scholarly journals Cytoplasmic interactions of syndecan-4 orchestrate adhesion receptor and growth factor receptor signalling

2002 ◽  
Vol 368 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Mark D. BASS ◽  
Martin J. HUMPHRIES
Keyword(s):  
Growth Factors ◽  
Pdz Domain ◽  
Adhesion Formation ◽  
Growth Factor Receptor ◽  
Focal Adhesions ◽  
Cytoplasmic Domain ◽  
C Terminus ◽  
Protein Kinase Cα ◽  
And Migration

Syndecan-4 is a ubiquitous transmembrane proteoglycan that localizes to the focal adhesions of adherent cells and binds to a range of extracellular ligands, including growth factors and extracellular-matrix proteins. Engagement of syndecan-4 is essential for adhesion formation in cells adhering via certain integrins, and for cell proliferation and migration in response to growth factors. The cytoplasmic domain of syndecan-4 interacts with a number of signalling and structural proteins, and both extracellular and cytoplasmic domains are necessary for regulated activation of associated transmembrane receptors. PDZ domain-containing scaffold proteins (syntenin and CASK) bind to the C-terminus of the syndecan-4 cytoplasmic domain and co-ordinate clustering of receptors and connection to the actin cytoskeleton. Syndecan-4 also binds and activates protein kinase Cα in the presence of phosphatidylinositol 4,5-bisphosphate, and regulates signalling by Rho-family GTPases and focal adhesion kinase. This review discusses the cytoplasmic interactions of syndecan-4 and how they affect cell behaviour as a consequence of the interaction with extracellular ligands. These conclusions also offer an insight into the role of syndecan-4 in vivo, and are consistent with phenotypes generated as a consequence of abnormal syndecan-4 expression in pathologies and gene disruption studies.

scholarly journals Mapping in vivo associations of cytoplasmic proteins with integrin beta 1 cytoplasmic domain mutants.

1995 ◽  
Vol 6 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J M Lewis ◽  
M A Schwartz
Keyword(s):  
Intracellular Signaling ◽  
Focal Adhesions ◽  
Cytoplasmic Domain ◽  
Cytoskeletal Proteins ◽  
In Vitro Assays ◽  
Integrin Subunit ◽  
Cytoplasmic Proteins ◽  
C Terminus ◽  
Beta 1 Integrin

Integrins promote formation of focal adhesions and trigger intracellular signaling pathways through cytoplasmic proteins such as talin, alpha-actinin, and focal adhesion kinase (FAK). The beta 1 integrin subunit has been shown to bind talin and alpha-actinin in in vitro assays, and these proteins may link integrin to the actin cytoskeleton either directly or through linkages to other proteins such as vinculin. However, it is unknown which of these associations are necessary in vivo for formation of focal contacts, or which regions of beta 1 integrin bind to specific cytoskeletal proteins in vivo. We have developed an in vivo assay to address these questions. Microbeads were coated with anti-chicken beta 1 antibodies to selectively cluster chicken beta 1 integrins expressed in cultured mouse fibroblasts. The ability of cytoplasmic domain mutant beta 1 integrins to induce co-localization of proteins was assessed by immunofluorescence and compared with that of wild-type integrin. As expected, mutant beta 1 lacking the entire cytoplasmic domain had a reduced ability to induce co-localization of talin, alpha-actinin, F-actin, vinculin, and FAK. The ability of beta 1 integrin to co-localize talin and FAK was found to require a sequence near the C-terminus of beta 1. The region of beta 1 required to co-localize alpha-actinin was found to reside in a different sequence, several amino acids further from the C-terminus of beta 1. Deletion of 13 residues from the C-terminus blocked co-localization of talin, FAK, and actin, but not alpha-actinin. Association of alpha-actinin with clustered integrin is therefore not sufficient to induce the co-localization of F-actin.

