Internalization of activated platelet-derived growth factor receptor-phosphatidylinositol-3' kinase complexes: potential interactions with the microtubule cytoskeleton

1993 ◽  
Vol 13 (10) ◽  
pp. 6052-6063
Author(s):  
R Kapeller ◽  
R Chakrabarti ◽  
L Cantley ◽  
F Fay ◽  
S Corvera
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinases ◽  
Growth Factor Receptor ◽  
Endocytic Pathway ◽  
Platelet Derived Growth Factor ◽  
Cell Periphery ◽  
Perinuclear Region ◽  
High Concentration ◽  
Microtubule Cytoskeleton ◽  
Microtubule Network

Phosphatidylinositol (PI)-3' kinase catalyzes the formation of PI 3,4-diphosphate and PI 3,4,5-triphosphate in response to stimulation of cells by platelet-derived growth factor (PDGF). Here we report that tyrosine-phosphorylated PDGF receptors, the p85 subunit of PI-3' kinase (p85), and activated PI-3' kinase are found in isolated clathrin-coated vesicles within 2 min of exposure of cells to PDGF, indicating that both receptor and activated PI-3' kinase enter the endocytic pathway. Immunofluorescence analysis of p85 in serum-starved cells revealed a punctate/reticular staining pattern, concentrated in the perinuclear region and displaying high focal concentration at the centrosome. In addition, partial coalignment of p85 with microtubules was observed after optical sectioning microscopy and image reconstruction. The association of p85 with the microtubule network was further evidenced by the microtubule-depolymerizing drug nocodazole, which caused a redistribution of p85 from the perinuclear region to the cell periphery. Interestingly, the most significant effect of PDGF on the distribution of p85 was an increase in the staining intensity of this protein in the perinuclear region, and this effect was eliminated by prior treatment of cells with nocodazole. These results suggest that PDGF receptor-p85 complexes internalize and transit in association with the microtubule cytoskeleton. In addition, the high concentration of p85 in intracellular structures in the absence of PDGF stimulation suggests additional roles for this protein independent of its association with receptor tyrosine kinases.

scholarly journals Internalization of activated platelet-derived growth factor receptor-phosphatidylinositol-3' kinase complexes: potential interactions with the microtubule cytoskeleton.

1993 ◽  
Vol 13 (10) ◽  
pp. 6052-6063 ◽  
Author(s):  
R Kapeller ◽  
R Chakrabarti ◽  
L Cantley ◽  
F Fay ◽  
S Corvera
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinases ◽  
Growth Factor Receptor ◽  
Endocytic Pathway ◽  
Platelet Derived Growth Factor ◽  
Cell Periphery ◽  
Perinuclear Region ◽  
High Concentration ◽  
Microtubule Cytoskeleton ◽  
Microtubule Network

Phosphatidylinositol (PI)-3' kinase catalyzes the formation of PI 3,4-diphosphate and PI 3,4,5-triphosphate in response to stimulation of cells by platelet-derived growth factor (PDGF). Here we report that tyrosine-phosphorylated PDGF receptors, the p85 subunit of PI-3' kinase (p85), and activated PI-3' kinase are found in isolated clathrin-coated vesicles within 2 min of exposure of cells to PDGF, indicating that both receptor and activated PI-3' kinase enter the endocytic pathway. Immunofluorescence analysis of p85 in serum-starved cells revealed a punctate/reticular staining pattern, concentrated in the perinuclear region and displaying high focal concentration at the centrosome. In addition, partial coalignment of p85 with microtubules was observed after optical sectioning microscopy and image reconstruction. The association of p85 with the microtubule network was further evidenced by the microtubule-depolymerizing drug nocodazole, which caused a redistribution of p85 from the perinuclear region to the cell periphery. Interestingly, the most significant effect of PDGF on the distribution of p85 was an increase in the staining intensity of this protein in the perinuclear region, and this effect was eliminated by prior treatment of cells with nocodazole. These results suggest that PDGF receptor-p85 complexes internalize and transit in association with the microtubule cytoskeleton. In addition, the high concentration of p85 in intracellular structures in the absence of PDGF stimulation suggests additional roles for this protein independent of its association with receptor tyrosine kinases.

