Platelet-derived growth factor receptor mediates activation of ras through different signaling pathways in different cell types

A series of pieces of evidence have shown that Ras protein acts as a transducer of the platelet-derived growth factor (PDGF) receptor-mediated signaling pathway: (i) formation of Ras.GTP is detected immediately on PDGF stimulation, and (ii) a dominant inhibitory mutant Ras, as well as a neutralizing anti-Ras antibody, can interfere with PDGF-induced responses. On the other hand, several signal transducing molecules including phosphatidylinositol 3-kinase (PI3-K), GTPase-activating protein (GAP), and phospholipase C gamma (PLC gamma) bind directly to the PDGF receptor and become tyrosine phosphorylated. Recently, it was shown that specific phosphorylated tyrosines of the PDGF receptor are responsible for interaction between the receptor and each signaling molecule. However, the roles of these signaling molecules have not been elucidated, and it remains unclear which molecules are implicated in the Ras pathway. In this study, we measured Ras activation in cell lines expressing mutant PDGF receptors that are deficient in coupling with specific molecules. In fibroblast CHO cells, a mutant receptor (Y708F/Y719F [PI3-K-binding sites]) was unable to stimulate Ras, whereas another mutant (Y739F [the GAP-binding site]) could do so, suggesting an indispensable role of PI3-K or a protein that binds to the same sites as PI3-K for PDGF-stimulated Ras activation. By contrast, both of the above mutants were capable of stimulating Ras protein in a pro-B-cell line, BaF3. Furthermore, a mutant receptor (Y977F/Y989F [PLC gamma-binding sites]) could fully activate Ras, and the direct activation of protein kinase C and calcium mobilization had almost no effect on the GDP/GTP state of Ras in this cell line. These results suggest that, in the pro-B-cell transfectants, each of the above pathways (PI3-K, GAP, and PLC gamma) can be eliminated without a loss of Ras activation. It remains unclear whether another unknown essential pathway which regulates Ras protein exists within BaF3 cells. Therefore, it is likely that several different PDGF receptor-mediated signaling pathways function upstream of Ras, and the extent of the contribution of each pathway for the regulation of Ras may differ among different cell types.

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Platelet-derived growth factor and its role in health and disease

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1990.0051 ◽

1990 ◽

Vol 327 (1239) ◽

pp. 155-169 ◽

Cited By ~ 78

Keyword(s):

Growth Factor ◽

Wound Repair ◽

Cell Types ◽

Cell Surface Receptor ◽

Platelet Derived Growth Factor ◽

Intracellular Signals ◽

Surface Receptor ◽

Health And Disease ◽

Different Cell Types ◽

Different Levels

Platelet-derived growth factor (PDGF) was first discovered in platelets because they are the principal source of mitogenic activity in whole blood serum for mesenchymal cells in culture, PDGF is ubiquitous in that it can be formed by a large number of normal cells as well as many varieties of transformed cells. However, its expression and biological activity appear to be controlled at a number of different levels. The molecule consists of two peptide chains (termed ‘A’ and ‘B’) and is found as one of at least three possible isoforms, (AB, AA or BB). Each of these isoforms binds to a high-affinity cell-surface receptor that is composed of two different subunits, each of which has specificity for one or the other of the peptide chains of PDGF. The two receptor subunits are present in differing amounts on different cell types, and therefore the capacity of the different isoforms of PDGF to induce mitogenesis depends on the specific PDGF isoform and the relative numbers of receptor subunits present on the responding cell. In addition to inducing cell replication, PDGF elicits a number of intracellular signals related to mitogenesis, is chemotactic, is a vasoconstrictor, activates leukocytes, and modulates extracellular matrix turnover. This growth factor is probably involved in a number of biologically important events including wound repair, embryogenesis and development, and inflammation, leading to fibrosis, atherosclerosis and neoplasia.

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Platelet-derived Growth Factor (PDGF)-induced Ca2+Signaling in the CG4 Oligodendroglial Cell Line and in Transformed Oligodendrocytes Expressing the β-PDGF Receptor

Journal of Biological Chemistry ◽

10.1074/jbc.272.7.4351 ◽

1997 ◽

Vol 272 (7) ◽

pp. 4351-4358 ◽

Cited By ~ 28

Author(s):

Alessandro Fatatis ◽

Richard J. Miller

Keyword(s):

Growth Factor ◽

Cell Line ◽

Platelet Derived Growth Factor ◽

Pdgf Receptor ◽

Oligodendroglial Cell

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Midkine Binds to Anaplastic Lymphoma Kinase (ALK) and Acts as a Growth Factor for Different Cell Types

Journal of Biological Chemistry ◽

10.1074/jbc.m205749200 ◽

2002 ◽

Vol 277 (39) ◽

pp. 35990-35998 ◽

Cited By ~ 228

Author(s):

Gerald E. Stoica ◽

Angera Kuo ◽

Ciaran Powers ◽

Emma T. Bowden ◽

Elaine Buchert Sale ◽

...