Control of morphology, cytoskeleton and migration by syndecan-4

1999 ◽  
Vol 112 (20) ◽  
pp. 3421-3431 ◽  
Author(s):  
R.L. Longley ◽  
A. Woods ◽  
A. Fleetwood ◽  
G.J. Cowling ◽  
J.T. Gallagher ◽  
...  
Keyword(s):  
Focal Adhesion ◽  
Core Protein ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Cytoplasmic Domain ◽  
Fiber Formation ◽  
Microfilament Bundle ◽  
Focal Adhesion Formation ◽  
And Migration

Syndecan-4 is a widely expressed transmembrane heparan sulfate proteoglycan which localizes to focal adhesions. Previous studies showed that the syndecan-4 cytoplasmic domain can associate with and potentiate the activity of protein kinase C, which is required for focal adhesion formation. To examine further the role of syndecan-4 in cell adhesion, we expressed syndecan-4 cDNA constructs in CHO-K1 cells. Syndecan-2 transfection was used to confirm effects seen were specific for syndecan-4. Cells overexpressing full length syndecan-4 core protein exhibited a more flattened, fibroblastic morphology, with increased focal adhesion formation and decreased cell motility. Expression of a syndecan-4 core protein with either a partial or complete deletion of the cytoplasmic domain or of an antisense construct led to markedly decreased spreading and focal adhesion formation, a more epithelioid morphology, and decreased motility. Overexpression of syndecan-2 changed the adhesive phenotype, but did not markedly alter focal adhesion and microfilament bundle formation. The data suggest that syndecan-4 is a regulator of focal adhesion and stress fiber formation, and influences both morphology and migration.

scholarly journals The roles and prognostic significance of ABI1-TSV-11 expression in patients with left-sided colorectal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Zhang ◽  
Zhaohui Zhong ◽  
Mei Li ◽  
Jingyi Chen ◽  
Tingru Lin ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Prognostic Significance ◽  
Growth Factor Receptor ◽  
The Cancer Genome Atlas ◽  
Actin Dynamics ◽  
Elevated Expression ◽  
Sw480 Cells ◽  
And Migration

AbstractAbnormally expressed and/or phosphorylated Abelson interactor 1 (ABI1) participates in the metastasis and progression of colorectal cancer (CRC). ABI1 presents as at least 12 transcript variants (TSVs) by mRNA alternative splicing, but it is unknown which of them is involved in CRC metastasis and prognosis. Here, we firstly identified ABI1-TSV-11 as a key TSV affecting the metastasis and prognosis of left-sided colorectal cancer (LsCC) and its elevated expression is related to lymph node metastasis and shorter overall survival (OS) in LsCC by analyzing data from The Cancer Genome Atlas and TSVdb. Secondly, ABI1-TSV-11 overexpression promoted LoVo and SW480 cells adhesion and migration in vitro, and accelerated LoVo and SW480 cells lung metastasis in vivo. Finally, mechanism investigations revealed that ABI1-isoform-11 interacted with epidermal growth factor receptor pathway substrate 8 (ESP8) and regulated actin dynamics to affect LoVo and SW480 cells biological behaviors. Taken together, our data demonstrated that ABI1-TSV-11 plays an oncogenic role in LsCC, it is an independent risk factor of prognosis and may be a potential molecular marker and therapeutic target in LsCC.

scholarly journals Syndecan Transmembrane Domain Specifically Regulates Downstream Signaling Events of the Transmembrane Receptor Cytoplasmic Domain

2021 ◽  
Vol 22 (15) ◽  
pp. 7918
Author(s):  
Jisun Hwang ◽  
Bohee Jang ◽  
Ayoung Kim ◽  
Yejin Lee ◽  
Joonha Lee ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
Growth Factor Receptor ◽  
Cytoplasmic Domain ◽  
Nih3t3 Cells ◽  
C Elegans ◽  
Downstream Signaling ◽  
Downstream Effectors ◽  
Signaling Events

