scholarly journals Impaired development of V gamma 3 dendritic epidermal T cells in p56lck protein tyrosine kinase-deficient and CD45 protein tyrosine phosphatase-deficient mice.

1995 ◽  
Vol 181 (1) ◽  
pp. 345-349 ◽  
Author(s):  
K Kawai ◽  
K Kishihara ◽  
T J Molina ◽  
V A Wallace ◽  
T W Mak ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Phosphatase ◽  
Protein Tyrosine Kinase ◽  
Tyrosine Phosphatase ◽  
Fetal Thymus ◽  
Protein Tyrosine ◽  
Heat Stable Antigen ◽  
Dendritic Epidermal T Cells

To determine whether p56lck protein tyrosine kinase and CD45 protein tyrosine phosphatase are involved in the signal transduction during intrathymic differentiation of gamma/delta T cells, we have examined the development of T cells expressing V gamma 3 T cell receptor (TCR) in mice deficient for either protein. The skin from both mice contained significantly reduced numbers of dendritic epidermal T cells expressing decreased levels of V gamma 3 TCR at the cell surface. Analysis of the fetal thymus from these mice suggested that maturation of V gamma 3 thymocytes was blocked at the immature stage that was characterized by the low level of V gamma 3 TCR and the high level of heat stable antigen. These results imply that both p56lck and CD45 are involved in the signal transduction during maturation of V gamma 3 T cells in the fetal thymus.

scholarly journals Disruption of Lymphocyte Function and Signaling in CD45–associated Protein–null Mice

1998 ◽  
Vol 187 (11) ◽  
pp. 1863-1870 ◽  
Author(s):  
Akio Matsuda ◽  
Satoshi Motoya ◽  
Shioko Kimura ◽  
Renee McInnis ◽  
Abby L. Maizel ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Kinases ◽  
Tyrosine Phosphatase ◽  
Antigen Receptor ◽  
Lymphocyte Function ◽  
Receptor Signaling ◽  
Protein Tyrosine ◽  
Antigen Receptor Signaling

CD45-AP specifically associates with CD45, a protein tyrosine phosphatase essential for lymphocyte differentiation and antigen receptor–mediated signal transduction. CD45 is thought to mediate antigen receptor signaling by dephosphorylating regulatory tyrosine residues on Src family protein tyrosine kinases such as Lck. However, the mechanism for regulating CD45 protein tyrosine phosphatase activity remains unclear. CD45-AP–null mice were created to examine the role of CD45-AP in CD45-mediated signal transduction. T and B lymphocytes showed reduced proliferation in response to antigen receptor stimulation. Both mixed leukocyte reaction and cytotoxic T lymphocyte functions of T cells were also markedly decreased in CD45-AP–null mice. Interestingly, the interaction between CD45 and Lck was significantly reduced in CD45-AP–null T cells, indicating that CD45-AP directly or indirectly mediates the interaction of CD45 with Lck. Our data indicate that CD45-AP is required for normal antigen receptor signaling and function in lymphocytes.

Effects of protein tyrosine kinase and protein tyrosine phosphatase on apical K+ channels in the TAL

2001 ◽  
Vol 281 (4) ◽  
pp. C1188-C1195 ◽  
Author(s):  
Rui-Min Gu ◽  
Yuan Wei ◽  
John R. Falck ◽  
U. Murali Krishna ◽  
Wen-Hui Wang
Keyword(s):  
Tyrosine Kinase ◽  
Protein Tyrosine Phosphatase ◽  
Protein Tyrosine Kinase ◽  
Tyrosine Phosphatase ◽  
K Channel ◽  
Thick Ascending Limb ◽  
Patch Clamp Technique ◽  
K Channels ◽  
Protein Tyrosine ◽  
Herbimycin A

