scholarly journals Residue 182 influences the second step of protein-tyrosine phosphatase-mediated catalysis

2004 ◽  
Vol 378 (2) ◽  
pp. 421-433 ◽  
Author(s):  
Anja K. PEDERSEN ◽  
Xiao-Ling GUO ◽  
Karin B. MØLLER ◽  
Günther H. PETERS ◽  
Henrik S. ANDERSEN ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Single Point ◽  
Critical Role ◽  
Enzyme Kinetic ◽  
Protein Tyrosine ◽  
General Base ◽  
Mediated Catalysis ◽  
Formation Step

Previous enzyme kinetic and structural studies have revealed a critical role for Asp181 (PTP1B numbering) in PTP (protein-tyrosine phosphatase)-mediated catalysis. In the E-P (phosphoenzyme) formation step, Asp181 functions as a general acid, while in the E-P hydrolysis step it acts as a general base. Most of our understanding of the role of Asp181 is derived from studies with the Yersinia PTP and the mammalian PTP1B, and to some extent also TC (T-cell)-PTP and the related PTPα and PTP∊. The neighbouring residue 182 is a phenylalanine in these four mammalian enzymes and a glutamine in Yersinia PTP. Surprisingly, little attention has been paid to the fact that this residue is a histidine in most other mammalian PTPs. Using a reciprocal single-point mutational approach with introduction of His182 in PTP1B and Phe182 in PTPH1, we demonstrate here that His182-PTPs, in comparison with Phe182-PTPs, have significantly decreased kcat values, and to a lesser degree, decreased kcat/Km values. Combined enzyme kinetic, X-ray crystallographic and molecular dynamics studies indicate that the effect of His182 is due to interactions with Asp181 and with Gln262. We conclude that residue 182 can modulate the functionality of both Asp181 and Gln262 and therefore affect the E-P hydrolysis step of PTP-mediated catalysis.

scholarly journals Inhibition of Protein Tyrosine Phosphatase Improves Angiogenesis via Enhancing Ang-1/Tie-2 Signaling in Diabetes

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jian-Xiong Chen ◽  
Qinhui Tuo ◽  
Duan-Fang Liao ◽  
Heng Zeng
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Critical Role ◽  
Vascular Complications ◽  
Microvascular Endothelial Cell ◽  
Mouse Heart ◽  
Protein Tyrosine ◽  
Enos Phosphorylation ◽  
Kinase Phosphorylation

Diabetes is associated with impairment of angiogenesis such as reduction of myocardial capillary formation. Our previous studies demonstrate that disruption of Angiopoietin-1 (Ang-1)/Tie-2 signaling pathway contributes to the diabetes-associated impairment of angiogenesis. Protein tyrosine phosphatase (PTP) has a critical role in the regulation of insulin signal by inhibition of tyrosine kinase phosphorylation. In present study, we examined the role of protein tyrosine phosphatase-1 (SHP-1) in diabetes-associated impairment of Ang-1/Tie-2 angiogenic signaling and angiogenesis. SHP-1 expression was significantly increased in diabetic db/db mouse hearts. Furthermore, SHP-1 bond to Tie-2 receptor and stimulation with Ang-1 led to SHP-1 dissociation from Tie-2 in mouse heart microvascular endothelial cell (MHMEC). Exposure of MHMEC to high glucose (HG, 30 mmol/L) increased SHP-1/Tie-2 association accompanied by a significant reduction of Tie-2 phosphorylation. Exposure of MHMEC to HG also blunted Ang-1-mediated SHP-1/Tie-2 dissociation. Knockdown of SHP-1 significantly attenuated HG-induced caspase-3 activation and apoptosis in MHMEC. Treatment with PTP inhibitors restored Ang-1-induced Akt/eNOS phosphorylation and angiogenesis. Our data implicate a critical role of SHP-1 in diabetes-associated vascular complications, and that upregulation of Ang-1/Tie-2 signaling by targeting SHP-1 should be considered as a new therapeutic strategy for the treatment of diabetes-associated impairment of angiogenesis.

