scholarly journals Tyrosine phosphorylation induced by cross-linking of Fc γ-receptor type II in human neutrophils

1995 ◽  
Vol 306 (2) ◽  
pp. 489-495 ◽  
Author(s):  
L Liang ◽  
C K Huang

Neutrophils express several receptors for the Fc region of IgG molecules. Specific cross-linking of the type II receptor (Fc gamma RII) can be achieved by treating neutrophils with the Fab fragment of a specific monoclonal antibody IV.3 against the receptor followed by goat anti-mouse IgG F(ab′)2 fragment. Such treatment initiates a number of neutrophil responses including the release of O2-. and increased protein tyrosine phosphorylation. The increase in tyrosine phosphorylation is rapid and transient and correlates with O2-. release. Both responses are inhibited by pretreatment of neutrophils with a protein tyrosine kinase inhibitor, genistein. The increase in protein tyrosine phosphorylation is not inhibited by pretreatment of neutrophils with pertussis toxin or an intracellular Ca2+ chelator, but is enhanced by a phosphoprotein phosphatase inhibitor, okadaic acid. The activity of a neutrophil Ca2+/calmodulin-dependent protein kinase II (CAMPKII) is also stimulated by cross-linking Fc gamma RII. The increase in CAMPKII activity is inhibited by pretreatment with either genistein or Ca2+ chelator. The results suggest that the increase in protein tyrosine phosphorylation induced by cross-linking of Fc gamma RII requires neither pertussis-toxin-sensitive G-proteins nor a rise in intracellular Ca2+ but can be regulated by protein phosphatases. Furthermore, protein tyrosine phosphorylation may be an early signal functionally linked to Fc gamma RII-mediated signal transduction leading to CAMPKII activation and O2-. release in human neutrophils.

Blood ◽  
1997 ◽  
Vol 89 (5) ◽  
pp. 1590-1598 ◽  
Author(s):  
Mutsumasa Yanabu ◽  
Yukio Ozaki ◽  
Shosaku Nomura ◽  
Tetsuya Miyake ◽  
Yasuhiko Miyazaki ◽  
...  

Abstract NNKY5-5, an IgG monoclonal antibody directed against the von Willebrand factor-binding domain of glycoprotein (GP) Ibα, induced weak but irreversible aggregation (or association) of platelets in citrate-anticoagulated platelet-rich plasma. This phenomenon was defined as small aggregate formation (SAF ). Platelets in hirudin-anticoagulated plasma or washed platelets showed little response to NNKY5-5 alone, but the antibody potentiated aggregation induced by low concentrations of adenosine diphosphate or platelet-activating factor. NNKY5-5 did not induce granule release or intracellular Ca2+ mobilization. However, NNKY5-5 caused tyrosine phosphorylation of a 64-kD protein and activation of a tyrosine kinase, p72syk. An anti-FcγII receptor antibody had no effect on SAF, suggesting that NNKY5-5 activated platelets by interacting with glycoprotein Ib. Fab′ fragments of NNKY5-5 did not induce SAF, but potentiated aggregation induced by other agonists. The Fab′ fragment of NNKY5-5 induced the activation of p72syk, suggesting that such activation was independent of the FcγII receptor. Cross-linking of the receptor-bound Fab′ fragment of NNKY5-5 with a secondary antibody induced SAF. GRGDS peptide, chelation of extracellular Ca2+, and an anti-GPIIb/IIIa antibody inhibited NNKY5-5-induced SAF, but had no effect on 64-kD protein tyrosine phosphorylation or p72syk activations. Various inhibitors, including aspirin and protein kinase C, had no effect on SAF, protein tyrosine phosphorylation, or p72syk activation. In contrast, tyrphostin 47, a potent tyrosine kinase inhibitor, inhibited NNKY5-5–induced SAF as well as tyrosine phosphorylation and p72syk activation. Our findings suggest that binding of NNKY5-5 to GPIb potentiates platelet aggregation by facilitating the interaction between fibrinogen and GPIIb/IIIa through a mechanism associated with p72syk activation and tyrosine phosphorylation of a 64-kD protein.


