scholarly journals The Second Catalytic Domain of Protein Tyrosine Phosphatase δ (PTPδ) Binds to and Inhibits the First Catalytic Domain of PTPς

1998 ◽  
Vol 18 (5) ◽  
pp. 2608-2616 ◽  
Author(s):  
Megan J. Wallace ◽  
Christopher Fladd ◽  
Jane Batt ◽  
Daniela Rotin
Keyword(s):  
Mammalian Cells ◽  
Catalytic Domain ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatases ◽  
Regulatory Function ◽  
Yeast Two Hybrid ◽  
Protein Tyrosine ◽  
Catalytic Domains ◽  
Two Hybrid

ABSTRACT The LAR family protein tyrosine phosphatases (PTPs), including LAR, PTPδ, and PTPς, are transmembrane proteins composed of a cell adhesion molecule-like ectodomain and two cytoplasmic catalytic domains: active D1 and inactive D2. We performed a yeast two-hybrid screen with the first catalytic domain of PTPς (PTPς-D1) as bait to identify interacting regulatory proteins. Using this screen, we identified the second catalytic domain of PTPδ (PTPδ-D2) as an interactor of PTPς-D1. Both yeast two-hybrid binding assays and coprecipitation from mammalian cells revealed strong binding between PTPς-D1 and PTPδ-D2, an association which required the presence of the wedge sequence in PTPς-D1, a sequence recently shown to mediate D1-D1 homodimerization in the phosphatase RPTPα. This interaction was not reciprocal, as PTPδ-D1 did not bind PTPς-D2. Addition of a glutathione S-transferase (GST)–PTPδ-D2 fusion protein (but not GST alone) to GST–PTPς-D1 led to ∼50% inhibition of the catalytic activity of PTPς-D1, as determined by an in vitro phosphatase assay againstp-nitrophenylphosphate. A similar inhibition of PTPς-D1 activity was obtained with coimmunoprecipitated PTPδ-D2. Interestingly, the second catalytic domains of LAR (LAR-D2) and PTPς (PTPς-D2), very similar in sequence to PTPδ-D2, bound poorly to PTPς-D1. PTPδ-D1 and LAR-D1 were also able to bind PTPδ-D2, but more weakly than PTPς-D1, with a binding hierarchy of PTPς-D1>>PTPδ-D1>LAR-D1. These results suggest that association between PTPς-D1 and PTPδ-D2, possibly via receptor heterodimerization, provides a negative regulatory function and that the second catalytic domains of this and likely other receptor PTPs, which are often inactive, may function instead to regulate the activity of the first catalytic domains.

scholarly journals In Vitro Characterization of the Bacillus subtilis Protein Tyrosine Phosphatase YwqE

2005 ◽  
Vol 187 (10) ◽  
pp. 3384-3390 ◽  
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.

scholarly journals Murine protein tyrosine phosphatase-PEST, a stable cytosolic protein tyrosine phosphatase

1995 ◽  
Vol 308 (2) ◽  
pp. 425-432 ◽  
Author(s):  
A Charest ◽  
J Wagner ◽  
S H Shen ◽  
M L Tremblay
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Northern Blot Analysis ◽  
Catalytic Domain ◽  
Tyrosine Phosphatase ◽  
Glutathione S Transferase ◽  
Epitope Tag ◽  
Reading Frame ◽  
Protein Tyrosine ◽  
Cytosolic Protein

We have isolated the murine cDNA homologue of the human protein tyrosine phosphatase PTP-PEST (MPTP-PEST) from an 18.5-day mouse embryonic kidney library. The cDNA isolated has a single open reading frame predicting a protein of 775 amino acids. When expressed in vitro as a glutathione S-transferase fusion protein, the catalytic domain (residues 1-453) shows intrinsic phosphatase activity. Reverse transcriptase PCR and Northern-blot analysis show that MPTP-PEST mRNA is expressed throughout murine development. Indirect immunofluorescence in COS-1 cells against a heterologous epitope tag attached to the N-terminus of MPTP-PEST, together with cellular fractionation and Western-blot experiments from different murine cell lines, indicate that MPTP-PEST is a free cytosolic protein of 112 kDa. Finally, sequence analysis indicates that the C-terminal portion of the protein contains four regions rich in proline, glutamate, serine and threonine, otherwise known as PEST sequences. These are characteristic of proteins that display very short intracellular half-lives. Despite the presence of these motifs, pulse-chase labelling experiments demonstrate that MPTP-PEST has a half-life of more than 4 h.

scholarly journals A novel receptor-type protein tyrosine phosphatase with a single catalytic domain is specifically expressed in mouse brain