Abstract 1630: Critical role of Shp2 protein tyrosine phosphatase in tumorigenesis of carcinoma

2010 ◽  
Author(s):  
Yuan Ren ◽  
Zhengming Chen ◽  
Liwei Chen ◽  
Hla WinPiazza ◽  
Steven Enkemann ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Critical Role ◽  
Protein Tyrosine

scholarly journals Role of Chondroitin Sulfate (CS) Modification in the Regulation of Protein-tyrosine Phosphatase Receptor Type Z (PTPRZ) Activity

2016 ◽  
Vol 291 (35) ◽  
pp. 18117-18128 ◽  
Author(s):  
Kazuya Kuboyama ◽  
Akihiro Fujikawa ◽  
Ryoko Suzuki ◽  
Naomi Tanga ◽  
Masaharu Noda
Keyword(s):  
Chondroitin Sulfate ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Receptor Type ◽  
Protein Tyrosine

scholarly journals AP-1 elements and TCL1 protein regulate expression of the gene encoding protein tyrosine phosphatase PTPROt in leukemia

Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6132-6140 ◽  
Author(s):  
Tasneem Motiwala ◽  
Nicola Zanesi ◽  
Jharna Datta ◽  
Satavisha Roy ◽  
Huban Kutay ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Lymphocytic Leukemia ◽  
Potential Mechanism ◽  
Wild Type ◽  
Truncated Form ◽  
Gene Encoding ◽  
Protein Tyrosine ◽  
Encoding Protein

Abstract We previously demonstrated that the gene encoding PTPROt, the truncated form of protein tyrosine phosphatase receptor type O expressed predominantly in hematopoietic cells, is a candidate tumor suppressor and is down-regulated in chronic lymphocytic leukemia (CLL). Here, we show that PTPROt expression is significantly reduced in CD19+ spleen B cells from Eμ-T cell leukemia 1 (TCL1) transgenic mice relative to the wild-type mice. Strikingly, as much as a 60% decrease in PTPROt expression occurs at 7 weeks independently of promoter methylation. To elucidate the potential mechanism for this early suppression of PTPROt in these mice, we explored the role of activating protein-1 (AP-1) in its expression. We first demonstrate that AP-1 activation by 12-O-tetradecanoylphorbol-13-acetate induces PTPROt expression with concurrent recruitment of c-fos and c-jun to its promoter. The PTPROt promoter is also responsive to over- and underexpression of AP-1, confirming the role of AP-1 in PTPROt expression. Next, we demonstrate that TCL1 can repress the PTPROt promoter by altering c-fos expression and c-jun activation state. Finally, using primary CLL cells we have shown an inverse relationship between TCL1 and PTPROt expression. These findings further substantiate the role of TCL1 in PTPROt suppression and its importance in the pathogenesis of CLL.

scholarly journals The role of T‐cell protein tyrosine phosphatase in epithelial carcinogenesis

2019 ◽  
Vol 58 (9) ◽  
pp. 1640-1647
Author(s):  
Liza D. Morales ◽  
Anna K. Archbold ◽  
Serena Olivarez ◽  
Thomas J. Slaga ◽  
John DiGiovanni ◽  
...  
Keyword(s):  
T Cell ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Cell Protein ◽  
Protein Tyrosine

The role of receptor protein tyrosine phosphatase α in neuronal differentiation of embryonic stem cells

1996 ◽  
Vol 91 (2) ◽  
pp. 304-307 ◽  
Author(s):  
Wouter G. van Inzen ◽  
Maikel P. Peppelenbosch ◽  
Maria W.M. van den Brand ◽  
Leon G.J. Tertoolen ◽  
Siegfried de Laat
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Neuronal Differentiation ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Embryonic Stem ◽  
Receptor Protein ◽  
Protein Tyrosine ◽  
Receptor Protein Tyrosine Phosphatase

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.

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