scholarly journals The Nonreceptor Protein Tyrosine Phosphatase PTP1B Binds to the Cytoplasmic Domain of N-Cadherin and Regulates the Cadherin–Actin Linkage

1998 ◽  
Vol 143 (2) ◽  
pp. 523-532 ◽  
Author(s):  
Janne Balsamo ◽  
Carlos Arregui ◽  
TinChung Leung ◽  
Jack Lilien
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Cytoplasmic Domain ◽  
Dominant Negative ◽  
Wild Type ◽  
Protein Tyrosine ◽  
Tyrosine Residues ◽  
Cytoplasmic Proteins ◽  
Inactive Form

Cadherin-mediated adhesion depends on the association of its cytoplasmic domain with the actin-containing cytoskeleton. This interaction is mediated by a group of cytoplasmic proteins: α-and β- or γ- catenin. Phosphorylation of β-catenin on tyrosine residues plays a role in controlling this association and, therefore, cadherin function. Previous work from our laboratory suggested that a nonreceptor protein tyrosine phosphatase, bound to the cytoplasmic domain of N-cadherin, is responsible for removing tyrosine-bound phosphate residues from β-catenin, thus maintaining the cadherin–actin connection (Balsamo et al., 1996). Here we report the molecular cloning of the cadherin-associated tyrosine phosphatase and identify it as PTP1B. To definitively establish a causal relationship between the function of cadherin-bound PTP1B and cadherin-mediated adhesion, we tested the effect of expressing a catalytically inactive form of PTP1B in L cells constitutively expressing N-cadherin. We find that expression of the catalytically inactive PTP1B results in reduced cadherin-mediated adhesion. Furthermore, cadherin is uncoupled from its association with actin, and β-catenin shows increased phosphorylation on tyrosine residues when compared with parental cells or cells transfected with the wild-type PTP1B. Both the transfected wild-type and the mutant PTP1B are found associated with N-cadherin, and recombinant mutant PTP1B binds to N-cadherin in vitro, indicating that the catalytically inactive form acts as a dominant negative, displacing endogenous PTP1B, and rendering cadherin nonfunctional. Our results demonstrate a role for PTP1B in regulating cadherin-mediated cell adhesion.

scholarly journals Protein Tyrosine Phosphatase φ Regulates Paxillin Tyrosine Phosphorylation and Mediates Colony-Stimulating Factor 1-Induced Morphological Changes in Macrophages

2001 ◽  
Vol 21 (5) ◽  
pp. 1795-1809 ◽  
Author(s):  
Fiona J. Pixley ◽  
Pierre S. W. Lee ◽  
John S. Condeelis ◽  
E. Richard Stanley
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Catalytic Domain ◽  
Morphological Changes ◽  
Tyrosine Phosphatase ◽  
Dominant Negative ◽  
Colony Stimulating Factor ◽  
Macrophage Cell ◽  
Protein Tyrosine ◽  
Stimulating Factor

ABSTRACT Removal of colony-stimulating factor 1 (CSF-1) causes macrophages to round up and to increase their expression of protein tyrosine phosphatase φ (PTPφ). This is accompanied by the disruption of focal complexes and the formation of ruffles. Here we have overexpressed wild-type (WT) PTPφ and a phosphatase-inactive (C325S) mutant in a macrophage cell line in the presence and absence of CSF-1. In the presence of CSF-1, WT PTPφ induces cell rounding and ruffle formation, while C325S PTPφ has no effect. In contrast, in CSF-1-starved cells, C325S PTPφ behaves in a dominant negative fashion, preventing rounding and ruffling. Furthermore, C325S PTPφ increases adhesion in cycling cells, while WT PTPφ enhances motility. In WT PTPφ-overexpressing cells, the focal contact protein paxillin is selectively depleted from focal complexes and specifically dephosphorylated on tyrosine. In contrast, paxillin is hyperphosphorylated in C325S PTPφ-expressing cells. Moreover, a complex containing PTPφ, paxillin, and a paxillin-associated tyrosine kinase, Pyk2, can be immunoprecipitated from macrophage lysates, and the catalytic domain of PTPφ selectively binds paxillin and Pyk2 in vitro. Although PTPφ and Pyk2 do not colocalize with paxillin in focal complexes, all three proteins are colocalized in dorsal ruffles. The results suggest that paxillin is dephosphorylated by PTPφ in dorsal ruffles, using Pyk2 as a bridging molecule, resulting in a reduced pool of tyrosine-phosphorylated paxillin available for incorporation into focal complexes, thereby mediating CSF-1 regulation of macrophage morphology, adhesion, and motility.

