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Sample records for nuclear dbf-2-related kinases

  1. HIV-1 incorporates and proteolytically processes human NDR1 and NDR2 serine-threonine kinases

    International Nuclear Information System (INIS)

    Devroe, Eric; Silver, Pamela A.; Engelman, Alan

    2005-01-01

    Mammalian genomes encode two related serine-threonine kinases, nuclear Dbf2 related (NDR)1 and NDR2, which are homologous to the Saccharomyces cerevisiae Dbf2 kinase. Recently, a yeast genetic screen implicated the Dbf2 kinase in Ty1 retrotransposition. Since several virion-incorporated kinases regulate the infectivity of human immunodeficiency virus type 1 (HIV-1), we speculated that the human NDR1 and NDR2 kinases might play a role in the HIV-1 life cycle. Here we show that the NDR1 and NDR2 kinases were incorporated into HIV-1 particles. Furthermore, NDR1 and NDR2 were cleaved by the HIV-1 protease (PR), both within virions and within producer cells. Truncation at the PR cleavage site altered NDR2 subcellular localization and inhibited NDR1 and NDR2 enzymatic activity. These studies identify two new virion-associated host cell enzymes and suggest a novel mechanism by which HIV-1 alters the intracellular environment of human cells

  2. The wheat AGC kinase TaAGC1 is a positive contributor to host resistance to the necrotrophic pathogen Rhizoctonia cerealis.

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    Zhu, Xiuliang; Yang, Kun; Wei, Xuening; Zhang, Qiaofeng; Rong, Wei; Du, Lipu; Ye, Xingguo; Qi, Lin; Zhang, Zengyan

    2015-11-01

    Considerable progress has been made in understanding the roles of AGC kinases in mammalian systems. However, very little is known about the roles of AGC kinases in wheat (Triticum aestivum). The necrotrophic fungus Rhizoctonia cerealis is the major pathogen of the destructive disease sharp eyespot of wheat. In this study, the wheat AGC kinase gene TaAGC1, responding to R. cerealis infection, was isolated, and its properties and role in wheat defence were characterized. R. cerealis-resistant wheat lines expressed TaAGC1 at higher levels than susceptible wheat lines. Sequence and phylogenetic analyses showed that the TaAGC1 protein is a serine/threonine kinase belonging to the NDR (nuclear Dbf2-related) subgroup of AGC kinases. Kinase activity assays proved that TaAGC1 is a functional kinase and the Asp-239 residue located in the conserved serine/threonine kinase domain of TaAGC1 is required for the kinase activity. Subcellular localization assays indicated that TaAGC1 localized in the cytoplasm and nucleus. Virus-induced TaAGC1 silencing revealed that the down-regulation of TaAGC1 transcripts significantly impaired wheat resistance to R. cerealis. The molecular characterization and responses of TaAGC1 overexpressing transgenic wheat plants indicated that TaAGC1 overexpression significantly enhanced resistance to sharp eyespot and reduced the accumulation of reactive oxygen species (ROS) in wheat plants challenged with R. cerealis. Furthermore, ROS-scavenging and certain defence-associated genes were up-regulated in resistant plants overexpressing TaAGC1 but down-regulated in susceptible knock-down plants. These results suggested that the kinase TaAGC1 positively contributes to wheat immunity to R. cerealis through regulating expression of ROS-related and defence-associated genes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Nuclear localization of Lyn tyrosine kinase mediated by inhibition of its kinase activity

    International Nuclear Information System (INIS)

    Ikeda, Kikuko; Nakayama, Yuji; Togashi, Yuuki; Obata, Yuuki; Kuga, Takahisa; Kasahara, Kousuke; Fukumoto, Yasunori; Yamaguchi, Naoto

    2008-01-01

    Src-family kinases, cytoplasmic enzymes that participate in various signaling events, are found at not only the plasma membrane but also subcellular compartments, such as the nucleus, the Golgi apparatus and late endosomes/lysosomes. Lyn, a member of the Src-family kinases, is known to play a role in DNA damage response and cell cycle control in the nucleus. However, it is still unclear how the localization of Lyn to the nucleus is regulated. Here, we investigated the mechanism of the distribution of Lyn between the cytoplasm and the nucleus in epitheloid HeLa cells and hematopoietic THP-1 cells. Lyn was definitely detected in purified nuclei by immunofluorescence and immunoblotting analyses. Nuclear accumulation of Lyn was enhanced upon treatment of cells with leptomycin B (LMB), an inhibitor of Crm1-mediated nuclear export. Moreover, Lyn mutants lacking the sites for lipid modification were highly accumulated in the nucleus upon LMB treatment. Intriguingly, inhibition of the kinase activity of Lyn by SU6656, Csk overexpression, or point mutation in the ATP-binding site induced an increase in nuclear Lyn levels. These results suggest that Lyn being imported into and rapidly exported from the nucleus preferentially accumulates in the nucleus by inhibition of the kinase activity and lipid modification

  4. Nuclear translocation of doublecortin-like protein kinase and phosphorylation of a transcription factor JDP2

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    Nagamine, Tadashi; Nomada, Shohgo; Onouchi, Takashi; Kameshita, Isamu; Sueyoshi, Noriyuki, E-mail: sueyoshi@ag.kagawa-u.ac.jp

    2014-03-28

    Highlights: • Doublecortin-like protein kinase (DCLK) is a microtubule-associated protein kinase. • In living cells, DCLK was cleaved into two functional fragments. • zDCLK(kinase) was translocated into the nucleus by osmotic stresses. • Jun dimerization protein 2 (JDP2) was identified as zDCLK(kinase)-binding protein. • JDP2 was efficiently phosphorylated by zDCLK(kinase) only when histone was present. - Abstract: Doublecortin-like protein kinase (DCLK) is a microtubule-associated protein kinase predominantly expressed in brain. In a previous paper, we reported that zebrafish DCLK2 (zDCLK) was cleaved into two functional fragments; the N-terminal zDCLK(DC + SP) with microtubule-binding activity and the C-terminal zDCLK(kinase) with a Ser/Thr protein kinase activity. In this study, we demonstrated that zDCLK(kinase) was widely distributed in the cytoplasm and translocated into the nucleus when the cells were treated under hyperosmotic conditions with NaCl or mannitol. By two-hybrid screening using the C-terminal domain of DCLK, Jun dimerization protein 2 (JDP2), a nuclear transcription factor, was identified as zDCLK(kinase)-binding protein. Furthermore, JDP2 served as an efficient substrate for zDCLK(kinase) only when histone was present. These results suggest that the kinase fragment of DCLK is translocated into the nucleus upon hyperosmotic stresses and that the kinase efficiently phosphorylates JDP2, a possible target in the nucleus, with the aid of histones.

  5. Human Cytomegalovirus Nuclear Capsids Associate with the Core Nuclear Egress Complex and the Viral Protein Kinase pUL97.

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    Milbradt, Jens; Sonntag, Eric; Wagner, Sabrina; Strojan, Hanife; Wangen, Christina; Lenac Rovis, Tihana; Lisnic, Berislav; Jonjic, Stipan; Sticht, Heinrich; Britt, William J; Schlötzer-Schrehardt, Ursula; Marschall, Manfred

    2018-01-13

    The nuclear phase of herpesvirus replication is regulated through the formation of regulatory multi-component protein complexes. Viral genomic replication is followed by nuclear capsid assembly, DNA encapsidation and nuclear egress. The latter has been studied intensely pointing to the formation of a viral core nuclear egress complex (NEC) that recruits a multimeric assembly of viral and cellular factors for the reorganization of the nuclear envelope. To date, the mechanism of the association of human cytomegalovirus (HCMV) capsids with the NEC, which in turn initiates the specific steps of nuclear capsid budding, remains undefined. Here, we provide electron microscopy-based data demonstrating the association of both nuclear capsids and NEC proteins at nuclear lamina budding sites. Specifically, immunogold labelling of the core NEC constituent pUL53 and NEC-associated viral kinase pUL97 suggested an intranuclear NEC-capsid interaction. Staining patterns with phospho-specific lamin A/C antibodies are compatible with earlier postulates of targeted capsid egress at lamina-depleted areas. Important data were provided by co-immunoprecipitation and in vitro kinase analyses using lysates from HCMV-infected cells, nuclear fractions, or infectious virions. Data strongly suggest that nuclear capsids interact with pUL53 and pUL97. Combined, the findings support a refined concept of HCMV nuclear trafficking and NEC-capsid interaction.

  6. Human Cytomegalovirus Nuclear Capsids Associate with the Core Nuclear Egress Complex and the Viral Protein Kinase pUL97

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    Jens Milbradt

    2018-01-01

    Full Text Available The nuclear phase of herpesvirus replication is regulated through the formation of regulatory multi-component protein complexes. Viral genomic replication is followed by nuclear capsid assembly, DNA encapsidation and nuclear egress. The latter has been studied intensely pointing to the formation of a viral core nuclear egress complex (NEC that recruits a multimeric assembly of viral and cellular factors for the reorganization of the nuclear envelope. To date, the mechanism of the association of human cytomegalovirus (HCMV capsids with the NEC, which in turn initiates the specific steps of nuclear capsid budding, remains undefined. Here, we provide electron microscopy-based data demonstrating the association of both nuclear capsids and NEC proteins at nuclear lamina budding sites. Specifically, immunogold labelling of the core NEC constituent pUL53 and NEC-associated viral kinase pUL97 suggested an intranuclear NEC-capsid interaction. Staining patterns with phospho-specific lamin A/C antibodies are compatible with earlier postulates of targeted capsid egress at lamina-depleted areas. Important data were provided by co-immunoprecipitation and in vitro kinase analyses using lysates from HCMV-infected cells, nuclear fractions, or infectious virions. Data strongly suggest that nuclear capsids interact with pUL53 and pUL97. Combined, the findings support a refined concept of HCMV nuclear trafficking and NEC-capsid interaction.

  7. Protein kinases responsible for the phosphorylation of the nuclear egress core complex of human cytomegalovirus.

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    Sonntag, Eric; Milbradt, Jens; Svrlanska, Adriana; Strojan, Hanife; Häge, Sigrun; Kraut, Alexandra; Hesse, Anne-Marie; Amin, Bushra; Sonnewald, Uwe; Couté, Yohann; Marschall, Manfred

    2017-10-01

    Nuclear egress of herpesvirus capsids is mediated by a multi-component nuclear egress complex (NEC) assembled by a heterodimer of two essential viral core egress proteins. In the case of human cytomegalovirus (HCMV), this core NEC is defined by the interaction between the membrane-anchored pUL50 and its nuclear cofactor, pUL53. NEC protein phosphorylation is considered to be an important regulatory step, so this study focused on the respective role of viral and cellular protein kinases. Multiply phosphorylated pUL50 varieties were detected by Western blot and Phos-tag analyses as resulting from both viral and cellular kinase activities. In vitro kinase analyses demonstrated that pUL50 is a substrate of both PKCα and CDK1, while pUL53 can also be moderately phosphorylated by CDK1. The use of kinase inhibitors further illustrated the importance of distinct kinases for core NEC phosphorylation. Importantly, mass spectrometry-based proteomic analyses identified five major and nine minor sites of pUL50 phosphorylation. The functional relevance of core NEC phosphorylation was confirmed by various experimental settings, including kinase knock-down/knock-out and confocal imaging, in which it was found that (i) HCMV core NEC proteins are not phosphorylated solely by viral pUL97, but also by cellular kinases; (ii) both PKC and CDK1 phosphorylation are detectable for pUL50; (iii) no impact of PKC phosphorylation on NEC functionality has been identified so far; (iv) nonetheless, CDK1-specific phosphorylation appears to be required for functional core NEC interaction. In summary, our findings provide the first evidence that the HCMV core NEC is phosphorylated by cellular kinases, and that the complex pattern of NEC phosphorylation has functional relevance.

  8. Identification of nuclear protein targets for six leukemogenic tyrosine kinases governed by post-translational regulation.

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    Andrew Pierce

    Full Text Available Mutated tyrosine kinases are associated with a number of different haematological malignancies including myeloproliferative disorders, lymphoma and acute myeloid leukaemia. The potential commonalities in the action of six of these leukemogenic proteins on nuclear proteins were investigated using systematic proteomic analysis. The effects on over 3600 nuclear proteins and 1500 phosphopeptide sites were relatively quantified in seven isogenic cell lines. The effects of the kinases were diverse although some commonalities were found. Comparison of the nuclear proteomic data with transcriptome data and cytoplasmic proteomic data indicated that the major changes are due to post-translational mechanisms rather than changes in mRNA or protein distribution. Analysis of the promoter regions of genes whose protein levels changed in response to the kinases showed the most common binding site found was that for NFκB whilst other sites such as those for the glucocorticoid receptor were also found. Glucocorticoid receptor levels and phosphorylation were decreased by all 6 PTKs. Whilst Glucocorticoid receptor action can potentiate NFκB action those proteins where genes have NFκB binding sites were in often regulated post-translationally. However all 6 PTKs showed evidence of NFkB pathway modulation via activation via altered IkB and NFKB levels. Validation of a common change was also undertaken with PMS2, a DNA mismatch repair protein. PMS2 nuclear levels were decreased in response to the expression of all 6 kinases, with no concomitant change in mRNA level or cytosolic protein level. Response to thioguanine, that requires the mismatch repair pathway, was modulated by all 6 oncogenic kinases. In summary common targets for 6 oncogenic PTKs have been found that are regulated by post-translational mechanisms. They represent potential new avenues for therapies but also demonstrate the post-translational regulation is a key target of leukaemogenic kinases.

  9. Nuclear localization of Src-family tyrosine kinases is required for growth factor-induced euchromatinization

    International Nuclear Information System (INIS)

    Takahashi, Akinori; Obata, Yuuki; Fukumoto, Yasunori; Nakayama, Yuji; Kasahara, Kousuke; Kuga, Takahisa; Higashiyama, Yukihiro; Saito, Takashi; Yokoyama, Kazunari K.; Yamaguchi, Naoto

    2009-01-01

    Src-family kinases (SFKs), which participate in various signaling events, are found at not only the plasma membrane but also several subcellular compartments, including the nucleus. Nuclear structural changes are frequently observed during transcription, cell differentiation, senescence, tumorigenesis, and cell cycle. However, little is known about signal transduction in the alteration of chromatin texture. Here, we develop a pixel imaging method for quantitatively evaluating chromatin structural changes. Growth factor stimulation increases euchromatic hypocondensation and concomitant heterochromatic hypercondensation in G 1 phase, and the levels reach a plateau by 30 min, sustain for at least 5 h and return to the basal levels after 24 h. Serum-activated SFKs in the nucleus were more frequently detected in the euchromatin areas than the heterochromatin areas. Nuclear expression of kinase-active SFKs, but not unrelated Syk kinase, drastically increases both euchromatinization and heterochromatinization in a manner dependent on the levels of nuclear tyrosine phosphorylation. However, growth factor stimulation does not induce chromatin structural changes in SYF cells lacking SFKs, and reintroduction of one SFK member into SYF cells can, albeit insufficiently, induce chromatin structural changes. These results suggest that nuclear tyrosine phosphorylation by SFKs plays an important role in chromatin structural changes upon growth factor stimulation.

  10. Role of regulatory subunits and protein kinase inhibitor (PKI) in determining nuclear localization and activity of the catalytic subunit of protein kinase A.

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    Wiley, J C; Wailes, L A; Idzerda, R L; McKnight, G S

    1999-03-05

    Regulation of protein kinase A by subcellular localization may be critical to target catalytic subunits to specific substrates. We employed epitope-tagged catalytic subunit to correlate subcellular localization and gene-inducing activity in the presence of regulatory subunit or protein kinase inhibitor (PKI). Transiently expressed catalytic subunit distributed throughout the cell and induced gene expression. Co-expression of regulatory subunit or PKI blocked gene induction and prevented nuclear accumulation. A mutant PKI lacking the nuclear export signal blocked gene induction but not nuclear accumulation, demonstrating that nuclear export is not essential to inhibit gene induction. When the catalytic subunit was targeted to the nucleus with a nuclear localization signal, it was not sequestered in the cytoplasm by regulatory subunit, although its activity was completely inhibited. PKI redistributed the nuclear catalytic subunit to the cytoplasm and blocked gene induction, demonstrating that the nuclear export signal of PKI can override a strong nuclear localization signal. With increasing PKI, the export process appeared to saturate, resulting in the return of catalytic subunit to the nucleus. These results demonstrate that both the regulatory subunit and PKI are able to completely inhibit the gene-inducing activity of the catalytic subunit even when the catalytic subunit is forced to concentrate in the nuclear compartment.

  11. Speeding through cell cycle roadblocks: Nuclear cyclin D1-dependent kinase and neoplastic transformation

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    Diehl J Alan

    2008-09-01

    Full Text Available Abstract Mitogenic induction of cyclin D1, the allosteric regulator of CDK4/6, is a key regulatory event contributing to G1 phase progression. Following the G1/S transition, cyclin D1 activation is antagonized by GSK3β-dependent threonine-286 (Thr-286 phosphorylation, triggering nuclear export and subsequent cytoplasmic degradation mediated by the SCFFbx4-αBcrystallin E3 ubiquitin ligase. Although cyclin D1 overexpression occurs in numerous malignancies, overexpression of cyclin D1 alone is insufficient to drive transformation. In contrast, cyclin D1 mutants refractory to phosphorylation-dependent nuclear export and degradation are acutely transforming. This raises the question of whether overexpression of cyclin D1 is a significant contributor to tumorigenesis or an effect of neoplastic transformation. Significantly, recent work strongly supports a model wherein nuclear accumulation of cyclin D1-dependent kinase during S-phase is a critical event with regard to transformation. The identification of mutations within SCFFbx4-αBcrystallin ligase in primary tumors provides mechanistic insight into cyclin D1 accumulation in human cancer. Furthermore, analysis of mouse models expressing cyclin D1 mutants refractory to degradation indicate that nuclear cyclin D1/CDK4 kinase triggers DNA re-replication and genomic instability. Collectively, these new findings provide a mechanism whereby aberrations in post-translational regulation of cyclin D1 establish a cellular environment conducive to mutations that favor neoplastic growth.

  12. Multi-lobulation of the nucleus in prolonged S phase by nuclear expression of Chk tyrosine kinase.

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    Nakayama, Yuji; Yamaguchi, Naoto

    2005-04-01

    Chk tyrosine kinase phosphorylates Src-family tyrosine kinases and suppresses their kinase activity. We recently showed that Chk localizes to the nucleus as well as the cytoplasm and inhibits cell proliferation. To investigate the role of nuclear Chk in proliferation, various Chk mutants were constructed and expressed. Nuclear localization of Chk-induced dynamic multi-lobulation of the nucleus and prolonged S phase of the cell cycle. The N-terminal domain of Chk and a portion of its kinase domain but not the kinase activity were responsible for induction of the multi-lobulation. Cell sorting analysis revealed that nuclear multi-lobulated cells were enriched in late S phase. Multi-lobulated nuclei were surrounded with lamin B1 that was particularly concentrated in concave regions of the nuclei. Furthermore, treatment with nocodazole or taxol disrupted multi-lobulation of the nucleus. These results suggest that nuclear multi-lobulation in late S phase, which is dependent on polymerization and depolymerization of microtubules, may be involved in nuclear Chk-induced inhibition of proliferation.

  13. Multi-lobulation of the nucleus in prolonged S phase by nuclear expression of Chk tyrosine kinase

    International Nuclear Information System (INIS)

    Nakayama, Yuji; Yamaguchi, Naoto

    2005-01-01

    Chk tyrosine kinase phosphorylates Src-family tyrosine kinases and suppresses their kinase activity. We recently showed that Chk localizes to the nucleus as well as the cytoplasm and inhibits cell proliferation. To investigate the role of nuclear Chk in proliferation, various Chk mutants were constructed and expressed. Nuclear localization of Chk-induced dynamic multi-lobulation of the nucleus and prolonged S phase of the cell cycle. The N-terminal domain of Chk and a portion of its kinase domain but not the kinase activity were responsible for induction of the multi-lobulation. Cell sorting analysis revealed that nuclear multi-lobulated cells were enriched in late S phase. Multi-lobulated nuclei were surrounded with lamin B1 that was particularly concentrated in concave regions of the nuclei. Furthermore, treatment with nocodazole or taxol disrupted multi-lobulation of the nucleus. These results suggest that nuclear multi-lobulation in late S phase, which is dependent on polymerization and depolymerization of microtubules, may be involved in nuclear Chk-induced inhibition of proliferation

  14. Phosphorylation of zona occludens-2 by protein kinase C epsilon regulates its nuclear exportation.

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    Chamorro, David; Alarcón, Lourdes; Ponce, Arturo; Tapia, Rocio; González-Aguilar, Héctor; Robles-Flores, Martha; Mejía-Castillo, Teresa; Segovia, José; Bandala, Yamir; Juaristi, Eusebio; González-Mariscal, Lorenza

    2009-09-01

    Here, we have analyzed the subcellular destiny of newly synthesized tight junction protein zona occludens (ZO)-2. After transfection in sparse cells, 74% of cells exhibit ZO-2 at the nucleus, and after 18 h the value decreases to 17%. The mutation S369A located within the nuclear exportation signal 1 of ZO-2 impairs the nuclear export of the protein. Because Ser369 represents a putative protein kinase C (PKC) phosphorylation site, we tested the effect of PKC inhibition and stimulation on the nuclear export of ZO-2. Our results strongly suggest that the departure of ZO-2 from the nucleus is regulated by phosphorylation at Ser369 by novel PKCepsilon. To test the route taken by ZO-2 from synthesis to the plasma membrane, we devised a novel nuclear microinjection assay in which the nucleus served as a reservoir for anti-ZO-2 antibody. Through this assay, we demonstrate that a significant amount of newly synthesized ZO-2 goes into the nucleus and is later relocated to the plasma membrane. These results constitute novel information for understanding the mechanisms that regulate the intracellular fate of ZO-2.

  15. DMPD: Manipulation of mitogen-activated protein kinase/nuclear factor-kappaB-signalingcascades during intracellular Toxoplasma gondii infection. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15361242 Manipulation of mitogen-activated protein kinase/nuclear factor-kappaB-sig...mmunol Rev. 2004 Oct;201:191-205. (.png) (.svg) (.html) (.csml) Show Manipulation of mitogen-activated prote... gondii infection. PubmedID 15361242 Title Manipulation of mitogen-activated protein kinase/nuclear factor-k

  16. Control of cytoplasmic and nuclear protein kinase A by phosphodiesterases and phosphatases in cardiac myocytes

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    Haj Slimane, Zeineb; Bedioune, Ibrahim; Lechêne, Patrick; Varin, Audrey; Lefebvre, Florence; Mateo, Philippe; Domergue-Dupont, Valérie; Dewenter, Matthias; Richter, Wito; Conti, Marco; El-Armouche, Ali; Zhang, Jin; Fischmeister, Rodolphe; Vandecasteele, Grégoire

    2014-01-01

    Aims The cAMP-dependent protein kinase (PKA) mediates β-adrenoceptor (β-AR) regulation of cardiac contraction and gene expression. Whereas PKA activity is well characterized in various subcellular compartments of adult cardiomyocytes, its regulation in the nucleus remains largely unknown. The aim of the present study was to compare the modalities of PKA regulation in the cytoplasm and nucleus of cardiomyocytes. Methods and results Cytoplasmic and nuclear cAMP and PKA activity were measured with targeted fluorescence resonance energy transfer probes in adult rat ventricular myocytes. β-AR stimulation with isoprenaline (Iso) led to fast cAMP elevation in both compartments, whereas PKA activity was fast in the cytoplasm but markedly slower in the nucleus. Iso was also more potent and efficient in activating cytoplasmic than nuclear PKA. Similar slow kinetics of nuclear PKA activation was observed upon adenylyl cyclase activation with L-858051 or phosphodiesterase (PDE) inhibition with 3-isobutyl-1-methylxantine. Consistently, pulse stimulation with Iso (15 s) maximally induced PKA and myosin-binding protein C phosphorylation in the cytoplasm, but marginally activated PKA and cAMP response element-binding protein phosphorylation in the nucleus. Inhibition of PDE4 or ablation of the Pde4d gene in mice prolonged cytoplasmic PKA activation and enhanced nuclear PKA responses. In the cytoplasm, phosphatase 1 (PP1) and 2A (PP2A) contributed to the termination of PKA responses, whereas only PP1 played a role in the nucleus. Conclusion Our study reveals a differential integration of cytoplasmic and nuclear PKA responses to β-AR stimulation in cardiac myocytes. This may have important implications in the physiological and pathological hypertrophic response to β-AR stimulation. PMID:24550350

  17. Photochemically induced dynamic nuclear polarization NMR study of yeast and horse muscle phosphoglycerate kinase

    International Nuclear Information System (INIS)

    Scheffler, J.E.; Cohn, M.

    1986-01-01

    A photochemically induced dynamic nuclear polarization (photo-CIDNP) study of yeast and horse muscle phosphoglycerate kinase with flavin dyes was undertaken to identify the histidine, tryptophan, and tyrosine resonances in the aromatic region of the simplified 1 H NMR spectra of these enzymes and to investigate the effect of substrates on the resonances observable by CIDNP. Identification of the CIDNP-enhanced resonances with respect to the type of amino acid residue has been achieved since only tyrosine yields emission peaks and the dye 8-aminoriboflavin enhances tryptophan but not histidine. By use of the known amino acid sequences and structures derived from X-ray crystallographic studies of the enzymes from the two species, assignment of the specific residues in the protein sequences giving rise to the CIDNP spectra was partially achieved. In addition, flavin dye accessibility was used to probe any changes in enzyme structure induced by substrate binding. The accessibility of a tyrosine to photoexcited flavin is reduced in the presence of MgATP. Since the tyrosine residues are located some distance from the MgATP binding site of the catalytic center, it is proposed either that this change is due to a distant conformational change or that a second metal-ATP site inferred from other studies lies close to one of the tyrosines. Horse muscle phosphoglycerate kinase exhibits seven resonances by CIDNP NMR. The addition of 3-phosphoglycerate and MgATP results in the appearance of two additional resonances in the CIDNP spectrum due to a histidine residue that is inaccessible to flavin in both the enzyme alone and its binary complex with 3-phosphoglycerate. The CIDNP spectra are consistent with the suggestions that binding of 3-phosphoglycerate alone is insufficient to effect domain movement and that binding of both substrates are required for conversion of the horse muscle enzyme to its catalytically active form

  18. Nuclear glycogen synthase kinase-3 {beta} (GSK-3) in Rhipicephalus (Boophilus) microplus tick embryogenesis

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    Mentzingen, Leticia; Andrade, Josiana G. de; Logullo, Carlos [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Centro de Biociencias e Biotecnologia. Lab. de Quimica e Funcao de Proteinas e Peptideos (LQFPP); Andrade, Caroline P. de; Vaz Junior, Itabajara [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Centro de Biotecnologia

    2008-07-01

    Full text: Glycogen synthase kinase-3 (GSK3) is recognized as a key component of a large number of cellular processes and diseases. Several mechanisms play a part in controlling the actions of GSK3, including phosphorylation, protein complex formation, and subcellular distribution. Recent observations point to functions for phosphorylases several transcription factors in the nucleus. Also, GSK3b participate of the canonical W nt signalling pathway, which has been studied intensively in embryonic and cancer cells. Like in many other signaling pathways, most components in W nt signal transduction were highly conserved during the evolution. More than 40 proteins have been reported to be phosphorylated by GSK3, including over a dozen transcription factors. Although the mechanisms regulating GSK3 are not fully understood, precise control appears to be achieved by a combination of phosphorylation, localization, and interactions with GSK3-binding proteins. Although GSK3 is traditionally considered a cytosolic protein, it is also present in nuclei. Nuclear GSK3 is particularly interesting because of the many transcription factors that it regulates enabling GSK3 to influence many signaling pathways that converge on these transcription factors, thereby regulating the expression of many genes. Our group identified that GSK-3 {beta} could be detected in different stage eggs of R. micro plus. In this work we detected the GSK-3 in isolated nuclear fraction from the egg homogenates of R. micro plus by western-blot analysis, using anti-GSK- 3 {beta} antibodies. The enzyme activity was also detected radiochemically throughout embryogenesis in same fraction. The GSK-3 activity was inhibiting by using SB 216763 (selective molecule inhibitors of GSK-3). Taken together our results suggest that GSK-3 {beta} isoform probably is involved in gene transcription factors during R. micro plus embryo development.

  19. Combined therapeutic potential of nuclear receptors with receptor tyrosine kinase inhibitors in lung cancer

    International Nuclear Information System (INIS)

    Wairagu, Peninah M.; Park, Kwang Hwa; Kim, Jihye; Choi, Jong-Whan; Kim, Hyun-Won; Yeh, Byung-Il; Jung, Soon-Hee; Yong, Suk-Joong; Jeong, Yangsik

    2014-01-01

    Highlights: • The 48 NR genes and 48 biological anti-cancer targets are profiled in paired-cells. • Growth inhibition by NR ligands or TKIs is target receptor level-dependent. • T0901317 with gefitinib/PHA665752 shows additive growth inhibition in lung cells. - Abstract: Cancer heterogeneity is a big hurdle in achieving complete cancer treatment, which has led to the emergence of combinational therapy. In this study, we investigated the potential use of nuclear receptor (NR) ligands for combinational therapy with other anti-cancer drugs. We first profiled all 48 NRs and 48 biological anti-cancer targets in four pairs of lung cell lines, where each pair was obtained from the same patient. Two sets of cell lines were normal and the corresponding tumor cell lines while the other two sets consisted of primary versus metastatic tumor cell lines. Analysis of the expression profile revealed 11 NRs and 15 cancer targets from the two pairs of normal versus tumor cell lines, and 9 NRs and 9 cancer targets from the primary versus metastatic tumor cell lines had distinct expression patterns in each category. Finally, the evaluation of nuclear receptor ligand T0901317 for liver X receptor (LXR) demonstrated its combined therapeutic potential with tyrosine kinase inhibitors. The combined treatment of cMET inhibitor PHA665752 or EGFR inhibitor gefitinib with T0901317 showed additive growth inhibition in both H2073 and H1993 cells. Mechanistically, the combined treatment suppressed cell cycle progression by inhibiting cyclinD1 and cyclinB expression. Taken together, this study provides insight into the potential use of NR ligands in combined therapeutics with other biological anti-cancer drugs

  20. Cell-cycle-specific interaction of nuclear DNA-binding proteins with a CCAAT sequence from the human thymidine kinase gene

    International Nuclear Information System (INIS)

    Knight, G.B.; Gudas, J.M.; Pardee, A.B.

    1987-01-01

    Induction of thymidine kinase parallels the onset of DNA synthesis. To investigate the transcriptional regulation of the thymidine kinase gene, the authors have examined whether specific nuclear factors interact in a cell-cycle-dependent manner with sequences upstream of this gene. Two inverted CCAAT boxes near the transcriptional initiation sites were observed to form complexes with nuclear DNA-binding proteins. The nature of the complexes changes dramatically as the cells approach DNA synthesis and correlates well with the previously reported transcriptional increase of the thymidine kinase gene

  1. Protein kinase A activation enhances β-catenin transcriptional activity through nuclear localization to PML bodies.

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    Mei Zhang

    Full Text Available The Protein Kinase A (PKA and Wnt signaling cascades are fundamental pathways involved in cellular development and maintenance. In the osteoblast lineage, these pathways have been demonstrated functionally to be essential for the production of mineralized bone. Evidence for PKA-Wnt crosstalk has been reported both during tumorigenesis and during organogenesis, and the nature of the interaction is thought to rely on tissue and cell context. In this manuscript, we analyzed bone tumors arising from mice with activated PKA caused by mutation of the PKA regulatory subunit Prkar1a. In primary cells from these tumors, we observed relocalization of β-catenin to intranuclear punctuate structures, which were identified as PML bodies. Cellular redistribution of β-catenin could be recapitulated by pharmacologic activation of PKA. Using 3T3-E1 pre-osteoblasts as a model system, we found that PKA phosphorylation sites on β-catenin were required for nuclear re-localization. Further, β-catenin's transport to the nucleus was accompanied by an increase in canonical Wnt-dependent transcription, which also required the PKA sites. PKA-Wnt crosstalk in the cells was bi-directional, including enhanced interactions between β-catenin and the cAMP-responsive element binding protein (CREB and transcriptional crosstalk between the Wnt and PKA signaling pathways. Increases in canonical Wnt/β-catenin signaling were associated with a decrease in the activity of the non-canonical Wnt/Ror2 pathway, which has been shown to antagonize canonical Wnt signaling. Taken together, this study provides a new understanding of the complex regulation of the subcellular distribution of β-catenin and its differential protein-protein interaction that can be modulated by PKA signaling.

  2. Identification of a novel receptor-like protein kinase that interacts with a geminivirus nuclear shuttle protein

    International Nuclear Information System (INIS)

    Mariano, Andrea C.; Andrade, Maxuel O.; Santos, Anesia A.; Carolino, Sonia M.B.; Oliveira, Marli L.; Baracat-Pereira, Maria Cristina; Brommonshenkel, Sergio H.; Fontes, Elizabeth P.B.

    2004-01-01

    Despite extensive studies in plant virus-host interactions, the molecular mechanisms of geminivirus movement and interactions with host components remain largely unknown. A tomato kinase protein and its soybean homolog were found to interact specifically with the nuclear shuttle protein (NSP) of Tomato golden mosaic virus (TGMV) and Tomato crinkle leaf yellows virus (TCrLYV) through yeast two-hybrid screening and in vitro protein binding assays. These proteins, designated LeNIK (Lycopersicon esculentum NSP-Interacting Kinase) and GmNIK (Glycine max NIK), belong to the LRR-RLK (leucine rich-repeat receptor-like kinase) family that is involved in plant developmental processes and/or resistance response. As such, NIK is structurally organized into characteristic domains, including a serine/threonine kinase domain with a nucleotide binding site at the C-terminal region, an internal transmembrane segment and leucine-rich repeats (LRR) at the N-terminal portion. The potential significance of the NSP-NIK interaction is discussed

  3. Nuclear Overhauser effect studies on the conformation of magnesium adenosine 5'-triphosphate bound to rabbit muscle creatine kinase

    International Nuclear Information System (INIS)

    Rosevear, P.R.; Powers, V.M.; Dowhan, D.; Mildvan, A.S.; Kenyon, G.L.

    1987-01-01

    Nuclear Overhauser effects were used to determine interproton distances on MgATP bound to rabbit muscle creatine kinase. The internuclear distances were used in a distance geometry program that objectively determines both the conformation of the bound MgATP and its uniqueness. Two classes of structures were found that satisfied the measured interproton distances. Both classes had the same anti glycosidic torsional angle (X = 78 +/- 10 0 ) but differed in their ribose ring puckers (O1'-endo or C4'-exo). The uniqueness of the glycosidic torsional angle is consistent with the preference of creatine kinase for adenine nucleotides. One of these conformations of MgATP bound to creatine kinase is indistinguishable from the conformation found for Co(NH 3 ) 4 ATP bound to the catalytic subunit of protein kinase, which also has a high specificity for adenine nucleotides. Distance geometry calculations also suggest that upper limit distances, when low enough (≤ 3.4 A), can be used instead of measured distances to define, within experimental error, the glycosidic torsional angle of bound nucleotides. However, this approach does not permit an evaluation of the ribose ring pucker

  4. Nuclear pool of phosphatidylinositol 4 phosphate 5 kinase 1α is modified by polySUMO-2 during apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarti, Rajarshi; Bhowmick, Debajit; Bhargava, Varsha; Bhar, Kaushik; Siddhanta, Anirban, E-mail: asiddhanto@yahoo.com

    2013-09-20

    Highlights: •Nuclear pool of PIP5K is SUMOylated. •Enhancement of SUMOylated nuclear PIP5K during apoptosis. •Nuclear PIP5K is modified by polySUMO-1 during apoptosis. •Nuclear PIP5K is modified by polySUMO-2 chain during apoptosis. -- Abstract: Phosphatidylinositol 4 phosphate 5 kinase 1α (PIP5K) is mainly localized in the cytosol and plasma membrane. Studies have also indicated its prominent association with nuclear speckles. The exact nature of this nuclear pool of PIP5K is not clear. Using biochemical and microscopic techniques, we have demonstrated that the nuclear pool of PIP5K is modified by SUMO-1 in HEK-293 cells stably expressing PIP5K. Moreover, this SUMOylated pool of PIP5K increased during apoptosis. PolySUMO-2 chain conjugated PIP5K was detected by pull-down experiment using affinity-tagged RNF4, a polySUMO-2 binding protein, during late apoptosis.

  5. Identification of a nuclear localization signal in the retinitis pigmentosa-mutated RP26 protein, ceramide kinase-like protein

    International Nuclear Information System (INIS)

    Inagaki, Yuichi; Mitsutake, Susumu; Igarashi, Yasuyuki

    2006-01-01

    Retinitis pigmentosa (RP) is a genetically heterogeneous disease characterized by degeneration of the retina. A mutation in a new ceramide kinase (CERK) homologous gene, named CERK-like protein (CERKL), was found to cause autosomal recessive retinitis pigmentosa (RP26). Here, we show a point mutation of one of two putative nuclear localization signal (NLS) sequences inhibited the nuclear localization of the protein. Furthermore, the tetra-GFP-tagged NLS, which cannot passively enter the nucleus, was observed not only in the nucleus but also in the nucleolus. Our results provide First evidence of the active nuclear import of CERKL and suggest that the identified NLS might be responsible for nucleolar retention of the protein. As recent studies have shown other RP-related proteins are localized in the nucleus or the nucleolus, our identification of NLS in CERKL suggests that CERKL likely plays important roles for retinal functions in the nucleus and the nucleolus

  6. Nuclear localization of lymphocyte-specific protein tyrosine kinase (Lck) and its role in regulating LIM domain only 2 (Lmo2) gene

    Energy Technology Data Exchange (ETDEWEB)

    Venkitachalam, Srividya; Chueh, Fu-Yu [Department of Microbiology and Immunology, H. M. Bligh Cancer Research Laboratories, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 (United States); Yu, Chao-Lan, E-mail: chaolan.yu@rosalindfranklin.edu [Department of Microbiology and Immunology, H. M. Bligh Cancer Research Laboratories, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 (United States)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Lmo2 expression is elevated in Lck-transformed cells. Black-Right-Pointing-Pointer Both endogenous and exogenous Lck localize in the nucleus. Black-Right-Pointing-Pointer Nuclear Lck is active in Lck-transformed cells. Black-Right-Pointing-Pointer Lck binds to the promoter region of Lmo2 gene in vivo. Black-Right-Pointing-Pointer In contrast to JAK2, Lck does not increase histone H3 phosphorylation on Tyr 41. -- Abstract: LIM domain only protein 2 (Lmo2) is a transcription factor that plays a critical role in the development of T-acute lymphoblastic leukemia (T-ALL). A previous report established a link between Lmo2 expression and the nuclear presence of oncogenic Janus kinase 2 (JAK2), a non-receptor protein tyrosine kinase. The oncogenic JAK2 kinase phosphorylates histone H3 on Tyr 41 that leads to the relief of Lmo2 promoter repression and subsequent gene expression. Similar to JAK2, constitutive activation of lymphocyte-specific protein tyrosine kinase (Lck) has been implicated in lymphoid malignancies. However, it is not known whether oncogenic Lck regulates Lmo2 expression through a similar mechanism. We show here that Lmo2 expression is significantly elevated in T cell leukemia LSTRA overexpressing active Lck kinase and in HEK 293 cells expressing oncogenic Y505FLck kinase. Nuclear localization of active Lck kinase was confirmed in both Lck-transformed cells by subcellular fractionation and immunofluorescence microscopy. More importantly, in contrast to oncogenic JAK2, oncogenic Lck kinase does not result in significant increase in histone H3 phosphorylation on Tyr 41. Instead, chromatin immunoprecipitation experiment shows that oncogenic Y505FLck kinase binds to the Lmo2 promoter in vivo. This result raises the possibility that oncogenic Lck may activate Lmo2 promoter through direct interaction.

  7. Nuclear expression of Lyn, a Src family kinase member, is associated with poor prognosis in renal cancer patients.

    Science.gov (United States)

    Roseweir, Antonia K; Qayyum, Tahir; Lim, Zhi; Hammond, Rachel; MacDonald, Alasdair I; Fraser, Sioban; Oades, Grenville M; Aitchison, Michael; Jones, Robert J; Edwards, Joanne

    2016-03-16

    8000 cases of renal cancer are diagnosed each year in the UK, with a five-year survival rate of 50%. Treatment options are limited; a potential therapeutic target is the Src family kinases (SFKs). SFKs have roles in multiple oncogenic processes and promote metastases in solid tumours. The aim of this study was to investigate SFKs as potential therapeutic targets for clear cell renal cell carcinoma (ccRCC). SFKs expression was assessed in a tissue microarray consisting of 192 ccRCC patients with full clinical follow-up. SFK inhibitors, dasatinib and saracatinib, were assessed in early ccRCC cell lines, 786-O and 769-P and a metastatic ccRCC cell line, ACHN (± Src) for effects on protein expression, apoptosis, proliferation and wound healing. High nuclear expression of Lyn and the downstream marker of activation, paxillin, were associated with decreased patient survival. Conversely, high cytoplasmic expression of other SFK members and downstream marker of activation, focal adhesion kinase (FAK) were associated with increased patient survival. Treatment of non-metastatic 786-O and 769-P cells with dasatinib, dose dependently reduced SFK activation, shown via SFK (Y(419)) and FAK (Y(861)) phosphorylation, with no effect in metastatic ACHN cells. Dasatinib also increased apoptosis, while decreasing proliferation and migration in 786-O and 769-P cell lines, both in the presence and absence of Src protein. Our data suggests that nuclear Lyn is a potential therapeutic target for ccRCC and dasatinib affects cellular functions associated with cancer progression via a Src kinase independent mechanism.

  8. Characterization, subcellular localization and nuclear targeting of casein kinase 2 from Zea mays

    DEFF Research Database (Denmark)

    Peracchia, G; Jensen, A B; Culiáñez-Macià, F A

    1999-01-01

    We have isolated and characterized the genomic clone of maize casein kinase 2 (CK2) alpha subunit using the previously described alphaCK2-1 cDNA clone as a probe. The genomic clone is 7.5 kb long and contains 10 exons, separated by 9 introns of different size, two larger than 1.5 kb and the others...

  9. MAP kinase-signaling controls nuclear translocation of tripeptidyl-peptidase II in response to DNA damage and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Preta, Giulio; Klark, Rainier de; Chakraborti, Shankhamala [Center for Molecular Medicine (CMM), Department of Medicine, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm (Sweden); Glas, Rickard, E-mail: rickard.glas@ki.se [Center for Molecular Medicine (CMM), Department of Medicine, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm (Sweden)

    2010-08-27

    Research highlights: {yields} Nuclear translocation of TPPII occurs in response to different DNA damage inducers. {yields} Nuclear accumulation of TPPII is linked to ROS and anti-oxidant enzyme levels. {yields} MAPKs control nuclear accumulation of TPPII. {yields} Inhibited nuclear accumulation of TPPII decreases DNA damage-induced {gamma}-H2AX expression. -- Abstract: Reactive oxygen species (ROS) are a continuous hazard in eukaroytic cells by their ability to cause damage to biomolecules, in particular to DNA. Previous data indicated that the cytosolic serine peptidase tripeptidyl-peptidase II (TPPII) translocates into the nucleus of most tumor cell lines in response to {gamma}-irradiation and ROS production; an event that promoted p53 expression as well as caspase-activation. We here observed that nuclear translocation of TPPII was dependent on signaling by MAP kinases, including p38MAPK. Further, this was caused by several types of DNA-damaging drugs, a DNA cross-linker (cisplatinum), an inhibitor of topoisomerase II (etoposide), and to some extent also by nucleoside-analogues (5-fluorouracil, hydroxyurea). In the minority of tumor cell lines where TPPII was not translocated into the nucleus in response to DNA damage we observed reduced intracellular ROS levels, and the expression levels of redox defense systems were increased. Further, treatment with the ROS-inducer {gamma}-hexa-chloro-cyclohexane ({gamma}-HCH, lindane), an inhibitor of GAP junctions, restored nuclear translocation of TPPII in these cell lines upon {gamma}-irradiation. Moreover, blocking nuclear translocation of TPPII in etoposide-treated cells, by using a peptide-derived inhibitor (Z-Gly-Leu-Ala-OH), attenuated expression of {gamma}-H2AX in {gamma}-irradiated melanoma cells. Our results indicated a role for TPPII in MAPK-dependent DNA damage signaling.

  10. Tau-Induced Ca2+/Calmodulin-Dependent Protein Kinase-IV Activation Aggravates Nuclear Tau Hyperphosphorylation.

    Science.gov (United States)

    Wei, Yu-Ping; Ye, Jin-Wang; Wang, Xiong; Zhu, Li-Ping; Hu, Qing-Hua; Wang, Qun; Ke, Dan; Tian, Qing; Wang, Jian-Zhi

    2018-04-01

    Hyperphosphorylated tau is the major protein component of neurofibrillary tangles in the brains of patients with Alzheimer's disease (AD). However, the mechanism underlying tau hyperphosphorylation is not fully understood. Here, we demonstrated that exogenously expressed wild-type human tau40 was detectable in the phosphorylated form at multiple AD-associated sites in cytoplasmic and nuclear fractions from HEK293 cells. Among these sites, tau phosphorylated at Thr205 and Ser214 was almost exclusively found in the nuclear fraction at the conditions used in the present study. With the intracellular tau accumulation, the Ca 2+ concentration was significantly increased in both cytoplasmic and nuclear fractions. Further studies using site-specific mutagenesis and pharmacological treatment demonstrated that phosphorylation of tau at Thr205 increased nuclear Ca 2+ concentration with a simultaneous increase in the phosphorylation of Ca 2+ /calmodulin-dependent protein kinase IV (CaMKIV) at Ser196. On the other hand, phosphorylation of tau at Ser214 did not significantly change the nuclear Ca 2+ /CaMKIV signaling. Finally, expressing calmodulin-binding protein-4 that disrupts formation of the Ca 2+ /calmodulin complex abolished the okadaic acid-induced tau hyperphosphorylation in the nuclear fraction. We conclude that the intracellular accumulation of phosphorylated tau, as detected in the brains of AD patients, can trigger nuclear Ca 2+ /CaMKIV signaling, which in turn aggravates tau hyperphosphorylation. Our findings provide new insights for tauopathies: hyperphosphorylation of intracellular tau and an increased Ca 2+ concentration may induce a self-perpetuating harmful loop to promote neurodegeneration.

  11. Nuclear and nucleolar localization signals and their targeting function in phosphatidylinositol 4-kinase PI4K230

    International Nuclear Information System (INIS)

    Kakuk, Annamaria; Friedlaender, Elza; Vereb, Gyoergy; Lisboa, Duarte; Bagossi, Peter; Toth, Gabor; Gergely, Pal; Vereb, Gyoergy

    2008-01-01

    PI4K230, an isoform of phosphatidylinositol 4-kinase, known primarily as a cytoplasmic membrane-bound enzyme, was detected recently also in the nucleolus of several cells. Here we provide mechanistic insight on the targeting function of its putative nuclear localization signal (NLS) sequences using molecular modeling, digitonin-permeabilized HeLa cells and binding to various importins. The synthetic sequence 916 NFNHIHKRIRRVADKYLSG 934 comprising a putative monopartite NLS (NLS1), targeted covalently bound fluorescent BSA to the nucleoplasm via classical importin α/β mechanism employing importins α1 and α3 but not α5. This transport was inhibited by wheat germ agglutinin and GTPγS. The sequence 1414 SKKTNRGSQLHKYYMKRRTL 1433 , a putative bipartite NLS (NLS2) proved ineffective in nuclear targeting if conjugated to fluorescently labeled BSA. Nonetheless, NLS2 or either of its basic clusters directed to the nucleolus soybean trypsin inhibitor that can pass the nuclear pore complex passively; moreover, an expressed 58 kDa fragment of PI4K230 (AA1166-1667) comprising NLS2 was also imported into the nucleus by import factors of reticulocyte lysate or by importin α1/β or α3/β complexes and localized to the nucleolus. We conclude that the putative bipartite NLS itself is a nucleolar targeting signal, and for nuclear import PI4K230 requires a larger sequence around it or, alternatively, the monopartite NLS

  12. Oryza sativa (Rice) Hull Extract Inhibits Lipopolysaccharide-Induced Inflammatory Response in RAW264.7 Macrophages by Suppressing Extracellular Signal-regulated Kinase, c-Jun N-terminal Kinase, and Nuclear Factor-κB Activation.

    Science.gov (United States)

    Ha, Sang Keun; Sung, Jeehye; Choi, Inwook; Kim, Yoonsook

    2016-01-01

    Rice ( Oryza sativa ) is a major cereal crop in many Asian countries and an important staple food source. Rice hulls have been reported to possess antioxidant activities. In this study, we evaluated the antiinflammatory effects of rice hull extract and associated signal transduction mechanisms in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We found that rice hull extract inhibited nitric oxide (NO) and prostaglandin E 2 by suppressing the expression of inducible NO synthase and cyclooxygenase-2, respectively. The release of interleukin-1β and tumor necrosis factor-α was also reduced in a dose-dependent manner. Furthermore, rice hull extract attenuated the activation of nuclear factor-kappa B (NF-κB), as well as the phosphorylation of mitogen-activated protein kinases, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK), in LPS-stimulated RAW264.7 cells. This suggests that rice hull extract decreases the production of inflammatory mediators by downregulating ERK and JNK and the NF-κB signal pathway in RAW 264.7 cells. Rice hull extract inhibits the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages.Rice hull extract inhibited nitric oxide and prostaglandin E 2 by suppressing the expression of inducible NO synthase and cyclooxygenase-2, respectively.Rice hull extract exerted anti-inflammatory effect through inhibition of nuclear factor-kappa B, extracellular signal-regulated kinase and c-Jun N-terminal kinase signaling pathways.Rice hull extract may provide a potential therapeutic approach for inflammatory diseases. Abbreviations used: COX-2: cyclooxygenase-2, ERK: extracellular signal-regulated kinase, IκB: inhibitory kappa B, IL-1β: interleukin-1β, iNOS: inducible NO synthase, JNK: c-Jun N-terminal kinase, LPS: lipopolysaccharide, MAPKs: mitogen-activated protein kinases, NF-κB: nuclear factor-κB, NO: nitric oxide, PGE2: prostaglandin E2, RHE: rice hull extract, ROS: reactive oxygen species

  13. Angiogenin-induced protein kinase B/Akt activation is necessary for angiogenesis but is independent of nuclear translocation of angiogenin in HUVE cells

    International Nuclear Information System (INIS)

    Kim, Hye-Mi; Kang, Dong-Ku; Kim, Hak Yong; Kang, Sang Sun; Chang, Soo-Ik

    2007-01-01

    Angiogenin, a potent angiogenic factor, binds to endothelial cells and is endocytosed and rapidly translocated to and concentrated in the nucleolus where it binds to DNA. In this study, we report that angiogenin induces transient phosphorylation of protein kinase B/Akt in cultured human umbilical vein endothelial (HUVE) cells. LY294002 inhibits the angiogenin-induced protein kinase B/Akt activation and also angiogenin-induced cell migration in vitro as well as angiogenesis in chick embryo chorioallantoic membrane in vivo without affecting nuclear translocation of angiogenin in HUVE cells. These results suggest that cross-talk between angiogenin and protein kinase B/Akt signaling pathways is essential for angiogenin-induced angiogenesis in vitro and in vivo, and that angiogenin-induced PKB/Akt activation is independent of nuclear translocation of angiogenin in HUVE cells

  14. Evidence that phosphorylation by the mitotic kinase Cdk1 promotes ICER monoubiquitination and nuclear delocalization

    Energy Technology Data Exchange (ETDEWEB)

    Memin, Elisabeth, E-mail: molinac@mail.montclair.edu [Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 07103 (United States); Genzale, Megan [Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 07103 (United States); Crow, Marni; Molina, Carlos A. [Department of Biology and Molecular Biology, Montclair State University, Montclair, NJ, 07043 (United States)

    2011-10-15

    In contrast to normal prostatic cells, the transcriptional repressor Inducible cAMP Early Repressor (ICER) is undetected in the nuclei of prostate cancer cells. The molecular mechanisms for ICER abnormal expression in prostate cancer cells remained largely unknown. In this report data is presented demonstrating that ICER is phosphorylated by the mitotic kinase cdk1. Phosphorylation of ICER on a discrete residue targeted ICER to be monoubiquitinated. Different from unphosphorylated, phosphorylated and polyubiquitinated ICER, monoubiquitinated ICER was found to be cytosolic. Taken together, these results hinted on a mechanism for the observed abnormal subcellular localization of ICER in human prostate tumors.

  15. Significance of host cell kinases in herpes simplex virus type 1 egress and lamin-associated protein disassembly from the nuclear lamina

    International Nuclear Information System (INIS)

    Leach, Natalie R.; Roller, Richard J.

    2010-01-01

    The nuclear lamina is thought to be a steric barrier to the herpesvirus capsid. Disruption of the lamina accompanied by phosphorylation of lamina proteins is a conserved feature of herpesvirus infection. In HSV-1-infected cells, protein kinase C (PKC) alpha and delta isoforms are recruited to the nuclear membrane and PKC delta has been implicated in phosphorylation of emerin and lamin B. We tested two critical hypotheses about the mechanism and significance of lamina disruption. First, we show that chemical inhibition of all PKC isoforms reduced viral growth five-fold and inhibited capsid egress from the nucleus. However, specific inhibition of either conventional PKCs or PKC delta does not inhibit viral growth. Second, we show hyperphosphorylation of emerin by viral and cellular kinases is required for its disassociation from the lamina. These data support hypothesis that phosphorylation of lamina components mediates lamina disruption during HSV nuclear egress.

  16. Theobromine, the primary methylxanthine found in Theobroma cacao, prevents malignant glioblastoma proliferation by negatively regulating phosphodiesterase-4, extracellular signal-regulated kinase, Akt/mammalian target of rapamycin kinase, and nuclear factor-kappa B.

    Science.gov (United States)

    Sugimoto, Naotoshi; Miwa, Shinji; Hitomi, Yoshiaki; Nakamura, Hiroyuki; Tsuchiya, Hiroyuki; Yachie, Akihiro

    2014-01-01

    Theobromine, a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. We previously showed that methylxanthines, including caffeine and theophylline, have antitumor and antiinflammatory effects, which are in part mediated by their inhibition of phosphodiesterase (PDE). A member of the PDE family, PDE4, is widely expressed in and promotes the growth of glioblastoma, the most common type of brain tumor. The purpose of this study was to determine whether theobromine could exert growth inhibitory effects on U87-MG, a cell line derived from human malignant glioma. We show that theobromine treatment elevates intracellular cAMP levels and increases the activity of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase, whereas it attenuates p44/42 extracellular signal-regulated kinase activity and the Akt/mammalian target of rapamycin kinase and nuclear factor-kappa B signal pathways. It also inhibits cell proliferation. These results suggest that foods and beverages containing cocoa bean extracts, including theobromine, might be extremely effective in preventing human glioblastoma.

  17. Nuclear phosphoproteome of developing chickpea seedlings (Cicer arietinum L.) and protein-kinase interaction network.

    Science.gov (United States)

    Kumar, Rajiv; Kumar, Amit; Subba, Pratigya; Gayali, Saurabh; Barua, Pragya; Chakraborty, Subhra; Chakraborty, Niranjan

    2014-06-13

    Nucleus, the control centre of eukaryotic cell, houses most of the genetic machineries required for gene expression and their regulation. Post translational modifications of proteins, particularly phosphorylation control a wide variety of cellular processes but its functional connectivity, in plants, is still elusive. This study profiled the nuclear phosphoproteome of a grain legume, chickpea, to gain better understanding of such event. Intact nuclei were isolated from 3-week-old seedlings using two independent methods, and nuclear proteins were resolved by 2-DE. In a separate set of experiments, phosphoproteins were enriched using IMAC method and resolved by 1-DE. The separated proteins were stained with phosphospecific Pro-Q Diamond stain. Proteomic analyses led to the identification of 107 putative phosphoproteins, of which 86 were non-redundant. Multiple sites of phosphorylation were predicted on several key elements, which included both regulatory and functional proteins. The analysis revealed an array of phosphoproteins, presumably involved in a variety of cellular functions, viz., protein folding (24%), signalling and gene regulation (22%), DNA replication, repair and modification (16%), and metabolism (13%), among others. These results represent the first nucleus-specific phosphoproteome map of a non-model legume, which would provide insights into the possible function of protein phosphorylation in plants. Chickpea is grown over 10 million hectares of land worldwide, and global production hovers around 8.5 million metric tons annually. Despite its nutritional merits, it is often referred to as 'orphan' legume and has remained outside the realm of large-scale functional genomics studies. While current chickpea genome initiative has primarily focused on sequence information and functional annotation, proteomics analyses are limited. It is thus important to study the proteome of the cell organelle particularly the nucleus, which harbors most of the genetic

  18. Obesity-Linked Phosphorylation of SIRT1 by Casein Kinase 2 Inhibits Its Nuclear Localization and Promotes Fatty Liver.

    Science.gov (United States)

    Choi, Sung E; Kwon, Sanghoon; Seok, Sunmi; Xiao, Zhen; Lee, Kwan-Woo; Kang, Yup; Li, Xiaoling; Shinoda, Kosaku; Kajimura, Shingo; Kemper, Byron; Kemper, Jongsook Kim

    2017-08-01

    Sirtuin1 (SIRT1) deacetylase delays and improves many obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD) and diabetes, and has received great attention as a drug target. SIRT1 function is aberrantly low in obesity, so understanding the underlying mechanisms is important for drug development. Here, we show that obesity-linked phosphorylation of SIRT1 inhibits its function and promotes pathological symptoms of NAFLD. In proteomic analysis, Ser-164 was identified as a major serine phosphorylation site in SIRT1 in obese, but not lean, mice, and this phosphorylation was catalyzed by casein kinase 2 (CK2), the levels of which were dramatically elevated in obesity. Mechanistically, phosphorylation of SIRT1 at Ser-164 substantially inhibited its nuclear localization and modestly affected its deacetylase activity. Adenovirus-mediated liver-specific expression of SIRT1 or a phosphor-defective S164A-SIRT1 mutant promoted fatty acid oxidation and ameliorated liver steatosis and glucose intolerance in diet-induced obese mice, but these beneficial effects were not observed in mice expressing a phosphor-mimic S164D-SIRT1 mutant. Remarkably, phosphorylated S164-SIRT1 and CK2 levels were also highly elevated in liver samples of NAFLD patients and correlated with disease severity. Thus, inhibition of phosphorylation of SIRT1 by CK2 may serve as a new therapeutic approach for treatment of NAFLD and other obesity-related diseases. Copyright © 2017 American Society for Microbiology.

  19. Heterogeneous nuclear ribonucleoprotein B1 protein impairs DNA repair mediated through the inhibition of DNA-dependent protein kinase activity

    International Nuclear Information System (INIS)

    Iwanaga, Kentaro; Sueoka, Naoko; Sato, Akemi; Hayashi, Shinichiro; Sueoka, Eisaburo

    2005-01-01

    Heterogeneous nuclear ribonucleoprotein B1, an RNA binding protein, is overexpressed from the early stage of lung cancers; it is evident even in bronchial dysplasia, a premalignant lesion. We evaluated the proteins bound with hnRNP B1 and found that hnRNP B1 interacted with DNA-dependent protein kinase (DNA-PK) complex, and recombinant hnRNP B1 protein dose-dependently inhibited DNA-PK activity in vitro. To test the effect of hnRNP B1 on DNA repair, we performed comet assay after irradiation, using normal human bronchial epithelial (HBE) cells treated with siRNA for hnRNP A2/B1: reduction of hnRNP B1 treated with siRNA for hnRNP A2/B1 induced faster DNA repair in normal HBE cells. Considering these results, we assume that overexpression of hnRNP B1 occurring in the early stage of carcinogenesis inhibits DNA-PK activity, resulting in subsequent accumulation of erroneous rejoining of DNA double-strand breaks, causing tumor progression

  20. Nuclear cGMP-dependent kinase regulates gene expression via activity-dependent recruitment of a conserved histone deacetylase complex.

    Directory of Open Access Journals (Sweden)

    Yan Hao

    2011-05-01

    Full Text Available Elevation of the second messenger cGMP by nitric oxide (NO activates the cGMP-dependent protein kinase PKG, which is key in regulating cardiovascular, intestinal, and neuronal functions in mammals. The NO-cGMP-PKG signaling pathway is also a major therapeutic target for cardiovascular and male reproductive diseases. Despite widespread effects of PKG activation, few molecular targets of PKG are known. We study how EGL-4, the Caenorhabditis elegans PKG ortholog, modulates foraging behavior and egg-laying and seeks the downstream effectors of EGL-4 activity. Using a combination of unbiased forward genetic screen and proteomic analysis, we have identified a conserved SAEG-1/SAEG-2/HDA-2 histone deacetylase complex that is specifically recruited by activated nuclear EGL-4. Gene expression profiling by microarrays revealed >40 genes that are sensitive to EGL-4 activity in a SAEG-1-dependent manner. We present evidence that EGL-4 controls egg laying via one of these genes, Y45F10C.2, which encodes a novel protein that is expressed exclusively in the uterine epithelium. Our results indicate that, in addition to cytoplasmic functions, active EGL-4/PKG acts in the nucleus via a conserved Class I histone deacetylase complex to regulate gene expression pertinent to behavioral and physiological responses to cGMP. We also identify transcriptional targets of EGL-4 that carry out discrete components of the physiological response.

  1. Nuclear Phosphatidylinositol-Phosphate Type I Kinase α-Coupled Star-PAP Polyadenylation Regulates Cell Invasion.

    Science.gov (United States)

    A P, Sudheesh; Laishram, Rakesh S

    2018-03-01

    Star-PAP, a nuclear phosphatidylinositol (PI) signal-regulated poly(A) polymerase (PAP), couples with type I PI phosphate kinase α (PIPKIα) and controls gene expression. We show that Star-PAP and PIPKIα together regulate 3'-end processing and expression of pre-mRNAs encoding key anti-invasive factors ( KISS1R , CDH1 , NME1 , CDH13 , FEZ1 , and WIF1 ) in breast cancer. Consistently, the endogenous Star-PAP level is negatively correlated with the cellular invasiveness of breast cancer cells. While silencing Star-PAP or PIPKIα increases cellular invasiveness in low-invasiveness MCF7 cells, Star-PAP overexpression decreases invasiveness in highly invasive MDA-MB-231 cells in a cellular Star-PAP level-dependent manner. However, expression of the PIPKIα-noninteracting Star-PAP mutant or the phosphodeficient Star-PAP (S6A mutant) has no effect on cellular invasiveness. These results strongly indicate that PIPKIα interaction and Star-PAP S6 phosphorylation are required for Star-PAP-mediated regulation of cancer cell invasion and give specificity to target anti-invasive gene expression. Our study establishes Star-PAP-PIPKIα-mediated 3'-end processing as a key anti-invasive mechanism in breast cancer. Copyright © 2018 A.P. and Laishram.

  2. Receptor for activated protein kinase C 1 suppresses gastric tumor progression through nuclear factor-kB pathway.

    Science.gov (United States)

    Yong-Zheng, X; Wan-Li, M; Ji-Ming, M; Xue-Qun, R

    2015-12-01

    Nuclear factor-kB (NF-kB) activity is crucial for survival and proliferation of many kinds of malignancies, including gastric cancer (GC). The receptor for activated protein kinase C 1 (RACK1) is known to regulate tumor development, whereas the underlined mechanism has not been described clearly. We analyzed expression of RACK1 in paired human GC samples by both real-time polymerase chain reaction (PCR) and western blot. Effects of RACK inhibition with small interfering RNA or its overexpression in cultured GC cell lines were evaluated in cell viabilities. NF-kB signaling was investigated using luciferase reporter assay and real-time PCR. RACK1 was significantly decreased in GC samples. Knockdown of RACK elevated GC cell viabilities, whereas overexpression of RACK1 suppressed tumorigenesis of GC cells. Importantly, NF-kB signaling was enhanced after RACK1 expression was inhibited, suggesting the negative regulation of the pro-oncogenic NF-kB activity by RACK1 might contribute to its tumor suppressor role in GC cells. Our results support that RACK1 suppresses gastric tumor progression through the NF-kB signaling pathway.

  3. Rho-kinase signaling controls nucleocytoplasmic shuttling of class IIa Histone Deacetylase (HDAC7) and transcriptional activation of orphan nuclear receptor NR4A1

    Energy Technology Data Exchange (ETDEWEB)

    Compagnucci, Claudia; Barresi, Sabina [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Petrini, Stefania [Research Laboratories, Confocal Microscopy Core Facility, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Bertini, Enrico [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Zanni, Ginevra, E-mail: ginevra.zanni@opbg.net [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy)

    2015-04-03

    Rho-kinase (ROCK) has been well documented to play a key role in RhoA-induced actin remodeling. ROCK activation results in myosin light chain (MLC) phosphorylation either by direct action on MLC kinase (MLCK) or by inhibition of MLC phosphatase (MLCP), modulating actin–myosin contraction. We found that inhibition of the ROCK pathway in induced pluripotent stem cells, leads to nuclear export of HDAC7 and transcriptional activation of the orphan nuclear receptor NR4A1 while in cells with constitutive ROCK hyperactivity due to loss of function of the RhoGTPase activating protein Oligophrenin-1 (OPHN1), the orphan nuclear receptor NR4A1 is downregulated. Our study identify a new target of ROCK signaling via myosin phosphatase subunit (MYPT1) and Histone Deacetylase (HDAC7) at the nuclear level and provide new insights in the cellular functions of ROCK. - Highlights: • ROCK regulates nucleocytoplasmic shuttling of HDAC7 via phosphorylation of MYPT1. • Nuclear export of HDAC7 and upregulation of NR4A1 occurs with low ROCK activity. • High levels of ROCK activity due to OPHN1 loss of function downregulate NR4A1.

  4. Protein Kinase C-{delta} mediates down-regulation of heterogeneous nuclear ribonucleoprotein K protein: involvement in apoptosis induction

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Feng-Hou [NO.3 People' s Hospital affiliated to Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 201900 (China); The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Wu, Ying-Li [The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Zhao, Meng [Institute of Health Science, SJTU-SM/Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai (China); Liu, Chuan-Xu; Wang, Li-Shun [The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Chen, Guo-Qiang, E-mail: chengq@shsmu.edu.cn [The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Institute of Health Science, SJTU-SM/Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai (China)

    2009-11-15

    We reported previously that NSC606985, a camptothecin analogue, induces apoptosis of acute myeloid leukemia (AML) cells through proteolytic activation of protein kinase C delta ({Delta}PKC-{delta}). By subcellular proteome analysis, heterogeneous nuclear ribonucleoprotein K (hnRNP K) was identified as being significantly down-regulated in NSC606985-treated leukemic NB4 cells. HnRNP K, a docking protein for DNA, RNA, and transcriptional or translational molecules, is implicated in a host of processes involving the regulation of gene expression. However, the molecular mechanisms of hnRNP K reduction and its roles during apoptosis are still not understood. In the present study, we found that, following the appearance of the {Delta}PKC-{delta}, hnRNP K protein was significantly down-regulated in NSC606985, doxorubicin, arsenic trioxide and ultraviolet-induced apoptosis. We further provided evidence that {Delta}PKC-{delta} mediated the down-regulation of hnRNP K protein during apoptosis: PKC-{delta} inhibitor could rescue the reduction of hnRNP K; hnRNP K failed to be decreased in PKC-{delta}-deficient apoptotic KG1a cells; conditional induction of {Delta}PKC-{delta} in U937T cells directly down-regulated hnRNP K protein. Moreover, the proteasome inhibitor also inhibited the down-regulation of hnRNP K protein by apoptosis inducer and the conditional expression of {Delta}PKC-{delta}. More intriguingly, the suppression of hnRNP K with siRNA transfection significantly induced apoptosis. To our knowledge, this is the first demonstration that proteolytically activated PKC-{delta} down-regulates hnRNP K protein in a proteasome-dependent manner, which plays an important role in apoptosis induction.

  5. Fisetin Ameliorated Photodamage by Suppressing the Mitogen-Activated Protein Kinase/Matrix Metalloproteinase Pathway and Nuclear Factor-κB Pathways.

