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Sample records for highly conserved tyrosine

  1. A highly conserved tyrosine of Tim-3 is phosphorylated upon stimulation by its ligand galectin-9

    International Nuclear Information System (INIS)

    Weyer, Philipp S. van de; Muehlfeit, Michael; Klose, Christoph; Bonventre, Joseph V.; Walz, Gerd; Kuehn, E. Wolfgang

    2006-01-01

    Tim-3 is a member of the TIM family of proteins (T-cell immunoglobulin mucin) involved in the regulation of CD4+ T-cells. Tim-3 is a T H 1-specific type 1 membrane protein and regulates T H 1 proliferation and the development of tolerance. Binding of galectin-9 to the extracellular domain of Tim-3 results in apoptosis of T H 1 cells, but the intracellular pathways involved in the regulatory function of Tim-3 are unknown. Unlike Tim-1, which is expressed in renal epithelia and cancer, Tim-3 has not been described in cells other than neuronal or T-cells. Using RT-PCR we demonstrate that Tim-3 is expressed in malignant and non-malignant epithelial tissues. We have cloned Tim-3 from an immortalized liver cell carcinoma line and identified a highly conserved tyrosine in the intracellular tail of Tim-3 (Y265). We demonstrate that Y265 is specifically phosphorylated in vivo by the interleukin inducible T cell kinase (ITK), a kinase which is located in close proximity of the TIM genes on the allergy susceptibility locus 5q33.3. Stimulation of Tim-3 by its ligand galectin-9 results in increased phosphorylation of Y265, suggesting that this tyrosine residue plays an important role in downstream signalling events regulating T-cell fate. Given the role of TIM proteins in autoimmunity and cancer, the conserved SH2 binding domain surrounding Y265 could represent a possible target site for pharmacological intervention

  2. HD-PTP is a catalytically inactive tyrosine phosphatase due to a conserved divergence in its phosphatase domain.

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    Marie-Claude Gingras

    Full Text Available The HD-PTP protein has been described as a tumor suppressor candidate and based on its amino acid sequence, categorized as a classical non-transmembrane protein tyrosine phosphatase (PTP. To date, no HD-PTP phosphorylated substrate has been identified and controversial results concerning its catalytic activity have been recently reported.Here we report a rigorous enzymatic analysis demonstrating that the HD-PTP protein does not harbor tyrosine phosphatase or lipid phosphatase activity using the highly sensitive DiFMUP substrate and a panel of different phosphatidylinositol phosphates. We found that HD-PTP tyrosine phosphatase inactivity is caused by an evolutionary conserved amino acid divergence of a key residue located in the HD-PTP phosphatase domain since its back mutation is sufficient to restore the HD-PTP tyrosine phosphatase activity. Moreover, in agreement with a tumor suppressor activity, HD-PTP expression leads to colony growth reduction in human cancer cell lines, independently of its catalytic PTP activity status.In summary, we demonstrate that HD-PTP is a catalytically inactive protein tyrosine phosphatase. As such, we identify one residue involved in its inactivation and show that its colony growth reduction activity is independent of its PTP activity status in human cancer cell lines.

  3. An evolutionarily conserved glycine-tyrosine motif forms a folding core in outer membrane proteins.

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    Marcin Michalik

    Full Text Available An intimate interaction between a pair of amino acids, a tyrosine and glycine on neighboring β-strands, has been previously reported to be important for the structural stability of autotransporters. Here, we show that the conservation of this interacting pair extends to nearly all major families of outer membrane β-barrel proteins, which are thought to have originated through duplication events involving an ancestral ββ hairpin. We analyzed the function of this motif using the prototypical outer membrane protein OmpX. Stopped-flow fluorescence shows that two folding processes occur in the millisecond time regime, the rates of which are reduced in the tyrosine mutant. Folding assays further demonstrate a reduction in the yield of folded protein for the mutant compared to the wild-type, as well as a reduction in thermal stability. Taken together, our data support the idea of an evolutionarily conserved 'folding core' that affects the folding, membrane insertion, and thermal stability of outer membrane protein β-barrels.

  4. Pseudomonas aeruginosa 4-amino-4-deoxychorismate lyase: spatial conservation of an active site tyrosine and classification of two types of enzyme.

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    Patrick E F O'Rourke

    Full Text Available 4-Amino-4-deoxychorismate lyase (PabC catalyzes the formation of 4-aminobenzoate, and release of pyruvate, during folate biosynthesis. This is an essential activity for the growth of gram-negative bacteria, including important pathogens such as Pseudomonas aeruginosa. A high-resolution (1.75 Å crystal structure of PabC from P. aeruginosa has been determined, and sequence-structure comparisons with orthologous structures are reported. Residues around the pyridoxal 5'-phosphate cofactor are highly conserved adding support to aspects of a mechanism generic for enzymes carrying that cofactor. However, we suggest that PabC can be classified into two groups depending upon whether an active site and structurally conserved tyrosine is provided from the polypeptide that mainly forms an active site or from the partner subunit in the dimeric assembly. We considered that the conserved tyrosine might indicate a direct role in catalysis: that of providing a proton to reduce the olefin moiety of substrate as pyruvate is released. A threonine had previously been suggested to fulfill such a role prior to our observation of the structurally conserved tyrosine. We have been unable to elucidate an experimentally determined structure of PabC in complex with ligands to inform on mechanism and substrate specificity. Therefore we constructed a computational model of the catalytic intermediate docked into the enzyme active site. The model suggests that the conserved tyrosine helps to create a hydrophobic wall on one side of the active site that provides important interactions to bind the catalytic intermediate. However, this residue does not appear to participate in interactions with the C atom that undergoes an sp(2 to sp(3 conversion as pyruvate is produced. The model and our comparisons rather support the hypothesis that an active site threonine hydroxyl contributes a proton used in the reduction of the substrate methylene to pyruvate methyl in the final stage of

  5. A protein-binding domain, EH, identified in the receptor tyrosine kinase substrate Eps15 and conserved in evolution

    DEFF Research Database (Denmark)

    Wong, W T; Schumacher, C; Salcini, A E

    1995-01-01

    In this report we structurally and functionally define a binding domain that is involved in protein association and that we have designated EH (for Eps15 homology domain). This domain was identified in the tyrosine kinase substrate Eps15 on the basis of regional conservation with several heteroge......In this report we structurally and functionally define a binding domain that is involved in protein association and that we have designated EH (for Eps15 homology domain). This domain was identified in the tyrosine kinase substrate Eps15 on the basis of regional conservation with several...... heterogeneous proteins of yeast and nematode. The EH domain spans about 70 amino acids and shows approximately 60% overall amino acid conservation. We demonstrated the ability of the EH domain to specifically bind cytosolic proteins in normal and malignant cells of mesenchymal, epithelial, and hematopoietic...... (for Eps15-related). Structural comparison of Eps15 and Eps15r defines a family of signal transducers possessing extensive networking abilities including EH-mediated binding and association with Src homology 3-containing proteins....

  6. c-Abl phosphorylation of Yin Yang 1's conserved tyrosine 254 in the spacer region modulates its transcriptional activity.

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    Daraiseh, Susan I; Kassardjian, Ari; Alexander, Karen E; Rizkallah, Raed; Hurt, Myra M

    2018-05-25

    Yin Yang 1 (YY1) is a multifunctional transcription factor that can activate or repress transcription depending on the promotor and/or the co-factors recruited. YY1 is phosphorylated in various signaling pathways and is critical for different biological functions including embryogenesis, apoptosis, proliferation, cell-cycle regulation and tumorigenesis. Here we report that YY1 is a substrate for c-Abl kinase phosphorylation at conserved residue Y254 in the spacer region. Pharmacological inhibition of c-Abl kinase by imatinib, nilotinib and GZD824, knock-down of c-Abl using siRNA, and the use of c-Abl kinase-dead drastically reduces tyrosine phosphorylation of YY1. Both radioactive and non-radioactive in vitro kinase assays, as well as co-immunoprecipitation in different cell lines, show that the target of c-Abl phosphorylation is tyrosine residue 254. c-Abl phosphorylation has little effect on YY1 DNA binding ability or cellular localization in asynchronous cells. However, functional studies reveal that c-Abl mediated phosphorylation of YY1 regulates YY1's transcriptional ability in vivo. In conclusion, we demonstrate the novel role of c-Abl kinase in regulation of YY1's transcriptional activity, linking YY1 regulation with c-Abl tyrosine kinase signaling pathways. Copyright © 2018. Published by Elsevier B.V.

  7. Highly sensitive assay for tyrosine hydroxylase activity by high-performance liquid chromatography.

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    Nagatsu, T; Oka, K; Kato, T

    1979-07-21

    A highly sensitive assay for tyrosine hydroxylase (TH) activity by high-performance liquid chromatography (HPLC) with amperometric detection was devised based on the rapid isolation of enzymatically formed DOPA by a double-column procedure, the columns fitted together sequentially (the top column of Amberlite CG-50 and the bottom column of aluminium oxide). DOPA was adsorbed on the second aluminium oxide column, then eluted with 0.5 M hydrochloric acid, and assayed by HPLC with amperometric detection. D-Tyrosine was used for the control. alpha-Methyldopa was added to the incubation mixture as an internal standard after incubation. This assay was more sensitive than radioassays and 5 pmol of DOPA formed enzymatically could be measured in the presence of saturating concentrations of tyrosine and 6-methyltetrahydropterin. The TH activity in 2 mg of human putamen could be easily measured, and this method was found to be particularly suitable for the assay of TH activity in a small number of nuclei from animal and human brain.

  8. The tyrosine Y2502.39 in Frizzled 4 defines a conserved motif important for structural integrity of the receptor and recruitment of Disheveled.

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    Strakova, Katerina; Matricon, Pierre; Yokota, Chika; Arthofer, Elisa; Bernatik, Ondrej; Rodriguez, David; Arenas, Ernest; Carlsson, Jens; Bryja, Vitezslav; Schulte, Gunnar

    2017-10-01

    Frizzleds (FZDs) are unconventional G protein-coupled receptors, which activate diverse intracellular signaling pathways via the phosphoprotein Disheveled (DVL) and heterotrimeric G proteins. The interaction interplay of FZDs with DVL and G proteins is complex, involves different regions of FZD and the potential dynamics are poorly understood. In the present study, we aimed to characterize the function of a highly conserved tyrosine (Y250 2.39 ) in the intracellular loop 1 (IL1) of human FZD 4 . We have found Y250 2.39 to be crucial for DVL2 interaction and DVL2 translocation to the plasma membrane. Mutant FZD 4 -Y250 2.39 F, impaired in DVL2 binding, was defective in both β-catenin-dependent and β-catenin-independent WNT signaling induced in Xenopus laevis embryos. The same mutant maintained interaction with the heterotrimeric G proteins Gα 12 and Gα 13 and was able to mediate WNT-induced G protein dissociation and G protein-dependent YAP/TAZ signaling. We conclude from modeling and dynamics simulation efforts that Y250 2.39 is important for the structural integrity of the FZD-DVL, but not for the FZD-G protein interface and hypothesize that the interaction network of Y250 2.39 and H348 4.46 plays a role in specifying downstream signaling pathways induced by the receptor. Copyright © 2017. Published by Elsevier Inc.

  9. The roles of the conserved tyrosine in the β2-α2 loop of the prion protein.

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    Huang, Danzhi; Caflisch, Amedeo

    2015-01-01

    Prions cause neurodegenerative diseases for which no cure exists. Despite decades of research activities the function of the prion protein (PrP) in mammalians is not known. Moreover, little is known on the molecular mechanisms of the self-assembly of the PrP from its monomeric state (cellular PrP, PrP(C)) to the multimeric state. The latter state includes the toxic species (scrapie PrP, PrP(Sc)) knowledge of which would facilitate the development of drugs against prion diseases. Here we analyze the role of a tyrosine residue (Y169) which is strictly conserved in mammalian PrPs. Nuclear magnetic resonance (NMR) spectroscopy studies of many mammalian PrP(C) proteins have provided evidence of a conformational equilibrium between a 3(10)-helical turn and a type I β turn conformation in the β2-α2 loop (residues 165-175). In vitro cell-free experiments of the seeded conversion of PrP(C) indicate that non-aromatic residues at position 169 reduce the formation of proteinase K-resistant PrP. Recent molecular dynamics (MD) simulations of monomeric PrP and several single-point mutants show that Y169 stabilizes the 3(10)-helical turn conformation more than single-point mutants at position 169 or residues in contact with it. In the 3(10)-helical turn conformation the hydrophobic and aggregation-prone segment 169-YSNQNNF-175 is buried and thus not-available for self-assembly. From the combined analysis of simulation and experimental results it emerges that Y169 is an aggregation gatekeeper with a twofold role. Mutations related to 3 human prion diseases are interpreted on the basis of the gatekeeper role in the monomeric state. Another potential role of the Y169 side chain is the stabilization of the ordered aggregates, i.e., reduction of frangibility of filamentous protofibrils and fibrils, which is likely to reduce the generation of toxic species.

  10. High-pressure Raman spectra and DFT calculations of L-tyrosine hydrochloride crystal

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    dos Santos, C. A. A. S. S.; Carvalho, J. O.; da Silva Filho, J. G.; Rodrigues, J. L.; Lima, R. J. C.; Pinheiro, G. S.; Freire, P. T. C.; Façanha Filho, P. F.

    2018-02-01

    High-pressure Raman spectra of L-tyrosine hydrochloride crystal were obtained from 1.0 atm to 7.0 GPa in the 90-1800 cm-1 spectral region. At atmospheric pressure, the Raman spectrum was obtained in the 50-3200 cm-1 spectral range and the assignment of the normal modes based on density functional theory calculations was provided. We found good correspondence between the calculated and the observed intramolecular geometry parameters. This confirms the correct assignment of the normal modes, since it was crucial to understand the meaning of the changes observed in particular Raman active modes. Here we show that bands associated with internal modes undergo slight modifications during compression. However, an inversion of the relative intensity of bands around 125 cm-1 as well as a change of slope dω/dP from 1.0 to 1.5 GPa was understood as a conformational change involving a torsion of the L-tyrosine molecule. As a consequence, it is possible to conclude that the crystal remained in the same monoclinic structure in the 1 atm-7.0 GPa interval, although conformational change of the molecule was verified. A comparison of our results with other selected studies provided insights about the role of the amino acid side chain on the arrangement of hydrogen bonds. Finally, when the pressure was released back to 1 atm, the Raman spectrum was recovered and no hysteresis was observed.

  11. The conservation pattern of short linear motifs is highly correlated with the function of interacting protein domains

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    Wang Yiguo

    2008-10-01

    Full Text Available Abstract Background Many well-represented domains recognize primary sequences usually less than 10 amino acids in length, called Short Linear Motifs (SLiMs. Accurate prediction of SLiMs has been difficult because they are short (often Results Our combined approach revealed that SLiMs are highly conserved in proteins from functional classes that are known to interact with a specific domain, but that they are not conserved in most other protein groups. We found that SLiMs recognized by SH2 domains were highly conserved in receptor kinases/phosphatases, adaptor molecules, and tyrosine kinases/phosphatases, that SLiMs recognized by SH3 domains were highly conserved in cytoskeletal and cytoskeletal-associated proteins, that SLiMs recognized by PDZ domains were highly conserved in membrane proteins such as channels and receptors, and that SLiMs recognized by S/T kinase domains were highly conserved in adaptor molecules, S/T kinases/phosphatases, and proteins involved in transcription or cell cycle control. We studied Tyr-SLiMs recognized by SH2 domains in more detail, and found that SH2-recognized Tyr-SLiMs on the cytoplasmic side of membrane proteins are more highly conserved than those on the extra-cellular side. Also, we found that SH2-recognized Tyr-SLiMs that are associated with SH3 motifs and a tyrosine kinase phosphorylation motif are more highly conserved. Conclusion The interactome of protein domains is reflected by the evolutionary conservation of SLiMs recognized by these domains. Combining scoring matrixes derived from peptide libraries and conservation analysis, we would be able to find those protein groups that are more likely to interact with specific domains.

  12. Phosphorylation at tyrosine 114 of Proliferating Cell Nuclear Antigen (PCNA) is required for adipogenesis in response to high fat diet

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Yuan-Hung; Ho, Po-Chun; Chen, Min-Shan; Hugo, Eric; Ben-Jonathan, Nira [Department of Cancer Biology, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267-0521 (United States); Department of Environmental Health, University of Cincinnati College of Medicine, 3223 Eden Avenue, Kettering Laboratory, Cincinnati, OH 45267-0056 (United States); Wang, Shao-Chun, E-mail: shao-chun.wang@uc.edu [Department of Cancer Biology, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267-0521 (United States); Department of Environmental Health, University of Cincinnati College of Medicine, 3223 Eden Avenue, Kettering Laboratory, Cincinnati, OH 45267-0056 (United States)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Proliferating Cell Nuclear Antigen (PCNA) is phosphorylated at Y114. Black-Right-Pointing-Pointer Phospho-Y114 of PCNA is not required for cell proliferation for normal growth. Black-Right-Pointing-Pointer MCE during adipogenesis is abolished in the lack of the phosphorylation. Black-Right-Pointing-Pointer Homozygous Y114F mice are resistant to high fat diet induced obesity. Black-Right-Pointing-Pointer Our results shed light on the interface between proliferation and differentiation. -- Abstract: Clonal proliferation is an obligatory component of adipogenesis. Although several cell cycle regulators are known to participate in the transition between pre-adipocyte proliferation and terminal adipocyte differentiation, how the core DNA synthesis machinery is coordinately regulated in adipogenesis remains elusive. PCNA (Proliferating Cell Nuclear Antigen) is an indispensable component for DNA synthesis during proliferation. Here we show that PCNA is subject to phosphorylation at the highly conserved tyrosine residue 114 (Y114). Replacing the Y114 residue with phenylalanine (Y114F), which is structurally similar to tyrosine but cannot be phosphorylated, does not affect normal animal development. However, when challenged with high fat diet, mice carrying homozygous Y114F alleles (PCNA{sup F/F}) are resistant to adipose tissue enlargement in comparison to wild-type (WT) mice. Mouse embryonic fibroblasts (MEFs) harboring WT or Y114F mutant PCNA proliferate at similar rates. However, when subjected to adipogenesis induction in culture, PCNA{sup F/F} MEFs are not able to re-enter the cell cycle and fail to form mature adipocytes, while WT MEFs undergo mitotic clonal expansion in response to the adipogenic stimulation, accompanied by enhanced Y114 phosphorylation of PCNA, and differentiate to mature adipocytes. Consistent with the function of Y114 phosphorylation in clonal proliferation in adipogenesis, fat tissues isolated from WT

  13. Synthesis and characterization of L-tyrosine hydrochloride crystals submitted to high and low temperatures

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    Santos, C.A.A.S.; Facanha Filho, P.F.; Ribeiro, L.H.L.; Victor, F.M.S.; Abreu, D.C.; Santos, A.O. dos; Carvalho, J.O.; Soares, R.A.; Sousa, J.C.F.; Lima, R.C.; Cavaignac, A.O. [Universidade Federal do Maranhao (UFMA), MA (Brazil)

    2016-07-01

    Full text: New materials are emerging and generate advances in nonlinear optics that studies the phenomena related to changes in optical properties when occurs interaction of light with the matter. Semi organic crystals present such properties. The goal is this work is to produce semi organic single crystal of L-tyrosine hydrochloride (LTHCl) and verify their thermal stability when subjected to high and low temperatures. The single crystals of LTHCl were produced for solubilization of amino acid L-tyrosine in hydrochloric acid using slow solvent evaporation technique at a constant temperature of 25 deg C. The X-ray diffraction (XRD) and refining by the Rietveld method were used to confirm the structure of the material. The thermal stability was investigated using DSC, TGA-DTA. The LTHCl crystal belongs to the monoclinic system, with two molecules per unit cell. The refinement by the Rietveld method showed good results with Rwp= 8.49% and Rp= 6.29% with S=1.13. Thermal analysis shown an endothermic event at about 160°C, which can be associated with phase transition occurred in LTHCl crystal. It was also observed that the crystal melting point occurs at a temperature of 230°C. No water of crystallization was found in the crystal structure, which was confirmed by Raman spectroscopy and thermal analysis. From the Raman spectroscopy experiments in function of temperature, no significant changes was observe in the behavior of vibrational normal modes between temperatures of -253 and 170 deg C. Finally, a monoclinic crystal system LTHCl is stable up to 160°C at high temperatures and -253°C at low temperatures. Therefore, our investigation has proved that LTHCl crystals can be used in this range of temperature without the lost of their nonlinear optical properties. (author)

  14. L-tyrosine hydrochloride crystals under high pressures via Raman Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C.A.A.S.; Facanha Filho, P.F.; Santos, A.O. dos; Ribeiro, L.H.L.; Victor, F.M.S.; Abreu, D.C.; Carvalho, J.O.; Soares, R.A.; Sousa, J.C.F.; Lima, R.C.; Cavaignac, A.O. [Universidade Federal do Maranhao (UFMA), MA (Brazil)

    2016-07-01

    Full text: Amino acid single crystals have been attracted researchers in recent years due to their potential applications as second harmonic generator. The goal of this work is to produce semi organic single crystals of L-tyrosine hydrochloride (LTHCl) and verify the behavior of their vibrational normal modes under high pressures and the stability of material in these conditions extremes. The LTHCl single crystals were produced for solubilization of amino acid L-tyrosine in hydrochloric acid by slow evaporation technique of the solvent in room temperature. The technique of X-ray diffraction (XRD) and the refinement of structure by the Rietveld method were used to confirm the crystal structure. The LTHCl crystal belongs to the monoclinic crystal system having two molecules per unit cell. The refinement by the Rietveld method showed good results with Rwp = 8.49% and Rp = 6.29% with S = 1.13. Raman scattering measurements as a function of pressure was performed in a piece of crystal from the ambient pressure to 7.2 GPa and Nujol was used as pressure medium. It was observed the appearance of a weak band around 163 cm-1 between pressures of 0.5 and 1.0 GPa, which characterize an phase transition undergone by the crystal. Moreover, this band gains intensity as pressure increases while gradual decreasing relative intensity of the very strong band at 123 cm-1 for all range of pressure also was observed. In fact, almost all bands of the spectra have undergone strong decreasing up to 7.2 GPa. However, on release of pressure the crystal has reached the original phase again. Therefore, the results showed this material cannot be suitable for the application (NLO) in this range of pressure. (author)

  15. Determination of Phenylalanine and Tyrosine by High Performance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Peat, Judy; Garg, Uttam

    2016-01-01

    Hyperphenylalaninemia/phenylketonuria (PKU) is one of the most common inborn errors of amino acid metabolism affecting about 1:15,000 infants in the United States. PKU is an autosomal recessive disorder that if untreated results in mental retardation. The most common cause of PKU is deficiency of the enzyme phenylalanine hydroxylase that converts phenylalanine to tyrosine. Tyrosine deficiency results in impaired synthesis of catecholamines and thyroxine. Less commonly, it can result from defects in the synthesis or regeneration of tetrahydrobiopterin (BH4), an essential cofactor for the enzyme phenylalanine hydroxylase. Increased phenylalanine and decreased tyrosine in blood are used in the diagnosis and follow-up of patients with PKU. LC/MS/MS method is described for the quantification of phenylalanine and tyrosine.

  16. Highly Active and Specific Tyrosine Ammonia-Lyases from Diverse Origins Enable Enhanced Production of Aromatic Compounds in Bacteria and Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Jendresen, Christian Bille; Stahlhut, Steen Gustav; Li, Mingji

    2015-01-01

    Phenylalanine and tyrosine ammonia-lyases form cinnamic acid and p-coumaric acid, which are precursors of a wide range of aromatic compounds of biotechnological interest. Lack of highly active and specific tyrosine ammonia-lyases has previously been a limitation in metabolic engineering approaches...

  17. Conformational Clusters of Phosphorylated Tyrosine.

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    Abdelrasoul, Maha; Ponniah, Komala; Mao, Alice; Warden, Meghan S; Elhefnawy, Wessam; Li, Yaohang; Pascal, Steven M

    2017-12-06

    Tyrosine phosphorylation plays an important role in many cellular and intercellular processes including signal transduction, subcellular localization, and regulation of enzymatic activity. In 1999, Blom et al., using the limited number of protein data bank (PDB) structures available at that time, reported that the side chain structures of phosphorylated tyrosine (pY) are partitioned into two conserved conformational clusters ( Blom, N.; Gammeltoft, S.; Brunak, S. J. Mol. Biol. 1999 , 294 , 1351 - 1362 ). We have used the spectral clustering algorithm to cluster the increasingly growing number of protein structures with pY sites, and have found that the pY residues cluster into three distinct side chain conformations. Two of these pY conformational clusters associate strongly with a narrow range of tyrosine backbone conformation. The novel cluster also highly correlates with the identity of the n + 1 residue, and is strongly associated with a sequential pYpY conformation which places two adjacent pY side chains in a specific relative orientation. Further analysis shows that the three pY clusters are associated with distinct distributions of cognate protein kinases.

  18. The conserved dileucine- and tyrosine-based motifs in MLV and MPMV envelope glycoproteins are both important to regulate a common Env intracellular trafficking

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    Lopez-Vergès Sandra

    2006-09-01

    Full Text Available Abstract Background Retrovirus particles emerge from the assembly of two structural protein components, Gag that is translated as a soluble protein in the cytoplasm of the host cells, and Env, a type I transmembrane protein. Because both components are translated in different intracellular compartments, elucidating the mechanisms of retrovirus assembly thus requires the study of their intracellular trafficking. Results We used a CD25 (Tac chimera-based approach to study the trafficking of Moloney murine leukemia virus and Mason-Pfizer monkey virus Env proteins. We found that the cytoplasmic tails (CTs of both Env conserved two major signals that control a complex intracellular trafficking. A dileucine-based motif controls the sorting of the chimeras from the trans-Golgi network (TGN toward endosomal compartments. Env proteins then follow a retrograde transport to the TGN due to the action of a tyrosine-based motif. Mutation of either motif induces the mis-localization of the chimeric proteins and both motifs are found to mediate interactions of the viral CTs with clathrin adaptors. Conclusion This data reveals the unexpected complexity of the intracellular trafficking of retrovirus Env proteins that cycle between the TGN and endosomes. Given that Gag proteins hijack endosomal host proteins, our work suggests that the endosomal pathway may be used by retroviruses to ensure proper encountering of viral structural Gag and Env proteins in cells, an essential step of virus assembly.

  19. Readings in Wildlife and Fish Conservation, High School Conservation Curriculum Project.

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    Ensminger, Jack

    This publication is a tentative edition of readings on Wildlife and Fish Conservation in Louisiana, and as such it forms part of one of the four units of study designed for an experimental high school course, the "High School Conservation Curriculum Project." The other three units are concerned with Forest Conervation, Soil and Water…

  20. Second generation tyrosine kinase inhibitors prevent disease progression in high-risk (high CIP2A) chronic myeloid leukaemia patients.

    Science.gov (United States)

    Lucas, C M; Harris, R J; Holcroft, A K; Scott, L J; Carmell, N; McDonald, E; Polydoros, F; Clark, R E

    2015-07-01

    High cancerous inhibitor of PP2A (CIP2A) protein levels at diagnosis of chronic myeloid leukaemia (CML) are predictive of disease progression in imatinib-treated patients. It is not known whether this is true in patients treated with second generation tyrosine kinase inhibitors (2G TKI) from diagnosis, and whether 2G TKIs modulate the CIP2A pathway. Here, we show that patients with high diagnostic CIP2A levels who receive a 2G TKI do not progress, unlike those treated with imatinib (P=<0.0001). 2G TKIs induce more potent suppression of CIP2A and c-Myc than imatinib. The transcription factor E2F1 is elevated in high CIP2A patients and following 1 month of in vivo treatment 2G TKIs suppress E2F1 and reduce CIP2A; these effects are not seen with imatinib. Silencing of CIP2A, c-Myc or E2F1 in K562 cells or CML CD34+ cells reactivates PP2A leading to BCR-ABL suppression. CIP2A increases proliferation and this is only reduced by 2G TKIs. Patients with high CIP2A levels should be offered 2G TKI treatment in preference to imatinib. 2G TKIs disrupt the CIP2A/c-Myc/E2F1 positive feedback loop, leading to lower disease progression risk. The data supports the view that CIP2A inhibits PP2Ac, stabilising E2F1, creating a CIP2A/c-Myc/E2F1 positive feedback loop, which imatinib cannot overcome.

  1. Exposure of tropoelastin to peroxynitrous acid gives high yields of nitrated tyrosine residues, di-tyrosine cross-links and altered protein structure and function

    DEFF Research Database (Denmark)

    Degendorfer, Georg; Chuang, Christine Yu-Nung; Mariotti, Michele

    2018-01-01

    Elastin is an abundant extracellular matrix protein in elastic tissues, including the lungs, skin and arteries, and comprises 30–57% of the aorta by dry mass. The monomeric precursor, tropoelastin (TE), undergoes complex processing during elastogenesis to form mature elastic fibres. Peroxynitrous......-protein di-tyrosine cross-links have been characterized by mass spectrometry. Examination of human atherosclerotic lesions shows colocalization of 3-nitroTyr with elastin epitopes, consistent with TE or elastin modification in vivo, and also an association of 3-nitroTyr containing proteins and elastin...

  2. Tilapia and human CLIC2 structures are highly conserved.

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    Zeng, Jiao; Li, Zhengjun; Lui, Eei Yin; Lam, Siew Hong; Swaminathan, Kunchithapadam

    2018-01-08

    Chloride intracellular channels (CLICs) exist in soluble and membrane bound forms. We have determined the crystal structure of soluble Clic2 from the euryhaline teleost fish Oreochromis mossambicus. Structural comparison of tilapia and human CLIC2 with other CLICs shows that these proteins are highly conserved. We have also compared the expression levels of clic2 in selected osmoregulatory organs of tilapia, acclimated to freshwater, seawater and hypersaline water. Structural conservation of vertebrate CLICs implies that they might play conserved roles. Also, tissue-specific responsiveness of clic2 suggests that it might be involved in iono-osmoregulation under extreme conditions in tilapia. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. An in silico high-throughput screen identifies potential selective inhibitors for the non-receptor tyrosine kinase Pyk2

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    Meirson T

    2017-05-01

    Full Text Available Tomer Meirson, Abraham O Samson, Hava Gil-Henn Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel Abstract: The non-receptor tyrosine kinase proline-rich tyrosine kinase 2 (Pyk2 is a critical mediator of signaling from cell surface growth factor and adhesion receptors to cell migration, proliferation, and survival. Emerging evidence indicates that signaling by Pyk2 regulates hematopoietic cell response, bone density, neuronal degeneration, angiogenesis, and cancer. These physiological and pathological roles of Pyk2 warrant it as a valuable therapeutic target for invasive cancers, osteoporosis, Alzheimer’s disease, and inflammatory cellular response. Despite its potential as a therapeutic target, no potent and selective inhibitor of Pyk2 is available at present. As a first step toward discovering specific potential inhibitors of Pyk2, we used an in silico high-throughput screening approach. A virtual library of six million lead-like compounds was docked against four different high-resolution Pyk2 kinase domain crystal structures and further selected for predicted potency and ligand efficiency. Ligand selectivity for Pyk2 over focal adhesion kinase (FAK was evaluated by comparative docking of ligands and measurement of binding free energy so as to obtain 40 potential candidates. Finally, the structural flexibility of a subset of the docking complexes was evaluated by molecular dynamics simulation, followed by intermolecular interaction analysis. These compounds may be considered as promising leads for further development of highly selective Pyk2 inhibitors. Keywords: virtual screen, efficiency metrics, MM-GBSA, molecular dynamics

  4. Conservation

    NARCIS (Netherlands)

    Noteboom, H.P.

    1985-01-01

    The IUCN/WWF Plants Conservation Programme 1984 — 1985. World Wildlife Fund chose plants to be the subject of their fund-raising campaign in the period 1984 — 1985. The objectives were to: 1. Use information techniques to achieve the conservation objectives of the Plants Programme – to save plants;

  5. Conservation.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    This set of teaching aids consists of seven Audubon Nature Bulletins, providing the teacher and student with informational reading on various topics in conservation. The bulletins have these titles: Plants as Makers of Soil, Water Pollution Control, The Ground Water Table, Conservation--To Keep This Earth Habitable, Our Threatened Air Supply,…

  6. Characterisation of tryptic peptides of phosphorylated tyrosine hydroxylase by high-pressure liquid chromatography electrospray ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Graham, Mark E.; Dickson, Phillip W.; Dunkley, Peter R.; Nagy-Felsobuki, Ellak I. von

    2005-01-01

    Tyrosine hydroxylase (TH) is involved in the biosynthesis of catecholamines and is activated by phosphorylation. Phosphorylated TH was analysed using high-pressure liquid chromatography combined with electrospray mass spectrometry (HPLC ESI-MS). Two mass scanning methods were used to detect tryptic cleavage products of TH. In the positive electrospray ionisation mode (ESI+), the peptides that contain the phosphorylation sites of TH were identified. In the alternative method, a phosphopeptide was detected in the negative electrospray ionisation mode (ESI-) using single ion monitoring in combination with a sequential ESI+ switching experiment. A raised baseline interfered with detection of hydrophilic peptides in ESI-, with the signal-to-noise ratio indicating that the method was operating near the limit of detection for a conventional electrospray source. The switching method improved the certainty of identification of phosphopeptides

  7. Discernment of irradiated chicken meat by determination of O-tyrosine using high performance liquid chromatography and fluorescence detection

    International Nuclear Information System (INIS)

    Aflaki, F.; Roozbahani, A.; Salahinejad, M.

    2010-01-01

    O-Tyrosine is proposed as a marker for identification of irradiated protein-rich foods. In this study, HPLC/ Fluorescence method that allows accurate quantification of 0.1 ng of o-tyrosine has been used. The method involves freeze-drying of sample, acid hydrolysis and fractionation by HPLC. By using Spherisorb ODS2 column, the base-line separation of o-tyrosine from impurities was performed. The yield of o-tyrosine in the irradiated chicken meat was proportional to the irradiation dose. Since the variable levels of o-tyrosine were found in unirradiated chicken meat (0.15-0.42 μg/g per wet weight), this method is able to identify the irradiated chicken meat at 4 kGy or higher. Because the dose response curve can be extended over 50 kGy, the method is suitable for detecting the overdosed samples.

  8. Next generation of adeno-associated virus 2 vectors: Point mutations in tyrosines lead to high-efficiency transduction at lower doses

    Science.gov (United States)

    Zhong, Li; Li, Baozheng; Mah, Cathryn S.; Govindasamy, Lakshmanan; Agbandje-McKenna, Mavis; Cooper, Mario; Herzog, Roland W.; Zolotukhin, Irene; Warrington, Kenneth H.; Weigel-Van Aken, Kirsten A.; Hobbs, Jacqueline A.; Zolotukhin, Sergei; Muzyczka, Nicholas; Srivastava, Arun

    2008-01-01

    Recombinant adeno-associated virus 2 (AAV2) vectors are in use in several Phase I/II clinical trials, but relatively large vector doses are needed to achieve therapeutic benefits. Large vector doses also trigger an immune response as a significant fraction of the vectors fails to traffic efficiently to the nucleus and is targeted for degradation by the host cell proteasome machinery. We have reported that epidermal growth factor receptor protein tyrosine kinase (EGFR-PTK) signaling negatively affects transduction by AAV2 vectors by impairing nuclear transport of the vectors. We have also observed that EGFR-PTK can phosphorylate AAV2 capsids at tyrosine residues. Tyrosine-phosphorylated AAV2 vectors enter cells efficiently but fail to transduce effectively, in part because of ubiquitination of AAV capsids followed by proteasome-mediated degradation. We reasoned that mutations of the surface-exposed tyrosine residues might allow the vectors to evade phosphorylation and subsequent ubiquitination and, thus, prevent proteasome-mediated degradation. Here, we document that site-directed mutagenesis of surface-exposed tyrosine residues leads to production of vectors that transduce HeLa cells ≈10-fold more efficiently in vitro and murine hepatocytes nearly 30-fold more efficiently in vivo at a log lower vector dose. Therapeutic levels of human Factor IX (F.IX) are also produced at an ≈10-fold reduced vector dose. The increased transduction efficiency of tyrosine-mutant vectors is due to lack of capsid ubiquitination and improved intracellular trafficking to the nucleus. These studies have led to the development of AAV vectors that are capable of high-efficiency transduction at lower doses, which has important implications in their use in human gene therapy. PMID:18511559

  9. Receptor Tyrosine Kinases in Drosophila Development

    Science.gov (United States)

    Sopko, Richelle; Perrimon, Norbert

    2013-01-01

    Tyrosine phosphorylation plays a significant role in a wide range of cellular processes. The Drosophila genome encodes more than 20 receptor tyrosine kinases and extensive studies in the past 20 years have illustrated their diverse roles and complex signaling mechanisms. Although some receptor tyrosine kinases have highly specific functions, others strikingly are used in rather ubiquitous manners. Receptor tyrosine kinases regulate a broad expanse of processes, ranging from cell survival and proliferation to differentiation and patterning. Remarkably, different receptor tyrosine kinases share many of the same effectors and their hierarchical organization is retained in disparate biological contexts. In this comprehensive review, we summarize what is known regarding each receptor tyrosine kinase during Drosophila development. Astonishingly, very little is known for approximately half of all Drosophila receptor tyrosine kinases. PMID:23732470

  10. Generation of monoclonal antibodies against highly conserved antigens.

    Directory of Open Access Journals (Sweden)

    Hongzhe Zhou

    Full Text Available BACKGROUND: Therapeutic antibody development is one of the fastest growing areas of the pharmaceutical industry. Generating high-quality monoclonal antibodies against a given therapeutic target is very crucial for the success of the drug development. However, due to immune tolerance, some proteins that are highly conserved between mice and humans are not very immunogenic in mice, making it difficult to generate antibodies using a conventional approach. METHODOLOGY/PRINCIPAL FINDINGS: In this report, the impaired immune tolerance of NZB/W mice was exploited to generate monoclonal antibodies against highly conserved or self-antigens. Using two highly conserved human antigens (MIF and HMGB1 and one mouse self-antigen (TNF-alpha as examples, we demonstrate here that multiple clones of high affinity, highly specific antibodies with desired biological activities can be generated, using the NZB/W mouse as the immunization host and a T cell-specific tag fused to a recombinant antigen to stimulate the immune system. CONCLUSIONS/SIGNIFICANCE: We developed an efficient and universal method for generating surrogate or therapeutic antibodies against "difficult antigens" to facilitate the development of therapeutic antibodies.

  11. Characterization and response of newly developed high-grade glioma cultures to the tyrosine kinase inhibitors, erlotinib, gefitinib and imatinib.

    LENUS (Irish Health Repository)

    Kinsella, Paula

    2012-03-10

    High-grade gliomas (HGG), are the most common aggressive brain tumours in adults. Inhibitors targeting growth factor signalling pathways in glioma have shown a low clinical response rate. To accurately evaluate response to targeted therapies further in vitro studies are necessary. Growth factor pathway expression using epidermal growth factor receptor (EGFR), mutant EGFR (EGFRvIII), platelet derived growth factor receptor (PDGFR), C-Kit and C-Abl together with phosphatase and tensin homolog (PTEN) expression and downstream activation of AKT and phosphorylated ribosomal protein S6 (P70S6K) was analysed in 26 primary glioma cultures treated with the tyrosine kinase inhibitors (TKIs) erlotinib, gefitinib and imatinib. Response to TKIs was assessed using 50% inhibitory concentrations (IC(50)). Response for each culture was compared with the EGFR\\/PDGFR immunocytochemical pathway profile using hierarchical cluster analysis (HCA) and principal component analysis (PCA). Erlotinib response was not strongly associated with high expression of the growth factor pathway components. PTEN expression did not correlate with response to any of the three TKIs. Increased EGFR expression was associated with gefitinib response; increased PDGFR-α expression was associated with imatinib response. The results of this in vitro study suggest gefitinib and imatinib may have therapeutic potential in HGG tumours with a corresponding growth factor receptor expression profile.

  12. High Level of Soluble FMS-Like Tyrosine Kinase-1 (sFlt-1 Serum in Pregnancy as a Risk Factor of Preeclampsia

    Directory of Open Access Journals (Sweden)

    I Gede Mega Putra

    2016-07-01

    Full Text Available Background: Recently, etiology and pathogenesis of preeclampsia remain unknown. One of the theory indicating that hypoxia and ischemic placenta caused by abnormal cytotrophoblast invasion in preeclampsia. Soluble Fms-like tyrosine kinase-1 (sFlt-1 serum as a laboratory marker of hypoxia condition that contributes to the occurrence of endothelial damage and clinical manifestations in preeclampsia. Objective: This study was aimed at proving that high level of soluble Fms-like tyrosine kinase-1 (sFlt-1 serum in pregnancy as a risk factor for preeclampsia. Methods: This study was a case control. Among 58 pregnant women studied, 29 women with preeclampsia as a case group and 29 women with normal pregnancy as a control group. Soluble Fms-like tyrosine kinase-1 (sFlt-1 serum was analyzed in the Prodia Laboratory. Collected data were tested for normality using Kolmogorov-Smirnov, then analyzed with independent sample test. Chi-Square test used to determine soluble Fms-like tyrosine kinase-1 (sFlt-1 serum level in preeclampsia. Results: This research concluded that the average level of soluble Fms-like tyrosine kinase-1 (sFlt-1 serum in preeclampsia were 11231.00 ± 8390.3 pg/mL and 3981.62 ± 4921.5 pg/mL in normal pregnancy. Analysis of significance with independent t-test concluded that the value of t = 4.01 and p = 0.001. This mean the average levels of soluble Fms-like tyrosine kinase-1 (sFlt-1serum levels in both groups were difference significantly (p <0.05. Based on the cut-off point of sFlt-1 serum levels was 4505.50 pg/mL with 79.3% sensitivity and 82.8% specificity, the relative risk of preeclampsia was 18 times (OR = 18.40, IK 95% = 4.93 to 68.70, p = 0.001. Conclusion:  Based on this research, high levels of soluble Fms-like tyrosine kinase-1 (sFlt-1 in pregnancy was proved as a risk factor for preeclampsia.

  13. Evolutionary growth process of highly conserved sequences in vertebrate genomes.

    Science.gov (United States)

    Ishibashi, Minaka; Noda, Akiko Ogura; Sakate, Ryuichi; Imanishi, Tadashi

    2012-08-01

    Genome sequence comparison between evolutionarily distant species revealed ultraconserved elements (UCEs) among mammals under strong purifying selection. Most of them were also conserved among vertebrates. Because they tend to be located in the flanking regions of developmental genes, they would have fundamental roles in creating vertebrate body plans. However, the evolutionary origin and selection mechanism of these UCEs remain unclear. Here we report that UCEs arose in primitive vertebrates, and gradually grew in vertebrate evolution. We searched for UCEs in two teleost fishes, Tetraodon nigroviridis and Oryzias latipes, and found 554 UCEs with 100% identity over 100 bps. Comparison of teleost and mammalian UCEs revealed 43 pairs of common, jawed-vertebrate UCEs (jUCE) with high sequence identities, ranging from 83.1% to 99.2%. Ten of them retain lower similarities to the Petromyzon marinus genome, and the substitution rates of four non-exonic jUCEs were reduced after the teleost-mammal divergence, suggesting that robust conservation had been acquired in the jawed vertebrate lineage. Our results indicate that prototypical UCEs originated before the divergence of jawed and jawless vertebrates and have been frozen as perfect conserved sequences in the jawed vertebrate lineage. In addition, our comparative sequence analyses of UCEs and neighboring regions resulted in a discovery of lineage-specific conserved sequences. They were added progressively to prototypical UCEs, suggesting step-wise acquisition of novel regulatory roles. Our results indicate that conserved non-coding elements (CNEs) consist of blocks with distinct evolutionary history, each having been frozen since different evolutionary era along the vertebrate lineage. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Hemolymph Melanization in the Silkmoth Bombyx mori Involves Formation of a High Molecular Mass Complex That Metabolizes Tyrosine*

    Science.gov (United States)

    Clark, Kevin D.; Strand, Michael R.

    2013-01-01

    The phenoloxidase (PO) cascade regulates the melanization of blood (hemolymph) in insects and other arthropods. Most studies indicate that microbial elicitors activate the PO cascade, which results in processing of the zymogen PPO to PO. PO is then thought to oxidize tyrosine and o-diphenols to quinones, which leads to melanin. However, different lines of investigation raise questions as to whether these views are fully correct. Here we report that hemolymph from the silkmoth, Bombyx mori, rapidly melanizes after collection from a wound site. Prior studies indicated that in vitro activated PPO hydroxylates Tyr inefficiently. Measurement of in vivo substrate titers, however, suggested that Tyr was the only PO substrate initially present in B. mori plasma and that it is rapidly metabolized by PO. Fractionation of plasma by gel filtration chromatography followed by bioassays indicated that melanization activity was primarily associated with a high mass complex (∼670 kDa) that contained PO. The prophenoloxidase-activating protease inhibitor Egf1.0 blocked formation of this complex and Tyr metabolism, but the addition of phenylthiourea to plasma before fractionation enhanced complex formation and Tyr metabolism. Mass spectrometry analysis indicated that the complex contained PO plus other proteins. Taken together, our results indicate that wounding alone activates the PO cascade in B. mori. They also suggest that complex formation is required for efficient use of Tyr as a substrate. PMID:23553628

  15. Ror receptor tyrosine kinases: orphans no more

    OpenAIRE

    Green, Jennifer L.; Kuntz, Steven G.; Sternberg, Paul W.

    2008-01-01

    Receptor tyrosine kinase-like orphan receptor (Ror) proteins are a conserved family of tyrosine kinase receptors that function in developmental processes including skeletal and neuronal development, cell movement and cell polarity. Although Ror proteins were originally named because the associated ligand and signaling pathway were unknown, recent studies in multiple species have now established that Ror proteins are Wnt receptors. Depending on the cellular context, Ror proteins can either act...

  16. Biochemical characterization of a novel tyrosine phenol-lyase from Fusobacterium nucleatum for highly efficient biosynthesis of l-DOPA.

    Science.gov (United States)

    Zheng, Ren-Chao; Tang, Xiao-Ling; Suo, Hui; Feng, Li-Lin; Liu, Xiao; Yang, Jian; Zheng, Yu-Guo

    2018-05-01

    Tyrosine phenol-lyase (TPL) catalyzes the reversible cleavage of l-tyrosine to phenol, pyruvate and ammonia. When pyrocatechol is substituted for phenol, l-dihydroxyphenylalanine (l-DOPA) is produced. The TPL-catalyzed route was regarded as the most economic process for l-DOPA production. In this study, a novel TPL from Fusobacterium nucleatum (Fn-TPL) was successfully overexpressed in Escherichia coli and screened for l-DOPA synthesis with a specific activity of 2.69Umg -1 . Fn-TPL was found to be a tetramer, and the optimal temperature and pH for α, β-elimination of l-tyrosine was 60°C and pH 8.5, respectively. The enzyme showed broad substrate specificity toward natural and synthetic l-amino acids. Kinetic analysis suggested that the k cat /K m value for l-tyrosine decomposition was much higher than that for l-DOPA decomposition, while Fn-TPL exhibited similar catalytic efficiency for synthesis of l-tyrosine and l-DOPA. With whole cells of recombinant E. coli as biocatalyst, l-DOPA yield reached 110gL -1 with a pyrocatechol conversion of 95%, which was comparable to the reported highest level. The results demonstrated the great potential of Fn-TPL for industrial production of l-DOPA. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Characterization and response of newly developed high-grade glioma cultures to the tyrosine kinase inhibitors, erlotinib, gefitinib and imatinib

    International Nuclear Information System (INIS)

    Kinsella, Paula; Howley, Rachel; Doolan, Padraig; Clarke, Colin; Madden, Stephen F.; Clynes, Martin; Farrell, Michael; Amberger-Murphy, Verena

    2012-01-01

    High-grade gliomas (HGG), are the most common aggressive brain tumours in adults. Inhibitors targeting growth factor signalling pathways in glioma have shown a low clinical response rate. To accurately evaluate response to targeted therapies further in vitro studies are necessary. Growth factor pathway expression using epidermal growth factor receptor (EGFR), mutant EGFR (EGFRvIII), platelet derived growth factor receptor (PDGFR), C-Kit and C-Abl together with phosphatase and tensin homolog (PTEN) expression and downstream activation of AKT and phosphorylated ribosomal protein S6 (P70S6K) was analysed in 26 primary glioma cultures treated with the tyrosine kinase inhibitors (TKIs) erlotinib, gefitinib and imatinib. Response to TKIs was assessed using 50% inhibitory concentrations (IC 50 ). Response for each culture was compared with the EGFR/PDGFR immunocytochemical pathway profile using hierarchical cluster analysis (HCA) and principal component analysis (PCA). Erlotinib response was not strongly associated with high expression of the growth factor pathway components. PTEN expression did not correlate with response to any of the three TKIs. Increased EGFR expression was associated with gefitinib response; increased PDGFR-α expression was associated with imatinib response. The results of this in vitro study suggest gefitinib and imatinib may have therapeutic potential in HGG tumours with a corresponding growth factor receptor expression profile. -- Highlights: ► Non-responders had low EGFR expression, high PDGFR-β, and a low proliferation rate. ► PTEN is not indicative of response to a TKI. ► Erlotinib response was not associated with expression of the proteins examined. ► Imatinib-response correlated with expression of PDGFR-α. ► Gefitinib response correlated with increased expression of EGFR.

  18. ABCE1 is a highly conserved RNA silencing suppressor.

    Directory of Open Access Journals (Sweden)

    Kairi Kärblane

    Full Text Available ATP-binding cassette sub-family E member 1 (ABCE1 is a highly conserved protein among eukaryotes and archaea. Recent studies have identified ABCE1 as a ribosome-recycling factor important for translation termination in mammalian cells, yeast and also archaea. Here we report another conserved function of ABCE1. We have previously described AtRLI2, the homolog of ABCE1 in the plant Arabidopsis thaliana, as an endogenous suppressor of RNA silencing. In this study we show that this function is conserved: human ABCE1 is able to suppress RNA silencing in Nicotiana benthamiana plants, in mammalian HEK293 cells and in the worm Caenorhabditis elegans. Using co-immunoprecipitation and mass spectrometry, we found a number of potential ABCE1-interacting proteins that might support its function as an endogenous suppressor of RNA interference. The interactor candidates are associated with epigenetic regulation, transcription, RNA processing and mRNA surveillance. In addition, one of the identified proteins is translin, which together with its binding partner TRAX supports RNA interference.

  19. Impact of [F-18]-fluoro-ethyl-tyrosine PET imaging on target definition for radiation therapy of high-grade glioma

    DEFF Research Database (Denmark)

    af Rosenschold, Per Munck; Costa, Junia; Engelholm, Svend Aage

    2015-01-01

    BACKGROUND: We sought to assess the impact of amino-acid (18)F-fluoro-ethyl-tyrosine (FET) positron emission tomography (PET) on the volumetric target definition for radiation therapy of high-grade glioma versus the current standard using MRI alone. Specifically, we investigated the influence....... Patients with grade IV glioma were found to be the primary candidates for PET-guided radiation therapy planning....

  20. High-resolution finite-difference algorithms for conservation laws

    International Nuclear Information System (INIS)

    Towers, J.D.

    1987-01-01

    A new class of Total Variation Decreasing (TVD) schemes for 2-dimensional scalar conservation laws is constructed using either flux-limited or slope-limited numerical fluxes. The schemes are proven to have formal second-order accuracy in regions where neither u/sub x/ nor y/sub y/ vanishes. A new class of high-resolution large-time-step TVD schemes is constructed by adding flux-limited correction terms to the first-order accurate large-time-step version of the Engquist-Osher scheme. The use of the transport-collapse operator in place of the exact solution operator for the construction of difference schemes is studied. The production of spurious extrema by difference schemes is studied. A simple condition guaranteeing the nonproduction of spurious extrema is derived. A sufficient class of entropy inequalities for a conservation law with a flux having a single inflection point is presented. Finite-difference schemes satisfying a discrete version of each entropy inequality are only first-order accurate

  1. Dynamic Epigenetic Control of Highly Conserved Noncoding Elements

    KAUST Repository

    Seridi, Loqmane

    2014-10-07

    Background Many noncoding genomic loci have remained constant over long evolutionary periods, suggesting that they are exposed to strong selective pressures. The molecular functions of these elements have been partially elucidated, but the fundamental reason for their extreme conservation is still unknown. Results To gain new insights into the extreme selection of highly conserved noncoding elements (HCNEs), we used a systematic analysis of multi-omic data to study the epigenetic regulation of such elements during the development of Drosophila melanogaster. At the sequence level, HCNEs are GC-rich and have a characteristic oligomeric composition. They have higher levels of stable nucleosome occupancy than their flanking regions, and lower levels of mononucleosomes and H3.3, suggesting that these regions reside in compact chromatin. Furthermore, these regions showed remarkable modulations in histone modification and the expression levels of adjacent genes during development. Although HCNEs are primarily initiated late in replication, about 10% were related to early replication origins. Finally, HCNEs showed strong enrichment within lamina-associated domains. Conclusion HCNEs have distinct and protective sequence properties, undergo dynamic epigenetic regulation, and appear to be associated with the structural components of the chromatin, replication origins, and nuclear matrix. These observations indicate that such elements are likely to have essential cellular functions, and offer insights into their epigenetic properties.

  2. Dynamic Epigenetic Control of Highly Conserved Noncoding Elements

    KAUST Repository

    Seridi, Loqmane; Ryu, Tae Woo; Ravasi, Timothy

    2014-01-01

    Background Many noncoding genomic loci have remained constant over long evolutionary periods, suggesting that they are exposed to strong selective pressures. The molecular functions of these elements have been partially elucidated, but the fundamental reason for their extreme conservation is still unknown. Results To gain new insights into the extreme selection of highly conserved noncoding elements (HCNEs), we used a systematic analysis of multi-omic data to study the epigenetic regulation of such elements during the development of Drosophila melanogaster. At the sequence level, HCNEs are GC-rich and have a characteristic oligomeric composition. They have higher levels of stable nucleosome occupancy than their flanking regions, and lower levels of mononucleosomes and H3.3, suggesting that these regions reside in compact chromatin. Furthermore, these regions showed remarkable modulations in histone modification and the expression levels of adjacent genes during development. Although HCNEs are primarily initiated late in replication, about 10% were related to early replication origins. Finally, HCNEs showed strong enrichment within lamina-associated domains. Conclusion HCNEs have distinct and protective sequence properties, undergo dynamic epigenetic regulation, and appear to be associated with the structural components of the chromatin, replication origins, and nuclear matrix. These observations indicate that such elements are likely to have essential cellular functions, and offer insights into their epigenetic properties.

  3. High performance microbiological transformation of L-tyrosine to L-dopa by Yarrowia lipolytica NRRL-143

    Directory of Open Access Journals (Sweden)

    Shultz Jeffry L

    2007-08-01

    Full Text Available Abstract Background The 3,4-dihydroxy phenyl L-alanine (L-dopa is a drug of choice for Parkinson's disease, controlling changes in energy metabolism enzymes of the myocardium following neurogenic injury. Aspergillus oryzae is commonly used for L-dopa production; however, potential improvements in ease of handling, growth rate and environmental impact have led to an interest in exploiting alternative yeasts. The two important elements required for L-dopa production are intracellular tyrosinases (thus pre-grown yeast cells are required for the transformation of L-tyrosine to L-dopa and L-ascorbate, which acts as a reducing agent. Results Pre-grown cells of Yarrowia lipolytica NRRL-143 were used for the microbiological transformation of L-tyrosine to L-dopa. Different diatomite concentrations (0.5–3.0 mg/ml were added to the acidic (pH 3.5 reaction mixture. Maximum L-dopa biosynthesis (2.96 mg/ml L-dopa from 2.68 mg/ml L-tyrosine was obtained when 2.0 mg/ml diatomite was added 15 min after the start of the reaction. After optimizing reaction time (30 min, and yeast cell concentration (2.5 mg/ml, an overall 12.5 fold higher L-dopa production rate was observed when compared to the control. Significant enhancements in Yp/s, Qs and qs over the control were observed. Conclusion Diatomite (2.0 mg/ml addition 15 min after reaction commencement improved microbiological transformation of L-tyrosine to L-dopa (3.48 mg/ml; p ≤ 0.05 by Y. lipolytica NRRL-143. A 35% higher substrate conversion rate was achieved when compared to the control.

  4. Radiolytic dimerization of tyrosine in alkaline solutions of poly-L-tyrosine, glycyl-L-tyrosine and tyrosine

    International Nuclear Information System (INIS)

    Boguta, G.; Dancewicz, A.M.

    1982-01-01

    Blue fluorescence characteristic of dityrosine appeared in γ-irradiated solutions of tyrosine, glycyl-L-tyrosine or polytyrosine (MW 110,000). The intensity of fluorescence was used for the determination of the dityrosine concentration in hydrolysed samples. The radiation-induced formation of dityrosine depended on pH and on the presence of oxygen during radiolysis carried out with a total dose of the order of 1000 Gy. The presence of oxygen in the system suppressed the formation of dityrosine in solution at low or neutral pH but had no effect on this process in alkaline solutions. Except for the radiolysis of air-saturated poly-L-tyrosine solutions, where G(Dityrosine) = 0.35, the yields of dityrosine at high pH were lower than the yields obtained during radiolysis at low pH and in the absence of oxygen. (author)

  5. High cumulants of conserved charges and their statistical uncertainties

    Science.gov (United States)

    Li-Zhu, Chen; Ye-Yin, Zhao; Xue, Pan; Zhi-Ming, Li; Yuan-Fang, Wu

    2017-10-01

    We study the influence of measured high cumulants of conserved charges on their associated statistical uncertainties in relativistic heavy-ion collisions. With a given number of events, the measured cumulants randomly fluctuate with an approximately normal distribution, while the estimated statistical uncertainties are found to be correlated with corresponding values of the obtained cumulants. Generally, with a given number of events, the larger the cumulants we measure, the larger the statistical uncertainties that are estimated. The error-weighted averaged cumulants are dependent on statistics. Despite this effect, however, it is found that the three sigma rule of thumb is still applicable when the statistics are above one million. Supported by NSFC (11405088, 11521064, 11647093), Major State Basic Research Development Program of China (2014CB845402) and Ministry of Science and Technology (MoST) (2016YFE0104800)

  6. Tyrosine phosphorylation in human lymphomas

    NARCIS (Netherlands)

    Haralambieva, E; Jones, M.; Roncador, GM; Cerroni, L; Lamant, L; Ott, G; Rosenwald, A; Sherman, C; Thorner, P; Kusec, R; Wood, KM; Campo, E; Falini, B; Ramsay, A; Marafioti, T; Stein, H; Kluin, PM; Pulford, K; Mason, DY

    2002-01-01

    In a previous study, we showed that the high level of protein tyrosine phosphorylation present in lymphomas containing an anaplastic lymphoma kinase (ALK) can be demonstrated in routinely processed paraffin tissue sections using immunolabelling techniques. In the present study we investigated

  7. Highly conserved small subunit residues influence rubisco large subunit catalysis.

    Science.gov (United States)

    Genkov, Todor; Spreitzer, Robert J

    2009-10-30

    The chloroplast enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the rate-limiting step of photosynthetic CO(2) fixation. With a deeper understanding of its structure-function relationships and competitive inhibition by O(2), it may be possible to engineer an increase in agricultural productivity and renewable energy. The chloroplast-encoded large subunits form the active site, but the nuclear-encoded small subunits can also influence catalytic efficiency and CO(2)/O(2) specificity. To further define the role of the small subunit in Rubisco function, the 10 most conserved residues in all small subunits were substituted with alanine by transformation of a Chlamydomonas reinhardtii mutant that lacks the small subunit gene family. All the mutant strains were able to grow photosynthetically, indicating that none of the residues is essential for function. Three of the substitutions have little or no effect (S16A, P19A, and E92A), one primarily affects holoenzyme stability (L18A), and the remainder affect catalysis with or without some level of associated structural instability (Y32A, E43A, W73A, L78A, P79A, and F81A). Y32A and E43A cause decreases in CO(2)/O(2) specificity. Based on the x-ray crystal structure of Chlamydomonas Rubisco, all but one (Glu-92) of the conserved residues are in contact with large subunits and cluster near the amino- or carboxyl-terminal ends of large subunit alpha-helix 8, which is a structural element of the alpha/beta-barrel active site. Small subunit residues Glu-43 and Trp-73 identify a possible structural connection between active site alpha-helix 8 and the highly variable small subunit loop between beta-strands A and B, which can also influence Rubisco CO(2)/O(2) specificity.

  8. Unsupervised consensus cluster analysis of [18F]-fluoroethyl-L-tyrosine positron emission tomography identified textural features for the diagnosis of pseudoprogression in high-grade glioma.

    Science.gov (United States)

    Kebir, Sied; Khurshid, Zain; Gaertner, Florian C; Essler, Markus; Hattingen, Elke; Fimmers, Rolf; Scheffler, Björn; Herrlinger, Ulrich; Bundschuh, Ralph A; Glas, Martin

    2017-01-31

    Timely detection of pseudoprogression (PSP) is crucial for the management of patients with high-grade glioma (HGG) but remains difficult. Textural features of O-(2-[18F]fluoroethyl)-L-tyrosine positron emission tomography (FET-PET) mirror tumor uptake heterogeneity; some of them may be associated with tumor progression. Fourteen patients with HGG and suspected of PSP underwent FET-PET imaging. A set of 19 conventional and textural FET-PET features were evaluated and subjected to unsupervised consensus clustering. The final diagnosis of true progression vs. PSP was based on follow-up MRI using RANO criteria. Three robust clusters have been identified based on 10 predominantly textural FET-PET features. None of the patients with PSP fell into cluster 2, which was associated with high values for textural FET-PET markers of uptake heterogeneity. Three out of 4 patients with PSP were assigned to cluster 3 that was largely associated with low values of textural FET-PET features. By comparison, tumor-to-normal brain ratio (TNRmax) at the optimal cutoff 2.1 was less predictive of PSP (negative predictive value 57% for detecting true progression, p=0.07 vs. 75% with cluster 3, p=0.04). Clustering based on textural O-(2-[18F]fluoroethyl)-L-tyrosine PET features may provide valuable information in assessing the elusive phenomenon of pseudoprogression.

  9. Tyrosine hydroxylase in the ventral tegmental area of rams with high or low libido-A role for dopamine.

    Science.gov (United States)

    Kramer, A C; Mirto, A J; Austin, K J; Roselli, C E; Alexander, B M

    2017-12-01

    Dopamine synthesis in the ventral tegmental area (VTA) is necessary for the reinforcement of sexual behavior. The objective of this study determined if sexual stimuli initiates reward, and whether reward is attenuated in sexually inactive rams. Sexually active rams were exposed to urine from estrous (n=4) or ovariectomized (n=3) ewes with inactive rams (n=3) exposed to urine from estrous ewes. Following exposure, rams were exsanguinated and brains perfused. Alternating sections of the VTA were stained for Fos related antigens (FRA), tyrosine hydroxylase, and dopamine beta-hydroxylase activity. Forebrain tissue, mid-sagittal ventral to the anterior corpus callosum, was stained for dopamine D 2 receptors. Concentrations of cortisol was determined prior to and following exposure. Exposure to ovariectomized-ewe urine in sexually active rams did not influence (P=0.6) FRA expression, but fewer (PSexually inactive rams had fewer (Psexually active rams following exposure to estrous ewe urine. VTA neurons staining positive for dopamine beta-hydroxylase did not differ by sexual activity (P=0.44) or urine exposure (P=0.07). Exposure to stimulus did not influence (P=0.46) numbers of forebrain neurons staining positive for dopamine D2 receptors in sexually active rams, but fewer (P=0.04) neurons stain positive in inactive rams. Serum concentrations of cortisol did not differ (P≥0.52) among rams prior to or following stimulus. In conclusion sexual inactivity is unlikely due to stress, but may be partially a result of decreased tyrosine hydroxylase and/or the response to dopamine. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Eucaryotic operon genes can define highly conserved syntenies

    Czech Academy of Sciences Publication Activity Database

    Trachtulec, Zdeněk

    2004-01-01

    Roč. 50, - (2004), s. 1-6 ISSN 0015-5500 R&D Projects: GA ČR GA204/01/0997; GA MŠk LN00A079 Institutional research plan: CEZ:AV0Z5052915 Keywords : eukaryotic operon * conserved synteny Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.507, year: 2004

  11. SH3 domain tyrosine phosphorylation--sites, role and evolution.

    Directory of Open Access Journals (Sweden)

    Zuzana Tatárová

    Full Text Available BACKGROUND: SH3 domains are eukaryotic protein domains that participate in a plethora of cellular processes including signal transduction, proliferation, and cellular movement. Several studies indicate that tyrosine phosphorylation could play a significant role in the regulation of SH3 domains. RESULTS: To explore the incidence of the tyrosine phosphorylation within SH3 domains we queried the PhosphoSite Plus database of phosphorylation sites. Over 100 tyrosine phosphorylations occurring on 20 different SH3 domain positions were identified. The tyrosine corresponding to c-Src Tyr-90 was by far the most frequently identified SH3 domain phosphorylation site. A comparison of sequences around this tyrosine led to delineation of a preferred sequence motif ALYD(Y/F. This motif is present in about 15% of human SH3 domains and is structurally well conserved. We further observed that tyrosine phosphorylation is more abundant than serine or threonine phosphorylation within SH3 domains and other adaptor domains, such as SH2 or WW domains. Tyrosine phosphorylation could represent an important regulatory mechanism of adaptor domains. CONCLUSIONS: While tyrosine phosphorylation typically promotes signaling protein interactions via SH2 or PTB domains, its role in SH3 domains is the opposite - it blocks or prevents interactions. The regulatory function of tyrosine phosphorylation is most likely achieved by the phosphate moiety and its charge interfering with binding of polyproline helices of SH3 domain interacting partners.

  12. Energy conservation and pomeron loops in high energy evolution

    International Nuclear Information System (INIS)

    Gustafson, Goesta

    2007-01-01

    We present a formalism which modifies the Mueller Dipole Model such that it incorporates energy-momentum conservation as well as important colour suppressed effects in the cascade evolution. The formalism is implemented in a Monte Carlo simulation program, and the results are compared to inclusive data from HERA and the Tevatron. We here find a generally very good agreement between our model and the experimental data. (author)

  13. Usherin expression is highly conserved in mouse and human tissues.

    Science.gov (United States)

    Pearsall, Nicole; Bhattacharya, Gautam; Wisecarver, Jim; Adams, Joe; Cosgrove, Dominic; Kimberling, William

    2002-12-01

    Usher syndrome is an autosomal recessive disease that results in varying degrees of hearing loss and retinitis pigmentosa. Three types of Usher syndrome (I, II, and III) have been identified clinically with Usher type II being the most common of the three types. Usher type II has been localized to three different chromosomes 1q41, 3p, and 5q, corresponding to Usher type 2A, 2B, and 2C respectively. Usherin is a basement membrane protein encoded by the USH2A gene. Expression of usherin has been localized in the basement membrane of several tissues, however it is not ubiquitous. Immunohistochemistry detected usherin in the following human tissues: retina, cochlea, small and large intestine, pancreas, bladder, prostate, esophagus, trachea, thymus, salivary glands, placenta, ovary, fallopian tube, uterus, and testis. Usherin was absent in many other tissues such as heart, lung, liver, kidney, and brain. This distribution is consistent with the usherin distribution seen in the mouse. Conservation of usherin is also seen at the nucleotide and amino acid level when comparing the mouse and human gene sequences. Evolutionary conservation of usherin expression at the molecular level and in tissues unaffected by Usher 2a supports the important structural and functional role this protein plays in the human. In addition, we believe that these results could lead to a diagnostic procedure for the detection of Usher syndrome and those who carry an USH2A mutation.

  14. Effect of ghrelin receptor agonist and antagonist on the activity of arcuate nucleus tyrosine hydroxylase containing neurons in C57BL/6 male mice exposed to normal or high fat diet

    Czech Academy of Sciences Publication Activity Database

    Pirník, Z.; Majerčíková, Z.; Holubová, Martina; Pirník, R.; Železná, Blanka; Maletínská, Lenka; Kiss, A.

    2014-01-01

    Roč. 65, č. 4 (2014), s. 477-486 ISSN 0867-5910 Institutional support: RVO:61388963 Keywords : growth hormone secretagogue receptor * ghrelin receptor agonist * ghrelin receptor antagonist * high fat diet * tyrosine hydroxylase * arcuate nucleus * food intake Subject RIV: CE - Biochemistry Impact factor: 2.386, year: 2014

  15. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    Science.gov (United States)

    Li, Bin; Eyer, Peter; Eddleston, Michael; Jiang, Wei; Schopfer, Lawrence M.; Lockridge, Oksana

    2013-01-01

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. PMID:23566956

  16. Tyrosine supplementation for phenylketonuria.

    Science.gov (United States)

    Webster, Diana; Wildgoose, Joanne

    2013-06-05

    Phenylketonuria is an inherited disease for which the main treatment is the dietary restriction of the amino acid phenylalanine. The diet has to be initiated in the neonatal period to prevent or reduce mental handicap. However, the diet is very restrictive and unpalatable and can be difficult to follow. A deficiency of the amino acid tyrosine has been suggested as a cause of some of the neuropsychological problems exhibited in phenylketonuria. Therefore, this review aims to assess the efficacy of tyrosine supplementation for phenylketonuria. To assess the effects of tyrosine supplementation alongside or instead of a phenylalanine-restricted diet for people with phenylketonuria, who commenced on diet at diagnosis and either continued on the diet or relaxed the diet later in life. To assess the evidence that tyrosine supplementation alongside, or instead of a phenylalanine-restricted diet improves intelligence, neuropsychological performance, growth and nutritional status, mortality rate and quality of life. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register which is comprised of references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Additional studies were identified from handsearches of the Journal of Inherited Metabolic Disease (from inception in 1978 to 1998). The manufacturers of prescribable dietary products used in the treatment of phenylketonuria were also contacted for further references.Date of the most recent search of the Group's Inborn Errors of Metabolism Trials Register: 28 June 2012. All randomised or quasi-randomised trials investigating the use of tyrosine supplementation versus placebo in people with phenylketonuria in addition to, or instead of, a phenylalanine-restricted diet. People treated for maternal phenylketonuria were excluded. Two authors independently assessed the trial eligibility, methodological quality

  17. Protein tyrosine kinase and mitogen-activated protein kinase signalling pathways contribute to differences in heterophil-mediated innate immune responsiveness between two lines of broilers

    Science.gov (United States)

    Protein tyrosine phosphorylation mediates signal transduction of cellular processes, with protein tyrosine kinases (PTKs) regulating virtually all signaling events. The mitogen-activated protein kinase (MAPK) super-family consists of three conserved pathways that convert receptor activation into ce...

  18. Telomeric expression sites are highly conserved in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Christiane Hertz-Fowler

    Full Text Available Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs. The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology.

  19. Exploring oxidative modifications of tyrosine

    DEFF Research Database (Denmark)

    Houée-Lévin, C; Bobrowski, K; Horakova, L

    2015-01-01

    residues are oxidised in vivo with impact on cellular homeostasis and redox signalling pathways. A notable example is tyrosine, which can undergo a number of oxidative post-translational modifications to form 3-hydroxy-tyrosine, tyrosine crosslinks, 3-nitrotyrosine and halogenated tyrosine, with different...... effects on cellular functions. Tyrosine oxidation has been studied extensively in vitro, and this has generated detailed information about the molecular mechanisms that may occur in vivo. An important aspect of studying tyrosine oxidation both in vitro and in biological systems is the ability to monitor...... residues modified and the nature of the modification. These approaches have helped understanding of the consequences of tyrosine oxidation in biological systems, especially its effects on cell signalling and cell dysfunction, linking to roles in disease. There is mounting evidence that tyrosine oxidation...

  20. Determination of o-tyrosine in irradiated chicken

    International Nuclear Information System (INIS)

    Zoller, O.; Schoeni, D.; Zimmerli, B.

    1991-01-01

    The author explains his method to determine O-Tyrosine in irradiated chickens with a high-performance liquid chromatography. The method is simple and fast, but a proper chromatographic separation is difficult. The detection limit with a high sensitive detector is about 0.05-0.1 mg O-Tyrosine/kg meat (9 refs)

  1. Elevated blood plasma levels of epinephrine, norepinephrine, tyrosine hydroxylase, TGFβ1, and TNFα associated with high-altitude pulmonary edema in Indian population

    Directory of Open Access Journals (Sweden)

    Pandey P

    2016-08-01

    Full Text Available Priyanka Pandey,1,2 Zahara Ali,1,2 Ghulam Mohammad,3 MA Qadar Pasha1,2 1Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi, 2Department of Biotechnology, Savitribai Phule Pune University, Pune, 3Department of Medicine, SNM Hospital, Ladakh, Jammu and Kashmir, India Abstract: Biomarkers are essential to unravel the locked pathophysiology of any disease. This study investigated the role of biomarkers and their interactions with each other and with the clinical parameters to study the physiology of high-altitude pulmonary edema (HAPE in HAPE-patients (HAPE-p against adapted highlanders (HLs and healthy sojourners, HAPE-controls (HAPE-c. For this, seven circulatory biomarkers, namely, epinephrine, norepinephrine, tyrosine hydroxylase, transforming growth factor beta 1, tumor necrosis factor alpha (TNFα, platelet-derived growth factor beta beta, and C-reactive protein (CRP, were measured in blood plasma of the three study groups. All the subjects were recruited at ~3,500 m, and clinical features such as arterial oxygen saturation (SaO2, body mass index, and mean arterial pressure were measured. Increased levels of epinephrine, norepinephrine, tyrosine hydroxylase, transforming growth factor-beta 1, and TNFα were observed in HAPE-p against the healthy groups, HAPE-c, and HLs (P<0.0001. CRP levels were decreased in HAPE-p against HAPE-c and HLs (P<0.0001. There was no significant difference or very marginal difference in the levels of these biomarkers in HAPE-c and HLs (P>0.01. Correlation analysis revealed a negative correlation between epinephrine and norepinephrine (P=4.6E-06 in HAPE-p and positive correlation in HAPE-c (P=0.004 and HLs (P=9.78E-07. A positive correlation was observed between TNFα and CRP (P=0.004 in HAPE-p and a negative correlation in HAPE-c (P=4.6E-06. SaO2 correlated negatively with platelet-derived growth factor beta beta (HAPE-p; P=0.05, norepinephrine (P=0.01, and TNFα (P=0.005 and

  2. Homologous high-throughput expression and purification of highly conserved E coli proteins

    Directory of Open Access Journals (Sweden)

    Duchmann Rainer

    2007-06-01

    Full Text Available Abstract Background Genetic factors and a dysregulated immune response towards commensal bacteria contribute to the pathogenesis of Inflammatory Bowel Disease (IBD. Animal models demonstrated that the normal intestinal flora is crucial for the development of intestinal inflammation. However, due to the complexity of the intestinal flora, it has been difficult to design experiments for detection of proinflammatory bacterial antigen(s involved in the pathogenesis of the disease. Several studies indicated a potential association of E. coli with IBD. In addition, T cell clones of IBD patients were shown to cross react towards antigens from different enteric bacterial species and thus likely responded to conserved bacterial antigens. We therefore chose highly conserved E. coli proteins as candidate antigens for abnormal T cell responses in IBD and used high-throughput techniques for cloning, expression and purification under native conditions of a set of 271 conserved E. coli proteins for downstream immunologic studies. Results As a standardized procedure, genes were PCR amplified and cloned into the expression vector pQTEV2 in order to express proteins N-terminally fused to a seven-histidine-tag. Initial small-scale expression and purification under native conditions by metal chelate affinity chromatography indicated that the vast majority of target proteins were purified in high yields. Targets that revealed low yields after purification probably due to weak solubility were shuttled into Gateway (Invitrogen destination vectors in order to enhance solubility by N-terminal fusion of maltose binding protein (MBP, N-utilizing substance A (NusA, or glutathione S-transferase (GST to the target protein. In addition, recombinant proteins were treated with polymyxin B coated magnetic beads in order to remove lipopolysaccharide (LPS. Thus, 73% of the targeted proteins could be expressed and purified in large-scale to give soluble proteins in the range of 500

  3. Visualization of conserved structures by fusing highly variable datasets.

    Science.gov (United States)

    Silverstein, Jonathan C; Chhadia, Ankur; Dech, Fred

    2002-01-01

    Reality (VR) environment. The accuracy of the fusions was determined qualitatively by comparing the transformed atlas overlaid on the appropriate CT. It was examined for where the transformed structure atlas was incorrectly overlaid (false positive) and where it was incorrectly not overlaid (false negative). According to this method, fusions 1 and 2 were correct roughly 50-75% of the time, while fusions 3 and 4 were correct roughly 75-100%. The CT dataset augmented with transformed dataset was viewed arbitrarily in user-centered perspective stereo taking advantage of features such as scaling, windowing and volumetric region of interest selection. This process of auto-coloring conserved structures in variable datasets is a step toward the goal of a broader, standardized automatic structure visualization method for radiological data. If successful it would permit identification, visualization or deletion of structures in radiological data by semi-automatically applying canonical structure information to the radiological data (not just processing and visualization of the data's intrinsic dynamic range). More sophisticated selection of control points and patterns of warping may allow for more accurate transforms, and thus advances in visualization, simulation, education, diagnostics, and treatment planning.