scholarly journals Protein tyrosine phosphatase receptor type E (PTPRE) regulates the activation of wild-type KIT and KIT mutants differently

2021 ◽  
Vol 26 ◽  
pp. 100974
Author(s):  
Shaoting Zhang ◽  
Liangying Zhang ◽  
Zongying Jiang ◽  
Yue Guo ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Receptor Type ◽  
Wild Type ◽  
Protein Tyrosine

Analysis of in vitro interactions of protein tyrosine phosphatase 1B with insulin receptors

2001 ◽  
Vol 173 (1-2) ◽  
pp. 109-120 ◽  
Author(s):  
Xin-Yuan Wang ◽  
Katrin Bergdahl ◽  
Anna Heijbel ◽  
Charlotta Liljebris ◽  
John E. Bleasdale
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Insulin Receptors ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
In Vitro Interactions

scholarly journals Loss of T-Cell Protein Tyrosine Phosphatase Induces Recycling of the Platelet-derived Growth Factor (PDGF) β-Receptor but Not the PDGF α-Receptor

2006 ◽  
Vol 17 (11) ◽  
pp. 4846-4855 ◽  
Author(s):  
Susann Karlsson ◽  
Katarzyna Kowanetz ◽  
Åsa Sandin ◽  
Camilla Persson ◽  
Arne Östman ◽  
...  
Keyword(s):  
T Cell ◽  
Growth Factor ◽  
Cell Surface ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Dominant Negative ◽  
Platelet Derived Growth Factor ◽  
Cell Protein ◽  
Protein Tyrosine ◽  
Β Receptor

We have previously shown that the T-cell protein tyrosine phosphatase (TC-PTP) dephosphorylates the platelet-derived growth factor (PDGF) β-receptor. Here, we show that the increased PDGF β-receptor phosphorylation in TC-PTP knockout (ko) mouse embryonic fibroblasts (MEFs) occurs primarily on the cell surface. The increased phosphorylation is accompanied by a TC-PTP–dependent, monensin-sensitive delay in clearance of cell surface PDGF β-receptors and delayed receptor degradation, suggesting PDGF β-receptor recycling. Recycled receptors could also be directly detected on the cell surface of TC-PTP ko MEFs. The effect of TC-PTP depletion was specific for the PDGF β-receptor, because PDGF α-receptor homodimers were cleared from the cell surface at the same rate in TC-PTP ko MEFs as in wild-type MEFs. Interestingly, PDGF αβ-receptor heterodimers were recycling. Analysis by confocal microscopy revealed that, in TC-PTP ko MEFs, activated PDGF β-receptors colocalized with Rab4a, a marker for rapid recycling. In accordance with this, transient expression of a dominant-negative Rab4a construct increased the rate of clearance of cell surface receptors on TC-PTP ko MEFs. Thus, loss of TC-PTP specifically redirects the PDGF β-receptor toward rapid recycling, which is the first evidence of differential trafficking of PDGF receptor family members.

