A protein phosphatase related to the vaccinia virus VH1 is encoded in the genomes of several orthopoxviruses and a baculovirus.

Hakes, David J.; Martell, Karen J.; Zhao, Weiguo; Massung, Robert F.; Esposito, Joseph J.; Dixon, Jack E.

doi:10.1073/pnas.90.9.4017

Cited by 44 publications

(31 citation statements)

References 26 publications

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“…6E, wild-type virus-infected cell extracts showed some protein tyrosine phosphatase activity, as previously reported (26,34,53) and as expected from the presence of dual-specificity protein tyrosine phosphatases in the baculovirus. However, the Rec-PTPA virus-infected cell lysates released significantly more free phosphate than wild-type virusinfected cell lysates (P ϭ 0.02).…”

Section: Vol 78 2004 Bracovirus Protein Tyrosine Phosphatases 13095supporting

confidence: 50%

Bracoviruses Contain a Large Multigene Family Coding for Protein Tyrosine Phosphatases

Provost¹,

Varricchio

Arana

et al. 2004

J Virol

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The relationship between parasitic wasps and bracoviruses constitutes one of the few known mutualisms between viruses and eukaryotes. The virions produced in the wasp ovaries are injected into host lepidopteran larvae, where virus genes are expressed, allowing successful development of the parasite by inducing host immune suppression and developmental arrest. Bracovirus-bearing wasps have a common phylogenetic origin, and contemporary bracoviruses are hypothesized to have been inherited by chromosomal transmission from a virus that originally integrated into the genome of the common ancestor wasp living 73.7 ؎ 10 million years ago. However, so far no conserved genes have been described among different braconid wasp subfamilies. Here we show that a gene family is present in bracoviruses of different braconid wasp subfamilies (Cotesia congregata, Microgastrinae, and Toxoneuron nigriceps, Cardiochilinae) which likely corresponds to an ancient component of the bracovirus genome that might have been present in the ancestral virus. The genes encode proteins belonging to the protein tyrosine phosphatase family, known to play a key role in the control of signal transduction pathways. Bracovirus protein tyrosine phosphatase genes were shown to be expressed in different tissues of parasitized hosts, and two protein tyrosine phosphatases were produced with recombinant baculoviruses and tested for their biochemical activity. One protein tyrosine phosphatase is a functional phosphatase. These results strengthen the hypothesis that protein tyrosine phosphatases are involved in virally induced alterations of host physiology during parasitism.

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Section: Vol 78 2004 Bracovirus Protein Tyrosine Phosphatases 13095supporting

confidence: 50%

Bracoviruses Contain a Large Multigene Family Coding for Protein Tyrosine Phosphatases

Provost¹,

Varricchio

Arana

et al. 2004

J Virol

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“…Such differences in activity toward model substrates have previously been observed for other dual specificity phosphatases (see ref. 36, for example). These probably do not reflect differences in the intrinsic ability of the enzymes to dephosphorylate phosphoserine versus phosphotyrosine residues but instead likely reflect the ability of the enzyme to recognize phosphorylated residues in different contexts within artificial substrates.…”

Section: Resultsmentioning

confidence: 99%

“…3A). Several members of the tyrosine phosphatase family can dephosphorylate not only phosphotyrosyl but also phosphoseryl and phosphothreonyl residues (26,27,(35)(36)(37) determine whether KAP was a member of this group of dual-specificity phosphatases, we tested its ability to dephosphorylate phosphoseryl RCML. As shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

KAP: a dual specificity phosphatase that interactswith cyclin-dependent kinases.

Hannon

Casso

Beach

1994

Proc. Natl. Acad. Sci. U.S.A.