    Science.gov (United States)

    Chiang, Hsiu-Mei; Chan, Shih-Yun; Chu, Yin; Wen, Kuo-Ching

    2015-05-13

    Ultraviolet (UV) irradiation is one of the most important extrinsic factors contributing to skin photodamage. After UV irradiation, a series of signal transductions in the skin will be activated, leading to inflammatory response and photoaged skin. In this study, fisetin, a flavonol that exists in fruits and vegetables, was investigated for its photoprotective effects. The results revealed that 5-25 μM fisetin inhibits cyclooxygenase-2 (COX-2) and matrix metalloproteinase (MMP)-1, MMP-3, MMP-9 expression induced by ultraviolet B (UVB) irradiation in human skin fibroblasts. In addition, fisetin suppressed UVB-induced collagen degradation. With regard to its effect on upper-stream signal transduction, we found that fisetin reduced the expression of ultraviolet (UV)-induced ERK, JNK, and p38 phosphorylation in the mitogen-activated protein kinase (MAP kinase) pathway. Furthermore, fisetin reduced inhibitor κB (IκB) degradation and increased the amount of p65, which is a major subunit of nuclear factor-κB (NF-κB), in cytoplasm. It also suppressed NF-κB translocated to the nucleus and inhibited cAMP response element-binding protein (CREB) Ser-133 phosphorylation level in the phosphoinositide 3-kinase/protein kinase B/CREB (PI3K/AKT/CREB) pathway. Finally, fisetin inhibited UV-induced intracellular reactive oxygen species (ROS), prostaglandin E2 (PGE2), and nitric oxide (NO) generation. The mentioned effects and mechanisms suggest that fisetin can be used in the development of photoprotective agents.

  6. Protein kinase A antagonist inhibits β-catenin nuclear translocation, c-Myc and COX-2 expression and tumor promotion in ApcMin/+ mice

    Directory of Open Access Journals (Sweden)

    Brudvik Kristoffer W

    2011-12-01

    Full Text Available Abstract Background The adenomatous polyposis coli (APC protein is part of the destruction complex controlling proteosomal degradation of β-catenin and limiting its nuclear translocation, which is thought to play a gate-keeping role in colorectal cancer. The destruction complex is inhibited by Wnt-Frz and prostaglandin E2 (PGE2 - PI-3 kinase pathways. Recent reports show that PGE2-induced phosphorylation of β-catenin by protein kinase A (PKA increases nuclear translocation indicating two mechanisms of action of PGE2 on β-catenin homeostasis. Findings Treatment of ApcMin/+ mice that spontaneously develop intestinal adenomas with a PKA antagonist (Rp-8-Br-cAMPS selectively targeting only the latter pathway reduced tumor load, but not the number of adenomas. Immunohistochemical characterization of intestines from treated and control animals revealed that expression of β-catenin, β-catenin nuclear translocation and expression of the β-catenin target genes c-Myc and COX-2 were significantly down-regulated upon Rp-8-Br-cAMPS treatment. Parallel experiments in a human colon cancer cell line (HCT116 revealed that Rp-8-Br-cAMPS blocked PGE2-induced β-catenin phosphorylation and c-Myc upregulation. Conclusion Based on our findings we suggest that PGE2 act through PKA to promote β-catenin nuclear translocation and tumor development in ApcMin/+ mice in vivo, indicating that the direct regulatory effect of PKA on β-catenin nuclear translocation is operative in intestinal cancer.

  7. Herpesvirus gB-induced fusion between the virion envelope and outer nuclear membrane during virus egress is regulated by the viral US3 kinase.

    Science.gov (United States)

    Wisner, Todd W; Wright, Catherine C; Kato, Akihisa; Kawaguchi, Yasushi; Mou, Fan; Baines, Joel D; Roller, Richard J; Johnson, David C

    2009-04-01

    Herpesvirus capsids collect along the inner surface of the nuclear envelope and bud into the perinuclear space. Enveloped virions then fuse with the outer nuclear membrane (NM). We previously showed that herpes simplex virus (HSV) glycoproteins gB and gH act in a redundant fashion to promote fusion between the virion envelope and the outer NM. HSV mutants lacking both gB and gH accumulate enveloped virions in herniations, vesicles that bulge into the nucleoplasm. Earlier studies had shown that HSV mutants lacking the viral serine/threonine kinase US3 also accumulate herniations. Here, we demonstrate that HSV gB is phosphorylated in a US3-dependent manner in HSV-infected cells, especially in a crude nuclear fraction. Moreover, US3 directly phosphorylated the gB cytoplasmic (CT) domain in in vitro assays. Deletion of gB in the context of a US3-null virus did not add substantially to defects in nuclear egress. The majority of the US3-dependent phosphorylation of gB involved the CT domain and amino acid T887, a residue present in a motif similar to that recognized by US3 in other proteins. HSV recombinants lacking gH and expressing either gB substitution mutation T887A or a gB truncated at residue 886 displayed substantial defects in nuclear egress. We concluded that phosphorylation of the gB CT domain is important for gB-mediated fusion with the outer NM. This suggested a model in which the US3 kinase is incorporated into the tegument layer (between the capsid and envelope) in HSV virions present in the perinuclear space. By this packaging, US3 might be brought close to the gB CT tail, leading to phosphorylation and triggering fusion between the virion envelope and the outer NM.

  8. The Arabidopsis TOR Kinase Specifically Regulates the Expression of Nuclear Genes Coding for Plastidic Ribosomal Proteins and the Phosphorylation of the Cytosolic Ribosomal Protein S6.

    Science.gov (United States)

    Dobrenel, Thomas; Mancera-Martínez, Eder; Forzani, Céline; Azzopardi, Marianne; Davanture, Marlène; Moreau, Manon; Schepetilnikov, Mikhail; Chicher, Johana; Langella, Olivier; Zivy, Michel; Robaglia, Christophe; Ryabova, Lyubov A; Hanson, Johannes; Meyer, Christian

    2016-01-01

    Protein translation is an energy consuming process that has to be fine-tuned at both the cell and organism levels to match the availability of resources. The target of rapamycin kinase (TOR) is a key regulator of a large range of biological processes in response to environmental cues. In this study, we have investigated the effects of TOR inactivation on the expression and regulation of Arabidopsis ribosomal proteins at different levels of analysis, namely from transcriptomic to phosphoproteomic. TOR inactivation resulted in a coordinated down-regulation of the transcription and translation of nuclear-encoded mRNAs coding for plastidic ribosomal proteins, which could explain the chlorotic phenotype of the TOR silenced plants. We have identified in the 5' untranslated regions (UTRs) of this set of genes a conserved sequence related to the 5' terminal oligopyrimidine motif, which is known to confer translational regulation by the TOR kinase in other eukaryotes. Furthermore, the phosphoproteomic analysis of the ribosomal fraction following TOR inactivation revealed a lower phosphorylation of the conserved Ser240 residue in the C-terminal region of the 40S ribosomal protein S6 (RPS6). These results were confirmed by Western blot analysis using an antibody that specifically recognizes phosphorylated Ser240 in RPS6. Finally, this antibody was used to follow TOR activity in plants. Our results thus uncover a multi-level regulation of plant ribosomal genes and proteins by the TOR kinase.

  9. 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.

  10. Glycogen synthase kinase 3-{beta} phosphorylates novel S/T-P-S/T domains in Notch1 intracellular domain and induces its nuclear localization

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xiangzi [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Preventive Medicine, Yanbian University College of Medicine, Yanji (China); Ju, Ji-hyun [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Shin, Incheol, E-mail: incheol@hanyang.ac.kr [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer Novel S/T-P-S/T domains were identified in NICD. Black-Right-Pointing-Pointer Phosphorylation of NICD on the S/T-P-S/T domains induced nuclear localization. Black-Right-Pointing-Pointer GSK-3{beta} phosphorylated S and T residues in NICD S/T-P-S/T domains. -- Abstract: We identified two S/T-P-S/T domains (2122-2124, 2126-2128) inducing Notch intracellular domain (NICD) nuclear localization. The GFP-NICD (1963-2145) fusion protein deletion mutant without classical NLS was localized in the nucleus like the full length GFP-NICD. However, quadruple substitution mutant (T2122A T2124A S2126A T2128A) showed increased cytoplasmic localization. GSK-3{beta} enhanced nuclear localization and transcriptional activity of WT NICD but not of quadruple substitution mutant. In vitro kinase assays revealed that GSK-3{beta} phosphorylated S and T residues in NICD S/T-P-S/T domains. These results suggest that the novel S/T-P-S/T domain, phosphorylated by GSK-3{beta} is also involved in the nuclear localization of NICD as well as classical NLS.

  11. Period1 gates the circadian modulation of memory-relevant signaling in mouse hippocampus by regulating the nuclear shuttling of the CREB kinase pP90RSK.

    Science.gov (United States)

    Rawashdeh, Oliver; Jilg, Antje; Maronde, Erik; Fahrenkrug, Jan; Stehle, Jörg H

    2016-09-01

    Memory performance varies over a 24-h day/night cycle. While the detailed underlying mechanisms are yet unknown, recent evidence suggests that in the mouse hippocampus, rhythmic phosphorylation of mitogen-activated protein kinase (MAPK) and cyclic adenosine monophosphate response element-binding protein (CREB) are central to the circadian (~ 24 h) regulation of learning and memory. We recently identified the clock protein PERIOD1 (PER1) as a vehicle that translates information encoding time of day to hippocampal plasticity. We here elaborate how PER1 may gate the sensitivity of memory-relevant hippocampal signaling pathways. We found that in wild-type mice (WT), spatial learning triggers CREB phosphorylation only during the daytime, and that this effect depends on the presence of PER1. The time-of-day-dependent induction of CREB phosphorylation can be reproduced pharmacologically in acute hippocampal slices prepared from WT mice, but is absent in preparations made from Per1-knockout (Per1(-/-) ) mice. We showed that the PER1-dependent CREB phosphorylation is regulated downstream of MAPK. Stimulation of WT hippocampal neurons triggered the co-translocation of PER1 and the CREB kinase pP90RSK (pMAPK-activated ribosomal S6 kinase) into the nucleus. In hippocampal neurons from Per1(-/-) mice, however, pP90RSK remained perinuclear. A co-immunoprecipitation assay confirmed a high-affinity interaction between PER1 and pP90RSK. Knocking down endogenous PER1 in hippocampal cells inhibited adenylyl cyclase-dependent CREB activation. Taken together, the PER1-dependent modulation of cytoplasmic-to-nuclear signaling in the murine hippocampus provides a molecular explanation for how the circadian system potentially shapes a temporal framework for daytime-dependent memory performance, and adds a novel facet to the versatility of the clock gene protein PER1. We provide evidence that the circadian clock gene Period1 (Per1) regulates CREB phosphorylation in the mouse hippocampus

  12. Regulation of p53, nuclear factor κB and cyclooxygenase-2 expression by bromelain through targeting mitogen-activated protein kinase pathway in mouse skin

    International Nuclear Information System (INIS)

    Kalra, Neetu; Bhui, Kulpreet; Roy, Preeti; Srivastava, Smita; George, Jasmine; Prasad, Sahdeo; Shukla, Yogeshwer

    2008-01-01

    Bromelain is a pharmacologically active compound, present in stems and immature fruits of pineapples (Ananas cosmosus), which has been shown to have anti-edematous, anti-inflammatory, anti-thrombotic and anti-metastatic properties. In the present study, antitumorigenic activity of bromelain was recorded in 7,12-dimethylbenz(a)anthracene (DMBA)-initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted 2-stage mouse skin model. Results showed that bromelain application delayed the onset of tumorigenesis and reduced the cumulative number of tumors, tumor volume and the average number of tumors/mouse. To establish a cause and effect relationship, we targeted the proteins involved in the cell death pathway. Bromelain treatment resulted in upregulation of p53 and Bax and subsequent activation of caspase 3 and caspase 9 with concomitant decrease in antiapoptotic protein Bcl-2 in mouse skin. Since persistent induction of cyclooxygenase-2 (Cox-2) is frequently implicated in tumorigenesis and is regulated by nuclear factor-kappa B (NF-κB), we also investigated the effect of bromelain on Cox-2 and NF-κB expression. Results showed that bromelain application significantly inhibited Cox-2 and inactivated NF-κB by blocking phosphorylation and subsequent degradation of IκBα. In addition, bromelain treatment attenuated DMBA-TPA-induced phosphorylation of extracellular signal-regulated protein kinase (ERK1/2), mitogen-activated protein kinase (MAPK) and Akt. Taken together, we conclude that bromelain induces apoptosis-related proteins along with inhibition of NF-κB-driven Cox-2 expression by blocking the MAPK and Akt/protein kinase B signaling in DMBA-TPA-induced mouse skin tumors, which may account for its anti-tumorigenic effects

  13. Salidroside attenuates inflammatory responses by suppressing nuclear factor-κB and mitogen activated protein kinases activation in lipopolysaccharide-induced mastitis in mice.

    Science.gov (United States)

    Li, Depeng; Fu, Yunhe; Zhang, Wen; Su, Gaoli; Liu, Bo; Guo, Mengyao; Li, Fengyang; Liang, Dejie; Liu, Zhicheng; Zhang, Xichen; Cao, Yongguo; Zhang, Naisheng; Yang, Zhengtao

    2013-01-01

    Mastitis is defined as inflammation of the mammary gland in domestic dairy animals and humans. Salidroside, a major component isolated from Rhodiola rosea L., has potent anti-inflammatory properties, but whether it can be used in mastitis treatment has not yet been investigated. The aim of this study was to assess the protective effects of salidroside against lipopolysaccharide (LPS)-induced mastitis in mice and the mechanism of action. We used a mouse mastitis model in which mammary gland inflammation was induced by LPS challenge. Salidroside administered 1 h before LPS infusion significantly attenuated inflammatory cell infiltration, reduced the activity of myeloperoxidase in mammary tissue, and decreased the concentration of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in a dose-dependent manner. Further studies revealed that salidroside down-regulated phosphorylation of LPS-induced nuclear transcription factor-kappaB (NF-κB) p65 and inhibitor of NF-κB α (IκBα) in the NF-κB signal pathway, and suppressed phosphorylation of p38, extracellular signal-regulated kinase (ERK) and c-jun NH(2)-terminal kinase (JNK) in MAPKs signal pathways. This study demonstrates that salidroside is an effective suppressor of inflammation and may be a candidate for the prophylaxis of mastitis.

  14. Glycogen synthase kinase 3β regulation of nuclear factor of activated T-cells isoform c1 in the vascular smooth muscle cell response to injury

    International Nuclear Information System (INIS)

    Chow Winsion; Hou Guangpei; Bendeck, Michelle P.

    2008-01-01

    The migration and proliferation of vascular smooth muscle cells (vSMCs) are critical events in neointima formation during atherosclerosis and restenosis. The transcription factor nuclear factor of activated T-cells-isoform c1 (NFATc1) is regulated by atherogenic cytokines, and has been implicated in the migratory and proliferative responses of vSMCs through the regulation of gene expression. In T-cells, calcineurin de-phosphorylates NFATc1, leading to its nuclear import, while glycogen synthase kinase 3 β (GSK3β) phosphorylates NFATc1 and promotes its nuclear export. However, the relationship between NFATc1 and GSK3β has not been studied during SMC migration and proliferation. We investigated this by scrape wounding vSMCs in vitro, and studying wound repair. NFATc1 protein was transiently increased, reaching a peak at 8 h after wounding. Cell fractionation and immunocytochemistry revealed that NFATc1 accumulation in the nucleus was maximal at 4 h after injury, and this was coincident with a significant 9 fold increase in transcriptional activity. Silencing NFATc1 expression with siRNA or inhibition of NFAT with cyclosporin A (CsA) attenuated wound closure by vSMCs. Phospho-GSK3β (inactive) increased to a peak at 30 min after injury, preceding the nuclear accumulation of NFATc1. Overexpression of a constitutively active mutant of GSK3β delayed the nuclear accumulation of NFATc1, caused a 50% decrease in NFAT transcriptional activity, and attenuated vSMC wound repair. We conclude that NFATc1 promotes the vSMC response to injury, and that inhibition of GSK3β is required for the activation of NFAT during wound repair

  15. One- and two-dimensional chemical exchange nuclear magnetic resonance studies of the creatine kinase catalyzed reaction

    International Nuclear Information System (INIS)

    Gober, J.R.

    1988-01-01

    The equilibrium chemical exchange dynamics of the creatine kinase enzyme system were studied by one- and two-dimensional 31 P NMR techniques. Pseudo-first-order reaction rate constants were measured by the saturation transfer method under an array of experimental conditions of pH and temperature. Quantitative one-dimensional spectra were collected under the same conditions in order to calculate the forward and reverse reaction rates, the K eq , the hydrogen ion stoichiometry, and the standard thermodynamic functions. The pure absorption mode in four quadrant two-dimensional chemical exchange experiment was employed so that the complete kinetic matrix showing all of the chemical exchange process could be realized

  16. Mangiferin, a novel nuclear factor kappa B-inducing kinase inhibitor, suppresses metastasis and tumor growth in a mouse metastatic melanoma model

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Tomoya; Tsubaki, Masanobu; Sakamoto, Kotaro; Ichimura, Eri; Enomoto, Aya; Suzuki, Yuri [Division of Pharmacotherapy, Kinki University School of Pharmacy, Kowakae, Higashi-, Osaka (Japan); Itoh, Tatsuki [Department of Food Science and Nutrition, Kinki University School of Agriculture, Nara, Nara (Japan); Imano, Motohiro [Department of Surgery, Kinki University School of Medicine, Osakasayama, Osaka (Japan); Tanabe, Genzoh; Muraoka, Osamu [Laboratory of Pharmaceutical Organic Chemistry, School of Pharmacy, Kinki University, Kowakae, Higashi-, Osaka (Japan); Matsuda, Hideaki [Department of Natural Drugs Resources, Kinki University School of Pharmacy, Kowakae, Higashi-, Osaka (Japan); Satou, Takao [Department of Pathology, Kinki University School of Medicine, Osakasayama, Osaka (Japan); Nishida, Shozo, E-mail: nishida@phar.kindai.ac.jp [Division of Pharmacotherapy, Kinki University School of Pharmacy, Kowakae, Higashi-, Osaka (Japan)

    2016-09-01

    Advanced metastatic melanoma, one of the most aggressive malignancies, is currently without reliable therapy. Therefore, new therapies are urgently needed. Mangiferin is a naturally occurring glucosylxanthone and exerts many beneficial biological activities. However, the effect of mangiferin on metastasis and tumor growth of metastatic melanoma remains unclear. In this study, we evaluated the effect of mangiferin on metastasis and tumor growth in a mouse metastatic melanoma model. We found that mangiferin inhibited spontaneous metastasis and tumor growth. Furthermore, mangiferin suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated NF-κB-inducing kinase (NIK), inhibitor of kappa B kinase (IKK), and inhibitor of kappa B (IκB) and increases the expression of IκB protein in vivo. In addition, we found that mangiferin inhibited the expression of matrix metalloproteinases (MMPs) and very late antigens (VLAs) in vivo. Mangiferin treatment also increased the expression of cleaved caspase-3, cleaved Poly ADP ribose polymerase-1 (PARP-1), p53 upregulated modulator of apoptosis (PUMA), p53, and phosphorylated p53 proteins, and decreased the expression of Survivin and Bcl-associated X (Bcl-xL) proteins in vivo. These results indicate that mangiferin selectivity suppresses the NF-κB pathway via inhibition of NIK activation, thereby inhibiting metastasis and tumor growth. Importantly, the number of reported NIK selective inhibitors is limited. Taken together, our data suggest that mangiferin may be a potential therapeutic agent with a new mechanism of targeting NIK for the treatment of metastatic melanoma. - Highlights: • Mangiferin prolongs survival in mice by inhibiting metastasis and tumor growth • Mangiferin selectivity suppresses the NF-κB pathway via inhibition of NIK activation • Mangiferin regulates the expression of MMPs, VLAs, and apoptosis regulatory proteins.

  17. c-Jun NH2-terminal kinase activity in subcutaneous adipose tissue but not nuclear factor-kappaB activity in peripheral blood mononuclear cells is an independent determinant of insulin resistance in healthy individuals

    DEFF Research Database (Denmark)

    Sourris, Karly C; Lyons, Jasmine G; de Courten, Maximilian

    2009-01-01

    Chronic low-grade activation of the immune system (CLAIS) predicts type 2 diabetes via a decrease in insulin sensitivity. Our study investigated potential relationships between nuclear factor-kappaB (NF-kappaB) and c-Jun NH(2)-terminal kinase (JNK) pathways-two pathways proposed as the link between...

  18. Buddleja officinalis suppresses high glucose-induced vascular smooth muscle cell proliferation: role of mitogen-activated protein kinases, nuclear factor-kappaB and matrix metalloproteinases.

    Science.gov (United States)

    Lee, Yun Jung; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

    2010-02-01

    Diabetes mellitus is a well-established risk factor for vascular diseases caused by atherosclerosis. In the development of diabetic atherogenesis, vascular smooth muscle cell proliferation is recognized as a key event. Thus, we aimed to investigate whether an ethanol extract of Buddleja officinalis (EBO) suppresses high glucose-induced proliferation in primary cultured human aortic smooth muscle cells (HASMC). [(3)H]-thymidine incorporation revealed that incubation of HASMC with a high concentration of glucose (25 mmol/L) increased cell proliferation. The expression levels of cell cycle protein were also increased by treatment with high glucose concentration. Pretreatment of HASMC with EBO significantly attenuated the increase of high glucose-induced cell proliferation as well as p38 mitogen-activated protein kinases (MAPK) and JNK phosphorylation. EBO suppressed high glucose-induced matrix metalloproteinase (MMP)-9 activity in a dose-dependent manner. In addition, EBO suppressed nuclear factor-kappaB (NF-kappaB) nuclear translocation and transcriptional activity in high glucose conditions. Taken together, the present data suggest that EBO could suppress high glucose-induced atherosclerotic processes through inhibition of p38, JNK, NF-kappaB and MMP signal pathways in HASMC.

  19. Hepatoprotective Effect of Quercetin on Endoplasmic Reticulum Stress and Inflammation after Intense Exercise in Mice through Phosphoinositide 3-Kinase and Nuclear Factor-Kappa B

    Directory of Open Access Journals (Sweden)

    Yuhan Tang

    2016-01-01

    Full Text Available The mechanisms underlying intense exercise-induced liver damage and its potential treatments remain unclear. We explored the hepatoprotection and mechanisms of quercetin, a naturally occurring flavonoid, in strenuous exercise-derived endoplasmic reticulum stress (ERS and inflammation. Intense exercise (28 m/min at a 5° slope for 90 min resulted in the leakage of aminotransferases in the BALB/C mice. The hepatic ultrastructural malformations and oxidative stress levels were attenuated by quercetin (100 mg/kg·bw. Intense exercise and thapsigargin- (Tg- induced ERS (glucose-regulated protein 78, GRP78 and inflammatory cytokines levels (IL-6 and TNF-α were decreased with quercetin. Furthermore, quercetin resulted in phosphoinositide 3-kinase (PI3K induction, Ca2+ restoration, and blockade of the activities of Jun N-terminal kinase (JNK, activating transcription factor 6 (ATF6 and especially NF-κB (p65 and p50 nuclear translocation. A PI3K inhibitor abrogated the protection of quercetin on ERS and inflammation of mouse hepatocytes. SP600125 (JNK inhibitor, AEBSF (ATF6 inhibitor, and especially PDTC (NF-κB inhibitor enhanced the quercetin-induced protection against Tg stimulation. Collectively, intense exercise-induced ERS and inflammation were attenuated by quercetin. PI3K/Akt activation and JNK, ATF6, and especially NF-κB suppression were involved in the protection. Our results highlight a novel preventive strategy for treating ERS and inflammation-mediated liver damage induced by intense exercise using natural phytochemicals.

  20. Induction of activator protein (AP)-1 and nuclear factor-kappaB by CD28 stimulation involves both phosphatidylinositol 3-kinase and acidic sphingomyelinase signals.

    Science.gov (United States)

    Edmead, C E; Patel, Y I; Wilson, A; Boulougouris, G; Hall, N D; Ward, S G; Sansom, D M

    1996-10-15

    A major obstacle in understanding the signaling events that follow CD28 receptor ligation arises from the fact that CD28 acts as a costimulus to TCR engagement, making it difficult to assess the relative contribution of CD28 signals as distinct from those of the TCR. To overcome this problem, we have exploited the observation that activated human T cell blasts can be stimulated via the CD28 surface molecule in the absence of antigenic challenge; thus, we have been able to observe the response of normal T cells to CD28 activation in isolation. Using this system, we observed that CD28 stimulation by B7-transfected CHO cells induced a proliferative response in T cells that was not accompanied by measurable IL-2 production. However, subsequent analysis of transcription factor generation revealed that B7 stimulation induced both activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) complexes, but not NF-AT. In contrast, engagement of the TCR by class II MHC/superantigen, either with or without CD28 ligation, resulted in the induction of NF-AT, AP-1, and NF-kappaB as well as IL-2 production. Using selective inhibitors, we investigated the signaling pathways involved in the CD28-mediated induction of AP-1 and NF-kappaB. This revealed that NF-kappaB generation was sensitive to chloroquine, an inhibitor of acidic sphingomyelinase, but not to the phosphatidylinositol 3-kinase inhibitor, wortmannin. In contrast, AP-1 generation was inhibited by wortmannin and was also variably sensitive to chloroquine. These data suggest that in activated normal T cells, CD28-derived signals can stimulate proliferation at least in part via NF-kappaB and AP-1 generation, and that this response uses both acidic sphingomyelinase and phosphatidylinositol 3-kinase-linked pathways.

  1. Caloric Restriction Mimetic 2-Deoxyglucose Alleviated Inflammatory Lung Injury via Suppressing Nuclear Pyruvate Kinase M2–Signal Transducer and Activator of Transcription 3 Pathway

    Directory of Open Access Journals (Sweden)

    Kai Hu

    2018-03-01

    Full Text Available Inflammation is an energy-intensive process, and caloric restriction (CR could provide anti-inflammatory benefits. CR mimetics (CRM, such as the glycolytic inhibitor 2-deoxyglucose (2-DG, mimic the beneficial effects of CR without inducing CR-related physiologic disturbance. This study investigated the potential anti-inflammatory benefits of 2-DG and the underlying mechanisms in mice with lipopolysaccharide (LPS-induced lethal endotoxemia. The results indicated that pretreatment with 2-DG suppressed LPS-induced elevation of tumor necrosis factor alpha and interleukin 6. It also suppressed the upregulation of myeloperoxidase, attenuated Evans blue leakage, alleviated histological abnormalities in the lung, and improved the survival of LPS-challenged mice. Treatment with 2-DG had no obvious effects on the total level of pyruvate kinase M2 (PKM2, but it significantly suppressed LPS-induced elevation of PKM2 in the nuclei. Prevention of PKM2 nuclear accumulation by ML265 mimicked the anti-inflammatory benefits of 2-DG. In addition, treatment with 2-DG or ML265 suppressed the phosphorylation of nuclear signal transducer and activator of transcription 3 (STAT3. Inhibition of STAT3 by stattic suppressed LPS-induced inflammatory injury. Interestingly, posttreatment with 2-DG at the early stage post-LPS challenge also improved the survival of the experimental animals. This study found that treatment with 2-DG, a representative CRM, provided anti-inflammatory benefits in lethal inflammation. The underlying mechanisms included suppressed nuclear PKM2-STAT3 pathway. These data suggest that 2-DG might have potential value in the early intervention of lethal inflammation.

  2. Caloric Restriction Mimetic 2-Deoxyglucose Alleviated Inflammatory Lung Injury via Suppressing Nuclear Pyruvate Kinase M2-Signal Transducer and Activator of Transcription 3 Pathway.

    Science.gov (United States)

    Hu, Kai; Yang, Yongqiang; Lin, Ling; Ai, Qing; Dai, Jie; Fan, Kerui; Ge, Pu; Jiang, Rong; Wan, Jingyuan; Zhang, Li

    2018-01-01

    Inflammation is an energy-intensive process, and caloric restriction (CR) could provide anti-inflammatory benefits. CR mimetics (CRM), such as the glycolytic inhibitor 2-deoxyglucose (2-DG), mimic the beneficial effects of CR without inducing CR-related physiologic disturbance. This study investigated the potential anti-inflammatory benefits of 2-DG and the underlying mechanisms in mice with lipopolysaccharide (LPS)-induced lethal endotoxemia. The results indicated that pretreatment with 2-DG suppressed LPS-induced elevation of tumor necrosis factor alpha and interleukin 6. It also suppressed the upregulation of myeloperoxidase, attenuated Evans blue leakage, alleviated histological abnormalities in the lung, and improved the survival of LPS-challenged mice. Treatment with 2-DG had no obvious effects on the total level of pyruvate kinase M2 (PKM2), but it significantly suppressed LPS-induced elevation of PKM2 in the nuclei. Prevention of PKM2 nuclear accumulation by ML265 mimicked the anti-inflammatory benefits of 2-DG. In addition, treatment with 2-DG or ML265 suppressed the phosphorylation of nuclear signal transducer and activator of transcription 3 (STAT3). Inhibition of STAT3 by stattic suppressed LPS-induced inflammatory injury. Interestingly, posttreatment with 2-DG at the early stage post-LPS challenge also improved the survival of the experimental animals. This study found that treatment with 2-DG, a representative CRM, provided anti-inflammatory benefits in lethal inflammation. The underlying mechanisms included suppressed nuclear PKM2-STAT3 pathway. These data suggest that 2-DG might have potential value in the early intervention of lethal inflammation.

  3. Nemo-like kinase as a negative regulator of nuclear receptor Nurr1 gene transcription in prostate cancer

    International Nuclear Information System (INIS)

    Wang, Jian; Yang, Zhi-Hong; Chen, Hua; Li, Hua-Hui; Chen, Li-Yong; Zhu, Zhu; Zou, Ying; Ding, Cong-Cong; Yang, Jing; He, Zhi-Wei

    2016-01-01

    Nurr1, a member of the orphan receptor family, plays an important role in several types of cancer. Our previous work demonstrated that increased expression of Nurr1 plays a significant role in the initiation and progression of prostate cancer (PCa), though the mechanisms for regulation of Nurr1 expression remain unknown. In this study, we investigated the hypothesis that Nemo-like kinase (NLK) is a key regulator of Nurr1 expression in PCa. Immunohistochemistry and Western blot analysis were used to evaluate levels of NLK and Nurr1 in prostatic tissues and cell lines. The effects of overexpression or knockdown of Nurr1 were evaluated in PCa cells through use of PCR, Western blots and promoter reporter assays. The role of Nurr1 promoter cis element was studied by creation of two mutant Nurr1 promoter luciferase constructs, one with a mutated NF-κB binding site and one with a mutated CREB binding site. In addition, three specific inhibitors were used to investigate the roles of these proteins in transcriptional activation of Nurr1, including BAY 11–7082 (NF-κB inhibitor), KG-501 (CREB inhibitor) and ICG-001 (CREB binding protein, CBP, inhibitor). The function of CBP in NLK-mediated regulation of Nurr1 expression was investigated using immunofluorescence, co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation assays (ChIPs). NLK expression was inversely correlated with Nurr1 expression in prostate cancer tissues and cell lines. Overexpression of NLK suppressed Nurr1 promoter activity, leading to downregulation of Nurr1 expression. In contrast, knockdown of NLK demonstrated opposite results, leading to upregulation of Nurr1. When compared with the wild-type Nurr1 promoter, mutation of NF-κB- and CREB-binding sites of the Nurr1 promoter region significantly reduced the upregulation of Nurr1 induced by knockdown of NLK in LNCaP cells; treatment with inhibitors of CREB, CBP and NF-κB led to similar results. We also found that NLK directly interacts with CBP

  4. One isoform of Arg/Abl2 tyrosine kinase is nuclear and the other seven cytosolic isoforms differently modulate cell morphology, motility and the cytoskeleton

    International Nuclear Information System (INIS)

    Bianchi, Cristina; Torsello, Barbara; Di Stefano, Vitalba; Zipeto, Maria A.; Facchetti, Rita; Bombelli, Silvia; Perego, Roberto A.

    2013-01-01

    The non-receptor tyrosine kinase Abelson related gene (Arg/Abl2) regulates cell migration and morphogenesis by modulating the cytoskeleton. Arg promotes actin-based cell protrusions and spreading, and inhibits cell migration by attenuating stress fiber formation and contractility via activation of the RhoA inhibitor, p190RhoGAP, and by regulating focal adhesion dynamics also via CrkII phosphorylation. Eight full-length Arg isoforms with different N- and C-termini are endogenously expressed in human cells. In this paper, the eight Arg isoforms, subcloned in the pFLAG-CMV2 vector, were transfected in COS-7 cells in order to study their subcellular distribution and role in cell morphology, migration and cytoskeletal modulation. The transfected 1BSCTS Arg isoform has a nuclear distribution and phosphorylates CrkII in the nucleus, whilst the other isoforms are detected in the cytoplasm. The 1BLCTL, 1BSCTL, 1ASCTS isoforms were able to significantly decrease stress fibers, induce cell shrinkage and filopodia-like protrusions with a significant increase in p190RhoGAP phosphorylation. In contrast, 1ALCTL, 1ALCTS, 1ASCTL and 1BLCTS isoforms do not significantly decrease stress fibers and induce the formation of retraction tail-like protrusions. The 1BLCTL and 1ALCTL isoforms have different effects on cell migration and focal adhesions. All these data may open new perspectives to study the mechanisms of cell invasiveness. -Highlights: • Each of the eight Arg isoforms was transfected in COS-7 cells. • Only the 1BSCTS Arg isoform has a nuclear distribution in transfected cells. • The cytoplasmic isoforms and F-actin colocalize cortically and in cell protrusions. • Arg isoforms differently phosphorylate p190RhoGAP and CrkII. • Arg isoforms differently modulate stress fibers, cell protrusions and motility

  5. One isoform of Arg/Abl2 tyrosine kinase is nuclear and the other seven cytosolic isoforms differently modulate cell morphology, motility and the cytoskeleton

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Cristina; Torsello, Barbara; Di Stefano, Vitalba; Zipeto, Maria A.; Facchetti, Rita; Bombelli, Silvia; Perego, Roberto A., E-mail: roberto.perego@unimib.it

    2013-08-01

    The non-receptor tyrosine kinase Abelson related gene (Arg/Abl2) regulates cell migration and morphogenesis by modulating the cytoskeleton. Arg promotes actin-based cell protrusions and spreading, and inhibits cell migration by attenuating stress fiber formation and contractility via activation of the RhoA inhibitor, p190RhoGAP, and by regulating focal adhesion dynamics also via CrkII phosphorylation. Eight full-length Arg isoforms with different N- and C-termini are endogenously expressed in human cells. In this paper, the eight Arg isoforms, subcloned in the pFLAG-CMV2 vector, were transfected in COS-7 cells in order to study their subcellular distribution and role in cell morphology, migration and cytoskeletal modulation. The transfected 1BSCTS Arg isoform has a nuclear distribution and phosphorylates CrkII in the nucleus, whilst the other isoforms are detected in the cytoplasm. The 1BLCTL, 1BSCTL, 1ASCTS isoforms were able to significantly decrease stress fibers, induce cell shrinkage and filopodia-like protrusions with a significant increase in p190RhoGAP phosphorylation. In contrast, 1ALCTL, 1ALCTS, 1ASCTL and 1BLCTS isoforms do not significantly decrease stress fibers and induce the formation of retraction tail-like protrusions. The 1BLCTL and 1ALCTL isoforms have different effects on cell migration and focal adhesions. All these data may open new perspectives to study the mechanisms of cell invasiveness. -Highlights: • Each of the eight Arg isoforms was transfected in COS-7 cells. • Only the 1BSCTS Arg isoform has a nuclear distribution in transfected cells. • The cytoplasmic isoforms and F-actin colocalize cortically and in cell protrusions. • Arg isoforms differently phosphorylate p190RhoGAP and CrkII. • Arg isoforms differently modulate stress fibers, cell protrusions and motility.

  6. The comparison of nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS) with Ki67 proliferation marker expression in common skin tumors.

    Science.gov (United States)

    Zduniak, Krzysztof; Agrawal, Siddarth; Symonowicz, Krzysztof; Jurczyszyn, Kamil; Ziółkowski, Piotr

    2014-03-01

    Nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS) is a chromosomal protein of unknown function. Its amino acid composition and structure of its DNA binding domain resemble those of high mobility group A (HMGA) proteins which are associated with various malignancies. Since changes in expression of HMGA are considered as a marker of tumor progression, it is possible that similar changes in expression of NUCKS could be a useful tool in diagnosis of malignant skin tumors. To investigate this assumption we used specific antibodies against NUCKS for immunohistochemistry of squamous (SCC) and basal cell carcinoma (BCC) as well as keratoacanthoma (KA). We found high expression of NUCKS in nuclei of SCC and BCC cells which exceeded expression of the well-known proliferation marker Ki67. Expression of NUCKS in benign KA was much below that of malignant tumors. With the present study and based on our previous experience we would like to suggest the NUCKS protein as a novel proliferation marker for immunohistochemical evaluation of formalin-fixed and paraffin-embedded skin tumor specimens. We would like to emphasize that NUCKS abundance in malignant skin tumors is higher than that of the well-known proliferation marker Ki67, thus allowing more precise assessment of tumor proliferation potential.

  7. Cooperation and competition between adenylate kinase, nucleoside diphosphokinase, electron transport, and ATP synthase in plant mitochondria studied by 31P-nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Roberts, J.K.M.; Aubert, S.; Gout, E.; Bligny, R.; Douce, R.

    1997-01-01

    Nucleotide metabolism in potato (Solanum tuberosum) mitochondria was studied using 31P-nuclear magnetic resonance spectroscopy and the O2 electrode. Immediately following the addition of ADP, ATP synthesis exceeded the rate of oxidative phosphorylation, fueled by succinate oxidation, due to mitochondrial adenylate kinase (AK) activity two to four times the maximum activity of ATP synthase. Only when the AK reaction approached equilibrium was oxidative phosphorylation the primary mechanism for net ATP synthesis. A pool of sequestered ATP in mitochondria enabled AK and ATP synthase to convert AMP to ATP in the presence of exogenous inorganic phosphate. During this conversion, AK activity can indirectly influence rates of oxidation of both succinate and NADH via changes in mitochondrial ATP. Mitochondrial nucleoside diphosphokinase, in cooperation with ATP synthase, was found to facilitate phosphorylation of nucleoside diphosphates other than ADP at rates similar to the maximum rate of oxidative phosphorylation. These results demonstrate that plant mitochondria contain all of the machinery necessary to rapidly regenerate nucleoside triphosphates from AMP and nucleoside diphosphates made during cellular biosynthesis and that AK activity can affect both the amount of ADP available to ATP synthase and the level of ATP regulating electron transport

  8. Immunohistochemical and Proteomic Evaluation of Nuclear Ubiquitous Casein and Cyclin-Dependent Kinases Substrate in Invasive Ductal Carcinoma of the Breast

    Directory of Open Access Journals (Sweden)

    Piotr Ziółkowski

    2009-01-01

    Full Text Available Nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS is 27 kDa chromosomal protein of unknown function. Its amino acid composition as well as structure of its DNA binding domain resembles that of high-mobility group A, HMGA proteins. HMGA proteins are associated with various malignancies. Since changes in expression of HMGA are considered as marker of tumor progression, it is possible that similar changes in expression of NUCKS could be useful tool in diagnosis and prognosis of breast cancer. For identification and analysis of NUCKS we used proteomic and histochemical methods. Analysis of patient-matched samples of normal and breast cancer by mass spectrometry revealed elevated levels of NUCKS in protein extracts from ductal breast cancers. We elicited specific antibodies against NUCKS and used them for immunohistochemistry in invasive ductal carcinoma of breast. We found high expression of NUCKS in 84.3% of cancer cells. We suggest that such overexpression of NUCKS can play significant role in breast cancer biology.

  9. MBNL142 and MBNL143 gene isoforms, overexpressed in DM1-patient muscle, encode for nuclear proteins interacting with Src family kinases.

    Science.gov (United States)

    Botta, A; Malena, A; Tibaldi, E; Rocchi, L; Loro, E; Pena, E; Cenci, L; Ambrosi, E; Bellocchi, M C; Pagano, M A; Novelli, G; Rossi, G; Monaco, H L; Gianazza, E; Pantic, B; Romeo, V; Marin, O; Brunati, A M; Vergani, L

    2013-08-15

    Myotonic dystrophy type-1 (DM1) is the most prevalent form of muscular dystrophy in adults. This disorder is an RNA-dominant disease, caused by expansion of a CTG repeat in the DMPK gene that leads to a misregulation in the alternative splicing of pre-mRNAs. The longer muscleblind-like-1 (MBNL1) transcripts containing exon 5 and the respective protein isoforms (MBNL142-43) were found to be overexpressed in DM1 muscle and localized exclusively in the nuclei. In vitro assays showed that MBNL142-43 bind the Src-homology 3 domain of Src family kinases (SFKs) via their proline-rich motifs, enhancing the SFK activity. Notably, this association was also confirmed in DM1 muscle and myotubes. The recovery, mediated by an siRNA target to Ex5-MBNL142-43, succeeded in reducing the nuclear localization of both Lyn and MBNL142-43 proteins and in decreasing the level of tyrosine phosphorylated proteins. Our results suggest an additional molecular mechanism in the DM1 pathogenesis, based on an altered phosphotyrosine signalling pathway.

  10. Uncaria rhynchophylla and Rhynchophylline inhibit c-Jun N-terminal kinase phosphorylation and nuclear factor-kappaB activity in kainic acid-treated rats.

    Science.gov (United States)

    Hsieh, Ching-Liang; Ho, Tin-Yun; Su, Shan-Yu; Lo, Wan-Yu; Liu, Chung-Hsiang; Tang, Nou-Ying

    2009-01-01

    Our previous studies have shown that Uncaria rhynchophylla (UR) can reduce epileptic seizures. We hypothesized that UR and its major component rhynchophylline (RH), reduce epileptic seizures in rats treated with kainic acid (KA) by inhibiting nuclear factor-kappaB (NF-kappaB) and activator-protein-1 (AP-1) activity, and by eliminating superoxide anions. Therefore, the level of superoxide anions and the DNA binding activities of NF-kappaB and AP-1 were measured. Sprague-Dawley (SD) rats were pre-treated with UR (1.0 g/kg, i.p.), RH (0.25 mg/kg, i.p.), or valproic acid (VA, 250 mg/kg, i.p.) for 3 days and then KA was administered intra-peritoneal (i.p.). The results indicated that UR, RH, and VA can reduce epileptic seizures and the level of superoxide anions in the blood. Furthermore, KA was demonstrated to induce the DNA binding activities of NF-kappaB and AP-1. However, these inductions were inhibited by pre-treatment with UR, RH, or VA for 3 days. Moreover, UR and RH were shown to be involved in the suppression of c-Jun N-terminal kinase (JNK) phosphorylation. This study suggested that UR and RH have antiepileptic effects in KA-induced seizures and are associated with the regulation of the innate immune system via a reduction in the level of superoxide anions, JNK phosphorylation, and NF-kappaB activation.

  11. Glycogen synthase kinase 3 regulates expression of nuclear factor-erythroid-2 related transcription factor-1 (Nrf1) and inhibits pro-survival function of Nrf1

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Madhurima; Kwong, Erick K.; Park, Eujean; Nagra, Parminder; Chan, Jefferson Y., E-mail: jchan@uci.edu

    2013-08-01

    Nuclear factor E2-related factor-1 (Nrf1) is a basic leucine zipper transcription factor that is known to regulate antioxidant and cytoprotective gene expression. It was recently shown that Nrf1 is regulated by SCF–Fbw7 ubiquitin ligase. However our knowledge of upstream signals that targets Nrf1 for degradation by the UPS is not known. We report here that Nrf1 expression is negatively regulated by glycogen synthase kinase 3 (GSK3) in Fbw7-dependent manner. We show that GSK3 interacts with Nrf1 and phosphorylates the Cdc4 phosphodegron domain (CPD) in Nrf1. Mutation of serine residue in the CPD of Nrf1 to alanine (S350A), blocks Nrf1 from phosphorylation by GSK3, and stabilizes Nrf1. Knockdown of Nrf1 and expression of a constitutively active form of GSK3 results in increased apoptosis in neuronal cells in response to ER stress, while expression of the GSK3 phosphorylation resistant S350A–Nrf1 attenuates apoptotic cell death. Together these data suggest that GSK3 regulates Nrf1 expression and cell survival function in response to stress activation. Highlights: • The effect of GSK3 on Nrf1 expression was examined. • GSK3 destabilizes Nrf1 protein via Fbw7 ubiquitin ligase. • GSK3 binds and phosphorylates Nrf1. • Protection from stress-induced apoptosis by Nrf1 is inhibited by GSK3.

  12. Casein kinases

    DEFF Research Database (Denmark)

    Issinger, O G

    1993-01-01

    The present review on casein kinases focuses mainly on the possible metabolic role of CK-2, with special emphasis on its behavior in pathological tissues. From these data at least three ways to regulate CK-2 activity emerge: (i) CK-2 activity changes during embryogenesis, being high at certain...

  13. Kinases and Cancer

    OpenAIRE

    Jonas Cicenas; Egle Zalyte; Amos Bairoch; Pascale Gaudet

    2018-01-01

    Protein kinases are a large family of enzymes catalyzing protein phosphorylation. The human genome contains 518 protein kinase genes, 478 of which belong to the classical protein kinase family and 40 are atypical protein kinases [...

  14. Resveratrol Modulates Interleukin-1β-induced Phosphatidylinositol 3-Kinase and Nuclear Factor κB Signaling Pathways in Human Tenocytes

    Science.gov (United States)

    Busch, Franziska; Mobasheri, Ali; Shayan, Parviz; Lueders, Cora; Stahlmann, Ralf; Shakibaei, Mehdi

    2012-01-01

    Resveratrol, an activator of histone deacetylase Sirt-1, has been proposed to have beneficial health effects due to its antioxidant and anti-inflammatory properties. However, the mechanisms underlying the anti-inflammatory effects of resveratrol and the intracellular signaling pathways involved are poorly understood. An in vitro model of human tenocytes was used to examine the mechanism of resveratrol action on IL-1β-mediated inflammatory signaling. Resveratrol suppressed IL-1β-induced activation of NF-κB and PI3K in a dose- and time-dependent manner. Treatment with resveratrol enhanced the production of matrix components collagen types I and III, tenomodulin, and tenogenic transcription factor scleraxis, whereas it inhibited gene products involved in inflammation and apoptosis. IL-1β-induced NF-κB and PI3K activation was inhibited by resveratrol or the inhibitors of PI3K (wortmannin), c-Src (PP1), and Akt (SH-5) through inhibition of IκB kinase, IκBα phosphorylation, and inhibition of nuclear translocation of NF-κB, suggesting that PI3K signaling pathway may be one of the signaling pathways inhibited by resveratrol to abrogate NF-κB activation. Inhibition of PI3K by wortmannin attenuated IL-1β-induced Akt and p65 acetylation, suggesting that p65 is a downstream component of PI3K/Akt in these responses. The modulatory effects of resveratrol on IL-1β-induced activation of NF-κB and PI3K were found to be mediated at least in part by the association between Sirt-1 and scleraxis and deacetylation of NF-κB and PI3K. Overall, these results demonstrate that activated Sirt-1 plays an essential role in the anti-inflammatory effects of resveratrol and this may be mediated at least in part through inhibition/deacetylation of PI3K and NF-κB. PMID:22936809

  15. Fasting Induces Nuclear Factor E2-Related Factor 2 and ATP-Binding Cassette Transporters via Protein Kinase A and Sirtuin-1 in Mouse and Human

    Science.gov (United States)

    Kulkarni, Supriya R.; Donepudi, Ajay C.; Xu, Jialin; Wei, Wei; Cheng, Qiuqiong C.; Driscoll, Maureen V.; Johnson, Delinda A.; Johnson, Jeffrey A.; Li, Xiaoling

    2014-01-01

    Abstract Aims: The purpose of this study was to determine whether 3′-5′-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) and Sirtuin-1 (SIRT1) dependent mechanisms modulate ATP-binding Cassette (ABC) transport protein expression. ABC transport proteins (ABCC2–4) are essential for chemical elimination from hepatocytes and biliary excretion. Nuclear factor-E2 related-factor 2 (NRF2) is a transcription factor that mediates ABCC induction in response to chemical inducers and liver injury. However, a role for NRF2 in the regulation of transporter expression in nonchemical models of liver perturbation is largely undescribed. Results: Here we show that fasting increased NRF2 target gene expression through NRF2- and SIRT1–dependent mechanisms. In intact mouse liver, fasting induces NRF2 target gene expression by at least 1.5 to 5-fold. In mouse and human hepatocytes, treatment with 8-Bromoadenosine-cAMP, a cAMP analogue, increased NRF2 target gene expression and antioxidant response element activity, which was decreased by the PKA inhibitor, H-89. Moreover, fasting induced NRF2 target gene expression was decreased in liver and hepatocytes of SIRT1 liver-specific null mice and NRF2-null mice. Lastly, NRF2 and SIRT1 were recruited to MAREs and Antioxidant Response Elements (AREs) in the human ABCC2 promoter. Innovation: Oxidative stress mediated NRF2 activation is well described, yet the influence of basic metabolic processes on NRF2 activation is just emerging. Conclusion: The current data point toward a novel role of nutrient status in regulation of NRF2 activity and the antioxidant response, and indicates that cAMP/PKA and SIRT1 are upstream regulators for fasting-induced activation of the NRF2-ARE pathway. Antioxid. Redox Signal. 20, 15–30. PMID:23725046

  16. Berberine activates Nrf2 nuclear translocation and inhibits apoptosis induced by high glucose in renal tubular epithelial cells through a phosphatidylinositol 3-kinase/Akt-dependent mechanism.

    Science.gov (United States)

    Zhang, Xiuli; Liang, Dan; Lian, Xu; Jiang, Yan; He, Hui; Liang, Wei; Zhao, Yue; Chi, Zhi-Hong

    2016-06-01

    Apoptosis of tubular epithelial cells is a major feature of diabetic kidney disease, and hyperglycemia triggers the generation of free radicals and oxidant stress in tubular cells. Berberine (BBR) is identified as a potential anti-diabetic herbal medicine due to its beneficial effects on insulin sensitivity, glucose metabolism and glycolysis. In this study, the underlying mechanisms involved in the protective effects of BBR on high glucose-induced apoptosis were explored using cultured renal tubular epithelial cells (NRK-52E cells) and human kidney proximal tubular cell line (HK-2 cells). We identified the pivotal role of phosphatidylinositol 3-kinase (PI3K)/Akt in BBR cellular defense mechanisms and revealed the novel effect of BBR on nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2) and heme oxygenase (HO)-1 in NRK-52E and HK-2 cells. BBR attenuated reactive oxygen species production, antioxidant defense (GSH and SOD) and oxidant-sensitive proteins (Nrf2 and HO-1), which also were blocked by LY294002 (an inhibitor of PI3K) in HG-treated NRK-52E and HK-2 cells. Furthermore, BBR improved mitochondrial function by increasing mitochondrial membrane potential. BBR-induced anti-apoptotic function was demonstrated by decreasing apoptotic proteins (cytochrome c, Bax, caspase3 and caspase9). All these findings suggest that BBR exerts the anti-apoptosis effects through activation of PI3K/Akt signal pathways and leads to activation of Nrf2 and induction of Nrf2 target genes, and consequently protecting the renal tubular epithelial cells from HG-induced apoptosis.

  17. Transcriptional Regulation of S Phase Kinase-associated Protein 2 by NR4A Orphan Nuclear Receptor NOR1 in Vascular Smooth Muscle Cells*

    Science.gov (United States)

    Gizard, Florence; Zhao, Yue; Findeisen, Hannes M.; Qing, Hua; Cohn, Dianne; Heywood, Elizabeth B.; Jones, Karrie L.; Nomiyama, Takashi; Bruemmer, Dennis

    2011-01-01

    Members of the NR4A subgroup of the nuclear hormone receptor superfamily have emerged as key transcriptional regulators of proliferation and inflammation. NOR1 constitutes a ligand-independent transcription factor of this subgroup and induces cell proliferation; however, the transcriptional mechanisms underlying this mitogenic role remain to be defined. Here, we demonstrate that the F-box protein SKP2 (S phase kinase-associated protein 2), the substrate-specific receptor of the ubiquitin ligase responsible for the degradation of p27KIP1 through the proteasome pathway, constitutes a direct transcriptional target for NOR1. Mitogen-induced Skp2 expression is silenced in vascular smooth muscle cells (VSMC) isolated from Nor1-deficient mice or transfected with Nor1 siRNA. Conversely, adenovirus-mediated overexpression of NOR1 induces Skp2 expression in VSMC and decreases protein abundance of its target p27. Transient transfection experiments establish that NOR1 transactivates the Skp2 promoter through a nerve growth factor-induced clone B response element (NBRE). Electrophoretic mobility shift and chromatin immunoprecipitation assays further revealed that NOR1 is recruited to this NBRE site in the Skp2 promoter in response to mitogenic stimulation. In vivo Skp2 expression is increased during the proliferative response underlying neointima formation, and this transcriptional induction depends on the expression of NOR1. Finally, we demonstrate that overexpression of Skp2 rescues the proliferative arrest of Nor1-deficient VSMC. Collectively, these results characterize Skp2 as a novel NOR1-regulated target gene and detail a previously unrecognized transcriptional cascade regulating mitogen-induced VSMC proliferation. PMID:21868379

  18. Uncaria rhynchophylla inhibits the production of nitric oxide and interleukin-1β through blocking nuclear factor κB, Akt, and mitogen-activated protein kinase activation in macrophages.

    Science.gov (United States)

    Kim, Ji-Hee; Bae, Chang Hwan; Park, Sun Young; Lee, Sang Joon; Kim, YoungHee

    2010-10-01

    The stems with hook of Uncaria rhynchophylla have been used in traditional medicine as an antipyretic, antihypertensive, and anticonvulsant in China and Korea. In this study, we investigated the mechanism responsible for anti-inflammatory effects of U. rhynchophylla in RAW 264.7 macrophages. The aqueous extract of U. rhynchophylla inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and interleukin (IL)-1β secretion as well as inducible NO synthase (iNOS) expression, without affecting cell viability. Furthermore, U. rhynchophylla suppressed LPS-induced nuclear factor κB (NF-κB) activation, phosphorylation, and degradation of inhibitory protein IκB (IκB)-α, phosphorylation of Akt, extracellular signal-regulated kinase 1/2, p38 kinase, and c-Jun N-terminal kinase. These results suggest that U. rhynchophylla has the inhibitory effects on LPS-induced NO and IL-1β production in macrophages through blockade in the phosphorylation of Akt and mitogen-activated protein kinases, following IκB-α degradation and NF-κB activation.

  19. Protein Kinases in Human Breast Carcinoma

    National Research Council Canada - National Science Library

    Cane, William

    1998-01-01

    .... Rak is a novel nuclear tyrosine that our group has identified in breast cancer tissues and cell lines that has structural homology to the Src tyrosine kinase, with SH2 and SH3 domains at its amino terminus...

  20. Glycogen synthase kinase-3 inhibition disrupts nuclear factor-kappaB activity in pancreatic cancer, but fails to sensitize to gemcitabine chemotherapy

    Directory of Open Access Journals (Sweden)

    Mamaghani Shadi

    2009-04-01

    Full Text Available Abstract Background Aberrant activation NF-kappaB has been proposed as a mechanism of drug resistance in pancreatic cancer. Recently, inhibition of glycogen synthase kinase-3 has been shown to exert anti-tumor effects on pancreatic cancer cells by suppressing NF-kappaB. Consequently, we investigated whether inhibition of GSK-3 sensitizes pancreatic cancer cells to the chemotherapeutic agent gemcitabine. Methods GSK-3 inhibition was achieved using the pharmacological agent AR-A014418 or siRNA against GSK-3 alpha and beta isoforms. Cytotoxicity was measured using a Sulphorhodamine B assay and clonogenic survival following exposure of six different pancreatic cancer cell lines to a range of doses of either gemcitabine, AR-A014418 or both for 24, 48 and 72 h. We measured protein expression levels by immunoblotting. Basal and TNF-alpha induced activity of NF-kappaB was assessed using a luciferase reporter assay in the presence or absence of GSK-3 inhibition. Results GSK-3 inhibition reduced both basal and TNF-alpha induced NF-kappaB luciferase activity. Knockdown of GSK-3 beta reduced nuclear factor kappa B luciferase activity to a greater extent than GSK-3 alpha, and the greatest effect was seen with dual knockdown of both GSK-3 isoforms. GSK-3 inhibition also resulted in reduction of the NF-kappaB target proteins XIAP, Bcl-XL, and cyclin D1, associated with growth inhibition and decreased clonogenic survival. In all cell lines, treatment with either AR-A014418, or gemcitabine led to growth inhibition in a dose- and time-dependent manner. However, with the exception of PANC-1 where drug synergy occurred with some dose schedules, the inhibitory effect of combined drug treatment was additive, sub-additive, or even antagonistic. Conclusion GSK-3 inhibition has anticancer effects against pancreatic cancer cells with a range of genetic backgrounds associated with disruption of NF-kappaB, but does not significantly sensitize these cells to the standard

  1. Glycogen synthase kinase-3 inhibition disrupts nuclear factor-kappaB activity in pancreatic cancer, but fails to sensitize to gemcitabine chemotherapy

    International Nuclear Information System (INIS)

    Mamaghani, Shadi; Patel, Satish; Hedley, David W

    2009-01-01

    Aberrant activation NF-kappaB has been proposed as a mechanism of drug resistance in pancreatic cancer. Recently, inhibition of glycogen synthase kinase-3 has been shown to exert anti-tumor effects on pancreatic cancer cells by suppressing NF-kappaB. Consequently, we investigated whether inhibition of GSK-3 sensitizes pancreatic cancer cells to the chemotherapeutic agent gemcitabine. GSK-3 inhibition was achieved using the pharmacological agent AR-A014418 or siRNA against GSK-3 alpha and beta isoforms. Cytotoxicity was measured using a Sulphorhodamine B assay and clonogenic survival following exposure of six different pancreatic cancer cell lines to a range of doses of either gemcitabine, AR-A014418 or both for 24, 48 and 72 h. We measured protein expression levels by immunoblotting. Basal and TNF-alpha induced activity of NF-kappaB was assessed using a luciferase reporter assay in the presence or absence of GSK-3 inhibition. GSK-3 inhibition reduced both basal and TNF-alpha induced NF-kappaB luciferase activity. Knockdown of GSK-3 beta reduced nuclear factor kappa B luciferase activity to a greater extent than GSK-3 alpha, and the greatest effect was seen with dual knockdown of both GSK-3 isoforms. GSK-3 inhibition also resulted in reduction of the NF-kappaB target proteins XIAP, Bcl-X L , and cyclin D1, associated with growth inhibition and decreased clonogenic survival. In all cell lines, treatment with either AR-A014418, or gemcitabine led to growth inhibition in a dose- and time-dependent manner. However, with the exception of PANC-1 where drug synergy occurred with some dose schedules, the inhibitory effect of combined drug treatment was additive, sub-additive, or even antagonistic. GSK-3 inhibition has anticancer effects against pancreatic cancer cells with a range of genetic backgrounds associated with disruption of NF-kappaB, but does not significantly sensitize these cells to the standard chemotherapy agent gemcitabine. This lack of synergy might be

  2. Andrographolide stimulates p38 mitogen-activated protein kinase-nuclear factor erythroid-2-related factor 2-heme oxygenase 1 signaling in primary cerebral endothelial cells for definite protection against ischemic stroke in rats.

    Science.gov (United States)

    Yen, Ting-Lin; Chen, Ray-Jade; Jayakumar, Thanasekaran; Lu, Wan-Jung; Hsieh, Cheng-Ying; Hsu, Ming-Jen; Yang, Chih-Hao; Chang, Chao-Chien; Lin, Yen-Kuang; Lin, Kuan-Hung; Sheu, Joen-Rong

    2016-04-01

    Stroke pathogenesis involves complex oxidative stress-related pathways. The nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) pathways have been considered molecular targets in pharmacologic intervention for ischemic diseases. Andrographolide, a labdane diterpene, has received increasing attention in recent years because of its various pharmacologic activities. We determined that andrographolide modulates the mitogen-activated protein kinase (MAPK)-Nrf2-HO-1 signaling cascade in primary cerebral endothelial cells (CECs) to provide positive protection against middle cerebral artery occlusion (MCAO)-induced ischemic stroke in rats. In the present study, andrographolide (10 μM) increased HO-1 protein and messenger RNA expressions, Nrf2 phosphorylation, and nuclear translocation in CECs, and these activities were disrupted by a p38 MAPK inhibitor, SB203580, but not by the extracellular signal-regulated kinase inhibitor PD98059 or c-Jun amino-terminal kinase inhibitor SP600125. Similar results were observed in confocal microscopy analysis. Moreover, andrographolide-induced Nrf2 and HO-1 protein expressions were significantly inhibited by Nrf2 small interfering RNA. Moreover, HO-1 knockdown attenuated the protective effect of andrographolide against oxygen-glucose deprivation-induced CEC death. Andrographolide (0.1 mg/kg) significantly suppressed free radical formation, blood-brain barrier disruption, and brain infarction in MCAO-insulted rats, and these effects were reversed by the HO-1 inhibitor zinc protoporphyrin IX. The mechanism is attributable to HO-1 activation, as directly evidenced by andrographolide-induced pronounced HO-1 expression in brain tissues, which was highly localized in the cerebral capillary. In conclusion, andrographolide increased Nrf2-HO-1 expression through p38 MAPK regulation, confirming that it provides protection against MCAO-induced brain injury. These findings provide strong evidence that andrographolide could

  3. Clonorchis sinensis excretory-secretory products regulate migration and invasion in cholangiocarcinoma cells via extracellular signal-regulated kinase 1/2/nuclear factor-κB-dependent matrix metalloproteinase-9 expression.

    Science.gov (United States)

    Pak, Jhang Ho; Shin, Jimin; Song, In-Sung; Shim, Sungbo; Jang, Sung-Wuk

    2017-01-01

    Matrix metalloproteinase-9 plays an important role in the invasion and metastasis of various types of cancer cells. We have previously reported that excretory-secretory products from Clonorchis sinensis increases matrix metalloproteinase-9 expression. However, the regulatory mechanisms through which matrix metalloproteinase-9 expression affects cholangiocarcinoma development remain unclear. In the current study, we examined the potential role of excretory-secretory products in regulating the migration and invasion of various cholangiocarcinoma cell lines. We demonstrated that excretory-secretory products significantly induced matrix metalloproteinase-9 expression and activity in a concentration-dependent manner. Reporter gene and chromatin immunoprecipitation assays showed that excretory-secretory products induced matrix metalloproteinase-9 expression by enhancing the activity of nuclear factor-kappa B. Moreover, excretory-secretory products induced the degradation and phosphorylation of IκBα and stimulated nuclear factor-kappa B p65 nuclear translocation, which was regulated by extracellular signal-regulated kinase 1/2. Taken together, our findings indicated that the excretory-secretory product-dependent enhancement of matrix metalloproteinase-9 activity and subsequent induction of IκBα and nuclear factor-kappa B activities may contribute to the progression of cholangiocarcinoma. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

  4. Thymidine kinases in archaea

    DEFF Research Database (Denmark)

    Clausen, A.R.; Matakos, A.; Sandrini, Michael

    2006-01-01

    Twenty-six fully sequenced archaeal genomes were searched for genes coding for putative deoxyribonucleoside kinases (dNKs). We identified only 5 human-like thymidine kinase 1 genes (TK1s) and none for non-TK1 kinases. Four TK1s were identified in the Euryarchaea and one was found in the Crenarcha...

  5. Nuclear

    International Nuclear Information System (INIS)

    2014-01-01

    This document proposes a presentation and discussion of the main notions, issues, principles, or characteristics related to nuclear energy: radioactivity (presence in the environment, explanation, measurement, periods and activities, low doses, applications), fuel cycle (front end, mining and ore concentration, refining and conversion, fuel fabrication, in the reactor, back end with reprocessing and recycling, transport), the future of the thorium-based fuel cycle (motivations, benefits and drawbacks), nuclear reactors (principles of fission reactors, reactor types, PWR reactors, BWR, heavy-water reactor, high temperature reactor of HTR, future reactors), nuclear wastes (classification, packaging and storage, legal aspects, vitrification, choice of a deep storage option, quantities and costs, foreign practices), radioactive releases of nuclear installations (main released radio-elements, radioactive releases by nuclear reactors and by La Hague plant, gaseous and liquid effluents, impact of releases, regulation), the OSPAR Convention, management and safety of nuclear activities (from control to quality insurance, to quality management and to sustainable development), national safety bodies (mission, means, organisation and activities of ASN, IRSN, HCTISN), international bodies, nuclear and medicine (applications of radioactivity, medical imagery, radiotherapy, doses in nuclear medicine, implementation, the accident in Epinal), nuclear and R and D (past R and D programmes and expenses, main actors in France and present funding, main R and D axis, international cooperation)

  6. Inhibition of IkappaB kinase-nuclear factor-kappaB signaling pathway by 3,5-bis(2-flurobenzylidene)piperidin-4-one (EF24), a novel monoketone analog of curcumin.

    Science.gov (United States)

    Kasinski, Andrea L; Du, Yuhong; Thomas, Shala L; Zhao, Jing; Sun, Shi-Yong; Khuri, Fadlo R; Wang, Cun-Yu; Shoji, Mamoru; Sun, Aiming; Snyder, James P; Liotta, Dennis; Fu, Haian

    2008-09-01

    The nuclear factor-kappaB (NF-kappaB) signaling pathway has been targeted for therapeutic applications in a variety of human diseases, includuing cancer. Many naturally occurring substances, including curcumin, have been investigated for their actions on the NF-kappaB pathway because of their significant therapeutic potential and safety profile. A synthetic monoketone compound termed 3,5-bis(2-flurobenzylidene)piperidin-4-one (EF24) was developed from curcumin and exhibited potent anticancer activity. Here, we report a mechanism by which EF24 potently suppresses the NF-kappaB signaling pathway through direct action on IkappaB kinase (IKK). We demonstrate that 1) EF24 induces death of lung, breast, ovarian, and cervical cancer cells, with a potency about 10 times higher than that of curcumin; 2) EF24 rapidly blocks the nuclear translocation of NF-kappaB, with an IC(50) value of 1.3 microM compared with curcumin, with an IC(50) value of 13 microM; 3) EF24 effectively inhibits tumor necrosis factor (TNF)-alpha-induced IkappaB phosphorylation and degradation, suggesting a role of this compound in targeting IKK; and 4) EF24 indeed directly inhibits the catalytic activity of IKK in an in vitro-reconstituted system. Our study identifies IKK as an effective target for EF24 and provides a molecular explanation for a superior activity of EF24 over curcumin. The effective inhibition of TNF-alpha-induced NF-kappaB signaling by EF24 extends the therapeutic application of EF24 to other NF-kappaB-dependent diseases, including inflammatory diseases such as rheumatoid arthritis.

  7. Period1 gates the circadian modulation of memory-relevant signaling in mouse hippocampus by regulating the nuclear shuttling of the CREB kinase pP90RSK

    DEFF Research Database (Denmark)

    Rawashdeh, Oliver; Jilg, Antje; Maronde, Erik

    2016-01-01

    , the presence of PER1 in hippocampal neurons is a prerequisite for the time-of-day-dependent phosphorylation of CREB, as it regulates the shuttling of pP90RSK into the nucleus. Representative immunofluorescence images show a temporal difference in phosphorylated cAMP response element-binding protein (p...... activation. Taken together, the PER1-dependent modulation of cytoplasmic-to-nuclear signaling in the murine hippocampus provides a molecular explanation for how the circadian system potentially shapes a temporal framework for daytime-dependent memory performance, and adds a novel facet to the versatility......CREB; green color) levels in all regions of the dorsal hippocampus between a wild-type C3H mouse (WT; left) and a Period1-knockout (Per1−/−; right) mouse. Images were taken 2 h after lights on, thus, when fluctuating levels of pCREB peak in WT mouse hippocampus. Insets show a representative hippocampal neuron...

  8. Muscle phosphorylase kinase deficiency

    DEFF Research Database (Denmark)

    Preisler, N; Orngreen, M C; Echaniz-Laguna, A

    2012-01-01

    To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD).......To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD)....

  9. Nuclear

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The first text deals with a new circular concerning the collect of the medicine radioactive wastes, containing radium. This campaign wants to incite people to let go their radioactive wastes (needles, tubes) in order to suppress any danger. The second text presents a decree of the 31 december 1999, relative to the limitations of noise and external risks resulting from the nuclear facilities exploitation: noise, atmospheric pollution, water pollution, wastes management and fire prevention. (A.L.B.)

  10. Pyruvate kinase blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003357.htm Pyruvate kinase blood test To use the sharing features on this page, ... energy when oxygen levels are low. How the Test is Performed A blood sample is needed. In the laboratory, white blood ...

  11. Mangiferin ameliorates Porphyromonas gingivalis-induced experimental periodontitis by inhibiting phosphorylation of nuclear factor-κB and Janus kinase 1-signal transducer and activator of transcription signaling pathways.