  4. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    International Nuclear Information System (INIS)

    Li, Bin; Eyer, Peter; Eddleston, Michael; Jiang, Wei; Schopfer, Lawrence M.; Lockridge, Oksana

    2013-01-01

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates

  5. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin, E-mail: binli@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Eyer, Peter, E-mail: peter.eyer@lrz.uni-muenchen.de [Walther-Straub-Institut Für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München (Germany); Eddleston, Michael, E-mail: M.Eddleston@ed.ac.uk [Clinical Pharmacology Unit, University of Edinburgh, Edinburgh (United Kingdom); Jiang, Wei, E-mail: wjiang@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Schopfer, Lawrence M., E-mail: lmschopf@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Lockridge, Oksana, E-mail: olockrid@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States)

    2013-06-15

    Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates.

  6. Tyrosine metabolic enzymes from insects and mammals: a comparative perspective.

    Science.gov (United States)

    Vavricka, Christopher John; Han, Qian; Mehere, Prajwalini; Ding, Haizhen; Christensen, Bruce M; Li, Jianyong

    2014-02-01

    Differences in the metabolism of tyrosine between insects and mammals present an interesting example of molecular evolution. Both insects and mammals possess fine-tuned systems of enzymes to meet their specific demands for tyrosine metabolites; however, more homologous enzymes involved in tyrosine metabolism have emerged in many insect species. Without knowledge of modern genomics, one might suppose that mammals, which are generally more complex than insects and require tyrosine as a precursor for important catecholamine neurotransmitters and for melanin, should possess more enzymes to control tyrosine metabolism. Therefore, the question of why insects actually possess more tyrosine metabolic enzymes is quite interesting. It has long been known that insects rely heavily on tyrosine metabolism for cuticle hardening and for innate immune responses, and these evolutionary constraints are likely the key answers to this question. In terms of melanogenesis, mammals also possess a high level of regulation; yet mammalian systems possess more mechanisms for detoxification whereas insects accelerate pathways like melanogenesis and therefore must bear increased oxidative pressure. Our research group has had the opportunity to characterize the structure and function of many key proteins involved in tyrosine metabolism from both insects and mammals. In this mini review we will give a brief overview of our research on tyrosine metabolic enzymes in the scope of an evolutionary perspective of mammals in comparison to insects. © 2013 Institute of Zoology, Chinese Academy of Sciences.

  7. Analytic, high β, flux conserving equilibria for cylindrical tokamaks

    International Nuclear Information System (INIS)

    Sigmar, D.J.; Vahala, G.

    1978-09-01

    Using Grad's theory of generalized differential equations, the temporal evolution from low to high β due to ''adiabatic'' and nonadiabatic (i.e., neutral beam injection) heating of a cylindrical tokamak plasma with circular cross section and peaked current profiles is calculated analytically. The influence of shaping the initial safety factor profile and the beam deposition profile and the effect of minor radius compression on the equilibrium is analyzed

  8. Analytic, high β, flux conserving equilibria for cylindrical tokamaks

    International Nuclear Information System (INIS)

    Sigmar, D.J.; Vahala, G.

    1978-01-01

    Using Grad's theory of generalized differential equations, the temporal evolution from low to high β due to ''adiabatic'' and nonadiabatic (i.e., neutral beam injection) heating of a cylindrical tokamak plasma with circular cross section and peaked current profiles is calculated analytically. The influence of shaping the initial safety factor profile and the beam deposition profile and the effect of minor radius compression on the equilibrium is analyzed

  9. Ror receptor tyrosine kinases: orphans no more.

    Science.gov (United States)

    Green, Jennifer L; Kuntz, Steven G; Sternberg, Paul W

    2008-11-01

    Receptor tyrosine kinase-like orphan receptor (Ror) proteins are a conserved family of tyrosine kinase receptors that function in developmental processes including skeletal and neuronal development, cell movement and cell polarity. Although Ror proteins were originally named because the associated ligand and signaling pathway were unknown, recent studies in multiple species have now established that Ror proteins are Wnt receptors. Depending on the cellular context, Ror proteins can either activate or repress transcription of Wnt target genes and can modulate Wnt signaling by sequestering Wnt ligands. New evidence implicates Ror proteins in planar cell polarity, an alternative Wnt pathway. Here, we review the progress made in understanding these mysterious proteins and, in particular, we focus on their function as Wnt receptors.

  10. rse, a novel receptor-type tyrosine kinase with homology to Axl/Ufo, is expressed at high levels in the brain.

    Science.gov (United States)

    Mark, M R; Scadden, D T; Wang, Z; Gu, Q; Goddard, A; Godowski, P J

    1994-04-08

    We have isolated cDNA clones that encode the human and murine forms of a novel receptor-type tyrosine kinase termed Rse. Sequence analysis indicates that human Rse contains 890 amino acids, with an extracellular region composed of two immunoglobulin-like domains followed by two fibronectin type III domains. Murine Rse contains 880 amino acids and shares 90% amino acid identity with its human counterpart. Rse is structurally similar to the receptor-type tyrosine kinase Axl/Ufo, and the two proteins have 35 and 63% sequence identity in their extracellular and intracellular domains, respectively. To study the synthesis and activation of this putative receptor-type tyrosine kinase, we constructed a version of Rse (termed gD-Rse, where gD represents glycoprotein D) that contains an NH2-terminal epitope tag. NIH3T3 cells were engineered to express gD-Rse, which could be detected at the cell surface by fluorescence-activated cell sorting. Moreover, gD-Rse was rapidly phosphorylated on tyrosine residues upon incubation of the cells with an antibody directed against the epitope tag, suggesting that rse encodes an active tyrosine kinase. In the human tissues we examined, the highest level of expression of rse mRNA was observed in the brain; rse mRNA was also detected in the premegakaryocytopoietic cell lines CMK11-5 and Dami. The gene for rse was localized to human chromosome 15.

  11. Inhibition of biofilm formation by D-tyrosine: Effect of bacterial type and D-tyrosine concentration.

    Science.gov (United States)

    Yu, Cong; Li, Xuening; Zhang, Nan; Wen, Donghui; Liu, Charles; Li, Qilin

    2016-04-01

    D-Tyrosine inhibits formation and triggers disassembly of bacterial biofilm and has been proposed for biofouling control applications. This study probes the impact of D-tyrosine in different biofilm formation stages in both G+ and G- bacteria, and reveals a non-monotonic correlation between D-tyrosine concentration and biofilm inhibition effect. In the attachment stage, cell adhesion was studied in a flow chamber, where D-tyrosine caused significant reduction in cell attachment. Biofilms formed by Pseudomonas aeruginosa and Bacillus subtilis were characterized by confocal laser scanning microscopy as well as quantitative analysis of cellular biomass and extracellular polymeric substances. D-Tyrosine exhibited strong inhibitive effects on both biofilms with an effective concentration as low as 5 nM; the biofilms responded to D-tyrosine concentration change in a non-monotonic, bi-modal pattern. In addition, D-tyrosine showed notable and different impact on EPS production by G+ and G- bacteria. Extracellular protein was decreased in P. aeruginosa biofilms, but increased in those of B. subtilis. Exopolysaccharides production by P. aeruginosa was increased at low concentrations and reduced at high concentrations while no impact was found in B. subtilis. These results suggest that distinct mechanisms are at play at different D-tyrosine concentrations and they may be species specific. Dosage of D-tyrosine must be carefully controlled for biofouling control applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A conserved motif in the linker domain of STAT1 transcription factor is required for both recognition and release from high-affinity DNA-binding sites.

    Science.gov (United States)

    Hüntelmann, Bettina; Staab, Julia; Herrmann-Lingen, Christoph; Meyer, Thomas

    2014-01-01

    Binding to specific palindromic sequences termed gamma-activated sites (GAS) is a hallmark of gene activation by members of the STAT (signal transducer and activator of transcription) family of cytokine-inducible transcription factors. However, the precise molecular mechanisms involved in the signal-dependent finding of target genes by STAT dimers have not yet been very well studied. In this study, we have characterized a sequence motif in the STAT1 linker domain which is highly conserved among the seven human STAT proteins and includes surface-exposed residues in close proximity to the bound DNA. Using site-directed mutagenesis, we have demonstrated that a lysine residue in position 567 of the full-length molecule is required for GAS recognition. The substitution of alanine for this residue completely abolished both binding to high-affinity GAS elements and transcriptional activation of endogenous target genes in cells stimulated with interferon-γ (IFNγ), while the time course of transient nuclear accumulation and tyrosine phosphorylation were virtually unchanged. In contrast, two glutamic acid residues (E559 and E563) on each monomer are important for the dissociation of dimeric STAT1 from DNA and, when mutated to alanine, result in elevated levels of tyrosine-phosphorylated STAT1 as well as prolonged IFNγ-stimulated nuclear accumulation. In conclusion, our data indicate that the kinetics of signal-dependent GAS binding is determined by an array of glutamic acid residues located at the interior surface of the STAT1 dimer. These negatively charged residues appear to align the long axis of the STAT1 dimer in a position perpendicular to the DNA, thereby facilitating the interaction between lysine 567 and the phosphodiester backbone of a bound GAS element, which is a prerequisite for transient gene induction.

  13. High-resolution satellite imagery is an important yet underutilized resource in conservation biology.

    Science.gov (United States)

    Boyle, Sarah A; Kennedy, Christina M; Torres, Julio; Colman, Karen; Pérez-Estigarribia, Pastor E; de la Sancha, Noé U

    2014-01-01

    Technological advances and increasing availability of high-resolution satellite imagery offer the potential for more accurate land cover classifications and pattern analyses, which could greatly improve the detection and quantification of land cover change for conservation. Such remotely-sensed products, however, are often expensive and difficult to acquire, which prohibits or reduces their use. We tested whether imagery of high spatial resolution (≤5 m) differs from lower-resolution imagery (≥30 m) in performance and extent of use for conservation applications. To assess performance, we classified land cover in a heterogeneous region of Interior Atlantic Forest in Paraguay, which has undergone recent and dramatic human-induced habitat loss and fragmentation. We used 4 m multispectral IKONOS and 30 m multispectral Landsat imagery and determined the extent to which resolution influenced the delineation of land cover classes and patch-level metrics. Higher-resolution imagery more accurately delineated cover classes, identified smaller patches, retained patch shape, and detected narrower, linear patches. To assess extent of use, we surveyed three conservation journals (Biological Conservation, Biotropica, Conservation Biology) and found limited application of high-resolution imagery in research, with only 26.8% of land cover studies analyzing satellite imagery, and of these studies only 10.4% used imagery ≤5 m resolution. Our results suggest that high-resolution imagery is warranted yet under-utilized in conservation research, but is needed to adequately monitor and evaluate forest loss and conversion, and to delineate potentially important stepping-stone fragments that may serve as corridors in a human-modified landscape. Greater access to low-cost, multiband, high-resolution satellite imagery would therefore greatly facilitate conservation management and decision-making.

  14. Anti-tumor activity of high-dose EGFR tyrosine kinase inhibitor and sequential docetaxel in wild type EGFR non-small cell lung cancer cell nude mouse xenografts

    OpenAIRE

    Tang, Ning; Zhang, Qianqian; Fang, Shu; Han, Xiao; Wang, Zhehai

    2016-01-01

    Treatment of non-small-cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is still a challenge. This study explored antitumor activity of high-dose icotinib (an EGFR tyrosine kinase inhibitor) plus sequential docetaxel against wild-type EGFR NSCLC cells-generated nude mouse xenografts. Nude mice were subcutaneously injected with wild-type EGFR NSCLC A549 cells and divided into different groups for 3-week treatment. Tumor xenograft volumes were monitored and record...

  15. Deletion of protein tyrosine phosphatase 1B rescues against myocardial anomalies in high fat diet-induced obesity: Role of AMPK-dependent autophagy.

    Science.gov (United States)

    Kandadi, Machender R; Panzhinskiy, Evgeniy; Roe, Nathan D; Nair, Sreejayan; Hu, Dahai; Sun, Aijun

    2015-02-01

    Obesity-induced cardiomyopathy may be mediated by alterations in multiple signaling cascades involved in glucose and lipid metabolism. Protein tyrosine phosphatase-1B (PTP1B) is an important negative regulator of insulin signaling. This study was designed to evaluate the role of PTP1B in high fat diet-induced cardiac contractile anomalies. Wild-type and PTP1B knockout mice were fed normal (10%) or high (45%) fat diet for 5months prior to evaluation of cardiac function. Myocardial function was assessed using echocardiography and an Ion-Optix MyoCam system. Western blot analysis was employed to evaluate levels of AMPK, mTOR, raptor, Beclin-1, p62 and LC3-II. RT-PCR technique was employed to assess genes involved in hypertrophy and lipid metabolism. Our data revealed increased LV thickness and LV chamber size as well as decreased fractional shortening following high fat diet intake, the effect was nullified by PTP1B knockout. High fat diet intake compromised cardiomyocyte contractile function as evidenced by decreased peak shortening, maximal velocity of shortening/relengthening, intracellular Ca²⁺ release as well as prolonged duration of relengthening and intracellular Ca²⁺ decay, the effects of which were alleviated by PTP1B knockout. High fat diet resulted in enlarged cardiomyocyte area and increased lipid accumulation, which were attenuated by PTP1B knockout. High fat diet intake dampened myocardial autophagy as evidenced by decreased LC3-II conversion and Beclin-1, increased p62 levels as well as decreased phosphorylation of AMPK and raptor, the effects of which were significantly alleviated by PTP1B knockout. Pharmacological inhibition of AMPK using compound C disengaged PTP1B knockout-conferred protection against fatty acid-induced cardiomyocyte contractile anomalies. Taken together, our results suggest that PTP1B knockout offers cardioprotection against high fat diet intake through activation of AMPK. This article is part of a Special Issue entitled

  16. Highly localized interactions between sensory neurons and sprouting sympathetic fibers observed in a transgenic tyrosine hydroxylase reporter mouse

    Directory of Open Access Journals (Sweden)

    Zhang Jun-Ming

    2011-07-01

    Full Text Available Abstract Background Sprouting of sympathetic fibers into sensory ganglia occurs in many preclinical pain models, providing a possible anatomical substrate for sympathetically enhanced pain. However, the functional consequences of this sprouting have been controversial. We used a transgenic mouse in which sympathetic fibers expressed green fluorescent protein, observable in live tissue. Medium and large diameter lumbar sensory neurons with and without nearby sympathetic fibers were recorded in whole ganglion preparations using microelectrodes. Results After spinal nerve ligation, sympathetic sprouting was extensive by 3 days. Abnormal spontaneous activity increased to 15% and rheobase was reduced. Spontaneously active cells had Aαβ conduction velocities but were clustered near the medium/large cell boundary. Neurons with sympathetic basket formations had a dramatically higher incidence of spontaneous activity (71% and had lower rheobase than cells with no sympathetic fibers nearby. Cells with lower density nearby fibers had intermediate phenotypes. Immunohistochemistry of sectioned ganglia showed that cells surrounded by sympathetic fibers were enriched in nociceptive markers TrkA, substance P, or CGRP. Spontaneous activity began before sympathetic sprouting was observed, but blocking sympathetic sprouting on day 3 by cutting the dorsal ramus in addition to the ventral ramus of the spinal nerve greatly reduced abnormal spontaneous activity. Conclusions The data suggest that early sympathetic sprouting into the sensory ganglia may have highly localized, excitatory effects. Quantitatively, neurons with sympathetic basket formations may account for more than half of the observed spontaneous activity, despite being relatively rare. Spontaneous activity in sensory neurons and sympathetic sprouting may be mutually re-enforcing.

  17. Roles of the tyrosine isomers meta-tyrosine and ortho-tyrosine in oxidative stress.

    Science.gov (United States)

    Ipson, Brett R; Fisher, Alfred L

    2016-05-01

    The damage to cellular components by reactive oxygen species, termed oxidative stress, both increases with age and likely contributes to age-related diseases including Alzheimer's disease, atherosclerosis, diabetes, and cataract formation. In the setting of oxidative stress, hydroxyl radicals can oxidize the benzyl ring of the amino acid phenylalanine, which then produces the abnormal tyrosine isomers meta-tyrosine or ortho-tyrosine. While elevations in m-tyrosine and o-tyrosine concentrations have been used as a biological marker of oxidative stress, there is emerging evidence from bacterial, plant, and mammalian studies demonstrating that these isomers, particularly m-tyrosine, directly produce adverse effects to cells and tissues. These new findings suggest that the abnormal tyrosine isomers could in fact represent mediators of the effects of oxidative stress. Consequently the accumulation of m- and o-tyrosine may disrupt cellular homeostasis and contribute to disease pathogenesis, and as result, effective defenses against oxidative stress can encompass not only the elimination of reactive oxygen species but also the metabolism and ultimately the removal of the abnormal tyrosine isomers from the cellular amino acid pool. Future research in this area is needed to clarify the biologic mechanisms by which the tyrosine isomers damage cells and disrupt the function of tissues and organs and to identify the metabolic pathways involved in removing the accumulated isomers after exposure to oxidative stress. Published by Elsevier B.V.

  18. High-throughput sequencing, characterization and detection of new and conserved cucumber miRNAs.

    Directory of Open Access Journals (Sweden)

    Germán Martínez

    Full Text Available Micro RNAS (miRNAs are a class of endogenous small non coding RNAs involved in the post-transcriptional regulation of gene expression. In plants, a great number of conserved and specific miRNAs, mainly arising from model species, have been identified to date. However less is known about the diversity of these regulatory RNAs in vegetal species with agricultural and/or horticultural importance. Here we report a combined approach of bioinformatics prediction, high-throughput sequencing data and molecular methods to analyze miRNAs populations in cucumber (Cucumis sativus plants. A set of 19 conserved and 6 known but non-conserved miRNA families were found in our cucumber small RNA dataset. We also identified 7 (3 with their miRNA* strand not previously described miRNAs, candidates to be cucumber-specific. To validate their description these new C. sativus miRNAs were detected by northern blot hybridization. Additionally, potential targets for most conserved and new miRNAs were identified in cucumber genome.In summary, in this study we have identified, by first time, conserved, known non-conserved and new miRNAs arising from an agronomically important species such as C. sativus. The detection of this complex population of regulatory small RNAs suggests that similarly to that observe in other plant species, cucumber miRNAs may possibly play an important role in diverse biological and metabolic processes.

  19. High-Order Entropy Stable Finite Difference Schemes for Nonlinear Conservation Laws: Finite Domains

    Science.gov (United States)

    Fisher, Travis C.; Carpenter, Mark H.

    2013-01-01

    Developing stable and robust high-order finite difference schemes requires mathematical formalism and appropriate methods of analysis. In this work, nonlinear entropy stability is used to derive provably stable high-order finite difference methods with formal boundary closures for conservation laws. Particular emphasis is placed on the entropy stability of the compressible Navier-Stokes equations. A newly derived entropy stable weighted essentially non-oscillatory finite difference method is used to simulate problems with shocks and a conservative, entropy stable, narrow-stencil finite difference approach is used to approximate viscous terms.

  20. Paralog-Specific Patterns of Structural Disorder and Phosphorylation in the Vertebrate SH3-SH2-Tyrosine Kinase Protein Family.

    Science.gov (United States)

    Dos Santos, Helena G; Siltberg-Liberles, Jessica

    2016-09-19

    One of the largest multigene families in Metazoa are the tyrosine kinases (TKs). These are important multifunctional proteins that have evolved as dynamic switches that perform tyrosine phosphorylation and other noncatalytic activities regulated by various allosteric mechanisms. TKs interact with each other and with other molecules, ultimately activating and inhibiting different signaling pathways. TKs are implicated in cancer and almost 30 FDA-approved TK inhibitors are available. However, specific binding is a challenge when targeting an active site that has been conserved in multiple protein paralogs for millions of years. A cassette domain (CD) containing SH3-SH2-Tyrosine Kinase domains reoccurs in vertebrate nonreceptor TKs. Although part of the CD function is shared between TKs, it also presents TK specific features. Here, the evolutionary dynamics of sequence, structure, and phosphorylation across the CD in 17 TK paralogs have been investigated in a large-scale study. We establish that TKs often have ortholog-specific structural disorder and phosphorylation patterns, while secondary structure elements, as expected, are highly conserved. Further, domain-specific differences are at play. Notably, we found the catalytic domain to fluctuate more in certain secondary structure elements than the regulatory domains. By elucidating how different properties evolve after gene duplications and which properties are specifically conserved within orthologs, the mechanistic understanding of protein evolution is enriched and regions supposedly critical for functional divergence across paralogs are highlighted. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Spatial overlap between environmental policy instruments and areas of high conservation value in forest.

    Science.gov (United States)

    Sverdrup-Thygeson, Anne; Søgaard, Gunnhild; Rusch, Graciela M; Barton, David N

    2014-01-01

    In order to safeguard biodiversity in forest we need to know how forest policy instruments work. Here we use a nationwide network of 9400 plots in productive forest to analyze to what extent large-scale policy instruments, individually and together, target forest of high conservation value in Norway. We studied both instruments working through direct regulation; Strict Protection and Landscape Protection, and instruments working through management planning and voluntary schemes of forest certification; Wilderness Area and Mountain Forest. As forest of high conservation value (HCV-forest) we considered the extent of 12 Biodiversity Habitats and the extent of Old-Age Forest. We found that 22% of productive forest area contained Biodiversity Habitats. More than 70% of this area was not covered by any large-scale instruments. Mountain Forest covered 23%, while Strict Protection and Wilderness both covered 5% of the Biodiversity Habitat area. A total of 9% of productive forest area contained Old-Age Forest, and the relative coverage of the four instruments was similar as for Biodiversity Habitats. For all instruments, except Landscape Protection, the targeted areas contained significantly higher proportions of HCV-forest than areas not targeted by these instruments. Areas targeted by Strict Protection had higher proportions of HCV-forest than areas targeted by other instruments, except for areas targeted by Wilderness Area which showed similar proportions of Biodiversity Habitats. There was a substantial amount of spatial overlap between the policy tools, but no incremental conservation effect of overlapping instruments in terms of contributing to higher percentages of targeted HCV-forest. Our results reveal that although the current policy mix has an above average representation of forest of high conservation value, the targeting efficiency in terms of area overlap is limited. There is a need to improve forest conservation and a potential to cover this need by better

  2. Role of Tyrosine Isomers in Acute and Chronic Diseases Leading to Oxidative Stress - A Review.

    Science.gov (United States)

    Molnár, Gergő A; Kun, Szilárd; Sélley, Eszter; Kertész, Melinda; Szélig, Lívia; Csontos, Csaba; Böddi, Katalin; Bogár, Lajos; Miseta, Attila; Wittmann, István

    2016-01-01

    Oxidative stress plays a major role in the pathogenesis of a variety of acute and chronic diseases. Measurement of the oxidative stress-related end products may be performed, e.g. that of structural isomers of the physiological para-tyrosine, namely meta- and ortho-tyrosine, that are oxidized derivatives of phenylalanine. Recent data suggest that in sepsis, serum level of meta-tyrosine increases, which peaks on the 2(nd) and 3(rd) days (ptyrosine excretion correlated with both need of daily insulin dose and the insulin-glucose product in non-diabetic septic cases (ptyrosine excretion, urinary meta-tyrosine/para-tyrosine, urinary ortho-tyrosine/para-tyrosine and urinary (meta- + orthotyrosine)/ para-tyrosine proved to be markers of carbohydrate homeostasis. In a chronic rodent model, we tried to compensate the abnormal tyrosine isomers using para-tyrosine, the physiological amino acid. Rats were fed a standard high cholesterol-diet, and were given para-tyrosine or vehicle orally. High-cholesterol feeding lead to a significant increase in aortic wall meta-tyrosine content and a decreased vasorelaxation of the aorta to insulin and the glucagon-like peptide-1 analogue, liraglutide, that both could be prevented by administration of para-tyrosine. Concluding, these data suggest that meta- and ortho-tyrosine are potential markers of oxidative stress in acute diseases related to oxidative stress, and may also interfere with insulin action in septic humans. Competition of meta- and ortho-tyrosine by supplementation of para-tyrosine may exert a protective role in oxidative stress-related diseases.

  3. Prospects for Parity Non-conservation Experiments with Highly Charged Heavy Ions

    OpenAIRE

    Maul, M.; Schäfer, A.; Greiner, W.; Indelicato, P.

    1996-01-01

    We discuss the prospects for parity non-conservation experiments with highly charged heavy ions. Energy levels and parity mixing for heavy ions with two to five electrons are calculated. We investigate two-photon-transitions and the possibility to observe interference effects between weak-matrix elements and Stark matrix elements for periodic electric field configurations.

  4. Balancing forest-regeneration probabilities and maintenance costs in dry grasslands of high conservation priority

    Science.gov (United States)

    Bolliger, Janine; Edwards, Thomas C.; Eggenberg, Stefan; Ismail, Sascha; Seidl, Irmi; Kienast, Felix

    2011-01-01

    Abandonment of agricultural land has resulted in forest regeneration in species-rich dry grasslands across European mountain regions and threatens conservation efforts in this vegetation type. To support national conservation strategies, we used a site-selection algorithm (MARXAN) to find optimum sets of floristic regions (reporting units) that contain grasslands of high conservation priority. We sought optimum sets that would accommodate 136 important dry-grassland species and that would minimize forest regeneration and costs of management needed to forestall predicted forest regeneration. We did not consider other conservation elements of dry grasslands, such as animal species richness, cultural heritage, and changes due to climate change. Optimal sets that included 95–100% of the dry grassland species encompassed an average of 56–59 floristic regions (standard deviation, SD 5). This is about 15% of approximately 400 floristic regions that contain dry-grassland sites and translates to 4800–5300 ha of dry grassland out of a total of approximately 23,000 ha for the entire study area. Projected costs to manage the grasslands in these optimum sets ranged from CHF (Swiss francs) 5.2 to 6.0 million/year. This is only 15–20% of the current total estimated cost of approximately CHF30–45 million/year required if all dry grasslands were to be protected. The grasslands of the optimal sets may be viewed as core sites in a national conservation strategy.

  5. Technical evaluation on high aging, and performance conditions on long-term conservation program

    International Nuclear Information System (INIS)

    Yamashita, Atsushi

    2001-01-01

    In order to secure safety and safe operation of power plants, in every nuclear power plants, conservation actions based on preventive conservation are performed. They contain operative condition monitoring, patrolling inspection, and periodical tests on important systems and apparatus by operators under plant operation and condition monitoring by maintenance workers, and so on, and when finding out their abnormal conditions, their detailed survey is performed to adopt adequate countermeasures such as recovery, exchange, and so on. And, to equipments for nuclear power generation periodical conditions were obliged by legal examinations and by independent inspections. As a result of these conservation actions, even on a plant elapsed about 30 years since beginning of its operation it was thought that the plant was aged with elapsing time even if not recognizing any indication on its aged deterioration at that time. Therefore, for its concrete countermeasure, by supposing long-term operation of a plant with longer operation history, some technical evaluation on aged phenomena were carried out, to investigate on reflection of the obtained results to present conservation actions. Here were described on efforts on the high aging countermeasures, and performing conditions of long-term conservation in the Tsuruga Unit No. 1 Nuclear Power Station. (G.K.)

  6. High qualitative and quantitative conservation of alternative splicing in Caenorhabditis elegans and Caenorhabditis briggsae

    DEFF Research Database (Denmark)

    Rukov, Jakob Lewin; Irimia, Manuel; Mørk, Søren

    2007-01-01

    Alternative splicing (AS) is an important contributor to proteome diversity and is regarded as an explanatory factor for the relatively low number of human genes compared with less complex animals. To assess the evolutionary conservation of AS and its developmental regulation, we have investigated...... the qualitative and quantitative expression of 21 orthologous alternative splice events through the development of 2 nematode species separated by 85-110 Myr of evolutionary time. We demonstrate that most of these alternative splice events present in Caenorhabditis elegans are conserved in Caenorhabditis briggsae....... Moreover, we find that relative isoform expression levels vary significantly during development for 78% of the AS events and that this quantitative variation is highly conserved between the 2 species. Our results suggest that AS is generally tightly regulated through development and that the regulatory...

  7. Next generation of adeno-associated virus 2 vectors: Point mutations in tyrosines lead to high-efficiency transduction at lower doses

    OpenAIRE

    Zhong, Li; Li, Baozheng; Mah, Cathryn S.; Govindasamy, Lakshmanan; Agbandje-McKenna, Mavis; Cooper, Mario; Herzog, Roland W.; Zolotukhin, Irene; Warrington, Kenneth H.; Weigel-Van Aken, Kirsten A.; Hobbs, Jacqueline A.; Zolotukhin, Sergei; Muzyczka, Nicholas; Srivastava, Arun

    2008-01-01

    Recombinant adeno-associated virus 2 (AAV2) vectors are in use in several Phase I/II clinical trials, but relatively large vector doses are needed to achieve therapeutic benefits. Large vector doses also trigger an immune response as a significant fraction of the vectors fails to traffic efficiently to the nucleus and is targeted for degradation by the host cell proteasome machinery. We have reported that epidermal growth factor receptor protein tyrosine kinase (EGFR-PTK) signaling negatively...

  8. Genes involved in complex adaptive processes tend to have highly conserved upstream regions in mammalian genomes

    Directory of Open Access Journals (Sweden)

    Kohane Isaac

    2005-11-01

    Full Text Available Abstract Background Recent advances in genome sequencing suggest a remarkable conservation in gene content of mammalian organisms. The similarity in gene repertoire present in different organisms has increased interest in studying regulatory mechanisms of gene expression aimed at elucidating the differences in phenotypes. In particular, a proximal promoter region contains a large number of regulatory elements that control the expression of its downstream gene. Although many studies have focused on identification of these elements, a broader picture on the complexity of transcriptional regulation of different biological processes has not been addressed in mammals. The regulatory complexity may strongly correlate with gene function, as different evolutionary forces must act on the regulatory systems under different biological conditions. We investigate this hypothesis by comparing the conservation of promoters upstream of genes classified in different functional categories. Results By conducting a rank correlation analysis between functional annotation and upstream sequence alignment scores obtained by human-mouse and human-dog comparison, we found a significantly greater conservation of the upstream sequence of genes involved in development, cell communication, neural functions and signaling processes than those involved in more basic processes shared with unicellular organisms such as metabolism and ribosomal function. This observation persists after controlling for G+C content. Considering conservation as a functional signature, we hypothesize a higher density of cis-regulatory elements upstream of genes participating in complex and adaptive processes. Conclusion We identified a class of functions that are associated with either high or low promoter conservation in mammals. We detected a significant tendency that points to complex and adaptive processes were associated with higher promoter conservation, despite the fact that they have emerged

  9. Solution structure of the receptor tyrosine kinase EphB2 SAM domain and identification of two distinct homotypic interaction sites.

    OpenAIRE

    Smalla, M.; Schmieder, P.; Kelly, M.; Ter Laak, A.; Krause, G.; Ball, L.; Wahl, M.; Bork, P.; Oschkinat, H.

    1999-01-01

    The sterile alpha motif (SAM) is a protein interaction domain of around 70 amino acids present predominantly in the N- and C-termini of more than 60 diverse proteins that participate in signal transduction and transcriptional repression. SAM domains have been shown to homo- and hetero-oligomerize and to mediate specific protein-protein interactions. A highly conserved subclass of SAM domains is present at the intracellular C-terminus of more than 40 Eph receptor tyrosine kinases that are invo...

  10. Conservative Management for Stable High Ankle Injuries in Professional Football Players.

    Science.gov (United States)

    Knapik, Derrick M; Trem, Anthony; Sheehan, Joseph; Salata, Michael J; Voos, James E

    High ankle "syndesmosis" injuries are common in American football players relative to the general population. At the professional level, syndesmotic sprains represent a challenging and unique injury lacking a standardized rehabilitation protocol during conservative management. PubMed, Biosis Preview, SPORTDiscus, PEDro, and EMBASE databases were searched using the terms syndesmotic injuries, American football, conservative management, and rehabilitation. Clinical review. Level 3. When compared with lateral ankle sprains, syndesmosis injuries result in significantly prolonged recovery times and games lost. For stable syndesmotic injuries, conservative management features a brief period of immobilization and protected weightbearing followed by progressive strengthening exercises and running, and athletes can expect to return to competition in 2 to 6 weeks. Further research investigating the efficacy of dry needling and blood flow restriction therapy is necessary to evaluate the benefit of these techniques in the rehabilitation process. Successful conservative management of stable syndesmotic injuries in professional American football athletes requires a thorough understanding of the anatomy, injury mechanisms, diagnosis, and rehabilitation strategies utilized in elite athletes.

  11. Putative tyrosine kinases expressed in K-562 human leukemia cells

    International Nuclear Information System (INIS)

    Partanen, J.; Maekelae, T.P.; Lehvaeslaiho, H.; Alitalo, K.; Alitalo, R.

    1990-01-01

    Tyrosine phosphorylation is important in the transmission of growth and differentiation signals; known tyrosine kinases include several oncoproteins and growth factor receptors. Interestingly, some differentiated cell types, such as erythrocytes and platelets contain high amounts of phosphotyrosine. The authors analyzed tyrosine kinases expressed in the K-562 chronic myelogenous leukemia cell line, which has a bipotential erythroid and megakaryoblastoid differentiation capacity. Analysis of 359 polymerase chain reaction-amplified cDNA clones led to the identification of 14 different tyrosine kinase-related sequences (JTK1-14). Two of the clones (JTK2 and JTK4) represent unusual members of the fibroblast growth factor receptor gene family, and the clones JTK5, JTK11, and JTK14 may also belong to the family of receptor tyrosine kinases but lack a close relationship to any known tyrosine kinase. Each of these different genes has its own characteristic expression pattern in K-562 cells and several other human tumor cell lines. In addition, the JTK11 and JTK14 mRNAs are induced during the megakaryoblastoid differentiation of K-562 cells. These tyrosine kinases may have a role in the differentiation of megakaryoblasts or in the physiology of platelets

  12. Constrained dansyl derivatives reveal bacterial specificity of highly conserved thymidylate synthases.

    Science.gov (United States)

    Calò, Sanuele; Tondi, Donatella; Ferrari, Stefania; Venturelli, Alberto; Ghelli, Stefano; Costi, Maria Paola

    2008-03-25

    The elucidation of the structural/functional specificities of highly conserved enzymes remains a challenging area of investigation, and enzymes involved in cellular replication are important targets for functional studies and drug discovery. Thymidylate synthase (TS, ThyA) governs the synthesis of thymidylate for use in DNA synthesis. The present study focused on Lactobacillus casei TS (LcTS) and Escherichia coli TS (EcTS), which exhibit 50 % sequence identity and strong folding similarity. We have successfully designed and validated a chemical model in which linear, but not constrained, dansyl derivatives specifically complement the LcTS active site. Conversely, chemically constrained dansyl derivatives showed up to 1000-fold improved affinity for EcTS relative to the inhibitory activity of linear derivatives. This study demonstrates that the accurate design of small ligands can uncover functional features of highly conserved enzymes.

  13. Enhancing Conservation with High Resolution Productivity Datasets for the Conterminous United States

    Science.gov (United States)

    Robinson, Nathaniel Paul

    Human driven alteration of the earth's terrestrial surface is accelerating through land use changes, intensification of human activity, climate change, and other anthropogenic pressures. These changes occur at broad spatio-temporal scales, challenging our ability to effectively monitor and assess the impacts and subsequent conservation strategies. While satellite remote sensing (SRS) products enable monitoring of the earth's terrestrial surface continuously across space and time, the practical applications for conservation and management of these products are limited. Often the processes driving ecological change occur at fine spatial resolutions and are undetectable given the resolution of available datasets. Additionally, the links between SRS data and ecologically meaningful metrics are weak. Recent advances in cloud computing technology along with the growing record of high resolution SRS data enable the development of SRS products that quantify ecologically meaningful variables at relevant scales applicable for conservation and management. The focus of my dissertation is to improve the applicability of terrestrial gross and net primary productivity (GPP/NPP) datasets for the conterminous United States (CONUS). In chapter one, I develop a framework for creating high resolution datasets of vegetation dynamics. I use the entire archive of Landsat 5, 7, and 8 surface reflectance data and a novel gap filling approach to create spatially continuous 30 m, 16-day composites of the normalized difference vegetation index (NDVI) from 1986 to 2016. In chapter two, I integrate this with other high resolution datasets and the MOD17 algorithm to create the first high resolution GPP and NPP datasets for CONUS. I demonstrate the applicability of these products for conservation and management, showing the improvements beyond currently available products. In chapter three, I utilize this dataset to evaluate the relationships between land ownership and terrestrial production

  14. Entropy Viscosity Method for High-Order Approximations of Conservation Laws

    KAUST Repository

    Guermond, J. L.

    2010-09-17

    A stabilization technique for conservation laws is presented. It introduces in the governing equations a nonlinear dissipation function of the residual of the associated entropy equation and bounded from above by a first order viscous term. Different two-dimensional test cases are simulated - a 2D Burgers problem, the "KPP rotating wave" and the Euler system - using high order methods: spectral elements or Fourier expansions. Details on the tuning of the parameters controlling the entropy viscosity are given. © 2011 Springer.

  15. Entropy Viscosity Method for High-Order Approximations of Conservation Laws

    KAUST Repository

    Guermond, J. L.; Pasquetti, R.

    2010-01-01

    A stabilization technique for conservation laws is presented. It introduces in the governing equations a nonlinear dissipation function of the residual of the associated entropy equation and bounded from above by a first order viscous term. Different two-dimensional test cases are simulated - a 2D Burgers problem, the "KPP rotating wave" and the Euler system - using high order methods: spectral elements or Fourier expansions. Details on the tuning of the parameters controlling the entropy viscosity are given. © 2011 Springer.

  16. Highly conserved non-coding sequences are associated with vertebrate development.

    Directory of Open Access Journals (Sweden)

    Adam Woolfe

    2005-01-01

    Full Text Available In addition to protein coding sequence, the human genome contains a significant amount of regulatory DNA, the identification of which is proving somewhat recalcitrant to both in silico and functional methods. An approach that has been used with some success is comparative sequence analysis, whereby equivalent genomic regions from different organisms are compared in order to identify both similarities and differences. In general, similarities in sequence between highly divergent organisms imply functional constraint. We have used a whole-genome comparison between humans and the pufferfish, Fugu rubripes, to identify nearly 1,400 highly conserved non-coding sequences. Given the evolutionary divergence between these species, it is likely that these sequences are found in, and furthermore are essential to, all vertebrates. Most, and possibly all, of these sequences are located in and around genes that act as developmental regulators. Some of these sequences are over 90% identical across more than 500 bases, being more highly conserved than coding sequence between these two species. Despite this, we cannot find any similar sequences in invertebrate genomes. In order to begin to functionally test this set of sequences, we have used a rapid in vivo assay system using zebrafish embryos that allows tissue-specific enhancer activity to be identified. Functional data is presented for highly conserved non-coding sequences associated with four unrelated developmental regulators (SOX21, PAX6, HLXB9, and SHH, in order to demonstrate the suitability of this screen to a wide range of genes and expression patterns. Of 25 sequence elements tested around these four genes, 23 show significant enhancer activity in one or more tissues. We have identified a set of non-coding sequences that are highly conserved throughout vertebrates. They are found in clusters across the human genome, principally around genes that are implicated in the regulation of development

  17. Tyrosine kinases in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Kobayashi Akiko

    2011-08-01

    Full Text Available Abstract Rheumatoid arthritis (RA is an inflammatory, polyarticular joint disease. A number of cellular responses are involved in the pathogenesis of rheumatoid arthritis, including activation of inflammatory cells and cytokine expression. The cellular responses involved in each of these processes depends on the specific signaling pathways that are activated; many of which include protein tyrosine kinases. These pathways include the mitogen-activated protein kinase pathway, Janus kinases/signal transducers and activators transcription pathway, spleen tyrosine kinase signaling, and the nuclear factor κ-light-chain-enhancer of activated B cells pathway. Many drugs are in development to target tyrosine kinases for the treatment of RA. Based on the number of recently published studies, this manuscript reviews the role of tyrosine kinases in the pathogenesis of RA and the potential role of kinase inhibitors as new therapeutic strategies of RA.

  18. Protein tyrosine phosphatases: regulatory mechanisms.

    NARCIS (Netherlands)

    den Hertog, J.; Ostman, A.; Bohmer, F.D.

    2008-01-01

    Protein-tyrosine phosphatases are tightly controlled by various mechanisms, ranging from differential expression in specific cell types to restricted subcellular localization, limited proteolysis, post-translational modifications affecting intrinsic catalytic activity, ligand binding and

  19. Tyrosine phosphorylation of WW proteins

    Science.gov (United States)

    Reuven, Nina; Shanzer, Matan

    2015-01-01

    A number of key regulatory proteins contain one or two copies of the WW domain known to mediate protein–protein interaction via proline-rich motifs, such as PPxY. The Hippo pathway components take advantage of this module to transduce tumor suppressor signaling. It is becoming evident that tyrosine phosphorylation is a critical regulator of the WW proteins. Here, we review the current knowledge on the involved tyrosine kinases and their roles in regulating the WW proteins. PMID:25627656

  20. Formation of tyrosine isomers in aqueous phenylalanine solutions by gamma irradiation

    International Nuclear Information System (INIS)

    Aflaki, F.; Salahinejad, M.; Roozbehani, A.

    2009-01-01

    Ortho-tyrosine detection method can be used for detection of irradiated protein rich foods. Tyrosine isomers produced by gamma radiation of aqueous phenylalanine solutions at wide dose levels (0.1-50 k Gy) were examined to obtain basic information for o-tyrosine detection method of irradiated foods. Determination of tyrosines produced in aqueous phenylalanine solutions were carried out by high performance liquid chromatography and fluorescence detection. The detection limit of o-tyrosine was 0.01 ppm and the linear range of calibration and the relative standard deviation of analysis was 50 ng and 4-13%, respectively. The amounts of the tyrosines increased with the irradiation level up to 10 k Gy and no further tyrosine formation was observed when the dose level was increased. At a constant dose level, the yield of tyrosines initially increased with the phenylalanine concentration, while with further increase of phenylalanine concentration no effect on increase of tyrosine yield was observed. When the dose rate was varying from 2.3 k Gy/h to 1.2 k Gy/h with a total amount of 10 k Gy in each case, there was no significant effect on tyrosine isomers formation was observed. Also the results showed that tyrosine yield was affected by temperature, p H and the presence of oxygen

  1. Species Richness and Community Structure on a High Latitude Reef: Implications for Conservation and Management

    Directory of Open Access Journals (Sweden)

    Wayne Houston

    2011-07-01

    Full Text Available In spite of the wealth of research on the Great Barrier Reef, few detailed biodiversity assessments of its inshore coral communities have been conducted. Effective conservation and management of marine ecosystems begins with fine-scale biophysical assessments focused on diversity and the architectural species that build the structural framework of the reef. In this study, we investigate key coral diversity and environmental attributes of an inshore reef system surrounding the Keppel Bay Islands near Rockhampton in Central Queensland, Australia, and assess their implications for conservation and management. The Keppels has much higher coral diversity than previously found. The average species richness for the 19 study sites was ~40 with representatives from 68% of the ~244 species previously described for the southern Great Barrier Reef. Using scleractinian coral species richness, taxonomic distinctiveness and coral cover as the main criteria, we found that five out of 19 sites had particularly high conservation value. A further site was also considered to be of relatively high value. Corals at this site were taxonomically distinct from the others (representatives of two families were found here but not at other sites and a wide range of functionally diverse taxa were present. This site was associated with more stressful conditions such as high temperatures and turbidity. Highly diverse coral communities or biodiversity ‘hotspots’ and taxonomically distinct reefs may act as insurance policies for climatic disturbance, much like Noah’s Arks for reefs. While improving water quality and limiting anthropogenic impacts are clearly important management initiatives to improve the long-term outlook for inshore reefs, identifying, mapping and protecting these coastal ‘refugia’ may be the key for ensuring their regeneration against catastrophic climatic disturbance in the meantime.

  2. Impact of local empowerment on conservation practices in a highly developed country

    OpenAIRE

    Engen, Sigrid; Hausner, Vera Helene

    2017-01-01

    Source at http://dx.doi.org/10.1111/conl.12369 Community-based conservation, where local decision makers are responsible for balancing conservation and development, is often preferred to exclusion- ary conservation that prioritizes use-limitation through strict regulation. Un- raveling the evidence for conservation impact of different governance regimes is challenging. Focusing on conservation practices before and after a reform can provide an early indication of behaviora...

  3. Genome-Wide Identification and Characterization of Tyrosine Kinases in the Silkworm, Bombyx mori

    Directory of Open Access Journals (Sweden)

    Songzhen He

    2018-03-01

    Full Text Available The tyrosine kinases (TKs are important parts of metazoan signaling pathways and play significant roles in cell growth, development, apoptosis and disease. Genome-wide characterization of TKs has been conducted in many metazoans, however, systematic information about this family in Lepidoptera is still lacking. We retrieved 33 TK-encoding genes in silkworm and classified them into 25 subfamilies by sequence analysis, without members in AXL, FRK, PDGFR, STYK1 and TIE subfamilies. Although domain sequences in each subfamily are conserved, TKs in vertebrates tend to be remarkably conserved and stable. Our results of phylogenetic analysis supported the previous conclusion for the second major expansion of TK family. Gene-Ontology (GO analysis revealed that a higher proportion of BmTKs played roles in binding, catalysis, signal transduction, metabolism, biological regulation and response to stimulus, compared to all silkworm genes annotated in GO. Moreover, the expression profile analysis of BmTKs among multiple tissues and developmental stages demonstrated that many genes exhibited stage-specific and/or sex-related expression during embryogenesis, molting and metamorphosis, and that 8 BmTKs presented tissue-specific high expression. Our study provides systematic description of silkworm tyrosine kinases, and may also provide further insights into metazoan TKs and assist future studies addressing their functions.

  4. Use of ancient sedimentary DNA as a novel conservation tool for high-altitude tropical biodiversity.

    Science.gov (United States)

    Boessenkool, Sanne; McGlynn, Gayle; Epp, Laura S; Taylor, David; Pimentel, Manuel; Gizaw, Abel; Nemomissa, Sileshi; Brochmann, Christian; Popp, Magnus

    2014-04-01

    Conservation of biodiversity may in the future increasingly depend upon the availability of scientific information to set suitable restoration targets. In traditional paleoecology, sediment-based pollen provides a means to define preanthropogenic impact conditions, but problems in establishing the exact provenance and ecologically meaningful levels of taxonomic resolution of the evidence are limiting. We explored the extent to which the use of sedimentary ancient DNA (sedaDNA) may complement pollen data in reconstructing past alpine environments in the tropics. We constructed a record of afro-alpine plants retrieved from DNA preserved in sediment cores from 2 volcanic crater sites in the Albertine Rift, eastern Africa. The record extended well beyond the onset of substantial anthropogenic effects on tropical mountains. To ensure high-quality taxonomic inference from the sedaDNA sequences, we built an extensive DNA reference library covering the majority of the afro-alpine flora, by sequencing DNA from taxonomically verified specimens. Comparisons with pollen records from the same sediment cores showed that plant diversity recovered with sedaDNA improved vegetation reconstructions based on pollen records by revealing both additional taxa and providing increased taxonomic resolution. Furthermore, combining the 2 measures assisted in distinguishing vegetation change at different geographic scales; sedaDNA almost exclusively reflects local vegetation, whereas pollen can potentially originate from a wide area that in highlands in particular can span several ecozones. Our results suggest that sedaDNA may provide information on restoration targets and the nature and magnitude of human-induced environmental changes, including in high conservation priority, biodiversity hotspots, where understanding of preanthropogenic impact (or reference) conditions is highly limited. © 2013 Society for Conservation Biology.

  5. Proteome-wide mapping of the Drosophila acetylome demonstrates a high degree of conservation of lysine acetylation

    DEFF Research Database (Denmark)

    Weinert, Brian T; Wagner, Sebastian A; Horn, Heiko

    2011-01-01

    Posttranslational modification of proteins by acetylation and phosphorylation regulates most cellular processes in living organisms. Surprisingly, the evolutionary conservation of phosphorylated serine and threonine residues is only marginally higher than that of unmodified serines and threonines....... With high-resolution mass spectrometry, we identified 1981 lysine acetylation sites in the proteome of Drosophila melanogaster. We used data sets of experimentally identified acetylation and phosphorylation sites in Drosophila and humans to analyze the evolutionary conservation of these modification sites...... between flies and humans. Site-level conservation analysis revealed that acetylation sites are highly conserved, significantly more so than phosphorylation sites. Furthermore, comparison of lysine conservation in Drosophila and humans with that in nematodes and zebrafish revealed that acetylated lysines...

  6. Raman scattering tensors of tyrosine.

    Science.gov (United States)

    Tsuboi, M; Ezaki, Y; Aida, M; Suzuki, M; Yimit, A; Ushizawa, K; Ueda, T

    1998-01-01

    Polarized Raman scattering measurements have been made of a single crystal of L-tyrosine by the use of a Raman microscope with the 488.0-nm exciting beam from an argon ion laser. The L-tyrosine crystal belongs to the space group P2(1)2(1)2(1) (orthorhombic), and Raman scattering intensities corresponding to the aa, bb, cc, ab and ac components of the crystal Raman tensor have been determined for each prominent Raman band. A similar set of measurements has been made of L-tyrosine-d4, in which four hydrogen atoms on the benzene ring are replaced by deuterium atoms. The effects of NH3-->ND3 and OH-->OD on the Raman spectrum have also been examined. In addition, depolarization ratios of some bands of L-tyrosine in aqueous solutions of pH 13 and pH 1 were examined. For comparison with these experimental results, on the other hand, ab initio molecular orbital calculations have been made of the normal modes of vibration and their associated polarizability oscillations of the L-tyrosine molecule. On the basis of these experimental data and by referring to the results of the calculations, discussions have been presented on the Raman tensors associated to some Raman bands, including those at 829 cm-1 (benzene ring breathing), 642 cm-1 (benzene ring deformation), and 432 cm-1 (C alpha-C beta-C gamma bending).

  7. Low-Intensity Agricultural Landscapes in Transylvania Support High Butterfly Diversity: Implications for Conservation

    Science.gov (United States)

    Loos, Jacqueline; Dorresteijn, Ine; Hanspach, Jan; Fust, Pascal; Rakosy, László; Fischer, Joern

    2014-01-01

    European farmland biodiversity is declining due to land use changes towards agricultural intensification or abandonment. Some Eastern European farming systems have sustained traditional forms of use, resulting in high levels of biodiversity. However, global markets and international policies now imply rapid and major changes to these systems. To effectively protect farmland biodiversity, understanding landscape features which underpin species diversity is crucial. Focusing on butterflies, we addressed this question for a cultural-historic landscape in Southern Transylvania, Romania. Following a natural experiment, we randomly selected 120 survey sites in farmland, 60 each in grassland and arable land. We surveyed butterfly species richness and abundance by walking transects with four repeats in summer 2012. We analysed species composition using Detrended Correspondence Analysis. We modelled species richness, richness of functional groups, and abundance of selected species in response to topography, woody vegetation cover and heterogeneity at three spatial scales, using generalised linear mixed effects models. Species composition widely overlapped in grassland and arable land. Composition changed along gradients of heterogeneity at local and context scales, and of woody vegetation cover at context and landscape scales. The effect of local heterogeneity on species richness was positive in arable land, but negative in grassland. Plant species richness, and structural and topographic conditions at multiple scales explained species richness, richness of functional groups and species abundances. Our study revealed high conservation value of both grassland and arable land in low-intensity Eastern European farmland. Besides grassland, also heterogeneous arable land provides important habitat for butterflies. While butterfly diversity in arable land benefits from heterogeneity by small-scale structures, grasslands should be protected from fragmentation to provide

  8. High-order conservative discretizations for some cases of the rigid body motion

    International Nuclear Information System (INIS)

    Kozlov, Roman

    2008-01-01

    Modified vector fields can be used to construct high-order structure-preserving numerical integrators for ordinary differential equations. In the present Letter we consider high-order integrators based on the implicit midpoint rule, which conserve quadratic first integrals. It is shown that these integrators are particularly suitable for the rigid body motion with an additional quadratic first integral. In this case high-order integrators preserve all four first integrals of motion. The approach is illustrated on the Lagrange top (a rotationally symmetric rigid body with a fixed point on the symmetry axis). The equations of motion are considered in the space fixed frame because in this frame Lagrange top admits a neat description. The Lagrange top motion includes the spherical pendulum and the planar pendulum, which swings in a vertical plane, as particular cases

  9. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten

    2010-01-01

    in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by tyrosine......Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  10. Traveling waves and conservation laws for highly nonlinear wave equations modeling Hertz chains

    Science.gov (United States)

    Przedborski, Michelle; Anco, Stephen C.

    2017-09-01

    A highly nonlinear, fourth-order wave equation that models the continuum theory of long wavelength pulses in weakly compressed, homogeneous, discrete chains with a general power-law contact interaction is studied. For this wave equation, all solitary wave solutions and all nonlinear periodic wave solutions, along with all conservation laws, are derived. The solutions are explicitly parameterized in terms of the asymptotic value of the wave amplitude in the case of solitary waves and the peak of the wave amplitude in the case of nonlinear periodic waves. All cases in which the solution expressions can be stated in an explicit analytic form using elementary functions are worked out. In these cases, explicit expressions for the total energy and total momentum for all solutions are obtained as well. The derivation of the solutions uses the conservation laws combined with an energy analysis argument to reduce the wave equation directly to a separable first-order differential equation that determines the wave amplitude in terms of the traveling wave variable. This method can be applied more generally to other highly nonlinear wave equations.

  11. Genetics Home Reference: tyrosine hydroxylase deficiency

    Science.gov (United States)

    ... Email Facebook Twitter Home Health Conditions TH deficiency Tyrosine hydroxylase deficiency Printable PDF Open All Close All ... Javascript to view the expand/collapse boxes. Description Tyrosine hydroxylase (TH) deficiency is a disorder that primarily ...

  12. Excellent outcome of immunomodulation or Bruton’s tyrosine kinase inhibition in highly refractory primary cutaneous diffuse large B-cell lymphoma, leg type

    Directory of Open Access Journals (Sweden)

    Eva Gupta

    2015-12-01

    Full Text Available Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT is a rare diffuse large B-cell lymphoma confined to the skin of the legs. The typical presentation is characterized by solitary or multiple growing plaques, usually confined to one leg. We report a case of PCDLBCL-LT of activated B-cell subtype characterized by multiple local relapses in the legs, initially, and systemic relapses about seven years after the diagnosis. Local relapses were sensitive to radiation therapy. Cutaneous and systemic relapses responded well to immunomodulatory therapy with lenalidomide followed by Bruton’s tyrosine kinase inhibition with ibrutinib. Ibrutinib is the only treatment that resulted in long-lasting complete remission. Lenalidomide and especially ibrutinib appear to have a significant activity against this lymphoma and should be incorporated in the treatment of this resistant and aggressive lymphoma. To our knowledge, this is the first case of PCDLBCL-LT reported in the literature exhibiting a complete response to ibrutinib.

  13. Determining the drivers of population structure in a highly urbanized landscape to inform conservation planning.

    Science.gov (United States)

    Thomassen, Henri A; Harrigan, Ryan J; Semple Delaney, Kathleen; Riley, Seth P D; Serieys, Laurel E K; Pease, Katherine; Wayne, Robert K; Smith, Thomas B

    2018-02-01

    Understanding the environmental contributors to population structure is of paramount importance for conservation in urbanized environments. We used spatially explicit models to determine genetic population structure under current and future environmental conditions across a highly fragmented, human-dominated environment in Southern California to assess the effects of natural ecological variation and urbanization. We focused on 7 common species with diverse habitat requirements, home-range sizes, and dispersal abilities. We quantified the relative roles of potential barriers, including natural environmental characteristics and an anthropogenic barrier created by a major highway, in shaping genetic variation. The ability to predict genetic variation in our models differed among species: 11-81% of intraspecific genetic variation was explained by environmental variables. Although an anthropogenically induced barrier (a major highway) severely restricted gene flow and movement at broad scales for some species, genetic variation seemed to be primarily driven by natural environmental heterogeneity at a local level. Our results show how assessing environmentally associated variation for multiple species under current and future climate conditions can help identify priority regions for maximizing population persistence under environmental change in urbanized regions. © 2017 Society for Conservation Biology.

  14. An assessment of high carbon stock and high conservation value approaches to sustainable oil palm cultivation in Gabon

    Science.gov (United States)

    Austin, Kemen G.; Lee, Michelle E.; Clark, Connie; Forester, Brenna R.; Urban, Dean L.; White, Lee; Kasibhatla, Prasad S.; Poulsen, John R.

    2017-01-01

    Industrial-scale oil palm cultivation is rapidly expanding in Gabon, where it has the potential to drive economic growth, but also threatens forest, biodiversity and carbon resources. The Gabonese government is promoting an ambitious agricultural expansion strategy, while simultaneously committing to minimize negative environmental impacts of oil palm agriculture. This study estimates the extent and location of suitable land for oil palm cultivation in Gabon, based on an analysis of recent trends in plantation permitting. We use the resulting suitability map to evaluate two proposed approaches to minimizing negative environmental impacts: a High Carbon Stock (HCS) approach, which emphasizes forest protection and climate change mitigation, and a High Conservation Value (HCV) approach, which focuses on safeguarding biodiversity and ecosystems. We quantify the forest area, carbon stock, and biodiversity resources protected under each approach, using newly developed maps of priority species distributions and forest biomass for Gabon. We find 2.7-3.9 Mha of suitable or moderately suitable land that avoid HCS areas, 4.4 million hectares (Mha) that avoid HCV areas, and 1.2-1.7 Mha that avoid both. This suggests that Gabon’s oil palm production target could likely be met without compromising important ecosystem services, if appropriate safeguards are put in place. Our analysis improves understanding of suitability for oil palm in Gabon, determines how conservation strategies align with national targets for oil palm production, and informs national land use planning.

  15. Synthesis of deuterium and tritium labelled tyrosine

    International Nuclear Information System (INIS)

    Kanska, M.; Drabarek, S.

    1980-01-01

    A new method of synthesis of tyrosine labelled with deuterium and tritium in the aromatic ring has been developed. Deuterated and tritiated tyrosine was obtained by isotope exchange between tyrosine and deuterated or tritiated water at elevated temperature in hydrochloric acid medium using K 2 PtCl 4 as a catalyst. For synthesis of tritiated tyrosine 1 Ci HTO was used; the specific activity of the product was 5 mCi/mMol. (author)

  16. Tyrosine phosphorylation in signal transduction

    International Nuclear Information System (INIS)

    Roberts, T.M.; Kaplan, D.; Morgan, W.; Keller, T.; Mamon, H.; Piwnica-Worms, H.; Druker, B.; Whitman, M.; Morrison, D.; Cohen, B.; Schaffhausen, B.; Cantley, L.; Rapp, U.

    1988-01-01

    Recent work has focused on the elucidation of the mechanisms by which membrane-bound tyrosine kinases transmit signals within the cell. To examine the role of tyrosine phosphorylation the authors have employed the following strategy. First, they have utilized antibodies to phosphotyrosine (anti-P.Tyr) to identify candidate substrates of various tyrosine kinases, such as pp60 c-src , the CSF- receptor, or the platelet-derived growth factor (PDGF) receptor. Second, they have attempted to characterize the biochemical properties of the putative substrates and to determine in what manner these properties are modified by phosphorylation on tyrosine residues. In this endeavor, they are recapitulating the classic biochemical analysis used to study the effect of kinases on metabolism. The final portion of our work consists of using modern molecular biological strategies to clone the genes or cDNAs for the substrates and overproduce the relevant proteins for studies in vitro in defined systems. This paper describes the first and second aspects of this strategy, the identification and characterization of novel substrate molecules

  17. 21 CFR 582.5920 - Tyrosine.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tyrosine. 582.5920 Section 582.5920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS... § 582.5920 Tyrosine. (a) Product. Tyrosine (L- and DL-forms). (b) Conditions of use. This substance is...

  18. Data on electrical energy conservation using high efficiency motors for the confidence bounds using statistical techniques.

    Science.gov (United States)

    Shaikh, Muhammad Mujtaba; Memon, Abdul Jabbar; Hussain, Manzoor

    2016-09-01

    In this article, we describe details of the data used in the research paper "Confidence bounds for energy conservation in electric motors: An economical solution using statistical techniques" [1]. The data presented in this paper is intended to show benefits of high efficiency electric motors over the standard efficiency motors of similar rating in the industrial sector of Pakistan. We explain how the data was collected and then processed by means of formulas to show cost effectiveness of energy efficient motors in terms of three important parameters: annual energy saving, cost saving and payback periods. This data can be further used to construct confidence bounds for the parameters using statistical techniques as described in [1].

  19. Comparative transcriptome analysis within the Lolium/Festuca species complex reveals high sequence conservation

    DEFF Research Database (Denmark)

    Czaban, Adrian; Sharma, Sapna; Byrne, Stephen

    2015-01-01

    species from the Lolium-Festuca complex, ranging from 52,166 to 72,133 transcripts per assembly. We have also predicted a set of proteins and validated it with a high-confidence protein database from three closely related species (H. vulgare, B. distachyon and O. sativa). We have obtained gene family...... clusters for the four species using OrthoMCL and analyzed their inferred phylogenetic relationships. Our results indicate that VRN2 is a candidate gene for differentiating vernalization and non-vernalization types in the Lolium-Festuca complex. Grouping of the gene families based on their BLAST identity...... enabled us to divide ortholog groups into those that are very conserved and those that are more evolutionarily relaxed. The ratio of the non-synonumous to synonymous substitutions enabled us to pinpoint protein sequences evolving in response to positive selection. These proteins may explain some...

  20. Cortical cytasters: a highly conserved developmental trait of Bilateria with similarities to Ctenophora

    Directory of Open Access Journals (Sweden)

    Salinas-Saavedra Miguel

    2011-12-01

    Full Text Available Abstract Background Cytasters (cytoplasmic asters are centriole-based nucleation centers of microtubule polymerization that are observable in large numbers in the cortical cytoplasm of the egg and zygote of bilaterian organisms. In both protostome and deuterostome taxa, cytasters have been described to develop during oogenesis from vesicles of nuclear membrane that move to the cortical cytoplasm. They become associated with several cytoplasmic components, and participate in the reorganization of cortical cytoplasm after fertilization, patterning the antero-posterior and dorso-ventral body axes. Presentation of the hypothesis The specific resemblances in the development of cytasters in both protostome and deuterostome taxa suggest that an independent evolutionary origin is unlikely. An assessment of published data confirms that cytasters are present in several protostome and deuterostome phyla, but are absent in the non-bilaterian phyla Cnidaria and Ctenophora. We hypothesize that cytasters evolved in the lineage leading to Bilateria and were already present in the most recent common ancestor shared by protostomes and deuterostomes. Thus, cytasters would be an ancient and highly conserved trait that is homologous across the different bilaterian phyla. The alternative possibility is homoplasy, that is cytasters have evolved independently in different lineages of Bilateria. Testing the hypothesis So far, available published information shows that appropriate observations have been made in eight different bilaterian phyla. All of them present cytasters. This is consistent with the hypothesis of homology and conservation. However, there are several important groups for which there are no currently available data. The hypothesis of homology predicts that cytasters should be present in these groups. Increasing the taxonomic sample using modern techniques uniformly will test for evolutionary patterns supporting homology, homoplasy, or secondary loss of

  1. A highly conserved amino acid in VP1 regulates maturation of enterovirus 71.

    Directory of Open Access Journals (Sweden)

    Yong-Xin Zhang

    2017-09-01

    Full Text Available Enterovirus 71 (EV71 is the major causative agent of hand, foot and mouth disease (HFMD in children, causing severe clinical outcomes and even death. Here, we report an important role of the highly conserved alanine residue at position 107 in the capsid protein VP1 (VP1A107 in the efficient replication of EV71. Substitutional mutations of VP1A107 significantly diminish viral growth kinetics without significant effect on viral entry, expression of viral genes and viral production. The results of mechanistic studies reveal that VP1A107 regulates the efficient cleavage of the VP0 precursor during EV71 assembly, which is required, in the next round of infection, for the transformation of the mature virion (160S into an intermediate or A-particle (135S, a key step of virus uncoating. Furthermore, the results of molecular dynamic simulations and hydrogen-bond networks analysis of VP1A107 suggest that flexibility of the VP1 BC loop or the region surrounding the VP1107 residue directly correlates with viral infectivity. It is possible that sufficient flexibility of the region surrounding the VP1107 residue favors VP0 conformational change that is required for the efficient cleavage of VP0 as well as subsequent viral uncoating and viral replication. Taken together, our data reveal the structural role of the highly conserved VP1A107 in regulating EV71 maturation. Characterization of this novel determinant of EV71 virulence would promote the study on pathogenesis of Enteroviruses.

  2. CpG methylation differences between neurons and glia are highly conserved from mouse to human.

    Science.gov (United States)

    Kessler, Noah J; Van Baak, Timothy E; Baker, Maria S; Laritsky, Eleonora; Coarfa, Cristian; Waterland, Robert A

    2016-01-15

    Understanding epigenetic differences that distinguish neurons and glia is of fundamental importance to the nascent field of neuroepigenetics. A recent study used genome-wide bisulfite sequencing to survey differences in DNA methylation between these two cell types, in both humans and mice. That study minimized the importance of cell type-specific differences in CpG methylation, claiming these are restricted to localized genomic regions, and instead emphasized that widespread and highly conserved differences in non-CpG methylation distinguish neurons and glia. We reanalyzed the data from that study and came to markedly different conclusions. In particular, we found widespread cell type-specific differences in CpG methylation, with a genome-wide tendency for neuronal CpG-hypermethylation punctuated by regions of glia-specific hypermethylation. Alarmingly, our analysis indicated that the majority of genes identified by the primary study as exhibiting cell type-specific CpG methylation differences were misclassified. To verify the accuracy of our analysis, we isolated neuronal and glial DNA from mouse cortex and performed quantitative bisulfite pyrosequencing at nine loci. The pyrosequencing results corroborated our analysis, without exception. Most interestingly, we found that gene-associated neuron vs. glia CpG methylation differences are highly conserved across human and mouse, and are very likely to be functional. In addition to underscoring the importance of independent verification to confirm the conclusions of genome-wide epigenetic analyses, our data indicate that CpG methylation plays a major role in neuroepigenetics, and that the mouse is likely an excellent model in which to study the role of DNA methylation in human neurodevelopment and disease. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Evolutionary conservation of essential and highly expressed genes in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Scharfe Maren

    2010-04-01

    Full Text Available Abstract Background The constant increase in development and spread of bacterial resistance to antibiotics poses a serious threat to human health. New sequencing technologies are now on the horizon that will yield massive increases in our capacity for DNA sequencing and will revolutionize the drug discovery process. Since essential genes are promising novel antibiotic targets, the prediction of gene essentiality based on genomic information has become a major focus. Results In this study we demonstrate that pooled sequencing is applicable for the analysis of sequence variations of strain collections with more than 10 individual isolates. Pooled sequencing of 36 clinical Pseudomonas aeruginosa isolates revealed that essential and highly expressed proteins evolve at lower rates, whereas extracellular proteins evolve at higher rates. We furthermore refined the list of experimentally essential P. aeruginosa genes, and identified 980 genes that show no sequence variation at all. Among the conserved nonessential genes we found several that are involved in regulation, motility and virulence, indicating that they represent factors of evolutionary importance for the lifestyle of a successful environmental bacterium and opportunistic pathogen. Conclusion The detailed analysis of a comprehensive set of P. aeruginosa genomes in this study clearly disclosed detailed information of the genomic makeup and revealed a large set of highly conserved genes that play an important role for the lifestyle of this microorganism. Sequencing strain collections enables for a detailed and extensive identification of sequence variations as potential bacterial adaptation processes, e.g., during the development of antibiotic resistance in the clinical setting and thus may be the basis to uncover putative targets for novel treatment strategies.

  4. A guide to calculating habitat-quality metrics to inform conservation of highly mobile species

    Science.gov (United States)

    Bieri, Joanna A.; Sample, Christine; Thogmartin, Wayne E.; Diffendorfer, James E.; Earl, Julia E.; Erickson, Richard A.; Federico, Paula; Flockhart, D. T. Tyler; Nicol, Sam; Semmens, Darius J.; Skraber, T.; Wiederholt, Ruscena; Mattsson, Brady J.

    2018-01-01

    Many metrics exist for quantifying the relative value of habitats and pathways used by highly mobile species. Properly selecting and applying such metrics requires substantial background in mathematics and understanding the relevant management arena. To address this multidimensional challenge, we demonstrate and compare three measurements of habitat quality: graph-, occupancy-, and demographic-based metrics. Each metric provides insights into system dynamics, at the expense of increasing amounts and complexity of data and models. Our descriptions and comparisons of diverse habitat-quality metrics provide means for practitioners to overcome the modeling challenges associated with management or conservation of such highly mobile species. Whereas previous guidance for applying habitat-quality metrics has been scattered in diversified tracks of literature, we have brought this information together into an approachable format including accessible descriptions and a modeling case study for a typical example that conservation professionals can adapt for their own decision contexts and focal populations.Considerations for Resource ManagersManagement objectives, proposed actions, data availability and quality, and model assumptions are all relevant considerations when applying and interpreting habitat-quality metrics.Graph-based metrics answer questions related to habitat centrality and connectivity, are suitable for populations with any movement pattern, quantify basic spatial and temporal patterns of occupancy and movement, and require the least data.Occupancy-based metrics answer questions about likelihood of persistence or colonization, are suitable for populations that undergo localized extinctions, quantify spatial and temporal patterns of occupancy and movement, and require a moderate amount of data.Demographic-based metrics answer questions about relative or absolute population size, are suitable for populations with any movement pattern, quantify demographic

  5. Habitat Re-Creation (Ecological Restoration) as a Strategy for Conserving Insect Communities in Highly Fragmented Landscapes.

    Science.gov (United States)

    Shuey, John A

    2013-12-05

    Because of their vast diversity, measured by both numbers of species as well as life history traits, insects defy comprehensive conservation planning. Thus, almost all insect conservation efforts target individual species. However, serious insect conservation requires goals that are set at the faunal level and conservation success requires strategies that conserve intact communities. This task is complicated in agricultural landscapes by high levels of habitat fragmentation and isolation. In many regions, once widespread insect communities are now functionally trapped on islands of ecosystem remnants and subject to a variety of stressors associated with isolation, small population sizes and artificial population fragmentation. In fragmented landscapes ecological restoration can be an effective strategy for reducing localized insect extinction rates, but insects are seldom included in restoration design criteria. It is possible to incorporate a few simple conservation criteria into restoration designs that enhance impacts to entire insect communities. Restoration can be used as a strategy to address fragmentation threats to isolated insect communities if insect communities are incorporated at the onset of restoration planning. Fully incorporating insect communities into restoration designs may increase the cost of restoration two- to three-fold, but the benefits to biodiversity conservation and the ecological services provided by intact insect communities justify the cost.

  6. Butterflies of the high altitude Atacama Desert: habitat use and conservation

    Directory of Open Access Journals (Sweden)

    Emma eDespland

    2014-09-01

    Full Text Available The butterfly fauna of the high-altitude desert of Northern Chile, though depauperate, shows high endemism, is poorly known and is of considerable conservation concern. This study surveys butterflies along the Andean slope between 2400 and 500 m asl (prepuna, puna and Andean steppe habitats as well as in high and low altitude wetlands and in the neoriparian vegetation of agricultural sites. We also include historical sightings from museum records. We compare abundances between altitudes, between natural and impacted sites, as well as between two sampling years with different precipitation regimes. The results confirm high altitudinal turnover and show greatest similarity between wetland and slope faunas at similar altitudes. Results also underscore vulnerability to weather fluctuations, particularly in the more arid low-altitude sites, where abundances were much lower in the low precipitation sampling season and several species were not observed at all. Finally, we show that some species have shifted to the neoriparian vegetation of the agricultural landscape, whereas others were only observed in less impacted habitats dominated by native plants. These results suggest that acclimation to novel habitats depends on larval host plant use. The traditional agricultural environment can provide habitat for many, but not all, native butterfly species, but an estimation of the value of these habitats requires better understanding of butterfly life-history strategies and relationships with host plants.

  7. Cosmetic results in early stage breast cancer patients with high-dose brachytherapy after conservative surgery

    International Nuclear Information System (INIS)

    Torres, Felipe; Pineda, Beatriz E

    2004-01-01

    Purpose: to reveal cosmetic results in patients at early stages of low risk breast cancer treated with partial accelerated radiotherapy using high dose rate brachytherapy. Methods and materials: from March 2001 to July 2003,14 stages l and ll breast cancer patients were treated at the Colombian national cancer institute in Bogota with conservative surgery and radiotherapy upon the tumor bed (partial accelerated radiotherapy), using interstitial implants with iridium 192 (high dose rate brachytherapy) with a dose of 32 Gys, over 4 days, at 8 fractions twice a day. Results: with an average follow up of 17.7 months, good cosmetic results were found among 71.4 % of patients and excellent results among 14.3% of patients, furthermore none of the patients neither local nor regional or distant relapses. Conclusion: among patients who suffer from breast cancer at early stages, it showed is possible to apply partial accelerated radiotherapy upon the tumor bed with high doses over 4 days with good to excellent cosmetic results

  8. DETECTION AND PURIFICATION OF TYROSINE-SULFATED PROTEINS USING A NOVEL ANTI-SULFOTYROSINE MONOCLONAL ANTIBODY*

    Science.gov (United States)

    Hoffhines, Adam J.; Damoc, Eugen; Bridges, Kristie G.; Leary, Julie A.; Moore, Kevin L.

