scholarly journals A Unique Autophosphorylation Site on Tie2/Tek Mediates Dok-R Phosphotyrosine Binding Domain Binding and Function

2003 ◽  
Vol 23 (8) ◽  
pp. 2658-2668 ◽  
Author(s):  
Nina Jones ◽  
Stephen H. Chen ◽  
Celina Sturk ◽  
Zubin Master ◽  
Jennifer Tran ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Binding Domain ◽  
Signal Transduction Pathways ◽  
Pleckstrin Homology Domain ◽  
Dependent Manner ◽  
Tyrosine Residue ◽  
Phosphotyrosine Binding Domain ◽  
Autophosphorylation Site

ABSTRACT Tie2/Tek is an endothelial cell receptor tyrosine kinase that induces signal transduction pathways involved in cell migration upon angiopoietin-1 (Ang1) stimulation. To address the importance of the various tyrosine residues of Tie2 in signal transduction, we generated a series of Tie2 mutants and examined their signaling properties. Using this approach in conjunction with a phosphorylation state-specific antibody, we identified tyrosine residue 1106 on Tie2 as an Ang1-dependent autophosphorylation site that mediates binding and phosphorylation of the downstream-of-kinase-related (Dok-R) docking protein. This tyrosine residue is contained within a unique interaction motif for the phosphotyrosine binding domain of Dok-R, and the pleckstrin homology domain of Dok-R further contributes to Tie2 binding in a phosphatidylinositol 3′-kinase-dependent manner. Introduction of a Tie2 mutant lacking tyrosine residue 1106 into endothelial cells interferes with Dok-R phosphorylation in response to Ang1. Furthermore, this mutant is unable to restore the migration potential of endothelial cells derived from mice lacking Tie2. Together, these findings demonstrate that tyrosine residue 1106 on Tie2 is critical for coupling downstream cell migration signal transduction pathways with Ang1 stimulation in endothelial cells.

Heterogeneity of the signal transduction pathways for VEGF-induced MAPKs activation in human vascular endothelial cells

2001 ◽  
Vol 188 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Rei Yashima ◽  
Mayumi Abe ◽  
Katsuhiro Tanaka ◽  
Hikaru Ueno ◽  
Kenya Shitara ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Signal Transduction Pathways ◽  
Vascular Endothelial

scholarly journals Interrogation of kinase genetic interactions provides a global view of PAK1-mediated signal transduction pathways

2020 ◽  
Vol 295 (50) ◽  
pp. 16906-16919
Author(s):  
Jae-Hong Kim ◽  
Yeojin Seo ◽  
Myungjin Jo ◽  
Hyejin Jeon ◽  
Young-Seop Kim ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cell Migration ◽  
Intracellular Signaling ◽  
Mammalian Cells ◽  
Drug Targets ◽  
Large Scale ◽  
Genetic Interaction ◽  
Genetic Interactions ◽  
Signal Transduction Pathways ◽  
Global View

Kinases are critical components of intracellular signaling pathways and have been extensively investigated with regard to their roles in cancer. p21-activated kinase-1 (PAK1) is a serine/threonine kinase that has been previously implicated in numerous biological processes, such as cell migration, cell cycle progression, cell motility, invasion, and angiogenesis, in glioma and other cancers. However, the signaling network linked to PAK1 is not fully defined. We previously reported a large-scale yeast genetic interaction screen using toxicity as a readout to identify candidate PAK1 genetic interactions. En masse transformation of the PAK1 gene into 4,653 homozygous diploid Saccharomyces cerevisiae yeast deletion mutants identified ∼400 candidates that suppressed yeast toxicity. Here we selected 19 candidate PAK1 genetic interactions that had human orthologs and were expressed in glioma for further examination in mammalian cells, brain slice cultures, and orthotopic glioma models. RNAi and pharmacological inhibition of potential PAK1 interactors confirmed that DPP4, KIF11, mTOR, PKM2, SGPP1, TTK, and YWHAE regulate PAK1-induced cell migration and revealed the importance of genes related to the mitotic spindle, proteolysis, autophagy, and metabolism in PAK1-mediated glioma cell migration, drug resistance, and proliferation. AKT1 was further identified as a downstream mediator of the PAK1-TTK genetic interaction. Taken together, these data provide a global view of PAK1-mediated signal transduction pathways and point to potential new drug targets for glioma therapy.

Signal Transduction Pathways in Endothelial Cells

2015 ◽  
pp. 99-116
Author(s):  
Una S. Ryan ◽  
Marilyn K. Glassberg ◽  
Anthony Johns
Keyword(s):  
Signal Transduction ◽  
Endothelial Cells ◽  
Signal Transduction Pathways

scholarly journals The Inhibitory Effects of Gold Nanoparticles on VEGF-A-Induced Cell Migration in Choroid-Retina Endothelial Cells

2019 ◽  
Vol 21 (1) ◽  
pp. 109 ◽  
Author(s):  
Chi-Ming Chan ◽  
Chien-Yu Hsiao ◽  
Hsin-Ju Li ◽  
Jia-You Fang ◽  
Der-Chen Chang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Cell Adhesion ◽  
Age Related Macular Degeneration ◽  
Adhesion Assay ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Viability Assay ◽  
Age Related