    Science.gov (United States)

    Li, H; Wang, Q; Ding, Y; Bao, C; Li, W

    2017-02-01

    Mangiferin is a natural polyphenol compound with anti-inflammatory properties. However, there have been few reports on the effect of mangiferin on periodontitis. Here, we investigated the anti-inflammatory effects of this compound on experimental periodontitis and the underlying mechanisms. Mice were inoculated with Porphyromonas gingivalis to induce periodontitis, and treated with mangiferin orally (50 mg/kg bodyweight, once a day) for 8 wk. Then, the alveolar bone loss was examined using a scanning electronic microscope. Expression of tumor necrosis factor-α (TNF-α) and the phosphorylation levels of nuclear factor-κB (NF-κB) and Janus kinase 1-signal transducer and activator of adhesion (JAK1-STAT) pathways in the gingival epithelium were detected using western blot analysis and immunohistochemical staining. The results showed that mice with periodontitis exhibited greater alveolar bone loss, stronger expression of TNF-α and higher phosphorylation levels of NF-κB and JAK1-STAT1/3 pathways in gingival epithelia, compared with control mice with no periodontitis. Moreover, treatment with mangiferin could significantly inhibit alveolar bone loss, TNF-α production and phosphorylation of NF-κB and JAK1-STAT1/3 pathways in gingival epithelia. Mangiferin has anti-inflammatory effects on periodontitis, which is associated with its ability to down-regulate the phosphorylation of NF-κB and JAK1-STAT1/3 pathways in gingival epithelia. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Astaxanthin inhibits cytokines production and inflammatory gene expression by suppressing IκB kinase-dependent nuclear factor κB activation in pre and postpartum Murrah buffaloes during different seasons

    Directory of Open Access Journals (Sweden)

    Lakshmi Priyadarshini

    2018-06-01

    Full Text Available Aim: We examined regulatory function of astaxanthin on mRNA expression of nuclear factor κB (NF-κB p65, interleukin-6 (IL-6, tumor necrosis factor alpha (TNF-α, and interferon gamma (IFN-γ in peripheral blood mononuclear cells in pre and postpartum Murrah buffaloes during summer (temperature-humidity index [THI]=86; relative humidity [RH]=24 and winter (THI=58.74; RH=73 seasons. Materials and Methods: A total of 32 Murrah buffaloes apparently healthy and in their one to four parity were selected from National Dairy Research Institute herd and equally distributed randomly into four groups (control and supplemented groups of buffaloes during summer and winter season, respectively. All groups were fed according to the nutrient requirement of buffaloes (ICAR, 2013. The treatment group was supplemented with astaxanthin at 0.25 mg/kg body weight/animal/day during the period 30 days before expected date of calving and up to 30 days postpartum. Results: There was downregulation of NF-κB p65 gene in all the groups. NF-κB p65 mRNA expression was lower (p<0.05 in treatment than control group from prepartum to postpartum during summer, while mRNA expression was low only on day 21 after calving during winter season. The mRNA expression of IL-6, TNF-α, and IFN-γ was lower (p<0.05 in treatment than a control group of buffaloes during summer and winter seasons. The mRNA expression of NF-κB p65, IL-6, TNF-α, and IFN-γ was higher (p<0.05 in summer than in winter seasons. Conclusion: The xanthophyll carotenoid astaxanthin a reddish-colored C-40 compound is a powerful broad-ranging antioxidant that naturally occurs in a wide variety of living organisms, such as microalgae, fungi, crustaceans, and complex plants. Astaxanthin blocked nuclear translocation of NF-κB p65 subunit and IκBa degradation, which correlated with its inhibitory effect on IκB kinase (IKK activity. These results suggest that astaxanthin, probably due to its antioxidant activity

  13. Cocoa Procyanidins Suppress Transformation by Inhibiting Mitogen-activated Protein Kinase Kinase*S⃞

    Science.gov (United States)

    Kang, Nam Joo; Lee, Ki Won; Lee, Dong Eun; Rogozin, Evgeny A.; Bode, Ann M.; Lee, Hyong Joo; Dong, Zigang

    2008-01-01

    Cocoa was shown to inhibit chemically induced carcinogenesis in animals and exert antioxidant activity in humans. However, the molecular mechanisms of the chemopreventive potential of cocoa and its active ingredient(s) remain unknown. Here we report that cocoa procyanidins inhibit neoplastic cell transformation by suppressing the kinase activity of mitogen-activated protein kinase kinase (MEK). A cocoa procyanidin fraction (CPF) and procyanidin B2 at 5 μg/ml and 40 μm, respectively, inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic transformation of JB6 P+ mouse epidermal (JB6 P+) cells by 47 and 93%, respectively. The TPA-induced promoter activity and expression of cyclooxygenase-2, which is involved in tumor promotion and inflammation, were dose-dependently inhibited by CPF or procyanidin B2. The activation of activator protein-1 and nuclear factor-κB induced by TPA was also attenuated by CPF or procyanidin B2. The TPA-induced phosphorylation of MEK, extracellular signal-regulated kinase, and p90 ribosomal s6 kinase was suppressed by CPF or procyanidin B2. In vitro and ex vivo kinase assay data demonstrated that CPF or procyanidin B2 inhibited the kinase activity of MEK1 and directly bound with MEK1. CPF or procyanidin B2 suppressed JB6 P+ cell transformation induced by epidermal growth factor or H-Ras, both of which are known to be involved in MEK/ERK signal activation. In contrast, theobromine (up to 80 μm) had no effect on TPA-induced transformation, cyclooxygenase-2 expression, the transactivation of activator protein-1 or nuclear factor-κB, or MEK. Notably, procyanidin B2 exerted stronger inhibitory effects compared with PD098059 (a well known pharmacological inhibitor of MEK) on MEK1 activity and neoplastic cell transformation. PMID:18519570

  14. Phosphorylation of the Yeast Choline Kinase by Protein Kinase C

    Science.gov (United States)

    Choi, Mal-Gi; Kurnov, Vladlen; Kersting, Michael C.; Sreenivas, Avula; Carman, George M.

    2005-01-01

    The Saccharomyces cerevisiae CKI1-encoded choline kinase catalyzes the committed step in phosphatidylcholine synthesis via the Kennedy pathway. The enzyme is phosphorylated on multiple serine residues, and some of this phosphorylation is mediated by protein kinase A. In this work, we examined the hypothesis that choline kinase is also phosphorylated by protein kinase C. Using choline kinase as a substrate, protein kinase C activity was dose- and time-dependent, and dependent on the concentrations of choline kinase (Km = 27 μg/ml) and ATP (Km = 15 μM). This phosphorylation, which occurred on a serine residue, was accompanied by a 1.6-fold stimulation of choline kinase activity. The synthetic peptide SRSSS25QRRHS (Vmax/Km = 17.5 mM-1 μmol min-1 mg-1) that contains the protein kinase C motif for Ser25 was a substrate for protein kinase C. A Ser25 to Ala (S25A) mutation in choline kinase resulted in a 60% decrease in protein kinase C phosphorylation of the enzyme. Phosphopeptide mapping analysis of the S25A mutant enzyme confirmed that Ser25 was a protein kinase C target site. In vivo, the S25A mutation correlated with a decrease (55%) in phosphatidylcholine synthesis via the Kennedy pathway whereas an S25D phosphorylation site mimic correlated with an increase (44%) in phosphatidylcholine synthesis. Whereas the S25A (protein kinase C site) mutation did not affect the phosphorylation of choline kinase by protein kinase A, the S30A (protein kinase A site) mutation caused a 46% reduction in enzyme phosphorylation by protein kinase C. A choline kinase synthetic peptide (SQRRHS30LTRQ) containing Ser30 was a substrate (Vmax/Km = 3.0 mM−1 μmol min−1 mg−1) for protein kinase C. Comparison of phosphopeptide maps of the wild type and S30A mutant choline kinase enzymes phosphorylated by protein kinase C confirmed that Ser30 was also a target site for protein kinase C. PMID:15919656

  15. Enterococcus faecalis phosphomevalonate kinase

    Science.gov (United States)

    Doun, Stephanie S.; Burgner, John W.; Briggs, Scott D.; Rodwell, Victor W.

    2005-01-01

    The six enzymes of the mevalonate pathway of isopentenyl diphosphate biosynthesis represent potential for addressing a pressing human health concern, the development of antibiotics against resistant strains of the Gram-positive streptococci. We previously characterized the first four of the mevalonate pathway enzymes of Enterococcus faecalis, and here characterize the fifth, phosphomevalonate kinase (E.C. 2.7.4.2). E. faecalis genomic DNA and the polymerase chain reaction were used to clone DNA thought to encode phosphomevalonate kinase into pET28b(+). Double-stranded DNA sequencing verified the sequence of the recombinant gene. The encoded N-terminal hexahistidine-tagged protein was expressed in Escherichia coli with induction by isopropylthiogalactoside and purified by Ni++ affinity chromatography, yield 20 mg protein per liter. Analysis of the purified protein by MALDI-TOF mass spectrometry established it as E. faecalis phosphomevalonate kinase. Analytical ultracentrifugation revealed that the kinase exists in solution primarily as a dimer. Assay for phosphomevalonate kinase activity used pyruvate kinase and lactate dehydrogenase to couple the formation of ADP to the oxidation of NADH. Optimal activity occurred at pH 8.0 and at 37°C. The activation energy was ~5.6 kcal/mol. Activity with Mn++, the preferred cation, was optimal at about 4 mM. Relative rates using different phosphoryl donors were 100 (ATP), 3.6 (GTP), 1.6 (TTP), and 0.4 (CTP). Km values were 0.17 mM for ATP and 0.19 mM for (R,S)-5-phosphomevalonate. The specific activity of the purified enzyme was 3.9 μmol substrate converted per minute per milligram protein. Applications to an immobilized enzyme bioreactor and to drug screening and design are discussed. PMID:15802646

  16. From Phosphosites to Kinases

    DEFF Research Database (Denmark)

    Munk, Stephanie; Refsgaard, Jan C; Olsen, Jesper V

    2016-01-01

    Kinases play a pivotal role in propagating the phosphorylation-mediated signaling networks in living cells. With the overwhelming quantities of phosphoproteomics data being generated, the number of identified phosphorylation sites (phosphosites) is ever increasing. Often, proteomics investigations...... sequence motifs, mostly based on large scale in vivo and in vitro experiments. The context of the kinase and the phosphorylated proteins in a biological system is equally important for predicting association between the enzymes and substrates, an aspect that is also being tackled with available...

  17. Glycogen Synthase Kinase 3α Is the Main Isoform That Regulates the Transcription Factors Nuclear Factor-Kappa B and cAMP Response Element Binding in Bovine Endothelial Cells Infected with Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Octavio Silva-García

    2018-01-01

    Full Text Available Glycogen synthase kinase 3 (GSK3 is a constitutive enzyme implicated in the regulation of cytokine expression and the inflammatory response during bacterial infections. Mammals have two GSK3 isoforms named GSK3α and GSK3β that plays different but often overlapping functions. Although the role of GSK3β in cytokine regulation during the inflammatory response caused by bacteria is well described, GSK3α has not been found to participate in this process. Therefore, we tested if GSK3α may act as a regulatory isoform in the cytokine expression by bovine endothelial cells infected with Staphylococcus aureus because this bacterium is one of the major pathogens that cause tissue damage associated with inflammatory dysfunction. Interestingly, although both isoforms were phosphorylated–inactivated, we consistently observed a higher phosphorylation of GSK3α at Ser21 than that of GSK3β at Ser9 after bacterial challenge. During a temporal course of infection, we characterized a molecular switch from pro-inflammatory cytokine expression (IL-8, promoted by nuclear factor-kappa B (NF-κB, at an early stage (2 h to an anti-inflammatory cytokine expression (IL-10, promoted by cAMP response element binding (CREB, at a later stage (6 h. We observed an indirect effect of GSK3α activity on NF-κB activation that resulted in a low phosphorylation of CREB at Ser133, a decreased interaction between CREB and the co-activator CREB-binding protein (CBP, and a lower expression level of IL-10. Gene silencing of GSK3α and GSK3β with siRNA indicated that GSK3α knockout promoted the interaction between CREB and CBP that, in turn, increased the expression of IL-10, reduced the interaction of NF-κB with CBP, and reduced the expression of IL-8. These results indicate that GSK3α functions as the primary isoform that regulates the expression of IL-10 in endothelial cells infected with S. aureus.

  18. Pea DNA topoisomerase I is phosphorylated and stimulated by casein kinase 2 and protein kinase C.

    Science.gov (United States)

    Tuteja, Narendra; Reddy, Malireddy Kodandarami; Mudgil, Yashwanti; Yadav, Badam Singh; Chandok, Meena Rani; Sopory, Sudhir Kumar

    2003-08-01

    DNA topoisomerase I catalyzes the relaxation of superhelical DNA tension and is vital for DNA metabolism; therefore, it is essential for growth and development of plants. Here, we have studied the phosphorylation-dependent regulation of topoisomerase I from pea (Pisum sativum). The purified enzyme did not show autophosphorylation but was phosphorylated in an Mg(2+)-dependent manner by endogenous protein kinases present in pea nuclear extracts. This phosphorylation was abolished with calf intestinal alkaline phosphatase and lambda phosphatase. It was also phosphorylated by exogenous casein kinase 2 (CK2), protein kinase C (PKC; from animal sources), and an endogenous pea protein, which was purified using a novel phorbol myristate acetate affinity chromatography method. All of these phosphorylations were inhibited by heparin (inhibitor of CK2) and calphostin (inhibitor of PKC), suggesting that pea topoisomerase I is a bona fide substrate for these kinases. Spermine and spermidine had no effect on the CK2-mediated phosphorylation, suggesting that it is polyamine independent. Phospho-amino acid analysis showed that only serine residues were phosphorylated, which was further confirmed using antiphosphoserine antibody. The topoisomerase I activity increased after phosphorylation with exogenous CK2 and PKC. This study shows that these kinases may contribute to the physiological regulation of DNA topoisomerase I activity and overall DNA metabolism in plants.

  19. Protein Kinase Mitogen-activated Protein Kinase Kinase Kinase Kinase 4 (MAP4K4) Promotes Obesity-induced Hyperinsulinemia.

    Science.gov (United States)

    Roth Flach, Rachel J; Danai, Laura V; DiStefano, Marina T; Kelly, Mark; Menendez, Lorena Garcia; Jurczyk, Agata; Sharma, Rohit B; Jung, Dae Young; Kim, Jong Hun; Kim, Jason K; Bortell, Rita; Alonso, Laura C; Czech, Michael P

    2016-07-29

    Previous studies revealed a paradox whereby mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) acted as a negative regulator of insulin sensitivity in chronically obese mice, yet systemic deletion of Map4k4 did not improve glucose tolerance. Here, we report markedly reduced glucose-responsive plasma insulin and C-peptide levels in whole body Map4k4-depleted mice (M4K4 iKO) as well as an impaired first phase of insulin secretion from islets derived from M4K4 iKO mice ex vivo After long-term high fat diet (HFD), M4K4 iKO mice pancreata also displayed reduced β cell mass, fewer proliferating β cells and reduced islet-specific gene mRNA expression compared with controls, although insulin content was normal. Interestingly, the reduced plasma insulin in M4K4 iKO mice exposed to chronic (16 weeks) HFD was not observed in response to acute HFD challenge or short term treatment with the insulin receptor antagonist S961. Furthermore, the improved insulin sensitivity in obese M4K4 iKO mice was abrogated by high exogenous insulin over the course of a euglycemic clamp study, indicating that hypoinsulinemia promotes insulin sensitivity in chronically obese M4K4 iKO mice. These results demonstrate that protein kinase Map4k4 drives obesity-induced hyperinsulinemia and insulin resistance in part by promoting insulin secretion from β cells in mice. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Ribosomal S6 Kinase Cooperates with Casein Kinase 2 to Modulate the Drosophila Circadian Molecular Oscillator

    Science.gov (United States)

    Akten, Bikem; Tangredi, Michelle M.; Jauch, Eike; Roberts, Mary A.; Ng, Fanny; Raabe, Thomas; Jackson, F. Rob

    2009-01-01

    There is a universal requirement for post-translational regulatory mechanisms in circadian clock systems. Previous work in Drosophila has identified several kinases, phosphatases and an E3 ligase that are critical for determining the nuclear translocation and/or stability of clock proteins. The present study evaluated the function of p90 ribosomal S6 kinase (RSK) in the Drosophila circadian system. In mammals, RSK1 is a light- and clock-regulated kinase known to be activated by the MAPK pathway, but there is no direct evidence that it functions as a component of the circadian system. Here, we show that Drosophila S6KII RNA displays rhythms in abundance, indicative of circadian control. Importantly, an S6KII null mutant exhibits a short-period circadian phenotype that can be rescued by expression of the wild-type gene in clock neurons, indicating a role for S6KII in the molecular oscillator. Peak PER clock protein expression is elevated in the mutant, indicative of enhanced stability, whereas per mRNA level is decreased, consistent with enhanced feedback repression. Gene reporter assays show that decreased S6KII is associated with increased PER repression. Surprisingly, we demonstrate a physical interaction between S6KII and the Casein Kinase 2 regulatory subunit (CK2β), suggesting a functional relationship between the two kinases. In support of such a relationship, there are genetic interactions between S6KII and CK2 mutations, in vivo, which indicate that CK2 activity is required for S6KII action. We propose that the two kinases cooperate within clock neurons to fine-tune circadian period, improving the precision of the clock mechanism. PMID:19144847

  1. Regulation of Autophagy by Kinases

    International Nuclear Information System (INIS)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda

    2011-01-01

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets

  2. Regulation of Autophagy by Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda, E-mail: alakananda.basu@unthsc.edu [Department of Molecular Biology and Immunology, Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States)

    2011-06-09

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets.

  3. Regulation of Autophagy by Kinases

    Science.gov (United States)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda

    2011-01-01

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets. PMID:24212825

  4. Regulation of Autophagy by Kinases

    Directory of Open Access Journals (Sweden)

    Savitha Sridharan

    2011-06-01

    Full Text Available Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK and protein kinase C that are often deregulated in cancer and are important therapeutic targets.

  5. Visual Snapshots of Intracellular Kinase Activity At The Onset of Mitosis

    Science.gov (United States)

    Dai, Zhaohua; Dulyaninova, Natalya G.; Kumar, Sanjai; Bresnick, Anne R.; Lawrence, David S.

    2007-01-01

    Summary Visual snapshots of intracellular kinase activity can be acquired with exquisite temporal control using a light-activatable (caged) sensor, thereby providing a means to interrogate enzymatic activity at any point during the cell division cycle. Robust protein kinase activity transpires just prior to, but not immediately following, nuclear envelope breakdown (NEB). Furthermore, kinase activity is required for progression from prophase into metaphase. Finally, the application of selective protein kinase C (PKC) inhibitors, in combination with the caged sensor, correlates the action of the PKC β isoform with subsequent NEB. PMID:18022564

  6. 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....

  7. Molecular Imaging of the ATM Kinase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Terence M. [Department of Radiation Oncology, Ohio State University, Columbus, Ohio (United States); Nyati, Shyam [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Center for Molecular Imaging, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Ross, Brian D. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Rehemtulla, Alnawaz, E-mail: alnawaz@umich.edu [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Center for Molecular Imaging, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)

    2013-08-01

    Purpose: Ataxia telangiectasia mutated (ATM) is a serine/threonine kinase critical to the cellular DNA-damage response, including from DNA double-strand breaks. ATM activation results in the initiation of a complex cascade of events including DNA damage repair, cell cycle checkpoint control, and survival. We sought to create a bioluminescent reporter that dynamically and noninvasively measures ATM kinase activity in living cells and subjects. Methods and Materials: Using the split luciferase technology, we constructed a hybrid cDNA, ATM-reporter (ATMR), coding for a protein that quantitatively reports on changes in ATM kinase activity through changes in bioluminescence. Results: Treatment of ATMR-expressing cells with ATM inhibitors resulted in a dose-dependent increase in bioluminescence activity. In contrast, induction of ATM kinase activity upon irradiation resulted in a decrease in reporter activity that correlated with ATM and Chk2 activation by immunoblotting in a time-dependent fashion. Nuclear targeting improved ATMR sensitivity to both ATM inhibitors and radiation, whereas a mutant ATMR (lacking the target phosphorylation site) displayed a muted response. Treatment with ATM inhibitors and small interfering (si)RNA-targeted knockdown of ATM confirm the specificity of the reporter. Using reporter expressing xenografted tumors demonstrated the ability of ATMR to report in ATM activity in mouse models that correlated in a time-dependent fashion with changes in Chk2 activity. Conclusions: We describe the development and validation of a novel, specific, noninvasive bioluminescent reporter that enables monitoring of ATM activity in real time, in vitro and in vivo. Potential applications of this reporter include the identification and development of novel ATM inhibitors or ATM-interacting partners through high-throughput screens and in vivo pharmacokinetic/pharmacodynamic studies of ATM inhibitors in preclinical models.

  8. Receptor-interacting protein (RIP) kinase family

    OpenAIRE

    Zhang, Duanwu; Lin, Juan; Han, Jiahuai

    2010-01-01

    Receptor-interacting protein (RIP) kinases are a group of threonine/serine protein kinases with a relatively conserved kinase domain but distinct non-kinase regions. A number of different domain structures, such as death and caspase activation and recruitment domain (CARD) domains, were found in different RIP family members, and these domains should be keys in determining the specific function of each RIP kinase. It is known that RIP kinases participate in different biological processes, incl...

  9. A novel, non-canonical mechanism of regulation of MST3 (mammalian Sterile20-related kinase 3)

    OpenAIRE

    Fuller, Stephen J; McGuffin, Liam J; Marshall, Andrew K; Giraldo, Alejandro; Pikkarainen, Sampsa; Clerk, Angela; Sugden, Peter

    2012-01-01

    The canonical pathway of regulation of the GCK (germinal centre kinase) III subgroup member, MST3 (mammalian Sterile20-related kinase 3), involves a caspase-mediated cleavage between N-terminal catalytic and C-terminal regulatory domains with possible concurrent autophosphorylation of the activation loop MST3(Thr178), induction of serine/threonine protein kinase activity and nuclear localization. We identified an alternative ‘non-canonical’ pathway of MST3 activation (regulated primarily thro...

  10. Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae.

    Science.gov (United States)

    Qiu, Yixuan; Hassaninasab, Azam; Han, Gil-Soo; Carman, George M

    2016-12-16

    In the yeast Saccharomyces cerevisiae, Dgk1 diacylglycerol (DAG) kinase catalyzes the CTP-dependent phosphorylation of DAG to form phosphatidic acid (PA). The enzyme in conjunction with Pah1 PA phosphatase controls the levels of PA and DAG for the synthesis of triacylglycerol and membrane phospholipids, the growth of the nuclear/endoplasmic reticulum membrane, and the formation of lipid droplets. Little is known about how DAG kinase activity is regulated by posttranslational modification. In this work, we examined the phosphorylation of Dgk1 DAG kinase by casein kinase II (CKII). When phosphate groups were globally reduced using nonspecific alkaline phosphatase, Triton X-100-solubilized membranes from DGK1-overexpressing cells showed a 7.7-fold reduction in DAG kinase activity; the reduced enzyme activity could be increased 5.5-fold by treatment with CKII. Dgk1(1-77) expressed heterologously in Escherichia coli was phosphorylated by CKII on a serine residue, and its phosphorylation was dependent on time as well as on the concentrations of CKII, ATP, and Dgk1(1-77). We used site-specific mutagenesis, coupled with phosphorylation analysis and phosphopeptide mapping, to identify Ser-45 and Ser-46 of Dgk1 as the CKII target sites, with Ser-46 being the major phosphorylation site. In vivo, the S46A and S45A/S46A mutations of Dgk1 abolished the stationary phase-dependent stimulation of DAG kinase activity. In addition, the phosphorylation-deficient mutations decreased Dgk1 function in PA production and in eliciting pah1Δ phenotypes, such as the expansion of the nuclear/endoplasmic reticulum membrane, reduced lipid droplet formation, and temperature sensitivity. This work demonstrates that the CKII-mediated phosphorylation of Dgk1 regulates its function in the production of PA. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae*

    Science.gov (United States)

    Qiu, Yixuan; Hassaninasab, Azam; Han, Gil-Soo; Carman, George M.

    2016-01-01

    In the yeast Saccharomyces cerevisiae, Dgk1 diacylglycerol (DAG) kinase catalyzes the CTP-dependent phosphorylation of DAG to form phosphatidic acid (PA). The enzyme in conjunction with Pah1 PA phosphatase controls the levels of PA and DAG for the synthesis of triacylglycerol and membrane phospholipids, the growth of the nuclear/endoplasmic reticulum membrane, and the formation of lipid droplets. Little is known about how DAG kinase activity is regulated by posttranslational modification. In this work, we examined the phosphorylation of Dgk1 DAG kinase by casein kinase II (CKII). When phosphate groups were globally reduced using nonspecific alkaline phosphatase, Triton X-100-solubilized membranes from DGK1-overexpressing cells showed a 7.7-fold reduction in DAG kinase activity; the reduced enzyme activity could be increased 5.5-fold by treatment with CKII. Dgk1(1–77) expressed heterologously in Escherichia coli was phosphorylated by CKII on a serine residue, and its phosphorylation was dependent on time as well as on the concentrations of CKII, ATP, and Dgk1(1–77). We used site-specific mutagenesis, coupled with phosphorylation analysis and phosphopeptide mapping, to identify Ser-45 and Ser-46 of Dgk1 as the CKII target sites, with Ser-46 being the major phosphorylation site. In vivo, the S46A and S45A/S46A mutations of Dgk1 abolished the stationary phase-dependent stimulation of DAG kinase activity. In addition, the phosphorylation-deficient mutations decreased Dgk1 function in PA production and in eliciting pah1Δ phenotypes, such as the expansion of the nuclear/endoplasmic reticulum membrane, reduced lipid droplet formation, and temperature sensitivity. This work demonstrates that the CKII-mediated phosphorylation of Dgk1 regulates its function in the production of PA. PMID:27834677

  12. Mitogen-activated protein kinases interacting kinases are autoinhibited by a reprogrammed activation segment.

    Science.gov (United States)

    Jauch, Ralf; Cho, Min-Kyu; Jäkel, Stefan; Netter, Catharina; Schreiter, Kay; Aicher, Babette; Zweckstetter, Markus; Jäckle, Herbert; Wahl, Markus C

    2006-09-06

    Autoinhibition is a recurring mode of protein kinase regulation and can be based on diverse molecular mechanisms. Here, we show by crystal structure analysis, nuclear magnetic resonance (NMR)-based nucleotide affinity studies and rational mutagenesis that nonphosphorylated mitogen-activated protein (MAP) kinases interacting kinase (Mnk) 1 is autoinhibited by conversion of the activation segment into an autoinhibitory module. In a Mnk1 crystal structure, the activation segment is repositioned via a Mnk-specific sequence insertion at the N-terminal lobe with the following consequences: (i) the peptide substrate binding site is deconstructed, (ii) the interlobal cleft is narrowed, (iii) an essential Lys-Glu pair is disrupted and (iv) the magnesium-binding loop is locked into an ATP-competitive conformation. Consistently, deletion of the Mnk-specific insertion or removal of a conserved phenylalanine side chain, which induces a blockade of the ATP pocket, increase the ATP affinity of Mnk1. Structural rearrangements required for the activation of Mnks are apparent from the cocrystal structure of a Mnk2 D228G -staurosporine complex and can be modeled on the basis of crystal packing interactions. Our data suggest a novel regulatory mechanism specific for the Mnk subfamily.

  13. Diacylglycerol kinase regulation of protein kinase D during oxidative stress-induced intestinal cell injury

    International Nuclear Information System (INIS)

    Song Jun; Li Jing; Mourot, Joshua M.; Mark Evers, B.; Chung, Dai H.

    2008-01-01

    We recently demonstrated that protein kinase D (PKD) exerts a protective function during oxidative stress-induced intestinal epithelial cell injury; however, the exact role of DAG kinase (DGK)ζ, an isoform expressed in intestine, during this process is unknown. We sought to determine the role of DGK during oxidative stress-induced intestinal cell injury and whether DGK acts as an upstream regulator of PKD. Inhibition of DGK with R59022 compound or DGKζ siRNA transfection decreased H 2 O 2 -induced RIE-1 cell apoptosis as measured by DNA fragmentation and increased PKD phosphorylation. Overexpression of kinase-dead DGKζ also significantly increased PKD phosphorylation. Additionally, endogenous nuclear DGKζ rapidly translocated to the cytoplasm following H 2 O 2 treatment. Our findings demonstrate that DGK is involved in the regulation of oxidative stress-induced intestinal cell injury. PKD activation is induced by DGKζ, suggesting DGK is an upstream regulator of oxidative stress-induced activation of the PKD signaling pathway in intestinal epithelial cells

  14. Angiotensin II regulation of neuromodulation: downstream signaling mechanism from activation of mitogen-activated protein kinase.

    Science.gov (United States)

    Lu, D; Yang, H; Raizada, M K

    1996-12-01

    Angiotensin II (Ang II) stimulates expression of tyrosine hydroxylase and norepinephrine transporter genes in brain neurons; however, the signal-transduction mechanism is not clearly defined. This study was conducted to determine the involvement of the mitogen-activated protein (MAP) kinase signaling pathway in Ang II stimulation of these genes. MAP kinase was localized in the perinuclear region of the neuronal soma. Ang II caused activation of MAP kinase and its subsequent translocation from the cytoplasmic to nuclear compartment, both effects being mediated by AT1 receptor subtype. Ang II also stimulated SRE- and AP1-binding activities and fos gene expression and its translocation in a MAP kinase-dependent process. These observations are the first demonstration of a downstream signaling pathway involving MAP kinase in Ang II-mediated neuromodulation in noradrenergic neurons.

  15. Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay.

    Science.gov (United States)

    Cui, Heying; Loftus, Kyle M; Noell, Crystal R; Solmaz, Sozanne R

    2018-05-03

    Cyclin-dependent kinase 1 (Cdk1) is a master controller for the cell cycle in all eukaryotes and phosphorylates an estimated 8 - 13% of the proteome; however, the number of identified targets for Cdk1, particularly in human cells is still low. The identification of Cdk1-specific phosphorylation sites is important, as they provide mechanistic insights into how Cdk1 controls the cell cycle. Cell cycle regulation is critical for faithful chromosome segregation, and defects in this complicated process lead to chromosomal aberrations and cancer. Here, we describe an in vitro kinase assay that is used to identify Cdk1-specific phosphorylation sites. In this assay, a purified protein is phosphorylated in vitro by commercially available human Cdk1/cyclin B. Successful phosphorylation is confirmed by SDS-PAGE, and phosphorylation sites are subsequently identified by mass spectrometry. We also describe purification protocols that yield highly pure and homogeneous protein preparations suitable for the kinase assay, and a binding assay for the functional verification of the identified phosphorylation sites, which probes the interaction between a classical nuclear localization signal (cNLS) and its nuclear transport receptor karyopherin α. To aid with experimental design, we review approaches for the prediction of Cdk1-specific phosphorylation sites from protein sequences. Together these protocols present a very powerful approach that yields Cdk1-specific phosphorylation sites and enables mechanistic studies into how Cdk1 controls the cell cycle. Since this method relies on purified proteins, it can be applied to any model organism and yields reliable results, especially when combined with cell functional studies.

  16. Interação entre células do cumulus e atividade da proteína quinase C em diferentes fases da maturação nuclear de oócitos bovinos Interaction between cumulus cells and the activity of protein kinase C at different stages of bovine oocyte nuclear maturation

    Directory of Open Access Journals (Sweden)

    A.C. Bertagnolli

    2004-08-01

    Full Text Available Verificou-se a influência da proteína quinase C (PK-C no reinício e na progressão da meiose em oócitos bovinos, determinando se as células do cumulus são mediadoras da PK-C na regulação da maturação dos oócitos. Complexos cumulus-oócitos (CCO e oócitos desnudos (OD, distribuídos aleatoriamente em seis tratamentos (T com base na presença de um ativador da PK-C (PMA (T1 e T2, de um forbol éster incapaz de ativar a PK-C (4alfa-PDD-controle (T3 e T4 ou de apenas o meio básico (TCM-199-controle (T5 e T6, foram cultivados por 7, 9, 12, 18 e 22 horas. A percentagem de rompimento da vesícula germinativa no grupo cultivado com PMA foi maior do que nos dois grupos controle, com e sem células do cumulus. O cultivo de CCO e OD por 12 e 18 horas demonstrou que a PK-C influencia a progressão para os estádios de metáfase I (MI e metáfase II (MII de maneira dependente das células do cumulus. Nos períodos de 9 e 22 horas, não foi possível observar diferença entre os grupos quanto aos diferentes estádios de maturação. A ativação da PK-C acelera o reinício da meiose independentemente das células somáticas e acelera a progressão até os estádios de MI e MII na dependência das células do cumulus.The aim of this study was to evaluate the effect of protein kinase C (PK-C on the meiotic resumption and progression in bovine oocyte, and to determine if the cumulus cells mediate the PK-C action in the regulation of bovine oocyte nuclear maturation. Cumulus-oocyte complexes (COC and denuded oocytes (DO, randomly allotted to 6 treatments (T based on the presence of an activator of PK-C (PMA (T1 and T2, or a phorbol ester unable to activate PK-C (4alphaPDD-control (T3 and T4 or a basic culture medium (T5 and T6, were cultivated for 7, 9, 12, 18 and 22 hours. The percentage of germinal vesicle breakdown (GVBD was higher when the oocytes were cultured with PMA than in the control groups with and without cumulus cells. However, PK-C was

  17. Chitin and stress induced protein kinase activation

    DEFF Research Database (Denmark)

    Kenchappa, Chandra Shekar; Azevedo da Silva, Raquel; Bressendorff, Simon

    2017-01-01

    The assays described here are pertinent to protein kinase studies in any plant. They include an immunoblot phosphorylation/activation assay and an in-gel activity assay for MAP kinases (MPKs) using the general protein kinase substrate myelin basic protein. They also include a novel in-gel peptide...... substrate assay for Snf1-related kinase family 2 members (SnRK2s). This kinase family-specific assay overcomes some limitations of in-gel assays and permits the identification of different types of kinase activities in total protein extracts....

  18. Effect of triiodothyronine on rat liver chromatin protein kinase

    International Nuclear Information System (INIS)

    Kruh, J.; Tichonicky, L.

    1976-01-01

    1) Injection of triiodothyronine to rats stimulates protein kinase activity in liver chromatin nonhistone proteins. A significant increase was found after two daily injections. A 4-fold increase was observed with the purified enzyme after eight daily injections of the hormone. No variations were observed in cytosol protein kinase activity. Electrophoretic pattern, effect of heat denaturation, effect of p-hydroxymercuribenzoate seem to indicate that the enzyme present in treated rats is not identical to the enzyme in control animals, which suggests that thyroid hormone has induced nuclear protein kinase. Diiodothyronine, 3, 3', 5'-triiodothyronine have no effect on protein kinase. 2) Chromatin non-histone proteins isolated from rats injected with triiodothyronine incorporated more 32 P when incubated with [γ- 32 P]ATP than the chromatin proteins from untreated rats. Thyroidectomy reduced the in vitro 32 P incorporation. It is suggested that some of the biological activity of thyroid hormone could be mediated through its effect on chromatin non-histone proteins. (orig.) [de

  19. Non-Viral Deoxyribonucleoside Kinases

    DEFF Research Database (Denmark)

    Christiansen, Louise Slot; Munch-Petersen, Birgitte; Knecht, Wolfgang

    2015-01-01

    Deoxyribonucleoside kinases (dNKs) phosphorylate deoxyribonucleosides to their corresponding monophosphate compounds. dNks also phosphorylate deoxyribonucleoside analogues that are used in the treatment of cancer or viral infections. The study of the mammalian dNKs has therefore always been of gr...

  20. Sulforaphane Inhibits Lipopolysaccharide-Induced Inflammation, Cytotoxicity, Oxidative Stress, and miR-155 Expression and Switches to Mox Phenotype through Activating Extracellular Signal-Regulated Kinase 1/2-Nuclear Factor Erythroid 2-Related Factor 2/Antioxidant Response Element Pathway in Murine Microglial Cells.

    Science.gov (United States)

    Eren, Erden; Tufekci, Kemal Ugur; Isci, Kamer Burak; Tastan, Bora; Genc, Kursad; Genc, Sermin

    2018-01-01

    Sulforaphane (SFN) is a natural product with cytoprotective, anti-inflammatory, and antioxidant effects. In this study, we evaluated the mechanisms of its effects on lipopolysaccharide (LPS)-induced cell death, inflammation, oxidative stress, and polarization in murine microglia. We found that SFN protects N9 microglial cells upon LPS-induced cell death and suppresses LPS-induced levels of secreted pro-inflammatory cytokines, tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6. SFN is also a potent inducer of redox sensitive transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), which is responsible for the transcription of antioxidant, cytoprotective, and anti-inflammatory genes. SFN induced translocation of Nrf2 to the nucleus via extracellular signal-regulated kinase 1/2 (ERK1/2) pathway activation. siRNA-mediated knockdown study showed that the effects of SFN on LPS-induced reactive oxygen species, reactive nitrogen species, and pro-inflammatory cytokine production and cell death are partly Nrf2 dependent. Mox phenotype is a novel microglial phenotype that has roles in oxidative stress responses. Our results suggested that SFN induced the Mox phenotype in murine microglia through Nrf2 pathway. SFN also alleviated LPS-induced expression of inflammatory microRNA, miR-155. Finally, SFN inhibits microglia-mediated neurotoxicity as demonstrated by conditioned medium and co-culture experiments. In conclusion, SFN exerts protective effects on microglia and modulates the microglial activation state.

  1. Protein kinase CK2 in human diseases

    DEFF Research Database (Denmark)

    Guerra, Barbara; Issinger, Olaf-Georg

    2008-01-01

    Protein kinase CK2 (formerly referred to as casein kinase II) is an evolutionary conserved, ubiquitous protein kinase. There are two paralog catalytic subunits, i.e. alpha (A1) and alpha' (A2). The alpha and alpha' subunits are linked to two beta subunits to produce a heterotetrameric structure...

  2. Helicobacter pylori induces cell migration and invasion through casein kinase 2 in gastric epithelial cells.

    Science.gov (United States)

    Lee, Yeo Song; Lee, Do Yeon; Yu, Da Yeon; Kim, Shin; Lee, Yong Chan

    2014-12-01

    Chronic infection with Helicobacter pylori (H. pylori) is causally linked with gastric carcinogenesis. Virulent H. pylori strains deliver bacterial CagA into gastric epithelial cells. Induction of high motility and an elongated phenotype is considered to be CagA-dependent process. Casein kinase 2 plays a critical role in carcinogenesis through signaling pathways related to the epithelial mesenchymal transition. This study was aimed to investigate the effect of H. pylori infection on the casein kinase 2-mediated migration and invasion in gastric epithelial cells. AGS or MKN28 cells as human gastric epithelial cells and H. pylori strains Hp60190 (ATCC 49503, CagA(+)) and Hp8822 (CagA(-)) were used. Cells were infected with H. pylori at multiplicity of infection of 100 : 1 for various times. We measured in vitro kinase assay to examine casein kinase 2 activity and performed immunofluorescent staining to observe E-cadherin complex. We also examined β-catenin transactivation through promoter assay and MMP7 expression by real-time PCR and ELISA. H. pylori upregulates casein kinase 2 activity and inhibition of casein kinase 2 in H. pylori-infected cells profoundly suppressed cell invasiveness and motility. We confirmed that casein kinase 2 mediates membranous α-catenin depletion through dissociation of the α-/β-catenin complex in H. pylori-infected cells. We also found that H. pylori induces β-catenin nuclear translocation and increases MMP7 expressions mediated through casein kinase 2. We show for the first time that CagA(+) H. pylori upregulates cellular invasiveness and motility through casein kinase 2. The demonstration of a mechanistic interplay between H. pylori and casein kinase 2 provides important insights into the role of CagA(+) H. pylori in the gastric cancer invasion and metastasis. © 2014 John Wiley & Sons Ltd.

  3. Autoregulation of kinase dephosphorylation by ATP binding in AGC protein kinases.

    Science.gov (United States)

    Chan, Tung O; Pascal, John M; Armen, Roger S; Rodeck, Ulrich

    2012-02-01

    AGC kinases, including the three Akt (protein kinase B) isoforms, protein kinase A (PKA) and all protein kinase C (PKC) isoforms, require activation loop phosphorylation (threonine 308 in Akt1) as well as phosphorylation of a C-terminal residue (serine 473 in Akt1) for catalytic activity and phosphorylation of downstream targets. Conversely, phosphatases reverse these phosphorylations. Virtually all cellular processes are affected by AGC kinases, a circumstance that has led to intense scrutiny of the molecular mechanisms that regulate phosphorylation of these kinases. Here, we review a new layer of control of phosphorylation in Akt, PKA and PKC pointing to ATP binding pocket occupancy as a means to decelerate dephosphorylation of these and, potentially, other kinases. This additional level of kinase regulation opens the door to search for new functional motifs for the rational design of non- ATP-competitive kinase inhibitors that discriminate within and between protein kinase families.

  4. Autoregulation of kinase dephosphorylation by ATP binding to AGC protein kinases

    Science.gov (United States)

    Pascal, John M; Armen, Roger S

    2012-01-01

    AGC kinases, including the three Akt (protein kinase B) isoforms, protein kinase A (PKA) and all protein kinase C (PKC) isoforms, require activation loop phosphorylation (threonine 308 in Akt1) as well as phosphorylation of a C-terminal residue (serine 473 in Akt1) for catalytic activity and phosphorylation of downstream targets. Conversely, phosphatases reverse these phosphorylations. Virtually all cellular processes are affected by AGC kinases, a circumstance that has led to intense scrutiny of the molecular mechanisms that regulate phosphorylation of these kinases. Here, we review a new layer of control of phosphorylation in Akt, PKA and PKC pointing to ATP binding pocket occupancy as a means to decelerate dephosphorylation of these and, potentially, other kinases. This additional level of kinase regulation opens the door to search for new functional motifs for the rational design of non-ATP-competitive kinase inhibitors that discriminate within and between protein kinase families. PMID:22262182

  5. Structural changes in human cytomegalovirus cytoplasmic assembly sites in the absence of UL97 kinase activity

    International Nuclear Information System (INIS)

    Azzeh, Maysa; Honigman, Alik; Taraboulos, Albert; Rouvinski, Alexander; Wolf, Dana G.

    2006-01-01

    Studies of human cytomegalovirus (HCMV) UL97 kinase deletion mutant (ΔUL97) indicated a multi-step role for this kinase in early and late phases of the viral life cycle, namely, in DNA replication, capsid maturation and nuclear egress. Here, we addressed its possible involvement in cytoplasmic steps of HCMV assembly. Using the ΔUL97 and the UL97 kinase inhibitor NGIC-I, we demonstrate that the absence of UL97 kinase activity results in a modified subcellular distribution of the viral structural protein assembly sites, from compact structures impacting upon the nucleus to diffuse perinuclear structures punctuated by large vacuoles. Infection by either wild type or ΔUL97 viruses induced a profound reorganization of wheat germ agglutinin (WGA)-positive Golgi-related structures. Importantly, the viral-induced Golgi remodeling along with the reorganization of the nuclear architecture was substantially altered in the absence of UL97 kinase activity. These findings suggest that UL97 kinase activity might contribute to organization of the viral cytoplasmic assembly sites

  6. Conserved family of glycerol kinase loci in Drosophila melanogaster

    Science.gov (United States)

    Martinez Agosto, Julian A.; McCabe, Edward R.B.

    2009-01-01

    Glycerol kinase (GK) is an enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol, the rate-limiting step in glycerol utilization. We analyzed the genome of the model organism Drosophila melanogaster and identified five GK orthologs, including two loci with sequence homology to the mammalian Xp21 GK protein. Using a combination of sequence analysis and evolutionary comparisons of orthologs between species, we characterized functional domains in the protein required for GK activity. Our findings include additional conserved domains that suggest novel nuclear and mitochondrial functions for glycerol kinase in apoptosis and transcriptional regulation. Investigation of GK function in Drosophila will inform us about the role of this enzyme in development and will provide us with a tool to examine genetic modifiers of human metabolic disorders. PMID:16545593

  7. Src kinase regulation by phosphorylation and dephosphorylation

    International Nuclear Information System (INIS)

    Roskoski, Robert

    2005-01-01

    Src and Src-family protein-tyrosine kinases are regulatory proteins that play key roles in cell differentiation, motility, proliferation, and survival. The initially described phosphorylation sites of Src include an activating phosphotyrosine 416 that results from autophosphorylation, and an inhibiting phosphotyrosine 527 that results from phosphorylation by C-terminal Src kinase (Csk) and Csk homologous kinase. Dephosphorylation of phosphotyrosine 527 increases Src kinase activity. Candidate phosphotyrosine 527 phosphatases include cytoplasmic PTP1B, Shp1 and Shp2, and transmembrane enzymes include CD45, PTPα, PTPε, and PTPλ. Dephosphorylation of phosphotyrosine 416 decreases Src kinase activity. Thus far PTP-BL, the mouse homologue of human PTP-BAS, has been shown to dephosphorylate phosphotyrosine 416 in a regulatory fashion. The platelet-derived growth factor receptor protein-tyrosine kinase mediates the phosphorylation of Src Tyr138; this phosphorylation has no direct effect on Src kinase activity. The platelet-derived growth factor receptor and the ErbB2/HER2 growth factor receptor protein-tyrosine kinases mediate the phosphorylation of Src Tyr213 and activation of Src kinase activity. Src kinase is also a substrate for protein-serine/threonine kinases including protein kinase C (Ser12), protein kinase A (Ser17), and CDK1/cdc2 (Thr34, Thr46, and Ser72). Of the three protein-serine/threonine kinases, only phosphorylation by CDK1/cdc2 has been demonstrated to increase Src kinase activity. Although considerable information on the phosphoprotein phosphatases that catalyze the hydrolysis of Src phosphotyrosine 527 is at hand, the nature of the phosphatases that mediate the hydrolysis of phosphotyrosine 138 and 213, and phosphoserine and phosphothreonine residues has not been determined

  8. Multiple Duties for Spindle Assembly Checkpoint Kinases in Meiosis

    Science.gov (United States)

    Marston, Adele L.; Wassmann, Katja

    2017-01-01

    Cell division in mitosis and meiosis is governed by evolutionary highly conserved protein kinases and phosphatases, controlling the timely execution of key events such as nuclear envelope breakdown, spindle assembly, chromosome attachment to the spindle and chromosome segregation, and cell cycle exit. In mitosis, the spindle assembly checkpoint (SAC) controls the proper attachment to and alignment of chromosomes on the spindle. The SAC detects errors and induces a cell cycle arrest in metaphase, preventing chromatid separation. Once all chromosomes are properly attached, the SAC-dependent arrest is relieved and chromatids separate evenly into daughter cells. The signaling cascade leading to checkpoint arrest depends on several protein kinases that are conserved from yeast to man. In meiosis, haploid cells containing new genetic combinations are generated from a diploid cell through two specialized cell divisions. Though apparently less robust, SAC control also exists in meiosis. Recently, it has emerged that SAC kinases have additional roles in executing accurate chromosome segregation during the meiotic divisions. Here, we summarize the main differences between mitotic and meiotic cell divisions, and explain why meiotic divisions pose special challenges for correct chromosome segregation. The less-known meiotic roles of the SAC kinases are described, with a focus on two model systems: yeast and mouse oocytes. The meiotic roles of the canonical checkpoint kinases Bub1, Mps1, the pseudokinase BubR1 (Mad3), and Aurora B and C (Ipl1) will be discussed. Insights into the molecular signaling pathways that bring about the special chromosome segregation pattern during meiosis will help us understand why human oocytes are so frequently aneuploid. PMID:29322045

  9. Multiple Duties for Spindle Assembly Checkpoint Kinases in Meiosis

    Directory of Open Access Journals (Sweden)

    Adele L. Marston

    2017-12-01

    Full Text Available Cell division in mitosis and meiosis is governed by evolutionary highly conserved protein kinases and phosphatases, controlling the timely execution of key events such as nuclear envelope breakdown, spindle assembly, chromosome attachment to the spindle and chromosome segregation, and cell cycle exit. In mitosis, the spindle assembly checkpoint (SAC controls the proper attachment to and alignment of chromosomes on the spindle. The SAC detects errors and induces a cell cycle arrest in metaphase, preventing chromatid separation. Once all chromosomes are properly attached, the SAC-dependent arrest is relieved and chromatids separate evenly into daughter cells. The signaling cascade leading to checkpoint arrest depends on several protein kinases that are conserved from yeast to man. In meiosis, haploid cells containing new genetic combinations are generated from a diploid cell through two specialized cell divisions. Though apparently less robust, SAC control also exists in meiosis. Recently, it has emerged that SAC kinases have additional roles in executing accurate chromosome segregation during the meiotic divisions. Here, we summarize the main differences between mitotic and meiotic cell divisions, and explain why meiotic divisions pose special challenges for correct chromosome segregation. The less-known meiotic roles of the SAC kinases are described, with a focus on two model systems: yeast and mouse oocytes. The meiotic roles of the canonical checkpoint kinases Bub1, Mps1, the pseudokinase BubR1 (Mad3, and Aurora B and C (Ipl1 will be discussed. Insights into the molecular signaling pathways that bring about the special chromosome segregation pattern during meiosis will help us understand why human oocytes are so frequently aneuploid.

  10. Zerumbone, a Bioactive Sesquiterpene, Ameliorates Diabetes-Induced Retinal Microvascular Damage through Inhibition of Phospho-p38 Mitogen-Activated Protein Kinase and Nuclear Factor-κB Pathways

    Directory of Open Access Journals (Sweden)

    Wayne Young Liu

    2016-12-01

    Full Text Available Zerumbone ameliorates retinal damage by blocking advanced glycation end products and their receptor system in streptozotocin-diabetic rats. Because of the multiple factors involved in diabetic retinopathy (DR etiology, the mechanisms of zerumbone that are mainly responsible for its ameliorative effect on DR need to be further clarified. In the present study, zerumbone (20 mg or 40 mg/kg or fenofibric acid (100 mg/kg was orally administered to diabetic rats by intragastric gavage once daily for three consecutive months. Zerumbone displayed similar characteristics to fenofibric acid in reducing retinal vascular permeability and leukostasis in diabetic rats. Fundus photographs showed that large retinal vessel diameters were decreased in zerumbone-treated diabetic rats. Zerumbone not only down-regulated the gene expression of retinal angiogenic parameters, but also reduced the expression of inflammatory cytokines and chemokines in the retina of diabetic rats. Moreover, zerumbone reduced the p38 MAPK phosphorylation and abrogated the nuclear translocation of NF-κB p65 in the retina of diabetic rats. In conclusion, treatment of diabetic rats with zerumbone attenuates the severity of retinal inflammation and angiogenesis, via inhibition of p38 MAPK and NF-κB signaling pathways. These benefits of zerumbone for DR appear to be linked to its antihyperglycemic and antihyperlipidemic effects.

  11. Dietary α-lactalbumin induced fatty liver by enhancing nuclear liver X receptor αβ/sterol regulatory element-binding protein-1c/PPARγ expression and minimising PPARα/carnitine palmitoyltransferase-1 expression and AMP-activated protein kinase α phosphorylation associated with atherogenic dyslipidaemia, insulin resistance and oxidative stress in Balb/c mice.

    Science.gov (United States)

    López-Oliva, María Elvira; Garcimartin, Alba; Muñoz-Martínez, Emilia

    2017-12-01

    The effect and the role played by dietary α-lactalbumin (α-LAC) on hepatic fat metabolism are yet to be fully elucidated. We reported previously that α-LAC intake induced atherogenic dyslipidaemia in Balb/c mice. The aim of the present study was to investigate if this atherogenic effect could be due to a possible α-LAC-induced hepatic steatosis. We examine the ability of dietary α-LAC to induce liver steatosis, identifying the molecular mechanisms underlying hepatic lipid metabolism in association with the lipid profile, peripheral insulin resistance (IR) and changes in the hepatic oxidative environment. Male Balb/c mice (n 6) were fed with diets containing either chow or 14 % α-LAC for 4 weeks. The α-LAC-fed mice developed abdominal adiposity and IR. Moderate liver steatosis with increased TAG and NEFA contents was correlated with atherogenic dyslipidaemia. There was increased nuclear expression of liver X receptor αβ (LXRαβ), sterol regulatory element-binding protein-1c (SREBP-1c) and PPARγ transcription factors and of the cytosolic enzymes acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase involved in the hepatic de novo lipogenesis. The opposite was found for the nuclear receptor PPARα and the mitochondrial enzyme carnitine palmitoyltransferase-1 (CPT-1), leading to reduced fatty acid β-oxidation (FAO). These changes were associated with a significant decrease in both p-Thr172-AMP-activated protein kinase α (AMPKα) (inactivation) and p-Ser79-ACC1 (activation) and with a more oxidative liver environment increasing lipid peroxidation and protein oxidation and reducing GSH:GSSG ratio in the α-LAC-fed mice. In conclusion, 4 weeks of 14 % α-LAC feeding induced liver steatosis associated with atherogenic dyslipidaemia, IR and oxidative stress by enhancing nuclear LXRαβ/SREBP-1c/PPARγ expression and diminishing PPARα/CPT-1 expression and AMPKα phosphorylation shifting the hepatic FAO toward fatty acid synthesis in Balb/c mice.

  12. Three-Dimentional Structures of Autophosphorylation Complexes in Crystals of Protein Kinases

    KAUST Repository

    Dumbrack, Roland

    2016-01-26

    Protein kinase autophosphorylation is a common regulatory mechanism in cell signaling pathways. Several autophosphorylation complexes have been identified in crystals of protein kinases, with a known serine, threonine, or tyrosine autophosphorylation site of one kinase monomer sitting in the active site of another monomer of the same protein in the crystal. We utilized a structural bioinformatics method to identify all such autophosphorylation complexes in X-ray crystallographic structures in the Protein Data Bank (PDB) by generating all unique kinase/kinase interfaces within and between asymmetric units of each crystal and measuring the distance between the hydroxyl oxygen of potential autophosphorylation sites and the oxygen atoms of the active site aspartic acid residue side chain. We have identified 15 unique autophosphorylation complexes in the PDB, of which 5 complexes have not previously been described in the relevant publications on the crystal structures (N-terminal juxtamembrane regions of CSF1R and EPHA2, activation loop tyrosines of LCK and IGF1R, and a serine in a nuclear localization signal region of CLK2. Mutation of residues in the autophosphorylation complex interface of LCK either severely impaired autophosphorylation or increased it. Taking the autophosphorylation complexes as a whole and comparing them with peptide-substrate/kinase complexes, we observe a number of important features among them. The novel and previously observed autophosphorylation sites are conserved in many kinases, indicating that by homology we can extend the relevance of these complexes to many other clinically relevant drug targets.

  13. Signaling network of the Btk family kinases.

    Science.gov (United States)

    Qiu, Y; Kung, H J

    2000-11-20

    The Btk family kinases represent new members of non-receptor tyrosine kinases, which include Btk/Atk, Itk/Emt/Tsk, Bmx/Etk, and Tec. They are characterized by having four structural modules: PH (pleckstrin homology) domain, SH3 (Src homology 3) domain, SH2 (Src homology 2) domain and kinase (Src homology 1) domain. Increasing evidence suggests that, like Src-family kinases, Btk family kinases play central but diverse modulatory roles in various cellular processes. They participate in signal transduction in response to virtually all types of extracellular stimuli which are transmitted by growth factor receptors, cytokine receptors, G-protein coupled receptors, antigen-receptors and integrins. They are regulated by many non-receptor tyrosine kinases such as Src, Jak, Syk and FAK family kinases. In turn, they regulate many of major signaling pathways including those of PI3K, PLCgamma and PKC. Both genetic and biochemical approaches have been used to dissect the signaling pathways and elucidate their roles in growth, differentiation and apoptosis. An emerging new role of this family of kinases is cytoskeletal reorganization and cell motility. The physiological importance of these kinases was amply demonstrated by their link to the development of immunodeficiency diseases, due to germ-line mutations. The present article attempts to review the structure and functions of Btk family kinases by summarizing our current knowledge on the interacting partners associated with the different modules of the kinases and the diverse signaling pathways in which they are involved.

  14. Receptor-interacting protein (RIP) kinase family

    Science.gov (United States)

    Zhang, Duanwu; Lin, Juan; Han, Jiahuai

    2010-01-01

    Receptor-interacting protein (RIP) kinases are a group of threonine/serine protein kinases with a relatively conserved kinase domain but distinct non-kinase regions. A number of different domain structures, such as death and caspase activation and recruitment domain (CARD) domains, were found in different RIP family members, and these domains should be keys in determining the specific function of each RIP kinase. It is known that RIP kinases participate in different biological processes, including those in innate immunity, but their downstream substrates are largely unknown. This review will give an overview of the structures and functions of RIP family members, and an update of recent progress in RIP kinase research. PMID:20383176

  15. Oncoprotein protein kinase antibody kit

    Science.gov (United States)

    Karin, Michael [San Diego, CA; Hibi, Masahiko [San Diego, CA; Lin, Anning [La Jolla, CA

    2008-12-23

    An isolated polypeptide (JNK) characterized by having a molecular weight of 46 kD as determined by reducing SDS-PAGE, having serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

  16. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  17. β-Catenin is required for intrinsic but not extrinsic BCR-ABL1 kinase-independent resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.

    Science.gov (United States)

    Eiring, A M; Khorashad, J S; Anderson, D J; Yu, F; Redwine, H M; Mason, C C; Reynolds, K R; Clair, P M; Gantz, K C; Zhang, T Y; Pomicter, A D; Kraft, I L; Bowler, A D; Johnson, K; Partlin, M Mac; O'Hare, T; Deininger, M W

    2015-12-01

    Activation of nuclear β-catenin and expression of its transcriptional targets promotes chronic myeloid leukemia (CML) progression, tyrosine kinase inhibitor (TKI) resistance, and leukemic stem cell self-renewal. We report that nuclear β-catenin has a role in leukemia cell-intrinsic but not -extrinsic BCR-ABL1 kinase-independent TKI resistance. Upon imatinib inhibition of BCR-ABL1 kinase activity, β-catenin expression was maintained in intrinsically resistant cells grown in suspension culture and sensitive cells cultured in direct contact (DC) with bone marrow (BM) stromal cells. Thus, TKI resistance uncouples β-catenin expression from BCR-ABL1 kinase activity. In β-catenin reporter assays, intrinsically resistant cells showed increased transcriptional activity versus parental TKI-sensitive controls, and this was associated with restored expression of β-catenin target genes. In contrast, DC with BM stromal cells promoted TKI resistance, but had little effects on Lef/Tcf reporter activity and no consistent effects on cytoplasmic β-catenin levels, arguing against a role for β-catenin in extrinsic TKI resistance. N-cadherin or H-cadherin blocking antibodies abrogated DC-based resistance despite increasing Lef/Tcf reporter activity, suggesting that factors other than β-catenin contribute to extrinsic, BM-derived TKI resistance. Our data indicate that, while nuclear β-catenin enhances survival of intrinsically TKI-resistant CML progenitors, it is not required for extrinsic resistance mediated by the BM microenvironment.

  18. A proteomic approach for comprehensively screening substrates of protein kinases such as Rho-kinase.

    Directory of Open Access Journals (Sweden)

    Mutsuki Amano

    Full Text Available BACKGROUND: Protein kinases are major components of signal transduction pathways in multiple cellular processes. Kinases directly interact with and phosphorylate downstream substrates, thus modulating their functions. Despite the importance of identifying substrates in order to more fully understand the signaling network of respective kinases, efficient methods to search for substrates remain poorly explored. METHODOLOGY/PRINCIPAL FINDINGS: We combined mass spectrometry and affinity column chromatography of the catalytic domain of protein kinases to screen potential substrates. Using the active catalytic fragment of Rho-kinase/ROCK/ROK as the model bait, we obtained about 300 interacting proteins from the rat brain cytosol fraction, which included the proteins previously reported as Rho-kinase substrates. Several novel interacting proteins, including doublecortin, were phosphorylated by Rho-kinase both in vitro and in vivo. CONCLUSIONS/SIGNIFICANCE: This method would enable identification of novel specific substrates for kinases such as Rho-kinase with high sensitivity.

  19. Kinase cogs go forward and reverse in the Wnt signaling machine.

    Science.gov (United States)

    Dale, Trevor

    2006-01-01

    An important link between Wnt binding at the cell surface and nuclear -catenin-TCF-dependent transcription has been made with the identification of kinases that promote the association of the Wnt receptor and -catenin turnover complexes. Surprisingly, the enzymes implicated had previously been suggested to inhibit rather than promote Wnt signaling.

  20. Kinases Involved in Both Autophagy and Mitosis.

    Science.gov (United States)

    Li, Zhiyuan; Zhang, Xin

    2017-08-31

    Both mitosis and autophagy are highly regulated dynamic cellular processes and involve various phosphorylation events catalysed by kinases, which play vital roles in almost all physiological and pathological conditions. Mitosis is a key event during the cell cycle, in which the cell divides into two daughter cells. Autophagy is a process in which the cell digests its own cellular contents. Although autophagy regulation has mainly been studied in asynchronous cells, increasing evidence indicates that autophagy is in fact tightly regulated in mitosis. Here in this review, we will discuss kinases that were originally identified to be involved in only one of either mitosis or autophagy, but were later found to participate in both processes, such as CDKs (cyclin-dependent kinases), Aurora kinases, PLK-1 (polo-like kinase 1), BUB1 (budding uninhibited by benzimidazoles 1), MAPKs (mitogen-activated protein kinases), mTORC1 (mechanistic target of rapamycin complex 1), AMPK (AMP-activated protein kinase), PI3K (phosphoinositide-3 kinase) and protein kinase B (AKT). By focusing on kinases involved in both autophagy and mitosis, we will get a more comprehensive understanding about the reciprocal regulation between the two key cellular events, which will also shed light on their related therapeutic investigations.

  1. Kinases Involved in Both Autophagy and Mitosis

    Directory of Open Access Journals (Sweden)

    Zhiyuan Li

    2017-08-01

    Full Text Available Both mitosis and autophagy are highly regulated dynamic cellular processes and involve various phosphorylation events catalysed by kinases, which play vital roles in almost all physiological and pathological conditions. Mitosis is a key event during the cell cycle, in which the cell divides into two daughter cells. Autophagy is a process in which the cell digests its own cellular contents. Although autophagy regulation has mainly been studied in asynchronous cells, increasing evidence indicates that autophagy is in fact tightly regulated in mitosis. Here in this review, we will discuss kinases that were originally identified to be involved in only one of either mitosis or autophagy, but were later found to participate in both processes, such as CDKs (cyclin-dependent kinases, Aurora kinases, PLK-1 (polo-like kinase 1, BUB1 (budding uninhibited by benzimidazoles 1, MAPKs (mitogen-activated protein kinases, mTORC1 (mechanistic target of rapamycin complex 1, AMPK (AMP-activated protein kinase, PI3K (phosphoinositide-3 kinase and protein kinase B (AKT. By focusing on kinases involved in both autophagy and mitosis, we will get a more comprehensive understanding about the reciprocal regulation between the two key cellular events, which will also shed light on their related therapeutic investigations.

  2. Interleukin (IL) 36 gamma induces mucin 5AC, oligomeric mucus/gel-forming expression via IL-36 receptor-extracellular signal regulated kinase 1 and 2, and p38-nuclear factor kappa-light-chain-enhancer of activated B cells in human airway epithelial cells.

    Science.gov (United States)

    Bae, Chang Hoon; Choi, Yoon Seok; Na, Hyung Gyun; Song, Si-Youn; Kim, Yong-Dae

    2018-03-01

    Mucin 5AC, oligomeric mucus/gel-forming (MUC5AC) expression is significantly increased in allergic and inflammatory airway diseases. Interleukin (IL) 36 gamma is predominantly expressed in airway epithelial cells and plays an important role in innate and adaptive immune responses. IL-36 gamma is induced by many inflammatory mediators, including cytokines and bacterial and viral infections. However, the association between IL-36 gamma and mucin secretion in human airway epithelial cells has not yet been fully investigated. The objective of this study was to determine whether IL-36 gamma might play a role in the regulation of mucin secretion in airway epithelial cells. We investigated the effect and brief signaling pathway of IL-36 gamma on MUC5AC expression in human airway epithelial cells. Enzyme immunoassay, immunoblot analysis, immunofluorescence staining, reverse transcriptase-polymerase chain reaction (PCR), and real-time PCR were performed in mucin-producing human airway epithelial NCI-H292 cells and in human nasal epithelial cells after pretreatment with IL-36 gamma, several specific inhibitors, or small interfering RNAs (siRNA). IL-36 gamma induced MUC5AC expression and activated the phosphorylation of extracellular signal regulated kinase (ERK) 1 and 2, p38, and nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-kappa B). IL-36 receptor antagonist significantly attenuated these effects. The specific inhibitor and siRNA of ERK1, ERK2, p38, and NF-kappa B significantly attenuated IL-36 gamma induced MUC5AC expression. These results indicated that IL-36 gamma induced MUC5AC expression via the IL-36 receptor-mediated ERK1/2 and p38/NF-kappa B pathway in human airway epithelial cells.

  3. 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

  4. Nuclear law - Nuclear safety

    International Nuclear Information System (INIS)

    Pontier, Jean-Marie; Roux, Emmanuel; Leger, Marc; Deguergue, Maryse; Vallar, Christian; Pissaloux, Jean-Luc; Bernie-Boissard, Catherine; Thireau, Veronique; Takahashi, Nobuyuki; Spencer, Mary; Zhang, Li; Park, Kyun Sung; Artus, J.C.

    2012-01-01

    This book contains the contributions presented during a one-day seminar. The authors propose a framework for a legal approach to nuclear safety, a discussion of the 2009/71/EURATOM directive which establishes a European framework for nuclear safety in nuclear installations, a comment on nuclear safety and environmental governance, a discussion of the relationship between citizenship and nuclear, some thoughts about the Nuclear Safety Authority, an overview of the situation regarding the safety in nuclear waste burying, a comment on the Nome law with respect to electricity price and nuclear safety, a comment on the legal consequences of the Fukushima accident on nuclear safety in the Japanese law, a presentation of the USA nuclear regulation, an overview of nuclear safety in China, and a discussion of nuclear safety in the medical sector

  5. Engineering of kinase-based protein interacting devices: active expression of tyrosine kinase domains

    KAUST Repository

    Diaz Galicia, Miriam Escarlet

    2018-01-01

    is then translated into a FRET (Fluorescence Resonance Energy Transfer) signal is here proposed. To this end, DNA constructs for interaction amplification (split kinases), positive controls (intact kinase domains), scaffolding proteins and phosphopeptide - SH2-domain

  6. Measuring Kinase Activity-A Global Challenge.

    Science.gov (United States)

    Cann, Marissa L; McDonald, Ian M; East, Michael P; Johnson, Gary L; Graves, Lee M

    2017-11-01

    The kinase enzymes within a cell, known collectively as the kinome, play crucial roles in many signaling pathways, including survival, motility, differentiation, stress response, and many more. Aberrant signaling through kinase pathways is often linked to cancer, among other diseases. A major area of scientific research involves understanding the relationships between kinases, their targets, and how the kinome adapts to perturbations of the cellular system. This review will discuss many of the current and developing methods for studying kinase activity, and evaluate their applications, advantages, and disadvantages. J. Cell. Biochem. 118: 3595-3606, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Recent Advances in the Development and Application of Radiolabeled Kinase Inhibitors for PET Imaging

    Directory of Open Access Journals (Sweden)

    Vadim Bernard-Gauthier

    2015-12-01

    Full Text Available Over the last 20 years, intensive investigation and multiple clinical successes targeting protein kinases, mostly for cancer treatment, have identified small molecule kinase inhibitors as a prominent therapeutic class. In the course of those investigations, radiolabeled kinase inhibitors for positron emission tomography (PET imaging have been synthesized and evaluated as diagnostic imaging probes for cancer characterization. Given that inhibitor coverage of the kinome is continuously expanding, in vivo PET imaging will likely find increasing applications for therapy monitoring and receptor density studies both in- and outside of oncological conditions. Early investigated radiolabeled inhibitors, which are mostly based on clinically approved tyrosine kinase inhibitor (TKI isotopologues, have now entered clinical trials. Novel radioligands for cancer and PET neuroimaging originating from novel but relevant target kinases are currently being explored in preclinical studies. This article reviews the literature involving radiotracer design, radiochemistry approaches, biological tracer evaluation and nuclear imaging results of radiolabeled kinase inhibitors for PET reported between 2010 and mid-2015. Aspects regarding the usefulness of pursuing selective vs. promiscuous inhibitor scaffolds and the inherent challenges associated with intracellular enzyme imaging will be discussed.

