scholarly journals Cell-cell contact dictates life or death decisions following CD95 activation in cancer

2018 ◽  
Author(s):  
Gülce S. Gülcüler Balta ◽  
Cornelia Monzel ◽  
Susanne Kleber ◽  
Joel Beaudouin ◽  
Thomas Kaindl ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Cancer Cells ◽  
Tyrosine Phosphorylation ◽  
Kinase Activity ◽  
Cell Contact ◽  
Death Domain ◽  
Tyrosine Kinase Activity ◽  
Cell Contacts ◽  
Cell Cell

AbstractCancer cells react to CD95 activation with either apoptotic or tumorigenic responses. Yet, the determinants of these two antithetic reactions are fundamentally not understood. Here, we show that pre-confined CD95L molecules activate apoptosis of cancer cells in-vitro. For particular CD95L pre-confinement, apoptosis activation is most efficient. Surprisingly, in tumor models, the same pre-confinement yields enhanced proliferation of cancer cells. This shift is rooted in cell-cell interactions, as proliferation was also observed in tumorspheres in-vitro. Indeed, proliferation required death-domain tyrosine phosphorylation of CD95 that was facilitated by cell-cell contacts, whereas decreasing the levels of global tyrosine kinase activity favored apoptosis. Altogether, the response to CD95 activation is cell context-dependent and tunable by CD95L pre-confinement, thereby opening therapeutic opportunities in cancer.One Sentence SummaryCell-cell contact tunes tyrosine-kinase activity thereby dictating life or death upon CD95 activation by pre-confined CD95L.

scholarly journals Thrombin and thrombin receptor agonist peptide induce tyrosine phosphorylation and tyrosine kinases in the platelet cytoskeleton. Translocation of pp60c-src and integrin αIIbβ3 (glycoprotein IIb/IIIa) is not required for aggregation, but is dependent on formation of large aggregate structures

1993 ◽  
Vol 294 (1) ◽  
pp. 253-260 ◽  
Author(s):  
K M Pumiglia ◽  
M B Feinstein
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Receptor Agonist ◽  
Kinase Activity ◽  
Shear Stresses ◽  
Tyrosine Kinase Activity ◽  
Src Tyrosine Kinase ◽  
Agonist Peptide

The maximal aggregation of platelets induced by alpha-thrombin or by the receptor agonist peptide thrombin-(42-47)-peptide (TRP42/47) rapidly increased the pp60c-src associated with the cytoskeleton fraction. There was good correlation between the tyrosine kinase activity and the mass of pp60c-src. Tyrosine kinase activity associated with the cytoskeleton phosphorylated several endogenous cytoskeleton-associated proteins, as revealed by immunoblotting with anti-phosphotyrosine antibody following incubation with ATP in vitro. However, with the exception of pp60c-src, few phosphotyrosine-containing proteins were retained in the cytoskeleton in intact platelets when compared with total platelet lysates. Translocation of pp60c-src to the cytoskeleton induced by alpha-thrombin and TRP42/47 is dependent on glycoprotein IIb/IIIa (GPIIb/IIIa)-fibrinogen-mediated aggregation, but does not occur when ristocetin/von Willebrand factor produces GPIb-mediated platelet aggregation. The translocation of GPIIb/IIIa and pp60c-src to the cytoskeleton is not necessary for aggregation, as it is not seen when clearly visible small to moderate-sized aggregates are initially formed after exposure to thrombin. The linkage of these proteins to the cytoskeleton occurs only after later extensive formation of large aggregates. Translocation of GPIIa/IIIa to the cytoskeleton is not sufficient for the cytoskeletal association of pp60c-src, as the former occurs independently in platelets stimulated with concanavalin A in the absence of aggregation. Linkage of the integrin GPIIb/IIIa and pp60c-src to the internal cytoskeleton structure, and the corresponding tyrosine phosphorylation of certain proteins upon formation of large aggregates, may be an example of mechanochemical transduction by integrin receptors and may represent a structure with the requisite tensile strength to stabilize large platelet aggregates against high shear stresses.

scholarly journals The CD3 chains of the T cell antigen receptor associate with the ZAP-70 tyrosine kinase and are tyrosine phosphorylated after receptor stimulation.