Platelet-derived growth factor induces rapid and sustained tyrosine phosphorylation of phospholipase C-gamma in quiescent BALB/c 3T3 cells

1989 ◽  
Vol 9 (7) ◽  
pp. 2934-2943
Author(s):  
M I Wahl ◽  
N E Olashaw ◽  
S Nishibe ◽  
S G Rhee ◽  
W J Pledger ◽  
...  
Keyword(s):  
Growth Factor ◽  
Phospholipase C ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Hormonal Regulation ◽  
Growth Factor Receptor ◽  
Fold Increase ◽  
Platelet Derived Growth Factor ◽  
3T3 Cells ◽  
Pdgf Stimulation

Platelet-derived growth factor (PDGF) stimulates the proliferation of quiescent fibroblasts through a series of events initiated by activation of tyrosine kinase activity of the PDGF receptor at the cell surface. Physiologically significant substrates for this or other growth factor receptor or oncogene tyrosine kinases have been difficult to identify. Phospholipase C (PLC), a key enzyme of the phosphoinositide pathway, is believed to be an important site for hormonal regulation of the hydrolysis of phosphatidylinositol 4,5-bisphosphate, which produces the intracellular second-messenger molecules inositol 1,4,5-trisphosphate and 1,2-diacylglycerol. Treatment of BALB/c 3T3 cells with PDGF led to a rapid (within 1 min) and significant (greater than 50-fold) increase in PLC activity, as detected in eluates of proteins from a phosphotyrosine immunoaffinity matrix. This PDGF-stimulated increase in phosphotyrosine-immunopurified PLC activity occurred for up to 12 h after addition of growth factor to quiescent cells. Interestingly, the PDGF stimulation occurred at 3 as well as 37 degrees C and in the absence or presence of extracellular Ca2+. Immunoprecipitation of cellular proteins with monoclonal antibodies specific for three distinct cytosolic PLC isozymes demonstrated the presence of a 145-kilodalton isozyme, PLC-gamma (formerly PLC-II), in BALB/c 3T3 cells. Furthermore, these immunoprecipitation studies showed that PLC-gamma is rapidly phosphorylated on tyrosine residues after PDGF stimulation. The results suggest that mitogenic signaling by PDGF is coincident with tyrosine phosphorylation of PLC-gamma.

Two functionally distinct pools of Src kinases for PDGF receptor signalling

2005 ◽  
Vol 33 (6) ◽  
pp. 1313-1315 ◽  
Author(s):  
L. Veracini ◽  
M. Franco ◽  
A. Boureux ◽  
V. Simon ◽  
S. Roche ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Tyrosine Kinases ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Pdgf Receptor ◽  
Actin Assembly ◽  
Cell Responses ◽  
Receptor Signalling ◽  
And Migration

The cytoplasmic tyrosine kinases of the Src family (SFK) play important roles in cell responses induced by growth factors, including cell growth, survival and migration. Here, we review how SFK participate in PDGF (platelet-derived growth factor) receptor signalling leading to DNA synthesis and actin assembly. Furthermore, evidence for a spatial compartmentalization of SFK signalling is also discussed.

scholarly journals Selected Parameters of Angiogenesis and the JAK2, CALR, and MPL Mutations in Patients With Essential Thrombocythemia

2018 ◽  
Vol 24 (7) ◽  
pp. 1056-1060 ◽  
Author(s):  
Grażyna Gadomska ◽  
Alicja Bartoszewska-Kubiak ◽  
Joanna Boinska ◽  
Karolina Matiakowska ◽  
Katarzyna Ziołkowska ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Essential Thrombocythemia ◽  
Leukemia Virus ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Vascular Endothelial ◽  
High Concentration ◽  
Endothelial Growth Factor ◽  
Calr Mutation

The aim of the study was to evaluate selected angiogenic factors in patients with essential thrombocythemia (ET) depending on JAK2V617F, calreticulin gene (CALR) and myeloproliferative leukemia virus oncogene (MPL) mutations. Sixty ET patients and 20 healthy volunteers were enrolled in the study. The following tests were performed: vascular endothelial growth factor- A (VEGF-A), soluble vascular endothelial growth factor receptor-1 (sVEGFR-1),soluble vascular endothelial growth factor receptor-2 (sVEGFR-2), platelet-derived growth factor( PDGF-BB), and stromal-derived factor-1α (SDF-1α). We observed an increased PDGF-BB level in patients with ET compared to the controls. Patients with CALR mutation had significantly higher concentration of PDGF-BB and lower concentration of SDF-1α than patients with JAK2V617F mutation. High concentration of PDGF-BB and low concentration of SDF-1α in patients with CALR(+) ET may indicate a contribution of these chemokines in disturbed Ca2+ metabolism in platelets.

