scholarly journals PAG1 directs SRC-family kinase intracellular localization to mediate receptor tyrosine kinase-induced differentiation

2020 ◽  
Vol 31 (20) ◽  
pp. 2269-2282
Author(s):  
Lauren Foltz ◽  
Juan Palacios-Moreno ◽  
Makenzie Mayfield ◽  
Shelby Kinch ◽  
Jordan Dillon ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Neuronal Differentiation ◽  
Lipid Rafts ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Intracellular Localization ◽  
Multivesicular Bodies ◽  
Src Family Kinase ◽  
Cell Signaling Pathways

Different receptor tyrosine kinases employ shared downstream cell signaling pathways to induce differentiation or proliferation. The scaffold protein, PAG1 controls SRC-family kinase (SFK) activity in lipid rafts, and new data show that PAG1 also influences SFK sequestration in multivesicular bodies and is required for neuronal differentiation.

Signaling in new directions

1995 ◽  
Vol 73 (3-4) ◽  
pp. 133-136 ◽  
Author(s):  
Haleh Vahidi Samiei
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Tyrosine Kinase ◽  
Map Kinase ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Molecular Level ◽  
Clear Cut ◽  
New Directions

Many laboratories, using a variety of organisms, have contributed to deciphering the identity and the order of the components leading from ligand-bound receptor tyrosine kinases to various intracellular events, including changes in gene expression. The gaps have only been filled recently. This minireview summarizes the findings and points out the degree of conservation of the same pathway in distant organisms, both at the molecular level and in terms of the consecutive steps. The review also looks at points at which this pathway might be diverging and points onto which other pathways might be converging. These interactions are not always clear cut, and understanding them will be the challenge for the future.Key words: signal transduction, receptor tyrosine kinase, RAS, RAF, MAP kinase.

scholarly journals Helicobacter Pylori Targets the EPHA2 Receptor Tyrosine Kinase in Gastric Cells Modulating Key Cellular Functions

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 513 ◽  
Author(s):  
Marina Leite ◽  
Miguel S. Marques ◽  
Joana Melo ◽  
Marta T. Pinto ◽  
Bruno Cavadas ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Tyrosine Kinase ◽  
Signaling Pathways ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Receptor Activation ◽  
Degradation Pathway ◽  
Mrna Levels ◽  
H Pylori

Helicobacter pylori, a stomach-colonizing Gram-negative bacterium, is the main etiological factor of various gastroduodenal diseases, including gastric adenocarcinoma. By establishing a life-long infection of the gastric mucosa, H. pylori continuously activates host-signaling pathways, in particular those associated with receptor tyrosine kinases. Using two different gastric epithelial cell lines, we show that H. pylori targets the receptor tyrosine kinase EPHA2. For long periods of time post-infection, H. pylori induces EPHA2 protein downregulation without affecting its mRNA levels, an effect preceded by receptor activation via phosphorylation. EPHA2 receptor downregulation occurs via the lysosomal degradation pathway and is independent of the H. pylori virulence factors CagA, VacA, and T4SS. Using small interfering RNA, we show that EPHA2 knockdown affects cell–cell and cell–matrix adhesion, invasion, and angiogenesis, which are critical cellular processes in early gastric lesions and carcinogenesis mediated by the bacteria. This work contributes to the unraveling of the underlying mechanisms of H. pylori–host interactions and associated diseases. Additionally, it raises awareness for potential interference between H. pylori infection and the efficacy of gastric cancer therapies targeting receptors tyrosine kinases, given that infection affects the steady-state levels and dynamics of some receptor tyrosine kinases (RTKs) and their signaling pathways.

scholarly journals Downregulation of the Ras–Mitogen-Activated Protein Kinase Pathway by the EphB2 Receptor Tyrosine Kinase Is Required for Ephrin-Induced Neurite Retraction

2001 ◽  
Vol 21 (21) ◽  
pp. 7429-7441 ◽  
Author(s):  
Sabine Elowe ◽  
Sacha J. Holland ◽  
Sarang Kulkarni ◽  
Tony Pawson
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Mapk Pathway ◽  
Neuronal Cells ◽  
Mitogen Activated Protein Kinase ◽  
Neurite Retraction ◽  
Mitogen Activated Protein ◽  
Stimulation Of

