Negative Regulation of a Protein Tyrosine Phosphatase by Tyrosine Phosphorylation

2006 ◽  
Vol 128 (13) ◽  
pp. 4192-4193 ◽  
Author(s):  
Dirk Schwarzer ◽  
Zhongsen Zhang ◽  
Weiping Zheng ◽  
Philip A. Cole
Keyword(s):  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Negative Regulation ◽  
Protein Tyrosine

Protein tyrosine phosphatase-α complexes with the IGF-I receptor and undergoes IGF-I-stimulated tyrosine phosphorylation that mediates cell migration

2009 ◽  
Vol 297 (1) ◽  
pp. C133-C139 ◽  
Author(s):  
Shirley C. Chen ◽  
Ranvikram S. Khanna ◽  
Darrell C. Bessette ◽  
Lionel A. Samayawardhena ◽  
Catherine J. Pallen
Keyword(s):  
Cell Migration ◽  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Kinases ◽  
Tyrosine Phosphatase ◽  
Phosphorylation Site ◽  
Protein Tyrosine ◽  
Fibroblast Migration ◽  
Igf I ◽  
In Cells

Protein tyrosine phosphatase-α (PTPα) is a widely expressed receptor-type phosphatase that functions in multiple signaling systems. The actions of PTPα can be regulated by its phosphorylation on serine and tyrosine residues, although little is known about the conditions that promote PTPα phosphorylation. In this study, we tested the ability of several extracellular factors to stimulate PTPα tyrosine phosphorylation. The growth factors IGF-I and acidic FGF induced the highest increase in PTPα phosphorylation at tyrosine 789, followed by PMA and lysophosphatidic acid, while EGF had little effect. Further investigation of IGF-I-induced PTPα tyrosine phosphorylation demonstrated that this occurs through a novel Src family kinase-independent mechanism that does not require focal adhesion kinase, phosphatidylinositol 3-kinase, or MEK. We also show that PTPα physically interacts with the IGF-I receptor. In contrast to IGF-I-induced PTPα phosphorylation, this association does not require IGF-I. The interaction of PTPα and the IGF-I receptor is independent of PTPα catalytic activity, and expression of exogenous PTPα does not promote IGF-I receptor tyrosine dephosphorylation, indicating that PTPα does not act as an IGF-I receptor phosphatase. However, PTPα mediates IGF-I signaling, because IGF-I-stimulated fibroblast migration was reduced by ∼50% in cells lacking PTPα or in cells with mutant PTPα lacking the tyrosine 789 phosphorylation site. Our results suggest that PTPα tyrosine phosphorylation can occur in response to diverse stimuli and can be mediated by various tyrosine kinases. In the case of IGF-I, we propose that IGF-I-induced tyrosine 789 phosphorylation of PTPα, possibly catalyzed by the PTPα-associated IGF-I receptor tyrosine kinase, is required for efficient cell migration in response to this growth factor.

RPTPμ and protein tyrosine phosphorylation regulate K+channel mRNA expression in adult cardiac myocytes

2000 ◽  
Vol 278 (2) ◽  
pp. C397-C403 ◽  
Author(s):  
Kenneth M. Hershman ◽  
Edwin S. Levitan
Keyword(s):  
Mrna Expression ◽  
Tyrosine Phosphorylation ◽  
Cardiac Myocytes ◽  
Protein Tyrosine Phosphatase ◽  
Cardiac Myocyte ◽  
Tyrosine Phosphatase ◽  
Receptor Protein ◽  
Mrna Levels ◽  
Protein Tyrosine ◽  
Cell Cell

Previously, we reported that cell-cell contact regulates K+channel mRNA expression in cultured adult rat cardiac myocytes. Here we show that exposing cardiac myocytes to tyrosine kinase inhibitors (genistein, tyrphostin A25), but not inactive analogs, prevents downregulation of Kv1.5 mRNA and upregulation of Kv4.2 mRNA normally observed when they are cultured under low-density conditions. Furthermore, cardiac myocytes cocultured with cells that endogenously (Mv 1 Lu) or heterologously (Chinese hamster ovary cells) express the receptor-type protein tyrosine phosphatase μ (RPTPμ) display Kv1.5 mRNA levels paralleling that which was observed in myocytes cultured under high-density conditions and in intact tissue. In contrast, myocytes cocultured with control cells failed to produce this response. Finally, it is shown that Kv4.2 mRNA expression is unaffected by RPTPμ. These findings reveal that multiple tyrosine phosphorylation-dependent mechanisms control cardiac myocyte K+channel genes. Furthermore, we conclude that RPTPμ specifically regulates cardiac myocyte Kv1.5 mRNA expression. Thus this receptor protein tyrosine phosphatase may be important in responses to pathological conditions associated with the loss of cell-cell interactions in the heart.