Protein-tyrosine phosphatase activity of CD45 is activated by sequential phosphorylation by two kinases

1994 ◽  
Vol 14 (8) ◽  
pp. 5523-5532
Author(s):  
D R Stover ◽  
K A Walsh
Keyword(s):  
T Cell Activation ◽  
Protein Tyrosine Phosphatase ◽  
Time Course ◽  
Cell Activation ◽  
Regulatory Mechanism ◽  
Transmembrane Protein ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine

We describe a potential regulatory mechanism for the transmembrane protein-tyrosine phosphatase CD45. Phosphorylation on both tyrosine and serine residues in vitro results in an activation of CD45 specifically toward one artificial substrate but not another. The activation of these kinases appears to be order dependent, as it is enhanced when phosphorylation of tyrosine precedes that of serine but phosphorylation in the reverse order yields no activation. Any of four protein-tyrosine kinases tested, in combination with the protein-serine/threonine kinase, casein kinase II, was capable of mediating this activation in vitro. The time course of phosphorylation of CD45 in response to T-cell activation is consistent with the possibility that this regulatory mechanism is utilized in vivo.

scholarly journals Six New 3,5-Dimethylcoumarins from Chelonopsis praecox, Chelonopsis odontochila and Chelonopsis pseudobracteata

2021 ◽  
Author(s):  
Chang-An Geng ◽  
Zhen-Tao Deng ◽  
Qian Huang ◽  
Chun-Lei Xiang ◽  
Ji-Jun Chen
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
2D Nmr ◽  
Cell Protein ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
Aerial Parts ◽  
Spectroscopic Analyses ◽  
New Compounds

AbstractTen 3,5-dimethylcoumarins (1–6 and 8‒11) involving six new ones (1–6), together with a known 3-methylcoumarin (7), were isolated from the aerial parts of three Chelonopsis plants, C. praecox, C. odontochila, and C. pseudobracteata. The structures of the new compounds were determined by extensive HRESIMS, 1D and 2D NMR spectroscopic analyses. According to the substitution at C-5, these coumarins were classified into 5-methyl, 5-hydroxymethyl, 5-formyl, and 5-nor types. All the isolates were assayed for their inhibition on α-glucosidase, protein tyrosine phosphatase 1B, and T-cell protein tyrosine phosphatase in vitro. Graphic Abstract

scholarly journals Simulasi Docking Senyawa Aglikon Kurkuligosida A dan Turunannya pada Protein Tyrosine Phosphatase 1B (PTP1B)

2019 ◽  
Vol 16 (2) ◽  
pp. 216
Author(s):  
Nursamsiar Nursamsiar ◽  
Akbar Awaluddin ◽  
Megawati Megawati ◽  
Yulita M. Soko ◽  
Muhammad Aswad
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
Autodock 4.2 ◽  
Diabetes Melitus

Senyawa aglikon kurkuligosida A memiliki struktur yang mirip dengan senyawa licoagrochalcone yang terbukti memiliki aktivitas penghambatan yang kuat secara in vitro pada Protein Tyrosine Phosphatase 1B (PTP1B), yang dianggap sebagai target terapeutik untuk pengobatan diabetes melitus tipe 2. Penelitian ini bertujuan untuk mengetahui interaksi antara senyawa aglikon kurkuligosida A dan turunannya dengan PTP1B menggunakan metode simulasi docking. Simulasi docking dilakukan dengan menggunakan perangkat lunak AutoDock 4.2. Hasil docking menunjukan semua senyawa yang diuji dapat berinteraksi dengan sisi aktif PTP1B. Interaksi terbaik ditunjukkan oleh senyawa 31 (3,5-dihidroksibensil-3,5-dinitrobenzoate), senyawa 39 (3,5-dihidroksibensil-4-nitrobenzoate) dan senyawa 52 (4-hidroksibensil-4-nitro bensoat) dengan nilai energi bebas ikatan berturut-turut –9,40 kkal/mol ; –9,19 kkal/mol dan –9,03 kkal/mol. Ketiga senyawa tersebut memiliki interaksi dengan sisi aktif PTP1B dengan residu asam amino Ser216 dan Arg221. Semua senyawa turunan aglikon kurkuligosida A yang diuji juga memiliki pola pengikatan yang sama dengan ligan alami pada PTP1B.

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