1995 ◽  
Vol 305 (2) ◽  
pp. 499-504 ◽  
Author(s):  
W Hendriks ◽  
J Schepens ◽  
C Brugman ◽  
P Zeeuwen ◽  
B Wieringa
Keyword(s):  
Mouse Brain ◽  
Tyrosine Kinases ◽  
Catalytic Domain ◽  
Tyrosine Phosphatase ◽  
Cell Signalling ◽  
Protein Tyrosine Phosphatases ◽  
Pcr Amplification ◽  
Phosphatase Domain ◽  
Protein Tyrosine ◽  
The Brain

Protein tyrosine phosphatases (PTPases) are important regulatory proteins that, together with protein tyrosine kinases, determine the phosphotyrosine levels in cell signalling proteins. By PCR amplification of mouse brain cDNA fragments encoding the catalytic domains of these enzymes, we identified three novel members of the PTPase gene family. Northern-blot analysis showed that two of these novel clones represent brain-specific PTPases, whereas the third originates from a large-sized mRNA that is more ubiquitously expressed. A full-length cDNA encoding one of the brain-specific PTPases, PTP-SL, was isolated. Sequence analysis revealed a transmembrane PTPase containing a single catalytic phosphatase domain that has 45% homology to a rat cytoplasmic brain-specific PTPase named STEP. This suggests a role for PTP-SL in cell-cell signalling processes in the brain.

scholarly journals Involvement of the Mitochondrial Protein Tyrosine Phosphatase PTPM1 in the Promotion of Conidiation, Development, and Pathogenicity in Colletotrichum graminicola

2021 ◽  
Vol 11 ◽  
Author(s):  
Shaowei Wang ◽  
Guihua Li ◽  
Yi Wei ◽  
Gang Wang ◽  
Yuejia Dang ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Fungal Pathogens ◽  
Tyrosine Phosphatase ◽  
Mitochondrial Protein ◽  
Protein Tyrosine Phosphatases ◽  
Host Cells ◽  
Colletotrichum Graminicola ◽  
Protein Tyrosine

The phosphorylation status of proteins, which is determined by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), governs many cellular actions. In fungal pathogens, phosphorylation-mediated signal transduction has been considered to be one of the most important mechanisms in pathogenicity. Colletotrichum graminicola is an economically important corn pathogen. However, whether phosphorylation is involved in its pathogenicity is unknown. A mitochondrial protein tyrosine phosphatase gene, designated CgPTPM1, was deduced in C. graminicola through the use of bioinformatics and confirmed by enzyme activity assays and observation of its subcellular localization. We then created a CgPTPM1 deletion mutant (ΔCgPTPM1) to analyze its biological function. The results indicated that the loss of CgPTPM1 dramatically affected the formation of conidia and the development and differentiation into appressoria. However, the colony growth and conidial morphology of the ΔCgPTPM1 strains were unaffected. Importantly, the ΔCgPTPM1 mutant strains exhibited an obvious reduction of virulence, and the delayed infected hyphae failed to expand in the host cells. In comparison with the wild-type, ΔCgPTPM1 accumulated a larger amount of H2O2 and was sensitive to exogenous H2O2. Interestingly, the host cells infected by the mutant also exhibited an increased accumulation of H2O2 around the infection sites. Since the expression of the CgHYR1, CgGST1, CgGLR1, CgGSH1 and CgPAP1 genes was upregulated with the H2O2 treatment, our results suggest that the mitochondrial protein tyrosine phosphatase PTPM1 plays an essential role in promoting the pathogenicity of C. graminicola by regulating the excessive in vivo and in vitro production of H2O2.

scholarly journals PICK1: a perinuclear binding protein and substrate for protein kinase C isolated by the yeast two-hybrid system.

1995 ◽  
Vol 128 (3) ◽  
pp. 263-271 ◽  
Author(s):  
J Staudinger ◽  
J Zhou ◽  
R Burgess ◽  
S J Elledge ◽  
E N Olson
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Hybrid System ◽  
Catalytic Domain ◽  
Yeast Two Hybrid ◽  
Kinase C ◽  
Yeast Two Hybrid System ◽  
Wide Range ◽  
Two Hybrid

Protein kinase C (PKC) plays a central role in the control of proliferation and differentiation of a wide range of cell types by mediating the signal transduction response to hormones and growth factors. Upon activation by diacylglycerol, PKC translocates to different subcellular sites where it phosphorylates numerous proteins, most of which are unidentified. We used the yeast two-hybrid system to identify proteins that interact with activated PKC alpha. Using the catalytic region of PKC fused to the DNA binding domain of yeast GAL4 as "bait" to screen a mouse T cell cDNA library in which cDNA was fused to the GAL4 activation domain, we cloned several novel proteins that interact with C-kinase (PICKs). One of these proteins, designated PICK1, interacts specifically with the catalytic domain of PKC and is an efficient substrate for phosphorylation by PKC in vitro and in vivo. PICK1 is localized to the perinuclear region and is phosphorylated in response to PKC activation. PICK1 and other PICKs may play important roles in mediating the actions of PKC.

