1
|
Zhao X, Radford BN, Ungrin M, Dean W, Hemberger M. The Trophoblast Compartment Helps Maintain Embryonic Pluripotency and Delays Differentiation towards Cardiomyocytes. Int J Mol Sci 2023; 24:12423. [PMID: 37569800 PMCID: PMC10418709 DOI: 10.3390/ijms241512423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/28/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023] Open
Abstract
Normal developmental progression relies on close interactions between the embryonic and extraembryonic lineages in the pre- and peri-gastrulation stage conceptus. For example, mouse epiblast-derived FGF and NODAL signals are required to maintain a stem-like state in trophoblast cells of the extraembryonic ectoderm, while visceral endoderm signals are pivotal to pattern the anterior region of the epiblast. These developmental stages also coincide with the specification of the first heart precursors. Here, we established a robust differentiation protocol of mouse embryonic stem cells (ESCs) into cardiomyocyte-containing embryoid bodies that we used to test the impact of trophoblast on this key developmental process. Using trophoblast stem cells (TSCs) to produce trophoblast-conditioned medium (TCM), we show that TCM profoundly slows down the cardiomyocyte differentiation dynamics and specifically delays the emergence of cardiac mesoderm progenitors. TCM also strongly promotes the retention of pluripotency transcription factors, thereby sustaining the stem cell state of ESCs. By applying TCM from various mutant TSCs, we further show that those mutations that cause a trophoblast-mediated effect on early heart development in vivo alter the normal cardiomyocyte differentiation trajectory. Our approaches provide a meaningful deconstruction of the intricate crosstalk between the embryonic and the extraembryonic compartments. They demonstrate that trophoblast helps prolong a pluripotent state in embryonic cells and delays early differentiative processes, likely through production of leukemia inhibitory factor (LIF). These data expand our knowledge of the multifaceted signaling interactions among distinct compartments of the early conceptus that ensure normal embryogenesis, insights that will be of significance for the field of synthetic embryo research.
Collapse
Affiliation(s)
- Xiang Zhao
- Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada;
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada; (B.N.R.); (M.U.)
| | - Bethany N. Radford
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada; (B.N.R.); (M.U.)
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - Mark Ungrin
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada; (B.N.R.); (M.U.)
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - Wendy Dean
- Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada;
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada; (B.N.R.); (M.U.)
| | - Myriam Hemberger
- Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada; (B.N.R.); (M.U.)
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| |
Collapse
|
2
|
Sandouk A, Xu Z, Baruah S, Tremblay M, Hopkins JB, Chakravarthy S, Gakhar L, Schnicker NJ, Houtman JCD. GRB2 dimerization mediated by SH2 domain-swapping is critical for T cell signaling and cytokine production. Sci Rep 2023; 13:3505. [PMID: 36864087 PMCID: PMC9981690 DOI: 10.1038/s41598-023-30562-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/25/2023] [Indexed: 03/04/2023] Open
Abstract
GRB2 is an adaptor protein required for facilitating cytoplasmic signaling complexes from a wide array of binding partners. GRB2 has been reported to exist in either a monomeric or dimeric state in crystal and solution. GRB2 dimers are formed by the exchange of protein segments between domains, otherwise known as "domain-swapping". Swapping has been described between SH2 and C-terminal SH3 domains in the full-length structure of GRB2 (SH2/C-SH3 domain-swapped dimer), as well as between α-helixes in isolated GRB2 SH2 domains (SH2/SH2 domain-swapped dimer). Interestingly, SH2/SH2 domain-swapping has not been observed within the full-length protein, nor have the functional influences of this novel oligomeric conformation been explored. We herein generated a model of full-length GRB2 dimer with an SH2/SH2 domain-swapped conformation supported by in-line SEC-MALS-SAXS analyses. This conformation is consistent with the previously reported truncated GRB2 SH2/SH2 domain-swapped dimer but different from the previously reported, full-length SH2/C-terminal SH3 (C-SH3) domain-swapped dimer. Our model is also validated by several novel full-length GRB2 mutants that favor either a monomeric or a dimeric state through mutations within the SH2 domain that abrogate or promote SH2/SH2 domain-swapping. GRB2 knockdown and re-expression of selected monomeric and dimeric mutants in a T cell lymphoma cell line led to notable defects in clustering of the adaptor protein LAT and IL-2 release in response to TCR stimulation. These results mirrored similarly-impaired IL-2 release in GRB2-deficient cells. These studies show that a novel dimeric GRB2 conformation with domain-swapping between SH2 domains and monomer/dimer transitions are critical for GRB2 to facilitate early signaling complexes in human T cells.
Collapse
Affiliation(s)
- Aline Sandouk
- Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, 52242, USA
| | - Zhen Xu
- Protein and Crystallography Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Sankar Baruah
- Protein and Crystallography Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Mikaela Tremblay
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, 52242, USA
| | - Jesse B Hopkins
- Biophysics Collaborative Access Team, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Srinivas Chakravarthy
- Biophysics Collaborative Access Team, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Lokesh Gakhar
- Protein and Crystallography Facility, University of Iowa, Iowa City, IA, 52242, USA
- Department of Biochemistry and Molecular Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Nicholas J Schnicker
- Protein and Crystallography Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Jon C D Houtman
- Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, 52242, USA.
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, 52242, USA.
| |
Collapse
|
3
|
García-Mato Á, Cervantes B, Murillo-Cuesta S, Rodríguez-de la Rosa L, Varela-Nieto I. Insulin-like Growth Factor 1 Signaling in Mammalian Hearing. Genes (Basel) 2021; 12:genes12101553. [PMID: 34680948 PMCID: PMC8535591 DOI: 10.3390/genes12101553] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 02/06/2023] Open
Abstract
Insulin-like growth factor 1 (IGF-1) is a peptide hormone belonging to the insulin family of proteins. Almost all of the biological effects of IGF-1 are mediated through binding to its high-affinity tyrosine kinase receptor (IGF1R), a transmembrane receptor belonging to the insulin receptor family. Factors, receptors and IGF-binding proteins form the IGF system, which has multiple roles in mammalian development, adult tissue homeostasis, and aging. Consequently, mutations in genes of the IGF system, including downstream intracellular targets, underlie multiple common pathologies and are associated with multiple rare human diseases. Here we review the contribution of the IGF system to our understanding of the molecular and genetic basis of human hearing loss by describing, (i) the expression patterns of the IGF system in the mammalian inner ear; (ii) downstream signaling of IGF-1 in the hearing organ; (iii) mouse mutations in the IGF system, including upstream regulators and downstream targets of IGF-1 that inform cochlear pathophysiology; and (iv) human mutations in these genes causing hearing loss.
Collapse
Affiliation(s)
- Ángela García-Mato
- Institute for Biomedical Research “Alberto Sols” (IIBm), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (Á.G.-M.); (B.C.); (S.M.-C.)
- Rare Diseases Networking Biomedical Research Centre (CIBERER), CIBER, Carlos III Institute of Health, 28029 Madrid, Spain
| | - Blanca Cervantes
- Institute for Biomedical Research “Alberto Sols” (IIBm), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (Á.G.-M.); (B.C.); (S.M.-C.)
- Rare Diseases Networking Biomedical Research Centre (CIBERER), CIBER, Carlos III Institute of Health, 28029 Madrid, Spain
| | - Silvia Murillo-Cuesta
- Institute for Biomedical Research “Alberto Sols” (IIBm), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (Á.G.-M.); (B.C.); (S.M.-C.)
- Rare Diseases Networking Biomedical Research Centre (CIBERER), CIBER, Carlos III Institute of Health, 28029 Madrid, Spain
- La Paz Hospital Institute for Health Research (IdiPAZ), 28046 Madrid, Spain
| | - Lourdes Rodríguez-de la Rosa
- Rare Diseases Networking Biomedical Research Centre (CIBERER), CIBER, Carlos III Institute of Health, 28029 Madrid, Spain
- La Paz Hospital Institute for Health Research (IdiPAZ), 28046 Madrid, Spain
- Correspondence: (L.R.-d.l.R.); (I.V.-N.)
| | - Isabel Varela-Nieto
- Institute for Biomedical Research “Alberto Sols” (IIBm), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (Á.G.-M.); (B.C.); (S.M.-C.)
