scholarly journals Platelet-Derived Growth Factor Receptor Association with Na+/H+ Exchanger Regulatory Factor Potentiates Receptor Activity

2000 ◽  
Vol 20 (22) ◽  
pp. 8352-8363 ◽  
Author(s):  
Stuart Maudsley ◽  
A. Musa Zamah ◽  
Nadeem Rahman ◽  
Jeremy T. Blitzer ◽  
Louis M. Luttrell ◽  
...  
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinase ◽  
Intracellular Signaling ◽  
Pdz Domain ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Platelet Derived Growth Factor ◽  
Regulatory Factor ◽  
In Cells

ABSTRACT Platelet-derived growth factor (PDGF) is a potent mitogen for many cell types. The PDGF receptor (PDGFR) is a receptor tyrosine kinase that mediates the mitogenic effects of PDGF by binding to and/or phosphorylating a variety of intracellular signaling proteins upon PDGF-induced receptor dimerization. We show here that the Na+/H+ exchanger regulatory factor (NHERF; also known as EBP50), a protein not previously known to interact with the PDGFR, binds to the PDGFR carboxyl terminus (PDGFR-CT) with high affinity via a PDZ (PSD-95/Dlg/Z0-1 homology) domain-mediated interaction and potentiates PDGFR autophosphorylation and extracellular signal-regulated kinase (ERK) activation in cells. A point-mutated version of the PDGFR, with the terminal leucine changed to alanine (L1106A), cannot bind NHERF in vitro and is markedly impaired relative to the wild-type receptor with regard to PDGF-induced autophosphorylation and activation of ERK in cells. NHERF potentiation of PDGFR signaling depends on the capacity of NHERF to oligomerize. NHERF oligomerizes in vitro when bound with PDGFR-CT, and a truncated version of the first NHERF PDZ domain that can bind PDGFR-CT but which does not oligomerize reduces PDGFR tyrosine kinase activity when transiently overexpressed in cells. PDGFR activity in cells can also be regulated in a NHERF-dependent fashion by stimulation of the β2-adrenergic receptor, a known cellular binding partner for NHERF. These findings reveal that NHERF can directly bind to the PDGFR and potentiate PDGFR activity, thus elucidating both a novel mechanism by which PDGFR activity can be regulated and a new cellular role for the PDZ domain-containing adapter protein NHERF.

scholarly journals NHERF Links the N-Cadherin/Catenin Complex to the Platelet-derived Growth Factor Receptor to Modulate the Actin Cytoskeleton and Regulate Cell Motility

2007 ◽  
Vol 18 (4) ◽  
pp. 1220-1232 ◽  
Author(s):  
Christopher S. Theisen ◽  
James K. Wahl ◽  
Keith R. Johnson ◽  
Margaret J. Wheelock
Keyword(s):  
Cell Migration ◽  
Growth Factor ◽  
Kinase Inhibitor ◽  
Pdz Domain ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Platelet Derived Growth Factor ◽  
Binding Motif ◽  
Pdz Domains ◽  
Dependent Cell

Using phage display, we identified Na+/H+ exchanger regulatory factor (NHERF)-2 as a novel binding partner for the cadherin-associated protein, β-catenin. We showed that the second of two PSD-95/Dlg/ZO-1 (PDZ) domains of NHERF interacts with a PDZ-binding motif at the very carboxy terminus of β-catenin. N-cadherin expression has been shown to induce motility in a number of cell types. The first PDZ domain of NHERF is known to bind platelet-derived growth factor-receptor β (PDGF-Rβ), and the interaction of PDGF-Rβ with NHERF leads to enhanced cell spreading and motility. Here we show that β-catenin and N-cadherin are in a complex with NHERF and PDGF-Rβ at membrane ruffles in the highly invasive fibrosarcoma cell line HT1080. Using a stable short hairpin RNA system, we showed that HT1080 cells knocked down for either N-cadherin or NHERF had impaired ability to migrate into the wounded area in a scratch assay, similar to cells treated with a PDGF-R kinase inhibitor. Cells expressing a mutant NHERF that is unable to associate with β-catenin had increased stress fibers, reduced lamellipodia, and impaired cell migration. Using HeLa cells, which express little to no PDGF-R, we introduced PDGF-Rβ and showed that it coimmunoprecipitates with N-cadherin and that PDGF-dependent cell migration was reduced in these cells when we knocked-down expression of N-cadherin or NHERF. These studies implicate N-cadherin and β-catenin in cell migration via PDGF-R–mediated signaling through the scaffolding molecule NHERF.

scholarly journals Physical and Functional Interaction of Growth Hormone and Insulin-Like Growth Factor-I Signaling Elements