scholarly journals Protein tyrosine phosphatases ε and α perform nonredundant roles in osteoclasts

2014 ◽  
Vol 25 (11) ◽  
pp. 1808-1818 ◽  
Author(s):  
Eynat Finkelshtein ◽  
Sutada Lotinun ◽  
Einat Levy-Apter ◽  
Esther Arman ◽  
Jeroen den Hertog ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Bone Matrix ◽  
Protein Tyrosine Phosphatases ◽  
Structure Stability ◽  
Cellular Organization ◽  
Production Structure ◽  
Protein Tyrosine ◽  
Catalytic Domains

Female mice lacking protein tyrosine phosphatase ε (PTP ε) are mildly osteopetrotic. Osteoclasts from these mice resorb bone matrix poorly, and the structure, stability, and cellular organization of their podosomal adhesion structures are abnormal. Here we compare the role of PTP ε with that of the closely related PTP α in osteoclasts. We show that bone mass and bone production and resorption, as well as production, structure, function, and podosome organization of osteoclasts, are unchanged in mice lacking PTP α. The varying effects of either PTP on podosome organization in osteoclasts are caused by their distinct N-termini. Osteoclasts express the receptor-type PTP α (RPTPa), which is absent from podosomes, and the nonreceptor form of PTP ε (cyt-PTPe), which is present in these structures. The presence of the unique 12 N-terminal residues of cyt-PTPe is essential for podosome regulation; attaching this sequence to the catalytic domains of PTP α enables them to function in osteoclasts. Serine 2 within this sequence regulates cyt-PTPe activity and its effects on podosomes. We conclude that PTPs α and ε play distinct roles in osteoclasts and that the N-terminus of cyt-PTPe, in particular serine 2, is critical for its function in these cells.

scholarly journals No Obvious Abnormality in Mice Deficient in Receptor Protein Tyrosine Phosphatase β

2000 ◽  
Vol 20 (20) ◽  
pp. 7706-7715 ◽  
Author(s):  
S. Harroch ◽  
M. Palmeri ◽  
J. Rosenbluth ◽  
A. Custer ◽  
M. Okigaki ◽  
...  
Keyword(s):  
Nervous System ◽  
Neurite Outgrowth ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatases ◽  
Structural Features ◽  
Receptor Protein ◽  
Protein Tyrosine ◽  
Deficient Mice

ABSTRACT The development of neurons and glia is governed by a multitude of extracellular signals that control protein tyrosine phosphorylation, a process regulated by the action of protein tyrosine kinases and protein tyrosine phosphatases (PTPs). Receptor PTPβ (RPTPβ; also known as PTPζ) is expressed predominantly in the nervous system and exhibits structural features common to cell adhesion proteins, suggesting that this phosphatase participates in cell-cell communication. It has been proposed that the three isoforms of RPTPβ play a role in regulation of neuronal migration, neurite outgrowth, and gliogenesis. To investigate the biological functions of this PTP, we have generated mice deficient in RPTPβ. RPTPβ-deficient mice are viable, are fertile, and showed no gross anatomical alterations in the nervous system or other organs. In contrast to results of in vitro experiments, our study demonstrates that RPTPβ is not essential for neurite outgrowth and node formation in mice. The ultrastructure of nerves of the central nervous system in RPTPβ-deficient mice suggests a fragility of myelin. However, conduction velocity was not altered in RPTPβ-deficient mice. The normal development of neurons and glia in RPTPβ-deficient mice demonstrates that RPTPβ function is not necessary for these processes in vivo or that loss of RPTPβ can be compensated for by other PTPs expressed in the nervous system.

scholarly journals Nitropropenyl Benzodioxole, An Anti-Infective Agent with Action as a Protein Tyrosine Phosphatase Inhibitor

2014 ◽  
Vol 8 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Kylie S. White ◽  
Gina Nicoletti ◽  
Robert Borland
Keyword(s):  
Virulence Factors ◽  
Mammalian Cells ◽  
Tyrosine Phosphatase ◽  
Membrane Integrity ◽  
Protein Tyrosine Phosphatases ◽  
Heterogeneous Distribution ◽  
Protein Tyrosine ◽  
Atp Production ◽  
Cell Membrane Integrity ◽  
Infective Agent