- Rare Diseases Networking Biomedical Research Centre (CIBERER), CIBER, Carlos III Institute of Health, 28029 Madrid, Spain
- La Paz Hospital Institute for Health Research (IdiPAZ), 28046 Madrid, Spain
- Correspondence: (L.R.-d.l.R.); (I.V.-N.)
| |
Collapse
|
4
|
Xia Y, He K, Jiao L, Geng Y, Zhang D. Molecular characterization and expression analysis of protein enhancer of sevenless 2B from Artemia sinica at early embryonic development and during immune response to bacterial stimulation. FISH & SHELLFISH IMMUNOLOGY 2019; 87:582-589. [PMID: 30711491 DOI: 10.1016/j.fsi.2019.01.053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/22/2019] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
Protein enhancer of sevenless 2B, E(sev)2B, is a key adapter protein in the Ras/MAPK signaling pathway which has been reported to be involved in innate immunity. In this study, the gene that encodes AsE(sev)2B was isolated from A. sinica. It was found to contain a 636 bp open reading frame encoding 211 amino acids with a calculated molecular mass of 24.357 kDa and a predicted isoelectric point of 5.39. The predicted protein contains a N-terminal Src homology 3 domain (SH3), a central Src homology 2 domain (SH2), and a C-terminal Src homology 3 domain (SH3). Homology analysis revealed that AsE(sev)2B shares 49%-95% identity with E(sev)2B homologs from other species. In this study, the expression pattern and location of AsE(sev)2B during different stages of embryonic development and bacterial challenge were investigated by means of real-time qPCR, Western blotting and immunohistochemistry. Results showed that the highest expression level of AsE(sev)2B was at 0 h. After challenged by Gram-positive bacteria and Gram-negative bacteria, AsE(sev)2B was remarkably upregulated at 106 cellsL-1 bacterial concentrations. These results suggested that AsE(sev)2B plays a vital role during early embryonic development and in immune responses against bacterial challenge.
Collapse
Affiliation(s)
- Yu Xia
- The Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, 071002, Baoding, PR China
| | - Kang He
- The Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, 071002, Baoding, PR China
| | - Lili Jiao
- The Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, 071002, Baoding, PR China
| | - Yuanyuan Geng
- The Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, 071002, Baoding, PR China
| | - Daochuan Zhang
- The Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, 071002, Baoding, PR China.
| |
Collapse
|
5
|
Aliper AM, Korzinkin MB, Kuzmina NB, Zenin AA, Venkova LS, Smirnov PY, Zhavoronkov AA, Buzdin AA, Borisov NM. Mathematical Justification of Expression-Based Pathway Activation Scoring (PAS). Methods Mol Biol 2017; 1613:31-51. [PMID: 28849557 DOI: 10.1007/978-1-4939-7027-8_3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although modeling of activation kinetics for various cell signaling pathways has reached a high grade of sophistication and thoroughness, most such kinetic models still remain of rather limited practical value for biomedicine. Nevertheless, recent advancements have been made in application of signaling pathway science for real needs of prescription of the most effective drugs for individual patients. The methods for such prescription evaluate the degree of pathological changes in the signaling machinery based on two types of data: first, on the results of high-throughput gene expression profiling, and second, on the molecular pathway graphs that reflect interactions between the pathway members. For example, our algorithm OncoFinder evaluates the activation of molecular pathways on the basis of gene/protein expression data in the objects of the interest.Yet, the question of assessment of the relative importance for each gene product in a molecular pathway remains unclear unless one call for the methods of parameter sensitivity /stiffness analysis in the interactomic kinetic models of signaling pathway activation in terms of total concentrations of each gene product.Here we show two principal points: 1. First, the importance coefficients for each gene in pathways that were obtained using the extremely time- and labor-consuming stiffness analysis of full-scaled kinetic models generally differ from much easier-to-calculate expression-based pathway activation score (PAS) not more than by 30%, so the concept of PAS is kinetically justified. 2. Second, the use of pathway-based approach instead of distinct gene analysis, due to the law of large numbers, allows restoring the correlation between the similar samples that were examined using different transcriptome investigation techniques.
Collapse
Affiliation(s)
- Alexander M Aliper
- Drug Research and Design Department, Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR
- Department of Personalized Medicine, First Oncology Research and Advisory Center, Moscow, Russia
- Laboratory of Bioinformatics, D. Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Michael B Korzinkin
- Department of Personalized Medicine, First Oncology Research and Advisory Center, Moscow, Russia
- Laboratory of Bioinformatics, D. Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Natalia B Kuzmina
- Laboratory of Systems Biology, A.I. Burnazyan Federal Medical Biophysical Center, Moscow, 123182, Russia
| | - Alexander A Zenin
- Laboratory of Systems Biology, A.I. Burnazyan Federal Medical Biophysical Center, Moscow, 123182, Russia
| | - Larisa S Venkova
- Department of Personalized Medicine, First Oncology Research and Advisory Center, Moscow, Russia
- Laboratory of Bioinformatics, D. Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Philip Yu Smirnov
- Laboratory of Systems Biology, A.I. Burnazyan Federal Medical Biophysical Center, Moscow, 123182, Russia
| | - Alex A Zhavoronkov
- Drug Research and Design Department, Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR
- Department of Personalized Medicine, First Oncology Research and Advisory Center, Moscow, Russia
- Laboratory of Bioinformatics, D. Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Anton A Buzdin
- Drug Research and Design Department, Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR
- Department of Personalized Medicine, First Oncology Research and Advisory Center, Moscow, Russia
- Laboratory of Bioinformatics, D. Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
- National Research Centre "Kurchatov Institute", Centre for Convergence of Nano-, Bio-, Information and Cognitive Sciences and Technologies, Moscow, Russia
| | - Nikolay M Borisov
- Department of Personalized Medicine, First Oncology Research and Advisory Center, Moscow, Russia.
- Laboratory of Bioinformatics, D. Rogachev Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia.
- National Research Centre "Kurchatov Institute", Centre for Convergence of Nano-, Bio-, Information and Cognitive Sciences and Technologies, Moscow, Russia.
| |
Collapse
|
6
|
Abstract
This review addresses the developmental roles of 2 GTPases of the Rho family, RhoV/Chp and RhoU/Wrch. These two GTPases form a distinct subfamily related to Rac and Cdc42 proteins and were detected in a screen for Rho members that are particularly expressed in the neural crest, an embryonic tissue peculiar to vertebrates. The neural crest represents a physiological model of normal epithelial to mesenchymal transition (EMT), in which epithelial cells at the border of neural and non-neural ectoderm differentiate, lose their intercellular connections and migrate throughout the embryo. We showed that RhoV, transiently induced by the canonical Wnt pathway, is required for the full differentiation of neural crest cells, while RhoU, induced later by the non-canonical Wnt pathway, is necessary for the migration process. These two GTPases, which are highly conserved across vertebrates, are thus tightly functionally linked to Wnt signaling, whose implication in embryonic development and cancer progression is well established. In the light of the recent literature, we discuss how RhoV and RhoU may achieve their physiological functions.
Collapse
Affiliation(s)
- Sandrine Faure
- a Universités Montpellier 2 et 1; CRBM; UMS BioCampus ; Montpellier , France.,b INSERM ; Montpellier , France
| | - Philippe Fort
- a Universités Montpellier 2 et 1; CRBM; UMS BioCampus ; Montpellier , France.,c CNRS UMR 5237 ; Montpellier , France
| |
Collapse
|
7
|
Abstract
This review addresses the developmental roles of two GTPases of the Rho family, RhoV/Chp and RhoU/Wrch. These two GTPases form a distinct subfamily related to Rac and Cdc42 proteins and were detected in a screen for Rho members that are particularly expressed in the neural crest, an embryonic tissue peculiar to vertebrates. The neural crest represents a physiological model of normal epithelial to mesenchymal transition (EMT), in which epithelial cells at the border of neural and non-neural ectoderm differentiate, lose their intercellular connections and migrate throughout the embryo. We showed that RhoV, transiently induced by the canonical Wnt pathway, is required for the full differentiation of neural crest cells, while RhoU, induced later by the non-canonical Wnt pathway, is necessary for the migration process. These two GTPases, which are highly conserved across vertebrates, are thus tightly functionally linked to Wnt signaling, whose implication in embryonic development and cancer progression is well established. In the light of the recent literature, we discuss how RhoV and RhoU may achieve their physiological functions.
Collapse
|
8
|
Charron J, Bissonauth V, Nadeau V. Implication of MEK1 and MEK2 in the establishment of the blood-placenta barrier during placentogenesis in mouse. Reprod Biomed Online 2012; 25:58-67. [PMID: 22561024 DOI: 10.1016/j.rbmo.2012.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/02/2012] [Accepted: 02/02/2012] [Indexed: 02/07/2023]
Abstract
The ERK/MAPK signalling cascade is involved in many cellular functions. In mice, the targeted ablation of genes coding for members of this pathway is often associated with embryonic death due to the abnormal development of the placenta. The placenta is essential for nutritional and gaseous exchanges between maternal and embryonic circulations, as well as for the elimination of metabolic waste. These exchanges occur without direct contact between the two circulations. In mice, the blood-placenta barrier consists of a triple layer of trophoblast cells adjacent to endothelial cells from the embryo. In the ERK/MAPK cascade, MEK1 and MEK2 are dual-specificity kinases responsible for the activation of the ERK1 and ERK2 kinases. Inactivation of Mek1 causes placental malformations resulting from defective proliferation and differentiation of the labyrinthine trophoblast cells and leading to a severe delay in the development and the vascularization of the placenta, which explains the embryonic death. Although Mek2(-/-) mutants survive without any apparent phenotype, a large proportion of Mek1(+/-)Mek2(+/-) double heterozygous mutants die during gestation from placenta anomalies affecting the establishment of the blood-placenta barrier. Together, these data reveal how crucial is the role of the ERK/MAPK pathway during the formation of the placenta.