We have previously demonstrated that the protein level of c-Src, a nonreceptor type of protein tyrosine kinase (PTK), was higher in the renal medulla from rats on a K-deficient (KD) diet than that in rats on a high-K (HK) diet (Wang WH, Lerea KM, Chan M, and Giebisch G. Am J Physiol Renal Physiol 278: F165–F171, 2000). We have now used the patch-clamp technique to investigate the role of PTK in regulating the apical K channels in the medullary thick ascending limb (mTAL) of the rat kidney. Inhibition of PTK with herbimycin A increased NP o, a product of channel number ( N) and open probability ( P o), of the 70-pS K channel from 0.12 to 0.42 in the mTAL only from rats on a KD diet but had no significant effect in tubules from animals on a HK diet. In contrast, herbimycin A did not affect the activity of the 30-pS K channel in the mTAL from rats on a KD diet. Moreover, addition of N-methylsulfonyl-12,12-dibromododec-11-enamide, an agent that inhibits the cytochrome P-450-dependent production of 20-hydroxyeicosatetraenoic acid, further increased NP o of the 70-pS K channel in the presence of herbimycin A. Furthermore, Western blot detected the presence of PTP-1D, a membrane-associated protein tyrosine phosphatase (PTP), in the renal outer medulla. Inhibition of PTP with phenylarsine oxide (PAO) decreased NP o of the 70-pS K channel in the mTAL from rats on a HK diet. However, PAO did not inhibit the activity of the 30-pS K channel in the mTAL. The effect of PAO on the 70-pS K channel was due to indirectly stimulating PTK because pretreatment of the mTAL with herbimycin A abolished the inhibitory effect of PAO. Finally, addition of exogenous c-Src reversibly blocked the activity of the 70-pS K channel in inside-out patches. We conclude that PTK and PTP have no effect on the low-conductance K channels in the mTAL and that PTK-induced tyrosine phosphorylation inhibits, whereas PTP-induced tyrosine dephosphorylation stimulates, the apical 70-pS K channel in the mTAL.

scholarly journals Src-family protein tyrosine kinase phosphorylates WNK4 and modulates its inhibitory effect on KCNJ1 (ROMK)

2015 ◽  
Vol 112 (14) ◽  
pp. 4495-4500 ◽  
Author(s):  
Dao-Hong Lin ◽  
Peng Yue ◽  
Orlando Yarborough ◽  
Ute I. Scholl ◽  
Gerhard Giebisch ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Protein Tyrosine Phosphatase ◽  
Double Mutant ◽  
Protein Tyrosine Kinase ◽  
Tyrosine Phosphatase ◽  
Inhibitory Effect ◽  
Wild Type ◽  
Distal Nephron ◽  
Protein Tyrosine ◽  
Family Protein

With-no-lysine kinase 4 (WNK4) inhibits the activity of the potassium channel KCNJ1 (ROMK) in the distal nephron, thereby contributing to the maintenance of potassium homeostasis. This effect is inhibited via phosphorylation at Ser1196 by serum/glucocorticoid-induced kinase 1 (SGK1), and this inhibition is attenuated by the Src-family protein tyrosine kinase (SFK). Using Western blot and mass spectrometry, we now identify three sites in WNK4 that are phosphorylated by c-Src: Tyr1092, Tyr1094, and Tyr1143, and show that both c-Src and protein tyrosine phosphatase type 1D (PTP-1D) coimmunoprecipitate with WNK4. Mutation of Tyr1092 or Tyr1143 to phenylalanine decreased the association of c-Src or PTP-1D with WNK4, respectively. Moreover, the Tyr1092Phe mutation markedly reduced ROMK inhibition by WNK4; this inhibition was completely absent in the double mutant WNK4Y1092/1094F. Similarly, c-Src prevented SGK1-induced phosphorylation of WNK4 at Ser1196, an effect that was abrogated in the double mutant. WNK4Y1143F inhibited ROMK activity as potently as wild-type (WT) WNK4, but unlike WT, the inhibitory effect of WNK4Y1143F could not be reversed by SGK1. The failure to reverse WNK4Y1143F-induced inhibition of ROMK by SGK1 was possibly due to enhancing endogenous SFK effect on WNK4 by decreasing the WNK4–PTP-1D association because inhibition of SFK enabled SGK1 to reverse WNK4Y1143F-induced inhibition of ROMK. We conclude that WNK4 is a substrate of SFKs and that the association of c-Src and PTP-1D with WNK4 at Tyr1092 and Tyr1143 plays an important role in modulating the inhibitory effect of WNK4 on ROMK.

