scholarly journals Dimerization of the EphA1 Receptor Tyrosine Kinase Transmembrane Domain: Insights into the Mechanism of Receptor Activation

Biochemistry ◽  
2014 ◽  
Vol 53 (42) ◽  
pp. 6641-6652 ◽  
Author(s):  
Matthieu Chavent ◽  
Alan P. Chetwynd ◽  
Phillip J. Stansfeld ◽  
Mark S. P. Sansom
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Transmembrane Domain ◽  
Receptor Activation

scholarly journals Transmembrane Domain Sequence Requirements for Activation of the p185c-neu Receptor Tyrosine Kinase

1997 ◽  
Vol 137 (3) ◽  
pp. 619-631 ◽  
Author(s):  
Lucinda I. Chen ◽  
Melanie K. Webster ◽  
April N. Meyer ◽  
Daniel J. Donoghue
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Tandem Repeats ◽  
Transmembrane Domain ◽  
Recent Observation ◽  
Growth Factor Receptor ◽  
Receptor Activation ◽  
Transmembrane Domains ◽  
Activating Mutations ◽  
Sequence Requirements

The receptor tyrosine kinase p185c-neu can be constitutively activated by the transmembrane domain mutation Val664→ Glu, found in the oncogenic mutant p185neu. This mutation is predicted to allow intermolecular hydrogen bonding and receptor dimerization. Understanding the activation of p185c-neu has assumed greater relevance with the recent observation that achondroplasia, the most common genetic form of human dwarfism, is caused by a similar transmembrane domain mutation that activates fibroblast growth factor receptor (FGFR) 3. We have isolated novel transforming derivatives of p185c-neu using a large pool of degenerate oligonucleotides encoding variants of the transmembrane domain. Several of the transforming isolates identified were unusual in that they lacked a Glu at residue 664, and others were unique in that they contained multiple Glu residues within the transmembrane domain. The Glu residues in the transforming isolates often exhibited a spacing of seven residues or occurred in positions likely to represent the helical interface. However, the distinction between the sequences of the transforming clones and the nontransforming clones did not suggest clear rules for predicting which specific sequences would result in receptor activation and transformation. To investigate these requirements further, entirely novel transmembrane sequences were constructed based on tandem repeats of simple heptad sequences. Activation was achieved by transmembrane sequences such as [VVVEVVA]n or [VVVEVVV]n, whereas activation was not achieved by a transmembrane domain consisting only of Val residues. In the context of these transmembrane domains, Glu or Gln were equally activating, while Lys, Ser, and Asp were not. Using transmembrane domains with two Glu residues, the spacing between these was systematically varied from two to eight residues, with only the heptad spacing resulting in receptor activation. These results are discussed in the context of activating mutations in the transmembrane domain of FGFR3 that are responsible for the human developmental syndromes achondroplasia and acanthosis nigricans with Crouzon Syndrome.

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.

Oligomerization of the extracellular domain of Boss enhances its binding to the Sevenless receptor and its antagonistic effect on R7 induction

1998 ◽  
Vol 111 (6) ◽  
pp. 737-747 ◽  
Author(s):  
E.A. Sevrioukov ◽  
J.H. Walenta ◽  
A. Sunio ◽  
M. Phistry ◽  
H. Kramer
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Compound Eye ◽  
Transmembrane Domain ◽  
Extracellular Domain ◽  
Antagonistic Effect ◽  
Lac Repressor ◽  
Receptor Complexes

In the developing compound eye of Drosophila, neuronal differentiation of the R7 photoreceptor cell is induced by the interaction of the receptor tyrosine kinase Sevenless with its ligand Bride of sevenless (Boss), which is expressed on the neighboring R8 cell. Boss is an unusual ligand of a receptor tyrosine kinase: it is composed of a large extracellular domain, a transmembrane domain with seven membrane-spanning segments and a cytoplasmic tail. Expression of a monomeric, secreted form of the extracellular domain of Boss is not sufficient for Sevenless activation, and instead acts as a weak antagonist. Because oligomerization appears to be a critical step in the activation of receptor tyrosine kinases, we used oligomerized forms of the Boss extracellular domain to test their ability to bind to Sevenless in vivo and restore R7 induction in vivo. Oligomerization was achieved by fusion to the leucine zipper of the yeast transcription factor GCN4 or to the tetramerization helix of Lac repressor. Binding of these multivalent proteins to Sevenless could be detected in vitro by immunoprecipitation of cross-linked ligand/receptor complexes and in vivo by receptor-dependent ligand localization. However, neither R8-specific or ubiquitous expression of multivalent Exboss ligands rescued the boss phenotype. Instead, these ligands acted as competitive inhibitors for wild-type Boss protein and thereby suppressed R7 induction. Therefore the role of the transmembrane or cytoplasmic domains of Boss in the activation of the Sev receptor cannot be replaced by oligomerization.