  8. Engineering of kinase-based protein interacting devices: active expression of tyrosine kinase domains

    KAUST Repository

    Diaz Galicia, Miriam Escarlet

    2018-05-01

    Protein-protein interactions modulate cellular processes in health and disease. However, tracing weak or rare associations or dissociations of proteins is not a trivial task. Kinases are often regulated through interaction partners and, at the same time, themselves regulate cellular interaction networks. The use of kinase domains for creating a synthetic sensor device that reads low concentration protein-protein interactions and amplifies them to a higher concentration interaction which is then translated into a FRET (Fluorescence Resonance Energy Transfer) signal is here proposed. To this end, DNA constructs for interaction amplification (split kinases), positive controls (intact kinase domains), scaffolding proteins and phosphopeptide - SH2-domain modules for the reading of kinase activity were assembled and expression protocols for fusion proteins containing Lyn, Src, and Fak kinase domains in bacterial and in cell-free systems were optimized. Also, two non-overlapping methods for measuring the kinase activity of these proteins were stablished and, finally, a protein-fragment complementation assay with the split-kinase constructs was tested. In conclusion, it has been demonstrated that features such as codon optimization, vector design and expression conditions have an impact on the expression yield and activity of kinase-based proteins. Furthermore, it has been found that the defined PURE cell-free system is insufficient for the active expression of catalytic kinase domains. In contrast, the bacterial co-expression with phosphatases produced active kinase fusion proteins for two out of the three tested Tyrosine kinase domains.

  9. Nucleocytoplasmic shuttling of the HSV-2 serine/threonine kinase Us3

    International Nuclear Information System (INIS)

    Finnen, Renee L.; Johnston, Susan M.; Neron, Casey E.; Banfield, Bruce W.

    2011-01-01

    The alphaherpesvirus serine/threonine kinase Us3 plays diverse roles in virus multiplication and modifies both nuclear and cytoplasmic substrates. We recently reported that treatment of HSV-2 Us3-transfected and HSV-2-infected cells with leptomycin B, an inhibitor of nuclear export mediated by interaction of chromosomal regional maintenance protein (CRM1) with leucine rich nuclear export signals (NESs), resulted in nuclear trapping of Us3. Here, we utilized fluorescence loss in photobleaching to monitor nuclear export of HSV-2 Us3 and confirm that this process proceeds solely via a CRM1-mediated mechanism. Analysis of deletion derivatives of HSV-2 Us3 fused to a nuclear export reporter protein implicated the involvement of NES-like sequences in nuclear export. However, nuclear trapping of HSV-2 Us3 proteins carrying mutations in these potential NESs was not observed, indicating that these sequences are not functional in the context of full-length protein. Our analyses also revealed previously unidentified regions of HSV-2 Us3 that contribute to its kinase activity.

  10. Identifying three-dimensional structures of autophosphorylation complexes in crystals of protein kinases

    Science.gov (United States)

    Xu, Qifang; Malecka, Kimberly L.; Fink, Lauren; Jordan, E. Joseph; Duffy, Erin; Kolander, Samuel; Peterson, Jeffrey; Dunbrack, Roland L.

    2016-01-01

    Protein kinase autophosphorylation is a common regulatory mechanism in cell signaling pathways. Crystal structures of several homomeric protein kinase complexes have a serine, threonine, or tyrosine autophosphorylation site of one kinase monomer located in the active site of another monomer, a structural complex that we call an “autophosphorylation complex.” We developed and applied a structural bioinformatics method to identify all such autophosphorylation kinase complexes in X-ray crystallographic structures in the Protein Data Bank (PDB). We identified 15 autophosphorylation complexes in the PDB, of which 5 complexes had not previously been described in the publications describing the crystal structures. These 5 consist of tyrosine residues in the N-terminal juxtamembrane regions of colony stimulating factor 1 receptor (CSF1R, Tyr561) and EPH receptor A2 (EPHA2, Tyr594), tyrosine residues in the activation loops of the SRC kinase family member LCK (Tyr394) and insulin-like growth factor 1 receptor (IGF1R, Tyr1166), and a serine in a nuclear localization signal region of CDC-like kinase 2 (CLK2, Ser142). Mutations in the complex interface may alter autophosphorylation activity and contribute to disease; therefore we mutated residues in the autophosphorylation complex interface of LCK and found that two mutations impaired autophosphorylation (T445V and N446A) and mutation of Pro447 to Ala, Gly, or Leu increased autophosphorylation. The identified autophosphorylation sites are conserved in many kinases, suggesting that, by homology, these complexes may provide insight into autophosphorylation complex interfaces of kinases that are relevant drug targets. PMID:26628682

  11. Oncogenic Receptor Tyrosine Kinases Directly Phosphorylate Focal Adhesion Kinase (FAK) as a Resistance Mechanism to FAK-Kinase Inhibitors.

    Science.gov (United States)

    Marlowe, Timothy A; Lenzo, Felicia L; Figel, Sheila A; Grapes, Abigail T; Cance, William G

    2016-12-01

    Focal adhesion kinase (FAK) is a major drug target in cancer and current inhibitors targeted to the ATP-binding pocket of the kinase domain have entered clinical trials. However, preliminary results have shown limited single-agent efficacy in patients. Despite these unfavorable data, the molecular mechanisms that drive intrinsic and acquired resistance to FAK-kinase inhibitors are largely unknown. We have demonstrated that receptor tyrosine kinases (RTK) can directly bypass FAK-kinase inhibition in cancer cells through phosphorylation of FAK's critical tyrosine 397 (Y397). We also showed that HER2 forms a direct protein-protein interaction with the FAK-FERM-F1 lobe, promoting direct phosphorylation of Y397. In addition, FAK-kinase inhibition induced two forms of compensatory RTK reprogramming: (i) the rapid phosphorylation and activation of RTK signaling pathways in RTK High cells and (ii) the long-term acquisition of RTKs novel to the parental cell line in RTK Low cells. Finally, HER2 +: cancer cells displayed resistance to FAK-kinase inhibition in 3D growth assays using a HER2 isogenic system and HER2 + cancer cell lines. Our data indicate a novel drug resistance mechanism to FAK-kinase inhibitors whereby HER2 and other RTKs can rescue and maintain FAK activation (pY397) even in the presence of FAK-kinase inhibition. These data may have important ramifications for existing clinical trials of FAK inhibitors and suggest that individual tumor stratification by RTK expression would be important to predict patient response to FAK-kinase inhibitors. Mol Cancer Ther; 15(12); 3028-39. ©2016 AACR. ©2016 American Association for Cancer Research.

  12. A rice kinase-protein interaction map.

    Science.gov (United States)

    Ding, Xiaodong; Richter, Todd; Chen, Mei; Fujii, Hiroaki; Seo, Young Su; Xie, Mingtang; Zheng, Xianwu; Kanrar, Siddhartha; Stevenson, Rebecca A; Dardick, Christopher; Li, Ying; Jiang, Hao; Zhang, Yan; Yu, Fahong; Bartley, Laura E; Chern, Mawsheng; Bart, Rebecca; Chen, Xiuhua; Zhu, Lihuang; Farmerie, William G; Gribskov, Michael; Zhu, Jian-Kang; Fromm, Michael E; Ronald, Pamela C; Song, Wen-Yuan

    2009-03-01

    Plants uniquely contain large numbers of protein kinases, and for the vast majority of the 1,429 kinases predicted in the rice (Oryza sativa) genome, little is known of their functions. Genetic approaches often fail to produce observable phenotypes; thus, new strategies are needed to delineate kinase function. We previously developed a cost-effective high-throughput yeast two-hybrid system. Using this system, we have generated a protein interaction map of 116 representative rice kinases and 254 of their interacting proteins. Overall, the resulting interaction map supports a large number of known or predicted kinase-protein interactions from both plants and animals and reveals many new functional insights. Notably, we found a potential widespread role for E3 ubiquitin ligases in pathogen defense signaling mediated by receptor-like kinases, particularly by the kinases that may have evolved from recently expanded kinase subfamilies in rice. We anticipate that the data provided here will serve as a foundation for targeted functional studies in rice and other plants. The application of yeast two-hybrid and TAPtag analyses for large-scale plant protein interaction studies is also discussed.

  13. Discovery of inhibitors of bacterial histidine kinases

    NARCIS (Netherlands)

    Velikova, N.R.

    2014-01-01

    Discovery of Inhibitors of Bacterial Histidine Kinases Summary

    The thesis is on novel antibacterial drug discovery (http://youtu.be/NRMWOGgeysM). Using structure-based and fragment-based drug discovery approach, we have identified small-molecule histidine-kinase

  14. dependent/calmodulin- stimulated protein kinase from moss

    Indian Academy of Sciences (India)

    Unknown

    stimulated protein kinase; CDPK, calmodulin domain-like protein kinase; KM14, 14 amino acid synthetic peptide; .... used were obtained from Sigma Chemical Company, USA, ..... Plant chimeric Ca2+/Calmodulin-dependent protein kinase.

  15. The Protein Kinase RSK Family - Roles in Prostate Cancer

    National Research Council Canada - National Science Library

    Lannigan, Deborah

    2006-01-01

    The Ser/Thr protein kinase p90-kDa ribosomal S6 kinase (RSK) is an important downstream effector of mitogen-activated protein kinase but its roles in prostate cancer have not been previously examined...

  16. Structural coupling of SH2-kinase domains links Fes and Abl substrate recognition and kinase activation.

    Science.gov (United States)

    Filippakopoulos, Panagis; Kofler, Michael; Hantschel, Oliver; Gish, Gerald D; Grebien, Florian; Salah, Eidarus; Neudecker, Philipp; Kay, Lewis E; Turk, Benjamin E; Superti-Furga, Giulio; Pawson, Tony; Knapp, Stefan

    2008-09-05

    The SH2 domain of cytoplasmic tyrosine kinases can enhance catalytic activity and substrate recognition, but the molecular mechanisms by which this is achieved are poorly understood. We have solved the structure of the prototypic SH2-kinase unit of the human Fes tyrosine kinase, which appears specialized for positive signaling. In its active conformation, the SH2 domain tightly interacts with the kinase N-terminal lobe and positions the kinase alphaC helix in an active configuration through essential packing and electrostatic interactions. This interaction is stabilized by ligand binding to the SH2 domain. Our data indicate that Fes kinase activation is closely coupled to substrate recognition through cooperative SH2-kinase-substrate interactions. Similarly, we find that the SH2 domain of the active Abl kinase stimulates catalytic activity and substrate phosphorylation through a distinct SH2-kinase interface. Thus, the SH2 and catalytic domains of active Fes and Abl pro-oncogenic kinases form integrated structures essential for effective tyrosine kinase signaling.

  17. Glycogen Synthase Kinase-3β

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Lenskjold, Toke; Jacoby, Anne Sophie

    2016-01-01

    cells were quantitated using enzyme immunometric assays. The activity of GSK-3β (serine-9-phosphorylated GSK-3β/total GSK-3β) was lower at baseline compared with follow-up. No significant mean change over time was observed in levels of total GSK-3β and serine-9-phosphorylated GSK-3β. Exploratory......Evidence indicates a role for glycogen synthase kinase-3β (GSK-3β) in the pathophysiology of mood disorders and in cognitive disturbances; however, the natural variation in GSK-3β activity over time is unknown. We aimed to investigate GSK-3β activity over time and its possible correlation...... with emotional lability, subjective mood fluctuations and cognitive function in healthy individuals. Thirty-seven healthy subjects were evaluated with neuropsychological tests and blood samples at baseline and 12-week follow-up. Total GSK-3β and serine-9-phosphorylated GSK-3β in peripheral blood mononuclear...

  18. 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.

  19. Structural Insight into the 14-3-3 Protein-dependent Inhibition of Protein Kinase ASK1 (Apoptosis Signal-regulating kinase 1)

    Czech Academy of Sciences Publication Activity Database

    Petrvalská, Olivia; Košek, Dalibor; Kukačka, Zdeněk; Tošner, Z.; Man, Petr; Večeř, J.; Herman, P.; Obšilová, Veronika; Obšil, Tomáš

    2016-01-01

    Roč. 291, č. 39 (2016), s. 20753-20765 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA14-10061S Institutional support: RVO:67985823 ; RVO:61388971 Keywords : 14-3-3 protein * apoptosis signal-regulating kinase 1 (ASK1) * fluorescence * nuclear magnetic resonance (NMR) * protein cross-linking * small-angle x-ray scattering (SAXS) Subject RIV: CE - Biochemistry Impact factor: 4.125, year: 2016

  20. Nuclear Medicine

    Science.gov (United States)

    ... Parents/Teachers Resource Links for Students Glossary Nuclear Medicine What is nuclear medicine? What are radioactive tracers? ... funded researchers advancing nuclear medicine? What is nuclear medicine? Nuclear medicine is a medical specialty that uses ...

  1. Nuclear safety. Seguranca nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Aveline, A [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica

    1981-01-01

    What is nuclear safety Is there any technical way to reduce risks Is it possible to put them at reasonable levels Are there competitiveness and economic reliability to employ the nuclear energy by means of safety technics Looking for answers to these questions the author describes the sources of potential risks to nuclear reactors and tries to apply the answers to the Brazilian Nuclear Programme. (author).

  2. The cAMP-activated GTP exchange factor, Epac1 Upregulates Plasma Membrane and Nuclear Akt Kinase Activities in 8-CPT-2-O-Me-cAMP-Stimulated Macrophages: Gene silencing of the cAMP-activated GTP exchange Epac1 prevents 8-CPT-2-O-Me-cAMP activation of Akt activity in macrophages*

    OpenAIRE

    Misra, Uma K.; Kaczowka, Steven; Pizzo, Salvatore V.

    2008-01-01

    cAMP regulates a wide range of processes through its downstream effectors including PKA, and the family of guanine nucleotide exchange factors. Depending on the cell type, cAMP inhibits or stimulates growth and proliferation in a PKA-dependent or independent manner. PKA-independent effects are mediated by PI 3-kinases-Akt signaling and EPAC1 (exchange protein directly activated by cAMP) activation. Recently, we reported PKA-independent activation of the protein kinase Akt as well co-immunopre...

  3. Partial purification and characterization of a Ca(2+)-dependent protein kinase from pea nuclei

    Science.gov (United States)

    Li, H.; Dauwalder, M.; Roux, S. J.

    1991-01-01

    Almost all the Ca(2+)-dependent protein kinase activity in nuclei purified from etiolated pea (Pisum sativum, L.) plumules is present in a single enzyme that can be extracted from chromatin by 0.3 molar NaCl. This protein kinase can be further purified 80,000-fold by salt fractionation and high performance liquid chromatography, after which it has a high specific activity of about 100 picomoles per minute per microgram in the presence of Ca2+ and reaches half-maximal activation at about 3 x 10(-7) molar free Ca2+, without calmodulin. It is a monomer with a molecular weight near 90,000. It can efficiently use histone III-S, ribosomal S6 protein, and casein as artificial substrates, but it phosphorylates phosvitin only weakly. Its Ca(2+)-dependent kinase activity is half-maximally inhibited by 0.1 millimolar chlorpromazine, by 35 nanomolar K-252a and by 7 nanomolar staurosporine. It is insensitive to sphingosine, an inhibitor of protein kinase C, and to basic polypeptides that block other Ca(2+)-dependent protein kinases. It is not stimulated by exogenous phospholipids or fatty acids. In intact isolated pea nuclei it preferentially phosphorylates several chromatin-associated proteins, with the most phosphorylated protein band being near the same molecular weight (43,000) as a nuclear protein substrate whose phosphorylation has been reported to be stimulated by phytochrome in a calcium-dependent fashion.

  4. Adenylate Kinase and AMP Signaling Networks: Metabolic Monitoring, Signal Communication and Body Energy Sensing

    Directory of Open Access Journals (Sweden)

    Andre Terzic

    2009-04-01

    Full Text Available Adenylate kinase and downstream AMP signaling is an integrated metabolic monitoring system which reads the cellular energy state in order to tune and report signals to metabolic sensors. A network of adenylate kinase isoforms (AK1-AK7 are distributed throughout intracellular compartments, interstitial space and body fluids to regulate energetic and metabolic signaling circuits, securing efficient cell energy economy, signal communication and stress response. The dynamics of adenylate kinase-catalyzed phosphotransfer regulates multiple intracellular and extracellular energy-dependent and nucleotide signaling processes, including excitation-contraction coupling, hormone secretion, cell and ciliary motility, nuclear transport, energetics of cell cycle, DNA synthesis and repair, and developmental programming. Metabolomic analyses indicate that cellular, interstitial and blood AMP levels are potential metabolic signals associated with vital functions including body energy sensing, sleep, hibernation and food intake. Either low or excess AMP signaling has been linked to human disease such as diabetes, obesity and hypertrophic cardiomyopathy. Recent studies indicate that derangements in adenylate kinase-mediated energetic signaling due to mutations in AK1, AK2 or AK7 isoforms are associated with hemolytic anemia, reticular dysgenesis and ciliary dyskinesia. Moreover, hormonal, food and antidiabetic drug actions are frequently coupled to alterations of cellular AMP levels and associated signaling. Thus, by monitoring energy state and generating and distributing AMP metabolic signals adenylate kinase represents a unique hub within the cellular homeostatic network.

  5. Functions of mammalian Cdc7 kinase in initiation/monitoring of DNA replication and development

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Min; Yamada, Masayuki; Masai, Hisao

    2003-11-27

    Cdc7 kinase plays an essential role in firing of replication origins by phosphorylating components of the replication complexes. Cdc7 kinase has also been implicated in S phase checkpoint signaling downstream of the ATR and Chk1 kinases. Inactivation of Cdc7 in yeast results in arrest of cell growth with 1C DNA content after completion of the ongoing DNA replication. In contrast, conditional inactivation of Cdc7 in undifferentiated mouse embryonic stem (ES) cells leads to growth arrest with rapid cessation of DNA synthesis, suggesting requirement of Cdc7 functions for continuation of ongoing DNA synthesis. Furthermore, loss of Cdc7 function induces recombinational repair (nuclear Rad51 foci) and G2/M checkpoint responses (inhibition of Cdc2 kinase). Eventually, p53 becomes highly activated and the cells undergo massive p53-dependent apoptosis. Thus, defective origin activation in mammalian cells can generate DNA replication checkpoint signals. Efficient removal of those cells in which replication has been perturbed, through cell death, may be beneficial to maintain the highest level of genetic integrity in totipotent stem cells. Partial, rather than total, loss of Cdc7 kinase expression results in retarded growth at both cellular and whole body levels, with especially profound impairment of germ cell development.

  6. Functions of mammalian Cdc7 kinase in initiation/monitoring of DNA replication and development

    International Nuclear Information System (INIS)

    Kim, Jung Min; Yamada, Masayuki; Masai, Hisao

    2003-01-01

    Cdc7 kinase plays an essential role in firing of replication origins by phosphorylating components of the replication complexes. Cdc7 kinase has also been implicated in S phase checkpoint signaling downstream of the ATR and Chk1 kinases. Inactivation of Cdc7 in yeast results in arrest of cell growth with 1C DNA content after completion of the ongoing DNA replication. In contrast, conditional inactivation of Cdc7 in undifferentiated mouse embryonic stem (ES) cells leads to growth arrest with rapid cessation of DNA synthesis, suggesting requirement of Cdc7 functions for continuation of ongoing DNA synthesis. Furthermore, loss of Cdc7 function induces recombinational repair (nuclear Rad51 foci) and G2/M checkpoint responses (inhibition of Cdc2 kinase). Eventually, p53 becomes highly activated and the cells undergo massive p53-dependent apoptosis. Thus, defective origin activation in mammalian cells can generate DNA replication checkpoint signals. Efficient removal of those cells in which replication has been perturbed, through cell death, may be beneficial to maintain the highest level of genetic integrity in totipotent stem cells. Partial, rather than total, loss of Cdc7 kinase expression results in retarded growth at both cellular and whole body levels, with especially profound impairment of germ cell development

  7. Protein Kinase A in Cancer

    International Nuclear Information System (INIS)

    Caretta, Antonio; Mucignat-Caretta, Carla

    2011-01-01

    In the past, many chromosomal and genetic alterations have been examined as possible causes of cancer. However, some tumors do not display a clear molecular and/or genetic signature. Therefore, other cellular processes may be involved in carcinogenesis. Genetic alterations of proteins involved in signal transduction have been extensively studied, for example oncogenes, while modifications in intracellular compartmentalization of these molecules, or changes in the expression of unmodified genes have received less attention. Yet, epigenetic modulation of second messenger systems can deeply modify cellular functioning and in the end may cause instability of many processes, including cell mitosis. It is important to understand the functional meaning of modifications in second messenger intracellular pathways and unravel the role of downstream proteins in the initiation and growth of tumors. Within this framework, the cAMP system has been examined. cAMP is a second messenger involved in regulation of a variety of cellular functions. It acts mainly through its binding to cAMP-activated protein kinases (PKA), that were suggested to participate in the onset and progression of various tumors. PKA may represent a biomarker for tumor detection, identification and staging, and may be a potential target for pharmacological treatment of tumors

  8. Protein Kinase A in Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Caretta, Antonio; Mucignat-Caretta, Carla, E-mail: carla.mucignat@unipd.it [Department of Human Anatomy and Physiology, University of Padova, Via Marzolo 3, 35131 Padova (Italy)

    2011-02-28

    In the past, many chromosomal and genetic alterations have been examined as possible causes of cancer. However, some tumors do not display a clear molecular and/or genetic signature. Therefore, other cellular processes may be involved in carcinogenesis. Genetic alterations of proteins involved in signal transduction have been extensively studied, for example oncogenes, while modifications in intracellular compartmentalization of these molecules, or changes in the expression of unmodified genes have received less attention. Yet, epigenetic modulation of second messenger systems can deeply modify cellular functioning and in the end may cause instability of many processes, including cell mitosis. It is important to understand the functional meaning of modifications in second messenger intracellular pathways and unravel the role of downstream proteins in the initiation and growth of tumors. Within this framework, the cAMP system has been examined. cAMP is a second messenger involved in regulation of a variety of cellular functions. It acts mainly through its binding to cAMP-activated protein kinases (PKA), that were suggested to participate in the onset and progression of various tumors. PKA may represent a biomarker for tumor detection, identification and staging, and may be a potential target for pharmacological treatment of tumors.

  9. Protein kinase Cη activates NF-κB in response to camptothecin-induced DNA damage

    International Nuclear Information System (INIS)

    Raveh-Amit, Hadas; Hai, Naama; Rotem-Dai, Noa; Shahaf, Galit; Gopas, Jacob; Livneh, Etta

    2011-01-01

    Highlights: → Protein kinase C-eta (PKCη) is an upstream regulator of the NF-κB signaling pathway. → PKCη activates NF-κB in non-stressed conditions and in response to DNA damage. → PKCη regulates NF-κB by activating IκB kinase (IKK) and inducing IκB degradation. -- Abstract: The nuclear factor κB (NF-κB) family of transcription factors participates in the regulation of genes involved in innate- and adaptive-immune responses, cell death and inflammation. The involvement of the Protein kinase C (PKC) family in the regulation of NF-κB in inflammation and immune-related signaling has been extensively studied. However, not much is known on the role of PKC in NF-κB regulation in response to DNA damage. Here we demonstrate for the first time that PKC-eta (PKCη) regulates NF-κB upstream signaling by activating the IκB kinase (IKK) and the degradation of IκB. Furthermore, PKCη enhances the nuclear translocation and transactivation of NF-κB under non-stressed conditions and in response to the anticancer drug camptothecin. We and others have previously shown that PKCη confers protection against DNA damage-induced apoptosis. Our present study suggests that PKCη is involved in NF-κB signaling leading to drug resistance.

  10. Invisible nuclear; converting nuclear

    International Nuclear Information System (INIS)

    Park, Jongmoon

    1993-03-01

    This book consists of 14 chapters which are CNN era and big science, from East and West to North and South, illusory nuclear strategy, UN and nuclear arms reduction, management of armaments, advent of petroleum period, the track of nuclear power generation, view of energy, internationalization of environment, the war over water in the Middle East, influence of radiation and an isotope technology transfer and transfer armament into civilian industry, the end of nuclear period and the nuclear Nonproliferation, national scientific and technological power and political organ and executive organ.

  11. Regulation of the interaction between protein kinase C-related protein kinase 2 (PRK2) and its upstream kinase, 3-phosphoinositide-dependent protein kinase 1 (PDK1)

    DEFF Research Database (Denmark)

    Dettori, Rosalia; Sonzogni, Silvina; Meyer, Lucas

    2009-01-01

    of numerous AGC kinases, including the protein kinase C-related protein kinases (PRKs). Here we studied the docking interaction between PDK1 and PRK2 and analyzed the mechanisms that regulate this interaction. In vivo labeling of recombinant PRK2 by (32)P(i) revealed phosphorylation at two sites......, the activation loop and the Z/TM in the C-terminal extension. We provide evidence that phosphorylation of the Z/TM site of PRK2 inhibits its interaction with PDK1. Our studies further provide a mechanistic model to explain different steps in the docking interaction and regulation. Interestingly, we found...... that the mechanism that negatively regulates the docking interaction of PRK2 to the upstream kinase PDK1 is directly linked to the activation mechanism of PRK2 itself. Finally, our results indicate that the mechanisms underlying the regulation of the interaction between PRK2 and PDK1 are specific for PRK2 and do...

  12. Isoprenoid biosynthesis and mevalonate kinase deficiency

    NARCIS (Netherlands)

    Henneman, L.

    2011-01-01

    Mevalonaat Kinase Deficiëntie (MKD) is een aangeboren ziekte geassocieerd met heftige koortsaanvallen die drie tot vier dagen aanhouden en gepaard gaan met koude rillingen, gewrichtsklachten, huiduitslag, hoofdpijn, duizeligheid, buikpijn, braken en diarree. De koortsaanvallen treden gemiddeld eens

  13. 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...

  14. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt; Roux, Milena Edna; Petersen, Morten

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate ...

  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. Mediator kinase module and human tumorigenesis.

    Science.gov (United States)

    Clark, Alison D; Oldenbroek, Marieke; Boyer, Thomas G

    2015-01-01

    Mediator is a conserved multi-subunit signal processor through which regulatory informatiosn conveyed by gene-specific transcription factors is transduced to RNA Polymerase II (Pol II). In humans, MED13, MED12, CDK8 and Cyclin C (CycC) comprise a four-subunit "kinase" module that exists in variable association with a 26-subunit Mediator core. Genetic and biochemical studies have established the Mediator kinase module as a major ingress of developmental and oncogenic signaling through Mediator, and much of its function in signal-dependent gene regulation derives from its resident CDK8 kinase activity. For example, CDK8-targeted substrate phosphorylation impacts transcription factor half-life, Pol II activity and chromatin chemistry and functional status. Recent structural and biochemical studies have revealed a precise network of physical and functional subunit interactions required for proper kinase module activity. Accordingly, pathologic change in this activity through altered expression or mutation of constituent kinase module subunits can have profound consequences for altered signaling and tumor formation. Herein, we review the structural organization, biological function and oncogenic potential of the Mediator kinase module. We focus principally on tumor-associated alterations in kinase module subunits for which mechanistic relationships as opposed to strictly correlative associations are established. These considerations point to an emerging picture of the Mediator kinase module as an oncogenic unit, one in which pathogenic activation/deactivation through component change drives tumor formation through perturbation of signal-dependent gene regulation. It follows that therapeutic strategies to combat CDK8-driven tumors will involve targeted modulation of CDK8 activity or pharmacologic manipulation of dysregulated CDK8-dependent signaling pathways.

  17. Fibronectin phosphorylation by ecto-protein kinase

    International Nuclear Information System (INIS)

    Imada, Sumi; Sugiyama, Yayoi; Imada, Masaru

    1988-01-01

    The presence of membrane-associated, extracellular protein kinase (ecto-protein kinase) and its substrate proteins was examined with serum-free cultures of Swiss 3T3 fibroblast. When cells were incubated with [γ- 32 ]ATP for 10 min at 37 degree C, four proteins with apparent molecular weights between 150 and 220 kDa were prominently phosphorylated. These proteins were also radiolabeled by lactoperoxidase catalyzed iodination and were sensitive to mild tryptic digestion, suggesting that they localized on the cell surface or in the extracellular matrix. Phosphorylation of extracellular proteins with [γ- 32 P]ATP in intact cell culture is consistent with the existence of ecto-protein kinase. Anti-fibronectin antibody immunoprecipitated one of the phosphoproteins which comigrated with a monomer and a dimer form of fibronectin under reducing and nonreducing conditions of electrophoresis, respectively. The protein had affinity for gelatin as demonstrated by retention with gelatin-conjugated agarose. This protein substrate of ecto-protein kinase was thus concluded to be fibronectin. The sites of phosphorylation by ecto-protein kinase were compared with those of intracellularly phosphorylated fibronectin by the analysis of radiolabeled amino acids and peptides. Ecto-protein kinase phosphorylated fibronectin at serine and threonine residues which were distinct from the sites of intracellular fibronectin phosphorylation

  18. The PIM kinases in hematological cancers.

    Science.gov (United States)

    Alvarado, Yesid; Giles, Francis J; Swords, Ronan T

    2012-02-01

    The PIM genes represent a family of proto-oncogenes that encode three different serine/threonine protein kinases (PIM1, PIM2 and PIM3) with essential roles in the regulation of signal transduction cascades, which promote cell survival, proliferation and drug resistance. PIM kinases are overexpressed in several hematopoietic tumors and support in vitro and in vivo malignant cell growth and survival, through cell cycle regulation and inhibition of apoptosis. PIM kinases do not have an identified regulatory domain, which means that these proteins are constitutively active once transcribed. They appear to be critical downstream effectors of important oncoproteins and, when overexpressed, can mediate drug resistance to available agents, such as rapamycin. Recent crystallography studies reveal that, unlike other kinases, they possess a hinge region, which creates a unique binding pocket for ATP, offering a target for an increasing number of potent small-molecule PIM kinase inhibitors. Preclinical studies in models of various hematologic cancers indicate that these novel agents show promising activity and some of them are currently being evaluated in a clinical setting. In this review, we profile the PIM kinases as targets for therapeutics in hematologic malignancies.

  19. Pyruvate kinase M2: a potential target for regulating inflammation

    Directory of Open Access Journals (Sweden)

    Jose Carlos eAlves-Filho

    2016-04-01

    Full Text Available Pyruvate kinase (PK is the enzyme responsible for catalyzing the last step of glycolysis. Of the four PK isoforms expressed in mammalian cells, PKM2 has generated the most interest due to its impact on changes in cellular metabolism observed in cancer as well as in activated immune cells. As our understanding of dysregulated metabolism in cancer develops, and in light of the growing field of immunometabolism, intense efforts are in place to define the mechanism by which PKM2 regulates the metabolic profile of cancer as well as of immune cells. The enzymatic activity of PKM2 is heavily regulated by endogenous allosteric effectors as well as by intracellular signalling pathways, affecting both the enzymatic activity of PKM2 as a pyruvate kinase and the regulation of the recently described non-canonical nuclear functions of PKM2. We here review the current literature on PKM2 and its regulation, and discuss the potential for PKM2 as a therapeutic target in inflammatory and metabolic disorders.

  20. Role of phosphatidylinositol 3-kinase in angiotensin II regulation of norepinephrine neuromodulation in brain neurons of the spontaneously hypertensive rat.

    Science.gov (United States)

    Yang, H; Raizada, M K

    1999-04-01

    Chronic stimulation of norepinephrine (NE) neuromodulation by angiotensin II (Ang II) involves activation of the Ras-Raf-MAP kinase signal transduction pathway in Wistar Kyoto (WKY) rat brain neurons. This pathway is only partially responsible for this heightened action of Ang II in the spontaneously hypertensive rat (SHR) brain neurons. In this study, we demonstrate that the MAP kinase-independent signaling pathway in the SHR neuron involves activation of PI3-kinase and protein kinase B (PKB/Akt). Ang II stimulated PI3-kinase activity in both WKY and SHR brain neurons and was accompanied by its translocation from the cytoplasmic to the nuclear compartment. Although the magnitude of stimulation by Ang II was comparable, the stimulation was more persistent in the SHR neuron compared with the WKY rat neuron. Inhibition of PI3-kinase had no significant effect in the WKY rat neuron. However, it caused a 40-50% attenuation of the Ang II-induced increase in norepinephrine transporter (NET) and tyrosine hydroxylase (TH) mRNAs and [3H]-NE uptake in the SHR neuron. In contrast, inhibition of MAP kinase completely attenuated Ang II stimulation of NET and TH mRNA levels in the WKY rat neuron, whereas it caused only a 45% decrease in the SHR neuron. However, an additive attenuation was observed when both kinases of the SHR neurons were inhibited. Ang II also stimulated PKB/Akt activity in both WKY and SHR neurons. This stimulation was 30% higher and lasted longer in the SHR neuron compared with the WKY rat neuron. In conclusion, these observations demonstrate an exclusive involvement of PI3-kinase-PKB-dependent signaling pathway in a heightened NE neuromodulatory action of Ang II in the SHR neuron. Thus, this study offers an excellent potential for the development of new therapies for the treatment of centrally mediated hypertension.

  1. Loss of thymidine kinase 2 alters neuronal bioenergetics and leads to neurodegeneration

    OpenAIRE

    Bartesaghi, Stefano; Betts-Henderson, Joanne; Cain, Kelvin; Dinsdale, David; Zhou, Xiaoshan; Karlsson, Anna; Salomoni, Paolo; Nicotera, Pierluigi

    2010-01-01

    Mutations of thymidine kinase 2 (TK2), an essential component of the mitochondrial nucleotide salvage pathway, can give rise to mitochondrial DNA (mtDNA) depletion syndromes (MDS). These clinically heterogeneous disorders are characterized by severe reduction in mtDNA copy number in affected tissues and are associated with progressive myopathy, hepatopathy and/or encephalopathy, depending in part on the underlying nuclear genetic defect. Mutations of TK2 have previously been associated with a...

  2. Skin-specific regulation of SREBP processing and lipid biosynthesis by glycerol kinase 5

    OpenAIRE

    Zhang, Duanwu; Tomisato, Wataru; Su, Lijing; Sun, Lei; Choi, Jin Huk; Zhang, Zhao; Wang, Kuan-wen; Zhan, Xiaoming; Choi, Mihwa; Li, Xiaohong; Tang, Miao; Castro-Perez, Jose M.; Hildebrand, Sara; Murray, Anne R.; Moresco, Eva Marie Y.

    2017-01-01

    We discovered a previously unrecognized regulator of cholesterol biosynthesis, glycerol kinase 5 (GK5), which functions exclusively in the skin independently of cholesterol regulation in other tissues. GK5 negatively regulates the processing and nuclear localization of sterol regulatory element binding proteins, transcription factors that control expression of virtually all cholesterol synthesis enzymes. Excessive amounts of cholesterol, triglycerides, and ceramides were found in the skin of ...

  3. Nucleoporin 62 and Ca(2+)/calmodulin dependent kinase kinase 2 regulate androgen receptor activity in castrate resistant prostate cancer cells.

    Science.gov (United States)

    Karacosta, Loukia G; Kuroski, Laura A; Hofmann, Wilma A; Azabdaftari, Gissou; Mastri, Michalis; Gocher, Angela M; Dai, Shuhang; Hoste, Allen J; Edelman, Arthur M

    2016-02-15

    Re-activation of the transcriptional activity of the androgen receptor (AR) is an important factor mediating progression from androgen-responsive to castrate-resistant prostate cancer (CRPC). However, the mechanisms regulating AR activity in CRPC remain incompletely understood. Ca(2+) /calmodulin-dependent kinase kinase (CaMKK) 2 was previously shown to regulate AR activity in androgen-responsive prostate cancer cells. Our objective was to further explore the basis of this regulation in CRPC cells. The abundance of CaMKK2 in nuclear fractions of androgen-responsive prostate cancer and CRPC, cells were determined by subcellular fractionation and Western blotting. CaMKK2 association with nuclear pore complexes (NPCs) and nucleoporins (Nups) including Nup62, were imaged by structured illumination and super-resolution fluorescence microscopy and co-immunoprecipitation, respectively. The abundance and subcellular localization of CaMKK2 and Nup62 in human clinical specimens of prostate cancer was visualized by immunohistochemistry. The role of Nups in the growth and viability of CRPC cells was assessed by RNA interference and cell counting. The involvement of CaMKK2 and Nup62 in regulating AR transcriptional activity was addressed by RNA interference, chromatin immunoprecipitation, androgen response element reporter assay, and Western blotting. CaMKK2 was expressed at higher levels in the nuclear fraction of CPRC C4-2 cells, than in that of androgen-responsive LNCaP cells. In C4-2 cells, CaMKK2 associated with NPCs of the nuclear envelope and physically interacted with Nup62. CaMKK2 and Nup62 demonstrated pronounced, and similar increases in both expression and perinuclear/nuclear localization in human clinical specimens of advanced prostate cancer relative to normal prostate. Knockdown of Nup62, but not of Nups, 98 or 88, reduced growth and viability of C4-2 cells. Knockdown of Nup62 produced a greater reduction of the growth and viability of C4-2 cells than of non

  4. Involvement of the N-terminal unique domain of Chk tyrosine kinase in Chk-induced tyrosine phosphorylation in the nucleus

    International Nuclear Information System (INIS)

    Nakayama, Yuji; Kawana, Akiko; Igarashi, Asae; Yamaguchi, Naoto

    2006-01-01

    Chk tyrosine kinase phosphorylates Src-family kinases and suppresses their kinase activity. We recently showed that Chk localizes to the nucleus as well as the cytoplasm and inhibits cell proliferation. In this study, we explored the role of the N-terminal unique domain of Chk in nuclear localization and Chk-induced tyrosine phosphorylation in the nucleus. In situ binding experiments showed that the N-terminal domain of Chk was associated with the nucleus and the nuclear matrix. The presence of the N-terminal domain of Chk led to a fourfold increase in cell population exhibiting Chk-induced tyrosine phosphorylation in the nucleus. Expression of Chk but not kinase-deficient Chk induced tyrosine phosphorylation of a variety of proteins ranging from 23 kDa to ∼200 kDa, especially in Triton X-100-insoluble fraction that included chromatin and the nuclear matrix. Intriguingly, in situ subnuclear fractionations revealed that Chk induced tyrosine phosphorylation of proteins that were associated with the nuclear matrix. These results suggest that various unidentified substrates of Chk, besides Src-family kinases, may be present in the nucleus. Thus, our findings indicate that the importance of the N-terminal domain to Chk-induced tyrosine phosphorylation in the nucleus, implicating that these nuclear tyrosine-phosphorylated proteins may contribute to inhibition of cell proliferation

  5. Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival.

    Directory of Open Access Journals (Sweden)

    Daniel Thomas

    Full Text Available The dual specificity protein/lipid kinase, phosphoinositide 3-kinase (PI3K, promotes growth factor-mediated cell survival and is frequently deregulated in cancer. However, in contrast to canonical lipid-kinase functions, the role of PI3K protein kinase activity in regulating cell survival is unknown. We have employed a novel approach to purify and pharmacologically profile protein kinases from primary human acute myeloid leukemia (AML cells that phosphorylate serine residues in the cytoplasmic portion of cytokine receptors to promote hemopoietic cell survival. We have isolated a kinase activity that is able to directly phosphorylate Ser585 in the cytoplasmic domain of the interleukin 3 (IL-3 and granulocyte macrophage colony stimulating factor (GM-CSF receptors and shown it to be PI3K. Physiological concentrations of cytokine in the picomolar range were sufficient for activating the protein kinase activity of PI3K leading to Ser585 phosphorylation and hemopoietic cell survival but did not activate PI3K lipid kinase signaling or promote proliferation. Blockade of PI3K lipid signaling by expression of the pleckstrin homology of Akt1 had no significant impact on the ability of picomolar concentrations of cytokine to promote hemopoietic cell survival. Furthermore, inducible expression of a mutant form of PI3K that is defective in lipid kinase activity but retains protein kinase activity was able to promote Ser585 phosphorylation and hemopoietic cell survival in the absence of cytokine. Blockade of p110α by RNA interference or multiple independent PI3K inhibitors not only blocked Ser585 phosphorylation in cytokine-dependent cells and primary human AML blasts, but also resulted in a block in survival signaling and cell death. Our findings demonstrate a new role for the protein kinase activity of PI3K in phosphorylating the cytoplasmic tail of the GM-CSF and IL-3 receptors to selectively regulate cell survival highlighting the importance of targeting

  6. Non-degradative Ubiquitination of Protein Kinases.

    Directory of Open Access Journals (Sweden)

    K Aurelia Ball

    2016-06-01

    Full Text Available Growing evidence supports other regulatory roles for protein ubiquitination in addition to serving as a tag for proteasomal degradation. In contrast to other common post-translational modifications, such as phosphorylation, little is known about how non-degradative ubiquitination modulates protein structure, dynamics, and function. Due to the wealth of knowledge concerning protein kinase structure and regulation, we examined kinase ubiquitination using ubiquitin remnant immunoaffinity enrichment and quantitative mass spectrometry to identify ubiquitinated kinases and the sites of ubiquitination in Jurkat and HEK293 cells. We find that, unlike phosphorylation, ubiquitination most commonly occurs in structured domains, and on the kinase domain, ubiquitination is concentrated in regions known to be important for regulating activity. We hypothesized that ubiquitination, like other post-translational modifications, may alter the conformational equilibrium of the modified protein. We chose one human kinase, ZAP-70, to simulate using molecular dynamics with and without a monoubiquitin modification. In Jurkat cells, ZAP-70 is ubiquitinated at several sites that are not sensitive to proteasome inhibition and thus may have other regulatory roles. Our simulations show that ubiquitination influences the conformational ensemble of ZAP-70 in a site-dependent manner. When monoubiquitinated at K377, near the C-helix, the active conformation of the ZAP-70 C-helix is disrupted. In contrast, when monoubiquitinated at K476, near the kinase hinge region, an active-like ZAP-70 C-helix conformation is stabilized. These results lead to testable hypotheses that ubiquitination directly modulates kinase activity, and that ubiquitination is likely to alter structure, dynamics, and function in other protein classes as well.

  7. Crystal structure of Cryptosporidium parvum pyruvate kinase.

    Directory of Open Access Journals (Sweden)

    William J Cook

    Full Text Available Pyruvate kinase plays a critical role in cellular metabolism of glucose by serving as a major regulator of glycolysis. This tetrameric enzyme is allosterically regulated by different effector molecules, mainly phosphosugars. In response to binding of effector molecules and substrates, significant structural changes have been identified in various pyruvate kinase structures. Pyruvate kinase of Cryptosporidium parvum is exceptional among known enzymes of protozoan origin in that it exhibits no allosteric property in the presence of commonly known effector molecules. The crystal structure of pyruvate kinase from C. parvum has been solved by molecular replacement techniques and refined to 2.5 Å resolution. In the active site a glycerol molecule is located near the γ-phosphate site of ATP, and the protein structure displays a partially closed active site. However, unlike other structures where the active site is closed, the α6' helix in C. parvum pyruvate kinase unwinds and assumes an extended conformation. In the crystal structure a sulfate ion is found at a site that is occupied by a phosphate of the effector molecule in many pyruvate kinase structures. A new feature of the C. parvum pyruvate kinase structure is the presence of a disulfide bond cross-linking the two monomers in the asymmetric unit. The disulfide bond is formed between cysteine residue 26 in the short N-helix of one monomer with cysteine residue 312 in a long helix (residues 303-320 of the second monomer at the interface of these monomers. Both cysteine residues are unique to C. parvum, and the disulfide bond remained intact in a reduced environment. However, the significance of this bond, if any, remains unknown at this time.

  8. A systematic evaluation of protein kinase a-a-kinase anchoring protein interaction motifs

    NARCIS (Netherlands)

    Burgers, Pepijn P|info:eu-repo/dai/nl/341566551; van der Heyden, Marcel A G; Kok, Bart; Heck, Albert J R|info:eu-repo/dai/nl/105189332; Scholten, Arjen|info:eu-repo/dai/nl/313939780

    2015-01-01

    Protein kinase A (PKA) in vertebrates is localized to specific locations in the cell via A-kinase anchoring proteins (AKAPs). The regulatory subunits of the four PKA isoforms (RIα, RIβ, RIIα, and RIIβ) each form a homodimer, and their dimerization domain interacts with a small helical region present

  9. A systematic evaluation of protein kinase A-A-kinase anchoring protein interaction motifs

    NARCIS (Netherlands)

    Burgers, Pepijn P; van der Heyden, MAG; Kok, Bart; Heck, Albert J R; Scholten, Arjen

    2015-01-01

    Protein kinase A (PKA) in vertebrates is localized to specific locations in the cell via A-kinase anchoring proteins (AKAPs). The regulatory subunits of the four PKA isoforms (RIα, RIβ, RIIα, and RIIβ) each form a homodimer, and their dimerization domain interacts with a small helical region present

  10. Role of adiponectin/phosphatidylinositol 3-kinase/protein kinase B ...

    African Journals Online (AJOL)

    The adiponectin/phosphatidylinositol 3-kinase/protein kinase B (ADP/PI3k/Akt) signal transduction pathway has an important role in promoting cell survival. This study was designed to determine if the ADP/PI3K/Akt signaling pathway has a role in the mechanism of ischemia–reperfusion injury in vivo. Sprague–Dawley rats ...

  11. Phosphorylation of nm23/nucleoside diphosphate kinase by casein kinase 2 in vitro

    DEFF Research Database (Denmark)

    Engel, M; Issinger, O G; Lascu, I

    1994-01-01

    We have investigated phosphorylation of human nucleoside diphosphate kinase (NDPK) and of homologous NDPK from different species by human casein kinase 2 (CK-2). The human NDPK isotypes A and B were phosphorylated by CK-2 in vitro both when the purified proteins and total lysate of HL-60 leukemia...

  12. Survey of tyrosine kinase signaling reveals ROS kinase fusions in human cholangiocarcinoma.

    Directory of Open Access Journals (Sweden)

    Ting-Lei Gu

    Full Text Available Cholangiocarcinoma, also known as bile duct cancer, is the second most common primary hepatic carcinoma with a median survival of less than 2 years. The molecular mechanisms underlying the development of this disease are not clear. To survey activated tyrosine kinases signaling in cholangiocarcinoma, we employed immunoaffinity profiling coupled to mass spectrometry and identified DDR1, EPHA2, EGFR, and ROS tyrosine kinases, along with over 1,000 tyrosine phosphorylation sites from about 750 different proteins in primary cholangiocarcinoma patients. Furthermore, we confirmed the presence of ROS kinase fusions in 8.7% (2 out of 23 of cholangiocarcinoma patients. Expression of the ROS fusions in 3T3 cells confers transforming ability both in vitro and in vivo, and is responsive to its kinase inhibitor. Our data demonstrate that ROS kinase is a promising candidate for a therapeutic target and for a diagnostic molecular marker in cholangiocarcinoma. The identification of ROS tyrosine kinase fusions in cholangiocarcinoma, along with the presence of other ROS kinase fusions in lung cancer and glioblastoma, suggests that a more broadly based screen for activated ROS kinase in cancer is warranted.

  13. The SH2 domain of Abl kinases regulates kinase autophosphorylation by controlling activation loop accessibility

    Science.gov (United States)

    Lamontanara, Allan Joaquim; Georgeon, Sandrine; Tria, Giancarlo; Svergun, Dmitri I.; Hantschel, Oliver

    2014-11-01

    The activity of protein kinases is regulated by multiple molecular mechanisms, and their disruption is a common driver of oncogenesis. A central and almost universal control element of protein kinase activity is the activation loop that utilizes both conformation and phosphorylation status to determine substrate access. In this study, we use recombinant Abl tyrosine kinases and conformation-specific kinase inhibitors to quantitatively analyse structural changes that occur after Abl activation. Allosteric SH2-kinase domain interactions were previously shown to be essential for the leukemogenesis caused by the Bcr-Abl oncoprotein. We find that these allosteric interactions switch the Abl activation loop from a closed to a fully open conformation. This enables the trans-autophosphorylation of the activation loop and requires prior phosphorylation of the SH2-kinase linker. Disruption of the SH2-kinase interaction abolishes activation loop phosphorylation. Our analysis provides a molecular mechanism for the SH2 domain-dependent activation of Abl that may also regulate other tyrosine kinases.

  14. [Nuclear theory

    International Nuclear Information System (INIS)

    Haxton, W.

    1990-01-01

    This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion

  15. MAP kinase-independent signaling in angiotensin II regulation of neuromodulation in SHR neurons.

    Science.gov (United States)

    Yang, H; Raizada, M K

    1998-09-01

    Angiotensin II (Ang II), via its interaction with the angiotensin type 1 (AT1) receptor subtype, causes enhanced stimulation of norepinephrine (NE) neuromodulation. This involves increased transcription of NE transporter, tyrosine hydroxylase, and dopamine ss-hydroxylase genes in Wistar-Kyoto rat (WKY) brain neurons. AT1 receptor-mediated regulation of certain signaling events (such as activation of the Ras-Raf-1-mitogen activated protein (MAP) kinase signaling pathway, nuclear translocation of transcription factors such as Fos and Jun, and the interactions of these factors with AP-1 binding sites) is involved in this NE neuromodulation (Lu et al. J Cell Biol. 1996;135:1609-1617). The aim of this study was to compare the signal transduction mechanism of Ang II regulation of NE neuromodulation in WKY and spontaneously hypertensive rat (SHR) brain neurons, in view of the fact that AT1 receptor expression and Ang II stimulation of NE neuromodulation are higher in SHR neurons compared with WKY neurons. Despite this hyperactivity, Ang II stimulation of Ras, Raf-1, and MAP kinase activities was comparable between the neurons from WKY and SHR. Similarly, central injections of Ang II caused a comparable stimulation of MAP kinase in the hypothalamic and brain stem areas of adult WKY and SHR. Inhibition of MAP kinase by either an MAP kinase kinase inhibitor (PD98059) or an MAP kinase antisense oligonucleotide completely attenuated the stimulatory effects of Ang II on [3H]-NE uptake, NE transporter mRNA, and tyrosine hydroxylase mRNA levels in WKY neurons. These treatments resulted in only 43% to 50% inhibition of [3H]-NE uptake and NE transporter and tyrosine hydroxylase mRNAs in SHR neurons. Thus, Ang II stimulation of NE neuromodulation was completely blocked by MAP kinase inhibition in WKY neurons and only partially blocked in the SHR neurons. These observations suggest the presence of an additional signal transduction pathway involved in NE neuromodulation in SHR neurons

  16. The Link between Protein Kinase CK2 and Atypical Kinase Rio1

    Directory of Open Access Journals (Sweden)

    Konrad Kubiński

    2017-02-01

    Full Text Available The atypical kinase Rio1 is widespread in many organisms, ranging from Archaebacteria to humans, and is an essential factor in ribosome biogenesis. Little is known about the protein substrates of the enzyme and small-molecule inhibitors of the kinase. Protein kinase CK2 was the first interaction partner of Rio1, identified in yeast cells. The enzyme from various sources undergoes CK2-mediated phosphorylation at several sites and this modification regulates the activity of Rio1. The aim of this review is to present studies of the relationship between the two different kinases, with respect to CK2-mediated phosphorylation of Rio1, regulation of Rio1 activity, and similar susceptibility of the kinases to benzimidazole inhibitors.

  17. syk kinase activation by a src kinase-initiated activation loop phosphorylation chain reaction

    Science.gov (United States)

    El-Hillal, O.; Kurosaki, T.; Yamamura, H.; Kinet, J.-P.; Scharenberg, A. M.

    1997-01-01

    Activation of the syk tyrosine kinase occurs almost immediately following engagement of many types of antigen receptors, including Fc receptors, but the mechanism through which syk is activated is currently unclear. Here we demonstrate that Fc receptor-induced syk activation occurs as the result of phosphorylation of the syk activation loop by both src family kinases and other molecules of activated syk, suggesting that syk activation occurs as the result of a src kinase-initiated activation loop phosphorylation chain reaction. This type of activation mechanism predicts that syk activation would exhibit exponential kinetics, providing a potential explanation for its rapid and robust activation by even weak antigen receptor stimuli. We propose that a similar mechanism may be responsible for generating rapid activation of other cytoplasmic tyrosine kinases, such as those of the Bruton tyrosine kinase/tec family, as well. PMID:9050880

  18. Mechanism of polyphosphate kinase from Propionibacterium shermanii

    International Nuclear Information System (INIS)

    Robinson, N.A.

    1986-01-01

    Polyphosphate kinase, which catalyzes the reaction shown below, is one of two enzymes which have been reported to catalyze the synthesis of polyphosphate. Purification performed by ammonium sulfate precipitation (0-40% fraction) was followed by chromatography. The enzyme represents 70% of the protein in the hydroxylapatite pool and is stable at this level of purity. The subunit molecular weight was determined by SDS polyacrylamide gel analysis, (83,000 +/- 3000), nondenaturing polyacrylamide gel electrophoresis, (80,000 and 86,000 daltons), gel filtration (Biogel A 0.5m column was 85,000 +/- 4000.) Polyphosphate kinase appears to be a monomeric enzyme of ∼83,000 daltons. Four assays were developed for polyphosphate kinase. Basic proteins such as polylysine stimulate the synthesis of polyphosphate, these proteins cause precipitation of polyphosphate kinase from relatively impure enzyme extracts: Synthesized polyphosphate interacts noncovalently with the basic protein-enzyme precipitate. Efficient synthesis of polyphosphate requires the addition of either phosphate or short chain polyphosphate. Synthesis did occur at 1/10 the rate when neither of these two compounds were included. Initiation, elongation, and termination events of polyphosphate synthesis were examined. Short chain polyphosphate acts as a primer, with [ 32 P] short-chain polyphosphate incorporation into long chain polyphosphate by the kinase

  19. Radioimmunoassay of bovine heart protein kinase

    International Nuclear Information System (INIS)

    Fleischer, N.; Rosen, O.M.; Reichlin, M.

    1976-01-01

    Immunization of guinea pigs with bovine cardiac cAMP-dependent protein kinase (ATP : protein phosphotransferase, EC 2.7.1.37) resulted in the development of precipitating antibodies to the cAMP-binding subunit of the enzyme. Both the phosphorylated and nonphosphorylated cAMP-binding protein of the protein kinase reacted with the antiserum. A radioimmunoassay was developed that detects 10 ng of holoenzyme and permits measurement of enzyme concentrations in bovine cardiac muscle. Bovine liver, kidney, brain, and skeletal muscle contain protein kinases which are immunologically identical to those found in bovine cardiac muscle. However, the proportion of immunoreactive enzyme activity differed for each tissue. All of the immunologically nonreactive enzyme in skeletal muscle and heart was separable from immunoreactive enzyme by chromatography on DEAE-cellulose. Rat tissues and pig heart contained protein kinase activity that cross reacted immunologically in a nonparallel fashion with bovine cardiac enzyme. These results indicate that cAMP-dependent protein kinases within and between species are immunologically heterogeneous

  20. The target landscape of clinical kinase drugs.

    Science.gov (United States)

    Klaeger, Susan; Heinzlmeir, Stephanie; Wilhelm, Mathias; Polzer, Harald; Vick, Binje; Koenig, Paul-Albert; Reinecke, Maria; Ruprecht, Benjamin; Petzoldt, Svenja; Meng, Chen; Zecha, Jana; Reiter, Katrin; Qiao, Huichao; Helm, Dominic; Koch, Heiner; Schoof, Melanie; Canevari, Giulia; Casale, Elena; Depaolini, Stefania Re; Feuchtinger, Annette; Wu, Zhixiang; Schmidt, Tobias; Rueckert, Lars; Becker, Wilhelm; Huenges, Jan; Garz, Anne-Kathrin; Gohlke, Bjoern-Oliver; Zolg, Daniel Paul; Kayser, Gian; Vooder, Tonu; Preissner, Robert; Hahne, Hannes; Tõnisson, Neeme; Kramer, Karl; Götze, Katharina; Bassermann, Florian; Schlegl, Judith; Ehrlich, Hans-Christian; Aiche, Stephan; Walch, Axel; Greif, Philipp A; Schneider, Sabine; Felder, Eduard Rudolf; Ruland, Juergen; Médard, Guillaume; Jeremias, Irmela; Spiekermann, Karsten; Kuster, Bernhard

    2017-12-01

    Kinase inhibitors are important cancer therapeutics. Polypharmacology is commonly observed, requiring thorough target deconvolution to understand drug mechanism of action. Using chemical proteomics, we analyzed the target spectrum of 243 clinically evaluated kinase drugs. The data revealed previously unknown targets for established drugs, offered a perspective on the "druggable" kinome, highlighted (non)kinase off-targets, and suggested potential therapeutic applications. Integration of phosphoproteomic data refined drug-affected pathways, identified response markers, and strengthened rationale for combination treatments. We exemplify translational value by discovering SIK2 (salt-inducible kinase 2) inhibitors that modulate cytokine production in primary cells, by identifying drugs against the lung cancer survival marker MELK (maternal embryonic leucine zipper kinase), and by repurposing cabozantinib to treat FLT3-ITD-positive acute myeloid leukemia. This resource, available via the ProteomicsDB database, should facilitate basic, clinical, and drug discovery research and aid clinical decision-making. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  1. Janus kinase inhibitors: jackpot or potluck?

    Directory of Open Access Journals (Sweden)

    Pavithran Keechilat

    2012-06-01

    Full Text Available The reports of a unique mutation in the Janus kinase-2 gene (JAK2 in polycythemia vera by several independent groups in 2005 quickly spurred the development of the Janus kinase inhibitors. In one of the great victories of translational research in recent times, the first smallmolecule Janus kinase inhibitor ruxolitinib entered a phase I trial in 2007. With the approval of ruxolitinib by the US Federal Drug Administration in November 2011 for high-risk and intermediate-2 risk myelofibrosis, a change in paradigm has occurred in the management of a subset of myeloproliferative neoplasms (MPN: primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. Whereas the current evidence for ruxolitinib only covers high-risk and intermediate-2 risk myelofibrosis, inhibitors with greater potency are likely to offer better disease control and survival advantage in patients belonging to these categories, and possibly to the low-risk and intermediate-1 risk categories of MPN as well. But use of the Janus kinase inhibitors also probably has certain disadvantages, such as toxicity, resistance, withdrawal phenomenon, non-reversal of histology, and an implausible goal of disease clone eradication, some of which could offset the gains. In spite of this, Janus kinase inhibitors are here to stay, and for use in more than just myeloproliferative neoplasms.

  2. Nuclear topics

    International Nuclear Information System (INIS)

    Lukner, C.

    1982-07-01

    The pamphlet touches on all aspects of nuclear energy, from the world energy demands and consumption, the energy program of the Federal Government, nuclear power plants in the world, nuclear fusion, nuclear liability up to the nuclear fuel cycle and the shutdown of nuclear power plants. (HSCH) [de

  3. Protocols for the Design of Kinase-focused Compound Libraries.

    Science.gov (United States)

    Jacoby, Edgar; Wroblowski, Berthold; Buyck, Christophe; Neefs, Jean-Marc; Meyer, Christophe; Cummings, Maxwell D; van Vlijmen, Herman

    2018-05-01

    Protocols for the design of kinase-focused compound libraries are presented. Kinase-focused compound libraries can be differentiated based on the design goal. Depending on whether the library should be a discovery library specific for one particular kinase, a general discovery library for multiple distinct kinase projects, or even phenotypic screening, there exists today a variety of in silico methods to design candidate compound libraries. We address the following scenarios: 1) Datamining of SAR databases and kinase focused vendor catalogues; 2) Predictions and virtual screening; 3) Structure-based design of combinatorial kinase inhibitors; 4) Design of covalent kinase inhibitors; 5) Design of macrocyclic kinase inhibitors; and 6) Design of allosteric kinase inhibitors and activators. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Phosphatidylinositol 3-Kinase (PI3K) and phosphatidylinositol 3-kinase-related kinase (PIKK) inhibitors: importance of the morpholine ring

    Czech Academy of Sciences Publication Activity Database

    Andrs, M.; Kobarecny, J.; Jun, D.; Hodný, Zdeněk; Bartek, Jiří; Kuca, K.

    2015-01-01

    Roč. 58, č. 1 (2015), s. 41-71 ISSN 0022-2623 R&D Projects: GA MŠk(CZ) CZ.1.07/2.3.00/30.0044 Grant - others:University Hospital Hradec Kralove(CZ) 00179906; Faculty of Military Health Sciences, University of Defence(CZ) SV/FVZ201402 Institutional support: RVO:68378050 Keywords : DEPENDENT PROTEIN-KINASE * STRAND BREAK REPAIR * SELECTIVE PI3K-BETA INHIBITORS * TELANGIECTASIA MUTATED KINASE Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.589, year: 2015

  5. Nuclear power and nuclear weapons

    International Nuclear Information System (INIS)

    Vaughen, V.C.A.

    1983-01-01

    The proliferation of nuclear weapons and the expanded use of nuclear energy for the production of electricity and other peaceful uses are compared. The difference in technologies associated with nuclear weapons and nuclear power plants are described

  6. Subcellular distribution of cyclin-dependent kinase-like 5 (CDKL5) is regulated through phosphorylation by dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A).

    Science.gov (United States)

    Oi, Ami; Katayama, Syouichi; Hatano, Naoya; Sugiyama, Yasunori; Kameshita, Isamu; Sueyoshi, Noriyuki

    2017-01-08

    Cyclin-dependent kinase-like 5 (CDKL5) is a Ser/Thr protein kinase primarily expressed in the central nervous system and is known to cause X-linked neurodevelopmental disorders such as Rett syndrome. However, the mechanisms regulating CDKL5 have not yet been fully clarified. Therefore, in this study, we investigated the protein kinase that directly phosphorylates CDKL5, identifying it as dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), an enzyme binding to and phosphorylating CDKL5. We showed that subcellular distribution of CDKL5 was regulated by its phosphorylation by DYRK1A. In mouse neuroblastoma Neuro2a cells, CDKL5 was localized in both the cytosol and nucleus, whereas DYRK1A showed a typical nuclear localization. When CDKL5 and DYRK1A were co-expressed, the cytosolic localization of CDKL5 was significantly increased. Results of site-directed mutagenesis revealed that the phosphorylation site was Ser-308, in the vicinity of the nuclear localization signal. A mutation mimicking the phosphorylated serine residue by aspartate substitution (S308D) changed CDKL5 localization to the cytosol, whereas the corresponding alanine-substituted analog, CDKL5(S308A), was primarily localized to the nucleus. Taken together, these results strongly suggested that DYRK1A bound to CDKL5 and phosphorylated it on Ser-308, thus interfering with its nuclear localization. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Protein Kinases in Shaping Plant Architecture.

    Science.gov (United States)

    Wu, Juan; Wang, Bo; Xin, Xiaoyun; Ren, Dongtao

    2018-02-13

    Plant architecture, the three-dimensional organization of the plant body, includes the branching pattern and the size, shape, and position of organs. Plant architecture is genetically controlled and is influenced by environmental conditions. The regulations occur at most of the stages from the first division of the fertilized eggs to the final establishment of plant architecture. Among the various endogenous regulators, protein kinases and their associated signaling pathways have been shown to play important roles in regulating the process of plant architecture establishment. In this review, we summarize recent progress in the understanding of the mechanisms by which plant architecture formation is regulated by protein kinases, especially mitogen-activated protein kinase (MAPK). Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. The Role of PAS Kinase in PASsing the Glucose Signal

    Directory of Open Access Journals (Sweden)

    Julianne H. Grose

    2010-06-01

    Full Text Available PAS kinase is an evolutionarily conserved nutrient responsive protein kinase that regulates glucose homeostasis. Mammalian PAS kinase is activated by glucose in pancreatic beta cells, and knockout mice are protected from obesity, liver triglyceride accumulation, and insulin resistance when fed a high-fat diet. Yeast PAS kinase is regulated by both carbon source and cell integrity stress and stimulates the partitioning of glucose toward structural carbohydrate biosynthesis. In our current model for PAS kinase regulation, a small molecule metabolite binds the sensory PAS domain and activates the enzyme. Although bona fide PAS kinase substrates are scarce, in vitro substrate searches provide putative targets for exploration.

  9. Phosphorylation of varicella-zoster virus glycoprotein gpI by mammalian casein kinase II and casein kinase I

    International Nuclear Information System (INIS)

    Grose, C.; Jackson, W.; Traugh, J.A.

    1989-01-01

    Varicella-zoster virus (VZV) glycoprotein gpI is the predominant viral glycoprotein within the plasma membranes of infected cells. This viral glycoprotein is phosphorylated on its polypeptide backbone during biosynthesis. In this report, the authors investigated the protein kinases which participate in the phosphorylation events. Under in vivo conditions, VZV gpI was phosphorylated on its serine and threonine residues by protein kinases present within lysates of either VZV-infected or uninfected cells. Because this activity was diminished by heparin, a known inhibitor of casein kinase II, isolated gpI was incubated with purified casein kinase II and shown to be phosphorylated in an in vitro assay containing [γ- 32 P]ATP. The same glycoprotein was phosphorylated when [ 32 P]GTP was substituted for [ 32 P]ATP in the protein kinase assay. They also tested whether VZV gpI was phosphorylated by two other ubiquitous mammalian protein kinases--casein kinase I and cyclic AMP-dependent kinase--and found that only casein kinase I modified gpI. When the predicted 623-amino-acid sequence of gpI was examined, two phosphorylation sites known to be optimal for casein kinase II were observed. In summary, this study showed that VZV gpI was phosphorylated by each of two mammalian protein kinases (casein kinase I and casein kinase II) and that potential serine-threonine phosphorylation sites for each of these two kinases were present in the viral glycoprotein

  10. Identification of interphase functions for the NIMA kinase involving microtubules and the ESCRT pathway.

    Directory of Open Access Journals (Sweden)

    Meera Govindaraghavan

    2014-03-01

    Full Text Available The Never in Mitosis A (NIMA kinase (the founding member of the Nek family of kinases has been considered a mitotic specific kinase with nuclear restricted roles in the model fungus Aspergillus nidulans. By extending to A. nidulans the results of a synthetic lethal screen performed in Saccharomyces cerevisiae using the NIMA ortholog KIN3, we identified a conserved genetic interaction between nimA and genes encoding proteins of the Endosomal Sorting Complex Required for Transport (ESCRT pathway. Absence of ESCRT pathway functions in combination with partial NIMA function causes enhanced cell growth defects, including an inability to maintain a single polarized dominant cell tip. These genetic insights suggest NIMA potentially has interphase functions in addition to its established mitotic functions at nuclei. We therefore generated endogenously GFP-tagged NIMA (NIMA-GFP which was fully functional to follow its interphase locations using live cell spinning disc 4D confocal microscopy. During interphase some NIMA-GFP locates to the tips of rapidly growing cells and, when expressed ectopically, also locates to the tips of cytoplasmic microtubules, suggestive of non-nuclear interphase functions. In support of this, perturbation of NIMA function either by ectopic overexpression or through partial inactivation results in marked cell tip growth defects with excess NIMA-GFP promoting multiple growing cell tips. Ectopic NIMA-GFP was found to locate to the plus ends of microtubules in an EB1 dependent manner, while impairing NIMA function altered the dynamic localization of EB1 and the cytoplasmic microtubule network. Together, our genetic and cell biological analyses reveal novel non-nuclear interphase functions for NIMA involving microtubules and the ESCRT pathway for normal polarized fungal cell tip growth. These insights extend the roles of NIMA both spatially and temporally and indicate that this conserved protein kinase could help integrate cell

  11. 2-Aminobenzimidazoles as potent Aurora kinase inhibitors.

    Science.gov (United States)

    Zhong, Min; Bui, Minna; Shen, Wang; Baskaran, Subramanian; Allen, Darin A; Elling, Robert A; Flanagan, W Michael; Fung, Amy D; Hanan, Emily J; Harris, Shannon O; Heumann, Stacey A; Hoch, Ute; Ivy, Sheryl N; Jacobs, Jeffrey W; Lam, Stuart; Lee, Heman; McDowell, Robert S; Oslob, Johan D; Purkey, Hans E; Romanowski, Michael J; Silverman, Jeffrey A; Tangonan, Bradley T; Taverna, Pietro; Yang, Wenjin; Yoburn, Josh C; Yu, Chul H; Zimmerman, Kristin M; O'Brien, Tom; Lew, Willard

    2009-09-01

    This Letter describes the discovery and key structure-activity relationship (SAR) of a series of 2-aminobenzimidazoles as potent Aurora kinase inhibitors. 2-Aminobenzimidazole serves as a bioisostere of the biaryl urea residue of SNS-314 (1c), which is a potent Aurora kinase inhibitor and entered clinical testing in patients with solid tumors. Compared to SNS-314, this series of compounds offers better aqueous solubility while retaining comparable in vitro potency in biochemical and cell-based assays; in particular, 6m has also demonstrated a comparable mouse iv PK profile to SNS-314.

  12. Purification and characterization of a casein kinase 2-type protein kinase from pea nuclei

    Science.gov (United States)

    Li, H.; Roux, S. J.