Comparative study of protein tyrosine phosphatase-ɛ isoforms: membrane localization confers specificity in cellular signalling

2001 ◽  
Vol 354 (3) ◽  
pp. 581-590 ◽  
Author(s):  
Jannik N⊘rgaard ANDERSEN ◽  
Ari ELSON ◽  
Reiner LAMMERS ◽  
John RØMER ◽  
Jes Thorn CLAUSEN ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Subcellular Localization ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Phosphatase ◽  
Clonal Selection ◽  
Tyrosine Phosphatase ◽  
Inhibitory Response ◽  
Expression Levels ◽  
Protein Tyrosine ◽  
Cell Rounding

To study the influence of subcellular localization as a determinant of signal transduction specificity, we assessed the effects of wild-type transmembrane and cytoplasmic protein tyrosine phosphatase (PTP) ε on tyrosine kinase signalling in baby hamster kidney (BHK) cells overexpressing the insulin receptor (BHK-IR). The efficiency by which differently localized PTPε and PTPα variants attenuated insulin-induced cell rounding and detachment was determined in a functional clonal-selection assay and in stable cell lines. Compared with the corresponding receptor-type PTPs, the cytoplasmic PTPs (cytPTPs) were considerably less efficient in generating insulin-resistant clones, and exceptionally high compensatory expression levels were required to counteract phosphotyrosine-based signal transduction. Targeting of cytPTPε to the plasma membrane via the Lck-tyrosine kinase dual acylation motif restored high rescue efficiency and abolished the need for high cytPTPε levels. Consistent with these results, expression levels and subcellular localization of PTPε were also found to determine the phosphorylation level of cellular proteins including focal adhesion kinase (FAK). Furthermore, PTPε stabilized binding of phosphorylated FAK to Src, suggesting this complex as a possible mediator of the PTPε inhibitory response to insulin-induced cell rounding and detachment in BHK-IR cells. Taken together, the present localization–function study indicates that transcriptional control of the subcellular localization of PTPε may provide a molecular mechanism that determines PTPε substrate selectivity and isoform-specific function.

scholarly journals Regulation of the interaction of nicotinic acetylcholine receptors with the cytoskeleton by agrin-activated protein tyrosine kinase.

1995 ◽  
Vol 128 (6) ◽  
pp. 1121-1129 ◽  
Author(s):  
B G Wallace
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Nicotinic Acetylcholine Receptors ◽  
Protein Tyrosine Phosphatase ◽  
Acetylcholine Receptors ◽  
Protein Tyrosine Kinase ◽  
Tyrosine Phosphatase ◽  
Beta Subunit ◽  
Nicotinic Acetylcholine ◽  
Protein Tyrosine

Agrin induces the accumulation of nicotinic acetylcholine receptors (AChRs) in the myofiber membrane at synaptic sites in vertebrate skeletal muscle and causes an increase in tyrosine phosphorylation of the AChR beta subunit. To examine further the mechanism of agrin-induced AChR phosphorylation and the relationship between changes in protein phosphorylation and AChR aggregation, the effect of the protein tyrosine phosphatase inhibitor sodium pervanadate was tested on chick myotubes in culture. Pervanadate caused an increase in the phosphotyrosine content of a variety of proteins, including the AChR. Pervanadate also prevented agrin-induced AChR aggregation and slowed the rate at which AChRs were extracted from intact myotubes by mild detergent treatment. The rate at which phosphorylation of the AChR beta subunit and receptor detergent extractability changed following pervanadate-induced phosphatase inhibition was increased by agrin, indicating that agrin activates a protein tyrosine kinase rather than inhibiting a protein tyrosine phosphatase. The present results, taken together with previous findings on the inhibition of agrin-induced AChR aggregation by protein kinase inhibitors, demonstrate that protein tyrosine phosphorylation regulates the formation and stability of AChR aggregates, apparently by strengthening the interaction between AChRs and the cytoskelton.

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