Heterologous desensitization of EGF receptors and PDGF receptors by sequestration in caveolae

2002 ◽  
Vol 282 (4) ◽  
pp. C935-C946 ◽  
Author(s):  
Sergey V. Matveev ◽  
Eric J. Smart
Keyword(s):  
Growth Factor ◽  
Radioligand Binding ◽  
Subcellular Fractionation ◽  
Egf Receptors ◽  
Binding Studies ◽  
Kinase Activation ◽  
Caveolin 1 ◽  
Space Experiments ◽  
Extracellular Signal ◽  
Heterologous Desensitization

Epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) receptors have been reported to signal via caveolin-containing membranes called caveolae. In contrast, others report that EGF and PDGF receptors are exclusively associated with caveolin-devoid membranes called rafts. Our subcellular fractionation and coimmunoprecipitation studies demonstrate that, in the absence of ligand, EGF and PDGF receptors are associated with rafts. However, in the presence of ligand, EGF and PDGF receptors transiently associate with caveolae. Surprisingly, pretreatment of cells with EGF prevents PDGF-dependent phosphorylation of PDGF receptors and extracellular signal-regulated kinase (ERK) 1/2 kinase activation. Furthermore, cells pretreated with PDGF prevent EGF-dependent phosphorylation of EGF receptors and ERK1/2 kinase activation. Radioligand binding studies demonstrate that incubation of cells with EGF or PDGF causes both EGF and PDGF receptors to be reversibly sequestered from the extracellular space. Experiments with methyl-β-cyclodextrin, filipin, and antisense caveolin-1 demonstrate that sequestration of the receptors is dependent on cholesterol and caveolin-1. We conclude that ligand-induced stimulation of EGF or PDGF receptors can cause the heterologous desensitization of the other receptor by sequestration in cholesterol-rich, caveolin-containing membranes or caveolae.

p42/p44 MAP kinase activation is localized to caveolae-free membrane domains in airway smooth muscle

2007 ◽  
Vol 292 (5) ◽  
pp. L1163-L1172 ◽  
Author(s):  
Reinoud Gosens ◽  
Gordon Dueck ◽  
William T. Gerthoffer ◽  
Helmut Unruh ◽  
Johan Zaagsma ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Plasma Membrane ◽  
Growth Factor ◽  
Map Kinase ◽  
Membrane Domains ◽  
Kinase Activation ◽  
Caveolin 1 ◽  
Free Membrane ◽  
Kinase Phosphorylation

Caveolae are abundant plasma membrane invaginations in airway smooth muscle that may function as preorganized signalosomes by sequestering and regulating proteins that control cell proliferation, including receptor tyrosine kinases (RTKs) and their signaling effectors. We previously demonstrated, however, that p42/p44 MAP kinase, a critical effector for cell proliferation, does not colocalize with RTKs in caveolae of quiescent airway myocytes. Therefore, we investigated the subcellular sites of growth factor-induced MAP kinase activation. In quiescent myocytes, though epidermal growth factor receptor (EGFR) was almost exclusively found in caveolae, p42/p44 MAP kinase, Grb2, and Raf-1 were absent from these membrane domains. EGF induced concomitant phosphorylation of caveolin-1 and p42/p44 MAP kinase; however, EGF did not promote the localization of p42/p44 MAP kinase, Grb2, or Raf-1 to caveolae. Interestingly, stimulation of muscarinic M2 and M3 receptors that were enriched in caveolae-deficient membranes also induced p42/p44 MAP kinase phosphorylation, but this occurred in the absence of caveolin-1 phosphorylation. This suggests that the localization of receptors to caveolae and interaction with caveolin-1 is not directly required for p42/p44 MAP kinase phosphorylation. Furthermore, we found that EGF exposure induced rapid translocation of EGFR from caveolae to caveolae-free membranes. EGFR trafficking coincided temporally with EGFR and p42/p44 MAP kinase phosphorylation. Collectively, this indicates that although caveolae sequester some receptors associated with p42/p44 MAP kinase activation, the site of its activation is associated with caveolae-free membrane domains. This reveals that directed trafficking of plasma membrane EGFR is an essential element of signal transduction leading to p42/p44 MAP kinase activation.

Growth factor–dependent ErbB vesicular dynamics couple receptor signaling to spatially and functionally distinct Erk pools

2021 ◽  
Vol 14 (683) ◽  
pp. eabd9943
Author(s):  
Yannick Brüggemann ◽  
Lisa S. Karajannis ◽  
Angel Stanoev ◽  
Wayne Stallaert ◽  
Philippe I. H. Bastiaens
Keyword(s):  
Plasma Membrane ◽  
Growth Factor ◽  
Tyrosine Kinases ◽  
Cellular Responses ◽  
Cellular Motility ◽  
Egf Receptors ◽  
Downstream Signaling ◽  
Transient Activation ◽  
Extracellular Signal ◽  
Functionally Diverse

Growth factor–dependent vesicular dynamics allow cells to regulate the spatial distribution of growth factor receptors and thereby their coupling to downstream signaling effectors that guide cellular responses. We found that the ErbB ligands epidermal growth factor (EGF) and heregulin (HRG) generated distinct spatiotemporal patterns of cognate receptor activities to activate distinct subcellular pools of the extracellular signal–regulated kinase (Erk). Sustained plasma membrane activity of the receptor tyrosine kinases ErbB2/ErbB3 signaled to Erk complexed with the scaffold protein KSR to promote promigratory EphA2 phosphorylation and cellular motility upon HRG stimulation. In contrast, receptor-saturating EGF stimuli caused proliferation-inducing transient activation of cytoplasmic Erk due to the rapid internalization of EGF receptors (EGFR or ErbB1) toward endosomes. Paradoxically, promigratory signaling mediated by Erk complexed to KSR was sustained at low EGF concentrations by vesicular recycling that maintained steady-state amounts of active, phosphorylated EGFR at the plasma membrane. Thus, the effect of ligand identity and concentration on determining ErbB vesicular dynamics constitutes a mechanism by which cells can transduce growth factor composition through spatially distinct Erk pools to enable functionally diverse cellular responses.