scholarly journals The emerging complexity of PDGFRs: activation, internalization and signal attenuation

2020 ◽  
Vol 48 (3) ◽  
pp. 1167-1176
Author(s):  
Madison A. Rogers ◽  
Katherine A. Fantauzzo
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Growth Factor Receptor ◽  
Receptor Internalization ◽  
Platelet Derived Growth Factor ◽  
Receptor Recycling ◽  
Signal Attenuation ◽  
Ongoing Research ◽  
Fine Tune

The platelet-derived growth factor receptor (PDGFR) family of receptor tyrosine kinases allows cells to communicate with the environment to regulate diverse cellular activities. Here, we highlight recent data investigating the structural makeup of individual PDGFRs upon activation, revealing the importance of the whole receptor in the propagation of extracellular ligand binding and dimerization. Furthermore, we review ongoing research demonstrating the significance of receptor internalization and signal attenuation in the regulation of PDGFR activity. Interactions with internalization machinery, signaling from endosomes, receptor degradation and receptor recycling are physiological means by which cells fine-tune PDGFR responses to growth factor stimulation. In this review, we discuss the biophysical, structural, in silico and biochemical data that have provided evidence for these mechanisms. We further highlight the commonalities and differences between PDGFRα and PDGFRβ signaling, revealing critical gaps in knowledge. In total, this review provides a conclusive summary on the state of the PDGFR field and underscores the need for novel techniques to fully elucidate the mechanisms of PDGFR activation, internalization and signal attenuation.

scholarly journals Distinct Mechanisms of Activation of Stat1 and Stat3 by Platelet-Derived Growth Factor Receptor in a Cell-Free System

1999 ◽  
Vol 19 (5) ◽  
pp. 3727-3735 ◽  
Author(s):  
Marie-Luce Vignais ◽  
Michael Gilman
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinases ◽  
Membrane Fraction ◽  
Growth Factor Receptor ◽  
Direct Interaction ◽  
Platelet Derived Growth Factor ◽  
Cytosolic Fraction ◽  
Free System ◽  
Cell Free System ◽  
A Cell

ABSTRACT Ligand-dependent activation of the platelet-derived growth factor receptor (PDGFR) in fibroblasts in culture leads to the activation of the JAK family of protein-tyrosine kinases and of the transcription factors Stat1 and Stat3. To determine the biochemical mechanism of STAT activation by PDGFR, we devised a cell-free system composed of a membrane fraction from cells overexpressing PDGFR. When supplemented with crude cytosol, the membrane fraction supported PDGF- and ATP-dependent activation of both Stat1 and Stat3. However, the extent of Stat3 activation differed depending on the source of the cytosolic fraction. Using purified recombinant STAT proteins produced inEscherichia coli, we found that Stat1 could be activated by immunopurified PDGFR and showed no additional requirement for membrane- or cytosol-derived proteins. In contrast, activation of Stat3 exhibited a strong requirement for the cytosolic fraction. The activity present in the cytosolic fraction could be depleted with antibodies to JAK proteins. We conclude that the mechanisms of activation of Stat1 and Stat3 by PDGFR are distinct. Stat1 activation appears to result from a direct interaction with the receptor, whereas Stat3 activation additionally requires JAK proteins.

scholarly journals Evolutionary Divergence of Platelet-Derived Growth Factor Alpha Receptor Signaling Mechanisms

2003 ◽  
Vol 23 (11) ◽  
pp. 4013-4025 ◽  
Author(s):  
T. Guy Hamilton ◽  
Richard A. Klinghoffer ◽  
Philip D. Corrin ◽  
Philippe Soriano
Keyword(s):  
Growth Factor ◽  
Map Kinase ◽  
Signaling Pathways ◽  
Tyrosine Kinases ◽  
Expression Patterns ◽  
Growth Factor Receptor ◽  
Mouse Fibroblast ◽  
Platelet Derived Growth Factor ◽  
Evolutionary Divergence ◽  
Factor Alpha

