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Sample records for transduction peptide ctp

  1. Cytoplasmic transduction peptide (CTP): New approach for the delivery of biomolecules into cytoplasm in vitro and in vivo

    International Nuclear Information System (INIS)

    Kim, Daeyou; Jeon, Choonju; Kim, Jeong-Hwan; Kim, Mi-Seon; Yoon, Cheol-Hee; Choi, In-Soo; Kim, Sung-Hoon; Bae, Yong-Soo

    2006-01-01

    The protein transduction domain (PTD) of HIV-1 TAT has been extensively documented with regard to its membrane transduction potential, as well as its efficient delivery of biomolecules in vivo. However, the majority of PTD and PTD-conjugated molecules translocate to the nucleus rather than to the cytoplasm after transduction, due to the functional nuclear localization sequence (NLS). Here, we report a cytoplasmic transduction peptide (CTP), which was deliberately designed to ensure the efficient cytoplasmic delivery of the CTP-fused biomolecules. In comparison with PTD, CTP and its fusion partners exhibited a clear preference for cytoplasmic localization, and also markedly enhanced membrane transduction potential. Unlike the mechanism underlying PTD-mediated transduction, CTP-mediated transduction occurs independently of the lipid raft-dependent macropinocytosis pathway. The CTP-conjugated Smac/DIABLO peptide (Smac-CTP) was also shown to be much more efficient than Smac-PTD in the blockage of the antiapoptotic properties of XIAP, suggesting that cytoplasmic functional molecules can be more efficiently targeted by CTP-mediated delivery. In in vivo trafficking studies, CTP-fused β-gal exhibited unique organ tropisms to the liver and lymph nodes when systemically injected into mice, whereas PTD-β-gal exhibited no such tropisms. Taken together, our findings implicate CTP as a novel delivery peptide appropriate for (i) molecular targeting to cytoplasmic compartments in vitro, (ii) the development of class I-associated CTL vaccines, and (iii) special drug delivery in vivo, without causing any untoward effects on nuclear genetic material

  2. [Transduction peptides, the useful face of a new signaling mechanism].

    Science.gov (United States)

    Joliot, Alain; Prochiantz, Alain

    2005-03-01

    Transduction peptides that cross the plasma membrane of live cells are commonly used for the in vitro and in vivo targeting of hydrophilic drugs into the cell interior. Although this family of peptides has recently increased and will probably continue to do so, the two mainly used peptides are derived from transcription factors. Indeed, TAT is a 12 amino acid long arginine-rich peptide present in the HIV transcription factor, and penetratin - or its variants - corresponds to 16 amino acids that define the highly conserved third helix of the DNA-binding domain (homeodomain) of homeoprotein transcription factors. In this review, we shall recall the different steps that have led to the discovery of transduction peptides and present the most likely hypotheses concerning the mechanisms involved in their internalization. At the risk of being incomplete or, even, biased, we shall concentrate on penetratins and TAT. The reason is that these peptides have been studied for over ten years leading to the edification of robust knowledge regarding their properties. This attitude will not preclude comparisons with other peptides, if necessary. Our goal is to describe the mode of action of these transduction peptides, their range of activity in term of cell types that accept them and cargoes that they can transport, and, also, some of the limitations that one can encounter in their use. Finally, based on the idea that peptide transduction is the technological face of a physiological property of some transcription factors, we shall discuss the putative physiological function of homeoprotein transduction, and, as a consequence, the possibility to use these factors as therapeutic proteins.

  3. Therapeutic peptides for cancer therapy. Part I - peptide inhibitors of signal transduction cascades.

    Science.gov (United States)

    Bidwell, Gene L; Raucher, Drazen

    2009-10-01

    Therapeutic peptides have great potential as anticancer agents owing to their ease of rational design and target specificity. However, their utility in vivo is limited by low stability and poor tumor penetration. The authors review the development of peptide inhibitors with potential for cancer therapy. Peptides that inhibit signal transduction cascades are discussed. The authors searched Medline for articles concerning the development of therapeutic peptides and their delivery. Given our current knowledge of protein sequences, structures and interaction interfaces, therapeutic peptides that inhibit interactions of interest are easily designed. These peptides are advantageous because they are highly specific for the interaction of interest, and they are much more easily developed than small molecule inhibitors of the same interactions. The main hurdle to application of peptides for cancer therapy is their poor pharmacokinetic and biodistribution parameters. Therefore, successful development of peptide delivery vectors could potentially make possible the use of this new and very promising class of anticancer agents.

  4. Development of oral CTL vaccine using a CTP-integrated Sabin 1 poliovirus-based vector system.

    Science.gov (United States)

    Han, Seung-Soo; Lee, Jinjoo; Jung, Yideul; Kang, Myeong-Ho; Hong, Jung-Hyub; Cha, Min-Suk; Park, Yu-Jin; Lee, Ezra; Yoon, Cheol-Hee; Bae, Yong-Soo

    2015-09-11

    We developed a CTL vaccine vector by modification of the RPS-Vax system, a mucosal vaccine vector derived from a poliovirus Sabin 1 strain, and generated an oral CTL vaccine against HIV-1. A DNA fragment encoding a cytoplasmic transduction peptide (CTP) was integrated into the RPS-Vax system to generate RPS-CTP, a CTL vaccine vector. An HIV-1 p24 cDNA fragment was introduced into the RPS-CTP vector system and a recombinant poliovirus (rec-PV) named vRPS-CTP/p24 was produced. vRPS-CTP/p24 was genetically stable and efficiently induced Th1 immunity and p24-specific CTLs in immunized poliovirus receptor-transgenic (PVR-Tg) mice. In challenge experiments, PVR-Tg mice that were pre-immunized orally with vRPS-CTP/p24 were resistant to challenge with a lethal dose of p24-expressing recombinant vaccinia virus (rMVA-p24). These results suggested that the RPS-CTP vector system had potential for developing oral CTL vaccines against infectious diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Effects of the TAT peptide orientation and relative location on the protein transduction efficiency.

    Science.gov (United States)

    Guo, Qingguo; Zhao, Guojie; Hao, Fengjin; Guan, Yifu

    2012-05-01

    To understand the protein transduction domain (PTD)-mediated protein transduction behavior and to explore its potential in delivering biopharmaceutic drugs, we prepared four TAT-EGFP conjugates: TAT(+)-EGFP, TAT(-)-EGFP, EGFP-TAT(+) and EGFP-TAT(-), where TAT(+) and TAT(-) represent the original and the reversed TAT sequence, respectively. These four TAT-EGFP conjugates were incubated with HeLa and PC12 cells for in vitro study as well as injected intraperitoneally to mice for in vivo study. Flow cytometric results showed that four TAT-EGFP conjugates were able to traverse HeLa and PC12 cells with almost equal transduction efficiency. The in vivo study showed that the TAT-EGFP conjugates could be delivered into different organs of mice with different transduction capabilities. Bioinformatic analyses and CD spectroscopic data revealed that the TAT peptide has no defined secondary structure, and conjugating the TAT peptide to the EGFP cargo protein would not alter the native structure and the function of the EGFP protein. These results conclude that the sequence orientation, the spatial structure, and the relative location of the TAT peptide have much less effect on the TAT-mediated protein transduction. Thus, the TAT-fused conjugates could be constructed in more convenient and flexible formats for a wide range of biopharmaceutical applications. © 2011 John Wiley & Sons A/S.

  6. Antitumor activity of novel chimeric peptides derived from cyclinD/CDK4 and the protein transduction domain 4.

    Science.gov (United States)

    Wang, Haili; Chen, Xi; Chen, Yanping; Sun, Lei; Li, Guodong; Zhai, Mingxia; Zhai, Wenjie; Kang, Qiaozhen; Gao, Yanfeng; Qi, Yuanming

    2013-02-01

    CyclinD1/CDK4 and cyclinD3/CDK4 complexes are key regulators of the cell progression and therefore constitute promising targets for the design of anticancer agents. In the present study, the key peptide motifs were selected from these two complexes. Chimeric peptides with these peptides conjugated to the protein transduction domain 4 (PTD4) were designed and synthesized. The chimeric peptides, PTD4-D1, PTD4-D3, PTD4-K4 exhibited significant anti-proliferation effects on cancer cell lines. These peptides could compete with the cyclinD/CDK4 complex and induce the G1/S phase arrest and apoptosis of cancer cells. In the tumor challenge experiment, these peptides showed potent antitumor effects with no significant side effects. Our results suggested that these peptides could be served as novel leading compounds with potent antitumor activity.

  7. Elucidation of the Signal Transduction Pathways Activated by the Plant Natriuretic Peptide AtPNP-A

    KAUST Repository

    Turek, Ilona

    2014-11-01

    Plant natriuretic peptides (PNPs) comprise a novel class of hormones that share some sequence similarity in the active site with their animal analogues that function as regulators of salt and water balance. A PNP present in Arabidopsis thaliana (AtPNP-A) has been assigned a role in abiotic and biotic stress responses, and the recombinant protein has been demonstrated to elicit cyclic guanosine monophosphate (cGMP)-dependent stomatal guard cell opening, regulate ion movements, and induce osmoticum-dependent water uptake. Although the importance of the hormone in maintaining ion and fluid homeostasis has been established, key components of the AtPNP-A-dependent signal transduction pathway remain unknown. Since identification of the binding partners of AtPNP-A, including its receptor(s), is fundamental to understanding the mode of its action at the molecular level, comprehensive protein-protein interaction studies, involving yeast two-hybrid screening, affinity-based assays, protein cross-linking and co-immunoprecipitation followed by mass spectrometric (MS) analyses have been performed. Several candidate binding partners of AtPNP-A identified with at least two independent methods were subsequently expressed as recombinant proteins, purified, and the specificity of their interactions with the recombinant AtPNP-A was verified using surface plasmon resonance. Several specific binary interactants of AtPNP-A were subjected to functional assays aimed at unraveling the consequences of the interactions in planta. These experiments have revealed that reactive oxygen species (ROS) are novel secondary messengers involved in the transduction of AtPNP-A signal in suspension-cultured cells of A. thaliana (Col-0). Further insight into the AtPNP-A dependent signalling events occurring in suspension-cultured cells in ROS-dependent or ROS-independent manner have been obtained from the large-scale proteomics study employing tandem mass tag (TMT) labelling followed by MS analysis to

  8. RXP-E: a connexin43-binding peptide that prevents action potential propagation block

    DEFF Research Database (Denmark)

    Lewandowski, Rebecca; Procida, Kristina; Vaidyanathan, Ravi

    2008-01-01

    . Separately, RXP-E was concatenated to a cytoplasmic transduction peptide (CTP) for cytoplasmic translocation (CTP-RXP-E). The effect of RXP-E on action potential propagation was assessed by high-resolution optical mapping in monolayers of neonatal rat ventricular myocytes, containing approximately 20......% of randomly distributed myofibroblasts. In contrast to control experiments, when heptanol (2 mmol/L) was added to the superfusate of monolayers loaded with CTP-RXP-E, action potential propagation was maintained, albeit at a slower velocity. Similarly, intracellular acidification (pH(i) 6.2) caused a loss...... of action potential propagation in control monolayers; however, propagation was maintained in CTP-RXP-E-treated cells, although at a slower rate. Patch-clamp experiments revealed that RXP-E did not prevent heptanol-induced block of sodium currents, nor did it alter voltage dependence or amplitude of Kir2...

  9. The Central Trigger Processor (CTP)

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    The Central Trigger Processor (CTP) receives trigger information from the calorimeter and muon trigger processors, as well as from other sources of trigger. It makes the Level-1 decision (L1A) based on a trigger menu.

  10. CTP limitation increases expression of CTP synthase in Lactococcus lactis

    DEFF Research Database (Denmark)

    Jørgensen, C.M.; Hammer, Karin; Martinussen, Jan

    2003-01-01

    CTP synthase is encoded by the pyrG gene and catalyzes the conversion of UTP to CTP. A Lactococcus lactis pyrG mutant with a cytidine requirement was constructed, in which beta-galactosidase activity in a pyrG-lacLM transcriptional fusion was used to monitor gene expression of pyrG. A 10-fold...... decrease in the CTP pool induced by cytidine limitation was found to immediately increase expression of the L. lactis pyrG gene. The final level of expression of pyrG is 37-fold higher than the uninduced level. CTP limitation has pronounced effects on central cellular metabolism, and both RNA and protein...... for regulation of the pyrG gene. It is possible to fold the pyrG leader in an alternative structure that would prevent the formation of the terminator. We suggest a model for pyrG regulation in L. lactis, and probably in other gram-positive bacteria as well, in which pyrG expression is directly dependent...

  11. Elucidation of the Signal Transduction Pathways Activated by the Plant Natriuretic Peptide AtPNP-A

    KAUST Repository

    Turek, Ilona

    2014-01-01

    Plant natriuretic peptides (PNPs) comprise a novel class of hormones that share some sequence similarity in the active site with their animal analogues that function as regulators of salt and water balance. A PNP present in Arabidopsis thaliana (At

  12. Transmembrane signal transduction by peptide hormones via family B G protein-coupled receptors

    Directory of Open Access Journals (Sweden)

    Kelly J Culhane

    2015-11-01

    Full Text Available Although family B G protein-coupled receptors (GPCRs contain only 15 members, they play key roles in transmembrane signal transduction of hormones. Family B GPCRs are drug targets for developing therapeutics for diseases ranging from metabolic to neurological disorders. Despite their importance, the molecular mechanism of activation of family B GPCRs remains largely unexplored due to the challenges in expression and purification of functional receptors to the quantity for biophysical characterization. Currently, there is no crystal structure available of a full-length family B GPCR. However, structures of key domains, including the extracellular ligand binding regions and seven-helical transmembrane regions, have been solved by X-ray crystallography and NMR, providing insights into the mechanisms of ligand recognition and selectivity, and helical arrangements within the cell membrane. Moreover, biophysical and biochemical methods have been used to explore functions, key residues for signaling, and the kinetics and dynamics of signaling processes. This review summarizes the current knowledge of the signal transduction mechanism of family B GPCRs at the molecular level and comments on the challenges and outlook for mechanistic studies of family B GPCRs.