1994 ◽  
Vol 126 (4) ◽  
pp. 1111-1121 ◽  
Author(s):  
G Berton ◽  
L Fumagalli ◽  
C Laudanna ◽  
C Sorio

Stimulation of adherent human neutrophils (PMN) with tumor necrosis factor (TNF) triggers protein tyrosine phosphorylation (Fuortes, M., W. W. Jin, and C. Nathan. 1993. J. Cell Biol. 120:777-784). We investigated the dependence of this response on beta 2 integrins by using PMN isolated from a leukocyte adhesion deficiency (LAD) patient, which do not express beta 2 integrins, and by plating PMN on surface bound anti-beta 2 (CD18) antibodies. Protein tyrosine phosphorylation increased in PMN plated on fibrinogen and this phosphorylation was enhanced by TNF. Triggering of protein tyrosine phosphorylation did not occur in LAD PMN plated on fibrinogen either in the absence or the presence of TNF. Surface bound anti-CD18, but not isotype-matched anti-Class I major histocompatibility complex (MHC) antigens, antibodies triggered tyrosine phosphorylation in normal, but not in LAD PMN. As the major tyrosine phosphorylated proteins we found in our assay conditions migrated with an apparent molecular mass of 56-60 kD, we investigated whether beta 2 integrins are implicated in activation of members of the src family of intracellular protein-tyrosine kinases. We found that the fgr protein-tyrosine kinase (p58fgr) activity, and its extent of phosphorylation in tyrosine, in PMN adherent to fibrinogen, was enhanced by TNF. Activation of p58fgr in response to TNF was evident within 10 min of treatment and increased with times up to 30 min. Also other activators of beta 2 integrins such as phorbol-12-myristate 13-acetate (PMA), and formyl methionyl-leucyl-phenylalanine (FMLP), induced activation of p58fgr kinase activity. Activation of p58fgr kinase activity, and phosphorylation in tyrosine, did not occur in PMN of a LAD patient in response to TNF. Soluble anti-CD18, but not anti-Class I MHC antigens, antibodies inhibited activation of p58fgr kinase activity in PMN adherent to fibrinogen in response to TNF, PMA, and FMLP. These findings demonstrate that, in PMN, beta 2 integrins are implicated in triggering of protein tyrosine phosphorylation, and establish a link between beta 2 integrin-dependent adhesion and the protein tyrosine kinase fgr in cell signaling.


Blood ◽  
1997 ◽  
Vol 89 (5) ◽  
pp. 1590-1598 ◽  
Author(s):  
Mutsumasa Yanabu ◽  
Yukio Ozaki ◽  
Shosaku Nomura ◽  
Tetsuya Miyake ◽  
Yasuhiko Miyazaki ◽  
...  

NNKY5-5, an IgG monoclonal antibody directed against the von Willebrand factor-binding domain of glycoprotein (GP) Ibα, induced weak but irreversible aggregation (or association) of platelets in citrate-anticoagulated platelet-rich plasma. This phenomenon was defined as small aggregate formation (SAF ). Platelets in hirudin-anticoagulated plasma or washed platelets showed little response to NNKY5-5 alone, but the antibody potentiated aggregation induced by low concentrations of adenosine diphosphate or platelet-activating factor. NNKY5-5 did not induce granule release or intracellular Ca2+ mobilization. However, NNKY5-5 caused tyrosine phosphorylation of a 64-kD protein and activation of a tyrosine kinase, p72syk. An anti-FcγII receptor antibody had no effect on SAF, suggesting that NNKY5-5 activated platelets by interacting with glycoprotein Ib. Fab′ fragments of NNKY5-5 did not induce SAF, but potentiated aggregation induced by other agonists. The Fab′ fragment of NNKY5-5 induced the activation of p72syk, suggesting that such activation was independent of the FcγII receptor. Cross-linking of the receptor-bound Fab′ fragment of NNKY5-5 with a secondary antibody induced SAF. GRGDS peptide, chelation of extracellular Ca2+, and an anti-GPIIb/IIIa antibody inhibited NNKY5-5-induced SAF, but had no effect on 64-kD protein tyrosine phosphorylation or p72syk activations. Various inhibitors, including aspirin and protein kinase C, had no effect on SAF, protein tyrosine phosphorylation, or p72syk activation. In contrast, tyrphostin 47, a potent tyrosine kinase inhibitor, inhibited NNKY5-5–induced SAF as well as tyrosine phosphorylation and p72syk activation. Our findings suggest that binding of NNKY5-5 to GPIb potentiates platelet aggregation by facilitating the interaction between fibrinogen and GPIIb/IIIa through a mechanism associated with p72syk activation and tyrosine phosphorylation of a 64-kD protein.