Collapse
Affiliation(s)
- Jean Charron
- Centre de recherche en cancérologie de l'Université Laval, Centre Hospitalier Universitaire de Québec, L'Hôtel-Dieu de Québec, Canada.
| | | | | |
Collapse
|
9
|
Watson ED, Hughes M, Simmons DG, Natale DR, Sutherland AE, Cross JC. Cell-cell adhesion defects in Mrj mutant trophoblast cells are associated with failure to pattern the chorion during early placental development. Dev Dyn 2011; 240:2505-19. [DOI: 10.1002/dvdy.22755] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2011] [Indexed: 11/12/2022] Open
|
10
|
|
11
|
Mammalian Llgl2 is necessary for proper branching morphogenesis during placental development. Mol Cell Biol 2011; 31:2920-33. [PMID: 21606200 DOI: 10.1128/mcb.05431-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cell polarity plays a critical role in the development of all metazoans; however, the mechanisms of cell polarity and the specific role of cell polarity pathways in mammalian organisms are still poorly understood. Lethal giant larvae (Lgl) is an apical-basal polarity gene identified in Drosophila, where it functions as a tumor suppressor controlling self-renewal and differentiation of progenitor cells. There are two orthologs of Lgl in mammalian genomes: Llgl1 and Llgl2. While mammalian Lgls are assumed to be tumor suppressor genes, little is known about their function in vivo. Here we report the functional analysis of murine Llgl2. We generated Llgl2(-/-) mice and found that Llgl2 functions as a polarity protein required for proper branching morphogenesis during placental development. Llgl2(-/-) pups are born as runts but quickly catch up in size and grow into normal-size adults. Surprisingly, no prominent phenotypes or spontaneous tumors were observed in adult Llgl2(-/-) mice. Analyses of placental trophoblasts reveal a critical role for Llgl2 in cell polarization and polarized cell invasion. We conclude that mammalian Llgl2 is required for proper polarized invasion of trophoblasts and efficient branching morphogenesis during placental development, but, unlike its Drosophila ortholog, it does not function as a canonical tumor suppressor gene.
Collapse
|
12
|
Wöhrle FU, Daly RJ, Brummer T. Function, regulation and pathological roles of the Gab/DOS docking proteins. Cell Commun Signal 2009; 7:22. [PMID: 19737390 PMCID: PMC2747914 DOI: 10.1186/1478-811x-7-22] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Accepted: 09/08/2009] [Indexed: 01/13/2023] Open
Abstract
Since their discovery a little more than a decade ago, the docking proteins of the Gab/DOS family have emerged as important signalling elements in metazoans. Gab/DOS proteins integrate and amplify signals from a wide variety of sources including growth factor, cytokine and antigen receptors as well as cell adhesion molecules. They also contribute to signal diversification by channelling the information from activated receptors into signalling pathways with distinct biological functions. Recent approaches in protein biochemistry and systems biology have revealed that Gab proteins are subject to complex regulation by feed-forward and feedback phosphorylation events as well as protein-protein interactions. Thus, Gab/DOS docking proteins are at the centre of entire signalling subsystems and fulfil an important if not essential role in many physiological processes. Furthermore, aberrant signalling by Gab proteins has been increasingly linked to human diseases from various forms of neoplasia to Alzheimer's disease. In this review, we provide a detailed overview of the structure, effector functions, regulation and evolution of the Gab/DOS family. We also summarize recent findings implicating Gab proteins, in particular the Gab2 isoform, in leukaemia, solid tumours and other human diseases.
Collapse
Affiliation(s)
- Franziska U Wöhrle
- Centre for Biological Systems Analysis (ZBSA), Albert-Ludwigs-University of Freiburg, Germany.
| | | | | |
Collapse
|
13
|
Giubellino A, Burke TR, Bottaro DP. Grb2 signaling in cell motility and cancer. Expert Opin Ther Targets 2008; 12:1021-33. [PMID: 18620523 DOI: 10.1517/14728222.12.8.1021] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Metastasis is the primary cause of death in most human cancers, and understanding the molecular mechanisms underpinning this multistep process is fundamental to identifying novel molecular targets and developing more effective therapies. OBJECTIVE/METHODS Here we review the role of growth factor receptor-bound protein 2 (Grb2) in cancer and specifically in metastasis-related processes, and summarize the development of anticancer therapeutics selectively targeting this adapter protein. RESULTS/CONCLUSION Grb2 is a key molecule in intracellular signal transduction, linking activated cell surface receptors to downstream targets by binding to specific phosphotyrosine-containing and proline-rich sequence motifs. Grb2 signaling is critical for cell cycle progression and actin-based cell motility, and, consequently, more complex processes such as epithelial morphogenesis, angiogenesis and vasculogenesis. These functions make Grb2 a therapeutic target for strategies designed to prevent the spread of solid tumors through local invasion and metastasis.
Collapse
Affiliation(s)
- Alessio Giubellino
- National Cancer Institute, Urologic Oncology Branch, CCR, Building 10, 10 Center Drive MSC 1107, Bethesda, MD 20892-1107, USA.
| | | | | |
Collapse
|
14
|
Galliher-Beckley AJ, Schiemann WP. Grb2 binding to Tyr284 in TbetaR-II is essential for mammary tumor growth and metastasis stimulated by TGF-beta. Carcinogenesis 2008; 29:244-51. [PMID: 18174260 DOI: 10.1093/carcin/bgm245] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
We demonstrated previously that growth factor receptor-bound protein 2 (Grb2) associates with the transforming growth factor-beta (TGF-beta) type II receptor [TbetaR-II] upon its phosphorylation on Tyr284 by Src. Although this phosphotransferase reaction is critical in mediating TGF-beta stimulation of epithelial-mesenchymal transition (EMT) and invasion in mammary epithelial cells (MECs), the necessity of Grb2 in promoting these TGF-beta-dependent events remain purely correlative. Herein, we further evaluated the role of Grb2 in mediating the oncogenic activities of TGF-beta and show that the binding of Grb2 to TbetaR-II paralleled the induction of EMT in MECs stimulated by TGF-beta. Introducing siRNAs against Grb2 or expression of a TbetaR-II mutant that cannot bind Grb2 (i.e. Y284F-TbetaR-II) had no effect on the ability of TGF-beta to activate Smad3, but significantly impaired its stimulation of p38 mitogen-activated protein kinase (MAPK) in MECs. Importantly, these same cellular conditions also prevented the ability of MECs to undergo EMT in response to TGF-beta, and to invade synthetic basement membranes when stimulated by beta3 integrin and TGF-beta. Finally, we show that the ability of TGF-beta to stimulate breast cancer growth and pulmonary metastasis in mice required TbetaR-II to be phosphorylated on Tyr284, which activated p38 MAPK in developing and progressing mammary tumors. Collectively, our findings have established the necessity of Grb2 in mediating TGF-beta stimulation of EMT and invasion in MECs, as well as demonstrated the essential function of the alphavbeta3 integrin:Src:phospho-Y284-TbetaR-II:Grb2:p38 MAPK signaling axis to promote breast cancer growth and metastasis in vivo.
Collapse
Affiliation(s)
- Amy J Galliher-Beckley
- Department of Pharmacology, University of Colorado Health Sciences Center, Aurora, CO 80045, USA
| | | |
Collapse
|
15
|
Schaeper U, Vogel R, Chmielowiec J, Huelsken J, Rosario M, Birchmeier W. Distinct requirements for Gab1 in Met and EGF receptor signaling in vivo. Proc Natl Acad Sci U S A 2007; 104:15376-81. [PMID: 17881575 PMCID: PMC2000540 DOI: 10.1073/pnas.0702555104] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gab1 is a multiadaptor protein that has been shown to be required for multiple processes in embryonic development and oncogenic transformation. Gab1 functions by amplifying signal transduction downstream of various receptor tyrosine kinases through recruitment of multiple signaling effectors, including phosphatidylinositol 3-kinase and Shp2. Until now, the functional significance of individual interactions in vivo was not known. Here we have generated knockin mice that carry point mutations in either the P13K or Shp2 binding sites of Gab1. We show that different effector interactions with Gab1 play distinct biological roles downstream of Gab1 during the development of different organs. Recruitment of phosphatidylinositol 3-kinase by Gab1 is essential for EGF receptor-mediated embryonic eyelid closure and keratinocyte migration, and the Gab1-Shp2 interaction is crucial for Met receptor-directed placental development and muscle progenitor cell migration to the limbs. Furthermore, we investigate the dual association of Gab1 with the Met receptor. By analyzing knockin mice with mutations in the Grb2 or Met binding site of Gab1, we show that the requirements for Gab1 recruitment to Met varies in different biological contexts. Either the direct or the indirect interaction of Gab1 with Met is sufficient for Met-dependent muscle precursor cell migration, whereas both modes of interaction are required and neither is sufficient for placenta development, liver growth, and palatal shelf closure. These data demonstrate that Gab1 induces different biological responses through the recruitment of distinct effectors and that different modes of recruitment for Gab1 are required in different organs.