  13. Chimeric peptide-mediated siRNA transduction to inhibit HIV-1 infection.

    Science.gov (United States)

    Bivalkar-Mehla, Shalmali; Mehla, Rajeev; Chauhan, Ashok

    2017-04-01

    Persistent human immunodeficiency virus 1 (HIV-1) infection provokes immune activation and depletes CD4 +  lymphocytes, leading to acquired immunodeficiency syndrome. Uninterrupted administration of combination antiretroviral therapy (cART) in HIV-infected patients suppresses viral replication to below the detectable level and partially restores the immune system. However, cART-unresponsive residual HIV-1 infection and elusive transcriptionally silent but reactivatable viral reservoirs maintain a permanent viral DNA blue print. The virus rebounds within a few weeks after interruption of suppressive therapy. Adjunct gene therapy to control viral replication by ribonucleic acid interference (RNAi) is a post-transcriptional gene silencing strategy that could suppress residual HIV-1 burden and overcome viral resistance. Small interfering ribonucleic acids (siRNAs) are efficient transcriptional inhibitors, but need delivery systems to reach inside target cells. We investigated the potential of chimeric peptide (FP-PTD) to deliver specific siRNAs to HIV-1-susceptible and permissive cells. Chimeric FP-PTD peptide was designed with an RNA binding domain (PTD) to bind siRNA and a cell fusion peptide domain (FP) to enter cells. FP-PTD-siRNA complex entered and inhibited HIV-1 replication in susceptible cells, and could be a candidate for in vivo testing.

  14. The ALICE Central Trigger Processor (CTP) upgrade

    International Nuclear Information System (INIS)

    Krivda, M.; Alexandre, D.; Barnby, L.S.; Evans, D.; Jones, P.G.; Jusko, A.; Lietava, R.; Baillie, O. Villalobos; Pospíšil, J.

    2016-01-01

    The ALICE Central Trigger Processor (CTP) at the CERN LHC has been upgraded for LHC Run 2, to improve the Transition Radiation Detector (TRD) data-taking efficiency and to improve the physics performance of ALICE. There is a new additional CTP interaction record sent using a new second Detector Data Link (DDL), a 2 GB DDR3 memory and an extension of functionality for classes. The CTP switch has been incorporated directly onto the new LM0 board. A design proposal for an ALICE CTP upgrade for LHC Run 3 is also presented. Part of the development is a low latency high bandwidth interface whose purpose is to minimize an overall trigger latency

  15. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    International Nuclear Information System (INIS)

    Gou, Ke-Mian; Chang, Chia-Chun; Shen, Qing-Ji; Sung, Li-Ying; Liu, Ji-Long

    2014-01-01

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus

  16. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Gou, Ke-Mian [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193 (China); Chang, Chia-Chun [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Shen, Qing-Ji [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); Sung, Li-Ying, E-mail: liyingsung@ntu.edu.tw [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan, ROC (China); Liu, Ji-Long, E-mail: jilong.liu@dpag.ox.ac.uk [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom)

    2014-04-15

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus.

  17. Protein Transduction Based Therapies for Breast Cancer

    National Research Council Canada - National Science Library

    Robbins, Paul D

    2004-01-01

    We have demonstrated that certain transduction peptides such as 12 lysines and 12 arginines can facilitate internalization into breast tumor lines with higher efficiency than smaller polymers of cationic amino acids...

  18. Protein Transduction Based Therapies for Breast Cancer

    National Research Council Canada - National Science Library

    Robbins, Paul D

    2005-01-01

    We have demonstrated that certain transduction peptides such as 12 lysines and 12 arginines can facilitate internalization into breast tumor lines with higher efficiency than smaller polymers of cationic amino acids...

  19. Fabrication of CTP/HAp novel gradient composite bioceramics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Calcium-titanium-phosphate(CaTi4(PO4)6, CTP)/hydroxyapatite(HAp) is a kind of novel gradient composite bioceramics,which has excellent biocompatibility and bioactivity. CTP ceramic film was synthesized one-step on the surface of titanium using micro-arc oxidation(MAO). The CTP/HAp composite bioceramics were prepared by soaking CTP film in HAp inducing solution for several days. XRD, SEM and EDX were used to characterize the bio-ceramic films phase and composition, morphology and component. The influence of electrolyte molar ratio of Ca to P and the current density to the synthesis of film was studied, and the optimized value of parameters above were 1/6 and 15A/dm2. The parameters of HAp inducing solution, such as component and pH value were also studied and the best pH value which is adjusted by NaOH is 6.4.

  20. The ATLAS Level-1 Central Trigger Processor (CTP)

    CERN Document Server

    Spiwoks, Ralf; Ellis, Nick; Farthouat, P; Gällnö, P; Haller, J; Krasznahorkay, A; Maeno, T; Pauly, T; Pessoa-Lima, H; Resurreccion-Arcas, I; Schuler, G; De Seixas, J M; Torga-Teixeira, R; Wengler, T

    2005-01-01

    The ATLAS Level-1 Central Trigger Processor (CTP) combines information from calorimeter and muon trigger processors and makes the final Level-1 Accept (L1A) decision on the basis of lists of selection criteria (trigger menus). In addition to the event-selection decision, the CTP also provides trigger summary information to the Level-2 trigger and the data acquisition system. It further provides accumulated and bunch-by-bunch scaler data for monitoring of the trigger, detector and beam conditions. The CTP is presented and results are shown from tests with the calorimeter adn muon trigger processors connected to detectors in a particle beam, as well as from stand-alone full-system tests in the laboratory which were used to validate the CTP.

  1. Expression of Human CTP Synthetase in Saccharomyces cerevisiae Reveals Phosphorylation by Protein Kinase A*

    Science.gov (United States)

    Han, Gil-Soo; Sreenivas, Avula; Choi, Mal-Gi; Chang, Yu-Fang; Martin, Shelley S.; Baldwin, Enoch P.; Carman, George M.

    2005-01-01

    CTP synthetase (EC 6.3.4.2, UTP: ammonia ligase (ADP-forming)) is an essential enzyme in all organisms; it generates the CTP required for the synthesis of nucleic acids and membrane phospholipids. In this work we showed that the human CTP synthetase genes, CTPS1 and CTPS2, were functional in Saccharomyces cerevisiae and complemented the lethal phenotype of the ura7Δ ura8Δ mutant lacking CTP synthetase activity. The expression of the CTPS1-and CTPS2-encoded human CTP synthetase enzymes in the ura7Δ ura8Δ mutant was shown by immunoblot analysis of CTP synthetase proteins, the measurement of CTP synthetase activity, and the synthesis of CTP in vivo. Phosphoamino acid and phosphopeptide mapping analyses of human CTP synthetase 1 isolated from 32Pi-labeled cells revealed that the enzyme was phosphorylated on multiple serine residues in vivo. Activation of protein kinase A activity in yeast resulted in transient increases (2-fold) in the phosphorylation of human CTP synthetase 1 and the cellular level of CTP. Human CTP synthetase 1 was also phosphorylated by mammalian protein kinase A in vitro. Using human CTP synthetase 1 purified from Escherichia coli as a substrate, protein kinase A activity was dose- and time-dependent, and dependent on the concentrations of CTP synthetase1 and ATP. These studies showed that S. cerevisiae was useful for the analysis of human CTP synthetase phosphorylation. PMID:16179339

  2. Secretory TAT-peptide-mediated protein transduction of LIF receptor α-chain distal cytoplasmic motifs into human myeloid HL-60 cells

    Directory of Open Access Journals (Sweden)

    Q. Sun

    2012-10-01

    Full Text Available The distal cytoplasmic motifs of leukemia inhibitory factor receptor α-chain (LIFRα-CT3 can independently induce intracellular myeloid differentiation in acute myeloid leukemia (AML cells by gene transfection; however, there are significant limitations in the potential clinical use of these motifs due to liposome-derived genetic modifications. To produce a potentially therapeutic LIFRα-CT3 with cell-permeable activity, we constructed a eukaryotic expression pcDNA3.0-TAT-CT3-cMyc plasmid with a signal peptide (ss inserted into the N-terminal that codes for an ss-TAT-CT3-cMyc fusion protein. The stable transfection of Chinese hamster ovary (CHO cells via this vector and subsequent selection by Geneticin resulted in cell lines that express and secrete TAT-CT3-cMyc. The spent medium of pcDNA3.0-TAT-CT3-cMyc-transfected CHO cells could be purified using a cMyc-epitope-tag agarose affinity chromatography column and could be detected via SDS-PAGE, with antibodies against cMyc-tag. The direct administration of TAT-CT3-cMyc to HL-60 cell culture media caused the enrichment of CT3-cMyc in the cytoplasm and nucleus within 30 min and led to a significant reduction of viable cells (P < 0.05 8 h after exposure. The advantages of using this mammalian expression system include the ease of generating TAT fusion proteins that are adequately transcripted and the potential for a sustained production of such proteins in vitro for future AML therapy.

  3. Secretory TAT-peptide-mediated protein transduction of LIF receptor α-chain distal cytoplasmic motifs into human myeloid HL-60 cells

    International Nuclear Information System (INIS)

    Sun, Q.; Xiong, J.; Lu, J.; Xu, S.; Li, Y.; Zhong, X.P.; Gao, G.K.; Liu, H.Q.

    2012-01-01

    The distal cytoplasmic motifs of leukemia inhibitory factor receptor α-chain (LIFRα-CT3) can independently induce intracellular myeloid differentiation in acute myeloid leukemia (AML) cells by gene transfection; however, there are significant limitations in the potential clinical use of these motifs due to liposome-derived genetic modifications. To produce a potentially therapeutic LIFRα-CT3 with cell-permeable activity, we constructed a eukaryotic expression pcDNA3.0-TAT-CT3-cMyc plasmid with a signal peptide (ss) inserted into the N-terminal that codes for an ss-TAT-CT3-cMyc fusion protein. The stable transfection of Chinese hamster ovary (CHO) cells via this vector and subsequent selection by Geneticin resulted in cell lines that express and secrete TAT-CT3-cMyc. The spent medium of pcDNA3.0-TAT-CT3-cMyc-transfected CHO cells could be purified using a cMyc-epitope-tag agarose affinity chromatography column and could be detected via SDS-PAGE, with antibodies against cMyc-tag. The direct administration of TAT-CT3-cMyc to HL-60 cell culture media caused the enrichment of CT3-cMyc in the cytoplasm and nucleus within 30 min and led to a significant reduction of viable cells (P < 0.05) 8 h after exposure. The advantages of using this mammalian expression system include the ease of generating TAT fusion proteins that are adequately transcripted and the potential for a sustained production of such proteins in vitro for future AML therapy

  4. Secretory TAT-peptide-mediated protein transduction of LIF receptor α-chain distal cytoplasmic motifs into human myeloid HL-60 cells

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Q. [Department of Hyperbaric Medicine, No. 401 Hospital of PLA, Qingdao (China); Department of Histology and Embryology, Faculty of Basic Medical Sciences, Second Military Medical University, Shanghai (China); Xiong, J. [Department of Histology and Embryology, Faculty of Basic Medical Sciences, Second Military Medical University, Shanghai (China); Lu, J. [Office of Medical Education, Training Department, Second Military Medical University, Shanghai (China); Xu, S. [Department of Histology and Embryology, Faculty of Basic Medical Sciences, Second Military Medical University, Shanghai (China); Li, Y. [State Food and Drug Administration of China,Huangdao Branch, Qingdao (China); Zhong, X.P.; Gao, G.K. [Department of Hyperbaric Medicine, No. 401 Hospital of PLA, Qingdao (China); Liu, H.Q. [2Department of Histology and Embryology, Faculty of Basic Medical Sciences, Second Military Medical University, Shanghai (China)

    2012-06-22

    The distal cytoplasmic motifs of leukemia inhibitory factor receptor α-chain (LIFRα-CT3) can independently induce intracellular myeloid differentiation in acute myeloid leukemia (AML) cells by gene transfection; however, there are significant limitations in the potential clinical use of these motifs due to liposome-derived genetic modifications. To produce a potentially therapeutic LIFRα-CT3 with cell-permeable activity, we constructed a eukaryotic expression pcDNA3.0-TAT-CT3-cMyc plasmid with a signal peptide (ss) inserted into the N-terminal that codes for an ss-TAT-CT3-cMyc fusion protein. The stable transfection of Chinese hamster ovary (CHO) cells via this vector and subsequent selection by Geneticin resulted in cell lines that express and secrete TAT-CT3-cMyc. The spent medium of pcDNA3.0-TAT-CT3-cMyc-transfected CHO cells could be purified using a cMyc-epitope-tag agarose affinity chromatography column and could be detected via SDS-PAGE, with antibodies against cMyc-tag. The direct administration of TAT-CT3-cMyc to HL-60 cell culture media caused the enrichment of CT3-cMyc in the cytoplasm and nucleus within 30 min and led to a significant reduction of viable cells (P < 0.05) 8 h after exposure. The advantages of using this mammalian expression system include the ease of generating TAT fusion proteins that are adequately transcripted and the potential for a sustained production of such proteins in vitro for future AML therapy.

  5. CTP (Cochlin-tomoprotein) detection in the profuse fluid leakage (gusher) from cochleostomy.

    Science.gov (United States)

    Ikezono, Tetsuo; Sugizaki, Kazuki; Shindo, Susumu; Sekiguchi, Satomi; Pawankar, Ruby; Baba, Shunkichi; Yagi, Toshiaki

    2010-08-01

    By testing 125 samples, we confirmed that Cochlin-tomoprotein (CTP) is present in the perilymph, not in cerebrospinal fluid (CSF). Perilymph and CSF exist in two distinct compartments, even in the case of a malformed inner ear with a bony defect in the lamina cribrosa, as described here. Cochleostomy might have suddenly decreased the perilymph pressure, allowing the influx of CSF into the inner ear resulting in profuse fluid leakage, first perilymph then CSF. The first purpose of this study was to further confirm the specificity of the perilymph-specific protein CTP that we reported recently. Secondly, we assessed the nature of the fluid leakage from the cochleostomy using the CTP detection test. A standardized CTP detection test was performed on 65 perilymph and 60 CSF samples. Samples of profuse fluid leakage collected from cochleostomy during cochlear implantation surgery of one patient with branchio-oto-renal (BOR) syndrome were also tested by the CTP detection test. CTP was detected in 60 of 65 perilymph samples but not in any of the CSF samples. The leaked fluid was shown to contain CTP, i.e. perilymph, at the outset, and then the CTP detection signals gradually disappeared as time elapsed.