Background: Vascular endothelial growth factor (VEGF) is upregulated by hypoxia and is a crucial stimulator for choroidal neovascularization (CNV) in age-related macular degeneration and pathologic myopia, as well as retinal neovascularization in proliferative diabetic retinopathy. Retinal and choroidal endothelial cells play key roles in the development of retinal and CNV, and subsequent fibrosis. At present, the effects of gold nanoparticles (AuNPs) on the VEGF-induced choroid-retina endothelial (RF/6A) cells are still unknown. In our study, we investigated the effects of AuNPs on RF/6A cell viabilities and cell adhesion to fibronectin, a major ECM protein of fibrovascular membrane. Furthermore, the inhibitory effects of AuNPs on RF/6A cell migration induced by VEGF and its signaling were studied. Methods: The cell viability assay was used to determine the viability of cells treated with AuNPs. The migration of RF/6A cells was assessed by the Transwell migration assay. The cell adhesion to fibronectin was examined by an adhesion assay. The VEGF-induced signaling pathways were determined by western blotting. Results: The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) viability assay revealed no cytotoxicity of AuNPs on RF/6A cells. AuNPs inhibited VEGF-induced RF/6A cell migration in a concentration-dependent manner but showed no significant effects on RF/6A cell adhesion to fibronectin. Inhibitory effects of AuNPs on VEGF-induced Akt/eNOS were found. Conclusions: These results suggest that AuNPs are an effective inhibitor of VEGF-induced RF/6A cell migration through the Akt/eNOS pathways, but they have no effects on their cell viabilities and cell adhesion to fibronectin.

Time dependent phosphorylation in eNOS linked signal transduction pathways in endothelial cells reveals feedback mechanisms

Nitric Oxide ◽  
2014 ◽  
Vol 42 ◽  
pp. 103
Author(s):  
Carol Chrestensen ◽  
Tasia Nabors ◽  
Katy Helms ◽  
Jonathan McMurry ◽  
Megan Mickanen ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Endothelial Cells ◽  
Time Dependent ◽  
Signal Transduction Pathways ◽  
Feedback Mechanisms

Soluble factors fromLactobacillus GGactivate MAPKs and induce cytoprotective heat shock proteins in intestinal epithelial cells

2006 ◽  
Vol 290 (4) ◽  
pp. C1018-C1030 ◽  
Author(s):  
Yun Tao ◽  
Kenneth A. Drabik ◽  
Tonya S. Waypa ◽  
Mark W. Musch ◽  
John C. Alverdy ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Heat Shock ◽  
Epithelial Cells ◽  
Map Kinases ◽  
Intestinal Epithelial Cells ◽  
Oxidant Stress ◽  
Signal Transduction Pathways ◽  
Clinical Effects ◽  
Dependent Manner ◽  
Intestinal Epithelial

Conditioned media from the probiotic Lactobacillus GG (LGG-CM) induce heat shock protein (Hsp) expression in intestinal epithelial cells. LGG-CM induces both Hsp25 and Hsp72 in a time- and concentration-dependent manner. These effects are mediated by a low-molecular-weight peptide that is acid and heat stable. DNA microarray experiments demonstrate that Hsp72 is one of the most highly upregulated genes in response to LGG-CM treatment. Real-time PCR and electrophoretic mobility shift assay confirm that regulation of Hsp induction is at least in part transcriptional in nature, involving heat shock factor-1. Although Hsps are not induced for hours after exposure, transient exposure to LGG-CM is sufficient to initiate the signal for Hsp induction, suggesting that signal transduction pathways may be involved. Experiments confirm that LGG-CM modulates the activity of certain signaling pathways in intestinal epithelial cells by activating MAP kinases. Inhibitors of p38 and JNK block the expression of Hsp72 normally induced by LGG-CM. Functional studies indicate that LGG-CM treatment of gut epithelial cells protects them from oxidant stress, perhaps by preserving cytoskeletal integrity. By inducing the expression of cytoprotective Hsps in gut epithelial cells, and by activating signal transduction pathways, the peptide product(s) secreted by LGG may contribute to the beneficial clinical effects attributed to this probiotic.

scholarly journals Characterization of Signal Transduction Pathways in Human Bone Marrow Endothelial Cells

Blood ◽  
1997 ◽  
Vol 90 (6) ◽  
pp. 2253-2259 ◽  
Author(s):  
Zhong-Ying Liu ◽  
Ramesh K. Ganju ◽  
Jian-Feng Wang ◽  
Karin Schweitzer ◽  
Babette Weksler ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Bone Marrow ◽  
Endothelial Cells ◽  
Growth Factors ◽  
Growth Factor ◽  
T Antigen ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Signal Transduction Pathways ◽  
Stimulation Of

Human bone marrow endothelial cells immortalized with the T antigen of SV40 (TrHBMEC) have previously been characterized by us with regard to their properties that are similar to primary marrow endothelial cells and their utility as a model system. We now report that TrHBMEC express a recently discovered signal transduction molecule termed RAFTK (related adhesion focal tyrosine kinase), also called Pyk2 or CAK-β. RAFTK, the second member of the focal adhesion kinase (FAK) family, is known to be activated in response to calcium flux in neuronal cells and integrin stimulation in megakaryocytes and B cells. We have studied the effects of cytokines on RAFTK activation in TrHBMEC. Treatment of TrHBMEC with the vascular endothelial growth factor (VEGF ), as well as the VEGF-related protein (VRP), the recently identified ligand for the FLT-4 receptor, resulted in enhanced tyrosine phosphorylation of RAFTK. Similar changes in RAFTK phosphorylation were observed upon stimulation of TrHBMEC with basic fibroblast growth factor (bFGF ) or oncostatin M (OSM). Stimulation of these cells with growth factors also resulted in an increase in RAFTK activity and the c-Jun NH2 -terminal kinase (JNK). RAFTK coimmunoprecipitated with the cytoskeletal protein paxillin through its C-terminal proline-rich domain in TrHBMEC. These results suggest that, in marrow endothelium, activation of RAFTK by VEGF, VRP, OSM, and bFGF represents a new element in the signal transduction pathways used by these growth factors and likely acts to coordinate signaling from their surface receptors to the cytoskeleton, thereby modulating cell growth and function.

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