Two Duplicated Ptpn6 Homeologs Cooperatively and Negatively Regulate RLR-Mediated IFN Response in Hexaploid Gibel Carp

Src homology region 2 domain-containing phosphatase 1 (SHP1), encoded by the protein tyrosine phosphatase nonreceptor type 6 (ptpn6) gene, belongs to the family of protein tyrosine phosphatases (PTPs) and participates in multiple signaling pathways of immune cells. However, the mechanism of SHP1 in regulating fish immunity is largely unknown. In this study, we first identified two gibel carp (Carassius gibelio) ptpn6 homeologs (Cgptpn6-A and Cgptpn6-B), each of which had three alleles with high identities. Then, relative to Cgptpn6-B, dominant expression in adult tissues and higher upregulated expression of Cgptpn6-A induced by polyinosinic-polycytidylic acid (poly I:C), poly deoxyadenylic-deoxythymidylic (dA:dT) acid and spring viremia of carp virus (SVCV) were uncovered. Finally, we demonstrated that CgSHP1-A (encoded by the Cgptpn6-A gene) and CgSHP1-B (encoded by the Cgptpn6-B gene) act as negative regulators of the RIG-I-like receptor (RLR)-mediated interferon (IFN) response via two mechanisms: the inhibition of CaTBK1-induced phosphorylation of CaMITA shared by CgSHP1-A and CgSHP1-B, and the autophagic degradation of CaMITA exclusively by CgSHP1-A. Meanwhile, the data support that CgSHP1-A and CgSHP1-B have sub-functionalized and that CgSHP1-A overwhelmingly dominates CgSHP1-B in the process of RLR-mediated IFN response. The current study not only sheds light on the regulative mechanism of SHP1 in fish immunity, but also provides a typical case of duplicated gene evolutionary fates.

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mSiglec-E, a novel mouse CD33-related siglec (sialic acid-binding immunoglobulin-like lectin) that recruits Src homology 2 (SH2)-domain-containing protein tyrosine phosphatases SHP-1 and SHP-2

Biochemical Journal ◽

10.1042/bj3530483 ◽

2001 ◽

Vol 353 (3) ◽

pp. 483-492 ◽

Cited By ~ 12

Author(s):

Zhenbao YU ◽

Meryem MAOUI ◽

Liangtang WU ◽

Denis BANVILLE ◽

Shi-Hsiang SHEN

Keyword(s):

Sialic Acid ◽

Sequence Similarity ◽

Tyrosine Phosphatase ◽

Protein Tyrosine Phosphatases ◽

Sh2 Domain ◽

Immunoglobulin Superfamily ◽

Protein Tyrosine ◽

Src Homology 2 ◽

Sialic Acid Binding ◽

Src Homology

The sialic acid-binding immunoglobulin-like lectins (siglecs) represent a recently defined distinct subset of the immunoglobulin superfamily. By using the Src homology 2 (SH2)-domain-containing protein tyrosine phosphatase SHP-1 as bait in a yeast two-hybrid screen, we have identified a new member of the mouse siglec family, mSiglec-E. The mSiglec-E cDNA encodes a protein of 467 amino acids that contains three extracellular immunoglobulin-like domains, a transmembrane region and a cytoplasmic tail bearing two immunoreceptor tyrosine-based inhibitory motifs (ITIMs). mSiglec-E is highly expressed in mouse spleen, a tissue rich in leucocytes. The ITIMs of mSiglec-E can recruit SHP-1 and SHP-2, two inhibitory regulators of immunoreceptor signal transduction. This suggests that the function of mSiglec-E is probably an involvement in haematopoietic cells and the immune system as an inhibitory receptor. When expressed in COS-7 cells, mSiglec-E was able to mediate sialic acid-dependent binding to human red blood cells, suggesting that mSiglec-E may function through cell–cell interactions. In comparison with the known members of the siglec family, mSiglec-E exhibits a high degree of sequence similarity to both human siglec-7 and siglec-9. The gene encoding mSiglec-E is localized in the same chromosome as that encoding mouse CD33. Phylogenetic analysis reveals that neither mouse mSiglec-E nor CD33 shows a clear relationship with any human siglecs so far identified.