Collapse
Affiliation(s)
- Ute Schaeper
- Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Regina Vogel
- Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Jolanta Chmielowiec
- Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Joerg Huelsken
- Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Marta Rosario
- Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Walter Birchmeier
- Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
16
|
Dackor J, Strunk KE, Wehmeyer MM, Threadgill DW. Altered trophoblast proliferation is insufficient to account for placental dysfunction in Egfr null embryos. Placenta 2007; 28:1211-8. [PMID: 17822758 PMCID: PMC2121666 DOI: 10.1016/j.placenta.2007.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Revised: 07/22/2007] [Accepted: 07/23/2007] [Indexed: 01/27/2023]
Abstract
Homozygosity for the Egfr(tm1Mag) null allele in mice leads to genetic background dependent placental abnormalities and embryonic lethality. Molecular mechanisms or genetic modifiers that differentiate strains with surviving versus non-surviving Egfr nullizygous embryos have yet to be identified. Egfr transcripts in wildtype placenta were quantified by ribonuclease protection assay (RPA) and the lowest level of Egfr mRNA expression was found to coincide with Egfr(tm1Mag) homozygous lethality. Immunohistochemical analysis of ERBB family receptors, ERBB2, ERBB3, and ERBB4, showed similar expression between Egfr wildtype and null placentas indicating that Egfr null trophoblast do not up-regulate these receptors to compensate for EGFR deficiency. Significantly fewer numbers of bromodeoxyuridine (BrdU) positive trophoblast were observed in Egfr nullizygous placentas and Cdc25a and Myc, genes associated with proliferation, were significantly down-regulated in null placentas. However, strains with both mild and severe placental phenotypes exhibit reduced proliferation suggesting that this defect alone does not account for strain-specific embryonic lethality. Consistent with this hypothesis, intercrosses generating mice null for cell cycle checkpoint genes (Trp53, Rb1, Cdkn1a, Cdkn1b or Cdkn2c) in combination with Egfr deficiency did not increase survival of Egfr nullizygous embryos. Since complete development of the spongiotrophoblast compartment is not required for survival of Egfr nullizygous embryos, reduction of this layer that is commonly observed in Egfr nullizygous placentas likely accounts for the decrease in proliferation.
Collapse
Affiliation(s)
- J. Dackor
- Department of Genetics, , University of North Carolina, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - K. E. Strunk
- Department of Genetics, , University of North Carolina, Chapel Hill, North Carolina 27599, USA
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee 37221, USA
| | - M. M. Wehmeyer
- Department of Genetics, , University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - D. W. Threadgill
- Department of Genetics, , University of North Carolina, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
- Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA
- **Corresponding author: David Threadgill, Department of Genetics, CB#7264, University of North Carolina, Chapel Hill, North Carolina 27599, Tel: 919-843-6472, Fax: 919-966-3292, E-mail:
| |
Collapse
|
17
|
Inman KE, Downs KM. The murine allantois: emerging paradigms in development of the mammalian umbilical cord and its relation to the fetus. Genesis 2007; 45:237-58. [PMID: 17440924 DOI: 10.1002/dvg.20281] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The fertilized egg of the mammal gives rise to the embryo and its extraembryonic structures, all of which develop in intimate relation with each other. Yet, whilst the past several decades have witnessed a vast number of studies on the embryonic component of the conceptus, study of the extraembryonic tissues and their relation to the fetus have been largely ignored. The allantois, precursor tissue of the mature umbilical cord, is a universal feature of all placental mammals that establishes the vital vascular bridge between the fetus and its mother. The allantois differentiates into the umbilical blood vessels, which become secured onto the chorionic component of the placenta at one end and onto the fetus at the other. In this way, fetal blood is channeled through the umbilical cord for exchange with the mother. Despite the importance of this vascular bridge, little is known about how it is made. The aim of this review is to address current understanding of the biology of the allantois in the mouse and genetic control of its features and functions, and to highlight new paradigms concerning the developmental relationship between the fetus and its umbilical cord.
Collapse
Affiliation(s)
- Kimberly E Inman
- Department of Anatomy, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53706, USA
| | | |
Collapse
|
18
|
Papadaki C, Alexiou M, Cecena G, Verykokakis M, Bilitou A, Cross JC, Oshima RG, Mavrothalassitis G. Transcriptional repressor erf determines extraembryonic ectoderm differentiation. Mol Cell Biol 2007; 27:5201-13. [PMID: 17502352 PMCID: PMC1951951 DOI: 10.1128/mcb.02237-06] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Extraembryonic ectoderm differentiation and chorioallantoic attachment are fibroblast growth factor (FGF)- and transforming growth factor beta-regulated processes that are the first steps in the development of the placenta labyrinth and the establishment of the fetal-maternal circulation in the developing embryo. Only a small number of genes have been demonstrated to be important in trophoblast stem cell differentiation. Erf is a ubiquitously expressed Erk-regulated, ets domain transcriptional repressor expressed throughout embryonic development and adulthood. However, in the developing placenta, after 7.5 days postcoitum (dpc) its expression is restricted to the extraembryonic ectoderm, and its expression is restricted after 9.5 dpc in a subpopulation of labyrinth cells. Homozygous deletion of Erf in mice leads to a block of chorionic cell differentiation before chorioallantoic attachment, resulting in a persisting chorion layer, a persisting ectoplacental cone cavity, failure of chorioallantoic attachment, and absence of labyrinth. These defects result in embryo death by 10.5 dpc. Trophoblast stem cell lines derived from Erf(dl1/dl1) knockout blastocysts exhibit delayed differentiation and decreased expression of spongiotrophoblast markers, consistent with the persisting chorion layer, the expanded giant cell layer, and the diminished spongiotrophoblast layer observed in vivo. Our data suggest that attenuation of FGF/Erk signaling and consecutive Erf nuclear localization and function is required for extraembryonic ectoderm differentiation, ectoplacental cone cavity closure, and chorioallantoic attachment.
Collapse
Affiliation(s)
- Chara Papadaki
- Medical School, University of Crete, Voutes, Heraklion, Crete 710 03, Greece
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Watson ED, Geary-Joo C, Hughes M, Cross JC. The Mrj co-chaperone mediates keratin turnover and prevents the formation of toxic inclusion bodies in trophoblast cells of the placenta. Development 2007; 134:1809-17. [PMID: 17409114 DOI: 10.1242/dev.02843] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Defects in protein-folding and -degradation machinery have been identified as a major cause of intracellular protein aggregation and of aggregation-associated diseases. In general, it remains unclear how these aggregates are harmful to normal cellular function. We demonstrate here that,in the developing placenta of the mouse, the absence of the Mrj (Dnajb6)co-chaperone prevents proteasome degradation of keratin 18 (K18; Krt18)intermediate filaments, resulting in the formation of keratin inclusion bodies. These inclusions in chorionic trophoblast cells prevent chorioallantoic attachment during placental development. We show further that keratin-deficient embryos undergo chorioallantoic attachment and that, by genetically reducing keratin expression in Mrj-/-conceptuses, chorioallantoic attachment was rescued. Therefore, the chorioallantoic attachment phenotype in Mrj mutants is not due to a deficiency of the normal keratin cytoskeleton, but rather is cytotoxicity caused by keratin aggregates that disrupt chorion trophoblast cell organization and function.