  6. Identification and Characterization of the Nuclear Isoform of Drosophila melanogaster CTP:Phosphocholine Cytidylyltransferase

    Science.gov (United States)

    CTP:phosphocholine cytidylyltransferase (CCT) catalyzes the conversion of phosphocholine and cytidine 5'-triphosphate (CTP) to CDP-choline for the eventual synthesis of phosphatidylcholine (PC). The enzyme is regulated by reversible association with cellular membranes, with the rate of catalysis in...

  7. CTP synthase forms the cytoophidium in human hepatocellular carcinoma.

    Science.gov (United States)

    Chang, Chia-Chun; Jeng, Yung-Ming; Peng, Min; Keppeke, Gerson Dierley; Sung, Li-Ying; Liu, Ji-Long

    2017-12-15

    CTP synthase (CTPS) can aggregate into an intracellular macrostructure, the cytoophidium, in various organisms including human cells. Previous studies have shown that assembly of human CTPS cytoophidia may be correlated with the cellular metabolic status, and is able to promote the activity of CTPS. A correlation between the cytoophidium and cancer metabolism has been proposed but not yet been revealed. In the current study we provide clear evidence of the presence of CTPS cytoophidia in various human cancers and some non-cancerous tissues. Moreover, among 203 tissue samples of hepatocellular carcinoma, 56 (28%) samples exhibited many cytoophidia, whereas no cytoophidia were detected in adjacent non-cancerous hepatocytes for all samples. Our findings suggest that the CTPS cytoophidium may participate in the adaptive metabolism of human hepatocellular carcinoma. Copyright © 2017. Published by Elsevier Inc.

  8. Exact CTP renormalization group equation for the coarse-grained effective action

    International Nuclear Information System (INIS)

    Dalvit, D.A.; Mazzitelli, F.D.

    1996-01-01

    We consider a scalar field theory in Minkowski spacetime and define a coarse-grained closed time path (CTP) effective action by integrating quantum fluctuations of wavelengths shorter than a critical value. We derive an exact CTP renormalization group equation for the dependence of the effective action on the coarse-graining scale. We solve this equation using a derivative expansion approach. Explicit calculation is performed for the λφ 4 theory. We discuss the relevance of the CTP average action in the study of nonequilibrium aspects of phase transitions in quantum field theory. copyright 1996 The American Physical Society

  9. Structure of the dimeric form of CTP synthase from Sulfolobus solfataricus

    DEFF Research Database (Denmark)

    Lauritsen, Iben; Willemoës, Martin; Jensen, Kaj Frank

    2011-01-01

    CTP synthase catalyzes the last committed step in de novo pyrimidine-nucleotide biosynthesis. Active CTP synthase is a tetrameric enzyme composed of a dimer of dimers. The tetramer is favoured in the presence of the substrate nucleotides ATP and UTP; when saturated with nucleotide, the tetramer...... completely dominates the oligomeric state of the enzyme. Furthermore, phosphorylation has been shown to regulate the oligomeric states of the enzymes from yeast and human. The crystal structure of a dimeric form of CTP synthase from Sulfolobus solfataricus has been determined at 2.5 Å resolution...

  10. Analytical similarity assessment of rituximab biosimilar CT-P10 to reference medicinal product.

    Science.gov (United States)

    Lee, Kyoung Hoon; Lee, Jihun; Bae, Jin Soo; Kim, Yeon Jung; Kang, Hyun Ah; Kim, Sung Hwan; Lee, So Jung; Lim, Ki Jung; Lee, Jung Woo; Jung, Soon Kwan; Chang, Shin Jae

    2018-04-01

    CT-P10 (Truxima™) was recently approved as the world's first rituximab biosimilar product in the European Union (EU) and South Korea. To demonstrate biosimilarity of CT-P10 with the reference medicinal product (RMP), extensive 3-way similarity assessment has been conducted between CT-P10, EU-Rituximab and US-Rituximab, focusing on the physicochemical and biological quality attributes. A multitude of state-of-the-art analyses revealed that CT-P10 has identical primary and higher order structures compared to the original product. Purity/impurity profiles of CT-P10 measured by the levels of aggregates, fragments, non-glycosylated form and process-related impurities were also found to be comparable with those of RMPs. In terms of the post-translational modification, CT-P10 contains slightly less N-terminal pyro-glutamate variant, which has been known not to affect product efficacy or safety. Oligosaccharide profiling has revealed that, although CT-P10 contains the same conserved glycan species and relative proportion with the RMPs, the content of total afucosylated glycan in CT-P10 was slightly higher than in EU- or US-Rituximab. Nevertheless, the effect of the observed level of afucosylation in CT-P10 drug product on Fc receptor binding affinity or antibody-dependent cell-mediated cytotoxicity was found to be negligible based on the spiking study with highly afucosylated sample. Arrays of biological assays representative of known and putative mechanisms of action for rituximab have shown that biological activities of CT-P10 are within the quality range of RMPs. Recent results of clinical studies have further confirmed that the CT-P10 exhibits equivalent clinical efficacy and safety profiles compared to EU- and US-Rituximab. The current 3-way similarity assessment together with clinical study results confidently demonstrate that CT-P10 is highly similar with EU- and US-Rituximab in terms of physicochemical properties, biological activities, efficacy, and safety for

  11. The Antimetabolite ara-CTP Blocks Long-Term Memory of Conditioned Taste Aversion

    OpenAIRE

    Wang, Jianpeng; Ren, Keqin; Pérez, Javier; Silva, Alcino J.; Peña de Ortiz, Sandra

    2003-01-01

    We examined the hypothesis that processes related to DNA recombination and repair are involved in learning and memory. Rats received intracerebroventricular (icv) infusions of the antimetabolite 1-beta-D-arabinofuranosylcytosine triphosphate (ara-CTP) or its precursor cytosine arabinoside (ara-C) 30 min prior to conditioned taste aversion (CTA) training. Both ara-CTP and ara-C caused significant impairments in long-term memory (LTM) of CTA. Control experiments indicate that the effect of ara-...

  12. The antimetabolite ara-CTP blocks long-term memory of conditioned taste aversion.

    Science.gov (United States)

    Wang, Jianpeng; Ren, Keqin; Pérez, Javier; Silva, Alcino J; Peña de Ortiz, Sandra

    2003-01-01

    We examined the hypothesis that processes related to DNA recombination and repair are involved in learning and memory. Rats received intracerebroventricular (i.c.v.) infusions of the antimetabolite 1-beta-D-arabinofuranosylcytosine triphosphate (ara-CTP) or its precursor cytosine arabinoside (ara-C) 30 min prior to conditioned taste aversion (CTA) training. Both ara-CTP and ara-C caused significant impairments in long-term memory (LTM) of CTA. Control experiments indicate that the effect of ara-CTP on CTA memory is related to interference with learning. Furthermore, as it was previously demonstrated for the protein synthesis inhibitor anisomycin, ara-CTP had no effect on CTA memory when it was injected 1 h after training. Importantly, although both ara-CTP and anisomycin significantly blocked LTM in the task, short-term memory (STM) measured 1 h after training was not affected by either of the drugs. Finally, ara-CTP had no effect on in vitro transcription, but it did effectively block nonhomologous DNA end joining (NHEJ) activity of brain protein extracts. We suggest that DNA ligase-mediated DNA recombination and repair processes are necessary for the expression of LTM in the brain.

  13. Mechanish of dTTP Inhibition of the Bifunctional dCTP Deaminase:dUTPase Encoded by Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Helt, Signe Smedegaard; Thymark, Majbritt; Harris, Pernille

    2008-01-01

    Recombinant deoxycytidine triphosphate (dCTP) deaminase from Mycobacterium tuberculosis was produced in Escherichia coli and purified. The enzyme proved to be a bifunctional dCTP deaminase:deoxyuridine triphosphatase. As such, the M. tuberculosis enzyme is the second bifunctional enzyme to be cha......Recombinant deoxycytidine triphosphate (dCTP) deaminase from Mycobacterium tuberculosis was produced in Escherichia coli and purified. The enzyme proved to be a bifunctional dCTP deaminase:deoxyuridine triphosphatase. As such, the M. tuberculosis enzyme is the second bifunctional enzyme...

  14. A scientific update on biosimilar infliximab (CT-P13) in rheumatic diseases.

    Science.gov (United States)

    Taylor, Peter

    2015-01-01

    The development of biologic drugs has undoubtedly enhanced the spectrum of treatments available for immune-mediated inflammatory rheumatic diseases such as rheumatoid arthritis. However, despite their clear clinical benifits, use of biologics is often hindered by their high costs. The manufacture and subsequent approval of more cost-effective 'biosimilar' versions of these drugs may address this issue and improve patient access. CT-P13 (Remsima(®), Inflectra(®)), a biosimilar of infliximab (Remicade(®)), has shown comparable efficacy, safety and pharmacokinetics to its originator drug in clinical studies. The articles in this supplement present a scientific update on the development and use of biosimilars in rheumatic disorders, with specific focus on CT-P13. The information discussed highlights the predicted positive clinical and economic impact of biosimilars on the management of rheumatic diseases.

  15. Assessment of urgent impacts of greenhouse gas emissions—the climate tipping potential (CTP)

    DEFF Research Database (Denmark)

    Jørgensen, Susanne Vedel; Hauschild, Michael Zwicky; Nielsen, Per H.

    2014-01-01

    The impact of anthropogenic greenhouse gas (GHG) emissions on climate change receives much focus today. This impact is however often considered only in terms of global warming potential (GWP), which does not take into account the need for staying below climatic target levels, in order to avoid...... passing critical climate tipping points. Some suggestions to include a target level in climate change impact assessment have been made, but with the consequence of disregarding impacts beyond that target level. The aim of this paper is to introduce the climate tipping impact category, which represents...... as on the chosen climatic target level and background scenario for atmospheric GHG concentration development. In order to enable direct application in life cycle assessment (LCA), CTP characterisation factors are presented for the three main anthropogenic GHGs, CO2, CH4 and N2O.The CTP metric distinguishes...

  16. Cochlin-tomoprotein (CTP) detection test identified perilymph leakage preoperatively in revision stapes surgery.

    Science.gov (United States)

    Kataoka, Yuko; Ikezono, Tetsuo; Fukushima, Kunihiro; Yuen, Koji; Maeda, Yukihide; Sugaya, Akiko; Nishizaki, Kazunori

    2013-08-01

    Perilymphatic fistula (PLF) is defined as an abnormal leakage between perilymph from the labyrinth to the middle ear. Symptoms include hearing loss, tinnitus, and vertigo. The standard mode of PLF detection is intraoperative visualization of perilymph leakage and fistula, which ostensibly confirms the existence of PLF. Other possible methods of diagnosis include confirmation of pneumolabyrinth via diagnostic imaging. Recently, a cochlin-tomoprotein (CTP) detection test has been developed that allows definitive diagnosis of PLF-related hearing loss. We report the case of a 45-year-old man who presented with right-sided tinnitus, hearing loss, and dizziness 30 years after stapes surgery. Middle ear lavage was performed after myringotomy. A preoperative diagnosis of PLF was reached using the CTP detection test. Intraoperative observations included a necrotic long process of the incus, displaced wire piston, and fibrous tissue in the oval window. Perilymph leakage was not evident. The oval window was closed with fascia, and vertigo disappeared within 2 weeks postoperatively. When PLF is suspected after stapes surgery, the CTP detection test can be a useful, highly sensitive, and less invasive method for preoperative diagnosis. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. La-CTP: Loop-Aware Routing for Energy-Harvesting Wireless Sensor Networks.

    Science.gov (United States)

    Sun, Guodong; Shang, Xinna; Zuo, Yan

    2018-02-02

    In emerging energy-harvesting wireless sensor networks (EH-WSN), the sensor nodes can harvest environmental energy to drive their operation, releasing the user's burden in terms of frequent battery replacement, and even enabling perpetual sensing systems. In EH-WSN applications, usually, the node in energy-harvesting or recharging state has to stop working until it completes the energy replenishment. However, such temporary departures of recharging nodes severely impact the packet routing, and one immediate result is the routing loop problem. Controlling loops in connectivity-intermittent EH-WSN in an efficient way is a big challenge in practice, and so far, users still lack of effective and practicable routing protocols with loop handling. Based on the Collection Tree Protocol (CTP) widely used in traditional wireless sensor networks, this paper proposes a loop-aware routing protocol for real-world EH-WSNs, called La-CTP, which involves a new parent updating metric and a proactive, adaptive beaconing scheme to effectively suppress the occurrence of loops and unlock unavoidable loops, respectively. We constructed a 100-node testbed to evaluate La-CTP, and the experimental results showed its efficacy and efficiency.

  18. Inverse regulation of two classic Hippo pathway target genes in Drosophila by the dimerization hub protein Ctp.

    Science.gov (United States)

    Barron, Daniel A; Moberg, Kenneth

    2016-03-14

    The LC8 family of small ~8 kD proteins are highly conserved and interact with multiple protein partners in eukaryotic cells. LC8-binding modulates target protein activity, often through induced dimerization via LC8:LC8 homodimers. Although many LC8-interactors have roles in signaling cascades, LC8's role in developing epithelia is poorly understood. Using the Drosophila wing as a developmental model, we find that the LC8 family member Cut up (Ctp) is primarily required to promote epithelial growth, which correlates with effects on the pro-growth factor dMyc and two genes, diap1 and bantam, that are classic targets of the Hippo pathway coactivator Yorkie. Genetic tests confirm that Ctp supports Yorkie-driven tissue overgrowth and indicate that Ctp acts through Yorkie to control bantam (ban) and diap1 transcription. Quite unexpectedly however, Ctp loss has inverse effects on ban and diap1: it elevates ban expression but reduces diap1 expression. In both cases these transcriptional changes map to small segments of these promoters that recruit Yorkie. Although LC8 complexes with Yap1, a Yorkie homolog, in human cells, an orthologous interaction was not detected in Drosophila cells. Collectively these findings reveal that that Drosophila Ctp is a required regulator of Yorkie-target genes in vivo and suggest that Ctp may interact with a Hippo pathway protein(s) to exert inverse transcriptional effects on Yorkie-target genes.