ABSTRACT Activation of the EphB2 receptor tyrosine kinase by clustered ephrin-B1 induces growth cone collapse and neurite retraction in differentiated NG108 neuronal cells. We have investigated the cytoplasmic signaling events associated with EphB2-induced cytoskeletal reorganization in these neuronal cells. We find that unlike other receptor tyrosine kinases, EphB2 induces a pronounced downregulation of GTP-bound Ras and consequently of the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway. A similar inhibition of the Ras-MAPK pathway was observed on stimulation of endogenous EphB2 in COS-1 cells. Inactivation of Ras, induced by ephrin B1 stimulation of NG108 neuronal cells, requires EphB2 tyrosine kinase activity and is blocked by a truncated form of p120-Ras GTPase-activating protein (p120-RasGAP), suggesting that EphB2 signals through the SH2 domain protein p120-RasGAP to inhibit the Ras-MAPK pathway. Suppression of Ras activity appears functionally important, since expression of a constitutively active variant of Ras impaired the ability of EphB2 to induce neurite retraction. In addition, EphB2 attenuated the elevation in ERK activation induced by attachment of NG108 cells to fibronectin, indicating that the EphB2 receptor can modulate integrin signaling to the Ras GTPase. These results suggest that a primary function of EphB2, a member of the most populous family of receptor tyrosine kinases, is to inactivate the Ras-MAPK pathway in a fashion that contributes to cytoskeletal reorganization and adhesion responses in neuronal growth cones.

scholarly journals Novel p62dok family members, dok-4 and dok-5, are substrates of the c-Ret receptor tyrosine kinase and mediate neuronal differentiation

2001 ◽  
Vol 154 (2) ◽  
pp. 345-354 ◽  
Author(s):  
Jan Grimm ◽  
Martin Sachs ◽  
Stefan Britsch ◽  
Silvana Di Cesare ◽  
Thomas Schwarz-Romond ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Neuronal Differentiation ◽  
Pc12 Cells ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Family Members ◽  
Mitogen Activated Protein Kinase ◽  
New Family ◽  
Neuronal Tissues ◽  
Mitogen Activated Protein

Docking proteins are substrates of tyrosine kinases and function in the recruitment and assembly of specific signal transduction molecules. Here we found that p62dok family members act as substrates for the c-Ret receptor tyrosine kinase. In addition to dok-1, dok-2, and dok-3, we identified two new family members, dok-4 and dok-5, that can directly associate with Y1062 of c-Ret. Dok-4 and dok-5 constitute a subgroup of dok family members that is coexpressed with c-Ret in various neuronal tissues. Activated c-Ret promotes neurite outgrowth of PC12 cells; for this activity, Y1062 in c-Ret is essential. c-Ret/dok fusion proteins, in which Y1062 of c-Ret is deleted and replaced by the sequences of dok-4 or dok-5, induce ligand-dependent axonal outgrowth of PC12 cells, whereas a c-Ret fusion containing dok-2 sequences does not elicit this response. Dok-4 and dok-5 do not associate with rasGAP or Nck, in contrast to p62dok and dok-2. Moreover, dok-4 and dok-5 enhance c-Ret–dependent activation of mitogen-activated protein kinase. Thus, we have identified a subclass of p62dok proteins that are putative links with downstream effectors of c-Ret in neuronal differentiation.

scholarly journals PAG1 directs SRC-family kinase intracellular localization to mediate receptor tyrosine kinase-induced differentiation

2020 ◽  
Author(s):  
Lauren Foltz ◽  
Juan Palacios-Moreno ◽  
Makenzie Mayfield ◽  
Shelby Kinch ◽  
Jordan Dillon ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Cell Fate ◽  
Tyrosine Kinases ◽  
Intracellular Localization ◽  
Neuroblastoma Cell ◽  
Neuroblastoma Cell Line ◽  
Src Family Kinase ◽  
Control Activity ◽  
Cell Fate Decisions ◽  
Downstream Signaling

