A porcine cell surface receptor identified by monoclonal antibodies to SWC3 is a member of the signal regulatory protein family and associates with protein-tyrosine phosphatase SHP-1

2000 ◽  
Vol 55 (4) ◽  
pp. 342-351 ◽  
Author(s):  
B. Alvarez ◽  
C. Sanchez ◽  
R. Bullido ◽  
A. Marina ◽  
J. Lunney ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Surface ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Regulatory Protein ◽  
Protein Family ◽  
Cell Surface Receptor ◽  
Protein Tyrosine ◽  
Surface Receptor ◽  
Porcine Cell

scholarly journals The Cell-Specific Phenotype of the Polymorphic vacA Midregion Is Independent of the Appearance of the Cell Surface Receptor Protein Tyrosine Phosphatase β

2006 ◽  
Vol 74 (1) ◽  
pp. 49-55 ◽  
Author(s):  
David A. G. Skibinski ◽  
Christophe Genisset ◽  
Silvia Barone ◽  
John L. Telford
Keyword(s):  
Cell Surface ◽  
Cell Lines ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Cell Surface Receptor ◽  
Receptor Protein ◽  
Protein Tyrosine ◽  
Amino Acid Region ◽  
Receptor Protein Tyrosine Phosphatase ◽  
Surface Receptor

ABSTRACT There are two alleles, m1 and m2, of the midregion of the vacuolating cytotoxin gene (vacA) of Helicobacter pylori which code for toxins with different cell specificities. Here we describe the construction of five chimeric strains in which regions of vacA were exchanged between the two genotypes. By analyzing the toxicity of these strains for HeLa and RK13 cells we have confirmed that a 148-amino-acid region determines the phenotypic differences between the two forms of the protein and that this entire region is important for cytotoxicity. Furthermore, we have used our chimeric strains to investigate whether variations in the midregion of VacA have an effect on phorbol 12-myristate 13-acetate (PMA)-induced VacA sensitivity in HL-60 cells. The PMA-induced VacA sensitivity of HL-60 cells has been previously associated with the appearance of the cell surface receptor protein tyrosine phosphatase beta (RPTPβ). Our data indicate that both the m1 and m2 forms of VacA are able to utilize RPTPβ, and the cell-specific phenotype of the midregion is independent of the presence of RPTPβ. It appears that another as-yet-unidentified receptor exists in HL-60 cells that accounts for the m2 phenotype in this cell line. Also, by studying the effect of PMA on levels of RPTPβ in other cell lines and toxicity of VacA in these cell lines we have shown that RPTPβ does not play a major role in the vacuolation of HeLa cells.

Receptor protein tyrosine phosphatase μ: measuring where to stick

2008 ◽  
Vol 36 (2) ◽  
pp. 167-172 ◽  
Author(s):  
A. Radu Aricescu ◽  
Christian Siebold ◽  
E. Yvonne Jones
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Cell Surface Receptor ◽  
Receptor Protein ◽  
Protein Tyrosine ◽  
Receptor Protein Tyrosine Phosphatase ◽  
Extracellular Region ◽  
Fibronectin Type Iii ◽  
Surface Receptor ◽  
And Function

We review here recent results on the structure and function of a receptor protein tyrosine phosphatase, RPTPμ. In addition to their intercellular catalytic domains which bear the phosphatase activity, the RPTPs are cell-surface-receptor-type molecules and in many cases have large extracellular regions. What role can these extracellular regions play in function? For RPTPμ, the extracellular region is known to mediate homophilic adhesion. Sequence analysis indicates that it comprises six domains: an N-terminal MAM (meprin/A5/μ), one immunoglobulin-like domain and four fibronectin type III (FN) repeats. We have determined the crystal structure of the entire extracellular region for RPTPμ in the form of a functional adhesion dimer. The physical characteristics and dimensions of the adhesion dimer suggest a mechanism by which the location of this phosphatase can be influenced by cell–cell spacings.

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.

scholarly journals Receptor-like Protein-tyrosine Phosphatase α Enhances Cell Surface Expression of Neural Adhesion Molecule NB-3

2011 ◽  
Vol 286 (29) ◽  
pp. 26071-26080 ◽  
Author(s):  
Haihong Ye ◽  
Tian Zhao ◽  
Yen Ling Jessie Tan ◽  
Jianghong Liu ◽  
Catherine J. Pallen ◽  
...  
Keyword(s):  
Cell Surface ◽  
Adhesion Molecule ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Protein Tyrosine ◽  
Neural Adhesion Molecule

scholarly journals Identification of Major Binding Proteins and Substrates for the SH2-Containing Protein Tyrosine Phosphatase SHP-1 in Macrophages