Role and Regulation of CSF-1-Induced CSF-1 Receptor Interchain Disulfide Bonding in Receptor Activation in Macrophages

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3869-3869
Author(s):  
E. Richard Stanley ◽  
Ying Xiong ◽  
Da Song ◽  
Wenfeng Yu ◽  
Yee-Guide Yeung
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Receptor Tyrosine Kinase ◽  
Morphological Characteristics ◽  
Receptor Activation ◽  
Third Party ◽  
Mouse Bone Marrow ◽  
Pdgf Receptor ◽  
Class Iii ◽  
Disulfide Bonding

Abstract Colony stimulating factor-1 (CSF-1) is the major regulator of tissue macrophage development and function. The effects of CSF-1 are mediated by the CSF-1 receptor (CSF-1R), a class III receptor tyrosine kinase belonging to the PDGF receptor family. To study CSF-1R structure/function in macrophages using both genetic and proteomic approaches, we developed a novel, CSF-1R-deficient, mouse bone marrow macrophage (BMM) line (MacCsf1r−/−) (Yu et al., J. Leuk. Biol.84: in press, 2008). MacCsf1r−/− macrophages are maintained in GM-CSF. Retroviral expression of the wild type CSF-1R fully rescued the CSF-1-induced survival, proliferation, differentiation and morphological characteristics, which resemble those of primary BMM. We have studied CSF-1-induced covalent modifications of the receptor in MacCsf1r−/− cells. Activation of the CSF-1R involves ligand-induced receptor dimerization and trans-phosphorylation of the cytoplasmic domains. Besides tyrosine phosphorylation, CSF-1 stimulation results in disulfide bonding of the CSF-1R dimers and cysteine mutagenesis experiments revealed that specific residues in the kinase domain are involved. Inhibition of the disulfide bond formation significantly compromised CSF-1-induced CSF-1R tyrosine phosphorylation, indicating its requirement for full receptor activation. Analysis of the regulation of CSF-1-induced CSF-1R interchain disulfide bonding revealed the participation of third party molecules with additional CSF-1R post-translational modifications. The importance of ligand-induced disulfide bonding for class III receptor tyrosine kinase activation may not be restricted to the CSF-1R as interchain disulfide bonding of PDGF receptor dimers is also ligand-induced.

scholarly journals Modulation of Transmembrane Domain Interactions in Neu Receptor Tyrosine Kinase by Membrane Fluidity and Cholesterol

2019 ◽  
Vol 252 (4-5) ◽  
pp. 357-369 ◽  
Author(s):  
Muhammad Hasan ◽  
Dharmesh Patel ◽  
Natalie Ellis ◽  
Steven P. Brown ◽  
Józef R. Lewandowski ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Membrane Fluidity ◽  
Receptor Tyrosine Kinase ◽  
Transmembrane Domain ◽  
Domain Interactions

scholarly journals Sch proteins are localized on endoplasmic reticulum membranes and are redistributed after tyrosine kinase receptor activation.

