Epidermal growth factor stimulates phospholipase D activity in the absence of inositol lipid hydrolysis in Swiss 3T3 cells

1991 ◽  
Vol 19 (2) ◽  
pp. 108S-108S
Author(s):  
Simon J. Cook ◽  
Michael J. O. Wakelam
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Phospholipase D ◽  
3T3 Cells ◽  
Lipid Hydrolysis ◽  
Epidermal Growth ◽  
Swiss 3T3

scholarly journals Epidermal growth factor increases sn-1,2-diacylglycerol levels and activates phospholipase D-catalysed phosphatidylcholine breakdown in Swiss 3T3 cells in the absence of inositol-lipid hydrolysis

1992 ◽  
Vol 285 (1) ◽  
pp. 247-253 ◽  
Author(s):  
S J Cook ◽  
M J O Wakelam
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Phospholipase D ◽  
Egf Receptor ◽  
Kinase Inhibitor ◽  
3T3 Cells ◽  
Lipid Hydrolysis ◽  
Epidermal Growth ◽  
Swiss 3T3 ◽  
Pre Treatment

Addition of epidermal growth factor (EGF) to quiescent Swiss 3T3 cells resulted in a sustained increase in cellular diacylglycerol (DG) content in the absence of inositol-lipid hydrolysis. In the presence of non-cytotoxic concentrations of butan-1-ol, EGF stimulated the formation of phosphatidylbutanol, indicating that the EGF receptor was able to couple to the activation of phospholipase D (PLD). EGF-stimulated release of choline from Swiss 3T3 cells suggested that the major substrate for this PLD was phosphatidylcholine. Unlike bombesin-stimulated PLD activity, the response to EGF was not inhibited by a selective protein kinase C (PKC) inhibitor (Ro-31-8220), suggesting that it was not dependent on PKC activation. Pre-treatment of Swiss 3T3 cells with the EGF-receptor tyrosine kinase inhibitor AG18 selectively inhibited EGF-stimulated PLD activity; bombesin-stimulated PLD activity was unaffected. Butan-1-ol inhibited phorbol ester- and bombesin-stimulated DG formation suggesting a role for a coupled PLD/phosphatidate phosphohydrolase pathway; in contrast, EGF-stimulated DG formation was unaffected.

Epidermal growth factor and bombesin differ strikingly in the induction of early responses in Swiss 3T3 cells

1990 ◽  
Vol 142 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Arjo J. Bierman ◽  
Leo Koenderman ◽  
Anton J. Tool ◽  
W. De Laat Siegfried
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
3T3 Cells ◽  
Epidermal Growth ◽  
Swiss 3T3

scholarly journals Activation of Endogenous Thrombin Receptors Causes Clustering and Sensitization of Epidermal Growth Factor Receptors of Swiss 3t3 Cells without Transactivation

2001 ◽  
Vol 152 (2) ◽  
pp. 263-274 ◽  
Author(s):  
Michael F. Crouch ◽  
Deborah A. Davy ◽  
Francis S. Willard ◽  
Leise A. Berven
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Thrombin Receptor ◽  
3T3 Cells ◽  
Downstream Effectors ◽  
Epidermal Growth ◽  
Swiss 3T3 ◽  
G Protein Coupled ◽  
Stimulation Of

The G protein–coupled thrombin receptor can induce cellular responses in some systems by transactivating the epidermal growth factor (EGF) receptor. This is in part due to the stimulation of ectoproteases that generate EGF receptor ligands. We show here that this cannot account for the stimulation of proliferation or migration by thrombin of Swiss 3T3 cells. Thrombin has no direct effect on the activation state of the EGF receptor or of its downstream effectors. However, thrombin induces the subcellular clustering of the EGF receptor at filamentous actin–containing structures at the leading edge and actin arcs of migrating cells in association with other signaling molecules, including Shc and phospholipase Cγ1. In these thrombin-primed cells, the subsequent migratory response to EGF is potentiated. Thrombin did not potentiate the EGF-stimulated EGF receptor phosphorylation. Thus, in Swiss 3T3 cells the G protein–coupled thrombin receptor can potentiate the EGF tyrosine kinase receptor response when activated by EGF, and this appears to be due to the subcellular concentration of the receptor with downstream effectors and not to the overall ability of EGF to induce receptor transphosphorylation. Thus, the EGF receptor subcellular localization which is altered by thrombin appears to be an important determinant of the efficacy of downstream EGF receptor signaling in cell migration.