ABSTRACT Receptor tyrosine kinases (RTKs) direct diverse cellular and developmental responses by stimulating a relatively small number of overlapping signaling pathways. Specificity may be determined by RTK expression patterns or by differential activation of individual signaling pathways. To address this issue we generated knock-in mice in which the extracellular domain of the mouse platelet-derived growth factor alpha receptor (PDGFαR) is fused to the cytosolic domain of Drosophila Torso (αTor) or the mouse fibroblast growth factor receptor 1 (αFR). αTor homozygous embryos exhibit significant rescue of neural crest and angiogenesis defects normally found in PDGFαR-null embryos yet fail to rescue skeletal or extraembryonic defects. This phenotype was associated with the ability of αTor to stimulate the mitogen-activated protein (MAP) kinase pathway to near wild-type levels but failure to completely activate other pathways, such as phosphatidylinositol (PI) 3-kinase. The αFR chimeric receptor fails to rescue any aspect of the PDGFαR-null phenotype. Instead, αFR expression leads to a gain-of-function phenotype highlighted by ectopic bone development. The αFR phenotype was associated with a failure to limit MAP kinase signaling and to engage significant PI3-kinase response. These results suggest that precise regulation of divergent downstream signaling pathways is critical for specification of RTK function.

scholarly journals P033 Scleroderma-like fibrotic disorder associated with a gastro-intestinal stromal tumour which responded only to imatinib

Rheumatology ◽  
2021 ◽  
Vol 60 (Supplement_1) ◽  
Author(s):  
Zaran A Butt ◽  
Wan Lin NG ◽  
Donough Howard ◽  
Kamal Osman
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinases ◽  
Negative Symptoms ◽  
Kinase Inhibitors ◽  
Growth Factor Receptor ◽  
Gastric Fundus ◽  
Stromal Tumour ◽  
Platelet Derived Growth Factor ◽  
Rapid Improvement ◽  
Metastatic Recurrence

Abstract Background/Aims  Gastro-intestinal stromal tumour (GIST) is recognised as the most prevalent mesenchymal tumour of the gastro-intestinal (GI) tract. The vast majority of GIST display activating mutations in receptor tyrosine kinases, such as platelet-derived growth factor receptor alpha (PDGFRA) and c-kit. This characteristic has lead to the development and approval of targeted therapies such as Imatinib for metastatic GIST. Scleroderma is an idiopathic fibrotic syndrome which involves excess collagen deposition in multiple tissues and organs. There is emerging evidence that dysfunctional fibroblasts are central to the underlying pathogenesis of this disease. An increasing awareness of the complex interplay of these fibroblasts with other cells and inflammatory mediators, such as platelet-derived growth factor (PDGF), is being recognised. This novel case serves to further develop our understanding of these pathological interactions, and to highlight a prospective role for Imatinib in disrupting them. Methods  We present a case report below. Results  A 54-year-old Caucasian male was referred to our rheumatology clinic due to worsening Raynaud's syndrome, arthralgia, and dry cough. He subsequently developed weight loss, pyrosis and skin thickening. This clinical picture was suggestive of a new diagnosis of systemic sclerosis. However, fibrotic skin changes did not extend to the distal finger, and anti-nuclear antibody (ANA) was negative. Symptoms were also refractory to various vasodilator and immunosuppressive therapies, including nifedipine, repeated iloprost infusions, azathioprine, mycophenolic acid, prednisolone, and sildenafil. Computed tomography (CT) imaging revealed interstitial pulmonary fibrosis and a mass within the gastric fundus. Histopathologic features and immunological staining of this mass were consistent with a GIST. Resection of the tumour did not improve fibrotic symptoms. Surveillance imaging one-year later was highly concerning for metastatic recurrence, which was later confirmed with tissue biopsy. He was subsequently initiated on Imatinib therapy, which led to a rapid improvement in fibrotic changes within weeks. Conclusion  While there have been previous descriptions of para-neoplastic fibrotic syndromes, this is the first reported case of a scleroderma-mimicking disorder associated with GIST. It hints at an important potential overlap in the pathogenesis of these disease processes, and a potential role for tyrosine-kinase inhibitors in the treatment of scleroderma-like fibrotic disorders. Disclosure  Z.A. Butt: None. W. Ng: None. D. Howard: None. K. Osman: None.

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