1996 ◽  
Vol 16 (5) ◽  
pp. 1946-1954 ◽  
Author(s):  
L V Lotti ◽  
L Lanfrancone ◽  
E Migliaccio ◽  
C Zompetta ◽  
G Pelicci ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinase ◽  
Rough Endoplasmic Reticulum ◽  
Receptor Tyrosine Kinase ◽  
Receptor Activation ◽  
Kinase Activation ◽  
Epidermal Growth

The intracellular localization of Shc proteins was analyzed by immunofluorescence and immunoelectron microscopy in normal cells and cells expressing the epidermal growth factor receptor or the EGFR/erbB2 chimera. In unstimulated cells, the immunolabeling was localized in the central perinuclear area of the cell and mostly associated with the cytosolic side of rough endoplasmic reticulum membranes. Upon epidermal growth factor treatment and receptor tyrosine kinase activation, the immunolabeling became peripheral and was found to be associated with the cytosolic surface of the plasma membrane and endocytic structures, such as coated pits and endosomes, and with the peripheral cytosol. Receptor activation in cells expressing phosphorylation-defective mutants of Shc and erbB-2 kinase showed that receptor autophosphorylation, but not Shc phosphorylation, is required for redistribution of Shc proteins. The rough endoplasmic reticulum localization of Shc proteins in unstimulated cells and their massive recruitment to the plasma membrane, endocytic structures, and peripheral cytosol following receptor tyrosine kinase activation could account for multiple putative functions of the adaptor protein.

scholarly journals Differential receptor tyrosine kinase phosphorylation in the uterus of rats following developmental exposure to tetrabromobisphenol A

2021 ◽  
Vol 5 ◽  
pp. 239784732110471
Author(s):  
Lysandra Castro ◽  
Jingli Liu ◽  
Linda Yu ◽  
Alanna D Burwell ◽  
Trey O Saddler ◽  
...  
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Early Life ◽  
Endometrial Adenocarcinoma ◽  
Growth Factor Receptor ◽  
Receptor Activation ◽  
Tetrabromobisphenol A ◽  
Tyrosine Kinase Receptor ◽  
Uterine Tumors

Tetrabromobisphenol A (TBBPA) is a brominated flame retardant that induces endometrial adenocarcinoma and other uterine tumors in Wistar Han rats; however, early molecular events or biomarkers of TBBPA exposure remain unknown. We investigated the effects of TBBPA on growth factor receptor activation [phospho-receptor tyrosine kinases (RTKs)] in uteri of rats following early-life exposures. Pregnant Wistar Han rats were exposed to TBBPA (0, 0.1, 25, and 250 mg/kg bw/day) via oral gavage on gestation day 6 through weaning of pups on postnatal day (PND) 21. Pups were exposed in utero, through lactation, and by daily gavage from PND 22 to PND 90. Uterine horns were collected (at PND 21, PND 33, and PND 90) and formalin-fixed or frozen for histologic, immunohistochemical, phospho-RTK arrays, or western blot analysis. At PND 21, the phospho-RTKs, fibroblast growth factor receptor 2 and 3 (FGFR2 and FGFR3), neurotrophic tyrosine kinase receptor type 3 (TRKC), and EPH receptor A1 (EPHA1) were significantly increased at different treatment concentrations. Several phospho-RTKs were also significantly overexpressed at PND 33 which included epithelial growth factor receptor (EGFR), FGFR2, FGFR3, FGFR4, insulin-like growth factor receptor 1 (IGF1R), insulin receptor (INSR), AXL receptor tyrosine kinase (AXL), MER proto-oncogene, tyrosine kinase (MERTK), platelet derived growth factor receptor alpha and beta (PDGFRA and PDGFRB), ret proto-oncogene (RET), tyrosine kinase with immunoglobulin-like and EGF-like domains 1 and 2 (TIE1 and TIE2), TRKA, kinase insert domain receptor (KDR;VEGFR2), fms related receptor tyrosine kinase (FLT4; VEGFR3), and EPHA1 at different treatment concentrations. EGFR, a RTK overexpressed in endometrial cancer in women, remained significantly increased for all treatment groups at PND 90. Erb-B2 receptor tyrosine kinase 2 (ERBB2) and IGF1R were overexpressed at PND 33 and remained increased through PND 90, although ERBB2 was statistically significant at PND 90. The phospho-RTKs, FGFR3, AXL, TYRO3 protien tyrosine kinase (TYRO3; DTK), HGFR, TRKC, FLT1/VEGFR1, and EPHB2 and 4 were also statistically significant at PND 90 at different treatment doses. The downstream effector, phospho-MAPK44/42, was also increased in uteri of treated rats. Our findings show RTKs are dysregulated following early-life TBBPA exposures and their sustained activation may contribute to TBBPA-induced uterine tumors observed in rats later in life.

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