AbstractAll receptor tyrosine kinases (RTKs) activate similar downstream signaling pathways through a common set of effectors, yet it is not fully understood how different receptors elicit distinct cellular responses to cause cell proliferation, differentiation, or other cell fates. We tested the hypothesis that regulation of SRC Family Kinase (SFK) signaling by the scaffold protein, PAG1, influences cell fate decisions following RTK activation. We generated a neuroblastoma cell line expressing a PAG1 fragment that lacks the membrane spanning domain (PAG1™-) and localized to the cytoplasm. PAG1™- cells exhibited higher amounts of active SFKs and increased growth rate. PAG1™- cells were unresponsive to TRKA and RET signaling, two RTKs that induce neuronal differentiation, but retained responses to EGFR and KIT. Under differentiation conditions, PAG1™- cells continued to proliferate and did not extend neurites or increase β-III tubulin expression. FYN and LYN were sequestered in multivesicular bodies (MVBs), and dramatically more FYN and LYN were in the lumen of MVBs in PAG1™- cells. In particular, activated FYN was sequestered in PAG1™- cells, suggesting that disruption of FYN localization led to the observed defects in differentiation. The results demonstrate that PAG1 directs SFK intracellular localization to control activity and to mediate signaling by RTKs that induce neuronal differentiation.

scholarly journals Recent Advances in the Role of Discoidin Domain Receptor Tyrosine Kinase 1 and Discoidin Domain Receptor Tyrosine Kinase 2 in Breast and Ovarian Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Li Chen ◽  
Xiangyi Kong ◽  
Yi Fang ◽  
Shishir Paunikar ◽  
Xiangyu Wang ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tyrosine Kinase ◽  
Ligand Binding ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Kinase Activity ◽  
Receptor Tyrosine Kinases ◽  
Breast And Ovarian Cancer ◽  
Discoidin Domain Receptor

Discoidin domain receptor tyrosine kinases (DDRs) are a class of receptor tyrosine kinases (RTKs), and their dysregulation is associated with multiple diseases (including cancer, chronic inflammatory conditions, and fibrosis). The DDR family members (DDR1a-e and DDR2) are widely expressed, with predominant expression of DDR1 in epithelial cells and DDR2 in mesenchymal cells. Structurally, DDRs consist of three regions (an extracellular ligand binding domain, a transmembrane domain, and an intracellular region containing a kinase domain), with their kinase activity induced by receptor-specific ligand binding. Collagen binding to DDRs stimulates DDR phosphorylation activating kinase activity, signaling to MAPK, integrin, TGF-β, insulin receptor, and Notch signaling pathways. Abnormal DDR expression is detected in a range of solid tumors (including breast, ovarian, cervical liver, gastric, colorectal, lung, and brain). During tumorigenesis, abnormal activation of DDRs leads to invasion and metastasis, via dysregulation of cell adhesion, migration, proliferation, secretion of cytokines, and extracellular matrix remodeling. Differential expression or mutation of DDRs correlates with pathological classification, clinical characteristics, treatment response, and prognosis. Here, we discuss the discovery, structural characteristics, organizational distribution, and DDR-dependent signaling. Importantly, we highlight the key role of DDRs in the development and progression of breast and ovarian cancer.

scholarly journals Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-small cell lung cancer

2015 ◽  
Vol 3 (02) ◽  
pp. 81-87
Author(s):  
Lawaly Maman Manzo ◽  
Moudirat Lawaly ◽  
Lui YU
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Kinase Inhibitors ◽  
Receptor Tyrosine Kinases ◽  
Growth Factor Receptor ◽  
Endothelial Growth Factor ◽  
Receptor Tyrosine Kinase Inhibitors

Aberrant increased expression and activation of receptor tyrosine kinases occur frequently in human carcinomas. Several small molecules targeting receptor tyrosine kinases, which have crucial roles in the growth factor signaling that promote tumor progression in various malignancies, including non-small cell lung cancer (NSCLC), are currently in clinical development. Therapeutic strategies include inhibition of growth factor tyrosine kinase function. Drugs of this type include those that target the epidermal growth factor receptor tyrosine kinase, those that target vascular endothelial growth factor receptors tyrosine kinase and those that target anaplastic lymphoma receptor tyrosine kinase. In this review we first discuss the role of receptor tyrosine kinases in human malignancies, and focus on discussing the potential use of epidermal growth factor receptor tyrosine kinase inhibitors and the vascular endothelial growth factor receptors tyrosine kinase inhibitors in NSCLC. In addition, we discuss the contribution of growth factor receptor tyrosine kinase inhibitors to the clinically observed resistance, and toxicity.