    1992-01-01

    Almost all the polyamine-stimulated protein kinase activity associated with the chromatin fraction of nuclei purified from etiolated pea (Pisum sativum L.) plumules is present in a single enzyme that can be extracted from chromatin by 0.35 molar NaCl. This protein kinase can be further purified over 2000-fold by salt fractionation and anion-exchange and casein-agarose column chromatography, after which it is more than 90% pure. The purified kinase has a specific activity of about 650 nanomoles per minute per milligram protein in the absence of polyamines, with either ATP or GTP as phosphoryl donor. Spermidine can stimulate its activity fourfold, with half-maximal activation at about 2 millimolar. Spermine and putrescine also stimulate activity, although somewhat less effectively. This kinase has a tetrameric alpha 2 beta 2 structure with a native molecular weight of 130,000, and subunit molecular weights of 36,000 for the catalytic subunit (alpha) and 29,000 for the regulatory subunit (beta). In western blot analyses, only the alpha subunit reacts strongly with polyclonal antibodies to a Drosophila casein kinase II. The pea kinase can use casein and phosvitin as artificial substrates, phosphorylating both the serine and threonine residues of casein. It has a pH optimum near 8.0, a Vmax of 1.5 micromoles per minute per milligram protein, and a Km for ATP of approximately 75 micromolar. Its activity can be almost completely inhibited by heparin at 5 micrograms per milliliter, but is relatively insensitive to concentrations of staurosporine, K252a, and chlorpromazine that strongly antagonize Ca(2+) -regulated protein kinases. These results are discussed in relation to recent findings that casein kinase 2-type kinases may phosphorylate trans-acting factors that bind to light-regulated promoters in plants.

  13. CZK3, a MAP kinase kinase kinase homolog in Cercospora zeae-maydis, regulates cercosporin biosynthesis, fungal development, and pathogenesis.

    Science.gov (United States)

    Shim, Won-Bo; Dunkle, Larry D

    2003-09-01

    The fungus Cercospora zeae-maydis causes gray leaf spot of maize and produces cercosporin, a photosensitizing perylenequinone with toxic activity against a broad spectrum of organisms. However, little is known about the biosynthetic pathway or factors that regulate cercosporin production. Analysis of a cDNA subtraction library comprised of genes that are up-regulated during cercosporin synthesis revealed a sequence highly similar to mitogen-activated protein (MAP) kinases in other fungi. Sequencing and conceptual translation of the full-length genomic sequence indicated that the gene, which we designated CZK3, contains a 4,119-bp open reading frame devoid of introns and encodes a 1,373-amino acid sequence that is highly similar to Wis4, a MAP kinase kinase kinase in Schizosaccharomyces pombe. Targeted disruption of CZK3 suppressed expression of genes predicted to participate in cercosporin biosynthesis and abolished cercosporin production. The disrupted mutants grew faster on agar media than the wild type but were deficient in conidiation and elicited only small chlorotic spots on inoculated maize leaves compared with rectangular necrotic lesions incited by the wild type. Complementation of disruptants with the CZK3 open reading frame and flanking sequences restored wild-type levels of conidiation, growth rate, and virulence as well as the ability to produce cercosporin. The results suggest that cercosporin is a virulence factor in C. zeae-maydis during maize pathogenesis, but the pleiotropic effects of CZK3 disruption precluded definitive conclusions.

  14. Nuclear rights - nuclear wrongs

    Energy Technology Data Exchange (ETDEWEB)

    Paul, E.F.; Miller, F.D.; Paul, J.; Ahrens, J.

    1986-01-01

    This book contains 11 selections. The titles are: Three Ways to Kill Innocent Bystanders: Some Conundrums Concerning the Morality of War; The International Defense of Liberty; Two Concepts of Deterrence; Nuclear Deterrence and Arms Control; Ethical Issues for the 1980s; The Moral Status of Nuclear Deterrent Threats; Optimal Deterrence; Morality and Paradoxical Deterrence; Immoral Risks: A Deontological Critique of Nuclear Deterrence; No War Without Dictatorship, No Peace Without Democracy: Foreign Policy as Domestic Politics; Marxism-Leninism and its Strategic Implications for the United States; Tocqueveille War.

  15. Nuclear moments

    CERN Document Server

    Kopferman, H; Massey, H S W

    1958-01-01

    Nuclear Moments focuses on the processes, methodologies, reactions, and transformations of molecules and atoms, including magnetic resonance and nuclear moments. The book first offers information on nuclear moments in free atoms and molecules, including theoretical foundations of hyperfine structure, isotope shift, spectra of diatomic molecules, and vector model of molecules. The manuscript then takes a look at nuclear moments in liquids and crystals. Discussions focus on nuclear paramagnetic and magnetic resonance and nuclear quadrupole resonance. The text discusses nuclear moments and nucl

  16. Myosin light chain kinase phosphorylation in tracheal smooth muscle

    International Nuclear Information System (INIS)

    Stull, J.T.; Hsu, L.C.; Tansey, M.G.; Kamm, K.E.

    1990-01-01

    Purified myosin light chain kinase from smooth muscle is phosphorylated by cyclic AMP-dependent protein kinase, protein kinase C, and the multifunctional calmodulin-dependent protein kinase II. Because phosphorylation in a specific site (site A) by any one of these kinases desensitizes myosin light chain kinase to activation by Ca2+/calmodulin, kinase phosphorylation could play an important role in regulating smooth muscle contractility. This possibility was investigated in 32 P-labeled bovine tracheal smooth muscle. Treatment of tissues with carbachol, KCl, isoproterenol, or phorbol 12,13-dibutyrate increased the extent of kinase phosphorylation. Six primary phosphopeptides (A-F) of myosin light chain kinase were identified. Site A was phosphorylated to an appreciable extent only with carbachol or KCl, agents which contract tracheal smooth muscle. The extent of site A phosphorylation correlated to increases in the concentration of Ca2+/calmodulin required for activation. These results show that cyclic AMP-dependent protein kinase and protein kinase C do not affect smooth muscle contractility by phosphorylating site A in myosin light chain kinase. It is proposed that phosphorylation of myosin light chain kinase in site A in contracting tracheal smooth muscle may play a role in the reported desensitization of contractile elements to activation by Ca2+

  17. Protein kinase CK2 in health and disease: Protein kinase CK2: from structures to insights

    DEFF Research Database (Denmark)

    Niefind, K; Raaf, J; Issinger, Olaf-Georg

    2009-01-01

    the critical region of CK2alpha recruitment is pre-formed in the unbound state. In CK2alpha the activation segment - a key element of protein kinase regulation - adapts invariably the typical conformation of the active enzymes. Recent structures of human CK2alpha revealed a surprising plasticity in the ATP......Within the last decade, 40 crystal structures corresponding to protein kinase CK2 (former name 'casein kinase 2'), to its catalytic subunit CK2alpha and to its regulatory subunit CK2beta were published. Together they provide a valuable, yet by far not complete basis to rationalize the biochemical...

  18. Novel mechanisms of sildenafil in pulmonary hypertension involving cytokines/chemokines, MAP kinases and Akt.

    Directory of Open Access Journals (Sweden)

    Tamas Kiss

    Full Text Available Pulmonary arterial hypertension (PH is associated with high mortality due to right ventricular failure and hypoxia, therefore to understand the mechanism by which pulmonary vascular remodeling initiates these processes is very important. We used a well-characterized monocrotaline (MCT-induced rat PH model, and analyzed lung morphology, expression of cytokines, mitogen-activated protein kinase (MAPK phosphorylation, and phosphatidylinositol 3-kinase-Akt (PI-3k-Akt pathway and nuclear factor (NF-κB activation in order to elucidate the mechanisms by which sildenafil's protective effect in PH is exerted. Besides its protective effect on lung morphology, sildenafil suppressed multiple cytokines involved in neutrophil and mononuclear cells recruitment including cytokine-induced neutrophil chemoattractant (CINC-1, CINC-2α/β, tissue inhibitor of metalloproteinase (TIMP-1, interleukin (IL-1α, lipopolysaccharide induced CXC chemokine (LIX, monokine induced by gamma interferon (MIG, macrophage inflammatory protein (MIP-1α, and MIP-3α. NF-κB activation and phosphorylation were also attenuated by sildenafil. Furthermore, sildenafil reduced extracellular signal-regulated kinase (ERK1/2 and p38 MAPK activation while enhanced activation of the cytoprotective Akt pathway in PH. These data suggest a beneficial effect of sildenafil on inflammatory and kinase signaling mechanisms that substantially contribute to its protective effects, and may have potential implications in designing future therapeutic strategies in the treatment of pulmonary hypertension.

  19. HRR25, a putative protein kinase from budding yeast: Association with repair of damaged DNA

    International Nuclear Information System (INIS)

    Hoekstra, M.F.; Ou, A.C.; DeMaggio, A.J.; Burbee, D.G.; Liskay, R.M.; Heffron, F.

    1991-01-01

    In simple eukaryotes, protein kinases regulate mitotic and meiotic cell cycles, the response to polypeptide pheromones, and the initiation of nuclear DNA synthesis. The protein HRR25 from the budding yeast Saccharomyces cerevisiae was defined by the mutation hrr25-1. This mutation resulted in sensitivity to continuous expression of the HO double-strand endonuclease, to methyl methanesulfonate, and to x-irradiation. Homozygotes of hrr25-1 were unable to sporulate and disruption and deletion of HRR25 interfered with mitotic and meiotic cell division. Sequence analysis revealed two distinctive regions in the protein. The NH 2 -terminus of HRR25 contains the hallmark features of protein kinases, whereas the COOH-terminus is rich in proline and glutamine. Mutations in HRR25 at conserved residues found in all protein kinases inactivated the gene, and these mutants exhibited the hrr25 null phenotypes. Taken together, the hrr25 mutant phenotypes and the features of the gene product indicate that HRR25 is a distinctive member of the protein kinase superfamily

  20. FAK dimerization controls its kinase-dependent functions at focal adhesions

    KAUST Repository

    Brami-Cherrier, Karen; Gervasi, Nicolas; Arsenieva, Diana A.; Walkiewicz, Katarzyna; Boutterin, Marie Claude; Ortega, Á lvaro Darí o; Leonard, Paul G.; Seantier, Bastien; Gasmi, Laï la; Bouceba, Tahar; Kadaré , Gress; Girault -, Jean Antoine; Arold, Stefan T.

    2014-01-01

    Focal adhesion kinase (FAK) controls adhesion-dependent cell motility, survival, and proliferation. FAK has kinase-dependent and kinase-independent functions, both of which play major roles in embryogenesis and tumor invasiveness. The precise mechanisms of FAK activation are not known. Using x-ray crystallography, small angle x-ray scattering, and biochemical and functional analyses, we show that the key step for activation of FAK's kinase-dependent functions-autophosphorylation of tyrosine-397-requires site-specific dimerization of FAK. The dimers form via the association of the N-terminal FERM domain of FAK and are stabilized by an interaction between FERM and the C-terminal FAT domain. FAT binds to a basic motif on FERM that regulates co-activation and nuclear localization. FAK dimerization requires local enrichment, which occurs specifically at focal adhesions. Paxillin plays a dual role, by recruiting FAK to focal adhesions and by reinforcing the FAT:FERM interaction. Our results provide a structural and mechanistic framework to explain how FAK combines multiple stimuli into a site-specific function. The dimer interfaces we describe are promising targets for blocking FAK activation. © 2014 The Authors.

  1. Inhibitory effects of homeodomain-interacting protein kinase 2 on the aorta-gonad-mapharsen hematopoiesis

    International Nuclear Information System (INIS)

    Ohtsu, Naoki; Nobuhisa, Ikuo; Mochita, Miyuki; Taga, Tetsuya

    2007-01-01

    Definitive hematopoiesis starts in the aorta-gonad-mesonephros (AGM) region of the mouse embryo. Our previous studies revealed that STAT3, a gp130 downstream transcription factor, is required for AGM hematopoiesis and that homeodomain-interacting protein kinase 2 (HIPK2) phosphorylates serine-727 of STAT3. HIPK2 is a serine/threonine kinase known to be involved in transcriptional repression and apoptosis. In the present study, we examined the role of HIPK2 in hematopoiesis in mouse embryo. HIPK2 transcripts were found in fetal hematopoietic tissues such as the mouse AGM region and fetal liver. In cultured AGM cells, HIPK2 protein was detected in adherent cells. Functional analyses of HIPK2 were carried out by introducing wild-type and mutant HIPK2 constructs into AGM cultures. Production of CD45 + hematopoietic cells was suppressed by forced expression of HIPK2 in AGM cultures. This suppression required the kinase domain and nuclear localization signals of HIPK2, but the kinase activity was dispensable. HIPK2-overexpressing AGM-derived nonadherent cells did not form cobblestone-like colonies in cultures with stromal cells. Furthermore, overexpression of HIPK2 in AGM cultures impeded the expansion of CD45 low c-Kit + cells, which exhibit the immature hematopoietic progenitor phenotype. These data indicate that HIPK2 plays a negative regulatory role in AGM hematopoiesis in the mouse embryo

  2. FAK dimerization controls its kinase-dependent functions at focal adhesions

    KAUST Repository

    Brami-Cherrier, Karen

    2014-01-30

    Focal adhesion kinase (FAK) controls adhesion-dependent cell motility, survival, and proliferation. FAK has kinase-dependent and kinase-independent functions, both of which play major roles in embryogenesis and tumor invasiveness. The precise mechanisms of FAK activation are not known. Using x-ray crystallography, small angle x-ray scattering, and biochemical and functional analyses, we show that the key step for activation of FAK\\'s kinase-dependent functions-autophosphorylation of tyrosine-397-requires site-specific dimerization of FAK. The dimers form via the association of the N-terminal FERM domain of FAK and are stabilized by an interaction between FERM and the C-terminal FAT domain. FAT binds to a basic motif on FERM that regulates co-activation and nuclear localization. FAK dimerization requires local enrichment, which occurs specifically at focal adhesions. Paxillin plays a dual role, by recruiting FAK to focal adhesions and by reinforcing the FAT:FERM interaction. Our results provide a structural and mechanistic framework to explain how FAK combines multiple stimuli into a site-specific function. The dimer interfaces we describe are promising targets for blocking FAK activation. © 2014 The Authors.

  3. Side-effects of protein kinase inhibitors on ion channels

    Indian Academy of Sciences (India)

    2013-11-06

    Nov 6, 2013 ... with aberrant kinase activity, including cancers, arthritis and cardiovascular disorders. Several strategies .... family, the β-adrenergic receptor kinase (βARK), the ribosomal S6 ..... urinary bladder smooth muscle cells. While no ...

  4. Creatine kinase activity is associated with blood pressure

    NARCIS (Netherlands)

    Brewster, Lizzy M.; Mairuhu, Gideon; Bindraban, Navin R.; Koopmans, Richard P.; Clark, Joseph F.; van Montfrans, Gert A.

    2006-01-01

    BACKGROUND: We previously hypothesized that high activity of creatine kinase, the central regulatory enzyme of energy metabolism, facilitates the development of high blood pressure. Creatine kinase rapidly provides adenosine triphosphate to highly energy-demanding processes, including cardiovascular

  5. Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

    DEFF Research Database (Denmark)

    Knecht, Wolfgang; Mikkelsen, N.E.; Clausen, A.R.

    2009-01-01

    Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) can additionally sensitize human cancer cell lines towards the anti-cancer drug gemcitabine. We show that this property is based on the Dm-dNK ability to efficiently phosphorylate gemcitabine. The 2.2 angstrom resolution...

  6. Deoxyribonucleoside kinases in mitochondrial DNA depletion.

    Science.gov (United States)

    Saada-Reisch, Ann

    2004-10-01

    Mitochondrial DNA (mtDNA) depletion syndromes (MDS) are a heterogeneous group of mitochondrial disorders, manifested by a decreased mtDNA copy number and respiratory chain dysfunction. Primary MDS are inherited autosomally and may affect a single organ or multiple tissues. Mutated mitochondrial deoxyribonucleoside kinases; deoxyguanosine kinase (dGK) and thymidine kinase 2 (TK2), were associated with the hepatocerebral and myopathic forms of MDS respectively. dGK and TK2 are key enzymes in the mitochondrial nucleotide salvage pathway, providing the mitochondria with deoxyribonucleotides (dNP) essential for mtDNA synthesis. Although the mitochondrial dNP pool is physically separated from the cytosolic one, dNP's may still be imported through specific transport. Non-replicating tissues, where cytosolic dNP supply is down regulated, are thus particularly vulnerable to dGK and TK2 deficiency. The overlapping substrate specificity of deoxycytidine kinase (dCK) may explain the relative sparing of muscle in dGK deficiency, while low basal TK2 activity render this tissue susceptible to TK2 deficiency. The precise pathophysiological mechanisms of mtDNA depletion due to dGK and TK2 deficiencies remain to be determined, though recent findings confirm that it is attributed to imbalanced dNTP pools.

  7. Allosteric small-molecule kinase inhibitors

    DEFF Research Database (Denmark)

    Wu, Peng; Clausen, Mads Hartvig; Nielsen, Thomas E.

    2015-01-01

    current barriers of kinase inhibitors, including poor selectivity and emergence of drug resistance. In spite of the small number of identified allosteric inhibitors in comparison with that of inhibitors targeting the ATP pocket, encouraging results, such as the FDA-approval of the first small...

  8. Plant PA signaling via diacylglycerol kinase

    NARCIS (Netherlands)

    Arisz, S.A.; Testerink, C.; Munnik, T.

    2009-01-01

    Accumulating evidence suggests that phosphatidic acid (PA) plays a pivotal role in the plant's response to environmental signals. Besides phospholipase D (PLD) activity, PA can also be generated by diacylglycerol kinase (DGK). To establish which metabolic route is activated, a differential

  9. Nonorthologous gene displacement of phosphomevalonate kinase

    NARCIS (Netherlands)

    Houten, S. M.; Waterham, H. R.

    2001-01-01

    Phosphomevalonate kinase (PMK; EC 2.7.4.2) catalyzes the phosphorylation of 5-phosphomevalonate into 5-diphosphomevalonate, an essential step in isoprenoid biosynthesis via the mevalonate pathway. So far, two nonorthologous genes encoding PMK have been described, the Saccharomyces cerevisiae ERG8

  10. Casein kinase-2 structure-function relationship

    DEFF Research Database (Denmark)

    Boldyreff, B; Meggio, F; Pinna, L A

    1992-01-01

    Nine mutants of human casein kinase-2 beta subunit have been created and assayed for their ability to assemble with the catalytic alpha subunit to give, at a 1:1 molar ratio, a fully competent CK-2 holoenzyme as judged by the following criteria: 1) the generation of an active heterotetrameric form...

  11. Mitogen-activated protein kinases mediate Mycobacterium ...

    Indian Academy of Sciences (India)

    2012-01-19

    Jan 19, 2012 ... CD44, an adhesion molecule, has been reported to be a binding site for ... receptors in mediating mitogen-activated protein kinase activation. ... surface expression and tumour necrosis factor-alpha levels, ... Abbreviations used: Abs, antibodies; ANOVA, analysis of variance; AP-1, activator protein -1; BCG, ...

  12. Kinase-Centric Computational Drug Development

    NARCIS (Netherlands)

    Kooistra, Albert J.; Volkamer, Andrea

    2017-01-01

    Kinases are among the most studied drug targets in industry and academia, due to their involvement in a majority of cellular processes and, upon dysregulation, in a variety of diseases including cancer, inflammation, and autoimmune disorders. The high interest in this druggable protein family

  13. Kinases involved in Rec8 phosphorylation revealed

    Czech Academy of Sciences Publication Activity Database

    Anger, Martin

    2010-01-01

    Roč. 9, č. 14 (2010), s. 2708-2708 ISSN 1538-4101 Institutional research plan: CEZ:AV0Z50450515 Keywords : kinases * Rec8 * meisosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.999, year: 2010

  14. Gene regulation by MAP kinase cascades

    DEFF Research Database (Denmark)

    Fiil, Berthe Katrine; Petersen, Klaus; Petersen, Morten

    2009-01-01

    Mitogen-activated protein kinase (MAPK) cascades are signaling modules that transduce extracellular stimuli to a range of cellular responses. Research in yeast and metazoans has shown that MAPK-mediated phosphorylation directly or indirectly regulates the activity of transcription factors. Plant ...

  15. Preparation of kinase-biased compounds in the search for lead inhibitors of kinase targets.

    Science.gov (United States)

    Lai, Justine Y Q; Langston, Steven; Adams, Ruth; Beevers, Rebekah E; Boyce, Richard; Burckhardt, Svenja; Cobb, James; Ferguson, Yvonne; Figueroa, Eva; Grimster, Neil; Henry, Andrew H; Khan, Nawaz; Jenkins, Kerry; Jones, Mark W; Judkins, Robert; Major, Jeremy; Masood, Abid; Nally, James; Payne, Helen; Payne, Lloyd; Raphy, Gilles; Raynham, Tony; Reader, John; Reader, Valérie; Reid, Alison; Ruprah, Parminder; Shaw, Michael; Sore, Hannah; Stirling, Matthew; Talbot, Adam; Taylor, Jess; Thompson, Stephen; Wada, Hiroki; Walker, David

    2005-05-01

    This work describes the preparation of approximately 13,000 compounds for rapid identification of hits in high-throughput screening (HTS). These compounds were designed as potential serine/threonine or tyrosine kinase inhibitors. The library consists of various scaffolds, e.g., purines, oxindoles, and imidazoles, whereby each core scaffold generally includes the hydrogen bond acceptor/donor properties known to be important for kinase binding. Several of these are based upon literature kinase templates, or adaptations of them to provide novelty. The routes to their preparation are outlined. A variety of automation techniques were used to prepare >500 compounds per scaffold. Where applicable, scavenger resins were employed to remove excess reagents and when necessary, preparative high performance liquid chromatography (HPLC) was used for purification. These compounds were screened against an 'in-house' kinase panel. The success rate in HTS was significantly higher than the corporate compound collection. Copyright (c) 2004 Wiley Periodicals, Inc.

  16. Kinase detection with gallium nitride based high electron mobility transistors.

    Science.gov (United States)

    Makowski, Matthew S; Bryan, Isaac; Sitar, Zlatko; Arellano, Consuelo; Xie, Jinqiao; Collazo, Ramon; Ivanisevic, Albena

    2013-07-01

    A label-free kinase detection system was fabricated by the adsorption of gold nanoparticles functionalized with kinase inhibitor onto AlGaN/GaN high electron mobility transistors (HEMTs). The HEMTs were operated near threshold voltage due to the greatest sensitivity in this operational region. The Au NP/HEMT biosensor system electrically detected 1 pM SRC kinase in ionic solutions. These results are pertinent to drug development applications associated with kinase sensing.

  17. Diversity, classification and function of the plant protein kinase superfamily

    OpenAIRE

    Lehti-Shiu, Melissa D.; Shiu, Shin-Han

    2012-01-01

    Eukaryotic protein kinases belong to a large superfamily with hundreds to thousands of copies and are components of essentially all cellular functions. The goals of this study are to classify protein kinases from 25 plant species and to assess their evolutionary history in conjunction with consideration of their molecular functions. The protein kinase superfamily has expanded in the flowering plant lineage, in part through recent duplications. As a result, the flowering plant protein kinase r...

  18. p21-activated Kinase1(PAK1) can promote ERK activation in a kinase independent manner

    DEFF Research Database (Denmark)

    Wang, Zhipeng; Fu, Meng; Wang, Lifeng

    2013-01-01

    204) although phosphorylation of b-Raf (Ser445) and c-Raf (Ser 338) remained unchanged. Furthermore, increased activation of the PAK1 activator Rac1 induced the formation of a triple complex of Rac1, PAK1 and Mek1, independent of the kinase activity of PAK1. These data suggest that PAK1 can stimulate...... MEK activity in a kinase independent manner, probably by serving as a scaffold to facilitate interaction of c-Raf....

  19. The Roles of Protein Kinases in Learning and Memory

    Science.gov (United States)

    Giese, Karl Peter; Mizuno, Keiko

    2013-01-01

    In the adult mammalian brain, more than 250 protein kinases are expressed, but only a few of these kinases are currently known to enable learning and memory. Based on this information it appears that learning and memory-related kinases either impact on synaptic transmission by altering ion channel properties or ion channel density, or regulate…

  20. Kinase impact assessment in the landscape of fusion genes that retain kinase domains: a pan-cancer study

    Science.gov (United States)

    Kim, Pora; Jia, Peilin; Zhao, Zhongming

    2018-01-01

    Abstract Assessing the impact of kinase in gene fusion is essential for both identifying driver fusion genes (FGs) and developing molecular targeted therapies. Kinase domain retention is a crucial factor in kinase fusion genes (KFGs), but such a systematic investigation has not been done yet. To this end, we analyzed kinase domain retention (KDR) status in chimeric protein sequences of 914 KFGs covering 312 kinases across 13 major cancer types. Based on 171 kinase domain-retained KFGs including 101 kinases, we studied their recurrence, kinase groups, fusion partners, exon-based expression depth, short DNA motifs around the break points and networks. Our results, such as more KDR than 5′-kinase fusion genes, combinatorial effects between 3′-KDR kinases and their 5′-partners and a signal transduction-specific DNA sequence motif in the break point intronic sequences, supported positive selection on 3′-kinase fusion genes in cancer. We introduced a degree-of-frequency (DoF) score to measure the possible number of KFGs of a kinase. Interestingly, kinases with high DoF scores tended to undergo strong gene expression alteration at the break points. Furthermore, our KDR gene fusion network analysis revealed six of the seven kinases with the highest DoF scores (ALK, BRAF, MET, NTRK1, NTRK3 and RET) were all observed in thyroid carcinoma. Finally, we summarized common features of ‘effective’ (highly recurrent) kinases in gene fusions such as expression alteration at break point, redundant usage in multiple cancer types and 3′-location tendency. Collectively, our findings are useful for prioritizing driver kinases and FGs and provided insights into KFGs’ clinical implications. PMID:28013235

  1. Inositol pyrophosphates promote tumor growth and metastasis by antagonizing liver kinase B1

    Science.gov (United States)

    Rao, Feng; Xu, Jing; Fu, Chenglai; Cha, Jiyoung Y.; Gadalla, Moataz M.; Xu, Risheng; Barrow, James C.; Snyder, Solomon H.

    2015-01-01

    The inositol pyrophosphates, molecular messengers containing an energetic pyrophosphate bond, impact a wide range of biologic processes. They are generated primarily by a family of three inositol hexakisphosphate kinases (IP6Ks), the principal product of which is diphosphoinositol pentakisphosphate (IP7). We report that IP6K2, via IP7 synthesis, is a major mediator of cancer cell migration and tumor metastasis in cell culture and in intact mice. IP6K2 acts by enhancing cell-matrix adhesion and decreasing cell–cell adhesion. This action is mediated by IP7-elicited nuclear sequestration and inactivation of the tumor suppressor liver kinase B1 (LKB1). Accordingly, inhibitors of IP6K2 offer promise in cancer therapy. PMID:25617365

  2. Arabidopsis MAP Kinase 4 regulates gene expression via transcription factor release in the nucleus

    DEFF Research Database (Denmark)

    Qiu, Jin-Long; Fiil, Berthe Katrine; Petersen, Klaus

    2008-01-01

    kinase 4 (MPK4) exists in nuclear complexes with the WRKY33 transcription factor. This complex depends on the MPK4 substrate MKS1. Challenge with Pseudomonas syringae or flagellin leads to the activation of MPK4 and phosphorylation of MKS1. Subsequently, complexes with MKS1 and WRKY33 are released from...... MPK4, and WRKY33 targets the promoter of PHYTOALEXIN DEFICIENT3 (PAD3) encoding an enzyme required for the synthesis of antimicrobial camalexin. Hence, wrky33 mutants are impaired in the accumulation of PAD3 mRNA and camalexin production upon infection. That WRKY33 is an effector of MPK4 is further...... supported by the suppression of PAD3 expression in mpk4-wrky33 double mutant backgrounds. Our data establish direct links between MPK4 and innate immunity and provide an example of how a plant MAP kinase can regulate gene expression by releasing transcription factors in the nucleus upon activation....

  3. n-Butyrate inhibits Jun NH(2)-terminal kinase activation and cytokine transcription in mast cells

    International Nuclear Information System (INIS)

    Diakos, Christos; Prieschl, Eva E.; Saeemann, Marcus D.; Boehmig, Georg A.; Csonga, Robert; Sobanov, Yury; Baumruker, Thomas; Zlabinger, Gerhard J.

    2006-01-01

    Mast cells are well known to contribute to type I allergic conditions but only recently have been brought in association with chronic relapsing/remitting autoimmune diseases such as celiac disease and ulcerative colitis. Since the bacterial metabolite n-butyrate is considered to counteract intestinal inflammation we investigated the effects of this short chain fatty acid on mast cell activation. Using RNAse protection assays and reporter gene technology we show that n-butyrate downregulates TNF-α transcription. This correlates with an impaired activation of the Jun NH(2)-terminal kinase (JNK) but not other MAP kinases such as ERK and p38 that are largely unaffected by n-butyrate. As a consequence, we observed a decreased nuclear activity of AP-1 and NF-AT transcription factors. These results indicate that n-butyrate inhibits critical inflammatory mediators in mast cells by relatively selectively targeting the JNK signalling

  4. Physical and functional interactions between ZIP kinase and UbcH5

    International Nuclear Information System (INIS)

    Ohbayashi, Norihiko; Okada, Katsuya; Kawakami, Shiho; Togi, Sumihito; Sato, Noriko; Ikeda, Osamu; Kamitani, Shinya; Muromoto, Ryuta; Sekine, Yuichi; Kawai, Taro; Akira, Shizuo; Matsuda, Tadashi

    2008-01-01

    Zipper-interacting protein kinase (ZIPK) is a widely expressed serine/threonine kinase that has been implicated in cell death and transcriptional regulation, but its mechanism of regulation remains unknown. In our previous study, we showed that leukemia inhibitory factor stimulated threonine-265 phosphorylation of ZIPK, thereby leading to phosphorylation and activation of signal transducer and activator of transcription 3. Here, we identified UbcH5c as a novel ZIPK-binding partner by yeast two-hybrid screening. Importantly, we found that UbcH5c induced ubiquitination of ZIPK. Small-interfering RNA-mediated reduction of endogenous UbcH5 expression decreased ZIPK ubiquitination. Furthermore, coexpression of UbcH5c with ZIPK influenced promyelocytic leukemia protein nuclear body (PML-NB) formation. These results suggest that UbcH5 regulates ZIPK accumulation in PML-NBs by interacting with ZIPK and stimulating its ubiquitination

  5. Depletion of WRN protein causes RACK1 to activate several protein kinase C isoforms

    DEFF Research Database (Denmark)

    Massip, L; Garand, C; Labbé, A

    2010-01-01

    show that a knock down of the WRN protein in normal human fibroblasts induces phosphorylation and activation of several protein kinase C (PKC) enzymes. Using a tandem affinity purification strategy, we found that WRN physically and functionally interacts with receptor for activated C-kinase 1 (RACK1......), a highly conserved anchoring protein involved in various biological processes, such as cell growth and proliferation. RACK1 binds strongly to the RQC domain of WRN and weakly to its acidic repeat region. Purified RACK1 has no impact on the helicase activity of WRN, but selectively inhibits WRN exonuclease...... activity in vitro. Interestingly, knocking down RACK1 increased the cellular frequency of DNA breaks. Depletion of the WRN protein in return caused a fraction of nuclear RACK1 to translocate out of the nucleus to bind and activate PKCdelta and PKCbetaII in the membrane fraction of cells. In contrast...

  6. Nuclear power

    International Nuclear Information System (INIS)

    Abd Khalik Wood

    2005-01-01

    This chapter discussed the following topics related to the nuclear power: nuclear reactions, nuclear reactors and its components - reactor fuel, fuel assembly, moderator, control system, coolants. The topics titled nuclear fuel cycle following subtopics are covered: , mining and milling, tailings, enrichment, fuel fabrication, reactor operations, radioactive waste and fuel reprocessing. Special topic on types of nuclear reactor highlighted the reactors for research, training, production, material testing and quite detail on reactors for electricity generation. Other related topics are also discussed: sustainability of nuclear power, renewable nuclear fuel, human capital, environmental friendly, emission free, impacts on global warming and air pollution, conservation and preservation, and future prospect of nuclear power

  7. Roles of Apicomplexan protein kinases at each life cycle stage.

    Science.gov (United States)

    Kato, Kentaro; Sugi, Tatsuki; Iwanaga, Tatsuya

    2012-06-01

    Inhibitors of cellular protein kinases have been reported to inhibit the development of Apicomplexan parasites, suggesting that the functions of protozoan protein kinases are critical for their life cycle. However, the specific roles of these protein kinases cannot be determined using only these inhibitors without molecular analysis, including gene disruption. In this report, we describe the functions of Apicomplexan protein kinases in each parasite life stage and the potential of pre-existing protein kinase inhibitors as Apicomplexan drugs against, mainly, Plasmodium and Toxoplasma. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Puerarin activates endothelial nitric oxide synthase through estrogen receptor-dependent PI3-kinase and calcium-dependent AMP-activated protein kinase

    International Nuclear Information System (INIS)

    Hwang, Yong Pil; Kim, Hyung Gyun; Hien, Tran Thi; Jeong, Myung Ho; Jeong, Tae Cheon; Jeong, Hye Gwang

    2011-01-01

    The cardioprotective properties of puerarin, a natural product, have been attributed to the endothelial nitric oxide synthase (eNOS)-mediated production of nitric oxide (NO) in EA.hy926 endothelial cells. However, the mechanism by which puerarin activates eNOS remains unclear. In this study, we sought to identify the intracellular pathways underlying eNOS activation by puerarin. Puerarin induced the activating phosphorylation of eNOS on Ser1177 and the production of NO in EA.hy926 cells. Puerarin-induced eNOS phosphorylation required estrogen receptor (ER)-mediated phosphatidylinositol 3-kinase (PI3K)/Akt signaling and was reversed by AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent kinase II (CaMKII) inhibition. Importantly, puerarin inhibited the adhesion of tumor necrosis factor (TNF)-α-stimulated monocytes to endothelial cells and suppressed the TNF-α induced expression of intercellular cell adhesion molecule-1. Puerarin also inhibited the TNF-α-induced nuclear factor-κB activation, which was attenuated by pretreatment with N G -nitro-L-arginine methyl ester, a NOS inhibitor. These results indicate that puerarin stimulates eNOS phosphorylation and NO production via activation of an estrogen receptor-mediated PI3K/Akt- and CaMKII/AMPK-dependent pathway. Puerarin may be useful for the treatment or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease. -- Highlights: ► Puerarin induced the phosphorylation of eNOS and the production of NO. ► Puerarin activated eNOS through ER-dependent PI3-kinase and Ca 2+ -dependent AMPK. ► Puerarin-induced NO was involved in the inhibition of NF-kB activation. ► Puerarin may help for prevention of vascular dysfunction and diabetes.

  9. Puerarin activates endothelial nitric oxide synthase through estrogen receptor-dependent PI3-kinase and calcium-dependent AMP-activated protein kinase

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Pil; Kim, Hyung Gyun [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Hien, Tran Thi [College of Pharmacy, Chosun University, Gwangju (Korea, Republic of); Jeong, Myung Ho [Heart Research Center, Chonnam National University Hospital, Gwangju (Korea, Republic of); Jeong, Tae Cheon, E-mail: taecheon@ynu.ac.kr [College of Pharmacy, Yeungnam University, Gyungsan (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2011-11-15

    The cardioprotective properties of puerarin, a natural product, have been attributed to the endothelial nitric oxide synthase (eNOS)-mediated production of nitric oxide (NO) in EA.hy926 endothelial cells. However, the mechanism by which puerarin activates eNOS remains unclear. In this study, we sought to identify the intracellular pathways underlying eNOS activation by puerarin. Puerarin induced the activating phosphorylation of eNOS on Ser1177 and the production of NO in EA.hy926 cells. Puerarin-induced eNOS phosphorylation required estrogen receptor (ER)-mediated phosphatidylinositol 3-kinase (PI3K)/Akt signaling and was reversed by AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent kinase II (CaMKII) inhibition. Importantly, puerarin inhibited the adhesion of tumor necrosis factor (TNF)-{alpha}-stimulated monocytes to endothelial cells and suppressed the TNF-{alpha} induced expression of intercellular cell adhesion molecule-1. Puerarin also inhibited the TNF-{alpha}-induced nuclear factor-{kappa}B activation, which was attenuated by pretreatment with N{sup G}-nitro-L-arginine methyl ester, a NOS inhibitor. These results indicate that puerarin stimulates eNOS phosphorylation and NO production via activation of an estrogen receptor-mediated PI3K/Akt- and CaMKII/AMPK-dependent pathway. Puerarin may be useful for the treatment or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease. -- Highlights: Black-Right-Pointing-Pointer Puerarin induced the phosphorylation of eNOS and the production of NO. Black-Right-Pointing-Pointer Puerarin activated eNOS through ER-dependent PI3-kinase and Ca{sup 2+}-dependent AMPK. Black-Right-Pointing-Pointer Puerarin-induced NO was involved in the inhibition of NF-kB activation. Black-Right-Pointing-Pointer Puerarin may help for prevention of vascular dysfunction and diabetes.

  10. The kinase activity of the Ser/Thr kinase BUB1 promotes TGF-β signaling.

    Science.gov (United States)

    Nyati, Shyam; Schinske-Sebolt, Katrina; Pitchiaya, Sethuramasundaram; Chekhovskiy, Katerina; Chator, Areeb; Chaudhry, Nauman; Dosch, Joseph; Van Dort, Marcian E; Varambally, Sooryanarayana; Kumar-Sinha, Chandan; Nyati, Mukesh Kumar; Ray, Dipankar; Walter, Nils G; Yu, Hongtao; Ross, Brian Dale; Rehemtulla, Alnawaz

    2015-01-06

    Transforming growth factor-β (TGF-β) signaling regulates cell proliferation and differentiation, which contributes to development and disease. Upon binding TGF-β, the type I receptor (TGFBRI) binds TGFBRII, leading to the activation of the transcription factors SMAD2 and SMAD3. Using an RNA interference screen of the human kinome and a live-cell reporter for TGFBR activity, we identified the kinase BUB1 (budding uninhibited by benzimidazoles-1) as a key mediator of TGF-β signaling. BUB1 interacted with TGFBRI in the presence of TGF-β and promoted the heterodimerization of TGFBRI and TGFBRII. Additionally, BUB1 interacted with TGFBRII, suggesting the formation of a ternary complex. Knocking down BUB1 prevented the recruitment of SMAD3 to the receptor complex, the phosphorylation of SMAD2 and SMAD3 and their interaction with SMAD4, SMAD-dependent transcription, and TGF-β-mediated changes in cellular phenotype including epithelial-mesenchymal transition (EMT), migration, and invasion. Knockdown of BUB1 also impaired noncanonical TGF-β signaling mediated by the kinases AKT and p38 MAPK (mitogen-activated protein kinase). The ability of BUB1 to promote TGF-β signaling depended on the kinase activity of BUB1. A small-molecule inhibitor of the kinase activity of BUB1 (2OH-BNPP1) and a kinase-deficient mutant of BUB1 suppressed TGF-β signaling and formation of the ternary complex in various normal and cancer cell lines. 2OH-BNPP1 administration to mice bearing lung carcinoma xenografts reduced the amount of phosphorylated SMAD2 in tumor tissue. These findings indicated that BUB1 functions as a kinase in the TGF-β pathway in a role beyond its established function in cell cycle regulation and chromosome cohesion. Copyright © 2015, American Association for the Advancement of Science.

  11. 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.

  12. A Global Protein Kinase and Phosphatase Interaction Network in Yeast

    Science.gov (United States)

    Breitkreutz, Ashton; Choi, Hyungwon; Sharom, Jeffrey R.; Boucher, Lorrie; Neduva, Victor; Larsen, Brett; Lin, Zhen-Yuan; Breitkreutz, Bobby-Joe; Stark, Chris; Liu, Guomin; Ahn, Jessica; Dewar-Darch, Danielle; Reguly, Teresa; Tang, Xiaojing; Almeida, Ricardo; Qin, Zhaohui Steve; Pawson, Tony; Gingras, Anne-Claude; Nesvizhskii, Alexey I.; Tyers, Mike

    2011-01-01

    The interactions of protein kinases and phosphatases with their regulatory subunits and substrates underpin cellular regulation. We identified a kinase and phosphatase interaction (KPI) network of 1844 interactions in budding yeast by mass spectrometric analysis of protein complexes. The KPI network contained many dense local regions of interactions that suggested new functions. Notably, the cell cycle phosphatase Cdc14 associated with multiple kinases that revealed roles for Cdc14 in mitogen-activated protein kinase signaling, the DNA damage response, and metabolism, whereas interactions of the target of rapamycin complex 1 (TORC1) uncovered new effector kinases in nitrogen and carbon metabolism. An extensive backbone of kinase-kinase interactions cross-connects the proteome and may serve to coordinate diverse cellular responses. PMID:20489023

  13. Molecular and biochemical analysis of symbiotic plant receptor kinase complexes

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Douglas R; Riely, Brendan K

    2010-09-01

    DE-FG02-01ER15200 was a 36-month project, initiated on Sept 1, 2005 and extended with a one-year no cost extension to August 31, 2009. During the project period we published seven manuscripts (2 in review). Including the prior project period (2002-2005) we published 12 manuscripts in journals that include Science, PNAS, The Plant Cell, Plant Journal, Plant Physiology, and MPMI. The primary focus of this work was to further elucidate the function of the Nod factor signaling pathway that is involved in initiation of the legume-rhizobium symbiosis and in particular to explore the relationship between receptor kinase-like proteins and downstream effectors of symbiotic development. During the project period we have map-base cloned two additional players in symbiotic development, including an ERF transcription factor and an ethylene pathway gene (EIN2) that negatively regulates symbiotic signaling; we have also further characterized the subcellular distribution and function of a nuclear-localized symbiosis-specific ion channel, DMI1. The major outcome of the work has been the development of systems for exploring and validating protein-protein interactions that connect symbiotic receptor-like proteins to downstream responses. In this regard, we have developed both homologous (i.e., in planta) and heterologous (i.e., in yeast) systems to test protein interactions. Using yeast 2-hybrid screens we isolated the only known interactor of the nuclear-localized calcium-responsive kinase DMI3. We have also used yeast 2-hybrid methodology to identify interactions between symbiotic signaling proteins and certain RopGTPase/RopGEF proteins that regulate root hair polar growth. More important to the long-term goals of our work, we have established a TAP tagging system that identifies in planta interactions based on co-immuno precipitation and mass spectrometry. The validity of this approach has been shown using known interactors that either co-iummnoprecipate (i.e., remorin) or co

  14. Protein phosphatases active on acetyl-CoA carboxylase phosphorylated by casein kinase I, casein kinase II and the cAMP-dependent protein kinase

    International Nuclear Information System (INIS)

    Witters, L.A.; Bacon, G.W.

    1985-01-01

    The protein phosphatases in rat liver cytosol, active on rat liver acetyl-CoA carboxylase (ACC) phosphorylated by casein kinase I, casein kinase II and the cAMP-dependent protein kinase, have been partially purified by anion-exchange and gel filtration chromatography. The major phosphatase activities against all three substrates copurify through fractionation and appear to be identical to protein phosphatases 2A1 and 2A2. No unique protein phosphatase active on 32 P-ACC phosphorylated by the casein kinases was identified

  15. Src family kinases in chronic kidney disease.

    Science.gov (United States)

    Wang, Jun; Zhuang, Shougang

    2017-09-01

    Src family kinases (SFKs) belong to nonreceptor protein tyrosine kinases and have been implicated in the regulation of numerous cellular processes, including cell proliferation, differentiation, migration and invasion, and angiogenesis. The role and mechanisms of SFKs in tumorgenesis have been extensively investigated, and some SFK inhibitors are currently under clinical trials for tumor treatment. Recent studies have also demonstrated the importance of SFKs in regulating the development of various fibrosis-related chronic diseases (e.g., idiopathic pulmonary fibrosis, liver fibrosis, renal fibrosis, and systemic sclerosis). In this article, we summarize the roles of SFKs in various chronic kidney diseases, including glomerulonephritis, diabetic nephropathy, human immunodeficiency virus-associated nephropathy, autosomal dominant form of polycystic kidney disease, and obesity-associated kidney disease, and discuss the mechanisms involved. Copyright © 2017 the American Physiological Society.

  16. 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

  17. Phosphatidylinositol 4-kinases: Function, structure, and inhibition

    International Nuclear Information System (INIS)

    Boura, Evzen; Nencka, Radim

    2015-01-01

    The phosphatidylinositol 4-kinases (PI4Ks) synthesize phosphatidylinositol 4-phosphate (PI4P), a key member of the phosphoinositide family. PI4P defines the membranes of Golgi and trans-Golgi network (TGN) and regulates trafficking to and from the Golgi. Humans have two type II PI4Ks (α and β) and two type III enzymes (α and β). Recently, the crystal structures were solved for both type II and type III kinase revealing atomic details of their function. Importantly, the type III PI4Ks are hijacked by +RNA viruses to create so-called membranous web, an extensively phosphorylated and modified membrane system dedicated to their replication. Therefore, selective and potent inhibitors of PI4Ks have been developed as potential antiviral agents. Here we focus on the structure and function of PI4Ks and their potential in human medicine

  18. Phosphatidylinositol 4-kinases: Function, structure, and inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Boura, Evzen, E-mail: boura@uochb.cas.cz; Nencka, Radim, E-mail: nencka@uochb.cas.cz

    2015-10-01

    The phosphatidylinositol 4-kinases (PI4Ks) synthesize phosphatidylinositol 4-phosphate (PI4P), a key member of the phosphoinositide family. PI4P defines the membranes of Golgi and trans-Golgi network (TGN) and regulates trafficking to and from the Golgi. Humans have two type II PI4Ks (α and β) and two type III enzymes (α and β). Recently, the crystal structures were solved for both type II and type III kinase revealing atomic details of their function. Importantly, the type III PI4Ks are hijacked by +RNA viruses to create so-called membranous web, an extensively phosphorylated and modified membrane system dedicated to their replication. Therefore, selective and potent inhibitors of PI4Ks have been developed as potential antiviral agents. Here we focus on the structure and function of PI4Ks and their potential in human medicine.

  19. 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.

  20. Aurora kinase inhibitors: Progress towards the clinic

    Czech Academy of Sciences Publication Activity Database

    Kollareddy, M.; Zheleva, D.; Dzubak, P.; Brahmkshatriya, Pathik; Lepšík, Martin; Hajduch, M.

    2012-01-01

    Roč. 30, č. 6 (2012), s. 2411-2432 ISSN 0167-6997 Grant - others:GA ČR(CZ) GA301/08/1649; GA ČR(CZ) GD303/09/H048 Program:GA; GD Institutional research plan: CEZ:AV0Z40550506 Keywords : Aurora kinases * cancer * inhibitors Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.498, year: 2012

  1. MAP kinases in inflammatory bowel disease

    DEFF Research Database (Denmark)

    Coskun, Mehmet; Olsen, Jørgen; Seidelin, Jakob Benedict

    2011-01-01

    The mammalian family of mitogen-activated protein kinases (MAPKs) is activated by diverse extracellular and intracellular stimuli, and thereby they play an essential role in connecting cell-surface receptors to changes in transcriptional programs. The MAPK signaling pathways regulate a wide range...... these signaling pathways have been exploited for the development of therapeutics and discuss the current knowledge of potential MAPK inhibitors and their anti-inflammatory effects in clinical trials related to IBD....

  2. Phosphatidylinositol 4-kinases: Function, structure, and inhibition

    Czech Academy of Sciences Publication Activity Database

    Bouřa, Evžen; Nencka, Radim

    2015-01-01

    Roč. 337, č. 2 (2015), s. 136-145 ISSN 0014-4827 R&D Projects: GA ČR GJ15-21030Y; GA MŠk LO1302; GA ČR GA15-09310S EU Projects: European Commission(XE) 333916 - STARPI4K Institutional support: RVO:61388963 Keywords : phosphatidylinositol 4-kinase * inhibitor * crystal structure * virus Subject RIV: CC - Organic Chemistry Impact factor: 3.378, year: 2015

  3. Nuclear science

    International Nuclear Information System (INIS)

    1989-01-01

    This fact sheet answers specific questions about the Department of Energy's possible acquisition and conversion of a partially completed commercial nuclear power plant to a nuclear materials production facility. The nuclear power plant is the Washington Nuclear Plant number sign 1 owned by the Washington Public Power Supply System and is located on DOE's Hanford Reservation near Richland, Washington

  4. Nuclear science

    International Nuclear Information System (INIS)

    1989-04-01

    This report answers questions about the Department of Energy's possible acquisition and conversion of a partially completed commercial nuclear power plant to a nuclear materials production facility. The nuclear power plant is the Washington Nuclear Plant No.1 owned by the Washington Public Power Supply System and is located on DOE's Hanford Reservation near Richland, Washington

  5. Nuclear medicine

    International Nuclear Information System (INIS)

    Lentle, B.C.

    1986-01-01

    Several growth areas for nuclear medicine were defined. Among them were: cardiac nuclear medicine, neuro-psychiatric nuclear medicine, and cancer diagnosis through direct tumor imaging. A powerful new tool, Positron Emission Tomography (PET) was lauded as the impetus for new developments in nuclear medicine. The political environment (funding, degree of autonomy) was discussed, as were the economic and scientific environments

  6. Nuclear option

    Energy Technology Data Exchange (ETDEWEB)

    Kemm, K R

    1978-05-01

    The global outlook is that nuclear reactors are here to stay and South Africa has already entered the nuclear power stakes. This article discusses the rocketing oil prices, and the alternatives that can be used in power generation, the good safety record of the nuclear industry and the effect that South Africa's first nuclear power station should have on the environment.

  7. Nuclear resisters

    International Nuclear Information System (INIS)

    1981-01-01

    The booklet contains six papers by different authors, under the headings: dangers along the nuclear fuel cycle; the nuclear profiteers; the nuclear state is a police state; a non-disposable future (renewable energy sources, energy conservation); nuclear weapons - out of control; man made madness. (U.K.)

  8. ERK5 and cell proliferation: nuclear localization is what matters

    Directory of Open Access Journals (Sweden)

    Nestor Gomez

    2016-09-01

    Full Text Available ERK5, the last MAP kinase family member discovered, is activated by the upstream kinase MEK5 in response to growth factors and stress stimulation. MEK5-ERK5 pathway has been associated to different cellular processes, playing a crucial role in cell proliferation in normal and cancer cells by mechanisms that are both dependent and independent of its kinase activity. Thus, nuclear ERK5 activates transcription factors by either direct phosphorylation or acting as co-activator thanks to a unique transcriptional activation TAD domain located at its C-terminal tail. Consequently, ERK5 has been proposed as an interesting target to tackle different cancers, and either inhibitors of ERK5 activity or silencing the protein have shown antiproliferative activity in cancer cells and to block tumour growth in animal models. Here, we review the different mechanisms involved in ERK5 nuclear translocation and their consequences. Inactive ERK5 resides in the cytosol, forming a complex with Hsp90-Cdc37 superchaperone. In a canonical mechanism, MEK5-dependent activation results in ERK5 C-terminal autophosphorylation, Hsp90 dissociation and nuclear translocation. This mechanism integrates signals such as growth factors and stresses that activate the MEK5-ERK5 pathway. Importantly, two other mechanisms, MEK5-independent, have been recently described. These mechanisms allow nuclear shuttling of kinase-inactive forms of ERK5. Although lacking kinase activity, these forms activate transcription by interacting with transcription factors through the TAD domain. Both mechanisms also require Hsp90 dissociation previous to nuclear translocation. One mechanism involves phosphorylation of the C-terminal tail of ERK5 by kinases that are activated during mitosis, such as Cyclin-dependent kinase-1. The second mechanism involves overexpression of chaperone Cdc37, an oncogene that is overexpressed in cancers such as prostate adenocarcinoma, where it collaborates with ERK5 to promote

  9. Nuclear links

    International Nuclear Information System (INIS)

    1981-01-01

    The subject is dealt with in sections: introduction; energy and the third world; world energy consumption 1978; oil -the energy dilemma; nuclear chains - introduction; uranium; Namibia; enrichment and reprocessing; countries with enrichment and reprocessing facilities; waste; conclusion; why take the nuclear option; third world countries with nuclear reactors; the arms connection; government spending and human resources 1977 (by countries); nuclear power - the final solution; the fascists; world bank; campaigns; community action in Plogoff; Australian labour movement; NUM against nuclear power; Scottish campaign; students against nuclear energy; anti-nuclear campaign; partizans; 3W1 disarmament and development; campaign ATOM; CANUC; 3W1; SANE. (U.K.)

  10. CIKS, a connection to Ikappa B kinase and stress-activated protein kinase.

    Science.gov (United States)

    Leonardi, A; Chariot, A; Claudio, E; Cunningham, K; Siebenlist, U

    2000-09-12

    Pathogens, inflammatory signals, and stress cause acute transcriptional responses in cells. The induced expression of genes in response to these signals invariably involves transcription factors of the NF-kappaB and AP-1/ATF families. Activation of NF-kappaB factors is thought to be mediated primarily via IkappaB kinases (IKK), whereas that of AP-1/ATF can be mediated by stress-activated protein kinases (SAPKs; also named Jun kinases or JNKs). IKKalpha and IKKbeta are two catalytic subunits of a core IKK complex that also contains the regulatory subunit NEMO (NF-kappaB essential modulator)/IKKgamma. The latter protein is essential for activation of the IKKs, but its mechanism of action is not known. Here we describe the molecular cloning of CIKS (connection to IKK and SAPK/JNK), a previously unknown protein that directly interacts with NEMO/IKKgamma in cells. When ectopically expressed, CIKS stimulates IKK and SAPK/JNK kinases and it transactivates an NF-kappaB-dependent reporter. Activation of NF-kappaB is prevented in the presence of kinase-deficient, interfering mutants of the IKKs. CIKS may help to connect upstream signaling events to IKK and SAPK/JNK modules. CIKS could coordinate the activation of two stress-induced signaling pathways, functions reminiscent of those noted for tumor necrosis factor receptor-associated factor adaptor proteins.

  11. CIKS, a connection to IκB kinase and stress-activated protein kinase

    Science.gov (United States)

    Leonardi, Antonio; Chariot, Alain; Claudio, Estefania; Cunningham, Kirk; Siebenlist, Ulrich

    2000-01-01

    Pathogens, inflammatory signals, and stress cause acute transcriptional responses in cells. The induced expression of genes in response to these signals invariably involves transcription factors of the NF-κB and AP-1/ATF families. Activation of NF-κB factors is thought to be mediated primarily via IκB kinases (IKK), whereas that of AP-1/ATF can be mediated by stress-activated protein kinases (SAPKs; also named Jun kinases or JNKs). IKKα and IKKβ are two catalytic subunits of a core IKK complex that also contains the regulatory subunit NEMO (NF-κB essential modulator)/IKKγ. The latter protein is essential for activation of the IKKs, but its mechanism of action is not known. Here we describe the molecular cloning of CIKS (connection to IKK and SAPK/JNK), a previously unknown protein that directly interacts with NEMO/IKKγ in cells. When ectopically expressed, CIKS stimulates IKK and SAPK/JNK kinases and it transactivates an NF-κB-dependent reporter. Activation of NF-κB is prevented in the presence of kinase-deficient, interfering mutants of the IKKs. CIKS may help to connect upstream signaling events to IKK and SAPK/JNK modules. CIKS could coordinate the activation of two stress-induced signaling pathways, functions reminiscent of those noted for tumor necrosis factor receptor-associated factor adaptor proteins. PMID:10962033

  12. The NIMA Kinase Is Required To Execute Stage-Specific Mitotic Functions after Initiation of Mitosis

    Science.gov (United States)

    Govindaraghavan, Meera; Lad, Alisha A.

    2014-01-01

    The G2-M transition in Aspergillus nidulans requires the NIMA kinase, the founding member of the Nek kinase family. Inactivation of NIMA results in a late G2 arrest, while overexpression of NIMA is sufficient to promote mitotic events independently of cell cycle phase. Endogenously tagged NIMA-GFP has dynamic mitotic localizations appearing first at the spindle pole body and then at nuclear pore complexes before transitioning to within nuclei and the mitotic spindle and back at the spindle pole bodies at mitotic exit, suggesting that it functions sequentially at these locations. Since NIMA is indispensable for mitotic entry, it has been difficult to determine the requirement of NIMA for subaspects of mitosis. We show here that when NIMA is partially inactivated, although mitosis can be initiated, a proportion of cells fail to successfully generate two daughter nuclei. We further define the mitotic defects to show that normal NIMA function is required for the formation of a bipolar spindle, nuclear pore complex disassembly, completion of chromatin segregation, and the normal structural rearrangements of the nuclear envelope required to generate two nuclei from one. In the remaining population of cells that enter mitosis with inadequate NIMA, two daughter nuclei are generated in a manner dependent on the spindle assembly checkpoint, indicating highly penetrant defects in mitotic progression without sufficient NIMA activity. This study shows that NIMA is required not only for mitotic entry but also sequentially for successful completion of stage-specific mitotic events. PMID:24186954

  13. Nuclear translocation and retention of growth hormone

    DEFF Research Database (Denmark)

    Mertani, Hichem C; Raccurt, Mireille; Abbate, Aude

    2003-01-01

    We have previously demonstrated that GH is subject to rapid receptor-dependent nuclear translocation. Here, we examine the importance of ligand activation of the GH-receptor (GHR)-associated Janus kinase (JAK) 2 and receptor dimerization for hormone internalization and nuclear translocation by use...... of cells stably transfected with cDNA for the GHR. Staurosporine and herbimycin A treatment of cells did not affect the ability of GH to internalize but resulted in increased nuclear accumulation of hormone. Similarly, receptor mutations, which prevent the association and activation of JAK2, did not affect...... the ability of the hormone to internalize or translocate to the nucleus but resulted in increased nuclear accumulation of GH. These results were observed both by nuclear isolation and confocal laser scanning microscopy. Staurosporine treatment of cells in which human GH (hGH) was targeted to the cytoplasm...

  14. The Pim kinases: new targets for drug development.

    Science.gov (United States)

    Swords, Ronan; Kelly, Kevin; Carew, Jennifer; Nawrocki, Stefan; Mahalingam, Devalingam; Sarantopoulos, John; Bearss, David; Giles, Francis

    2011-12-01

    The three Pim kinases are a small family of serine/threonine kinases regulating several signaling pathways that are fundamental to cancer development and progression. They were first recognized as pro-viral integration sites for the Moloney Murine Leukemia virus. Unlike other kinases, they possess a hinge region which creates a unique binding pocket for ATP. Absence of a regulatory domain means that these proteins are constitutively active once transcribed. Pim kinases are critical downstream effectors of the ABL (ableson), JAK2 (janus kinase 2), and Flt-3 (FMS related tyrosine kinase 1) oncogenes and are required by them to drive tumorigenesis. Recent investigations have established that the Pim kinases function as effective inhibitors of apoptosis and when overexpressed, produce resistance to the mTOR (mammalian target of rapamycin) inhibitor, rapamycin . Overexpression of the PIM kinases has been reported in several hematological and solid tumors (PIM 1), myeloma, lymphoma, leukemia (PIM 2) and adenocarcinomas (PIM 3). As such, the Pim kinases are a very attractive target for pharmacological inhibition in cancer therapy. Novel small molecule inhibitors of the human Pim kinases have been designed and are currently undergoing preclinical evaluation.

  15. PAK4 crystal structures suggest unusual kinase conformational movements.

    Science.gov (United States)

    Zhang, Eric Y; Ha, Byung Hak; Boggon, Titus J

    2018-02-01

    In order for protein kinases to exchange nucleotide they must open and close their catalytic cleft. These motions are associated with rotations of the N-lobe, predominantly around the 'hinge region'. We conducted an analysis of 28 crystal structures of the serine-threonine kinase, p21-activated kinase 4 (PAK4), including three newly determined structures in complex with staurosporine, FRAX486, and fasudil (HA-1077). We find an unusual motion between the N-lobe and C-lobe of PAK4 that manifests as a partial unwinding of helix αC. Principal component analysis of the crystal structures rationalizes these movements into three major states, and analysis of the kinase hydrophobic spines indicates concerted movements that create an accessible back pocket cavity. The conformational changes that we observe for PAK4 differ from previous descriptions of kinase motions, and although we observe these differences in crystal structures there is the possibility that the movements observed may suggest a diversity of kinase conformational changes associated with regulation. Protein kinases are key signaling proteins, and are important drug targets, therefore understanding their regulation is important for both basic research and clinical points of view. In this study, we observe unusual conformational 'hinging' for protein kinases. Hinging, the opening and closing of the kinase sub-domains to allow nucleotide binding and release, is critical for proper kinase regulation and for targeted drug discovery. We determine new crystal structures of PAK4, an important Rho-effector kinase, and conduct analyses of these and previously determined structures. We find that PAK4 crystal structures can be classified into specific conformational groups, and that these groups are associated with previously unobserved hinging motions and an unusual conformation for the kinase hydrophobic core. Our findings therefore indicate that there may be a diversity of kinase hinging motions, and that these may

  16. A framework for classification of prokaryotic protein kinases.

    Directory of Open Access Journals (Sweden)

    Nidhi Tyagi

    Full Text Available BACKGROUND: Overwhelming majority of the Serine/Threonine protein kinases identified by gleaning archaeal and eubacterial genomes could not be classified into any of the well known Hanks and Hunter subfamilies of protein kinases. This is owing to the development of Hanks and Hunter classification scheme based on eukaryotic protein kinases which are highly divergent from their prokaryotic homologues. A large dataset of prokaryotic Serine/Threonine protein kinases recognized from genomes of prokaryotes have been used to develop a classification framework for prokaryotic Ser/Thr protein kinases. METHODOLOGY/PRINCIPAL FINDINGS: We have used traditional sequence alignment and phylogenetic approaches and clustered the prokaryotic kinases which represent 72 subfamilies with at least 4 members in each. Such a clustering enables classification of prokaryotic Ser/Thr kinases and it can be used as a framework to classify newly identified prokaryotic Ser/Thr kinases. After series of searches in a comprehensive sequence database we recognized that 38 subfamilies of prokaryotic protein kinases are associated to a specific taxonomic level. For example 4, 6 and 3 subfamilies have been identified that are currently specific to phylum proteobacteria, cyanobacteria and actinobacteria respectively. Similarly subfamilies which are specific to an order, sub-order, class, family and genus have also been identified. In addition to these, we also identify organism-diverse subfamilies. Members of these clusters are from organisms of different taxonomic levels, such as archaea, bacteria, eukaryotes and viruses. CONCLUSION/SIGNIFICANCE: Interestingly, occurrence of several taxonomic level specific subfamilies of prokaryotic kinases contrasts with classification of eukaryotic protein kinases in which most of the popular subfamilies of eukaryotic protein kinases occur diversely in several eukaryotes. Many prokaryotic Ser/Thr kinases exhibit a wide variety of modular

  17. Partial purification and characterization of a wortmannin-sensitive and insulin-stimulated protein kinase that activates heart 6-phosphofructo-2-kinase.

    OpenAIRE

    Deprez, J; Bertrand, L; Alessi, D R; Krause, U; Hue, L; Rider, M H

    2000-01-01

    A wortmannin-sensitive and insulin-stimulated protein kinase (WISK), which phosphorylates and activates cardiac 6-phosphofructo-2-kinase (PFK-2), was partially purified from perfused rat hearts. Immunoblotting showed that WISK was devoid of protein kinase B (PKB), serum- and glucocorticoid-regulated protein kinase and protein kinase Czeta (PKCzeta). Comparison of the inhibition of WISK, PKCalpha and PKCzeta by different protein kinase inhibitors suggested that WISK was not a member of the PKC...

  18. Diacylglycerol kinase ζ regulates RhoA activation via a kinase-independent scaffolding mechanism

    DEFF Research Database (Denmark)

    Ard, Ryan; Mulatz, Kirk; Abramovici, Hanan

    2012-01-01

    , but the underlying mechanisms are unclear. Diacylglycerol kinase ζ (DGKζ), which phosphorylates diacylglycerol to yield phosphatidic acid, selectively dissociates Rac1 by stimulating PAK1-mediated phosphorylation of RhoGDI on Ser-101/174. Similarly, phosphorylation of RhoGDI on Ser-34 by protein kinase Cα (PKCα......GDI and was required for efficient interaction of PKCα and RhoA. DGKζ-null fibroblasts had condensed F-actin bundles and altered focal adhesion distribution, indicative of aberrant RhoA signaling. Two targets of the RhoA effector ROCK showed reduced phosphorylation in DGKζ-null cells. Collectively our findings suggest...

  19. Deoxycytidine and Deoxythymidine Treatment for Thymidine Kinase 2 Deficiency.

    Science.gov (United States)

    Lopez-Gomez, Carlos; Levy, Rebecca J; Sanchez-Quintero, Maria J; Juanola-Falgarona, Martí; Barca, Emanuele; Garcia-Diaz, Beatriz; Tadesse, Saba; Garone, Caterina; Hirano, Michio

    2017-05-01

    Thymidine kinase 2 (TK2), a critical enzyme in the mitochondrial pyrimidine salvage pathway, is essential for mitochondrial DNA (mtDNA) maintenance. Mutations in the nuclear gene, TK2, cause TK2 deficiency, which manifests predominantly in children as myopathy with mtDNA depletion. Molecular bypass therapy with the TK2 products, deoxycytidine monophosphate (dCMP) and deoxythymidine monophosphate (dTMP), prolongs the life span of Tk2-deficient (Tk2 -/- ) mice by 2- to 3-fold. Because we observed rapid catabolism of the deoxynucleoside monophosphates to deoxythymidine (dT) and deoxycytidine (dC), we hypothesized that: (1) deoxynucleosides might be the major active agents and (2) inhibition of deoxycytidine deamination might enhance dTMP+dCMP therapy. To test these hypotheses, we assessed two therapies in Tk2 -/- mice: (1) dT+dC and (2) coadministration of the deaminase inhibitor, tetrahydrouridine (THU), with dTMP+dCMP. We observed that dC+dT delayed disease onset, prolonged life span of Tk2-deficient mice and restored mtDNA copy number as well as respiratory chain enzyme activities and levels. In contrast, dCMP+dTMP+THU therapy decreased life span of Tk2 -/- animals compared to dCMP+dTMP. Our studies demonstrate that deoxynucleoside substrate enhancement is a novel therapy, which may ameliorate TK2 deficiency in patients. Ann Neurol 2017;81:641-652. © 2017 American Neurological Association.

  20. Characterization of the Zebrafish Homolog of Zipper Interacting Protein Kinase

    Directory of Open Access Journals (Sweden)

    Brandon W. Carr

    2014-06-01

    Full Text Available Zipper-interacting protein kinase (ZIPK is a conserved vertebrate-specific regulator of actomyosin contractility in smooth muscle and non-muscle cells. Murine ZIPK has undergone an unusual divergence in sequence and regulation compared to other ZIPK orthologs. In humans, subcellular localization is controlled by phosphorylation of threonines 299 and 300. In contrast, ZIPK subcellular localization in mouse and rat is controlled by interaction with PAR-4. We carried out a comparative biochemical characterization of the regulation of the zebrafish ortholog of ZIPK. Like the human orthologs zebrafish ZIPK undergoes nucleocytoplasmic-shuttling and is abundant in the cytoplasm, unlike the primarily nuclear rat ZIPK. Rat ZIPK, but not human or zebrafish ZIPK, interacts with zebrafish PAR-4. Mutation of the conserved residues required for activation of the mammalian orthologs abrogated activity of the zebrafish ZIPK. In contrast to the human ortholog, mutation of threonine 299 and 300 in the zebrafish ZIPK has no effect on the activity or subcellular localization. Thus, we found that zebrafish ZIPK functions in a manner most similar to the human ZIPK and quite distinct from murine orthologs, yet the regulation of subcellular localization is not conserved.

  1. Nucleocytoplasmic shuttling of STK16 (PKL12), a Golgi-resident serine/threonine kinase involved in VEGF expression regulation

    International Nuclear Information System (INIS)

    Guinea, Barbara; Ligos, Jose Manuel; Lain de Lera, Teresa; Martin-Caballero, Juan; Flores, Juana; Gonzalez de la Pena, Manuel; Garcia-Castro, Javier; Bernad, Antonio

    2006-01-01

    PKL12/STK16 protein is the first identified mammalian member of a ser/thr kinase subfamily that is conserved across several kingdoms, with a broad expression pattern in murine tissues and cell types. Endogenous STK16 subcellular localization was evaluated by indirect immunofluorescence in NIH/3T3 and NRK cells, demonstrating a Golgi-associated pattern that appears to be independent of signals provided by integrin pathways. When cells were treated with brefeldin A (BFA) or nocodazole, drugs that promote Golgi disorganization, we observed STK16 translocation to the nuclear compartment. Constitutive overexpression of this protein by retroviral vectors also promotes accumulation of STK16 in the nuclear compartment, as shown by subfractionation studies. A kinase-dead STK16 mutant (E202A) was used to demonstrate that both the Golgi association and the nuclear translocation capabilities seem to be independent of the STK16 kinase activity. In addition, we show that STK16 overexpression in several cell lines enhances their capacity to produce and secrete VEGF. To confirm these data in vivo, we injected tumor cells overexpressing STK16 into immunodeficient BALBc/SCID mice. HT1080-derived tumors overexpressing STK16 showed increased volume and number of blood vessels compared to controls. Altogether, these data concur with previous reports suggesting a potential role for STK16 as a transcriptional co-activator

  2. Nuclear Power

    International Nuclear Information System (INIS)

    Douglas-Hamilton, J.; Home Robertson, J.; Beith, A.J.