Despite the known importance of the transmembrane domain (TMD) of syndecan receptors in cell adhesion and signaling, the molecular basis for syndecan TMD function remains unknown. Using in vivo invertebrate models, we found that mammalian syndecan-2 rescued both the guidance defects in C. elegans hermaphrodite-specific neurons and the impaired development of the midline axons of Drosophila caused by the loss of endogenous syndecan. These compensatory effects, however, were reduced significantly when syndecan-2 dimerization-defective TMD mutants were introduced. To further investigate the role of the TMD, we generated a chimera, 2eTPC, comprising the TMD of syndecan-2 linked to the cytoplasmic domain of platelet-derived growth factor receptor (PDGFR). This chimera exhibited SDS-resistant dimer formation that was lost in the corresponding dimerization-defective syndecan-2 TMD mutant, 2eT(GL)PC. Moreover, 2eTPC specifically enhanced Tyr 579 and Tyr 857 phosphorylation in the PDGFR cytoplasmic domain, while the TMD mutant failed to support such phosphorylation. Finally, 2eTPC, but not 2eT(GL)PC, induced phosphorylation of Src and PI3 kinase (known downstream effectors of Tyr 579 phosphorylation) and promoted Src-mediated migration of NIH3T3 cells. Taken together, these data suggest that the TMD of a syndecan-2 specifically regulates receptor cytoplasmic domain function and subsequent downstream signaling events controlling cell behavior.

scholarly journals Influence of Molecular Design on the Targeting Properties of ABD-Fused Mono- and Bi-Valent Anti-HER3 Affibody Therapeutic Constructs

Cells ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 164 ◽  
Author(s):  
Mohamed Altai ◽  
Charles Leitao ◽  
Sara Rinne ◽  
Anzhelika Vorobyeva ◽  
Christina Atterby ◽  
...  
Keyword(s):  
Half Life ◽  
Molecular Design ◽  
Growth Factor Receptor ◽  
Fusion Construct ◽  
Affibody Molecules ◽  
Binding Domains ◽  
Biodistribution Studies ◽  
C Terminus ◽  
Type 3

Overexpression of human epidermal growth factor receptor type 3 (HER3) is associated with tumour cell resistance to HER-targeted therapies. Monoclonal antibodies (mAbs) targeting HER3 are currently being investigated for treatment of various types of cancers. Cumulative evidence suggests that affibody molecules may be appropriate alternatives to mAbs. We previously reported a fusion construct (3A3) containing two HER3-targeting affibody molecules flanking an engineered albumin-binding domain (ABD035) included for the extension of half-life in circulation. The 3A3 fusion protein (19.7 kDa) was shown to delay tumour growth in mice bearing HER3-expressing xenografts and was equipotent to the mAb seribantumab. Here, we have designed and explored a series of novel formats of anti-HER3 affibody molecules fused to the ABD in different orientations. All constructs inhibited heregulin-induced phosphorylation in HER3-expressing BxPC-3 and DU-145 cell lines. Biodistribution studies demonstrated extended the half-life of all ABD-fused constructs, although at different levels. The capacity of our ABD-fused proteins to accumulate in HER3-expressing tumours was demonstrated in nude mice bearing BxPC-3 xenografts. Formats where the ABD was located on the C-terminus of affibody binding domains (3A, 33A, and 3A3) provided the best tumour targeting properties in vivo. Further development of these promising candidates for treatment of HER3-overexpressing tumours is therefore justified.

Binding of the Src SH2 domain to phosphopeptides is determined by residues in both the SH2 domain and the phosphopeptides

1993 ◽  
Vol 13 (12) ◽  
pp. 7278-7287
Author(s):  
K B Bibbins ◽  
H Boeuf ◽  
H E Varmus
Keyword(s):  
Intramolecular Interaction ◽  
Growth Factor Receptor ◽  
Sh2 Domain ◽  
Binding Properties ◽  
Vitro Assay ◽  
Sh2 Domains ◽  
Free Peptide ◽  
C Terminus

