support the idea that rg plays an important role in the integration of different signals required for the exact regulation of cone cell development and survival.

A Kinase Anchor Proteins↗
PubMed2005

Chaperone activity of protein O-fucosyltransferase 1 promotes notch receptor folding.

Notch proteins are receptors for a conserved signaling pathway that affects numerous cell fate decisions. We found that in Drosophila, Protein O-fucosyltransferase 1 (OFUT1), an enzyme that glycosylates epidermal growth factor-like domains of Notch, also has a distinct Notch chaperone activity. OFUT1 is an endoplasmic reticulum protein, and its localization was essential for function in vivo. OFUT1 could bind to Notch, was required for the trafficking of wild-type Notch out of the endoplasmic reticulum, and could partially rescue defects in secretion and ligand binding associated with Notch point mutations. This ability of OFUT1 to facilitate folding of Notch did not require its fucosyltransferase activity. Thus, a glycosyltransferase can bind its substrate in the endoplasmic reticulum to facilitate normal folding.

Amino Acid Motifs↗
PubMed2006

Structure-function analysis of delta trafficking, receptor binding and signaling in Drosophila.

The transmembrane proteins Delta and Notch act as ligand and receptor in a conserved signaling pathway required for a variety of cell fate specification events in many organisms. Binding of Delta to Notch results in a proteolytic cascade that releases the Notch intracellular domain, allowing it to participate in transcriptional activation in the nucleus. Recent research has implicated the endocytic and ubiquitylation machinery as essential components of Delta-Notch signaling. Our analysis of chimeric and missense Delta variants has delineated a number of structural requirements for Delta trafficking, receptor binding, and signaling. We find that while the Delta N-terminal domain is necessary and sufficient for binding to Notch, the integrity of the epidermal-growth-factor-like repeat (ELR) 2 is also required for Notch binding. Screening of 117 Delta mutant lines for proteins that exhibit aberrant subcellular trafficking has led to the identification of 18 Delta alleles (DlTD alleles) that encode "trafficking-defective" Delta proteins. We find, unexpectedly, that many DlTD alleles contain missense mutations in ELRs within the Delta extracellular domain. Finally, we find that two DlTD alleles contain lysine missense mutations within the Delta intracellular domain (DeltaICD) that may identify residues important for DeltaICD mono-ubiquitylation and subsequent Delta endocytosis and signaling.

Amino Acid Sequence↗
PubMed2006

Critical role for c-kit (CD117) in T cell lineage commitment and early thymocyte development in vitro.

The precise roles played by the transmembrane receptor tyrosine kinase c-kit and its ligand stem cell factor in early T cell development are difficult to study. Using cloned Pax5-deficient progenitor B cells, we show that following Notch signaling, which induces their commitment to the T cell developmental pathway, c-kit expression is rapidly up-regulated at both the transcriptional and cell surface level. Using either an anti-c-kit monoclonal antibody or Gleevec, a pharmacological inhibitor of c-kit signaling, we show that the Notch-induced T cell differentiation of either Pax5-deficient progenitor B cells, or the equivalent cell from the bone marrow of normal mice, is strictly dependent on c-kit signaling, whereas the differentiation of normal progenitors into the B cell lineage is not. Moreover, we show that the Notch and IL-7 signaling-induced proliferation and differentiation of CD44+CD25-c-kit(high) and CD44+CD25+c-kithigh thymocytes along the T cell, but not natural killer cell or macrophage, pathway also requires c-kit signaling, whereas the Notch-induced proliferation and differentiation of CD44-CD25+c-kitint cells along the T cell pathway is independent of c-kit. These results further highlight the complex inter-relationships existing between c-kit, Notch and IL-7 receptor signaling that control the proliferation and differentiation of early T cell progenitors.

Animals↗
PubMed2002

New alleles of Notch draw a blueprint for multifunctionality.

The Drosophila Notch protein is one of a family of receptors that mediate an essential and perhaps universal function in the assignation of cell fates during development. Activation of Notch by its ligand, Delta, leads to the cleavage of the intracellular domain of the receptor. This domain relocates to the nucleus, where it combines with the transcription factor Suppressor of Hairless to regulate gene expression. In a recent report, Ramain, Heitzler and colleagues reveal the existence of a second Notch signalling activity that is independent of Suppressor of Hairless and might be used to link Notch activity to that of other signalling pathways, most notably Wingless/Wnt signalling. This link might be a central element in many processes of cell-fate assignation during development.

Alleles↗
PubMed2006

In vitro and in vivo arterial differentiation of human multipotent adult progenitor cells.

