scholarly journals Signal transduction by the platelet integrin alpha IIb beta 3: induction of calcium oscillations required for protein-tyrosine phosphorylation and ligand-induced spreading of stably transfected cells.

1992 ◽  
Vol 3 (9) ◽  
pp. 989-998 ◽  
Author(s):  
A J Pelletier ◽  
S C Bodary ◽  
A D Levinson
Keyword(s):  
Signal Transduction ◽  
Molecular Weight ◽  
Cell Line ◽  
Tyrosine Phosphorylation ◽  
Calcium Oscillations ◽  
Parent Cell ◽  
Protein Tyrosine Phosphorylation ◽  
Transfected Cells ◽  
293 Cells ◽  
Stimulation Of

We demonstrate an example of signal transduction by an integrin and have begun to define the pathway through which this signaling is achieved. We constructed a stably transfected derivative of 293 cells (ATCC 1573) that expresses the platelet integrin GPIIbIIIa (alpha IIb beta 3). This cell line, clone B, adheres to and spreads on fibrinogen, a ligand for alpha IIb beta 3, while the parent cell line does not. Stimulation of these cells either by adhesion to fibrinogen or with antiserum directed against alpha IIb beta 3 results in induction of calcium oscillations, followed by tyrosine phosphorylation of at least one protein of molecular weight approximately 125 kDa. We establish that this phosphorylation, as well as the morphological rearrangements, requires the mobilization of calcium.

scholarly journals Interleukin-2 induces tyrosine phosphorylation of the vav proto-oncogene product in human T cells: lack of requirement for the tyrosine kinase lck

1993 ◽  
Vol 294 (2) ◽  
pp. 339-342 ◽  
Author(s):  
G A Evans ◽  
O M Z Howard ◽  
R Erwin ◽  
W L Farrar
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
Tyrosine Kinase ◽  
Cell Line ◽  
Tyrosine Phosphorylation ◽  
Interleukin 2 ◽  
Maximum Increase ◽  
Human T Cell ◽  
Human T Cells ◽  
Stimulation Of

The haematopoietic protein, p95vav, has been shown to be a tyrosine kinase substrate and to have tyrosine kinase-modulated guanine-nucleotide-releasing-factor activity. This implies a function in the control of ras or ras-like proteins. Because ras activation has been shown to be a downstream event following stimulation of the interleukin-2 (IL-2) receptor, we investigated the possibility that vav was involved in IL-2 signal transduction pathways, using human T cells as a model. We found rapid tyrosine phosphorylation of vav in response to IL-2 within 1 min, with maximum increase of phosphorylation of 5-fold occurring by 5 min after treatment in normal human T cells. IL-2 stimulation of the human T-cell line YT and a subclone of the YT cell line (YTlck-) that does not express message for the src-family kinase p56lck also results in a rapid rate of tyrosine phosphorylation of vav of more than 5-fold by 5 min. These results suggest that vav may play an important role in IL-2-stimulated signal transduction and that there is not a strict requirement for the tyrosine kinase p56lck.

scholarly journals Lymphoma regression induced by monoclonal anti-idiotypic antibodies correlates with their ability to induce Ig signal transduction and is not prevented by tumor expression of high levels of bcl-2 protein

Blood ◽  
1994 ◽  
Vol 83 (4) ◽  
pp. 899-906 ◽  
Author(s):  
WM Vuist ◽  
R Levy ◽  
DG Maloney
Keyword(s):  
Signal Transduction ◽  
Tumor Cells ◽  
Tyrosine Phosphorylation ◽  
Tumor Regression ◽  
Cellular Protein ◽  
Protein Tyrosine Phosphorylation ◽  
Custom Made ◽  
Tumor Expression ◽  
Complete Tumor

Abstract Custom-made monoclonal anti-idiotype antibodies (anti-Id MoAbs) have been tested as a treatment modality in 34 non-Hodgkin's lymphoma (NHL) patients. Partial or complete tumor remissions have been induced with this treatment in 68% of these patients. One mechanism by which anti- idiotype antibodies may have induced these tumor responses is via a direct antiproliferative effect on the tumor cells, resulting in apoptosis. Primary NHL cells do not proliferate well enough in vitro to test this hypothesis directly. Therefore, we studied the effect of anti-idiotype antibodies on signal transduction through the surface Ig receptor as measured by the induction of cellular protein tyrosine phosphorylation. To assess whether bcl-2 protein could protect lymphoma cells from death induced by anti-Id MoAb, we also measured the level of bcl-2 protein in the same tumor cells. We found a strong correlation between the ability of an anti-Id MoAb to induce an increase in tyrosine phosphorylation in vitro and its ability to induce a tumor regression in the patient. By contrast, the level of bcl-2 expressed by the tumor cells was not correlated with clinical response to anti-Id MoAb treatment.

scholarly journals Internalization of the granulocyte-macrophage colony-stimulating factor receptor is not required for induction of protein tyrosine phosphorylation in human myeloid cells

Blood ◽  
1991 ◽  
Vol 78 (8) ◽  
pp. 1928-1935 ◽  
Author(s):  
K Okuda ◽  
B Druker ◽  
Y Kanakura ◽  
M Koenigsmann ◽  
JD Griffin
Keyword(s):  
Signal Transduction ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Receptor Internalization ◽  
Protein Tyrosine Phosphorylation ◽  
Protein Tyrosine ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Abstract Granulocyte-macrophage colony-stimulating factor (GM-CSF) exerts its biologic activities through binding to specific high-affinity cell surface receptors. After binding, the ligand/receptor complex is rapidly internalized in most hematopoietic cells. Using a human factor- dependent cell line, MO7, and normal human neutrophils, we found that the internalization is exquisitely temperature-dependent, such that ligand/receptor internalization does not detectably occur at 4 degrees C. Activation of the GM-CSF receptor has previously been shown to stimulate a number of postreceptor signal transduction pathways, including activation of a tyrosine kinase and activation of the serine/threonine kinase, Raf-1. The GM-CSF-stimulated increase in tyrosine kinase activity occurs rapidly at both 4 degrees C and 37 degrees C, and therefore is likely to be independent of receptor internalization. At 37 degrees C, the protein tyrosine phosphorylation was transient in MO7 cells, with maximum phosphorylation observed after 5 to 15 minutes, followed by a rapid decline. At 4 degrees C, the protein tyrosine phosphorylation of the same substrates was greater than at 37 degrees C, and no decline in substrate phosphorylation was observed for at least 90 minutes. In contrast to tyrosine phosphorylation, the activation and hyper-phosphorylation of Raf-1 observed at 37 degrees C in both MO7 cells and neutrophils was markedly diminished at 4 degrees C. These results indicate that at least one postreceptor signal transduction mechanism, activation of a tyrosine kinase, does not require ligand/receptor internalization, and indicate that receptor internalization may be a consequence, rather than the initiator, of signal transduction.

Stimulation of protein tyrosine phosphorylation by platelet-activating factor and progesterone in human spermatozoa

1995 ◽  
Vol 108 (1-2) ◽  
pp. 35-42 ◽  
Author(s):  
Michaela Luconi ◽  
Lorella Bonaccorsi ◽  
Csilla Krausz ◽  
Ginetta Gervasi ◽  
Gianni Forti ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Platelet Activating Factor ◽  
Human Spermatozoa ◽  
Protein Tyrosine Phosphorylation ◽  
Protein Tyrosine ◽  
Stimulation Of
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