Role of insulin and insulin-like growth factor receptors in regulation of T84 cell monolayer permeability

1994 ◽  
Vol 267 (5) ◽  
pp. G883-G891 ◽  
Author(s):  
J. A. McRoberts ◽  
N. E. Riley
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Biological Effect ◽  
Radioligand Binding ◽  
Cross Linking ◽  
Continuous Exposure ◽  
Binding Studies ◽  
T84 Cells ◽  
Igf I ◽  
Radioligand Binding Studies

We previously showed that insulin and insulin-like growth factor (IGF)-I and IGF-II caused a dose-dependent increase in permeability through the paracellular pathway of T84 cell monolayers over 3-4 days. Here we have determined which cell surface receptors were involved in this response. Using radioligand binding studies and receptor cross-linking studies, we found that T84 cells possess insulin and IGF-I receptors. There were approximately 20 x 10(3) insulin receptors/cell with a dissociation constant (KD) of 0.5 nM and 29 x 10(3) IGF-I receptors with a KD of 0.6 nM for IGF-I. Cross-linking studies identified the alpha-subunit of insulin and IGF-I receptors with deduced molecular weights of 126 x 10(3) and 128 x 10(3), respectively. IGF-II bound to T84 cells with an apparent KD of approximately 2.0 nM. Radioreceptor cross-linking indicated that IGF-II interacted principally with the IGF-I receptor, although low levels of the IGF-II/mannose 6-phosphate receptor were also expressed on the cell surface. We then correlated the biological effect with the radioligand binding studies. It was first demonstrated that insulin and IGF-I were degraded in medium in the presence of cells. In addition, we showed that continuous exposure for 2-3 days to insulin or IGF-I was required to produce their biological effect on permeability. Taking into account the rate of degradation and the requirement for continuous exposure, we found a close correlation between radioligand binding and the half-maximal effective concentration for the hormonal effects on transepithelial permeability.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Role of Gab1 in Heart, Placenta, and Skin Development and Growth Factor- and Cytokine-Induced Extracellular Signal-Regulated Kinase Mitogen-Activated Protein Kinase Activation

2000 ◽  
Vol 20 (10) ◽  
pp. 3695-3704 ◽  
Author(s):  
Motoyuki Itoh ◽  
Yuichi Yoshida ◽  
Keigo Nishida ◽  
Masahiro Narimatsu ◽  
Masahiko Hibi ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Map Kinases ◽  
Cytokine Signaling ◽  
Kinase Activation ◽  
Skin Development ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Stimulation Of

ABSTRACT Gab1 is a member of the Gab/DOS (Daughter of Sevenless) family of adapter molecules, which contain a pleckstrin homology (PH) domain and potential binding sites for SH2 and SH3 domains. Gab1 is tyrosine phosphorylated upon stimulation of various cytokines, growth factors, and antigen receptors in cell lines and interacts with signaling molecules, such as SHP-2 and phosphatidylinositol 3-kinase, although its biological roles have not yet been established. To reveal the functions of Gab1 in vivo, we generated mice lacking Gab1 by gene targeting. Gab1-deficient embryos died in utero and displayed developmental defects in the heart, placenta, and skin, which were similar to phenotypes observed in mice lacking signals of the hepatocyte growth factor/scatter factor, platelet-derived growth factor, and epidermal growth factor pathways. Consistent with these observations, extracellular signal-regulated kinase mitogen-activated protein (ERK MAP) kinases were activated at much lower levels in cells from Gab1-deficient embryos in response to these growth factors or to stimulation of the cytokine receptor gp130. These results indicate that Gab1 is a common player in a broad range of growth factor and cytokine signaling pathways linking ERK MAP kinase activation.

scholarly journals Ras activation in response to lysophosphatidic acid requires a permissive input from the epidermal growth factor receptor

2003 ◽  
Vol 376 (3) ◽  
pp. 571-576 ◽  
Author(s):  
Ignacio RUBIO ◽  
Knut RENNERT ◽  
Ute WITTIG ◽  
Reinhard WETZKER
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Lysophosphatidic Acid ◽  
Growth Factor Receptor ◽  
Nucleotide Exchange ◽  
Kinase Activation ◽  
Egfr Inhibition ◽  
Extracellular Signal ◽  
Epidermal Growth

The topology of the signalling pathway linking the G-protein-coupled receptor agonist lysophosphatidic acid (LPA) to extracellular-signal-regulated kinase activation remains undeciphered. In the present study, we report that analysis of LPA signals at the level of Ras-GTP formation and Ras nucleotide exchange discriminates true mediatory signals from permissive activities that do not participate in signal relay. Hence, whereas pertussis toxin (PTX) treatment impairs stimulation of nucleotide exchange, epidermal growth factor receptor (EGFR) inhibition does not compromise LPA-induced acceleration of nucleotide exchange, but instead attenuates basal nucleotide turnover on Ras. Our data indicate that LPA activation of Ras proceeds via PTX-sensitive Gi/o-proteins and requires a permissive input from basal EGFR activity.

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