The putative wnt receptor Xenopus frizzled-7 functions upstream of beta-catenin in vertebrate dorsoventral mesoderm patterning

Development ◽  
2000 ◽  
Vol 127 (9) ◽  
pp. 1981-1990 ◽  
Author(s):  
S. Sumanas ◽  
P. Strege ◽  
J. Heasman ◽  
S.C. Ekker

We have isolated one member of the frizzled family of wnt receptors from Xenopus (Xfz7) to study the role of cell-cell communication in the establishment of the vertebrate axis. We demonstrate that this maternally encoded protein specifically synergizes with wnt proteins in ectopic axis induction. Embryos derived from oocytes depleted of maternal Xfz7 RNA by antisense oligonucleotide injection are deficient in dorsoanterior structures. Xfz7-depleted embryos are deficient in dorsal but not ventral mesoderm due to the reduced expression of the wnt target genes siamois, Xnr3 and goosecoid. These signaling defects can be restored by the addition of beta-catenin but not Xwnt8b. Xfz7 thus functions upstream of the known GSK-3/axin/beta-catenin intracellular signaling complex in vertebrate dorsoventral mesoderm specification.

FACE ◽  
2021 ◽  
pp. 273250162110243
Author(s):  
Mikhail Pakvasa ◽  
Andrew B. Tucker ◽  
Timothy Shen ◽  
Tong-Chuan He ◽  
Russell R. Reid

Hedgehog signaling was discovered more than 40 years ago in experiments demonstrating that it is a fundamental mediator of limb development. Since that time, it has been shown to be important in development, homeostasis, and disease. The hedgehog pathway proceeds through a pathway highly conserved throughout animals beginning with the extracellular diffusion of hedgehog ligands, proceeding through an intracellular signaling cascade, and ending with the activation of specific target genes. A vast amount of research has been done elucidating hedgehog signaling mechanisms and regulation. This research has found a complex system of genetics and signaling that helps determine how organisms develop and function. This review provides an overview of what is known about hedgehog genetics and signaling, followed by an in-depth discussion of the role of hedgehog signaling in craniofacial development and carcinogenesis.


2002 ◽  
Vol 29 (3) ◽  
pp. 265-279 ◽  
Author(s):  
SL Samson ◽  
NC Wong

Sp1 is a ubiquitous nuclear factor that plays a key role in maintaining basal transcription of 'house-keeping' genes. However, recent evidence points to a more important function for Sp1 in mediating 'cross-talk' between selected signaling cascades to regulate the target genes that respond to these pathways. The role of Sp1 in mediating the actions of the peptide hormone insulin is of specific interest and serves as a model for detailing effects of intracellular signaling on Sp1 activity. This review summarizes studies suggesting that changes in Sp1 phosphorylation provide one potential mechanism for manipulating activity of this protein. A growing body of evidence reveals that the DNA binding and transcription activity of Sp1 may increase or decrease in response to changes in phosphorylation. This enables 'fine-tuning' of Sp1 activity for regulation of gene transcription. Several mechanisms exist by which Sp1 alters gene activity in response to insulin. These include independent Sp1 activity as well as collaboration or competition with others factors. This review points to an ever-increasing role for Sp1 in regulating the transcription of genes in response to extracellular signals such as insulin.


Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4000
Author(s):  
Esra’a Keewan ◽  
Ksenia Matlawska-Wasowska

Cytokines are pleiotropic signaling molecules that execute an essential role in cell-to-cell communication through binding to cell surface receptors. Receptor binding activates intracellular signaling cascades in the target cell that bring about a wide range of cellular responses, including induction of cell proliferation, migration, differentiation, and apoptosis. The Janus kinase and transducers and activators of transcription (JAK/STAT) signaling pathways are activated upon cytokines and growth factors binding with their corresponding receptors. The SOCS family of proteins has emerged as a key regulator of cytokine signaling, and SOCS insufficiency leads to constitutive activation of JAK/STAT signaling and oncogenic transformation. Dysregulation of SOCS expression is linked to various solid tumors with invasive properties. However, the roles of SOCS in hematological malignancies, such as leukemia, are less clear. In this review, we discuss the recent advances pertaining to SOCS dysregulation in leukemia development and progression. We also highlight the roles of specific SOCS in immune cells within the tumor microenvironment and their possible involvement in anti-tumor immunity. Finally, we discuss the epigenetic, genetic, and post-transcriptional modifications of SOCS genes during tumorigenesis, with an emphasis on leukemia.


2001 ◽  
Vol 12 (2) ◽  
pp. 152-165 ◽  
Author(s):  
Lorenzo Lo Muzio

Reductions in cell-cell adhesion and stromal and vascular invasion are essential steps in the progression from localized malignancy to metastatic disease for all cancers. Proteins involved in intercellular adhesion, such as E-cadherin and catenin, probably play an important role in metastatic processes and cellular differentiation. While E-cadherin and beta-catenin expression has been extensively studied in many forms of human cancers, less is known about the role of the Wingless-Type-1 (WNT-1 ) pathway in human tumors. A large body of genetic and biochemical evidence has identified beta-catenin as a key downstream component of the WNT signaling pathway, and recent studies of colorectal tumors have shown a functional link among beta-catenin, adenomatous polyposis coli gene product (APC), and other components of the WNT-1 pathway. WNT-1 pathway signaling is thought to be mediated via interactions between beta-catenin and members of the LEF-1/TCF family of transcription factors. The WNT signal stabilizes beta-catenin protein and promotes its accumulation in the cytoplasm and nucleus. In the nucleus, beta-catenin associates with TCF to form a functional transcription factor which mediates the transactivation of target genes involved in the promotion of tumor progression, invasion, and metastasis, such as C-Myc, cyclin DI, c-jun, fra-1, and u-PAR. There is a strong correlation between the ability of the WNT-1 gene to induce beta-catenin accumulation and its transforming potential in vivo, suggesting that the WNT-1 gene activates an intracellular signaling pathway that can induce the morphological transformation of cells. For these reasons, data obtained from the study of the WNT-1 pathway could be important in our understanding of the mechanisms of epithelial tumors, in general, and probably also of oral squamous cell carcinoma, in particular.


Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1126 ◽  
Author(s):  
Michela Cintio ◽  
Giulia Polacchini ◽  
Elisa Scarsella ◽  
Tommaso Montanari ◽  
Bruno Stefanon ◽  
...  

Recent advances in ruminants’ milk-derived exosomes (EXO) have indicated a role of microRNAs (miRNAs) in cell-to-cell communication in dairy ruminants. The miRNAs EXO retain peculiar mechanisms of uptake from recipient cells, which enables the selective delivery of cargos, with a specific regulation of target genes. Although many studies have been published on the miRNAs contained in milk, less information is available on the role of miRNAs EXO, which are considered stable over time and resistant to digestion and milk processing. Several miRNAs EXO have been implicated in the cellular signaling pathway, as in the regulation of immune response. Moreover, they exert epigenetic control, as extenuating the expression of DNA methyltransferase 1. However, the study of miRNAs EXO is still challenging due to the difficulty of isolating EXO. In fact, there are not agreed protocols, and different methods, often time-consuming, are used, making it difficult to routinely process a large number of samples. The regulation of cell functions in mammary glands by miRNAs EXO, and their applications as genomic markers in livestock, is presented.


2020 ◽  
Vol 21 (22) ◽  
pp. 8847
Author(s):  
Rossella Gratton ◽  
Paola Maura Tricarico ◽  
Adamo Pio d'Adamo ◽  
Anna Monica Bianco ◽  
Ronald Moura ◽  
...  

Notch pathway is a highly conserved intracellular signaling route that modulates a vast variety of cellular processes including proliferation, differentiation, migration, cell fate and death. Recently, the presence of a strict crosstalk between Notch signaling and inflammation has been described, although the precise molecular mechanisms underlying this interplay have not yet been fully unravelled. Disruptions in Notch cascade, due both to direct mutations and/or to an altered regulation in the core components of Notch signaling, might lead to hypo- or hyperactivation of Notch target genes and signaling molecules, ultimately contributing to the onset of autoinflammatory diseases. To date, alterations in Notch signaling have been reported as associated with three autoinflammatory disorders, therefore, suggesting a possible role of Notch in the pathogenesis of the following diseases: hidradenitis suppurativa (HS), Behçet disease (BD), and giant cell arteritis (GCA). In this review, we aim at better characterizing the interplay between Notch and autoinflammatory diseases, trying to identify the role of this signaling route in the context of these disorders.


2003 ◽  
Vol 27 (4) ◽  
pp. 192-200 ◽  
Author(s):  
Donna H. Korzick

The primary purpose of this paper is to present a basic overview of some “relatively” new ideas related to the regulation of cardiac performance and underlying excitation-contraction (EC) coupling that have yet to be incorporated to textbooks currently used for introductory graduate-level physiology courses. Within the context of cardiac EC coupling, this review incorporates information on microdomains and local control theory, with particular emphasis on the role of Ca2+ sparks as a key regulatory component of ventricular myocyte contraction dynamics. Recent information pertaining to Ca2+ release mechanisms specific to the sarcoplasmic reticulum is also presented, as well as the idea of the ryanodine receptor as a macromolecular signaling complex. Because of the potential relationship to maladaptive functional responses under conditions of cardiovascular pathology, the regulatory role of cardiac adrenergic and additional G protein-coupled receptors known to regulate cardiac function is included, and fundamental concepts related to intracellular signaling are discussed. Finally, information on the roles of vascular and cardiac nitric oxide as an important regulator of cardiac performance is included to allow students to begin to think about the ubiquitous role of nitric oxide in the regulation of the cardiovascular system. An important point of emphasis is that whole organ cardiac dynamics can be traced back to the cellular events regulating intracellular Ca2+ homeostasis and as such provides an important conceptual framework from which the students can begin to think about whole organ physiology in health and disease.


2000 ◽  
Vol 113 (6) ◽  
pp. 911-919 ◽  
Author(s):  
J. Behrens

The Wnt signal transduction pathway regulates various aspects of embryonal development and is involved in cancer formation. Wnts induce the stabilisation of cytosolic (beta)-catenin, which then associates with TCF transcription factors to regulate expression of Wnt-target genes. At various levels the Wnt pathway is subject to cross-regulation by other components. Recent evidence suggests that a specific MAP kinase pathway involving the MAP kinase kinase kinase TAK1 and the MAP kinase NLK counteract Wnt signalling. In particular, homologues of TAK1 and NLK, MOM-4 and LIT-1, negatively regulate Wnt-controlled cell fate decision in the early Caenorhabditis elegans embryo. Moreover, TAK1 activates NLK, which phosphorylates TCFs bound to (beta)-catenin. This blocks nuclear localization and DNA binding of TCFs. Since TAK1 is activated by TGF-(beta) and various cytokines, it might provide an entry point for regulation of the Wnt system by other pathways. In addition, alterations in TAK1-NLK might play a role in cancer.


Sign in / Sign up

Export Citation Format

Share Document