We report on the activities of a broad spectrum antimicrobial compound,nitropropenyl benzodioxole (NPBD) which are of relevance to its potential as an anti-infective drug. These investigations support the proposal that a major mechanism of NPBD is action as a tyrosine mimetic, competitively inhibiting bacterial and fungal protein tyrosine phosphatases (PTP).NPBD did not affect major anti-bacterial drug targets, namely, ATP production, cell wall or cell membrane integrity, or transcription and translation of RNA. NPBD inhibited bacterial YopH and human PTP1B and not human CD45 in enzyme assays. NPBD inhibited PTP-associated bacterial virulence factors, namely, endospore formation inBacillus cereus,prodigiosin secretion inSerratia marcescens, motility inProteusspp., and adherence and invasion of mammalian cells byYersinia enterocolitica. NPBD acts intracellularly to inhibit the early development stages of theChlamydia trachomatisinfection cycle in mammalian cells known to involve sequestration of host cell PTPs. NPBD thus both kills pathogens and inhibits virulence factors relevant to early infection, making it a suitable candidate for development as an anti-infective agent, particularly for pathogens that enter through, or cause infections at, mucosal surfaces. Though much is yet to be understood about bacterial PTPs, they are proposed as suitable anti-infective targets and have been linked to agents similar to NPBD. The structural and functional diversity and heterogeneous distribution of PTPs across microbial species make them suitably selective targets for the development of both broadly active and pathogen-specific drugs.

scholarly journals Std1p (Msn3p) Positively Regulates the Snf1 Kinase in Saccharomyces cerevisiae

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 507-514 ◽  
Author(s):  
Sergei Kuchin ◽  
Valmik K Vyas ◽  
Ellen Kanter ◽  
Seung-Pyo Hong ◽  
Marian Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Kinase Activity ◽  
Catalytic Domain ◽  
Snf1 Kinase ◽  
Glucose Signaling ◽  
Catalytic Domains ◽  
Upstream Kinase ◽  
Two Hybrid

Abstract The Snf1 protein kinase of the glucose signaling pathway in Saccharomyces cerevisiae is regulated by an autoinhibitory interaction between the regulatory and catalytic domains of Snf1p. Transitions between the autoinhibited and active states are controlled by an upstream kinase and the Reg1p-Glc7p protein phosphatase 1. Previous studies suggested that Snf1 kinase activity is also modulated by Std1p (Msn3p), which interacts physically with Snf1p and also interacts with glucose sensors. Here we address the relationship between Std1p and the Snf1 kinase. Two-hybrid assays showed that Std1p interacts with the catalytic domain of Snf1p, and analysis of mutant kinases suggested that this interaction is incompatible with the autoinhibitory interaction of the regulatory and catalytic domains. Overexpression of Std1p increased the two-hybrid interaction of Snf1p with its activating subunit Snf4p, which is diagnostic of an open, uninhibited conformation of the kinase complex. Overexpression of Std1p elevated Snf1 kinase activity in both in vitro and in vivo assays. These findings suggest that Std1p stimulates the Snf1 kinase by an interaction with the catalytic domain that antagonizes autoinhibition and promotes an active conformation of the kinase.

Cloning and Characterization of a Lymphoid-Specific, Inducible Human Protein Tyrosine Phosphatase, Lyp

Blood ◽  
1999 ◽  
Vol 93 (6) ◽  
pp. 2013-2024 ◽  
Author(s):  
Shai Cohen ◽  
Harjit Dadi ◽  
Ester Shaoul ◽  
Nigel Sharfe ◽  
Chaim M. Roifman
Keyword(s):  
T Cells ◽  
Tyrosine Phosphorylation ◽  
Protein Kinases ◽  
Cell Activation ◽  
Catalytic Domain ◽  
Tyrosine Phosphatase ◽  
Control Cell ◽  
Protein Tyrosine Phosphatases ◽  
Lymphoid Tissues ◽  
Protein Tyrosine

Protein tyrosine phosphatases act in conjunction with protein kinases to regulate the tyrosine phosphorylation events that control cell activation and differentiation. We have isolated a previously undescribed human phosphatase, Lyp, that encodes an intracellular 105-kD protein containing a single tyrosine phosphatase catalytic domain. The noncatalytic domain contains four proline-rich potential SH3 domain binding sites and an NXXY motif that, if phosphorylated, may be recognized by phosphotyrosine binding (PTB) domains. Comparison of the Lyp amino acid sequence with other known proteins shows 70% identity with the murine phosphatase PEP. The human Lyp gene was localized to chromosome 1p13 by fluorescence in situ hybridization analysis. We also identified an alternative spliced form of Lyp RNA, Lyp2. This isoform encodes a smaller 85-kD protein with an alternative C-terminus. The lyp phosphatases are predominantly expressed in lymphoid tissues and cells, with Lyp1 being highly expressed in thymocytes and both mature B and T cells. Increased Lyp1 expression can be induced by activation of resting peripheral T lymphocytes with phytohemagglutinin or anti-CD3. Lyp1 was found to be constitutively associated with the proto-oncogene c-Cbl in thymocytes and T cells. Overexpression of lyp1 reduces Cbl tyrosine phosphorylation, suggesting that it may be a substrate of the phosphatase. Thus, Lyp may play a role in regulating the function of Cbl and its associated protein kinases.

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