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Design and Biological Evaluation of Novel Imidazolyl Flavonoids as Potent and Selective Protein Tyrosine Phosphatase Inhibitors

Medicinal Chemistry ◽

10.2174/1573406415666190430125547 ◽

2020 ◽

Vol 16 (4) ◽

pp. 563-574 ◽

Cited By ~ 1

Author(s):

Rong Y. Han ◽

Yu Ge ◽

Ling Zhang ◽

Qing M. Wang

Keyword(s):

Protein Tyrosine Phosphatase ◽

Tyrosine Phosphatase ◽

Protein Tyrosine Phosphatases ◽

Structural Features ◽

Biological Evaluation ◽

Cell Protein ◽

Phosphatase Inhibitors ◽

Protein Tyrosine ◽

Therapeutic Development ◽

Chemical Studies

Background: Protein tyrosine phosphatases 1B are considered to be a desirable validated target for therapeutic development of type II diabetes and obesity. Methods: A new series of imidazolyl flavonoids as potential protein tyrosine phosphatase inhibitors were synthesized and evaluated. Results: Bioactive results indicated that some synthesized compounds exhibited potent protein phosphatase 1B (PTP1B) inhibitory activities at the micromolar range. Especially, compound 8b showed the best inhibitory activity (IC50=1.0 µM) with 15-fold selectivity for PTP1B over the closely related T-cell protein tyrosine phosphatase (TCPTP). Cell viability assays indicated that 8b is cell permeable with lower cytotoxicity. Molecular modeling and dynamics studies revealed the reason for selectivity of PTP1B over TCPTP. Quantum chemical studies were carried out on these compounds to understand the structural features essential for activity. Conclusion: Compound 8b should be a potential selective PTP1B inhibitor.

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Development of a Robust High-Throughput Screening Platform for Inhibitors of the Striatal-Enriched Tyrosine Phosphatase (STEP)

International Journal of Molecular Sciences ◽

10.3390/ijms22094417 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4417

Author(s):

Lester J Lambert ◽

Stefan Grotegut ◽

Maria Celeridad ◽

Palak Gosalia ◽

Laurent JS De Backer ◽

...

Keyword(s):

Drug Discovery ◽

High Throughput ◽

Tyrosine Kinases ◽

High Throughput Screening ◽

Kinase Inhibitors ◽

Tyrosine Phosphatase ◽

Protein Tyrosine Phosphatases ◽

Synaptic Function ◽

Label Free ◽

Protein Tyrosine

Many human diseases are the result of abnormal expression or activation of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Not surprisingly, more than 30 tyrosine kinase inhibitors (TKIs) are currently in clinical use and provide unique treatment options for many patients. PTPs on the other hand have long been regarded as “undruggable” and only recently have gained increased attention in drug discovery. Striatal-enriched tyrosine phosphatase (STEP) is a neuron-specific PTP that is overactive in Alzheimer’s disease (AD) and other neurodegenerative and neuropsychiatric disorders, including Parkinson’s disease, schizophrenia, and fragile X syndrome. An emergent model suggests that the increase in STEP activity interferes with synaptic function and contributes to the characteristic cognitive and behavioral deficits present in these diseases. Prior efforts to generate STEP inhibitors with properties that warrant clinical development have largely failed. To identify novel STEP inhibitor scaffolds, we developed a biophysical, label-free high-throughput screening (HTS) platform based on the protein thermal shift (PTS) technology. In contrast to conventional HTS using STEP enzymatic assays, we found the PTS platform highly robust and capable of identifying true hits with confirmed STEP inhibitory activity and selectivity. This new platform promises to greatly advance STEP drug discovery and should be applicable to other PTP targets.