2018 ◽  
Vol 66 (4) ◽  
pp. 241 ◽  
Author(s):  
Β. MACÍAS-GARCÍA ◽  
Τ. GUIMARÃES ◽  
G. LOPES ◽  
A. ROCHA ◽  
L. GONZÁLEZ-FERNÁNDEZ

Cryopreservation negatively affects equine sperm quality post-thaw: an excessive release of reactive oxygen species (ROS) and increased protein tyrosine phosphorylation (known as cryocapacitation) have been demonstrated in frozenthawed equine sperm diminishing its lifespan. The objective of this study was to determine the possible beneficial effect of genistein addition (a ROS scavenger and protein tyrosine kinase inhibitor) to a commercial freezing extender. Equine sperm were frozen in the presence of different genistein concentrations ranging from 0 to 800 μM. After thawing, the sperm viability (eosinnigrosin), acrosome integrity using peanut agglutinin (PNA), protein tyrosine phosphorylation (PY) and motility were assessed at times 0 and 1 hr. In addition PY was studied in fresh and frozen sperm incubated in Modified Whitten’s (MW) medium with 25 mM Bicarbonate (MW+Bic). Genistein did not affect the viability, total or progressive motility or acrosome status of frozenthawed equine sperm. Immediately after thawing, positive PY staining in the equatorial band was observed and genistein addition did not exert any change in PY. Fresh sperm incubated in MW+Bic showed a significant increase in PY staining along the tail compared to frozen-thawed sperm. In our study sperm viability immediately post-thaw was 58.25% ± 5.35 and progressive motility 14.46% ± 5.7 (mean ± S.E.M.) and genistein did not improve the post-thaw quality of equine sperm. In addition, cryopreservation did not induce PY immediately post-thaw or enhanced frozen-thawed equine sperm susceptibility to PY induction.


Parasitology ◽  
2007 ◽  
Vol 135 (3) ◽  
pp. 337-345 ◽  
Author(s):  
A. J. WALKER ◽  
D. ROLLINSON

SUMMARYMolecular interplay during snail-schistosome interactions is poorly understood and there is much to discover concerning the effect of snail host molecules on molecular processes in schistosomes. Using the Biomphalaria glabrata – Schistosoma mansoni host-parasite system, the effects of exposure to haemolymph, derived from schistosome-resistant and susceptible snail strains, on protein tyrosine phosphorylation in miracidia have been investigated. Western blotting revealed several tyrosine phosphorylated proteins in this larval stage. Exposure of miracidia to haemolymph from susceptible snails for 60 min resulted in a striking, 5-fold, increase in the tyrosine phosphorylation of a 56 kDa (p56) S. mansoni protein. In contrast, haemolymph from resistant snails had little effect on protein tyrosine phosphorylation levels in miracidia. Confocal microscopy revealed that tyrosine phosphorylation was predominantly associated with proteins present in the tegument. Finally, treatment of miracidia with the tyrosine kinase inhibitor genistein significantly impaired their development into primary sporocysts. The results open avenues for research that focus on the potential importance of phospho-p56 to the outcome of schistosome infection in snails, and the significance of protein tyrosine kinase-mediated signalling events to the transformation of S. mansoni larvae.


1994 ◽  
Vol 72 (06) ◽  
pp. 937-941 ◽  
Author(s):  
Karim Rezaul ◽  
Shigeru Yanagi ◽  
Kiyonao Sada ◽  
Takanobu Taniguchi ◽  
Hirohei Yamamura

SummaryIt has been demonstrated that activation of platelets by platelet-activating factor (PAF) results in a dramatic increase in tyrosine phosphorylation of several cellular proteins. We report here that p72 syk is a potential candidate for the protein-tyrosine phosphorylation following PAF stimulation in porcine platelets. Immunoprecipitation kinase assay revealed that PAF stimulation resulted in a rapid activation of p72 syk which peaked at 10 s. The level of activation was found to be dose dependent and could be completely inhibited by the PAF receptor antagonist, CV3988. Phosphorylation at the tyrosine residues of p72 syk coincided with activation of yllsyk. Pretreatment of platelets with aspirin and apyrase did not affect PAF induced activation of p72 syk .Furthermore, genistein, a potent protein-tyrosine-kinase inhibitor, diminished PAF-induced p72 syk activation and Ca2+ mobilization as well as platelet aggregation. These results suggest that p72 syk may play a critical role in PAF-induced aggregation, possibly through regulation of Ca2+ mobilization.