  19. Investigation of the charge effect on the electrochemical transduction in a quinone-based DNA sensor

    DEFF Research Database (Denmark)

    Reisberg, S.; Piro, B.; Noel, V.

    2008-01-01

    To elucidate the mechanism involved in the electrochemical transduction process of a conducting polymer-based DNA sensor, peptide nucleic acids (PNA) were used. PNA are DNA analogues having similar hybridization properties but are neutral. This allows to discriminate the electrostatic effect of D...... strands from the steric hindrance generated on the bioelectrode upon hybridization. It can be concluded that DNA conformational changes are determinant in the transduction process and that the electrostatic effect is negligible....

  20. The Role of Cgrp-Receptor Component Protein (Rcp in Cgrp-Mediated Signal Transduction

    Directory of Open Access Journals (Sweden)

    M. A. Prado

    2001-01-01

    Full Text Available The calcitonin gene-related peptide (CGRP-receptor component protein (RCP is a 17-kDa intracellular peripheral membrane protein required for signal transduction at CGRP receptors. To determine the role of RCP in CGRP-mediated signal transduction, RCP was depleted from NIH3T3 cells using antisense strategy. Loss of RCP protein correlated with loss of cAMP production by CGRP in the antisense cells. In contrast, loss of RCP had no effect on CGRP-mediated binding; therefore RCP is not acting as a chaperone for the CGRP receptor. Instead, RCP is a novel signal transduction molecule that couples the CGRP receptor to the cellular signal transduction machinery. RCP thus represents a prototype for a new class of signal transduction proteins that are required for regulation of G protein-coupled receptors.

  1. Efficacy and safety of switching from reference infliximab to CT-P13 compared with maintenance of CT-P13 in ankylosing spondylitis: 102-week data from the PLANETAS extension study.

    Science.gov (United States)

    Park, Won; Yoo, Dae Hyun; Miranda, Pedro; Brzosko, Marek; Wiland, Piotr; Gutierrez-Ureña, Sergio; Mikazane, Helena; Lee, Yeon-Ah; Smiyan, Svitlana; Lim, Mie-Jin; Kadinov, Vladimir; Abud-Mendoza, Carlos; Kim, HoUng; Lee, Sang Joon; Bae, YunJu; Kim, SuYeon; Braun, Jürgen

    2017-02-01

    To investigate the efficacy and safety of switching from infliximab reference product (RP) to its biosimilar or maintaining biosimilar treatment in patients with ankylosing spondylitis (AS). This open-label extension study recruited patients with AS who completed a 54-week, randomised controlled study comparing CT-P13 with RP (PLANETAS). CT-P13 (5 mg/kg) was administered intravenously every 8 weeks from week 62 to week 102. Efficacy end points included the proportion of patients achieving Assessment of SpondyloArthritis international Society (ASAS)20. Antidrug antibodies (ADAs) were measured using an electrochemiluminescent method. Data were analysed for patients treated with CT-P13 in the main PLANETAS study and the extension (maintenance group) and those who were switched to CT-P13 during the extension study (switch group). Overall, 174 (82.9%) of 210 patients who completed the first 54 weeks of PLANETAS and agreed to participate in the extension were enrolled. Among these, 88 were maintained on CT-P13 and 86 were switched to CT-P13 from RP. In these maintenance and switch groups, respectively, ASAS20 response rates at week 102 were 80.7% and 76.9%. ASAS40 and ASAS partial remission were also similar between groups. ADA positivity rates were comparable (week 102: 23.3% vs 27.4%). Adverse events led to treatment discontinuation during the extension study in 3 (3.3%) and 4 (4.8%) patients, respectively. This is the first study to show that switching from RP to its biosimilar CT-P13 is possible without negative effects on safety or efficacy in patients with AS. In the maintenance group, CT-P13 was effective and well tolerated over 2 years of treatment. NCT01571206; Results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Allosteric regulation of the GTP activated and CTP inhibited uracil phosphoribosyltransferase from the thermophilic archaeon Sulfolobus solfataricus

    DEFF Research Database (Denmark)

    Jensen, Kaj Frank; Arent, Susan; Larsen, Sine

    2005-01-01

    The upp gene, encoding uracil phosphoribosyltransferase (UPRTase) from the thermoacidophilic archaeon Sulfolobus solfataricus, was cloned and expressed in Escherichia coli. The enzyme was purified to homogeneity. It behaved as a tetramer in solution and showed optimal activity at pH 5.5 when...... assayed at 60 °C. Enzyme activity was strongly stimulated by GTP and inhibited by CTP. GTP caused an approximately 20-fold increase in the turnover number kcat and raised the Km values for 5-phosphoribosyl-1-diphosphate (PRPP) and uracil by two- and >10-fold, respectively. The inhibition by CTP...... was complex as it depended on the presence of the reaction product UMP. Neither CTP nor UMP were strong inhibitors of the enzyme, but when present in combination their inhibition was extremely powerful. Ligand binding analyses showed that GTP and PRPP bind cooperatively to the enzyme and that the inhibitors...

  3. CTP:phosphocholine cytidylyltransferase and protein kinase C recognize different physical features of membranes: differential responses to an oxidized phosphatidylcholine

    NARCIS (Netherlands)

    Drobnies, A.E.; Davies, S.M.A.; Kraayenhof, R.; Epand, R.F.; Epand, R.M.; Cornell, R.B.

    2002-01-01

    Protein kinase C (PKC) and CTP:phosphocholine cytidylyltransferase (CT) are two examples of enzymes that are regulated by reversible binding to membranes, and this binding is influenced by membrane physical properties. CT activation by oxidized phosphatidylcholines was recently demonstrated and was

  4. Liver X Receptor Agonists Inhibit the Phospholipid Regulatory Gene CTP: Phosphoethanolamine Cytidylyltransferase-Pcyt2

    Directory of Open Access Journals (Sweden)

    Lin Zhu

    2008-01-01

    Full Text Available Metabolic pulse-chase experiments demonstrated that 25-hydroxycholesterol (25-OH, the endogenous activator of the liver X receptor (LXR, significantly reduced the biosynthesis of phosphatidylethanolamine via CDP-ethanolamine (Kennedy pathway at the step catalyzed by CTP: phosphoethanolamine cytidylyltransferase (Pcyt2. In the mouse embryonic fibroblasts C3H10T1/2, the LXR synthetic agonist TO901317 lowered Pcyt2 promoter-luciferase activity in a concentration-dependent manner. Furthermore, 25-OH and TO901317 reduced mouse Pcyt2 mRNA and protein levels by 35–60%. The inhibitory effects of oxysterols and TO901317 on the Pcyt2 promoter function, mRNA and protein expression were conserved in the human breast cancer cells MCF-7. These studies identify the Pcyt2 gene as a novel target whereby LXR agonists may indirectly modulate inflammatory responses and atherosclerosis.

  5. Evaluation of the Cross-reactivity of Antidrug Antibodies to CT-P13 and Infliximab Reference Product (Remicade): An Analysis Using Immunoassays Tagged with Both Agents.

    Science.gov (United States)

    Reinisch, Walter; Jahnsen, Jørgen; Schreiber, Stefan; Danese, Silvio; Panés, Julián; Balsa, Alejandro; Park, Won; Kim, JiSoo; Lee, Jee Un; Yoo, Dae Hyun

    2017-06-01

    During two pivotal clinical trials of the infliximab biosimilar CT-P13 (PLANETAS and PLANETRA), antidrug antibodies (ADAs) and neutralising antibodies (NAbs) were detected in the sera of patients treated with CT-P13 and the reference product (RP; Remicade). The aim was to assess the comparability of Remicade- and CT-P13-tagged immunoassays for the detection of ADAs and NAbs using data from these trials, in order to determine the cross-reactivity of CT-P13 and RP ADAs. Sera from patients with rheumatoid arthritis and ankylosing spondylitis were analysed using an electrochemiluminescence (ECL) bridging assay or Gyros immunoassay, tagged with Remicade or CT-P13 at screening, weeks 14, 30 and 54, and the end of study visit. NAb titre was compared at screening and weeks 14 and 30. The proportion of cross-reactive samples was determined and an inter-rater agreement analysis performed to assess the concordance of results between assays. In PLANETAS, 93.1% (94/101) of RP ADA-positive samples and 93.0% (93/100) of RP NAb-positive samples cross-reacted with CT-P13; 99.0% (103/104) of CT-P13 ADA-positive and 98.0% (98/100) of CT-P13 NAb-positive samples cross-reacted with the RP. In PLANETRA, 94.7% (426/450) of RP ADA-positive samples and 94.3% (415/440) of RP NAb-positive samples cross-reacted with CT-P13, and 96.6% (458/474) of CT-P13 ADA-positive and 96.4% (452/469) of CT-P13 NAb-positive samples cross-reacted with the RP. In both studies, there was strong agreement in outcome between assays at all post-screening time points (PLANETAS: Cohen's κ 0.89-0.98 for ADA, 0.86-0.98 for NAb; PLANETRA: 0.92-0.94 for both ADA and NAb, all p PLANETAS: Spearman's ρ 0.73 and 0.74, respectively; PLANETRA: 0.61 and 0.72, respectively; all p < 0.001). This study has demonstrated that ADAs and NAbs against CT-P13 and RP are cross-reactive, indicating that CT-P13 and RP share immunodominant epitopes.

  6. Quantum Transduction with Adaptive Control

    Science.gov (United States)

    Zhang, Mengzhen; Zou, Chang-Ling; Jiang, Liang

    2018-01-01

    Quantum transducers play a crucial role in hybrid quantum networks. A good quantum transducer can faithfully convert quantum signals from one mode to another with minimum decoherence. Most investigations of quantum transduction are based on the protocol of direct mode conversion. However, the direct protocol requires the matching condition, which in practice is not always feasible. Here we propose an adaptive protocol for quantum transducers, which can convert quantum signals without requiring the matching condition. The adaptive protocol only consists of Gaussian operations, feasible in various physical platforms. Moreover, we show that the adaptive protocol can be robust against imperfections associated with finite squeezing, thermal noise, and homodyne detection, and it can be implemented to realize quantum state transfer between microwave and optical modes.

  7. Cellular semiotics and signal transduction

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio

    2007-01-01

    Semiosis, the processes of production, communication and interpretation of signs - coding and de-coding - takes place within and between organisms. The term "endosemiosis" refers to the processes of interpretation and sign transmission inside an organism (as opposed to "exosemiosis", which refers...... to the processes of sign interpretation and transmission between organisms of the same or different species). In Biosemiotics it is customary to recognise the cell as the most elementary integration unit for semiosis. Therefore intra and intercellular communication constitute the departure point for the study...... considering semiotic logic in order to construct our understanding of living phenomena. Given the central integrating role of signal transduction in physiological and ecological studies, this chapter outlines its semiotic implications. The multi-modality and modularity of signal molecules and relative...

  8. Quantum Transduction with Adaptive Control.

    Science.gov (United States)

    Zhang, Mengzhen; Zou, Chang-Ling; Jiang, Liang

    2018-01-12

    Quantum transducers play a crucial role in hybrid quantum networks. A good quantum transducer can faithfully convert quantum signals from one mode to another with minimum decoherence. Most investigations of quantum transduction are based on the protocol of direct mode conversion. However, the direct protocol requires the matching condition, which in practice is not always feasible. Here we propose an adaptive protocol for quantum transducers, which can convert quantum signals without requiring the matching condition. The adaptive protocol only consists of Gaussian operations, feasible in various physical platforms. Moreover, we show that the adaptive protocol can be robust against imperfections associated with finite squeezing, thermal noise, and homodyne detection, and it can be implemented to realize quantum state transfer between microwave and optical modes.

  9. Architectures and representations for string transduction

    NARCIS (Netherlands)

    Chrupala, Grzegorz

    2015-01-01

    String transduction problems are ubiquitous in natural language processing: they include transliteration, grapheme-to-phoneme conversion, text normalization and translation. String transduction can be reduced to the simpler problems of sequence labeling by expressing the target string as a sequence

  10. Human hematopoietic cell culture, transduction, and analyses

    DEFF Research Database (Denmark)

    Bonde, Jesper; Wirthlin, Louisa; Kohn, Donald B

    2008-01-01

    This unit provides methods for introducing genes into human hematopoietic progenitor cells. The Basic Protocol describes isolation of CD34(+) cells, transduction of these cells with a retroviral vector on fibronectin-coated plates, assaying the efficiency of transduction, and establishing long-te...

  11. Infliximab Biosimilar (CT-P13; Infliximab-dyyb): A Review in Autoimmune Inflammatory Diseases.

    Science.gov (United States)

    Blair, Hannah A; Deeks, Emma D

    2016-10-01

    Infliximab biosimilar (CT-P13/infliximab-dyyb; Remsima ® , Inflectra ® ) is approved in several countries for use in all indications for which reference infliximab (Remicade ® ) is approved, including rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis, psoriasis, Crohn's disease, and ulcerative colitis. Clinical data contributing to the EU approval of infliximab biosimilar were obtained from two pivotal double-blind clinical trials in patients with AS (PLANETAS) or RA (PLANETRA). Infliximab biosimilar demonstrated equivalence to reference infliximab in terms of its pharmacokinetic profile in patients with AS, patients with RA, and in healthy volunteers, and in terms of its efficacy in patients with RA. Clinical response rates in patients with RA or AS were maintained over the longer term (up to 102 weeks). In addition, the efficacy of infliximab biosimilar in patients with RA or Crohn's disease and ulcerative colitis [i.e. inflammatory bowel disease (IBD)] has been demonstrated in the real-world setting. Infliximab biosimilar was generally well tolerated, with a tolerability profile similar to that of reference infliximab. Switching from reference infliximab to infliximab biosimilar had no detrimental effect on efficacy, safety, or immunogenicity compared with continuous infliximab biosimilar therapy, according to the extensions of PLANETAS and PLANETRA, and real-world data in IBD. Current evidence therefore suggests that infliximab biosimilar is a useful alternative to reference infliximab in patients with autoimmune inflammatory diseases.