    2006-01-01

    Protein-tyrosine O-sulfation is a post-translational modification mediated by one of two Golgi tyrosylprotein sulfotransferases (TPST-1 & TPST-2) that catalyze the transfer of sulfate to tyrosine residues in secreted and transmembrane proteins. Tyrosine sulfation plays a role in protein-protein interactions in several well-defined systems. Although dozens of tyrosine-sulfated proteins are known, many more are likely to exist and await description. Advancing our understanding of the importance of tyrosine sulfation in biological systems requires the development of new tools for the detection and study of tyrosine-sulfated proteins. We have developed a novel anti-sulfotyrosine monoclonal antibody, called PSG2, that binds with high affinity and exquisite specificity to sulfotyrosine residues in peptides and proteins independent of sequence context. We show that it can detect tyrosinesulfated proteins in complex biological samples and can be used as a probe to assess the role of tyrosine sulfation in protein function. We also demonstrate the utility of PSG2 in the purification of tyrosine-sulfated proteins from crude tissue samples. Finally, Western blot analysis using PSG2 indicates that certain sperm/epididymal proteins are undersulfated in Tpst2−/− mice. This indicates that TPST-1 and TPST-2 have distinct macromolecular substrate specificities and provides clues as to the molecular mechanism of the infertility of Tpst2−/− males. PSG2 should be widely applicable for identification of tyrosine-sulfated proteins in other systems and organisms. PMID:17046811

  9. Swertia chirayta, a Threatened High-Value Medicinal Herb: Microhabitats and Conservation Challenges in Sikkim Himalaya, India

    Directory of Open Access Journals (Sweden)

    Bharat Kumar Pradhan

    2015-11-01

    Full Text Available Assessing the impact of threats, identifying favorable growing conditions, and predicting future population scenarios are vital for the conservation and management of threatened species. This study investigated the availability, microhabitat characteristics, threat status, and community associations of Swertia chirayta, a highly threatened Himalayan medicinal herb, in 22 populations in Sikkim, India, using the vertical belt transect method. Of the 14 microhabitats identified, open grassy slope emerged as the most favorable and wet grassy slope as the least favorable for S. chirayta. The species was dominant in 8 of the 10 major plant communities identified. Among 9 major types of disturbance identified, human movement and collection of non-timber forest products appeared as the biggest threats to S. chirayta. Disturbances significantly affected the availability of the species. S. chirayta, though under high anthropogenic threat, maintains high microhabitat pliability, which is vital for its conservation and management, provided immediate conservation measures are taken.

  10. Evaluation of highly conserved hsp65-specific nested PCR primers for diagnosing Mycobacterium tuberculosis.

    Science.gov (United States)

    Priyadarshini, P; Tiwari, K; Das, A; Kumar, D; Mishra, M N; Desikan, P; Nath, G

    2017-02-01

    To evaluate the sensitivity and specificity of a new nested set of primers designed for the detection of Mycobacterium tuberculosis complex targeting a highly conserved heat shock protein gene (hsp65). The nested primers were designed using multiple sequence alignment assuming the nucleotide sequence of the M. tuberculosis H37Rv hsp65 genome as base. Multidrug-resistant Mycobacterium species along with other non-mycobacterial and fungal species were included to evaluate the specificity of M. tuberculosis hsp65 gene-specific primers. The sensitivity of the primers was determined using serial 10-fold dilutions, and was 100% as shown by the bands in the case of M. tuberculosis complex. None of the other non M. tuberculosis complex bacterial and fungal species yielded any band on nested polymerase chain reaction (PCR). The first round of amplification could amplify 0.3 ng of the template DNA, while nested PCR could detect 0.3 pg. The present hsp65-specific primers have been observed to be sensitive, specific and cost-effective, without requiring interpretation of biochemical tests, real-time PCR, sequencing or high-performance liquid chromatography. These primer sets do not have the drawbacks associated with those protocols that target insertion sequence 6110, 16S rDNA, rpoB, recA and MPT 64.

  11. Isothiazolidinone (IZD) as a phosphoryl mimetic in inhibitors of the Yersinia pestis protein tyrosine phosphatase YopH

    International Nuclear Information System (INIS)

    Kim, Sung-Eun; Bahta, Medhanit; Lountos, George T.; Ulrich, Robert G.; Burke, Terrence R. Jr; Waugh, David S.

    2011-01-01

    The first X-ray crystal structure of the Y. pestis protein tyrosine phosphatase YopH in complex with an isothiazolidinone-based lead-fragment compound is reported. Isothiazolidinone (IZD) heterocycles can act as effective components of protein tyrosine phosphatase (PTP) inhibitors by simultaneously replicating the binding interactions of both a phosphoryl group and a highly conserved water molecule, as exemplified by the structures of several PTP1B–inhibitor complexes. In the first unambiguous demonstration of IZD interactions with a PTP other than PTP1B, it is shown by X-ray crystallography that the IZD motif binds within the catalytic site of the Yersinia pestis PTP YopH by similarly displacing a highly conserved water molecule. It is also shown that IZD-based bidentate ligands can inhibit YopH in a nonpromiscuous fashion at low micromolar concentrations. Hence, the IZD moiety may represent a useful starting point for the development of YopH inhibitors

  12. A highly conserved basidiomycete peptide synthetase produces a trimeric hydroxamate siderophore.

    Science.gov (United States)

    Brandenburger, Eileen; Gressler, Markus; Leonhardt, Robin; Lackner, Gerald; Habel, Andreas; Hertweck, Christian; Brock, Matthias; Hoffmeister, Dirk

    2017-08-25

    The model white-rot basidiomycete Ceriporiopsis ( Gelatoporia ) subvermispora B encodes putative natural product biosynthesis genes. Among them is the gene for the seven-domain nonribosomal peptide synthetase CsNPS2. It is a member of the as-yet uncharacterized fungal type VI siderophore synthetase family which is highly conserved and widely distributed among the basidiomycetes. These enzymes include only one adenylation (A) domain, i.e., one complete peptide synthetase module and two thiolation/condensation (T-C) di-domain partial modules which, together, constitute an AT 1 C 1 T 2 C 2 T 3 C 3 domain setup. The full-length CsNPS2 enzyme (274.5 kDa) was heterologously produced as polyhistidine fusion in Aspergillus niger as soluble and active protein. N 5 -acetyl- N 5 -hydroxy-l-ornithine (l-AHO) and N 5 - cis -anhydromevalonyl- N 5 -hydroxy-l-ornithine (l-AMHO) were accepted as substrates, as assessed in vitro using the substrate-dependent [ 32 P]ATP-pyrophosphate radioisotope exchange assay. Full-length holo -CsNPS2 catalyzed amide bond formation between three l-AHO molecules to release the linear l-AHO trimer, called basidioferrin, as product in vitro , which was verified by LC-HRESIMS. Phylogenetic analyses suggest that type VI family siderophore synthetases are widespread in mushrooms and have evolved in a common ancestor of basidiomycetes. Importance : The basidiomycete nonribosomal peptide synthetase CsNPS2 represents a member of a widely distributed but previously uninvestigated class (type VI) of fungal siderophore synthetases. Genes orthologous to CsNPS2 are highly conserved across various phylogenetic clades of the basidiomycetes. Hence, our work serves as a broadly applicable model for siderophore biosynthesis and iron metabolism in higher fungi. Also, our results on the amino acid substrate preference of CsNPS2 supports further understanding of the substrate selectivity of fungal adenylation domains. Methodologically, this report highlights the

  13. Differential Regulation of Receptor Activation and Agonist Selectivity by Highly Conserved Tryptophans in the Nicotinic Acetylcholine Receptor Binding Site

    OpenAIRE

    Williams, Dustin K.; Stokes, Clare; Horenstein, Nicole A.; Papke, Roger L.

    2009-01-01

    We have shown previously that a highly conserved Tyr in the nicotinic acetylcholine receptor (nAChR) ligand-binding domain (LBD) (α7 Tyr188 or α4 Tyr195) differentially regulates the activity of acetylcholine (ACh) and the α7-selective agonist 3-(4-hydroxy,2-methoxybenzylidene)anabaseine (4OH-GTS-21) in α4β2 and α7 nAChR. In this study, we mutated two highly conserved LBD Trp residues in human α7 and α4β2 and expressed the receptors in Xenopus laevis oocytes. α7 Re...

  14. Acacia shrubs respond positively to high severity wildfire: Implications for conservation and fuel hazard management.

    Science.gov (United States)

    Gordon, Christopher E; Price, Owen F; Tasker, Elizabeth M; Denham, Andrew J

    2017-01-01

    High severity wildfires pose threats to human assets, but are also perceived to impact vegetation communities because a small number of species may become dominant immediately after fire. However there are considerable gaps in our knowledge about species-specific responses of plants to different fire severities, and how this influences fuel hazard in the short and long-term. Here we conduct a floristic survey at sites before and two years after a wildfire of unprecedented size and severity in the Warrumbungle National Park (Australia) to explore relationships between post-fire growth of a fire responsive shrub genera (Acacia), total mid-story vegetation cover, fire severity and fuel hazard. We then survey 129 plots surrounding the park to assess relationships between mid-story vegetation cover and time-since-fire. Acacia species richness and cover were 2.3 and 4.3 times greater at plots after than before the fire. However the same common dominant species were present throughout the study. Mid-story vegetation cover was 1.5 times greater after than before the wildfire, and Acacia species contribution to mid-story cover increased from 10 to 40%. Acacia species richness was not affected by fire severity, however strong positive associations were observed between Acacia and total mid-story vegetation cover and severity. Our analysis of mid-story vegetation recovery showed that cover was similarly high between 2 and 30years post-fire, then decreased until 52years. Collectively, our results suggest that Acacia species are extremely resilient to high severity wildfire and drive short to mid-term increases in fuel hazard. Our results are discussed in relation to fire regime management from the twin perspectives of conserving biodiversity and mitigating human losses due to wildfire. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. A dominant EV71-specific CD4+ T cell epitope is highly conserved among human enteroviruses.

    Directory of Open Access Journals (Sweden)

    Ruicheng Wei

    Full Text Available CD4+ T cell-mediated immunity plays a central role in determining the immunopathogenesis of viral infections. However, the role of CD4+ T cells in EV71 infection, which causes hand, foot and mouth disease (HFMD, has yet to be elucidated. We applied a sophisticated method to identify promiscuous CD4+ T cell epitopes contained within the sequence of the EV71 polyprotein. Fifteen epitopes were identified, and three of them are dominant ones. The most dominant epitope is highly conserved among enterovirus species, including HFMD-related coxsackieviruses, HFMD-unrelated echoviruses and polioviruses. Furthermore, the CD4+ T cells specific to the epitope indeed cross-reacted with the homolog of poliovirus 3 Sabin. Our findings imply that CD4+ T cell responses to poliovirus following vaccination, or to other enteroviruses to which individuals may be exposed in early childhood, may have a modulating effect on subsequent CD4+ T cell response to EV71 infection or vaccine.

  16. Comparative analyses reveal high levels of conserved colinearity between the finger millet and rice genomes.

    Science.gov (United States)

    Srinivasachary; Dida, Mathews M; Gale, Mike D; Devos, Katrien M

    2007-08-01

    Finger millet is an allotetraploid (2n = 4x = 36) grass that belongs to the Chloridoideae subfamily. A comparative analysis has been carried out to determine the relationship of the finger millet genome with that of rice. Six of the nine finger millet homoeologous groups corresponded to a single rice chromosome each. Each of the remaining three finger millet groups were orthologous to two rice chromosomes, and in all the three cases one rice chromosome was inserted into the centromeric region of a second rice chromosome to give the finger millet chromosomal configuration. All observed rearrangements were, among the grasses, unique to finger millet and, possibly, the Chloridoideae subfamily. Gene orders between rice and finger millet were highly conserved, with rearrangements being limited largely to single marker transpositions and small putative inversions encompassing at most three markers. Only some 10% of markers mapped to non-syntenic positions in rice and finger millet and the majority of these were located in the distal 14% of chromosome arms, supporting a possible correlation between recombination and sequence evolution as has previously been observed in wheat. A comparison of the organization of finger millet, Panicoideae and Pooideae genomes relative to rice allowed us to infer putative ancestral chromosome configurations in the grasses.

  17. A highly conserved metalloprotease effector enhances virulence in the maize anthracnose fungus Colletotrichum graminicola.

    Science.gov (United States)

    Sanz-Martín, José M; Pacheco-Arjona, José Ramón; Bello-Rico, Víctor; Vargas, Walter A; Monod, Michel; Díaz-Mínguez, José M; Thon, Michael R; Sukno, Serenella A

    2016-09-01

    Colletotrichum graminicola causes maize anthracnose, an agronomically important disease with a worldwide distribution. We have identified a fungalysin metalloprotease (Cgfl) with a role in virulence. Transcriptional profiling experiments and live cell imaging show that Cgfl is specifically expressed during the biotrophic stage of infection. To determine whether Cgfl has a role in virulence, we obtained null mutants lacking Cgfl and performed pathogenicity and live microscopy assays. The appressorium morphology of the null mutants is normal, but they exhibit delayed development during the infection process on maize leaves and roots, showing that Cgfl has a role in virulence. In vitro chitinase activity assays of leaves infected with wild-type and null mutant strains show that, in the absence of Cgfl, maize leaves exhibit increased chitinase activity. Phylogenetic analyses show that Cgfl is highly conserved in fungi. Similarity searches, phylogenetic analysis and transcriptional profiling show that C. graminicola encodes two LysM domain-containing homologues of Ecp6, suggesting that this fungus employs both Cgfl-mediated and LysM protein-mediated strategies to control chitin signalling. © 2015 BSPP and John Wiley & Sons Ltd.

  18. Pig epidermal growth factor precursor contains segments that are highly conserved among species

    DEFF Research Database (Denmark)

    Jørgensen, P E; Jensen, L.G.; Sørensen, B S

    1998-01-01

    segment with that of the human, the rat and the mouse EGF precursors, in order to identify highly conserved domains. The examined part of the precursor contains EGF itself and six so-called EGF-like modules. The overall amino acid identity among the four species is 64%. However, the amino acid identity...... differed from around 30% in some segments to around 70% in others. The highest amino acid identity, 71%, was observed for a 345-aa segment that contains three EGF-like modules and which is homologous to a part of the low-density lipoprotein receptor (LDL receptor). The amino acid identities are 64% for EGF...... itself, and 50-67% for the remaining three EGF-like modules. The segment of the LDL receptor that is homologous to a part of the EGF precursor is important for the function of the LDL receptor, and EGF-like modules seem to be involved in protein-protein interactions in a number of proteins. In conclusion...

  19. Current situation of energy conservation in high energy-consuming industries in Taiwan

    International Nuclear Information System (INIS)

    Chan, D.Y.-L.; Yang, K.-H.; Hsu, C.-H.; Chien, M.-H.; Hong, G.-B.

    2007-01-01

    Growing concern in Taiwan has arisen about energy consumption and its adverse environmental impact. The current situation of energy conservation in high energy-consuming industries in Taiwan, including the iron and steel, chemical, cement, pulp and paper, textiles and electric/electrical industries has been presented. Since the energy consumption of the top 100 energy users (T100) comprised over 50% of total industry energy consumption, focusing energy consumption reduction efforts on T100 energy users can achieve significant results. This study conducted on-site energy audits of 314 firms in Taiwan during 2000-2004, and identified potential electricity savings of 1,022,656 MWH, fuel oil savings of 174,643 kiloliters (KL), steam coal savings of 98,620 ton, and natural gas (NG) savings of 10,430 kilo cubic meters. The total potential energy saving thus was 489,505 KL of crude oil equivalent (KLOE), representing a reduction of 1,447,841 ton in the carbon dioxide emissions, equivalent to the annual carbon dioxide absorption capacity of a 39,131-ha plantation forest

  20. Fourier transform infrared difference spectroscopy of bacteriorhodopsin and its photoproducts regenerated with deuterated tyrosine

    International Nuclear Information System (INIS)

    Dollinger, G.; Eisenstein, L.; Lin, S.L.; Nakanishi, K.; Termini, J.

    1986-01-01

    Fourier transform infrared (FTIR) difference spectroscopy has been used to detect the vibrational modes due to tyrosine residues in the protein that change in position or intensity between light-adapted bacteriorhodopsin (LA) and other species, namely, the K and M intermediates and dark-adapted bacteriorhodopsin (DA). To aid in the identification of the bands that change in these various species, the FTIR spectra of the free amino acids Tyr-d0, Tyr-d2 ( 2 H at positions ortho to OH), and Tyr-d4 ( 2 H at positions ortho and meta to OH) were measured in H 2 O and D 2 O at low and high pH. The characteristic frequencies of the Tyr species obtained in this manner were then used to identify the changes in protonation state of the tyrosine residues in the various bacteriorhodopsin species. The two diagnostically most useful bands were the approximately 1480-cm-1 band of Tyr(OH)-d2 and the approximately 1277-cm-1 band of Tyr(O-)-d0. Mainly by observing the appearance or disappearance of these bands in the difference spectra of pigments incorporating the tyrosine isotopes, it was possible to identify the following: in LA, one tyrosine and one tyrosinate; in the K intermediate, two tyrosines; in the M intermediate, one tyrosine and one tyrosinate; and in DA, two tyrosines. Since these residues were observed in the difference spectra K/LA, M/LA, and DA/LA, they represent the tyrosine or tyrosinate groups that most likely undergo changes in protonation state due to the conversions. These changes are most likely linked to the proton translocation process of bacteriorhodopsin

  1. High precision conformal radiotherapy employing conservative margins in childhood benign and low-grade brain tumours

    International Nuclear Information System (INIS)

    Jalali, Rakesh; Budrukkar, Ashwini; Sarin, Rajiv; Sharma, Dayananda S.

    2005-01-01

    Background and purpose: To report local control and follow up outcome data of high precision conformal radiotherapy in childhood brain tumours. Materials and methods: Between December 1999 and December 2002, 26 children (17 boys and 9 girls, median age 11.5 years) with incompletely excised or recurrent benign and low-grade brain tumours [13 craniopharyngiomas, 11 low-grade gliomas (LGG) and 2 others] were treated with three-dimensional (3D) conformal radiotherapy (CRT) (12 patients) and stereotactic conformal radiotherapy (SCRT) (14 patients). Gross tumour volume (GTV) included neuro-imaging based visible tumour and/or resected tumour bed. Clinical target volume (CTV) consisted of GTV + 5 mm margin and planning target volume (PTV) consisted of additional 5 mm margin for CRT and 2 mm for SCRT. Treatment was delivered with 3-9 conformal fixed fields to a median dose of 54 Gy/30 fractions. Results: The actuarial 2 and 3 year disease free and overall survival was 96 and 100%, respectively (median follow up: 25 months, range 12-47 months). Radiological follow up available in 25 patients revealed complete response in 1, partial regression in 10, stable disease in 13 and progression in 1 patient (within the CTV). One patient with craniopharyngioma on a routine imaging revealed a mild asymptomatic cyst enlargement, which resolved with conservative management. A patient with chiasmatic glioma developed cystic degeneration and hydrocephalus 9 months after SCRT requiring cyst drainage and placement of a ventriculoperitoneal shunt. Conclusion: High-precision conformal techniques delivering irradiation to a computer generated target volume employing 7-10 mm 3D margins beyond the visible tumour and/or resected tumour bed appear to be safe in children with incompletely resected or recurrent benign and low-grade brain tumours, based on these data

  2. The Highly Conserved Proline at Position 438 in Pseudorabies Virus gH Is Important for Regulation of Membrane Fusion

    OpenAIRE

    Schröter, Christina; Klupp, Barbara G.; Fuchs, Walter; Gerhard, Marika; Backovic, Marija; Rey, Felix A.; Mettenleiter, Thomas C.

    2014-01-01

    Membrane fusion in herpesviruses requires viral glycoproteins (g) gB and gH/gL. While gB is considered the actual fusion protein but is nonfusogenic per se, the function of gH/gL remains enigmatic. Crystal structures for different gH homologs are strikingly similar despite only moderate amino acid sequence conservation. A highly conserved sequence motif comprises the residues serine-proline-cysteine corresponding to positions 437 to 439 in pseudorabies virus (PrV) gH. The PrV-gH structure sho...

  3. Evidence for association of the cloned liver growth hormone receptor with a tyrosine kinase

    DEFF Research Database (Denmark)

    Wang, X; Uhler, M D; Billestrup, N

    1992-01-01

    The ability of the cloned liver growth hormone (GH) receptor, when expressed in mammalian cell lines, to copurify with tyrosine kinase activity and be tyrosyl phosphorylated was examined. 125I-human growth hormone-GH receptor complexes isolated from COS-7 cells transiently expressing high levels...... of tyrosine kinase activity with cloned liver GH receptor. The level of phosphorylation of the GH receptor was very low, as compared with the endogenous GH receptor in 3T3-F442A cells, suggesting that tyrosine kinase activity is not intrinsic to the cloned GH receptor but rather resides with a kinase present...... in a variety of cell types. The finding that the level of phosphorylation of GH receptor appears to vary with cell type is consistent with the cloned liver GH receptor being a substrate for an associated tyrosine kinase and with the amount of such a GH receptor-associated tyrosine kinase being cell type-specific....

  4. Interaction between O-GlcNAc modification and tyrosine phosphorylation of prohibitin: implication for a novel binary switch.

    Directory of Open Access Journals (Sweden)

    Sudharsana R Ande

    Full Text Available Prohibitin (PHB or PHB1 is an evolutionarily conserved, multifunctional protein which is present in various cellular compartments including the plasma membrane. However, mechanisms involved in various functions of PHB are not fully explored yet. Here we report for the first time that PHB interacts with O-linked beta-N-acetylglucosamine transferase (O-GlcNAc transferase, OGT and is O-GlcNAc modified; and also undergoes tyrosine phosphorylation in response to insulin. Tyrosine 114 (Tyr114 and tyrosine 259 (Tyr259 in PHB are in the close proximity of potential O-GlcNAc sites serine 121 (Ser121 and threonine 258 (Thr258 respectively. Substitution of Tyr114 and Tyr259 residues in PHB with phenylalanine by site-directed mutagenesis results in reduced tyrosine phosphorylation as well as reduced O-GlcNAc modification of PHB. Surprisingly, this also resulted in enhanced tyrosine phosphorylation and activity of OGT. This is attributed to the presence of similar tyrosine motifs in PHB and OGT. Substitution of Ser121 and Thr258 with alanine and isoleucine respectively resulted in attenuation of O-GlcNAc modification and increased tyrosine phosphorylation of PHB suggesting an association between these two dynamic modifications. Sequence analysis of O-GlcNAc modified proteins having known O-GlcNAc modification site(s or known tyrosine phosphorylation site(s revealed a strong potential association between these two posttranslational modifications in various proteins. We speculate that O-GlcNAc modification and tyrosine phosphorylation of PHB play an important role in tyrosine kinase signaling pathways including insulin, growth factors and immune receptors signaling. In addition, we propose that O-GlcNAc modification and tyrosine phosphorylation is a novel previously unidentified binary switch which may provide new mechanistic insights into cell signaling pathways and is open for direct experimental examination.

  5. Dose-dependent effects of oral tyrosine administration on plasma tyrosine levels and cognition in aging

    NARCIS (Netherlands)

    Rest, van de Ondine; Bloemendaal, Mirjam; Heus, De Rianne; Aarts, Esther

    2017-01-01

    The effects of tyrosine on plasma response and cognition in aging are unknown. We assessed the dose-dependent response to tyrosine administration in older adults in both plasma tyrosine concentrations and working memory performance. In this double blind randomized cross-over trial 17 older adults

  6. Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging

    NARCIS (Netherlands)

    Rest, O. van de; Bloemendaal, M.; Heus, R.A.A. de; Aarts, E.

    2017-01-01

    The effects of tyrosine on plasma response and cognition in aging are unknown. We assessed the dose-dependent response to tyrosine administration in older adults in both plasma tyrosine concentrations and working memory performance. In this double blind randomized cross-over trial 17 older adults

  7. RNA expression in a cartilaginous fish cell line reveals ancient 3′ noncoding regions highly conserved in vertebrates

    Science.gov (United States)

    Forest, David; Nishikawa, Ryuhei; Kobayashi, Hiroshi; Parton, Angela; Bayne, Christopher J.; Barnes, David W.

    2007-01-01

    We have established a cartilaginous fish cell line [Squalus acanthias embryo cell line (SAE)], a mesenchymal stem cell line derived from the embryo of an elasmobranch, the spiny dogfish shark S. acanthias. Elasmobranchs (sharks and rays) first appeared >400 million years ago, and existing species provide useful models for comparative vertebrate cell biology, physiology, and genomics. Comparative vertebrate genomics among evolutionarily distant organisms can provide sequence conservation information that facilitates identification of critical coding and noncoding regions. Although these genomic analyses are informative, experimental verification of functions of genomic sequences depends heavily on cell culture approaches. Using ESTs defining mRNAs derived from the SAE cell line, we identified lengthy and highly conserved gene-specific nucleotide sequences in the noncoding 3′ UTRs of eight genes involved in the regulation of cell growth and proliferation. Conserved noncoding 3′ mRNA regions detected by using the shark nucleotide sequences as a starting point were found in a range of other vertebrate orders, including bony fish, birds, amphibians, and mammals. Nucleotide identity of shark and human in these regions was remarkably well conserved. Our results indicate that highly conserved gene sequences dating from the appearance of jawed vertebrates and representing potential cis-regulatory elements can be identified through the use of cartilaginous fish as a baseline. Because the expression of genes in the SAE cell line was prerequisite for their identification, this cartilaginous fish culture system also provides a physiologically valid tool to test functional hypotheses on the role of these ancient conserved sequences in comparative cell biology. PMID:17227856

  8. Gains of ubiquitylation sites in highly conserved proteins in the human lineage

    Directory of Open Access Journals (Sweden)

    Kim Dong Seon

    2012-11-01

    Full Text Available Abstract Background Post-translational modification of lysine residues of specific proteins by ubiquitin modulates the degradation, localization, and activity of these target proteins. Here, we identified gains of ubiquitylation sites in highly conserved regions of human proteins that occurred during human evolution. Results We analyzed human ubiquitylation site data and multiple alignments of orthologous mammalian proteins including those from humans, primates, other placental mammals, opossum, and platypus. In our analysis, we identified 281 ubiquitylation sites in 252 proteins that first appeared along the human lineage during primate evolution: one protein had four novel sites; four proteins had three sites each; 18 proteins had two sites each; and the remaining 229 proteins had one site each. PML, which is involved in neurodevelopment and neurodegeneration, acquired three sites, two of which have been reported to be involved in the degradation of PML. Thirteen human proteins, including ERCC2 (also known as XPD and NBR1, gained human-specific ubiquitylated lysines after the human-chimpanzee divergence. ERCC2 has a Lys/Gln polymorphism, the derived (major allele of which confers enhanced DNA repair capacity and reduced cancer risk compared with the ancestral (minor allele. NBR1 and eight other proteins that are involved in the human autophagy protein interaction network gained a novel ubiquitylation site. Conclusions The gain of novel ubiquitylation sites could be involved in the evolution of protein degradation and other regulatory networks. Although gains of ubiquitylation sites do not necessarily equate to adaptive evolution, they are useful candidates for molecular functional analyses to identify novel advantageous genetic modifications and innovative phenotypes acquired during human evolution.

  9. High risks of losing genetic diversity in an endemic Mauritian gecko: implications for conservation.

    Directory of Open Access Journals (Sweden)

    Steeves Buckland

    Full Text Available Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko, is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA markers in 13 subpopulations to: (i assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii estimate effective population sizes and migration rates of subpopulations; and (iii examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P. guimbeaui. We identified 18 threatened and 12 viable subpopulations and discuss a range of management options that include translocation of threatened subpopulations to retain maximum allelic diversity, and habitat restoration and assisted migration to decrease genetic erosion and inbreeding for the viable

  10. The existence of High Conservation Value Forest (HCVF in Perum Perhutani KPH Kendal to support Implementation of FSC Certification

    Directory of Open Access Journals (Sweden)

    Sulistyowati Sri

    2018-01-01

    Full Text Available High Conservation Value Forest (HCVF is the identification of High Conservation Values that are important and need to be protected. Under FSC certification mechanism, HCVF becomes one of Principles and Criteria to attain certification. In this study, we identify the existence of HCVF in Perum Perhutani KPH Kendal to support implementation process of FSC certification. Qualitative method was conducted through observation and secondary data from Perum Perhutani KPH Kendal. Data analysis showed through ecolabel certification, Perum Perhutani KPH Kendal has been identified HCVF area covering 2,715.5 hectares consists of HCV 1 until 6. Secondary Natural Forest (HAS Subah and Kaliwungu for Ulolanang and Pagerwunung Nature Reserve buffer zone include as HCV 1.1, conservation area of leopard (Panthera pardus melas and Pangolin (Manis javanica.for HCV 1.2, conservation area of lutung (Trachypiyhecus auratus as endemic species for CITES App I and Critically Endangered species include as HCV 1.3, Goa kiskendo for bats species habitat include as HCV 1.4, regions of interest species for Deer (Cervus timorensis and Kepodang (Oriolus chinensis as HCV 2.3, Germplasm Protection Region/ KPPN area with high biodiversity include as HCV 3, river border area and water springs for HCV 4. While, utilization of firewood, grass for cattle fodder include as HCV 5 and 14 cultural sites include as HCV 6. From monitoring and evaluation of HCVF data, showed that in 2011-2015 the level of diversity for flora and fauna were increased.

  11. The existence of High Conservation Value Forest (HCVF) in Perum Perhutani KPH Kendal to support Implementation of FSC Certification

    Science.gov (United States)

    Sulistyowati, Sri; Hadi, Sudharto P.

    2018-02-01

    High Conservation Value Forest (HCVF) is the identification of High Conservation Values that are important and need to be protected. Under FSC certification mechanism, HCVF becomes one of Principles and Criteria to attain certification. In this study, we identify the existence of HCVF in Perum Perhutani KPH Kendal to support implementation process of FSC certification. Qualitative method was conducted through observation and secondary data from Perum Perhutani KPH Kendal. Data analysis showed through ecolabel certification, Perum Perhutani KPH Kendal has been identified HCVF area covering 2,715.5 hectares consists of HCV 1 until 6. Secondary Natural Forest (HAS) Subah and Kaliwungu for Ulolanang and Pagerwunung Nature Reserve buffer zone include as HCV 1.1, conservation area of leopard (Panthera pardus melas) and Pangolin (Manis javanica).for HCV 1.2, conservation area of lutung (Trachypiyhecus auratus) as endemic species for CITES App I and Critically Endangered species include as HCV 1.3, Goa kiskendo for bats species habitat include as HCV 1.4, regions of interest species for Deer (Cervus timorensis) and Kepodang (Oriolus chinensis) as HCV 2.3, Germplasm Protection Region/ KPPN area with high biodiversity include as HCV 3, river border area and water springs for HCV 4. While, utilization of firewood, grass for cattle fodder include as HCV 5 and 14 cultural sites include as HCV 6. From monitoring and evaluation of HCVF data, showed that in 2011-2015 the level of diversity for flora and fauna were increased.

  12. The mechanism of the tyrosine transporter TyrP supports a proton motive tyrosine decarboxylation pathway in Lactobacillus brevis

    NARCIS (Netherlands)

    Wolken, WAM; Lucas, PM; Lonvaud-Funel, A; Lolkema, JS; Wolken, Wout A.M.; Lucas, Patrick M.

    The tyrosine decarboxylase operon of Lactobacillus brevis IOEB9809 contains, adjacent to the tyrosine decarboxylase gene, a gene for TyrP, a putative tyrosine transporter. The two genes potentially form a proton motive tyrosine decarboxylation pathway. The putative tyrosine transporter gene of L.

  13. Anti-tumor activity of high-dose EGFR tyrosine kinase inhibitor and sequential docetaxel in wild type EGFR non-small cell lung cancer cell nude mouse xenografts

    Science.gov (United States)

    Tang, Ning; Zhang, Qianqian; Fang, Shu; Han, Xiao; Wang, Zhehai

    2017-01-01

    Treatment of non-small-cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is still a challenge. This study explored antitumor activity of high-dose icotinib (an EGFR tyrosine kinase inhibitor) plus sequential docetaxel against wild-type EGFR NSCLC cells-generated nude mouse xenografts. Nude mice were subcutaneously injected with wild-type EGFR NSCLC A549 cells and divided into different groups for 3-week treatment. Tumor xenograft volumes were monitored and recorded, and at the end of experiments, tumor xenografts were removed for Western blot and immunohistochemical analyses. Compared to control groups (negative control, regular-dose icotinib [IcoR], high-dose icotinib [IcoH], and docetaxel [DTX]) and regular icotinib dose (60 mg/kg) with docetaxel, treatment of mice with a high-dose (1200 mg/kg) of icotinib plus sequential docetaxel for 3 weeks (IcoH-DTX) had an additive effect on suppression of tumor xenograft size and volume (P Icotinib-containing treatments markedly reduced phosphorylation of EGFR, mitogen activated protein kinase (MAPK), and protein kinase B (Akt), but only the high-dose icotinib-containing treatments showed an additive effect on CD34 inhibition (P icotinib plus docetaxel had a similar effect on mouse weight loss (a common way to measure adverse reactions in mice), compared to the other treatment combinations. The study indicate that the high dose of icotinib plus sequential docetaxel (IcoH-DTX) have an additive effect on suppressing the growth of wild-type EGFR NSCLC cell nude mouse xenografts, possibly through microvessel density reduction. Future clinical trials are needed to confirm the findings of this study. PMID:27852073

  14. Pervanadate induces Mammalian Ste20 Kinase 3 (MST3) tyrosine phosphorylation but not activation.

    Science.gov (United States)

    Kan, Wei-Chih; Lu, Te-Ling; Ling, Pin; Lee, Te-Hsiu; Cho, Chien-Yu; Huang, Chi-Ying F; Jeng, Wen-Yih; Weng, Yui-Ping; Chiang, Chun-Yen; Wu, Jin Bin; Lu, Te-Jung

    2016-07-01

    The yeast Ste20 (sterile) protein kinase, which is a serine/threonine kinase, responds to the stimulation of the G proteincoupled receptor (GPCR) pheromone receptor. Ste20 protein kinase serves as the critical component that links signaling from the GPCR/G proteins to the mitogen-activated protein kinase (MAPK) cascade in yeast. The yeast Ste20p functions as a MAP kinase kinase kinase kinase (MAP4K) in the pheromone response. Ste20-like kinases are structurally conserved from yeast to mammals. The mechanism by which MAP4K links GPCR to the MAPK pathway is less clearly defined in vertebrates. In addition to MAP4K, the tyrosine kinase cascade bridges G proteins and the MAPK pathway in vertebrate cells. Mammalian Ste20 Kinase 3 (MST3) has been categorized into the Ste20 family and has been reported to function in the regulation of cell polarity and migration. However, whether MST3 tyrosine phosphorylation regulates diverse signaling pathways is unknown. In this study, the tyrosine phosphatase inhibitor pervanadate was found to induce MST3 tyrosine phosphorylation in intact cells, and the activity of tyrosine-phosphorylated MST3 was measured. This tyrosine-directed phosphorylation was independent of MST3 activity. Parameters including protein conformation, Triton concentration and ionic concentration influenced the sensitivity of MST3 activity. Taken together, our data suggests that the serine/threonine kinase MST3 undergoes tyrosinedirected phosphorylation. The tyrosine-phosphorylated MST3 may create a docking site for the structurally conserved SH2/SH3 (Src Homology 2 and 3) domains within the Src oncoprotein. The unusual tyrosinephosphorylated MST3 may recruit MST3 to various signaling components. Copyright © 2016. Published by Elsevier Inc.

  15. High-frequency ultrasound for intraoperative margin assessments in breast conservation surgery: a feasibility study

    International Nuclear Information System (INIS)

    Doyle, Timothy E; Neumayer, Leigh A; Factor, Rachel E; Ellefson, Christina L; Sorensen, Kristina M; Ambrose, Brady J; Goodrich, Jeffrey B; Hart, Vern P; Jensen, Scott C; Patel, Hemang

    2011-01-01

    In addition to breast imaging, ultrasound offers the potential for characterizing and distinguishing between benign and malignant breast tissues due to their different microstructures and material properties. The aim of this study was to determine if high-frequency ultrasound (20-80 MHz) can provide pathology sensitive measurements for the ex vivo detection of cancer in margins during breast conservation surgery. Ultrasonic tests were performed on resected margins and other tissues obtained from 17 patients, resulting in 34 specimens that were classified into 15 pathology categories. Pulse-echo and through-transmission measurements were acquired from a total of 57 sites on the specimens using two single-element 50-MHz transducers. Ultrasonic attenuation and sound speed were obtained from time-domain waveforms. The waveforms were further processed with fast Fourier transforms to provide ultrasonic spectra and cepstra. The ultrasonic measurements and pathology types were analyzed for correlations. The specimens were additionally re-classified into five pathology types to determine specificity and sensitivity values. The density of peaks in the ultrasonic spectra, a measure of spectral structure, showed significantly higher values for carcinomas and precancerous pathologies such as atypical ductal hyperplasia than for normal tissue. The slopes of the cepstra for non-malignant pathologies displayed significantly greater values that differentiated them from the normal and malignant tissues. The attenuation coefficients were sensitive to fat necrosis, fibroadenoma, and invasive lobular carcinoma. Specificities and sensitivities for differentiating pathologies from normal tissue were 100% and 86% for lobular carcinomas, 100% and 74% for ductal carcinomas, 80% and 82% for benign pathologies, and 80% and 100% for fat necrosis and adenomas. Specificities and sensitivities were also determined for differentiating each pathology type from the other four using a multivariate

  16. High-frequency ultrasound for intraoperative margin assessments in breast conservation surgery: a feasibility study

    Directory of Open Access Journals (Sweden)

    Hart Vern P

    2011-10-01

    Full Text Available Abstract Background In addition to breast imaging, ultrasound offers the potential for characterizing and distinguishing between benign and malignant breast tissues due to their different microstructures and material properties. The aim of this study was to determine if high-frequency ultrasound (20-80 MHz can provide pathology sensitive measurements for the ex vivo detection of cancer in margins during breast conservation surgery. Methods Ultrasonic tests were performed on resected margins and other tissues obtained from 17 patients, resulting in 34 specimens that were classified into 15 pathology categories. Pulse-echo and through-transmission measurements were acquired from a total of 57 sites on the specimens using two single-element 50-MHz transducers. Ultrasonic attenuation and sound speed were obtained from time-domain waveforms. The waveforms were further processed with fast Fourier transforms to provide ultrasonic spectra and cepstra. The ultrasonic measurements and pathology types were analyzed for correlations. The specimens were additionally re-classified into five pathology types to determine specificity and sensitivity values. Results The density of peaks in the ultrasonic spectra, a measure of spectral structure, showed significantly higher values for carcinomas and precancerous pathologies such as atypical ductal hyperplasia than for normal tissue. The slopes of the cepstra for non-malignant pathologies displayed significantly greater values that differentiated them from the normal and malignant tissues. The attenuation coefficients were sensitive to fat necrosis, fibroadenoma, and invasive lobular carcinoma. Specificities and sensitivities for differentiating pathologies from normal tissue were 100% and 86% for lobular carcinomas, 100% and 74% for ductal carcinomas, 80% and 82% for benign pathologies, and 80% and 100% for fat necrosis and adenomas. Specificities and sensitivities were also determined for differentiating each

  17. Geometrid moth assemblages reflect high conservation value of naturally regenerated secondary forests in temperate China

    NARCIS (Netherlands)

    Zou, Yi; Sang, Weiguo; Warren-Thomas, Eleanor; Axmacher, Jan Christoph

    2016-01-01

    The widespread destruction of mature forests in China has led to massive ecological degradation, counteracted in recent decades by substantial efforts to promote forest plantations and protect secondary forest ecosystems. The value of the resulting forests for biodiversity conservation is widely

  18. Liberals, Conservatives and Romantic Nationalists in Interwar Education Policy in Greece: "The High Mountains" Episode

    Science.gov (United States)

    Athanasiades, Harris

    2015-01-01

    Greek historiography of interwar education policy unproblematically accepts the assumption that the bone of contention between the "Liberal demoticists" and the "Conservative purists" was the language issue; particularly whether "demotic" or "katharevousa" should be the language of instruction in schooling.…

  19. Gene co-regulation is highly conserved in the evolution of eukaryotes and prokaryotes.

    NARCIS (Netherlands)

    Snel, B.; Noort, V. van; Huynen, M.A.

    2004-01-01

    Differences between species have been suggested to largely reside in the network of connections among the genes. Nevertheless, the rate at which these connections evolve has not been properly quantified. Here, we measure the extent to which co-regulation between pairs of genes is conserved over

  20. Androgen receptor status is highly conserved during tumor progression of breast cancer.

    Science.gov (United States)

    Grogg, André; Trippel, Mafalda; Pfaltz, Katrin; Lädrach, Claudia; Droeser, Raoul A; Cihoric, Nikola; Salhia, Bodour; Zweifel, Martin; Tapia, Coya

    2015-11-09

    highly conserved during tumor progression and a change only occurs in a small fraction (4.1 %). Our study supports the notion that targeting AR could be effective for many BC patients and that re-testing of AR status in formerly negative or mixed type BC's is recommended.

  1. Androgen receptor status is highly conserved during tumor progression of breast cancer

    International Nuclear Information System (INIS)

    Grogg, André; Trippel, Mafalda; Pfaltz, Katrin; Lädrach, Claudia; Droeser, Raoul A.; Cihoric, Nikola; Salhia, Bodour; Zweifel, Martin; Tapia, Coya

    2015-01-01

    With the advent of new and more efficient anti-androgen drugs targeting androgen receptor (AR) in breast cancer (BC) is becoming an increasingly important area of investigation. This would potentially be most useful in triple negative BC (TNBC), where better therapies are still needed. The assessment of AR status is generally performed on the primary tumor even if the tumor has already metastasized. Very little is known regarding discrepancies of AR status during tumor progression. To determine the prevalence of AR positivity, with emphasis on TNBCs, and to investigate AR status during tumor progression, we evaluated a large series of primary BCs and matching metastases and recurrences. AR status was performed on 356 primary BCs, 135 matching metastases, and 12 recurrences using a next-generation Tissue Microarray (ngTMA). A commercially available AR antibody was used to determine AR-status by immunohistochemistry. AR positivity was defined as any nuclear staining in tumor cells ≥1 %. AR expression was correlated with pathological tumor features of the primary tumor. Additionally, the concordance rate of AR expression between the different tumor sites was determined. AR status was positive in: 87 % (307/353) of primary tumors, 86.1 % (105/122) of metastases, and in 66.7 % (8/12) of recurrences. TNBC tested positive in 11.4 %, (4/35) of BCs. A discrepant result was seen in 4.3 % (5/117) of primary BC and matching lymph node (LN) metastases. Three AR negative primary BCs were positive in the matching LN metastasis, representing 17.6 % of all negative BCs with lymph node metastases (3/17). Two AR positive primary BCs were negative in the matching LN metastasis, representing 2.0 % of all AR positive BCs with LN metastases (2/100). No discrepancies were seen between primary BC and distant metastases or recurrence (n = 17). Most primary (87 %) and metastasized (86.1 %) BCs are AR positive including a significant fraction of TNBCs (11.4 %). Further, AR status is highly

  2. Conservation hotspots for the turtles on the high seas of the Atlantic Ocean.

    Directory of Open Access Journals (Sweden)

    Hsiang-Wen Huang

    Full Text Available Understanding the distribution of bycaught sea turtles could inform conservation strategies and priorities. This research analyses the distribution of turtles caught as longline fisheries bycatch on the high seas of the Atlantic Ocean. This research collected 18,142 bycatch observations and 47.1 million hooks from large-scale Taiwanese longline vessels in the Atlantic Ocean from June 2002 to December 2013. The coverage rates were ranged from 0.48% to 17.54% by year. Seven hundred and sixty-seven turtles were caught, and the major species were leatherback (59.8%, olive ridley (27.1% and loggerhead turtles (8.7%. Most olive ridley (81.7% and loggerhead (82.1% turtles were hooked, while the leatherbacks were both hooked (44.0% and entangled (31.8%. Depending on the species, 21.4% to 57.7% were dead when brought onboard. Most of the turtles were caught in tropical areas, especially in the Gulf of Guinea (15°N-10°S, 30°W-10°E, but loggerheads were caught in the south Atlantic Ocean (25°S-35°S, 40°W-10°E and 30°S-40°S, 55°W-45°W. The bycatch rate was the highest at 0.030 per 1000 hooks for leatherbacks in the tropical area. The bycatch rates of olive ridley ranged from 0 to 0.010 per thousand hooks. The loggerhead bycatch rates were higher in the northern and southern Atlantic Ocean and ranged from 0.0128 to 0.0239 per thousand hooks. Due to the characteristics of the Taiwanese deep-set longline fleet, bycatch rates were lower than those of coastal longline fisheries, but mortality rates were higher because of the long hours of operation. Gear and bait modification should be considered to reduce sea turtle bycatch and increase survival rates while reducing the use of shallow hooks would also be helpful.

  3. Conservation hotspots for the turtles on the high seas of the Atlantic Ocean.

    Science.gov (United States)

    Huang, Hsiang-Wen

    2015-01-01

    Understanding the distribution of bycaught sea turtles could inform conservation strategies and priorities. This research analyses the distribution of turtles caught as longline fisheries bycatch on the high seas of the Atlantic Ocean. This research collected 18,142 bycatch observations and 47.1 million hooks from large-scale Taiwanese longline vessels in the Atlantic Ocean from June 2002 to December 2013. The coverage rates were ranged from 0.48% to 17.54% by year. Seven hundred and sixty-seven turtles were caught, and the major species were leatherback (59.8%), olive ridley (27.1%) and loggerhead turtles (8.7%). Most olive ridley (81.7%) and loggerhead (82.1%) turtles were hooked, while the leatherbacks were both hooked (44.0%) and entangled (31.8%). Depending on the species, 21.4% to 57.7% were dead when brought onboard. Most of the turtles were caught in tropical areas, especially in the Gulf of Guinea (15°N-10°S, 30°W-10°E), but loggerheads were caught in the south Atlantic Ocean (25°S-35°S, 40°W-10°E and 30°S-40°S, 55°W-45°W). The bycatch rate was the highest at 0.030 per 1000 hooks for leatherbacks in the tropical area. The bycatch rates of olive ridley ranged from 0 to 0.010 per thousand hooks. The loggerhead bycatch rates were higher in the northern and southern Atlantic Ocean and ranged from 0.0128 to 0.0239 per thousand hooks. Due to the characteristics of the Taiwanese deep-set longline fleet, bycatch rates were lower than those of coastal longline fisheries, but mortality rates were higher because of the long hours of operation. Gear and bait modification should be considered to reduce sea turtle bycatch and increase survival rates while reducing the use of shallow hooks would also be helpful.

  4. Integration of an In Situ MALDI-Based High-Throughput Screening Process: A Case Study with Receptor Tyrosine Kinase c-MET.

    Science.gov (United States)

    Beeman, Katrin; Baumgärtner, Jens; Laubenheimer, Manuel; Hergesell, Karlheinz; Hoffmann, Martin; Pehl, Ulrich; Fischer, Frank; Pieck, Jan-Carsten

    2017-12-01

    Mass spectrometry (MS) is known for its label-free detection of substrates and products from a variety of enzyme reactions. Recent hardware improvements have increased interest in the use of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS for high-throughput drug discovery. Despite interest in this technology, several challenges remain and must be overcome before MALDI-MS can be integrated as an automated "in-line reader" for high-throughput drug discovery. Two such hurdles include in situ sample processing and deposition, as well as integration of MALDI-MS for enzymatic screening assays that usually contain high levels of MS-incompatible components. Here we adapt our c-MET kinase assay to optimize for MALDI-MS compatibility and test its feasibility for compound screening. The pros and cons of the Echo (Labcyte) as a transfer system for in situ MALDI-MS sample preparation are discussed. We demonstrate that this method generates robust data in a 1536-grid format. We use the MALDI-MS to directly measure the ratio of c-MET substrate and phosphorylated product to acquire IC50 curves and demonstrate that the pharmacology is unaffected. The resulting IC50 values correlate well between the common label-based capillary electrophoresis and the label-free MALDI-MS detection method. We predict that label-free MALDI-MS-based high-throughput screening will become increasingly important and more widely used for drug discovery.

  5. Role of tyrosine phosphatase inhibitors in cancer treatment with emphasis on SH2 domain-containing tyrosine phosphatases (SHPs)

    NARCIS (Netherlands)

    Irandoust, Mahban; van den Berg, Timo K.; Kaspers, Gertjan J. L.; Cloos, Jacqueline

    2009-01-01

    Protein tyrosine phosphorylation is one of the key mechanisms involved in signal transduction pathways. This modification is regulated by concerted action of protein tyrosine phosphatases and protein tyrosine kinases. Deregulation of either of these key regulators lead to abnormal cellular

  6. Dietary Tyrosine Benefits Cognitive and Psychomotor Performance During Body Cooling

    National Research Council Canada - National Science Library

    O'Brien, Catherine; Mahoney, Caroline; Tharion, William J; Sils, Ingrid V; Castellani, John W

    2007-01-01

    Supplemental tyrosine is effective at limiting cold-induced decreases in working memory, presumably by augmenting brain catecholamine levels, since tyrosine is a precursor for catecholamine synthesis...

  7. TYROSINE KINASE INHIBITORS AND PREGNANCY

    Directory of Open Access Journals (Sweden)

    Elisabetta Abruzzese

    2014-04-01

    Full Text Available The management of patients with chronic myeloid leukemia (CML during pregnancy has became recently a matter of continuous debate.  The introduction of the Tyrosine Kinase Inhibitors (TKIs in clinical practice has dramatically changed the prognosis of CML patients.  Patients diagnosed in chronic phase can reasonably expect many years of excellent disease control and good quality of life, as well as a normal life expectancy.  This fact has come the necessity to address issues relating to fertility and pregnancy. Physicians are not infrequently being asked for advice regarding the need for, and or the appropriateness of, stopping treatment in order to conceive. In this report we will review the data published in terms of fertility, conception, pregnancy, pregnancy outcome and illness control for all the approved TKIs, as well as suggest how to manage a planned and/or unplanned pregnancy.

  8. Redshift of the purple membrane absorption band and the deprotonation of tyrosine residues at high pH: Origin of the parallel photocycles of trans-bacteriorhodopsin

    OpenAIRE

    Balashov, S. P.; Govindjee, R.; Ebrey, T. G.

    1991-01-01

    At high pH (> 8) the 570 nm absorption band of all-trans bacteriorhodopsin (bR) in purple membrane undergoes a small (1.5 nm) shift to longer wavelengths, which causes a maximal increase in absorption at 615 nm. The pK of the shift is 9.0 in the presence of 167 mM KCl, and its intrinsic pK is ∼8.3. The red shift of the trans-bR absorption spectrum correlates with the appearance of the fast component in the light-induced L to M transition, and absorption increases at 238 and 297 nm which are a...

  9. High Resolution Mapping of Soils and Landforms for the Desert Renewable Energy Conservation Plan (DRECP)

    Science.gov (United States)

    Potter, Christopher S.; Li, Shuang

    2014-01-01

    The Desert Renewable Energy Conservation Plan (DRECP), a major component of California's renewable energy planning efforts, is intended to provide effective protection and conservation of desert ecosystems, while allowing for the sensible development of renewable energy projects. This NASA mapping report was developed to support the DRECP and the Bureau of Land Management (BLM). We outline in this document remote sensing image processing methods to deliver new maps of biological soils crusts, sand dune movements, desert pavements, and sub-surface water sources across the DRECP area. We focused data processing first on the largely unmapped areas most likely to be used for energy developments, such as those within Renewable Energy Study Areas (RESA) and Solar Energy Zones (SEZs). We used imagery (multispectral and radar) mainly from the years 2009-2011.

  10. High-Quality 3d Models and Their Use in a Cultural Heritage Conservation Project

    Science.gov (United States)

    Tucci, G.; Bonora, V.; Conti, A.; Fiorini, L.

    2017-08-01

    Cultural heritage digitization and 3D modelling processes are mainly based on laser scanning and digital photogrammetry techniques to produce complete, detailed and photorealistic three-dimensional surveys: geometric as well as chromatic aspects, in turn testimony of materials, work techniques, state of preservation, etc., are documented using digitization processes. The paper explores the topic of 3D documentation for conservation purposes; it analyses how geomatics contributes in different steps of a restoration process and it presents an overview of different uses of 3D models for the conservation and enhancement of the cultural heritage. The paper reports on the project to digitize the earthenware frieze of the Ospedale del Ceppo in Pistoia (Italy) for 3D documentation, restoration work support, and digital and physical reconstruction and integration purposes. The intent to design an exhibition area suggests new ways to take advantage of 3D data originally acquired for documentation and scientific purposes.

  11. A High-Accuracy Linear Conservative Difference Scheme for Rosenau-RLW Equation

    Directory of Open Access Journals (Sweden)

    Jinsong Hu

    2013-01-01

    Full Text Available We study the initial-boundary value problem for Rosenau-RLW equation. We propose a three-level linear finite difference scheme, which has the theoretical accuracy of Oτ2+h4. The scheme simulates two conservative properties of original problem well. The existence, uniqueness of difference solution, and a priori estimates in infinite norm are obtained. Furthermore, we analyze the convergence and stability of the scheme by energy method. At last, numerical experiments demonstrate the theoretical results.

  12. Hearing sensitivity in context: Conservation implications for a highly vocal endangered species

    OpenAIRE

    Owen, Megan A.; Keating, Jennifer L.; Denes, Samuel K.; Hawk, Kathy; Fiore, Angela; Thatcher, Julie; Becerra, Jennifer; Hall, Suzanne; Swaisgood, Ronald R.

    2016-01-01

    Hearing sensitivity is a fundamental determinant of a species’ vulnerability to anthropogenic noise, however little is known about the hearing capacities of most conservation dependent species. When audiometric data are integrated with other aspects of species’ acoustic ecology, life history, and characteristic habitat topography and soundscape, predictions can be made regarding probable vulnerability to the negative impacts of different types of anthropogenic noise. Here we used an adaptive ...

  13. A protein-tyrosine phosphatase with sequence similarity to the SH2 domain of the protein-tyrosine kinases.

    Science.gov (United States)

    Shen, S H; Bastien, L; Posner, B I; Chrétien, P

    1991-08-22

    The phosphorylation of proteins at tyrosine residues is critical in cellular signal transduction, neoplastic transformation and control of the mitotic cycle. These mechanisms are regulated by the activities of both protein-tyrosine kinases (PTKs) and protein-tyrosine phosphatases (PTPases). As in the PTKs, there are two classes of PTPases: membrane associated, receptor-like enzymes and soluble proteins. Here we report the isolation of a complementary DNA clone encoding a new form of soluble PTPase, PTP1C. The enzyme possesses a large noncatalytic region at the N terminus which unexpectedly contains two adjacent copies of the Src homology region 2 (the SH2 domain) found in various nonreceptor PTKs and other cytoplasmic signalling proteins. As with other SH2 sequences, the SH2 domains of PTP1C formed high-affinity complexes with the activated epidermal growth factor receptor and other phosphotyrosine-containing proteins. These results suggest that the SH2 regions in PTP1C may interact with other cellular components to modulate its own phosphatase activity against interacting substrates. PTPase activity may thus directly link growth factor receptors and other signalling proteins through protein-tyrosine phosphorylation.

  14. Lattice modes of the chirally pure and racemic phases of tyrosine crystals

    Energy Technology Data Exchange (ETDEWEB)

    Belyanchikov, M. A. [Moscow Institute of Physics and Technology (Russian Federation); Gorelik, V. S., E-mail: gorelik@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Gorshunov, B. P. [Moscow Institute of Physics and Technology (Russian Federation); Pyatyshev, A. Yu., E-mail: jb-valensia@mail.ru [Bauman Moscow State Technical University (Russian Federation)

    2017-01-15

    High-Q librational modes have been found to be present in the infrared absorption and Raman spectra of chirally pure L-tyrosine. Such modes can serve as terahertz radiation detectors and generators in chirally pure biostructures.

  15. Innovative Surgical Management of the Synovial Chondromatosis of Temporo-Mandibular Joints: Highly Conservative Surgical Technique.

    Science.gov (United States)

    Ionna, Franco; Amantea, Massimiliano; Mastrangelo, Filiberto; Ballini, Andrea; Maglione, Maria Grazia; Aversa, Corrado; De Cecio, Rossella; Russo, Daniela; Marrelli, Massimo; Tatullo, Marco

    2016-07-01

    Synovial chondromatosis (SC) is an uncommon disease characterized by a benign nodular cartilaginous proliferation arising from the joint synovium, bursae, or tendon sheaths. Although the temporomandibular joint is rarely affected by neoplastic lesions, SC is the most common neoplastic lesion of this joint. The treatment of this disease consists in the extraoral surgery with a wide removal of the lesion; in this study, the authors described a more conservative intraoral surgical approach. Patient with SC of temporomandibular joint typically refer a limitation in the mouth opening, together with a persistent not physiological mandibular protrusion and an appearance of a neoformation located at the right preauricular region: the authors reported 1 scholar patient. After biopsy of the neoformation, confirming the synovial chondromatosis, the patient underwent thus to the surgical excision of the tumor, via authors' conservative transoral approach, to facilitate the enucleation of the neoformation. The mass fully involved the pterygo-maxillary fossa with involvement of the parotid lodge and of the right TMJ: this multifocal extension suggested for a trans-oral surgical procedure, in the light of the suspicion of a possible malignant nature of the neoplasm. Our intraoral conservative approach to surgery is aimed to reduce the presence of unaesthetic scars in preauricular and facial regions, with surgical results undoubtedly comparable to the traditional surgical techniques much more aggressive. Our technique could be a valid, alternative, and safe approach to treat this rare and complex kind of oncological disease.

  16. The Value of 5-Aminolevulinic Acid in Low-grade Gliomas and High-grade Gliomas Lacking Glioblastoma Imaging Features: An Analysis Based on Fluorescence, Magnetic Resonance Imaging, 18F-Fluoroethyl Tyrosine Positron Emission Tomography, and Tumor Molecular Factors.

    Science.gov (United States)

    Jaber, Mohammed; Wölfer, Johannes; Ewelt, Christian; Holling, Markus; Hasselblatt, Martin; Niederstadt, Thomas; Zoubi, Tarek; Weckesser, Matthias; Stummer, Walter

    2016-03-01

    Approximately 20% of grade II and most grade III gliomas fluoresce after 5-aminolevulinic acid (5-ALA) application. Conversely, approximately 30% of nonenhancing gliomas are actually high grade. The aim of this study was to identify preoperative factors (ie, age, enhancement, 18F-fluoroethyl tyrosine positron emission tomography [F-FET PET] uptake ratios) for predicting fluorescence in gliomas without typical glioblastomas imaging features and to determine whether fluorescence will allow prediction of tumor grade or molecular characteristics. Patients harboring gliomas without typical glioblastoma imaging features were given 5-ALA. Fluorescence was recorded intraoperatively, and biopsy specimens collected from fluorescing tissue. World Health Organization (WHO) grade, Ki-67/MIB-1 index, IDH1 (R132H) mutation status, O-methylguanine DNA methyltransferase (MGMT) promoter methylation status, and 1p/19q co-deletion status were assessed. Predictive factors for fluorescence were derived from preoperative magnetic resonance imaging and F-FET PET. Classification and regression tree analysis and receiver-operating-characteristic curves were generated for defining predictors. Of 166 tumors, 82 were diagnosed as WHO grade II, 76 as grade III, and 8 as glioblastomas grade IV. Contrast enhancement, tumor volume, and F-FET PET uptake ratio >1.85 predicted fluorescence. Fluorescence correlated with WHO grade (P fluorescing grade III gliomas was higher than in nonfluorescing tumors, whereas in fluorescing and nonfluorescing grade II tumors, no differences were noted. Age, tumor volume, and F-FET PET uptake are factors predicting 5-ALA-induced fluorescence in gliomas without typical glioblastoma imaging features. Fluorescence was associated with an increased Ki-67/MIB-1 index and high-grade pathology. Whether fluorescence in grade II gliomas identifies a subtype with worse prognosis remains to be determined.

  17. Association between the high soluble fms-like tyrosine kinase-1 to placental growth factor ratio and adverse outcomes in asymptomatic women with early-onset fetal growth restriction.

    Science.gov (United States)

    Shinohara, Satoshi; Uchida, Yuzo; Kasai, Mayuko; Sunami, Rei

    2017-08-01

    To assess whether the high soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) ratio is associated with adverse outcomes (e.g., HELLP syndrome [hemolysis, elevated liver enzymes, and low platelets], severe hypertension uncontrolled by medication, non-reassuring fetal status, placental abruption, pulmonary edema, growth arrest, maternal death, or fetal death) and a shorter duration to delivery in early-onset fetal growth restriction (FGR). Thirty-four women with FGR diagnosed at Women who developed adverse outcomes within a week had a significantly higher sFlt-1/PlGF ratio than did those who did not develop complications. A cutoff value of 86.2 for the sFlt-1/PlGF ratio predicted adverse outcomes, with a sensitivity and specificity of 77.8% and 80.0%, respectively. Moreover, 58.4% of women with an sFlt-1/PlGF ratio ≥86.2 versus 9.1% of those with an sFlt-1/PlGF ratio <86.2 delivered within a week of presentation (p < 0.001). In multivariate analyses, an sFlt-1/PlGF ratio ≥86.2 (adjusted odds ratio 9.52; 95% confidence interval, 1.25-72.8) was associated with adverse maternal and neonatal outcomes. A high sFlt-1/PlGF ratio was associated with adverse outcomes and a shorter duration to delivery in early-onset FGR.

  18. Synthesis of 6-[18F] and 4-[18F]fluoro-L-m-tyrosines via regioselective radiofluorodestannylation

    International Nuclear Information System (INIS)

    Namavari, Mohammad; Satyamurthy, N.; Phelps, M.E.; Barrio, J.R.; California Univ., Los Angeles, CA

    1993-01-01

    The regioselective radiofluorodestannylation of 6-trimethylstannyl-L-m-tyrosine derivative with [ 18 F]F 2 and [ 18 F]acetyl hypofluorite afforded, after acid hydrolysis, 6-[ 18 F]fluoro-L-m-tyrosine in radiochemical yields of 23 and 17%, respectively. Similarly, 4-[ 18 F]fluoro-L-m-tyrosine was synthesized in 11% radiochemical yield from the corresponding 4-trimethylstannyl-L-m-tyrosine derivative using [ 18 F]F 2 . The structural analyses of precursors, intermediates, and the final products (after 18 F decay), were carried out by 1 H, 13 C, 19 F, 119 Sn-NMR and high resolution mass spectroscopy. (author)

  19. Rates and energetics of tyrosine ring flips in yeast iso-2-cytochrome c

    International Nuclear Information System (INIS)

    Nall, B.T.; Zuniga, E.H.

    1990-01-01

    Isotope-edited nuclear magnetic resonance spectroscopy is used to monitor ring flip motion of the five tyrosine side chains in the oxidized and reduced forms of yeast iso-2-cytochrome c. With specifically labeled protein purified from yeast grown on media containing [3,5- 13 C]tyrosine, isotope-edited one-dimensional proton spectra have been collected over a 5-55 degree C temperature range. The spectra allow selective observation of the 10 3,5 tyrosine ring proton resonances and, using a two-site exchange model, allow estimation of the temperature dependence of ring flip rates from motion-induced changes in proton line shapes. For the reduced protein, tyrosines II and IV are in fast exchange throughout the temperature range investigated, or lack resolvable differences in static chemical shifts for the 3,5 ring protons. Tyrosines I, III, and V are in sloe exchange at low temperatures and in fast exchange at high temperatures. Spectral simulations give flip rates for individual tyrosines in a range of one flip per second at low temperatures to thousands of flips per second at high temperatures. Eyring plots show that two of the tyrosines (I and III) have essentially the same activation parameters. Tentative sequence-specific assignments for the tyrosines in reduced iso-2 are suggested by comparison to horse cytochrome c. For oxidized iso-2, five resonances are observed at high temperatures, suggesting flip rates for all five tyrosines sufficient to average static chemical shift differences. At lower temperatures, there is evidence of intermediate and slow flipping for some of the rings

  20. Dielectric analysis of aqueous poly(l-glutamic acid and poly-l-(glutamic acid4, Tyrosine1 solutions at high frequencies from capacitance measurements

    Directory of Open Access Journals (Sweden)

    Jorge Monreal

    2016-12-01

    Full Text Available A new parallel-plate capacitor fixture has been designed and successfully used to measure dielectric loss of polyelectrolyte solutions with volumes as low as droplets of 13–26 μL. It is particularly useful when studying polypeptides that are either high-cost or can be synthesized only in limited quantities. The ease with which the fixture can be used to obtain preliminary dielectric loss data yields savings in time and cost. In this study capacitance measurements were performed in a wide range of frequencies between 1 and 800 MHz using an Agilent 4191RF Impedance Analyzer. Accuracy of measurements was carefully examined through a comparison of measured conductivity of 1M NaCl against Stogryn's equation for conductivity. A 0.3% difference between the experimentally measured and theoretically calculated results has been found, demonstrating the validity of the proposed analysis method.

  1. Processes for the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention generally relates to the field of biotechnology as it applies to the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity. More particularly, the present invention pertains to polypeptides having tyrosine ammonia lyase activity and high...... substrate specificity towards tyrosine, which makes them particularly suitable in the production of p-coumaric acid and other hydroxycinnamic acids. The present invention thus provides processes for the production of p-coumaric acid and other hydroxycinnamic acids employing these polypeptides as well...

  2. The importance of incorporating functional habitats into conservation planning for highly mobile species in dynamic systems.

    Science.gov (United States)

    Webb, Matthew H; Terauds, Aleks; Tulloch, Ayesha; Bell, Phil; Stojanovic, Dejan; Heinsohn, Robert

    2017-10-01

    The distribution of mobile species in dynamic systems can vary greatly over time and space. Estimating their population size and geographic range can be problematic and affect the accuracy of conservation assessments. Scarce data on mobile species and the resources they need can also limit the type of analytical approaches available to derive such estimates. We quantified change in availability and use of key ecological resources required for breeding for a critically endangered nomadic habitat specialist, the Swift Parrot (Lathamus discolor). We compared estimates of occupied habitat derived from dynamic presence-background (i.e., presence-only data) climatic models with estimates derived from dynamic occupancy models that included a direct measure of food availability. We then compared estimates that incorporate fine-resolution spatial data on the availability of key ecological resources (i.e., functional habitats) with more common approaches that focus on broader climatic suitability or vegetation cover (due to the absence of fine-resolution data). The occupancy models produced significantly (P increase or decrease in the area of one functional habitat (foraging or nesting) did not necessarily correspond to an increase or decrease in the other. Thus, an increase in the extent of occupied area may not equate to improved habitat quality or function. We argue these patterns are typical for mobile resource specialists but often go unnoticed because of limited data over relevant spatial and temporal scales and lack of spatial data on the availability of key resources. Understanding changes in the relative availability of functional habitats is crucial to informing conservation planning and accurately assessing extinction risk for mobile resource specialists. © 2017 Society for Conservation Biology.

  3. Crystal structure of AFV3-109, a highly conserved protein from crenarchaeal viruses

    Directory of Open Access Journals (Sweden)

    Quevillon-Cheruel Sophie

    2007-01-01

    Full Text Available Abstract The extraordinary morphologies of viruses infecting hyperthermophilic archaea clearly distinguish them from bacterial and eukaryotic viruses. Moreover, their genomes code for proteins that to a large extend have no related sequences in the extent databases. However, a small pool of genes is shared by overlapping subsets of these viruses, and the most conserved gene, exemplified by the ORF109 of the Acidianus Filamentous Virus 3, AFV3, is present on genomes of members of three viral familes, the Lipothrixviridae, Rudiviridae, and "Bicaudaviridae", as well as of the unclassified Sulfolobus Turreted Icosahedral Virus, STIV. We present here the crystal structure of the protein (Mr = 13.1 kD, 109 residues encoded by the AFV3 ORF 109 in two different crystal forms at 1.5 and 1.3 Å resolution. The structure of AFV3-109 is a five stranded β-sheet with loops on one side and three helices on the other. It forms a dimer adopting the shape of a cradle that encompasses the best conserved regions of the sequence. No protein with a related fold could be identified except for the ortholog from STIV1, whose structure was deposited at the Protein Data Bank. We could clearly identify a well bound glycerol inside the cradle, contacting exclusively totally conserved residues. This interaction was confirmed in solution by fluorescence titration. Although the function of AFV3-109 cannot be deduced directly from its structure, structural homology with the STIV1 protein, and the size and charge distribution of the cavity suggested it could interact with nucleic acids. Fluorescence quenching titrations also showed that AFV3-109 interacts with dsDNA. Genomic sequence analysis revealed bacterial homologs of AFV3-109 as a part of a putative previously unidentified prophage sequences in some Firmicutes.

  4. Synthesis of 2-[18F]fluoro-L-tyrosine via regiospecific fluoro-de-stannylation

    International Nuclear Information System (INIS)

    Hess, E.; Sichler, S.; Kluge, A.; Coenen, H.H.

    2002-01-01

    2-[ 18 F]Fluoro-L-tyrosine is a fluorine labelled amino acid, known to be incorporated into newly synthesised proteins, rendering it a potentially suitable tracer to image protein metabolism in vivo using positron emission tomography. For the electrophilic preparation of 2-[ 18 F]fluoro-L-tyrosine three protected 2-trialkylstannyl tyrosine derivatives have been synthesised for the first time as precursors. While O,N-di-Boc-2-triethylstannyl-L-tyrosine ethylester has proved to be suitable as precursor for radiosynthesis, imidazolidinon-derivatives of 2-triaklylstannyl tyrosine have not because of difficult fast hydrolysis of a phenolic O-methyl protective group. The di-Boc-tin derivative of tyrosine ethylester readily reacted with [ 18 F]F 2 , which was prepared via the 18 O(p,n) 18 F nuclear reaction. 2-[ 18 F]Fluoro-L-tyrosine was isolated after full deprotection with aqueous hydrobromic acid and HPLC purification with activities of 1.41±0.32 GBq. The isomeric and enantiomeric purity is high (both >99%). The preparation procedure is facile and easy to automate. The chemical yields of this fluoro-de-stannylation reaction as well as of the synthesis of 6-[ 18 F]fluoro-L-dopa, determined with an analogous precursor and non-radioactive fluorine under identical conditions, amounted to 42.7±1.6% and 60.2±2.8%, respectively

  5. Novel Mutations in the Tyrosine Hydroxylase Gene in the First Czech Patient with Tyrosine Hydroxylase Deficiency

    Directory of Open Access Journals (Sweden)

    K. Szentiványi

    2012-01-01

    Full Text Available Tyrosine hydroxylase deficiency manifests mainly in early childhood and includes two clinical phenotypes: an infantile progressive hypokinetic-rigid syndrome with dystonia (type A and a neonatal complex encephalopathy (type B. The biochemical diagnostics is exclusively based on the quantitative determination of the neurotransmitters or their metabolites in cerebrospinal fluid (CSF. The implementation of neurotransmitter analysis in clinical praxis is necessary for early diagnosis and adequate treatment. Neurotransmitter metabolites in CSF were analyzed in 82 children (at the age 1 month to 17 years with clinical suspicion for neurometabolic disorders using high performance liquid chromatography (HPLC with electrochemical detection. The CSF level of homovanillic acid (HVA was markedly decreased in three children (64, 79 and 94 nmol/l in comparison to age related controls (lower limit 218–450 nmol/l. Neurological findings including severe psychomotor retardation, quadruspasticity and microcephaly accompanied with marked dystonia, excessive sweating in the first patient was compatible with the diagnosis of tyrosine hydroxylase (TH deficiency (type B and subsequent molecular analysis revealed two novel heterozygous mutations c.636A>C and c.1124G>C in the TH gene. The treatment with L-DOPA/carbidopa resulted in the improvement of dystonia. Magnetic resonance imaging studies in two other patients with microcephaly revealed postischaemic brain damage, therefore secondary HVA deficit was considered in these children. Diagnostic work-up in patients with neurometabolic disorders should include analysis of neurotransmitter metabolites in CSF.

  6. Comparative analyses of six solanaceous transcriptomes reveal a high degree of sequence conservation and species-specific transcripts

    Directory of Open Access Journals (Sweden)

    Ouyang Shu

    2005-09-01

    Full Text Available Abstract Background The Solanaceae is a family of closely related species with diverse phenotypes that have been exploited for agronomic purposes. Previous studies involving a small number of genes suggested sequence conservation across the Solanaceae. The availability of large collections of Expressed Sequence Tags (ESTs for the Solanaceae now provides the opportunity to assess sequence conservation and divergence on a genomic scale. Results All available ESTs and Expressed Transcripts (ETs, 449,224 sequences for six Solanaceae species (potato, tomato, pepper, petunia, tobacco and Nicotiana benthamiana, were clustered and assembled into gene indices. Examination of gene ontologies revealed that the transcripts within the gene indices encode a similar suite of biological processes. Although the ESTs and ETs were derived from a variety of tissues, 55–81% of the sequences had significant similarity at the nucleotide level with sequences among the six species. Putative orthologs could be identified for 28–58% of the sequences. This high degree of sequence conservation was supported by expression profiling using heterologous hybridizations to potato cDNA arrays that showed similar expression patterns in mature leaves for all six solanaceous species. 16–19% of the transcripts within the six Solanaceae gene indices did not have matches among Solanaceae, Arabidopsis, rice or 21 other plant gene indices. Conclusion Results from this genome scale analysis confirmed a high level of sequence conservation at the nucleotide level of the coding sequence among Solanaceae. Additionally, the results indicated that part of the Solanaceae transcriptome is likely to be unique for each species.

  7. Suppression of adhesion-induced protein tyrosine phosphorylation decreases invasive and metastatic potentials of B16-BL6 melanoma cells by protein tyrosine kinase inhibitor genistein.

    Science.gov (United States)

    Yan, C; Han, R

    1997-01-01

    Protein tyrosine kinase (PTK) appears to be involved in the activation of signaling during cell attachment to and spreading on extracellular matrix (ECM) in the metastatic cascade. To verify the assumption that PTK inhibitors might impair ECM signaling and prevent cancer metastasis, the highly metastatic B16-BL6 mouse melanoma cells were exposed to the PTK inhibitor genistein for 3 days. The ability of the cells to invade through reconstituted basement membrane (Matrigel) and to establish experimental pulmonary metastatic foci in C57BL/6 mice decreased after genistein exposure. The genistein-treated cells were also prevented from attaching to Matrigel and spread extremely poorly on the ECM substratum. Immunoblot analysis showed that tyrosine phosphorylation of a 125-kD protein in response to cell spreading on Matrigel was suppressed in the genistein-treated cells. Adhesion-induced protein tyrosine phosphorylation represents the earlier and specific event in the activation of ECM signaling, so this result implied ECM signaling was impaired in the treated cells. With immunofluorescence microscopy, the adhesion-induced tyrosine phosphorylated proteins were located at the pericytoplasms of well-spread cells, but not at the periphery of poorly spread genistein-treated cells. Therefore, this paper suggests that genistein might impair ECM signaling and subsequently prevent cancer cells from spreading well and invading or establishing metastasis through the suppression of adhesion-induced protein tyrosine phosphorylation. PTKs and adhesion-induced protein tyrosine phosphorylation might play a role in the control of invasion and metastasis.