Collapse
Affiliation(s)
- Erica D Watson
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | | | | | | |
Collapse
|
20
|
Cross JC, Nakano H, Natale DRC, Simmons DG, Watson ED. Branching morphogenesis during development of placental villi. Differentiation 2006; 74:393-401. [PMID: 16916377 DOI: 10.1111/j.1432-0436.2006.00103.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The placenta forms a complex interface between the mother and fetus during development that is designed for efficient nutrient exchange. A large surface area is created by extensive branching morphogenesis of the trophoblast-derived epithelium to create a villous network, called the labyrinth in rodents. These villi are subsequently vascularized with an elaborate capillary network. Morphogenesis begins with selection of a subset of trophoblast cells in the basal layer of the chorion that express the Gcm1 transcription factor. These cells leave the cell cycle and undergo cell shape changes that initiate a process of involution to create primary villi into which fetal blood vessels grow. Much less is known about the regulation of subsequent events in branching, certainly compared with other organs. However, over 60 different mouse mutants have defects during later labyrinth development. Some of these mutant genes encode components of signaling pathways such as the fibroblast growth factor and Wnt pathways that play evolutionarily conserved roles in other branched organs, These mutants represent a still largely untapped resource as most of them have not been studied in detail in relation to placental morphogenesis.
Collapse
Affiliation(s)
- James C Cross
- Department of Biochemistry & Molecular Biology, University of Calgary, HSC Room 2279, 3330 Hospital Drive NW, Calgary AB, Canada T2N 4N1.
| | | | | | | | | |
Collapse
|
21
|
Kiyatkin A, Aksamitiene E, Markevich NI, Borisov NM, Hoek JB, Kholodenko BN. Scaffolding protein Grb2-associated binder 1 sustains epidermal growth factor-induced mitogenic and survival signaling by multiple positive feedback loops. J Biol Chem 2006; 281:19925-38. [PMID: 16687399 PMCID: PMC2312093 DOI: 10.1074/jbc.m600482200] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Grb2-associated binder 1 (GAB1) is a scaffold protein involved in numerous interactions that propagate signaling by growth factor and cytokine receptors. Here we explore in silico and validate in vivo the role of GAB1 in the control of mitogenic (Ras/MAPK) and survival (phosphatidylinositol 3-kinase (PI3K)/Akt) signaling stimulated by epidermal growth factor (EGF). We built a comprehensive mechanistic model that allows for reliable predictions of temporal patterns of cellular responses to EGF under diverse perturbations, including different EGF doses, GAB1 suppression, expression of mutant proteins, and pharmacological inhibitors. We show that the temporal dynamics of GAB1 tyrosine phosphorylation is significantly controlled by positive GAB1-PI3K feedback and negative MAPK-GAB1 feedback. Our experimental and computational results demonstrate that the essential function of GAB1 is to enhance PI3K/Akt activation and extend the duration of Ras/MAPK signaling. By amplifying positive interactions between survival and mitogenic pathways, GAB1 plays the critical role in cell proliferation and tumorigenesis.
Collapse
Affiliation(s)
- Anatoly Kiyatkin
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | | | | | | | | | | |
Collapse
|
22
|
Teal HE, Ni S, Xu J, Finkelstein LD, Cheng AM, Paulson RF, Feng GS, Correll PH. GRB2-mediated recruitment of GAB2, but not GAB1, to SF-STK supports the expansion of Friend virus-infected erythroid progenitor cells. Oncogene 2005; 25:2433-43. [PMID: 16314834 DOI: 10.1038/sj.onc.1209288] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Friend virus induces the development of erythroleukemia in mice through the interaction of a viral glycoprotein, gp55, with a truncated form of the Stk receptor tyrosine kinase, short form-Stk (Sf-Stk), and the EpoR. We have shown previously that the ability of Sf-Stk to participate in the transformation of Friend virus-infected cells requires the kinase activity and Grb2-binding site of Sf-Stk. Here we show that Grb2 heterozygous mice exhibit decreased susceptibility to Friend erythroleukemia and that expansion of erythroid progenitors in response to infection requires the C-terminal SH3 domain of Grb2. A fusion protein in which the Grb2-binding site in Sf-Stk is replaced by Gab2, supports the growth of progenitors from mice lacking Sf-Stk, whereas a Sf-Stk/Gab1 fusion protein does not. Gab2 is expressed in spleens from Friend virus-infected mice, co-immunoprecipitates with Sf-Stk and is tyrosine phosphorylated in the presence of Sf-Stk. Mice with a targeted deletion in Gab2 are less susceptible to Friend erythroleukemia and the expansion of erythroid progenitor cells in response to infection can be rescued by expression of Gab2, but not Gab1. Taken together, these data indicate that a Sf-Stk/Grb2/Gab2 complex mediates the growth of primary erythroid progenitor cells in response to Friend virus.
Collapse
Affiliation(s)
- H E Teal
- Department of Veterinary and Biomedical Science, Center for Molecular Immunology and Infectious Disease, The Pennsylvania State University, University Park, PA 16802-3500, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Watson ED, Cross JC. Development of structures and transport functions in the mouse placenta. Physiology (Bethesda) 2005; 20:180-93. [PMID: 15888575 DOI: 10.1152/physiol.00001.2005] [Citation(s) in RCA: 387] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The placenta is essential for sustaining the growth of the fetus during gestation, and defects in its function result in fetal growth restriction or, if more severe, fetal death. Several molecular pathways have been identified that are essential for development of the placenta, and mouse mutants offer new insights into the cell biology of placental development and physiology of nutrient transport.
Collapse
Affiliation(s)
- Erica D Watson
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | | |
Collapse
|
24
|
Abraham N, Ma MC, Snow JW, Miners MJ, Herndier BG, Goldsmith MA. Haploinsufficiency identifies STAT5 as a modifier of IL-7-induced lymphomas. Oncogene 2005; 24:5252-7. [PMID: 15870688 DOI: 10.1038/sj.onc.1208726] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The requirement for receptor components and the signalling effector, signal transducer and activator of transcription (STAT) 5A/5B, was assessed genetically in a lymphoma development model induced by interleukin-7 (IL-7). This growth factor for T- and B-cell progenitors and mature lymphocytes activates survival and proliferative pathways including Bcl-2, phosphatidylinositol-3 kinase and STAT5. Overexpression of IL-7 in vivo causes early mortality from lymphoma development. Mice overexpressing IL-7 that were heterozygous for the IL-7Ralpha subunit showed improved survival compared to wild-type mice. In addition, STAT5A/5B+/- compound heterozygous mice with one targeted allele each of STAT5A and STAT5B showed striking amelioration of IL-7-induced mortality and disease development. STAT5A/5B+/- compound heterozygous mice were otherwise normal in stem cell and lymphocyte development and cellularity. Lower STAT5 protein levels accompanied the reduction in STAT5A/5B copy number, which suggests that STAT5 haploinsufficiency is a modifier of IL-7 signal strength.
Collapse
Affiliation(s)
- Ninan Abraham
- Department of Microbiology and Immunology, The University of British Columbia, #300-6174, University Boulevard, BC, Canada.
| | | | | | | | | | | |
Collapse
|
25
|
Xie Y, Wang Y, Sun T, Wang F, Trostinskaia A, Puscheck E, Rappolee DA. Six post-implantation lethal knockouts of genes for lipophilic MAPK pathway proteins are expressed in preimplantation mouse embryos and trophoblast stem cells. Mol Reprod Dev 2005; 71:1-11. [PMID: 15736129 DOI: 10.1002/mrd.20116] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mitogen-activated protein kinase (MAPK) signaling pathways play an important role in controlling embryonic proliferation and differentiation. It has been demonstrated that sequential lipophilic signal transduction mediators that participate in the MAPK pathway are null post-implantation lethal. It is not clear why the lethality of these null mutants arises after implantation and not before. One hypothesis is that the gene product of these post-implantation lethal null mutants are not present before implantation in normal embryos and do not have function until after implantation. To test this hypothesis, we selected a set of lipophilic genes mediating MAPK signal transduction pathways whose null mutants result in early peri-implantation or placental lethality. These included FRS2alpha, GAB1, GRB2, SOS1, Raf-B, and Raf1. Products of these selected genes were detected and their locations and functions indicated by indirect immunocytochemistry and Western blotting for proteins and RT-polymerase chain reaction (PCR) for mRNA transcription. We report here that all six signal mediators are detected at the protein level in preimplantation mouse embryo, placental trophoblasts, and in cultured trophoblast stem cells (TSC). Proteins are all detected in E3.5 embryos at a time when the first known mitogenic intercellular communication has been documented. mRNA transcripts of two post-implantation null mutant genes are expressed in mouse preimplantation embryos and unfertilized eggs. These mRNA transcripts were detected as maternal mRNA in unfertilized eggs that could delay the lethality of null mutants. All of the proteins were detected in the cytoplasm or in the cell membrane. This study of spatial and temporal expression revealed that all of these six null mutants post-implantation genes in MAPK pathway are expressed and, where tested, phosphorylated/activated proteins are detected in the blastocyst. Studies on RNA expression using RT-PCR suggest that maternal RNA could play an important role in delaying the presence of the lethal phenotype of null mutations.