Many stem cell types have been shown to differentiate into endothelial cells (ECs); however, their specification to arterial or venous endothelium remains unexplored. We tested whether a specific arterial or venous EC fate could be induced in human multipotent adult progenitor cells (hMAPCs) and AC133(+) cells (hAC133(+)). In vitro, in the presence of VEGF(165), hAC133(+) cells only adopted a venous and microvascular EC phenotype, while hMAPCs differentiated into both arterial and venous ECs, possibly because hMAPCs expressed significantly more sonic hedgehog (Shh) and its receptors as well as Notch 1 and 3 receptors and some of their ligands. Accordingly, blocking either of those pathways attenuated in vitro arterial EC differentiation from hMAPCs. Complementarily, stimulating these pathways by addition of Delta-like 4 (Dll-4), a Notch ligand, and Shh to VEGF(165) further boosted arterial differentiation in hMAPCs both in vitro and in an in vivo Matrigel model. These results represent the first demonstration of adult stem cells with the potential to be differentiated into different types of ECs in vitro and in vivo and provide a useful human model to study arteriovenous specification.

AC133 Antigen↗
PubMed2006

New paradigms in signal transduction.

Signal transduction is a dynamic field in which established pathways evolve and new pathways emerge. The purpose of this commentary is to highlight new paradigms of signal transduction that have developed over the past few years. This discussion proposes a third member of the generic models of membrane receptors in addition to the 7-transmembrane pass receptor and the enzyme-linked receptor: the non-enzymatic nucleating receptor. Also discussed are the new paradigms of signal transduction by proteolysis which includes signaling by Notch, signaling through the Hedgehog and Wnt pathways, signaling through histidine phosphorylation, and reactive oxygen species in signal transduction.

Animals↗
PubMed1993

Drosophila shaggy kinase and rat glycogen synthase kinase-3 have conserved activities and act downstream of Notch.

During neurogenesis in Drosophila, groups of equipotential, neurally competent cells choose between epidermal and neural fates. Notch, a phylogenetically conserved transmembrane protein, may act as a receptor in a lateral signalling pathway in which a single neural precursor is chosen from each group and the neural fate of the other cells is inhibited, causing them to differentiate into epidermis. Possible intracellular transduction events mediating signals from Notch are, however, unknown. shaggy is also required for the lateral signal and encodes serine/threonine protein kinases with homology to the glycogen synthase kinase-3 (GSK-3) enzymes that act in signal transduction pathways in vertebrates. We report here that, in transgenic flies, GSK-3 beta can substitute for shaggy, and we also present a study of epistatic relationships between shaggy and gain and loss of function alleles of Notch. The results indicate that shaggy/GSK-3 is part of a signalling pathway downstream of Notch.

Animals↗
PubMed1999

Presenilin-1 deficiency leads to loss of Cajal-Retzius neurons and cortical dysplasia similar to human type 2 lissencephaly.

BACKGROUND: Presenilin-1 (PS1) is a transmembrane protein that is located in the endoplasmic reticulum and the cis Golgi apparatus. Missense mutations of PS1 that modify gamma-secretase function, leading to a pathologic processing of amyloid precursor protein, are an important cause of familial Alzheimer's disease. Physiologically, the presenilins are involved in the Notch and Wnt-beta-catenin signaling pathways. RESULTS: PS1-deficient mice develop a cortical dysplasia resembling human type 2 lissencephaly, with leptomeningeal fibrosis and migration of cortical-plate neurons beyond their normal position into the marginal zone and subarachnoid space. This disorder of neuronal migration is associated with the disappearance of the majority of the cells of the marginal zone, notably most of the Cajal-Retzius pioneer neurons, between embryonic days E14 and E18, and is preceded and accompanied by disorganization of Notch-1 immunoreactivity on the neuronal cell membranes. The marginal zone also becomes depleted of the extracellular matrix protein reelin and chondroitin sulfate proteoglycans. At that stage PS1 is transiently expressed in leptomeningeal fibroblasts, which are mandatory for the trophic support of Cajal-Retzius neurons. CONCLUSIONS: In agreement with models in which neuronal migration disorders have been linked to a defect in Cajal-Retzius cells, the loss of most of these cells in PS1-deficient mice leads to cortical dysplasia. Because PS1 is normally expressed in the leptomeninges, and these become fibrotic in the PS1-knockout mice, we favor the hypothesis that the loss of Cajal-Retzius cells is caused by a defective trophic interaction with leptomeningeal cells, possibly involving disruption of Notch signaling.

Amyloid Precursor Protein Secretases↗
PubMed2004

Notch activation regulates the segregation and differentiation of rhombomere boundary cells in the zebrafish hindbrain.

During segmentation of the vertebrate hindbrain, a distinct population of boundary cells forms at the interface between each segment. Little is known regarding mechanisms that regulate the formation or functions of these cells. We have investigated a potential role of Notch signaling and find that in the zebrafish hindbrain, radical fringe is expressed in boundary cells and delta genes are expressed adjacent to boundaries, consistent with a sustained activation of Notch in boundary cells. Mosaic expression experiments reveal that activation of the Notch/Su(H) pathway regulates cell affinity properties that segregate cells to boundaries. In addition, Notch signaling correlates with a delayed neurogenesis at hindbrain boundaries and is required to inhibit premature neuronal differentiation of boundary cells. These findings reveal that Notch activation couples the regulation of location and differentiation in hindbrain boundary cells. Such coupling may be important for these cells to act as a stable signaling center.

Animals↗