  8. NFAT5 regulates HIV-1 in primary monocytes via a highly conserved long terminal repeat site.

    Directory of Open Access Journals (Sweden)

    Shahin Ranjbar

    2006-12-01

    Full Text Available To replicate, HIV-1 capitalizes on endogenous cellular activation pathways resulting in recruitment of key host transcription factors to its viral enhancer. RNA interference has been a powerful tool for blocking key checkpoints in HIV-1 entry into cells. Here we apply RNA interference to HIV-1 transcription in primary macrophages, a major reservoir of the virus, and specifically target the transcription factor NFAT5 (nuclear factor of activated T cells 5, which is the most evolutionarily divergent NFAT protein. By molecularly cloning and sequencing isolates from multiple viral subtypes, and performing DNase I footprinting, electrophoretic mobility shift, and promoter mutagenesis transfection assays, we demonstrate that NFAT5 functionally interacts with a specific enhancer binding site conserved in HIV-1, HIV-2, and multiple simian immunodeficiency viruses. Using small interfering RNA to ablate expression of endogenous NFAT5 protein, we show that the replication of three major HIV-1 viral subtypes (B, C, and E is dependent upon NFAT5 in human primary differentiated macrophages. Our results define a novel host factor-viral enhancer interaction that reveals a new regulatory role for NFAT5 and defines a functional DNA motif conserved across HIV-1 subtypes and representative simian immunodeficiency viruses. Inhibition of the NFAT5-LTR interaction may thus present a novel therapeutic target to suppress HIV-1 replication and progression of AIDS.

  9. Proteomic Analysis of Pathogenic Fungi Reveals Highly Expressed Conserved Cell Wall Proteins

    Directory of Open Access Journals (Sweden)

    Jackson Champer

    2016-01-01

    Full Text Available We are presenting a quantitative proteomics tally of the most commonly expressed conserved fungal proteins of the cytosol, the cell wall, and the secretome. It was our goal to identify fungi-typical proteins that do not share significant homology with human proteins. Such fungal proteins are of interest to the development of vaccines or drug targets. Protein samples were derived from 13 fungal species, cultured in rich or in minimal media; these included clinical isolates of Aspergillus, Candida, Mucor, Cryptococcus, and Coccidioides species. Proteomes were analyzed by quantitative MSE (Mass Spectrometry—Elevated Collision Energy. Several thousand proteins were identified and quantified in total across all fractions and culture conditions. The 42 most abundant proteins identified in fungal cell walls or supernatants shared no to very little homology with human proteins. In contrast, all but five of the 50 most abundant cytosolic proteins had human homologs with sequence identity averaging 59%. Proteomic comparisons of the secreted or surface localized fungal proteins highlighted conserved homologs of the Aspergillus fumigatus proteins 1,3-β-glucanosyltransferases (Bgt1, Gel1-4, Crf1, Ecm33, EglC, and others. The fact that Crf1 and Gel1 were previously shown to be promising vaccine candidates, underlines the value of the proteomics data presented here.

  10. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants

    Science.gov (United States)

    Woodcock, Paul; Edwards, David P.; Fayle, Tom M.; Newton, Rob J.; Khen, Chey Vun; Bottrell, Simon H.; Hamer, Keith C.

    2011-01-01

    South East Asia is widely regarded as a centre of threatened biodiversity owing to extensive logging and forest conversion to agriculture. In particular, forests degraded by repeated rounds of intensive logging are viewed as having little conservation value and are afforded meagre protection from conversion to oil palm. Here, we determine the biological value of such heavily degraded forests by comparing leaf-litter ant communities in unlogged (natural) and twice-logged forests in Sabah, Borneo. We accounted for impacts of logging on habitat heterogeneity by comparing species richness and composition at four nested spatial scales, and examining how species richness was partitioned across the landscape in each habitat. We found that twice-logged forest had fewer species occurrences, lower species richness at small spatial scales and altered species composition compared with natural forests. However, over 80 per cent of species found in unlogged forest were detected within twice-logged forest. Moreover, greater species turnover among sites in twice-logged forest resulted in identical species richness between habitats at the largest spatial scale. While two intensive logging cycles have negative impacts on ant communities, these degraded forests clearly provide important habitat for numerous species and preventing their conversion to oil palm and other crops should be a conservation priority. PMID:22006966

  11. Tyrosine phosphorylation of LRP6 by Src and Fer inhibits Wnt/β-catenin signalling

    Science.gov (United States)

    Chen, Qing; Su, Yi; Wesslowski, Janine; Hagemann, Anja I; Ramialison, Mirana; Wittbrodt, Joachim; Scholpp, Steffen; Davidson, Gary

    2014-01-01

    Low-density lipoprotein receptor-related proteins 5 and 6 (LRP5/6) function as transmembrane receptors to transduce Wnt signals. A key mechanism for signalling is Wnt-induced serine/threonine phosphorylation at conserved PPPSPxS motifs in the LRP6 cytoplasmic domain, which promotes pathway activation. Conserved tyrosine residues are positioned close to all PPPSPxS motifs, which suggests they have a functional significance. Using a cell culture-based cDNA expression screen, we identified the non-receptor tyrosine kinases Src and Fer as novel LRP6 modifiers. Both Src and Fer associate with LRP6 and phosphorylate LRP6 directly. In contrast to the known PPPSPxS Ser/Thr kinases, tyrosine phosphorylation by Src and Fer negatively regulates LRP6-Wnt signalling. Epistatically, they function upstream of β-catenin to inhibit signalling and in agreement with a negative role in regulating LRP6, MEF cells lacking these kinases show enhanced Wnt signalling. Wnt3a treatment of cells enhances tyrosine phosphorylation of endogenous LRP6 and, mechanistically, Src reduces cell surface LRP6 levels and disrupts LRP6 signalosome formation. Interestingly, CK1γ inhibits Fer-induced LRP6 phosphorylation, suggesting a mechanism whereby CK1γ acts to de-represses inhibitory LRP6 tyrosine phosphorylation. We propose that LRP6 tyrosine phosphorylation by Src and Fer serves a negative regulatory function to prevent over-activation of Wnt signalling at the level of the Wnt receptor, LRP6. Subject Categories Membrane & Intracellular Transport; Post-translational Modifications, Proteolysis & Proteomics PMID:25391905

  12. Structure determination of T-cell protein-tyrosine phosphatase

    DEFF Research Database (Denmark)

    Iversen, L.F.; Møller, K. B.; Pedersen, A.K.

    2002-01-01

    Protein-tyrosine phosphatase 1B (PTP1B) has recently received much attention as a potential drug target in type 2 diabetes. This has in particular been spurred by the finding that PTP1B knockout mice show increased insulin sensitivity and resistance to diet-induced obesity. Surprisingly, the highly...... homologous T cell protein-tyrosine phosphatase (TC-PTP) has received much less attention, and no x-ray structure has been provided. We have previously co-crystallized PTP1B with a number of low molecular weight inhibitors that inhibit TC-PTP with similar efficiency. Unexpectedly, we were not able to co...... the high degree of functional and structural similarity between TC-PTP and PTP1B, we have been able to identify areas close to the active site that might be addressed to develop selective inhibitors of each enzyme....

  13. Mechanism of papain-catalyzed synthesis of oligo-tyrosine peptides.

    Science.gov (United States)

    Mitsuhashi, Jun; Nakayama, Tsutomu; Narai-Kanayama, Asako

    2015-01-01

    Di-, tri-, and tetra-tyrosine peptides with angiotensin I-converting enzyme inhibitory activity were synthesized by papain-catalyzed polymerization of L-tyrosine ethyl ester in aqueous media at 30 °C. Varying the reaction pH from 6.0 to 7.5 and the initial concentration of the ester substrate from 25 to 100 mM, the highest yield of oligo-tyrosine peptides (79% on a substrate basis) was produced at pH 6.5 and 75 mM, respectively. In the reaction initiated with 100 mM of the substrate, approx. 50% yield of insoluble, highly polymerized peptides accumulated. At less than 15 mM, the reaction proceeded poorly; however, from 30 mM to 120 mM a dose-dependent increase in the consumption rate of the substrate was observed with a sigmoidal curve. Meanwhile, each of the tri- and tetra-tyrosine peptides, even at approx. 5mM, was consumed effectively by papain but was not elongated to insoluble polymers. For deacylation of the acyl-papain intermediate through which a new peptide bond is made, L-tyrosine ethyl ester, even at 5mM, showed higher nucleophilic activity than di- and tri-tyrosine. These results indicate that the mechanism through which papain polymerizes L-tyrosine ethyl ester is as follows: the first interaction between papain and the ester substrate is a rate-limiting step; oligo-tyrosine peptides produced early in the reaction period are preferentially used as acyl donors, while the initial ester substrate strongly contributes as a nucleophile to the elongation of the peptide product; and the balance between hydrolytic fragmentation and further elongation of oligo-tyrosine peptides is dependent on the surrounding concentration of the ester substrate. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. 21 CFR 862.1730 - Free tyrosine test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Free tyrosine test system. 862.1730 Section 862....1730 Free tyrosine test system. (a) Identification. A free tyrosine test system is a device intended to measure free tyrosine (an amono acid) in serum and urine. Measurements obtained by this device are used in...

  15. Impacts of Tropical Forest Disturbance Upon Avifauna on a Small Island with High Endemism: Implications for Conservation

    Directory of Open Access Journals (Sweden)

    Martin Thomas

    2010-01-01

    Full Text Available Tropical forests are rapidly being lost across Southeast Asia and this is predicted to have severe implications for many of the region′s bird species. However, relationships between forest disturbance and avifaunal assemblages remain poorly understood, particularly on small island ecosystems such as those found in the biodiversity ′hotspot′ of Wallacea. This study examines how avifaunal richness varies across a disturbance gradient in a forest reserve on Buton Island, southeast Sulawesi. Particular emphasis is placed upon examining responses in endemic and red-listed species with high conservation importance. Results indicate that overall avian richness increases between primary and 30-year-old regenerating secondary forest and then decreases through disturbed secondary forest, but is highest in cleared farmland. However, high species richness in farmland does not signify high species distinctiveness; bird community composition here differs significantly from that found in forest sites, and is poor in supporting forest specialists and endemic species. Certain large-bodied endemics such as the Knobbed Hornbill (Rhyticeros cassidix appear to be sensitive to moderate disturbance, with populations occurring at greatest density within primary forest. However, overall endemic species richness, as well as that of endemic frugivores and insectivores, is similar in primary and secondary forest types. Results indicate that well-established secondary forest in particular has an important role in supporting species with high conservational importance, possessing community composition similar to that found in primary forest and supporting an equally high richness of endemic species.

  16. Expression Profiling of Tyrosine Kinase Genes

    National Research Council Canada - National Science Library

    Weier, Heinz

    2000-01-01

    ... of these genes parallels the progression of tumors to a more malignant phenotype. We developed a DNA micro-array based screening system to monitor the level of expression of tyrosine kinase (tk...

  17. Rapid enzymatic analysis of plasma for tyrosine.

    Science.gov (United States)

    Shimizu, H; Taniguchi, K; Sugiyama, M; Kanno, T

    1990-01-01

    In this rapid, simple, and convenient enzymatic method for measurement of tyrosine in plasma, tyrosine is converted to tyramine by action of tyrosine decarboxylase (EC 4.1.1.25) and the tyramine produced is oxidized to p-hydroxybenzyl aldehyde and hydrogen peroxide by action of tyramine oxidase (EC 1.4.3.9). The hydrogen peroxide is reacted with 4-aminoantipyrine and N-ethyl-N-(2-hydroxy-3-sulfopropyl)-m-toluidine in the presence of peroxidase (EC 1.11.1.7) to obtain quinoneimine dye, the absorbance of which is measured at 570 nm. Thus tyrosine is measured in the visible range. The CV was 4.6% or less, and the measurement was unaffected by other amino acids, except for phenylalanine. The values obtained (y) correlated well with those obtained with an amino acid analyzer (x): y = 0.902x + 3.92 mumol/L (Syx = 12.3; r = 0.985; n = 54).

  18. Excess amounts of 3-iodo-l-tyrosine induce Parkinson-like features in experimental approaches of Parkinsonism.

    Science.gov (United States)

    Fernández-Espejo, Emilio; Bis-Humbert, Cristian

    2018-06-06

    3-iodo-l-tyrosine might play a role in Parkinson's disease since this molecule is able, at high concentration, to inhibit tyrosine-hydroxylase activity, the rate-limiting enzyme in dopamine biosynthesis. The possible Parkinson-like effects of 3-iodo-l-tyrosine were tested on three experimental approaches in mice: cultured substantia nigra neurons, the enteric nervous system of the jejunum after intra-peritoneal infusions, and the nigrostriatal system following unilateral intrabrain injections. 3-iodo-l-tyrosine, a physiological molecule, was used at concentrations higher than its serum levels in humans. Parkinson-like signs were evaluated through abnormal aggregation of α-synuclein and tyrosine-hydroxylase, loss of tyrosine-hydroxylase-expressing and striatum-projecting neurons and fibers, reduced tyrosine-hydroxylase density, and Parkinson-like motor and non-motor deficits. The retrograde tracer FluoroGold was used in the brain model. The findings revealed that excess amounts of 3-iodo-l-tyrosine induce Parkinson-like effects in the three experimental approaches. Thus, culture neurons of substantia nigra show, after 3-iodo-l-tyrosine exposure, intracytoplasmic inclusions that express α-synuclein and tyrosine-hydroxylase. Intra-peritoneal infusions of 3-iodo-l-tyrosine cause, in the long-term, α-synuclein aggregation, thicker α-synuclein-positive fibers, and loss of tyrosine-hydroxylase-positive cells and fibers in intramural plexuses and ganglia of the jejunum. Infusion of 3-iodo-l-tyrosine into the left dorsal striata of mice damages the nigrostriatal system, as revealed through lower striatal tyrosine-hydroxylase density, reduced number of tyrosine-hydroxylase-expressing and striatum-projecting neurons in the left substantia nigra, as well as the emergence of Parkinson-like behavioral deficits such as akinesia, bradykinesia, motor disbalance, and locomotion directional bias. In conclusion, excess amounts of 3-iodo-l-tyrosine induce Parkinson-like features in

  19. The Tyrosine Aminomutase TAM1 Is Required for β-Tyrosine Biosynthesis in Rice

    Science.gov (United States)

    Yan, Jian; Aboshi, Takako; Teraishi, Masayoshi; Strickler, Susan R.; Spindel, Jennifer E.; Tung, Chih-Wei; Takata, Ryo; Matsumoto, Fuka; Maesaka, Yoshihiro; McCouch, Susan R.; Okumoto, Yutaka; Mori, Naoki; Jander, Georg

    2015-01-01

    Non-protein amino acids, often isomers of the standard 20 protein amino acids, have defense-related functions in many plant species. A targeted search for jasmonate-induced metabolites in cultivated rice (Oryza sativa) identified (R)-β-tyrosine, an isomer of the common amino acid (S)-α-tyrosine in the seeds, leaves, roots, and root exudates of the Nipponbare cultivar. Assays with 119 diverse cultivars showed a distinct presence/absence polymorphism, with β-tyrosine being most prevalent in temperate japonica cultivars. Genetic mapping identified a candidate gene on chromosome 12, which was confirmed to encode a tyrosine aminomutase (TAM1) by transient expression in Nicotiana benthamiana and in vitro enzyme assays. A point mutation in TAM1 eliminated β-tyrosine production in Nipponbare. Rice cultivars that do not produce β-tyrosine have a chromosome 12 deletion that encompasses TAM1. Although β-tyrosine accumulation was induced by the plant defense signaling molecule jasmonic acid, bioassays with hemipteran and lepidopteran herbivores showed no negative effects at physiologically relevant β-tyrosine concentrations. In contrast, root growth of Arabidopsis thaliana and other tested dicot plants was inhibited by concentrations as low as 1 μM. As β-tyrosine is exuded into hydroponic medium at higher concentrations, it may contribute to the allelopathic potential of rice. PMID:25901084

  20. Neuro-cognitive effects of acute tyrosine administration on reactive and proactive response inhibition in healthy older adults

    NARCIS (Netherlands)

    Bloemendaal, Mirjam; Froböse, Monja Isabel; Wegman, Joost; Zandbelt, Bram Bastiaan; Rest, van de Ondine; Cools, Roshan; Aarts, Esther

    2018-01-01

    The aging brain is characterized by altered dopamine signaling. The amino acid tyrosine, a catecholamine precursor, is known to improve cognitive performance in young adults, especially during high environmental demands. Tyrosine administration might also affect catecholamine transmission in the

  1. Noise exposure and hearing conservation practices in an industry with high incidence of workers' compensation claims for hearing loss.

    Science.gov (United States)

    Daniell, William E; Swan, Susan S; McDaniel, Mary M; Stebbins, John G; Seixas, Noah S; Morgan, Michael S

    2002-10-01

    Washington State has experienced a striking increase in workers' compensation claims for hearing loss. This cross-sectional study examined noise exposures and hearing conservation practices in one industry with a high rate of hearing loss claims. We evaluated 10 representative foundries with personal noise dosimetry, management interviews, employee interviews, and existing audiometry. Noise levels routinely exceeded 85 dBA. All companies were out of compliance with hearing conservation regulations. Most employees with important findings on audiograms were not aware of their findings. There was a significant positive correlation between management-interview scores and worksite-average employee-interview scores (r = 0.70, P = 0.02). Companies where more effort is put into hearing conservation program activities can achieve a greater positive impact on employee awareness. However, there were broad deficiencies even in the better programs in this sample, suggesting that workers in this industry probably face a continuing substantial risk of occupational hearing loss. Copyright 2002 Wiley-Liss, Inc.

  2. Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, Anwar M. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Microbiology, Faculty of Medicine, King Abdulaziz University, Jeddah (Saudi Arabia); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada); Van Domselaar, Gary [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Li, Changgui; Wang, Junzhi [National Institute for the Control of Pharmaceutical and Biological Products, Beijing (China); She, Yi-Min; Cyr, Terry D. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Sui, Jianhua [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); He, Runtao [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Marasco, Wayne A. [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); Li, Xuguang, E-mail: Sean.Li@hc-sc.gc.ca [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada)

    2010-12-10

    Research highlights: {yields} The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. {yields} Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. {yields} The universal antibodies cross-neutralize different influenza A subtypes. {yields} The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

  3. Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus

    International Nuclear Information System (INIS)

    Hashem, Anwar M.; Van Domselaar, Gary; Li, Changgui; Wang, Junzhi; She, Yi-Min; Cyr, Terry D.; Sui, Jianhua; He, Runtao; Marasco, Wayne A.; Li, Xuguang

    2010-01-01

    Research highlights: → The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. → Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. → The universal antibodies cross-neutralize different influenza A subtypes. → The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

  4. A high-order relaxation method with projective integration for solving nonlinear systems of hyperbolic conservation laws

    Science.gov (United States)

    Lafitte, Pauline; Melis, Ward; Samaey, Giovanni

    2017-07-01

    We present a general, high-order, fully explicit relaxation scheme which can be applied to any system of nonlinear hyperbolic conservation laws in multiple dimensions. The scheme consists of two steps. In a first (relaxation) step, the nonlinear hyperbolic conservation law is approximated by a kinetic equation with stiff BGK source term. Then, this kinetic equation is integrated in time using a projective integration method. After taking a few small (inner) steps with a simple, explicit method (such as direct forward Euler) to damp out the stiff components of the solution, the time derivative is estimated and used in an (outer) Runge-Kutta method of arbitrary order. We show that, with an appropriate choice of inner step size, the time step restriction on the outer time step is similar to the CFL condition for the hyperbolic conservation law. Moreover, the number of inner time steps is also independent of the stiffness of the BGK source term. We discuss stability and consistency, and illustrate with numerical results (linear advection, Burgers' equation and the shallow water and Euler equations) in one and two spatial dimensions.

  5. Global alteration of the drug-binding pocket of human P-glycoprotein (ABCB1) by substitution of fifteen conserved residues reveals a negative correlation between substrate size and transport efficiency.

    Science.gov (United States)

    Vahedi, Shahrooz; Chufan, Eduardo E; Ambudkar, Suresh V

    2017-11-01

    P-glycoprotein (P-gp), an ATP-dependent efflux pump, is linked to the development of multidrug resistance in cancer cells. However, the drug-binding sites and translocation pathways of this transporter are not yet well-characterized. We recently demonstrated the important role of tyrosine residues in regulating P-gp ATP hydrolysis via hydrogen bond formations with high affinity modulators. Since tyrosine is both a hydrogen bond donor and acceptor, and non-covalent interactions are key in drug transport, in this study we investigated the global effect of enrichment of tyrosine residues in the drug-binding pocket on the drug binding and transport function of P-gp. By employing computational analysis, 15 conserved residues in the drug-binding pocket of human P-gp that interact with substrates were identified and then substituted with tyrosine, including 11 phenylalanine (F72, F303, F314, F336, F732, F759, F770, F938, F942, F983, F994), two leucine (L339, L975), one isoleucine (I306), and one methionine (M949). Characterization of the tyrosine-rich P-gp mutant in HeLa cells demonstrated that this major alteration in the drug-binding pocket by introducing fifteen additional tyrosine residues is well tolerated and has no measurable effect on total or cell surface expression of this mutant. Although the tyrosine-enriched mutant P-gp could transport small to moderate size (transport large (>1000 Daltons) substrates such as NBD-cyclosporine A, Bodipy-paclitaxel and Bodipy-vinblastine was significantly decreased. This was further supported by the physico-chemical characterization of seventeen tested substrates, which revealed a negative correlation between drug transport and molecular size for the tyrosine-enriched P-gp mutant. Published by Elsevier Inc.

  6. A new world monkey microsatellite (ap74) highly conserved in primates

    International Nuclear Information System (INIS)

    Oklander, Luciana Ines; Steinberg, Eliana Ruth; Dolores Mudry, Marta

    2012-01-01

    Given their great variability, microsatellites or STRS became the most commonly used genetic markers over the last 15 years. The analysis of these markers requires minimum quantities of DNA, allowing the use of noninvasive samples, such as feces or hair. We amplified the microsatellite ap74 in blood and hair samples in order to analyze the levels of genomic conservation among a wide range of primates including: lemur catta, alouatta caraya, ateles belzebuth, ateles chamek, pan troglodytes, papio sp., and Homo sapiens. in all cases we obtained amplification products that exhibited similar size both in monkeys and human (oscillating between 126 and 176 bp), except in the lemur where the detected fragment presented a size of approximately 1000 bp. the analysis of the nucleotide sequences permitted the evaluation of the molecular modifications experienced during the evolutionary process in primates.

  7. Protein tyrosine nitration in the cell cycle

    International Nuclear Information System (INIS)

    Jia, Min; Mateoiu, Claudia; Souchelnytskyi, Serhiy

    2011-01-01

    Highlights: → Enrichment of 3-nitrotyrosine containing proteins from cells synchronized in different phases of the cell cycle. → Identification of 76 tyrosine nitrated proteins that change expression during the cell cycle. → Nineteen identified proteins were previously described as regulators of cell proliferation. -- Abstract: Nitration of tyrosine residues in proteins is associated with cell response to oxidative/nitrosative stress. Tyrosine nitration is relatively low abundant post-translational modification that may affect protein functions. Little is known about the extent of protein tyrosine nitration in cells during progression through the cell cycle. Here we report identification of proteins enriched for tyrosine nitration in cells synchronized in G0/G1, S or G2/M phases of the cell cycle. We identified 27 proteins in cells synchronized in G0/G1 phase, 37 proteins in S phase synchronized cells, and 12 proteins related to G2/M phase. Nineteen of the identified proteins were previously described as regulators of cell proliferation. Thus, our data indicate which tyrosine nitrated proteins may affect regulation of the cell cycle.

  8. Functionalization of protected tyrosine via Sonogashira reaction: synthesis of 3-(1,2,3-triazolyl)-tyrosine.

    Science.gov (United States)

    Vasconcelos, Stanley N S; Shamim, Anwar; Ali, Bakhat; de Oliveira, Isadora M; Stefani, Hélio A

    2016-05-01

    1,2,3-Triazol tyrosines were synthesized from tyrosine alkynes that were in turn prepared via Sonogashira cross-coupling reaction. The tyrosine alkynes were subjected to click-chemistry reaction conditions leading to the corresponding 3-(1,2,3-triazolyl)-tyrosines in yields ranging from moderate to good.

  9. Tyrosine-sensitized photodimerization of thymine in aqueous solution

    International Nuclear Information System (INIS)

    Kaneko, M.; Matsuyama, A.; Nagata, C.

    1978-01-01

    Photodimerization of thymine in aqueous solution in the presence of tyrosine was studied with monochromatic UV irradiation. The total dimer formation was sensitized in the presence of tyrosine. The action spectrum of sensitized total dimer formation has a peak near 280 nm corresponding to the absorption maximum of tyrosine. Triplet quenchers reduced the sensitization substantially. It seems probable that tyrosine-sensitized photodimerization of thymine occurred via triplet-triplet energy transfer from tyrosine to thymine. (author)

  10. Oligonucleotide aptamers against tyrosine kinase receptors: Prospect for anticancer applications.

    Science.gov (United States)

    Camorani, Simona; Crescenzi, Elvira; Fedele, Monica; Cerchia, Laura

    2018-04-01

    Transmembrane receptor tyrosine kinases (RTKs) play crucial roles in cancer cell proliferation, survival, migration and differentiation. Area of intense research is searching for effective anticancer therapies targeting these receptors and, to date, several monoclonal antibodies and small-molecule tyrosine kinase inhibitors have entered the clinic. However, some of these drugs show limited efficacy and give rise to acquired resistance. Emerging highly selective compounds for anticancer therapy are oligonucleotide aptamers that interact with their targets by recognizing a specific three-dimensional structure. Because of their nucleic acid nature, the rational design of advanced strategies to manipulate aptamers for both diagnostic and therapeutic applications is greatly simplified over antibodies. In this manuscript, we will provide a comprehensive overview of oligonucleotide aptamers as next generation strategies to efficiently target RTKs in human cancers. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Structural basis for the regulation mechanism of the tyrosine kinase CapB from Staphylococcus aureus

    DEFF Research Database (Denmark)

    Olivares-Illana, Vanesa; Meyer, Philippe; Bechet, Emmanuelle

    2008-01-01

    Bacteria were thought to be devoid of tyrosine-phosphorylating enzymes. However, several tyrosine kinases without similarity to their eukaryotic counterparts have recently been identified in bacteria. They are involved in many physiological processes, but their accurate functions remain poorly...... understood due to slow progress in their structural characterization. They have been best characterized as copolymerases involved in the synthesis and export of extracellular polysaccharides. These compounds play critical roles in the virulence of pathogenic bacteria, and bacterial tyrosine kinases can thus...... be considered as potential therapeutic targets. Here, we present the crystal structures of the phosphorylated and unphosphorylated states of the tyrosine kinase CapB from the human pathogen Staphylococcus aureus together with the activator domain of its cognate transmembrane modulator CapA. This first high...

  12. The presence of tyrosine glucoside in the haemolymph of lepidopteran insects

    International Nuclear Information System (INIS)

    Ishizaki, Yumi; Umebachi, Yoshishige

    1980-01-01

    A ninhydrin-positive substance from the haemolymph of Papilio xuthus was purified and identified as β-glucosyl-O-tyrosine by (1) color reactions, (2) incorporation of 14 C-tyrosine, (3) identification and estimation of hydrolysis products, (4) α- and β-glucosidase tests, and (5) UV-spectrum. The concentration of the tyrosine glucoside in haemolymph reaches a maximum at the prepupal stage, then decreases, and is on a low level during the middle stage of pupa. At the late pupal stage, the level again rises and is kept high before emergence. After emergence, it rapidly decreases. The same tyrosine glucoside has proved to be also present in the haemolymph of twelve other species of Lepidoptera. (author)

  13. Hearing sensitivity in context: Conservation implications for a highly vocal endangered species

    Directory of Open Access Journals (Sweden)

    Megan A. Owen

    2016-04-01

    Full Text Available Hearing sensitivity is a fundamental determinant of a species’ vulnerability to anthropogenic noise, however little is known about the hearing capacities of most conservation dependent species. When audiometric data are integrated with other aspects of species’ acoustic ecology, life history, and characteristic habitat topography and soundscape, predictions can be made regarding probable vulnerability to the negative impacts of different types of anthropogenic noise. Here we used an adaptive psychoacoustic technique to measure hearing thresholds in the endangered giant panda; a species that uses acoustic communication to coordinate reproduction. Our results suggest that giant pandas have functional hearing into the ultrasonic range, with good sensitivity between 10.0 and 16.0 kHz, and best sensitivity measured at 12.5–14.0 kHz. We estimated the lower and upper limits of functional hearing as 0.10 and 70.0 kHz respectively. While these results suggest that panda hearing is similar to that of some other terrestrial carnivores, panda hearing thresholds above 14.0 kHz were significantly lower (i.e., more sensitive than those of the polar bear, the only other bear species for which data are available. We discuss the implications of this divergence, as well as the relationship between hearing sensitivity and the spectral parameters of panda vocalizations. We suggest that these data, placed in context, can be used towards the development of a sensory-based model of noise disturbance for the species.

  14. 77 FR 11785 - Energy Conservation Program: Public Meeting and Availability of the Framework Document for High...

    Science.gov (United States)

    2012-02-28

    ... standards for high-intensity discharge (HID) lamps. Accordingly, DOE will hold a public meeting to discuss..._standards/commercial/high_intensity_discharge_lamps.html . DATES: The Department will hold a public meeting... Technologies Program, Mailstop EE-2J, Framework Document for High-Intensity Discharge Lamps, EERE-2010-BT-STD...

  15. Surgical versus conservative treatment for high-risk stress fractures of the lower leg (anterior tibial cortex, navicular and fifth metatarsal base): a systematic review

    NARCIS (Netherlands)

    Mallee, Wouter H.; Weel, Hanneke; van Dijk, C. Niek; van Tulder, Maurits W.; Kerkhoffs, Gino M.; Lin, Chung-Wei Christine

    2015-01-01

    To compare surgical and conservative treatment for high-risk stress fractures of the anterior tibial cortex, navicular and proximal fifth metatarsal. Systematic searches of CENTRAL, MEDLINE, EMBASE, CINAHL, SPORTDiscus and PEDro were performed to identify relevant prospective and retrospective

  16. Curli Fibers Are Highly Conserved between Salmonella typhimurium and Escherichia coli with Respect to Operon Structure and Regulation

    Science.gov (United States)

    Römling, Ute; Bian, Zhao; Hammar, Mårten; Sierralta, Walter D.; Normark, Staffan

    1998-01-01

    Mouse-virulent Salmonella typhimurium strains SR-11 and ATCC 14028-1s express curli fibers, thin aggregative fibers, at ambient temperature on plates as judged by Western blot analysis and electron microscopy. Concomitantly with curli expression, cells develop a rough and dry colony morphology and bind the dye Congo red (called the rdar morphotype). Cloning and characterization of the two divergently transcribed operons required for curli biogenesis, csgBA(C) and csgDEFG, from S. typhimurium SR-11 revealed the same gene order and flanking genes as in Escherichia coli. The divergence of the curli region between S. typhimurium and E. coli at the nucleotide level is above average (22.4%). However, a high level of conservation at the protein level, which ranged from 86% amino acid homology for the fiber subunit CsgA to 99% homology for the lipoprotein CsgG, implies functional constraints on the gene products. Consequently, S. typhimurium genes on low-copy-number plasmids were able to complement respective E. coli mutants, although not always to wild-type levels. rpoS and ompR are required for transcriptional activation of (at least) the csgD promoter. The high degree of conservation at the protein level and the identical regulation patterns in E. coli and S. typhimurium suggest similar roles of curli fibers in the same ecological niche in the two species. PMID:9457880

  17. Conserved host response to highly pathogenic avian influenza virus infection in human cell culture, mouse and macaque model systems

    Directory of Open Access Journals (Sweden)

    McDermott Jason E

    2011-11-01

    Full Text Available Abstract Background Understanding host response to influenza virus infection will facilitate development of better diagnoses and therapeutic interventions. Several different experimental models have been used as a proxy for human infection, including cell cultures derived from human cells, mice, and non-human primates. Each of these systems has been studied extensively in isolation, but little effort has been directed toward systematically characterizing the conservation of host response on a global level beyond known immune signaling cascades. Results In the present study, we employed a multivariate modeling approach to characterize and compare the transcriptional regulatory networks between these three model systems after infection with a highly pathogenic avian influenza virus of the H5N1 subtype. Using this approach we identified functions and pathways that display similar behavior and/or regulation including the well-studied impact on the interferon response and the inflammasome. Our results also suggest a primary response role for airway epithelial cells in initiating hypercytokinemia, which is thought to contribute to the pathogenesis of H5N1 viruses. We further demonstrate that we can use a transcriptional regulatory model from the human cell culture data to make highly accurate predictions about the behavior of important components of the innate immune system in tissues from whole organisms. Conclusions This is the first demonstration of a global regulatory network modeling conserved host response between in vitro and in vivo models.

  18. Tyrosine kinome sequencing of pediatric acute lymphoblastic leukemia: a report from the Children's Oncology Group TARGET Project | Office of Cancer Genomics

    Science.gov (United States)

    TARGET researchers sequenced the tyrosine kinome and downstream signaling genes in 45 high-risk pediatric ALL cases with activated kinase signaling, including Ph-like ALL, to establish the incidence of tyrosine kinase mutations in this cohort. The study confirmed previously identified somatic mutations in JAK and FLT3, but did not find novel alterations in any additional tyrosine kinases or downstream genes. The mechanism of kinase signaling activation in this high-risk subgroup of pediatric ALL remains largely unknown.

  19. Formation of a tyrosine adduct involved in lignin degradation by Trametopsis cervina lignin peroxidase: a novel peroxidase activation mechanism

    Science.gov (United States)

    Yuta Miki; Rebecca Pogni; Sandra Acebes; Fatima Lucas; Elena Fernandez-Fueyo; Maria Camilla Baratto; Maria I. Fernandez; Vivian De Los Rios; Francisco J. Ruiz-duenas; Adalgisa Sinicropi; Riccardo Basosi; Kenneth E. Hammel; Victor Guallar; Angel T. Martinez

    2013-01-01

    LiP (lignin peroxidase) from Trametopsis cervina has an exposed catalytic tyrosine residue (Tyr181) instead of the tryptophan conserved in other lignin-degrading peroxidases. Pristine LiP showed a lag period in VA (veratryl alcohol) oxidation. However, VA-LiP (LiP after treatment with H2O2...

  20. TATN-1 mutations reveal a novel role for tyrosine as a metabolic signal that influences developmental decisions and longevity in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Annabel A Ferguson

    Full Text Available Recent work has identified changes in the metabolism of the aromatic amino acid tyrosine as a risk factor for diabetes and a contributor to the development of liver cancer. While these findings could suggest a role for tyrosine as a direct regulator of the behavior of cells and tissues, evidence for this model is currently lacking. Through the use of RNAi and genetic mutants, we identify tatn-1, which is the worm ortholog of tyrosine aminotransferase and catalyzes the first step of the conserved tyrosine degradation pathway, as a novel regulator of the dauer decision and modulator of the daf-2 insulin/IGF-1-like (IGFR signaling pathway in Caenorhabditis elegans. Mutations affecting tatn-1 elevate tyrosine levels in the animal, and enhance the effects of mutations in genes that lie within the daf-2/insulin signaling pathway or are otherwise upstream of daf-16/FOXO on both dauer formation and worm longevity. These effects are mediated by elevated tyrosine levels as supplemental dietary tyrosine mimics the phenotypes produced by a tatn-1 mutation, and the effects still occur when the enzymes needed to convert tyrosine into catecholamine neurotransmitters are missing. The effects on dauer formation and lifespan require the aak-2/AMPK gene, and tatn-1 mutations increase phospho-AAK-2 levels. In contrast, the daf-16/FOXO transcription factor is only partially required for the effects on dauer formation and not required for increased longevity. We also find that the controlled metabolism of tyrosine by tatn-1 may function normally in dauer formation because the expression of the TATN-1 protein is regulated both by daf-2/IGFR signaling and also by the same dietary and environmental cues which influence dauer formation. Our findings point to a novel role for tyrosine as a developmental regulator and modulator of longevity, and support a model where elevated tyrosine levels play a causal role in the development of diabetes and cancer in people.

  1. TATN-1 Mutations Reveal a Novel Role for Tyrosine as a Metabolic Signal That Influences Developmental Decisions and Longevity in Caenorhabditis elegans

    Science.gov (United States)

    Ferguson, Annabel A.; Dumas, Kathleen J.; Ritov, Vladimir B.; Matern, Dietrich; Hu, Patrick J.; Fisher, Alfred L.

    2013-01-01

    Recent work has identified changes in the metabolism of the aromatic amino acid tyrosine as a risk factor for diabetes and a contributor to the development of liver cancer. While these findings could suggest a role for tyrosine as a direct regulator of the behavior of cells and tissues, evidence for this model is currently lacking. Through the use of RNAi and genetic mutants, we identify tatn-1, which is the worm ortholog of tyrosine aminotransferase and catalyzes the first step of the conserved tyrosine degradation pathway, as a novel regulator of the dauer decision and modulator of the daf-2 insulin/IGF-1-like (IGFR) signaling pathway in Caenorhabditis elegans. Mutations affecting tatn-1 elevate tyrosine levels in the animal, and enhance the effects of mutations in genes that lie within the daf-2/insulin signaling pathway or are otherwise upstream of daf-16/FOXO on both dauer formation and worm longevity. These effects are mediated by elevated tyrosine levels as supplemental dietary tyrosine mimics the phenotypes produced by a tatn-1 mutation, and the effects still occur when the enzymes needed to convert tyrosine into catecholamine neurotransmitters are missing. The effects on dauer formation and lifespan require the aak-2/AMPK gene, and tatn-1 mutations increase phospho-AAK-2 levels. In contrast, the daf-16/FOXO transcription factor is only partially required for the effects on dauer formation and not required for increased longevity. We also find that the controlled metabolism of tyrosine by tatn-1 may function normally in dauer formation because the expression of the TATN-1 protein is regulated both by daf-2/IGFR signaling and also by the same dietary and environmental cues which influence dauer formation. Our findings point to a novel role for tyrosine as a developmental regulator and modulator of longevity, and support a model where elevated tyrosine levels play a causal role in the development of diabetes and cancer in people. PMID:24385923

  2. Structural basis for the regulation mechanism of the tyrosine kinase CapB from Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Vanesa Olivares-Illana

    2008-06-01

    Full Text Available Bacteria were thought to be devoid of tyrosine-phosphorylating enzymes. However, several tyrosine kinases without similarity to their eukaryotic counterparts have recently been identified in bacteria. They are involved in many physiological processes, but their accurate functions remain poorly understood due to slow progress in their structural characterization. They have been best characterized as copolymerases involved in the synthesis and export of extracellular polysaccharides. These compounds play critical roles in the virulence of pathogenic bacteria, and bacterial tyrosine kinases can thus be considered as potential therapeutic targets. Here, we present the crystal structures of the phosphorylated and unphosphorylated states of the tyrosine kinase CapB from the human pathogen Staphylococcus aureus together with the activator domain of its cognate transmembrane modulator CapA. This first high-resolution structure of a bacterial tyrosine kinase reveals a 230-kDa ring-shaped octamer that dissociates upon intermolecular autophosphorylation. These observations provide a molecular basis for the regulation mechanism of the bacterial tyrosine kinases and give insights into their copolymerase function.

  3. PTB domain-directed substrate targeting in a tyrosine kinase from the unicellular choanoflagellate Monosiga brevicollis.

    Directory of Open Access Journals (Sweden)

    Victoria Prieto-Echagüe

    2011-04-01

    Full Text Available Choanoflagellates are considered to be the closest living unicellular relatives of metazoans. The genome of the choanoflagellate Monosiga brevicollis contains a surprisingly high number and diversity of tyrosine kinases, tyrosine phosphatases, and phosphotyrosine-binding domains. Many of the tyrosine kinases possess combinations of domains that have not been observed in any multicellular organism. The role of these protein interaction domains in M. brevicollis kinase signaling is not clear. Here, we have carried out a biochemical characterization of Monosiga HMTK1, a protein containing a putative PTB domain linked to a tyrosine kinase catalytic domain. We cloned, expressed, and purified HMTK1, and we demonstrated that it possesses tyrosine kinase activity. We used immobilized peptide arrays to define a preferred ligand for the third PTB domain of HMTK1. Peptide sequences containing this ligand sequence are phosphorylated efficiently by recombinant HMTK1, suggesting that the PTB domain of HMTK1 has a role in substrate recognition analogous to the SH2 and SH3 domains of mammalian Src family kinases. We suggest that the substrate recruitment function of the noncatalytic domains of tyrosine kinases arose before their roles in autoinhibition.

  4. Catchment-scale conservation units identified for the threatened Yarra pygmy perch (Nannoperca obscura) in highly modified river systems.

    Science.gov (United States)

    Brauer, Chris J; Unmack, Peter J; Hammer, Michael P; Adams, Mark; Beheregaray, Luciano B

    2013-01-01

    Habitat fragmentation caused by human activities alters metapopulation dynamics and decreases biological connectivity through reduced migration and gene flow, leading to lowered levels of population genetic diversity and to local extinctions. The threatened Yarra pygmy perch, Nannoperca obscura, is a poor disperser found in small, isolated populations in wetlands and streams of southeastern Australia. Modifications to natural flow regimes in anthropogenically-impacted river systems have recently reduced the amount of habitat for this species and likely further limited its opportunity to disperse. We employed highly resolving microsatellite DNA markers to assess genetic variation, population structure and the spatial scale that dispersal takes place across the distribution of this freshwater fish and used this information to identify conservation units for management. The levels of genetic variation found for N. obscura are amongst the lowest reported for a fish species (mean heterozygosity of 0.318 and mean allelic richness of 1.92). We identified very strong population genetic structure, nil to little evidence of recent migration among demes and a minimum of 11 units for conservation management, hierarchically nested within four major genetic lineages. A combination of spatial analytical methods revealed hierarchical genetic structure corresponding with catchment boundaries and also demonstrated significant isolation by riverine distance. Our findings have implications for the national recovery plan of this species by demonstrating that N. obscura populations should be managed at a catchment level and highlighting the need to restore habitat and avoid further alteration of the natural hydrology.

  5. High Elevation Refugia for Bombus terricola (Hymenoptera: Apidae) Conservation and Wild Bees of the White Mountain National Forest.

    Science.gov (United States)

    Tucker, Erika M; Rehan, Sandra M

    2017-01-01

    Many wild bee species are in global decline, yet much is still unknown about their diversity and contemporary distributions. National parks and forests offer unique areas of refuge important for the conservation of rare and declining species populations. Here we present the results of the first biodiversity survey of the bee fauna in the White Mountain National Forest (WMNF). More than a thousand specimens were collected from pan and sweep samples representing 137 species. Three species were recorded for the first time in New England and an additional seven species were documented for the first time in the state of New Hampshire. Four introduced species were also observed in the specimens collected. A checklist of the species found in the WMNF, as well as those found previously in Strafford County, NH, is included with new state records and introduced species noted as well as a map of collecting locations. Of particular interest was the relatively high abundance of Bombus terricola Kirby 1837 found in many of the higher elevation collection sites and the single specimen documented of Bombus fervidus (Fabricius 1798). Both of these bumble bee species are known to have declining populations in the northeast and are categorized as vulnerable on the International Union for Conservation of Nature's Red List. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  6. Characterization of STIP, a multi-domain nuclear protein, highly conserved in metazoans, and essential for embryogenesis in Caenorhabditis elegans

    International Nuclear Information System (INIS)

    Ji Qiongmei; Huang, C.-H.; Peng Jianbin; Hashmi, Sarwar; Ye Tianzhang; Chen Ying

    2007-01-01

    We report here the identification and characterization of STIP, a multi-domain nuclear protein that contains a G-patch, a coiled-coil, and several short tryptophan-tryptophan repeats highly conserved in metazoan species. To analyze their functional role in vivo, we cloned nematode stip-1 genes and determined the spatiotemporal pattern of Caenorhabditis elegans STIP-1 protein. RNA analyses and Western blots revealed that stip-1 mRNA was produced via trans-splicing and translated as a 95-kDa protein. Using reporter constructs, we found STIP-1 to be expressed at all developmental stages and in many tissue/cell types including worm oocyte nuclei. We found that STIP-1 is targeted to the nucleus and forms large polymers with a rod-like shape when expressed in mammalian cells. Using deletion mutants, we mapped the regions of STIP-1 involved in nuclear import and polymer assembly. We further showed that knockdown of C. elegans stip-1 by RNA interference arrested development and resulted in morphologic abnormalities around the 16-cell stage followed by 100% lethality, suggesting its essential role in worm embryogenesis. Importantly, the embryonic lethal phenotype could be faithfully rescued with Drosophila and human genes via transgenic expression. Our data provide the first direct evidence that STIP have a conserved essential nuclear function across metazoans from worms to humans

  7. High Re-Operation Rates Using Conserve Metal-On-Metal Total Hip Articulations

    DEFF Research Database (Denmark)

    Mogensen, S L; Jakobsen, Thomas; Christoffersen, Hardy

    2016-01-01

    INTRODUCTION: Metal-on-metal hip articulations have been intensely debated after reports of adverse reactions and high failure rates. The aim of this study was to retrospectively evaluate the implant of a metal-on.metal total hip articulation (MOM THA) from a single manufacture in a two-center st......INTRODUCTION: Metal-on-metal hip articulations have been intensely debated after reports of adverse reactions and high failure rates. The aim of this study was to retrospectively evaluate the implant of a metal-on.metal total hip articulation (MOM THA) from a single manufacture in a two...

  8. High spatial resolution mapping of land cover types in a priority area for conservation in the Brazilian savanna

    Science.gov (United States)

    Ribeiro, F.; Roberts, D. A.; Hess, L. L.; Davis, F. W.; Caylor, K. K.; Nackoney, J.; Antunes Daldegan, G.

    2017-12-01

    Savannas are heterogeneous landscapes consisting of highly mixed land cover types that lack clear distinct boundaries. The Brazilian Cerrado is a Neotropical savanna considered a biodiversity hotspot for conservation due to its biodiversity richness and rapid transformation of its landscape by crop and pasture activities. The Cerrado is one of the most threatened Brazilian biomes and only 2.2% of its original extent is strictly protected. Accurate mapping and monitoring of its ecosystems and adjacent land use are important to select areas for conservation and to improve our understanding of the dynamics in this biome. Land cover mapping of savannas is difficult due to spectral similarity between land cover types resulting from similar vegetation structure, floristically similar components, generalization of land cover classes, and heterogeneity usually expressed as small patch sizes within the natural landscape. These factors are the major contributor to misclassification and low map accuracies among remote sensing studies in savannas. Specific challenges to map the Cerrado's land cover types are related to the spectral similarity between classes of land use and natural vegetation, such as natural grassland vs. cultivated pasture, and forest ecosystem vs. crops. This study seeks to classify and evaluate the land cover patterns across an area ranked as having extremely high priority for future conservation in the Cerrado. The main objective of this study is to identify the representativeness of each vegetation type across the landscape using high to moderate spatial resolution imagery using an automated scheme. A combination of pixel-based and object-based approaches were tested using RapidEye 3A imagery (5m spatial resolution) to classify the Cerrado's major land cover types. The random forest classifier was used to map the major ecosystems present across the area, and demonstrated to have an effective result with 68% of overall accuracy. Post

  9. Identification of a highly conserved valine-glycine-phenylalanine amino acid triplet required for HIV-1 Nef function

    Directory of Open Access Journals (Sweden)

    Meuwissen Pieter J

    2012-04-01

    Full Text Available Abstract Background The Nef protein of HIV facilitates virus replication and disease progression in infected patients. This role as pathogenesis factor depends on several genetically separable Nef functions that are mediated by interactions of highly conserved protein-protein interaction motifs with different host cell proteins. By studying the functionality of a series of nef alleles from clinical isolates, we identified a dysfunctional HIV group O Nef in which a highly conserved valine-glycine-phenylalanine (VGF region, which links a preceding acidic cluster with the following proline-rich motif into an amphipathic surface was deleted. In this study, we aimed to study the functional importance of this VGF region. Results The dysfunctional HIV group O8 nef allele was restored to the consensus sequence, and mutants of canonical (NL4.3, NA-7, SF2 and non-canonical (B2 and C1422 HIV-1 group M nef alleles were generated in which the amino acids of the VGF region were changed into alanines (VGF→AAA and tested for their capacity to interfere with surface receptor trafficking, signal transduction and enhancement of viral replication and infectivity. We found the VGF motif, and each individual amino acid of this motif, to be critical for downregulation of MHC-I and CXCR4. Moreover, Nef’s association with the cellular p21-activated kinase 2 (PAK2, the resulting deregulation of cofilin and inhibition of host cell actin remodeling, and targeting of Lck kinase to the trans-golgi-network (TGN were affected as well. Of particular interest, VGF integrity was essential for Nef-mediated enhancement of HIV virion infectivity and HIV replication in peripheral blood lymphocytes. For targeting of Lck kinase to the TGN and viral infectivity, especially the phenylalanine of the triplet was essential. At the molecular level, the VGF motif was required for the physical interaction of the adjacent proline-rich motif with Hck. Conclusion Based on these findings, we

  10. Tyrosine and carboxyl protonation changes in the bacteriorhodopsin photocycle. 2. Tyrosine-26 and -64

    International Nuclear Information System (INIS)

    Roepe, P.; Scherrer, P.; Ahl, P.L.; Gupta, S.K.D.; Bogomolni, R.A.; Herzfeld, J.; Rothschild, K.J.

    1987-01-01

    Low-temperature Fourier transform infrared (FTIR) and UV difference spectroscopies combined with selective tyrosine nitration and tyrosine isotopic labeling have been used to investigate the participation of tyrosines-26 and -64 in the bacteriorhodopsin (bR) photocycle. Nitration of Tyr-26 has no detectable effect on the FTIR or UV difference spectra of the BR 570 → K 630 or BR 570 → M 412 transitions. In contrast, nitration of Tyr-64 causes changes in both the FTIR and UV spectra of these transitions. However, this nitration does not alter tyrosine peaks in the FTIR difference spectra which have previously been associated with the protonation of a tyrosinate by K 630 and the deprotonation of a tyrosine by M 412 . Instead, Tyr-64 nitration appears to affect other tyrosine peaks. These results and changes in UV difference spectra upon Tyr-64 nitration are consistent with the deprotonation of Tyr-64 by M 412 as concluded previously. Effects on chromophore vibrations caused by Tyr-64 nitration are unaltered upon reducing the nitrotyrosine to aminotyrosine with sodium dithionite. Finally, nitro-Tyr-64 causes a shift in the frequency of a positive peak at 1739 cm -1 in the BR 570 → M 412 FTIR difference spectrum which reflects the protonation of a carboxyl-containing residue. The shift does not occur for samples containing amino-Tyr-64. These data suggest that Tyr-64 may interact with this carboxyl group

  11. Ancient Exaptation of a CORE-SINE Retroposon into a Highly Conserved Mammalian Neuronal Enhancer of the Proopiomelanocortin Gene

    Science.gov (United States)

    Bumaschny, Viviana F; Low, Malcolm J; Rubinstein, Marcelo

    2007-01-01

    The proopiomelanocortin gene (POMC) is expressed in the pituitary gland and the ventral hypothalamus of all jawed vertebrates, producing several bioactive peptides that function as peripheral hormones or central neuropeptides, respectively. We have recently determined that mouse and human POMC expression in the hypothalamus is conferred by the action of two 5′ distal and unrelated enhancers, nPE1 and nPE2. To investigate the evolutionary origin of the neuronal enhancer nPE2, we searched available vertebrate genome databases and determined that nPE2 is a highly conserved element in placentals, marsupials, and monotremes, whereas it is absent in nonmammalian vertebrates. Following an in silico paleogenomic strategy based on genome-wide searches for paralog sequences, we discovered that opossum and wallaby nPE2 sequences are highly similar to members of the superfamily of CORE-short interspersed nucleotide element (SINE) retroposons, in particular to MAR1 retroposons that are widely present in marsupial genomes. Thus, the neuronal enhancer nPE2 originated from the exaptation of a CORE-SINE retroposon in the lineage leading to mammals and remained under purifying selection in all mammalian orders for the last 170 million years. Expression studies performed in transgenic mice showed that two nonadjacent nPE2 subregions are essential to drive reporter gene expression into POMC hypothalamic neurons, providing the first functional example of an exapted enhancer derived from an ancient CORE-SINE retroposon. In addition, we found that this CORE-SINE family of retroposons is likely to still be active in American and Australian marsupial genomes and that several highly conserved exonic, intronic and intergenic sequences in the human genome originated from the exaptation of CORE-SINE retroposons. Together, our results provide clear evidence of the functional novelties that transposed elements contributed to their host genomes throughout evolution. PMID:17922573

  12. Ancient exaptation of a CORE-SINE retroposon into a highly conserved mammalian neuronal enhancer of the proopiomelanocortin gene.

    Directory of Open Access Journals (Sweden)

    Andrea M Santangelo

    2007-10-01

    Full Text Available The proopiomelanocortin gene (POMC is expressed in the pituitary gland and the ventral hypothalamus of all jawed vertebrates, producing several bioactive peptides that function as peripheral hormones or central neuropeptides, respectively. We have recently determined that mouse and human POMC expression in the hypothalamus is conferred by the action of two 5' distal and unrelated enhancers, nPE1 and nPE2. To investigate the evolutionary origin of the neuronal enhancer nPE2, we searched available vertebrate genome databases and determined that nPE2 is a highly conserved element in placentals, marsupials, and monotremes, whereas it is absent in nonmammalian vertebrates. Following an in silico paleogenomic strategy based on genome-wide searches for paralog sequences, we discovered that opossum and wallaby nPE2 sequences are highly similar to members of the superfamily of CORE-short interspersed nucleotide element (SINE retroposons, in particular to MAR1 retroposons that are widely present in marsupial genomes. Thus, the neuronal enhancer nPE2 originated from the exaptation of a CORE-SINE retroposon in the lineage leading to mammals and remained under purifying selection in all mammalian orders for the last 170 million years. Expression studies performed in transgenic mice showed that two nonadjacent nPE2 subregions are essential to drive reporter gene expression into POMC hypothalamic neurons, providing the first functional example of an exapted enhancer derived from an ancient CORE-SINE retroposon. In addition, we found that this CORE-SINE family of retroposons is likely to still be active in American and Australian marsupial genomes and that several highly conserved exonic, intronic and intergenic sequences in the human genome originated from the exaptation of CORE-SINE retroposons. Together, our results provide clear evidence of the functional novelties that transposed elements contributed to their host genomes throughout evolution.

  13. Identification of immunogenic HLA-B7 "Achilles' heel" epitopes within highly conserved regions of HIV

    DEFF Research Database (Denmark)

    De Groot, Anne S; Rivera, Daniel S; McMurry, Julie A

    2008-01-01

    Genetic polymorphisms in class I human leukocyte antigen molecules (HLA) have been shown to determine susceptibility to HIV infection as well as the rate of progression to AIDS. In particular, the HLA-B7 supertype has been shown to be associated with high viral loads and rapid progression to dise...

  14. Chlorinated tyrosine derivatives in insect cuticle

    DEFF Research Database (Denmark)

    Andersen, Svend Olav

    2004-01-01

    A method for quantitative measurement of 3-monochlorotyrosine and 3,5-dichlorotyrosine in insect cuticles is described, and it is used for determination of their distribution in various cuticular regions in nymphs and adults of the desert locust, Schistocerca gregaria. The two chlorinated tyrosine......, not-yet sclerotized cuticle of adult femur and tibia, the amounts increased rapidly during the first 24 h after ecdysis and more slowly during the next two weeks. Control analyses using stable isotope dilution mass spectrometry have confirmed that the chlorinated tyrosines are not artifacts formed...

  15. Protein-Tyrosine Phosphorylation in Bacillus subtilis

    DEFF Research Database (Denmark)

    Mijakovic, Ivan; Petranovic, Dina; Bottini, N.

    2005-01-01

    phosphorylation, indicating that this post-translational modifi cation could regulate physiological processes ranging from stress response and exopolysaccharide synthesis to DNA metabolism. Some interesting work in this fi eld was done in Bacillus subtilis , and we here present the current state of knowledge...... on protein-tyrosine phosphorylation in this gram-positive model organism. With its two kinases, two kinase modulators, three phosphatases and at least four different tyrosine-phosphorylated substrates, B. subtilis is the bacterium with the highest number of presently known participants in the global network...

  16. Tyrosine kinase fusion genes in pediatric BCR-ABL1-like acute lymphoblastic leukemia

    Science.gov (United States)

    Boer, Judith M.; Steeghs, Elisabeth M.P.; Marchante, João R.M.; Boeree, Aurélie; Beaudoin, James J.; Berna Beverloo, H.; Kuiper, Roland P.; Escherich, Gabriele; van der Velden, Vincent H.J.; van der Schoot, C. Ellen; de Groot-Kruseman, Hester A.; Pieters, Rob; den Boer, Monique L.

    2017-01-01

    Approximately 15% of pediatric B cell precursor acute lymphoblastic leukemia (BCP-ALL) is characterized by gene expression similar to that of BCR-ABL1-positive disease and unfavorable prognosis. This BCR-ABL1-like subtype shows a high frequency of B-cell development gene aberrations and tyrosine kinase-activating lesions. To evaluate the clinical significance of tyrosine kinase gene fusions in children with BCP-ALL, we studied the frequency of recently identified tyrosine kinase fusions, associated genetic features, and prognosis in a representative Dutch/German cohort. We identified 14 tyrosine kinase fusions among 77 BCR-ABL1-like cases (18%) and none among 76 non-BCR-ABL1-like B-other cases. Novel exon fusions were identified for RCSD1-ABL2 and TERF2-JAK2. JAK2 mutation was mutually exclusive with tyrosine kinase fusions and only occurred in cases with high CRLF2 expression. The non/late response rate and levels of minimal residual disease in the fusion-positive BCR-ABL1-like group were higher than in the non-BCR-ABL1-like B-others (p<0.01), and also higher, albeit not statistically significant, compared with the fusion-negative BCR-ABL1-like group. The 8-year cumulative incidence of relapse in the fusion-positive BCR-ABL1-like group (35%) was comparable with that in the fusion-negative BCR-ABL1-like group (35%), and worse than in the non-BCR-ABL1-like B-other group (17%, p=0.07). IKZF1 deletions, predominantly other than the dominant-negative isoform and full deletion, co-occurred with tyrosine kinase fusions. This study shows that tyrosine kinase fusion-positive cases are a high-risk subtype of BCP-ALL, which warrants further studies with specific kinase inhibitors to improve outcome. PMID:27894077

  17. A highly conserved Poc1 protein characterized in embryos of the hydrozoan Clytia hemisphaerica: localization and functional studies.

    Directory of Open Access Journals (Sweden)

    Cécile Fourrage

    Full Text Available Poc1 (Protein of Centriole 1 proteins are highly conserved WD40 domain-containing centriole components, well characterized in the alga Chlamydomonas, the ciliated protazoan Tetrahymena, the insect Drosophila and in vertebrate cells including Xenopus and zebrafish embryos. Functions and localizations related to the centriole and ciliary axoneme have been demonstrated for Poc1 in a range of species. The vertebrate Poc1 protein has also been reported to show an additional association with mitochondria, including enrichment in the specialized "germ plasm" region of Xenopus oocytes. We have identified and characterized a highly conserved Poc1 protein in the cnidarian Clytia hemisphaerica. Clytia Poc1 mRNA was found to be strongly expressed in eggs and early embryos, showing a punctate perinuclear localization in young oocytes. Fluorescence-tagged Poc1 proteins expressed in developing embryos showed strong localization to centrioles, including basal bodies. Anti-human Poc1 antibodies decorated mitochondria in Clytia, as reported in human cells, but failed to recognise endogenous or fluorescent-tagged Clytia Poc1. Injection of specific morpholino oligonucleotides into Clytia eggs prior to fertilization to repress Poc1 mRNA translation interfered with cell division from the blastula stage, likely corresponding to when neosynthesis normally takes over from maternally supplied protein. Cell cycle lengthening and arrest were observed, phenotypes consistent with an impaired centriolar biogenesis or function. The specificity of the defects could be demonstrated by injection of synthetic Poc1 mRNA, which restored normal development. We conclude that in Clytia embryos, Poc1 has an essentially centriolar localization and function.

  18. Phenylketonuria : tyrosine supplementation in phenylalanine-restricted diets

    NARCIS (Netherlands)

    van Spronsen, FJ; van Rijn, M; Bekhof, J; Koch, R; Smit, PGA

    Treatment of phenylketonuria (PKU) consists of restriction of natural protein and provision of a protein substitute that lacks phenylalanine but is enriched in tyrosine. Large and unexplained differences exist, however, in the tyrosine enrichment of the protein substitutes. Furthermore, some

  19. Receptor tyrosine kinase signaling: a view from quantitative proteomics

    DEFF Research Database (Denmark)

    Dengjel, Joern; Kratchmarova, Irina; Blagoev, Blagoy

    2009-01-01

    Growth factor receptor signaling via receptor tyrosine kinases (RTKs) is one of the basic cellular communication principals found in all metazoans. Extracellular signals are transferred via membrane spanning receptors into the cytoplasm, reversible tyrosine phosphorylation being the hallmark of all...

  20. Computation and Analysis of High Rocky Slope Safety in a Water Conservancy Project

    Directory of Open Access Journals (Sweden)

    Meng Yang

    2015-01-01

    Full Text Available An integrated method, covering the actual monitoring analysis, practical geological model, and theoretical mathematical simulation model, is systematically proposed and successfully applied. Deformation characteristic of a unique high rocky slope was firstly analyzed from multiple angles and multiple layers by changeable elevations and distances. Arrangements of monitoring points were listed and monitoring equipment was designed to comprise a complete monitoring system. Present larger displacement was concluded for bottom larger displacement caused by water erosion and middle larger displacement formed by seepage. Temporal and spatial displacements rule study of multiple-points linkage effects with water factor proved this conclusion. To better excavate useful message and analyze the deep rule from the practical monitoring data, the slope geological model was conducted and rock mechanic parameters were researched. Finally, a unique three-dimensional finite element model was applied to approach the structure character using numerical simulations. The corresponding strength criterion was used to determine the safety coefficient by selecting a typical section. Subsequently, an integrated three-dimensional finite element model of the slope and dam was developed and more detailed deformation evolution mechanism was revealed. This study is expected to provide a powerful and systematic method to analyze very high, important, and dangerous slopes.

  1. Constrained instanton and baryon number non-conservation at high energies

    International Nuclear Information System (INIS)

    Sil'vestrov, P.G.

    1992-01-01

    The main subject of this paper is the calculation of corrections to instanton action ΔS∼(mρ) 4 log(mρ)/g 2 (ρ is the intanton radius) in the SU(2) Yang-Mills theory. The total cross section for baryon number violating processes at high energies is usually parametrized as σ tat ∝exp(4π/αF(ε)), where α=g 2 /4π, ε=√s/E 0 , E 0 =√6πm w /α. In the present paper the third nontrivial term of the F(ε) expansion is obtained. The unknown correction to F(ε) are expected to be of the order of ε 8/3 . The total cross section is extremely sensitive to the value of single instanton action. For sufficiently heavy Higgs boson the ρ-dependent part of the instanton action is changed drastically. 21 refs.; 1 fig

  2. Oncogenic activation of v-kit involves deletion of a putative tyrosine-substrate interaction site.

    Science.gov (United States)

    Herbst, R; Munemitsu, S; Ullrich, A

    1995-01-19

    The transforming gene of the Hardy-Zuckerman-4 strain of feline sarcoma virus, v-kit, arose by transduction of the cellular c-kit gene, which encodes the receptor tyrosine kinase (RTK) p145c-kit. To gain insight into the molecular basis of the v-kit transforming potential, we characterized the feline c-kit by cDNA cloning. Comparison of the feline v-kit and c-kit sequences revealed, in addition to deletions of the extracellular and transmembrane domains, three additional mutations in the v-kit oncogene product: deletion of tyrosine-569 and valine-570, the exchange of aspartate at position 761 to glycine, and replacement of the C-terminal 50 amino acids by five unrelated residues. Examinations of individual v-kit mutations in the context of chimeric receptors yielded inhibitory effects for some mutants on both autophosphorylation and substrate phosphorylation functions. In contrast, deletion of tyrosine-569 and valine-570 significantly enhanced transforming and mitogenic activities of p145c-kit, while the other mutations had no significant effects. Conservation in subclass III RTKs and the identification of the corresponding residue in beta PDGF-R, Y579, as a binding site for src family tyrosine kinases suggests an important role for Y568 in kit signal regulation and the definition of its oncogenic potential. Repositioning of Y571 by an inframe two codon deletion may be the crucial alteration resulting in enhancement of v-kit oncogenic activity.

  3. Evolution: Weevils Get Tough on Symbiotic Tyrosine.

    Science.gov (United States)

    Dale, Colin

    2017-12-04

    Weevils, which represent one of the most diverse groups of terrestrial insects in nature, obtain a tough exoskeleton through the activity of an ancient bacterial symbiont with a tiny genome that serves as a factory for the production of tyrosine. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Morphological Features of Tyrosine Hydroxylase Immunoreactive ...

    African Journals Online (AJOL)

    The current immunohistochemical study used the antibody against tyrosine hydroxylase (TH) to observe the immunoreactive elements in the mouse pancreas. The results indicated the presence of immunoreactive nerve fibers and endocrine cells. The immunopositive nerve fibers appeared as thick and thin bundles; thick ...

  5. Enzyme kinetic characterization of protein tyrosine phosphatases

    DEFF Research Database (Denmark)

    Peters, Günther H.J.; Branner, S.; Møller, K. B.

    2003-01-01

    Protein tyrosine phosphatases (PTPs) play a central role in cellular signaling processes, resulting in an increased interest in modulating the activities of PTPs. We therefore decided to undertake a detailed enzyme kinetic evaluation of various transmembrane and cytosolic PTPs (PTPalpha, PTPbeta...

  6. [Development and Application of Catalytic Tyrosine Modification].

    Science.gov (United States)

    Sato, Shinichi; Tsushima, Michihiko; Nakamura, Kosuke; Nakamura, Hiroyuki

    2018-01-01

     The chemical labeling of proteins with synthetic probes is a key technique used in chemical biology, protein-based therapy, and material science. Much of the chemical labeling of native proteins, however, depends on the labeling of lysine and cysteine residues. While those methods have significantly contributed to native protein labeling, alternative methods that can modify different amino acid residues are still required. Herein we report the development of a novel methodology of tyrosine labeling, inspired by the luminol chemiluminescence reaction. Tyrosine residues are often exposed on a protein's surface and are thus expected to be good targets for protein functionalization. In our studies so far, we have found that 1) hemin oxidatively activates luminol derivatives as a catalyst, 2) N-methyl luminol derivative specifically forms a covalent bond with a tyrosine residue among the 20 kinds of natural amino acid residues, and 3) the efficiency of tyrosine labeling with N-methyl luminol derivative is markedly improved by using horseradish peroxidase (HRP) as a catalyst. We were able to use molecular oxygen as an oxidant under HRP/NADH conditions. By using these methods, the functionalization of purified proteins was carried out. Because N-methyl luminol derivative is an excellent protein labeling reagent that responds to the activation of peroxidase, this new method is expected to open doors to such biological applications as the signal amplification of HRP-conjugated antibodies and the detection of protein association in combination with peroxidase-tag technology.

  7. Phenylketonuria : Tyrosine beyond the phenylalanine-restricted diet

    NARCIS (Netherlands)

    van Spronsen, FJ; Smit, PGA; Koch, R

    Controversies exist on the role of tyrosine in the pathogenesis of phenylketonuria (PKU) and, consequently, on the therapeutic role of tyrosine. This review examines data and theoretical considerations on the role of tyrosine in the pathogenesis and treatment of PKU. It is concluded that treatment

  8. Mice selectively bred for high voluntary wheel-running behavior conserve more fat despite increased exercise.

    Science.gov (United States)

    Hiramatsu, Layla; Garland, Theodore

    2018-04-20

    Physical activity is an important component of energy expenditure, and acute changes in activity can lead to energy imbalances that affect body composition, even under ad libitum food availability. One example of acute increases in physical activity is four replicate, selectively-bred High Runner (HR) lines of mice that voluntarily run ~3-fold more wheel revolutions per day over 6-day trials and are leaner, as compared with four non-selected control (C) lines. We expected that voluntary exercise would increase food consumption, build lean mass, and reduce fat mass, but that these effects would likely differ between HR and C lines or between the sexes. We compared wheel running, cage activity, food consumption, and body composition between HR and C lines for young adults of both sexes, and examined interrelationships of those traits across 6 days of wheel access. Before wheel testing, HR mice weighed less than C, primarily due to reduced lean mass, and females were lighter than males, entirely due to lower lean mass. Over 6 days of wheel access, all groups tended to gain small amounts of lean mass, but lose fat mass. HR mice lost less fat than C mice, in spite of much higher activity levels, resulting in convergence to a fat mass of ~1.7 g for all 4 groups. HR mice consumed more food than C mice (with body mass as a covariate), even accounting for their higher activity levels. No significant sex-by-linetype interactions were observed for any of the foregoing traits. Structural equation models showed that the four sex-by-linetype groups differed considerably in the complex phenotypic architecture of these traits. Interrelationships among traits differed by genetic background and sex, lending support to the idea that recommendations regarding weight management, diet, and exercise may need to be tailored to the individual level. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Expression and genomic analysis of midasin, a novel and highly conserved AAA protein distantly related to dynein

    Directory of Open Access Journals (Sweden)

    Gibbons I R

    2002-07-01

    Full Text Available Abstract Background The largest open reading frame in the Saccharomyces genome encodes midasin (MDN1p, YLR106p, an AAA ATPase of 560 kDa that is essential for cell viability. Orthologs of midasin have been identified in the genome projects for Drosophila, Arabidopsis, and Schizosaccharomyces pombe. Results Midasin is present as a single-copy gene encoding a well-conserved protein of ~600 kDa in all eukaryotes for which data are available. In humans, the gene maps to 6q15 and encodes a predicted protein of 5596 residues (632 kDa. Sequence alignments of midasin from humans, yeast, Giardia and Encephalitozoon indicate that its domain structure comprises an N-terminal domain (35 kDa, followed by an AAA domain containing six tandem AAA protomers (~30 kDa each, a linker domain (260 kDa, an acidic domain (~70 kDa containing 35–40% aspartate and glutamate, and a carboxy-terminal M-domain (30 kDa that possesses MIDAS sequence motifs and is homologous to the I-domain of integrins. Expression of hemagglutamin-tagged midasin in yeast demonstrates a polypeptide of the anticipated size that is localized principally in the nucleus. Conclusions The highly conserved structure of midasin in eukaryotes, taken in conjunction with its nuclear localization in yeast, suggests that midasin may function as a nuclear chaperone and be involved in the assembly/disassembly of macromolecular complexes in the nucleus. The AAA domain of midasin is evolutionarily related to that of dynein, but it appears to lack a microtubule-binding site.

  10. Toxicity and cosmetic result of partial breast high-dose-rate interstitial brachytherapy for conservatively operated early breast cancer

    International Nuclear Information System (INIS)

    Xiu Xia; Tripuraneni Prabhakar; Giap Huan; Lin Ray; Chu Colin

    2007-01-01

    Objective: Objective To study the method, side effects and cosmetic outcome of high- dose-rate (HDR) accelerated partial breast interstitial irradiation (APBI) alone in early stage breast cancer' after conservative surgery. Methods: From February 2002 to June 2003,47 breast cancer lesions from 46 patients suffering from stage I/II breast cancer were treated with HDR 192 Ir APBI after conservative surgery. All patients were over 40 year-old, with T1-2N0-1 (≤3 lymph nodes positive), surgical margin > 1-2 mm, but those having lobular or inflammatory breast cancer were excluded. HDR brachytherapy with 34 Gy, 10 fractions/5 days was used after surgery, toxic reaction and cosmetic outcome were observed in one month, 6 and 12 months respectively. Results: Follow up of 1846 months, 34 months was carried out for the whole group. During the treatment, acute reactions including: erythema, edema, tenderness and infection, all under I-II grade, none of III-IV grade were observed in 21 patients(46%); late toxicity reactions: skin fibrosis, breast tenderness, fat necrosis, and telangiectasia, totally 20 patients (43%) were observed: 2 patients in III grade but one patient received 6 cycle chemotherapy. The result of cosmetic outcome evaluation was excellent or good, at 6 months 95% and 12 months 98%, respectively, but there was no recurfence. Conclusions: Excellent and favorable cosmetic results are noted after APBI by interstitial alone. Acute and late reactions are few. Long term observation is necessary for the rate of' local control. (authors)

  11. Tracer experiment administering L-phenylalanine-U-14C and L-tyrosine-U-14C to the tissue slices of bamboo shoots

    International Nuclear Information System (INIS)

    Kozukue, E.; Mizuno, S.

    1987-01-01

    Uniformly 14 C-labeled L-phenylalanine and L-tyrosine were administered to tissue slices of both top and base sections of bamboo shoots. Alcohol soluble substances were extracted and then separated into organic acid, sugar and amino acid fractions by ion exchange chromatography. The homogentisic acid fraction among the organic acids was collected by high-performance liquid chromatography (HPLC) and its radioactivity was measured, while the alcohol insoluble residue was used for the analysis of lignin aldehyde by the method of alkaline nitrobenzene oxidation. 1. The two labeled amino acids were steadily incorporated into the tissues during incubation and rapidly converted to organic acid, sugar and alcohol insoluble residue, especially the latter. 2. On determining the amount of phenylalanine converted to tyrosine, it was found that this was extremely small. 3. The incorporation of phenylalanine-U- 14 C into alcohol insoluble residue was higher than that of tyrosine in both sections. 4. Although the conversion into lignin aldehyde from phenylalanine-U- 14 C was higher than that from tyrosine-U- 14 C, it was found that tyrosine incorporated into the shoots was converted to a remarkable extent for formation of lignin aldehyde. 5. The incorporation of phenylalanine and tyrosine into homogentisic acid was very low. From these results, we assume that the conversion of phenylalanine to tyrosine or of tyrosine to homogentisic acid is very small, and that a part of the high amount of tyrosine in the shoots may be used for formation of lignin

  12. A microbially derived tyrosine-sulfated peptide mimics a plant peptide hormone.

    Science.gov (United States)

    Pruitt, Rory N; Joe, Anna; Zhang, Weiguo; Feng, Wei; Stewart, Valley; Schwessinger, Benjamin; Dinneny, José R; Ronald, Pamela C

    2017-07-01

    The biotrophic pathogen Xanthomonas oryzae pv. oryzae (Xoo) produces a sulfated peptide named RaxX, which shares similarity to peptides in the PSY (plant peptide containing sulfated tyrosine) family. We hypothesize that RaxX mimics the growth-stimulating activity of PSY peptides. Root length was measured in Arabidopsis and rice treated with synthetic RaxX peptides. We also used comparative genomic analyses and reactive oxygen species burst assays to evaluate the activity of RaxX and PSY peptides. Here we found that a synthetic sulfated RaxX derivative comprising 13 residues (RaxX13-sY), highly conserved between RaxX and PSY, induces root growth in Arabidopsis and rice in a manner similar to that triggered by PSY. We identified residues that are required for activation of immunity mediated by the rice XA21 receptor but that are not essential for root growth induced by PSY. Finally, we showed that a Xanthomonas strain lacking raxX is impaired in virulence. These findings suggest that RaxX serves as a molecular mimic of PSY peptides to facilitate Xoo infection and that XA21 has evolved the ability to recognize and respond specifically to the microbial form of the peptide. © 2017 UT-Battelle LLC. New Phytologist © 2017 New Phytologist Trust.