    1987-01-01

    In this debate the Government's policy on nuclear power is discussed. Government policy is that nuclear power is the safest and cleanest way of generating electricity and is cheap. Other political parties who do not endorse a nuclear energy policy are considered not to be acting in the people's best interests. The debate ranged over the risks from nuclear power, the UK safety record, safety regulations, and the environmental effects of nuclear power. The Torness nuclear power plant was mentioned specifically. The energy policy of the opposition parties is strongly criticised. The debate lasted just over an hour and is reported verbatim. (UK)

  3. The secret life of kinases: functions beyond catalysis.

    LENUS (Irish Health Repository)

    Rauch, Jens

    2011-10-28

    Abstract Protein phosphorylation participates in the regulation of all fundamental biological processes, and protein kinases have been intensively studied. However, while the focus was on catalytic activities, accumulating evidence suggests that non-catalytic properties of protein kinases are essential, and in some cases even sufficient for their functions. These non-catalytic functions include the scaffolding of protein complexes, the competition for protein interactions, allosteric effects on other enzymes, subcellular targeting, and DNA binding. This rich repertoire often is used to coordinate phosphorylation events and enhance the specificity of substrate phosphorylation, but also can adopt functions that do not rely on kinase activity. Here, we discuss such kinase independent functions of protein and lipid kinases focussing on kinases that play a role in the regulation of cell proliferation, differentiation, apoptosis, and motility.

  4. Interacting factors and cellular localization of SR protein-specific kinase Dsk1

    International Nuclear Information System (INIS)

    Tang, Zhaohua; Luca, Maria; Taggart-Murphy, Laura; Portillio, Jessica; Chang, Cathey; Guven, Ayse; Lin, Ren-Jang; Murray, Johanne; Carr, Antony

    2012-01-01

    Schizosaccharomyces pombe Dsk1 is an SR protein-specific kinase (SRPK), whose homologs have been identified in every eukaryotic organism examined. Although discovered as a mitotic regulator with protein kinase activity toward SR splicing factors, it remains largely unknown about what and how Dsk1 contributes to cell cycle and pre-mRNA splicing. In this study, we investigated the Dsk1 function by determining interacting factors and cellular localization of the kinase. Consistent with its reported functions, we found that pre-mRNA processing and cell cycle factors are prominent among the proteins co-purified with Dsk1. The identification of these factors led us to find Rsd1 as a novel Dsk1 substrate, as well as the involvement of Dsk1 in cellular distribution of poly(A) + RNA. In agreement with its role in nuclear events, we also found that Dsk1 is mainly localized in the nucleus during G 2 phase and at mitosis. Furthermore, we revealed the oscillation of Dsk1 protein in a cell cycle-dependent manner. This paper marks the first comprehensive analysis of in vivo Dsk1-associated proteins in fission yeast. Our results reflect the conserved role of SRPK family in eukaryotic organisms, and provide information about how Dsk1 functions in pre-mRNA processing and cell-division cycle.

  5. Biglycan- and Sphingosine Kinase-1 Signaling Crosstalk Regulates the Synthesis of Macrophage Chemoattractants

    Directory of Open Access Journals (Sweden)

    Louise Tzung-Harn Hsieh

    2017-03-01

    Full Text Available In its soluble form, the extracellular matrix proteoglycan biglycan triggers the synthesis of the macrophage chemoattractants, chemokine (C-C motif ligand CCL2 and CCL5 through selective utilization of Toll-like receptors (TLRs and their adaptor molecules. However, the respective downstream signaling events resulting in biglycan-induced CCL2 and CCL5 production have not yet been defined. Here, we show that biglycan stimulates the production and activation of sphingosine kinase 1 (SphK1 in a TLR4- and Toll/interleukin (IL-1R domain-containing adaptor inducing interferon (IFN-β (TRIF-dependent manner in murine primary macrophages. We provide genetic and pharmacological proof that SphK1 is a crucial downstream mediator of biglycan-triggered CCL2 and CCL5 mRNA and protein expression. This is selectively driven by biglycan/SphK1-dependent phosphorylation of the nuclear factor NF-κB p65 subunit, extracellular signal-regulated kinase (Erk1/2 and p38 mitogen-activated protein kinases. Importantly, in vivo overexpression of soluble biglycan causes Sphk1-dependent enhancement of renal CCL2 and CCL5 and macrophage recruitment into the kidney. Our findings describe the crosstalk between biglycan- and SphK1-driven extracellular matrix- and lipid-signaling. Thus, SphK1 may represent a new target for therapeutic intervention in biglycan-evoked inflammatory conditions.

  6. Characterization and functional analyses of the human G protein-coupled receptor kinase 4 gene promoter.

    Science.gov (United States)

    Hasenkamp, Sandra; Telgmann, Ralph; Staessen, Jan A; Hagedorn, Claudia; Dördelmann, Corinna; Bek, Martin; Brand-Herrmann, Stefan-Martin; Brand, Eva

    2008-10-01

    The G protein-coupled receptor kinase 4 is involved in renal sodium handling and blood pressure regulation. Missense variants have already been tested functionally and are associated with hypertension, but no data on promoter analyses are yet available. We scanned 94 hypertensive white subjects for genetic variation and performed promoter reporter gene analyses in HEK293T, COS7, and SaOs-2 cells. Transient transfections with various full lengths and wild-type deletion constructs revealed that 1851 bp of the flanking region and 275 bp of the 5'-untranslated region were sufficient for transcriptional activities and composed a powerful cis-active element in the distal 293 bp. The -1702T and +2T alleles resulted in drastic general reductions of promoter function, whereas an activity increasing effect of +268C was cell type specific. Electrophoretic mobility-shift assay, supershift, and cotransfection analyses of transcription factor binding sites predicted in silico (Alibaba2.1/Transfac7) resulted in allele-specific binding patterns of nuclear proteins and identified the participation of CCAAT/enhancer-binding protein transcription factor family members. The G protein-coupled receptor kinase 4 core promoter resides in the first 1851 bp upstream of its transcription start site. The 4 identified genetic variants within this region exert allele-specific impact on both cell type- and stimulation-dependent transcription and may affect the expression balance of renal G protein-coupled receptor kinase 4.

  7. Interacting factors and cellular localization of SR protein-specific kinase Dsk1

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zhaohua, E-mail: ztang@jsd.claremont.edu [W.M. Keck Science Center, The Claremont Colleges, Claremont, CA 91711 (United States); Luca, Maria; Taggart-Murphy, Laura; Portillio, Jessica; Chang, Cathey; Guven, Ayse [W.M. Keck Science Center, The Claremont Colleges, Claremont, CA 91711 (United States); Lin, Ren-Jang [Department of Molecular and Cellular Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010 (United States); Murray, Johanne; Carr, Antony [Genome Damage and Stability Center, University of Sussex, Falmer, BN1 9RQ (United Kingdom)

    2012-10-01

    Schizosaccharomyces pombe Dsk1 is an SR protein-specific kinase (SRPK), whose homologs have been identified in every eukaryotic organism examined. Although discovered as a mitotic regulator with protein kinase activity toward SR splicing factors, it remains largely unknown about what and how Dsk1 contributes to cell cycle and pre-mRNA splicing. In this study, we investigated the Dsk1 function by determining interacting factors and cellular localization of the kinase. Consistent with its reported functions, we found that pre-mRNA processing and cell cycle factors are prominent among the proteins co-purified with Dsk1. The identification of these factors led us to find Rsd1 as a novel Dsk1 substrate, as well as the involvement of Dsk1 in cellular distribution of poly(A){sup +} RNA. In agreement with its role in nuclear events, we also found that Dsk1 is mainly localized in the nucleus during G{sub 2} phase and at mitosis. Furthermore, we revealed the oscillation of Dsk1 protein in a cell cycle-dependent manner. This paper marks the first comprehensive analysis of in vivo Dsk1-associated proteins in fission yeast. Our results reflect the conserved role of SRPK family in eukaryotic organisms, and provide information about how Dsk1 functions in pre-mRNA processing and cell-division cycle.

  8. Inhibition of the MEK-1/p42 MAP kinase reduces aryl hydrocarbon receptor-DNA interactions

    International Nuclear Information System (INIS)

    Yim, Sujin; Oh, Myoungsuk; Choi, Su Mi; Park, Hyunsung

    2004-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces expression of the cytochrome P450 1A1 gene, cyp1a1, by binding to its receptor, aryl hydrocarbon receptor (AhR). TCDD-bound AhR translocates to the nucleus and forms a heterodimer with its partner protein, AhR nuclear translocator (Arnt). The AhR/Arnt heterodimer then binds to the dioxin-response elements (DREs) in the cyp1a1 enhancer and stimulates transcription of cyp1a1. We tested whether kinase pathways are involved in this process by treating Hepa1c1c7 cells with kinase inhibitors. The MEK-1 inhibitor PD98059 reduced TCDD-induced transcription of cyp1a1. TCDD treatment results in phosphorylation of p44/p42 mitogen-activated protein kinase (MAPK), a substrate of MEK-1. Overexpression of dominant negative form of p42 MAPK suppressed TCDD-dependent transcription of a reporter gene controlled by dioxin-response elements (DREs), and pretreatment with PD98059 also blocked this transcription. PD98059 pretreatment also inhibited TCDD-induced DRE binding of the AhR/Arnt heterodimer. Together these results indicate that TCDD activates the MEK-1/p44/p42 MAPK pathway, which in turn activates AhR and so facilitates binding of AhR to the cyp1a1 DRE

  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. Structural basis for substrate specificities of cellular deoxyribonucleoside kinases

    DEFF Research Database (Denmark)

    Johansson, K.; Ramaswamy, S.; Ljungcrantz, C.

    2001-01-01

    Deoxyribonucleoside kinases phosphorylate deoxyribonucleosides and activate a number of medically important nucleoside analogs. Here we report the structure of the Drosophila deoxyribonucleoside kinase with deoxycytidine bound at the nucleoside binding site and that of the human deoxyguanosine ki......; this is apparently due to the presence of Arg 118, which provides favorable hydrogen bonding interactions with the substrate. The two new structures provide an explanation for the substrate specificity of cellular deoxyribonucleoside kinases....

  11. JPRS Report, Nuclear Developments

    National Research Council Canada - National Science Library

    1991-01-01

    Partial Contents: Medium Range Missiles, Rocket Engine, Nuclear Submarine, Nuclear Reactor, Nuclear Inspection, Nuclear Weapons, Transfer Technology, Scud, Safety, Nuclear Power, Chernobyl Trial, ,CHemical Weapons...

  12. Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, Wolfgang [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Mikkelsen, Nils Egil [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Clausen, Anders Ranegaard [Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden); Willer, Mette [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Eklund, Hans [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Gojkovic, Zoran [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Piskur, Jure, E-mail: Jure.Piskur@cob.lu.se [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden)

    2009-05-01

    Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) can additionally sensitize human cancer cell lines towards the anti-cancer drug gemcitabine. We show that this property is based on the Dm-dNK ability to efficiently phosphorylate gemcitabine. The 2.2 A resolution structure of Dm-dNK in complex with gemcitabine shows that the residues Tyr70 and Arg105 play a crucial role in the firm positioning of gemcitabine by extra interactions made by the fluoride atoms. This explains why gemcitabine is a good substrate for Dm-dNK.

  13. Distribution of protein kinase Mzeta and the complete protein kinase C isoform family in rat brain

    DEFF Research Database (Denmark)

    Naik, M U; Benedikz, Eirikur; Hernandez, I

    2000-01-01

    Protein kinase C (PKC) is a multigene family of at least ten isoforms, nine of which are expressed in brain (alpha, betaI, betaII, gamma, delta, straightepsilon, eta, zeta, iota/lambda). Our previous studies have shown that many of these PKCs participate in synaptic plasticity in the CA1 region...

  14. Peptide substrates for Rho-associated kinase 2 (Rho-kinase 2/ROCK2.

    Directory of Open Access Journals (Sweden)

    Jeong-Hun Kang

    Full Text Available Peptide substrates sensitive for a certain protein kinase could be important for new-drug development and to understand the mechanism of diseases. Rho-associated kinase (Rho-kinase/ROCK is a serine/threonine kinase, and plays an important part in cardiovascular disease, migration and invasion of tumor cells, and in neurological disorders. The purpose of this study was to find substrates with high affinity and sensitivity for ROCK2. We synthesized 136 peptide substrates from protein substrates for ROCK2 with different lengths and charged peptides. Incorporation of (32P [counts per minute (CPM] for each peptide substrate was determined by the radiolabel assay using [γ-(32P]ATP. When the top five peptide substrates showing high CPMs (R4, R22, R133, R134, and R135 were phosphorylated by other enzymes (PKA, PKCα, and ERK1, R22, R133, and R135 displayed the highest CPM level for ROCK2 compared with other enzymes, whereas R4 and R134 showed similar CPM levels for ROCK2 and PKCα. We hypothesize that R22, R133, and R135 can be useful peptide substrates for ROCK2.

  15. Characterization of cyclin-dependent kinases and Cdc2/Cdc28 kinase subunits in Trichomonas vaginalis.

    Science.gov (United States)

    Amador, Erick; López-Pacheco, Karla; Morales, Nataly; Coria, Roberto; López-Villaseñor, Imelda

    2017-04-01

    Cyclin-dependent kinases (CDKs) have important roles in regulating key checkpoints between stages of the cell cycle. Their activity is tightly regulated through a variety of mechanisms, including through binding with cyclin proteins and the Cdc2/Cdc28 kinase subunit (CKS), and their phosphorylation at specific amino acids. Studies of the components involved in cell cycle control in parasitic protozoa are limited. Trichomonas vaginalis is the causative agent of trichomoniasis in humans and is therefore important in public health; however, some of the basic biological processes used by this organism have not been defined. Here, we characterized proteins potentially involved in cell cycle regulation in T. vaginalis. Three genes encoding protein kinases were identified in the T. vaginalis genome, and the corresponding recombinant proteins (TvCRK1, TvCRK2, TvCRK5) were studied. These proteins displayed similar sequence features to CDKs. Two genes encoding CKSs were also identified, and the corresponding recombinant proteins were found to interact with TvCRK1 and TvCRK2 by a yeast two-hybrid system. One putative cyclin B protein from T. vaginalis was found to bind to and activate the kinase activities of TvCRK1 and TvCRK5, but not TvCRK2. This work is the first characterization of proteins involved in cell cycle control in T. vaginalis.

  16. A-Raf kinase is a new interacting partner of protein kinase CK2 beta subunit

    DEFF Research Database (Denmark)

    Boldyreff, B; Issinger, O G

    1997-01-01

    In a search for protein kinase CK2 beta subunit binding proteins using the two-hybrid system, more than 1000 positive clones were isolated. Beside clones for the alpha' and beta subunit of CK2, there were clones coding for a so far unknown protein, whose partial cDNA sequence was already deposited...

  17. Structures of down syndrome kinases, DYRKs, reveal mechanisms of kinase activation and substrate recognition

    DEFF Research Database (Denmark)

    Soundararajan, M.; Roos, A.K.; Savitsky, P.

    2013-01-01

    Dual-specificity tyrosine-(Y)-phosphorylation-regulated kinases (DYRKs) play key roles in brain development, regulation of splicing, and apoptosis, and are potential drug targets for neurodegenerative diseases and cancer. We present crystal structures of one representative member of each DYRK sub...

  18. Comparative Molecular Dynamics Simulations of Mitogen-Activated Protein Kinase-Activated Protein Kinase 5

    Directory of Open Access Journals (Sweden)

    Inger Lindin

    2014-03-01

    Full Text Available The mitogen-activated protein kinase-activated protein kinase MK5 is a substrate of the mitogen-activated protein kinases p38, ERK3 and ERK4. Cell culture and animal studies have demonstrated that MK5 is involved in tumour suppression and promotion, embryogenesis, anxiety, cell motility and cell cycle regulation. In the present study, homology models of MK5 were used for molecular dynamics (MD simulations of: (1 MK5 alone; (2 MK5 in complex with an inhibitor; and (3 MK5 in complex with the interaction partner p38α. The calculations showed that the inhibitor occupied the active site and disrupted the intramolecular network of amino acids. However, intramolecular interactions consistent with an inactive protein kinase fold were not formed. MD with p38α showed that not only the p38 docking region, but also amino acids in the activation segment, αH helix, P-loop, regulatory phosphorylation region and the C-terminal of MK5 may be involved in forming a very stable MK5-p38α complex, and that p38α binding decreases the residual fluctuation of the MK5 model. Electrostatic Potential Surface (EPS calculations of MK5 and p38α showed that electrostatic interactions are important for recognition and binding.

  19. Expression of Plant Receptor Kinases in Tobacco BY-2 Cells.

    Science.gov (United States)

    Shinohara, Hidefumi; Matsubayashi, Yoshikatsu

    2017-01-01

    Although more than 600 single-transmembrane receptor kinase genes have been found in the Arabidopsis genome, only a few of them have known physiological functions, and even fewer plant receptor kinases have known specific ligands. Ligand-binding analysis must be operated using the functionally expressed receptor form. However, the relative abundance of native receptor kinase molecules in the plasma membrane is often quite low. Here, we present a method for stable and functional expression of plant receptor kinases in tobacco BY-2 cells that allows preparation of microsomal fractions containing the receptor. This procedure provides a sufficient amount of receptor proteins while maintaining its ligand-binding activities.

  20. How protein kinases co-ordinate mitosis in animal cells.

    Science.gov (United States)

    Ma, Hoi Tang; Poon, Randy Y C

    2011-04-01

    Mitosis is associated with profound changes in cell physiology and a spectacular surge in protein phosphorylation. To accomplish these, a remarkably large portion of the kinome is involved in the process. In the present review, we will focus on classic mitotic kinases, such as cyclin-dependent kinases, Polo-like kinases and Aurora kinases, as well as more recently characterized players such as NIMA (never in mitosis in Aspergillus nidulans)-related kinases, Greatwall and Haspin. Together, these kinases co-ordinate the proper timing and fidelity of processes including centrosomal functions, spindle assembly and microtubule-kinetochore attachment, as well as sister chromatid separation and cytokinesis. A recurrent theme of the mitotic kinase network is the prevalence of elaborated feedback loops that ensure bistable conditions. Sequential phosphorylation and priming phosphorylation on substrates are also frequently employed. Another important concept is the role of scaffolds, such as centrosomes for protein kinases during mitosis. Elucidating the entire repertoire of mitotic kinases, their functions, regulation and interactions is critical for our understanding of normal cell growth and in diseases such as cancers.

  1. SH2 domains: modulators of nonreceptor tyrosine kinase activity.

    Science.gov (United States)

    Filippakopoulos, Panagis; Müller, Susanne; Knapp, Stefan

    2009-12-01

    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 that the presence of the SH2 domain is frequently required for catalytic activity, suggesting a crucial function stabilizing the active state of many nonreceptor tyrosine kinases. Recently, the structure of the SH2-kinase domain of Fes revealed that the SH2 domain stabilizes the active kinase conformation by direct interactions with the regulatory helix alphaC. Stabilizing interactions between the SH2 and the kinase domains have also been observed in the structures of active Csk and Abl. Interestingly, mutations in the SH2 domain found in human disease can be explained by SH2 domain destabilization or incorrect positioning of the SH2. Here we summarize our understanding of mechanisms that lead to tyrosine kinase activation by direct interactions mediated by the SH2 domain and discuss how mutations in the SH2 domain trigger kinase inactivation.

  2. 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.

  3. Nuclear forensics

    International Nuclear Information System (INIS)

    Venugopal, V.

    2010-01-01

    Nuclear forensics is the analysis of nuclear materials recovered from either the capture of unused materials, or from the radioactive debris following a nuclear explosion and can contribute significantly to the identification of the sources of the materials and the industrial processes used to obtain them. In the case of an explosion, nuclear forensics can also reconstruct key features of the nuclear device. Nuclear forensic analysis works best in conjunction with other law enforcement, radiological protection dosimetry, traditional forensics, and intelligence work to provide the basis for attributing the materials and/or nuclear device to its originators. Nuclear forensics is a piece of the overall attribution process, not a stand-alone activity

  4. Nuclear power

    International Nuclear Information System (INIS)

    1987-01-01

    ''Nuclear Power'' describes how a reactor works and examines the different designs including Magnox, AGR, RBMK and PWR. It charts the growth of nuclear generation in the world and its contributions to world energy resources. (author)

  5. Nuclear Scans

    Science.gov (United States)

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  6. Phosphoinositide-3-kinases p110alpha and p110beta mediate S phase entry in astroglial cells in the marginal zone of rat neocortex

    Directory of Open Access Journals (Sweden)

    Rabea eMüller

    2013-03-01

    Full Text Available In cells cultured from neocortex of newborn rats, phosphoinositide-3-kinases of class I regulate the DNA synthesis in a subgroup of astroglial cells. We have studied the location of these cells as well as the kinase isoforms which facilitate the S phase entry. Using dominant negative isoforms as well as selective pharmacological inhibitors we quantified S phase entry by nuclear labeling with bromodeoxyuridine. Only in astroglial cells harvested from the marginal zone of the neocortex inhibition of phosphoinositide-3-kinases reduced the nuclear labeling with bromodeoxyuridine, indicating that neocortical astroglial cells differ in the regulation of proliferation. The two kinase isoforms p110 and p110were essential for S phase entry. p110 diminished the level of the p27Kip1 which inactivates the complex of cyclin E and CDK2 necessary for entry into the S phase. p110phosphorylated and inhibited glycogen synthase kinase-3which can prevent S-phase entry. Taken together, both isoforms mediated S phase in a subgroup of neocortical astroglial cells and acted via distinct pathways.

  7. Cyclin-dependent kinase suppression by WEE1 kinase protects the genome through control of replication initiation and nucleotide consumption

    DEFF Research Database (Denmark)

    Beck, Halfdan; Nähse-Kumpf, Viola; Larsen, Marie Sofie Yoo

    2012-01-01

    Activation of oncogenes or inhibition of WEE1 kinase deregulates Cyclin-dependent kinase (CDK) activity and leads to replication stress, however, the underlying mechanism is not understood. We now show that elevation of CDK activity by inhibiting WEE1 kinase rapidly increases initiation of replic......Activation of oncogenes or inhibition of WEE1 kinase deregulates Cyclin-dependent kinase (CDK) activity and leads to replication stress, however, the underlying mechanism is not understood. We now show that elevation of CDK activity by inhibiting WEE1 kinase rapidly increases initiation...... of replication. This leads to nucleotide shortage and reduces replication fork speed, which is followed by SLX4/MUS81-mediated DNA double-strand breakage. Fork speed is normalized and DNA double-strand break (DSB) formation is suppressed when CDT1, a key factor for replication initiation, is depleted...

  8. A casein-kinase-2-related protein kinase is tightly associated with the large T antigen of simian virus 40

    DEFF Research Database (Denmark)

    Götz, C; Koenig, M G; Issinger, O G

    1995-01-01

    by the addition of protein kinase CK2 suggest that at least one of the T-antigen-associated protein kinases is CK2 or a protein-kinase-CK2-related enzyme. The association of recombinant CK2 with T antigen was strongly confirmed by in vitro binding studies. Experiments with temperature-sensitive SV40-transformed......The simian virus 40 (SV40) large T antigen is a multifunctional protein involved in SV40 cell transformation and lytic virus infection. Some of its activities are regulated by interaction with cellular proteins and/or by phosphorylation of T antigen by various protein kinases. In this study, we...... show that immuno-purified T antigen from SV40-transformed cells and from baculovirus-infected insect cells is tightly associated with a protein kinase that phosphorylates T antigen in vitro. In the presence of heparin or a peptide resembling a protein kinase CK2 recognition site, the phosphorylation...

  9. HAM-5 functions as a MAP kinase scaffold during cell fusion in Neurospora crassa.

    Directory of Open Access Journals (Sweden)

    Wilfried Jonkers

    2014-11-01

    Full Text Available Cell fusion in genetically identical Neurospora crassa germlings and in hyphae is a highly regulated process involving the activation of a conserved MAP kinase cascade that includes NRC-1, MEK-2 and MAK-2. During chemotrophic growth in germlings, the MAP kinase cascade members localize to conidial anastomosis tube (CAT tips every ∼8 minutes, perfectly out of phase with another protein that is recruited to the tip: SOFT, a recently identified scaffold for the MAK-1 MAP kinase pathway in Sordaria macrospora. How the MAK-2 oscillation process is initiated, maintained and what proteins regulate the MAP kinase cascade is currently unclear. A global phosphoproteomics approach using an allele of mak-2 (mak-2Q100G that can be specifically inhibited by the ATP analog 1NM-PP1 was utilized to identify MAK-2 kinase targets in germlings that were potentially involved in this process. One such putative target was HAM-5, a protein of unknown biochemical function. Previously, Δham-5 mutants were shown to be deficient for hyphal fusion. Here we show that HAM-5-GFP co-localized with NRC-1, MEK-2 and MAK-2 and oscillated with identical dynamics from the cytoplasm to CAT tips during chemotropic interactions. In the Δmak-2 strain, HAM-5-GFP localized to punctate complexes that did not oscillate, but still localized to the germling tip, suggesting that MAK-2 activity influences HAM-5 function/localization. However, MAK-2-GFP showed cytoplasmic and nuclear localization in a Δham-5 strain and did not localize to puncta. Via co-immunoprecipitation experiments, HAM-5 was shown to physically interact with NRC-1, MEK-2 and MAK-2, suggesting that it functions as a scaffold/transport hub for the MAP kinase cascade members for oscillation and chemotropic interactions during germling and hyphal fusion in N. crassa. The identification of HAM-5 as a scaffold-like protein will help to link the activation of MAK-2 cascade to upstream factors and proteins involved in this

  10. Nuclear energy

    International Nuclear Information System (INIS)

    Kuhn, W.

    1986-01-01

    This loose-leaf collection is made up of five didactically prepared units covering the following subjects: basic knowledge on nuclear energy, nuclear energy in relation to energy economy, site issues, environmental compatibility of nuclear energy, and nuclear energy in the focus of political and social action. To this was added a comprehensive collection of material: specific scientific background material, a multitude of tables, diagrams, charts etc. for copying, as well as 44 transparent charts, mostly in four colours. (orig./HP) [de

  11. Nuclear structure

    International Nuclear Information System (INIS)

    Eastham, D.A.; Joy, T.

    1986-01-01

    The paper on 'nuclear structure' is the Appendix to the Daresbury (United Kingdom) Annual Report 1985/86, and contains the research work carried out at the Nuclear Structure Facility, Daresbury, within that period. During the year a total of 74 experiments were scheduled covering the main areas of activity including: nuclear collective motion, nuclei far from stability, and nuclear collisions. The Appendix contains brief reports on these experiments and associated theory. (U.K.)

  12. Isolation of nucleotide binding site-leucine rich repeat and kinase resistance gene analogues from sugarcane (Saccharum spp.).

    Science.gov (United States)

    Glynn, Neil C; Comstock, Jack C; Sood, Sushma G; Dang, Phat M; Chaparro, Jose X

    2008-01-01

    Resistance gene analogues (RGAs) have been isolated from many crops and offer potential in breeding for disease resistance through marker-assisted selection, either as closely linked or as perfect markers. Many R-gene sequences contain kinase domains, and indeed kinase genes have been reported as being proximal to R-genes, making kinase analogues an additionally promising target. The first step towards utilizing RGAs as markers for disease resistance is isolation and characterization of the sequences. Sugarcane clone US01-1158 was identified as resistant to yellow leaf caused by the sugarcane yellow leaf virus (SCYLV) and moderately resistant to rust caused by Puccinia melanocephala Sydow & Sydow. Degenerate primers that had previously proved useful for isolating RGAs and kinase analogues in wheat and soybean were used to amplify DNA from sugarcane (Saccharum spp.) clone US-01-1158. Sequences generated from 1512 positive clones were assembled into 134 contigs of between two and 105 sequences. Comparison of the contig consensuses with the NCBI sequence database using BLASTx showed that 20 had sequence homology to nuclear binding site and leucine rich repeat (NBS-LRR) RGAs, and eight to kinase genes. Alignment of the deduced amino acid sequences with similar sequences from the NCBI database allowed the identification of several conserved domains. The alignment and resulting phenetic tree showed that many of the sequences had greater similarity to sequences from other species than to one another. The use of degenerate primers is a useful method for isolating novel sugarcane RGA and kinase gene analogues. Further studies are needed to evaluate the role of these genes in disease resistance.

  13. Nuclear terrorism

    International Nuclear Information System (INIS)

    2002-01-01

    Recent reports of alleged terrorist plans to build a 'dirty bomb' have heightened longstanding concerns about nuclear terrorism. This briefing outlines possible forms of attack, such as: detonation of a nuclear weapon; attacks involving radioactive materials; attacks on nuclear facilities. Legislation addressing these risks and the UK's strategy for coping with them are also considered

  14. Nuclear power

    International Nuclear Information System (INIS)

    d'Easum, Lille.

    1976-03-01

    An environmentalist's criticism of nuclear energy is given, on a layman's level. Such subjects as conflict of interest in controlling bodies, low-level radiation, reactor safety, liability insurance, thermal pollution, economics, heavy water production, export of nuclear technology, and the history of the anti-nuclear movement are discussed in a sensationalistic tone. (E.C.B.)

  15. Nuclear alerts

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Anti-nuclear demonstrations against the deployment of new US missiles were held in Nato Europe. As no agreement has yet been reached at the US-Soviet Intermediate Nuclear Forces talks in Geneva, the deployment of nuclear missiles in Europe has started

  16. Nuclear questions

    International Nuclear Information System (INIS)

    Berg, Eugene

    2012-01-01

    Civilian and military nuclear questions fill a multitude of publications these days, especially after the Japanese tsunami and the Fukushima disaster. The author analyses some of them and highlights the links between civil and military nuclear industries, the realities of the nuclear cycle and related industrial questions before concluding on the controversial issue of weapons and their proliferation potential

  17. Nuclear decommissioning

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The paper on nuclear decommissioning was presented by Dr H. Lawton to a meeting of the British Nuclear Energy Society and Institution of Nuclear Engineers, 1986. The decommissioning work currently being undertaken on the Windscale advanced gas cooled reactor (WAGR) is briefly described, along with projects in other countries, development work associated with the WAGR operation and costs. (U.K.)

  18. Nuclear electronics

    International Nuclear Information System (INIS)

    Friese, T.

    1981-09-01

    A short survey is given on nuclear radiation detectors and nuclear electronics. It is written for newcomers and those, who are not very familiar with this technique. Some additional information is given on typical failures in nuclear measurement systems. (orig.) [de

  19. SH2/SH3 adaptor proteins can link tyrosine kinases to a Ste20-related protein kinase, HPK1.

    Science.gov (United States)

    Anafi, M; Kiefer, F; Gish, G D; Mbamalu, G; Iscove, N N; Pawson, T

    1997-10-31

    Ste20-related protein kinases have been implicated as regulating a range of cellular responses, including stress-activated protein kinase pathways and the control of cytoskeletal architecture. An important issue involves the identities of the upstream signals and regulators that might control the biological functions of mammalian Ste20-related protein kinases. HPK1 is a protein-serine/threonine kinase that possesses a Ste20-like kinase domain, and in transfected cells activates a protein kinase pathway leading to the stress-activated protein kinase SAPK/JNK. Here we have investigated candidate upstream regulators that might interact with HPK1. HPK1 possesses an N-terminal catalytic domain and an extended C-terminal tail with four proline-rich motifs. The SH3 domains of Grb2 bound in vitro to specific proline-rich motifs in the HPK1 tail and functioned synergistically to direct the stable binding of Grb2 to HPK1 in transfected Cos1 cells. Epidermal growth factor (EGF) stimulation did not affect the binding of Grb2 to HPK1 but induced recruitment of the Grb2.HPK1 complex to the autophosphorylated EGF receptor and to the Shc docking protein. Several activated receptor and cytoplasmic tyrosine kinases, including the EGF receptor, stimulated the tyrosine phosphorylation of the HPK1 serine/threonine kinase. These results suggest that HPK1, a mammalian Ste20-related protein-serine/threonine kinase, can potentially associate with protein-tyrosine kinases through interactions mediated by SH2/SH3 adaptors such as Grb2. Such interaction may provide a possible mechanism for cross-talk between distinct biochemical pathways following the activation of tyrosine kinases.

  20. Subcellular distribution of cyclin-dependent kinase-like 5 (CDKL5) is regulated through phosphorylation by dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A)

    International Nuclear Information System (INIS)

    Oi, Ami; Katayama, Syouichi; Hatano, Naoya; Sugiyama, Yasunori; Kameshita, Isamu; Sueyoshi, Noriyuki

    2017-01-01

    Cyclin-dependent kinase-like 5 (CDKL5) is a Ser/Thr protein kinase primarily expressed in the central nervous system and is known to cause X-linked neurodevelopmental disorders such as Rett syndrome. However, the mechanisms regulating CDKL5 have not yet been fully clarified. Therefore, in this study, we investigated the protein kinase that directly phosphorylates CDKL5, identifying it as dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), an enzyme binding to and phosphorylating CDKL5. We showed that subcellular distribution of CDKL5 was regulated by its phosphorylation by DYRK1A. In mouse neuroblastoma Neuro2a cells, CDKL5 was localized in both the cytosol and nucleus, whereas DYRK1A showed a typical nuclear localization. When CDKL5 and DYRK1A were co-expressed, the cytosolic localization of CDKL5 was significantly increased. Results of site-directed mutagenesis revealed that the phosphorylation site was Ser-308, in the vicinity of the nuclear localization signal. A mutation mimicking the phosphorylated serine residue by aspartate substitution (S308D) changed CDKL5 localization to the cytosol, whereas the corresponding alanine-substituted analog, CDKL5(S308A), was primarily localized to the nucleus. Taken together, these results strongly suggested that DYRK1A bound to CDKL5 and phosphorylated it on Ser-308, thus interfering with its nuclear localization. - Highlights: • We investigated the mechanism regulating subcellular localization of CDKL5. • DYRK1A was identified as an enzyme that bound to and phosphorylated CDKL5. • The phosphorylation site of CDKL5 was Ser-308, in the vicinity of the NLS. • When DYRK1A was co-expressed, the cytosolic CDKL5 was significantly increased. • In conclusion, DYRK1A regulates CDKL5 localization via phosphorylation on Ser-308.

  1. Radioimmunoassay of creatine kinase BB isoenzyme

    Energy Technology Data Exchange (ETDEWEB)

    Jianguo, Geng [Shanghai Medical Univ. (China). Zhongshan Hospital; and others

    1988-11-01

    A radioimmunoassay of creatine kinase BB isoenzyme (CK-BB) was developed by using CK-BB purified from human brain. The CK-BB antiserum was raised by immunizing rabbite and {sup 125}I-CK-BB iodinated with Bolton-Hunter reagent. The affinity constant was 3.0 x 10{sup 9} mol/L. No cross reactions with creatine kinase MM isoenzyme and neuron-specific enolase were found. The measuring range was 3.5 x 10{sup -8} {approx} 1.2 x 10{sup -5} mmol/L, the average recovery rate 97.5%, with the inter and intrassay CV 3.1% and 12%, respectively. The average serum CK-BB concentration in 83 normal persons was 1.5 x 10{sup -7} +- 8.1 x 10{sup -8} mmol/L, quite different from the values of acute myocardial infarction (5.2 x 10{sup -6} +- 1.2 x 10{sup -4} mmol/L, n = 28) and cerebral vascular accident (8.4 x 10{sup -4} +- 5.0 x 10{sup -4} mmol/L, n = 10).

  2. Targeting the Pim kinases in multiple myeloma.

    LENUS (Irish Health Repository)

    Keane, N A

    2015-07-17

    Multiple myeloma (MM) is a plasma cell malignancy that remains incurable. Novel treatment strategies to improve survival are urgently required. The Pims are a small family of serine\\/threonine kinases with increased expression across the hematological malignancies. Pim-2 shows highest expression in MM and constitutes a promising therapeutic target. It is upregulated by the bone marrow microenvironment to mediate proliferation and promote MM survival. Pim-2 also has a key role in the bone destruction typically seen in MM. Additional putative roles of the Pim kinases in MM include trafficking of malignant cells, promoting oncogenic signaling in the hypoxic bone marrow microenvironment and mediating resistance to therapy. A number of Pim inhibitors are now under development with lead compounds entering the clinic. The ATP-competitive Pim inhibitor LGH447 has recently been reported to have single agent activity in MM. It is anticipated that Pim inhibition will be of clinical benefit in combination with standard treatments and\\/or with novel drugs targeting other survival pathways in MM.

  3. Radioimmunoassay of creatine kinase BB isoenzyme

    International Nuclear Information System (INIS)

    Geng Jianguo

    1988-01-01

    A radioimmunoassay of creatine kinase BB isoenzyme (CK-BB) was developed by using CK-BB purified from human brain. The CK-BB antiserum was raised by immunizing rabbite and 125 I-CK-BB iodinated with Bolton-Hunter reagent. The affinity constant was 3.0 x 10 9 mol/L. No cross reactions with creatine kinase MM isoenzyme and neuron-specific enolase were found. The measuring range was 3.5 x 10 -8 ∼ 1.2 x 10 -5 mmol/L, the average recovery rate 97.5%, with the inter and intrassay CV 3.1% and 12%, respectively. The average serum CK-BB concentration in 83 normal persons was 1.5 x 10 -7 +- 8.1 x 10 -8 mmol/L, quite different from the values of acute myocardial infarction (5.2 x 10 -6 +- 1.2 x 10 -4 mmol/L, n = 28) and cerebral vascular accident (8.4 x 10 -4 +- 5.0 x 10 -4 mmol/L, n = 10)

  4. Activation of oocyte phosphatidylinositol kinase by polyamines

    International Nuclear Information System (INIS)

    Allende, J.E.; Carrasco, D.; Allende, C.C.

    1987-01-01

    Membrane bound phosphatidylinositol is phosphorylated by a specific membrane enzyme to form phosphatidylinositol 4 phosphate (PIP) which in turn is again phosphorylated to generate phosphatidylinositol 4,5 biphosphate (PIPP). The regulation of phosphatidylinositol phosphorylation and hydrolysis is relevant to the possible role of inositol phosphates as second messengers of hormone action. The membranes of Xenopus laevis oocytes contain a phosphatidylinositol kinase that can generate radioactive PIP after incubation with [ 32 ATP]. The radioactive product is extracted with methanol-chloroform and isolated by thin layer chromatography. The oocyte enzyme has an app Km for ATP of 80 μM and cannot use GTP as a phosphate donor. The formation of PIP is greatly stimulated by the addition of synthetic peptides containing clusters of polylysine at concentrations 0.5 mM. A similar effect is observed with a lysine rich peptide that corresponds to the 14 amino acids of the carboxyl terminus of the Kirstein ras 2 protein and also by polyornithine. Polyarginine and histone H 1 have much lower effects. Peptides containing polylysine clusters have also been found to affect the activity of other key membrane enzymes such as protein kinases and adenylate cyclase

  5. Kinome profiling of Arabidopsis using arrays of kinase consensus substrates

    Directory of Open Access Journals (Sweden)

    Pieterse Corné MJ

    2007-02-01

    Full Text Available Abstract Background Kinome profiling aims at the parallel analysis of kinase activities in a cell. Novel developed arrays containing consensus substrates for kinases are used to assess those kinase activities. The arrays described in this paper were already used to determine kinase activities in mammalian systems, but since substrates from many organisms are present we decided to test these arrays for the determination of kinase activities in the model plant species Arabidopsis thaliana. Results Kinome profiling using Arabidopsis cell extracts resulted in the labelling of many consensus peptides by kinases from the plant, indicating the usefulness of this kinome profiling tool for plants. Method development showed that fresh and frozen plant material could be used to make cell lysates containing active kinases. Dilution of the plant extract increased the signal to noise ratio and non-radioactive ATP enhances full development of spot intensities. Upon infection of Arabidopsis with an avirulent strain of the bacterial pathogen Pseudomonas syringae pv. tomato, we could detect differential kinase activities by measuring phosphorylation of consensus peptides. Conclusion We show that kinome profiling on arrays with consensus substrates can be used to monitor kinase activities in plants. In a case study we show that upon infection with avirulent P. syringae differential kinase activities can be found. The PepChip can for example be used to purify (unknown kinases that play a role in P. syringae infection. This paper shows that kinome profiling using arrays of consensus peptides is a valuable new tool to study signal-transduction in plants. It complements the available methods for genomics and proteomics research.

  6. Nuclear energy

    International Nuclear Information System (INIS)

    2007-01-01

    This digest document was written by members of the union of associations of ex-members and retired people of the Areva group (UARGA). It gives a comprehensive overview of the nuclear industry world, starting from radioactivity and its applications, and going on with the fuel cycle (front-end, back-end, fuel reprocessing, transports), the nuclear reactors (PWR, BWR, Candu, HTR, generation 4 systems), the effluents from nuclear facilities, the nuclear wastes (processing, disposal), and the management and safety of nuclear activities. (J.S.)

  7. Nuclear orientation and nuclear structure

    International Nuclear Information System (INIS)

    Krane, K.S.

    1988-01-01

    The present generation of on-line nuclear orientation facilities promises to revolutionize the gathering of nuclear structure information, especially for the hitherto poorly known and understood nuclei far from stability. Following a brief review of the technological developments that have facilitated these experiments, the nuclear spectroscopic information that can be obtained is summarized. Applications to understanding nuclear structure are reviewed, and challenges for future studies are discussed. (orig.)

  8. Anks3 alters the sub-cellular localization of the Nek7 kinase

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, Haribaskar; Engel, Christina; Müller, Barbara [Renal Division, Department of Medicine, University Freiburg Medical Center, Hugstetter Str. 55, 79106 Freiburg (Germany); Dengjel, Jörn [Department of Dermatology, University Freiburg Medical Center and Center of Biological Systems Analysis, Habsburgerstr. 49, 79104 Freiburg (Germany); Walz, Gerd [Renal Division, Department of Medicine, University Freiburg Medical Center, Hugstetter Str. 55, 79106 Freiburg (Germany); Center for Biological Signaling Studies (BIOSS), Albertstr. 19, 79104 Freiburg (Germany); Yakulov, Toma A., E-mail: toma.antonov.yakulov@uniklinik-freiburg.de [Renal Division, Department of Medicine, University Freiburg Medical Center, Hugstetter Str. 55, 79106 Freiburg (Germany)

    2015-08-28

    Nephronophthisis (NPH) is an autosomal recessive cystic kidney disease, and a frequent cause of end-stage renal failure in children. To date, 17 NPH-associated gene products (NPHPs) have been identified. Most NPHPs participate in large multi-protein complexes that localize to the cilium and/or basal body; however, the precise composition of these complexes and their biological function remain largely unknown. We recently observed that the ankyrin repeat protein Anks3 interacts with the NPH family member Anks6. Both Anks3 and Anks6 form complexes with multiple other NPHPs, suggesting that both proteins function in similar or overlapping signaling pathways. Here, we show that Anks3, but not Anks6 interacted with the NIMA-related kinase Nek7, and was heavily modified in the presence of Nek7, resulting in an approximately 20 kD increase in molecular weight. Although mass spectrometry revealed increased serine and threonine phosphorylation of Anks3 primarily within the N-terminal ankyrin repeats also required for Nek7 interaction, the molecular weight increase occurred even in the presence of a kinase-dead Nek7 mutant, indicating that this modification was not caused by Nek7-dependent Anks3 phosphorylation. Furthermore, the Anks3 modification was specific for Nek7, and did not occur in the presence of Nek8. Importantly, Anks3 retained Nek7 in the cytoplasm, suggesting that, Nek7 triggers the modification of Anks3, which in turn prevents the nuclear localization of Nek7. - Highlights: • Anks3 interacted with Nek7 kinase, and was heavily modified in the presence of Nek7. • Anks3 N-terminal ankyrin repeats, but not SAM domain required for Nek7 interaction. • Nek7 increased Ser/Thr phosphorylation of Anks3 primarily within ankyrin domain. • Interaction with Anks3 led to cytoplasmic retention and nuclear exclusion of Nek7.

  9. Nuclear power

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The committee concludes that the nature of the proliferation problem is such that even stopping nuclear power completely could not stop proliferation completely. Countries can acquire nuclear weapons by means independent of commercial nuclear power. It is reasonable to suppose if a country is strongly motivated to acquire nuclear weapons, it will have them by 2010, or soon thereafter, no matter how nuclear power is managed in the meantime. Unilateral and international diplomatic measures to reduce the motivations that lead to proliferation should be high on the foreign policy agenda of the United States. A mimimum antiproliferation prescription for the management of nuclear power is to try to raise the political barriers against proliferation through misuse of nuclear power by strengthening the Non-Proliferation Treaty, and to seek to raise the technological barriers by placing fuel-cycle operations involving weapons-usable material under international control. Any such measures should be considered tactics to slow the spread of nuclear weapons and thus earn time for the exercise of statesmanship. The committee concludes the following about technical factors that should be considered in formulating nuclear policy: (1) rate of growth of electricity use is a primary factor; (2) growth of conventional nuclear power will be limited by producibility of domestic uranium sources; (3) greater contribution of nuclear power beyond 400 GWe past the year 2000 can only be supported by advanced reactor systems; and (4) several different breeder reactors could serve in principle as candidates for an indefinitely sustainable source of energy

  10. Nuclear physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Explains the concepts in detail and in depth. Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook explains the experimental basics, effects and theory of nuclear physics. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams help to better understand the explanations. A better feeling to the subject of the book is given with sketches about the historical development of nuclear physics. The main topics of this book include the phenomena associated with passage of charged particles and radiation through matter which are related to nuclear resonance fluorescence and the Moessbauer effect., Gamov's theory of alpha decay, Fermi theory of beta decay, electron capture and gamma decay. The discussion of general properties of nuclei covers nuclear sizes and nuclear force, nuclear spin, magnetic dipole moment and electric quadrupole moment. Nuclear instability against various modes of decay and Yukawa theory are explained. Nuclear models such as Fermi Gas Model, Shell Model, Liquid Drop Model, Collective Model and Optical Model are outlined to explain various experimental facts related to nuclear structure. Heavy ion reactions, including nuclear fusion, are explained. Nuclear fission and fusion power production is treated elaborately.

  11. Functional interaction between nonreceptor tyrosine kinase c-Abl and SR-Rich protein RBM39

    International Nuclear Information System (INIS)

    Mai, Sanyue; Qu, Xiuhua; Li, Ping; Ma, Qingjun; Liu, Xuan; Cao, Cheng

    2016-01-01

    RBM39, also known as splicing factor HCC1.4, acts as a transcriptional coactivator for the steroid nuclear receptors JUN/AP-1, ESR1/ER-α and ESR2/ER-β. RBM39 is involved in the regulation of the transcriptional responses of these steroid nuclear receptors and promotes transcriptional initiation. In this paper, we report that RBM39 interacts with the nonreceptor tyrosine kinase c-Abl. Both the Src homology (SH) 2 and SH3 domains of c-Abl interact with RBM39. The major tyrosine phosphorylation sites on RBM39 that are phosphorylated by c-Abl are Y95 and Y99, as demonstrated by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) and mutational analysis. c-Abl was shown boost the transcriptional coactivation activity of RBM39 for ERα and PRβ in a tyrosine kinase-dependent manner. The results suggest that mammalian c-Abl plays an important role in steroid hormone receptor-mediated transcription by regulating RBM39. - Highlights: • c-Abl interacts with RBM39. • RBM39 is phosphorylated by c-Abl. • c-Abl regulates transcriptional coactivation activity of RBM39 on the ERα and PRβ.

  12. Casein Kinase 1 Coordinates Cohesin Cleavage, Gametogenesis, and Exit from M Phase in Meiosis II.

    Science.gov (United States)

    Argüello-Miranda, Orlando; Zagoriy, Ievgeniia; Mengoli, Valentina; Rojas, Julie; Jonak, Katarzyna; Oz, Tugce; Graf, Peter; Zachariae, Wolfgang

    2017-01-09

    Meiosis consists of DNA replication followed by two consecutive nuclear divisions and gametogenesis or spore formation. While meiosis I has been studied extensively, less is known about the regulation of meiosis II. Here we show that Hrr25, the conserved casein kinase 1δ of budding yeast, links three mutually independent key processes of meiosis II. First, Hrr25 induces nuclear division by priming centromeric cohesin for cleavage by separase. Hrr25 simultaneously phosphorylates Rec8, the cleavable subunit of cohesin, and removes from centromeres the cohesin protector composed of shugoshin and the phosphatase PP2A. Second, Hrr25 initiates the sporulation program by inducing the synthesis of membranes that engulf the emerging nuclei at anaphase II. Third, Hrr25 mediates exit from meiosis II by activating pathways that trigger the destruction of M-phase-promoting kinases. Thus, Hrr25 synchronizes formation of the single-copy genome with gamete differentiation and termination of meiosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The inhibitors of cyclin-dependent kinases and GSK-3β enhance osteoclastogenesis

    Directory of Open Access Journals (Sweden)

    Yosuke Akiba

    2016-03-01

    Full Text Available Osteoclasts are multinucleated cells with bone resorption activity that is crucial for bone remodeling. RANK‐RANKL (receptor activator of nuclear factor κB ligand signaling has been shown as a main signal pathway for osteoclast differentiation. However, the molecular mechanism and the factors regulating osteoclastogenesis remain to be fully understood. In this study, we performed a chemical genetic screen, and identified a Cdks/GSK-3β (cyclin-dependent kinases/glycogen synthase kinase 3β inhibitor, kenpaullone, and two Cdks inhibitors, olomoucine and roscovitine, all of which significantly enhance osteoclastogenesis of RAW264.7 cells by upregulating NFATc1 (nuclear factor of activated T cells, cytoplasmic 1 levels. We also determined that the all three compounds increase the number of osteoclast differentiated from murine bone marrow cells. Furthermore, the three inhibitors, especially kenpaullone, promoted maturation of cathepsin K, suggesting that the resorption activity of the resultant osteoclasts is also activated. Our findings indicate that inhibition of GSK-3β and/or Cdks enhance osteoclastogenesis by modulating the RANK–RANKL signaling pathway.

  14. Functional interaction between nonreceptor tyrosine kinase c-Abl and SR-Rich protein RBM39

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Sanyue [Beijing Institute of Biotechnology, 27 Taiping Rd, Haidian District, Beijing 100850 (China); Qu, Xiuhua [General Navy Hospital of PLA, 6 Fucheng Rd, Haidian District, Beijing 100037 (China); Li, Ping; Ma, Qingjun [Beijing Institute of Biotechnology, 27 Taiping Rd, Haidian District, Beijing 100850 (China); Liu, Xuan, E-mail: liux931932@163.com [Beijing Institute of Biotechnology, 27 Taiping Rd, Haidian District, Beijing 100850 (China); Cao, Cheng, E-mail: cao_c@sohu.com [Beijing Institute of Biotechnology, 27 Taiping Rd, Haidian District, Beijing 100850 (China)

    2016-04-22

    RBM39, also known as splicing factor HCC1.4, acts as a transcriptional coactivator for the steroid nuclear receptors JUN/AP-1, ESR1/ER-α and ESR2/ER-β. RBM39 is involved in the regulation of the transcriptional responses of these steroid nuclear receptors and promotes transcriptional initiation. In this paper, we report that RBM39 interacts with the nonreceptor tyrosine kinase c-Abl. Both the Src homology (SH) 2 and SH3 domains of c-Abl interact with RBM39. The major tyrosine phosphorylation sites on RBM39 that are phosphorylated by c-Abl are Y95 and Y99, as demonstrated by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) and mutational analysis. c-Abl was shown boost the transcriptional coactivation activity of RBM39 for ERα and PRβ in a tyrosine kinase-dependent manner. The results suggest that mammalian c-Abl plays an important role in steroid hormone receptor-mediated transcription by regulating RBM39. - Highlights: • c-Abl interacts with RBM39. • RBM39 is phosphorylated by c-Abl. • c-Abl regulates transcriptional coactivation activity of RBM39 on the ERα and PRβ.

  15. Nuclear chemistry

    International Nuclear Information System (INIS)

    Vertes, A.; Kiss, I.

    1987-01-01

    This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors

  16. Nuclear chemistry

    International Nuclear Information System (INIS)

    Vertes, A.; Kiss, I.

    1987-01-01

    This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors. (Auth.)

  17. Nuclear forensics

    International Nuclear Information System (INIS)

    Karadeniz, O.; Guenalp, G.

    2010-01-01

    This review discusses the methodology of nuclear forensics and illicit trafficking of nuclear materials. Nuclear forensics is relatively new scientific branch whose aim it is to read out material inherent from nuclear material. Nuclear forensics investigations have to be considered as part of a comprehensive set of measures for detection,interception, categorization and characterization of illicitly trafficking nuclear material. Prevention, detection and response are the main elements in combating illicit trafficking. Forensics is a key element in the response process. Forensic science is defined as the application of a broad spectrum of sciences to answer questions of interest to the legal system. Besides, in this study we will explain age determination of nuclear materials.

  18. Nuclear fuels

    International Nuclear Information System (INIS)

    Gangwani, Saloni; Chakrabortty, Sumita

    2011-01-01

    Nuclear fuel is a material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned for energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials. Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different. The following paper will also include the uses. advancements, advantages, disadvantages, various processes and behavior of nuclear fuels

  19. Nuclear networking.

    Science.gov (United States)

    Xie, Wei; Burke, Brian

    2017-07-04

    Nuclear lamins are intermediate filament proteins that represent important structural components of metazoan nuclear envelopes (NEs). By combining proteomics and superresolution microscopy, we recently reported that both A- and B-type nuclear lamins form spatially distinct filament networks at the nuclear periphery of mouse fibroblasts. In particular, A-type lamins exhibit differential association with nuclear pore complexes (NPCs). Our studies reveal that the nuclear lamina network in mammalian somatic cells is less ordered and more complex than that of amphibian oocytes, the only other system in which the lamina has been visualized at high resolution. In addition, the NPC component Tpr likely links NPCs to the A-type lamin network, an association that appears to be regulated by C-terminal modification of various A-type lamin isoforms. Many questions remain, however, concerning the structure and assembly of lamin filaments, as well as with their mode of association with other nuclear components such as peripheral chromatin.

  20. Regulatory role of tumor necrosis factor receptor-associated factor 6 in breast cancer by activating the protein kinase B/glycogen synthase kinase 3β signaling pathway.

    Science.gov (United States)

    Shen, Hongyu; Li, Liangpeng; Yang, Sujin; Wang, Dandan; Zhou, Siying; Chen, Xiu; Tang, Jinhai

    2017-08-01

    Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an endogenous adaptor of innate and adaptive immune responses, and serves a crucial role in tumor necrosis factor receptor and toll‑like/interleukin‑1 receptor signaling. Although studies have demonstrated that TRAF6 has oncogenic activity, its potential contributions to breast cancer in human remains largely uninvestigated. The present study examined the expression levels and function of TRAF6 in breast carcinoma (n=32) and adjacent healthy (n=25) tissue samples. Compared with adjacent healthy tissues, TRAF6 protein expression levels were significantly upregulated in breast cancer tissues. Reverse transcription‑quantitative polymerase chain reaction analysis revealed a significant upregulation of the cellular proliferative marker Ki‑67 and proliferation cell nuclear antigen expression levels in breast carcinoma specimens. Furthermore, protein expression levels of the accessory molecule, transforming growth factor β‑activated kinase 1 (TAK1), were significantly increased in breast cancer patients, as detected by western blot analysis. As determined by MTT assay, TRAF6 exerted profoundly proliferative effects in the MCF‑7 breast cancer cell line; however, these detrimental effects were ameliorated by TAK1 inhibition. Notably, protein kinase B (AKT)/glycogen synthase kinase (GSK)3β phosphorylation levels were markedly upregulated in breast cancer samples, compared with adjacent healthy tissues. In conclusion, an altered TRAF6‑TAK1 axis and its corresponding downstream AKT/GSK3β signaling molecules may contribute to breast cancer progression. Therefore, TRAF6 may represent a potential therapeutic target for the treatment of breast cancer.

  1. Creatine kinase isozyme expression in embryonic chicken heart

    NARCIS (Netherlands)

    Lamers, W. H.; Geerts, W. J.; Moorman, A. F.; Dottin, R. P.

    1989-01-01

    The distribution pattern of creatine kinase (EC 2.7.3.2) isozymes in developing chicken heart was studied by immunohistochemistry. Creatine kinase M, which is absent from adult heart, is transiently expressed between 4 and 11 days of incubation. During that period, numerous muscular cells in the

  2. 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

  3. Oral protein kinase c β inhibition using ruboxistaurin

    DEFF Research Database (Denmark)

    Aiello, Lloyd Paul; Vignati, Louis; Sheetz, Matthew J

    2011-01-01

    To evaluate efficacy, safety, and causes of vision loss among 813 patients (1,392 eyes) with moderately severe to very severe nonproliferative diabetic retinopathy from the Protein Kinase C β Inhibitor-Diabetic Retinopathy Study and Protein Kinase C β Inhibitor-Diabetic Retinopathy Study 2 ruboxi...

  4. Enhanced expression of a calcium-dependent protein kinase

    Indian Academy of Sciences (India)

    Among the downstream targets of calcium in plants, calcium-dependent protein kinases (CDPKs) form an interesting class of kinases which are activated by calcium binding. They have been implicated in a diverse array of responses to hormonal and environmental stimuli. In order to dissect the role of CDPKs in the moss ...

  5. Molecular cloning and characterization of a novel human kinase ...

    Indian Academy of Sciences (India)

    throughput cDNA sequencing. It encodes a protein of 341 amino acids, which shows 69% identity with the human kinase CLIK1 (AAL99353), which was suggested to be the CLP-36 interacting kinase. Bioinformatics analysis suggests that the ...

  6. Preclinical validation of Aurora kinases-targeting drugs in osteosarcoma

    NARCIS (Netherlands)

    Tavanti, E.; Sero, V.; Vella, S.; Fanelli, M.; Michelacci, F.; Landuzzi, L.; Magagnoli, G.; Versteeg, R.; Picci, P.; Hattinger, C. M.; Serra, M.

    2013-01-01

    Aurora kinases are key regulators of cell cycle and represent new promising therapeutic targets in several human tumours. Biological relevance of Aurora kinase-A and -B was assessed on osteosarcoma clinical samples and by silencing these genes with specific siRNA in three human osteosarcoma cell

  7. ATR kinase regulates its attenuation via PPM1D phosphatase ...

    Indian Academy of Sciences (India)

    In eukaryotes, in response to replication stress, DNA damage response kinase, ATR is activated, whose signalling abrogationleads to cell lethality due to aberrant fork remodelling and excessive origin firing. Here we report that inhibition ofATR kinase activity specifically during replication stress recovery results in persistent ...

  8. A cGMP kinase mutant with increased sensitivity to the protein kinase inhibitor peptide PKI(5-24).

    Science.gov (United States)

    Ruth, P; Kamm, S; Nau, U; Pfeifer, A; Hofmann, F

    1996-01-01

    Synthetic peptides corresponding to the active domain of the heat-stable inhibitor protein PKI are very potent inhibitors of cAMP-dependent protein kinase, but are extremely weak inhibitors of cGMP-dependent protein kinase. In this study, we tried to confer PKI sensitivity to cGMP kinase by site-directed mutagenesis. The molecular requirements for high affinity inhibition by PKI were deduced from the crystal structure of the cAMP kinase/PKI complex. A prominent site of interaction are residues Tyr235 and Phe239 in the catalytic subunit, which from a sandwich-like structure with Phe10 of the PKI(5-24) peptide. To increase the sensitivity for PKI, the cGMP kinase codons at the corresponding sites, Ser555 and Ser559, were changed to Tyr and Phe. The mutant cGMP kinase was stimulated half maximally by cGMP at 3-fold higher concentrations (240 nM) than the wild type (77 nM). Wild type and mutant cGMP kinase did not differ significantly in their Km and Vmax for three different substrate peptides. The PKI(5-24) peptide inhibited phosphotransferase activity of the mutant cGMP kinase with higher potency than that of wild type, with Ki values of 42 +/- .3 microM and 160 +/- .7 microM, respectively. The increased affinity of the mutant cGMP kinase was specific for the PKI(5-24) peptide. Mutation of the essential Phe10 in the PKI(5-24) sequence to an Ala yielded a peptide that inhibited mutant and wild type cGMP kinase with similar potency, with Ki values of 160 +/- 11 and 169 +/- 27 microM, respectively. These results suggest that the mutations Ser555Tyr and Ser559Phe are required, but not sufficient, for high affinity inhibition of cGMP kinase by PKI.

  9. Raf Kinase Inhibitory Protein Function Is Regulated via a Flexible Pocket and Novel Phosphorylation-Dependent Mechanism▿ †

    Science.gov (United States)

    Granovsky, Alexey E.; Clark, Matthew C.; McElheny, Dan; Heil, Gary; Hong, Jia; Liu, Xuedong; Kim, Youngchang; Joachimiak, Grazyna; Joachimiak, Andrzej; Koide, Shohei; Rosner, Marsha Rich

    2009-01-01

    Raf kinase inhibitory protein (RKIP/PEBP1), a member of the phosphatidylethanolamine binding protein family that possesses a conserved ligand-binding pocket, negatively regulates the mammalian mitogen-activated protein kinase (MAPK) signaling cascade. Mutation of a conserved site (P74L) within the pocket leads to a loss or switch in the function of yeast or plant RKIP homologues. However, the mechanism by which the pocket influences RKIP function is unknown. Here we show that the pocket integrates two regulatory signals, phosphorylation and ligand binding, to control RKIP inhibition of Raf-1. RKIP association with Raf-1 is prevented by RKIP phosphorylation at S153. The P74L mutation increases kinase interaction and RKIP phosphorylation, enhancing Raf-1/MAPK signaling. Conversely, ligand binding to the RKIP pocket inhibits kinase interaction and RKIP phosphorylation by a noncompetitive mechanism. Additionally, ligand binding blocks RKIP association with Raf-1. Nuclear magnetic resonance studies reveal that the pocket is highly dynamic, rationalizing its capacity to interact with distinct partners and be involved in allosteric regulation. Our results show that RKIP uses a flexible pocket to integrate ligand binding- and phosphorylation-dependent interactions and to modulate the MAPK signaling pathway. This mechanism is an example of an emerging theme involving the regulation of signaling proteins and their interaction with effectors at the level of protein dynamics. PMID:19103740

  10. Raf kinase inhibitory protein function is regulated via a flexible pocket and novel phosphorylation-dependent mechanism.

    Science.gov (United States)

    Granovsky, Alexey E; Clark, Matthew C; McElheny, Dan; Heil, Gary; Hong, Jia; Liu, Xuedong; Kim, Youngchang; Joachimiak, Grazyna; Joachimiak, Andrzej; Koide, Shohei; Rosner, Marsha Rich

    2009-03-01

    Raf kinase inhibitory protein (RKIP/PEBP1), a member of the phosphatidylethanolamine binding protein family that possesses a conserved ligand-binding pocket, negatively regulates the mammalian mitogen-activated protein kinase (MAPK) signaling cascade. Mutation of a conserved site (P74L) within the pocket leads to a loss or switch in the function of yeast or plant RKIP homologues. However, the mechanism by which the pocket influences RKIP function is unknown. Here we show that the pocket integrates two regulatory signals, phosphorylation and ligand binding, to control RKIP inhibition of Raf-1. RKIP association with Raf-1 is prevented by RKIP phosphorylation at S153. The P74L mutation increases kinase interaction and RKIP phosphorylation, enhancing Raf-1/MAPK signaling. Conversely, ligand binding to the RKIP pocket inhibits kinase interaction and RKIP phosphorylation by a noncompetitive mechanism. Additionally, ligand binding blocks RKIP association with Raf-1. Nuclear magnetic resonance studies reveal that the pocket is highly dynamic, rationalizing its capacity to interact with distinct partners and be involved in allosteric regulation. Our results show that RKIP uses a flexible pocket to integrate ligand binding- and phosphorylation-dependent interactions and to modulate the MAPK signaling pathway. This mechanism is an example of an emerging theme involving the regulation of signaling proteins and their interaction with effectors at the level of protein dynamics.

  11. Characterization of a protein kinase activity associated with purified capsids of the granulosis virus infecting Plodia interpunctella.

    Science.gov (United States)

    Wilson, M E; Consigli, R A

    1985-06-01

    A cyclic-nucleotide independent protein kinase activity has been demonstrated in highly purified preparations of the granulosis virus infecting the Indian meal moth, Plodia interpunctella. A divalent cation was required for activity. Manganese was the preferred cation and a pH of 8.0 resulted in optimal incorporation of 32P radiolabel into acid-precipitable protein. Although both ATP and GTP could serve as phosphate donors, ATP was utilized more efficiently by the enzyme. The kinase activity was localized to purified capsids; and the basic, internal core protein, VP12, was found to be the predominant viral acceptor. Histones and protamine sulfate could also serve as acceptors for the capsid-associated kinase activity. Using acid hydrolysis and phosphoamino acid analysis of phosphorylated nucleocapsid protein and nuclear magnetic resonance of phosphorylated VP12, it was determined that the enzyme catalyzes the transfer of phosphate to both serine and arginine residues of acceptor proteins. We believe this kinase activity may play a significant role in the viral replication cycle.

  12. Lyn tyrosine kinase promotes silencing of ATM-dependent checkpoint signaling during recovery from DNA double-strand breaks

    International Nuclear Information System (INIS)

    Fukumoto, Yasunori; Kuki, Kazumasa; Morii, Mariko; Miura, Takahito; Honda, Takuya; Ishibashi, Kenichi; Hasegawa, Hitomi; Kubota, Sho; Ide, Yudai; Yamaguchi, Noritaka; Nakayama, Yuji; Yamaguchi, Naoto

    2014-01-01

    Highlights: • Inhibition of Src family kinases decreased γ-H2AX signal. • Inhibition of Src family increased ATM-dependent phosphorylation of Chk2 and Kap1. • shRNA-mediated knockdown of Lyn increased phosphorylation of Kap1 by ATM. • Ectopic expression of Src family kinase suppressed ATM-mediated Kap1 phosphorylation. • Src is involved in upstream signaling for inactivation of ATM signaling. - Abstract: DNA damage activates the DNA damage checkpoint and the DNA repair machinery. After initial activation of DNA damage responses, cells recover to their original states through completion of DNA repair and termination of checkpoint signaling. Currently, little is known about the process by which cells recover from the DNA damage checkpoint, a process called checkpoint recovery. Here, we show that Src family kinases promote inactivation of ataxia telangiectasia mutated (ATM)-dependent checkpoint signaling during recovery from DNA double-strand breaks. Inhibition of Src activity increased ATM-dependent phosphorylation of Chk2 and Kap1. Src inhibition increased ATM signaling both in G2 phase and during asynchronous growth. shRNA knockdown of Lyn increased ATM signaling. Src-dependent nuclear tyrosine phosphorylation suppressed ATM-mediated Kap1 phosphorylation. These results suggest that Src family kinases are involved in upstream signaling that leads to inactivation of the ATM-dependent DNA damage checkpoint

  13. Nuclear blackmail and nuclear balance

    International Nuclear Information System (INIS)

    Betts, R.K.

    1987-01-01

    This book raises pointed questions about nuclear saber rattling. More than a dozen cases since the bombing of Hiroshima and Magasaki in which some sort of nuclear threat was used as a sparring technique in tense confrontations are cited. Each incident is described and analyzed. Two theories offered to explain America's use of nuclear threats, the balance of interest theory and the balance of power theory, are contrasted throughout the book. This book helps to fill the gap in the understanding of nuclear weapons and their uses, while pointing out that nuclear bravado could lead to an unintended unleashing of these weapons

  14. Nuclear energy and nuclear weapons

    International Nuclear Information System (INIS)

    Robertson, J.A.L.

    1983-06-01

    We all want to prevent the use of nuclear weapons. The issue before us is how best to achieve this objective; more specifically, whether the peaceful applications of nuclear energy help or hinder, and to what extent. Many of us in the nuclear industry are working on these applications from a conviction that without peaceful nuclear energy the risk of nuclear war would be appreciably greater. Others, however, hold the opposite view. In discussing the subject, a necessary step in allaying fears is understanding some facts, and indeed facing up to some unpalatable facts. When the facts are assessed, and a balance struck, the conclusion is that peaceful nuclear energy is much more part of the solution to preventing nuclear war than it is part of the problem

  15. 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.

  16. 2-Aminopyridine-Based Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (MAP4K4) Inhibitors: Assessment of Mechanism-Based Safety.

    Science.gov (United States)

    Dow, Robert L; Ammirati, Mark; Bagley, Scott W; Bhattacharya, Samit K; Buckbinder, Leonard; Cortes, Christian; El-Kattan, Ayman F; Ford, Kristen; Freeman, Gary B; Guimarães, Cristiano R W; Liu, Shenping; Niosi, Mark; Skoura, Athanasia; Tess, David

    2018-04-12

    Studies have linked the serine-threonine kinase MAP4K4 to the regulation of a number of biological processes and/or diseases, including diabetes, cancer, inflammation, and angiogenesis. With a majority of the members of our lead series (e.g., 1) suffering from time-dependent inhibition (TDI) of CYP3A4, we sought design avenues that would eliminate this risk. One such approach arose from the observation that carboxylic acid-based intermediates employed in our discovery efforts retained high MAP4K4 inhibitory potency and were devoid of the TDI risk. The medicinal chemistry effort that led to the discovery of this central nervous system-impaired inhibitor together with its preclinical safety profile is described.