1993 ◽  
Vol 178 (5) ◽  
pp. 1523-1530 ◽  
Author(s):  
D B Straus ◽  
A Weiss
Keyword(s):  
T Cell ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Kinase Activity ◽  
Antigen Receptor ◽  
Tyrosine Kinase Activity ◽  
Cell Antigen Receptor ◽  
Cell Antigen ◽  
Signaling Function ◽  
Signaling Events

Recent work indicates that signaling events resulting from stimulation of the T cell antigen receptor (TCR) can be initiated by the CD3 complex (gamma, delta, epsilon) as well as the zeta chains of the receptor. To help characterize the signaling function of CD3 we examined its associated tyrosine kinase activity since induction of tyrosine phosphorylation is one of the earliest signaling events. Our results indicate that at least two kinases, lck and ZAP-70, contribute to the CD3-associated kinase activity. A likely target of this activity is the CD3 complex itself since we observed that TCR stimulation resulted in rapid tyrosine phosphorylation of the CD3 epsilon and delta chains. To examine the function of the CD3 epsilon chain in particular, we constructed a chimera that fused the extracellular and transmembrane domains of CD8 to the cytoplasmic domain of CD3 epsilon. This chimera demonstrated that CD3 epsilon was independently capable of associating with proteins having tyrosine kinase activity, including ZAP-70. Our results show that the kinase activity that associates with the CD3 complex has characteristics that are quite similar to the previously characterized zeta-associated kinase activity. This finding suggests that both these components of the TCR initiate signaling events using a common mechanism. However, differences in their signaling function could result from recognition of distinct substrates.

Modulation of pp60c-src activity and cellular localization during differentiation of human trophoblast cells in culture

1993 ◽  
Vol 105 (3) ◽  
pp. 629-636 ◽  
Author(s):  
C. Rebut-Bonneton ◽  
S. Boutemy-Roulier ◽  
D. Evain-Brion
Keyword(s):  
Tyrosine Kinase ◽  
Cellular Localization ◽  
Kinase Activity ◽  
Cell Aggregation ◽  
Trophoblast Cells ◽  
Tyrosine Kinase Activity ◽  
Human Trophoblast ◽  
Human Trophoblast Cells ◽  
E Cadherin

The morphological and functional differentiation of human trophoblast cells ends with the formation of terminally differentiated multinucleated syncytial trophoblasts. This in vivo differentiation is mimicked in vitro during the primary culture of extravillous cytotrophoblasts: isolated mononuclear cytotrophoblasts aggregate and fuse to form syncytia. This in vitro differentiation is associated with an increase in epidermal growth factor receptor (EGF-R) expression and a transitory increase in E-cadherin expression during cell aggregation. In the present study, we investigated the expression of pp60c-src during morphological differentiation of trophoblast cells. Cultures were terminated at various time intervals and pp60c-src was analysed by immunocytochemistry using a specific antibody. In addition, pp60c-src was investigated by western blot analysis and its tyrosine kinase activity was measured concomitantly. In mononuclear cytotrophoblasts, pp60c-src was localized at cell-matrix contacts and during the aggregation of cytotrophoblasts, pp60c-src was distributed on the cell surface at points of cell-cell contact being colocalized with EGF-R and E-cadherin. The kinase activity of the pp60c-src protein increased significantly at day 2 when cells were completely aggregated and started to fuse, and remained elevated while cells underwent further differentiation. Inhibition of pp60c-src by herbimycin A at 0.25 to 1 microgram/ml during the first day of culture was associated with a decreased expression of tyrosine kinase activity of EGF-R and an increase in E-cadherin expression. These data suggest that pp60c-src is involved in the modulation of trophoblast cell aggregation and fusion leading to syncytial formation.

Reduction of tyrosine kinase activity and protein tyrosine dephosphorylation by anoxic stimulation in vitro

Neuroscience ◽  
1997 ◽  
Vol 82 (1) ◽  
pp. 161-170 ◽  
Author(s):  
J.L Braunton ◽  
V Wong ◽  
W Wang ◽  
M.W Salter ◽  
J Roder ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Tyrosine Kinase Activity ◽  
Protein Tyrosine

scholarly journals Identification of Fer Tyrosine Kinase Localized on Microtubules as a Platelet Endothelial Cell Adhesion Molecule-1 Phosphorylating Kinase in Vascular Endothelial Cells