scholarly journals Inhibition of the binding of 125I-labelled epidermal growth factor to mouse cells by a mitogen in goat mammary secretions

1983 ◽  
Vol 212 (2) ◽  
pp. 465-472 ◽  
Author(s):  
K D Brown ◽  
D M Blakeley
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Temperature Sensitive ◽  
Egf Receptors ◽  
3T3 Cells ◽  
Epidermal Growth ◽  
Swiss 3T3

Pre-colostrum and colostrum from goats cause a marked inhibition of the binding of 125I-labelled epidermal growth factor (125I-EGF) to Swiss 3T3 cells. The ability of these secretions to inhibit 125I-EGF binding is closely correlated with the ability to stimulate DNA synthesis in quiescent 3T3 cell cultures, suggesting that goat mammary secretions may contain an EGF-related mitogen. However, the material in colostrum which inhibits 125I-EGF binding to Swiss 3T3 cells is a basic protein with Mr greater than 20000 and is thus quite different from mouse and human EGF. Furthermore, the colostral-mediated inhibition of 125I-EGF binding, although rapid and apparently competitive, differs from the inhibition of binding induced by native, unlabelled EGF. Thus, the inhibitory effect of colostrum is markedly decreased when the assay temperature is shifted from 37 degrees C to 4 degrees C whereas unlabelled EGF is an effective competitive inhibitor at both 37 degrees C and 4 degrees C. Incubation of cells with EGF causes a reduction in cell surface EGF receptors whereas exposure to colostrum does not induce down-regulation of the EGF receptor. Our results suggest that the colostral factor does not bind directly to EGF receptors but inhibits 125I-EGF binding by an indirect mechanism which involves a temperature-sensitive step.

scholarly journals The epidermal growth factor-like domain of recombinant human thrombomodulin exhibits mitogenic activity for Swiss 3T3 cells

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 225-233 ◽  
Author(s):  
H Hamada ◽  
H Ishii ◽  
K Sakyo ◽  
S Horie ◽  
K Nishiki ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Dna Synthesis ◽  
Cell Line ◽  
Control Level ◽  
Mitogenic Activity ◽  
Thymidine Uptake ◽  
3T3 Cells ◽  
Epidermal Growth ◽  
Swiss 3T3