  17. Protein kinase substrate identification on functional protein arrays

    Directory of Open Access Journals (Sweden)

    Zhou Fang

    2008-02-01

    Full Text Available Abstract Background Over the last decade, kinases have emerged as attractive therapeutic targets for a number of different diseases, and numerous high throughput screening efforts in the pharmaceutical community are directed towards discovery of compounds that regulate kinase function. The emerging utility of systems biology approaches has necessitated the development of multiplex tools suitable for proteomic-scale experiments to replace lower throughput technologies such as mass spectroscopy for the study of protein phosphorylation. Recently, a new approach for identifying substrates of protein kinases has applied the miniaturized format of functional protein arrays to characterize phosphorylation for thousands of candidate protein substrates in a single experiment. This method involves the addition of protein kinases in solution to arrays of immobilized proteins to identify substrates using highly sensitive radioactive detection and hit identification algorithms. Results To date, the factors required for optimal performance of protein array-based kinase substrate identification have not been described. In the current study, we have carried out a detailed characterization of the protein array-based method for kinase substrate identification, including an examination of the effects of time, buffer compositions, and protein concentration on the results. The protein array approach was compared to standard solution-based assays for assessing substrate phosphorylation, and a correlation of greater than 80% was observed. The results presented here demonstrate how novel substrates for protein kinases can be quickly identified from arrays containing thousands of human proteins to provide new clues to protein kinase function. In addition, a pooling-deconvolution strategy was developed and applied that enhances characterization of specific kinase-substrate relationships and decreases reagent consumption. Conclusion Functional protein microarrays are an

  18. 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 via a polyproline type II left-handed helix. The SH2 and SH3 domains occur on the backside of the kinase domain away from the active site where they stabilize a dormant enzyme conformation. Protein-tyrosine phosphatases such as PTPα displace phosphotyrosine 527 from the Src SH2 domain and mediate its dephosphorylation leading to Src kinase activation. C-terminal Src kinase consists of an SH3, SH2, and kinase domain; it lacks an N-terminal myristoyl group and a C-terminal regulatory tail. Its X-ray structure has been determined, and the SH2 lobe occupies a position that is entirely different from that of Src. Unlike Src, the C-terminal Src kinase SH2 and SH3 domains stabilize an active enzyme conformation. Amino acid residues in the αD helix near the catalytic loop in the large lobe of C-terminal Src kinase serve as a docking site for the physiological substrate (Src) but not for an artificial substrate (polyGlu 4 Tyr)

  19. Structural studies of Schistosoma mansoni adenylate kinases

    International Nuclear Information System (INIS)

    Marques, I.A.; Pereira, H.M.; Garrat, R.C.

    2012-01-01

    Full text: Parasitic diseases are a major cause of death in developing countries, however receive little or no attention from pharmaceutical companies for the development of novel therapies. In this respect, the Center for Structural Molecular Biology (CBME) of the Institute of Physics of Sao Carlos (IFSC / USP) has developed expertise in all stages of the development of active compounds against target enzymes from parasitic diseases. The present work focuses on the adenylate kinase enzymes (ADK's) from Schistosoma mansoni. These enzymes are widely distributed and catalyze the reaction of phosphoryl exchange between nucleotides in the reaction 2ADP to ATP + AMP, which is critical for the cells life cycle. Due to the particular property of the reaction catalyzed, the ADK's are recognized as reporters of the cells energetic state, translating small changes in the balance between ATP and ADP into a large change in concentration of AMP. The genome of S. mansoni was recently sequenced by the Sanger Center in England. On performing searches for genes encoding adenylate kinases we found two such genes. The corresponding gene products were named ADK1 (197 residues) and ADK2 (239 residues), and the two sequences share only 28 percent identity. Both have been cloned into the pET-28a(+)vector, expressed in E. coli and purified. Preliminary tests of activity have been performed only for ADK1 showing it to be catalytically active. Crystallization trials were performed for both proteins and thus far, crystals of ADK1 have been obtained which diffract to 2.05 at the LNLS beamline MX2 and the structure solved by molecular replacement. Understanding, at the atomic level, the function of these enzymes may help in the development of specific inhibitors and may provide tools for developing diagnostic tests for schistosomiasis. (author)

  20. Hybrid and rogue kinases encoded in the genomes of model eukaryotes.

    Directory of Open Access Journals (Sweden)

    Ramaswamy Rakshambikai

    Full Text Available The highly modular nature of protein kinases generates diverse functional roles mediated by evolutionary events such as domain recombination, insertion and deletion of domains. Usually domain architecture of a kinase is related to the subfamily to which the kinase catalytic domain belongs. However outlier kinases with unusual domain architectures serve in the expansion of the functional space of the protein kinase family. For example, Src kinases are made-up of SH2 and SH3 domains in addition to the kinase catalytic domain. A kinase which lacks these two domains but retains sequence characteristics within the kinase catalytic domain is an outlier that is likely to have modes of regulation different from classical src kinases. This study defines two types of outlier kinases: hybrids and rogues depending on the nature of domain recombination. Hybrid kinases are those where the catalytic kinase domain belongs to a kinase subfamily but the domain architecture is typical of another kinase subfamily. Rogue kinases are those with kinase catalytic domain characteristic of a kinase subfamily but the domain architecture is typical of neither that subfamily nor any other kinase subfamily. This report provides a consolidated set of such hybrid and rogue kinases gleaned from six eukaryotic genomes-S.cerevisiae, D. melanogaster, C.elegans, M.musculus, T.rubripes and H.sapiens-and discusses their functions. The presence of such kinases necessitates a revisiting of the classification scheme of the protein kinase family using full length sequences apart from classical classification using solely the sequences of kinase catalytic domains. The study of these kinases provides a good insight in engineering signalling pathways for a desired output. Lastly, identification of hybrids and rogues in pathogenic protozoa such as P.falciparum sheds light on possible strategies in host-pathogen interactions.

  1. Overcoming Resistance to Inhibitors of the Akt Protein Kinase by Modulation of the Pim Kinase Pathway

    Science.gov (United States)

    2017-01-01

    v e V ia b il it y Figure 8. PC3-LN4 cells in normoxia or hypoxia were treated with Pim inhibitors. Left panel shows a Western blot and the...3728-36, PMID 25241892 4. Warfel, NA, Kraft, AS. Pim kinase (and Akt) biology and signaling in tumors. Pharmacol Ther. 2015 Jul; 151: 41 - 9. doi: 10.1016...Associated Fibroblast Biology in Prostate Cancer These studies will accelerate and significantly advance the rational development of targeted agents

  2. Transphosphorylation of E. coli proteins during production of recombinant protein kinases provides a robust system to characterize kinase specificity

    Science.gov (United States)

    Protein kinase specificity is of fundamental importance to pathway regulation and signal transduction. Here, we report a convenient system to monitor the activity and specificity of recombinant protein kinases expressed in E.coli. We apply this to the study of the cytoplasmic domain of the plant rec...

  3. Creatine kinase and creatine kinase subunit-B in coronary sinus blood in pacing-induced angina pectoris

    DEFF Research Database (Denmark)

    Bagger, J P; Ingerslev, J; Heinsvig, E M

    1982-01-01

    In nine out of 10 patients with angiographic documented coronary artery disease, pacing-induced angina pectoris provoked myocardial production of lactate, whereas no significant release of either creatine kinase or creatine kinase subunit-B to coronary sinus and peripheral venous blood could...

  4. Identifying kinase dependency in cancer cells by integrating high-throughput drug screening and kinase inhibition data.

    Science.gov (United States)

    Ryall, Karen A; Shin, Jimin; Yoo, Minjae; Hinz, Trista K; Kim, Jihye; Kang, Jaewoo; Heasley, Lynn E; Tan, Aik Choon

    2015-12-01

    Targeted kinase inhibitors have dramatically improved cancer treatment, but kinase dependency for an individual patient or cancer cell can be challenging to predict. Kinase dependency does not always correspond with gene expression and mutation status. High-throughput drug screens are powerful tools for determining kinase dependency, but drug polypharmacology can make results difficult to interpret. We developed Kinase Addiction Ranker (KAR), an algorithm that integrates high-throughput drug screening data, comprehensive kinase inhibition data and gene expression profiles to identify kinase dependency in cancer cells. We applied KAR to predict kinase dependency of 21 lung cancer cell lines and 151 leukemia patient samples using published datasets. We experimentally validated KAR predictions of FGFR and MTOR dependence in lung cancer cell line H1581, showing synergistic reduction in proliferation after combining ponatinib and AZD8055. KAR can be downloaded as a Python function or a MATLAB script along with example inputs and outputs at: http://tanlab.ucdenver.edu/KAR/. aikchoon.tan@ucdenver.edu. Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Nuclear materials

    International Nuclear Information System (INIS)

    1996-01-01

    In 1998, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) performed 38 inspections, 25 of them were performed in co-operation with IAEA inspectors. There is no fresh nuclear fuel at Bohunice A-1 NPP at present. Fresh fuel of Bohunice V-1 and V-2 NPPs is inspected in the fresh fuel storage.There are 327 fresh fuel assemblies in Mochovce NPP fresh fuel storage. In addition to that, are also 71 small users of nuclear materials in Slovakia. In most cases they use: covers made of depleted uranium for non-destructive works, detection of level in production plants, covers for therapeutical sources at medical facilities. In. 1995, NRA SR issued 4 new licences for nuclear material withdrawal. In the next part manipulation with nuclear materials, spent fuel stores and illegal trafficking in nuclear materials are reported

  6. Nuclear Law

    International Nuclear Information System (INIS)

    Wiesbauer, Bruno

    1978-01-01

    This book is the first attempt of a comprehensive compilation of national Austrian Nuclear Law (Nuclear Liability Act; Radiation protection Act, Radiation Protection Ordinance, Security Control Act, Act on the uses of Nuclear Energy - Zwentendorf Nuclear Power Plant) and the most important international agreements to which Austria is a party. Furthermore, the book contains the most important Nuclear Liability Conventions to which Austria is not yet a party, but which are applicable in neighbouring; the Paris Convention served as a model for the national Nuclear Liability Act and may be used for its interpretation. The author has translated a number of international instruments into German, such as the Expose des Motifs of the Paris Convention. (NEA) [fr

  7. Nuclear nonproliferation

    International Nuclear Information System (INIS)

    Neubert, M.

    1992-01-01

    The following motion was put before the United Kingdom House of Commons on 3rd February 1992 and agreed; that this House, recognising the potential dangers of the rapidly changing world order, welcomes the recent proposals for substantial reductions in nuclear weaponry, the growing support for the non-proliferation treaty and progress in the implementation of the United Nations Security Council Resolutions concerning the dismantling of Iraqi nuclear, chemical and biological capabilities; urges the Government to play their full part in helping the relevant authorities in the Commonwealth of Independent States to dismantle their nuclear devices, to safeguard their nuclear components and to discourage the proliferation of nuclear expertise; and believes it is of the first importance that Britain retains an effective and credible minimum nuclear deterrent as security in a world where there remain many sources of instability. The record of arguments for and against the motion in the debate is presented. (author)

  8. Nuclear energy

    International Nuclear Information System (INIS)

    Panait, A.

    1994-01-01

    This is a general report presenting the section VII entitled Nuclear Power of the National Conference on Energy (CNE '94) held in Neptun, Romania, on 13-16 June 1994. The problems addressed were those relating to electric power produced by nuclear power plant, to heat secondary generation, to quality assurance, to safety, etc. A special attention was paid to the commissioning of the first Romanian nuclear power unit, the Cernavoda-1 reactor of CANDU type. The communications were grouped in four subsections. These were: 1. Quality assurance, nuclear safety, and environmental protection; 2. Nuclear power plant, commissioning, and operation; 3. Nuclear power plant inspection, maintenance, and repairs, heavy water technology; 4. Public opinion education. There were 22 reports, altogether

  9. Nuclear power

    International Nuclear Information System (INIS)

    King, P.

    1990-01-01

    Written from the basis of neutrality, neither for nor against nuclear power this book considers whether there are special features of nuclear power which mean that its development should be either promoted or restrained by the State. The author makes it dear that there are no easy answers to the questions raised by the intervention of nuclear power but calls for openness in the nuclear decision making process. First, the need for energy is considered; most people agree that energy is the power to progress. Then the historicalzed background to the current position of nuclear power is given. Further chapters consider the fuel cycle, environmental impacts including carbon dioxide emission and the greenhouse effect, the costs, safety and risks and waste disposal. No conclusion either for or against nuclear power is made. The various shades of opinion are outlined and the arguments presented so that readers can come to their own conclusions. (UK)

  10. Nuclear power

    International Nuclear Information System (INIS)

    Porter, Arthur.

    1980-01-01

    This chapter of the final report of the Royal Commission on Electric Power Planning in Ontario updates its interim report on nuclear power in Ontario (1978) in the light of the Three Mile Island accident and presents the commission's general conclusions and recommendations relating to nuclear power. The risks of nuclear power, reactor safety with special reference to Three Mile Island and incidents at the Bruce generating station, the environmental effects of uranium mining and milling, waste management, nuclear power economics, uranium supplies, socio-political issues, and the regulation of nuclear power are discussed. Specific recommendations are made concerning the organization and public control of Ontario Hydro, but the commission concluded that nuclear power is acceptable in Ontario as long as satisfactory progress is made in the disposal of uranium mill tailings and spent fuel wastes. (LL)

  11. Interaction between focal adhesion kinase and Crk-associated tyrosine kinase substrate p130Cas.

    Science.gov (United States)

    Polte, T R; Hanks, S K

    1995-11-07

    The focal adhesion kinase (FAK) has been implicated in integrin-mediated signaling events and in the mechanism of cell transformation by the v-Src and v-Crk oncoproteins. To gain further insight into FAK signaling pathways, we used a two-hybrid screen to identify proteins that interact with mouse FAK. The screen identified two proteins that interact with FAK via their Src homology 3 (SH3) domains: a v-Crk-associated tyrosine kinase substrate (Cas), p130Cas, and a still uncharacterized protein, FIPSH3-2, which contains an SH3 domain closely related to that of p130Cas. These SH3 domains bind to the same proline-rich region of FAK (APPKPSR) encompassing residues 711-717. The mouse p130Cas amino acid sequence was deduced from cDNA clones, revealing an overall high degree of similarity to the recently reported rat sequence. Coimmunoprecipitation experiments confirmed that p130Cas and FAK are associated in mouse fibroblasts. The stable interaction between p130Cas and FAK emerges as a likely key element in integrin-mediated signal transduction and further represents a direct molecular link between the v-Src and v-Crk oncoproteins. The Src family kinase Fyn, whose Src homology 2 (SH2) domain binds to the major FAK autophosphorylation site (tyrosine 397), was also identified in the two-hybrid screen.

  12. Protein kinase C mediates platelet secretion and thrombus formation through protein kinase D2.

    Science.gov (United States)

    Konopatskaya, Olga; Matthews, Sharon A; Harper, Matthew T; Gilio, Karen; Cosemans, Judith M E M; Williams, Christopher M; Navarro, Maria N; Carter, Deborah A; Heemskerk, Johan W M; Leitges, Michael; Cantrell, Doreen; Poole, Alastair W

    2011-07-14

    Platelets are highly specialized blood cells critically involved in hemostasis and thrombosis. Members of the protein kinase C (PKC) family have established roles in regulating platelet function and thrombosis, but the molecular mechanisms are not clearly understood. In particular, the conventional PKC isoform, PKCα, is a major regulator of platelet granule secretion, but the molecular pathway from PKCα to secretion is not defined. Protein kinase D (PKD) is a family of 3 kinases activated by PKC, which may represent a step in the PKC signaling pathway to secretion. In the present study, we show that PKD2 is the sole PKD member regulated downstream of PKC in platelets, and that the conventional, but not novel, PKC isoforms provide the upstream signal. Platelets from a gene knock-in mouse in which 2 key phosphorylation sites in PKD2 have been mutated (Ser707Ala/Ser711Ala) show a significant reduction in agonist-induced dense granule secretion, but not in α-granule secretion. This deficiency in dense granule release was responsible for a reduced platelet aggregation and a marked reduction in thrombus formation. Our results show that in the molecular pathway to secretion, PKD2 is a key component of the PKC-mediated pathway to platelet activation and thrombus formation through its selective regulation of dense granule secretion.

  13. Retrospective natural history of thymidine kinase 2 deficiency.

    Science.gov (United States)

    Garone, Caterina; Taylor, Robert W; Nascimento, Andrés; Poulton, Joanna; Fratter, Carl; Domínguez-González, Cristina; Evans, Julie C; Loos, Mariana; Isohanni, Pirjo; Suomalainen, Anu; Ram, Dipak; Hughes, M Imelda; McFarland, Robert; Barca, Emanuele; Lopez Gomez, Carlos; Jayawant, Sandeep; Thomas, Neil D; Manzur, Adnan Y; Kleinsteuber, Karin; Martin, Miguel A; Kerr, Timothy; Gorman, Grainne S; Sommerville, Ewen W; Chinnery, Patrick F; Hofer, Monika; Karch, Christoph; Ralph, Jeffrey; Cámara, Yolanda; Madruga-Garrido, Marcos; Domínguez-Carral, Jana; Ortez, Carlos; Emperador, Sonia; Montoya, Julio; Chakrapani, Anupam; Kriger, Joshua F; Schoenaker, Robert; Levin, Bruce; Thompson, John L P; Long, Yuelin; Rahman, Shamima; Donati, Maria Alice; DiMauro, Salvatore; Hirano, Michio

    2018-03-30

    Thymine kinase 2 (TK2) is a mitochondrial matrix protein encoded in nuclear DNA and phosphorylates the pyrimidine nucleosides: thymidine and deoxycytidine. Autosomal recessive TK2 mutations cause a spectrum of disease from infantile onset to adult onset manifesting primarily as myopathy. To perform a retrospective natural history study of a large cohort of patients with TK2 deficiency. The study was conducted by 42 investigators across 31 academic medical centres. We identified 92 patients with genetically confirmed diagnoses of TK2 deficiency: 67 from literature review and 25 unreported cases. Based on clinical and molecular genetics findings, we recognised three phenotypes with divergent survival: (1) infantile-onset myopathy (42.4%) with severe mitochondrial DNA (mtDNA) depletion, frequent neurological involvement and rapid progression to early mortality (median post-onset survival (POS) 1.00, CI 0.58 to 2.33 years); (2) childhood-onset myopathy (40.2%) with mtDNA depletion, moderate-to-severe progression of generalised weakness and median POS at least 13 years; and (3) late-onset myopathy (17.4%) with mild limb weakness at onset and slow progression to respiratory insufficiency with median POS of 23 years. Ophthalmoparesis and facial weakness are frequent in adults. Muscle biopsies show multiple mtDNA deletions often with mtDNA depletion. In TK2 deficiency, age at onset, rate of weakness progression and POS are important variables that define three clinical subtypes. Nervous system involvement often complicates the clinical course of the infantile-onset form while extraocular muscle and facial involvement are characteristic of the late-onset form. Our observations provide essential information for planning future clinical trials in this disorder. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. Pyruvate Dehydrogenase Kinase as a Novel Therapeutic Target in Oncology

    Directory of Open Access Journals (Sweden)

    Gopinath eSutendra

    2013-03-01

    Full Text Available Current drug development in oncology is non-selective as it typically focuses on pathways essential for the survival of all dividing cells. The unique metabolic profile of cancer, which is characterized by increased glycolysis and suppressed mitochondrial glucose oxidation provides cancer cells with a proliferative advantage, conducive with apoptosis resistance and even increased angiogenesis. Recent evidence suggests that targeting the cancer-specific metabolic and mitochondrial remodeling may offer selectivity in cancer treatment. Pyruvate dehydrogenase kinase (PDK is a mitochondrial enzyme that is activated in a variety of cancers and results in the selective inhibition of pyruvate dehydrogenase (PDH, a complex of enzymes that converts cytosolic pyruvate to mitochondrial acetyl-CoA, the substrate for the Krebs’ cycle. Inhibition of PDK with either small interfering RNAs or the orphan drug dichloroacetate (DCA shifts the metabolism of cancer cells from glycolysis to glucose oxidation and reverses the suppression of mitochondria-dependent apoptosis. In addition, this therapeutic strategy increases the production of diffusible Krebs’ cycle intermediates and mitochondria-derived reactive oxygen species (mROS, activating p53 or inhibiting pro-proliferative and pro-angiogenic transcription factors like nuclear factor of activated T-cells (NFAT and hypoxia-inducible factor 1α (HIF1α. These effects result in decreased tumor growth and angiogenesis in a variety of cancers with high selectivity. In a small but mechanistic clinical trial in patients with glioblastoma, a highly aggressive and vascular form of brain cancer, DCA decreased tumor angiogenesis and tumor growth, suggesting that metabolic targeting therapies can be translated directly to patients. Therefore, reversing the mitochondrial suppression with metabolic-modulating drugs, like PDK inhibitors holds promise in the rapidly expanding field of metabolic oncology.

  15. Contractions activate hormone-sensitive lipase in rat muscle by protein kinase C and mitogen-activated protein kinase

    DEFF Research Database (Denmark)

    Donsmark, Morten; Langfort, Jozef; Holm, Cecilia

    2003-01-01

    and contractions. Adrenaline acts via cAMP-dependent protein kinase (PKA). The signalling mediating the effect of contractions is unknown and was explored in this study. Incubated soleus muscles from 70 g male rats were electrically stimulated to perform repeated tetanic contractions for 5 min. The contraction......Intramuscular triacylglycerol is an important energy store and is also related to insulin resistance. The mobilization of fatty acids from this pool is probably regulated by hormone-sensitive lipase (HSL), which has recently been shown to exist in muscle and to be activated by both adrenaline......-induced activation of HSL was abolished by the protein kinase C (PKC) inhibitors bisindolylmaleimide I and calphostin C and reduced 50% by the mitogen-activated protein kinase kinase (MEK) inhibitor U0126, which also completely blocked extracellular signal-regulated kinase (ERK) 1 and 2 phosphorylation. None...

  16. Nuclear astrophysics

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1992-01-01

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized

  17. Nuclear physics

    International Nuclear Information System (INIS)

    Patel, S.B.

    1991-01-01

    This book is a simple and direct introduction to the tools of modern nuclear physics, both experimental and mathematical. Emphasizes physical intuition and illuminating analogies, rather than formal mathematics. Topics covered include particle accelerators, radioactive series, types of nuclear reactions, detection of the neutrino, nuclear isomerism, binding energy of nuclei, fission chain reactions, and predictions of the shell model. Each chapter contains problems and illustrative examples. Pre-requisites are calculus and elementary vector analysis

  18. Nuclear energy

    International Nuclear Information System (INIS)

    Hesketh, Ross.

    1985-01-01

    The subject is treated under the headings: nuclear energy -what is it; fusion (principles; practice); fission (principles); reactor types and systems (fast (neutron) reactors as breeders; fast reactors; thermal reactors; graphite-moderated thermal reactors; the CANDU reactor; light water reactors - the BWR and the PWR); the nuclear fuel cycle (waste storage; fuel element manufacture; enrichment processes; uranium mining); safety and risk assessment; the nuclear power industry and the economy (regulating authorities; economics; advantages and disadvantages). (U.K.)

  19. Nuclear Asia

    National Research Council Canada - National Science Library

    Ferguson, Joseph; Tarleton, Gael

    2004-01-01

    .... This event was an opportunity for policy makers, security analysts, nuclear scientists and engineers, regional experts, and military planners to share perspectives and identify those issues requiring...

  20. Nuclear cardiology

    International Nuclear Information System (INIS)

    Fish, M.B.

    2002-01-01

    Recent advances in nuclear medicine instrumentation and software, including myocardial perfusion imaging, offer increased accuracy in the detection, diagnosis and prognosis of coronary artery disease. (orig.)

  1. Nuclear medicine

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The area of nuclear medicine, the development of artificially produced radioactive isotopes for medical applications, is relatively recent. Among the subjects covered in a lengthy discussion are the following: history of development; impact of nuclear medicine; understanding the most effective use of radioisotopes; most significant uses of nuclear medicine radioimmunoassays; description of equipment designed for use in the field of nuclear medicine (counters, scanning system, display systems, gamma camera); description of radioisotopes used and their purposes; quality control. Numerous historical photographs are included. 52 refs

  2. Nuclear Law

    International Nuclear Information System (INIS)

    Pascal, Maurice.

    1979-01-01

    This book on nuclear law is the first of a series of analytical studies to be published by the French Energy Commission (CEA) concerning all the various nuclear activities. It describes national and international legislation applicable in France covering the following main sectors: the licensing procedure for nuclear installations, the law of the sea and nuclear law, the legal system governing radioisotopes, the transport of radioactive materials, third party liability and insurance and radiation protection. In each chapter, the overall analysis is supplemented by the relevant regulatory texts and by organisation charts in annex. (NEA) [fr

  3. Nuclear Safety

    Energy Technology Data Exchange (ETDEWEB)

    Silver, E G [ed.

    1989-01-01

    This document is a review journal that covers significant developments in the field of nuclear safety. Its scope includes the analysis and control of hazards associated with nuclear energy, operations involving fissionable materials, and the products of nuclear fission and their effects on the environment. Primary emphasis is on safety in reactor design, construction, and operation; however, the safety aspects of the entire fuel cycle, including fuel fabrication, spent-fuel processing, nuclear waste disposal, handling of radioisotopes, and environmental effects of these operations, are also treated.

  4. Nuclear power

    International Nuclear Information System (INIS)

    Bupp, I.C.

    1991-01-01

    Is a nuclear power renaissance likely to occur in the United States? This paper investigates the many driving forces that will determine the answer to that question. This analysis reveals some frequently overlooked truths about the current state of nuclear technology: An examination of the issues also produces some noteworthy insights concerning government regulations and related technologies. Public opinion will play a major role in the unfolding story of the nuclear power renaissance. Some observers are betting that psychological, sociological, and political considerations will hod sway over public attitudes. Others wager that economic and technical concerns will prevail. The implications for the nuclear power renaissance are striking

  5. Protein kinase inhibitor peptide (PKI): a family of endogenous neuropeptides that modulate neuronal cAMP-dependent protein kinase function.

    Science.gov (United States)

    Dalton, George D; Dewey, William L

    2006-02-01

    Signal transduction cascades involving cAMP-dependent protein kinase are highly conserved among a wide variety of organisms. Given the universal nature of this enzyme it is not surprising that cAMP-dependent protein kinase plays a critical role in numerous cellular processes. This is particularly evident in the nervous system where cAMP-dependent protein kinase is involved in neurotransmitter release, gene transcription, and synaptic plasticity. Protein kinase inhibitor peptide (PKI) is an endogenous thermostable peptide that modulates cAMP-dependent protein kinase function. PKI contains two distinct functional domains within its amino acid sequence that allow it to: (1) potently and specifically inhibit the activity of the free catalytic subunit of cAMP-dependent protein kinase and (2) export the free catalytic subunit of cAMP-dependent protein kinase from the nucleus. Three distinct PKI isoforms (PKIalpha, PKIbeta, PKIgamma) have been identified and each isoform is expressed in the brain. PKI modulates neuronal synaptic activity, while PKI also is involved in morphogenesis and symmetrical left-right axis formation. In addition, PKI also plays a role in regulating gene expression induced by cAMP-dependent protein kinase. Future studies should identify novel physiological functions for endogenous PKI both in the nervous system and throughout the body. Most interesting will be the determination whether functional differences exist between individual PKI isoforms which is an intriguing possibility since these isoforms exhibit: (1) cell-type specific tissue expression patterns, (2) different potencies for the inhibition of cAMP-dependent protein kinase activity, and (3) expression patterns that are hormonally, developmentally and cell-cycle regulated. Finally, synthetic peptide analogs of endogenous PKI will continue to be invaluable tools that are used to elucidate the role of cAMP-dependent protein kinase in a variety of cellular processes throughout the nervous

  6. The NDR kinase scaffold HYM1/MO25 is essential for MAK2 map kinase signaling in Neurospora crassa.

    Directory of Open Access Journals (Sweden)

    Anne Dettmann

    2012-09-01

    Full Text Available Cell communication is essential for eukaryotic development, but our knowledge of molecules and mechanisms required for intercellular communication is fragmentary. In particular, the connection between signal sensing and regulation of cell polarity is poorly understood. In the filamentous ascomycete Neurospora crassa, germinating spores mutually attract each other and subsequently fuse. During these tropic interactions, the two communicating cells rapidly alternate between two different physiological states, probably associated with signal delivery and response. The MAK2 MAP kinase cascade mediates cell-cell signaling. Here, we show that the conserved scaffolding protein HYM1/MO25 controls the cell shape-regulating NDR kinase module as well as the signal-receiving MAP kinase cascade. HYM1 functions as an integral part of the COT1 NDR kinase complex to regulate the interaction with its upstream kinase POD6 and thereby COT1 activity. In addition, HYM1 interacts with NRC1, MEK2, and MAK2, the three kinases of the MAK2 MAP kinase cascade, and co-localizes with MAK2 at the apex of growing cells. During cell fusion, the three kinases of the MAP kinase module as well as HYM1 are recruited to the point of cell-cell contact. hym-1 mutants phenocopy all defects observed for MAK2 pathway mutants by abolishing MAK2 activity. An NRC1-MEK2 fusion protein reconstitutes MAK2 signaling in hym-1, while constitutive activation of NRC1 and MEK2 does not. These data identify HYM1 as a novel regulator of the NRC1-MEK2-MAK2 pathway, which may coordinate NDR and MAP kinase signaling during cell polarity and intercellular communication.

  7. hnRNP-U is a specific DNA-dependent protein kinase substrate phosphorylated in response to DNA double-strand breaks

    International Nuclear Information System (INIS)

    Berglund, Fredrik M.; Clarke, Paul R.

    2009-01-01

    Cellular responses to DNA damage are orchestrated by the large phosphoinositol-3-kinase related kinases ATM, ATR and DNA-PK. We have developed a cell-free system to dissect the biochemical mechanisms of these kinases. Using this system, we identify heterogeneous nuclear ribonucleoprotein U (hnRNP-U), also termed scaffold attachment factor A (SAF-A), as a specific substrate for DNA-PK. We show that hnRNP-U is phosphorylated at Ser59 by DNA-PK in vitro and in cells in response to DNA double-strand breaks. Phosphorylation of hnRNP-U suggests novel functions for DNA-PK in the response to DNA damage.

  8. RhoA/Rho-Kinase in the Cardiovascular System.

    Science.gov (United States)

    Shimokawa, Hiroaki; Sunamura, Shinichiro; Satoh, Kimio

    2016-01-22

    Twenty years ago, Rho-kinase was identified as an important downstream effector of the small GTP-binding protein, RhoA. Thereafter, a series of studies demonstrated the important roles of Rho-kinase in the cardiovascular system. The RhoA/Rho-kinase pathway is now widely known to play important roles in many cellular functions, including contraction, motility, proliferation, and apoptosis, and its excessive activity induces oxidative stress and promotes the development of cardiovascular diseases. Furthermore, the important role of Rho-kinase has been demonstrated in the pathogenesis of vasospasm, arteriosclerosis, ischemia/reperfusion injury, hypertension, pulmonary hypertension, and heart failure. Cyclophilin A is secreted by vascular smooth muscle cells and inflammatory cells and activated platelets in a Rho-kinase-dependent manner, playing important roles in a wide range of cardiovascular diseases. Thus, the RhoA/Rho-kinase pathway plays crucial roles under both physiological and pathological conditions and is an important therapeutic target in cardiovascular medicine. Recently, functional differences between ROCK1 and ROCK2 have been reported in vitro. ROCK1 is specifically cleaved by caspase-3, whereas granzyme B cleaves ROCK2. However, limited information is available on the functional differences and interactions between ROCK1 and ROCK2 in the cardiovascular system in vivo. Herein, we will review the recent advances about the importance of RhoA/Rho-kinase in the cardiovascular system. © 2016 American Heart Association, Inc.

  9. Kinase inhibition by the Jamaican ball moss, Tillandsia recurvata L.

    Science.gov (United States)

    Lowe, Henry I C; Watson, Charah T; Badal, Simone; Toyang, Ngeh J; Bryant, Joseph

    2012-10-01

    This research was undertaken in order to investigate the inhibitory potential of the Jamaican ball moss, Tillandsia recurvata against several kinases. The inhibition of these kinases has emerged as a potential solution to restoring the tight regulation of normal cellular growth, the loss of which leads to cancer cell formation. Kinase inhibition was investigated using competition binding (to the ATP sites) assays, which have been previously established and authenticated. Four hundred and fifty one kinases were tested against the Jamaican ball moss extract and a dose-response was tested on 40 kinases, which were inhibited by more than 35% compared to the control. Out of the 40 kinases, the Jamaican ball moss selectively inhibited 5 (CSNK2A2, MEK5, GAK, FLT and DRAK1) and obtained Kd(50)s were below 20 μg/ml. Since MEK5 and GAK kinases have been associated with aggressive prostate cancer, the inhibitory properties of the ball moss against them, coupled with its previously found bioactivity towards the PC-3 cell line, makes it promising in the arena of drug discovery towards prostate cancer.

  10. Structure of the intact ATM/Tel1 kinase

    Science.gov (United States)

    Wang, Xuejuan; Chu, Huanyu; Lv, Mengjuan; Zhang, Zhihui; Qiu, Shuwan; Liu, Haiyan; Shen, Xuetong; Wang, Weiwu; Cai, Gang

    2016-05-01

    The ataxia-telangiectasia mutated (ATM) protein is an apical kinase that orchestrates the multifaceted DNA-damage response. Normally, ATM kinase is in an inactive, homodimer form and is transformed into monomers upon activation. Besides a conserved kinase domain at the C terminus, ATM contains three other structural modules, referred to as FAT, FATC and N-terminal helical solenoid. Here we report the first cryo-EM structure of ATM kinase, which is an intact homodimeric ATM/Tel1 from Schizosaccharomyces pombe. We show that two monomers directly contact head-to-head through the FAT and kinase domains. The tandem N-terminal helical solenoid tightly packs against the FAT and kinase domains. The structure suggests that ATM/Tel1 dimer interface and the consecutive HEAT repeats inhibit the binding of kinase substrates and regulators by steric hindrance. Our study provides a structural framework for understanding the mechanisms of ATM/Tel1 regulation as well as the development of new therapeutic agents.

  11. The nuclear import of ribosomal proteins is regulated by mTOR

    Science.gov (United States)

    Kazyken, Dubek; Kaz, Yelimbek; Kiyan, Vladimir; Zhylkibayev, Assylbek A.; Chen, Chien-Hung; Agarwal, Nitin K.; Sarbassov, Dos D.

    2014-01-01

    Mechanistic target of rapamycin (mTOR) is a central component of the essential signaling pathway that regulates cell growth and proliferation by controlling anabolic processes in cells. mTOR exists in two distinct mTOR complexes known as mTORC1 and mTORC2 that reside mostly in cytoplasm. In our study, the biochemical characterization of mTOR led to discovery of its novel localization on nuclear envelope where it associates with a critical regulator of nuclear import Ran Binding Protein 2 (RanBP2). We show that association of mTOR with RanBP2 is dependent on the mTOR kinase activity that regulates the nuclear import of ribosomal proteins. The mTOR kinase inhibitors within thirty minutes caused a substantial decrease of ribosomal proteins in the nuclear but not cytoplasmic fraction. Detection of a nuclear accumulation of the GFP-tagged ribosomal protein rpL7a also indicated its dependence on the mTOR kinase activity. The nuclear abundance of ribosomal proteins was not affected by inhibition of mTOR Complex 1 (mTORC1) by rapamycin or deficiency of mTORC2, suggesting a distinctive role of the nuclear envelope mTOR complex in the nuclear import. Thus, we identified that mTOR in association with RanBP2 mediates the active nuclear import of ribosomal proteins. PMID:25294810

  12. Nuclear stress test

    Science.gov (United States)

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  13. Src-family kinases negatively regulate NFAT signaling in resting human T cells.

    Directory of Open Access Journals (Sweden)

    Alan Baer

    Full Text Available T cell signaling is required for activation of both natural and therapeutic T cells including chimeric antigen receptor (CAR T cells. Identification of novel factors and pathways regulating T cell signaling may aid in development of effective T cell therapies. In resting human T cells, the majority of Src-family of tyrosine kinases (SFKs are inactive due to phosphorylation of a conserved carboxy-terminal tyrosine residue. Recently, a pool of enzymatically active SFKs has been identified in resting T cells; however, the significance of these is incompletely understood. Here, we characterized the role of active SFKs in resting human T cells. Pharmacologic inhibition of active SFKs enhanced distal TCR signaling as measured by IL-2 release and CD25 surface expression following TCR-independent activation. Mechanistically, inhibition of the active pool of SFKs induced nuclear translocation of NFAT1, and enhanced NFAT1-dependent signaling in resting T cells. The negative regulation of NFAT1 signaling was in part mediated by the Src-kinase Lck as human T cells lacking Lck had increased levels of nuclear NFAT1 and demonstrated enhanced NFAT1-dependent gene expression. Inhibition of active SFKs in resting primary human T cells also increased nuclear NFAT1 and enhanced NFAT1-dependent signaling. Finally, the calcineurin inhibitor FK506 and Cyclosporin A reversed the effect of SFKs inhibition on NFAT1. Together, these data identified a novel role of SFKs in preventing aberrant NFAT1 activation in resting T cells, and suggest that maintaining this pool of active SFKs in therapeutic T cells may increase the efficacy of T cell therapies.

  14. Nuclear physics for nuclear fusion

    International Nuclear Information System (INIS)

    Li Xingzhong; Liu Bin; Wei Qingming; Ren Xianzhe

    2004-01-01

    The D-T fusion cross-section is calculated using quantum mechanics with the model of square nuclear potential well and Coulomb potential barrier. The agreement between ENDF data and the theoretically calculated results is well in the range of 0.2-280 keV. It shows that the application of Breit-Wigner formula is not suitable for the case of the light nuclei fusion reaction. When this model is applied to the nuclear reaction between the charged particles confined in a lattice, it explains the 'abnormal phenomena'. It implies a prospect of nuclear fusion energy without strong nuclear radiations

  15. Nuclear installations

    International Nuclear Information System (INIS)

    2001-01-01

    This document presents the fulfilling of the Brazilian obligations under the Convention on Nuclear Safety. The Chapter 2 of the document contains some details about the existing Brazilian nuclear installations. Also, safety improvements at Angra 1 and aspects of Angra 2 and 3 are reported

  16. Nuclear safety

    International Nuclear Information System (INIS)

    1991-02-01

    This book reviews the accomplishments, operations, and problems faced by the defense Nuclear Facilities Safety Board. Specifically, it discusses the recommendations that the Safety Board made to improve safety and health conditions at the Department of Energy's defense nuclear facilities, problems the Safety Board has encountered in hiring technical staff, and management problems that could affect the Safety Board's independence and credibility

  17. Nuclear violence

    International Nuclear Information System (INIS)

    Mullen, R.K.

    1987-01-01

    A great deal of attention has been paid in the past decade or so to the characteristics of terrorists and their apparent goals and objectives, capabilities, and evolving strategy and tactics with respect to nuclear terrorism. In contrast, little has been said about the procedural aspects of nuclear terrorism, and even less about the way in which such endeavors can fail. This latter omission is important because it bears directly on the ability to evaluate credibly the potential for nuclear terrorism. Here, the author addresses the requirements inherent in acquiring a nuclear explosive capability by three routes: separation of plutonium from irradiated light or heavy water reactor (LWR or HWR) fuel, processing, or use of separated fissile material, and theft of a nuclear weapon. In addition, he deals with other potential acts of nuclear terrorism: sabotage of power reactors, uranium enrichment facilities and spent nuclear fuel in transport, and dispersal of radioactive materials, in particular, plutonium. He specifically does not look at the design or production of a nuclear weapon. Finally, the discussion here assumes that the terrorist is subnational; that is, a nation is not involved. Also, the discussion of subnational participation does not address the possibility of collusion with insiders

  18. Nuclear installations

    International Nuclear Information System (INIS)

    1998-01-01

    This document presents the fulfilling of the Brazilian obligations under the Convention on Nuclear Safety. The Chapter 2 of the document contains some details about the existing Brazilian nuclear installations. Also, safety improvements at Angra 1 and aspects of Angra 2 and 3 are reported

  19. Nuclear power

    International Nuclear Information System (INIS)

    Abd Khalik Wood

    2003-01-01

    This chapter discuss on nuclear power and its advantages. The concept of nucleus fission, fusion, electric generation are discussed in this chapter. Nuclear power has big potential to become alternative energy to substitute current conventional energy from coal, oil and gas

  20. Nuclear energy

    International Nuclear Information System (INIS)

    1978-01-01

    This brochure is intended as a contribution to a better and more general understanding of one of the most urgent problems of present society. Emphasis is laid on three issues that are always raised in the nuclear debate: 1) Fuel cycle, 2) environmental effects of nuclear power plants, 3) waste disposal problems. (GL) [de

  1. Nuclear pollution

    International Nuclear Information System (INIS)

    Ramade, Francois

    1979-01-01

    In this chapter devoted to nuclear pollution the following topics were studied: fundamentals of radiobiology (ecological importance of the various radioisotopes, biological effects of ionizing radiations); ecological effects of radioactive fallout (contamination of atmosphere, terrestrial ecosystems, oceans). The electronuclear industry and its environmental impact. PWR type reactors, fuel reprocessing plants, contamination of trophic chains by radionuclides released in the environment from nuclear installations [fr

  2. Nuclear lifetimes

    International Nuclear Information System (INIS)

    Caraca, J.M.G.

    1976-01-01

    The importance of the results obtained in experiments of measurement of lifetimes for a detailed knowledge of nuclear structure is referred. Direct methods of measurement of nuclear lifetimes are described, namely, electronic methods, recoil-distance method, doppler shift atenuation method and blocking-method. A brief reference is made to indirect methods for measurement of life-times

  3. Nuclear facts

    International Nuclear Information System (INIS)

    1982-01-01

    The subject is discussed as follows: the case for using nuclear energy (Britain's energy needs; energy policy); safety; transport of spent fuel; radiation (natural radioactivity); environment (land use of nuclear power plants; storage and disposal of radioactive wastes). (U.K.)

  4. The 'retro-design' concept for novel kinase inhibitors.

    Science.gov (United States)

    Müller, Gerhard; Sennhenn, Peter C; Woodcock, Timothy; Neumann, Lars

    2010-07-01

    Protein kinases are among the most attractive therapeutic targets for a broad range of diseases. This feature review highlights and classifies the main design principles employed to generate active and selective kinase inhibitors. In particular, emphasis is focused on a fragment-based lead-generation approach, which constitutes a novel design method for developing type II kinase inhibitors with distinct binding kinetic attributes. This 'retro-design' strategy relies on a customized fragment library, and contrasts the traditional approach used in the design of type II inhibitors.

  5. Second-generation inhibitors of Bruton tyrosine kinase

    Directory of Open Access Journals (Sweden)

    Jingjing Wu

    2016-09-01

    Full Text Available Abstract Bruton tyrosine kinase (BTK is a critical effector molecule for B cell development and plays a major role in lymphoma genesis. Ibrutinib is the first-generation BTK inhibitor. Ibrutinib has off-target effects on EGFR, ITK, and Tec family kinases, which explains the untoward effects of ibrutinib. Resistance to ibrutinib was also reported. The C481S mutation in the BTK kinase domain was reported to be a major mechanism of resistance to ibrutinib. This review summarizes the clinical development of novel BTK inhibitors, ACP-196 (acalabrutinib, ONO/GS-4059, and BGB-3111.

  6. Nucleolin (C23), a physiological substrate for casein kinase II

    DEFF Research Database (Denmark)

    Schneider, H R; Issinger, O G

    1988-01-01

    Nucleolin (C23), a 110 kDa phosphoprotein, which is mainly found in the nucleolus has been shown to be a physiological substrate for casein kinase II (CKII). Nucleolin was identified and characterized by immunodetection using an anti-nucleolin antibody. Phosphopeptide patterns from nucleolin...... phosphorylated by purified casein kinase II and of phosphorylated nucleolin which had been isolated from tumor cells grown in the presence of [32P]-o-phosphate, were identical. The partial tryptic digest revealed nine phosphopeptides. Nucleolin isolated from Krebs II mouse ascites cells was phosphorylated...... by purified casein kinase II with about two moles phosphate per one mole of nucleolin....

  7. Resveratrol upregulates Egr-1 expression and activity involving extracellular signal-regulated protein kinase and ternary complex factors

    Energy Technology Data Exchange (ETDEWEB)

    Rössler, Oliver G.; Glatzel, Daniel; Thiel, Gerald, E-mail: gerald.thiel@uks.eu

    2015-03-01

    Many intracellular functions have been attributed to resveratrol, a polyphenolic phytoalexin found in grapes and in other plants. Here, we show that resveratrol induces the expression of the transcription factor Egr-1 in human embryonic kidney cells. Using a chromosomally embedded Egr-1-responsive reporter gene, we show that the Egr-1 activity was significantly elevated in resveratrol-treated cells, indicating that the newly synthesized Egr-1 protein was biologically active. Stimulus-transcription coupling leading to the resveratrol-induced upregulation of Egr-1 expression and activity requires the protein kinases Raf and extracellular signal-regulated protein kinase ERK, while MAP kinase phosphatase-1 functions as a nuclear shut-off device that interrupts the signaling cascade connecting resveratrol stimulation with enhanced Egr-1 expression. On the transcriptional level, Elk-1, a key transcriptional regulator of serum response element-driven gene transcription, connects the intracellular signaling cascade elicited by resveratrol with transcription of the Egr-1 gene. These data were corroborated by the observation that stimulation of the cells with resveratrol increased the transcriptional activation potential of Elk-1. The SRE as well as the GC-rich DNA binding site of Egr-1 function as resveratrol-responsive elements. Thus, resveratrol regulates gene transcription via activation of the stimulus-regulated protein kinases Raf and ERK and the stimulus-responsive transcription factors TCF and Egr-1. - Highlights: • The plant polyphenol resveratrol upregulates Egr-1 expression and activity. • The stimulation of Egr-1 requires the protein kinases ERK and Raf. • Resveratrol treatment upregulates the transcriptional activation potential of Elk-1. • Resveratrol-induced stimulation of Egr-1 requires ternary complex factors. • Two distinct resveratrol-responsive elements were identified.

  8. Resveratrol upregulates Egr-1 expression and activity involving extracellular signal-regulated protein kinase and ternary complex factors

    International Nuclear Information System (INIS)

    Rössler, Oliver G.; Glatzel, Daniel; Thiel, Gerald

    2015-01-01

    Many intracellular functions have been attributed to resveratrol, a polyphenolic phytoalexin found in grapes and in other plants. Here, we show that resveratrol induces the expression of the transcription factor Egr-1 in human embryonic kidney cells. Using a chromosomally embedded Egr-1-responsive reporter gene, we show that the Egr-1 activity was significantly elevated in resveratrol-treated cells, indicating that the newly synthesized Egr-1 protein was biologically active. Stimulus-transcription coupling leading to the resveratrol-induced upregulation of Egr-1 expression and activity requires the protein kinases Raf and extracellular signal-regulated protein kinase ERK, while MAP kinase phosphatase-1 functions as a nuclear shut-off device that interrupts the signaling cascade connecting resveratrol stimulation with enhanced Egr-1 expression. On the transcriptional level, Elk-1, a key transcriptional regulator of serum response element-driven gene transcription, connects the intracellular signaling cascade elicited by resveratrol with transcription of the Egr-1 gene. These data were corroborated by the observation that stimulation of the cells with resveratrol increased the transcriptional activation potential of Elk-1. The SRE as well as the GC-rich DNA binding site of Egr-1 function as resveratrol-responsive elements. Thus, resveratrol regulates gene transcription via activation of the stimulus-regulated protein kinases Raf and ERK and the stimulus-responsive transcription factors TCF and Egr-1. - Highlights: • The plant polyphenol resveratrol upregulates Egr-1 expression and activity. • The stimulation of Egr-1 requires the protein kinases ERK and Raf. • Resveratrol treatment upregulates the transcriptional activation potential of Elk-1. • Resveratrol-induced stimulation of Egr-1 requires ternary complex factors. • Two distinct resveratrol-responsive elements were identified

  9. Interaction of the regulatory subunit of the cAMP-dependent protein kinase with PATZ1 (ZNF278)

    International Nuclear Information System (INIS)

    Yang, Weng-Lang; Ravatn, Roald; Kudoh, Kazuya; Alabanza, Leah; Chin, Khew-Voon

    2010-01-01

    The effects of cAMP in cell are predominantly mediated by the cAMP-dependent protein kinase (PKA), which is composed of two genetically distinct subunits, catalytic (C) and regulatory (R), forming a tetrameric holoenzyme R 2 C 2 . The only known function for the R subunit is that of inhibiting the activity of the C subunit kinase. It has been shown that overexpression of RIα, but not the C subunit kinase, is associated with neoplastic transformation. In addition, it has also been demonstrated that mutation in the RIα, but not the C subunit is associated with increased resistance to the DNA-damaging anticancer drug cisplatin, thus suggesting that the RIα subunit of PKA may have functions independent of the kinase. We show here that the RIα subunit interacts with a BTB/POZ domain zinc-finger transcription factor, PATZ1 (ZNF278), and co-expression with RIα results in its sequestration in the cytoplasm. The cytoplasmic/nuclear translocation is inducible by cAMP. C-terminus deletion abolishes PATZ1 interaction with RIα and results in its localization in the nucleus. PATZ1 transactivates the cMyc promoter and the presence of cAMP and co-expression with RIα modulates its transactivation. Moreover, PATZ1 is aberrantly expressed in cancer. Taken together, our results showed a potentially novel mechanism of cAMP signaling mediated through the interaction of RIα with PATZ1 that is independent of the kinase activity of PKA, and the aberrant expression of PATZ1 in cancer point to its role in cell growth regulation.

  10. Interaction of the regulatory subunit of the cAMP-dependent protein kinase with PATZ1 (ZNF278)

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Weng-Lang [Long Island Jewish Medical Center, North Shore University Hospital, Manhasset, NY 11030 (United States); Ravatn, Roald [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States); Kudoh, Kazuya [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States); Department of Obstetrics and Gynecology, National Defense Medical College, Tokorozawa, Saitama (Japan); Alabanza, Leah [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States); Chin, Khew-Voon, E-mail: khew-voon.chin@utoledo.edu [Department of Medicine, University of Toledo, College of Medicine, Toledo, OH 43614 (United States)

    2010-01-15

    The effects of cAMP in cell are predominantly mediated by the cAMP-dependent protein kinase (PKA), which is composed of two genetically distinct subunits, catalytic (C) and regulatory (R), forming a tetrameric holoenzyme R{sub 2}C{sub 2}. The only known function for the R subunit is that of inhibiting the activity of the C subunit kinase. It has been shown that overexpression of RI{alpha}, but not the C subunit kinase, is associated with neoplastic transformation. In addition, it has also been demonstrated that mutation in the RI{alpha}, but not the C subunit is associated with increased resistance to the DNA-damaging anticancer drug cisplatin, thus suggesting that the RI{alpha} subunit of PKA may have functions independent of the kinase. We show here that the RI{alpha} subunit interacts with a BTB/POZ domain zinc-finger transcription factor, PATZ1 (ZNF278), and co-expression with RI{alpha} results in its sequestration in the cytoplasm. The cytoplasmic/nuclear translocation is inducible by cAMP. C-terminus deletion abolishes PATZ1 interaction with RI{alpha} and results in its localization in the nucleus. PATZ1 transactivates the cMyc promoter and the presence of cAMP and co-expression with RI{alpha} modulates its transactivation. Moreover, PATZ1 is aberrantly expressed in cancer. Taken together, our results showed a potentially novel mechanism of cAMP signaling mediated through the interaction of RI{alpha} with PATZ1 that is independent of the kinase activity of PKA, and the aberrant expression of PATZ1 in cancer point to its role in cell growth regulation.

  11. Nuclear measurements

    International Nuclear Information System (INIS)

    Schenkel, R.

    2005-01-01

    Nuclear measurements play a fundamental role in the development of nuclear technology and the assurance of its peaceful use. They are also required in many non-power nuclear applications such as in nuclear medicine, agriculture, environmental protection, etc. This presentation will show examples of most recent advances in measurement methodology or technology in the areas described below. The Generation IV International Forum has selected six innovative reactor systems as candidates for a next generation of sustainable, economic and safe nuclear energy systems. The choice of the best options relies heavily on the availability of accurate nuclear data that can only be obtained, in an international effort, using highly specialised facilities. Significant efforts are being directed towards the partitioning and transmutation of highly active nuclear waste. Different concepts involving fast reactors or accelerator-driven systems are being studied in view of their transmutation capabilities. State of the art equipment has been developed to assess basic properties of nuclear fuel at very high burn-up; some fine examples of this work will be shown. Physical and chemical methods play a crucial role in the detection and identification of radioisotopes used in various stages of the nuclear fuel cycle. Radiation measurement techniques are used, for example, to monitor the quantities of uranium, plutonium and other actinide elements in fuel enrichment and reprocessing facilities. Another field of application of physical and chemical methods is the characterisation of nuclear material seized from illicit trafficking. Seized material has to be analysed in order to obtain clues on its origin and intended use and to prevent diversion of nuclear material from the same source in the future. A recent highlight in basic physics relates to nuclear fission and transmutation with high intensity lasers. Ultra-fast high intensity lasers can produce high energy (tens of MeV) photons through

  12. Structural Studies of Archaealthermophilic Adenylate Kinase; TOPICAL

    International Nuclear Information System (INIS)

    Konisky, J.

    2002-01-01

    Through this DOE-sponsored program Konisky has studied the evolution and molecular biology of microbes that live in extreme environments. The emphasis of this work has been the determination of the structural features of thermophilic enzymes that allow them to function optimally at near 100 C. The laboratory has focused on a comparative study of adenylate kinase (ADK), an enzyme that functions to interconvert adenine nucleotides. Because of the close phylogenetic relatedness of members of the Methanococci, differences in the structure of their ADKs will be dominated by structural features that reflect contributions to their optimal temperature for activity, rather than differences due to phylogenetic divergence. We have cloned, sequenced and modeled the secondary structure for several methanococcal ADKs. Using molecular modeling threading approaches that are based on the solved structure for the porcine ADK, we have also proposed a general low resolution three dimensional structure for each of the methanococcal enzymes. These analyses have allowed us to propose structural features that confer hyperthermoactivity to those enzymes functioning in the hyperthermophilic members of the Methanococci. Using protein engineering methodologies, we have tested our hypotheses by examining the effects of selective structural changes on thermoactivity. Despite possessing between 68-81% sequence identity, the methanococcal AKs had significantly different stability against thermal denaturation, with melting points ranging from 69-103 C. The construction of several chimerical AKs by linking regions of the MVO and MJA AKs demonstrated the importance of cooperative interactions between amino- and carboxyl-terminal regions in influencing thermostability. Addition of MJA terminal fragments to the MVO AK increased thermal stability approximately 20 C while maintaining 88% of the mesophilic sequence. Further analysis using structural models suggested that hydrophobic interactions are

  13. Nuclear rockets

    International Nuclear Information System (INIS)

    Sarram, M.

    1972-01-01

    Nuclear energy has found many applications in space projects. This article deals with these applications. The first application is the use of nuclear energy for the production of electricity in space and the second main application is the use of nuclear energy for propulsion purposes in space flight. The main objective is to develop a 75000 pound thrust flight engine call NERVA by heating liquid hydrogen, in a nuclear reactor, from 420F to 4000 0 F. The paper describes in detail the salient features of the NERVA rocket as well as its comparison with the conventional chemical rockets. It is shown that a nuclear rocket using liquid hydrogen as medium is at least 85% more efficient as compared with the chemical rockets such as those used for the APOLLO moon flight

  14. Nuclear rockets

    Energy Technology Data Exchange (ETDEWEB)

    Sarram, M [Teheran Univ. (Iran). Inst. of Nuclear Science and Technology

    1972-02-01

    Nuclear energy has found many applications in space projects. This article deals with these applications. The first application is the use of nuclear energy for the production of electricity in space and the second main application is the use of nuclear energy for propulsion purposes in space flight. The main objective is to develop a 75000 pound thrust flight engine called NERVA by heating liquid hydrogen in a nuclear reactor. The paper describes in detail the salient features of the NERVA rocket as well as its comparison with the conventional chemical rockets. It is shown that a nuclear rocket using liquid hydrogen as medium is at least 85% more efficient as compared with the chemical rockets such as those used for the APOLLO moon flight.

  15. Nuclear haematology

    International Nuclear Information System (INIS)

    Masjhur, J.S.

    1992-01-01

    Nuclear techniques have been applied to study diagnose and treat various haematological disorders for more than five decades. Two scientists are regarded as pioneers in this field, i.e. John Lawrence who in 1938 used 32 P to treat chronic myeloid leukaemia and George Hevessy who used 32 P labelled erythrocytes to measure blood volume in 1939. At present, many nuclear medicine procedures are available for diagnosis and therapy of a variety of haematological disorders. Although nuclear techniques are somewhat complex, they give direct and quantitative assessment of the kinetics of blood elements as compared to other non-isotopic haematological tests. Basically, equipment required for nuclear haematology is very simple such as well scintillation counters to measure radioactivity in blood samples. More sophisticated equipment like rectilinear scanner or gamma camera is required when imaging is necessary. An overview of the basic principles and clinical applications of nuclear haematology is given

  16. Nuclear forensics

    International Nuclear Information System (INIS)

    Venugopal, V.

    2010-01-01

    Increasing threat by terrorists for a possible nuclear attack is particularly alarming in recent years. The likelihood of such an event is highly uncertain but cannot be ruled out. The consequence of such an event would be highly disastrous and the implications could be far-reaching both socially and politically. It is feared that significant amount of nuclear weapons materials may be kept under poor security. Therefore, there is a greater demand with utmost priority to curb nuclear terrorism by adapting proper security measures. One of the most important measures is to stop illicit trafficking of nuclear materials which are the source of building nuclear explosive devices. According to the IAEA illicit trafficking database (ITDB) report, a total number of 252 incidents were reported in 2006, of which 150 occurred in 2006 and the remaining 102 had taken place prior to that year, mainly in 2005

  17. Nuclear Safety

    International Nuclear Information System (INIS)

    1978-09-01

    In this short paper it has only been possible to deal in a rather general way with the standards of safety used in the UK nuclear industry. The record of the industry extending over at least twenty years is impressive and, indeed, unique. No other industry has been so painstaking in protection of its workers and in its avoidance of damage to the environment. Headings are: introduction; how a nuclear power station works; radiation and its effects (including reference to ICRP, the UK National Radiological Protection Board, and safety standards); typical radiation doses (natural radiation, therapy, nuclear power programme and other sources); safety of nuclear reactors - design; key questions (matters of concern which arise in the public mind); safety of operators; safety of people in the vicinity of a nuclear power station; safety of the general public; safety bodies. (U.K.)

  18. Nuclear proliferation

    International Nuclear Information System (INIS)

    Stencel, S.

    1978-01-01

    The terms and reactions to President Carter's nuclear policy, culminating in the 1978 Nuclear Non-Proliferation Act, are reviewed and analyzed. The new law increases restrictions on nuclear exports, encourages continued use of light water reactors in preference to plutonium-fueled reactors, and emphasizes technical solutions to proliferation problems. Critics of the law point out that it will hurt U.S. trade unfairly, that other countries do not have as many fuel options as the U.S. has, and that nuclear sales have as many political and economic as technical solutions. Compromise areas include new international safety guidelines, the possibility of an international nuclear fuel bank, and a willingness to consider each case on its merits. 21 references

  19. Nuclear privatization

    International Nuclear Information System (INIS)

    Jeffs, E.

    1995-01-01

    The United Kingdom government announced in May 1995 plans to privatize the country's two nuclear generating companies, Nuclear Electric and Scottish Nuclear. Under the plan, the two companies will become operating divisions of a unified holding company, to be called British Electric, with headquarters in Scotland. Britain's nuclear plants were left out of the initial privatization in 1989 because the government believed the financial community would be unwilling to accept the open-ended liability of decommissioning the original nine stations based on the Magnox gas-cooled reactor. Six years later, the government has found a way around this by retaining these power stations in state ownership, leaving the new nuclear company with the eight Advanced Gas-cooled Reactor (AGR) stations and the recently completed Sizewell B PWR stations. The operating Magnox stations are to be transferred to BNFL, which operates two Magnox stations of their own at Calder Hall and Chapelcross

  20. Nuclear haematology

    Energy Technology Data Exchange (ETDEWEB)

    Masjhur, J S

    1993-12-31

    Nuclear techniques have been applied to study diagnose and treat various haematological disorders for more than five decades. Two scientists are regarded as pioneers in this field, i.e. John Lawrence who in 1938 used {sup 32}P to treat chronic myeloid leukaemia and George Hevessy who used {sup 32}P labelled erythrocytes to measure blood volume in 1939. At present, many nuclear medicine procedures are available for diagnosis and therapy of a variety of haematological disorders. Although nuclear techniques are somewhat complex, they give direct and quantitative assessment of the kinetics of blood elements as compared to other non-isotopic haematological tests. Basically, equipment required for nuclear haematology is very simple such as well scintillation counters to measure radioactivity in blood samples. More sophisticated equipment like rectilinear scanner or gamma camera is required when imaging is necessary. An overview of the basic principles and clinical applications of nuclear haematology is given

  1. Aurora B kinase inhibition in mitosis: strategies for optimising the use of aurora kinase inhibitors such as AT9283.

    Science.gov (United States)

    Curry, Jayne; Angove, Hayley; Fazal, Lynsey; Lyons, John; Reule, Matthias; Thompson, Neil; Wallis, Nicola

    2009-06-15

    Aurora kinases play a key role in regulating mitotic division and are attractive oncology targets. AT9283, a multi-targeted kinase inhibitor with potent activity against Aurora A and B kinases, inhibited growth and survival of multiple solid tumor cell lines and was efficacious in mouse xenograft models. AT9283-treatment resulted in endoreduplication and ablation of serine-10 histone H3 phosphorylation in both cells and tumor samples, confirming that in these models it acts as an Aurora B kinase inhibitor. In vitro studies demonstrated that exposure to AT9283 for one complete cell cycle committed an entire population of p53 checkpoint-compromised cells (HCT116) to multinucleation and death whereas treatment of p53 checkpoint-competent cells (HMEC, A549) for a similar length of time led to a reversible arrest of cells with 4N DNA. Further studies in synchronized cell populations suggested that exposure to AT9283 during mitosis was critical for optimal cytotoxicity. We therefore investigated ways in which these properties might be exploited to optimize the efficacy and therapeutic index of Aurora kinase inhibitors for p53 checkpoint compromised tumors in vivo. Combining Aurora B kinase inhibition with paclitaxel, which arrests cells in mitosis, in a xenograft model resulted in promising efficacy without additional toxicity. These findings have implications for optimizing the efficacy of Aurora kinase inhibitors in clinical practice.

  2. ROS and CDPK-like kinase-mediated activation of MAP kinase in rice roots exposed to lead.

    Science.gov (United States)

    Huang, Tsai-Lien; Huang, Hao-Jen

    2008-04-01

    Lead (Pb2+) is a cytotoxic metal ion in plants, the mechanism of which is not yet established. The aim of this study is to investigate the signalling pathways that are activated by elevated concentrations of Pb2+ in rice roots. Root growth was stunted and cell death was accelerated when exposed to different dosages of Pb2+ during extended time periods. Using ROS-sensitive dye and Ca2+ indicator, we demonstrated that Pb2+ induced ROS production and Ca2+ accumulation, respectively. In addition, Pb2+ elicited a remarkable increase in myelin basic protein (MBP) kinase activities. By immunoblot and immunoprecipitation analysis, 40- and 42-kDa MBP kinases that were activated by Pb2+ were identified to be mitogen-activated protein (MAP) kinases. Pre-treatment of rice roots with an antioxidant and a NADPH oxidase inhibitor, glutathione (GSH) and diphenylene iodonium (DPI), effectively reduced Pb2+-induced cell death and MAP kinase activation. Moreover, calcium-dependent protein kinase (CDPK) antagonist, W7, attenuated Pb2+-induced cell death and MAP kinase activation. These results suggested that the ROS and CDPK may function in the Pb2+-triggered cell death and MAP kinase signalling pathway in rice roots.

  3. Nuclear questions

    Energy Technology Data Exchange (ETDEWEB)

    Durrani, M. [Physics World (United Kingdom)

    2006-01-01

    The future of nuclear power has returned to centre stage. Freezing weather on both sides of the Atlantic and last month's climate-change talks in Montreal have helped to put energy and the future of nuclear power right back on the political agenda. The issue is particularly pressing for those countries where existing nuclear stations are reaching the end of their lives. In the UK, prime minister Tony Blair has commissioned a review of energy, with a view to deciding later this year whether to build new nuclear power plants. The review comes just four years after the Labour government published a White Paper on energy that said the country should keep the nuclear option open but did not follow this up with any concrete action. In Germany, new chancellor and former physicist Angela Merkel is a fan of nuclear energy and had said she would extend the lifetime of its nuclear plants beyond 2020, when they are due to close. However, that commitment has had to be abandoned, at least for the time being, following negotiations with her left-wing coalition partners. The arguments in favour of nuclear power will be familiar to all physicists - it emits almost no carbon dioxide and can play a vital role in maintaining a diverse energy supply. To over-rely on imported supplies of oil and gas can leave a nation hostage to fortune. The arguments against are equally easy to list - the public is scared of nuclear power, it generates dangerous waste with potentially huge clean-up costs, and it is not necessarily cheap. Nuclear plants could also be a target for terrorist attacks. Given political will, many of these problems can be resolved, or at least tackled. China certainly sees the benefits of nuclear power, as does Finland, which is building a new 1600 MW station - the world's most powerful - that is set to open in 2009. Physicists, of course, are essential to such developments. They play a vital role in ensuring the safety of such plants and developing new types of

  4. Biliverdin reductase: more than a namesake - the reductase, its Peptide fragments, and biliverdin regulate activity of the three classes of protein kinase C.

    Science.gov (United States)

    Gibbs, Peter E M; Tudor, Cicerone; Maines, Mahin D

    2012-01-01

    The expanse of human biliverdin reductase (hBVR) functions in the cells is arguably unmatched by any single protein. hBVR is a Ser/Thr/Tyr-kinase, a scaffold protein, a transcription factor, and an intracellular transporter of gene regulators. hBVR is an upstream activator of the insulin/IGF-1 signaling pathway and of protein kinase C (PKC) kinases in the two major arms of the pathway. In addition, it is the sole means for generating the antioxidant bilirubin-IXα. hBVR is essential for activation of ERK1/2 kinases by upstream MAPKK-MEK and by PKCδ, as well as the nuclear import and export of ERK1/2. Small fragments of hBVR are potent activators and inhibitors of the ERK kinases and PKCs: as such, they suggest the potential application of BVR-based technology in therapeutic settings. Presently, we have reviewed the function of hBVR in cell signaling with an emphasis on regulation of PKCδ activity.

  5. Biliverdin Reductase: More than a Namesake – The Reductase, Its Peptide Fragments, and Biliverdin Regulate Activity of the Three Classes of Protein Kinase C

    Science.gov (United States)

    Gibbs, Peter E. M.; Tudor, Cicerone; Maines, Mahin. D.