1998 ◽  
Vol 18 (7) ◽  
pp. 3838-3850 ◽  
Author(s):  
John F. Timms ◽  
Kristen Carlberg ◽  
Haihua Gu ◽  
Haiyan Chen ◽  
Shubhangi Kamatkar ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Kinase Activity ◽  
Tyrosine Phosphatase ◽  
Regulatory Protein ◽  
Protein Tyrosine ◽  
Sh2 Domains ◽  
Receptor Complexes ◽  
Multiple Signaling ◽  
Tyrosyl Phosphorylation ◽  
Stimulating Factor

ABSTRACT The protein tyrosine phosphatase SHP-1 is a critical regulator of macrophage biology, but its detailed mechanism of action remains largely undefined. SHP-1 associates with a 130-kDa tyrosyl-phosphorylated species (P130) in macrophages, suggesting that P130 might be an SHP-1 regulator and/or substrate. Here we show that P130 consists of two transmembrane glycoproteins, which we identify as PIR-B/p91A and the signal-regulatory protein (SIRP) family member BIT. These proteins also form separate complexes with SHP-2. BIT, but not PIR-B, is in a complex with the colony-stimulating factor 1 receptor (CSF-1R), suggesting that BIT may direct SHP-1 to the CSF-1R. BIT and PIR-B bind preferentially to substrate-trapping mutants of SHP-1 and are hyperphosphorylated in macrophages from motheaten viable mice, which express catalytically impaired forms of SHP-1, indicating that these proteins are SHP-1 substrates. However, BIT and PIR-B are hypophosphorylated in motheaten macrophages, which completely lack SHP-1 expression. These data suggest a model in which SHP-1 dephosphorylates specific sites on BIT and PIR-B while protecting other sites from dephosphorylation via its SH2 domains. Finally, BIT and PIR-B associate with two tyrosyl phosphoproteins and a tyrosine kinase activity. Tyrosyl phosphorylation of these proteins and the level of the associated kinase activity are increased in the absence of SHP-1. Our data suggest that BIT and PIR-B recruit multiple signaling molecules to receptor complexes, where they are regulated by SHP-1 and/or SHP-2.

Cell-surface-bound Yersinia translocate the protein tyrosine phosphatase YopH by a polarized mechanism into the target cell

1995 ◽  
Vol 18 (1) ◽  
pp. 135-150 ◽  
Author(s):  
Cathrine Persson ◽  
Roland Nordfelth ◽  
Anna Holmstrom ◽  
Sebastian H>>kansson ◽  
Roland Rosqvist ◽  
...  
Keyword(s):  
Cell Surface ◽  
Target Cell ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine

Do Lipocalins Play a Role in Mast Cell Physiology?.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1645-1645
Author(s):  
Lennart E. Logdberg ◽  
Bo Akerstrom ◽  
Gregory A. Hair ◽  
Maria Allhorn ◽  
Tatyana Vikulina ◽  
...  
Keyword(s):  
Mast Cell ◽  
Monoclonal Antibodies ◽  
Mast Cells ◽  
Cell Surface ◽  
Gene Transcription ◽  
Cell Surface Receptor ◽  
Cell Surface Expression ◽  
Cell Physiology ◽  
Myeloma Protein ◽  
Surface Receptor

Abstract Introduction. Aiming to identify molecular properties of allergens responsible for their “intrinsic allergenicity”, we focus on a subset of xenogeneic lipocalins (LCs) that comprise the major mammalian respiratory allergens. These structurally and functionally homologous molecules likely possess conserved molecular motifs promoting IgE-dependent allergy. We hypothesize that such LC “allergenicity” depends on non-IgE interactions of LCs with components of the innate immune system. Herein we describe a possible basis for such interactions between LCs and mast cells. Materials and Methods. Two sources of human mast cells were used; primary cultures derived from peripheral blood CD34+ progenitor cells; or the LAD-2 cell line. Cells were cultured in serum-free medium with recombinant human stem cell factor (SCF; 100 ng/ml). Monoclonal antibodies to human gp330/megalin (MAb E11) were a kind gift of Prof. Lars Rask (Uppsala University, Sweden). Cell surface protein expression was assessed by flow cytometry and gene transcription was measured by real-time PCR. Results. Monoclonal antibodies to an endocytic cell surface receptor (megalin, also known as low-density lipoprotein receptor-related protein (LRP)-2) known to bind multiple LCs stained the mast cell lines. This putative expression of megalin by the mast cells corresponded to their transcription of megalin mRNA as shown as by PCR. Moreover, mast cell megalin gene transcription could be induced (≥ 1000-fold) by overnight culture with monomeric IgE myeloma protein (100 ng/ml), and such induction of the megalin message correlated with both an increase in cell surface expression of the molecule and the specific binding of a purified human LC (a-1 microglobulin). Conclusion. Megalin, an LC-binding cell surface receptor, appears to be constitutively expressed by both progenitor and mature mast cells, and its expression seems to be strongly upregulated by culture with monomeric IgE. This is consistent with a role for direct mast cell-LC interactions in the development of IgE-dependent allergy. In addition, and also of potential clinical relevance, endogenous LCs may play a functional role in normal mast cell physiology.

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