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Investigating the reason for loss-of-function of Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2) caused by Y279C mutation through molecular dynamics simulation

Journal of Biomolecular Structure and Dynamics ◽

10.1080/07391102.2019.1634641 ◽

2019 ◽

Vol 38 (9) ◽

pp. 2509-2520 ◽

Cited By ~ 2

Author(s):

Wen-Shan Liu ◽

Rui-Rui Wang ◽

Wei-Ya Li ◽

Mei Rong ◽

Chi-Lu Liu ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Protein Tyrosine Phosphatase ◽

Tyrosine Phosphatase ◽

Dynamics Simulation ◽

Loss Of Function ◽

Protein Tyrosine ◽

Src Homology 2 ◽

Src Homology ◽

Src Homology 2 Domain

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Coordinated Regulation of Insulin Signaling by the Protein Tyrosine Phosphatases PTP1B and TCPTP

Molecular and Cellular Biology ◽

10.1128/mcb.25.2.819-829.2005 ◽

2005 ◽

Vol 25 (2) ◽

pp. 819-829 ◽

Cited By ~ 127

Author(s):

Sandra Galic ◽

Christine Hauser ◽

Barbara B. Kahn ◽

Fawaz G. Haj ◽

Benjamin G. Neel ◽

...

Keyword(s):

Insulin Signaling ◽

Tyrosine Phosphatase ◽

Protein Tyrosine Phosphatases ◽

Negative Regulator ◽

Mitogen Activated Protein Kinase ◽

Protein Tyrosine ◽

Akt Activation ◽

Protein Levels ◽

Mitogen Activated Protein

ABSTRACT The protein tyrosine phosphatase PTP1B is a negative regulator of insulin signaling and a therapeutic target for type 2 diabetes. Our previous studies have shown that the closely related tyrosine phosphatase TCPTP might also contribute to the regulation of insulin receptor (IR) signaling in vivo (S. Galic, M. Klingler-Hoffmann, M. T. Fodero-Tavoletti, M. A. Puryer, T. C. Meng, N. K. Tonks, and T. Tiganis, Mol. Cell. Biol. 23:2096-2108, 2003). Here we show that PTP1B and TCPTP function in a coordinated and temporally distinct manner to achieve an overall regulation of IR phosphorylation and signaling. Whereas insulin-induced phosphatidylinositol 3-kinase/Akt signaling was prolonged in both TCPTP−/− and PTP1B−/− immortalized mouse embryo fibroblasts (MEFs), mitogen-activated protein kinase ERK1/2 signaling was elevated only in PTP1B-null MEFs. By using phosphorylation-specific antibodies, we demonstrate that both IR β-subunit Y1162/Y1163 and Y972 phosphorylation are elevated in PTP1B−/− MEFs, whereas Y972 phosphorylation was elevated and Y1162/Y1163 phosphorylation was sustained in TCPTP−/− MEFs, indicating that PTP1B and TCPTP differentially contribute to the regulation of IR phosphorylation and signaling. Consistent with this, suppression of TCPTP protein levels by RNA interference in PTP1B−/− MEFs resulted in no change in ERK1/2 signaling but caused prolonged Akt activation and Y1162/Y1163 phosphorylation. These results demonstrate that PTP1B and TCPTP are not redundant in insulin signaling and that they act to control both common as well as distinct insulin signaling pathways in the same cell.

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In Vitro Characterization of the Bacillus subtilis Protein Tyrosine Phosphatase YwqE

Journal of Bacteriology ◽

10.1128/jb.187.10.3384-3390.2005 ◽

2005 ◽

Vol 187 (10) ◽

pp. 3384-3390 ◽

Cited By ~ 31

Author(s):

Ivan Mijakovic ◽

Lucia Musumeci ◽

Lutz Tautz ◽

Dina Petranovic ◽

Robert A. Edwards ◽

...

Keyword(s):

Bacillus Subtilis ◽

Tyrosine Phosphatase ◽

Protein Tyrosine Phosphatases ◽

Class Ii ◽

Gram Positive ◽

Protein Tyrosine ◽

Gram Positive Bacteria ◽

New Family ◽

In Vitro Characterization

ABSTRACT Both gram-negative and gram-positive bacteria possess protein tyrosine phosphatases (PTPs) with a catalytic Cys residue. In addition, many gram-positive bacteria have acquired a new family of PTPs, whose first characterized member was CpsB from Streptococcus pneumoniae. Bacillus subtilis contains one such CpsB-like PTP, YwqE, in addition to two class II Cys-based PTPs, YwlE and YfkJ. The substrates for both YwlE and YfkJ are presently unknown, while YwqE was shown to dephosphorylate two phosphotyrosine-containing proteins implicated in UDP-glucuronate biosynthesis, YwqD and YwqF. In this study, we characterize YwqE, compare the activities of the three B. subtilis PTPs (YwqE, YwlE, and YfkJ), and demonstrate that the two B. subtilis class II PTPs do not dephosphorylate the physiological substrates of YwqE.