    2012-01-01

    The expanse of human biliverdin reductase (hBVR) functions in the cells is arguably unmatched by any single protein. hBVR is a Ser/Thr/Tyr-kinase, a scaffold protein, a transcription factor, and an intracellular transporter of gene regulators. hBVR is an upstream activator of the insulin/IGF-1 signaling pathway and of protein kinase C (PKC) kinases in the two major arms of the pathway. In addition, it is the sole means for generating the antioxidant bilirubin-IXα. hBVR is essential for activation of ERK1/2 kinases by upstream MAPKK-MEK and by PKCδ, as well as the nuclear import and export of ERK1/2. Small fragments of hBVR are potent activators and inhibitors of the ERK kinases and PKCs: as such, they suggest the potential application of BVR-based technology in therapeutic settings. Presently, we have reviewed the function of hBVR in cell signaling with an emphasis on regulation of PKCδ activity. PMID:22419908

  6. Stimulation of p38 (HOG1) kinase pathway by ionizing radiation results in downstream modulation of ATF/CREB transcription factor activity in NIH-3T3 cells

    International Nuclear Information System (INIS)

    Stevenson, Mary Ann; Yao Jin

    1997-01-01

    Purpose/Objective:p38 kinase, a member of the MAP kinase family, is activated in response to stresses such as high osmolarity and UV irradiation as well exposure to cytokines such as IL1β and TNFα. The kinase is part of a signal transduction pathway that leads from receptor activation through a three kinase cascade resulting in the activation of p38. p38 activation then leads to the phosphorylation of target proteins that include transcription factors such as nuclear factor of interleukin 6 and members of the activating transcription factor (ATF) family, and in addition, the stress protein, HSP27, via activation of MAPKAP2 kinase. In the present report, we have investigated the potential role of p38 in the response of NIH-3T3 cells to ionizing radiation. Materials and Methods:NIH-3T3 cells were grown to confluence in DMEM+10%CS and then serum deprived for 24 hours in DMEM+0.1%CS. Radiation exposures were delivered using a Philips RT250 (250Kvp X-ray tube). Activated forms of p38 kinase and ATF/CREB transcription factors were identified using immunoblotting techniques employing activation specific antibodies raised against the phosphorylated forms of the kinases/transcription factors. Kinase activity was directly measured using immunokinase assays. DNA binding of transcription factors to their respective consensus sequences was assayed by EMSA. Results:We found that p38 becomes rapidly phosphorylated and activated by exposure to ionizing radiation. Significantly, p38 is activated to a similar degree and with a similar time course by serum derpviation and entry of cells into a non-proliferating G 0 state, suggesting a causal role for p38 in quiescence. Phosphorylation of p38 directly correlated with phosphorylation and activation of ATF/CREB family members as well as DNA binding by these activated factors. Conclusion:Activation of p38 kinase and downstream transcription factors may play an important role in the response of cells to ionizing radiation. We are

  7. Potassium sensing histidine kinase in Bacillus subtilis.

    Science.gov (United States)

    López, Daniel; Gontang, Erin A; Kolter, Roberto

    2010-01-01

    The soil-dwelling organism Bacillus subtilis is able to form multicellular aggregates known as biofilms. It was recently reported that the process of biofilm formation is activated in response to the presence of various, structurally diverse small-molecule natural products. All of these small-molecule natural products made pores in the membrane of the bacterium, causing the leakage of potassium cations from the cytoplasm of the cell. The potassium cation leakage was sensed by the membrane histidine kinase KinC, triggering the genetic pathway to the production of the extracellular matrix that holds cells within the biofilm. This chapter presents the methodology used to characterize the leakage of cytoplasmic potassium as the signal that induces biofilm formation in B. subtilis via activation of KinC. Development of novel techniques to monitor activation of gene expression in microbial populations led us to discover the differentiation of a subpopulation of cells specialized to produce the matrix that holds all cells together within the biofilm. This phenomenon of cell differentiation was previously missed by conventional techniques used to monitor transcriptional gene expression. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Stress-induced activation of protein kinase CK2 by direct interaction with p38 mitogen-activated protein kinase

    DEFF Research Database (Denmark)

    Sayed, M; Kim, S O; Salh, B S

    2000-01-01

    Protein kinase CK2 has been implicated in the regulation of a wide range of proteins that are important in cell proliferation and differentiation. Here we demonstrate that the stress signaling agents anisomycin, arsenite, and tumor necrosis factor-alpha stimulate the specific enzyme activity of CK2...... in the human cervical carcinoma HeLa cells by up to 8-fold, and this could be blocked by the p38 MAP kinase inhibitor SB203580. We show that p38alpha MAP kinase, in a phosphorylation-dependent manner, can directly interact with the alpha and beta subunits of CK2 to activate the holoenzyme through what appears...

  9. Mitogen-Activated Protein Kinase Kinase 3 Regulates Seed Dormancy in Barley.

    Science.gov (United States)

    Nakamura, Shingo; Pourkheirandish, Mohammad; Morishige, Hiromi; Kubo, Yuta; Nakamura, Masako; Ichimura, Kazuya; Seo, Shigemi; Kanamori, Hiroyuki; Wu, Jianzhong; Ando, Tsuyu; Hensel, Goetz; Sameri, Mohammad; Stein, Nils; Sato, Kazuhiro; Matsumoto, Takashi; Yano, Masahiro; Komatsuda, Takao

    2016-03-21

    Seed dormancy has fundamental importance in plant survival and crop production; however, the mechanisms regulating dormancy remain unclear [1-3]. Seed dormancy levels generally decrease during domestication to ensure that crops successfully germinate in the field. However, reduction of seed dormancy can cause devastating losses in cereals like wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) due to pre-harvest sprouting, the germination of mature seed (grain) on the mother plant when rain occurs before harvest. Understanding the mechanisms of dormancy can facilitate breeding of crop varieties with the appropriate levels of seed dormancy [4-8]. Barley is a model crop [9, 10] and has two major seed dormancy quantitative trait loci (QTLs), SD1 and SD2, on chromosome 5H [11-19]. We detected a QTL designated Qsd2-AK at SD2 as the single major determinant explaining the difference in seed dormancy between the dormant cultivar "Azumamugi" (Az) and the non-dormant cultivar "Kanto Nakate Gold" (KNG). Using map-based cloning, we identified the causal gene for Qsd2-AK as Mitogen-activated Protein Kinase Kinase 3 (MKK3). The dormant Az allele of MKK3 is recessive; the N260T substitution in this allele decreases MKK3 kinase activity and appears to be causal for Qsd2-AK. The N260T substitution occurred in the immediate ancestor allele of the dormant allele, and the established dormant allele became prevalent in barley cultivars grown in East Asia, where the rainy season and harvest season often overlap. Our findings show fine-tuning of seed dormancy during domestication and provide key information for improving pre-harvest sprouting tolerance in barley and wheat. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Nuclear energy

    International Nuclear Information System (INIS)

    Rippon, S.

    1984-01-01

    Do we need nuclear energy. Is it safe. What are the risks. Will it lead to proliferation. The questions are endless, the answers often confused. In the vigorous debates that surround the siting and operation of nuclear power plants, it is all too easy to lose sight of the central issues amid the mass of arguments and counter-arguments put forward. And there remains the doubt, who do we believe. This book presents the facts, simply, straightforwardly, and comprehensibly. It describes the different types of nuclear reactor, how they work, how energy is produced and transformed into usable power, how nuclear waste is handled, what safeguards are built in to prevent accident, contamination and misuse. More important, it does this in the context of the real world, examining the benefits as well as the dangers of a nuclear power programme, quantifying the risks, and providing an authoritative account of the nuclear industry worldwide. Technically complex and politically controversial, the contribution of nuclear energy to our future energy requirements is a crucial topic of our time. (author)

  11. EGFR kinase-dependent and kinase-independent roles in clear cell renal cell carcinoma.

    Science.gov (United States)

    Cossu-Rocca, Paolo; Muroni, Maria R; Sanges, Francesca; Sotgiu, Giovanni; Asunis, Anna; Tanca, Luciana; Onnis, Daniela; Pira, Giovanna; Manca, Alessandra; Dore, Simone; Uras, Maria G; Ena, Sara; De Miglio, Maria R

    2016-01-01

    Epidermal growth factor receptor (EGFR) is associated with progression of many epithelial malignancies and represents a significant therapeutic target. Although clear cell renal cell carcinoma (CCRCC) has been widely investigated for EGFR molecular alterations, genetic evidences of EGFR gene activating mutations and/or gene amplification have been rarely confirmed in the literature. Therefore, until now EGFR-targeted therapies in clinical trials have been demonstrated unsuccessful. New evidence has been given about the interactions between EGFR and the sodium glucose co-transporter-1 (SGLT1) in maintaining the glucose basal intracellular level to favour cancer cell growth and survival; thus a new functional role may be attributed to EGFR, regardless of its kinase activity. To define the role of EGFR in CCRCC an extensive investigation of genetic changes and functional kinase activities was performed in a series of tumors by analyzing the EGFR mutational status and expression profile, together with the protein expression of downstream signaling pathways members. Furthermore, we investigated the co-expression of EGFR and SGLT1 proteins and their relationships with clinic-pathological features in CCRCC. EGFR protein expression was identified in 98.4% of CCRCC. Furthermore, it was described for the first time that SGLT1 is overexpressed in CCRCC (80.9%), and that co-expression with EGFR is appreciable in 79.4% of the tumours. Moreover, the activation of downstream EGFR pathways was found in about 79.4% of SGLT1-positive CCRCCs. The mutational status analysis of EGFR failed to demonstrate mutations on exons 18 to 24 and the presence of EGFR-variantIII (EGFRvIII) in all CCRCCs analyzed. FISH analysis revealed absence of EGFR amplification, and high polysomy of chromosome 7. Finally, the EGFR gene expression profile showed gene overexpression in 38.2% of CCRCCs. Our study contributes to define the complexity of EGFR role in CCRCC, identifying its bivalent kinase

  12. Regulatory crosstalk by protein kinases on CFTR trafficking and activity

    Science.gov (United States)

    Farinha, Carlos Miguel; Swiatecka-Urban, Agnieszka; Brautigan, David; Jordan, Peter

    2016-01-01

    Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a member of the ATP binding cassette (ABC) transporter superfamily that functions as a cAMP-activated chloride ion channel in fluid-transporting epithelia. There is abundant evidence that CFTR activity (i.e. channel opening and closing) is regulated by protein kinases and phosphatases via phosphorylation and dephosphorylation. Here, we review recent evidence for the role of protein kinases in regulation of CFTR delivery to and retention in the plasma membrane. We review this information in a broader context of regulation of other transporters by protein kinases because the overall functional output of transporters involves the integrated control of both their number at the plasma membrane and their specific activity. While many details of the regulation of intracellular distribution of CFTR and other transporters remain to be elucidated, we hope that this review will motivate research providing new insights into how protein kinases control membrane transport to impact health and disease.

  13. Engineering and Functional Analysis of Mitotic Kinases Through Chemical Genetics.

    Science.gov (United States)

    Jones, Mathew J K; Jallepalli, Prasad V

    2016-01-01

    During mitosis, multiple protein kinases transform the cytoskeleton and chromosomes into new and highly dynamic structures that mediate the faithful transmission of genetic information and cell division. However, the large number and strong conservation of mammalian kinases in general pose significant obstacles to interrogating them with small molecules, due to the difficulty in identifying and validating those which are truly selective. To overcome this problem, a steric complementation strategy has been developed, in which a bulky "gatekeeper" residue within the active site of the kinase of interest is replaced with a smaller amino acid, such as glycine or alanine. The enlarged catalytic pocket can then be targeted in an allele-specific manner with bulky purine analogs. This strategy provides a general framework for dissecting kinase function with high selectivity, rapid kinetics, and reversibility. In this chapter we discuss the principles and techniques needed to implement this chemical genetic approach in mammalian cells.

  14. Localization of two mammalian cyclin dependent kinases during mammalian meiosis

    NARCIS (Netherlands)

    Ashley, T.; Walpita, D.; de rooij, D. G.

    2001-01-01

    Mammalian meiotic progression, like mitotic cell cycle progression, is regulated by cyclins and cyclin dependent kinases (CDKs). However, the unique requirements of meiosis (homologous synapsis, reciprocal recombination and the dual divisions that segregate first homologues, then sister chromatids)

  15. Adenosine monophosphate-activated protein kinase from the mud ...

    Indian Academy of Sciences (India)

    2016-12-01

    Dec 1, 2016 ... to the understanding of the molecular mechanism of acclimation to cold hardiness in S. ... have shown that the stress associated with cold temperature ..... vation by cyclic-AMP-dependent protein kinase, studied using.

  16. Profiling bacterial kinase activity using a genetic circuit

    DEFF Research Database (Denmark)

    van der Helm, Eric; Bech, Rasmus; Lehning, Christina Eva

    Phosphorylation is a post-translational modification that regulates the activity of several key proteins in bacteria and eukaryotes. Accordingly, a variety of tools has been developed to measure kinase activity. To couple phosphorylation to an in vivo fluorescent readout we used the Bacillus...... subtilis kinase PtkA, transmembrane activator TkmA and the repressor FatR to construct a genetic circuit in E. coli. By tuning the repressor and kinase expression level at the same time, we were able to show a 4.2-fold increase in signal upon kinase induction. We furthermore validated that the previously...... reported FatR Y45E mutation1 attenuates operator repression. This genetic circuit provides a starting point for computational protein design and a metagenomic library-screening tool....

  17. Phenotypic and molecular genetic analysis of Pyruvate Kinase ...

    African Journals Online (AJOL)

    Jaouani Mouna

    2015-09-26

    Sep 26, 2015 ... to several mutations at the Pyruvate Kinase gene (PKLR) located on chromosome .... Tunisians (Fig. 2) [21]. The screening of whole PKLR gene revealed the presence of ..... newborns: the pitfalls of diagnosis. J Pediatr 2007 ...

  18. Protein kinase A regulatory subunit distribution in medulloblastoma

    International Nuclear Information System (INIS)

    Mucignat-Caretta, Carla; Denaro, Luca; Redaelli, Marco; D'Avella, Domenico; Caretta, Antonio

    2010-01-01

    Previous studies showed a differential distribution of the four regulatory subunits of cAMP-dependent protein kinases inside the brain, that changed in rodent gliomas: therefore, the distribution of these proteins inside the brain can give information on the functional state of the cells. Our goal was to examine human brain tumors to provide evidence for a differential distribution of protein kinase A in different tumors. The distribution of detergent insoluble regulatory (R1 and R2) and catalytic subunits of cAMP dependent kinases was examined in pediatric brain tumors by immunohistochemistry and fluorescent cAMP analogues binding. R2 is organized in large single dots in medulloblastomas, while it has a different appearance in other tumors. Fluorescent cAMP labelling was observed only in medulloblastoma. A different distribution of cAMP dependent protein kinases has been observed in medulloblastoma

  19. Phenotypic and molecular genetic analysis of Pyruvate Kinase ...

    African Journals Online (AJOL)

    Phenotypic and molecular genetic analysis of Pyruvate Kinase deficiency in a Tunisian family. Jaouani Mouna, Hamdi Nadia, Chaouch Leila, Kalai Miniar, Mellouli Fethi, Darragi Imen, Boudriga Imen, Chaouachi Dorra, Bejaoui Mohamed, Abbes Salem ...

  20. 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...

  1. 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...

  2. 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...

  3. Nuclear Hostages

    International Nuclear Information System (INIS)

    Cooper, C.L.

    1978-01-01

    The global spread of nuclear reactors for the production of energy seems inevitable. Nuclear power plants will be supplied--if not by the United States, then by one of several other exporters. But other aspects of this development are less certain. One is the relationship between proliferation of nuclear energy plants and that of nuclear weapons. Another is the actual constraint that such vulnerable potential targets as nuclear power plants would have on would-be aggressors. In the last analysis, this would depend on the rationality of a nation's leadership. What can be said for the concept of nuclear power plants as potential hostages is that by installing a reactor on its territory, a country increases its vulnerability to grave, possibly unacceptable damage in the event of war. As a result, that nation's leaders might be inclined to raise the threshold of their sensitivity to provocation by neighbors and to restrain their own inclinations toward aggression. Admittedly this is a frail substitute for robust international agreements, but in the present order of things it is not a trivial consideration. Many incidents once regarded by the great powers as easi belli have more recently been either resolved by diplomacy or ignored altogether. The idea must not be pressed too far. The export of a nuclear power plant to a Third World country cannot be advocated simply as a means to constrain its own military adventurism. Aside from the promise of a vast increase in energy supply for developing nations, nuclear powered generating stations could actually improve relations among countries. The risk of widespread radioactive contamination by nuclear power plants hit by even conventional bombs could introduce a positive new element into the military calculations of powers outside the NATO-Warsaw Pact arena. As they balance military and diplomatic solutions to local conflicts, moderation rather than bellicosity might become the better part of valor

  4. Nuclear medicine

    International Nuclear Information System (INIS)

    Kand, Purushottam

    2012-01-01

    Nuclear medicine is a specialized area of radiology that uses very small amounts of radioactive materials to examine organ function and structure. Nuclear medicine is older than CT, ultrasound and MRI. It was first used in patients over 60-70 years ago. Today it is an established medical specialty and offers procedures that are essential in many medical specialities like nephrology, pediatrics, cardiology, psychiatry, endocrinology and oncology. Nuclear medicine refers to medicine (a pharmaceutical) that is attached to a small quantity of radioactive material (a radioisotope). This combination is called a radiopharmaceutical. There are many radiopharmaceuticals like DTPA, DMSA, HIDA, MIBI and MDP available to study different parts of the body like kidneys, heart and bones etc. Nuclear medicine uses radiation coming from inside a patient's body where as conventional radiology exposes patients to radiation from outside the body. Thus nuclear imaging study is a physiological imaging, whereas diagnostic radiology is anatomical imaging. It combines many different disciplines like chemistry, physics mathematics, computer technology, and medicine. It helps in diagnosis and to treat abnormalities very early in the progression of a disease. The information provides a quick and accurate diagnosis of wide range of conditions and diseases in a person of any age. These tests are painless and most scans expose patients to only minimal and safe amounts of radiation. The amount of radiation received from a nuclear medicine procedure is comparable to, or often many times less than, that of a diagnostic X-ray. Nuclear medicine provides an effective means of examining whether some tissues/organs are functioning properly. Therapy using nuclear medicine in an effective, safe and relatively inexpensive way of controlling and in some cases eliminating, conditions such as overactive thyroid, thyroid cancer and arthritis. Nuclear medicine imaging is unique because it provides doctors with

  5. Nuclear inheritance

    International Nuclear Information System (INIS)

    Delpech, Therese

    1997-01-01

    Since the end of the East-West confronting, the nuclear weapon issue has been focused in an international debate with obvious repercussions in Europe, because it is the European continent which indicated first the significance of nuclear deterrence. This debate refers first upon the past, as the German unification allowed capturing numerous documents of Warsaw treaty which revealed the intentions and the plans of Soviet Union during the cold war, and secondly concerns the future, since the role of nuclear weapons must be re-thought in a new context. This is the subject of this book, which refers also to the problem of the nuclear proliferation in the world and evolution of different countries in a political and regional context. The extension of the non-proliferation treaty for an undefined duration, in May 1995, is a incontestable victory because this treaty rules the renouncement to nuclear weapons of 185 countries. However, it does not solve most sensible problems like the Iraq case, for which a specific inspection regime has been instituted, or the case of Iran, which is suspected to acquire the bomb, although no clear evidence has been provided up to now. This is also the case of Israel, India and Pakistan which allege plainly their willingness of keeping open, from security reasons, their nuclear option. The content is displayed in five chapters: 1. Introduction; 2. The role of the nuclear weapons after the cold war; 3. The nuclear proliferation at crossroads; 4. Undefined extension of the NPT, a striking but fragile victory; 5. Conclusions. An appendix containing the text of the Nuclear Weapon Non-Proliferation Treaty and a chronology are added

  6. Roles of protein kinase R in cancer: Potential as a therapeutic target.

    Science.gov (United States)

    Watanabe, Takao; Imamura, Takeshi; Hiasa, Yoichi

    2018-04-01

    Double-stranded (ds) RNA-dependent protein kinase (PKR) is a ubiquitously expressed serine/threonine protein kinase. It was initially identified as an innate immune antiviral protein induced by interferon (IFN) and activated by dsRNA. PKR is recognized as a key executor of antiviral host defense. Moreover, it contributes to inflammation and immune regulation through several signaling pathways. In addition to IFN and dsRNA, PKR is activated by multiple stimuli and regulates various signaling pathways including the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells pathways. PKR was initially thought to be a tumor suppressor as a result of its ability to suppress cell growth and interact with major tumor suppressor genes. However, in several types of malignant disease, such as colon and breast cancers, its role remains controversial. In hepatocellular carcinoma, hepatitis C virus (HCV) is the main cause of liver cancer, and PKR inhibits HCV replication, indicating its role as a tumor suppressor. However, PKR is overexpressed in cirrhotic patients, and acts as a tumor promoter through enhancement of cancer cell growth by mediating MAPK or signal transducer and activator of transcription pathways. Moreover, PKR is reportedly required for the activation of inflammasomes and influences metabolic disorders. In the present review, we introduce the multifaceted roles of PKR such as antiviral function, tumor cell growth, regulation of inflammatory immune responses, and maintaining metabolic homeostasis; and discuss future perspectives on PKR biology including its potential as a therapeutic target for liver cancer. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  7. Unchanged thymidine triphosphate pools and thymidine metabolism in two lines of thymidine kinase 2-mutated fibroblasts.

    Science.gov (United States)

    Frangini, Miriam; Rampazzo, Chiara; Franzolin, Elisa; Lara, Mari-Carmen; Vilà, Maya R; Martí, Ramon; Bianchi, Vera

    2009-02-01

    Mitochondrial thymidine kinase (TK2) catalyzes the phosphorylation of thymidine in mitochondria. Its function becomes essential for dTTP synthesis in noncycling cells, where cytosolic dTTP synthesis via R1/R2 ribonucleotide reductase and thymidine kinase 1 is turned down. Mutations in the nuclear gene for TK2 cause a fatal mtDNA depletion syndrome. Only selected cell types are affected, suggesting that the other cells compensate for the TK2 deficiency by adapting the enzyme network that regulates dTTP synthesis outside S-phase. Here we looked for such metabolic adaptation in quiescent cultures of fibroblasts from two TK2-deficient patients with a slow-progressing syndrome. In cell extracts, we measured the activities of TK2, deoxycytidine kinase, thymidine phosphorylase, deoxynucleotidases and the amounts of the three ribonucleotide reductase subunits. Patient cells contained 40% or 5% TK2 activity and unchanged activities of the other enzymes. However, their mitochondrial and cytosolic dTTP pools were unchanged, and also the overall composition of the dNTP pools was normal. TK2-dependent phosphorylation of [(3)H]thymidine in intact cells and the turnover of the dTTP pool showed that even the fibroblasts with 5% residual TK2 activity synthesized dTTP at an almost normal rate. Normal fibroblasts apparently contain more TK2 than needed to maintain dTTP during quiescence, which would explain why TK2-mutated fibroblasts do not manifest mtDNA depletion despite their reduced TK2 activity.

  8. Role of phosphoinositide 3-kinase in the pathogenesis of acute pancreatitis.

    Science.gov (United States)

    Lupia, Enrico; Pigozzi, Luca; Goffi, Alberto; Hirsch, Emilio; Montrucchio, Giuseppe

    2014-11-07

    A large body of experimental and clinical data supports the notion that inflammation in acute pancreatitis has a crucial role in the pathogenesis of local and systemic damage and is a major determinant of clinical severity. Thus, research has recently focused on molecules that can regulate the inflammatory processes, such as phosphoinositide 3-kinases (PI3Ks), a family of lipid and protein kinases involved in intracellular signal transduction. Studies using genetic ablation or pharmacologic inhibitors of different PI3K isoforms, in particular the class I PI3Kδ and PI3Kγ, have contributed to a greater understanding of the roles of these kinases in the modulation of inflammatory and immune responses. Recent data suggest that PI3Ks are also involved in the pathogenesis of acute pancreatitis. Activation of the PI3K signaling pathway, and in particular of the class IB PI3Kγ isoform, has a significant role in those events which are necessary for the initiation of acute pancreatic injury, namely calcium signaling alteration, trypsinogen activation, and nuclear factor-κB transcription. Moreover, PI3Kγ is instrumental in modulating acinar cell apoptosis, and regulating local neutrophil infiltration and systemic inflammatory responses during the course of experimental acute pancreatitis. The availability of PI3K inhibitors selective for specific isoforms may provide new valuable therapeutic strategies to improve the clinical course of this disease. This article presents a brief summary of PI3K structure and function, and highlights recent advances that implicate PI3Ks in the pathogenesis of acute pancreatitis.

  9. Mitogen activated protein kinases selectively regulate palytoxin-stimulated gene expression in mouse keratinocytes

    International Nuclear Information System (INIS)

    Zeliadt, Nicholette A.; Warmka, Janel K.; Wattenberg, Elizabeth V.

    2003-01-01

    We have been investigating how the novel skin tumor promoter palytoxin transmits signals through mitogen activated protein kinases (MAPKs). Palytoxin activates three major MAPKs, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, in a keratinocyte cell line derived from initiated mouse skin (308). We previously showed that palytoxin requires ERK to increase matrix metalloproteinase-13 (MMP-13) gene expression, an enzyme implicated in carcinogenesis. Diverse stimuli require JNK and p38 to increase MMP-13 gene expression, however. We therefore used the JNK and p38 inhibitors SP 600125 and SB 202190, respectively, to investigate the role of these MAPKs in palytoxin-induced MMP-13 gene expression. Surprisingly, palytoxin does not require JNK and p38 to increase MMP-13 gene expression. Accordingly, ERK activation, independent of palytoxin and in the absence of JNK and p38 activation, is sufficient to induce MMP-13 gene expression in 308 keratinocytes. Dexamethasone, a synthetic glucocorticoid that inhibits activator protein-1 (AP-1), blocked palytoxin-stimulated MMP-13 gene expression. Therefore, the AP-1 site present in the promoter of the MMP-13 gene appears to be functional and to play a key role in palytoxin-stimulated gene expression. Previous studies showed that palytoxin simulates an ERK-dependent selective increase in the c-Fos content of AP-1 complexes that bind to the promoter of the MMP-13 gene. JNK and p38 can also modulate c-Fos. Palytoxin does not require JNK or p38 to increase c-Fos binding, however. Altogether, these studies indicate that ERK plays a distinctly essential role in transmitting palytoxin-stimulated signals to specific nuclear targets in keratinocytes derived from initiated mouse skin

  10. Adenosine monophosphate-activated protein kinase modulates the activated phenotype of hepatic stellate cells.

    Science.gov (United States)

    Caligiuri, Alessandra; Bertolani, Cristiana; Guerra, Cristina Tosti; Aleffi, Sara; Galastri, Sara; Trappoliere, Marco; Vizzutti, Francesco; Gelmini, Stefania; Laffi, Giacomo; Pinzani, Massimo; Marra, Fabio

    2008-02-01

    Adiponectin limits the development of liver fibrosis and activates adenosine monophosphate-activated protein kinase (AMPK). AMPK is a sensor of the cellular energy status, but its possible modulation of the fibrogenic properties of hepatic stellate cells (HSCs) has not been established. In this study, we investigated the role of AMPK activation in the biology of activated human HSCs. A time-dependent activation of AMPK was observed in response to a number of stimuli, including globular adiponectin, 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR), or metformin. All these compounds significantly inhibited platelet-derived growth factor (PDGF)-stimulated proliferation and migration of human HSCs and reduced the secretion of monocyte chemoattractant protein-1. In addition, AICAR limited the secretion of type I procollagen. Knockdown of AMPK by gene silencing increased the mitogenic effects of PDGF, confirming the negative modulation exerted by this pathway on HSCs. AMPK activation did not reduce PDGF-dependent activation of extracellular signal-regulated kinase (ERK) or Akt at early time points, whereas a marked inhibition was observed 24 hours after addition of PDGF, reflecting a block in cell cycle progression. In contrast, AICAR blocked short-term phosphorylation of ribosomal S6 kinase (p70(S6K)) and 4E binding protein-1 (4EBP1), 2 downstream effectors of the mammalian target of rapamycin (mTOR) pathway, by PDGF. The ability of interleukin-a (IL-1) to activate nuclear factor kappa B (NF-kappaB) was also reduced by AICAR. Activation of AMPK negatively modulates the activated phenotype of HSCs.

  11. Bombyx mori cyclin-dependent kinase inhibitor is involved in regulation of the silkworm cell cycle.

    Science.gov (United States)

    Tang, X-F; Zhou, X-L; Zhang, Q; Chen, P; Lu, C; Pan, M-H

    2018-06-01

    Cyclin-dependent kinase inhibitors (CKIs) are negative regulators of the cell cycle. They can bind to cyclin-dependent kinase (CDK)-cyclin complexes and inhibit CDK activities. We identified a single homologous gene of the CDK interacting protein/kinase inhibitory protein (Cip/Kip) family, BmCKI, in the silkworm, Bombyx mori. The gene transcribes two splice variants: a 654-bp-long BmCKI-L (the longer splice variant) encoding a protein with 217 amino acids and a 579-bp-long BmCKI-S (the shorter splice variant) encoding a protein with 192 amino acids. BmCKI-L and BmCKI-S contain the Cip/Kip family conserved cyclin-binding domain and the CDK-binding domain. They are localized in the nucleus and have an unconventional bipartite nuclear localization signal at amino acid residues 181-210. Overexpression of BmCKI-L or BmCKI-S affected cell cycle progression; the cell cycle was arrested in the first gap phase of cell cycle (G1). RNA interference of BmCKI-L or BmCKI-S led to cells accumulating in the second gap phase and the mitotic phase of cell cycle (G2/M). Both BmCKI-L and BmCKI-S are involved in cell cycle regulation and probably have similar effects. The transgenic silkworm with BmCKI-L overexpression (BmCKI-L-OE), exhibited embryonic lethal, larva developmental retardation and lethal phenotypes. These results suggest that BmCKI-L might regulate the growth and development of silkworm. These findings clarify the function of CKIs and increase our understanding of cell cycle regulation in the silkworm. © 2018 The Royal Entomological Society.

  12. Nuclear energy

    International Nuclear Information System (INIS)

    Hladky, S.

    1985-01-01

    This booklet appeared in a series on technical history. It tries to communicate some of the scientific, technical and social stresses, which have been connected with the application of nuclear energy since its discovery. The individual sections are concerned with the following subjects: the search for the 'smallest particles'; the atomic nucleus; nuclear fission; the 'Manhattan Project'; the time after this - from the euphoria of the 1950's via disillusionment and change of opinion to the state of nuclear energy at the start of the 1980's. The booklet contains many details and is generously illustrated. (HSCH) [de

  13. Nuclear transport

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    During january and february 2003, a unique event concerning nuclear transport was reported and rated 1 on the INES scale. This event concerns the absence of a maintenance operation on a shipping cask. This shipping cask was used for several years for nuclear transport inside La-hague site before being re-assigned to transport on public thoroughfare. The re-assignment of the cask should have been preceded and conditioned by a maintenance operation whose purpose is to check the efficiency of its radiation shield. During this period 2 on-site inspections concerning the transport of nuclear materials were performed. (A.C.)

  14. Nuclear energy

    International Nuclear Information System (INIS)

    Luxo, Armand.

    1977-01-01

    The reasons and conditions of utilizing nuclear power in developing countries are examined jointly with the present status and future uses already evaluated by some organizations. Some consequences are deduced in the human, financial scientific and technological fields, with provisional suggestions for preparing the nuclear industry development in these countries. As a conclusion trends are given to show how the industrialized countries having gained a long scientific and technological experience in nuclear energy can afford their assistance in this field, to developing countries [fr

  15. Nuclear questions

    International Nuclear Information System (INIS)

    Hohlfeld, W.

    1977-01-01

    This brochure 'nuclear problems' deals with the attitude of the protestant church in the region around the northern Elbe towards further quantitative economic growth, esp. nuclear energy, with the following essays: preaching the Gospel in an environment in danger: the Christian occident and the problems of the third world, facing the problems of exhausted supplies, the role of the prophet, problem of environment - a problem of theology, the political dimension, against ATW, signal Brokdorf, strange effects (defense of the church from unqualified teachings by non-professionals), Christian liberty, church and nuclear energy, violence and robes. (HP) [de

  16. Rotterdam Nuclear

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    In 1965 Rotterdam Nuclear received an order for the design, supply of materials, manufacture, testing, inspection and preparation for shipment of one 450MW Boiling Water Reactor pressure vessel. This was one of the first orders for a reactor pressure vessel, ever obtained by a European Manufacturer. The Company has since supplied 19 reactor pressure vessels for nuclear power stations, having a total weight of about 10,000,000kg. The nuclear power stations in which these are installed represent an electrical output of about 15,000MW and they are located in seven different countries (USA, Spain, Switzerland, Argentina, Sweden, Germany and the Netherlands). (Auth.)

  17. Nuclear law

    International Nuclear Information System (INIS)

    Bringuier, P.

    2009-01-01

    The object of this report is to present the evolution of the nuclear law during the period from 2006 to 2008, period that was characterized in France by a real rewriting from the implementation of a control authority. The prescriptive backing of nuclear activities has been deeply changed by numerous texts. In this first part are presented: (1) the institutional aspects, (2) openness and public information, (7) radioactive wastes and (9) liability and insurance. In a next publication will be treated: (3) safety and radiation protection; (4) nuclear matter, inspection, physical protection; (5) transports; (6) trade, non-proliferation; (8) radiological accidents. (N.C.)

  18. Nuclear fuel

    International Nuclear Information System (INIS)

    D Hondt, P.

    1998-01-01

    The research and development programme on nuclear fuel at the Belgian Nuclear Research Centre SCK/CEN is described. The objective of this programme is to enhance the quantitative prediction of the operational limits of nuclear fuel and to assess the behaviour of fuel under incidental and accidental conditions. Progress is described in different domains including the modelling of fission gas release in LWR fuel, thermal conductivity, basic physical phenomena, post-irradiation examination for fuel performance assessment, and conceptual studies of incidental and accidental fuel experiments

  19. Nuclear energy

    International Nuclear Information System (INIS)

    Wethe, Per Ivar

    2009-01-01

    Today we know two forms of nuclear energy: fission and fusion. Fission is the decomposition of heavy nuclei, while fusion is the melting together of light nuclei. Both processes create a large surplus of energy. Technologically, we can currently only use fission to produce energy in today's nuclear power plants, but there is intense research worldwide in order to realize a controlled fusion process. In a practical context, today's nuclear energy is a sustained source of energy since the resource base is virtually unlimited. When fusion technology is realized, the resource supply will be a marginal problem. (AG)

  20. Nuclear electronics

    International Nuclear Information System (INIS)

    Lucero B, E.

    1989-01-01

    The rapid technical development of Colombia over the past years, resulted among others, a considerable increase in the number of measuring instrumentation and testing laboratories, scientific research and metrology centers, in industry, agriculture, public health, education on the nuclear field, etc. IAN is a well organized institution with qualified management, trained staff and reasonably equipped laboratories to carry out tasks as: Metrology, standardization, quality control and maintenance and repair of nuclear instruments. The government of Colombia has adopted a policy to establish and operate through the country maintenance and repair facilities for nuclear instrumentation. This policy is reflected in the organization of electronic laboratories in Bogota-IAN

  1. Expression, purification and kinase activity analysis of maize ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... Kinase activity is essential for a protein kinase to perform its biological function. In previous study we have cloned a novel plant SnRK2 subfamily gene from maize and named it as ZmSPK1. In this study the. cDNA of ZmSPK1 with dHA-His6 tag was amplified by PCR and was subcloned into the yeast.

  2. Janus Associated Kinases Inhibitors in the Pharmacological Thera

    Directory of Open Access Journals (Sweden)

    Daniela Santos1

    2017-01-01

    Full Text Available Janus associated kinases inhibitors are a new strategy for the treatment of different clinical conditions like immunologic, inflammatory and oncology disorders. The aim of this study was to perform a review of all Janus associated kinases inhibitors available in national and international pharmaceutical market, their therapeutic indications and adverse effects, and the potential indications for investigation of those already available in the pharmaceutical market. It was also performed a review of the main new Janus associated kinases inhibitors that are still in clinical research. A literature review was conducted by consulting the summary of product characteristics of Janus associated kinases inhibitors available in the pharmaceutical market and a research in the bibliographic database PubMed using the terms «JAK inhibitors», «Janus associated kinases inhibitors» and «Janus kinases inhibitors». Ninety-five publications were included in the present review, published from January 2014 to January 2015. Drug databases of the European Medicines Agency and United States Food and Drug Administration were also consulted to search for Janus associated kinases inhibitors authorized in clinical practice. Currently, ruxolitinib and tofacitinib are available in the pharmaceutical market and oclatinib is approved as a veterinary medicinal product. Both drugs approved for human use have major adverse effects at hematological and immunological levels, which enhance the importance of the pharmacist’s role in the monitoring of patients involved in these treatments. However, several molecules are in pre-clinical and clinical studies trying to prove its potential in the treatment of several immunologic, inflammatory and oncology disorders. Thus, it is still necessary to deepen the knowledge in this area in order to overcome the risks of therapy with these agents. These risks weighed against the benefits of its clinical use have compromised the progress of

  3. Protein kinase C signaling and cell cycle regulation

    OpenAIRE

    Black, Adrian R.; Black, Jennifer D.

    2013-01-01

    A link between T cell proliferation and the protein kinase C (PKC) family of serine/threonine kinases has been recognized for about thirty years. However, despite the wealth of information on PKC-mediated control of T cell activation, understanding of the effects of PKCs on the cell cycle machinery in this cell type remains limited. Studies in other systems have revealed important cell cycle-specific effects of PKC signaling that can either positively or negatively impact proliferation. Th...

  4. Structural analysis of the Csk homologous kinase CHK

    International Nuclear Information System (INIS)

    Mulhern, T.; Chong, Y.-P.; Cheng, H.-C.

    2003-01-01

    Full text: CHK (Csk homologous kinase) is an intracellular protein tyrosine kinase, which is highly expressed in the haematopoietic system and the brain. The in vivo role of CHK is to specifically phosphorylate and deactivate the Src family of protein tyrosine kinases. The members of the Src family: Src, Blk, Fyn, Fgr, Hck, Lck, Lyn, Yes and Yrk are major players in numerous cell signalling pathways and exquisitely tuned control of Src family activity is fundamental to many processes in normal cells (reviewed in Lowell and Soriano, 1996). For example, the Src family kinase Fyn is highly expressed in the brain and its activity is vital for memory and learning. In the haematopoietic system, the Src family kinase Hck controls cytoskeletal reorganization, cell motility and immunologic activation. While the Csk family enzymes are closely related to the Src proteins (∼37% identity), the x-ray crystal structures of Src (Xu et al., 1997) and Csk (Ogawa et al., 2002) do display several important differences. Unlike Src, the Csk the SH2 and SH3 domains do not bind intramolecular ligands and they adopt a strikingly different disposition to that observed in Src. Another interesting feature is that the linkers between the SH3 and SH2 domains and between the SH2 and kinase domains, are in intimate contact with the N-lobe of kinase and both appear to play important roles in regulation of the kinase activity. However, the structural and functional basis of how this can be altered is still unclear. We describe the results of biochemical analyses of CHK mediated deactivation of Hck, which suggest that in addition to direct tail-phosphorylation, protein-protein interactions are important. We also describe heteronuclear NMR studies of the structure and ligand binding properties of the CHK SH2 and SH3 domains with a particular emphasis on the transmission of regulatory signals from the ligand binding sites to the interdomain linkers

  5. High-throughput screening to identify inhibitors which stabilize inactive kinase conformations in p38 alpha

    NARCIS (Netherlands)

    Simard, J.R.; Grutter, C.; Pawar, V.; Aust, B.; Wolf, A.; Rabiller, M.; Wulfert, S.; Robubi, A.; Kluter, S.; Ottmann, C.; Rauh, D.

    2009-01-01

    Small molecule kinase inhibitors are an attractive means to modulate kinase activities in medicinal chemistry and chemical biology research. In the physiological setting of a cell, kinase function is orchestrated by a plethora of regulatory processes involving the structural transition of kinases

  6. Ghrelin augments murine T-cell proliferation by activation of the phosphatidylinositol-3-kinase, extracellular signal-regulated kinase and protein kinase C signaling pathways

    Science.gov (United States)

    Lee, Jun Ho; Patel, Kalpesh; Tae, Hyun Jin; Lustig, Ana; Kim, Jie Wan; Mattson, Mark P.; Taub, Dennis D.

    2014-01-01

    Thymic atrophy occurs during normal aging, and is accelerated by exposure to chronic stressors that elevate glucocorticoid levelsand impair the naïve T cell output. The orexigenic hormone ghrelin was recently shown to attenuate age-associated thymic atrophy. Here, we report that ghrelin enhances the proliferation of murine CD4+ primary T cells and a CD4+ T-cell line. Ghrelin induced activation of the ERK1/2 and Akt signaling pathways, via upstream activation of phosphatidylinositol-3-kinase and protein kinase C, to enhance T-cell proliferation. Moreover, ghrelin induced expression of the cell cycle proteins cyclin D1, cyclin E, cyclin-dependent kinase 2 (CDK2) and retinoblastoma phosphorylation. Finally, ghrelin activated the above-mentioned signaling pathways and stimulated thymocyte proliferation in young and older mice in vivo. PMID:25447526

  7. Identification of the protein kinase C phosphorylation site in neuromodulin

    International Nuclear Information System (INIS)

    Apel, E.D.; Byford, M.F.; Au, D.; Walsh, K.A.; Storm, D.R.

    1990-01-01

    Neuromodulin (P-57, GAP-43, B-50, F-1) is a neurospecific calmodulin binding protein that is phosphorylated by protein kinase C. Phosphorylation by protein kinase C has been shown to abolish the affinity of neuromodulin for calmodulin and the authors have proposed that the concentration of free CaM in neurons may be regulated by phosphorylation and dephosphorylation of neuromodulin. The purpose of this study was to identify the protein kinase C phosphorylation site(s) in neuromodulin using recombinant neuromodulin as a substrate. Toward this end, it was demonstrated that recombinant neuromodulin purified from Escherichia coli and bovine neuromodulin were phosphorylated with similar K m values and stoichiometries and that protein kinase C mediated phosphorylation of both proteins abolished binding to calmodulin-Sepharose. Recombinant neuromodulin was phosphorylated by using protein kinase C and [γ- 32 P]ATP and digested with trypsin, and the resulting peptides were separated by HPLC. Only one 32 P-labeled tryptic peptide was generated from phosphorylated neuromodulin. They conclude that serine-41 is the protein kinase C phosphorylation site of neuromodulin and that phosphorylation of this amino acid residue blocks binding of calmoculin to neuromodulin. The proximity of serine-41 to the calmodulin binding domain in neuromodulin very likely explains the effect of phosphorylation on the affinity of neuromodulin for calmodulin

  8. Quantitative and Dynamic Imaging of ATM Kinase Activity.

    Science.gov (United States)

    Nyati, Shyam; Young, Grant; Ross, Brian Dale; Rehemtulla, Alnawaz

    2017-01-01

    Ataxia telangiectasia mutated (ATM) is a serine/threonine kinase critical to the cellular DNA-damage response, including DNA double-strand breaks (DSBs). ATM activation results in the initiation of a complex cascade of events facilitating DNA damage repair, cell cycle checkpoint control, and survival. Traditionally, protein kinases have been analyzed in vitro using biochemical methods (kinase assays using purified proteins or immunological assays) requiring a large number of cells and cell lysis. Genetically encoded biosensors based on optical molecular imaging such as fluorescence or bioluminescence have been developed to enable interrogation of kinase activities in live cells with a high signal to background. We have genetically engineered a hybrid protein whose bioluminescent activity is dependent on the ATM-mediated phosphorylation of a substrate. The engineered protein consists of the split luciferase-based protein complementation pair with a CHK2 (a substrate for ATM kinase activity) target sequence and a phospho-serine/threonine-binding domain, FHA2, derived from yeast Rad53. Phosphorylation of the serine residue within the target sequence by ATM would lead to its interaction with the phospho-serine-binding domain, thereby preventing complementation of the split luciferase pair and loss of reporter activity. Bioluminescence imaging of reporter expressing cells in cultured plates or as mouse xenografts provides a quantitative surrogate for ATM kinase activity and therefore the cellular DNA damage response in a noninvasive, dynamic fashion.

  9. Crystal structure of human protein kinase CK2

    DEFF Research Database (Denmark)

    Niefind, K; Guerra, B; Ermakowa, I

    2001-01-01

    The crystal structure of a fully active form of human protein kinase CK2 (casein kinase 2) consisting of two C-terminally truncated catalytic and two regulatory subunits has been determined at 3.1 A resolution. In the CK2 complex the regulatory subunits form a stable dimer linking the two catalyt...... as a docking partner for various protein kinases. Furthermore it shows an inter-domain mobility in the catalytic subunit known to be functionally important in protein kinases and detected here for the first time directly within one crystal structure.......The crystal structure of a fully active form of human protein kinase CK2 (casein kinase 2) consisting of two C-terminally truncated catalytic and two regulatory subunits has been determined at 3.1 A resolution. In the CK2 complex the regulatory subunits form a stable dimer linking the two catalytic...... subunits, which make no direct contact with one another. Each catalytic subunit interacts with both regulatory chains, predominantly via an extended C-terminal tail of the regulatory subunit. The CK2 structure is consistent with its constitutive activity and with a flexible role of the regulatory subunit...

  10. 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

  11. Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint.

    Directory of Open Access Journals (Sweden)

    M Kasim Diril

    2016-09-01

    Full Text Available The Greatwall kinase/Mastl is an essential gene that indirectly inhibits the phosphatase activity toward mitotic Cdk1 substrates. Here we show that although Mastl knockout (MastlNULL MEFs enter mitosis, they progress through mitosis without completing cytokinesis despite the presence of misaligned chromosomes, which causes chromosome segregation defects. Furthermore, we uncover the requirement of Mastl for robust spindle assembly checkpoint (SAC maintenance since the duration of mitotic arrest caused by microtubule poisons in MastlNULL MEFs is shortened, which correlates with premature disappearance of the essential SAC protein Mad1 at the kinetochores. Notably, MastlNULL MEFs display reduced phosphorylation of a number of proteins in mitosis, which include the essential SAC kinase MPS1. We further demonstrate that Mastl is required for multi-site phosphorylation of MPS1 as well as robust MPS1 kinase activity in mitosis. In contrast, treatment of MastlNULL cells with the phosphatase inhibitor okadaic acid (OKA rescues the defects in MPS1 kinase activity, mislocalization of phospho-MPS1 as well as Mad1 at the kinetochore, and premature SAC silencing. Moreover, using in vitro dephosphorylation assays, we demonstrate that Mastl promotes persistent MPS1 phosphorylation by inhibiting PP2A/B55-mediated MPS1 dephosphorylation rather than affecting Cdk1 kinase activity. Our findings establish a key regulatory function of the Greatwall kinase/Mastl->PP2A/B55 pathway in preventing premature SAC silencing.

  12. Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint.

    Science.gov (United States)

    Diril, M Kasim; Bisteau, Xavier; Kitagawa, Mayumi; Caldez, Matias J; Wee, Sheena; Gunaratne, Jayantha; Lee, Sang Hyun; Kaldis, Philipp

    2016-09-01

    The Greatwall kinase/Mastl is an essential gene that indirectly inhibits the phosphatase activity toward mitotic Cdk1 substrates. Here we show that although Mastl knockout (MastlNULL) MEFs enter mitosis, they progress through mitosis without completing cytokinesis despite the presence of misaligned chromosomes, which causes chromosome segregation defects. Furthermore, we uncover the requirement of Mastl for robust spindle assembly checkpoint (SAC) maintenance since the duration of mitotic arrest caused by microtubule poisons in MastlNULL MEFs is shortened, which correlates with premature disappearance of the essential SAC protein Mad1 at the kinetochores. Notably, MastlNULL MEFs display reduced phosphorylation of a number of proteins in mitosis, which include the essential SAC kinase MPS1. We further demonstrate that Mastl is required for multi-site phosphorylation of MPS1 as well as robust MPS1 kinase activity in mitosis. In contrast, treatment of MastlNULL cells with the phosphatase inhibitor okadaic acid (OKA) rescues the defects in MPS1 kinase activity, mislocalization of phospho-MPS1 as well as Mad1 at the kinetochore, and premature SAC silencing. Moreover, using in vitro dephosphorylation assays, we demonstrate that Mastl promotes persistent MPS1 phosphorylation by inhibiting PP2A/B55-mediated MPS1 dephosphorylation rather than affecting Cdk1 kinase activity. Our findings establish a key regulatory function of the Greatwall kinase/Mastl->PP2A/B55 pathway in preventing premature SAC silencing.

  13. SH2-dependent autophosphorylation within the Tec family kinase Itk.

    Science.gov (United States)

    Joseph, Raji E; Severin, Andrew; Min, Lie; Fulton, D Bruce; Andreotti, Amy H

    2009-08-07

    The Tec family kinase, Itk (interleukin-2 tyrosine kinase), undergoes an in cis autophosphorylation on Y180 within its Src homology 3 (SH3) domain. Autophosphorylation of the Itk SH3 domain by the Itk kinase domain is strictly dependent on the presence of the intervening Src homology 2 (SH2) domain. A direct docking interaction between the Itk kinase and SH2 domains brings the Itk SH3 domain into the active site where Y180 is then phosphorylated. We now identify the residues on the surface of the Itk SH2 domain responsible for substrate docking and show that this SH2 surface mediates autophosphorylation in the full-length Itk molecule. The canonical phospholigand binding site on the SH2 domain is not involved in substrate docking, instead the docking site consists of side chains from three loop regions (AB, EF and BG) and part of the betaD strand. These results are extended into Btk (Bruton's tyrosine kinase), a Tec family kinase linked to the B-cell deficiency X-linked agammaglobulinemia (XLA). Our results suggest that some XLA-causing mutations might impair Btk phosphorylation.

  14. A conserved p38 MAP kinase pathway in Caenorhabditis elegans innate immunity.

    Science.gov (United States)

    Kim, Dennis H; Feinbaum, Rhonda; Alloing, Geneviève; Emerson, Fred E; Garsin, Danielle A; Inoue, Hideki; Tanaka-Hino, Miho; Hisamoto, Naoki; Matsumoto, Kunihiro; Tan, Man-Wah; Ausubel, Frederick M

    2002-07-26

    A genetic screen for Caenorhabditis elegans mutants with enhanced susceptibility to killing by Pseudomonas aeruginosa led to the identification of two genes required for pathogen resistance: sek-1, which encodes a mitogen-activated protein (MAP) kinase kinase, and nsy-1, which encodes a MAP kinase kinase kinase. RNA interference assays and biochemical analysis established that a p38 ortholog, pmk-1, functions as the downstream MAP kinase required for pathogen defense. These data suggest that this MAP kinase signaling cassette represents an ancient feature of innate immune responses in evolutionarily diverse species.

  15. Auxin efflux by PIN-FORMED proteins is activated by two different protein kinases, D6 PROTEIN KINASE and PINOID

    KAUST Repository

    Zourelidou, Melina; Absmanner, Birgit; Weller, Benjamin; Barbosa, Inê s CR; Willige, Bjö rn C; Fastner, Astrid; Streit, Verena; Port, Sarah A; Colcombet, Jean; de la Fuente van Bentem, Sergio; Hirt, Heribert; Kuster, Bernhard; Schulze, Waltraud X; Hammes, Ulrich Z; Schwechheimer, Claus

    2014-01-01

    The development and morphology of vascular plants is critically determined by synthesis and proper distribution of the phytohormone auxin. The directed cell-to-cell distribution of auxin is achieved through a system of auxin influx and efflux transporters. PIN-FORMED (PIN) proteins are proposed auxin efflux transporters, and auxin fluxes can seemingly be predicted based on the-in many cells-asymmetric plasma membrane distribution of PINs. Here, we show in a heterologous Xenopus oocyte system as well as in Arabidopsis thaliana inflorescence stems that PIN-mediated auxin transport is directly activated by D6 PROTEIN KINASE (D6PK) and PINOID (PID)/WAG kinases of the Arabidopsis AGCVIII kinase family. At the same time, we reveal that D6PKs and PID have differential phosphosite preferences. Our study suggests that PIN activation by protein kinases is a crucial component of auxin transport control that must be taken into account to understand auxin distribution within the plant.

  16. Auxin efflux by PIN-FORMED proteins is activated by two different protein kinases, D6 PROTEIN KINASE and PINOID

    KAUST Repository

    Zourelidou, Melina

    2014-06-19

    The development and morphology of vascular plants is critically determined by synthesis and proper distribution of the phytohormone auxin. The directed cell-to-cell distribution of auxin is achieved through a system of auxin influx and efflux transporters. PIN-FORMED (PIN) proteins are proposed auxin efflux transporters, and auxin fluxes can seemingly be predicted based on the-in many cells-asymmetric plasma membrane distribution of PINs. Here, we show in a heterologous Xenopus oocyte system as well as in Arabidopsis thaliana inflorescence stems that PIN-mediated auxin transport is directly activated by D6 PROTEIN KINASE (D6PK) and PINOID (PID)/WAG kinases of the Arabidopsis AGCVIII kinase family. At the same time, we reveal that D6PKs and PID have differential phosphosite preferences. Our study suggests that PIN activation by protein kinases is a crucial component of auxin transport control that must be taken into account to understand auxin distribution within the plant.

  17. Nuclear wastes

    International Nuclear Information System (INIS)

    2002-01-01

    This scientific document presents an introduction to the nuclear wastes problems, the separation process and the transmutation, the political and technical aspects of the storage, the radioprotection standards and the biological effects. (A.L.B.)

  18. Nuclear Disarmament.

    Science.gov (United States)

    Johnson, Christopher

    1982-01-01

    Material about nuclear disarmament and the arms race should be included in secondary school curricula. Teachers can present this technical, controversial, and frightening material in a balanced and comprehensible way. Resources for instructional materials are listed. (PP)

  19. Nuclear analysis

    International Nuclear Information System (INIS)

    1988-01-01

    Basic studies in nuclear analytical techniques include the examination of underlying assumptions and the development and extention of techniques involving the use of ion beams for elemental and mass analysis. 1 ref., 1 tab

  20. Nuclear reaction

    CERN Multimedia

    Penwarden, C

    2001-01-01

    At the European Research Organization for Nuclear Research, Nobel laureates delve into the mysteries of particle physics. But when they invited artists from across the continent to visit their site in Geneva, they wanted a new kind of experiment.

  1. [Nuclear theory

    International Nuclear Information System (INIS)

    1989-06-01

    This report discusses concepts in nuclear theory such as: neutrino nucleosynthesis; double beta decay; neutrino oscillations; chiral symmetry breaking; T invariance; quark propagator; cold fusion; and other related topics

  2. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    1999-01-01

    This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 1 to 56. (A.L.B.)

  3. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    2000-01-01

    This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 56 to 68. (A.L.B.)

  4. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    1998-01-01

    This paper is made of two tables. The first table describes the different particles (bosons and fermions) while the second one gives the nuclear constants of isotopes from the different elements with Z = 1 to 25. (J.S.)

  5. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    1999-01-01

    This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 56 to 68. (A.L.B.)

  6. Nuclear transmutations

    International Nuclear Information System (INIS)

    Mikulaj, V.

    1992-01-01

    Two types of nuclear transmutations are outlined, namely the radioactive transmutations and nuclear reactions. The basic characteristics are given of radioactive transmutations (gamma transmutations and isomeric transitions, beta, alpha transmutations, spontaneous fission and spontaneous emission of nucleons), their kinetics and the influence of the physical and chemical state of the radionuclide on the transmutation rate. The basic characteristics are described of nuclear reactions (reactions of neutrons including fission, reactions induced by charged particles and photons), their kinetics, effective cross sections and their mechanism. Chemical reactions caused by nuclear transmutations are discussed (recoil energy, properties of hot atoms, Szilard-Chalmers effect). A brief information is given on the behavior of radionuclides in trace concentrations. (Z.S.) 2 tabs., 19 figs., 12 refs

  7. Nuclear waste

    International Nuclear Information System (INIS)

    1992-05-01

    The Nuclear Waste Policy Act of 1982, as amended in 1987, directed the Secretary of Energy to, among other things, investigate Yucca Mountain, Nevada, as a potential site for permanently disposing of highly radioactive wastes in an underground repository. In April 1991, the authors testified on Yucca Mountain project expenditures before your Subcommittee. Because of the significance of the authors findings regrading DOE's program management and expenditures, you asked the authors to continue reviewing program expenditures in depth. As agreed with your office, the authors reviewed the expenditures of project funds made available to the Department of Energy's (DOE) Lawrence Livermore National Laboratory, which is the lead project contractor for developing a nuclear waste package that wold be used for disposing of nuclear waste at Yucca Mountain. This report discusses the laboratory's use of nuclear waste funds to support independent research projects and to manage Yucca Mountain project activities. It also discusses the laboratory's project contracting practices

  8. Nuclear shields

    International Nuclear Information System (INIS)

    Linares, R.C.; Nienart, L.F.; Toelcke, G.A.

    1976-01-01

    A process is described for preparing melt-processable nuclear shielding compositions from chloro-fluoro substituted ethylene polymers, particularly PCTFE and E-CTFE, containing 1 to 75 percent by weight of a gadolinium compound. 13 claims, no drawings

  9. Nuclear option

    International Nuclear Information System (INIS)

    Olson, P.S.

    1983-01-01

    The energy demand complexion of this country is always changing and promises to change in the future. The nuclear industry is responding to changing energy demands through standards writing activities. Since the oil embargo of 1973, there has been a change in the mix of fuels contributing to energy growth in this country; virtually all of the energy growth has come from coal and nuclear power. The predicted expansion of coal use by 1985, over 1977 level, is 37%, while the use of oil is expected to decline by 17%. Use of nuclear power is expected to increase 62% from the 1977 level. The feasibility of using nuclear energy to meet the needs of the USA for electric power is discussed

  10. Nuclear safety

    International Nuclear Information System (INIS)

    Tarride, Bruno

    2015-10-01

    The author proposes an overview of methods and concepts used in the nuclear industry, at the design level as well as at the exploitation level, to ensure an acceptable safety level, notably in the case of nuclear reactors. He first addresses the general objectives of nuclear safety and the notion of acceptable risk: definition and organisation of nuclear safety (relationships between safety authorities and operators), notion of acceptable risk, deterministic safety approach and main safety principles (safety functions and confinement barriers, concept of defence in depth). Then, the author addresses the safety approach at the design level: studies of operational situations, studies of internal and external aggressions, safety report, design principles for important-for-safety systems (failure criterion, redundancy, failure prevention, safety classification). The next part addresses safety during exploitation and general exploitation rules: definition of the operation domain and of its limits, periodic controls and tests, management in case of incidents, accidents or aggressions

  11. Nuclear fission

    International Nuclear Information System (INIS)

    Kodama, T.

    1981-01-01

    The nuclear fission process is pedagogically reviewed from a macroscopic-microscopic point of view. The Droplet model is considered. The fission dynamics is discussed utilizing path integrals and semiclassical methods. (L.C.) [pt

  12. Nuclear physics

    International Nuclear Information System (INIS)

    Connell, K.A.; Warner, D.D.

    1990-01-01

    The first volume of the Annual Report for 1989/90 gives an overview of the Nuclear Structure Facility at Daresbury, its development and a selection of highlights of the year's programme. This volume is complementary, presenting brief specialist reports, submitted by the users, describing the progress and results of each individual proposal. The contents reflect the extremely successful year due in good measure to the performance of the tandem accelerator which provided a record number of hours with ''beam on target''. Reports are grouped in four sections: research into nuclear structure with contributions ordered in increasing Z numbers of the nuclei studied; investigations of nuclear reaction mechanisms; nuclear theory; accelerator operations and development plus experimental instrumentation and techniques. The appendix forms a concise summary of the work at the facility for the year. (author)

  13. Nuclear waste

    International Nuclear Information System (INIS)

    Pligt, J. van der

    1989-01-01

    This chapter present a brief overview of the current situation of siting radioactive wastes. This is followed by an overview of various psychological approaches attempting to analyse public reactions to nuclear facilities. It will be argued that public reactions to nuclear waste factilities must be seen in the context of more general attitudes toward nuclear energy. The latter are not only based upon perceptions of the health and environmental risks but are built on values, and sets of attributes which need not be similar to the representations o the experts and policy-makers. The issue of siting nuclear waste facilities is also embedded in a wider moral and political domain. This is illustrated by the importance of equity issues in siting radioactive wastes. In the last section, the implications of the present line of argument for risk communication and public participation in decisions about siting radioactive wastes will be briefly discussed. (author). 49 refs

  14. Transgene expression of Drosophila melanogaster nucleoside kinase reverses mitochondrial thymidine kinase 2 deficiency.

    Science.gov (United States)

    Krishnan, Shuba; Zhou, Xiaoshan; Paredes, João A; Kuiper, Raoul V; Curbo, Sophie; Karlsson, Anna

    2013-02-15

    A strategy to reverse the symptoms of thymidine kinase 2 (TK2) deficiency in a mouse model was investigated. The nucleoside kinase from Drosophila melanogaster (Dm-dNK) was expressed in TK2-deficient mice that have been shown to present with a severe phenotype caused by mitochondrial DNA depletion. The Dm-dNK(+/-) transgenic mice were shown to be able to rescue the TK2-deficient mice. The Dm-dNK(+/-)TK2(-/-) mice were normal as judged by growth and behavior during the observation time of 6 months. The Dm-dNK-expressing mice showed a substantial increase in thymidine-phosphorylating activity in investigated tissues. The Dm-dNK expression also resulted in highly elevated dTTP pools. The dTTP pool alterations did not cause specific mitochondrial DNA mutations or deletions when 6-month-old mice were analyzed. The mitochondrial DNA was also detected at normal levels. In conclusion, the Dm-dNK(+/-)TK2(-/-) mouse model illustrates how dTMP synthesized in the cell nucleus can compensate for loss of intramitochondrial dTMP synthesis in differentiated tissue. The data presented open new possibilities to treat the severe symptoms of TK2 deficiency.

  15. Transgene Expression of Drosophila melanogaster Nucleoside Kinase Reverses Mitochondrial Thymidine Kinase 2 Deficiency*♦

    Science.gov (United States)

    Krishnan, Shuba; Zhou, Xiaoshan; Paredes, João A.; Kuiper, Raoul V.; Curbo, Sophie; Karlsson, Anna

    2013-01-01

    A strategy to reverse the symptoms of thymidine kinase 2 (TK2) deficiency in a mouse model was investigated. The nucleoside kinase from Drosophila melanogaster (Dm-dNK) was expressed in TK2-deficient mice that have been shown to present with a severe phenotype caused by mitochondrial DNA depletion. The Dm-dNK+/− transgenic mice were shown to be able to rescue the TK2-deficient mice. The Dm-dNK+/−TK2−/− mice were normal as judged by growth and behavior during the observation time of 6 months. The Dm-dNK-expressing mice showed a substantial increase in thymidine-phosphorylating activity in investigated tissues. The Dm-dNK expression also resulted in highly elevated dTTP pools. The dTTP pool alterations did not cause specific mitochondrial DNA mutations or deletions when 6-month-old mice were analyzed. The mitochondrial DNA was also detected at normal levels. In conclusion, the Dm-dNK+/−TK2−/− mouse model illustrates how dTMP synthesized in the cell nucleus can compensate for loss of intramitochondrial dTMP synthesis in differentiated tissue. The data presented open new possibilities to treat the severe symptoms of TK2 deficiency. PMID:23288848

  16. Activation of GABAB receptors inhibits protein kinase B /Glycogen Synthase Kinase 3 signaling

    Directory of Open Access Journals (Sweden)

    Lu Frances Fangjia

    2012-11-01

    Full Text Available Abstract Accumulated evidence has suggested that potentiation of cortical GABAergic inhibitory neurotransmission may be a key mechanism in the treatment of schizophrenia. However, the downstream molecular mechanisms related to GABA potentiation remain unexplored. Recent studies have suggested that dopamine D2 receptor antagonists, which are used in the clinical treatment of schizophrenia, modulate protein kinase B (Akt/glycogen synthase kinase (GSK-3 signaling. Here we report that activation of GABAB receptors significantly inhibits Akt/GSK-3 signaling in a β-arrestin-dependent pathway. Agonist stimulation of GABAB receptors enhances the phosphorylation of Akt (Thr-308 and enhances the phosphorylation of GSK-3α (Ser-21/β (Ser-9 in both HEK-293T cells expressing GABAB receptors and rat hippocampal slices. Furthermore, knocking down the expression of β-arrestin2 using siRNA abolishes the GABAB receptor-mediated modulation of GSK-3 signaling. Our data may help to identify potentially novel targets through which GABAB receptor agents may exert therapeutic effects in the treatment of schizophrenia.

  17. Inflammatory Signaling by NOD-RIPK2 Is Inhibited by Clinically Relevant Type II Kinase Inhibitors.

    Science.gov (United States)

    Canning, Peter; Ruan, Qui; Schwerd, Tobias; Hrdinka, Matous; Maki, Jenny L; Saleh, Danish; Suebsuwong, Chalada; Ray, Soumya; Brennan, Paul E; Cuny, Gregory D; Uhlig, Holm H; Gyrd-Hansen, Mads; Degterev, Alexei; Bullock, Alex N

    2015-09-17

    RIPK2 mediates pro-inflammatory signaling from the bacterial sensors NOD1 and NOD2, and is an emerging therapeutic target in autoimmune and inflammatory diseases. We observed that cellular RIPK2 can be potently inhibited by type II inhibitors that displace the kinase activation segment, whereas ATP-competitive type I inhibition was only poorly effective. The most potent RIPK2 inhibitors were the US Food and Drug Administration-approved drugs ponatinib and regorafenib. Their mechanism of action was independent of NOD2 interaction and involved loss of downstream kinase activation as evidenced by lack of RIPK2 autophosphorylation. Notably, these molecules also blocked RIPK2 ubiquitination and, consequently, inflammatory nuclear factor κB signaling. In monocytes, the inhibitors selectively blocked NOD-dependent tumor necrosis factor production without affecting lipopolysaccharide-dependent pathways. We also determined the first crystal structure of RIPK2 bound to ponatinib, and identified an allosteric site for inhibitor development. These results highlight the potential for type II inhibitors to treat indications of RIPK2 activation as well as inflammation-associated cancers. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Activation of peroxisome proliferator-activated receptors (PPARs) by their ligands and protein kinase A activators

    Science.gov (United States)

    Lazennec, Gwendal; Canaple, Laurence; Saugy, Damien; Wahli, Walter

    2000-01-01

    The nuclear peroxisome proliferator-activated receptors (PPARs) α, β and γ activate the transcription of multiple genes involved in lipid metabolism. Several natural and synthetic ligands have been identified for each PPAR isotype but little is known about the phosphorylation state of these receptors. We show here that activators of protein kinase A (PKA) can enhance mouse PPAR activity in the absence and the presence of exogenous ligands in transient transfection experiments. The activation function 1 (AF-1) of PPARs was dispensable for transcriptional enhancement, whereas the activation function 2 (AF-2) was required for this effect. We also show that several domains of PPAR can be phosphorylated by PKA in vitro. Moreover, gel experiments suggest that PKA stabilizes binding of the liganded PPAR to DNA. PKA inhibitors decreased not only the kinase dependent induction of PPARs but also their ligand-dependent induction, suggesting that the ligands may also mobilize the PKA pathway to lead to maximal transcriptional induction by PPARs. Moreover, comparing PPARα KO with PPARα wild-type mice, we show that the expression of the ACO gene can be regulated by PKA-activated PPARα in liver. These data demonstrate that the PKA pathway is an important modulator of PPAR activity and we propose a model associating this pathway in the control of fatty acid β-oxidation under conditions of fasting, stress and exercise. PMID:11117527

  19. Iκb Kinase α Is Essential for Mature B Cell Development and Function

    Science.gov (United States)

    Kaisho, Tsuneyasu; Takeda, Kiyoshi; Tsujimura, Tohru; Kawai, Taro; Nomura, Fumiko; Terada, Nobuyuki; Akira, Shizuo

    2001-01-01

    IκB kinase (IKK) α and β phosphorylate IκB proteins and activate the transcription factor, nuclear factor (NF)-κB. Although both are highly homologous kinases, gene targeting experiments revealed their differential roles in vivo. IKKα is involved in skin and limb morphogenesis, whereas IKKβ is essential for cytokine signaling. To elucidate in vivo roles of IKKα in hematopoietic cells, we have generated bone marrow chimeras by transferring control and IKKα-deficient fetal liver cells. The mature B cell population was decreased in IKKα−/− chimeras. IKKα−/− chimeras also exhibited a decrease of serum immunoglobulin basal level and impaired antigen-specific immune responses. Histologically, they also manifested marked disruption of germinal center formation and splenic microarchitectures that depend on mature B cells. IKKα−/− B cells not only showed impairment of survival and mitogenic responses in vitro, accompanied by decreased, although inducible, NF-κB activity, but also increased turnover rate in vivo. In addition, transgene expression of bcl-2 could only partially rescue impaired B cell development in IKKα−/− chimeras. Taken together, these results demonstrate that IKKα is critically involved in the prevention of cell death and functional development of mature B cells. PMID:11181694

  20. Molecular nuclear cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Soo; Paeng, Jin Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2004-04-01

    Molecular nuclear cardiac imaging has included Tc-99m Annexin imaging to visualize myocardial apoptosis, but is now usually associated with gene therapy and cell-based therapy. Cardiac gene therapy was not successful so far but cardiac reporter gene imaging was made possible using HSV-TK (herpes simplex virus thymidine kinase) and F-18 FHBG (fluoro-hydroxymethylbutyl guanine) or I-124 FIAU (fluoro-deoxyiodo-arabino-furanosyluracil). Gene delivery was performed by needle injection with or without catheter guidance. TK expression did not last longer than 2 weeks in myocardium. Cell-based therapy of ischemic heart or failing heart looks promising, but biodistribution and differentiation of transplanted cells are not known. Reporter genes can be transfected to the stem/progenitor cells and cells containing these genes can be transplanted to the recipients using catheter-based purging or injection. Repeated imaging should be available and if promoter are varied to let express reporter transgenes, cellular (trans)differentiation can be studied. NIS (sodium iodide symporter) or D2R receptor genes are promising in this aspect.