Src homology 2 (SH2) domains are found in a variety of signaling proteins and bind phosphotyrosine-containing peptide sequences. To explore the binding properties of the SH2 domain of the Src protein kinase, we used immobilized phosphopeptides to bind purified glutathione S-transferase-Src SH2 fusion proteins. With this assay, as well as a free-peptide competition assay, we have estimated the affinities of the Src SH2 domain for various phosphopeptides relative to a Src SH2-phosphopeptide interaction whose Kd has been determined previously (YEEI-P; Kd = 4 nM). Two Src-derived phosphopeptides, one containing the regulatory C-terminal Tyr-527 and another containing the autophosphorylation site Tyr-416, bind the Src SH2 domain in a specific though low-affinity manner (with about 10(4)-lower affinity than the YEEI-P peptide). A platelet-derived growth factor receptor (PDGF-R) phosphopeptide containing Tyr-857 does not bind appreciably to the Src SH2 domain, suggesting it is not the PDGF-R binding site for Src as previously reported. However, another PDGF-R-derived phosphopeptide containing Tyr-751 does bind the Src SH2 domain (with an affinity approximately 2 orders of magnitude lower than that of YEEI-P). All of the phosphopeptides which bind to the Src SH2 domain contain a glutamic acid at position -3 or -4 with respect to phosphotyrosine; changing this residue to alanine greatly diminishes binding. We have also tested Src SH2 mutants for their binding properties and have interpreted our results in light of the recent crystal structure solution for the Src SH2 domain. Mutations in various conserved and nonconserved residues (R155A, R155K, N198E, H201R, and H201L) cause slight reductions in binding, while two mutations cause severe reductions. The W148E mutant domain, which alters the invariant tryptophan that marks the N-terminal border of the SH2 domain, binds poorly to phosphopeptides. Inclusion of the SH3 domain in the fusion protein partially restores the binding by the W148E mutant. A change in the invariant arginine that coordinates twice with phosphotyrosine in the peptide (R175L) results in a nearly complete loss of binding. The R175L mutant does display high affinity for the PDGF-R peptide containing Tyr-751, via an interaction that is at least partly phosphotyrosine independent. We have used this interaction to show that the R175L mutation also disrupts the intramolecular interaction between the Src SH2 domain and the phosphorylated C terminus within the context of the entire Src protein; thus, the binding properties observed for mutant domains in an in vitro assay appear to mimic those that occur in vivo.

scholarly journals Multiparametric analysis of focal adhesion formation by RNAi-mediated gene knockdown

2009 ◽  
Vol 186 (3) ◽  
pp. 423-436 ◽  
Author(s):  
Sabina E. Winograd-Katz ◽  
Shalev Itzkovitz ◽  
Zvi Kam ◽  
Benjamin Geiger
Keyword(s):  
Cell Adhesion ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Gene Families ◽  
Adaptor Proteins ◽  
Small Interfering Rnas ◽  
Comprehensive Information ◽  
Focal Adhesion Formation ◽  
Multiple Cell ◽  
And Migration

Cell adhesion to the extracellular matrix is mediated by elaborate networks of multiprotein complexes consisting of adhesion receptors, cytoskeletal components, signaling molecules, and diverse adaptor proteins. To explore how specific molecular pathways function in the assembly of focal adhesions (FAs), we performed a high-throughput, high-resolution, microscopy-based screen. We used small interfering RNAs (siRNAs) to target human kinases, phosphatases, and migration- and adhesion-related genes. Multiparametric image analysis of control and of siRNA-treated cells revealed major correlations between distinct morphological FA features. Clustering analysis identified different gene families whose perturbation induced similar effects, some of which uncoupled the interfeature correlations. Based on these findings, we propose a model for the molecular hierarchy of FA formation, and tested its validity by dynamic analysis of FA formation and turnover. This study provides a comprehensive information resource on the molecular regulation of multiple cell adhesion features, and sheds light on signaling mechanisms regulating the formation of integrin adhesions.

