T Cell Developmental Defects in ‘Viable Motheaten’ Mice Deficient in SHP-1 Protein-Tyrosine Phosphatase. Developmental Defects are Corrected in vitro in the Presence of Normal Hematopoietic-Origin Stromal Cells and in vivo by Exogenous IL-7

2002 ◽  
Vol 18 (2) ◽  
pp. 119-130 ◽  
Author(s):  
Sherri W Christianson ◽  
Dale L Greiner ◽  
Dominick Deluca ◽  
Jean Leif ◽  
Nancy E Phillips ◽  
...  
Keyword(s):  
T Cell ◽  
Protein Tyrosine Phosphatase ◽  
Stromal Cells ◽  
Tyrosine Phosphatase ◽  
Developmental Defects ◽  
Protein Tyrosine

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.

Selective Inhibitors of the Protein Tyrosine Phosphatase SHP2 Block Cellular Motility and Growth of Cancer Cells in vitro and in vivo

ChemMedChem ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. 815-826 ◽  
Author(s):  
Stefanie Grosskopf ◽  
Chris Eckert ◽  
Christoph Arkona ◽  
Silke Radetzki ◽  
Kerstin Böhm ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Cellular Motility ◽  
Selective Inhibitors ◽  
Protein Tyrosine

Lithium regulates protein tyrosine phosphatase activity in vitro and in vivo

2002 ◽  
Vol 162 (4) ◽  
pp. 379-384 ◽  
Author(s):  
Xuechu Zhen ◽  
Claudio Torres ◽  
Eitan Friedman
Keyword(s):  
Phosphatase Activity ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine

scholarly journals Control of Dendritic Cell Migration, T Cell-Dependent Immunity, and Autoimmunity by Protein Tyrosine Phosphatase PTPN12 Expressed in Dendritic Cells

2013 ◽  
Vol 34 (5) ◽  
pp. 888-899 ◽  
Author(s):  
Inmoo Rhee ◽  
Ming-Chao Zhong ◽  
Boris Reizis ◽  
Cheolho Cheong ◽  
André Veillette
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Genetically Engineered ◽  
Lymphoid Tissues ◽  
Peripheral Tissues ◽  
Protein Tyrosine

Dendritic cells (DCs) capture and process antigens in peripheral tissues, migrate to lymphoid tissues, and present the antigens to T cells. PTPN12, also known as PTP-PEST, is an intracellular protein tyrosine phosphatase (PTP) involved in cell-cell and cell-substratum interactions. Herein, we examined the role of PTPN12 in DCs, using a genetically engineered mouse lacking PTPN12 in DCs. Our data indicated that PTPN12 was not necessary for DC differentiation, DC maturation, or cytokine production in response to inflammatory stimuli. However, it was needed for full induction of T cell-dependent immune responsesin vivo. This function largely correlated with the need of PTPN12 for DC migration from peripheral sites to secondary lymphoid tissues. Loss of PTPN12 in DCs resulted in hyperphosphorylation of the protein tyrosine kinase Pyk2 and its substrate, the adaptor paxillin. Pharmacological inhibition of Pyk2 or downregulation of Pyk2 expression also compromised DC migration, suggesting that Pyk2 deregulation played a pivotal role in the migration defect caused by PTPN12 deficiency. Together, these findings identified PTPN12 as a key regulator in the ability of DCs to induce antigen-induced T cell responses. This is due primarily to the role of PTPN12 in DC migration from peripheral sites to secondary lymphoid organs through regulation of Pyk2.

scholarly journals Identification of a Nuclear Stat1 Protein Tyrosine Phosphatase

2002 ◽  
Vol 22 (16) ◽  
pp. 5662-5668 ◽  
Author(s):  
Johanna ten Hoeve ◽  
Maria de Jesus Ibarra-Sanchez ◽  
Yubin Fu ◽  
Wei Zhu ◽  
Michel Tremblay ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Nuclear Extract ◽  
Null Mouse ◽  
Protein Tyrosine ◽  
Nuclear Extracts ◽  
Unknown Protein ◽  
Stat1 Protein

ABSTRACT Upon interferon (IFN) stimulation, Stat1 becomes tyrosine phosphorylated and translocates into the nucleus, where it binds to DNA to activate transcription. The activity of Stat1 is dependent on tyrosine phosphorylation, and its inactivation in the nucleus is accomplished by a previously unknown protein tyrosine phosphatase (PTP). We have now purified a Stat1 PTP activity from HeLa cell nuclear extract and identified it as TC45, the nuclear isoform of the T-cell PTP (TC-PTP). TC45 can dephosphorylate Stat1 both in vitro and in vivo. Nuclear extracts lacking TC45 fail to dephosphorylate Stat1. Furthermore, the dephosphorylation of IFN-induced tyrosine-phosphorylated Stat1 is defective in TC-PTP-null mouse embryonic fibroblasts (MEFs) and primary thymocytes. Reconstitution of TC-PTP-null MEFs with TC45, but not the endoplasmic reticulum (ER)-associated isoform TC48, rescues the defect in Stat1 dephosphorylation. The dephosphorylation of Stat3, but not Stat5 or Stat6, is also affected in TC-PTP-null cells. Our results identify TC45 as a PTP responsible for the dephosphorylation of Stat1 in the nucleus.

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