Collapse
Affiliation(s)
- Yufen Xie
- CS Mott Center for Human Growth and Development of Ob/Gyn, Wayne State University School of Medicine, East Hancock, Detroit, Michigan 48201, USA
| | | | | | | | | | | | | |
Collapse
|
26
|
Mattoon DR, Lamothe B, Lax I, Schlessinger J. The docking protein Gab1 is the primary mediator of EGF-stimulated activation of the PI-3K/Akt cell survival pathway. BMC Biol 2004; 2:24. [PMID: 15550174 PMCID: PMC534114 DOI: 10.1186/1741-7007-2-24] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Accepted: 11/18/2004] [Indexed: 12/02/2022] Open
Abstract
Background Gab1 is a docking protein that recruits phosphatidylinositol-3 kinase (PI-3 kinase) and other effector proteins in response to the activation of many receptor tyrosine kinases (RTKs). As the autophosphorylation sites on EGF-receptor (EGFR) do not include canonical PI-3 kinase binding sites, it is thought that EGF stimulation of PI-3 kinase and its downstream effector Akt is mediated by an indirect mechanism. Results We used fibroblasts isolated from Gab1-/- mouse embryos to explore the mechanism of EGF stimulation of the PI-3 kinase/Akt anti-apoptotic cell signaling pathway. We demonstrate that Gab1 is essential for EGF stimulation of PI-3 kinase and Akt in these cells and that these responses are mediated by complex formation between p85, the regulatory subunit of PI-3 kinase, and three canonical tyrosine phosphorylation sites on Gab1. Furthermore, complex formation between Gab1 and the protein tyrosine phosphatase Shp2 negatively regulates Gab1 mediated PI-3 kinase and Akt activation following EGF-receptor stimulation. We also demonstrate that tyrosine phosphorylation of ErbB3 may lead to recruitment and activation of PI-3 kinase and Akt in Gab1-/- MEFs. Conclusions The primary mechanism of EGF-induced stimulation of the PI-3 kinase/Akt anti-apoptotic pathway occurs via the docking protein Gab1. However, in cells expressing ErbB3, EGF and neuroregulin can stimulate PI-3 kinase and Akt activation in a Gab1-dependent or Gab1-independent manner.
Collapse
Affiliation(s)
- Dawn R Mattoon
- Department of Pharmacology, Yale University School of Medicine, PO Box 208066, New Haven, CT 06520-8066, USA
- Current address: Protometrix, Inc./Invitrogen, 688 East Main Street, Branford, CT 06405, USA
| | - Betty Lamothe
- Department of Pharmacology, Yale University School of Medicine, PO Box 208066, New Haven, CT 06520-8066, USA
- Current address: Department of Bioimmunotherapy, M.D. Anderson Cancer Center, 1515 Holcombe Blvd. Box 0143. Houston, TX 77030, USA
| | - Irit Lax
- Department of Pharmacology, Yale University School of Medicine, PO Box 208066, New Haven, CT 06520-8066, USA
| | - Joseph Schlessinger
- Department of Pharmacology, Yale University School of Medicine, PO Box 208066, New Haven, CT 06520-8066, USA
| |
Collapse
|
27
|
Cully M, Elia A, Ong SH, Stambolic V, Pawson T, Tsao MS, Mak TW. grb2 heterozygosity rescues embryonic lethality but not tumorigenesis in pten+/- mice. Proc Natl Acad Sci U S A 2004; 101:15358-63. [PMID: 15492213 PMCID: PMC524460 DOI: 10.1073/pnas.0406613101] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PTEN is a tumor suppressor gene implicated in both sporadic cancers and inherited tumor-prone syndromes. Here we show that pten+/- mice display a partially penetrant embryonic lethality. This lethality is associated with defects in both neural and placental development. Notably, this lethality is completely rescued by grb2 haploinsufficiency. In contrast, grb2 heterozygosity did not alter tumorigenesis in either pten+/- or T cell-specific pten-/- mice. grb2-/hypomorph murine embryonic fibroblasts (MEFs) show decreased activation of both PKB and Erk upon stimulation with epidermal growth factor, whereas grb2-/hypomorph; pten+/- MEFs activate PKB but not Erk normally. Similarly, grb2-/hypomorph fibroblasts die in low serum, and this phenotype is rescued by pten haploinsufficiency. Activation of both PKB and Erk as well as survival in low serum-containing media are all rescued by reexpression of Grb2 containing mutations within the N-terminal Src homology 3 (SH3) domain, but not by C-terminal SH3 domain mutants. The N-terminal SH3 domain mutants fail to bind to Sos, whereas the C-terminal SH3 domain mutants fail to bind to Gab1, suggesting that Erk and PKB activation in fibroblasts in response to epidermal growth factor depends on Gab1 or other C-terminal SH3 domain-interacting proteins, but not on Sos. Thus, PTEN/phosphatidylinositol 3' kinase signaling requires Grb2 during both embryonic development and fibroblast survival, but Grb2 heterozygosity does not effect tumorigenesis in pten-deficient mice. In fibroblasts, survival signals emanating from the epidermal growth factor receptor appear to be PKB-dependent, and this activation depends on the C-terminal SH3 domain of Grb2, likely through the interaction of Grb2 with Gab1.
Collapse
Affiliation(s)
- Megan Cully
- Department of Medical Biophysics, University of Toronto, Ontario Cancer Institute, Princess Margaret Hospital, 610 University Avenue, Room 7-411, Toronto, ON, Canada M5G 2M9
| | | | | | | | | | | | | |
Collapse
|
28
|
Hemberger M, Zechner U. Genetic and genomic approaches to study placental development. Cytogenet Genome Res 2004; 105:257-69. [PMID: 15237215 DOI: 10.1159/000078197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2003] [Accepted: 12/23/2003] [Indexed: 11/19/2022] Open
Abstract
Recent technological advances in genetic manipulation and expression profiling offer excellent opportunities to elucidate the molecular mechanisms controlling developmental processes during embryogenesis. Thus, this revolution also strongly benefits studies of the molecular genetics of placental development. Here we review the findings of several expression profiling analyses in extraembryonic tissues and assess how this work can contribute to the identification of essential components governing placental development. We further discuss the relevance of these components in the context of genetic manipulation experiments. In conclusion, the intelligent combination of genetic and genomic approaches will substantially accelerate the progress in identifying the key molecular pathways of placental development.
Collapse
Affiliation(s)
- M Hemberger
- Genes and Development Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | | |
Collapse
|
29
|
Myers AP, Corson LB, Rossant J, Baker JC. Characterization of mouse Rsk4 as an inhibitor of fibroblast growth factor-RAS-extracellular signal-regulated kinase signaling. Mol Cell Biol 2004; 24:4255-66. [PMID: 15121846 PMCID: PMC400469 DOI: 10.1128/mcb.24.10.4255-4266.2004] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Receptor tyrosine kinase (RTK) signals regulate the specification of a varied array of tissue types by utilizing distinct modules of proteins to elicit diverse effects. The RSK proteins are part of the RTK signal transduction pathway and are thought to relay these signals by acting downstream of extracellular signal-regulated kinase (ERK). In this study we report the identification of ribosomal S6 kinase 4 (Rsk4) as an inhibitor of RTK signals. Among the RSK proteins, RTK inhibition is specific to RSK4 and, in accordance, is dependent upon a region of the RSK4 protein that is divergent from other RSK family members. We demonstrate that Rsk4 inhibits the transcriptional activation of specific targets of RTK signaling as well as the activation of ERK. Developmentally, Rsk4 is expressed in extraembryonic tissue, where RTK signals are known to have critical roles. Further examination of Rsk4 expression in the extraembryonic tissues demonstrates that its expression is inversely correlated with the presence of activated ERK 1/2. These studies demonstrate a new and divergent function for RSK4 and support a role for RSK proteins in the specification of RTK signals during early mouse development.
Collapse
Affiliation(s)
- Andrea Pomrehn Myers
- Department of Genetics, Stanford Medical School, Stanford, California 94305, USA
| | | | | | | |
Collapse
|
30
|
Hatano N, Mori Y, Oh-hora M, Kosugi A, Fujikawa T, Nakai N, Niwa H, Miyazaki JI, Hamaoka T, Ogata M. Essential role for ERK2 mitogen-activated protein kinase in placental development. Genes Cells 2003; 8:847-56. [PMID: 14622137 DOI: 10.1046/j.1365-2443.2003.00680.x] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Extracellular signal-regulated kinase 2 (ERK2) has been implicated in cell proliferation, differentiation, and survival. However, its role in vivo remains to be determined. RESULTS Here we show that the targeted disruption of the mouse ERK2 gene results in embryonic lethality by E11.5 and severe abnormality of the placenta. In these animals, the labyrinthine layer of the placenta is very thin and few foetal blood vessels are observed. ERK2 mutants can be rescued by the transgenic expression of ERK2, demonstrating that these abnormalities are caused by ERK2-deficiency. Although ERK2-deficient fetuses are much smaller than wild-type littermates, this seems to be secondary to malfunction of the placenta. When the placental defect is rescued by tetraploid-aggregation, ERK2-deficient foetuses grow as well as littermate controls. CONCLUSION These observations indicate that ERK2 is essential for placental development and suggest that ERK2 in the trophoblast compartment may be indispensable for the vascularization of the labyrinth.