Two functionally distinct pools of Src kinases for PDGF receptor signalling

2005 ◽  
Vol 33 (6) ◽  
pp. 1313-1315 ◽  
Author(s):  
L. Veracini ◽  
M. Franco ◽  
A. Boureux ◽  
V. Simon ◽  
S. Roche ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Tyrosine Kinases ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Pdgf Receptor ◽  
Actin Assembly ◽  
Cell Responses ◽  
Receptor Signalling ◽  
And Migration

The cytoplasmic tyrosine kinases of the Src family (SFK) play important roles in cell responses induced by growth factors, including cell growth, survival and migration. Here, we review how SFK participate in PDGF (platelet-derived growth factor) receptor signalling leading to DNA synthesis and actin assembly. Furthermore, evidence for a spatial compartmentalization of SFK signalling is also discussed.

scholarly journals FGFRL1 Promotes Ovarian Cancer Progression by Crosstalk with Hedgehog Signaling

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Haiyan Tai ◽  
Zhiyong Wu ◽  
Su’an Sun ◽  
Zhigang Zhang ◽  
Congjian Xu
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor Receptor ◽  
Growth Factor Receptor ◽  
Fibroblast Growth ◽  
Hh Signaling ◽  
And Migration

Fibroblast growth factor receptor-like-1 (FGFRL1) has been identified as the fifth fibroblast growth factor receptor. So far, little is known about its biological functions, particularly in cancer development. Here, for the first time, we demonstrated the roles of FGFRL1 in ovarian carcinoma (OC). An array and existing databases were used to investigate the expression profile of FGFRL1 and the relationship between FGFRL1 expression and clinicopathological parameters. FGFRL1 was significantly upregulated in OC patients, and high FGFRL1 expression was correlated with poor prognosis. In vitro cell proliferation, apoptosis and migration assays, and in vivo subcutaneous xenograft tumor models were used to determine the role of FGFRL1. Loss of function of FGFRL1 significantly influenced cell proliferation, apoptosis, and migration of OC cells in vitro and tumor growth in vivo. Chromatin immunoprecipitation PCR analysis and microarray hybridization were performed to uncover the mechanism. FGFRL1 expression could be induced by hypoxia through hypoxia-inducible factor 1α, which directly binds to the promoter elements of FGFRL1. FGFRL1 promoted tumor progression by crosstalk with Hedgehog (Hh) signaling. Taken together, FGFRL1 is a potential predictor and plays an important role in tumor growth and Hh signaling which could serve as potential therapeutic targets for the treatment of OC.

scholarly journals HER2 missense mutations have distinct effects on oncogenic signaling and migration

2015 ◽  
Vol 112 (45) ◽  
pp. E6205-E6214 ◽  
Author(s):  
Daniel J. Zabransky ◽  
Christopher L. Yankaskas ◽  
Rory L. Cochran ◽  
Hong Yuen Wong ◽  
Sarah Croessmann ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Genetic Alterations ◽  
Missense Mutations ◽  
Breast Cancers ◽  
Oncogenic Signaling ◽  
Pathway Activation ◽  
And Migration ◽  
Endogenous Loci

Recurrent human epidermal growth factor receptor 2 (HER2) missense mutations have been reported in human cancers. These mutations occur primarily in the absence of HER2 gene amplification such that most HER2-mutant tumors are classified as “negative” by FISH or immunohistochemistry assays. It remains unclear whether nonamplified HER2 missense mutations are oncogenic and whether they are targets for HER2-directed therapies that are currently approved for the treatment of HER2 gene-amplified breast cancers. Here we functionally characterize HER2 kinase and extracellular domain mutations through gene editing of the endogenous loci in HER2 nonamplified human breast epithelial cells. In in vitro and in vivo assays, the majority of HER2 missense mutations do not impart detectable oncogenic changes. However, the HER2 V777L mutation increased biochemical pathway activation and, in the context of a PIK3CA mutation, enhanced migratory features in vitro. However, the V777L mutation did not alter in vivo tumorigenicity or sensitivity to HER2-directed therapies in proliferation assays. Our results suggest the oncogenicity and potential targeting of HER2 missense mutations should be considered in the context of cooperating genetic alterations and provide previously unidentified insights into functional analysis of HER2 mutations and strategies to target them.

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