Anaplastic Lymphoma Kinase Is Activated through the Pleiotrophin/Receptor Protein Tyrosine Phosphatase (RPTP)β/ζ Signaling Pathway: A Unique Mechanism of Activation of Receptor Protein Tyrosine Kinases.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4355-4355
Author(s):  
Pablo Perez-Pinera ◽  
Wei Zhang ◽  
Zhaoyi Wang ◽  
James R. Berenson ◽  
Thomas F. Deuel
Keyword(s):  
Tyrosine Kinase ◽  
Signaling Pathway ◽  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Kinases ◽  
Tyrosine Phosphatase ◽  
Receptor Protein ◽  
Protein Tyrosine ◽  
Anaplastic Lymphoma ◽  
Unique Mechanism

Abstract Anaplastic Lymphoma Kinase (ALK) is a receptor-type transmembrane tyrosine kinase (RTK) of the insulin receptor superfamily that structurally is most closely related to leukocyte tyrosine kinase. It was first discovered as a chimeric protein (NPM-ALK) of nucleophosmin and the C-terminal (kinase) domain of ALK in anaplastic large cell lymphomas (ALCL). NPM-ALK is constitutively active and generates the oncogenic signals that are the pathogenic mechanisms of these highly malignant cancers. The full-length ALK also is believed to have an important role in the pathogenesis of other human malignancies, since its expression is found in rhabdomyosarcomas, neuroblastomas, neuroectodermal tumors, glioblastomas, breast carcinomas, and melanomas. Recently it was proposed that pleiotrophin (PTN the protein, Ptn the gene) is the ligand that stimulates ALK to transduce signals to activate downstream targets. However, this proposal contrasted with earlier studies that demonstrated Receptor Protein Tyrosine Phosphatase (RPTP)β/ζ is the functional receptor for PTN. PTN was shown to inactivate RPTPβ/ζ and thereby permit the activity of different tyrosine kinases to increase tyrosine phosphorylation of the substrates of RPTPβ/ζ at the sites that are dephosphorylated by RPTPβ/ζ in cells not stimulated by PTN. Subsequent studies identified β-catenin, β-adducin, Fyn, GIT1/Cat-1, P190RhoGAP, and histone deacetylase 2 (HDAC-2) as downstream targets of the PTN/RPTPβ/ζ signaling pathway and demonstrated that their levels of tyrosine phosphorylation increase in PTN-stimulated cells. This diversity of PTN-regulated targets is one basis for the pleiotrophic activities of PTN. We now demonstrate that tyrosine phosphorylation of ALK is increased in PTN-stimulated cells through the PTN/RPTPβ/ζ signaling pathway. It is furthermore shown that ALK is activated in PTN-stimulated cells when it is expressed in cells without its extracellular domain, that β-catenin is a substrate of ALK, that the tyrosine phosphorylation site in β-catenin phosphorylated by ALK is the same site dephosphorylated by RPTPβ/ζ, and that PTN-stimulated tyrosine phosphorylation of β-catenin requires expression of ALK. The data suggest a unique mechanism to activate ALK; the data support a mechanism in which β-catenin is phosphorylated in tyrosine through the coordinated inactivation of RPTPβ/ζ, the activation of the tyrosine kinase activity of ALK, and the phosphorylation of β-catenin by ALK at the same site regulated by RPTPβ/ζ in PTN-stimulated cells. Since PTN often is inappropriately expressed in the same malignancies that express ALK, the data suggest a mechanism through which ALK signaling may contribute to those malignancies that express full length ALK through the activity of PTN to signal constitutively the same pathways as NPM-ALK in ALCL.

scholarly journals Protein tyrosine phosphatase containing SH2 domains: characterization, preferential expression in hematopoietic cells, and localization to human chromosome 12p12-p13.

1992 ◽  
Vol 12 (2) ◽  
pp. 836-846 ◽  
Author(s):  
T L Yi ◽  
J L Cleveland ◽  
J N Ihle
Keyword(s):  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Phosphatase ◽  
Human Gene ◽  
Tyrosine Phosphatase ◽  
Hematopoietic Cells ◽  
Protein Tyrosine Phosphatases ◽  
Hematopoietic Cell ◽  
Protein Tyrosine Phosphorylation ◽  
Tyrosine Phosphatases ◽  
Protein Tyrosine

Protein tyrosine phosphorylation has been implicated in the growth and functional responses of hematopoietic cells. Recently, approaches have been developed to characterize the protein tyrosine phosphatases that may contribute to regulation of protein tyrosine phosphorylation. One novel protein tyrosine phosphatase was expressed predominantly in hematopoietic cells. Hematopoietic cell phosphatase encodes a 68-kDa protein that contains a single phosphatase conserved domain. Unlike other known protein tyrosine phosphatases, hematopoietic cell phosphatase contains two src homology 2 domains. We also cloned the human homolog, which has 95% amino acid sequence identity. Both the murine and human gene products have tyrosine-specific phosphatase activity, and both are expressed predominantly in hematopoietic cells. Importantly, the human gene maps to chromosome 12 region p12-p13. This region is associated with rearrangements in approximately 10% of cases of acute lymphocytic leukemia in children.

scholarly journals NLRP3 tyrosine phosphorylation is controlled by protein tyrosine phosphatase PTPN22

2016 ◽  
Vol 126 (11) ◽  
pp. 4388-4388 ◽  
Author(s):  
Marianne R. Spalinger ◽  
Stephanie Kasper ◽  
Claudia Gottier ◽  
Silvia Lang ◽  
Kirstin Atrott ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine
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