scholarly journals Association between B-lymphocyte membrane immunoglobulin and multiple members of the Src family of protein tyrosine kinases.

1992 ◽  
Vol 12 (5) ◽  
pp. 2315-2321 ◽  
Author(s):  
M A Campbell ◽  
B M Sefton
Keyword(s):  
B Cells ◽  
B Cell ◽  
Tyrosine Kinases ◽  
B Lymphocyte ◽  
Protein Tyrosine Kinases ◽  
Cell Type ◽  
Protein Tyrosine ◽  
Membrane Immunoglobulin ◽  
Family Protein

Treatment of B lymphocytes with antibodies to membrane immunoglobulin (Ig) stimulates protein tyrosine phosphorylation. We have examined the phosphorylation in vitro of proteins associated with membrane Ig. The Src family protein tyrosine kinases p53/56lyn, p59fyn, and p56lck are associated with membrane Ig in spleen B cells and B-cell lines and undergo phosphorylation in vitro. The pattern of expression of Src family protein tyrosine kinases in B cells varied. Our studies suggest that multiple kinases can potentially interact with membrane Ig and that within any one B-cell type, all of the Src family kinases expressed can be found in association with membrane Ig. We also observed that the Ig-associated Ig alpha protein, multiple forms of Ig beta, and proteins of 100 and 25 kDa were tyrosine phosphorylated in vitro. The 100- and 25-kDa proteins remain unidentified.

Association between B-lymphocyte membrane immunoglobulin and multiple members of the Src family of protein tyrosine kinases

1992 ◽  
Vol 12 (5) ◽  
pp. 2315-2321
Author(s):  
M A Campbell ◽  
B M Sefton
Keyword(s):  
B Cells ◽  
B Cell ◽  
Tyrosine Kinases ◽  
B Lymphocyte ◽  
Protein Tyrosine Kinases ◽  
Cell Type ◽  
Protein Tyrosine ◽  
Membrane Immunoglobulin ◽  
Family Protein

Treatment of B lymphocytes with antibodies to membrane immunoglobulin (Ig) stimulates protein tyrosine phosphorylation. We have examined the phosphorylation in vitro of proteins associated with membrane Ig. The Src family protein tyrosine kinases p53/56lyn, p59fyn, and p56lck are associated with membrane Ig in spleen B cells and B-cell lines and undergo phosphorylation in vitro. The pattern of expression of Src family protein tyrosine kinases in B cells varied. Our studies suggest that multiple kinases can potentially interact with membrane Ig and that within any one B-cell type, all of the Src family kinases expressed can be found in association with membrane Ig. We also observed that the Ig-associated Ig alpha protein, multiple forms of Ig beta, and proteins of 100 and 25 kDa were tyrosine phosphorylated in vitro. The 100- and 25-kDa proteins remain unidentified.

Essential role of Src-family protein tyrosine kinases in NF-κB activation during B cell development

10.1038/ni893 ◽  
2003 ◽  
Vol 4 (3) ◽  
pp. 274-279 ◽  
Author(s):  
Kaoru Saijo ◽  
Christian Schmedt ◽  
I-hsin Su ◽  
Hajime Karasuyama ◽  
Clifford A. Lowell ◽  
...  
Keyword(s):  
B Cell ◽  
Tyrosine Kinases ◽  
Essential Role ◽  
Cell Development ◽  
B Cell Development ◽  
Protein Tyrosine Kinases ◽  
Protein Tyrosine ◽  
Family Protein

HIV infection in vitro enhances the activity of src-family protein tyrosine kinases

AIDS ◽  
1996 ◽  
Vol 10 (11) ◽  
pp. 1191-1198 ◽  
Author(s):  
David J. Phipps ◽  
Stanley E. Read ◽  
John P. Piovesan ◽  
Gordon B. Mills ◽  
Donald R. Branch
Keyword(s):  
Hiv Infection ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinases ◽  
Protein Tyrosine ◽  
Family Protein

scholarly journals Haemophilus ducreyi Targets Src Family Protein Tyrosine Kinases To Inhibit Phagocytic Signaling

2005 ◽  
Vol 73 (12) ◽  
pp. 7808-7816 ◽  
Author(s):  
Jason R. Mock ◽  
Merja Vakevainen ◽  
Kaiping Deng ◽  
Jo L. Latimer ◽  
Jennifer A. Young ◽  
...  
Keyword(s):  
Tyrosine Kinases ◽  
Immune Cell ◽  
Transmitted Disease ◽  
Etiologic Agent ◽  
Haemophilus Ducreyi ◽  
Protein Tyrosine Kinases ◽  
Wild Type ◽  
Protein Tyrosine ◽  
Family Protein

ABSTRACTHaemophilus ducreyi, the etiologic agent of the sexually transmitted disease chancroid, has been shown to inhibit phagocytosis of both itself and secondary targets in vitro. Immunodepletion of LspA proteins fromH. ducreyiculture supernatant fluid abolished this inhibitory effect, indicating that the LspA proteins are necessary for the inhibition of phagocytosis byH. ducreyi. Fluorescence microscopy revealed that macrophages incubated with wild-typeH. ducreyi, but not with alspA1 lspA2mutant, were unable to complete development of the phagocytic cup around immunoglobulin G-opsonized targets. Examination of the phosphotyrosine protein profiles of these two sets of macrophages showed that those incubated with wild-typeH. ducreyihad greatly reduced phosphorylation levels of proteins in the 50-to-60-kDa range. Subsequent experiments revealed reductions in the catalytic activities of both Lyn and Hck, two members of the Src family of protein tyrosine kinases that are known to be involved in the proximal signaling steps of Fcγ receptor-mediated phagocytosis. Additional experiments confirmed reductions in the levels of both active Lyn and active Hck in three different immune cell lines, but not in HeLa cells, exposed to wild-typeH. ducreyi. This is the first example of a bacte-rial pathogen that suppresses Src family protein tyrosine kinase activity to subvert phagocytic signaling in hostcells.

scholarly journals In vivo and in vitro specificity of protein tyrosine kinases for immunoglobulin G receptor (FcgammaRII) phosphorylation.