scholarly journals Novel Receptor Tyrosine Kinase Pathway Inhibitors for Targeted Radionuclide Therapy of Glioblastoma

2021 ◽  
Vol 14 (7) ◽  
pp. 626
Author(s):  
Julie Bolcaen ◽  
Shankari Nair ◽  
Cathryn H. S. Driver ◽  
Tebatso M. G. Boshomane ◽  
Thomas Ebenhan ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Radionuclide Therapy ◽  
Kinase Inhibitors ◽  
Nuclear Imaging ◽  
Therapy Resistance ◽  
Targeted Radionuclide Therapy ◽  
Therapy Strategy ◽  
Dismal Prognosis

Glioblastoma (GB) remains the most fatal brain tumor characterized by a high infiltration rate and treatment resistance. Overexpression and/or mutation of receptor tyrosine kinases is common in GB, which subsequently leads to the activation of many downstream pathways that have a critical impact on tumor progression and therapy resistance. Therefore, receptor tyrosine kinase inhibitors (RTKIs) have been investigated to improve the dismal prognosis of GB in an effort to evolve into a personalized targeted therapy strategy with a better treatment outcome. Numerous RTKIs have been approved in the clinic and several radiopharmaceuticals are part of (pre)clinical trials as a non-invasive method to identify patients who could benefit from RTKI. The latter opens up the scope for theranostic applications. In this review, the present status of RTKIs for the treatment, nuclear imaging and targeted radionuclide therapy of GB is presented. The focus will be on seven tyrosine kinase receptors, based on their central role in GB: EGFR, VEGFR, MET, PDGFR, FGFR, Eph receptor and IGF1R. Finally, by way of analyzing structural and physiological characteristics of the TKIs with promising clinical trial results, four small molecule RTKIs were selected based on their potential to become new therapeutic GB radiopharmaceuticals.

scholarly journals TrkB deubiquitylation by USP8 regulates receptor levels and BDNF-dependent neuronal differentiation

2020 ◽  
Vol 133 (24) ◽  
pp. jcs247841 ◽  
Author(s):  
Carlos Martín-Rodríguez ◽  
Minseok Song ◽  
Begoña Anta ◽  
Francisco J. González-Calvo ◽  
Rubén Deogracias ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Neurotrophic Factor ◽  
Tyrosine Kinases ◽  
Hippocampal Neurons ◽  
Receptor Tyrosine Kinases ◽  
Neurotrophin Receptor ◽  
C Terminus ◽  
Carboxyl Terminal

ABSTRACTUbiquitylation of receptor tyrosine kinases (RTKs) regulates both the levels and functions of these receptors. The neurotrophin receptor TrkB (also known as NTRK2), a RTK, is ubiquitylated upon activation by brain-derived neurotrophic factor (BDNF) binding. Although TrkB ubiquitylation has been demonstrated, there is a lack of knowledge regarding the precise repertoire of proteins that regulates TrkB ubiquitylation. Here, we provide mechanistic evidence indicating that ubiquitin carboxyl-terminal hydrolase 8 (USP8) modulates BDNF- and TrkB-dependent neuronal differentiation. USP8 binds to the C-terminus of TrkB using its microtubule-interacting domain (MIT). Immunopurified USP8 deubiquitylates TrkB in vitro, whereas knockdown of USP8 results in enhanced ubiquitylation of TrkB upon BDNF treatment in neurons. As a consequence of USP8 depletion, TrkB levels and its activation are reduced. Moreover, USP8 protein regulates the differentiation and correct BDNF-dependent dendritic formation of hippocampal neurons in vitro and in vivo. We conclude that USP8 positively regulates the levels and activation of TrkB, modulating BDNF-dependent neuronal differentiation.This article has an associated First Person interview with the first author of the paper.

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