Keyword(s):

Growth Factor ◽

Anaplastic Lymphoma Kinase ◽

Cell Types ◽

Anaplastic Lymphoma ◽

Different Cell Types

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Involvement of a phosphotyrosine protein phosphatase in the suppression of platelet-derived growth factor receptor autophosphorylation in ras-transformed cells

Biochemical Journal ◽

10.1042/bj2930215 ◽

1993 ◽

Vol 293 (1) ◽

pp. 215-221 ◽

Cited By ~ 9

Author(s):

L Tomáska ◽

R J Resnick

Keyword(s):

Growth Factor ◽

Phosphatase Activity ◽

Receptor Tyrosine Kinase ◽

Protein Phosphatase ◽

Kinase Activity ◽

Platelet Derived Growth Factor ◽

Transformed Cells ◽

Pdgf Receptor ◽

Tyrosine Kinase Activity ◽

Phosphotyrosine Protein Phosphatase

The nature of the suppression of platelet-derived growth factor (PDGF) receptor autophosphorylation in ras-transformed NIH 3T3 fibroblasts was investigated. The PDGF receptor from ras-transformed cells that had been purified by wheatgerm-lectin affinity chromatography displayed normal PDGF-induced autophosphorylation, indicating that the receptor is not irreversibly modified. Various phosphotyrosine-protein-phosphatase inhibitors did not reverse the inhibition of PDGF-receptor kinase in crude membrane preparations from ras-transformed cells. However, treatment of intact ras-transformed cells both with 2 mM sodium orthovanadate and with 20 microM phenylarsine oxide restored PDGF-receptor tyrosine-kinase activity to a level similar to that observed in normal cells. Direct measurement of the phosphatase activities in crude cellular fractions revealed a 2.5-fold higher membrane-associated phosphotyrosine-protein-phosphatase activity in ras-transformed cells, whereas phosphoserine-protein-phosphatase activity remained unchanged between the cell lines. These data suggest that the suppression of the PDGF-receptor tyrosine-kinase activity in ras-transformed cells is mediated via an inhibitory component, distinct from the receptor, that may be positively regulated by the dephosphorylation of tyrosine residue(s).

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A small v-sis/platelet-derived growth factor (PDGF) B-protein domain in which subtle conformational changes abrogate PDGF receptor interaction and transforming activity

Molecular and Cellular Biology ◽

10.1128/mcb.10.10.5496-5501.1990 ◽

1990 ◽

Vol 10 (10) ◽

pp. 5496-5501

Author(s):

N Giese ◽

W J LaRochelle ◽

M May-Siroff ◽

K C Robbins ◽

S A Aaronson

Keyword(s):

Monoclonal Antibody ◽

Growth Factor ◽

Conformational Changes ◽

Protein Domain ◽

Platelet Derived Growth Factor ◽

Receptor Interaction ◽

Pdgf Receptor ◽

Amino Acid Residues ◽

Disulfide Linkages ◽

Transforming Activity

Deletion scanning mutagenesis within the transforming region of the v-sis oncogene was used to dissect structure-function relationships. Mutations affecting codons within a domain encoding amino acids 136 through 148 had no effect upon homodimer formation or recognition by antisera which detect determinants dependent upon native intrachain disulfide linkages, yet the same mutations completely abolished transforming activity. A platelet-derived growth factor B (PDGF B) monoclonal antibody that prevents its interaction with PDGF receptors recognized v-sis, delta 142 (deletion of codon 142), and delta 148 but not delta 136, delta 137, or delta 139 mutants. These findings mapped the epitope recognized by this monoclonal antibody to include amino acid residues 136 to 139. Furthermore, mutations in the codon 136 to 148 domain caused markedly impaired ability to induce PDGF receptor tyrosine phosphorylation. Thus, subtle conformational alterations in this small domain critically affect PDGF receptor recognition and/or functional activation.

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Platelet-derived growth factor (PDGF)-dependent association of phospholipase C-gamma with the PDGF receptor signaling complex

Molecular and Cellular Biology ◽

10.1128/mcb.10.5.2359-2366.1990 ◽

1990 ◽

Vol 10 (5) ◽

pp. 2359-2366

Author(s):

D K Morrison ◽

D R Kaplan ◽

S G Rhee ◽

L T Williams

Keyword(s):

Growth Factor ◽

Tyrosine Phosphorylation ◽

Serine Phosphorylation ◽

Platelet Derived Growth Factor ◽

Pdgf Receptor ◽

Wild Type ◽

Receptor Proteins ◽

Signaling Complex

We investigated the interaction of phospholipase C-gamma (PLC-gamma) with wild-type and mutant forms of the platelet-derived growth factor (PDGF) beta-receptor both in vivo and in vitro. After PDGF treatment of CHO cell lines expressing wild-type or either of two mutant (delta Ki and Y825F) PDGF receptors, PLC-gamma became tyrosine phosphorylated and associated with the receptor proteins. The receptor association and tyrosine phosphorylation of PLC-gamma correlated with the ability of these receptors to mediate ligand-induced phosphatidylinositol turnover. However, both the delta Ki and Y825F mutant receptors were deficient in transmitting mitogenic signals, suggesting that the PDGF-induced tyrosine phosphorylation and receptor association of PLC-gamma are not sufficient to account for the growth-stimulatory activity of PDGF. Wild-type and delta Ki mutant PDGF receptor proteins expressed with recombinant baculovirus vectors also associated in vitro with mammalian PLC-gamma. However, baculovirus-expressed c-fms, v-fms, c-src, and Raf-1 proteins failed to associate with PLC-gamma under similar conditions. Phosphatase treatment of the baculovirus-expressed PDGF receptor greatly decreased its association with PLC-gamma. This requirement for receptor phosphorylation was also observed in vivo, where PLC-gamma could not associate with a mutant PDGF receptor (K602A) defective in autophosphorylation. PLC-gamma also coimmunoprecipitated with two other putative receptor substrates, the serine-threonine kinase Raf-1 and the 85-kilodalton phosphatidylinositol-3' kinase, presumably through its association with the ligand-activated receptor. Furthermore, baculovirus-expressed Raf-1 phosphorylated purified PLC-gamma in vitro at sites which showed increased serine phosphorylation in vivo in response to PDGF. These results suggest that PDGF directly influences PLC activity by inducing the association of PLC-gamma with a receptor signaling complex, resulting in increased tyrosine and serine phosphorylation of PLC-gamma.

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