  13. Selective Sensing of Tyrosine Phosphorylation in Peptides Using Terbium(III Complexes

    Directory of Open Access Journals (Sweden)

    Jun Sumaoka

    2016-01-01

    Full Text Available Phosphorylation of tyrosine residues in proteins, as well as their dephosphorylation, is closely related to various diseases. However, this phosphorylation is usually accompanied by more abundant phosphorylation of serine and threonine residues in the proteins and covers only 0.05% of the total phosphorylation. Accordingly, highly selective detection of phosphorylated tyrosine in proteins is an urgent subject. In this review, recent developments in this field are described. Monomeric and binuclear TbIII complexes, which emit notable luminescence only in the presence of phosphotyrosine (pTyr, have been developed. There, the benzene ring of pTyr functions as an antenna and transfers its photoexcitation energy to the TbIII ion as the emission center. Even in the coexistence of phosphoserine (pSer and phosphothreonine (pThr, pTyr can be efficintly detected with high selectivity. Simply by adding these TbIII complexes to the solutions, phosphorylation of tyrosine in peptides by protein tyrosine kinases and dephosphorylation by protein tyrosine phosphatases can be successfully visualized in a real-time fashion. Furthermore, the activities of various inhibitors on these enzymes are quantitatively evaluated, indicating a strong potential of the method for efficient screening of eminent inhibitors from a number of candidates.

  14. Identification and analysis of a novel protein-tyrosine kinase from bovine thymus

    International Nuclear Information System (INIS)

    Zioncheck, T.F.; Harrison, M.L.; Geahlen, R.L.

    1986-01-01

    A cytosolic protein-tyrosine kinase has been identified and purified to near homogeneity from calf thymus by using the phosphorylation of the tyrosine-containing peptide angiotensin I as an assay. Specific peptide phosphorylating activity was enhanced by carrying out the assay at high ionic strength (2M NaCl). The inclusion of NaCl at this concentration acts to stimulate endogenous protein-tyrosine kinase activity while simultaneously inhibiting other endogenous kinases. The purification procedure involved extraction of the enzyme from calf-thymus and sequential chromatography on columns of DEAE-cellulose, heparin-agarose, casein-sepharose, butylagarose, and Sephadex G-75. Analysis of the most highly purified preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single Coomassie blue-stained band of 41 KDa. This molecular weight was consistent with results obtained from gel filtration, indicating that the enzyme exists as a monomer. The enzyme has also been found to catalyze an autophosphorylation reaction. Incubation of the enzyme with Mn 2+ and [γ- 32 P]ATP led to its modification on a tyrosine residue. Phosphopeptide mapping experiments indicated that the 41 KDa kinase was distinct from p56, the major membrane-associated protein-tyrosine kinase in T lymphocytes

  15. Distinct activation phenotype of a highly conserved novel HLA-B57-restricted epitope during dengue virus infection.

    Science.gov (United States)

    Townsley, Elizabeth; Woda, Marcia; Thomas, Stephen J; Kalayanarooj, Siripen; Gibbons, Robert V; Nisalak, Ananda; Srikiatkhachorn, Anon; Green, Sharone; Stephens, Henry A F; Rothman, Alan L; Mathew, Anuja

    2014-01-01

    Variation in the sequence of T-cell epitopes between dengue virus (DENV) serotypes is believed to alter memory T-cell responses during second heterologous infections. We identified a highly conserved, novel, HLA-B57-restricted epitope on the DENV NS1 protein. We predicted higher frequencies of B57-NS1(26-34) -specific CD8(+) T cells in peripheral blood mononuclear cells from individuals undergoing secondary rather than primary DENV infection. However, high tetramer-positive T-cell frequencies during acute infection were seen in only one of nine subjects with secondary infection. B57-NS1(26-34) -specific and other DENV epitope-specific CD8(+) T cells, as well as total CD8(+) T cells, expressed an activated phenotype (CD69(+) and/or CD38(+)) during acute infection. In contrast, expression of CD71 was largely limited to DENV epitope-specific CD8(+) T cells. In vitro stimulation of cell lines indicated that CD71 expression was differentially sensitive to stimulation by homologous and heterologous variant peptides. CD71 may represent a useful marker of antigen-specific T-cell activation. © 2013 John Wiley & Sons Ltd.

  16. Genome Analysis of Conserved Dehydrin Motifs in Vascular Plants

    Directory of Open Access Journals (Sweden)

    Ahmad A. Malik

    2017-05-01

    Full Text Available Dehydrins, a large family of abiotic stress proteins, are defined by the presence of a mostly conserved motif known as the K-segment, and may also contain two other conserved motifs known as the Y-segment and S-segment. Using the dehydrin literature, we developed a sequence motif definition of the K-segment, which we used to create a large dataset of dehydrin sequences by searching the Pfam00257 dehydrin dataset and the Phytozome 10 sequences of vascular plants. A comprehensive analysis of these sequences reveals that lysine residues are highly conserved in the K-segment, while the amino acid type is often conserved at other positions. Despite the Y-segment name, the central tyrosine is somewhat conserved, but can be substituted with two other small aromatic amino acids (phenylalanine or histidine. The S-segment contains a series of serine residues, but in some proteins is also preceded by a conserved LHR sequence. In many dehydrins containing all three of these motifs the S-segment is linked to the K-segment by a GXGGRRKK motif (where X can be any amino acid, suggesting a functional linkage between these two motifs. An analysis of the sequences shows that the dehydrin architecture and several biochemical properties (isoelectric point, molecular mass, and hydrophobicity score are dependent on each other, and that some dehydrin architectures are overexpressed during certain abiotic stress, suggesting that they may be optimized for a specific abiotic stress while others are involved in all forms of dehydration stress (drought, cold, and salinity.

  17. The biological activity of the human epidermal growth factor receptor is positively regulated by its C-terminal tyrosines

    DEFF Research Database (Denmark)

    Helin, K; Velu, T; Martin, P

    1991-01-01

    mutants in the full length receptor. EGF-dependent transforming ability of the single point mutants is similar to that of the wild type, while that of double mutants is decreased and an even lower activity is present in the triple mutant. In each bioassay, including EGF-dependent focal transformation...... biologically. The EGF-R kinase activity is affected by tyrosine substitution since in vitro phosphorylation of exogenous substrates is reduced in the double and triple mutants. Autophosphorylation, in vivo and in vitro, is also reduced, but not totally abolished in the triple point mutant and Dc123 indicating......The epidermal growth factor receptor (EGF-R) C-terminus contains three conserved tyrosines (Y-1068, Y-1148, Y-1173) which are phosphorylated upon EGF activation. To clarify the functional role of these tyrosines, each has been mutated to phenylalanine and studied as single, double and triple...

  18. A Web-Based GIS for Reporting Water Usage in the High Plains Underground Water Conservation District

    Science.gov (United States)

    Jia, M.; Deeds, N.; Winckler, M.

    2012-12-01

    The High Plains Underground Water Conservation District (HPWD) is the largest and oldest of the Texas water conservation districts, and oversees approximately 1.7 million irrigated acres. Recent rule changes have motivated HPWD to develop a more automated system to allow owners and operators to report well locations, meter locations, meter readings, the association between meters and wells, and contiguous acres. INTERA, Inc. has developed a web-based interactive system for HPWD water users to report water usage and for the district to better manage its water resources. The HPWD web management system utilizes state-of-the-art GIS techniques, including cloud-based Amazon EC2 virtual machine, ArcGIS Server, ArcSDE and ArcGIS Viewer for Flex, to support web-based water use management. The system enables users to navigate to their area of interest using a well-established base-map and perform a variety of operations and inquiries against their spatial features. The application currently has six components: user privilege management, property management, water meter registration, area registration, meter-well association and water use report. The system is composed of two main databases: spatial database and non-spatial database. With the help of Adobe Flex application at the front end and ArcGIS Server as the middle-ware, the spatial feature geometry and attributes update will be reflected immediately in the back end. As a result, property owners, along with the HPWD staff, collaborate together to weave the fabric of the spatial database. Interactions between the spatial and non-spatial databases are established by Windows Communication Foundation (WCF) services to record water-use report, user-property associations, owner-area associations, as well as meter-well associations. Mobile capabilities will be enabled in the near future for field workers to collect data and synchronize them to the spatial database. The entire solution is built on a highly scalable cloud

  19. Conservation Value

    OpenAIRE

    Tisdell, Clement A.

    2010-01-01

    This paper outlines the significance of the concept of conservation value and discusses ways in which it is determined paying attention to views stemming from utilitarian ethics and from deontological ethics. The importance of user costs in relation to economic decisions about the conservation and use of natural resources is emphasised. Particular attention is given to competing views about the importance of conserving natural resources in order to achieve economic sustainability. This then l...

  20. Quantitative Tyrosine Phosphoproteomics of Epidermal Growth Factor Receptor (EGFR) Tyrosine Kinase Inhibitor-treated Lung Adenocarcinoma Cells Reveals Potential Novel Biomarkers of Therapeutic Response.

    Science.gov (United States)

    Zhang, Xu; Maity, Tapan; Kashyap, Manoj K; Bansal, Mukesh; Venugopalan, Abhilash; Singh, Sahib; Awasthi, Shivangi; Marimuthu, Arivusudar; Charles Jacob, Harrys Kishore; Belkina, Natalya; Pitts, Stephanie; Cultraro, Constance M; Gao, Shaojian; Kirkali, Guldal; Biswas, Romi; Chaerkady, Raghothama; Califano, Andrea; Pandey, Akhilesh; Guha, Udayan

    2017-05-01

    Mutations in the Epidermal growth factor receptor (EGFR) kinase domain, such as the L858R missense mutation and deletions spanning the conserved sequence 747 LREA 750 , are sensitive to tyrosine kinase inhibitors (TKIs). The gatekeeper site residue mutation, T790M accounts for around 60% of acquired resistance to EGFR TKIs. The first generation EGFR TKIs, erlotinib and gefitinib, and the second generation inhibitor, afatinib are FDA approved for initial treatment of EGFR mutated lung adenocarcinoma. The predominant biomarker of EGFR TKI responsiveness is the presence of EGFR TKI-sensitizing mutations. However, 30-40% of patients with EGFR mutations exhibit primary resistance to these TKIs, underscoring the unmet need of identifying additional biomarkers of treatment response. Here, we sought to characterize the dynamics of tyrosine phosphorylation upon EGFR TKI treatment of mutant EGFR-driven human lung adenocarcinoma cell lines with varying sensitivity to EGFR TKIs, erlotinib and afatinib. We employed stable isotope labeling with amino acids in cell culture (SILAC)-based quantitative mass spectrometry to identify and quantify tyrosine phosphorylated peptides. The proportion of tyrosine phosphorylated sites that had reduced phosphorylation upon erlotinib or afatinib treatment correlated with the degree of TKI-sensitivity. Afatinib, an irreversible EGFR TKI, more effectively inhibited tyrosine phosphorylation of a majority of the substrates. The phosphosites with phosphorylation SILAC ratios that correlated with the TKI-sensitivity of the cell lines include sites on kinases, such as EGFR-Y1197 and MAPK7-Y221, and adaptor proteins, such as SHC1-Y349/350, ERRFI1-Y394, GAB1-Y689, STAT5A-Y694, DLG3-Y705, and DAPP1-Y139, suggesting these are potential biomarkers of TKI sensitivity. DAPP1, is a novel target of mutant EGFR signaling and Y-139 is the major site of DAPP1 tyrosine phosphorylation. We also uncovered several off-target effects of these TKIs, such as MST1R-Y1238

  1. Tyrosine 110 in the measles virus phosphoprotein is required to block STAT1 phosphorylation

    International Nuclear Information System (INIS)

    Devaux, Patricia; Messling, Veronika von; Songsungthong, Warangkhana; Springfeld, Christoph; Cattaneo, Roberto

    2007-01-01

    The measles virus (MV) P gene encodes three proteins: P, an essential polymerase cofactor, and C and V, which have multiple functions including immune evasion. We show here that the MV P protein also contributes to immune evasion, and that tyrosine 110 is required to block nuclear translocation of the signal transducer and activator of transcription factors (STAT) after interferon type I treatment. In particular, MV P inhibits STAT1 phosphorylation. This is shown not only by transient expression but also by reverse genetic analyses based on a new functional infectious cDNA derived from a MV vaccine vial (Moraten strain). Our study also identifies a conserved sequence around P protein tyrosine 110 as a candidate interaction site with a cellular protein

  2. Tyrosine 842 in the activation loop is required for full transformation by the oncogenic mutant FLT3-ITD.

    Science.gov (United States)

    Kazi, Julhash U; Chougule, Rohit A; Li, Tianfeng; Su, Xianwei; Moharram, Sausan A; Rupar, Kaja; Marhäll, Alissa; Gazi, Mohiuddin; Sun, Jianmin; Zhao, Hui; Rönnstrand, Lars

    2017-07-01

    The type III receptor tyrosine kinase FLT3 is frequently mutated in acute myeloid leukemia. Oncogenic FLT3 mutants display constitutive activity leading to aberrant cell proliferation and survival. Phosphorylation on several critical tyrosine residues is known to be essential for FLT3 signaling. Among these tyrosine residues, Y842 is located in the so-called activation loop. The position of this tyrosine residue is well conserved in all receptor tyrosine kinases. It has been reported that phosphorylation of the activation loop tyrosine is critical for catalytic activity for some but not all receptor tyrosine kinases. The role of Y842 residue in FLT3 signaling has not yet been studied. In this report, we show that Y842 is not important for FLT3 activation or ubiquitination but plays a critical role in regulating signaling downstream of the receptor as well as controlling receptor stability. We found that mutation of Y842 in the FLT3-ITD oncogenic mutant background reduced cell viability and increased apoptosis. Furthermore, the introduction of the Y842 mutation in the FLT3-ITD background led to a dramatic reduction in in vitro colony forming capacity. Additionally, mice injected with cells expressing FLT3-ITD/Y842F displayed a significant delay in tumor formation, compared to FLT3-ITD expressing cells. Microarray analysis comparing gene expression regulated by FLT3-ITD versus FLT3-ITD/Y842F demonstrated that mutation of Y842 causes suppression of anti-apoptotic genes. Furthermore, we showed that cells expressing FLT3-ITD/Y842F display impaired activity of the RAS/ERK pathway due to reduced interaction between FLT3 and SHP2 leading to reduced SHP2 activation. Thus, we suggest that Y842 is critical for FLT3-mediated RAS/ERK signaling and cellular transformation.

  3. Measurement of protein synthesis: in vitro comparison of (68)Ga-DOTA-puromycin, [ (3)H]tyrosine, and 2-fluoro-[ (3)H]tyrosine.

    Science.gov (United States)

    Eigner, Sebastian; Beckford Vera, Denis R; Fellner, Marco; Loktionova, Natalia S; Piel, Markus; Melichar, Frantisek; Rösch, Frank; Roß, Tobias L; Lebeda, Ondrej; Henke, Katerina Eigner

    2013-01-01

    )Ga-DOTA-Pur. No significant differences in the behavior of [(3)H]tyrosine and 2-fluoro-[(3)H]tyrosine were observed. Uptake of both tyrosine derivatives was decreased by inhibition of protein synthesis, but only to a level of 45-55% of initial uptake, indicating no direct link between tyrosine uptake and protein synthesis. In contrast, (68)Ga-DOTA-Pur uptake was directly linked to ribosomal activity and, therefore, to protein synthesis. (68)Ga-DOTA-Pur μPET imaging in rats revealed high tumor-to-background ratios and clearly defined regions of interest in the investigated tumors. Whereas the metabolic pathway of (68)Ga-DOTA-Pur is directly connected with the process of protein synthesis and shows high tumor uptake during μPET imaging, neither [(3)H]tyrosine nor 2-fluoro-[(3)H]tyrosine can be considered useful for determination of protein synthesis.

  4. Tyrosine 402 Phosphorylation of Pyk2 Is Involved in Ionomycin-Induced Neurotransmitter Release

    Science.gov (United States)

    Zhang, Zhao; Zhang, Yun; Mou, Zheng; Chu, Shifeng; Chen, Xiaoyu; He, Wenbin; Guo, Xiaofeng; Yuan, Yuhe; Takahashi, Masami; Chen, Naihong

    2014-01-01

    Protein tyrosine kinases, which are highly expressed in the central nervous system, are implicated in many neural processes. However, the relationship between protein tyrosine kinases and neurotransmitter release remains unknown. In this study, we found that ionomycin, a Ca2+ ionophore, concurrently induced asynchronous neurotransmitter release and phosphorylation of a non-receptor protein tyrosine kinase, proline-rich tyrosine kinase 2 (Pyk2), in clonal rat pheochromocytoma PC12 cells and cerebellar granule cells, whereas introduction of Pyk2 siRNA dramatically suppressed ionomycin-induced neurotransmitter release. Further study indicated that Tyr-402 (Y402) in Pyk2, instead of other tyrosine sites, underwent rapid phosphorylation after ionomycin induction in 1 min to 2 min. We demonstrated that the mutant of Pyk2 Y402 could abolish ionomycin-induced dopamine (DA) release by transfecting cells with recombinant Pyk2 and its mutants (Y402F, Y579F, Y580F, and Y881F). In addition, Src inhibition could prolong phosphorylation of Pyk2 Y402 and increase DA release. These findings suggested that Pyk2 was involved in ionomycin-induced neurotransmitter release through phosphorylation of Y402. PMID:24718602

  5. Development of amperometric L-tyrosine sensor based on Fe-doped hydroxyapatite nanoparticles

    International Nuclear Information System (INIS)

    Kanchana, P.; Lavanya, N.; Sekar, C.

    2014-01-01

    A novel biosensor based on Fe-doped hydroxyapatite (Fe-HA) nanoparticles and tyrosinase has been developed for the detection of L-tyrosine. Nanostructured Fe-HA was synthesized by a simple microwave irradiation method, and its phase formation, morphology and magnetic property were examined by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Electrochemical performance of the nano Fe-HA/tyrosinase modified glassy carbon electrode (GCE) for detection of L-tyrosine was investigated by cyclic voltammetry (CV) and amperometric methods. The fabricated biosensor exhibited a linear response to L-tyrosine over a wide concentration range of 1.0 × 10 −7 to 1.0 × 10 −5 M with a detection limit of 245 nM at pH 7.0. In addition, the fabricated sensor showed an excellent selectivity, good reproducibility, long-term stability and anti-interference towards the determination of L-tyrosine. - Highlights: • A novel amperometric L-tyrosine biosensor has been fabricated using nanostructured Fe-HA. • The fabricated sensor exhibits a wide linear range, good stability and high reproducibility. • Fe-HA assists microenvironment and direct electron transfer between enzyme and electrode surface. • The nano Fe-HA and electrode fabrication procedure are simple and less expensive

  6. New tyrosinase inhibitory decapeptide: Molecular insights into the role of tyrosine residues.

    Science.gov (United States)

    Ochiai, Akihito; Tanaka, Seiya; Imai, Yuta; Yoshida, Hisashi; Kanaoka, Takumi; Tanaka, Takaaki; Taniguchi, Masayuki

    2016-06-01

    Tyrosinase, a rate-limiting enzyme in melanin biosynthesis, catalyzes the hydroxylation of l-tyrosine to 3,4-dihydroxy-l-phenylalanine (l-dopa) (monophenolase reaction) and the subsequent oxidation of l-dopa to l-dopaquinone (diphenolase reaction). Thus, tyrosinase inhibitors have been proposed as skin-lightening agents; however, many of the existing inhibitors cannot be widely used in the cosmetic industry due to their high cytotoxicity and instability. On the other hand, some tyrosinase inhibitory peptides have been reported as safe. In this study, we found that the peptide TH10, which has a similar sequence to the characterized inhibitory peptide P4, strongly inhibits the monophenolase reaction with a half-maximal inhibitory concentration of 102 μM. Seven of the ten amino acid residues in TH10 were identical to P4; however, TH10 possesses one N-terminal tyrosine, whereas P4 contains three tyrosine residues located at its N-terminus, center, and C-terminus. Subsequent analysis using sequence-shuffled variants indicated that the tyrosine residues located at the N-terminus and center of P4 have little to no contribution to its inhibitory activity. Furthermore, docking simulation analysis of these peptides with mushroom tyrosinase demonstrated that the active tyrosine residue was positioned close to copper ions, suggesting that TH10 and P4 bind to tyrosinase as a substrate analogue. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Analysis of tyrosine-O-sulfation

    DEFF Research Database (Denmark)

    Bundgaard, J.R.; Sen, J.W.; Johnsen, A.H.

    2008-01-01

    Tyrosine O-sulfation was first described about 50 years ago as a post-translational modification of fibrinogen. In the following 30 years it was considered to be a rare modification affecting only a few proteins and peptides. However, in the beginning of the 1980s tyrosine (Tyr) sulfation was shown...... to be a common modification and since then an increasing number of proteins have been identified as sulfated. The target proteins belong to the classes of secretory, plasma membrane, and lysosomal proteins, which reflects the intracellular localization of the enzymes catalyzing Tyr sulfation, the tyrosylprotein...... sulfotransferases (TPSTs).Traditionally, Tyr sulfation has been analyzed by incorporation of radiolabeled sulfate into target cells followed by purification of the target protein. Subsequently, the protein is degraded enzymatically or by alkaline hydrolysis followed by thin-layer electrophoresis to demonstrate...

  8. Tyrosine kinase signalling in breast cancer

    International Nuclear Information System (INIS)

    Hynes, Nancy E

    2000-01-01

    Cells are continuously exposed to diverse stimuli ranging from soluble endocrine and paracrine factors to signalling molecules on neighbouring cells. Receptors of the tyrosine kinase family play an important role in the integration and interpretation of these external stimuli, allowing a cell to respond appropriately to its environment. The activation of receptor tyrosine kinases (RTKs) is tightly controlled, allowing a normal cell to correctly integrate its external environment with internal signal transduction pathways. In contrast, due to numerous molecular alterations arising during the course of malignancy, a tumour is characterized by an abnormal response to its environment, which allows cancer cells to evade the normal mechanisms controlling cellular proliferation. Alterations in the expression of various RTKs, in their activation, and in the signalling molecules lying downstream of the receptors play important roles in the development of cancer. This topic is the major focus of the thematic review section of this issue of Breast Cancer Research

  9. Loss of a highly conserved sterile alpha motif domain gene (WEEP) results in pendulous branch growth in peach trees.

    Science.gov (United States)

    Hollender, Courtney A; Pascal, Thierry; Tabb, Amy; Hadiarto, Toto; Srinivasan, Chinnathambi; Wang, Wanpeng; Liu, Zhongchi; Scorza, Ralph; Dardick, Chris

    2018-05-15

    Plant shoots typically grow upward in opposition to the pull of gravity. However, exceptions exist throughout the plant kingdom. Most conspicuous are trees with weeping or pendulous branches. While such trees have long been cultivated and appreciated for their ornamental value, the molecular basis behind the weeping habit is not known. Here, we characterized a weeping tree phenotype in Prunus persica (peach) and identified the underlying genetic mutation using a genomic sequencing approach. Weeping peach tree shoots exhibited a downward elliptical growth pattern and did not exhibit an upward bending in response to 90° reorientation. The causative allele was found to be an uncharacterized gene, Ppa013325 , having a 1.8-Kb deletion spanning the 5' end. This gene, dubbed WEEP , was predominantly expressed in phloem tissues and encodes a highly conserved 129-amino acid protein containing a sterile alpha motif (SAM) domain. Silencing WEEP in the related tree species Prunus domestica (plum) resulted in more outward, downward, and wandering shoot orientations compared to standard trees, supporting a role for WEEP in directing lateral shoot growth in trees. This previously unknown regulator of branch orientation, which may also be a regulator of gravity perception or response, provides insights into our understanding of how tree branches grow in opposition to gravity and could serve as a critical target for manipulating tree architecture for improved tree shape in agricultural and horticulture applications. Copyright © 2018 the Author(s). Published by PNAS.

  10. Neuronal patterning of the tubular collar cord is highly conserved among enteropneusts but dissimilar to the chordate neural tube.

    Science.gov (United States)

    Kaul-Strehlow, Sabrina; Urata, Makoto; Praher, Daniela; Wanninger, Andreas

    2017-08-01

    A tubular nervous system is present in the deuterostome groups Chordata (cephalochordates, tunicates, vertebrates) and in the non-chordate Enteropneusta. However, the worm-shaped enteropneusts possess a less complex nervous system featuring only a short hollow neural tube, whereby homology to its chordate counterpart remains elusive. Since the majority of data on enteropneusts stem from the harrimaniid Saccoglossus kowalevskii, putative interspecific variations remain undetected resulting in an unreliable ground pattern that impedes homology assessments. In order to complement the missing data from another enteropneust family, we investigated expression of key neuronal patterning genes in the ptychoderid Balanoglossus misakiensis. The collar cord of B. misakiensis shows anterior Six3/6 and posterior Otx + Engrailed expression, in a region corresponding to the chordate brain. Neuronal Nk2.1/Nk2.2 expression is absent. Interestingly, we found median Dlx and lateral Pax6 expression domains, i.e., a condition that is reversed compared to chordates. Comparative analyses reveal that adult nervous system patterning is highly conserved among the enteropneust families Harrimaniidae, Spengelidae and Ptychoderidae. BmiDlx and BmiPax6 have no corresponding expression domains in the chordate brain, which may be indicative of independent acquisition of a tubular nervous system in Enteropneusta and Chordata.

  11. Assessment of some high-order finite difference schemes on the scalar conservation law with periodical conditions

    Directory of Open Access Journals (Sweden)

    Alina BOGOI

    2016-12-01

    Full Text Available Supersonic/hypersonic flows with strong shocks need special treatment in Computational Fluid Dynamics (CFD in order to accurately capture the discontinuity location and his magnitude. To avoid numerical instabilities in the presence of discontinuities, the numerical schemes must generate low dissipation and low dispersion error. Consequently, the algorithms used to calculate the time and space-derivatives, should exhibit a low amplitude and phase error. This paper focuses on the comparison of the numerical results obtained by simulations with some high resolution numerical schemes applied on linear and non-linear one-dimensional conservation low. The analytical solutions are provided for all benchmark tests considering smooth periodical conditions. All the schemes converge to the proper weak solution for linear flux and smooth initial conditions. However, when the flux is non-linear, the discontinuities may develop from smooth initial conditions and the shock must be correctly captured. All the schemes accurately identify the shock position, with the price of the numerical oscillation in the vicinity of the sudden variation. We believe that the identification of this pure numerical behavior, without physical relevance, in 1D case is extremely useful to avoid problems related to the stability and convergence of the solution in the general 3D case.

  12. A highly Conserved Aspartic Acid Residue of the Chitosanase from Bacillus Sp. TS Is Involved in the Substrate Binding.

    Science.gov (United States)

    Zhou, Zhanping; Zhao, Shuangzhi; Liu, Yang; Chang, Zhengying; Ma, Yanhe; Li, Jian; Song, Jiangning

    2016-11-01

    The chitosanase from Bacillus sp. TS (CsnTS) is an enzyme belonging to the glycoside hydrolase family 8. The sequence of CsnTS shares 98 % identity with the chitosanase from Bacillus sp. K17. Crystallography analysis and site-direct mutagenesis of the chitosanase from Bacillus sp. K17 identified the important residues involved in the catalytic interaction and substrate binding. However, despite progress in understanding the catalytic mechanism of the chitosanase from the family GH8, the functional roles of some residues that are highly conserved throughout this family have not been fully elucidated. This study focused on one of these residues, i.e., the aspartic acid residue at position 318. We found that apart from asparagine, mutation of Asp318 resulted in significant loss of enzyme activity. In-depth investigations showed that mutation of this residue not only impaired enzymatic activity but also affected substrate binding. Taken together, our results showed that Asp318 plays an important role in CsnTS activity.

  13. The highly conserved codon following the slippery sequence supports -1 frameshift efficiency at the HIV-1 frameshift site.

    Directory of Open Access Journals (Sweden)

    Suneeth F Mathew

    Full Text Available HIV-1 utilises -1 programmed ribosomal frameshifting to translate structural and enzymatic domains in a defined proportion required for replication. A slippery sequence, U UUU UUA, and a stem-loop are well-defined RNA features modulating -1 frameshifting in HIV-1. The GGG glycine codon immediately following the slippery sequence (the 'intercodon' contributes structurally to the start of the stem-loop but has no defined role in current models of the frameshift mechanism, as slippage is inferred to occur before the intercodon has reached the ribosomal decoding site. This GGG codon is highly conserved in natural isolates of HIV. When the natural intercodon was replaced with a stop codon two different decoding molecules-eRF1 protein or a cognate suppressor tRNA-were able to access and decode the intercodon prior to -1 frameshifting. This implies significant slippage occurs when the intercodon is in the (perhaps distorted ribosomal A site. We accommodate the influence of the intercodon in a model of frame maintenance versus frameshifting in HIV-1.

  14. The implications of RCRA [Resource Conservation and Recovery Act] regulation for the disposal of transuranic and high-level waste

    International Nuclear Information System (INIS)

    Sigmon, C.F.; Sharples, F.E.; Smith, E.D.

    1988-01-01

    In May of 1987 the Department of Energy (DOE) published a rule interpreting the definition of ''byproduct'' under the Atomic Energy Act. This byproduct rule clarified the role of the Resource Conservation and Recovery Act (RCRA) in the regulation of DOE's radioactive waste management activities. According to the rule, only the radioactive portion of DOE's mixed radioactive and hazardous waste (mixed waste), including mixed transuranic (TRU) and high-level waste (HLW), is exempt from RCRA under the byproduct exemption. The portion of a waste that is hazardous as defined by RCRA is subject to full regulation under RCRA. Because the radioactive and hazardous portions of m any, if not most, DOE wastes are likely to be inseparable, the rule in effect makes most mixed wastes subject to dual regulation. The potential application of RCRA to facilities such as the Waste Isolation Pilot Plant (WIPP) and the HLW repository creates unique challenges for both the DOE and regulatory authorities. Strategies must be developed to assure compliance with RCRA without either causing excessive administrative burdens or abandoning the goal of minimizing radiation exposure. This paper will explore some of the potential regulatory options for and recent trends in the regulation of TRU and HLW under RCRA

  15. Highly conserved serine residue 40 in HIV-1 p6 regulates capsid processing and virus core assembly

    Directory of Open Access Journals (Sweden)

    Solbak Sara MØ

    2011-02-01

    Full Text Available Abstract Background The HIV-1 p6 Gag protein regulates the final abscission step of nascent virions from the cell membrane by the action of two late assembly (L- domains. Although p6 is located within one of the most polymorphic regions of the HIV-1 gag gene, the 52 amino acid peptide binds at least to two cellular budding factors (Tsg101 and ALIX, is a substrate for phosphorylation, ubiquitination, and sumoylation, and mediates the incorporation of the HIV-1 accessory protein Vpr into viral particles. As expected, known functional domains mostly overlap with several conserved residues in p6. In this study, we investigated the importance of the highly conserved serine residue at position 40, which until now has not been assigned to any known function of p6. Results Consistently with previous data, we found that mutation of Ser-40 has no effect on ALIX mediated rescue of HIV-1 L-domain mutants. However, the only feasible S40F mutation that preserves the overlapping pol open reading frame (ORF reduces virus replication in T-cell lines and in human lymphocyte tissue cultivated ex vivo. Most intriguingly, L-domain mediated virus release is not dependent on the integrity of Ser-40. However, the S40F mutation significantly reduces the specific infectivity of released virions. Further, it was observed that mutation of Ser-40 selectively interferes with the cleavage between capsid (CA and the spacer peptide SP1 in Gag, without affecting cleavage of other Gag products. This deficiency in processing of CA, in consequence, led to an irregular morphology of the virus core and the formation of an electron dense extra core structure. Moreover, the defects induced by the S40F mutation in p6 can be rescued by the A1V mutation in SP1 that generally enhances processing of the CA-SP1 cleavage site. Conclusions Overall, these data support a so far unrecognized function of p6 mediated by Ser-40 that occurs independently of the L-domain function, but selectively

  16. Kinetic alteration of a human dihydrodiol/3alpha-hydroxysteroid dehydrogenase isoenzyme, AKR1C4, by replacement of histidine-216 with tyrosine or phenylalanine.

    Science.gov (United States)

    Ohta, T; Ishikura, S; Shintani, S; Usami, N; Hara, A

    2000-01-01

    Human dihydrodiol dehydrogenase with 3alpha-hydroxysteroid dehydrogenase activity exists in four forms (AKR1C1-1C4) that belong to the aldo-keto reductase (AKR) family. Recent crystallographic studies on the other proteins in this family have indicated a role for a tyrosine residue (corresponding to position 216 in these isoenzymes) in stacking the nicotinamide ring of the coenzyme. This tyrosine residue is conserved in most AKR family members including AKR1C1-1C3, but is replaced with histidine in AKR1C4 and phenylalanine in some AKR members. In the present study we prepared mutant enzymes of AKR1C4 in which His-216 was replaced with tyrosine or phenylalanine. The two mutations decreased 3-fold the K(m) for NADP(+) and differently influenced the K(m) and k(cat) for substrates depending on their structures. The kinetic constants for bile acids with a 12alpha-hydroxy group were decreased 1.5-7-fold and those for the other substrates were increased 1.3-9-fold. The mutation also yielded different changes in sensitivity to competitive inhibitors such as hexoestrol analogues, 17beta-oestradiol, phenolphthalein and flufenamic acid and 3,5,3', 5'-tetraiodothyropropionic acid analogues. Furthermore, the mutation decreased the stimulatory effects of the enzyme activity by sulphobromophthalein, clofibric acid and thyroxine, which increased the K(m) for the coenzyme and substrate of the mutant enzymes more highly than those of the wild-type enzyme. These results indicate the importance of this histidine residue in creating the cavity of the substrate-binding site of AKR1C4 through the orientation of the nicotinamide ring of the coenzyme, as well as its involvement in the conformational change by binding non-essential activators. PMID:11104674

  17. Contributions of F-BAR and SH2 domains of Fes protein tyrosine kinase for coupling to the FcepsilonRI pathway in mast cells.

    Science.gov (United States)

    McPherson, Victor A; Everingham, Stephanie; Karisch, Robert; Smith, Julie A; Udell, Christian M; Zheng, Jimin; Jia, Zongchao; Craig, Andrew W B

    2009-01-01

    This study investigates the roles of Fer-CIP4 homology (FCH)-Bin/amphiphysin/Rvs (F-BAR) and SH2 domains of Fes protein tyrosine kinase in regulating its activation and signaling downstream of the high-affinity immunoglobulin G (IgE) receptor (FcepsilonRI) in mast cells. Homology modeling of the Fes F-BAR domain revealed conservation of some basic residues implicated in phosphoinositide binding (R113/K114). The Fes F-BAR can bind phosphoinositides and induce tubulation of liposomes in vitro. Mutation of R113/K114 to uncharged residues (RK/QQ) caused a significant reduction in phosphoinositide binding in vitro and a more diffuse cytoplasmic localization in transfected COS-7 cells. RBL-2H3 mast cells expressing full-length Fes carrying the RK/QQ mutation show defects in FcepsilonRI-induced Fes tyrosine phosphorylation and degranulation compared to cells expressing wild-type Fes. This correlated with reduced localization to Lyn kinase-containing membrane fractions for the RK/QQ mutant compared to wild-type Fes in mast cells. The Fes SH2 domain also contributes to Fes signaling in mast cells, via interactions with the phosphorylated FcepsilonRI beta chain and the actin regulatory protein HS1. We show that Fes phosphorylates C-terminal tyrosine residues in HS1 implicated in actin stabilization. Thus, coordinated actions of the F-BAR and SH2 domains of Fes allow for coupling to FcepsilonRI signaling and potential regulation the actin reorganization in mast cells.

  18. High conservation level of CD8(+) T cell immunogenic regions within an unusual H1N2 human influenza variant.

    Science.gov (United States)

    Komadina, Naomi; Quiñones-Parra, Sergio M; Kedzierska, Katherine; McCaw, James M; Kelso, Anne; Leder, Karin; McVernon, Jodie

    2016-10-01

    Current seasonal influenza vaccines require regular updates due to antigenic drift causing loss of effectiveness and therefore providing little or no protection against novel influenza A subtypes. Next generation vaccines capable of eliciting CD8(+) T cell (CTL) mediated cross-protective immunity may offer a long-term alternative strategy. However, measuring pre- and existing levels of CTL cross-protection in humans is confounded by differences in infection histories across individuals. During 2000-2003, H1N2 viruses circulated persistently in the human population for the first time and we hypothesized that the viral nucleoprotein (NP) contained novel CTL epitopes that may have contributed to the survival of the viruses. This study describes the immunogenic NP peptides of H1N1, H2N2, and H3N2 influenza viruses isolated from humans over the past century, 1918-2003, by comparing this historical dataset to reference NP peptides from H1N2 that circulated in humans during 2000-2003. Observed peptides sequences ranged from highly conserved (15%) to highly variable (12%), with variation unrelated to reported immunodominance. No unique NP peptides which were exclusive to the H1N2 viruses were noted. However, the virus had inherited the NP from a recently emerged H3N2 variant containing novel peptides, which may have assisted its persistence. Any advantage due to this novelty was subsequently lost with emergence of a newer H3N2 variant in 2003. Our approach has potential to provide insight into the population context in which influenza viruses emerge, and may help to inform immunogenic peptide selection for CTL-inducing influenza vaccines. J. Med. Virol. 88:1725-1732, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Effect of tyrosine kinase blockade on norepinephrine-induced cytosolic calcium response in rat afferent arterioles

    DEFF Research Database (Denmark)

    Salomonsson, Max; Arendshorst, William J

    2004-01-01

    We used genistein (Gen) and tyrphostin 23 (Tyr-23) to evaluate the importance of tyrosine phosphorylation in norepinephrine (NE)-induced changes in intracellular free calcium concentration ([Ca(2+)](i)) in rat afferent arterioles. [Ca(2+)](i) was measured in microdissected arterioles using...... ratiometric photometry of fura 2 fluorescence. The control [Ca(2+)](i) response to NE (1 microM) consisted of a rapid initial peak followed by a plateau phase sustained above baseline. Pretreatment with the tyrosine kinase inhibitor Tyr-23 (50 microM, 10 min) caused a slow 40% increase in baseline [Ca(2+)](i...... of nifedipine and Tyr-23 were not additive. Nifedipine had no inhibitory effect after Tyr-23 pretreatment, indicating Tyr-23 inhibition of Ca(2+) entry. Another tyrosine kinase inhibitor, Gen (5 and 50 microM), did not affect baseline [Ca(2+)](i). High-dose Gen inhibited the peak and plateau response to NE...

  20. Versatile and Efficient Site-Specific Protein Functionalization by Tubulin Tyrosine Ligase.

    Science.gov (United States)

    Schumacher, Dominik; Helma, Jonas; Mann, Florian A; Pichler, Garwin; Natale, Francesco; Krause, Eberhard; Cardoso, M Cristina; Hackenberger, Christian P R; Leonhardt, Heinrich

    2015-11-09

    A novel chemoenzymatic approach for simple and fast site-specific protein labeling is reported. Recombinant tubulin tyrosine ligase (TTL) was repurposed to attach various unnatural tyrosine derivatives as small bioorthogonal handles to proteins containing a short tubulin-derived recognition sequence (Tub-tag). This novel strategy enables a broad range of high-yielding and fast chemoselective C-terminal protein modifications on isolated proteins or in cell lysates for applications in biochemistry, cell biology, and beyond, as demonstrated by the site-specific labeling of nanobodies, GFP, and ubiquitin. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Tyrosine kinase inhibition: A therapeutic target for the management of chronic-phase chronic myeloid leukemia

    Science.gov (United States)

    Jabbour, Elias J; Cortes, Jorge E; Kantarjian, Hagop M

    2014-01-01

    Chronic myeloid leukemia (CML) is a hematologic neoplasm with a progressive, ultimately terminal, disease course. In most cases, CML arises owing to the aberrant formation of a chimeric gene for a constitutively active tyrosine kinase. Inhibition of the signaling activity of this kinase has proved to be a highly successful treatment target transforming the prognosis of patients with CML. New tyrosine kinase inhibitors (TKIs) continue to improve the management of CML, offering alternative options for those resistant to or intolerant of standard TKIs. Here we review the pathobiology of CML and explore emerging strategies to optimize the management of chronic-phase CML, particularly first-line treatment. PMID:24236822

  2. Surgical versus conservative treatment for high-risk stress fractures of the lower leg (anterior tibial cortex, navicular and fifth metatarsal base): a systematic review

    NARCIS (Netherlands)

    Mallee, W.H.; Weel, H.; van Dijk, C.N.; van Tulder, M.W.; Kerkhoffs, G.M.; Lin, C.W.C.

    2015-01-01

    Aim To compare surgical and conservative treatment for high-risk stress fractures of the anterior tibial cortex, navicular and proximal fifth metatarsal. Methods Systematic searches of CENTRAL, MEDLINE, EMBASE, CINAHL, SPORTDiscus and PEDro were performed to identify relevant prospective and

  3. Comparing the cost-effectiveness of water conservation policies in a depleting aquifer:A dynamic analysis of the Kansas High Plains

    Science.gov (United States)

    This research analyzes two groundwater conservation policies in the Kansas High Plains located within the Ogallala aquifer: 1) cost-share assistance to increase irrigation efficiency; and 2) incentive payments to convert irrigated crop production to dryland crop production. To compare the cost-effec...

  4. Spatially conserved regulatory elements identified within human and mouse Cd247 gene using high-throughput sequencing data from the ENCODE project

    DEFF Research Database (Denmark)

    Pundhir, Sachin; Hannibal, Tine Dahlbæk; Bang-Berthelsen, Claus Heiner

    2014-01-01

    . In this study, we have utilized the wealth of high-throughput sequencing data produced during the Encyclopedia of DNA Elements (ENCODE) project to identify spatially conserved regulatory elements within the Cd247 gene from human and mouse. We show the presence of two transcription factor binding sites...

  5. Tyrosine phosphorylation in T cells is regulated by phosphatase activity: studies with phenylarsine oxide.

    OpenAIRE

    Garcia-Morales, P; Minami, Y; Luong, E; Klausner, R D; Samelson, L E

    1990-01-01

    Activation of T cells induces rapid tyrosine phosphorylation on the T-cell receptor zeta chain and other substrates. These phosphorylations can be regulated by a number of protein-tyrosine kinases (ATP: protein-tyrosine O-phosphotransferase, EC 2.7.1.112) and protein-tyrosine-phosphatases (protein-tyrosine-phosphate phosphohydrolase, EC 3.1.3.48). In this study, we demonstrate that phenylarsine oxide can inhibit tyrosine phosphatases while leaving tyrosine kinase function intact. We use this ...

  6. A Resource Conservation Unit.

    Science.gov (United States)

    Porter, Philip D.

    1979-01-01

    Describes a variety of learning activities for teaching elementary and junior high students about air, water, and energy conservation techniques. Suggests community resources, social studies objectives, language skills, and 20 activities. (CK)

  7. Metal ion interaction with phosphorylated tyrosine analogue monolayers on gold.

    Science.gov (United States)

    Petoral, Rodrigo M; Björefors, Fredrik; Uvdal, Kajsa

    2006-11-23

    Phosphorylated tyrosine analogue molecules (pTyr-PT) were assembled onto gold substrates, and the resulting monolayers were used for metal ion interaction studies. The monolayers were characterized by X-ray photoelectron spectroscopy (XPS), infrared reflection-absorption spectroscopy (IRAS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), both prior to and after exposure to metal ions. XPS verified the elemental composition of the molecular adsorbate and the presence of metal ions coordinated to the phosphate groups. Both the angle-dependent XPS and IRAS results were consistent with the change in the structural orientation of the pTyr-PT monolayer upon exposure to metal ions. The differential capacitance of the monolayers upon coordination of the metal ions was evaluated using EIS. These metal ions were found to significantly change the capacitance of the pTyr-PT monolayers in contrast to the nonphosphorylated tyrosine analogue (TPT). CV results showed reduced electrochemical blocking capabilities of the phosphorylated analogue monolayer when exposed to metal ions, supporting the change in the structure of the monolayer observed by XPS and IRAS. The largest change in the structure and interfacial capacitance was observed for aluminum ions, compared to calcium, magnesium, and chromium ions. This type of monolayer shows an excellent capability to coordinate metal ions and has a high potential for use as sensing layers in biochip applications to monitor the presence of metal ions.

  8. Model My Watershed: A high-performance cloud application for public engagement, watershed modeling and conservation decision support

    Science.gov (United States)

    Aufdenkampe, A. K.; Tarboton, D. G.; Horsburgh, J. S.; Mayorga, E.; McFarland, M.; Robbins, A.; Haag, S.; Shokoufandeh, A.; Evans, B. M.; Arscott, D. B.

    2017-12-01

    The Model My Watershed Web app (https://app.wikiwatershed.org/) and the BiG-CZ Data Portal (http://portal.bigcz.org/) and are web applications that share a common codebase and a common goal to deliver high-performance discovery, visualization and analysis of geospatial data in an intuitive user interface in web browser. Model My Watershed (MMW) was designed as a decision support system for watershed conservation implementation. BiG CZ Data Portal was designed to provide context and background data for research sites. Users begin by creating an Area of Interest, via an automated watershed delineation tool, a free draw tool, selection of a predefined area such as a county or USGS Hydrological Unit (HUC), or uploading a custom polygon. Both Web apps visualize and provide summary statistics of land use, soil groups, streams, climate and other geospatial information. MMW then allows users to run a watershed model to simulate different scenarios of human impacts on stormwater runoff and water-quality. BiG CZ Data Portal allows users to search for scientific and monitoring data within the Area of Interest, which also serves as a prototype for the upcoming Monitor My Watershed web app. Both systems integrate with CUAHSI cyberinfrastructure, including visualizing observational data from CUAHSI Water Data Center and storing user data via CUAHSI HydroShare. Both systems also integrate with the new EnviroDIY Water Quality Data Portal (http://data.envirodiy.org/), a system for crowd-sourcing environmental monitoring data using open-source sensor stations (http://envirodiy.org/mayfly/) and based on the Observations Data Model v2.

  9. The maize INDETERMINATE1 flowering time regulator defines a highly conserved zinc finger protein family in higher plants

    Directory of Open Access Journals (Sweden)

    Colasanti Joseph

    2006-06-01

    Full Text Available Abstract Background The maize INDETERMINATE1 gene, ID1, is a key regulator of the transition to flowering and the founding member of a transcription factor gene family that encodes a protein with a distinct arrangement of zinc finger motifs. The zinc fingers and surrounding sequence make up the signature ID domain (IDD, which appears to be found in all higher plant genomes. The presence of zinc finger domains and previous biochemical studies showing that ID1 binds to DNA suggests that members of this gene family are involved in transcriptional regulation. Results Comparison of IDD genes identified in Arabidopsis and rice genomes, and all IDD genes discovered in maize EST and genomic databases, suggest that ID1 is a unique member of this gene family. High levels of sequence similarity amongst all IDD genes from maize, rice and Arabidopsis suggest that they are derived from a common ancestor. Several unique features of ID1 suggest that it is a divergent member of the maize IDD family. Although no clear ID1 ortholog was identified in the Arabidopsis genome, highly similar genes that encode proteins with identity extending beyond the ID domain were isolated from rice and sorghum. Phylogenetic comparisons show that these putative orthologs, along with maize ID1, form a group separate from other IDD genes. In contrast to ID1 mRNA, which is detected exclusively in immature leaves, several maize IDD genes showed a broad range of expression in various tissues. Further, Western analysis with an antibody that cross-reacts with ID1 protein and potential orthologs from rice and sorghum shows that all three proteins are detected in immature leaves only. Conclusion Comparative genomic analysis shows that the IDD zinc finger family is highly conserved among both monocots and dicots. The leaf-specific ID1 expression pattern distinguishes it from other maize IDD genes examined. A similar leaf-specific localization pattern was observed for the putative ID1 protein

  10. Solubilization and characterization of a novel tyrosine kinase from rat adipocytes

    International Nuclear Information System (INIS)

    Yagaloff, K.A.; Czech, M.P.

    1987-01-01

    The authors report the efficient solubilization and characterization of a Triton X-100 insoluble tyrosine kinase from rat adipocytes. Plasma membranes were prepared from rat epididymal fat pads and were solubilized in 1% Triton X-100. Following centrifugation, the pellet was solubilized for 15 min at 4 0 C using both ionic and non-ionic detergents. Tyrosine kinase activity was measured in the soluble and particulate fractions using the exogenous substrate poly(glu-tyr) in a TCA precipitation assay. Reactions were performed in 50mM Hepes, 10mM MgCl 2 and 100μM gamma[ 32 P]-ATP (10Ci/mmol) at 4 0 C with or without 1mg/ml of the polyaminoacid. Incorporation rates of 100 to 1000 pmol/min/mg were obtained, while endogenous [ 32 P] incorporation was typically less than 10% of that in the presence of poly(glu-tyr). More than 75% of the tyrosine kinase activity was recovered in the soluble supernatant using this assay methodology. The solubilized tyrosine kinase was found to require Mg 2+ or Mn 2+ but preferred Mg 2+ and was inhibited by high levels of Mn 2+ . Kinase activity was strongly inhibited by Ca 2+ (>50% at 1mM), NaCl (>50% at 250mM) and NH 4 SO 4 (>50% at 50mM) but was activated by 10μM heparin and 5mM dithiothreitol. These properties distinguish the solubilized tyrosine kinase from other cellular tyrosine kinases

  11. Tyrosine Mutation in AAV9 Capsid Improves Gene Transfer to the Mouse Lung.

    Science.gov (United States)

    Martini, Sabrina V; Silva, Adriana L; Ferreira, Debora; Rabelo, Rafael; Ornellas, Felipe M; Gomes, Karina; Rocco, Patricia R M; Petrs-Silva, Hilda; Morales, Marcelo M

    2016-01-01

    Adeno-associated virus (AAV) vectors are being increasingly used as the vector of choice for in vivo gene delivery and gene therapy for many pulmonary diseases. Recently, it was shown that phosphorylation of surface-exposed tyrosine residues from AAV capsid targets the viral particles for ubiquitination and proteasome-mediated degradation, and mutations of these tyrosine residues lead to highly efficient vector transduction in vitro and in vivo in different organs. In this study, we evaluated the pulmonary transgene expression efficacy of AAV9 vectors containing point mutations in surface-exposed capsid tyrosine residues. Eighteen C57BL/6 mice were randomly assigned into three groups: (1) a control group (CTRL) animals underwent intratracheal (i.t.) instillation of saline, (2) the wild-type AAV9 group (WT-AAV9, 1010 vg), and (3) the tyrosine-mutant Y731F AAV9 group (M-AAV9, 1010 vg), which received (i.t.) self-complementary AAV9 vectors containing the DNA sequence of enhanced green fluorescence protein (eGFP). Four weeks after instillation, lung mechanics, morphometry, tissue cellularity, gene expression, inflammatory cytokines, and growth factor expression were analyzed. No significant differences were observed in lung mechanics and morphometry among the experimental groups. However, the number of polymorphonuclear cells was higher in the WT-AAV9 group than in the CTRL and M-AAV9 groups, suggesting that the administration of tyrosine-mutant AAV9 vectors was better tolerated. Tyrosine-mutant AAV9 vectors significantly improved transgene delivery to the lung (30%) compared with their wild-type counterparts, without eliciting an inflammatory response. Our results provide the impetus for further studies to exploit the use of AAV9 vectors as a tool for pulmonary gene therapy. © 2016 The Author(s) Published by S. Karger AG, Basel.

  12. Acute phenylalanine/tyrosine depletion of phasic dopamine in the rat brain.

    Science.gov (United States)

    Shnitko, Tatiana A; Taylor, Sarah C; Stringfield, Sierra J; Zandy, Shannon L; Cofresí, Roberto U; Doherty, James M; Lynch, William B; Boettiger, Charlotte A; Gonzales, Rueben A; Robinson, Donita L

    2016-06-01

    Dopamine plays a critical role in striatal and cortical function, and depletion of the dopamine precursors phenylalanine and tyrosine is used in humans to temporarily reduce dopamine and probe the role of dopamine in behavior. This method has been shown to alter addiction-related behaviors and cognitive functioning presumably by reducing dopamine transmission, but it is unclear what specific aspects of dopamine transmission are altered. We performed this study to confirm that administration of an amino acid mixture omitting phenylalanine and tyrosine (Phe/Tyr[-]) reduces tyrosine tissue content in the prefrontal cortex (PFC) and nucleus accumbens (NAc), and to test the hypothesis that Phe/Tyr[-] administration reduces phasic dopamine release in the NAc. Rats were injected with a Phe/Tyr[-] amino acid mixture, a control amino acid mixture, or saline. High-performance liquid chromatography was used to determine the concentration of tyrosine, dopamine, or norepinephrine in tissue punches from the PFC and ventral striatum. In a separate group of rats, phasic dopamine release was measured with fast-scan cyclic voltammetry in the NAc core after injection with either the Phe/Tyr[-] mixture or the control amino acid solution. Phe/Tyr[-] reduced tyrosine content in the PFC and NAc, but dopamine and norepinephrine tissue content were not reduced. Moreover, Phe/Tyr[-] decreased the frequency of dopamine transients, but not their amplitude, in freely moving rats. These results indicate that depletion of tyrosine via Phe/Tyr[-] decreases phasic dopamine transmission, providing insight into the mechanism by which this method modifies dopamine-dependent behaviors in human imaging studies.

  13. Euglena mitochondria and chloroplasts form tyrosine-O-sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Saidha, T.; Hanfstingl, U.; Schiff, J.A. (Brandeis Univ., Waltham, MA (USA))

    1989-04-01

    Mitochondria from light-grown wild-type Euglena gracilis var. bacillaris Cori or dark-grown mutant W{sub 10}BSmL incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, or with {sup 14}C-tyrosine, non-radioactive sulfate and ATP accumulate a labeled compound in the medium. Since this compound shows exact coelectrophoresis with tyrosine-O-sulfate (TOS) at pH 2.0, 5.8 or 8.0., yields sulfate and tyrosine on acid hydrolysis, and treatment with aryl sulfatase from Aerobacter aerogenes yields sulfate and tyrosine but no tyrosine methyl ester, it is identified as TOS. No TOS is found outside purified developing chloroplasts incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, but both chloroplasts and mitochondria form to {sup 35}S externally when incubated with adenosine 3{prime} phosphate 5{prime}phospho({sup 35}S) sulfate (PAP{sup 35}S). Since no tyrosine need be added, tyrosine is provided from endogenous sources. Although TOS is found in the free pool of Euglena cells it cannot be detected in proteins of cells or mucus ruling our sulfation of tyrosine of protein or incorporation of TOS into proteins. The system forming TOS is membrane-bound and may be involved in tyrosine transport.

  14. Dietary Tyrosine Benefits Cognitive and Psychomotor Performance During Body Cooling

    National Research Council Canada - National Science Library

    O'Brien, Catherine; Mahoney, Caroline; Tharion, William J; Sils, Ingrid V; Castellani, John W

    2007-01-01

    ... examined. This study evaluated the effect of tyrosine supplementation on cognitive, psychomotor, and physical performance following a cold water immersion protocol that lowered body core temperature...

  15. Tyrosine Residues Regulate Multiple Nuclear Functions of P54nrb.

    Science.gov (United States)

    Lee, Ahn R; Hung, Wayne; Xie, Ning; Liu, Liangliang; He, Leye; Dong, Xuesen

    2017-04-01

    The non-POU-domain-containing octamer binding protein (NONO; also known as p54nrb) has various nuclear functions ranging from transcription, RNA splicing, DNA synthesis and repair. Although tyrosine phosphorylation has been proposed to account for the multi-functional properties of p54nrb, direct evidence on p54nrb as a phosphotyrosine protein remains unclear. To investigate the tyrosine phosphorylation status of p54nrb, we performed site-directed mutagenesis on the five tyrosine residues of p54nrb, replacing the tyrosine residues with phenylalanine or alanine, and immunoblotted for tyrosine phosphorylation. We then preceded with luciferase reporter assays, RNA splicing minigene assays, co-immunoprecipitation, and confocal microscopy to study the function of p54nrb tyrosine residues on transcription, RNA splicing, protein-protein interaction, and cellular localization. We found that p54nrb was not phosphorylated at tyrosine residues. Rather, it has non-specific binding affinity to anti-phosphotyrosine antibodies. However, replacement of tyrosine with phenylalanine altered p54nrb activities in transcription co-repression and RNA splicing in gene context-dependent fashions by means of differential regulation of p54nrb protein association with its interacting partners and co-regulators of transcription and splicing. These results demonstrate that tyrosine residues, regardless of phosphorylation status, are important for p54nrb function. J. Cell. Physiol. 232: 852-861, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Tyrosine phosphorylation of Grb14 by Tie2

    Directory of Open Access Journals (Sweden)

    Dumont Daniel J

    2010-10-01

    Full Text Available Abstract Background Growth factor receptor bound (Grb proteins 7, 10 and 14 are a family of structurally related multi-domain adaptor proteins involved in a variety of biological processes. Grb7, 10 and 14 are known to become serine and/or threonine phosphorylated in response to growth factor (GF stimulation. Grb7 and 10 have also been shown to become tyrosine phosphorylated under certain conditions. Under experimental conditions Grb7 is tyrosine phosphorylated by the Tie2/Tie-2/Tek angiogenic receptor tyrosine kinase (RTK. Furthermore, Grb14 has also been shown to interact with Tie2, however tyrosine phosphorylation of this Grb family member has yet to be reported. Results Here we report for the first time tyrosine phosphorylation of Grb14. This phosphorylation requires a kinase competent Tie2 as well as intact tyrosines 1100 and 1106 (Y1100 and Y1106 on the receptor. Furthermore, a complete SH2 domain on Grb14 is required for Grb14 tyrosine phosphorylation by Tie2. Grb14 was also able to become tyrosine phosphorylated in primary endothelial cells when treated with a soluble and potent variant of the Tie2 ligand, cartilage oligomeric matrix protein (COMP Ang1. Conclusion Our results show that Grb14, like its family members Grb7 and Grb10, is able to be tyrosine phosphorylated. Furthermore, our data indicate a role for Grb14 in endothelial signaling downstream of the Tie2 receptor.

  17. Molecular Mechanisms of SH2- and PTB-Domain-Containing Proteins in Receptor Tyrosine Kinase Signaling

    Science.gov (United States)

    Wagner, Melany J.; Stacey, Melissa M.; Liu, Bernard A.; Pawson, Tony

    2013-01-01

    Intracellular signaling is mediated by reversible posttranslational modifications (PTMs) that include phosphorylation, ubiquitination, and acetylation, among others. In response to extracellular stimuli such as growth factors, receptor tyrosine kinases (RTKs) typically dimerize and initiate signaling through phosphorylation of their cytoplasmic tails and downstream scaffolds. Signaling effectors are recruited to these phosphotyrosine (pTyr) sites primarily through Src homology 2 (SH2) domains and pTyr-binding (PTB) domains. This review describes how these conserved domains specifically recognize pTyr residues and play a major role in mediating precise downstream signaling events. PMID:24296166

  18. Molecular mechanisms of SH2- and PTB-domain-containing proteins in receptor tyrosine kinase signaling.

    Science.gov (United States)

    Wagner, Melany J; Stacey, Melissa M; Liu, Bernard A; Pawson, Tony

    2013-12-01

    Intracellular signaling is mediated by reversible posttranslational modifications (PTMs) that include phosphorylation, ubiquitination, and acetylation, among others. In response to extracellular stimuli such as growth factors, receptor tyrosine kinases (RTKs) typically dimerize and initiate signaling through phosphorylation of their cytoplasmic tails and downstream scaffolds. Signaling effectors are recruited to these phosphotyrosine (pTyr) sites primarily through Src homology 2 (SH2) domains and pTyr-binding (PTB) domains. This review describes how these conserved domains specifically recognize pTyr residues and play a major role in mediating precise downstream signaling events.

  19. Large daily fluctuations in plasma tyrosine in treated patients with phenylketonuria

    NARCIS (Netherlands)

    vanSpronsen, FJ; vanDijk, T; Smit, GPA; vanRijn, M; Reijngoud, DJ; Berger, Ruud; Heymans, HSA

    1996-01-01

    In patients with phenylketonuria (PKU), extra tyrosine supplementation is advocated in addition to tyrosine-enriched amino acid mixtures. PKU patients have low fasting plasma tyrosine concentrations, but little is known about tyrosine fluctuations during the day. Plasma tyrosine concentrations were

  20. Cluster analysis of indicators of liver functional and preoperative low branched-chain amino acid tyrosine ration indicate a high risk of early recurrence in analysis of 165 hepatocellular carcinoma patients after initial hepatectomy.

    Science.gov (United States)

    Nakamura, Yukio; Mizuguchi, Toru; Kawamoto, Masaki; Meguro, Makoto; Harada, Kohei; Ota, Shigenori; Hirata, Koichi

    2011-08-01

    Cluster analysis is used for dividing many prognostic indicators, including liver function, tumor progression, and operative variables, into specific clusters. The albumin (ALB), hepatocyte growth factor (HGF), and branched chain amino-acid to tyrosine ratio (BTR) may represent the severity of liver disease and function of the hepatic reserve. We developed the ALB-BTR and HGF-BTR classifications depending on each level to find specific unique subgroups. Our aim was to identify specific subgroups destined for favorable and poor prognoses after initial hepatectomy. Between 2002 and 2008, 165 patients were analyzed retrospectively. Liver function indicators, including BTR, tumor-related factors, and operative variables, were evaluated by cluster analysis with Ward's criterion. The ALB-BTR classification was divided into 4 groups depending on ALB (cutoff value, 4.0 g/dL) and BTR (cutoff value, 6.0). The HGF-BTR classification was also divided into 4 groups depending on HGF (cutoff value, 0.35 ng/mL) and BTR (cutoff value, 6.0). The prognoses of the subgroups were compared by the log-rank test. Cluster analysis divided multiple indicators into 5 different clusters. In each cluster, we further analyzed subgroups using the ALB-BTR and HGF-BTR classification. Mean recurrence-free survival times in ALB-GI (19.1 ± 2.4 months) and HGF-GIII (29.4 ± 3.8 months) were less than their mean overall survival times. Cluster analysis is useful to find similar and different indicators. Even though liver function was well preserved, low BTR could identify early recurrence in hepatocellular carcinoma patients after resection. Copyright © 2011 Mosby, Inc. All rights reserved.

  1. Ex Situ gene conservation in high elevation white pine species in the United States-a beginning

    Science.gov (United States)

    Richard A. Sniezko; Anna Schoettle; Joan Dunlap; Detlev Vogler; David Conklin; Andrew Bower; Chris Jensen; Rob Mangold; Doug Daoust; Gary Man

    2011-01-01

    The eight white pine species native to the western United States face an array of biotic and abiotic challenges that impact the viability of populations or the species themselves. Well-established programs are already in place to conserve and restore Pinus monticola Dougl. ex D. Don and P. lambertiana Dougl. throughout significant portions of their geographic ranges....

  2. A Highly Conserved GEQYQQLR Epitope Has Been Identified in the Nucleoprotein of Ebola Virus by Using an In Silico Approach

    Directory of Open Access Journals (Sweden)

    Mohammad Tuhin Ali

    2015-01-01

    Full Text Available Ebola virus (EBOV is a deadly virus that has caused several fatal outbreaks. Recently it caused another outbreak and resulted in thousands afflicted cases. Effective and approved vaccine or therapeutic treatment against this virus is still absent. In this study, we aimed to predict B-cell epitopes from several EBOV encoded proteins which may aid in developing new antibody-based therapeutics or viral antigen detection method against this virus. Multiple sequence alignment (MSA was performed for the identification of conserved region among glycoprotein (GP, nucleoprotein (NP, and viral structural proteins (VP40, VP35, and VP24 of EBOV. Next, different consensus immunogenic and conserved sites were predicted from the conserved region(s using various computational tools which are available in Immune Epitope Database (IEDB. Among GP, NP, VP40, VP35, and VP30 protein, only NP gave a 100% conserved GEQYQQLR B-cell epitope that fulfills the ideal features of an effective B-cell epitope and could lead a way in the milieu of Ebola treatment. However, successful in vivo and in vitro studies are prerequisite to determine the actual potency of our predicted epitope and establishing it as a preventing medication against all the fatal strains of EBOV.

  3. "Toward High School Biology": Helping Middle School Students Understand Chemical Reactions and Conservation of Mass in Nonliving and Living Systems

    Science.gov (United States)

    Herrmann-Abell, Cari F.; Koppal, Mary; Roseman, Jo Ellen

    2016-01-01

    Modern biology has become increasingly molecular in nature, requiring students to understand basic chemical concepts. Studies show, however, that many students fail to grasp ideas about atom rearrangement and conservation during chemical reactions or the application of these ideas to biological systems. To help provide students with a better…

  4. Inhibitory control and visuo-spatial reversibility in Piaget’s seminal number conservation task: A high-density ERP study.

    Directory of Open Access Journals (Sweden)

    Gregoire eBorst

    2013-12-01

    Full Text Available The present high-density ERP study on 13 adults aimed to determine whether number conservation relies on the ability to inhibit the overlearned length-equals-number strategy and then imagine the shortening of the row that was lengthened. Participants performed the number-conservation task and, after the EEG session, the mental imagery task. In the number-conservation task, first two rows with the same number of tokens and the same length were presented on a computer screen (COV condition and then, the tokens in one of the two rows were spread apart (INT condition. Participants were instructed to determine whether the two rows had an identical number of tokens. In the mental imagery task, two rows with different lengths but the same number of tokens were presented and participants were instructed to imagine the tokens in the longer row aligning with the tokens in the shorter row. In the number-conservation task, we found that the amplitudes of the centro-parietal N2 and fronto-central P3 were higher in the INT than in the COV conditions. In addition, the differences in response times between the two conditions were correlated with the differences in the amplitudes of the fronto-central P3. In light of previous results reported on the number-conservation task in adults, the present results suggest that inhibition might be necessary to succeed the number-conservation task in adults even when the transformation of the length of one of the row is displayed. Finally, we also reported correlations between the speed at which participants could imagine the shortening of one of the row in the mental imagery task, the speed at which participants could determine that the two rows had the same number of tokens after the tokens in one of the row were spread apart and the latency of the late positive parietal component in the number-conservation task. Therefore, performing the number-conservation task might involve mental transformation processes in adults.

  5. A zebrafish screen for craniofacial mutants identifies wdr68 as a highly conserved gene required for endothelin-1 expression

    Directory of Open Access Journals (Sweden)

    Amsterdam Adam

    2006-06-01

    identification of approximately 25% of the essential genes required for craniofacial development. The identification of zebrafish models for two human disease syndromes indicates that homologs to the other genes are likely to also be relevant for human craniofacial development. The initial characterization of wdr68 suggests an important role in craniofacial development for the highly conserved Wdr68-Dyrk1 protein complexes.

  6. Functional and genetic evidence that nucleoside transport is highly conserved in Leishmania species: Implications for pyrimidine-based chemotherapy.

    Science.gov (United States)

    Alzahrani, Khalid J H; Ali, Juma A M; Eze, Anthonius A; Looi, Wan Limm; Tagoe, Daniel N A; Creek, Darren J; Barrett, Michael P; de Koning, Harry P

    2017-08-01

    Leishmania pyrimidine salvage is replete with opportunities for therapeutic intervention with enzyme inhibitors or antimetabolites. Their uptake into cells depends upon specific transporters; therefore it is essential to establish whether various Leishmania species possess similar pyrimidine transporters capable of drug uptake. Here, we report a comprehensive characterization of pyrimidine transport in L. major and L. mexicana. In both species, two transporters for uridine/adenosine were detected, one of which also transported uracil and the antimetabolites 5-fluoruracil (5-FU) and 5F,2'deoxyuridine (5F,2'dUrd), and was designated uridine-uracil transporter 1 (UUT1); the other transporter mediated uptake of adenosine, uridine, 5F,2'dUrd and thymidine and was designated Nucleoside Transporter 1 (NT1). To verify the reported L. donovani model of two NT1-like genes encoding uridine/adenosine transporters, and an NT2 gene encoding an inosine transporter, we cloned the corresponding L. major and L. mexicana genes, expressing each in T. brucei. Consistent with the L. donovani reports, the NT1-like genes of either species mediated the adenosine-sensitive uptake of [ 3 H]-uridine but not of [ 3 H]-inosine. Conversely, the NT2-like genes mediated uptake of [ 3 H]-inosine but not [ 3 H]-uridine. Among pyrimidine antimetabolites tested, 5-FU and 5F,2'dUrd were the most effective antileishmanials; resistance to both analogs was induced in L. major and L. mexicana. In each case it was found that the resistant cells had lost the transport capacity for the inducing drug. Metabolomics analysis found that the mechanism of action of 5-FU and 5F-2'dUrd was similar in both Leishmania species, with major changes in deoxynucleotide metabolism. We conclude that the pyrimidine salvage system is highly conserved in Leishmania species - essential information for the development of pyrimidine-based chemotherapy. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights

  7. Functional and genetic evidence that nucleoside transport is highly conserved in Leishmania species: Implications for pyrimidine-based chemotherapy

    Directory of Open Access Journals (Sweden)

    Khalid J.H. Alzahrani

    2017-08-01

    Full Text Available Leishmania pyrimidine salvage is replete with opportunities for therapeutic intervention with enzyme inhibitors or antimetabolites. Their uptake into cells depends upon specific transporters; therefore it is essential to establish whether various Leishmania species possess similar pyrimidine transporters capable of drug uptake. Here, we report a comprehensive characterization of pyrimidine transport in L. major and L. mexicana. In both species, two transporters for uridine/adenosine were detected, one of which also transported uracil and the antimetabolites 5-fluoruracil (5-FU and 5F,2′deoxyuridine (5F,2′dUrd, and was designated uridine-uracil transporter 1 (UUT1; the other transporter mediated uptake of adenosine, uridine, 5F,2′dUrd and thymidine and was designated Nucleoside Transporter 1 (NT1. To verify the reported L. donovani model of two NT1-like genes encoding uridine/adenosine transporters, and an NT2 gene encoding an inosine transporter, we cloned the corresponding L. major and L. mexicana genes, expressing each in T. brucei. Consistent with the L. donovani reports, the NT1-like genes of either species mediated the adenosine-sensitive uptake of [3H]-uridine but not of [3H]-inosine. Conversely, the NT2-like genes mediated uptake of [3H]-inosine but not [3H]-uridine. Among pyrimidine antimetabolites tested, 5-FU and 5F,2′dUrd were the most effective antileishmanials; resistance to both analogs was induced in L. major and L. mexicana. In each case it was found that the resistant cells had lost the transport capacity for the inducing drug. Metabolomics analysis found that the mechanism of action of 5-FU and 5F-2′dUrd was similar in both Leishmania species, with major changes in deoxynucleotide metabolism. We conclude that the pyrimidine salvage system is highly conserved in Leishmania species - essential information for the development of pyrimidine-based chemotherapy. Keywords: Leishmania, Pyrimidine metabolism, Uracil

  8. Conservation endocrinology

    Science.gov (United States)

    McCormick, Stephen; Romero, L. Michael

    2017-01-01

    Endocrinologists can make significant contributions to conservation biology by helping to understand the mechanisms by which organisms cope with changing environments. Field endocrine techniques have advanced rapidly in recent years and can provide substantial information on the growth, stress, and reproductive status of individual animals, thereby providing insight into current and future responses of populations to changes in the environment. Environmental stressors and reproductive status can be detected nonlethally by measuring a number of endocrine-related endpoints, including steroids in plasma, living and nonliving tissue, urine, and feces. Information on the environmental or endocrine requirements of individual species for normal growth, development, and reproduction will provide critical information for species and ecosystem conservation. For many taxa, basic information on endocrinology is lacking, and advances in conservation endocrinology will require approaches that are both “basic” and “applied” and include integration of laboratory and field approaches.

  9. Bruton tyrosine kinase inhibition in chronic lymphocytic leukemia.

    Science.gov (United States)

    Maddocks, Kami; Jones, Jeffrey A

    2016-04-01

    Chronic lymphocytic leukemia (CLL) is the most common adult leukemia and remains incurable outside of the setting of allogeneic stem cell transplant. While the standard therapy for both initial and relapsed CLL has traditionally included monoclonal antibody therapy in combination with chemotherapy, there are patients with high-risk disease features including unmutated IgVH, del(11q22) and del(17p13) that are associated with poor overall responses to these therapies with short time to relapse and shortened overall survival. Additionally, many of these therapies have a high rate of infectious toxicity in a population already at increased risk. Targeting the B-cell receptor (BCR) signaling pathway has emerged as a promising therapeutic advance in a variety of B-cell malignancies, including CLL. Bruton agammaglobulinemia tyrosine kinase (Btk) is a tyrosine kinase in the BCR pathway critical to the survival of both normal and malignant B cells and inhibition of this kinase has shown to block the progression of CLL. Ibrutinib, a first in class oral inhibitor of Btk, has shown promise as a very effective agent in the treatment of CLL-in both relapsed and upfront therapy, alone and in combination with other therapies, and in patients of all-risk disease-which has led to its approval in relapsed CLL and as frontline therapy in patients with the high-risk del(17p13) disease. Several studies are ongoing to evaluate the efficacy and safety of ibrutinib in combination with chemotherapy as frontline treatment for CLL and investigation into newer-generation Btk inhibitors is also underway. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Multidisciplinary approach for the esophageal carcinoma with intent to conserve the esophagus centering on high-dose radiotherapy and concurrent chemotherapy

    International Nuclear Information System (INIS)

    Murakami, Masao; Kuroda, Yasumasa; Okamoto, Yoshiaki

    1997-01-01

    Forty-seven patients with operable squamous cell carcinoma of the thoracic esophagus were treated by initial concurrent chemoradiotherapy (CDDP-5 FU-44 Gy) followed by definitive high-dose of radiotherapy (CRT group: 35 patients) or surgery (CRT-S group: 12 patients). Clinical CR rate showed 86% in CRT group; and pathological CR rate 18% in CRT-S group. The overall median survival was 45 months, survival at 1, 3, 5 years being 96%, 52%, 48%, respectively. No treatment-related mortality was observed. The rate of the 'esophagus conservation' was 66%. Our results demonstrated that the multidisciplinary approach with intent to conserve the esophagus centering on high-dose radiotherapy and concurrent chemotherapy provides a significant improvement of both survival and quality of life in patients with operable esophageal carcinoma. (author)

  11. Highly transparent poly(2-ethyl-2-oxazoline)-TiO2 nanocomposite coatings for the conservation of matte painted artworks

    OpenAIRE

    Colombo, A.; Gherardi, Francesca; Goidanich, S.; Delaney, J. K.; de la Rie, E. R.; Ubaldi, M. C.; Toniolo, L.; Simonutti, R.