142

120

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The cyclin-dependent kinases are key cell cycle regulators whose activation is required for passage from one cell cyde phase to the next. In mammalian cells, CDK2 has been implicated in control ofthe G, and S phases. We have used a two-hybrid protein interaction screen to identify cDNAs encoding proteins that can interact with CDK2. Among those identified was a protein (KAP), which contained the HCXX-XXGR motif characteristic of protein tyrosine phosphatases. KAP showed phosphatase activity toward substrates containing either phosphotyrosine or phosphoserine residues. Since KAP is not significantly similar to known phosphatases beyond the catalytic core motif, it represents an additional class of dual specificity phosphatase. KAP interacted with cdc2 and CDK2 in yeast. In mammalian cells, KAP also associated with cdc2 and CDK2 but showed a preference for cdc2. The ability of KAP to bind multiple cyclin-dependent kinases suggests that it may play a role in cell cycle regulation.In fission and budding yeasts, control of both the G1/S and G2/M transitions is accomplished through the activity of a single cycin-dependent kinase known as cdc2 in Schizosaccharomyces pombe Phosphatase Assays. The entire coding sequence of the KAP cDNA was inserted into the bacterial expression vector pGEX-KG to form a plasmid that directed the expression of a fusion between glutathione S-transferase (GST) and KAP (pGST-KAPw). We also constructed a similar plasmid encoding a fusion between GST and a mutant KAP protein in which Cys-139 had been changed to Ser (pGST-KAPm). These plasmids were transformed into Escherichia coli BL21 for fusion protein expression. Cells containing each plasmid were grown at 370C to a density of OD600 = 0.5; the cultures were then shifted to 230C-250C, and isopropyl P-Dthiogalactopyranoside was added to 0.4 mM. After 12-14 hr, cells were harvested, washed once in phosphate-buffered saline, and resuspended in GCB [50 mM TrisHCl, pH 8.0/200 mM NaCl/1 mM EDTA, 1% Triton X-100/1 mM dithiothreitol (DTT)/1 x protease inhibitors (2 ,g of leupeptin per ml/2 ,ug of aprotinin per ml/0.3 ,.g of benzamide per ml/10 yg of soybean trypsin inhibitor per ml/100 /Ag of L-1-tosylamido-2-phenylethyl chloromethyl ketone per ml/50

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“…The low specific activity of IAR toward p-NPP may reflect a narrow substrate specificity of this phosphatase. Several nonreceptor PTPs have substitutions at the same position in the active site, for example bVH1 and cdc25 have a histidine residue in this position, whereas human VHR has a glutamic acid residue (32)(33)(34). These substitutions do not preclude catalysis, since all are active PTPs.…”

Section: Identification and Cdna Cloning Of Iar Ptp-to Search Formentioning

confidence: 99%

Cloning and Characterization of Islet Cell Antigen-related Protein-tyrosine Phosphatase (PTP), a Novel Receptor-like PTP and Autoantigen in Insulin-dependent Diabetes

Cui

DeAizpurua

et al. 1996

Journal of Biological Chemistry

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Cloning of the cDNA encoding a novel human proteintyrosine phosphatase (PTP) called islet cell antigen-related PTP (IAR) predicts a receptor-like molecule with an extracellular domain of 614 amino acids containing a hydrophobic signal peptide, one potential N-glycosylation site, and an RGDS peptide which is a possible adhesive recognition sequence. The 376-amino acid intracellular region contains a single catalytic domain. Recombinant IAR polypeptide has phosphatase activity. Northern blot analysis shows tissue-specific expression of two IAR transcripts of 5.5 and 3.7 kilobases, which are most abundant in brain and pancreas. The IAR PTP is homologous in its intracellular region to IA-2, a putative PTP that is an insulin-dependent diabetes mellitus (IDDM) autoantigen. IAR is also reactive with IDDM patient sera. IAR and IA-2 may distinguish different populations of IDDM autoantibodies since they identify overlapping but nonidentical sets of IDDM patients. Thus IAR is likely to be an islet cell antigen useful in the preclinical screening of individuals for risk of IDDM.

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A protein phosphatase related to the vaccinia virus VH1 is encoded in the genomes of several orthopoxviruses and a baculovirus.

Cited by 44 publications

References 26 publications

Bracoviruses Contain a Large Multigene Family Coding for Protein Tyrosine Phosphatases

Bracoviruses Contain a Large Multigene Family Coding for Protein Tyrosine Phosphatases

KAP: a dual specificity phosphatase that interactswith cyclin-dependent kinases.

Cloning and Characterization of Islet Cell Antigen-related Protein-tyrosine Phosphatase (PTP), a Novel Receptor-like PTP and Autoantigen in Insulin-dependent Diabetes

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