Collapse
Affiliation(s)
- Naoya Hatano
- Department of Pathology and Pathophysiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Lock LS, Frigault MM, Saucier C, Park M. Grb2-independent recruitment of Gab1 requires the C-terminal lobe and structural integrity of the Met receptor kinase domain. J Biol Chem 2003; 278:30083-90. [PMID: 12766170 DOI: 10.1074/jbc.m302675200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Gab1 docking protein forms a platform for the assembly of a multiprotein signaling complex downstream from receptor tyrosine kinases. In general, recruitment of Gab1 occurs indirectly, via the adapter protein Grb2. In addition, Gab1 interacts with the Met/hepatocyte growth factor receptor in a Grb2-independent manner. This interaction requires a Met binding domain (MBD) in Gab1 and is essential for Met-mediated epithelial morphogenesis. The Gab1 MBD has been proposed to act as a phosphotyrosine binding domain that binds Tyr-1349 in the Met receptor. We show that a 16-amino acid motif within the Gab1 MBD is sufficient for interaction with the Met receptor, suggesting that it is unlikely that the Gab1 MBD forms a structured domain. Alternatively, the structural integrity of the Met receptor, and residues upstream of Tyr-1349 located in the C-terminal lobe of the kinase domain, are required for Grb2-independent interaction with the Gab1 MBD. Moreover, the substitution of Tyr-1349 with an acidic residue allows for the recruitment of the Gab1 MBD and for phosphorylation of Gab1. We propose that Gab1 and the Met receptor interact in a novel manner, such that the activated kinase domain of Met and the negative charge of phosphotyrosine 1349 engage the Gab1 MBD as an extended peptide ligand.
Collapse
Affiliation(s)
- Lisa S Lock
- Department of Biochemistry, Molecular Oncology Group, McGill University Health Centre, Montreal, Quebec H3A 1A1, Canada
| | | | | | | |
Collapse
|
32
|
Thumkeo D, Keel J, Ishizaki T, Hirose M, Nonomura K, Oshima H, Oshima M, Taketo MM, Narumiya S. Targeted disruption of the mouse rho-associated kinase 2 gene results in intrauterine growth retardation and fetal death. Mol Cell Biol 2003; 23:5043-55. [PMID: 12832488 PMCID: PMC162229 DOI: 10.1128/mcb.23.14.5043-5055.2003] [Citation(s) in RCA: 208] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rho-associated kinase (ROCK), including the ROCK-I and ROCK-II isoforms, is a protein kinase involved in signaling from Rho to actin cytoskeleton. However, in vivo functions of each ROCK isoform remain largely unknown. We generated mice deficient in ROCK-II by gene targeting. ROCK-II(-/-) embryos were found at the expected Mendelian frequency until 13.5 days postcoitum, but approximately 90% died thereafter in utero. ROCK-II(-/-) mice of both genders that survived were born runts, subsequently developed without gross abnormality, and were fertile. Whole-mount staining for a knocked-in lacZ reporter gene revealed that ROCK-II was highly expressed in the labyrinth layer of the placenta. Disruption of architecture and extensive thrombus formation were found in the labyrinth layer of ROCK-II(-/-) mice. While no obvious alteration in actin filament structures was found in the labyrinth layer of ROCK-II(-/-) placenta and stress fibers were formed in cultured ROCK-II(-/-) trophoblasts, elevated expression of plasminogen activator inhibitor 1 was found in ROCK-II(-/-) placenta. These results suggest that ROCK-II is essential in inhibiting blood coagulation and maintaining blood flow in the endothelium-free labyrinth layer and that loss of ROCK-II leads to thrombus formation, placental dysfunction, intrauterine growth retardation, and fetal death.
Collapse
Affiliation(s)
- Dean Thumkeo
- Department of Pharmacology, Kyoto University Faculty of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Cross JC, Simmons DG, Watson ED. Chorioallantoic morphogenesis and formation of the placental villous tree. Ann N Y Acad Sci 2003; 995:84-93. [PMID: 12814941 DOI: 10.1111/j.1749-6632.2003.tb03212.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The placenta is a highly specialized organ whose primary function is to promote the exchange of nutrients and oxygen between maternal and fetal blood, essential for survival and growth of the baby. The surface area for nutrient transport is a highly convoluted villous structure that forms by branching morphogenesis. In mice, this process begins after embryonic day 8.5, following attachment of allantoic mesoderm to the chorion, and continues through the end of gestation. Gene targeting studies in mice have identified a large number of genes that are essential for chorioallantoic development to give rise to the layer of the placenta called the labyrinth. Collectively, these studies reveal that a number of signaling pathways regulate four distinct phases of labyrinth development: chorioallantoic attachment (involving VCAM1 and its receptor alpha4 integrin, Bmp5/7, and Wnt7b, as well as the cochaperone Mrj), initiation of branching (involving the Gcm1 transcription factor to select sites of branch initiation), extension of villous branching (involving FGF, EGF, and HGF/Met signaling, through the Grb2/Sos1/Mek1/p38alpha MAPK pathway), followed by vascularization of the villous tree. The restricted expression and/or action of the signaling components indicate that a series of intercellular interactions regulate chorioallantoic development.
Collapse
Affiliation(s)
- James C Cross
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
| | | | | |
Collapse
|
34
|
Zhang YW, Vande Woude GF. HGF/SF-met signaling in the control of branching morphogenesis and invasion. J Cell Biochem 2003; 88:408-17. [PMID: 12520544 DOI: 10.1002/jcb.10358] [Citation(s) in RCA: 257] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hepatocyte growth factor/Scatter factor (HGF/SF) is a multifunctional growth factor which can induce diverse biological events. In vitro, these include scattering, invasion, proliferation and branching morphogenesis. In vivo, HGF/SF is responsible for many processes during embryonic development and a variety of activities in adults, and many of these normal activities have been implicated in its role in tumorgenesis and metastasis. The c-Met receptor tyrosine kinase is the only known receptor for HGF/SF and mediates all HGF/SF induced biological activities. Upon HGF/SF stimulation, the c-Met receptor is tyrosine-phosphorylated which is followed by the recruitment of a group of signaling molecules and/or adaptor proteins to its cytoplasmic domain and its multiple docking sites. This action leads to the activation of several different signaling cascades that form a complete network of intra and extracellular responses. Different combinations of signaling pathways and signaling molecules and/or differences in magnitude of responses contribute to these diverse series of HGF/SF-Met induced activities and most certainly are influenced by cell type as well as different cellular environments. In this review, we focus on HGF/SF-induced branching morphogenesis and invasion, and bring together recent new findings which provide insight into how HGF/SF, via c-Met induces this response.
Collapse
Affiliation(s)
- Yu-Wen Zhang
- Laboratory of Molecular Oncology, Van Andel Research Institute, 333 Bostwick Ave. NE, Grand Rapids, Michigan 49503, USA
| | | |
Collapse
|
35
|
Katow H, Aizu G. Essential role of growth factor receptor-mediated signal transduction through the mitogen-activated protein kinase pathway in early embryogenesis of the echinoderm. Dev Growth Differ 2002; 44:437-55. [PMID: 12392577 DOI: 10.1046/j.1440-169x.2002.00657.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In this study it was shown that growth factor receptors (GFR) play a crucial role in early embryogenesis of the echinoderms Hemicentrotus pulcherrimus and Clypeaster japonicus by transmitting signals to the mitogen-activated protein kinase (MAPK) pathway. The phosphorylation ratio of extracellular signal-regulated kinase 1 (ERK1) changed dynamically during early embryogenesis and showed a peak at the swimming blastula (sBl) stage. Suramin, an inhibitor of GFR, when applied during the sBl stage perturbed morphogenesis, including primary mesenchyme cell (PMC) migration, cell proliferation, archenteron elongation, spiculogenesis, pigment cell differentiation and phosphorylation of myosin light chains (MLC). Genistein, a receptor-type protein tyrosine kinase inhibitor, severely inhibited PMC migration, gastrulation and the phosphorylation of MLC. Manumycin A, a Ras inhibitor, inhibited spiculogenesis and invagination. PD98059, a MAPK/ERK kinase inhibitor, perturbed early PMC migration and pigment cell differentiation, but not spiculogenesis and gastrulation (although these two events were significantly delayed). PMC ingression was not perturbed by genistein, suramin, manumycin A or PD98059. All of the inhibitors perturbed the phosphorylation of ERK1, which was completely restored by exogenous platelet-derived growth factor (PDGF)-AB. PDGF-AB also partially restored elongation of the archenteron by restoring cell proliferation that had been perturbed by suramin.