  12. Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

    Science.gov (United States)

    Ahmed, Marya

    2017-10-24

    Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

  13. Usefulness of three-dimensional CT pancreatography (3D-CTP) after the balloon-ERP for pancreatic diseases

    International Nuclear Information System (INIS)

    Ueki, Toshiharu; Oishi, Yayoi; Sakaguchi, Seigo; Sakurai, Toshihiro; Yao, Tsuneyoshi; Ichimaru, Yoshihiko; Koga, Yuki; Ikeda, Seiyo

    1998-01-01

    The clinical usefulness of 3D-CTP combined with the balloon-ERP and helical-CT was discussed. Authors diagnosed 42 patients with pancreatic diseases, including 5 of pancreatic carcinoma, 3 of serous cystadenoma, 6 of muciparous pancreatic cyst, 28 of chronic pancreatitis (including 8 cases of complicated pseudocyst). The images could reconstruct three-dimensionally the tapering constriction in the main pancreatic duct for all 5 cases of pancreatic carcinoma, the exclusion in the main pancreatic duct for 3 cases of serous cystadenoma and 1 case of muciparous pancreatic cyst, the parietal irregularity for 14 cases and the smooth constriction for 9 cases in main pancreatic duct of chronic pancreatitis, the morphology of the cyst and the spatial relationship between the cyst and the pancreatic duct in 5 of 6 cases of muciparous pancreatic cyst and 7 of 8 cases of complicated pseudocyst. Furthermore, the 3D-CTP could demonstrate the branched pancreatic duct at the constriction site which was not detected by the balloon-ERP in 2 cases of chronic pancreatitis with the constriction at the main pancreatic duct, and the joining manner of cyst to the pancreatic duct which was indistinct by the balloon-ERP in 6 cases of pancreatic cyst. These results show that 3D-CTP is useful for the qualitative diagnosis and applicable for the understanding of pancreatic diseases and for the simulation of surgery. (K.H.)

  14. Progress in biosimilar monoclonal antibody development: the infliximab biosimilar CT-P13 in the treatment of rheumatic diseases.

    Science.gov (United States)

    Braun, Jürgen; Kudrin, Alex

    2015-01-01

    Biosimilars are biologic medical products whose active drug substance is made by a living organism or derived from it. The term is used to describe a subsequent version of an innovator biopharmaceutical product aiming at approval following patent expiry on the reference product. Biosimilars of monoclonal need to demonstrate similar but not identical quality of nonclinical and clinical attributes. Not all data of the originator product need to be recapitulated, as large numbers of patient-years of exposure data are already available. Thus, biosimilar development is largely based on the safety profiles of the originator product. The evaluation of biosimilarity includes immunogenicity attributed risks. CT-P13 (Remsima™/Inflectra™, Celltrion/Hospira), a biosimilar of the innovator drug infliximab (INF), was the first approved complex biosimilar monoclonal antibody in the EU, within the framework of WHO, EMA and US FDA biosimilar guidelines. CT-P13 has shown analytical and nonclinical features highly similar to INF including pharmacokinetics, efficacy, safety and immunogenicity profiles in ankylosing spondylitis and rheumatoid arthritis. The objective of this article is to highlight the recent biosimilar development and to review the results from the studies PLANETRA and PLANETAS, which have supported the approval of CT-P13 for several indications.

  15. Signal transduction in mitogenesis: Further evidence for multiple pathways

    International Nuclear Information System (INIS)

    Rozengurt, E.; Erusalimsky, J.; Mehmet, H.; Morris, C.; Nanberg, E.; Sinnett-Smith, J.

    1988-01-01

    Growth factors are implicated in a wide variety of physiological and pathological processes, including embryogenesis, hematopoiesis, would healing, immune responses, atherosclerosis, and neoplasia. An important link between growth factors and their receptors and oncogene products has also been established. Thus, the elucidation of the mechanism of action of growth factors has emerged as one of the fundamental problems in biology and may prove crucial for understanding the unrestrained proliferation of cancer cells. A new and intriguing development is the discovery that neuropeptides localized in neural and neuroendocrine cells of mammalian tissue can also act as growth factors for cells in culture. Furthermore, indirect evidence is accumulating that the mitogenic effects of neuropeptides may be relevant for a variety of long-term biological processes, including development and oncogenesis. In this context, the peptides of the bombesin family are of particular significance. These peptides are potent mitogens for Swiss 3T3 cells and may act as autocrine growth factors for small cell lung cancer. Here, the authors summarize their recent studies using bombesin-like peptides for elucidating the signal transduction pathways leading to mitogenesis and compare these pathways with those elicited by other growth factors

  16. Towards the systematic discovery of signal transduction networks using phosphorylation dynamics data

    Directory of Open Access Journals (Sweden)

    Yachie Nozomu

    2010-05-01

    Full Text Available Abstract Background Phosphorylation is a ubiquitous and fundamental regulatory mechanism that controls signal transduction in living cells. The number of identified phosphoproteins and their phosphosites is rapidly increasing as a result of recent mass spectrometry-based approaches. Results We analyzed time-course phosphoproteome data obtained previously by liquid chromatography mass spectrometry with the stable isotope labeling using amino acids in cell culture (SILAC method. This provides the relative phosphorylation activities of digested peptides at each of five time points after stimulating HeLa cells with epidermal growth factor (EGF. We initially calculated the correlations between the phosphorylation dynamics patterns of every pair of peptides and connected the strongly correlated pairs to construct a network. We found that peptides extracted from the same intracellular fraction (nucleus vs. cytoplasm tended to be close together within this phosphorylation dynamics-based network. The network was then analyzed using graph theory and compared with five known signal-transduction pathways. The dynamics-based network was correlated with known signaling pathways in the NetPath and Phospho.ELM databases, and especially with the EGF receptor (EGFR signaling pathway. Although the phosphorylation patterns of many proteins were drastically changed by the EGF stimulation, our results suggest that only EGFR signaling transduction was both strongly activated and precisely controlled. Conclusions The construction of a phosphorylation dynamics-based network provides a useful overview of condition-specific intracellular signal transduction using quantitative time-course phosphoproteome data under specific experimental conditions. Detailed prediction of signal transduction based on phosphoproteome dynamics remains challenging. However, since the phosphorylation profiles of kinase-substrate pairs on the specific pathway were localized in the dynamics

  17. Purinergic mechanosensory transduction and visceral pain

    Directory of Open Access Journals (Sweden)

    Burnstock Geoffrey

    2009-11-01

    Full Text Available Abstract In this review, evidence is presented to support the hypothesis that mechanosensory transduction occurs in tubes and sacs and can initiate visceral pain. Experimental evidence for this mechanism in urinary bladder, ureter, gut, lung, uterus, tooth-pulp and tongue is reviewed. Potential therapeutic strategies are considered for the treatment of visceral pain in such conditions as renal colic, interstitial cystitis and inflammatory bowel disease by agents that interfere with mechanosensory transduction in the organs considered, including P2X3 and P2X2/3 receptor antagonists that are orally bioavailable and stable in vivo and agents that inhibit or enhance ATP release and breakdown.

  18. Regulation of dCTP deaminase from Escherichia coli by nonallosteric dTTP binding to an inactive form of the enzyme

    DEFF Research Database (Denmark)

    Johansson, Eva; Thymark, Majbritt; Bynck, Julie H

    2007-01-01

    -maximal activity and the cooperativity of dCTP saturation. Likewise, increasing concentrations of dCTP increase the cooperativity of dTTP inhibition. Previous structural studies showed that the complexes of inactive mutant protein, E138A, with dUTP or dCTP bound, and wild-type enzyme with dUTP bound were all...... highly similar and characterized by having an ordered C-terminal. When comparing with a new structure in which dTTP is bound to the active site of E138A, the region between Val120 and His125 was found to be in a new conformation. This and the previous conformation were mutually exclusive within...

  19. Crystal Structure of the CTP1L Endolysin Reveals How Its Activity Is Regulated by a Secondary Translation Product.

    Science.gov (United States)

    Dunne, Matthew; Leicht, Stefan; Krichel, Boris; Mertens, Haydyn D T; Thompson, Andrew; Krijgsveld, Jeroen; Svergun, Dmitri I; Gómez-Torres, Natalia; Garde, Sonia; Uetrecht, Charlotte; Narbad, Arjan; Mayer, Melinda J; Meijers, Rob

    2016-03-04

    Bacteriophages produce endolysins, which lyse the bacterial host cell to release newly produced virions. The timing of lysis is regulated and is thought to involve the activation of a molecular switch. We present a crystal structure of the activated endolysin CTP1L that targets Clostridium tyrobutyricum, consisting of a complex between the full-length protein and an N-terminally truncated C-terminal cell wall binding domain (CBD). The truncated CBD is produced through an internal translation start site within the endolysin gene. Mutants affecting the internal translation site change the oligomeric state of the endolysin and reduce lytic activity. The activity can be modulated by reconstitution of the full-length endolysin-CBD complex with free CBD. The same oligomerization mechanism applies to the CD27L endolysin that targets Clostridium difficile and the CS74L endolysin that targets Clostridium sporogenes. When the CTP1L endolysin gene is introduced into the commensal bacterium Lactococcus lactis, the truncated CBD is also produced, showing that the alternative start codon can be used in other bacterial species. The identification of a translational switch affecting oligomerization presented here has implications for the design of effective endolysins for the treatment of bacterial infections. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Cell targeting peptides as smart ligands for targeting of therapeutic or diagnostic agents: a systematic review.

    Science.gov (United States)

    Mousavizadeh, Ali; Jabbari, Ali; Akrami, Mohammad; Bardania, Hassan

    2017-10-01

    Cell targeting peptides (CTP) are small peptides which have high affinity and specificity to a cell or tissue targets. They are typically identified by using phage display and chemical synthetic peptide library methods. CTPs have attracted considerable attention as a new class of ligands to delivery specifically therapeutic and diagnostic agents, because of the fact they have several advantages including easy synthesis, smaller physical sizes, lower immunogenicity and cytotoxicity and their simple and better conjugation to nano-carriers and therapeutic or diagnostic agents compared to conventional antibodies. In this systematic review, we will focus on the basic concepts concerning the use of cell-targeting peptides (CTPs), following the approaches of selecting them from peptide libraries. We discuss several developed strategies for cell-specific delivery of different cargos by CTPs, which are designed for drug delivery and diagnostic applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. The sugarcane signal transduction (SUCAST catalogue: prospecting signal transduction in sugarcane

    Directory of Open Access Journals (Sweden)

    Glaucia Mendes Souza

    2001-12-01

    Full Text Available EST sequencing has enabled the discovery of many new genes in a vast array of organisms, and the utility of this approach to the scientific community is greatly increased by the establishment of fully annotated databases. The present study aimed to identify sugarcane ESTs sequenced in the sugarcane expressed sequence tag (SUCEST project (http://sucest.lad.ic.unicamp.br that corresponded to signal transduction components. We also produced a sugarcane signal transduction (SUCAST catalogue (http://sucest.lad.ic.unicamp.br/private/mining-reports/QG/QG-mining.htm that covered the main categories and pathways. Expressed sequence tags (ESTs encoding enzymes for hormone (gibberellins, ethylene, auxins, abscisic acid and jasmonic acid biosynthetic pathways were found and tissue specificity was inferred from their relative frequency of occurrence in the different libraries. Whenever possible, transducers of hormones and plant peptide signaling were catalogued to the respective pathway. Over 100 receptors were found in sugarcane, which contains a large family of Ser/Thr kinase receptors and also photoreceptors, histidine kinase receptors and their response regulators. G-protein and small GTPases were analyzed and compared to known members of these families found in mammalian and plant systems. Major kinase and phosphatase pathways were mapped, with special attention being given to the MAP kinase and the inositol pathway, both of which are well known in plants.O sequenciamento de ESTs (etiquetas de sequencias transcritas tem possibilitado a descoberta de muitos novos genes em uma ampla variedade de organismos. Um aumento do aproveitamento desta informação pela comunidade científica tem sido possível graças ao desenvolvimento de base de dados contendo seqüências completamente anotadas. O trabalho aqui relatado teve como objetivo a identificação de ESTs de cana de açúcar seqüenciadas através do projeto SUCEST (http://sucest.lad.ic. unicamp.br que

  2. Mechanical transduction via a single soft polymer

    Science.gov (United States)

    Hou, Ruizheng; Wang, Nan; Bao, Weizhu; Wang, Zhisong

    2018-04-01

    Molecular machines from biology and nanotechnology often depend on soft structures to perform mechanical functions, but the underlying mechanisms and advantages or disadvantages over rigid structures are not fully understood. We report here a rigorous study of mechanical transduction along a single soft polymer based on exact solutions to the realistic three-dimensional wormlike-chain model and augmented with analytical relations derived from simpler polymer models. The results reveal surprisingly that a soft polymer with vanishingly small persistence length below a single chemical bond still transduces biased displacement and mechanical work up to practically significant amounts. This "soft" approach possesses unique advantages over the conventional wisdom of rigidity-based transduction, and potentially leads to a unified mechanism for effective allosterylike transduction and relay of mechanical actions, information, control, and molecules from one position to another in molecular devices and motors. This study also identifies an entropy limit unique to the soft transduction, and thereby suggests a possibility of detecting higher efficiency for kinesin motor and mutants in future experiments.