Thrombomodulin (TM) is an anticoagulant endothelial cell surface glycoprotein containing six tandem epidermal growth factor (EGF)-like structures. We prepared a recombinant TM peptide (rTME1–6, from R214GHWA to DSGK466 of native TM) composed of these six EGF-like structures and investigated the effect of rTME1–6 peptide on the growth of the Swiss 3T3 fibroblast cell line. It was found that rTME1–6 induced proliferation of Swiss 3T3 cells and accelerated [3H]thymidine uptake into their DNA. [3H]Thymidine uptake increased in a dose- dependent manner, plateauing at 50 ng/mL rTME1–6, which was 1.8 times the control level. rTME1–6 peptide (50 ng/mL) also accelerated the DNA synthesis of human dermal fibroblasts (HDFs), A549 (a human lung cancer cell line), HepG2 (a human hepatocarcinoma cell line), and U937 cells (a human monocytic cell line) to 1.5, 1.6, 1.4, and 1.2 times the control level, respectively. The magnitude of the acceleration of DNA synthesis in Swiss 3T3 induced by rTME1–6 was approximately 20% of that of EGF on a molar basis. The uptake of [3H]thymidine was accelerated synergistically by coculture of the cells with rTME1–6 and insulin, similar to the coculture with EGF and insulin. The effects of rTME1–6 were abolished by addition of polyclonal antihuman TM IgG, whereas the actions of insulin and EGF were not influenced. Glucose uptake in Swiss 3T3 cells also increased 1.6 times over control levels by culture with 50 ng/mL rTME1–6 (1.25 nmol/L), compared with 2.7 times by 10 ng/mL EGF (1.66 nmol/L). Binding of [125I]EGF (0.5 ng/mL, 0.083 nmol/L) by the cells was inhibited by about 60% by addition of an eight-fold molar excess of nonlabeled EGF (0.664 nmol/L), whereas no inhibition of [125I]EGF binding was observed, even in the presence of a 1,000-fold molar excess (83 nmol/L) of rTME1–6. Specific binding of [125I]rTME1–6 on the cells showed a saturation curve, and the apparent concentration of rTME1–6 required for half maximum binding of the peptide on the cells was calculated to be 31.5 ng/mL. Thus, the overall results indicated that the rTME1–6 peptide had mitogenic activity for Swiss 3T3 cells, accelerated DNA synthesis and glucose uptake, and that the mitogenic activity might be mediated by binding of the peptide to a specific site different from the EGF receptor.

scholarly journals Early events elicited by bombesin and structurally related peptides in quiescent Swiss 3T3 cells. I. Activation of protein kinase C and inhibition of epidermal growth factor binding.

1986 ◽  
Vol 102 (6) ◽  
pp. 2211-2222 ◽  
Author(s):  
I Zachary ◽  
J W Sinnett-Smith ◽  
E Rozengurt
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Cellular Protein ◽  
3T3 Cells ◽  
Kinase C ◽  
Epidermal Growth ◽  
Swiss 3T3

Addition of bombesin to quiescent cultures of Swiss 3T3 cells caused a rapid increase in the phosphorylation of an Mr 80,000 cellular protein (designated 80k). The effect was both concentration and time dependent; enhancement in 80k phosphorylation could be detected as early as 10 s after the addition of peptide. Recently, a rapid increase in the phosphorylation of an 80k cellular protein after treatment with phorbol esters or diacylglycerol has been shown to reflect the activation of protein kinase C in intact fibroblasts (Rozengurt, E., A. Rodriguez-Pena, and K. A. Smith, 1983, Proc. Natl. Acad. Sci. USA., 80:7244-7248; Rozengurt, E., A. Rodriguez-Pena, M. Coombs, and J. Sinnett-Smith, 1984, Proc. Natl. Acad. Sci. USA., 81:5748-5752). The 80k phosphoproteins generated in response to bombesin and to phorbol 12,13-dibutyrate were identical as judged by one- and two-dimensional PAGE and by peptide mapping after partial proteolysis with Staphylococcus aureus V8 protease. In addition, prolonged pretreatment of 3T3 cells with phorbol 12,13-dibutyrate, which leads to the disappearance of protein kinase C activity, blocked the ability of bombesin to stimulate 80k. Bombesin also caused a rapid (1 min) inhibition of 125I-labeled epidermal growth factor (125I-EGF) binding to Swiss 3T3 cells. The inhibition was both concentration and temperature dependent and resulted from a marked decrease in the affinity of the EGF receptor for its ligand. Peptides structurally related to bombesin, including gastrin-releasing peptide, also stimulated 80k phosphorylation and inhibited 125I-EGF binding; both effects were selectively blocked by a novel bombesin antagonist. These results strongly suggest that these responses are mediated by specific high-affinity receptors that recognize the peptides of the bombesin family in Swiss 3T3 cells. While an increase in cytosolic Ca2+ concentration does not mediate the bombesin inhibition of 125I-EGF binding, the activation of protein kinase C in intact Swiss 3T3 cells by peptides of the bombesin family may lead to rapid inhibition of the binding of 125I-EGF to its cellular receptor.

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