    2015-01-01

    A nanocomposite coating based on TiO2 nanoparticles and poly(2-ethyl-2-oxazoline) is used as consolidant of matte painted surfaces (temperas, watercolors, modern paintings). The aim of this work is to provide advances in the conservation of these works of art, while preserving their optical appearance, in terms of colour and gloss. Fiber Optic Reflectance Spectroscopy (FORS) measurements of a painting-model (an acrylic black monochrome) treated with the nanocomposite coatings revealed that it...

  12. Behavioral and cognitive effects of tyrosine intake in healthy human adults

    NARCIS (Netherlands)

    Hase, Adrian; Jung, Sophie E.; aan het Rot, Marije

    2015-01-01

    The amino acid tyrosine is the precursor to the catecholamine neurotransmitters dopamine and norepinephrine. Increasing tyrosine uptake may positively influence catecholamine-related psychological functioning. We conducted a systematic review to examine the effects of tyrosine on behavior and

  13. DNA analysis indicates that Asian elephants are native to Borneo and are therefore a high priority for conservation.

    Directory of Open Access Journals (Sweden)

    Prithiviraj Fernando

    2003-10-01

    Full Text Available The origin of Borneo's elephants is controversial. Two competing hypotheses argue that they are either indigenous, tracing back to the Pleistocene, or were introduced, descending from elephants imported in the 16th-18th centuries. Taxonomically, they have either been classified as a unique subspecies or placed under the Indian or Sumatran subspecies. If shown to be a unique indigenous population, this would extend the natural species range of the Asian elephant by 1300 km, and therefore Borneo elephants would have much greater conservation importance than if they were a feral population. We compared DNA of Borneo elephants to that of elephants from across the range of the Asian elephant, using a fragment of mitochondrial DNA, including part of the hypervariable d-loop, and five autosomal microsatellite loci. We find that Borneo's elephants are genetically distinct, with molecular divergence indicative of a Pleistocene colonisation of Borneo and subsequent isolation. We reject the hypothesis that Borneo's elephants were introduced. The genetic divergence of Borneo elephants warrants their recognition as a separate evolutionary significant unit. Thus, interbreeding Borneo elephants with those from other populations would be contraindicated in ex situ conservation, and their genetic distinctiveness makes them one of the highest priority populations for Asian elephant conservation.

  14. Complex formation of EphB1/Nck/Caskin1 leads to tyrosine phosphorylation and structural changes of the Caskin1 SH3 domain

    Directory of Open Access Journals (Sweden)

    Pesti Szabolcs

    2012-11-01

    Full Text Available Abstract Background Scaffold proteins have an important role in the regulation of signal propagation. These proteins do not possess any enzymatic activity but can contribute to the formation of multiprotein complexes. Although scaffold proteins are present in all cell types, the nervous system contains them in the largest amount. Caskin proteins are typically present in neuronal cells, particularly, in the synapses. However, the signaling mechanisms by which Caskin proteins are regulated are largely unknown. Results Here we demonstrate that EphB1 receptor tyrosine kinase can recruit Caskin1 through the adaptor protein Nck. Upon activation of the receptor kinase, the SH2 domain of Nck binds to one of its tyrosine residues, while Nck SH3 domains interact with the proline-rich domain of Caskin1. Complex formation of the receptor, adaptor and scaffold proteins results in the tyrosine phosphorylation of Caskin1 on its SH3 domain. The phosphorylation sites were identified by mass-spectrometry as tyrosines 296 and 336. To reveal the structural consequence of this phosphorylation, CD spectroscopy was performed. This measurement suggests that upon tyrosine phosphorylation the structure of the Caskin1 SH3 domain changes significantly. Conclusion Taken together, we propose that the scaffold protein Caskin1 can form a complex with the EphB1 tyrosine kinase via the Nck protein as a linker. Complex formation results in tyrosine phosphorylation of the Caskin1 SH3 domain. Although we were not able to identify any physiological partner of the SH3 domain so far, we could demonstrate that phosphorylation on conserved tyrosine residues results in marked changes in the structure of the SH3 domain.

  15. Tyrosine Kinase Receptor Landscape in Lung Cancer: Therapeutical Implications

    Directory of Open Access Journals (Sweden)

    A. Quintanal-Villalonga

    2016-01-01

    Full Text Available Lung cancer is a heterogeneous disease responsible for the most cases of cancer-related deaths. The majority of patients are clinically diagnosed at advanced stages, with a poor survival rate. For this reason, the identification of oncodrivers and novel biomarkers is decisive for the future clinical management of this pathology. The rise of high throughput technologies popularly referred to as “omics” has accelerated the discovery of new biomarkers and drivers for this pathology. Within them, tyrosine kinase receptors (TKRs have proven to be of importance as diagnostic, prognostic, and predictive tools and, due to their molecular nature, as therapeutic targets. Along this review, the role of TKRs in the different lung cancer histologies, research on improvement of anti-TKR therapy, and the current approaches to manage anti-TKR resistance will be discussed.

  16. The selective conservative management of small traumatic pneumothoraces following stab injuries is safe: experience from a high-volume trauma service in South Africa.

    Science.gov (United States)

    Kong, V Y; Oosthuizen, G V; Clarke, D L

    2015-02-01

    The selective conservative management of small pneumothoraces (PTXs) following stab injuries is controversial. We reviewed a cohort of patients managed conservatively in a high volume trauma service in South Africa. A retrospective review over a 2-year period identified 125 asymptomatic patients with small PTXs measuring chest radiograph who were managed conservatively. Of the 125 patients included in the study, 92% were male (115/125), and the median age for all patients was 21 years (19-24). Ninety-seven per cent (121/125) of the weapons involved were knives, and 3% (4/125) were screwdrivers. Sixty-one per cent of all injuries were on the left side. Eighty-two per cent (102/125) sustained a single stab, and 18% (23/125) had multiple stabs. Thirty-nine per cent (49/125) had a PTX <0.5 cm (Group A), 26% (32/125) were ≥ 0.5 to <1 cm (Group B), 19% (24/125) were ≥ 1 to <1.5 cm (Group C) and 15% (20/125) were ≥ 1.5 to <2 cm (Group D). Three per cent of all patients (4/125) eventually required ICDs (one in Group C, three in Group D). All four patients had ICDs in situ for 24 h. The remaining 97% (121/125) were all managed successfully by active clinical observation alone. There were no subsequent readmissions, morbidity or mortality as a direct result of our conservative approach. The selective conservative management of asymptomatic small PTXs from stab injuries is safe if undertaken in the appropriate setting.

  17. [Conservation Units.

    Science.gov (United States)

    Texas Education Agency, Austin.

    Each of the six instructional units deals with one aspect of conservation: forests, water, rangeland, minerals (petroleum), and soil. The area of the elementary school curriculum with which each correlates is indicated. Lists of general and specific objectives are followed by suggested teaching procedures, including ideas for introducing the…

  18. Creative conservation

    NARCIS (Netherlands)

    Bentham, Roelof J.

    1968-01-01

    The increasing exploitation of our natural resources, the unlimited occupation of ever more new areas, and the intensification of land-use, make it necessary for us to expand the concept of conservation. But we also need to reconsider that concept itself. For the changing conditions in the

  19. Reshaping conservation

    DEFF Research Database (Denmark)

    Funder, Mikkel; Danielsen, Finn; Ngaga, Yonika

    2013-01-01

    members strengthen the monitoring practices to their advantage, and to some extent move them beyond the reach of government agencies and conservation and development practitioners. This has led to outcomes that are of greater social and strategic value to communities than the original 'planned' benefits...

  20. Importance of tyrosine phosphorylation in receptor kinase complexes.

    Science.gov (United States)

    Macho, Alberto P; Lozano-Durán, Rosa; Zipfel, Cyril

    2015-05-01

    Tyrosine phosphorylation is an important post-translational modification that is known to regulate receptor kinase (RK)-mediated signaling in animals. Plant RKs are annotated as serine/threonine kinases, but recent work has revealed that tyrosine phosphorylation is also crucial for the activation of RK-mediated signaling in plants. These initial observations have paved the way for subsequent detailed studies on the mechanism of activation of plant RKs and the biological relevance of tyrosine phosphorylation for plant growth and immunity. In this Opinion article we review recent reports on the contribution of RK tyrosine phosphorylation in plant growth and immunity; we propose that tyrosine phosphorylation plays a major regulatory role in the initiation and transduction of RK-mediated signaling in plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Requirements for superoxide-dependent tyrosine hydroperoxide formation in peptides

    DEFF Research Database (Denmark)

    Winterbourn, Christine C; Parsons-Mair, Helena N; Gebicki, Silvia

    2004-01-01

    Superoxide reacts rapidly with other radicals, but these reactions have received little attention in the context of oxidative stress. For tyrosyl radicals, reaction with superoxide is 3-fold faster than dimerization, and forms the addition product tyrosine hydroperoxide. We have explored structural...... requirements for hydroperoxide formation using tyrosine analogues and di- and tri-peptides. Superoxide and phenoxyl radicals were generated using xanthine oxidase, peroxidase and the respective tyrosine derivative, or by gamma-radiation. Peroxides were measured using FeSO4/Xylenol Orange. Tyrosine and tyramine...... formed stable hydroperoxides, but N-acetyltyrosine and p-hydroxyphenylacetic acid did not, demonstrating a requirement for a free amino group. Using [14C]tyrosine, the hydroperoxide and dityrosine were formed at a molar ratio of 1.8:1. Studies with pre-formed hydroperoxides, and measurements of substrate...

  2. Detection of tyrosine hydroxylase in dopaminergic neuron cell using gold nanoparticles-based barcode DNA.

    Science.gov (United States)

    An, Jeung Hee; Oh, Byung-Keun; Choi, Jeong Woo

    2013-04-01

    Tyrosine hydroxylase, the rate-limiting enzyme of catecholamine biosysthesis, is predominantly expressed in several cell groups within the brain, including the dopaminergic neurons of the substantia nigra and ventral tegmental area. We evaluated the efficacy of this protein-detection method in detecting tyrosine hydroxylase in normal and oxidative stress damaged dopaminergic cells. In this study, a coupling of DNA barcode and bead-based immnunoassay for detecting tyrosine hydroxylaser with PCR-like sensitivity is reported. The method relies on magnetic nanoparticles with antibodies and nanoparticles that are encoded with DNA and antibodies that can sandwich the target protein captured by the nanoparticle-bound antibodies. The aggregate sandwich structures are magnetically separated from solution, and treated to remove the conjugated barcode DNA. The DNA barcodes were identified by PCR analysis. The concentration of tyrosine hydroxylase in dopaminergic cell can be easily and rapidly detected using bio-barcode assay. The bio-barcode assay is a rapid and high-throughput screening tool to detect of neurotransmitter such as dopamine.

  3. Integrating conservation costs into sea level rise adaptive conservation prioritization

    Directory of Open Access Journals (Sweden)

    Mingjian Zhu

    2015-07-01

    Full Text Available Biodiversity conservation requires strategic investment as resources for conservation are often limited. As sea level rises, it is important and necessary to consider both sea level rise and costs in conservation decision making. In this study, we consider costs of conservation in an integrated modeling process that incorporates a geomorphological model (SLAMM, species habitat models, and conservation prioritization (Zonation to identify conservation priorities in the face of landscape dynamics due to sea level rise in the Matanzas River basin of northeast Florida. Compared to conservation priorities that do not consider land costs in the analysis process, conservation priorities that consider costs in the planning process change significantly. The comparison demonstrates that some areas with high conservation values might be identified as lower priorities when integrating economic costs in the planning process and some areas with low conservation values might be identified as high priorities when considering costs in the planning process. This research could help coastal resources managers make informed decisions about where and how to allocate conservation resources more wisely to facilitate biodiversity adaptation to sea level rise.

  4. Protein Tyrosine Nitration : Selectivity, Physicochemical and Biological Consequences, Denitration, and Proteomics Methods for the Identification of Tyrosine-Nitrated Proteins

    NARCIS (Netherlands)

    Abello, Nicolas; Kerstjens, Huib A. M.; Postma, Dirkje S.; Bischoff, Rainer

    Protein tyrosine nitration (PTN) is a post-translational modification occurring under the action of a nitrating agent. Tyrosine is modified in the 3-position of the phenolic ring through the addition of a nitro group (NO(2)). In the present article, we review the main nitration reactions and

  5. The Carboxy-Terminal ?N Helix of the Archaeal XerA Tyrosine Recombinase Is a Molecular Switch to Control Site-Specific Recombination

    OpenAIRE

    Serre, Marie-Claude; El Arnaout, Toufic; Brooks, Mark A.; Durand, Dominique; Lisboa, Johnny; Lazar, Noureddine; Raynal, Bertrand; van Tilbeurgh, Herman; Quevillon-Cheruel, Sophie

    2013-01-01

    Tyrosine recombinases are conserved in the three kingdoms of life. Here we present the first crystal structure of a full-length archaeal tyrosine recombinase, XerA from Pyrococcus abyssi, at 3.0 Å resolution. In the absence of DNA substrate XerA crystallizes as a dimer where each monomer displays a tertiary structure similar to that of DNA-bound Tyr-recombinases. Active sites are assembled in the absence of dif except for the catalytic Tyr, which is extruded and located equidistant from each ...

  6. Spectroscopic studies of fluorescent complexes of tyrosine 8-hydroxyquinoline and tyrosine-8-hydroxyquinaldine in aqueous phase

    International Nuclear Information System (INIS)

    Jakhrani, M.A.; Kazi, T.G.

    2002-01-01

    A new method has been developed by preparing complexes involving condensation of tyrosine with 8-hydroxyquinoline (Oxine) and 8-hydroxyquinaldine (Quinaldine) respectively, producing fluorescent products. The products obtained have been investigated for identification and quantitative estimation using different spectroscopic techniques including fluorescence activity of newly synthesized products. 8-hydroxyquinaldine and 8-hydroxyquinoline (Oxine) condensed with tyrosine separately produced water soluble fluorescent complexes. The complexes have been investigated for identification and quantitative estimation of amino acids. Identification of amino acids in nano mole or below than nano mole has become possible by present fluorometric activity of these complexes involving different excitation and emission wavelengths. The fluorometric activity of complexes has been observed to be 100 to 1000 times higher than assay method involving ninhydrin and amino acid analyzer. The method adopted in our laboratory is rapid, versatile with good reproducibility and provides excellent results for adoption by analytical, agricultural and biomedical laboratories to estimate amino acids and metals in composite matrix. (author)

  7. Inhibition of receptor tyrosine kinase signalling by small molecule agonist of T-cell protein tyrosine phosphatase

    International Nuclear Information System (INIS)

    Mattila, Elina; Marttila, Heidi; Sahlberg, Niko; Kohonen, Pekka; Tähtinen, Siri; Halonen, Pasi; Perälä, Merja; Ivaska, Johanna

    2010-01-01

    T-cell protein tyrosine phosphatase (TCPTP/TC45) is a ubiquitously expressed intra-cellular non-receptor protein tyrosine phosphatase involved in the negative regulation of several cancer relevant cellular signalling pathways. We have previously shown that interaction between the α-cytoplasmic tail of α1β1 integrin and TCPTP activates TCPTP by disrupting an inhibitory intra-molecular bond in TCPTP. Thus, inhibition of the regulatory interaction in TCPTP is a desirable strategy for TCPTP activation and attenuation of oncogenic RTK signalling. However, this is challenging with low molecular weight compounds. We developed a high-throughput compatible assay to analyse activity of recombinant TCPTP in vitro. Using this assay we have screened 64280 small molecules to identify novel agonists for TCPTP. Dose-dependent response to TCPTP agonist was performed using the in vitro assay. Inhibition effects and specificity of TCPTP agonists were evaluated using TCPTP expressing and null mouse embryonic fibroblasts. Western blot analysis was used to evaluate attenuation of PDGFRβ and EGFR phosphorylation. Inhibition of VEGF signalling was analysed with VEGF-induced endothelial cell sprouting assays. From the screen we identified six TCPTP agonists. Two compounds competed with α1-cytoplasmic domain for binding to TCPTP, suggesting that they activate TCPTP similar to α1-cyt by disrupting the intra-molecular bond in TCPTP. Importantly, one of the compounds (spermidine) displayed specificity towards TCPTP in cells, since TCPTP -/- cells were 43-fold more resistant to the compound than TCPTP expressing cells. This compound attenuates PDGFRβ and VEGFR2 signalling in cells in a TCPTP-dependent manner and functions as a negative regulator of EGFR phosphorylation in cancer cells. In this study we showed that small molecules mimicking TCPTP-α1 interaction can be used as TCPTP agonists. These data provide the first proof-of-concept description of the use of high-throughput screening

  8. Cytoplasmic protein binding to highly conserved sequences in the 3' untranslated region of mouse protamine 2 mRNA, a translationally regulated transcript of male germ cells

    International Nuclear Information System (INIS)

    Kwon, Y.K.; Hecht, N.B.

    1991-01-01

    The expression of the protamines, the predominant nuclear proteins of mammalian spermatozoa, is regulated translationally during male germ-cell development. The 3' untranslated region (UTR) of protamine 1 mRNA has been reported to control its time of translation. To understand the mechanisms controlling translation of the protamine mRNAs, we have sought to identify cis elements of the 3' UTR of protamine 2 mRNA that are recognized by cytoplasmic factors. From gel retardation assays, two sequence elements are shown to form specific RNA-protein complexes. Protein binding sites of the two complexes were determined by RNase T1 mapping, by blocking the putative binding sites with antisense oligonucleotides, and by competition assays. The sequences of these elements, located between nucleotides + 537 and + 572 in protamine 2 mRNA, are highly conserved among postmeiotic translationally regulated nuclear proteins of the mammalian testis. Two closely linked protein binding sites were detected. UV-crosslinking studies revealed that a protein of about 18 kDa binds to one of the conserved sequences. These data demonstrate specific protein binding to a highly conserved 3' UTR of translationally regulated testicular mRNA

  9. Tyrosine kinases, drugs, and Shigella flexneri dissemination.

    Science.gov (United States)

    Dragoi, Ana-Maria; Agaisse, Hervé

    2014-01-01

    Shigella flexneri is an enteropathogenic bacterium responsible for approximately 100 million cases of severe dysentery each year. S. flexneri colonization of the human colonic epithelium is supported by direct spread from cell to cell, which relies on actin-based motility. We have recently uncovered that, in intestinal epithelial cells, S. flexneri actin-based motility is regulated by the Bruton's tyrosine kinase (Btk). Consequently, treatment with Ibrutinib, a specific Btk inhibitor currently used in the treatment of B-cell malignancies, effectively impaired S. flexneri spread from cell to cell. Thus, therapeutic intervention capitalizing on drugs interfering with host factors supporting the infection process may represent an effective alternative to treatments with antimicrobial compounds.

  10. The Highly Conserved COPII Coat Complex Sorts Cargo from the Endoplasmic Reticulum and Targets It to the Golgi

    OpenAIRE

    Lord, Christopher; Ferro-Novick, Susan; Miller, Elizabeth A.

    2013-01-01

    Protein egress from the endoplasmic reticulum (ER) is driven by a conserved cytoplasmic coat complex called the COPII coat. The COPII coat complex contains an inner shell (Sec23/Sec24) that sorts cargo into ER-derived vesicles and an outer cage (Sec13/Sec31) that leads to coat polymerization. Once released from the ER, vesicles must tether to and fuse with the target membrane to deliver their protein and lipid contents. This delivery step also depends on the COPII coat, with coat proteins bin...

  11. Receptor tyrosine phosphatase R-PTP-alpha is tyrosine-phosphorylated and associated with the adaptor protein Grb2

    DEFF Research Database (Denmark)

    Su, J; Batzer, A; Sap, J

    1994-01-01

    Receptor tyrosine phosphatases (R-PTPases) have generated interest because of their suspected involvement in cellular signal transduction. The adaptor protein Grb2 has been implicated in coupling receptor tyrosine kinases to Ras. We report that a ubiquitous R-PTPase, R-PTP-alpha, is tyrosine......-phosphorylated and associated in vivo with the Grb2 protein. This association can be reproduced in stably and transiently transfected cells, as well as in vitro using recombinant Grb2 protein. Association requires the presence of an intact SH2 domain in Grb2, as well as tyrosine phosphorylation of R-PTP-alpha. This observation...... links a receptor tyrosine phosphatase with a key component of a central cellular signalling pathway and provides a basis for addressing R-PTP-alpha function....

  12. Egress of CD19(+)CD5(+) cells into peripheral blood following treatment with the Bruton tyrosine kinase inhibitor ibrutinib in mantle cell lymphoma patients

    NARCIS (Netherlands)

    Chang, Betty Y.; Francesco, Michelle; de Rooij, Martin F. M.; Magadala, Padmaja; Steggerda, Susanne M.; Huang, Min Mei; Kuil, Annemieke; Herman, Sarah E. M.; Chang, Stella; Pals, Steven T.; Wilson, Wyndham; Wiestner, Adrian; Spaargaren, Marcel; Buggy, Joseph J.; Elias, Laurence

    2013-01-01

    Ibrutinib (PCI-32765) is a highly potent oral Bruton tyrosine kinase (BTK) inhibitor in clinical development for treating B-cell lymphoproliferative diseases. Patients with chronic lymphocytic leukemia (CLL) often show marked, transient increases of circulating CLL cells following ibrutinib

  13. Conservation of Charge and Conservation of Current

    OpenAIRE

    Eisenberg, Bob

    2016-01-01

    Conservation of current and conservation of charge are nearly the same thing: when enough is known about charge movement, conservation of current can be derived from conservation of charge, in ideal dielectrics, for example. Conservation of current is enforced implicitly in ideal dielectrics by theories that conserve charge. But charge movement in real materials like semiconductors or ionic solutions is never ideal. We present an apparently universal derivation of conservation of current and ...

  14. Global Conservation of Protein Status between Cell Lines and Xenografts

    Directory of Open Access Journals (Sweden)

    Julian Biau

    2016-08-01

    Full Text Available Common preclinical models for testing anticancer treatment include cultured human tumor cell lines in monolayer, and xenografts derived from these cell lines in immunodeficient mice. Our goal was to determine how similar the xenografts are compared with their original cell line and to determine whether it is possible to predict the stability of a xenograft model beforehand. We studied a selection of 89 protein markers of interest in 14 human cell cultures and respective subcutaneous xenografts using the reverse-phase protein array technology. We specifically focused on proteins and posttranslational modifications involved in DNA repair, PI3K pathway, apoptosis, tyrosine kinase signaling, stress, cell cycle, MAPK/ERK signaling, SAPK/JNK signaling, NFκB signaling, and adhesion/cytoskeleton. Using hierarchical clustering, most cell culture-xenograft pairs cluster together, suggesting a global conservation of protein signature. Particularly, Akt, NFkB, EGFR, and Vimentin showed very stable protein expression and phosphorylation levels highlighting that 4 of 10 pathways were highly correlated whatever the model. Other proteins were heterogeneously conserved depending on the cell line. Finally, cell line models with low Akt pathway activation and low levels of Vimentin gave rise to more reliable xenograft models. These results may be useful for the extrapolation of cell culture experiments to in vivo models in novel targeted drug discovery.

  15. High-Throughput Sequencing Reveals Diverse Sets of Conserved, Nonconserved, and Species-Specific miRNAs in Jute

    Directory of Open Access Journals (Sweden)

    Md. Tariqul Islam

    2015-01-01

    Full Text Available MicroRNAs play a pivotal role in regulating a broad range of biological processes, acting by cleaving mRNAs or by translational repression. A group of plant microRNAs are evolutionarily conserved; however, others are expressed in a species-specific manner. Jute is an agroeconomically important fibre crop; nonetheless, no practical information is available for microRNAs in jute to date. In this study, Illumina sequencing revealed a total of 227 known microRNAs and 17 potential novel microRNA candidates in jute, of which 164 belong to 23 conserved families and the remaining 63 belong to 58 nonconserved families. Among a total of 81 identified microRNA families, 116 potential target genes were predicted for 39 families and 11 targets were predicted for 4 among the 17 identified novel microRNAs. For understanding better the functions of microRNAs, target genes were analyzed by Gene Ontology and their pathways illustrated by KEGG pathway analyses. The presence of microRNAs identified in jute was validated by stem-loop RT-PCR followed by end point PCR and qPCR for randomly selected 20 known and novel microRNAs. This study exhaustively identifies microRNAs and their target genes in jute which will ultimately pave the way for understanding their role in this crop and other crops.

  16. Relatively High Complication and Revision Rates of the Mayo® Metaphysical Conservative Femoral Stem in Young Patients.

    Science.gov (United States)

    Rutenberg, Tal Frenkel; Warshevski, Yaniv; Gold, Aviram; Shasha, Nadav; Snir, Nimrod; Chechik, Ofir; Dolkart, Oleg; Eilig, Dynai; Herman, Amir; Rath, Ehud; Kramer, Moti; Drexler, Michael

    2018-05-08

    The Mayo metaphysical conservative femoral stem (Zimmer, Warsaw, Indiana) is a wedge-shaped implant designed to transfer loads proximally, reduce femoral destruction, and enable the preservation of bone stock in the proximal femur. Thus, it is a potentially preferred prosthesis for active, non-elderly patients who may require additional future surgeries. This retrospective case study analyzed the outcomes of consecutive patients who underwent total hip replacements with this stem between May 2001 and February 2013. All patients underwent clinical assessment, radiological evaluation for the presence and development of radiolucent lines, and functional assessment (numerical analog scale, Harris hip score, and Short Form-12 questionnaire). Ninety-five hips (79 patients) were available for analysis. The patients' mean age was 43 years (range, 18-64 years), and the mean follow-up was 97 months (range, 26.9-166 months). The postoperative clinical assessments and functional assessments revealed significant improvements. Sixteen patients (20.3%) had 18 orthopedic complications, the most common of which were an intraoperative femoral fracture and implant dislocation requiring revision surgeries in 10 hips (10.5%). Radiological analysis revealed evidence of femoral remodeling in 64 (67.4%) implants, spot welds (neocortex) in 35 (36.8%), and osteolysis in 3 (3.2%). These results suggest that the conservative hip femoral implant has an unacceptable complication rate for non-elderly patients. [Orthopedics. 201x; xx(x):xx-xx.]. Copyright 2018, SLACK Incorporated.

  17. A highly conserved phenylalanine in the alpha, beta-T cell receptor (TCR) constant region determines the integrity of TCR/CD3 complexes

    DEFF Research Database (Denmark)

    Caspar-Bauguil, S; Arnaud, J; Huchenq, A

    1994-01-01

    In the present study, we have investigated the importance of a phenylalanine (phe195) in the Tcr-C alpha region on Tcr-alpha,beta/CD3 membrane expression. An exchange of phe195 with a tyrosine residue does not affect Tcr/CD3 membrane expression; however, exchange with aspartic acid, histidine or ...

  18. Diesel conservation: GSRTC'S experience

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh Kumar, I V

    1980-01-01

    The Gujarat State Road Transport Corporation (GSRTC) in India has a fleet of about 6000 buses. The increasing cost of fuel and lubricants added to uncertainty in supplies, has necessitated the need for conserving High Speed Diesel Oil (HSD). GSRTC had achieved an overall average Kilometre Per Litre (kmpl) of 4.44 in the year 1976-1977 due to a variety of measures. In the year 1978-1979 the average kmpl was 4.52 and it is expected to be 4.60 for 1979-1980. The case study outlined describes the measures taken by GSRTC in conserving high speed diesel oil by various methods.

  19. Comparative interactomics: analysis of arabidopsis 14-3-3 complexes reveals highly conserved 14-3-3 interactions between humans and plants.

    Science.gov (United States)

    Paul, Anna-Lisa; Liu, Li; McClung, Scott; Laughner, Beth; Chen, Sixue; Ferl, Robert J

    2009-04-01

    As a first step in the broad characterization of plant 14-3-3 multiprotein complexes in vivo, stringent and specific antibody affinity purification was used to capture 14-3-3s together with their interacting proteins from extracts of Arabidopsis cell suspension cultures. Approximately 120 proteins were identified as potential in vivo 14-3-3 interacting proteins by mass spectrometry of the recovered complexes. Comparison of the proteins in this data set with the 14-3-3 interacting proteins from a similar study in human embryonic kidney cell cultures revealed eight interacting proteins that likely represent reasonably abundant, fundamental 14-3-3 interaction complexes that are highly conserved across all eukaryotes. The Arabidopsis 14-3-3 interaction data set was also compared to a yeast in vivo 14-3-3 interaction data set. Four 14-3-3 interacting proteins are conserved in yeast, humans, and Arabidopsis. Comparisons of the data sets based on biochemical function revealed many additional similarities in the human and Arabidopsis data sets that represent conserved functional interactions, while also leaving many proteins uniquely identified in either Arabidopsis or human cells. In particular, the Arabidopsis interaction data set is enriched for proteins involved in metabolism.

  20. Tracer experiment administering L-phenylalanine-U-{sup 14}C and L-tyrosine-U-{sup 14}C to the tissue slices of bamboo shoots

    Energy Technology Data Exchange (ETDEWEB)

    Kozukue, E. [Kenmei Women' s Junior Coll., Himeji, Hyogo (Japan); Mizuno, S.

    1987-09-15

    Uniformly {sup 14}C-labeled L-phenylalanine and L-tyrosine were administered to tissue slices of both top and base sections of bamboo shoots. Alcohol soluble substances were extracted and then separated into organic acid, sugar and amino acid fractions by ion exchange chromatography. The homogentisic acid fraction among the organic acids was collected by high-performance liquid chromatography (HPLC) and its radioactivity was measured, while the alcohol insoluble residue was used for the analysis of lignin aldehyde by the method of alkaline nitrobenzene oxidation. 1. The two labeled amino acids were steadily incorporated into the tissues during incubation and rapidly converted to organic acid, sugar and alcohol insoluble residue, especially the latter. 2. On determining the amount of phenylalanine converted to tyrosine, it was found that this was extremely small. 3. The incorporation of phenylalanine-U-{sup 14}C into alcohol insoluble residue was higher than that of tyrosine in both sections. 4. Although the conversion into lignin aldehyde from phenylalanine-U-{sup 14}C was higher than that from tyrosine-U-{sup 14}C, it was found that tyrosine incorporated into the shoots was converted to a remarkable extent for formation of lignin aldehyde. 5. The incorporation of phenylalanine and tyrosine into homogentisic acid was very low. From these results, we assume that the conversion of phenylalanine to tyrosine or of tyrosine to homogentisic acid is very small, and that a part of the high amount of tyrosine in the shoots may be used for formation of lignin.

  1. Robotic synthesis of L-[1-11C]tyrosine

    International Nuclear Information System (INIS)

    Luurtsema, Gert; Medema, Jitze; Elsinga, P.H.; Visser, G.M.; Vaalburg, Willem

    1994-01-01

    L-[1- 11 C]tyrosine promises to become an important tracer for determination of the protein synthesis rate (PSR) in tumor tissue and brain. The commercially available Anatech RB-86 robotic system is utilized for the automation of the L-[1- 11 C]tyrosine production via the isocyanide method as reported by Bolster et al. (Eur. J. Nucl. Med. 12, 321-324, 1986). The total synthesis time, including HPLC-purification and enantiomeric separation is 60 min. With a practical yield of 20 mCi L-[1- 11 C]tyrosine at a specific activity > 1000 Ci/mmol. (author)

  2. Comparison of the uptake of [123/125I]-2-iodo-D-tyrosine and [123/125I]-2-iodo-L-tyrosine in R1M rhabdomyosarcoma cells in vitro and in R1M tumor-bearing Wag/Rij rats in vivo

    International Nuclear Information System (INIS)

    Bauwens, Matthias; Lahoutte, Tony; Kersemans, Ken; Gallez, Carol; Bossuyt, Axel; Mertens, John

    2006-01-01

    Introduction: Recently, promising results concerning uptake in vivo in tumors of D-amino acids have been published. Therefore, we decided to evaluate the tumor uptake of the D-analogue of [ 123 I]-2-iodo-L-tyrosine, a tracer recently introduced by our group into clinical trials. The uptake of 2-amino-3-(4-hydroxy-2-[ 123/125 I]iodophenyl)-D-propanoic acid (2-iodo-D-tyrosine) was studied in vitro in LAT1-expressing R1M rat rhabdomyosarcoma cells and in vivo in R1M tumor-bearing Wag/Rij rats. Methods: The uptake of [ 125 I]-2-iodo-L-tyrosine and [ 125 I]-2-iodo-D-tyrosine into R1M cells was determined in appropriate buffers, allowing the study of the involved transport systems. In vivo, the biodistribution in R1M-bearing rats of [ 123 I]-2-iodo-L-tyrosine and [ 123 I]-2-iodo-D-tyrosine was performed by both dynamic and static planar imaging with a gamma camera. Results: In in vitro conditions, the uptake of both [ 125 I]-2-iodo-L-tyrosine and [ 125 I]-2-iodo-D-tyrosine in the HEPES buffer was 25% higher in the presence of Na + ions. In the absence of Na + ions, [ 125 I]-2-iodo-D-tyrosine was taken up reversibly in the R1M cells, with an apparent accumulation, probably for the larger part by the LAT1 system. Dynamic planar imaging showed that the uptake in the tumors of [ 123 I]-2-iodo-D-tyrosine was somewhat lower than that of [ 123 I]-2-iodo-L-tyrosine. At 30 min postinjection, the mean differential uptake ratio values of the L- and D-enantiomers are 2.5±0.7 and 1.7±0.6, respectively. Although the uptake of the D-isomer is lower, probably due to a faster clearance from the blood, the tumor-background ratio is the same as that of the L-analogue. Conclusion: A large part (75%) of [ 125 I]-2-iodo-D-tyrosine in vitro and [ 123 I]-2-iodo-D-tyrosine in vivo is reversibly highly taken up in R1M tumor cells by Na + -independent LAT transport systems, more likely by the LAT1. The clearance from the blood of [ 123 I]-2-iodo-D-tyrosine in the rats is faster than that of the

  3. What is a conservation actor?

    Directory of Open Access Journals (Sweden)

    Paul Jepson

    2011-01-01

    Full Text Available As a crisis-oriented discipline, conservation biology needs actions to understand the state of nature and thwart declines in biodiversity. Actors-traditionally individuals, institutions, and collectives-have been central to delivering such goals in practice. However, the definition of actors within the discipline has been narrow and their role in influencing conservation outcomes inadequately conceptualised. In this paper, we examine the question ′What is a conservation actor?′ Who or what creates the capacity to influence conservation values and actions? Drawing from theoretical developments in Actor-Network Theory and collective governance, we argue that the concept of an actor in conservation biology should be broadened to include non-humans, such as species and devices, because they have the agency and ability to influence project goals and outcomes. We illustrate this through four examples: the Asian elephant, International Union for Conservation of Nature red lists, the High Conservation Value approach, and an Integrated Conservation and Development Project. We argue that a broader conceptualisation of actors in conservation biology will produce new forms of understanding that could open up new areas of conservation research, enhance practice and draw attention to spheres of conservation activity that might require stronger oversight and governance.

  4. Determination of 5 '-leader sequences from radically disparate strains of porcine reproductive and respiratory syndrome virus reveals the presence of highly conserved sequence motifs

    DEFF Research Database (Denmark)

    Oleksiewicz, M.B.; Bøtner, Anette; Nielsen, Jens

    1999-01-01

    We determined the untranslated 5'-leader sequence for three different isolates of porcine reproductive and respiratory syndrome virus (PRRSV): pathogenic European- and American-types, as well as an American-type vaccine strain. 5'-leader from European- and American-type PRRSV differed in length...... (220 and 190 nt, respectively), and exhibited only approximately 50% nucleotide homology. Nevertheless, highly conserved areas were identified in the leader of all 3 PRRSV isolates, which constitute candidate motifs for binding of protein(s) involved in viral replication. These comparative data provide...

  5. UK114, a YjgF/Yer057p/UK114 family protein highly conserved from bacteria to mammals, is localized in rat liver peroxisomes

    International Nuclear Information System (INIS)

    Antonenkov, Vasily D.; Ohlmeier, Steffen; Sormunen, Raija T.; Hiltunen, J. Kalervo

    2007-01-01

    Mammalian UK114 belongs to a highly conserved family of proteins with unknown functions. Although it is believed that UK114 is a cytosolic or mitochondrial protein there is no detailed study of its intracellular localization. Using analytical subcellular fractionation, electron microscopic colloidal gold technique, and two-dimensional gel electrophoresis of peroxisomal matrix proteins combined with mass spectrometric analysis we show here that a large portion of UK114 is present in rat liver peroxisomes. The peroxisomal UK114 is a soluble matrix protein and it is not inducible by the peroxisomal proliferator clofibrate. The data predict involvement of UK114 in peroxisomal metabolism

  6. Tyrosine phosphorylation of a 66KD soluble protein and augmentation of lectin induced mitogenesis by DMSO in human T lymphocytes

    International Nuclear Information System (INIS)

    Wedner, H.J.; Bass, G.

    1986-01-01

    The authors have demonstrated that induction of mitogenesis in human T lymphocytes is associated with the tyrosine phosphorylation of a 66KD soluble substrate-TPP 66. Since DMSO has been shown to be a non-specific stimulator of tyrosine protein kinases they have examined the effect of DMSO on both activation and tyrosine phosphorylation in human T cells. Human peripheral blood T lymphocytes were isolated by dextran sedimentation, Ficol/Paque centrifugation and nylon wool filtration. Phosphorylation was performed in cells incubated with [ 32 P] orthophosphate followed by DMSO for 30 min. TPP 66 was identified by 2-D PAGE, autoradiography, and HV electrophoresis of the hydrolyzed protein. Concentrations of DMSO from 1% to 50% induced the tyrosine phosphorylation of TPP 66 with maximal stimulation seen at 20%. DMSO alone did not activate the T cells (measured by [ 3 H] thymidine incorporation) when tested at high concentrations for 30 sec to 10 min. (longer incubations were markedly toxic) or low concentrations for 12 to 48 hrs. Low concentrations of DMSO 0.1%-0.5% did however, markedly augment [ 3 H] thymidine incorporation induced by PHA or Con A. These data suggest that tyrosine phosphorylation of TPP 66 alone may not constitute sufficient signal for the activation sequence to begin but the phosphorylation of this soluble substrate may be a critical factor in the propagation of the activation sequence

  7. Nano titanium dioxide photocatalytic protein tyrosine nitration: A potential hazard of TiO2 on skin

    International Nuclear Information System (INIS)

    Lu, Naihao; Zhu Zhening; Zhao Xuqi; Tao Ran; Yang Xiangliang; Gao Zhonghong

    2008-01-01

    Protein tyrosine nitration is a prevalent post-translational modification which occurs as a result of oxidative and nitrative stress, it may be directly involved in the onset and/or progression of diseases. Considering the existence of nano titanium dioxide (TiO 2 ) in environment and sunscreen products along with the high content of nitrite in sweat, the UV-exposed skin may be a significant target for the photosensitized damage. In this paper, tyrosine nitration of bovine serum albumin (BSA) was initiated in the UV-irradiated reaction mixture containing 0.2-3.0 mg/ml of three commercially nano TiO 2 products and 0.25-1.0 mM NO 2 - . It was found that anatase TiO 2 and Degussa P25 TiO 2 showed prominent photocatalytic activity on promoting the formation of protein tyrosine nitration, and the optimum condition for the reaction was around physiological pH. Meanwhile, the photocatalytic effect of rutile on protein tyrosine nitration was subtle. The potential physiological significance of nano TiO 2 -photocatalytic protein nitration was also demonstrated in mouse skin homogenate. Although the relationship between photocatalytic protein tyrosine nitration and chronic cutaneous diseases needs further study, the toxicity of nano TiO 2 to the skin disease should be paid more attention in the production and utilization process

  8. Eating to stop: Tyrosine supplementation enhances inhibitory control but not response execution

    NARCIS (Netherlands)

    Colzato, L.S.; Jongkees, B.J.; Sellaro, R.; van den Wildenberg, W.P.M.; Hommel, B.

    2014-01-01

    Animal studies and research in humans have shown that the supplementation of tyrosine, or tyrosine-containing diets, increase the plasma tyrosine and enhance brain dopamine (DA). However, the strategy of administering tyrosine (and the role of DA therein) to enhance cognition is unclear and heavily

  9. Cytochrome c Is Tyrosine 97 Phosphorylated by Neuroprotective Insulin Treatment

    Czech Academy of Sciences Publication Activity Database

    Sanderson, T. H.; Mahapatra, G.; Pecina, Petr; Ji, Q.; Yu, K.; Sinkler, Ch.; Varughese, A.; Kumar, R.; Bukowski, M. J.; Tousignant, R. N.; Salomon, A. R.; Lee, I.; Hüttemann, M.

    2013-01-01

    Roč. 8, č. 11 (2013), e78627 E-ISSN 1932-6203 Institutional support: RVO:67985823 Keywords : cytochrome c * tyrosine phosphorylation * brain ischemia * insulin Subject RIV: ED - Physiology Impact factor: 3.534, year: 2013

  10. Tyrosine Kinase Gene Expression Profiling in Prostate Cancer

    National Research Council Canada - National Science Library

    Weier, Heinz-Ulrich

    2001-01-01

    ... of these genes parallels the progression of tumors to a more malignant phenotype. We developed a DNA micro-array based screening system to monitor the level of expression of tyrosine kinase (tk...

  11. Tyrosine Kinase Gene Expression Profiling in Prostate Cancer

    National Research Council Canada - National Science Library

    Weier, Heinz-Ulrich

    2002-01-01

    ... of these genes parallels the progression of tumors to a more malignant phenotype. We developed a DNA micro-array based screening system to monitor the level of expression of tyrosine kinase (tk...

  12. Electrode Potentials of l-Tryptophan, l-Tyrosine, 3-Nitro-l-tyrosine, 2,3-Difluoro-l-tyrosine, and 2,3,5-Trifluoro-l-tyrosine.

    Science.gov (United States)

    Mahmoudi, Leila; Kissner, Reinhard; Nauser, Thomas; Koppenol, Willem H

    2016-05-24

    Electrode potentials for aromatic amino acid radical/amino acid couples were deduced from cyclic voltammograms and pulse radiolysis experiments. The amino acids investigated were l-tryptophan, l-tyrosine, N-acetyl-l-tyrosine methyl ester, N-acetyl-3-nitro-l-tyrosine ethyl ester, N-acetyl-2,3-difluoro-l-tyrosine methyl ester, and N-acetyl-2,3,5-trifluoro-l-tyrosine methyl ester. Conditional potentials were determined at pH 7.4 for all compounds listed; furthermore, Pourbaix diagrams for l-tryptophan, l-tyrosine, and N-acetyl-3-nitro-l-tyrosine ethyl ester were obtained. Electron transfer accompanied by proton transfer is reversible, as confirmed by detailed analysis of the current waves, and because the slopes of the Pourbaix diagrams obey Nernst's law. E°'(Trp(•),H(+)/TrpH) and E°'(TyrO(•),H(+)/TyrOH) at pH 7 are 0.99 ± 0.01 and 0.97 ± 0.01 V, respectively. Pulse radiolysis studies of two dipeptides that contain both amino acids indicate a difference in E°' of approximately 0.06 V. Thus, in small peptides, we recommend values of 1.00 and 0.96 V for E°'(Trp(•),H(+)/TrpH) and E°'(TyrO(•),H(+)/TyrOH), respectively. The electrode potential of N-acetyl-3-nitro-l-tyrosine ethyl ester is higher, while because of mesomeric stabilization of the radical, those of N-acetyl-2,3-difluoro-l-tyrosine methyl ester and N-acetyl-2,3,5-trifluoro-l-tyrosine methyl ester are lower than that of tyrosine. Given that the electrode potentials at pH 7 of E°'(Trp(•),H(+)/TrpH) and E°'(TyrO(•),H(+)/TyrOH) are nearly equal, they would be, in principle, interchangeable. Proton-coupled electron transfer pathways in proteins that use TrpH and TyrOH are thus nearly thermoneutral.

  13. Tyrosine phosphorylation switching of a G protein.

    Science.gov (United States)

    Li, Bo; Tunc-Ozdemir, Meral; Urano, Daisuke; Jia, Haiyan; Werth, Emily G; Mowrey, David D; Hicks, Leslie M; Dokholyan, Nikolay V; Torres, Matthew P; Jones, Alan M

    2018-03-30

    Heterotrimeric G protein complexes are molecular switches relaying extracellular signals sensed by G protein-coupled receptors (GPCRs) to downstream targets in the cytoplasm, which effect cellular responses. In the plant heterotrimeric GTPase cycle, GTP hydrolysis, rather than nucleotide exchange, is the rate-limiting reaction and is accelerated by a receptor-like regulator of G signaling (RGS) protein. We hypothesized that posttranslational modification of the Gα subunit in the G protein complex regulates the RGS-dependent GTPase cycle. Our structural analyses identified an invariant phosphorylated tyrosine residue (Tyr 166 in the Arabidopsis Gα subunit AtGPA1) located in the intramolecular domain interface where nucleotide binding and hydrolysis occur. We also identified a receptor-like kinase that phosphorylates AtGPA1 in a Tyr 166 -dependent manner. Discrete molecular dynamics simulations predicted that phosphorylated Tyr 166 forms a salt bridge in this interface and potentially affects the RGS protein-accelerated GTPase cycle. Using a Tyr 166 phosphomimetic substitution, we found that the cognate RGS protein binds more tightly to the GDP-bound Gα substrate, consequently reducing its ability to accelerate GTPase activity. In conclusion, we propose that phosphorylation of Tyr 166 in AtGPA1 changes the binding pattern with AtRGS1 and thereby attenuates the steady-state rate of the GTPase cycle. We coin this newly identified mechanism "substrate phosphoswitching." © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Tyrosine biosynthesis, metabolism, and catabolism in plants.

    Science.gov (United States)

    Schenck, Craig A; Maeda, Hiroshi A

    2018-05-01

    L-Tyrosine (Tyr) is an aromatic amino acid (AAA) required for protein synthesis in all organisms, but synthesized de novo only in plants and microorganisms. In plants, Tyr also serves as a precursor of numerous specialized metabolites that have diverse physiological roles as electron carriers, antioxidants, attractants, and defense compounds. Some of these Tyr-derived plant natural products are also used in human medicine and nutrition (e.g. morphine and vitamin E). While the Tyr biosynthesis and catabolic pathways have been extensively studied in microbes and animals, respectively, those of plants have received much less attention until recently. Accumulating evidence suggest that the Tyr biosynthetic pathways differ between microbes and plants and even within the plant kingdom, likely to support the production of lineage-specific plant specialized metabolites derived from Tyr. The interspecies variations of plant Tyr pathway enzymes can now be used to enhance the production of Tyr and Tyr-derived compounds in plants and other synthetic biology platforms. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. A high-order finite-volume method for hyperbolic conservation laws on locally-refined grids

    Energy Technology Data Exchange (ETDEWEB)

    McCorquodale, Peter; Colella, Phillip

    2011-01-28

    We present a fourth-order accurate finite-volume method for solving time-dependent hyperbolic systems of conservation laws on Cartesian grids with multiple levels of refinement. The underlying method is a generalization of that in [5] to nonlinear systems, and is based on using fourth-order accurate quadratures for computing fluxes on faces, combined with fourth-order accurate Runge?Kutta discretization in time. To interpolate boundary conditions at refinement boundaries, we interpolate in time in a manner consistent with the individual stages of the Runge-Kutta method, and interpolate in space by solving a least-squares problem over a neighborhood of each target cell for the coefficients of a cubic polynomial. The method also uses a variation on the extremum-preserving limiter in [8], as well as slope flattening and a fourth-order accurate artificial viscosity for strong shocks. We show that the resulting method is fourth-order accurate for smooth solutions, and is robust in the presence of complex combinations of shocks and smooth flows.

  16. Toward High School Biology: Helping Middle School Students Understand Chemical Reactions and Conservation of Mass in Nonliving and Living Systems

    Science.gov (United States)

    Herrmann-Abell, Cari F.; Koppal, Mary; Roseman, Jo Ellen

    2016-01-01

    Modern biology has become increasingly molecular in nature, requiring students to understand basic chemical concepts. Studies show, however, that many students fail to grasp ideas about atom rearrangement and conservation during chemical reactions or the application of these ideas to biological systems. To help provide students with a better foundation, we used research-based design principles and collaborated in the development of a curricular intervention that applies chemistry ideas to living and nonliving contexts. Six eighth grade teachers and their students participated in a test of the unit during the Spring of 2013. Two of the teachers had used an earlier version of the unit the previous spring. The other four teachers were randomly assigned either to implement the unit or to continue teaching the same content using existing materials. Pre- and posttests were administered, and the data were analyzed using Rasch modeling and hierarchical linear modeling. The results showed that, when controlling for pretest score, gender, language, and ethnicity, students who used the curricular intervention performed better on the posttest than the students using existing materials. Additionally, students who participated in the intervention held fewer misconceptions. These results demonstrate the unit’s promise in improving students’ understanding of the targeted ideas. PMID:27909024

  17. Highly conserved non-coding elements on either side of SOX9 associated with Pierre Robin sequence.

    Science.gov (United States)

    Benko, Sabina; Fantes, Judy A; Amiel, Jeanne; Kleinjan, Dirk-Jan; Thomas, Sophie; Ramsay, Jacqueline; Jamshidi, Negar; Essafi, Abdelkader; Heaney, Simon; Gordon, Christopher T; McBride, David; Golzio, Christelle; Fisher, Malcolm; Perry, Paul; Abadie, Véronique; Ayuso, Carmen; Holder-Espinasse, Muriel; Kilpatrick, Nicky; Lees, Melissa M; Picard, Arnaud; Temple, I Karen; Thomas, Paul; Vazquez, Marie-Paule; Vekemans, Michel; Roest Crollius, Hugues; Hastie, Nicholas D; Munnich, Arnold; Etchevers, Heather C; Pelet, Anna; Farlie, Peter G; Fitzpatrick, David R; Lyonnet, Stanislas

    2009-03-01

    Pierre Robin sequence (PRS) is an important subgroup of cleft palate. We report several lines of evidence for the existence of a 17q24 locus underlying PRS, including linkage analysis results, a clustering of translocation breakpoints 1.06-1.23 Mb upstream of SOX9, and microdeletions both approximately 1.5 Mb centromeric and approximately 1.5 Mb telomeric of SOX9. We have also identified a heterozygous point mutation in an evolutionarily conserved region of DNA with in vitro and in vivo features of a developmental enhancer. This enhancer is centromeric to the breakpoint cluster and maps within one of the microdeletion regions. The mutation abrogates the in vitro enhancer function and alters binding of the transcription factor MSX1 as compared to the wild-type sequence. In the developing mouse mandible, the 3-Mb region bounded by the microdeletions shows a regionally specific chromatin decompaction in cells expressing Sox9. Some cases of PRS may thus result from developmental misexpression of SOX9 due to disruption of very-long-range cis-regulatory elements.

  18. High spatial resolution mapping of the Cerrado's land cover and land use types in the priority area for conservation Chapada da Contagem, Brazil.

    Science.gov (United States)

    Ribeiro, F.; Roberts, D. A.; Davis, F. W.; Antunes Daldegan, G.; Nackoney, J.; Hess, L. L.

    2016-12-01

    The Brazilian savanna, Cerrado, is the second largest biome over South America and the most floristically diverse savanna in the world. This biome is considered a conservation hotspot in respect to its biodiversity importance and rapid transformation of its landscape. The Cerrado's natural vegetation has been severely transformed by agriculture and pasture activities. Currently it is the main agricultural frontier in Brazil and one of the most threatened Brazilian biomes. This scenario results in environmental impacts such as ecosystems fragmentation as well as losses in connectivity, biodiversity and gene flow, changes in the microclimate and energy, carbon and nutrients cycles, among others. The Priority Areas for Conservation is a governmental program from Brazil that identifies areas with high conservation priority. One of this program's recommendation is a natural vegetation map including their major ecosystem classes. This study aims to generate more precise information for the Cerrado's vegetation. The main objective of this study is to identify which ecosystems are being prioritized and/or threatened by land use, refining information for further protection. In order to test methods, the priority area for conservation Chapada da Contagem was selected as the study site. This area is ranked as "extremely high priority" by the government and is located in the Federal District and Goias State, Brazil. Satellites with finer spatial resolution may improve the classification of the Cerrado's vegetation. Remote sensing methods and two criteria were tested using RapidEye 3A imagery (5m spatial resolution) collected in 2014 in order to classify the Cerrado's major land cover types of this area, as well as its land use. One criterion considers the Cerrado's major terrestrial ecosystems, which are divided into forest, savanna and grassland. The other involves scaling it down to the major physiognomic groups of each ecosystem. Other sources of environmental dataset such

  19. Autophosphorylation of JAK2 on tyrosines 221 and 570 regulates its activity

    DEFF Research Database (Denmark)

    Argetsinger, Lawrence S; Kouadio, Jean-Louis K; Steen, Hanno

    2004-01-01

    or which of the 49 tyrosines in JAK2 are autophosphorylated. In this study, mass spectrometry and two-dimensional peptide mapping were used to determine that tyrosines 221, 570, and 1007 in JAK2 are autophosphorylated. Phosphorylation of tyrosine 570 is particularly robust. In response to growth hormone......, JAK2 was rapidly and transiently phosphorylated at tyrosines 221 and 570, returning to basal levels by 60 min. Analysis of the sequences surrounding tyrosines 221 and 570 in JAK2 and tyrosines in other proteins that are phosphorylated in response to ligands that activate JAK2 suggests that the YXX......[L/I/V] motif is one of the motifs recognized by JAK2. Experiments using JAK2 with tyrosines 221 and 570 mutated to phenylalanine suggest that tyrosines 221 and 570 in JAK2 may serve as regulatory sites in JAK2, with phosphorylation of tyrosine 221 increasing kinase activity and phosphorylation of tyrosine 570...

  20. Phosphotyrosine phosphatase and tyrosine kinase inhibition modulate airway pressure-induced lung injury.

    Science.gov (United States)

    Parker, J C; Ivey, C L; Tucker, A

    1998-11-01

    We determined whether drugs which modulate the state of protein tyrosine phosphorylation could alter the threshold for high airway pressure-induced microvascular injury in isolated perfused rat lungs. Lungs were ventilated for successive 30-min periods with peak inflation pressures (PIP) of 7, 20, 30, and 35 cmH2O followed by measurement of the capillary filtration coefficient (Kfc), a sensitive index of hydraulic conductance. In untreated control lungs, Kfc increased by 1.3- and 3.3-fold relative to baseline (7 cmH2O PIP) after ventilation with 30 and 35 cmH2O PIP. However, in lungs treated with 100 microM phenylarsine oxide (a phosphotyrosine phosphatase inhibitor), Kfc increased by 4.7- and 16.4-fold relative to baseline at these PIP values. In lungs treated with 50 microM genistein (a tyrosine kinase inhibitor), Kfc increased significantly only at 35 cmH2O PIP, and the three groups were significantly different from each other. Thus phosphotyrosine phosphatase inhibition increased the susceptibility of rat lungs to high-PIP injury, and tyrosine kinase inhibition attenuated the injury relative to the high-PIP control lungs.

  1. Tyrosine kinase inhibitors: Multi-targeted or single-targeted?

    Science.gov (United States)

    Broekman, Fleur; Giovannetti, Elisa; Peters, Godefridus J

    2011-02-10

    Since in most tumors multiple signaling pathways are involved, many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases. The most important tyrosine kinase families in the development of tyrosine kinase inhibitors are the ABL, SCR, platelet derived growth factor, vascular endothelial growth factor receptor and epidermal growth factor receptor families. Both multi-kinase inhibitors and single-kinase inhibitors have advantages and disadvantages, which are related to potential resistance mechanisms, pharmacokinetics, selectivity and tumor environment. In different malignancies various tyrosine kinases are mutated or overexpressed and several resistance mechanisms exist. Pharmacokinetics is influenced by interindividual differences and differs for two single targeted inhibitors or between patients treated by the same tyrosine kinase inhibitor. Different tyrosine kinase inhibitors have various mechanisms to achieve selectivity, while differences in gene expression exist between tumor and stromal cells. Considering these aspects, one type of inhibitor can generally not be preferred above the other, but will depend on the specific genetic constitution of the patient and the tumor, allowing personalized therapy. The most effective way of cancer treatment by using tyrosine kinase inhibitors is to consider each patient/tumor individually and to determine the strategy that specifically targets the consequences of altered (epi)genetics of the tumor. This strategy might result in treatment by a single multi kinase inhibitor for one patient, but in treatment by a couple of single kinase inhibitors for other patients.

  2. Synthesis of 14C-labelled α-methyl tyrosine

    International Nuclear Information System (INIS)

    Rajagopal, S.; Venkatachalam, T.K.; Conway, T.; Diksic, M.

    1992-01-01

    A new route for the preparation of radioactively labelled α-methyl L-tyrosine is described. The labelling at the α position has been successfully achieved with 14 C-, 11 C- (very preliminary, unpublished), and 3 H-labelled methyl iodide. A detailed report on 14 C-labelling at the α position and the hydrolysis of 4-methoxy α-methyl phenylalanine is presented. The alkylation proceeds via the methylation of the carbanion of N-benzylidene 4-methoxy phenylalanine methyl ester 2. Hydrolysis of 4-O methyl tyrosine to tyrosine by HBr and HI were analysed and used in the optimization of the hydrolysis conditions of 4. Enantiomeric purity of the isolated L-isomer has been found to be 99% as judged by HPLC. Pseudo first-order rate constant for the hydrolysis of 14 C-labelled α-methyl 4-methoxy phenyl alanine methyl ester was determined. Preliminary findings of the 3 H- and 11 C-radiolabelled α-methyl tyrosine (methyl labelled) are also mentioned. For the first time it was shown that α-methyl D,L-tyrosine can be separated into enantiomerically pure α-methyl D- and L-tyrosine using a CHIRALPAK WH column. (author)

  3. Conservation of Mangifera sylvatica

    DEFF Research Database (Denmark)

    Akhter, Sayma

    and conservation of these valuable species. The present study considers an underutilised and threatened species of Bangladesh, namely wild mango (Mangifera sylvatica Roxb.). Although this wild mango is one of the genetically closest species to the common mango (Mangifera indica L.) research is very limited...... and mostly focused on wood quality and phylogenetic relationships. Therefore, this study investigated the conservation potential of wild mango considering its contribution for food, nutrition and livelihoods. To do so, an assessment was made of the current and future distribution of the species, which...... explored. The study conveyed five key messages: 1. Wild mango may become extinct under future climate change scenarios so it is high time to start thinking about conservation initiatives. 2. Wild mango is a small sized mango with a large kernel in relation to other Mangifera species which provides...

  4. High-Level Systemic Expression of Conserved Influenza Epitope in Plants on the Surface of Rod-Shaped Chimeric Particles

    Directory of Open Access Journals (Sweden)

    Natalia V. Petukhova

    2014-04-01

    Full Text Available Recombinant viruses based on the cDNA copy of the tobacco mosaic virus (TMV genome carrying different versions of the conserved M2e epitope from influenza virus A cloned into the coat protein (CP gene were obtained and partially characterized by our group previously; cysteines in the human consensus M2e sequence were changed to serine residues. This work intends to show some biological properties of these viruses following plant infections. Agroinfiltration experiments on Nicotiana benthamiana confirmed the efficient systemic expression of M2e peptides, and two point amino acid substitutions in recombinant CPs significantly influenced the symptoms and development of viral infections. Joint expression of RNA interference suppressor protein p19 from tomato bushy stunt virus (TBSV did not affect the accumulation of CP-M2e-ser recombinant protein in non-inoculated leaves. RT-PCR analysis of RNA isolated from either infected leaves or purified TMV-M2e particles proved the genetic stability of TMV‑based viral vectors. Immunoelectron microscopy of crude plant extracts demonstrated that foreign epitopes are located on the surface of chimeric virions. The rod‑shaped geometry of plant-produced M2e epitopes is different from the icosahedral or helical filamentous arrangement of M2e antigens on the carrier virus-like particles (VLP described earlier. Thereby, we created a simple and efficient system that employs agrobacteria and plant viral vectors in order to produce a candidate broad-spectrum flu vaccine.

  5. Toward High School Biology: Helping Middle School Students Understand Chemical Reactions and Conservation of Mass in Nonliving and Living Systems.

    Science.gov (United States)

    Herrmann-Abell, Cari F; Koppal, Mary; Roseman, Jo Ellen

    2016-01-01

    Modern biology has become increasingly molecular in nature, requiring students to understand basic chemical concepts. Studies show, however, that many students fail to grasp ideas about atom rearrangement and conservation during chemical reactions or the application of these ideas to biological systems. To help provide students with a better foundation, we used research-based design principles and collaborated in the development of a curricular intervention that applies chemistry ideas to living and nonliving contexts. Six eighth grade teachers and their students participated in a test of the unit during the Spring of 2013. Two of the teachers had used an earlier version of the unit the previous spring. The other four teachers were randomly assigned either to implement the unit or to continue teaching the same content using existing materials. Pre- and posttests were administered, and the data were analyzed using Rasch modeling and hierarchical linear modeling. The results showed that, when controlling for pretest score, gender, language, and ethnicity, students who used the curricular intervention performed better on the posttest than the students using existing materials. Additionally, students who participated in the intervention held fewer misconceptions. These results demonstrate the unit's promise in improving students' understanding of the targeted ideas. © 2016 C. F. Herrmann-Abell et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  6. An attempt to conserve whatnot somniferum (L.) dual - a highly essential medicinal plant, through in vitro callus culture

    International Nuclear Information System (INIS)

    Rout, J.R.; Sahoo, S.

    2011-01-01

    A simple effective protocol was developed for conservation and plant propagation through callus cultures of Withania somnifera (Ashwagandha). Seed germination percentage reached a maximum value of 64.3% on half MS + GA3 0.25 mg/l at third week of culture. Three different basal media compared for seed germination, MS was most effective. Out of 25 combinations of growth regulators evaluated, MS + 1.0 mg/l BA + 1.0 mg/l 2, 4-D found to be best for callus induction and proliferation regardless to explants. Among the four different explants tested, In vivo leaf explant was found most suitable for callus induction, proliferation and fresh weight gain. The highest callus induction frequency percentage 86.4% was recorded with In vivo leaf explant whereas, 43.4% in In vitro leaf explant at day 30 on MS augmented with 1.0 mg/l BA + 1.0 mg/l 2,4-D. Among different growth regulator combinations tested in augmentation with MS for shoot initiation and elongation, 2.0 mg/l BA + 1.0 mg/l NAA was the best eliciting a maximum of 82.3% shoot induction with highest shoot number 4.8 shoots/callus. The original callus was sub-cultured 2 times on fresh shoot multiplication medium after each harvest of the shoots. Of three different auxins tested for In vitro rooting, IBA was most effective compared to IPA and NAA. Half-strength MS medium containing IBA at an optimum concentration of 2.0 mg/l induced rooting in 83.1% of the In vitro derived shoots. The rooted plantlets were acclimated and eventually established in soil. (author)

  7. Salivary peptide tyrosine-tyrosine 3-36 modulates ingestive behavior without inducing taste aversion.

    Science.gov (United States)

    Hurtado, Maria D; Sergeyev, Valeriy G; Acosta, Andres; Spegele, Michael; La Sala, Michael; Waler, Nickolas J; Chiriboga-Hurtado, Juan; Currlin, Seth W; Herzog, Herbert; Dotson, Cedrick D; Gorbatyuk, Oleg S; Zolotukhin, Sergei

    2013-11-20

    Hormone peptide tyrosine-tyrosine (PYY) is secreted into circulation from the gut L-endocrine cells in response to food intake, thus inducing satiation during interaction with its preferred receptor, Y2R. Clinical applications of systemically administered PYY for the purpose of reducing body weight were compromised as a result of the common side effect of visceral sickness. We describe here a novel approach of elevating PYY in saliva in mice, which, although reliably inducing strong anorexic responses, does not cause aversive reactions. The augmentation of salivary PYY activated forebrain areas known to mediate feeding, hunger, and satiation while minimally affecting brainstem chemoreceptor zones triggering nausea. By comparing neuronal pathways activated by systemic versus salivary PYY, we identified a metabolic circuit associated with Y2R-positive cells in the oral cavity and extending through brainstem nuclei into hypothalamic satiety centers. The discovery of this alternative circuit that regulates ingestive behavior without inducing taste aversion may open the possibility of a therapeutic application of PYY for the treatment of obesity via direct oral application.

  8. Structure of genes for dermaseptins B, antimicrobial peptides from frog skin. Exon 1-encoded prepropeptide is conserved in genes for peptides of highly different structures and activities.

    Science.gov (United States)

    Vouille, V; Amiche, M; Nicolas, P

    1997-09-01

    We cloned the genes of two members of the dermaseptin family, broad-spectrum antimicrobial peptides isolated from the skin of the arboreal frog Phyllomedusa bicolor. The dermaseptin gene Drg2 has a 2-exon coding structure interrupted by a small 137-bp intron, wherein exon 1 encoded a 22-residue hydrophobic signal peptide and the first three amino acids of the acidic propiece; exon 2 contained the 18 additional acidic residues of the propiece plus a typical prohormone processing signal Lys-Arg and a 32-residue dermaseptin progenitor sequence. The dermaseptin genes Drg2 and Drg1g2 have conserved sequences at both untranslated ends and in the first and second coding exons. In contrast, Drg1g2 comprises a third coding exon for a short version of the acidic propiece and a second dermaseptin progenitor sequence. Structural conservation between the two genes suggests that Drg1g2 arose recently from an ancestral Drg2-like gene through amplification of part of the second coding exon and 3'-untranslated region. Analysis of the cDNAs coding precursors for several frog skin peptides of highly different structures and activities demonstrates that the signal peptides and part of the acidic propieces are encoded by conserved nucleotides encompassed by the first coding exon of the dermaseptin genes. The organization of the genes that belong to this family, with the signal peptide and the progenitor sequence on separate exons, permits strikingly different peptides to be directed into the secretory pathway. The recruitment of such a homologous 'secretory' exon by otherwise non-homologous genes may have been an early event in the evolution of amphibian.

  9. Comprehensive Non-Destructive Conservation Documentation of Lunar Samples Using High-Resolution Image-Based 3D Reconstructions and X-Ray CT Data

    Science.gov (United States)

    Blumenfeld, E. H.; Evans, C. A.; Oshel, E. R.; Liddle, D. A.; Beaulieu, K.; Zeigler, R. A.; Hanna, R. D.; Ketcham, R. A.

    2015-01-01

    Established contemporary conservation methods within the fields of Natural and Cultural Heritage encourage an interdisciplinary approach to preservation of heritage material (both tangible and intangible) that holds "Outstanding Universal Value" for our global community. NASA's lunar samples were acquired from the moon for the primary purpose of intensive scientific investigation. These samples, however, also invoke cultural significance, as evidenced by the millions of people per year that visit lunar displays in museums and heritage centers around the world. Being both scientifically and culturally significant, the lunar samples require a unique conservation approach. Government mandate dictates that NASA's Astromaterials Acquisition and Curation Office develop and maintain protocols for "documentation, preservation, preparation and distribution of samples for research, education and public outreach" for both current and future collections of astromaterials. Documentation, considered the first stage within the conservation methodology, has evolved many new techniques since curation protocols for the lunar samples were first implemented, and the development of new documentation strategies for current and future astromaterials is beneficial to keeping curation protocols up to date. We have developed and tested a comprehensive non-destructive documentation technique using high-resolution image-based 3D reconstruction and X-ray CT (XCT) data in order to create interactive 3D models of lunar samples that would ultimately be served to both researchers and the public. These data enhance preliminary scientific investigations including targeted sample requests, and also provide a new visual platform for the public to experience and interact with the lunar samples. We intend to serve these data as they are acquired on NASA's Astromaterials Acquisistion and Curation website at http://curator.jsc.nasa.gov/. Providing 3D interior and exterior documentation of astromaterial

  10. Mammals of the high altitudes of western Arunachal Pradesh, eastern Himalaya: an assessment of threats and conservation needs

    NARCIS (Netherlands)

    Mishra, C.; Madhusudan, M.D.; Datta, A.

    2006-01-01

    he high altitudes of Arunachal Pradesh, India, located in the Eastern Himalaya biodiversity hotspot, remain zoologically unexplored and unprotected. We report results of recent mammal surveys in the high altitude habitats of western Arunachal Pradesh. A total of 35 mammal species (including 12

  11. Use of deuterated tyrosine and phenylalanine in the study of catecholamine and aromatic acid metabolism

    International Nuclear Information System (INIS)

    Curtius, H.C.; Redweik, U.; Steinmann, B.; Leimbacher, W.; Wegmann, H.

    1975-01-01

    Deuterated tyrosine and phenylalanine have been used for the study of their respective metabolism in patients with phenylketonuria (PKU) and in healthy persons. Urinary excretion of dopamine and its metabolites was studied by GC-MS after oral administration of deuterated L-tyrosine in 2 patients with PKU and in normal controls at low and high plasma phenylalanine levels. From these studies it seemed that the in vivo tyrosine 3-hydroxylase activity and thus the formation of L-dopa depend on the phenylalanine concentration in plasma and also in tissues. After loading 3 mentally retarded patients with 3,5-[ 2 H 2 ]-4-hydroxyphenylalanine, we found, among others, excretion of deuterated m-hydroxyphenyl-hydracrylic acid, p-hydroxymandelic acid, p-hydroxybenzoic acid, p-hydroxyhippuric acid, benzoic acid and hippuric acid. An intramolecular rearrangement is postulated. Deuterated phenylalanine was used to investigate phenylalanine and dopa metabolism in PKU. In addition, one untreated person with PKU of normal intelligence and normal excretion of catecholamines at high plasma phenylalanine concentration was investigated in order to see whether there exists an alternative metabolic pathway from phenylalanine to dopa formation

  12. Implications of tyrosine phosphoproteomics in cervical carcinogenesis

    Directory of Open Access Journals (Sweden)

    DeFord James

    2008-01-01

    Full Text Available Abstract Background Worldwide cervical cancer remains a leading cause of mortality from gynecologic malignancies. The link between cervical cancer and persistent infection with HPV has been established. At a molecular level little is known about the transition from the precancerous state to invasive cancer. To elucidate this process, cervical biopsies from human specimens were obtained from precancerous state to stage III disease. Methods Cervical biopsies were obtained from patients with a diagnosis of cervical cancer undergoing definitive surgery or staging operation. Biopsies were obtained from patients with precancerous lesions at the time of their excisional procedure. Control samples were obtained from patients undergoing hysterectomy for benign conditions such as fibroids. Samples were subjected to proteomic profiling using two dimensional gel electrophoresis with subsequent trypsin digestion followed by MALDI-TOF protein identification. Candidate proteins were then further studied using western blotting, immunoprecipitation and immunohistochemistry. Results Annexin A1 and DNA-PKcs were found to be differentially expressed. Phosphorylated annexin A1 was up regulated in diseased states in comparison to control and its level was strongly detected in the serum of cervical cancer patients compared to controls. DNA-PKcs was noted to be hyperphosphorylated and fragmented in cancer when compared to controls. By immunohistochemistry annexin A1 was noted in the vascular environment in cancer and certain precancerous samples. Conclusion This study suggests a probable role for protein tyrosine phosphorylation in cervical carcinogenesis. Annexin A1 and DNA-PK cs may have synergistic effects with HPV infection. Precancerous lesions that may progress to cervical cancer may be differentiated from lesions that will not base on similar immunohistochemical profile to invasive squamous cell carcinoma.

  13. The relationship between the Resource Conservation and Recovery Act and the storage and disposal of spent nuclear fuel and high-level waste

    International Nuclear Information System (INIS)

    Gertz, C.P.; Cloke, P.L.

    1993-01-01

    This paper addresses the potential applicability of the requirements of the Resource Conservation and Recovery Act (RCRA) to the disposal of spent commercial nuclear fuel and of high-level (vitrified) radioactive waste. The Atomic Energy Act of 1954, as amended, and the associated regulations issued by the US NRC provides many requirements that apply to these waste forms and largely, if not entirely, pre-empts the applicability of RCRA. The RCRA would apply only to the non-radioactive components of these wastes, and then only in respect to hazardous components. In view of these restrictions it becomes important to evaluate whether any components of spent fuel or high-level waste are toxic, as defined by the RCRA regulations. Present indications are that they are not and, hence, the US DOE is proceeding on the basis that these wastes and others that may be generated in the future are non-hazardous in respect to RCRA definitions

  14. Multivariate analysis and clustering reveal high morphological diversity in Tunisian autochthonous grapes (Vitis vinifera: insights into characterization, conservation and commercialization

    Directory of Open Access Journals (Sweden)

    Myriam Lamine

    2014-06-01

    Significance and impact of the study: In this investigation, we highlight the importance of importance of breeding programs, commercialization and evaluation of economically valuable characteristics of the highly diverse autochthonous grapevine cultivars from Tunisia.

  15. Dynamic substrate enhancement for the identification of specific, second-site-binding fragments targeting a set of protein tyrosine phosphatases

    NARCIS (Netherlands)

    Schmidt, Marco F; Groves, Matthew R; Rademann, Jörg

    2011-01-01

    Protein tyrosine phosphatases (PTPs) are key regulators in living systems and thus are attractive drug targets. The development of potent, selective PTP inhibitors has been a difficult challenge mainly due to the high homology of the phosphotyrosine substrate pockets. Here, a strategy of dynamic

  16. Restricted expression of Neuroglobin in the mouse retina and co-localization with Melanopsin and Tyrosine Hydroxylase

    International Nuclear Information System (INIS)

    Hundahl, C.A.; Fahrenkrug, J.; Luuk, H.; Hay-Schmidt, A.; Hannibal, J.

    2012-01-01

    Highlights: ► Restricted Neuroglobin expression in the mouse retina. ► Antibody validation using Neuroglobin-null mice. ► Co-expression of Neuroglobin with Melanopsin and tyrosine hydroxylase. ► No effect of Neuroglobin deficiency on neuronal survival. -- Abstract: Neuroglobin (Ngb), a neuronal specific oxygen binding heme-globin, reported to be expressed at high levels in most layers of the murine retina. Ngb’s function is presently unknown, but based on its high expression level and oxygen binding capabilities Ngb was proposed to function as an oxygen reservoir facilitating oxygen metabolism in highly active neurons or to function as a neuroprotectant. In the present study, we re-examined the expression pattern of Ngb in the retina using a highly validated antibody. Furthermore, intactness of retino-hypothalamic projections and the retinal expression level of Melanopsin and Tyrosine Hydroxylase were investigated in Ngb-null mice. Ngb-immunoreactivity was found in a few neurons of the ganglion cell and inner nuclear layers co-expressing Melanopsin and Tyrosine Hydroxylase, respectively. Ngb deficiency neither affected the level of Melanopsin and Tyrosine Hydroxylase proteins nor the intactness of PACAP-positive retinohypothalamic projections in the suprachiasmatic nucleus. Based on the present results, it seems unlikely that Ngb could have a major role in retinal oxygen homeostasis and neuronal survival under normal conditions. The present study suggests that a number of previously published reports have relied on antibodies with dubious specificity.

  17. A novel, highly conserved metallothionein family in basidiomycete fungi and characterization of two representative SlMTa and SlMTb genes in the ectomycorrhizal fungus Suillus luteus.