1996 ◽  
Vol 109 (3) ◽  
pp. 699-704 ◽  
Author(s):  
M. Cervello ◽  
V. Matranga ◽  
P. Durbec ◽  
G. Rougon ◽  
S. Gomez

The glycosyl-phosphatidylinositol (GPI)-anchored F3 molecule, a member of the Ig superfamily made up of Ig and FNIII-like domains, is involved in cell-cell adhesion, neuronal pathfinding and fasciculation. Little is known about the mechanism(s) that governs the F3-mediated cell-cell recognition. In particular, it is not known whether F3 transduces signals across the membrane. Here we show that in F3-transfected CHO cells (1A cells) an increase in tyrosine phosphorylation occurs during F3-mediated aggregation. Moreover, under aggregation conditions F3 immunoprecipitated from 32P-metabolically labeled 1A cells associated with three major phosphorylated proteins. Interestingly, genistein inhibited the F3-mediated aggregation. Increased tyrosine phosphorylation was also observed using antibody-mediated F3-cross-linking. Furthermore, F3 expressed both in 1A cells and in post-natal mouse cerebellum forms non-covalent soluble complexes with protein tyrosine kinase(s). In cerebellum the F3-associated kinase was identified as fyn. By contrast, a truncated F3 protein, expressed in CHO cells, from which all the FN type III repeats have been deleted, does not associate with a kinase. Cross-linking of the F3-truncated form does not induce modulation of tyrosine phosphorylation. Taken together these data demonstrate that F3 is a molecule that transduces signals through both association with protein tyrosine kinase and modulation of protein tyrosine phosphorylation. The presence of FN type III domains is essential for the activation of the intracellular signaling pathway.


1995 ◽  
Vol 181 (3) ◽  
pp. 1005-1014 ◽  
Author(s):  
K M Kim ◽  
M Reth

Most mature B lymphocytes coexpress two classes of antigen receptor, immunoglobulin (Ig)M and IgD. The differences in the signal transduction from the two receptors are still a matter of controversy. We have analyzed B cell lines expressing IgM or IgD antigen receptors with the same antigen specificity. Cross-linking of these receptors with either antigen, or class-specific antibodies, results in the activation of protein tyrosine kinases and the phosphorylation of the same substrate proteins. The kinetic and the intensity of phosphorylation, however, was quite different between the two receptors when they were cross-linked by antigen. In membrane IgM-expressing cells, the substrate phosphorylation reached a maximum after 1 minute and diminished after 60 minutes whereas, in the membrane IgD-expressing cells, the substrate phosphorylation increased further over time, reached its maximum at 60 minutes, and persisted longer than 240 minutes after exposure to antigen. As a result, the intensity of protein tyrosine phosphorylation induced by cross-linking of membrane IgD was stronger than that induced by membrane IgM. Studies of chimeric receptors demonstrate that only the membrane-proximal C domain and/or the transmembrane part of membrane-bound IgD molecule is required for the long-lasting substrate phosphorylation. Together, these data suggest that the signal emission from the two receptors is controlled differently.


1993 ◽  
Vol 289 (2) ◽  
pp. 387-394 ◽  
Author(s):  
M Biffen ◽  
M Shiroo ◽  
D R Alexander

The possible involvement of G-proteins in T cell antigen-receptor complex (TCR)-mediated inositol phosphate production was investigated in HPB-ALL T-cells, which were found to express the phospholipase C gamma 1 and beta 3 isoforms. Cross-linking the CD3 antigen on streptolysin-O-permeabilized cells stimulated a dose-dependent increase in inositol phosphate production, as did addition of guanosine 5′-[gamma-thio]triphosphate (GTP[S]) or vanadate, a phosphotyrosine phosphatase inhibitor. It was possible, therefore, that the CD3-antigen-mediated production of inositol phosphates was either via a G-protein-dependent mechanism or by stimulation of protein tyrosine phosphorylation. The CD3-induced inositol phosphate production was potentiated by addition of vanadate, but not by addition of GTP[S]. Guanosine 5′-[beta-thio]diphosphate (GDP[S]) inhibited the rise in inositol phosphates induced by GTP[S], vanadate or cross-linking the CD3 antigen. The increase in protein tyrosine phosphorylation stimulated by vanadate or the OKT3 monoclonal antibody was not observed in the presence of GDP[S], showing that in permeabilized HPB-ALL cells, GDP[S] inhibits the actions of tyrosine kinases as well as G-protein function. Addition of either ADP[S] or phenylarsine oxide inhibited CD3- and vanadate-mediated increases in both tyrosine phosphorylation and inositol phosphate production, but did not inhibit GTP[S]-stimulated inositol phosphate production. On the other hand, pretreatment of cells with phorbol 12,13-dibutyrate inhibited subsequent GTP[S]-stimulated inositol phosphate production but did not inhibit significantly inositol phosphate production stimulated by either OKT3 F(ab')2 fragments or vanadate. Our results are consistent with the CD3 antigen stimulating inositol phosphate production by increasing the level of protein tyrosine phosphorylation, but not by activating a G-protein.


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