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Absence of CTLA-4 Lowers the Activation Threshold of Primed CD8+ TCR-Transgenic T Cells: Lack of Correlation with Src Homology Domain 2-Containing Protein Tyrosine Phosphatase

The Journal of Immunology ◽

10.4049/jimmunol.166.6.3900 ◽

2001 ◽

Vol 166 (6) ◽

pp. 3900-3907 ◽

Cited By ~ 37

Author(s):

Thomas F. Gajewski ◽

Francesca Fallarino ◽

Patrick E. Fields ◽

Fabiola Rivas ◽

Maria-Luisa Alegre

Keyword(s):

T Cells ◽

Protein Tyrosine Phosphatase ◽

Tyrosine Phosphatase ◽

Activation Threshold ◽

Protein Tyrosine ◽

Src Homology

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Streptococcus sanguis-induced platelet activation involves two waves of tyrosine phosphorylation mediated by FcγRIIA and αIIbβ3

Thrombosis and Haemostasis ◽

10.1160/th04-08-0482 ◽

2005 ◽

Vol 93 (05) ◽

pp. 932-939 ◽

Cited By ~ 23

Author(s):

Caroline Pampolina ◽

Archibald McNicol

Keyword(s):

Signal Transduction ◽

Platelet Aggregation ◽

Tyrosine Phosphorylation ◽

Platelet Activation ◽

Tyrosine Phosphatase ◽

Protein Tyrosine Phosphatases ◽

Lag Phase ◽

Dependent Manner ◽

Protein Tyrosine ◽

Streptococcus Sanguis

SummaryThe low-affinity IgG receptor, FcγRIIA, has been implicated in Streptococcus sanguis-induced platelet aggregation. Therefore, it is likely that signal transduction is at least partly mediated by FcγRIIA activation and a tyrosine kinase-dependent pathway. In this study the signal transduction mechanisms associated with platelet activation in response to the oral bacterium, S. sanguis were characterised. In the presence of IgG, S. sanguis strain 2017–78 caused the tyrosine phosphorylation of FcγRIIA 30s following stimulation, which led to the phosphorylation of Syk, LAT, and PLCγ2. These early events were dependent on Src family kinases but independent of either TxA2 or the engagement of the αIIbβ3 integrin. During the lag phase prior to platelet aggregation, FcγRIIA, Syk, LAT, and PLCγ2 were each dephosphorylated, but were re-phosphorylated as aggregation occurred. Platelet stimulation by 2017–78 also induced the tyrosine phosphorylation of PECAM-1, an ITIM-containing receptor that recruits protein tyrosine phosphatases. PECAM-1 co-precipitated with the protein tyrosine phosphatase SHP-1 in the lag phase. SHP-1 was also maximally tyrosine phosphorylated during this phase, suggesting a possible role for SHP-1 in the observed dephosphorylation events. As aggregation occurred, SHP-1 was dephosphorylated, while FcγRIIA, Syk, LAT, and PLCγ2 were rephosphorylated in an RGDS-sensitive, and therefore αIIbβ3-dependent, manner. Additionally, TxA2 release, 5-hydro-xytryptamine secretion and phosphatidic acid formation were all blocked by RGDS. Aspirin also abolished these events, but only partially inhibited αIIbβ3-mediated re-phosphorylation. Therefore, S.sanguis-bound IgG cross links FcγRIIA and initiates a signaling pathway that is down-regulated by PECAM-1-bound SHP-1. Subsequent engagement of αIIbβ3 leads to SHP-1 dephosphorylation permiting a second wave of signaling leading to TxA2 release and consequent platelet aggregation.

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