    Science.gov (United States)

    Nguyen, Hoai; Rineau, François; Vangronsveld, Jaco; Cuypers, Ann; Colpaert, Jan V; Ruytinx, Joske

    2017-07-01

    The basidiomycete Suillus luteus is an important member of the ectomycorrhizal community that thrives in heavy metal polluted soils covered with pioneer pine forests. This study aimed to identify potential heavy metal chelators in S. luteus. Two metallothionein (MT) coding genes, SlMTa and SlMTb, were identified. When heterologously expressed in yeast, both SlMTa and SlMTb can rescue the Cu sensitive mutant from Cu toxicity. In S. luteus, transcription of both SlMTa and SlMTb is induced by Cu but not Cd or Zn. Several putative Cu-sensing and metal-response elements are present in the promoter sequences. These results indicate that SlMTa and SlMTb function as Cu-thioneins. Homologs of the S. luteus MTs are present in 49 species belonging to 10 different orders of the subphylum Agaricomycotina and are remarkably conserved. The length of the proteins, number and distribution of cysteine residues indicate a novel family of fungal MTs. The ubiquitous and highly conserved features of these MTs suggest that they are important for basic cellular functions in species in the subphylum Agaricomycotina. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41.

    Science.gov (United States)

    Sabin, Charles; Corti, Davide; Buzon, Victor; Seaman, Mike S; Lutje Hulsik, David; Hinz, Andreas; Vanzetta, Fabrizia; Agatic, Gloria; Silacci, Chiara; Mainetti, Lara; Scarlatti, Gabriella; Sallusto, Federica; Weiss, Robin; Lanzavecchia, Antonio; Weissenhorn, Winfried

    2010-11-18

    The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for C-clade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

  19. Snake venomics of Lachesis muta rhombeata and genus-wide antivenomics assessment of the paraspecific immunoreactivity of two antivenoms evidence the high compositional and immunological conservation across Lachesis.

    Science.gov (United States)

    Pla, Davinia; Sanz, Libia; Molina-Sánchez, Pedro; Zorita, Virginia; Madrigal, Marvin; Flores-Díaz, Marietta; Alape-Girón, Alberto; Núñez, Vitelbina; Andrés, Vicente; Gutiérrez, José María; Calvete, Juan J

    2013-08-26

    We report the proteomic analysis of the Atlantic bushmaster, Lachesis muta rhombeata, from Brazil. Along with previous characterization of the venom proteomes of L. stenophrys (Costa Rica), L. melanocephala (Costa Rica), L. acrochorda (Colombia), and L. muta muta (Bolivia), the present study provides the first overview of the composition and distribution of venom proteins across this wide-ranging genus, and highlights the remarkable similar compositional and pharmacological profiles across Lachesis venoms. The paraspecificity of two antivenoms, produced at Instituto Vital Brazil (Brazil) and Instituto Clodomiro Picado (Costa Rica) using different conspecific taxa in the immunization mixtures, was assessed using genus-wide comparative antivenomics. This study confirms that the proteomic similarity among Lachesis sp. venoms is mirrored in their high immunological conservation across the genus. The clinical and therapeutic consequences of genus-wide venomics and antivenomics investigations of Lachesis venoms are discussed. The proteomics characterization of L. m. rhombeata venom completes the overview of Lachesis venom proteomes and confirms the remarkable toxin profile conservation across the five clades of this wide-ranging genus. Genus-wide antivenomics showed that two antivenoms, produced against L. stenophrys or L. m. rhombeata, exhibit paraspecificity towards all other congeneric venoms. Our venomics study shows that, despite the broad geographic distribution of the genus, monospecific antivenoms may achieve clinical coverage for any Lachesis sp. envenoming. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Subsets of Women With Close or Positive Margins After Breast-Conserving Surgery With High Local Recurrence Risk Despite Breast Plus Boost Radiotherapy

    International Nuclear Information System (INIS)

    Lupe, Krystine; Truong, Pauline T.; Alexander, Cheryl; Lesperance, Mary; Speers, Caroline; Tyldesley, Scott

    2011-01-01

    Purpose: (1) To examine the effect of surgical margin status on local recurrence (LR) and survival following breast-conserving therapy; (2) To identify subsets with close or positive margins with high LR risk despite whole breast radiotherapy (RT) plus boost. Methods and Materials: Subjects were 2,264 women with pT1–3, any N, M0 invasive breast cancer, treated with breast-conserving surgery and whole breast ± boost RT. Five-year Kaplan-Meier (KM) LR, breast cancer–specific and overall survival (BCSS and OS) were compared between cohorts with negative (n = 1,980), close (n = 222), and positive (n = 62) margins. LR rates were analyzed according to clinicopathologic characteristics. Multivariable Cox regression modeling and matched analysis of close/positive margin cases and negative margin controls were performed. Results: Median follow-up was 5.2 years. Boost RT was used in 92% of patients with close or positive margins. Five-year KM LR rates in the negative, close and positive margin cohorts were 1.3%, 4.0%, and 5.2%, respectively (p = 0.001). BCSS and OS were similar in the three margin subgroups. In the close/positive margin cohort, LR rates were 10.2% with age 10% despite whole breast plus boost RT. These patients should be considered for more definitive surgery.

  1. High throughput sequencing of small RNA component of leaves and inflorescence revealed conserved and novel miRNAs as well as phasiRNA loci in chickpea.

    Science.gov (United States)

    Srivastava, Sangeeta; Zheng, Yun; Kudapa, Himabindu; Jagadeeswaran, Guru; Hivrale, Vandana; Varshney, Rajeev K; Sunkar, Ramanjulu

    2015-06-01

    Among legumes, chickpea (Cicer arietinum L.) is the second most important crop after soybean. MicroRNAs (miRNAs) play important roles by regulating target gene expression important for plant development and tolerance to stress conditions. Additionally, recently discovered phased siRNAs (phasiRNAs), a new class of small RNAs, are abundantly produced in legumes. Nevertheless, little is known about these regulatory molecules in chickpea. The small RNA population was sequenced from leaves and flowers of chickpea to identify conserved and novel miRNAs as well as phasiRNAs/phasiRNA loci. Bioinformatics analysis revealed 157 miRNA loci for the 96 highly conserved and known miRNA homologs belonging to 38 miRNA families in chickpea. Furthermore, 20 novel miRNAs belonging to 17 miRNA families were identified. Sequence analysis revealed approximately 60 phasiRNA loci. Potential target genes likely to be regulated by these miRNAs were predicted and some were confirmed by modified 5' RACE assay. Predicted targets are mostly transcription factors that might be important for developmental processes, and others include superoxide dismutases, plantacyanin, laccases and F-box proteins that could participate in stress responses and protein degradation. Overall, this study provides an inventory of miRNA-target gene interactions for chickpea, useful for the comparative analysis of small RNAs among legumes. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  2. Energy conservation in nationalised transportation sector

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, R C

    1980-01-01

    About 60% of high speed diesel is consumed by the road transport industry. The hike in fuel prices calls for urgent measures to conserve diesel. The paper discusses the various measures undertaken to conserve diesel in the nationalized transport sector.

  3. Biodiversity conservation in a telecoupled world

    Directory of Open Access Journals (Sweden)

    L. Roman Carrasco

    2017-09-01

    Conservation practitioners need to adopt a global perspective on telecoupling and focus on the new conservation opportunities represented by shaping the social norms of affluent consumers in emerging and high-income economies.

  4. The highly conserved 5' untranslated region as an effective target towards the inhibition of Enterovirus 71 replication by unmodified and appropriate 2'-modified siRNAs

    Directory of Open Access Journals (Sweden)

    Deng Jun-Xia

    2012-08-01

    Full Text Available Abstract Background Enterovirus 71 (EV71 is a highly infectious agent that plays an etiological role in hand, foot, and mouth disease. It is associated with severe neurological complications and has caused significant mortalities in recent large-scale outbreaks. Currently, no effective vaccine or specific clinical therapy is available against EV71. Methods Unmodified 21 nucleotide small interfering RNAs (siRNAs and classic 2′-modified (2′-O-methylation or 2′-fluoro modification siRNAs were designed to target highly conserved 5′ untranslated region (UTR of the EV71 genome and employed as anti-EV71 agents. Real-time TaqMan RT-PCR, western blot analysis and plaque assays were carried out to evaluate specific viral inhibition by the siRNAs. Results Transfection of rhabdomyosarcoma (RD cells with siRNAs targeting the EV71 genomic 5′ UTR significantly delayed and alleviated the cytopathic effects of EV71 infection, increased cell viability in EV71-infected RD cells. The inhibitory effect on EV71 replication was sequence-specific and dosage-dependent, with significant corresponding decreases in viral RNA, VP1 protein and viral titer. Appropriate 2′-modified siRNAs exhibited similar RNA interference (RNAi activity with dramatically increased serum stability in comparison with unmodified counterparts. Conclusion Sequences were identified within the highly conserved 5′ UTR that can be targeted to effectively inhibit EV71 replication through RNAi strategies. Appropriate 2′-modified siRNAs provide a promising approach to optimizing siRNAs to overcome barriers on RNAi-based antiviral therapies for broader administration.

  5. Inhibition of Hepatitis C Virus in Mice by a Small Interfering RNA Targeting a Highly Conserved Sequence in Viral IRES Pseudoknot.

    Directory of Open Access Journals (Sweden)

    Jae-Su Moon

    Full Text Available The hepatitis C virus (HCV internal ribosome entry site (IRES that directs cap-independent viral translation is a primary target for small interfering RNA (siRNA-based HCV antiviral therapy. However, identification of potent siRNAs against HCV IRES by bioinformatics-based siRNA design is a challenging task given the complexity of HCV IRES secondary and tertiary structures and association with multiple proteins, which can also dynamically change the structure of this cis-acting RNA element. In this work, we utilized siRNA tiling approach whereby siRNAs were tiled with overlapping sequences that were shifted by one or two nucleotides over the HCV IRES stem-loop structures III and IV spanning nucleotides (nts 277-343. Based on their antiviral activity, we mapped a druggable region (nts 313-343 where the targets of potent siRNAs were enriched. siIE22, which showed the greatest anti-HCV potency, targeted a highly conserved sequence across diverse HCV genotypes, locating within the IRES subdomain IIIf involved in pseudoknot formation. Stepwise target shifting toward the 5' or 3' direction by 1 or 2 nucleotides reduced the antiviral potency of siIE22, demonstrating the importance of siRNA accessibility to this highly structured and sequence-conserved region of HCV IRES for RNA interference. Nanoparticle-mediated systemic delivery of the stability-improved siIE22 derivative gs_PS1 siIE22, which contains a single phosphorothioate linkage on the guide strand, reduced the serum HCV genome titer by more than 4 log10 in a xenograft mouse model for HCV replication without generation of resistant variants. Our results provide a strategy for identifying potent siRNA species against a highly structured RNA target and offer a potential pan-HCV genotypic siRNA therapy that might be beneficial for patients resistant to current treatment regimens.

  6. SeqAPASS to evaluate conservation of high-throughput screening targets across non-mammalian species

    Science.gov (United States)

    Cell-based high-throughput screening (HTS) and computational technologies are being applied as tools for toxicity testing in the 21st century. The U.S. Environmental Protection Agency (EPA) embraced these technologies and created the ToxCast Program in 2007, which has served as a...

  7. Allosteric inhibition of SHP2 phosphatase inhibits cancers driven by receptor tyrosine kinases

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying-Nan P.; LaMarche, Matthew J.; Chan, Ho Man; Fekkes, Peter; Garcia-Fortanet, Jorge; Acker, Michael G.; Antonakos, Brandon; Chen, Christine Hiu-Tung; Chen, Zhouliang; Cooke, Vesselina G.; Dobson, Jason R.; Deng, Zhan; Fei, Feng; Firestone, Brant; Fodor, Michelle; Fridrich, Cary; Gao, Hui; Grunenfelder, Denise; Hao, Huai-Xiang; Jacob, Jaison; Ho, Samuel; Hsiao, Kathy; Kang, Zhao B.; Karki, Rajesh; Kato, Mitsunori; Larrow, Jay; La Bonte, Laura R.; Lenoir, Francois; Liu, Gang; Liu, Shumei; Majumdar, Dyuti; Meyer, Matthew J.; Palermo, Mark; Perez, Lawrence; Pu, Minying; Price, Edmund; Quinn, Christopher; Shakya, Subarna; Shultz, Michael D.; Slisz, Joanna; Venkatesan, Kavitha; Wang, Ping; Warmuth, Markus; Williams, Sarah; Yang, Guizhi; Yuan, Jing; Zhang, Ji-Hu; Zhu, Ping; Ramsey, Timothy; Keen, Nicholas J.; Sellers, William R.; Stams, Travis; Fortin , Pascal D. (Novartis)

    2016-06-29

    The non-receptor protein tyrosine phosphatase SHP2, encoded by PTPN11, has an important role in signal transduction downstream of growth factor receptor signalling and was the first reported oncogenic tyrosine phosphatase1. Activating mutations of SHP2 have been associated with developmental pathologies such as Noonan syndrome and are found in multiple cancer types, including leukaemia, lung and breast cancer and neuroblastoma1, 2, 3, 4, 5. SHP2 is ubiquitously expressed and regulates cell survival and proliferation primarily through activation of the RAS–ERK signalling pathway2, 3. It is also a key mediator of the programmed cell death 1 (PD-1) and B- and T-lymphocyte attenuator (BTLA) immune checkpoint pathways6, 7. Reduction of SHP2 activity suppresses tumour cell growth and is a potential target of cancer therapy8, 9. Here we report the discovery of a highly potent (IC50 = 0.071 μM), selective and orally bioavailable small-molecule SHP2 inhibitor, SHP099, that stabilizes SHP2 in an auto-inhibited conformation. SHP099 concurrently binds to the interface of the N-terminal SH2, C-terminal SH2, and protein tyrosine phosphatase domains, thus inhibiting SHP2 activity through an allosteric mechanism. SHP099 suppresses RAS–ERK signalling to inhibit the proliferation of receptor-tyrosine-kinase-driven human cancer cells in vitro and is efficacious in mouse tumour xenograft models. Together, these data demonstrate that pharmacological inhibition of SHP2 is a valid therapeutic approach for the treatment of cancers.

  8. Phorbol ester-induced serine phosphorylation of the insulin receptor decreases its tyrosine kinase activity.

    Science.gov (United States)

    Takayama, S; White, M F; Kahn, C R

    1988-03-05

    The effect of 12-O-tetradecanoylphorbol-13-acetate (TPA) on the function of the insulin receptor was examined in intact hepatoma cells (Fao) and in solubilized extracts purified by wheat germ agglutinin chromatography. Incubation of ortho[32P]phosphate-labeled Fao cells with TPA increased the phosphorylation of the insulin receptor 2-fold after 30 min. Analysis of tryptic phosphopeptides from the beta-subunit of the receptor by reverse-phase high performance liquid chromatography and determination of their phosphoamino acid composition suggested that TPA predominantly stimulated phosphorylation of serine residues in a single tryptic peptide. Incubation of the Fao cells with insulin (100 nM) for 1 min stimulated 4-fold the phosphorylation of the beta-subunit of the insulin receptor. Prior treatment of the cells with TPA inhibited the insulin-stimulated tyrosine phosphorylation by 50%. The receptors extracted with Triton X-100 from TPA-treated Fao cells and purified on immobilized wheat germ agglutinin retained the alteration in kinase activity and exhibited a 50% decrease in insulin-stimulated tyrosine autophosphorylation and phosphotransferase activity toward exogenous substrates. This was due primarily to a decrease in the Vmax for these reactions. TPA treatment also decreased the Km of the insulin receptor for ATP. Incubation of the insulin receptor purified from TPA-treated cells with alkaline phosphatase decreased the phosphate content of the beta-subunit to the control level and reversed the inhibition, suggesting that the serine phosphorylation of the beta-subunit was responsible for the decreased tyrosine kinase activity. Our results support the notion that the insulin receptor is a substrate for protein kinase C in the Fao cell and that the increase in serine phosphorylation of the beta-subunit of the receptor produced by TPA treatment inhibited tyrosine kinase activity in vivo and in vitro. These data suggest that protein kinase C may regulate the function

  9. Tyrosine kinase receptor status in endometrial stromal sarcoma: an immunohistochemical and genetic-molecular analysis.

    Science.gov (United States)

    Cossu-Rocca, Paolo; Contini, Marcella; Uras, Maria Gabriela; Muroni, Maria Rosaria; Pili, Francesca; Carru, Ciriaco; Bosincu, Luisanna; Massarelli, Giovannino; Nogales, Francisco F; De Miglio, Maria Rosaria

    2012-11-01

    Endometrial stromal sarcomas (ESS) are rare uterine malignant mesenchymal neoplasms, which are currently treated by surgery, as effective adjuvant therapies have not yet been established. Tyrosine kinase inhibitors have rarely been applied in ESS therapy, with few reports describing imatinib responsivity. The aim of this study was to analyze the status of different tyrosine kinase receptors in an ESS series, in order to evaluate their potential role as molecular targets. Immunohistochemistry was performed for EGFR, c-KIT, PDGFR-α, PDGFR-β, and ABL on 28 ESS. EGFR, PDGFR-α, and PDGFR-β gene expression was investigated by real-time polymerase chain reaction (qRT-PCR) on selected cases. "Hot-spot" mutations were screened for on EGFR, c-KIT, PDGFR-α, and PDGFR-β genes, by sequencing. All analysis was executed from formalin-fixed, paraffin-embedded specimens. Immunohistochemical overexpression of 2 or more tyrosine kinase receptors was observed in 18 of 28 tumors (64%), whereas only 5 tumors were consistently negative. Gene expression profiles were concordant with immunohistochemical overexpression in only 1 tumor, which displayed both high mRNA levels and specific immunoreactivity for PDGFR-α, and PDGFR-β. No activating mutations were found on the tumors included in the study. This study confirms that TKRs expression is frequently observed in ESS. Considering that the responsiveness to tyrosine kinase inhibitors is known to be related to the presence of specific activating mutations or gene over-expression, which are not detectable in ESS, TKRs immunohistochemical over-expression alone should not be considered as a reliable marker for targeted therapies in ESS. Specific post-translational abnormalities, responsible for activation of TKRs, should be further investigated.

  10. Cross-phosphorylation of bacterial serine/threonine and tyrosine protein kinases on key regulatory residues

    Directory of Open Access Journals (Sweden)

    Lei eShi

    2014-09-01

    Full Text Available Bacteria possess protein serine/threonine and tyrosine kinases which resemble eukaryal kinases in their capacity to phosphorylate multiple substrates. We hypothesized that the analogy might extend further, and bacterial kinases may also undergo mutual phosphorylation and activation, which is currently considered as a hallmark of eukaryal kinase networks. In order to test this hypothesis, we explored the capacity of all members of four different classes of serine/threonine and tyrosine kinases present in the firmicute model organism Bacillus subtilis to phosphorylate each other in vitro and interact with each other in vivo. The interactomics data suggested a high degree of connectivity among all types of kinases, while phosphorylation assays revealed equally wide-spread cross-phosphorylation events. Our findings suggest that the Hanks-type kinases PrkC, PrkD and YabT exhibit the highest capacity to phosphorylate other B. subtilis kinases, while the BY-kinase PtkA and the two-component-like kinases RsbW and SpoIIAB show the highest propensity to be phosphorylated by other kinases. Analysis of phosphorylated residues on several selected recipient kinases suggests that most cross-phosphorylation events concern key regulatory residues. Therefore, cross-phosphorylation events are very likely to influence the capacity of recipient kinases to phosphorylate substrates downstream in the signal transduction cascade. We therefore conclude that bacterial serine/threonine and tyrosine kinases probably engage in a network-type behavior previously described only in eukaryal cells.

  11. A role for the tyrosine kinase ACK1 in neurotrophin signaling and neuronal extension and branching

    Science.gov (United States)

    La Torre, A; del Mar Masdeu, M; Cotrufo, T; Moubarak, R S; del Río, J A; Comella, J X; Soriano, E; Ureña, J M

    2013-01-01

    Neurotrophins are involved in many crucial cellular functions, including neurite outgrowth, synapse formation, and plasticity. Although these events have long been known, the molecular determinants underlying neuritogenesis have not been fully characterized. Ack1 (activated Cdc42-associated tyrosine kinase) is a non-receptor tyrosine kinase that is highly expressed in the brain. Here, we demonstrate that Ack1 is a molecular constituent of neurotrophin signaling cascades in neurons and PC12 cells. We report that Ack1 interacts with Trk receptors and becomes tyrosine phosphorylated and its kinase activity is increased in response to neurotrophins. Moreover, our data indicate that Ack1 acts upstream of the Akt and MAPK pathways. We show that Ack1 overexpression induces neuritic outgrowth and promotes branching in neurotrophin-treated neuronal cells, whereas the expression of Ack1 dominant negatives or short-hairpin RNAs counteract neurotrophin-stimulated differentiation. Our results identify Ack1 as a novel regulator of neurotrophin-mediated events in primary neurons and in PC12 cells. PMID:23598414

  12. Insulin stimulates the tyrosine phosphorylation of a Mr = 160,000 glycoprotein in adipocyte plasma membranes

    International Nuclear Information System (INIS)

    Yu, K.T.; Khalaf, N.; Czech, M.P.

    1986-01-01

    In an attempt to identify putative substrates for the insulin receptor kinase, adipocyte plasma membranes were incubated with [γ- 32 P]ATP in the presence and absence of insulin. Insulin stimulates the tyrosine phosphorylation of its receptor β subunit but does not detectably alter the phosphorylation of other membrane proteins. In contrast, when plasma membranes from insulin-treated adipocytes are phosphorylated, the 32 P-labeling of a Mr=160,000 species (p160) and insulin receptor β subunit are markedly increased when compared to controls. p160 exhibits a rapid response (max. at 1 min) and high sensitivity (ED 50 = 2 x 10 -10 M) to insulin. The stimulatory effect of insulin on the phosphorylation of p160 is rapidly reversed following the addition of anti-insulin serum. Cold chase experiments indicate that insulin promotes the phosphorylation of p160 rather than inhibiting its dephosphorylation. p160 is a glycoprotein as evidenced by its adsorption to immobilized lectins and does not represent the insulin receptor precursor. The action of insulin on p160 tyrosine phosphorylation is mimicked by concanavalin A but not by EGF and other insulin-like agents such as hydrogen peroxide and vanadate. These results suggest that p160 tyrosine phosphorylation is an insulin receptor-mediated event and may participate in signalling by the insulin receptor

  13. [Effects of psychological stress on performances in open-field test of rats and tyrosine's modulation].

    Science.gov (United States)

    Chen, Wei-Qiang; Cheng, Yi-Yong; Li, Shu-Tian; Hong, Yan; Wang, Dong-Lan; Hou, Yue

    2009-02-01

    To explore the effects of different doses of tyrosine modulation on behavioral performances in open field test of psychological stress rats. The animal model of psychological stress was developed by restraint stress for 21 days. Wistar rats were randomly assigned to five groups (n = 10) as follows: control group (CT), stress control group (SCT), low, medium and high-doses of tyrosine modulation stress groups (SLT, SMT and SIT). The changes of behavioral performances were examined by open-field test. Serum levels of cortisol, norepinephrine and dopamine were also detected. The levels of serum cortisol were all increased obviously in the four stress groups, and their bodyweight gainings were diminished. The behavioral performances of SCT rats in open-field test were changed significantly in contrast to that of CT rats. However, The behavioral performances of SMT and SHT rats were not different from that of CT rats. In addition, the serum levels of norepinephrine and dopamine were downregulated obviously in SCT and SLT groups, and no differences were observed in other groups. Psychological stress can impair body behavioral performances, and moderate tyrosine modulation may improve these abnormal changes. The related mechanisms may be involved with the changes of norepinephrine and dopamine.

  14. The intensity of tyrosine nitration is associated with selenite and selenate toxicity in Brassica juncea L.

    Science.gov (United States)

    Molnár, Árpád; Feigl, Gábor; Trifán, Vanda; Ördög, Attila; Szőllősi, Réka; Erdei, László; Kolbert, Zsuzsanna

    2018-01-01

    Selenium phytotoxicity involves processes like reactive nitrogen species overproduction and nitrosative protein modifications. This study evaluates the toxicity of two selenium forms (selenite and selenate at 0µM, 20µM, 50µM and 100µM concentrations) and its correlation with protein tyrosine nitration in the organs of hydroponically grown Indian mustard (Brassica juncea L.). Selenate treatment resulted in large selenium accumulation in both Brassica organs, while selenite showed slight root-to-shoot translocation resulting in a much lower selenium accumulation in the shoot. Shoot and root growth inhibition and cell viability loss revealed that Brassica tolerates selenate better than selenite. Results also show that relative high amounts of selenium are able to accumulate in Brassica leaves without obvious visible symptoms such as chlorosis or necrosis. The more severe phytotoxicity of selenite was accompanied by more intense protein tyrosine nitration as well as alterations in nitration pattern suggesting a correlation between the degree of Se forms-induced toxicities and nitroproteome size, composition in Brassica organs. These results imply the possibility of considering protein tyrosine nitration as novel biomarker of selenium phytotoxicity, which could help the evaluation of asymptomatic selenium stress of plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Fundamentals on the biochemistry of peroxynitrite and protein tyrosine nitration

    Directory of Open Access Journals (Sweden)

    Silvina Bartesaghi

    2018-04-01

    Full Text Available In this review we provide an analysis of the biochemistry of peroxynitrite and tyrosine nitration. Peroxynitrite is the product of the diffusion-controlled reaction between superoxide (O2•- and nitric oxide (•NO. This process is in competition with the enzymatic dismutation of O2•- and the diffusion of •NO across cells and tissues and its reaction with molecular targets (e.g. guanylate cyclase. Understanding the kinetics and compartmentalization of the O2•- / •NO interplay is critical to rationalize the shift of •NO from a physiological mediator to a cytotoxic intermediate. Once formed, peroxynitrite (ONOO- and ONOOH; pKa = 6,8 behaves as a strong one and two-electron oxidant towards a series of biomolecules including transition metal centers and thiols. In addition, peroxynitrite anion can secondarily evolve to secondary radicals either via its fast reaction with CO2 or through proton-catalyzed homolysis. Thus, peroxynitrite can participate in direct (bimolecular and indirect (through secondary radical intermediates oxidation reactions; through these processes peroxynitrite can participate as cytotoxic effector molecule against invading pathogens and/or as an endogenous pathogenic mediator. Peroxynitrite can cause protein tyrosine nitration in vitro and in vivo. Indeed, tyrosine nitration is a hallmark of the reactions of •NO-derived oxidants in cells and tissues and serves as a biomarker of oxidative damage. Protein tyrosine nitration can mediate changes in protein structure and function that affect cell homeostasis. Tyrosine nitration in biological systems is a free radical process that can be promoted either by peroxynitrite-derived radicals or by other related •NO-dependent oxidative processes. Recently, mechanisms responsible of tyrosine nitration in hydrophobic biostructures such as membranes and lipoproteins have been assessed and involve the parallel occurrence and connection with lipid

  16. Use of genotyping by sequencing data to develop a high-throughput and multifunctional SNP panel for conservation applications in Pacific lamprey.

    Science.gov (United States)

    Hess, Jon E; Campbell, Nathan R; Docker, Margaret F; Baker, Cyndi; Jackson, Aaron; Lampman, Ralph; McIlraith, Brian; Moser, Mary L; Statler, David P; Young, William P; Wildbill, Andrew J; Narum, Shawn R

    2015-01-01

    Next-generation sequencing data can be mined for highly informative single nucleotide polymorphisms (SNPs) to develop high-throughput genomic assays for nonmodel organisms. However, choosing a set of SNPs to address a variety of objectives can be difficult because SNPs are often not equally informative. We developed an optimal combination of 96 high-throughput SNP assays from a total of 4439 SNPs identified in a previous study of Pacific lamprey (Entosphenus tridentatus) and used them to address four disparate objectives: parentage analysis, species identification and characterization of neutral and adaptive variation. Nine of these SNPs are FST outliers, and five of these outliers are localized within genes and significantly associated with geography, run-timing and dwarf life history. Two of the 96 SNPs were diagnostic for two other lamprey species that were morphologically indistinguishable at early larval stages and were sympatric in the Pacific Northwest. The majority (85) of SNPs in the panel were highly informative for parentage analysis, that is, putatively neutral with high minor allele frequency across the species' range. Results from three case studies are presented to demonstrate the broad utility of this panel of SNP markers in this species. As Pacific lamprey populations are undergoing rapid decline, these SNPs provide an important resource to address critical uncertainties associated with the conservation and recovery of this imperiled species. © 2014 John Wiley & Sons Ltd.

  17. Urokinase receptor expression involves tyrosine phosphorylation of phosphoglycerate kinase.

    Science.gov (United States)

    Shetty, Praveenkumar; Velusamy, Thirunavukkarasu; Bhandary, Yashodhar P; Liu, Ming C; Shetty, Sreerama

    2010-02-01

    The interaction of urokinase-type plasminogen activator (uPA) with its receptor, uPAR, plays a central role in several pathophysiological processes, including cancer. uPA induces its own cell surface receptor expression through stabilization of uPAR mRNA. The mechanism involves binding of a 51 nt uPAR mRNA coding sequence with phosphoglycerate kinase (PGK) to down regulate cell surface uPAR expression. Tyrosine phosphorylation of PGK mediated by uPA treatment enhances uPAR mRNA stabilization. In contrast, inhibition of tyrosine phosphorylation augments PGK binding to uPAR mRNA and attenuates uPA-induced uPAR expression. Mapping the specific peptide region of PGK indicated that its first quarter (amino acids 1-100) interacts with uPAR mRNA. To determine if uPAR expression by uPA is regulated through activation of tyrosine residues of PGK, we mutated the specific tyrosine residue and tested mutant PGK for its ability to interfere with uPAR expression. Inhibition of tyrosine phosphorylation by mutating Y76 residue abolished uPAR expression induced by uPA treatment. These findings collectively demonstrate that Y76 residue present in the first quarter of the PGK molecule is involved in lung epithelial cell surface uPAR expression. This region can effectively mimic the function of a whole PGK molecule in inhibiting tumor cell growth.

  18. Tyrosine isomers mediate the classical phenomenon of concomitant tumor resistance.

    Science.gov (United States)

    Ruggiero, Raúl A; Bruzzo, Juan; Chiarella, Paula; di Gianni, Pedro; Isturiz, Martín A; Linskens, Susana; Speziale, Norma; Meiss, Roberto P; Bustuoabad, Oscar D; Pasqualini, Christiane D

    2011-11-15

    Concomitant tumor resistance (CR) is a phenomenon originally described in 1906 in which a tumor-bearing host is resistant to the growth of secondary tumor implants and metastasis. Although recent studies have indicated that T-cell-dependent processes mediate CR in hosts bearing immunogenic small tumors, manifestations of CR induced by immunogenic and nonimmunogenic large tumors have been associated with an elusive serum factor. In this study, we identify this serum factor as tyrosine in its meta and ortho isoforms. In three different murine models of cancer that generate CR, both meta-tyrosine and ortho-tyrosine inhibited tumor growth. In addition, we showed that both isoforms of tyrosine blocked metastasis in a fourth model that does not generate CR but is sensitive to CR induced by other tumors. Mechanistic studies showed that the antitumor effects of the tyrosine isoforms were mediated, in part, by early inhibition of mitogen-activated protein/extracellular signal-regulated kinase pathway and inactivation of STAT3, potentially driving tumor cells into a state of dormancy. By revealing a molecular basis for the classical phenomenon of CR, our findings may stimulate new generalized approaches to limit the development of metastases that arise after resection of primary tumors, an issue of pivotal importance to oncologists and their patients. ©2011 AACR

  19. Tyrosine sulfation modulates activity of tick-derived thrombin inhibitors

    Science.gov (United States)

    Thompson, Robert E.; Liu, Xuyu; Ripoll-Rozada, Jorge; Alonso-García, Noelia; Parker, Benjamin L.; Pereira, Pedro José Barbosa; Payne, Richard J.

    2017-09-01

    Madanin-1 and chimadanin are two small cysteine-free thrombin inhibitors that facilitate blood feeding in the tick Haemaphysalis longicornis. Here, we report a post-translational modification—tyrosine sulfation—of these two proteins that is critical for potent anti-thrombotic and anticoagulant activity. Inhibitors produced in baculovirus-infected insect cells displayed heterogeneous sulfation of two tyrosine residues within each of the proteins. One-pot ligation-desulfurization chemistry enabled access to homogeneous samples of all possible sulfated variants of the proteins. Tyrosine sulfation of madanin-1 and chimadanin proved crucial for thrombin inhibitory activity, with the doubly sulfated variants three orders of magnitude more potent than the unmodified inhibitors. The three-dimensional structure of madanin-1 in complex with thrombin revealed a unique mode of inhibition, with the sulfated tyrosine residues binding to the basic exosite II of the protease. The importance of tyrosine sulfation within this family of thrombin inhibitors, together with their unique binding mode, paves the way for the development of anti-thrombotic drug leads based on these privileged scaffolds.

  20. US/FRG joint report on the pebble bed high temperature reactor resource conservation potential and associated fuel cycle costs

    International Nuclear Information System (INIS)

    Teuchert, E.; Ruetten, H.J.; Worley, B.A.; Vondy, D.R.

    1979-11-01

    Independent analyses at ORNL and KFA have led to the general conclusion that the flexibility in design and operation of a high-temperature gas-cooled pebble-bed reactor (PBR) can result in favorable ore utilization and fuel costs in comparison with other reactor types, in particular, with light-water reactors (LWRs). Fuel reprocessign and recycle show considerable promise for reducing ore consumption, and even the PBR throwaway cycle is competitive with fuel recycle in an LWR. The best performance results from the use of highly enriched fuel. Proliferation-resistant measures can be taken using medium-enriched fuel at a modest ore penalty, while use of low-enriched fuel would incur further ore penalty. Breeding is possible but net generation of fuel at a significant rate would be expensive, becoming more feasible as ore costs increase substantially. The 233 U inventory for a breeder could be produced by prebreeders using 235 U fuel

  1. Resistance to EGF receptor inhibitors in glioblastoma mediated by phosphorylation of the PTEN tumor suppressor at tyrosine 240.

    Science.gov (United States)

    Fenton, Tim R; Nathanson, David; Ponte de Albuquerque, Claudio; Kuga, Daisuke; Iwanami, Akio; Dang, Julie; Yang, Huijun; Tanaka, Kazuhiro; Oba-Shinjo, Sueli Mieko; Uno, Miyuki; Inda, Maria del Mar; Wykosky, Jill; Bachoo, Robert M; James, C David; DePinho, Ronald A; Vandenberg, Scott R; Zhou, Huilin; Marie, Suely K N; Mischel, Paul S; Cavenee, Webster K; Furnari, Frank B

    2012-08-28

    Glioblastoma multiforme (GBM) is the most aggressive of the astrocytic malignancies and the most common intracranial tumor in adults. Although the epidermal growth factor receptor (EGFR) is overexpressed and/or mutated in at least 50% of GBM cases and is required for tumor maintenance in animal models, EGFR inhibitors have thus far failed to deliver significant responses in GBM patients. One inherent resistance mechanism in GBM is the coactivation of multiple receptor tyrosine kinases, which generates redundancy in activation of phosphoinositide-3'-kinase (PI3K) signaling. Here we demonstrate that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) tumor suppressor is frequently phosphorylated at a conserved tyrosine residue, Y240, in GBM clinical samples. Phosphorylation of Y240 is associated with shortened overall survival and resistance to EGFR inhibitor therapy in GBM patients and plays an active role in mediating resistance to EGFR inhibition in vitro. Y240 phosphorylation can be mediated by both fibroblast growth factor receptors and SRC family kinases (SFKs) but does not affect the ability of PTEN to antagonize PI3K signaling. These findings show that, in addition to genetic loss and mutation of PTEN, its modulation by tyrosine phosphorylation has important implications for the development and treatment of GBM.

  2. Ortho- and meta-tyrosine formation from phenylalanine in human saliva as a marker of hydroxyl radical generation during betel quid chewing.

    Science.gov (United States)

    Nair, U J; Nair, J; Friesen, M D; Bartsch, H; Ohshima, H

    1995-05-01

    The habit of betel quid chewing, common in South-East Asia and the South Pacific islands, is causally associated with an increased risk of oral cancer. Reactive oxygen species formed from polyphenolic betel quid ingredients and lime at alkaline pH have been implicated as the agents responsible for DNA and tissue damage. To determine whether hydroxyl radical (HO.) is generated in the human oral cavity during chewing of betel quid, the formation of o- and m-tyrosine from L-phenylalanine was measured. Both o- and m-tyrosine were formed in vitro in the presence of extracts of areca nut and/or catechu, transition metal ions such as Cu2+ and Fe2+ and lime or sodium carbonate (alkaline pH). Omission of any of these ingredients from the reaction mixture significantly reduced the yield of tyrosines. Hydroxyl radical scavengers such as ethanol, D-mannitol and dimethylsulfoxide inhibited the phenylalanine oxidation in a dose-dependent fashion. Five volunteers chewed betel quid consisting of betel leaf, areca nut, catechu and slaked lime (without tobacco). Their saliva, collected after chewing betel quid, contained high concentrations of p-tyrosine, but no appreciable amounts of o- or m-tyrosine. Saliva samples from the same subjects after chewing betel quid to which 20 mg phenylalanine had been added contained o- and m-tyrosine at concentrations ranging from 1010 to 3000 nM and from 1110 to 3140 nM respectively. These levels were significantly higher (P betel quid, which ranged from 14 to 70 nM for o-tyrosine and from 10 to 35 nM for m-tyrosine. These studies clearly demonstrate that the HO. radical is formed in the human oral cavity during betel quid chewing and is probably implicated in the genetic damage that has been observed in oral epithelial cells of chewers.

  3. The ORF59 DNA polymerase processivity factor homologs of Old World primate RV2 rhadinoviruses are highly conserved nuclear antigens expressed in differentiated epithelium in infected macaques

    Directory of Open Access Journals (Sweden)

    Burnside Kellie L

    2009-11-01

    Full Text Available Abstract Background ORF59 DNA polymerase processivity factor of the human rhadinovirus, Kaposi's sarcoma-associated herpesvirus (KSHV, is required for efficient copying of the genome during virus replication. KSHV ORF59 is antigenic in the infected host and is used as a marker for virus activation and replication. Results We cloned, sequenced and expressed the genes encoding related ORF59 proteins from the RV1 rhadinovirus homologs of KSHV from chimpanzee (PtrRV1 and three species of macaques (RFHVMm, RFHVMn and RFHVMf, and have compared them with ORF59 proteins obtained from members of the more distantly-related RV2 rhadinovirus lineage infecting the same non-human primate species (PtrRV2, RRV, MneRV2, and MfaRV2, respectively. We found that ORF59 homologs of the RV1 and RV2 Old World primate rhadinoviruses are highly conserved with distinct phylogenetic clustering of the two rhadinovirus lineages. RV1 and RV2 ORF59 C-terminal domains exhibit a strong lineage-specific conservation. Rabbit antiserum was developed against a C-terminal polypeptide that is highly conserved between the macaque RV2 ORF59 sequences. This anti-serum showed strong reactivity towards ORF59 encoded by the macaque RV2 rhadinoviruses, RRV (rhesus and MneRV2 (pig-tail, with no cross reaction to human or macaque RV1 ORF59 proteins. Using this antiserum and RT-qPCR, we determined that RRV ORF59 is expressed early after permissive infection of both rhesus primary fetal fibroblasts and African green monkey kidney epithelial cells (Vero in vitro. RRV- and MneRV2-infected foci showed strong nuclear expression of ORF59 that correlated with production of infectious progeny virus. Immunohistochemical studies of an MneRV2-infected macaque revealed strong nuclear expression of ORF59 in infected cells within the differentiating layer of epidermis corroborating previous observations that differentiated epithelial cells are permissive for replication of KSHV-like rhadinoviruses

  4. Repeated conservation threats across the Americas: High levels of blood and bone lead in the Andean Condor widen the problem to a continental scale.

    Science.gov (United States)

    Wiemeyer, Guillermo M; Pérez, Miguel A; Torres Bianchini, Laura; Sampietro, Luciano; Bravo, Guillermo F; Jácome, N Luis; Astore, Vanesa; Lambertucci, Sergio A

    2017-01-01

    Wildlife lead exposure is an increasing conservation threat that is being widely investigated. However, for some areas of the world (e.g., South America) and certain species, research on this subject is still scarce or only local information is available. We analyzed the extent and intensity of lead exposure for a widely distributed threatened species, the Andean Condor (Vultur gryphus). We conducted the study at two different scales: 1) sampling of birds received for rehabilitation or necropsy in Argentina, and 2) bibliographic review and extensive survey considering exposure event for the species' distribution in South America. Wild condors from Argentina (n = 76) presented high lead levels consistent with both recent and previous exposure (up to 104 μg/dL blood level, mean 15.47 ± 21.21 μg/dL and up to 148.20 ppm bone level, mean 23.08 ± 31.39 ppm). In contrast, captive bred individuals -not exposed to lead contamination- had much lower lead levels (mean blood level 5.63 ± 3.08 μg/dL, and mean bone level 2.76 ± 3.06 ppm). Condors were exposed to lead throughout their entire range in continental Argentina, which represents almost sixty percent (>4000 km) of their geographical distribution. We also present evidence of lead exposure events in Chile, Ecuador, and Peru. Lead poisoning is a widespread major conservation threat for the Andean Condor, and probably other sympatric carnivores from South America. The high number and wide range of Andean Condors with lead values complement the results for the California Condor and other scavengers in North America suggesting lead poisoning is a continental threat. Urgent actions are needed to reduce this poison in the wild. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Integrating Landsat Data and High-Resolution Imagery for Applied Conservation Assessment of Forest Cover in Latin American Heterogenous Landscapes

    Science.gov (United States)

    Thomas, N.; Rueda, X.; Lambin, E.; Mendenhall, C. D.

    2012-12-01

    Large intact forested regions of the world are known to be critical to maintaining Earth's climate, ecosystem health, and human livelihoods. Remote sensing has been successfully implemented as a tool to monitor forest cover and landscape dynamics over broad regions. Much of this work has been done using coarse resolution sensors such as AVHRR and MODIS in combination with moderate resolution sensors, particularly Landsat. Finer scale analysis of heterogeneous and fragmented landscapes is commonly performed with medium resolution data and has had varying success depending on many factors including the level of fragmentation, variability of land cover types, patch size, and image availability. Fine scale tree cover in mixed agricultural areas can have a major impact on biodiversity and ecosystem sustainability but may often be inadequately captured with the global to regional (coarse resolution and moderate resolution) satellite sensors and processing techniques widely used to detect land use and land cover changes. This study investigates whether advanced remote sensing methods are able to assess and monitor percent tree canopy cover in spatially complex human-dominated agricultural landscapes that prove challenging for traditional mapping techniques. Our study areas are in high altitude, mixed agricultural coffee-growing regions in Costa Rica and the Colombian Andes. We applied Random Forests regression tree analysis to Landsat data along with additional spectral, environmental, and spatial variables to predict percent tree canopy cover at 30m resolution. Image object-based texture, shape, and neighborhood metrics were generated at the Landsat scale using eCognition and included in the variable suite. Training and validation data was generated using high resolution imagery from digital aerial photography at 1m to 2.5 m resolution. Our results are promising with Pearson's correlation coefficients between observed and predicted percent tree canopy cover of .86 (Costa

  6. Deep-ocean disposal of high-activity nuclear wastes: a conservative assessment of the seafood critical pathway

    International Nuclear Information System (INIS)

    Baxter, M.S.; Economides, B.

    1984-01-01

    This paper applies conventional 'worst-case' assumptions to modelling the effects of possible future disposal of high-activity wastes in the oceans. It otherwise uses previously published and generally accepted data to assess the possible intakes of the waste nuclides via consumption of seaweeds, molluscs, crustaceans, plankton and fish. Model-predicted intakes for critical groups generally exceed ICRP-recommended limits, with 244 Cm, 241 Am and 137 Cs being the most potentially hazardous nuclides. The various seafood consumption pathways are found to rank, in decreasing order of potential hazard, as seaweeds > molluscs > plankton > fish > crustaceans. (Auth.)

  7. Breast-Conservative Surgery With Close or Positive Margins: Can the Breast Be Preserved With High-Dose-Rate Brachytherapy Boost?

    International Nuclear Information System (INIS)

    Guinot, Jose Luis; Roldan, Susana; Maronas, Maria; Tortajada, Isabel; Carrascosa, Maria; Chust, Maria Luisa; Estornell, Marian; Mengual, Jose Luis; Arribas, Leoncio

    2007-01-01

    Purpose: To evaluate the likelihood of preserving the breast in women who show close or positive margins after conservative surgery for early breast carcinoma. Methods and Materials: Since 1996, 125 women with less than 5 mm or positive margins and positive separate cavity margin sampling were entered in a prospective trial with high-dose radiotherapy. A standard dose of 50 Gy to the whole breast was followed by a high-dose-rate brachytherapy application delivering 3 fractions of 4.4 Gy in 24 hours. The median follow-up was 84 months. Results: There were only seven local recurrences, with an actuarial local control rate of 95.8% at 5 years and 91.1% at 9 years. Actuarial overall and cause-specific survival rates were 92.6% and 95% at 5 years and 86.7% and 90.4% at 9 years, respectively. Late fibrosis was the most common complication, in 30% of patients, with good or excellent cosmetic results in 77%. The final result was that 95.2% of breasts were preserved. Conclusions: Close or positive-margin breast cancer can be well managed with a high-dose boost in a wide tumor bed by means of high-dose-rate brachytherapy. This technique can avoid mastectomy or poor cosmetic resection, with minimal risk of local or general failure

  8. Tyrosine-like condensed derivatives as tyrosinase inhibitors.

    Science.gov (United States)

    Matos, Maria João; Santana, Lourdes; Uriarte, Eugenio; Serra, Silvia; Corda, Marcella; Fadda, Maria Benedetta; Era, Benedetta; Fais, Antonella

    2012-05-01

    We report the pharmacological evaluation of a new series of 3-aminocoumarins differently substituted with hydroxyl groups, which have been synthesized because they include in their structures the tyrosine fragment (tyrosine-like compounds), with the aim of discovering structural features necessary for tyrosinase inhibitory activity. The synthesized compounds 4 and 7-9 were evaluated in vitro as mushroom tyrosinase inhibitors. Two of the described compounds showed lower IC50 (concentration giving 50% inhibition of tyrosinase activity) than umbelliferone, used as a reference compound. Compound 7 (IC50=53µm) was the best tyrosinase inhibitor of this small series, having an IC50 value 10-fold lower than umbelliferone. Compound 7 (3-amino-7-hydroxycoumarin) had amino and hydroxyl groups precisely mimicking the same positions that both groups occupy on the tyrosine molecule. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

  9. Tyrosine residues modification studied by MALDI-TOF mass spectrometry

    International Nuclear Information System (INIS)

    Santrucek, Jiri; Strohalm, Martin; Kadlcik, Vojtech; Hynek, Radovan; Kodicek, Milan

    2004-01-01

    Amino acid residue-specific reactivity in proteins is of great current interest in structural biology as it provides information about solvent accessibility and reactivity of the residue and, consequently, about protein structure and possible interactions. In the work presented tyrosine residues of three model proteins with known spatial structure are modified with two tyrosine-specific reagents: tetranitromethane and iodine. Modified proteins were specifically digested by proteases and the mass of resulting peptide fragments was determined using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Our results show that there are only small differences in the extent of tyrosine residues modification by tetranitromethane and iodine. However, data dealing with accessibility of reactive residues obtained by chemical modifications are not completely identical with those obtained by nuclear magnetic resonance and X-ray crystallography. These interesting discrepancies can be caused by local molecular dynamics and/or by specific chemical structure of the residues surrounding

  10. Evaluation of Brachypodium distachyon L-Tyrosine Decarboxylase Using L-Tyrosine Over-Producing Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Shuhei Noda

    Full Text Available To demonstrate that herbaceous biomass is a versatile gene resource, we focused on the model plant Brachypodium distachyon, and screened the B. distachyon for homologs of tyrosine decarboxylase (TDC, which is involved in the modification of aromatic compounds. A total of 5 candidate genes were identified in cDNA libraries of B. distachyon and were introduced into Saccharomyces cerevisiae to evaluate TDC expression and tyramine production. It is suggested that two TDCs encoded in the transcripts Bradi2g51120.1 and Bradi2g51170.1 have L-tyrosine decarboxylation activity. Bradi2g51170.1 was introduced into the L-tyrosine over-producing strain of S. cerevisiae that was constructed by the introduction of mutant genes that promote deregulated feedback inhibition. The amount of tyramine produced by the resulting transformant was 6.6-fold higher (approximately 200 mg/L than the control strain, indicating that B. distachyon TDC effectively converts L-tyrosine to tyramine. Our results suggest that B. distachyon possesses enzymes that are capable of modifying aromatic residues, and that S. cerevisiae is a suitable host for the production of L-tyrosine derivatives.

  11. Skin peptide tyrosine-tyrosine, a member of the pancreatic polypeptide family: isolation, structure, synthesis, and endocrine activity.

    Science.gov (United States)

    Mor, A; Chartrel, N; Vaudry, H; Nicolas, P

    1994-10-25

    Pancreatic polypeptide, peptide tyrosine-tyrosine (PYY), and neuropeptide tyrosine (NPY), three members of a family of structurally related peptides, are mainly expressed in the endocrine pancreas, in endocrine cells of the gut, and in the brain, respectively. In the present study, we have isolated a peptide of the pancreatic polypeptide family from the skin of the South American arboreal frog Phyllomedusa bicolor. The primary structure of the peptide was established as Tyr-Pro-Pro-Lys-Pro-Glu-Ser-Pro-Gly-Glu10-Asp-Ala-Ser-Pro-Glu-Glu- Met-Asn- Lys-Tyr20-Leu-Thr-Ala-Leu-Arg-His-Tyr-Ile-Asn-Leu30-Val-Thr- Arg-Gln-Arg-Tyr-NH2 . This unusual peptide, named skin peptide tyrosine-tyrosine (SPYY), exhibits 94% similarity with PYY from the frog Rana ridibunda. A synthetic replicate of SPYY inhibits melanotropin release from perifused frog neurointermediate lobes in very much the same way as NPY. These results demonstrate the occurrence of a PYY-like peptide in frog skin. Our data also suggest the existence of a pituitary-skin regulatory loop in amphibians.

  12. High-throughput SHAPE analysis reveals structures in HIV-1 genomic RNA strongly conserved across distinct biological states.

    Directory of Open Access Journals (Sweden)

    Kevin A Wilkinson

    2008-04-01

    Full Text Available Replication and pathogenesis of the human immunodeficiency virus (HIV is tightly linked to the structure of its RNA genome, but genome structure in infectious virions is poorly understood. We invent high-throughput SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension technology, which uses many of the same tools as DNA sequencing, to quantify RNA backbone flexibility at single-nucleotide resolution and from which robust structural information can be immediately derived. We analyze the structure of HIV-1 genomic RNA in four biologically instructive states, including the authentic viral genome inside native particles. Remarkably, given the large number of plausible local structures, the first 10% of the HIV-1 genome exists in a single, predominant conformation in all four states. We also discover that noncoding regions functioning in a regulatory role have significantly lower (p-value < 0.0001 SHAPE reactivities, and hence more structure, than do viral coding regions that function as the template for protein synthesis. By directly monitoring protein binding inside virions, we identify the RNA recognition motif for the viral nucleocapsid protein. Seven structurally homologous binding sites occur in a well-defined domain in the genome, consistent with a role in directing specific packaging of genomic RNA into nascent virions. In addition, we identify two distinct motifs that are targets for the duplex destabilizing activity of this same protein. The nucleocapsid protein destabilizes local HIV-1 RNA structure in ways likely to facilitate initial movement both of the retroviral reverse transcriptase from its tRNA primer and of the ribosome in coding regions. Each of the three nucleocapsid interaction motifs falls in a specific genome domain, indicating that local protein interactions can be organized by the long-range architecture of an RNA. High-throughput SHAPE reveals a comprehensive view of HIV-1 RNA genome structure, and further

  13. Tyrosine-Nitrated Proteins: Proteomic and Bioanalytical Aspects.

    Science.gov (United States)

    Batthyány, Carlos; Bartesaghi, Silvina; Mastrogiovanni, Mauricio; Lima, Analía; Demicheli, Verónica; Radi, Rafael

    2017-03-01

    "Nitroproteomic" is under active development, as 3-nitrotyrosine in proteins constitutes a footprint left by the reactions of nitric oxide-derived oxidants that are usually associated to oxidative stress conditions. Moreover, protein tyrosine nitration can cause structural and functional changes, which may be of pathophysiological relevance for human disease conditions. Biological protein tyrosine nitration is a free radical process involving the intermediacy of tyrosyl radicals; in spite of being a nonenzymatic process, nitration is selectively directed toward a limited subset of tyrosine residues. Precise identification and quantitation of 3-nitrotyrosine in proteins has represented a "tour de force" for researchers. Recent Advances: A small number of proteins are preferential targets of nitration (usually less than 100 proteins per proteome), contrasting with the large number of proteins modified by other post-translational modifications such as phosphorylation, acetylation, and, notably, S-nitrosation. Proteomic approaches have revealed key features of tyrosine nitration both in vivo and in vitro, including selectivity, site specificity, and effects in protein structure and function. Identification of 3-nitrotyrosine-containing proteins and mapping nitrated residues is challenging, due to low abundance of this oxidative modification in biological samples and its unfriendly behavior in mass spectrometry (MS)-based technologies, that is, MALDI, electrospray ionization, and collision-induced dissociation. The use of (i) classical two-dimensional electrophoresis with immunochemical detection of nitrated proteins followed by protein ID by regular MS/MS in combination with (ii) immuno-enrichment of tyrosine-nitrated peptides and (iii) identification of nitrated peptides by a MIDAS™ experiment is arising as a potent methodology to unambiguously map and quantitate tyrosine-nitrated proteins in vivo. Antioxid. Redox Signal. 26, 313-328.

  14. Cortactin Tyrosine Phosphorylation Promotes Its Deacetylation and Inhibits Cell Spreading

    Science.gov (United States)

    Meiler, Eugenia; Nieto-Pelegrín, Elvira; Martinez-Quiles, Narcisa

    2012-01-01

    Background Cortactin is a classical Src kinase substrate that participates in actin cytoskeletal dynamics by activating the Arp2/3 complex and interacting with other regulatory proteins, including FAK. Cortactin has various domains that may contribute to the assembly of different protein platforms to achieve process specificity. Though the protein is known to be regulated by post-translational modifications such as phosphorylation and acetylation, how tyrosine phosphorylation regulates cortactin activity is poorly understood. Since the basal level of tyrosine phosphorylation is low, this question must be studied using stimulated cell cultures, which are physiologically relevant but unreliable and difficult to work with. In fact, their unreliability may be the cause of some contradictory findings about the dynamics of tyrosine phosphorylation of cortactin in different processes. Methodology/Principal Findings In the present study, we try to overcome these problems by using a Functional Interaction Trap (FIT) system, which involves cotransfecting cells with a kinase (Src) and a target protein (cortactin), both of which are fused to complementary leucine-zipper domains. The FIT system allowed us to control precisely the tyrosine phosphorylation of cortactin and explore its relationship with cortactin acetylation. Conclusions/Significance Using this system, we provide definitive evidence that a competition exists between acetylation and tyrosine phosphorylation of cortactin and that phosphorylation inhibits cell spreading. We confirmed the results from the FIT system by examining endogenous cortactin in different cell types. Furthermore, we demonstrate that cell spreading promotes the association of cortactin and FAK and that tyrosine phosphorylation of cortactin disrupts this interaction, which may explain how it inhibits cell spreading. PMID:22479425

  15. Modular Engineering of l-Tyrosine Production in Escherichia coli

    Science.gov (United States)

    Juminaga, Darmawi; Baidoo, Edward E. K.; Redding-Johanson, Alyssa M.; Batth, Tanveer S.; Burd, Helcio; Mukhopadhyay, Aindrila; Petzold, Christopher J.

    2012-01-01

    Efficient biosynthesis of l-tyrosine from glucose is necessary to make biological production economically viable. To this end, we designed and constructed a modular biosynthetic pathway for l-tyrosine production in E. coli MG1655 by encoding the enzymes for converting erythrose-4-phosphate (E4P) and phosphoenolpyruvate (PEP) to l-tyrosine on two plasmids. Rational engineering to improve l-tyrosine production and to identify pathway bottlenecks was directed by targeted proteomics and metabolite profiling. The bottlenecks in the pathway were relieved by modifications in plasmid copy numbers, promoter strength, gene codon usage, and the placement of genes in operons. One major bottleneck was due to the bifunctional activities of quinate/shikimate dehydrogenase (YdiB), which caused accumulation of the intermediates dehydroquinate (DHQ) and dehydroshikimate (DHS) and the side product quinate; this bottleneck was relieved by replacing YdiB with its paralog AroE, resulting in the production of over 700 mg/liter of shikimate. Another bottleneck in shikimate production, due to low expression of the dehydroquinate synthase (AroB), was alleviated by optimizing the first 15 codons of the gene. Shikimate conversion to l-tyrosine was improved by replacing the shikimate kinase AroK with its isozyme, AroL, which effectively consumed all intermediates formed in the first half of the pathway. Guided by the protein and metabolite measurements, the best producer, consisting of two medium-copy-number, dual-operon plasmids, was optimized to produce >2 g/liter l-tyrosine at 80% of the theoretical yield. This work demonstrates the utility of targeted proteomics and metabolite profiling in pathway construction and optimization, which should be applicable to other metabolic pathways. PMID:22020510

  16. The lytic origin of herpesvirus papio is highly homologous to Epstein-Barr virus ori-Lyt: evolutionary conservation of transcriptional activation and replication signals.

    Science.gov (United States)

    Ryon, J J; Fixman, E D; Houchens, C; Zong, J; Lieberman, P M; Chang, Y N; Hayward, G S; Hayward, S D

    1993-01-01

    Herpesvirus papio (HVP) is a B-lymphotropic baboon virus with an estimated 40% homology to Epstein-Barr virus (EBV). We have cloned and sequenced ori-Lyt of herpesvirus papio and found a striking degree of nucleotide homology (89%) with ori-Lyt of EBV. Transcriptional elements form an integral part of EBV ori-Lyt. The promoter and enhancer domains of EBV ori-Lyt are conserved in herpesvirus papio. The EBV ori-Lyt promoter contains four binding sites for the EBV lytic cycle transactivator Zta, and the enhancer includes one Zta and two Rta response elements. All five of the Zta response elements and one of the Rta motifs are conserved in HVP ori-Lyt, and the HVP DS-L leftward promoter and the enhancer were activated in transient transfection assays by the EBV Zta and Rta transactivators. The EBV ori-Lyt enhancer contains a palindromic sequence, GGTCAGCTGACC, centered on a PvuII restriction site. This sequence, with a single base change, is also present in the HVP ori-Lyt enhancer. DNase I footprinting demonstrated that the PvuII sequence was bound by a protein present in a Raji nuclear extract. Mobility shift and competition assays using oligonucleotide probes identified this sequence as a binding site for the cellular transcription factor MLTF. Mutagenesis of the binding site indicated that MLTF contributes significantly to the constitutive activity of the ori-Lyt enhancer. The high degree of conservation of cis-acting signal sequences in HVP ori-Lyt was further emphasized by the finding that an HVP ori-Lyt-containing plasmid was replicated in Vero cells by a set of cotransfected EBV replication genes. The central domain of EBV ori-Lyt contains two related AT-rich palindromes, one of which is partially duplicated in the HVP sequence. The AT-rich palindromes are functionally important cis-acting motifs. Deletion of these palindromes severely diminished replication of an ori-Lyt target plasmid. Images PMID:8389916

  17. Genetic structure analysis of a highly inbred captive population of the African antelope Addax nasomaculatus. Conservation and management implications.

    Science.gov (United States)

    Armstrong, E; Leizagoyen, C; Martínez, A M; González, S; Delgado, J V; Postiglioni, A

    2011-01-01

    The African antelope Addax nasomaculatus is a rare mammal at high risk of extinction, with no more than 300 individuals in the wild and 1,700 captive animals distributed in zoos around the world. In this work, we combine genetic data and genealogical information to assess the structure and genetic diversity of a captive population located at Parque Lecocq Zoo (N=27), originated from only two founders. We amplified 39 microsatellites previously described in other Artiodactyls but new to this species. Seventeen markers were polymorphic, with 2-4 alleles per locus (mean=2.71). Mean expected heterozygosity (He) per locus was between 0.050 (marker ETH3) and 0.650 (marker D5S2), with a global He of 0.43. The mean inbreeding coefficient of the population computed from pedigree records of all registered individuals (N=53) was 0.222. The mean coancestry of the population was 0.298 and F(IS) index was -0.108. These results reflect the importance of an adequate breeding management on a severely bottlenecked captive population, which would benefit by the incorporation of unrelated individuals. Thanks to the successful amplification of a large number of microsatellites commonly used in domestic bovids, this study will provide useful information for the management of this population and serve as future reference for similar studies in other captive populations of this species. © 2010 Wiley-Liss, Inc.

  18. Receptor tyrosine phosphatase R-PTP-kappa mediates homophilic binding

    DEFF Research Database (Denmark)

    Sap, J; Jiang, Y P; Friedlander, D

    1994-01-01

    Receptor tyrosine phosphatases (R-PTPases) feature PTPase domains in the context of a receptor-like transmembrane topology. The R-PTPase R-PTP-kappa displays an extracellular domain composed of fibronectin type III motifs, a single immunoglobulin domain, as well as a recently defined MAM domain (Y...... not require PTPase activity or posttranslational proteolytic cleavage of the R-PTP-kappa protein and is calcium independent. The results suggest that R-PTPases may provide a link between cell-cell contact and cellular signaling events involving tyrosine phosphorylation....

  19. Cloning and expression of a widely expressed receptor tyrosine phosphatase

    DEFF Research Database (Denmark)

    Sap, J; D'Eustachio, P; Givol, D

    1990-01-01

    We describe the identification of a widely expressed receptor-type (transmembrane) protein tyrosine phosphatase (PTPase; EC 3.1.3.48). Screening of a mouse brain cDNA library under low-stringency conditions with a probe encompassing the intracellular (phosphatase) domain of the CD45 lymphocyte...... antigen yielded cDNA clones coding for a 794-amino acid transmembrane protein [hereafter referred to as receptor protein tyrosine phosphatase alpha (R-PTP-alpha)] with an intracellular domain displaying clear homology to the catalytic domains of CD45 and LAR (45% and 53%, respectively). The 142-amino acid...

  20. SOCS proteins in regulation of receptor tyrosine kinase signaling

    DEFF Research Database (Denmark)

    Kazi, Julhash U.; Kabir, Nuzhat N.; Flores Morales, Amilcar

    2014-01-01

    Receptor tyrosine kinases (RTKs) are a family of cell surface receptors that play critical roles in signal transduction from extracellular stimuli. Many in this family of kinases are overexpressed or mutated in human malignancies and thus became an attractive drug target for cancer treatment....... The signaling mediated by RTKs must be tightly regulated by interacting proteins including protein-tyrosine phosphatases and ubiquitin ligases. The suppressors of cytokine signaling (SOCS) family proteins are well-known negative regulators of cytokine receptors signaling consisting of eight structurally similar...

  1. Natural compounds as a source of protein tyrosine phosphatase inhibitors : Application to the rational design of small-molecule derivatives

    NARCIS (Netherlands)

    Ferreira, Carmen V.; Justo, Giselle Z.; Souza, Ana C. S.; Queiroz, Karla C. S.; Zambuzzi, William F.; Aoyama, Hiroshi; Peppelenbosch, Maikel P.

    2006-01-01

    Reversible phosphorylation of tyrosine residues is a key regulatory mechanism for numerous cellular events. Protein tyrosine kinases and protein tyrosine phosphatases (PTPs) have a pivotal role in regulating both normal cell physiology and pathophysiology. Accordingly, deregulated activity of both

  2. Novel tyrosine phosphorylation sites in rat skeletal muscle revealed by phosphopeptide enrichment and HPLC-ESI-MS/MS

    DEFF Research Database (Denmark)

    Zhang, Xiangmin; Højlund, Kurt; Luo, Moulun

    2012-01-01

    Tyrosine phosphorylation plays a fundamental role in many cellular processes including differentiation, growth and insulin signaling. In insulin resistant muscle, aberrant tyrosine phosphorylation of several proteins has been detected. However, due to the low abundance of tyrosine phosphorylation (...

  3. Multi-species comparative analysis of the equine ACE gene identifies a highly conserved potential transcription factor binding site in intron 16.

    Science.gov (United States)

    Hamilton, Natasha A; Tammen, Imke; Raadsma, Herman W

    2013-01-01

    Angiotensin converting enzyme (ACE) is essential for control of blood pressure. The human ACE gene contains an intronic Alu indel (I/D) polymorphism that has been associated with variation in serum enzyme levels, although the functional mechanism has not been identified. The polymorphism has also been associated with cardiovascular disease, type II diabetes, renal disease and elite athleticism. We have characterized the ACE gene in horses of breeds selected for differing physical abilities. The equine gene has a similar structure to that of all known mammalian ACE genes. Nine common single nucleotide polymorphisms (SNPs) discovered in pooled DNA were found to be inherited in nine haplotypes. Three of these SNPs were located in intron 16, homologous to that containing the Alu polymorphism in the human. A highly conserved 18 bp sequence, also within that intron, was identified as being a potential binding site for the transcription factors Oct-1, HFH-1 and HNF-3β, and lies within a larger area of higher than normal homology. This putative regulatory element may contribute to regulation of the documented inter-individual variation in human circulating enzyme levels, for which a functional mechanism is yet to be defined. Two equine SNPs occurred within the conserved area in intron 16, although neither of them disrupted the putative binding site. We propose a possible regulatory mechanism of the ACE gene in mammalian species which was previously unknown. This advance will allow further analysis leading to a better understanding of the mechanisms underpinning the associations seen between the human Alu polymorphism and enzyme levels, cardiovascular disease states and elite athleticism.

  4. Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41.

    Directory of Open Access Journals (Sweden)

    Charles Sabin

    Full Text Available The human monoclonal antibody (mAb HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1 of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for C-clade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

  5. Multi-species comparative analysis of the equine ACE gene identifies a highly conserved potential transcription factor binding site in intron 16.

    Directory of Open Access Journals (Sweden)

    Natasha A Hamilton

    Full Text Available Angiotensin converting enzyme (ACE is essential for control of blood pressure. The human ACE gene contains an intronic Alu indel (I/D polymorphism that has been associated with variation in serum enzyme levels, although the functional mechanism has not been identified. The polymorphism has also been associated with cardiovascular disease, type II diabetes, renal disease and elite athleticism. We have characterized the ACE gene in horses of breeds selected for differing physical abilities. The equine gene has a similar structure to that of all known mammalian ACE genes. Nine common single nucleotide polymorphisms (SNPs discovered in pooled DNA were found to be inherited in nine haplotypes. Three of these SNPs were located in intron 16, homologous to that containing the Alu polymorphism in the human. A highly conserved 18 bp sequence, also within that intron, was identified as being a potential binding site for the transcription factors Oct-1, HFH-1 and HNF-3β, and lies within a larger area of higher than normal homology. This putative regulatory element may contribute to regulation of the documented inter-individual variation in human circulating enzyme levels, for which a functional mechanism is yet to be defined. Two equine SNPs occurred within the conserved area in intron 16, although neither of them disrupted the putative binding site. We propose a possible regulatory mechanism of the ACE gene in mammalian species which was previously unknown. This advance will allow further analysis leading to a better understanding of the mechanisms underpinning the associations seen between the human Alu polymorphism and enzyme levels, cardiovascular disease states and elite athleticism.

  6. High-affinity interaction of hnRNP A1 with conserved RNA structural elements is required for translation and replication of enterovirus 71.

    Science.gov (United States)

    Levengood, Jeffrey D; Tolbert, Michele; Li, Mei-Ling; Tolbert, Blanton S

    2013-07-01

    Human Enterovirus 71 (EV71) is an emerging pathogen of infectious disease and a serious threat to public health. Currently, there are no antivirals or vaccines to slow down or prevent EV71 infections, thus underscoring the urgency to better understand mechanisms of host-enterovirus interactions. EV71 uses a type I internal ribosome entry site (IRES) to recruit the 40S ribosomal subunit via a pathway that requires the cytoplasmic localization of hnRNP A1, which acts as an IRES trans-activating factor. The mechanism of how hnRNP A1 trans activates EV71 RNA translation is unknown, however. Here, we report that the UP1 domain of hnRNP A1 interacts specifically with stem loop II (SLII) of the IRES, via a thermodynamically well-defined biphasic transition that involves conserved bulge 5'-AYAGY-3' and hairpin 5'-RY(U/A)CCA-3' loops. Calorimetric titrations of wild-type and mutant SLII constructs reveal these structural elements are essential to form a high-affinity UP1-SLII complex. Mutations that alter the bulge and hairpin primary or secondary structures abrogate the biphasic transition and destabilize the complex. Notably, mutations within the bulge that destabilize the complex correlate with a large reduction in IRES-dependent translational activity and impair EV71 replication. Taken together, this study shows that a conserved SLII structure is necessary to form a functional hnRNP A1-IRES complex, suggesting that small molecules that target this stem loop may have novel antiviral properties.

  7. CT-image based conformal high-dose rate brachytherapy boost in the conservative treatment of stage I - II breast cancer - introducing the procedure

    International Nuclear Information System (INIS)

    Kubaszewska, M.; Skowronek, J.; Chichel, A.; Kanikowski, M.; Dymnicka, M.

    2008-01-01

    Aim: Breast-conserving surgery (BCS) followed by radiotherapy (RT) has become the standard treatment for the majority of patients with early breast cancer. With regard to boost technique some disagreements are found between groups that are emphasizing the value of electron boost treatment and groups pointing out the value of interstitial brachytherapy (BT) boost treatment. We present the preliminary results in treating selected patients with early-stage breast cancer using high-dose-rate brachytherapy (HD R-BT) as a boost after breast conservation therapy (BCT). Materials/Methods: Between January 2006 and August 2007, a total of 58 female patients with first and second stage breast cancer underwent BCT. This therapeutic procedure involves BCS, whole breast radiation therapy (WBRT) and additional irradiation to the tumour bed (boost) using interstitial HDR-BT via flexible implant tubes. A 10 Gy boost dose was received by all patients. The treatment planning was based on CT-guided 3D (three-dimensional) reconstruction of the surgical clips, implant tubes and critical structures localization (skin and ribs). The accuracy of tumour bed localization, the conformity of planning target volume and treated volume were analyzed. Results: The evaluations of implant parameters involved the use of: dose volume histogram (DVH), the volume encompassed by the 100% reference isodose surface (V100%), the high dose volumecalculation (V150%, V200%, V300%), the dose non-uniformity ratio (DNR), and the conformity index (COIN). Our results were as follows: the mean PTV volume, the mean high dose volume (V150%; V200%; V300%), the DNR and COIN mean value were estimated at 57.38, 42.98, 21.38, 7.90, 0.52 and 0.83 respectively. Conclusions: CT-guided 3D HDR-BT is most appropriate for planning the boost procedure after BT especially in large breast volume, in cases with a deep seated tumour bed, as well as in patients with high risk for local recurrences. This technique reduces the

  8. Conserved intron positions in FGFR genes reflect the modular structure of FGFR and reveal stepwise addition of domains to an already complex ancestral FGFR.

    Science.gov (United States)

    Rebscher, Nicole; Deichmann, Christina; Sudhop, Stefanie; Fritzenwanker, Jens Holger; Green, Stephen; Hassel, Monika

    2009-10-01

    We have analyzed the evolution of fibroblast growth factor receptor (FGFR) tyrosine kinase genes throughout a wide range of animal phyla. No evidence for an FGFR gene was found in Porifera, but we tentatively identified an FGFR gene in the placozoan Trichoplax adhaerens. The gene encodes a protein with three immunoglobulin-like domains, a single-pass transmembrane, and a split tyrosine kinase domain. By superimposing intron positions of 20 FGFR genes from Placozoa, Cnidaria, Protostomia, and Deuterostomia over the respective protein domain structure, we identified ten ancestral introns and three conserved intron groups. Our analysis shows (1) that the position of ancestral introns correlates to the modular structure of FGFRs, (2) that the acidic domain very likely evolved in the last common ancestor of triploblasts, (3) that splicing of IgIII was enabled by a triploblast-specific insertion, and (4) that IgI is subject to substantial loss or duplication particularly in quickly evolving genomes. Moreover, intron positions in the catalytic domain of FGFRs map to the borders of protein subdomains highly conserved in other serine/threonine kinases. Nevertheless, these introns were introduced in metazoan receptor tyrosine kinases exclusively. Our data support the view that protein evolution dating back to the Cambrian explosion took place in such a short time window that only subtle changes in the domain structure are detectable in extant representatives of animal phyla. We propose that the first multidomain FGFR originated in the last common ancestor of Placozoa, Cnidaria, and Bilateria. Additional domains were introduced mainly in the ancestor of triploblasts and in the Ecdysozoa.

  9. Promoting household energy conservation

    International Nuclear Information System (INIS)

    Steg, Linda

    2008-01-01

    It is commonly assumed that households must change their behaviour to reduce the problems caused by increasing levels of fossil energy use. Strategies for behaviour change will be more effective if they target the most important causes of the behaviour in question. Therefore, this paper first discusses the factors influencing household energy use. Three barriers to fossil fuel energy conservation are discussed: insufficient knowledge of effective ways to reduce household energy use, the low priority and high costs of energy savings, and the lack of feasible alternatives. Next, the paper elaborates on the effectiveness and acceptability of strategies aimed to promote household energy savings. Informational strategies aimed at changing individuals' knowledge, perceptions, cognitions, motivations and norms, as well as structural strategies aimed at changing the context in which decisions are made, are discussed. This paper focuses on the psychological literature on household energy conservation, which mostly examined the effects of informational strategies. Finally, this paper lists important topics for future research

  10. Receptor protein tyrosine phosphatase alpha is essential for hippocampal neuronal migration and long-term potentiation

    DEFF Research Database (Denmark)

    Petrone, Angiola; Battaglia, Fortunato; Wang, Cheng

    2003-01-01

    Despite clear indications of their importance in lower organisms, the contributions of protein tyrosine phosphatases (PTPs) to development or function of the mammalian nervous system have been poorly explored. In vitro studies have indicated that receptor protein tyrosine phosphatase alpha...

  11. Regulation of hematopoietic cell function by protein tyrosine kinase-encoding oncogenes, a review

    NARCIS (Netherlands)

    Punt, C. J.

    1992-01-01

    Tyrosine phosphorylation of proteins by protein tyrosine kinases (PTKs) is an important mechanism in the regulation of various cellular processes such as proliferation, differentiation, and transformation. Accumulating data implicate PTKs as essential intermediates in the transduction of

  12. Receptor-type Protein Tyrosine Phosphatase β Regulates Met Phosphorylation and Function in Head and Neck Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Yiru Xu

    2012-11-01

    Full Text Available Head and neck squamous cell carcinoma (HNSCC is the sixth most common cancer and has a high rate of mortality. Emerging evidence indicates that hepatocyte growth factor receptor (or Met pathway plays a pivotal role in HNSCC metastasis and resistance to chemotherapy. Met function is dependent on tyrosine phosphorylation that is under direct control by receptor-type protein tyrosine phosphatase β (RPTP-β. We report here that RPTP-β expression is significantly downregulated in HNSCC cells derived from metastatic tumors compared to subject-matched cells from primary tumors. Knockdown of endogenous RPTP-β in HNSCC cells from primary tumor potentiated Met tyrosine phosphorylation, downstream mitogen-activated protein (MAP kinase pathway activation, cell migration, and invasion. Conversely, restoration of RPTP-β expression in cells from matched metastatic tumor decreased Met tyrosine phosphorylation and downstream functions. Furthermore, we observed that six of eight HNSCC tumors had reduced levels of RPTP-β protein in comparison with normal oral tissues. Collectively, the results demonstrate the importance of RPTP-β in tumor biology of HNSCC through direct dephosphorylation of Met and regulation of downstream signal transduction pathways. Reduced RPTP-β levels, with or without Met overexpression, could promote Met activation in HNSCC tumors.