2004 ◽  
Vol 18 (6) ◽  
pp. 1471-1485 ◽  
Author(s):  
Yao Huang ◽  
Sung-Oh Kim ◽  
Ning Yang ◽  
Jing Jiang ◽  
Stuart J. Frank
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Intracellular Signaling ◽  
Kinase Inhibitor ◽  
Growth Factor Receptor ◽  
Janus Kinase ◽  
Intact Cells ◽  
Igf I

Abstract GH and IGF-I are critical regulators of growth and metabolism. GH interacts with the GH receptor (GHR), a cytokine superfamily receptor, to activate the cytoplasmic tyrosine kinase, Janus kinase 2 (JAK2), and initiate intracellular signaling cascades. IGF-I, produced in part in response to GH, binds to the heterotetrameric IGF-I receptor (IGF-IR), which is an intrinsic tyrosine kinase growth factor receptor that triggers proliferation, antiapoptosis, and other biological actions. Previous in vitro and overexpression studies have suggested that JAKs may interact with IGF-IR and that IGF-I stimulation may activate JAKs. In this study, we explore interactions between GHR-JAK2 and IGF-IR signaling pathway elements utilizing the GH and IGF-I-responsive 3T3-F442A and 3T3-L1 preadipocyte cell lines, which endogenously express both the GHR and IGF-IR. We find that GH induces formation of a complex that includes GHR, JAK2, and IGF-IR in these preadipocytes. The assembly of this complex in intact cells is rapid, GH concentration dependent, and can be prevented by a GH antagonist, G120K. However, it is not inhibited by the kinase inhibitor, staurosporine, which markedly inhibits GHR tyrosine phosphorylation. Moreover, complex formation does not appear dependent on GH-induced activation of the ERK or phosphatidylinositol 3-kinase signaling pathways or on the tyrosine phosphorylation of GHR, JAK2, or IGF-IR. These results suggest that GH-induced formation of the GHR-JAK2-IGF-IR complex is governed instead by GH-dependent conformational change(s) in the GHR and/or JAK2. We further demonstrate that GH and IGF-I can synergize in acute aspects of signaling and that IGF-I enhances GH-induced assembly of conformationally active GHRs. These findings suggest the existence of previously unappreciated relationships between these two hormones.

scholarly journals Bidirectional Signaling Links the Abelson Kinases to the Platelet-Derived Growth Factor Receptor

2004 ◽  
Vol 24 (6) ◽  
pp. 2573-2583 ◽  
Author(s):  
Rina Plattner ◽  
Anthony J. Koleske ◽  
Andrius Kazlauskas ◽  
Ann Marie Pendergast
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinase ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Nonreceptor Tyrosine Kinase ◽  
Membrane Ruffling ◽  
Bidirectional Signaling ◽  
Β Receptor

ABSTRACT The c-Abl nonreceptor tyrosine kinase is activated by growth factor signals such as the platelet-derived growth factor (PDGF) and functions downstream of the PDGF-β receptor (PDGFR) to mediate biological processes such as membrane ruffling, mitogenesis, and chemotaxis. Here, we show that the related kinase Arg is activated downstream of PDGFRs in a manner dependent on Src family kinases and phospholipase C γ1 (PLC-γ1)-mediated phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis, as we showed previously for c-Abl. PIP2, a highly abundant phosphoinositide known to regulate cytoskeletal and membrane proteins, inhibits the tyrosine kinase activities of both Arg and c-Abl in vitro and in cells. We now demonstrate that c-Abl and Arg form inducible complexes with and are phosphorylated by the PDGFR tyrosine kinase in vitro and in vivo. Moreover, c-Abl and Arg, in turn, phosphorylate the PDGFR. We show that c-Abl and Arg exhibit nonredundant functions downstream of the activated PDGFR. Reintroduction of c-Abl into Arg-Abl double-null fibroblasts rescues the ability of PLC-γ1 to increase PDGF-mediated chemotaxis, while reexpression of Arg fails to rescue the chemotaxis defect. These data show that, although both kinases are activated and form complexes with proteins in the PDGFR signaling pathway, only c-Abl functions downstream of PLC-γ1 to mediate chemotaxis.