  3. Peptide dendrimers

    Czech Academy of Sciences Publication Activity Database

    Niederhafner, Petr; Šebestík, Jaroslav; Ježek, Jan

    2005-01-01

    Roč. 11, - (2005), 757-788 ISSN 1075-2617 R&D Projects: GA ČR(CZ) GA203/03/1362 Institutional research plan: CEZ:AV0Z40550506 Keywords : multiple antigen peptides * peptide dendrimers * synthetic vaccine * multipleantigenic peptides Subject RIV: CC - Organic Chemistry Impact factor: 1.803, year: 2005

  4. The third helix of the murine Hoxc8 homeodomain facilitates protein transduction in mammalian cells

    International Nuclear Information System (INIS)

    Kong, Kyoung-Ah; Gadi, Jogeswar; Park, Hyoung Woo; Bok, Jinwoong; Kim, Myoung Hee

    2008-01-01

    Previously, we have demonstrated that purified Hoxc8 homeoprotein has the ability to penetrate the cellular membrane and can be transduced efficiently into COS-7 cells. Moreover, the Hoxc8 protein is able to form a complex with DNA molecules in vitro and helps the DNA be delivered intracellularly, serving as a gene delivery vehicle. Here, we further analyzed the membrane transduction activity of Hoxc8 protein and provide the evidence that the 16 amino acid (a.a.191-206, 2.23 kDa) third helix of murine Hoxc8 protein is an efficient protein transduction domain (PTD). When the 16 amino acid peptide was fused at the carboxyl terminal of enhanced green fluorescence protein (EGFP), the fusion proteins were transduced efficiently into the primary pig fetal fibroblast cells. The transduction efficiency increased in a concentration-dependent manner up to 1 μM, and appeared to plateau above a concentration of 1 μM. When tandem multimers of PTD, EGFP-PTD(2), EGFP-PTD(3), EGFP-PTD(4), and EGFP-PTD(5), were analyzed at 500 nM of concentration, the penetrating efficiency increased in a dose-dependent manner. As the number of PTDs increased, the EGFP signal also increased, although the signal maintained plateau after EGFP-PTD(3). These results indicate that the 16 amino acid third helix is the key element responsible for the membrane transduction activity of Hoxc8 proteins, and further suggest that the small peptide could serve as a therapeutic delivery vehicle for large cargo proteins

  5. A nationwide non-medical switch from originator infliximab to biosimilar CT-P13 in 802 patients with inflammatory arthritis

    DEFF Research Database (Denmark)

    Glintborg, Bente; Sørensen, Inge Juul; Loft, Anne Gitte

    2017-01-01

    Objectives According to guidelines, a nationwide non-medical switch from originator (INX, Remicade) to biosimilar infliximab (Remsima, CT-P13) was conducted in Danish patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (AxSpA). We investigated disease...

  6. A review of the literature analyzing benefits and concerns of infliximab biosimilar CT-P13 for the treatment of rheumatologic diseases: focus on interchangeability.

    Science.gov (United States)

    Becciolini, Andrea; Raimondo, Maria Gabriella; Crotti, Chiara; Agape, Elena; Biggioggero, Martina; Favalli, Ennio Giulio

    2017-01-01

    The introduction of biological agents drastically changed the treatment paradigm of inflammatory arthritides, ameliorating the natural history of the diseases but concomitantly increasing the drug costs due to the manufacturing process. On this concern, biosimilar drugs may represent a valid option for reducing this elevated cost and increasing the availability of these highly effective treatments. Recently, CT-P13, the first biosimilar of infliximab, has been approved with the same indications established for the reference product (RP), and its daily use is progressively increasing. However, the experience with biosimilar drugs in the field of rheumatology is still limited, raising potential doubts and concerns on their correct management in real-life settings. Comparability analysis between CT-P13 and its RP was evaluated in equivalence randomized controlled trials (RCTs) - PLANETRA and PLANETAS - performed on patients with rheumatoid arthritis and axial spondylitis, respectively. CT-P13 and RP showed similar profile in terms of quality, biological activity, safety, immunogenicity, and efficacy. However, the interchangeability between infliximab RP and its biosimilar still represents the most challenging issue because of a lack of a long-lasting experience. To date, reassuring preliminary data on this topic were reported in open-label extensions of PLANETRA and PLANETAS RCTs and in ongoing real-life observational studies. These findings, taken all together, significantly affect the landscape of biosimilar regulatory pathways and strongly support CT-P13 introduction as a great opportunity for expanding the accessibility to these very effective and high-cost therapies.

  7. Uracil phosphoribosyltransferase from the extreme thermoacidophilic archaebacterium Sulfolobus shibatae is an allosteric enzyme, activated by GTP and inhibited by CTP

    DEFF Research Database (Denmark)

    Linde, Lise; Jensen, Kaj Frank

    1996-01-01

    Uracil phosphoribosyltransferase, which catalyses the formation of UMP and pyrophosphate from uracil and 5-phosphoribosyl a-1-pyrophosphate (PRPP), was partly purified from the extreme thermophilic archaebacterium Sulfolobus shibatae. The enzyme required divalent metal ions for activity...... and it showed the highest activity at pH 6.4. The specific activity of the enzyme was 50-times higher at 95°C than at 37°C, but the functional half-life was short at 95°C. The activity of uracil phosphoribosyltransferase was strongly activated by GTP, which increased Vmax of the reaction by approximately 20......-fold without much effect on Km for the substrates. The concentration of GTP required for half-maximal activation was about 80 µM. CTP was a strong inhibitor and acted by raising the concentration of GTP needed for half-maximal activation of the enzyme. We conclude that uracil phosphoribosyltransferase...

  8. Signal transduction and chemotaxis in mast cells

    Czech Academy of Sciences Publication Activity Database

    Dráber, Petr; Hálová, Ivana; Polakovičová, Iva; Kawakami, T.

    2016-01-01

    Roč. 778, jaro (2016), s. 11-23 ISSN 0014-2999 R&D Projects: GA ČR(CZ) GA14-09807S; GA ČR(CZ) GBP302/12/G101; GA ČR(CZ) GA14-00703S Institutional support: RVO:68378050 Keywords : Mast cell * IgE receptor * KIT receptor * Signal transduction * Chemotaxis * Plasma membrane Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.896, year: 2016

  9. Macro-Fiber Composite Based Transduction

    Science.gov (United States)

    2016-03-01

    substrate Material properties of single crystal macro fiber composite actuators for active twist rotor blades Park, Jae-Sang (Seoul National...Passive Smart Structures and Integrated Systems 2007 Material properties of single crystal macro fiber composite actuators for active twist rotor ...19b. TELEPHONE NUMBER (Include area code) 10-03-20 16 Final Report 01 Jan 2013 - 31 Dec 2015 Macro-Fiber Composite Based Transduction N000-14-13-1-0212

  10. PVC esaslı CTP kesme atığı dolgulu malzemelerin termal özelliklerinin incelenmesi

    Directory of Open Access Journals (Sweden)

    Arzu Özüyağlı

    2016-08-01

    Full Text Available Bu çalışmada, PVC üretiminde kullanılan CaCO3 dolgu malzemesi yerine, sanayi atığı kullanılması sonucu termal özelliklerdeki değişim araştırılmıştır. Kullanılan sanayi atığı CTP boru üretiminden sulu kesim sırasında çıkmakta ve SiO2, cam elyaf ve polyester reçine içermektedir. Sulu çamur halinde filtre presten çıkan atık fabrikadan alındıktan sonra kurutma ve eleme işlemleri uygulanarak toz formuna getirilmiştir. Numuneler PVC, CTP atık tozu ve prosese yardımcı maddeler mikserde karıştırılarak ekstrüzyon yöntemi ile profil şeklinde üretilmiştir. Atık toz PVC’ye oranla ağırlıkça %5-%70 oranlarında dolgu malzemesi olarak kullanılmıştır. Kalsit (CaCO3 katkılı ve katkısız PVC numuneleri de benzer proses parametreleri kullanılarak üretilmiştir. Üretilen numuneler, seramik krozeler kullanılarak DTA-TG analizleri yapılmıştır.

  11. Cooperative binding of the bisubstrate analog N-(phosphonacetyl)-L-aspartate to aspartate transcarbamoylase and the heterotropic effects of ATP and CTP

    International Nuclear Information System (INIS)

    Newell, J.O.; Markby, D.W.; Schachman, H.K.

    1989-01-01

    Most investigations of the allosteric properties of the regulatory enzyme aspartate transcarbamoylase (ATCase) from Escherichia coli are based on the sigmoidal dependence of enzyme activity on substrate concentration and the effects of the inhibitor, CTP, and the activator, ATP, on the saturation curves. Interpretations of these effects in terms of molecular models are complicated by the inability to distinguish between changes in substrate binding and catalytic turnover accompanying the allosteric transition. In an effort to eliminate this ambiguity, the binding of the 3H-labeled bisubstrate analog N-(phosphonacetyl)-L-aspartate (PALA) to aspartate transcarbamoylase in the absence and presence of the allosteric effectors ATP and CTP has been measured directly by equilibrium dialysis at pH 7 in phosphate buffer. PALA binds with marked cooperativity to the holoenzyme with an average dissociation constant of 110 nM. ATP and CTP alter both the average affinity of ATCase for PALA and the degree of cooperativity in the binding process in a manner analogous to their effects on the kinetic properties of the enzyme; the average dissociation constant of PALA decreases to 65 nM in the presence of ATP and increases to 266 nM in the presence of CTP while the Hill coefficient, which is 1.95 in the absence of effectors, becomes 1.35 and 2.27 in the presence of ATP and CTP, respectively. The dissociation constant of PALA from the catalytic subunit is 95 nM. Interpretation of these results in terms of a thermodynamic scheme linking PALA binding to the assembly of ATCase from catalytic and regulatory subunits demonstrates that saturation of the enzyme with PALA shifts the equilibrium between holoenzyme and subunits slightly toward dissociation

  12. Fenspiride and membrane transduction signals in rat alveolar macrophages.

    Science.gov (United States)

    Féray, J C; Mohammadi, K; Taouil, K; Brunet, J; Garay, R P; Hannaert, P

    1997-07-15

    Fenspiride inhibits the calcium signal evoked by the inflammatory peptide formyl-Met-Leu-Phe (fMLP) in peritoneal macrophages, but at concentrations (approximately 1 mM) far above the therapeutic range (approximately 1 microM). Here, in rat alveolar macrophages, high fenspiride concentrations (1 mM) were required to inhibit the calcium signals evoked by the calcium agonist Bay K8644 or by ionomycin. Moreover, fenspiride (1 mM) was a poor inhibitor of the cell membrane depolarization induced by gramicidine D. By contrast, fenspiride blocked Na+-H+ antiport activation by (i) fMLP with an IC50 = 3.1 +/- 1.9 nM and (ii) PMA (phorbol 12-myristate 13-acetate) with an IC50 = 9.2 +/- 3.1 nM. Finally, protein kinase C (PKC) activity of macrophage homogenate was not significantly modified by 10 or 100 microM fenspiride (at 100 microM: 2.57 +/- 1.60 vs. 2.80 +/- 1.71 pmol/10(6) cells/min). In conclusion, fenspiride inhibits fMLP- and PMA-induced pH signals in rat alveolar macrophages, probably by acting distally on the PKC transduction signal. This pH antagonistic action may be relevant for the antiinflammatory mechanism of fenspiride and requires further investigation.

  13. Prenatal Alcohol Exposure Damages Brain Signal Transduction Systems

    National Research Council Canada - National Science Library

    Caldwell, Kevin

    2001-01-01

    .... One and twenty-four hours following fear conditioning this learning deficit is associated with altered brain signal transduction mechanisms that are dependent on an enzyme termed phosphatidylinositol...

  14. A review of the literature analyzing benefits and concerns of infliximab biosimilar CT-P13 for the treatment of rheumatologic diseases: focus on interchangeability

    Directory of Open Access Journals (Sweden)

    Becciolini A

    2017-06-01

    Full Text Available Andrea Becciolini,1 Maria Gabriella Raimondo,2 Chiara Crotti,2 Elena Agape,2 Martina Biggioggero,2 Ennio Giulio Favalli1 1Department of Rheumatology, 2Department of Clinical Sciences and Health Community, University of Milan, Division of Rheumatology, Gaetano Pini Institute, Milan, Italy Abstract: The introduction of biological agents drastically changed the treatment paradigm of inflammatory arthritides, ameliorating the natural history of the diseases but concomitantly increasing the drug costs due to the manufacturing process. On this concern, biosimilar drugs may represent a valid option for reducing this elevated cost and increasing the availability of these highly effective treatments. Recently, CT-P13, the first biosimilar of infliximab, has been approved with the same indications established for the reference product (RP, and its daily use is progressively increasing. However, the experience with biosimilar drugs in the field of rheumatology is still limited, raising potential doubts and concerns on their correct management in real-life settings. Comparability analysis between CT-P13 and its RP was evaluated in equivalence randomized controlled trials (RCTs – PLANETRA and PLANETAS – performed on patients with rheumatoid arthritis and axial spondylitis, respectively. CT-P13 and RP showed similar profile in terms of quality, biological activity, safety, immunogenicity, and efficacy. However, the interchangeability between infliximab RP and its biosimilar still represents the most challenging issue because of a lack of a long-lasting experience. To date, reassuring preliminary data on this topic were reported in open-label extensions of PLANETRA and PLANETAS RCTs and in ongoing real-life observational studies. These findings, taken all together, significantly affect the landscape of biosimilar regulatory pathways and strongly support CT-P13 introduction as a great opportunity for expanding the accessibility to these very effective and

  15. A web-based institutional DICOM distribution system with the integration of the Clinical Trial Processor (CTP).

    Science.gov (United States)

    Aryanto, K Y E; Broekema, A; Langenhuysen, R G A; Oudkerk, M; van Ooijen, P M A

    2015-05-01

    To develop and test a fast and easy rule-based web-environment with optional de-identification of imaging data to facilitate data distribution within a hospital environment. A web interface was built using Hypertext Preprocessor (PHP), an open source scripting language for web development, and Java with SQL Server to handle the database. The system allows for the selection of patient data and for de-identifying these when necessary. Using the services provided by the RSNA Clinical Trial Processor (CTP), the selected images were pushed to the appropriate services using a protocol based on the module created for the associated task. Five pipelines, each performing a different task, were set up in the server. In a 75 month period, more than 2,000,000 images are transferred and de-identified in a proper manner while 20,000,000 images are moved from one node to another without de-identification. While maintaining a high level of security and stability, the proposed system is easy to setup, it integrate well with our clinical and research practice and it provides a fast and accurate vendor-neutral process of transferring, de-identifying, and storing DICOM images. Its ability to run different de-identification processes in parallel pipelines is a major advantage in both clinical and research setting.