1996 ◽  
Vol 16 (9) ◽  
pp. 4735-4743 ◽  
Author(s):  
N Bewarder ◽  
V Weinrich ◽  
P Budde ◽  
D Hartmann ◽  
H Flaswinkel ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Immunoglobulin G ◽  
Tyrosine Kinases ◽  
Cell Activation ◽  
Vitro Assay ◽  
Protein Tyrosine ◽  
Phosphorylation Pattern

Human B cells express four immunoglobulin G receptors, FcgammaRIIa, FcgammaRIIb1, FcgammaRIIb2, and FcgammaRIIc. Coligation of either FcgammaRII isoform with the B-cell antigen receptor (BCR) results in the abrogation of B-cell activation, but only the FcgammaRIIa/c and FcgammaIIb1 isoforms become phosphorylated. To identify the FcgammaRII-phosphorylating protein tyrosine kinase (PTK), we used the combination of an in vitro and an in vivo approach. In an in vitro assay using recombinant cytoplasmic tails of the different FcgammaRII isoforms as well as tyrosine exchange mutants, we show that each of the BCR-associated PTKs (Lyn, Blk, Fyn, and Syk) shows different phosphorylation patterns with regard to the different FcgammaR isoforms and point mutants. While each PTK phosphorylated FcgammaRIIa/c, FcgammaRIIb1 was phosphorylated by Lyn and Blk whereas FcgammaRIIb2 became phosphorylated only by Blk. Mutants lacking both tyrosine residues of the immune receptor tyrosine-based activation motif (ITAM) of FcgammaRIIa/c were not phosphorylated by Blk and Fyn, while Lyn-mediated phosphorylation was dependent on the presence of the C-terminal tyrosine of the ITAM. Results obtained in assays using an FcgammaR- B-cell line transfected with wild-type or mutated FcgammaRIIa demonstrated that exchange of the C-terminal tyrosine of the ITAM of FcgammaRIIa/c was sufficient to abolish FcgammaRIIa/c phosphorylation in B cells. Additionally, we could show that Lyn and Fyn bind to FcgammaRIIa/c, with the ITAM being necessary for association. Comparison of the phosphorylation pattern of each PTK observed in vitro with the phosphorylation pattern observed in vivo suggests that Lyn is the most likely candidate for FcgammaRIIa/c and FcgammaRIIb1 phosphorylation in vivo.

scholarly journals Protein Tyrosine Kinase Involvement in Learning-Produced Changes in Hermissenda Type B Photoreceptors

2009 ◽  
Vol 102 (6) ◽  
pp. 3573-3595 ◽  
Author(s):  
Iksung Jin ◽  
Haojiang Huang ◽  
Benjamin Smith ◽  
Joseph Farley
Keyword(s):  
B Cells ◽  
B Cell ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Protein Tyrosine Phosphatases ◽  
Inactivation Kinetics ◽  
Type B ◽  
Protein Tyrosine ◽  
Voltage Dependent

Learning-correlated changes in the excitability and photoresponses of Hermissenda 's ocular type B photoreceptors are mediated by reductions in two distinct K+ currents, IA and IK-Ca. The suppression of these K+ currents has been linked to conditioning-produced activation of protein kinase C (PKC). The question of whether PKC accounts completely for the changes in excitability and K+ currents or whether other kinase(s) are involved has received little attention. In the present experiments, we asked whether protein tyrosine kinases (PTKs) might also contribute to conditioning-produced alterations in B cells. We found that the PTK inhibitors genistein and lavendustin A greatly reduced cumulative depolarization of type B cells, a short-term correlate of associative learning. This disruption occurred even when PKC activation had been either occluded by preexposure of type B cells to a phorbol ester or otherwise prevented by the pseudosubstrate inhibitor peptide PKC[19–31]. PTK inhibitors also increased the amplitude of the transient ( IA) and delayed ( IDelayed) components of voltage-dependent K+ current that have previously been shown to be selectively reduced by conditioning and to contribute to cumulative depolarization. Genistein partially prevented the reduction of IA and IDelayed due to in vitro conditioning and blocked the changes in their voltage dependencies. Ionophoresis of pervanadate ion, a potent inhibitor of protein tyrosine phosphatases, depolarized type B photoreceptors and occluded conditioning-produced cumulative depolarization. Pervanadate also suppressed IA and IDelayed, reduced their voltage dependence, and altered inactivation kinetics for IA, mimicking conditioning. Western blot analysis using a phosphotyrosine antibody indicated that conditioning increased the phosphotyrosine content of many proteins within the Hermissenda CNS. Collectively, our results suggest that in addition to PKC, one or more PTKs play an important role in conditioning-produced changes in type B cell excitability. PTKs and PKCs converge to effect reductions in B cell K+ currents during conditioning, apparently through distinct biophysical mechanisms.

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