  13. Small Molecule Tyrosine Kinase Inhibitors of ErbB2/HER2/Neu in the Treatment of Aggressive Breast Cancer

    Directory of Open Access Journals (Sweden)

    Richard L. Schroeder

    2014-09-01

    Full Text Available The human epidermal growth factor receptor 2 (HER2 is a member of the erbB class of tyrosine kinase receptors. These proteins are normally expressed at the surface of healthy cells and play critical roles in the signal transduction cascade in a myriad of biochemical pathways responsible for cell growth and differentiation. However, it is widely known that amplification and subsequent overexpression of the HER2 encoding oncogene results in unregulated cell proliferation in an aggressive form of breast cancer known as HER2-positive breast cancer. Existing therapies such as trastuzumab (Herceptin® and lapatinib (Tyverb/Tykerb®, a monoclonal antibody inhibitor and a dual EGFR/HER2 kinase inhibitor, respectively, are currently used in the treatment of HER2-positive cancers, although issues with high recurrence and acquired resistance still remain. Small molecule tyrosine kinase inhibitors provide attractive therapeutic targets, as they are able to block cell signaling associated with many of the proposed mechanisms for HER2 resistance. In this regard we aim to present a review on the available HER2 tyrosine kinase inhibitors, as well as those currently in development. The use of tyrosine kinase inhibitors as sequential or combinatorial therapeutic strategies with other HER family inhibitors is also discussed.

  14. Protein tyrosine phosphatase receptor delta acts as a neuroblastoma tumor suppressor by destabilizing the aurora kinase a oncogene

    LENUS (Irish Health Repository)

    Meehan, Maria

    2012-02-05

    Abstract Background Protein tyrosine phosphatase receptor delta (PTPRD) is a member of a large family of protein tyrosine phosphatases which negatively regulate tyrosine phosphorylation. Neuroblastoma is a major childhood cancer arising from precursor cells of the sympathetic nervous system which is known to acquire deletions and alterations in the expression patterns of PTPRD, indicating a potential tumor suppressor function for this gene. The molecular mechanism, however, by which PTPRD renders a tumor suppressor effect in neuroblastoma is unknown. Results As a molecular mechanism, we demonstrate that PTPRD interacts with aurora kinase A (AURKA), an oncogenic protein that is over-expressed in multiple forms of cancer, including neuroblastoma. Ectopic up-regulation of PTPRD in neuroblastoma dephosphorylates tyrosine residues in AURKA resulting in a destabilization of this protein culminating in interfering with one of AURKA\\'s primary functions in neuroblastoma, the stabilization of MYCN protein, the gene of which is amplified in approximately 25 to 30% of high risk neuroblastoma. Conclusions PTPRD has a tumor suppressor function in neuroblastoma through AURKA dephosphorylation and destabilization and a downstream destabilization of MYCN protein, representing a novel mechanism for the function of PTPRD in neuroblastoma.

  15. The Chthonomonas calidirosea Genome Is Highly Conserved across Geographic Locations and Distinct Chemical and Microbial Environments in New Zealand's Taupō Volcanic Zone.

    Science.gov (United States)

    Lee, Kevin C; Stott, Matthew B; Dunfield, Peter F; Huttenhower, Curtis; McDonald, Ian R; Morgan, Xochitl C

    2016-06-15

    Chthonomonas calidirosea T49(T) is a low-abundance, carbohydrate-scavenging, and thermophilic soil bacterium with a seemingly disorganized genome. We hypothesized that the C. calidirosea genome would be highly responsive to local selection pressure, resulting in the divergence of its genomic content, genome organization, and carbohydrate utilization phenotype across environments. We tested this hypothesis by sequencing the genomes of four C. calidirosea isolates obtained from four separate geothermal fields in the Taupō Volcanic Zone, New Zealand. For each isolation site, we measured physicochemical attributes and defined the associated microbial community by 16S rRNA gene sequencing. Despite their ecological and geographical isolation, the genome sequences showed low divergence (maximum, 1.17%). Isolate-specific variations included single-nucleotide polymorphisms (SNPs), restriction-modification systems, and mobile elements but few major deletions and no major rearrangements. The 50-fold variation in C. calidirosea relative abundance among the four sites correlated with site environmental characteristics but not with differences in genomic content. Conversely, the carbohydrate utilization profiles of the C. calidirosea isolates corresponded to the inferred isolate phylogenies, which only partially paralleled the geographical relationships among the sample sites. Genomic sequence conservation does not entirely parallel geographic distance, suggesting that stochastic dispersal and localized extinction, which allow for rapid population homogenization with little restriction by geographical barriers, are possible mechanisms of C. calidirosea distribution. This dispersal and extinction mechanism is likely not limited to C. calidirosea but may shape the populations and genomes of many other low-abundance free-living taxa. This study compares the genomic sequence variations and metabolisms of four strains of Chthonomonas calidirosea, a rare thermophilic bacterium from

  16. Fluorescence anisotropy of tyrosinate anion using one-, two- and three-photon excitation: tyrosinate anion fluorescence.

    Science.gov (United States)

    Kierdaszuk, Borys

    2013-03-01

    We examined the emission spectra and steady-state anisotropy of tyrosinate anion fluorescence with one-photon (250-310 nm), two-photon (570-620 nm) and three-photon (750-930 nm) excitation. Similar emission spectra of the neutral (pH 7.2) and anionic (pH 13) forms of N-acetyl-L-tyrosinamide (NATyrA) (pKa 10.6) were observed for all modes of excitation, with the maxima at 302 and 352 nm, respectively. Two-photon excitation (2PE) and three-photon excitation (3PE) spectra of the anionic form were the same as that for one-photon excitation (1PE). In contrast, 2PE spectrum from the neutral form showed ~30-nm shift to shorter wavelengths relative to 1PE spectrum (λmax 275 nm) at two-photon energy (550 nm), the latter being overlapped with 3PE spectrum, both at two-photon energy (550 nm). Two-photon cross-sections for NATyrA anion at 565-580 nm were 10 % of that for N-acetyl-L-tryptophanamide (NATrpA), and increased to 90 % at 610 nm, while for the neutral form of NATyrA decreased from 2 % of that for NATrpA at 570 nm to near zero at 585 nm. Surprisingly, the fundamental anisotropy of NATyrA anion in vitrified solution at -60 °C was ~0.05 for 2PE at 610 nm as compared to near 0.3 for 1PE at 305 nm, and wavelength-dependence appears to be a basic feature of its anisotropy. In contrast, the 3PE anisotropy at 900 nm was about 0.5, and 3PE and 1PE anisotropy values appear to be related by the cos(6) θ to cos(2) θ photoselection factor (approx. 10/6) independently of excitation wavelength. Attention is drawn to the possible effect of tyrosinate anions in proteins on their multi-photon induced fluorescence emission and excitation spectra as well as excitation anisotropy spectra.

  17. Geographies of Conservation I: De-extinction and Precision Conservation

    OpenAIRE

    Adams, William Mark

    2016-01-01

    Extinction has long been a central concern in biodiversity conservation. Today, de-extinction offers interesting possibilities of restoring charismatic species and ecosystem function, but also risks and costs. Most de-extinction depends on genetic engineering and synthetic biology. These technologies are also proposed for use in ‘gene tweaking’ in wild species to enhance their chance of survival. Within conservation, the resulting debates pit an optimistic world of high-tech ‘precision con...

  18. Evidence for a tyrosine protonation change during the primary phototransition of bacteriorhodopsin at low temperature.

    OpenAIRE

    Rothschild, K J; Roepe, P; Ahl, P L; Earnest, T N; Bogomolni, R A; Das Gupta, S K; Mulliken, C M; Herzfeld, J

    1986-01-01

    Isotopically labeled tyrosines have been selectively incorporated into bacteriorhodopsin (bR). A comparison of the low-temperature bR570 to K Fourier transform infrared-difference spectra of these samples and normal bR provides information about the role of tyrosine in the primary phototransition. Several tyrosine contributions to the difference spectrum are found. These results and comparison with the spectra of model compounds suggest that a tyrosinate group protonates during the bR570 to K...

  19. Evaluation the consistency of location of moist desquamation and skin high dose area for breast cancer patients receiving adjuvant radiotherapy after breast conservative surgery

    International Nuclear Information System (INIS)

    Sun, Li-Min; Huang, Eng-Yen; Liang, Ji-An; Meng, Fan-Yun; Chang, Gia-Hsin; Tsao, Min-Jen

    2013-01-01

    To evaluate whether the location of moist desquamation matches high dose area for breast cancer patients receiving adjuvant radiotherapy (RT) after breast conservative surgery. One hundred and nine breast cancer patients were enrolled to this study. Their highest skin dose area (the hot spot) was estimated from the treatment planning. We divided the irradiated field into breast; sternal/parasternal; axillary; and inframammary fold areas. The location for moist desquamation was recorded to see if it matches the hot spot. We also analyzed other possible risk factors which may be related to the moist desquamation. Forty-eight patients with 65 locations developed moist desquamation during the RT course. Patients with larger breast sizes and easy to sweat are two independent risk factors for moist desquamation. The distribution of moist desquamation occurred most in the axillary area. All nine patients with the hot spots located at the axillary area developed moist desquamation at the axillary area, and six out of seven patients with the hot spots located at the inframammary fold developed moist desquamation there. The majority of patients with moist desquamation over the breast or sternal/parasternal areas had the hot spots located at these areas. For a patient with moist desquamation, if a hot spot is located at the axillary or inframammary fold areas, it is very likely to have moist desquamation occur there. On the other hand, if moist desquamation occurs over the breast or sternal/parasternal areas, we can highly expect these two areas are also the hot spot locations

  20. Role of Bruton's tyrosine kinase in B cells and malignancies

    NARCIS (Netherlands)

    Pal Singh, S. (Simar); F. Dammeijer (Floris); R.W. Hendriks (Rudi)

    2018-01-01

    textabstractBruton's tyrosine kinase (BTK) is a non-receptor kinase that plays a crucial role in oncogenic signaling that is critical for proliferation and survival of leukemic cells in many B cell malignancies. BTK was initially shown to be defective in the primary immunodeficiency X-linked

  1. Anxious moments for the protein tyrosine phosphatase PTP1B

    OpenAIRE

    Krishnan, Navasona; Tonks, Nicholas K.

    2015-01-01

    Chronic stress can lead to the development of anxiety and mood disorders. Thus, novel therapies for preventing adverse effects of stress are vitally important. Recently, the protein tyrosine phosphatase PTP1B was identified as a novel regulator of stress-induced anxiety. This opens up exciting opportunities to exploit PTP1B inhibitors as anxiolytics.

  2. Eosin-sensitized photooxidation of substituted phenylalanines and tyrosines

    Energy Technology Data Exchange (ETDEWEB)

    Rizzuto, F.; Spikes, J.D.

    1977-01-01

    The cosin-sensitized photooxidation of tyrosine and a number of compounds related to tyrosine (substituted phenylalanines) was studied by steady-state kinetic and flash photolysis techniques. In particular, the role of the phenolic group and the amino and carboxyl groups of the alanyl side chain in the photooxidation mechanism was investigated in detail. Several relationships between substrate structure and susceptibility to photooxidation as well as effects of substrate structure on photooxidation mechanisms were found. For example, phenylalanine is not photooxidizable, but substitution of electron-donating (activating) groups such as -OH (as in tyrosine) or -NH/sub 2/ (as in p-aminophenylalanine) results in rapidly photooxidized derivatives. However, substituting deactivating groups such as -Cl (as in p-chlorophenylalanine) or weakly activating groups such as -OCH/sub 3/ (as in 4-methoxyphenylalanine) result in non-photooxidizable derivatives. Substitution of additional activating groups to the ring of hydroxy-substituted phenylalanines results in increased rates of photooxidation, whereas additional deactivating groups result in decreased photooxidation rates. The rate-determining step in the photooxidation mechanism is shown to be dependent on the presence and position of an electron-donating substituent on the benzenoid ring. Only minor involvement of the side chain amino and carboxyl groups was found. Both singlet oxygen and hydrogen abstraction mechanisms are involved in the eosin-sensitized photooxidation of hydroxy-substituted phenylalanines (e.g., tyrosine). The hydrogen abstraction mechanism probably predominates at both pH 8 and 11.

  3. Isolation of a tyrosine-activating enzyme from baker's yeast

    NARCIS (Netherlands)

    Ven, A.M. van de; Koningsberger, V.V.; Overbeek, J.Th.G.

    1958-01-01

    The extracts of ether-CO2-frozen baker's yeast contain enzymes that catalyze the ATP-linked amino acid activation by way of pyrophosphate elimination. From the extract a tyrosine-activating enzyme could be isolated, which, judging from ultracentrifugation and electrophoretic data, was about 70% pure

  4. Variability in bioavailability of small molecular tyrosine kinase inhibitors

    NARCIS (Netherlands)

    Herbrink, Maikel; Nuijen, Bastiaan; Schellens, Jan H M; Beijnen, Jos H.

    2015-01-01

    Small molecular tyrosine kinase inhibitors (smTKIs) are in the centre of the very quickly expanding area of personalized chemotherapy and oral applicability thereof. The number of drugs in this class is rapidly growing, with twenty current approvals by both the European Medicines Agency (EMA) and

  5. Expression of tyrosine kinase gene in mouse thymic stromal cells

    NARCIS (Netherlands)

    Rinke de Wit, T. F.; Izon, D. J.; Revilla, C.; Oosterwegel, M.; Bakker, A. Q.; van Ewijk, W.; Kruisbeek, A. M.

    1996-01-01

    Amongst the most important signal transduction molecules involved in regulating growth and differentiation are the protein tyrosine kinases (PTK). Since T cell development is a consequence of interactions between thymic stromal cells (TSC) and thymocytes, identification of the PTK in both

  6. ZDHHC3 Tyrosine Phosphorylation Regulates Neural Cell Adhesion Molecule Palmitoylation

    Science.gov (United States)

    Lievens, Patricia Marie-Jeanne; Kuznetsova, Tatiana; Kochlamazashvili, Gaga; Cesca, Fabrizia; Gorinski, Natalya; Galil, Dalia Abdel; Cherkas, Volodimir; Ronkina, Natalia; Lafera, Juri; Gaestel, Matthias

    2016-01-01

    The neural cell adhesion molecule (NCAM) mediates cell-cell and cell-matrix adhesion. It is broadly expressed in the nervous system and regulates neurite outgrowth, synaptogenesis, and synaptic plasticity. Previous in vitro studies revealed that palmitoylation of NCAM is required for fibroblast growth factor 2 (FGF2)-stimulated neurite outgrowth and identified the zinc finger DHHC (Asp-His-His-Cys)-containing proteins ZDHHC3 and ZDHHC7 as specific NCAM-palmitoylating enzymes. Here, we verified that FGF2 controlled NCAM palmitoylation in vivo and investigated molecular mechanisms regulating NCAM palmitoylation by ZDHHC3. Experiments with overexpression and pharmacological inhibition of FGF receptor (FGFR) and Src revealed that these kinases control tyrosine phosphorylation of ZDHHC3 and that ZDHHC3 is phosphorylated by endogenously expressed FGFR and Src proteins. By site-directed mutagenesis, we found that Tyr18 is an FGFR1-specific ZDHHC3 phosphorylation site, while Tyr295 and Tyr297 are specifically phosphorylated by Src kinase in cell-based and cell-free assays. Abrogation of tyrosine phosphorylation increased ZDHHC3 autopalmitoylation, enhanced interaction with NCAM, and upregulated NCAM palmitoylation. Expression of ZDHHC3 with tyrosine mutated in cultured hippocampal neurons promoted neurite outgrowth. Our findings for the first time highlight that FGFR- and Src-mediated tyrosine phosphorylation of ZDHHC3 modulates ZDHHC3 enzymatic activity and plays a role in neuronal morphogenesis. PMID:27247265

  7. Association of connexin43 with a receptor protein tyrosine phosphatase

    NARCIS (Netherlands)

    Giepmans, Ben N G; Feiken, Elles; Gebbink, Martijn F B G; Moolenaar, Wouter H

    2003-01-01

    Connexin-43(Cx43)-based gap junctional communication is transiently inhibited by certain G protein-coupled receptor agonists, including lysophosphatidic acid, endothelin and thrombin. Our previous studies have implicated the c-Src protein tyrosine kinase in mediating closure of Cx43 based gap

  8. Uptake of Tyrosine Amino Acid on Nano-Graphene Oxide

    Directory of Open Access Journals (Sweden)

    Hossam M. Nassef

    2018-01-01

    Full Text Available Graphene oxide (GO is emerging as a promising nanomaterial with potential application in the detection and analysis of amino acids, DNA, enzymes, and proteins in biological fluid samples. So, the reaction of GO with amino acids should be characterized and determined before using it in biosensing methods and devices. In this study, the reaction of tyrosine amino acid (Tyr with GO was characterized using FT-IR, UV-vis spectrophotometry, and scanning electron microscopy (SEM before its use. The optimum conditions for GO’s interaction with Tyr amino acid have been studied under variable conditions. The optimum conditions of pH, temperature, shaking time, and GO and tyrosine concentrations for the uptaking of tyrosine amino acid onto the GO’s surface from aqueous solution were determined. The SEM analysis showed that the GO supplied was in a particle size range between 5.4 and 8.1 nm. A pH of 8.4–9.4 at 25 °C and 5 min of shaking time were the optimum conditions for a maximum uptake of 1.4 μg/mL of tyrosine amino acid onto 0.2 mg/mL of GO.

  9. Constitutive Activity in an Ancestral Form of Abl Tyrosine Kinase.

    Directory of Open Access Journals (Sweden)

    Saadat U Aleem

    Full Text Available The c-abl proto-oncogene encodes a nonreceptor tyrosine kinase that is found in all metazoans, and is ubiquitously expressed in mammalian tissues. The Abl tyrosine kinase plays important roles in the regulation of mammalian cell physiology. Abl-like kinases have been identified in the genomes of unicellular choanoflagellates, the closest relatives to the Metazoa, and in related unicellular organisms. Here, we have carried out the first characterization of a premetazoan Abl kinase, MbAbl2, from the choanoflagellate Monosiga brevicollis. The enzyme possesses SH3, SH2, and kinase domains in a similar arrangement to its mammalian counterparts, and is an active tyrosine kinase. MbAbl2 lacks the N-terminal myristoylation and cap sequences that are critical regulators of mammalian Abl kinase activity, and we show that MbAbl2 is constitutively active. When expressed in mammalian cells, MbAbl2 strongly phosphorylates cellular proteins on tyrosine, and transforms cells much more potently than mammalian Abl kinase. Thus, MbAbl2 appears to lack the autoinhibitory mechanism that tightly constrains the activity of mammalian Abl kinases, suggesting that this regulatory apparatus arose more recently in metazoan evolution.

  10. Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase.

    Directory of Open Access Journals (Sweden)

    Małgorzata Cieńska

    Full Text Available Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA by immobilized tyrosinase in the presence of ascorbic acid (AH2, which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native to 30% (immobilized enzyme. To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme and 70% (immobilized. A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity.

  11. Alzheimer's disease pathological lesions activate the spleen tyrosine kinase.

    Science.gov (United States)

    Schweig, Jonas Elias; Yao, Hailan; Beaulieu-Abdelahad, David; Ait-Ghezala, Ghania; Mouzon, Benoit; Crawford, Fiona; Mullan, Michael; Paris, Daniel

    2017-09-06

    The pathology of Alzheimer's disease (AD) is characterized by dystrophic neurites (DNs) surrounding extracellular Aβ-plaques, microgliosis, astrogliosis, intraneuronal tau hyperphosphorylation and aggregation. We have previously shown that inhibition of the spleen tyrosine kinase (Syk) lowers Aβ production and tau hyperphosphorylation in vitro and in vivo. Here, we demonstrate that Aβ-overexpressing Tg PS1/APPsw, Tg APPsw mice, and tau overexpressing Tg Tau P301S mice exhibit a pathological activation of Syk compared to wild-type littermates. Syk activation is occurring in a subset of microglia and is age-dependently increased in Aβ-plaque-associated dystrophic neurites of Tg PS1/APPsw and Tg APPsw mice. In Tg Tau P301S mice, a pure model of tauopathy, activated Syk occurs in neurons that show an accumulation of misfolded and hyperphosphorylated tau in the cortex and hippocampus. Interestingly, the tau pathology is exacerbated in neurons that display high levels of Syk activation supporting a role of Syk in the formation of tau pathological species in vivo. Importantly, human AD brain sections show both pathological Syk activation in DNs around Aβ deposits and in neurons immunopositive for pathological tau species recapitulating the data obtained in transgenic mouse models of AD. Additionally, we show that Syk overexpression leads to increased tau accumulation and promotes tau hyperphosphorylation at multiple epitopes in human neuron-like SH-SY5Y cells, further supporting a role of Syk in the formation of tau pathogenic species. Collectively, our data show that Syk activation occurs following Aβ deposition and the formation of tau pathological species. Given that we have previously shown that Syk activation also promotes Aβ formation and tau hyperphosphorylation, our data suggest that AD pathological lesions may be self-propagating via a Syk dependent mechanism highlighting Syk as an attractive therapeutic target for the treatment of AD.

  12. Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase

    Science.gov (United States)

    Lewańczuk, Marcin; Koźlecki, Tomasz; Liesiene, Jolanta; Bryjak, Jolanta

    2016-01-01

    Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by immobilized tyrosinase in the presence of ascorbic acid (AH2), which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native) to 30% (immobilized enzyme). To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme) and 70% (immobilized). A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity. PMID:27711193

  13. Effective L-Tyrosine Hydroxylation by Native and Immobilized Tyrosinase.

    Science.gov (United States)

    Cieńska, Małgorzata; Labus, Karolina; Lewańczuk, Marcin; Koźlecki, Tomasz; Liesiene, Jolanta; Bryjak, Jolanta

    2016-01-01

    Hydroxylation of L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by immobilized tyrosinase in the presence of ascorbic acid (AH2), which reduces DOPA-quinone to L-DOPA, is characterized by low reaction yields that are mainly caused by the suicide inactivation of tyrosinase by L-DOPA and AH2. The main aim of this work was to compare processes with native and immobilized tyrosinase to identify the conditions that limit suicide inactivation and produce substrate conversions to L-DOPA of above 50% using HPLC analysis. It was shown that immobilized tyrosinase does not suffer from partitioning and diffusion effects, allowing a direct comparison of the reactions performed with both forms of the enzyme. In typical processes, additional aeration was applied and boron ions to produce the L-DOPA and AH2 complex and hydroxylamine to close the cycle of enzyme active center transformations. It was shown that the commonly used pH 9 buffer increased enzyme stability, with concomitant reduced reactivity of 76%, and that under these conditions, the maximal substrate conversion was approximately 25 (native) to 30% (immobilized enzyme). To increase reaction yield, the pH of the reaction mixture was reduced to 8 and 7, producing L-DOPA yields of approximately 95% (native enzyme) and 70% (immobilized). A three-fold increase in the bound enzyme load achieved 95% conversion in two successive runs, but in the third one, tyrosinase lost its activity due to strong suicide inactivation caused by L-DOPA processing. In this case, the cost of the immobilized enzyme preparation is not overcome by its reuse over time, and native tyrosinase may be more economically feasible for a single use in L-DOPA production. The practical importance of the obtained results is that highly efficient hydroxylation of monophenols by tyrosinase can be obtained by selecting the proper reaction pH and is a compromise between complexation and enzyme reactivity.

  14. It's not too late for the harpy eagle (Harpia harpyja: high levels of genetic diversity and differentiation can fuel conservation programs.

    Directory of Open Access Journals (Sweden)

    Heather R L Lerner

    2009-10-01

    Full Text Available The harpy eagle (Harpia harpyja is the largest Neotropical bird of prey and is threatened by human persecution and habitat loss and fragmentation. Current conservation strategies include local education, captive rearing and reintroduction, and protection or creation of trans-national habitat blocks and corridors. Baseline genetic data prior to reintroduction of captive-bred stock is essential for guiding such efforts but has not been gathered previously.We assessed levels of genetic diversity, population structure and demographic history for harpy eagles using samples collected throughout a large portion of their geographic distribution in Central America (n = 32 and South America (n = 31. Based on 417 bp of mitochondrial control region sequence data, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and South America, although haplotype diversity was significantly higher for South America. Historical restriction of gene flow across the Andes (i.e. between our Central and South American subgroups is supported by coalescent analyses, the haplotype network and significant F(ST values, however reciprocally monophyletic lineages do not correspond to geographical locations in maximum likelihood analyses. A sudden population expansion for South America is indicated by a mismatch distribution analysis, and further supported by significant (p<0.05 negative values of Fu and Li's D(F and F, and Fu's F(S. This expansion, estimated at approximately 60 000 years BP (99 000-36 000 years BP 95% CI, encompasses a transition from a warm and dry time period prior to 50 000 years BP to an interval of maximum precipitation (50 000-36 000 years BP. Notably, this time period precedes the climatic and habitat changes associated with the last glacial maximum. In contrast, a multimodal distribution of haplotypes was observed for Central America suggesting either population equilibrium or a recent decline.High levels of

  15. Non-native and native organisms moving into high elevation and high latitude ecosystems in an era of climate change: new challenges for ecology and conservation

    Science.gov (United States)

    Pauchard, Aníbal; Albihn, Ann; Alexander, Jake; Burgess, Treena; Daehler, Curt; Essl, Franz; Evengard, Birgitta; Greenwood, Greg; Haider, Sylvia; Lenoir, Jonathan; McDougall, K.; Milbau, Ann; Muths, Erin L.; Nunez, Martin; Pellissier, Lois; Rabitsch, Wolfgang; Rew, Lisa; Robertson, Mark; Sanders, Nathan; Kueffer, Christoph

    2016-01-01

    Cold environments at high elevation and high latitude are often viewed as resistant to biological invasions. However, climate warming, land use change and associated increased connectivity all increase the risk of biological invasions in these environments. Here we present a summary of the key discussions of the workshop ‘Biosecurity in Mountains and Northern Ecosystems: Current Status and Future Challenges’ (Flen, Sweden, 1–3 June 2015). The aims of the workshop were to (1) increase awareness about the growing importance of species expansion—both non-native and native—at high elevation and high latitude with climate change, (2) review existing knowledge about invasion risks in these areas, and (3) encourage more research on how species will move and interact in cold environments, the consequences for biodiversity, and animal and human health and wellbeing. The diversity of potential and actual invaders reported at the workshop and the likely interactions between them create major challenges for managers of cold environments. However, since these cold environments have experienced fewer invasions when compared with many warmer, more populated environments, prevention has a real chance of success, especially if it is coupled with prioritisation schemes for targeting invaders likely to have greatest impact. Communication and co-operation between cold environment regions will facilitate rapid response, and maximise the use of limited research and management resources.

  16. Making conservation work for everyone

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, J. [Veridian Corp., Ajax, ON (Canada)

    2004-07-01

    This presentation discussed the economic value of conservation, the optimal deployment of energy conservation. A sample load profile was presented to demonstrate how much electricity the average residential customer uses on a summer day. The average customer does not have the tools to understand the financial consequences of conservation for different types of equipment at different times of the day. Smart metering technology could help in this regard. Accurate unsubsidized prices are also considered to be the best incentive to conserve because customers will reduce electricity use when the prices are high. It was also suggested that standards for new appliances should be increased effectively to their economic value. The enablers to energy conservation include solid consumer education programs, real time metering in places where it is cost effective, real time pricing in places where it is practical, and power rates that reflect real costs. Barriers to energy conservation include the residual economic advantage that may be insufficient to justify investment; support from local distribution companies and transmission companies if the lost revenue adjustment mechanism (LRAM) is not sufficient to recover lost revenue and if LDCs are not sufficiently involved in the design of the electricity conservation program. 7 figs.

  17. IAA-Ala Resistant3, an evolutionarily conserved target of miR167, mediates Arabidopsis root architecture changes during high osmotic stress

    KAUST Repository

    Kinoshita, Natsuko

    2012-09-01

    The functions of microRNAs and their target mRNAs in Arabidopsis thaliana development have been widely documented; however, roles of stress-responsive microRNAs and their targets are not as well understood. Using small RNA deep sequencing and ATH1 microarrays to profile mRNAs, we identified IAA-Ala Resistant3 (IAR3) as a new target of miR167a. As expected, IAR3 mRNA was cleaved at the miR167a complementary site and under high osmotic stress miR167a levels decreased, whereas IAR3 mRNA levels increased. IAR3 hydrolyzes an inactive form of auxin (indole-3-acetic acid [IAA]-alanine) and releases bioactive auxin (IAA), a central phytohormone for root development. In contrast with the wild type, iar3 mutants accumulated reduced IAA levels and did not display high osmotic stress-induced root architecture changes. Transgenic plants expressing a cleavage-resistant form of IAR3 mRNA accumulated high levels of IAR3 mRNAs and showed increased lateral root development compared with transgenic plants expressing wild-type IAR3. Expression of an inducible noncoding RNA to sequester miR167a by target mimicry led to an increase in IAR3 mRNA levels, further confirming the inverse relationship between the two partners. Sequence comparison revealed the miR167 target site on IAR3 mRNA is conserved in evolutionarily distant plant species. Finally, we showed that IAR3 is required for drought tolerance. © 2012 American Society of Plant Biologists. All rights reserved.

  18. IAA-Ala Resistant3, an evolutionarily conserved target of miR167, mediates Arabidopsis root architecture changes during high osmotic stress

    KAUST Repository

    Kinoshita, Natsuko; Wang, Huan; Kasahara, Hiroyuki; Liu, Jun; MacPherson, Cameron R.; Machida, Yasunori; Kamiya, Yuji; Hannah, Matthew A.; Chuaa, Nam Hai

    2012-01-01

    The functions of microRNAs and their target mRNAs in Arabidopsis thaliana development have been widely documented; however, roles of stress-responsive microRNAs and their targets are not as well understood. Using small RNA deep sequencing and ATH1 microarrays to profile mRNAs, we identified IAA-Ala Resistant3 (IAR3) as a new target of miR167a. As expected, IAR3 mRNA was cleaved at the miR167a complementary site and under high osmotic stress miR167a levels decreased, whereas IAR3 mRNA levels increased. IAR3 hydrolyzes an inactive form of auxin (indole-3-acetic acid [IAA]-alanine) and releases bioactive auxin (IAA), a central phytohormone for root development. In contrast with the wild type, iar3 mutants accumulated reduced IAA levels and did not display high osmotic stress-induced root architecture changes. Transgenic plants expressing a cleavage-resistant form of IAR3 mRNA accumulated high levels of IAR3 mRNAs and showed increased lateral root development compared with transgenic plants expressing wild-type IAR3. Expression of an inducible noncoding RNA to sequester miR167a by target mimicry led to an increase in IAR3 mRNA levels, further confirming the inverse relationship between the two partners. Sequence comparison revealed the miR167 target site on IAR3 mRNA is conserved in evolutionarily distant plant species. Finally, we showed that IAR3 is required for drought tolerance. © 2012 American Society of Plant Biologists. All rights reserved.

  19. Mistaken identity: activating conservative political identities induces "conservative" financial decisions.

    Science.gov (United States)

    Morris, Michael W; Carranza, Erica; Fox, Craig R

    2008-11-01

    Four studies investigated whether activating a social identity can lead group members to choose options that are labeled in words associated with that identity. When political identities were made salient, Republicans (but not Democrats) became more likely to choose the gamble or investment option labeled "conservative." This shift did not occur in a condition in which the same options were unlabeled. Thus, the mechanism underlying the effect appears to be not activated identity-related values prioritizing low risk, but rather activated identity-related language (the group label "conservative"). Indeed, when political identities were salient, Republicans favored options labeled "conservative" regardless of whether the options were low or high risk. Finally, requiring participants to explain the label "conservative" before making their choice did not diminish the effect, which suggests that it does not merely reflect inattention to content or construct accessibility. We discuss the implications of these results for the literatures on identity, priming, choice, politics, and marketing.

  20. Sequence of cDNAs for mammalian H2A. Z, an evolutionarily diverged but highly conserved basal histone H2A isoprotein species

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, C L; Bonner, W M

    1988-02-11

    The nucleotide sequences of cDNAs for the evolutionarily diverged but highly conserved basal H2A isoprotein, H2A.Z, have been determined for the rat, cow, and human. As a basal histone, H2A.Z is synthesized throughout the cell cycle at a constant rate, unlinked to DNA replication, and at a much lower rate in quiescent cells. Each of the cDNA isolates encodes the entire H2A.Z polypeptide. The human isolate is about 1.0 kilobases long. It contains a coding region of 387 nucleotides flanked by 106 nucleotides of 5'UTR and 376 nucleotides of 3'UTR, which contains a polyadenylation signal followed by a poly A tail. The bovine and rat cDNAs have 97 and 94% nucleotide positional identity to the human cDNA in the coding region and 98% in the proximal 376 nucleotides of the 3'UTR which includes the polyadenylation signal. A potential stem-forming sequence imbedded in a direct repeat is found centered at 261 nucleotides into the 3'UTR. Each of the cDNA clones could be transcribed and translated in vitro to yield H2A.Z protein. The mammalian H2A.Z cDNA coding sequences are approximately 80% similar to those in chicken and 75% to those in sea urchin.

  1. Particle-number conserving analysis for the 2-quasiparticle and high-K multi-quasiparticle states in doubly-odd 174,176Lu

    International Nuclear Information System (INIS)

    Li Bingheng; Lei Yi'an; Zhang Zhenhua

    2013-01-01

    Two-quasiparticle bands and low-lying excited high-K four-, six-, and eight-quasiparticle bands in the doubly-odd 174,176 Lu are analyzed by using the cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method, in which the blocking effects are taken into account exactly. The proton and neutron Nilsson level schemes for 174,176 Lu are taken from the adjacent odd-A Lu and Hf isotopes, which are adopted to reproduce the experimental bandhead energies of the one-quasiproton and one-quasineutron bands of these odd-A Lu and Hf nuclei, respectively. Once the quasiparticle configurations are determined, the experimental bandhead energies and the moments of inertia of these two- and multi-quasiparticle bands are well reproduced by PNC-CSM calculations. The Coriolis mixing of the low-K (K=|Ω 1 -Ω 2 |) two-quasiparticle band of the Gallagher-Moszkowski doublet with one nucleon in the Ω=1/2 orbital is analyzed. (authors)

  2. NOA36 Protein Contains a Highly Conserved Nucleolar Localization Signal Capable of Directing Functional Proteins to the Nucleolus, in Mammalian Cells

    Science.gov (United States)

    de Melo, Ivan S.; Jimenez-Nuñez, Maria D.; Iglesias, Concepción; Campos-Caro, Antonio; Moreno-Sanchez, David; Ruiz, Felix A.; Bolívar, Jorge

    2013-01-01

    NOA36/ZNF330 is an evolutionarily well-preserved protein present in the nucleolus and mitochondria of mammalian cells. We have previously reported that the pro-apoptotic activity of this protein is mediated by a characteristic cysteine-rich domain. We now demonstrate that the nucleolar localization of NOA36 is due to a highly-conserved nucleolar localization signal (NoLS) present in residues 1–33. This NoLS is a sequence containing three clusters of two or three basic amino acids. We fused the amino terminal of NOA36 to eGFP in order to characterize this putative NoLS. We show that a cluster of three lysine residues at positions 3 to 5 within this sequence is critical for the nucleolar localization. We also demonstrate that the sequence as found in human is capable of directing eGFP to the nucleolus in several mammal, fish and insect cells. Moreover, this NoLS is capable of specifically directing the cytosolic yeast enzyme polyphosphatase to the target of the nucleolus of HeLa cells, wherein its enzymatic activity was detected. This NoLS could therefore serve as a very useful tool as a nucleolar marker and for directing particular proteins to the nucleolus in distant animal species. PMID:23516598

  3. Conservation potential of agricultural water conservation subsidies

    Science.gov (United States)

    Huffaker, Ray

    2008-07-01

    A current policy subsidizes farmers to invest in improved on-farm irrigation efficiency, expecting water to be conserved off farm. Contrary to expectation, water has been increasingly depleted in some regions after such improvements. This paper investigates the policy's failure to conserve water consistently by (1) formulating an economic model of irrigated crop production to determine a profit-maximizing irrigator's range of responses to a subsidy and (2) embedding these responses into hypothetical streamflow diagrams to ascertain their potential to conserve water under various hydrologic regimes. Testable hypotheses are developed to predict the conservation potential of a subsidy in real-world application.

  4. Method of localization and implantation of the lumpectomy site for high dose rate brachytherapy after conservative surgery for T1 and T2 breast cancer

    International Nuclear Information System (INIS)

    Perera, F.; Chisela, F.; Engel, J.; Venkatesan, V.

    1995-01-01

    Purpose: This article describes our technique of localization and implantation of the lumpectomy site of patients with T1 and T2 breast cancer. Our method was developed as part of our Phase I/II pilot study of high dose rate (HDR) brachytherapy alone after conservative surgery for early breast cancer. Methods and Materials: In March 1992, we started a pilot study of HDR brachytherapy to the lumpectomy site as the sole radiotherapy after conservative surgery for clinical T1 or T2 invasive breast cancer. Initially, the protocol required intraoperative placement of the interstitial needles at the time of definitive surgery to the breast. The protocol was then generalized to allow the implantation of the lumpectomy site after definitive surgery to the breast, either at the time of subsequent axillary nodal dissection or postoperatively. To date, five patients have been implanted intraoperatively at the time of definitive breast surgery. Twelve patients were implanted after definitive breast surgery, with 7 patients being done at the time of axillary nodal dissection and 5 patients postoperatively. We devised a method of accurately localizing and implanting the lumpectomy site after definitive breast surgery. The method relies on the previous placement of surgical clips by the referring surgeon to mark the lumpectomy site. For each patient, a breast mold is made with radio-opaque angiocatheters taped onto the mold in the supero-inferior direction. A planning CT scan is then obtained through the lumpectomy site. The volume of the lumpectomy site, the number of implant planes necessary, and the orientation of the implants are then determined from the CT scan. The angiocatheters provide a reference grid on the CT films to locate the entry and exit points of the interstitial needles on the plastic mold. The entry and exit points for reference needles are then transferred onto the patient's skin enabling implantation of the lumpectomy site. Needle positions with respect to

  5. Towards the conception of an amperometric sensor of L-tyrosine based on Hemin/PAMAM/MWCNT modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Ma Qiang; Ai Shiyun; Yin Huanshun; Chen Quanpeng; Tang Tiantian

    2010-01-01

    A novel amperometric sensor was fabricated based on the immobilization of hemin onto the poly (amidoamine)/multi-walled carbon nanotube (PAMAM/MWCNT) nanocomposite film modified glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and ultraviolet visible (UV-vis) adsorption spectroscopy were used to investigate the possible state and electrochemical activity of the immobilized hemin. In the Hemin/PAMAM/MWCNT nanocomposite film, MWCNT layer possessed excellent inherent conductivity to enhance the electron transfer rate, while the layer of PAMAM greatly enlarged the surface average concentration of hemin (Γ) on the modified electrode. Therefore, the nanocomposite film showed enhanced electrocatalytical activity towards the oxidation of L-tyrosine. The kinetic parameters of the modified electrode were investigated. In pH 7.0 phosphate buffer solution (PBS), the sensor exhibits a wide linear range from 0.1 μM to 28.8 μM L-tyrosine with a detection limit of 0.01 μM and a high sensitivity of 0.31 μA μM -1 cm -2 . In addition, the response time of the L-tyrosine sensor is less than 5 s. The excellent performance of the sensor is largely attributed to the electro-generated high reactive oxoiron (IV) porphyrin (O = Fe IV -P) which effectively catalyzed the oxidation of L-tyrosine. A mechanism was herein proposed for the catalytic oxidation of L-tyrosine by oxoiron (IV) porphyrin complexes.

  6. Downsizing Treatment with Tyrosine Kinase Inhibitors in Patients with Advanced Gastrointestinal Stromal Tumors Improved Resectability

    Science.gov (United States)

    Sjölund, Katarina; Andersson, Anna; Nilsson, Erik; Nilsson, Ola; Ahlman, Håkan

    2010-01-01

    Background Gastrointestinal stromal tumors (GISTs) express the receptor tyrosine kinase KIT. Most GISTs have mutations in the KIT or PDGFRA gene, causing activation of tyrosine kinase. Imatinib, a tyrosine kinase inhibitor (TKI), is the first-line palliative treatment for advanced GISTs. Sunitinib was introduced for patients with mutations not responsive to imatinib. The aim was to compare the survival of patients with high-risk resected GISTs treated with TKI prior to surgery with historical controls and to determine if organ-preserving surgery was facilitated. Methods Ten high-risk GIST-patients had downsizing/adjuvant TKI treatment: nine with imatinib and one with sunitinib. The patients were matched with historical controls (n = 89) treated with surgery alone, from our population-based series (n = 259). Mutational analysis of KIT and PDGFRA was performed in all cases. The progression-free survival was calculated. Results The primary tumors decreased in mean diameter from 20.4 cm to 10.5 cm on downsizing imatinib. Four patients with R0 resection and a period of adjuvant imatinib had no recurrences versus 67% in the historical control group. Four patients with residual liver metastases have stable disease on continuous imatinib treatment after surgery. One patient has undergone reoperation with liver resection. The downsizing treatment led to organ-preserving surgery in nine patients and improved preoperative nutritional status in one patient. Conclusions Downsizing TKI is recommended for patients with bulky tumors with invasion of adjacent organs. Sunitinib can be used for patients in case of imatinib resistance (e.g., wild-type GISTs), underlining the importance of mutational analysis for optimal surgical planning. PMID:20512492

  7. Angiogenic competency of biodegradable hydrogels fabricated from polyethylene glycol-crosslinked tyrosine-derived polycarbonates

    Directory of Open Access Journals (Sweden)

    HJ Sung

    2008-04-01

    Full Text Available Synthetic biomaterials can be used as instructive biological milieus to guide cellular behaviour and function. To further realize this application, we synthesized a series of structurally similar hydrogels and tested their ability to modulate angiogenesis. Hydrogels were synthesized from poly(DTE-co-x% DT carbonate crosslinked by y% poly(ethylene glycol (PEG. Hydrogel desaminotyrosyl tyrosine (DT contents (x% ranged from 10-100%, and crosslink densities (y% PEG-crosslinker ranged from 5-80%. The hydrogels were fashioned into porous scaffolds with highly interconnected macro- and micro-pore (>100 and <10 mm in diameter, respectively architecture using poly(DTE-co-10%DT carbonate crosslinked with 8% PEG. Under physiological conditions (in vitro, the hydrogels degraded into three major products: desaminotyrosyl-tyrosine ethyl ester (DTE, desaminotyrosyl tyrosine (DT, and poly(ethylene glycol-di-DT-hydrazide (PEG-di-DT hydrazide. Increasing either DT content or crosslink density brought quickened degradation. Because DT and DTE, two of the three major degradation products, have not demonstrated any noticeable cytotoxicity or angiogenic effect in previous studies, we measured the cytotoxicity of PEG-di-DT hydrazide, the third major degradation product. We found that PEG-di-DT hydrazide only displayed significant cytotoxicity at the high concentration of 100 mg/mL. Interestingly, PEG-di-DT hydrazide and its further degradation product PEG-dihydrazide stimulated in vitro endothelial cell migration and tubulogenesis, which is comparable to results found with FGF-beta treatment. Subcutaneous implantation of the PEG-crosslinked poly(DTE-co-10%DT carbonate scaffolds into the backs of rats elicited greater tissue growth over time and superior vascularization than poly(DTE carbonate implantation. These results show that this new class of biomaterials has a strong potential to modulate angiogenesis.

  8. Site specific interaction between ZnO nanoparticles and tyrosine: A density functional theory study

    Science.gov (United States)

    Singh, Satvinder; Singh, Janpreet; Singh, Baljinder; Singh, Gurinder; Kaura, Aman; Tripathi, S. K.

    2018-05-01

    First Principles Calculations have been performed on ZnO/Tyrosine atomic complex to study site specific interaction of Tyrosine and ZnO nanoparticles. Calculated results shows that -COOH group present in Tyrosine is energetically more favorable than -NH2 group. Interactions show ionic bonding between ZnO and Tyrosine. All the calculations have been performed under the Density Functional Theory (DFT) framework. Structural and electronic properties of (ZnO)3/Tyrosine complex have been studied. Gaussian basis set approach has been adopted for the calculations. A ring type most stable (ZnO)3 atomic cluster has been modeled, analyzed and used for the calculations.

  9. Ibrutinib Inhibits ERBB Receptor Tyrosine Kinases and HER2-Amplified Breast Cancer Cell Growth.

    Science.gov (United States)

    Chen, Jun; Kinoshita, Taisei; Sukbuntherng, Juthamas; Chang, Betty Y; Elias, Laurence

    2016-12-01

    Ibrutinib is a potent, small-molecule Bruton tyrosine kinase (BTK) inhibitor developed for the treatment of B-cell malignancies. Ibrutinib covalently binds to Cys481 in the ATP-binding domain of BTK. This cysteine residue is conserved among 9 other tyrosine kinases, including HER2 and EGFR, which can be targeted. Screening large panels of cell lines demonstrated that ibrutinib was growth inhibitory against some solid tumor cells, including those inhibited by other HER2/EGFR inhibitors. Among sensitive cell lines, breast cancer lines with HER2 overexpression were most potently inhibited by ibrutinib (ibrutinib coincided with downregulation of phosphorylation on HER2 and EGFR and their downstream targets, AKT and ERK. Irreversible inhibition of HER2 and EGFR in breast cancer cells was established after 30-minute incubation above 100 nmol/L or following 2-hour incubation at lower concentrations. Furthermore, ibrutinib inhibited recombinant HER2 and EGFR activity that was resistant to dialysis and rapid dilution, suggesting an irreversible interaction. The dual activity toward TEC family (BTK and ITK) and ERBB family kinases was unique to ibrutinib, as ERBB inhibitors do not inhibit or covalently bind BTK or ITK. Xenograft studies with HER2 + MDA-MB-453 and BT-474 cells in mice in conjunction with determination of pharmacokinetics demonstrated significant exposure-dependent inhibition of growth and key signaling molecules at levels that are clinically achievable. Ibrutinib's unique dual spectrum of activity against both TEC family and ERBB kinases suggests broader applications of ibrutinib in oncology. Mol Cancer Ther; 15(12); 2835-44. ©2016 AACR. ©2016 American Association for Cancer Research.

  10. Conservation and genetic characterisation of common bean landraces from Cilento region (southern Italy): high differentiation in spite of low genetic diversity.

    Science.gov (United States)

    De Luca, Daniele; Cennamo, Paola; Del Guacchio, Emanuele; Di Novella, Riccardo; Caputo, Paolo

    2018-02-01

    Since its introduction from Central-South America to Italy almost 500 years ago, the common bean (Phaseolus vulgaris L.) was largely cultivated across the peninsula in hundreds of different landraces. However, globalisation and technological modernisation of agricultural practices in the last decades promoted the cultivation of few varieties at the expense of traditional and local agro-ecotypes, which have been confined to local markets or have completely disappeared. The aim of this study was to evaluate the genetic diversity and differentiation in 12 common bean landraces once largely cultivated in the Cilento region (Campania region, southern Italy), and now the object of a recovery program to save them from extinction. The analysis conducted using 13 nuclear microsatellite loci in 140 individuals revealed a high degree of homozygosity within each landrace and a strong genetic differentiation that was reflected in the success in assigning individuals to the source landrace. On the contrary, internal transcribed spacers 1 and 2, analysed in one individual per landrace, were highly similar among common bean landraces but allowed the identification of a cowpea variety (Vigna unguiculata Walp.), a crop largely cultivated in the Old World before the arrival of common bean from Americas. In conclusion, our study highlighted that conservation of landraces is important not only for the cultural and socio-economic value that they have for local communities, but also because the time and conditions in which they have been selected have led to that genetic distinctiveness that is at the basis of many potential agronomical applications and dietary benefits.

  11. The albinism of the feral Asinara white donkeys (Equus asinus) is determined by a missense mutation in a highly conserved position of the tyrosinase (TYR) gene deduced protein.

    Science.gov (United States)

    Utzeri, V J; Bertolini, F; Ribani, A; Schiavo, G; Dall'Olio, S; Fontanesi, L

    2016-02-01

    A feral donkey population (Equus asinus), living in the Asinara National Park (an island north-west of Sardinia, Italy), includes a unique white albino donkey subpopulation or colour morph that is a major attraction of this park. Disrupting mutations in the tyrosinase (TYR) gene are known to cause recessive albinisms in humans (oculocutaneous albinism Type 1; OCA1) and other species. In this study, we analysed the donkey TYR gene as a strong candidate to identify the causative mutation of the albinism of these donkeys. The TYR gene was sequenced from 13 donkeys (seven Asinara white albino and six coloured animals). Seven single nucleotide polymorphisms were identified. A missense mutation (c.604C>G; p.His202Asp) in a highly conserved amino acid position (even across kingdoms), which disrupts the first copper-binding site (CuA) of functional protein, was identified in the homozygous condition (G/G or D/D) in all Asinara white albino donkeys and in the albino son of a trio (the grey parents had genotype C/G or H/D), supporting the recessive mode of inheritance of this mutation. Genotyping 82 donkeys confirmed that Asinara albino donkeys had genotype G/G whereas all other coloured donkeys had genotype C/C or C/G. Across-population association between the c.604C>G genotypes and the albino coat colour was highly significant (P = 6.17E-18). The identification of the causative mutation of the albinism in the Asinara white donkeys might open new perspectives to study the dynamics of this putative deleterious allele in a feral population and to manage this interesting animal genetic resource. © 2015 Stichting International Foundation for Animal Genetics.

  12. Tyrosine transport in winter flounder intestine: Interaction with Na+-K+-2Cl- cotransport

    International Nuclear Information System (INIS)

    Musch, M.W.; McConnell, F.M.; Goldstein, L.; Field, M.

    1987-01-01

    Tyrosine absorption across the brush border of the intestinal epithelium of the winter flounder Pseudopleuronectes americanus was studied in Ussing chambers modified to determine early rates of uptake. At 0.1 mM tyrosine, the 4-min rate of uptake (influx) of tyrosine across the brush border averaged 37.5 nmol·cm -2 ·h -1 . Omission of Na decreased influx by 60%, indicting that tyrosine influx occurs, at least in part, by a Na-coupled process. Ouabain inhibited influx by 80%. Inhibition of brush border Na + -K + -2Cl - cotransport by bumetanide, 8-bromo-cyclic GMP, or Cl replacement stimulated tyrosine influx 2.5- to 4-fold. However, atriopeptin III, which also inhibits Na + -K + -2Cl - cotransport, did not stimulate tyrosine influx. Cyclic AMP, which does not appear to inhibit ion cotransport, did not stimulate tyrosine influx. Both cyclic GMP and bumetanide also stimulated the net mucosa-to-serosa tyrosine flux (43 and 29%, respectively) and increased the cellular concentration of tyrosine by 50%. Thus tyrosine's influx is increased to a greater extent than is its transmural flux or its cellular concentration, suggesting that the main change occurs at the brush border and represents large increases in both influx and efflux of tyrosine across this membrane

  13. Autophosphorylation of JAK2 on tyrosines 221 and 570 regulates its activity.

    Science.gov (United States)

    Argetsinger, Lawrence S; Kouadio, Jean-Louis K; Steen, Hanno; Stensballe, Allan; Jensen, Ole N; Carter-Su, Christin

    2004-06-01

    The tyrosine kinase JAK2 is a key signaling protein for at least 20 receptors in the cytokine/hematopoietin receptor superfamily and is a component of signaling by insulin receptor and several G-protein-coupled receptors. However, there is only limited knowledge of the physical structure of JAK2 or which of the 49 tyrosines in JAK2 are autophosphorylated. In this study, mass spectrometry and two-dimensional peptide mapping were used to determine that tyrosines 221, 570, and 1007 in JAK2 are autophosphorylated. Phosphorylation of tyrosine 570 is particularly robust. In response to growth hormone, JAK2 was rapidly and transiently phosphorylated at tyrosines 221 and 570, returning to basal levels by 60 min. Analysis of the sequences surrounding tyrosines 221 and 570 in JAK2 and tyrosines in other proteins that are phosphorylated in response to ligands that activate JAK2 suggests that the YXX[L/I/V] motif is one of the motifs recognized by JAK2. Experiments using JAK2 with tyrosines 221 and 570 mutated to phenylalanine suggest that tyrosines 221 and 570 in JAK2 may serve as regulatory sites in JAK2, with phosphorylation of tyrosine 221 increasing kinase activity and phosphorylation of tyrosine 570 decreasing kinase activity and thereby contributing to rapid termination of ligand activation of JAK2.

  14. The role of GH receptor tyrosine phosphorylation in Stat5 activation

    DEFF Research Database (Denmark)

    Hansen, J A; Hansen, L H; Wang, X

    1997-01-01

    Stimulation of GH receptors leads to rapid activation of Jak2 kinase and subsequent tyrosine phosphorylation of the GH receptor. Three specific tyrosines located in the C-terminal domain of the GH receptor have been identified as being involved in GH-stimulated transcription of the Spi 2.1 promoter....... Mutated GH receptors lacking all but one of these three tyrosines are able to mediate a transcriptional response when transiently transfected into CHO cells together with a Spi 2.1 promoter/luciferase construct. Similarly, these GH receptors were found to be able to mediate activation of Stat5 DNA......-binding activity, whereas the GH receptor mutant lacking all intracellular tyrosines was not. Synthetic tyrosine phosphorylated peptides corresponding to the GH receptor sequence around the three tyrosines inhibited Stat5 DNA-binding activity while their non-phosphorylated counterparts were ineffective. Tyrosine...

  15. Project CHOICE: #26. A Career Education Unit for Junior High School. Careers in Conservation of the Environment and Natural Resources. (Agriculture and Ecological Studies Cluster; Science and Engineering Occupations Cluster).

    Science.gov (United States)

    Kern County Superintendent of Schools, Bakersfield, CA.

    This junior high teaching unit on careers in conservation of the environment and natural resources is one in a series of career guidebooks developed by Project CHOICE (Children Have Options in Career Education) to provide the classroom teacher with a source of career-related activities linking classroom experiences with the world of work. The unit…

  16. The immunoglobulin-like domains 1 and 2 of the protein tyrosine phosphatase LAR adopt an unusual horseshoe-like conformation

    Science.gov (United States)

    Biersmith, Bridget H.; Hammel, Michal; Geisbrecht, Erika R.; Bouyain, Samuel

    2011-01-01

    Neurogenesis depends on exquisitely regulated interactions between macromolecules on the cell surface and in the extracellular matrix. In particular, interactions between proteoglycans and members of the type IIa subgroup of receptor protein tyrosine phosphatases underlie critical developmental processes such as the formation of synapses at the neuromuscular junction and the migration of axons to their appropriate targets. We report here the crystal structures of the first and second immunoglobulin-like domains of the Drosophila type IIa receptor Dlar and its mouse homologue LAR. These two domains adopt an unusual antiparallel arrangement that has not been previously observed in tandem repeats of immunoglobulin-like domains and that is presumably conserved in all type IIa receptor protein tyrosine phosphatases. PMID:21402080

  17. Identification and optimization of tyrosine hydroxylase activity in Mucuna pruriens DC. var. utilis.

    Science.gov (United States)

    Luthra, Pratibha Mehta; Singh, Satendra

    2010-05-01

    Tyrosine hydroxylase, an iron containing tetrahydrobiopterin dependent monooxygenase (tyrosine 3-monooxygenase; EC 1.14.16.2), catalyzes the rate-limiting step in which L: -dopa is formed from the substrate L-tyrosine. L-Dopa concentration and activity of L-tyrosine hydroxylase enzyme were measured in roots, stem, leaves, pods, and immature seeds of Mucuna pruriens. Immature seeds contained maximum L-dopa content and mature leaves possessed maximum catalytic activity of tyrosine hydroxylase. Tyrosine hydroxylase from leaf homogenate was characterized as a 55 kDa protein by SDS-PAGE and Western-blot analysis with monoclonal mouse IgG2a tyrosine hydroxylase antibody. The conditions for maximum tyrosine hydroxylase activity from the leaf extract were optimized with respect to temperature, pH, cofactor 6-MPH(4), and divalent metal ions. The tyrosine hydroxylase from leaf extract possessed a K (m) value of 808.63 microM for L-tyrosine at 37 degrees C and pH 6.0. The activity of the enzyme was slightly inhibited at 2,000 microM L-tyrosine. Higher concentrations of the cofactor 6-MPH(4), however, completely inhibited the synthesis of L-dopa. Tyrosine hydroxylase converted specific monophenols such as L-tyrosine (808.63 microM) and tyramine (K (m) 1.1 mM) to diphenols L-dopa and dopamine, respectively. Fe(II) activated the enzyme while higher concentration of other divalent metals reduced its activity. For the first time, tyrosine hydroxylase from M. pruriens is being reported in this study.

  18. SERS study of transformation of phenylalanine to tyrosine under particle irradiation

    Science.gov (United States)

    Zhang, Jingjing; Huang, Qing; Yao, Guohua; Ke, Zhigang; Zhang, Hong; Lu, Yilin

    2014-08-01

    Surface enhanced Raman scattering or spectroscopy (SERS) is a very powerful analytical tool which has been widely applied in many scientific research and application fields. It is therefore also very intriguing for us to introduce SERS technique in the radiobiological research, where in many cases only a very few of biomolecules are subjected to changes which however can lead to significant biological effects. The radiation induced biochemical reactions are normally very sophisticated with different substances produced in the system, so currently it is still a big challenge for SERS to analyze such a mixture system which contains multiple analytes. In this context, this work aimed to establish and consolidate the feasibility of SERS as an effective tool in radiation chemistry, and this purpose, we employed SERS as a sensitive probe to a known process, namely, the oxidation of phenylalanine (Phe) under particle irradiation, where the energetic particles were obtained from either plasma discharge or electron-beam. During the irradiation, three types of tyrosine (Tyr), namely, p-Tyr, m-Tyr and o-Tyr were produced, and all these tyrosine isomers together with Phe could be identified and measured based on the SERS spectral analysis of the corresponding enhanced characteristic signals, namely, 1002 cm-1 for Phe, 1161 cm-1 for p-Tyr, 990 cm-1 for m-Tyr, and 970 cm-1 for o-Tyr, respectively. The estimation of the quantities of different tyrosine isomers were also given and verified by conventional method such as high performance liquid chromatography (HPLC). As for comparison of different ways of particle irradiation, our results also indicated that electron-beam irradiation was more efficient for converting Phe into Tyr than plasma discharge treatment, confirming the role of hydroxyl radicals in the Phe-Tyr conformation. Therefore, our work has not only demonstrated that SERS can be successfully applied in the radiobiological study, but also given insights into the

  19. Tyrosine sulfation of the amino terminus of PSGL-1 is critical for enterovirus 71 infection.

    Directory of Open Access Journals (Sweden)

    Yorihiro Nishimura

    Full Text Available Enterovirus 71 (EV71 is one of the major causative agents of hand, foot, and mouth disease, a common febrile disease in children; however, EV71 has been also associated with various neurological diseases including fatal cases in large EV71 outbreaks particularly in the Asia Pacific region. Recently we identified human P-selectin glycoprotein ligand-1 (PSGL-1 as a cellular receptor for entry and replication of EV71 in leukocytes. PSGL-1 is a sialomucin expressed on the surface of leukocytes, serves as a high affinity counterreceptor for selectins, and mediates leukocyte rolling on the endothelium. The PSGL-1-P-selectin interaction requires sulfation of at least one of three clustered tyrosines and an adjacent O-glycan expressing sialyl Lewis x in an N-terminal region of PSGL-1. To elucidate the molecular basis of the PSGL-1-EV71 interaction, we generated a series of PSGL-1 mutants and identified the post-translational modifications that are critical for binding of PSGL-1 to EV71. We expressed the PSGL-1 mutants in 293T cells and the transfected cells were assayed for their abilities to bind to EV71 by flow cytometry. We found that O-glycosylation on T57, which is critical for PSGL-1-selectin interaction, is not necessary for PSGL-1 binding to EV71. On the other hand, site-directed mutagenesis at one or more potential tyrosine sulfation sites in the N-terminal region of PSGL-1 significantly impaired PSGL-1 binding to EV71. Furthermore, an inhibitor of sulfation, sodium chlorate, blocked the PSGL-1-EV71 interaction and inhibited PSGL-1-mediated viral replication of EV71 in Jurkat T cells in a dose-dependent manner. Thus, the results presented in this study reveal that tyrosine sulfation, but not O-glycosylation, in the N-terminal region of PSGL-1 may facilitate virus entry and replication of EV71 in leukocytes.

  20. Molecular mechanism of ERK dephosphorylation by striatal-enriched protein tyrosine phosphatase (STEP)

    Science.gov (United States)

    Li, Hui; Li, Kang-shuai; Su, Jing; Chen, Lai-Zhong; Xu, Yun-Fei; Wang, Hong-Mei; Gong, Zheng; Cui, Guo-Ying; Yu, Xiao; Wang, Kai; Yao, Wei; Xin, Tao; Li, Min-Yong; Xiao, Kun-Hong; An, Xiao-fei; Huo, Yuqing; Xu, Zhi-gang; Sun, Jin-Peng; Pang, Qi

    2013-01-01

    Striatal-enriched tyrosine phosphatase (STEP) is an important regulator of neuronal synaptic plasticity, and its abnormal level or activity contributes to cognitive disorders. One crucial downstream effector and direct substrate of STEP is extracellular signal-regulated protein kinase (ERK), which has important functions in spine stabilisation and action potential transmission. The inhibition of STEP activity toward phospho-ERK has the potential to treat neuronal diseases, but the detailed mechanism underlying the dephosphorylation of phospho-ERK by STEP is not known. Therefore, we examined STEP activity toward pNPP, phospho-tyrosine-containing peptides, and the full-length phospho-ERK protein using STEP mutants with different structural features. STEP was found to be a highly efficient ERK tyrosine phosphatase that required both its N-terminal regulatory region and key residues in its active site. Specifically, both KIM and KIS of STEP were required for ERK interaction. In addition to the N-terminal KIS region, S245, hydrophobic residues L249/L251, and basic residues R242/R243 located in the KIM region were important in controlling STEP activity toward phospho-ERK. Further kinetic experiments revealed subtle structural differences between STEP and HePTP that affected the interactions of their KIMs with ERK. Moreover, STEP recognised specific positions of a phospho-ERK peptide sequence through its active site, and the contact of STEP F311 with phospho-ERK V205 and T207 were crucial interactions. Taken together, our results not only provide the information for interactions between ERK and STEP, but will also help in the development of specific strategies to target STEP-ERK recognition, which could serve as a potential therapy for neurological disorders. PMID:24117863

  1. Soluble TAM receptor tyrosine kinases in rheumatoid arthritis: correlation with disease activity and bone destruction.

    Science.gov (United States)

    Xu, L; Hu, F; Zhu, H; Liu, X; Shi, L; Li, Y; Zhong, H; Su, Y

    2018-04-01

    The TAM receptor tyrosine kinases (TAM RTK) are a subfamily of receptor tyrosine kinases, the role of which in autoimmune diseases such as systemic lupus erythematosus has been well explored, while their functions in rheumatoid arthritis (RA) remain largely unknown. In this study, we investigated the role of soluble TAM receptor tyrosine kinases (sAxl/sMer/sTyro3) in patients with RA. A total of 306 RA patients, 100 osteoarthritis (OA) patients and 120 healthy controls (HCs) were enrolled into this study. The serum concentrations of sAxl/sMer/sTyro3 were measured by enzyme-linked immunosorbent assay (ELISA), then the associations between sAxl/sMer/sTyro3 levels and clinical features of RA patients were analysed. We also investigated whether sTyro3 could promote osteoclast differentiation in vitro in RA patients. The results showed that compared with healthy controls (HCs), sTyro3 levels in the serum of RA patients were elevated remarkably and sMer levels were decreased significantly, whereas there was no difference between HCs and RA patients on sAxl levels. The sTyro3 levels were correlated weakly but positively with white blood cells (WBC), immunoglobulin (Ig)M, rheumatoid factor (RF), swollen joint counts, tender joint counts, total sharp scores and joint erosion scores. Conversely, there were no significant correlations between sMer levels and the above indices. Moreover, RA patients with high disease activity also showed higher sTyro3 levels. In-vitro osteoclast differentiation assay showed further that tartrate-resistant acid phosphatase (TRAP) + osteoclasts were increased significantly in the presence of sTyro3. Collectively, our study indicated that serum sTyro3 levels were elevated in RA patients and correlated positively with disease activity and bone destruction, which may serve as an important participant in RA pathogenesis. © 2017 British Society for Immunology.

  2. A Mass Spectrometry-Based Predictive Strategy Reveals ADAP1 is Phosphorylated at Tyrosine 364

    Energy Technology Data Exchange (ETDEWEB)

    Littrell, BobbiJo R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-16

    The goal of this work was to identify phosphorylation sites within the amino acid sequence of human ADAP1. Using traditional mass spectrometry-based techniques we were unable to produce interpretable spectra demonstrating modification by phosphorylation. This prompted us to employ a strategy in which phosphorylated peptides were first predicted using peptide mapping followed by targeted MS/MS acquisition. ADAP1 was immunoprecipitated from extracts of HEK293 cells stably-transfected with ADAP1 cDNA. Immunoprecipitated ADAP1 was digested with proteolytic enzymes and analyzed by LC-MS in MS1 mode by high-resolution quadrupole time-of-flight mass spectrometry (QTOF-MS). Peptide molecular features were extracted using an untargeted data mining algorithm. Extracted peptide neutral masses were matched against the ADAP1 amino acid sequence with phosphorylation included as a predicted modification. Peptides with predicted phosphorylation sites were analyzed by targeted LC-MS2. Acquired MS2 spectra were then analyzed using database search engines to confirm phosphorylation. Spectra of phosphorylated peptides were validated by manual interpretation. Further confirmation was performed by manipulating phospho-peptide abundance using calf intestinal phosphatase (CIP) and the phorbol ester, phorbol 12-myristate 13-acetate (PMA). Of five predicted phosphopeptides, one, comprised of the sequence AVDRPMLPQEYAVEAHFK, was confirmed to be phosphorylated on a Tyrosine at position 364. Pre-treatment of cells with PMA prior to immunoprecipitation increased the ratio of phosphorylated to unphosphorylated peptide as determined by area counts of extracted ion chromatograms (EIC). Addition of CIP to immunoprecipitation reactions eliminated the phosphorylated form. A novel phosphorylation site was identified at Tyrosine 364. Phosphorylation at this site is increased by treatment with PMA. PMA promotes membrane translocation and activation of protein kinase C (PKC), indicating that Tyrosine 364

  3. Amplified nanostructure electrochemical sensor for simultaneous determination of captopril, acetaminophen, tyrosine and hydrochlorothiazide

    Energy Technology Data Exchange (ETDEWEB)

    Karimi-Maleh, Hassan, E-mail: h.karimi.maleh@gmail.com [Department of Chemistry, Graduate University of Advanced Technology, Kerman (Iran, Islamic Republic of); Ganjali, Mohammad R.; Norouzi, Parviz; Bananezhad, Asma [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2017-04-01

    A novel nanomaterial-based voltammetric sensor has been developed for use a highly sensitive tool for the simultaneous determination of captopril (CA), acetaminophen (AC), tyrosine (TY) and hydrochlorothiazide (HCTZ). The device is based on the application of NiO/CNTs and (2-(3,4-dihydroxyphenethyl)isoindoline-1,3-dione) (DPID) to modify carbon paste electrodes. The NiO/CNTs nanocomposite was synthesized through a direct chemical precipitation approach and was characterized with X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). The NiO/CNTs/DPID/CPEs were found to facilitate the analysis of CA, AC, TY and HCTZ in the concentration ranges of 0.07–200.0, 0.8–550.0, 5.0–750.0 and 10.0–600.0 μM with the respective detection limits of 9.0 nM, 0.3 μM, 1.0 μM and 5.0 μM. The developed NiO/CNTs/DPID/CPEs were used for the determination of the mentioned analytes in pharmaceutical and biological real samples. - Graphical abstract: In this study a novel sensor based on NiO/CNTs and (2-(3,4-dihydroxyphenethyl)isoindoline-1,3-dione) (DPID) modified carbon paste electrode fabricated for simultaneous determination of captopril, acetaminophen, tyrosine and hydrochlorothiazide for the first time. - Highlights: • Fabrication of NiO/CNTs and new catechol derivative modified carbon paste electrode • Good ability of proposed sensor for biological and pharmaceutical analysis • Simultaneous determination captopril, acetaminophen, tyrosine and hydrochlorothiazide.

  4. Bone sialoprotein II synthesized by cultured osteoblasts contains tyrosine sulfate

    International Nuclear Information System (INIS)

    Ecarot-Charrier, B.; Bouchard, F.; Delloye, C.

    1989-01-01

    Isolated mouse osteoblasts that retain their osteogenic activity in culture were incubated with [35S] sulfate. Two radiolabeled proteins, in addition to proteoglycans, were extracted from the calcified matrix of osteoblast cultures. All the sulfate label in both proteins was in the form of tyrosine sulfate as assessed by amino acid analysis and thin layer chromatography following alkaline hydrolysis. The elution behavior on DEAE-Sephacel of the major sulfated protein and the apparent Mr on sodium dodecyl sulfate gels were characteristic of bone sialoprotein II extracted from rat. This protein was shown to cross-react with an antiserum raised against bovine bone sialoprotein II, indicating that bone sialoprotein II synthesized by cultured mouse osteoblasts is a tyrosine-sulfated protein. The minor sulfated protein was tentatively identified as bone sialoprotein I or osteopontin based on its elution properties on DEAE-Sephacel and anomalous behavior on sodium dodecyl sulfate gels similar to those reported for rat bone sialoprotein I

  5. Novel Bruton's tyrosine kinase inhibitors currently in development

    Directory of Open Access Journals (Sweden)

    D'Cruz OJ

    2013-03-01

    Full Text Available Osmond J D'Cruz,1 Fatih M Uckun1,21Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, CA, USA; 2Department of Pediatrics, University of Southern California, Los Angeles, CA, USAAbstract: Bruton's tyrosine kinase (Btk is intimately involved in multiple signal-transduction pathways regulating survival, activation, proliferation, and differentiation of B-lineage lymphoid cells. Btk is overexpressed and constitutively active in several B-lineage lymphoid malignancies. Btk has emerged as a new antiapoptotic molecular target for treatment of B-lineage leukemias and lymphomas. Preclinical and early clinical results indicate that Btk inhibitors may be useful in the treatment of leukemias and lymphomas.Keywords: tyrosine kinase, personalized therapy, kinase inhibitors, Btk, leukemia, lymphoma

  6. 78 FR 51463 - Energy Conservation Program: Energy Conservation Standards for Metal Halide Lamp Fixtures

    Science.gov (United States)

    2013-08-20

    ... merging the metal halide lamp fixture and the high-intensity discharge (HID) lamp rulemakings. This NOPR... Conservation Program: Energy Conservation Standards for Metal Halide Lamp Fixtures; Proposed Rule #0;#0;Federal...: Energy Conservation Standards for Metal Halide Lamp Fixtures AGENCY: Office of Energy Efficiency and...

  7. Planning for land use and conservation: Assessing GIS-based conservation software for land use planning

    Science.gov (United States)

    Rob Baldwin; Ryan Scherzinger; Don Lipscomb; Miranda Mockrin; Susan Stein

    2014-01-01

    Recent advances in planning and ecological software make it possible to conduct highly technical analyses to prioritize conservation investments and inform local land use planning. We review these tools, termed conservation planning tools, and assess the knowledge of a key set of potential users: the land use planning community. We grouped several conservation software...

  8. Proteomic analysis of tyrosine phosphorylation during human liver transplantation

    Directory of Open Access Journals (Sweden)

    Boutros Tarek

    2007-01-01

    Full Text Available Abstract Background Ischemia-reperfusion (I/R causes a dramatic reprogramming of cell metabolism during liver transplantation and can be linked to an alteration of the phosphorylation level of several cellular proteins. Over the past two decades, it became clear that tyrosine phosphorylation plays a pivotal role in a variety of important signalling pathways and was linked to a wide spectrum of diseases. Functional profiling of the tyrosine phosphoproteome during liver transplantation is therefore of great biological significance and is likely to lead to the identification of novel targets for drug discovery and provide a basis for novel therapeutic strategies. Results Using liver biopsies collected during the early phases of organ procurement and transplantation, we aimed at characterizing the global patterns of tyrosine phosphorylation during hepatic I/R. A proteomic approach, based on the purification of tyrosine phosphorylated proteins followed by their identification using mass spectrometry, allowed us to identify Nck-1, a SH2/SH3 adaptor, as a potential regulator of I/R injury. Using immunoblot, cell fractionation and immunohistochemistry, we demonstrate that Nck-1 phosphorylation, expression and localization were affected in liver tissue upon I/R. In addition, mass spectrometry identification of Nck-1 binding partners during the course of the transplantation also suggested a dynamic interaction between Nck-1 and actin during I/R. Conclusion Taken together, our data suggest that Nck-1 may play a role in I/R-induced actin reorganization, which was previously reported to be detrimental for the hepatocytes of the transplanted graft. Nck-1 could therefore represent a target of choice for the design of new organ preservation strategies, which could consequently help to reduce post-reperfusion liver damages and improve transplantation outcomes.

  9. SH2 domains: modulators of nonreceptor tyrosine kinase activity

    OpenAIRE

    Filippakopoulos, Panagis; Müller, Susanne; Knapp, Stefan

    2009-01-01

    The Src homology 2 (SH2) domain is a sequence-specific phosphotyrosine-binding module present in many signaling molecules. In cytoplasmic tyrosine kinases, the SH2 domain is located N-terminally to the catalytic kinase domain (SH1) where it mediates cellular localization, substrate recruitment, and regulation of kinase activity. Initially, structural studies established a role of the SH2 domain stabilizing the inactive state of Src family members. However, biochemical characterization showed ...

  10. Src protein-tyrosine kinase structure and regulation

    International Nuclear Information System (INIS)

    Roskoski, Robert

    2004-01-01

    Src and Src-family protein kinases are proto-oncogenes that play key roles in cell morphology, motility, proliferation, and survival. v-Src (a viral protein) is encoded by the chicken oncogene of Rous sarcoma virus, and Src (the cellular homologue) is encoded by a physiological gene, the first of the proto-oncogenes. From the N- to C-terminus, Src contains an N-terminal 14-carbon myristoyl group, a unique segment, an SH3 domain, an SH2 domain, a protein-tyrosine kinase domain, and a C-terminal regulatory tail. The chief phosphorylation sites of Src include tyrosine 416 that results in activation from autophosphorylation and tyrosine 527 that results in inhibition from phosphorylation by C-terminal Src kinase. In the restrained state, the SH2 domain forms a salt bridge with phosphotyrosine 527, and the SH3 domain binds to the kinase domain v