  16. Protein transduction therapy into cochleae via the round window niche in guinea pigs

    Directory of Open Access Journals (Sweden)

    Hiroki Takeda

    2016-01-01

    Full Text Available Cell-penetrating peptides (CPPs are short sequences of amino acids that facilitate the penetration of conjugated cargoes across mammalian cell membranes, and as such, they may provide a safe and effective method for drug delivery to the inner ear. Simple polyarginine peptides have been shown to induce significantly higher cell penetration rates among CPPs. Herein, we show that a peptide consisting of nine arginines (“9R” effectively delivered enhanced green fluorescent protein (EGFP into guinea pig cochleae via the round window niche without causing any deterioration in auditory function. A second application, 24 hours after the first, prolonged the presence of EGFP. To assess the feasibility of protein transduction using 9R-CPPs via the round window, we used “X-linked inhibitor of apoptosis protein” (XIAP bonded to a 9R peptide (XIAP-9R. XIAP-9R treatment prior to acoustic trauma significantly reduced putative hearing loss and the number of apoptotic hair cells loss in the cochleae. Thus, the topical application of molecules fused to 9R-CPPs may be a simple and promising strategy for treating inner ear diseases.

  17. Induction of cytoplasmic rods and rings structures by inhibition of the CTP and GTP synthetic pathway in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Wendy C Carcamo

    Full Text Available Cytoplasmic filamentous rods and rings (RR structures were identified using human autoantibodies as probes. In the present study, the formation of these conserved structures in mammalian cells and functions linked to these structures were examined.Distinct cytoplasmic rods (∼3-10 µm in length and rings (∼2-5 µm in diameter in HEp-2 cells were initially observed in immunofluorescence using human autoantibodies. Co-localization studies revealed that, although RR had filament-like features, they were not enriched in actin, tubulin, or vimentin, and not associated with centrosomes or other known cytoplasmic structures. Further independent studies revealed that two key enzymes in the nucleotide synthetic pathway cytidine triphosphate synthase 1 (CTPS1 and inosine monophosphate dehydrogenase 2 (IMPDH2 were highly enriched in RR. CTPS1 enzyme inhibitors 6-diazo-5-oxo-L-norleucine and Acivicin as well as the IMPDH2 inhibitor Ribavirin exhibited dose-dependent induction of RR in >95% of cells in all cancer cell lines tested as well as mouse primary cells. RR formation by lower concentration of Ribavirin was enhanced in IMPDH2-knockdown HeLa cells whereas it was inhibited in GFP-IMPDH2 overexpressed HeLa cells. Interestingly, RR were detected readily in untreated mouse embryonic stem cells (>95%; upon retinoic acid differentiation, RR disassembled in these cells but reformed when treated with Acivicin.RR formation represented response to disturbances in the CTP or GTP synthetic pathways in cancer cell lines and mouse primary cells and RR are the convergence physical structures in these pathways. The availability of specific markers for these conserved structures and the ability to induce formation in vitro will allow further investigations in structure and function of RR in many biological systems in health and diseases.

  18. Endothelial cell oxidative stress and signal transduction

    Directory of Open Access Journals (Sweden)

    ROCIO FONCEA

    2000-01-01

    Full Text Available Endothelial dysfunction (ED is an early event in atherosclerotic disease, preceding clinical manifestations and complications. Increased reactive oxygen species (ROS have been implicated as important mechanisms that contribute to ED, and ROS’s may function as intracellular messengers that modulate signaling pathways. Several intracellular signal events stimulated by ROS have been defined, including the identification of two members of the mitogen activated protein kinase family (ERK1/2 and big MAP kinase, BMK1, tyrosine kinases (Src and Syk and different isoenzymes of PKC as redox-sensitive kinases. ROS regulation of signal transduction components include the modification in the activity of transcriptional factors such as NFkB and others that result in changes in gene expression and modifications in cellular responses. In order to understand the intracellular mechanisms induced by ROS in endothelial cells (EC, we are studying the response of human umbilical cord vein endothelial cells to increased ROS generation by different pro-atherogenic stimuli. Our results show that Homocysteine (Hcy and oxidized LDL (oxLDL enhance the activity and expression of oxidative stress markers, such as NFkB and heme oxygenase 1. These results suggest that these pro-atherogenic stimuli increase oxidative stress in EC, and thus explain the loss of endothelial function associated with the atherogenic process

  19. Efficacy and Safety of the Biosimilar Infliximab CT-P13 Treatment in Inflammatory Bowel Diseases: A Prospective, Multicentre, Nationwide Cohort.

    Science.gov (United States)

    Gecse, Krisztina B; Lovász, Barbara D; Farkas, Klaudia; Banai, János; Bene, László; Gasztonyi, Beáta; Golovics, Petra Anna; Kristóf, Tünde; Lakatos, László; Csontos, Ágnes Anna; Juhász, Márk; Nagy, Ferenc; Palatka, Károly; Papp, Mária; Patai, Árpád; Lakner, Lilla; Salamon, Ágnes; Szamosi, Tamás; Szepes, Zoltán; Tóth, Gábor T; Vincze, Áron; Szalay, Balázs; Molnár, Tamás; Lakatos, Péter L

    2016-02-01

    Biosimilar infliximab CT-P13 is approved for all indications of the originator product in Europe. Prospective data on its efficacy, safety, and immunogenicity in inflammatory bowel diseases are lacking. A prospective, nationwide, multicentre, observational cohort was designed to examine the efficacy, safety, and immunogenicity of CT-P13 infliximab biosimilar in the induction treatment of Crohn's disease [CD] and ulcerative colitis [UC]. Demographic data were collected and a harmonised monitoring strategy was applied. Early clinical remission, response, and early biochemical response were evaluated at Week 14, steroid-free clinical remission was evaluated at Week 30. Therapeutic drug level was monitored using a conventional enzyme-linked immunosorbent assay. In all, 210 consecutive inflammatory bowel disease [126 CD and 84 UC] patients were included in the present cohort. At Week 14, 81.4% of CD and 77.6% of UC patients showed clinical response and 53.6% of CD and 58.6% of UC patients were in clinical remission. Clinical remission rates at Week 14 were significantly higher in CD and UC patients who were infliximab naïve, compared with those with previous exposure to the originator compound [p < 0.05]. Until Week 30, adverse events were experienced in 17.1% of all patients. Infusion reactions and infectious adverse events occurred in 6.6% and 5.7% of all patients, respectively. This prospective multicentre cohort shows that CT-P13 is safe and effective in the induction of clinical remission and response in both CD and UC. Patients with previous infliximab exposure exhibited decreased response rates and were more likely to develop allergic reactions. Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Efficient myogenic differentiation of human adipose-derived stem cells by the transduction of engineered MyoD protein

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Min Sun [Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Biosystems and Bioengineering Program, University of Science and Technology (UST), Daejeon 305-350 (Korea, Republic of); Mun, Ji-Young [Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Kwon, Ohsuk [Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Biosystems and Bioengineering Program, University of Science and Technology (UST), Daejeon 305-350 (Korea, Republic of); Kwon, Ki-Sun [Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Oh, Doo-Byoung, E-mail: dboh@kribb.re.kr [Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Biosystems and Bioengineering Program, University of Science and Technology (UST), Daejeon 305-350 (Korea, Republic of)

    2013-07-19

    Highlights: •MyoD was engineered to contain protein transduction domain and endosome-disruptive INF7 peptide. •The engineered MyoD-IT showed efficient nuclear targeting through an endosomal escape by INF7 peptide. •By applying MyoD-IT, human adipose-derived stem cells (hASCs) were differentiated into myogenic cells. •hASCs differentiated by applying MyoD-IT fused to myotubes through co-culturing with mouse myoblasts. •Myogenic differentiation using MyoD-IT is a safe method without the concern of altering the genome. -- Abstract: Human adipose-derived stem cells (hASCs) have great potential as cell sources for the treatment of muscle disorders. To provide a safe method for the myogenic differentiation of hASCs, we engineered the MyoD protein, a key transcription factor for myogenesis. The engineered MyoD (MyoD-IT) was designed to contain the TAT protein transduction domain for cell penetration and the membrane-disrupting INF7 peptide, which is an improved version of the HA2 peptide derived from influenza. MyoD-IT showed greatly improved nuclear targeting ability through an efficient endosomal escape induced by the pH-sensitive membrane disruption of the INF7 peptide. By applying MyoD-IT to a culture, hASCs were efficiently differentiated into long spindle-shaped myogenic cells expressing myosin heavy chains. Moreover, these cells differentiated by an application of MyoD-IT fused to myotubes with high efficiency through co-culturing with mouse C2C12 myoblasts. Because internalized proteins can be degraded in cells without altering the genome, the myogenic differentiation of hASCs using MyoD-IT would be a safe and clinically applicable method.

  1. Efficient myogenic differentiation of human adipose-derived stem cells by the transduction of engineered MyoD protein

    International Nuclear Information System (INIS)

    Sung, Min Sun; Mun, Ji-Young; Kwon, Ohsuk; Kwon, Ki-Sun; Oh, Doo-Byoung

    2013-01-01

    Highlights: •MyoD was engineered to contain protein transduction domain and endosome-disruptive INF7 peptide. •The engineered MyoD-IT showed efficient nuclear targeting through an endosomal escape by INF7 peptide. •By applying MyoD-IT, human adipose-derived stem cells (hASCs) were differentiated into myogenic cells. •hASCs differentiated by applying MyoD-IT fused to myotubes through co-culturing with mouse myoblasts. •Myogenic differentiation using MyoD-IT is a safe method without the concern of altering the genome. -- Abstract: Human adipose-derived stem cells (hASCs) have great potential as cell sources for the treatment of muscle disorders. To provide a safe method for the myogenic differentiation of hASCs, we engineered the MyoD protein, a key transcription factor for myogenesis. The engineered MyoD (MyoD-IT) was designed to contain the TAT protein transduction domain for cell penetration and the membrane-disrupting INF7 peptide, which is an improved version of the HA2 peptide derived from influenza. MyoD-IT showed greatly improved nuclear targeting ability through an efficient endosomal escape induced by the pH-sensitive membrane disruption of the INF7 peptide. By applying MyoD-IT to a culture, hASCs were efficiently differentiated into long spindle-shaped myogenic cells expressing myosin heavy chains. Moreover, these cells differentiated by an application of MyoD-IT fused to myotubes with high efficiency through co-culturing with mouse C2C12 myoblasts. Because internalized proteins can be degraded in cells without altering the genome, the myogenic differentiation of hASCs using MyoD-IT would be a safe and clinically applicable method

  2. Signal transduction in the footsteps of goethe and schiller.

    Science.gov (United States)

    Friedrich, Karlheinz; Lindquist, Jonathan A; Entschladen, Frank; Serfling, Edgar; Thiel, Gerald; Kieser, Arnd; Giehl, Klaudia; Ehrhardt, Christina; Feller, Stephan M; Ullrich, Oliver; Schaper, Fred; Janssen, Ottmar; Hass, Ralf

    2009-02-04

    The historical town of Weimar in Thuringia, the "green heart of Germany" was the sphere of Goethe and Schiller, the two most famous representatives of German literature's classic era. Not yet entirely as influential as those two cultural icons, the Signal Transduction Society (STS) has nevertheless in the last decade established within the walls of Weimar an annual interdisciplinary Meeting on "Signal Transduction - Receptors, Mediators and Genes", which is well recognized as a most attractive opportunity to exchange results and ideas in the field.The 12th STS Meeting was held from October 28 to 31 and provided a state-of-the-art overview of various areas of signal transduction research in which progress is fast and discussion lively. This report is intended to share with the readers of CCS some highlights of the Meeting Workshops devoted to specific aspects of signal transduction.

  3. Falsification of the ionic channel theory of hair cell transduction.

    Science.gov (United States)

    Rossetto, Michelangelo

    2013-11-01

    The hair cell provides the transduction of mechanical vibrations in the balance and acoustic sense of all vertebrates that swim, walk, or fly. The current theory places hair cell transduction in a mechanically controlled ion channel. Although the theory of a mechanical input modulating the flow of ions through an ion pore has been a useful tool, it is falsified by experimental data in the literature and can be definitively falsified by a proposed experiment.

  4. Peptide chemistry toolbox - Transforming natural peptides into peptide therapeutics.

    Science.gov (United States)

    Erak, Miloš; Bellmann-Sickert, Kathrin; Els-Heindl, Sylvia; Beck-Sickinger, Annette G

    2018-06-01

    The development of solid phase peptide synthesis has released tremendous opportunities for using synthetic peptides in medicinal applications. In the last decades, peptide therapeutics became an emerging market in pharmaceutical industry. The need for synthetic strategies in order to improve peptidic properties, such as longer half-life, higher bioavailability, increased potency and efficiency is accordingly rising. In this mini-review, we present a toolbox of modifications in peptide chemistry for overcoming the main drawbacks during the transition from natural peptides to peptide therapeutics. Modifications at the level of the peptide backbone, amino acid side chains and higher orders of structures are described. Furthermore, we are discussing the future of peptide therapeutics development and their impact on the pharmaceutical market. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Comparable long-term efficacy, as assessed by patient-reported outcomes, safety and pharmacokinetics, of CT-P13 and reference infliximab in patients with ankylosing spondylitis: 54-week results from the randomized, parallel-group PLANETAS study.