2003 ◽  
Vol 14 (9) ◽  
pp. 3553-3564 ◽  
Author(s):  
Naoko Kogata ◽  
Michitaka Masuda ◽  
Yuji Kamioka ◽  
Akiko Yamagishi ◽  
Akira Endo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Adhesion Molecule ◽  
Intracellular Signaling ◽  
Vascular Endothelial Cells ◽  
Expression Cloning ◽  
Vascular Endothelial ◽  
Cell Contacts ◽  
Cell Cell

Platelet endothelial adhesion molecule-1 (PECAM-1) is a part of intercellular junctions and triggers intracellular signaling cascades upon homophilic binding. The intracellular domain of PECAM-1 is tyrosine phosphorylated upon homophilic engagement. However, it remains unclear which tyrosine kinase phosphorylates PECAM-1. We sought to isolate tyrosine kinases responsible for PECAM-1 phosphorylation and identified Fer as a candidate, based on expression cloning. Fer kinase specifically phosphorylated PECAM-1 at the immunoreceptor tyrosine-based inhibitory motif. Notably, Fer induced tyrosine phosphorylation of SHP-2, which is known to bind to the immunoreceptor tyrosine-based inhibitory motif of PECAM-1, and Fer also induced tyrosine phosphorylation of Gab1 (Grb2-associated binder-1). Engagement-dependent PECAM-1 phosphorylation was inhibited by the overexpression of a kinase-inactive mutant of Fer, suggesting that Fer is responsible for the tyrosine phosphorylation upon PECAM-1 engagement. Furthermore, by using green fluorescent protein-tagged Fer and a time-lapse fluorescent microscope, we found that Fer localized at microtubules in polarized and motile vascular endothelial cells. Fer was dynamically associated with growing microtubules in the direction of cell-cell contacts, where p120catenin, which is known to associate with Fer, colocalized with PECAM-1. These results suggest that Fer localized on microtubules may play an important role in phosphorylation of PECAM-1, possibly through its association with p120catenin at nascent cell-cell contacts.

Tyrosine phosphorylation and tyrosine kinase activity of the trk proto-oncogene product induced by NGF

Nature ◽  
1991 ◽  
Vol 350 (6314) ◽  
pp. 158-160 ◽  
Author(s):  
David R. Kaplan ◽  
Dionisio Martin-Zanca ◽  
Luis F. Parada
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Kinase Activity ◽  
Tyrosine Kinase Activity

scholarly journals Activation of the c-abl oncogene by viral transduction or chromosomal translocation generates altered c-abl proteins with similar in vitro kinase properties.

1985 ◽  
Vol 5 (1) ◽  
pp. 204-213 ◽  
Author(s):  
R L Davis ◽  
J B Konopka ◽  
O N Witte
Keyword(s):  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Leukemia Virus ◽  
Leukemia Cell ◽  
Chromosomal Translocation ◽  
Leukemia Cell Line ◽  
Tyrosine Kinase Activity ◽  
Serine Kinase ◽  
Abelson Murine Leukemia Virus

The v-abl protein of Abelson murine leukemia virus is a tyrosine-specific kinase. Its normal cellular homolog, murine c-abl, does not possess detectable tyrosine kinase activity in vitro. Previously, we have detected tyrosine kinase activity in vitro for an altered c-abl gene product (c-abl P210) in the K562 human chronic myelogenous leukemia cell line. The expression of this variant c-abl gene product correlates with chromosomal translocation and amplification of the c-abl gene in K562 cells. Like v-abl, c-abl P210 is a fusion protein containing non-abl sequences near the amino terminus of c-abl. We compared the in vitro tyrosine kinase activity of c-abl P210 with that of wild-type murine v-abl. The remarkable similarities of these two proteins with respect to cis-acting autophosphorylation, trans-acting phosphorylation of exogenous substrates, and kinase inhibition, using site-directed abl-specific antisera, suggested that c-abl P210 could function similarly to v-abl in vivo. In addition, c-abl P210 possessed an associated serine kinase activity in immunoprecipitates. The serine kinase activity was not inhibited by site-directed, abl-specific antisera that inhibit the tyrosine kinase activity, suggesting that the serine kinase activity is not an intrinsic property of c-abl P210. Thus, the activation of the c-abl gene in a human leukemia cell line may have functional consequences analogous to activation of the c-abl gene in Abelson murine leukemia virus.

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