IQGAP1 binds the Axl receptor kinase and inhibits its signaling

2018 ◽  
Vol 475 (19) ◽  
pp. 3073-3086
Author(s):  
Laëtitia Gorisse ◽  
Zhigang Li ◽  
Andrew C. Hedman ◽  
David B. Sacks
Keyword(s):  
Growth Factor ◽  
Intracellular Signaling ◽  
Growth Factor Receptor ◽  
Direct Interaction ◽  
Specific Protein ◽  
Tyrosine Kinase Receptor ◽  
Proximity Ligation ◽  
Vitro Analysis ◽  
In Cells

Axl is a tyrosine kinase receptor that is important for hematopoiesis, the innate immune response, platelet aggregation, engulfment of apoptotic cells and cell survival. Binding of growth arrest-specific protein 6 (Gas6) activates Axl signaling, but the mechanism of inactivation of the Axl receptor is poorly understood. In the present study, we show that IQGAP1 modulates Axl signaling. IQGAP1 is a scaffold protein that integrates cell signaling pathways by binding several growth factor receptors and intracellular signaling molecules. Our in vitro analysis revealed a direct interaction between the IQ domain of IQGAP1 and Axl. Analysis by both immunoprecipitation and proximity ligation assays demonstrated an association between Axl and IQGAP1 in cells and this interaction was decreased by Gas6. Unexpectedly, reducing IQGAP1 levels in cells significantly enhanced the ability of Gas6 to stimulate both Axl phosphorylation and activation of Akt. Moreover, IQGAP1 regulates the interaction of Axl with the epidermal growth factor receptor. Our data identify IQGAP1 as a previously undescribed suppressor of Axl and provide insight into regulation of Axl function.

scholarly journals Ligand-induced recruitment of Na+/H+-exchanger regulatory factor to the PDGF (platelet-derived growth factor) receptor regulates actin cytoskeleton reorganization by PDGF

2003 ◽  
Vol 376 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Jean-Baptiste DEMOULIN ◽  
Jeong Kon SEO ◽  
Simon EKMAN ◽  
Eva GRAPENGIESSER ◽  
Ulf HELLMAN ◽  
...  
Keyword(s):  
Growth Factor ◽  
Ph Regulation ◽  
Pdz Domain ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Pdgf Receptor ◽  
Regulatory Factor ◽  
C Terminus ◽  
Cytoskeleton Reorganization

Proteins interacting with the human PDGF (platelet-derived growth factor) β-receptor were isolated using immobilized peptides derived from the receptor C-terminus as a bait. We identified two PDZ domain proteins, namely NHERF (Na+/H+ exchanger regulatory factor, also called EBP50) and NHERF2 (E3KARP, SIP-1, TKA-1), which have been shown previously to associate with the murine PDGF receptor [Maudsley, Zamah, Rahman, Blitzer, Luttrell, Lefkowitz and Hall (2000) Mol. Cell. Biol. 20, 8352–8363]. In porcine aortic endothelial cells and in fibroblasts, NHERF recruitment was induced by PDGF treatment, but the receptor kinase activity was not required for the formation of the complex, suggesting that NHERF was not recruited in a phosphotyrosine-dependent manner. Instead, the interaction was abolished by mutation of the consensus C-terminal PDZ-interacting domain of the receptor (Leu-1106 to Ala), or truncation of the last 75 amino acid residues of the receptor. Disruption of NHERF binding to the receptor enhanced actin filament reorganization, but did not affect PDGF-induced mitogenicity and chemotaxis. Although NHERF was initially characterized as a factor required for intracellular pH regulation by β2-adrenergic receptors, we observed that it was not involved in pH regulation by PDGF. Collectively, these results suggest that the ligand-induced association of NHERF PDZ domain with the PDGF receptor tyrosine kinase controls the extent of cytoskeleton reorganization in response to PDGF.

scholarly journals The cytoplasmic tyrosine kinase FER is associated with the catenin-like substrate pp120 and is activated by growth factors.

1995 ◽  
Vol 15 (8) ◽  
pp. 4553-4561 ◽  
Author(s):  
L Kim ◽  
T W Wong
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinase ◽  
Growth Factor Receptor ◽  
Sh2 Domain ◽  
Platelet Derived Growth Factor ◽  
Amino Terminus ◽  
A431 Cells ◽  
Epidermal Growth

The FER gene encodes a cytoplasmic tyrosine kinase with a single SH2 domain and an extensive amino terminus. In order to understand the cellular function of the FER kinase, we analyzed the effect of growth factor stimulation on the phosphorylation and activity of FER. Stimulation of A431 cells and 3T3 fibroblasts with epidermal growth factor or platelet-derived growth factor results in the phosphorylation of FER and two associated polypeptides. The associated polypeptides were shown to be the epidermal growth factor receptor or the platelet-derived growth factor receptor and a previously identified target, pp120. Since pp120 had previously been shown to interact with components of the cadherin-catenin complex, these results implicate FER in the regulation of cell-cell interactions. The physical association of FER with pp120 was found to be constitutive and was mediated by a 400-amino-acid sequence in the amino terminus of FER. Analyses of that sequence revealed that it has the ability to form coiled coils and that it oligomerizes in vitro. The identification of a coiled coil sequence in the FER kinase and the demonstration that the sequence mediates association with a potential substrate suggest a novel mechanism for signal transduction by cytoplasmic tyrosine kinases.

Sign in / Sign up

Export Citation Format

Share Document