Collapse
Affiliation(s)
- Hideki Katow
- Marine Biological Station, Graduate School of Science, University of Tohoku, Asamushi, Aomori, Aomori 039-3501, Japan.
| | | |
Collapse
|
36
|
Abstract
Ligand-mediated activation of receptor tyrosine kinases (RTKs) results in autophosphorylation of both the receptor catalytic domain and noncatalytic regions of the cytoplasmic domain. Catalytic domain phosphorylation leads to activation and potentiation of receptor kinase activity. Noncatalytic domain phosphorylation creates docking sites for downstream cytoplasmic targets, which bind to specific receptor phosphotyrosine residues. Downstream signaling pathways are constructed in a modular fashion. In addition to SH2 and PTB (phosphotyrosine binding) domains, downstream signal proteins also contain domains that recognize other protein and phospholipid motifs. The arrangement and re-arrangement of various combinations of modular domains in different signaling proteins (combinatorial use) has allowed for the creation of complex signaling networks and pathways. In addition to performing catalytic functions, signaling proteins serve as scaffolds for the assembly of multiprotein signaling complexes, as adaptors, as transcription factors and as signal pathway regulators. Recent results show that the juxtamembrane region of Eph receptors is important in receptor autoregulation. Mutations in the juxtamembrane region of several RTKs have been shown to play a role in oncogenesis. It is likely that dysregulation of other modular components of signaling pathways also plays a role in oncogenic transformation.
Collapse
Affiliation(s)
- Tony Pawson
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ont. M5G 1X5, Canada.
| |
Collapse
|
37
|
Philipp M, Brede ME, Hadamek K, Gessler M, Lohse MJ, Hein L. Placental alpha(2)-adrenoceptors control vascular development at the interface between mother and embryo. Nat Genet 2002; 31:311-5. [PMID: 12068299 DOI: 10.1038/ng919] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A substantial percentage of human pregnancies are lost as spontaneous abortions after implantation. This is often caused by an inadequately developed placenta. Proper development of the placental vascular system is essential to nutrient and gas exchange between mother and developing embryo. Here we show that alpha(2)-adrenoceptors, which are activated by adrenaline and noradrenaline, are important regulators of placental structure and function. Mice with deletions in the genes encoding alpha(2A)-, alpha(2B)- and alpha(2C)-adrenoceptors died between embryonic days 9.5 and 11.5 from a severe defect in yolk-sac and placenta development. In wildtype placentae, alpha(2)-adrenoceptors are abundantly expressed in giant cells, which secrete angiogenic factors to initiate development of the placental vascular labyrinth. In placentae deficient in alpha(2A)-, alpha(2B)- and alpha(2C)-adrenoceptors, the density of fetal blood vessels in the labyrinth was markedly lower than normal, leading to death of the embryos as a result of reduced oxygen and nutrient supply. Basal phosphorylation of the extracellular signal regulated kinases ERK1 and ERK2 was also lower than normal, suggesting that activation of the mitogen-activated protein kinase (MAP kinase) pathway by alpha(2)-adrenoceptors is required for placenta and yolk-sac vascular development. Thus, alpha(2)-adrenoceptors are essential at the placental interface between mother and embryo to establish the circulatory system of the placenta and thus maintain pregnancy.
Collapse
Affiliation(s)
- Melanie Philipp
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, Versbacher Strasse 9, 97078 Würzburg, Germany
| | | | | | | | | | | |
Collapse
|
38
|
Abstract
Gab proteins, including mammalian Gab1, Gab2, Gab3, Drosophila DOS and Caenorhabditis elegans Soc1, comprise a growing family of scaffolding/docking molecules involved in multiple signaling pathways mediated by receptor tyrosine kinases (RTKs) and non-RTK receptors. This paper reviews the structure/function relationships of Gab proteins and their biological roles during normal growth, differentiation and development programs.
Collapse
Affiliation(s)
- Yan Liu
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
| | | |
Collapse
|
39
|
Abstract
Many of the signaling pathways and regulatory systems in eukaryotic cells are controlled by proteins with multiple interaction domains that mediate specific protein-protein and protein-phospholipid interactions, and thereby determine the biological output of receptors for external and intrinsic signals. Here, we discuss the basic features of interaction domains, and suggest that rather simple binary interactions can be used in sophisticated ways to generate complex cellular responses.
Collapse
Affiliation(s)
- Tony Pawson
- Samuel Lumenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada M5G 1 X5.
| | | | | |
Collapse
|
40
|
Li S, Couvillon AD, Brasher BB, Van Etten RA. Tyrosine phosphorylation of Grb2 by Bcr/Abl and epidermal growth factor receptor: a novel regulatory mechanism for tyrosine kinase signaling. EMBO J 2001; 20:6793-804. [PMID: 11726515 PMCID: PMC125747 DOI: 10.1093/emboj/20.23.6793] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Growth factor receptor-binding protein-2 (Grb2) plays a key role in signal transduction initiated by Bcr/Abl oncoproteins and growth factors, functioning as an adaptor protein through its Src homology 2 and 3 (SH2 and SH3) domains. We found that Grb2 was tyrosine-phosphorylated in cells expressing BCR/ABL and in A431 cells stimulated with epidermal growth factor (EGF). Phosphorylation of Grb2 by Bcr/Abl or EGF receptor reduced its SH3-dependent binding to Sos in vivo, but not its SH2-dependent binding to Bcr/Abl. Tyr209 within the C-terminal SH3 domain of Grb2 was identified as one of the tyrosine phosphorylation sites, and phosphorylation of Tyr209 abolished the binding of the SH3 domain to a proline-rich Sos peptide in vitro. In vivo expression of a Grb2 mutant where Tyr209 was changed to phenylalanine enhanced BCR/ABL-induced ERK activation and fibroblast transformation, and potentiated and prolonged Grb2-mediated activation of Ras, mitogen-activated protein kinase and c-Jun N-terminal kinase in response to EGF stimulation. These results suggest that tyrosine phosphorylation of Grb2 is a novel mechanism of down-regulation of tyrosine kinase signaling.
Collapse
Affiliation(s)
- Shaoguang Li
- Center for Blood Research, Department of Genetics, Harvard Medical School, Boston, MA 02115 and
Division of Signal Transduction, Beth Israel-Deaconess Medical Center, Boston, MA, USA Present address: The Jackson Laboratory, Bar Harbor, ME, USA Present address: Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA Present address: Enanta Pharmaceuticals, Watertown, MA, USA Corresponding authors e-mail:
| | - Anthony D. Couvillon
- Center for Blood Research, Department of Genetics, Harvard Medical School, Boston, MA 02115 and
Division of Signal Transduction, Beth Israel-Deaconess Medical Center, Boston, MA, USA Present address: The Jackson Laboratory, Bar Harbor, ME, USA Present address: Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA Present address: Enanta Pharmaceuticals, Watertown, MA, USA Corresponding authors e-mail:
| | - Bradley B. Brasher
- Center for Blood Research, Department of Genetics, Harvard Medical School, Boston, MA 02115 and
Division of Signal Transduction, Beth Israel-Deaconess Medical Center, Boston, MA, USA Present address: The Jackson Laboratory, Bar Harbor, ME, USA Present address: Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA Present address: Enanta Pharmaceuticals, Watertown, MA, USA Corresponding authors e-mail:
| | - Richard A. Van Etten
- Center for Blood Research, Department of Genetics, Harvard Medical School, Boston, MA 02115 and
Division of Signal Transduction, Beth Israel-Deaconess Medical Center, Boston, MA, USA Present address: The Jackson Laboratory, Bar Harbor, ME, USA Present address: Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA Present address: Enanta Pharmaceuticals, Watertown, MA, USA Corresponding authors e-mail:
| |
Collapse
|
41
|
Abstract
The placenta is the first organ to form during mammalian embryogenesis. Problems in its formation and function underlie many aspects of early pregnancy loss and pregnancy complications in humans. Because the placenta is critical for survival, it is very sensitive to genetic disruption, as reflected by the ever-increasing list of targeted mouse mutations that cause placental defects. Recent studies of mouse mutants with disrupted placental development indicate that signalling interactions between the placental trophoblast and embryonic cells have a key role in placental morphogenesis. Furthering our understanding of mouse trophoblast development should provide novel insights into human placental function.
Collapse
Affiliation(s)
- J Rossant
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G 1X5.
| | | |
Collapse
|