    Science.gov (United States)

    Park, Won; Yoo, Dae Hyun; Jaworski, Janusz; Brzezicki, Jan; Gnylorybov, Andriy; Kadinov, Vladimir; Sariego, Irmgadt Goecke; Abud-Mendoza, Carlos; Escalante, William Jose Otero; Kang, Seong Wook; Andersone, Daina; Blanco, Francisco; Hong, Seung Suh; Lee, Sun Hee; Braun, Jürgen

    2016-01-20

    CT-P13 (Remsima®, Inflectra®) is a biosimilar of the infliximab reference product (RP; Remicade®) and is approved in Europe and elsewhere, mostly for the same indications as RP. The aim of this study was to compare the 54-week efficacy, immunogenicity, pharmacokinetics (PK) and safety of CT-P13 with RP in patients with ankylosing spondylitis (AS), with a focus on patient-reported outcomes (PROs). This was a multinational, double-blind, parallel-group study in patients with active AS. Participants were randomized (1:1) to receive CT-P13 (5 mg/kg) or RP (5 mg/kg) at weeks 0, 2, 6 and then every 8 weeks up to week 54. To assess responses, standardized assessment tools were used with an intention-to-treat analysis of observed data. Anti-drug antibodies (ADAs), PK parameters, and safety outcomes were also assessed. Of 250 randomized patients (n = 125 per group), 210 (84.0 %) completed 54 weeks of treatment, with similar completion rates between groups. At week 54, Assessment of Spondylo Arthritis international Society (ASAS)20 response, ASAS40 response and ASAS partial remission were comparable between treatment groups. Changes from baseline in PROs such as mean Bath Ankylosing Spondylitis Disease Activity Index (BASDAI; CT-P13 -3.1 versus RP -2.8), Bath Ankylosing Spondylitis Functional Index (BASFI; -2.9 versus -2.7), and Short Form Health Survey (SF-36) scores (9.26 versus 10.13 for physical component summary; 7.30 versus 6.54 for mental component summary) were similar between treatment groups. At 54 weeks, 19.5 % and 23.0 % of patients receiving CT-P13 and RP, respectively, had ADAs. All observed PK parameters of CT-P13 and RP, including maximum and minimum serum concentrations, were similar through 54 weeks. The influence of ADAs on PK was similar in the two treatment groups. Most adverse events were mild or moderate in severity. There was no notable difference between treatment groups in the incidence of adverse events, serious adverse events

  6. A randomised, double-blind, multicentre, parallel-group, prospective study comparing the pharmacokinetics, safety, and efficacy of CT-P13 and innovator infliximab in patients with ankylosing spondylitis: the PLANETAS study.

    Science.gov (United States)

    Park, Won; Hrycaj, Pawel; Jeka, Slawomir; Kovalenko, Volodymyr; Lysenko, Grygorii; Miranda, Pedro; Mikazane, Helena; Gutierrez-Ureña, Sergio; Lim, MieJin; Lee, Yeon-Ah; Lee, Sang Joon; Kim, HoUng; Yoo, Dae Hyun; Braun, Jürgen

    2013-10-01

    To compare the pharmacokinetics (PK), safety and efficacy of innovator infliximab (INX) and CT-P13, a biosimilar to INX, in patients with active ankylosing spondylitis (AS). Phase 1 randomised, double-blind, multicentre, multinational, parallel-group study. Patients were randomised to receive 5 mg/kg of CT-P13 (n=125) or INX (n=125). Primary endpoints were area under the concentration-time curve (AUC) at steady state and observed maximum steady state serum concentration (Cmax,ss) between weeks 22 and 30. Additional PK, efficacy endpoints, including 20% and 40% improvement response according to Assessment in Ankylosing Spondylitis International Working Group criteria (ASAS20 and ASAS40), and safety outcomes were also assessed. Geometric mean AUC was 32 765.8 μgh/ml for CT-P13 and 31 359.3 μgh/ml for INX. Geometric mean Cmax,ss was 147.0 μg/ml for CT-P13 and 144.8 μg/ml for INX. The ratio of geometric means was 104.5% (90% CI 94% to 116%) for AUC and 101.5% (90% CI 95% to 109%) for Cmax,ss. ASAS20 and ASAS40 responses at week 30 were 70.5% and 51.8% for CT-P13 and 72.4% and 47.4% for INX, respectively. In the CT-P13 and INX groups more than one adverse event occurred in 64.8% and 63.9% of patients, infusion reactions occurred in 3.9% and 4.9%, active tuberculosis occurred in 1.6% and 0.8%, and 27.4% and 22.5% of patients tested positive for anti-drug antibodies, respectively. The PK profiles of CT-P13 and INX were equivalent in patients with active AS. CT-P13 was well tolerated, with an efficacy and safety profile comparable to that of INX up to week 30.

  7. Reciprocity and gyrotropism in magnetic resonance transduction

    International Nuclear Information System (INIS)

    Tropp, James

    2006-01-01

    We give formulas for transduction in magnetic resonance - i.e., the appearance of an emf due to Larmor precession of spins - based upon the modified Lorentz reciprocity principle for gyrotropic (also called 'nonreciprocal') media, i.e., in which a susceptibility tensor is carried to its transpose by reversal of an external static field [cf., R. F. Harrington and A. T. Villeneuve IRE Trans. Microwave Theory and Technique MTT6, 308 (1958)]. Prior applications of reciprocity to magnetic resonance, despite much success, have ignored the gyrotropism which necessarily arises due to nuclear and/or unpaired electronic spins. For detection with linearly polarized fields, oscillating at the Larmor frequency, the emf is written in terms of a volume integral containing a product of two factors which we define as the antenna patterns, i.e. (H 1x ±iH 1y ), where, e.g., for a single transceive antenna, the H's are just the spatially dependent oscillatory magnetic field strengths, per the application of some reference current at the antenna terminals, with the negative sign obtaining for transmission, and the positive for reception. Similar expressions hold for separate transmit and receive antennas; expressions are also given for circular polarization of the fields. We then exhibit a receive-only array antenna of two elements for magnetic resonance imaging of protons, which, due an intensity artifact arising from stray reactive coupling of the elements, produces, despite its own bilateral symmetry, asymmetric proton NMR images of a symmetric cylindrical phantom containing aqueous saline solution [J. Tropp and T. Schirmer, J. Magn. Reson. 151, 146 (2001)]. Modification of this two-port antenna, to function in transmit-receive mode, allows us to demonstrate highly nonreciprocal behavior: that is, to record images (of cylindrical test phantoms containing aqueous saline solution) whose appearance dramatically changes, when the roles of transmission and reception are swapped between

  8. Nonpeptide and peptide growth hormone secretagogues act both as ghrelin receptor agonist and as positive or negative allosteric modulators of ghrelin signaling

    DEFF Research Database (Denmark)

    Holst, Birgitte; Brandt, Erik; Bach, Anders

    2005-01-01

    Two nonpeptide (L692,429 and MK-677) and two peptide [GH-releasing peptide (GHRP)-6 and ghrelin] agonists were compared in binding and in signal transduction assays: calcium mobilization, inositol phosphate turnover, cAMP-responsive element (CRE), and serum-responsive element (SRE) controlled tra...

  9. Theory and modeling of cylindrical thermo-acoustic transduction

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Lihong, E-mail: lhtong@ecjtu.edu.cn [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China); Lim, C.W. [Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Zhao, Xiushao; Geng, Daxing [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China)

    2016-06-03

    Models both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed and the corresponding acoustic pressure solutions are obtained. The acoustic pressure for an individual carbon nanotube (CNT) as a function of input power is investigated analytically and it is verified by comparing with the published experimental data. Further numerical analysis on the acoustic pressure response and characteristics for varying input frequency and distance are also examined both for solid and thinfilm-solid cylindrical thermo-acoustic transductions. Through detailed theoretical and numerical studies on the acoustic pressure solution for thinfilm-solid cylindrical transduction, it is concluded that a solid with smaller thermal conductivity favors to improve the acoustic performance. In general, the proposed models are applicable to a variety of cylindrical thermo-acoustic devices performing in different gaseous media. - Highlights: • Theory and modeling both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed. • The modeling is verified by comparing with the published experimental data. • Acoustic response characteristics of cylindrical thermo-acoustic transductions are predicted by the proposed model.

  10. Integrated Electromechanical Transduction Schemes for Polymer MEMS Sensors

    Directory of Open Access Journals (Sweden)

    Damien Thuau

    2018-04-01

    Full Text Available Polymer Micro ElectroMechanical Systems (MEMS have the potential to constitute a powerful alternative to silicon-based MEMS devices for sensing applications. Although the use of commercial photoresists as structural material in polymer MEMS has been widely reported, the integration of functional polymer materials as electromechanical transducers has not yet received the same amount of interest. In this context, we report on the design and fabrication of different electromechanical schemes based on polymeric materials ensuring different transduction functions. Piezoresistive transduction made of carbon nanotube-based nanocomposites with a gauge factor of 200 was embedded within U-shaped polymeric cantilevers operating either in static or dynamic modes. Flexible resonators with integrated piezoelectric transduction were also realized and used as efficient viscosity sensors. Finally, piezoelectric-based organic field effect transistor (OFET electromechanical transduction exhibiting a record sensitivity of over 600 was integrated into polymer cantilevers and used as highly sensitive strain and humidity sensors. Such advances in integrated electromechanical transduction schemes should favor the development of novel all-polymer MEMS devices for flexible and wearable applications in the future.

  11. The crucial role of cyclic GMP in the eclosion hormone mediated signal transduction in the silkworm metamorphoses.

    Science.gov (United States)

    Shibanaka, Y; Hayashi, H; Okada, N; Fujita, N

    1991-10-31

    The signal transduction of the peptide, eclosion hormone, in the silkworm Bombyx mori appears to be mediated via the second messenger cyclic GMP throughout their life cycle. Injection of 8-bromo-cGMP induced the ecdysis behavior in pharate adults with similar latency to eclosion hormone-induced ecdysis; the moulting occurred 50-70 min after the injection. The potency of 8Br-cGMP was 10(2) fold higher than that of cGMP and the efficacy was increased by the co-injection of the phosphodiesterase inhibitor IBMX. On the other hand, in the silkworm pupal ecdysis the eclosion hormone and also 8Br-cGMP induced the moulting behavior in a dose-dependent manner. The adult development of the ability to respond to 8Br-cGMP took place concomitantly with the response to the eclosion hormone. Both the developmental time courses were shifted by a shift of light and dark cycles. Accordingly, the sensitivities to the peptide and cyclic nucleotide developed correspondently under the light and dark circadian rhythm. Thus throughout the silkworm life cycle, eclosion hormone is effective to trigger the ecdysis behavior and cGMP plays a crucial role as the second messenger in the eclosion hormone-mediated signal transduction.

  12. Microenvironment Dependent Photobiomodulation on Function-Specific Signal Transduction Pathways

    Directory of Open Access Journals (Sweden)

    Timon Cheng-Yi Liu

    2014-01-01

    Full Text Available Cellular photobiomodulation on a cellular function has been shown to be homeostatic. Its function-specific pathway mechanism would be further discussed in this paper. The signal transduction pathways maintaining a normal function in its function-specific homeostasis (FSH, resisting the activation of many other irrelative signal transduction pathways, are so sparse that it can be supposed that there may be normal function-specific signal transduction pathways (NSPs. A low level laser irradiation or monochromatic light may promote the activation of partially activated NSP and/or its redundant NSP so that it may induce the second-order phase transition of a function from its dysfunctional one far from its FSH to its normal one in a function-specific microenvironment and may also induce the first-order functional phase transition of the normal function from low level to high level.

  13. Novel Antimicrobial Peptides That Inhibit Gram Positive Bacterial Exotoxin Synthesis

    Science.gov (United States)

    Merriman, Joseph A.; Nemeth, Kimberly A.; Schlievert, Patrick M.

    2014-01-01

    Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges. PMID:24748386

  14. Physical aspects of sensory transduction on seeing, hearing and smelling.

    Science.gov (United States)

    Yoshioka, Tohru; Sakakibara, Manabu

    2013-01-01

    What is the general principle of sensory transduction? Sensory transduction is defined as energy transformation from the external world to the internal world. The energy of the external world, such as thermal energy (heat), electro-magnetic energy (light), mechanical energy (sound) and the energy from molecules (chemicals), is converted into electrochemical events in the animal nervous system. The following five classes of special sense receptors are utilized for energy conversion: vision (photo); audition (sound); taste and smell (chemo); and tactile (mechano). There are also other special sense receptors, including thermo and noxious receptors. The focus of this study is on photoreceptors, sound-receptors and odorant-receptors because the transduction mechanisms of these receptors are explained biochemically and understood by a common physical principle; these biochemical models are well known in neuroscience. The following notable problems are inherent in these biochemical models: the cGMP ionophore model of the vertebrate photoreceptor cannot explain the fast photo-response (∼msec); the tip links connection model of stereocilia in the basilar membrane for opening the K(+) channel on the tip of a hair has difficulty explaining the high frequency vibration of hair cells without a damping of the oscillation, and the odorant shape-specific receptor model for olfactory transduction has difficulty in discriminating the minute differences among similar fragrant smells of essential oils with different molecular shapes. These difficulties might arise from a lack of the physical sense when the transduction models were proposed. This article will reconsider these problems and propose rational models for visual, olfactory and auditory transduction.

  15. Signal transduction pathways involved in mechanotransduction in bone cells

    International Nuclear Information System (INIS)

    Liedert, Astrid; Kaspar, Daniela; Blakytny, Robert; Claes, Lutz; Ignatius, Anita

    2006-01-01

    Several in vivo and in vitro studies with different loading regimens showed that mechanical stimuli have an influence on proliferation and differentiation of bone cells. Prerequisite for this influence is the transduction of mechanical signals into the cell, a phenomenon that is termed mechanotransduction, which is essential for the maintenance of skeletal homeostasis in adults. Mechanoreceptors, such as the integrins, cadherins, and stretch-activated Ca 2+ channels, together with various signal transduction pathways, are involved in the mechanotransduction process that ultimately regulates gene expression in the nucleus. Mechanotransduction itself is considered to be regulated by hormones, the extracellular matrix of the osteoblastic cells and the mode of the mechanical stimulus

  16. Scale-up and large-scale production of Tetraselmis sp. CTP4 (Chlorophyta) for CO2 mitigation: from an agar plate to 100-m3 industrial photobioreactors.

    Science.gov (United States)

    Pereira, Hugo; Páramo, Jaime; Silva, Joana; Marques, Ana; Barros, Ana; Maurício, Dinis; Santos, Tamára; Schulze, Peter; Barros, Raúl; Gouveia, Luísa; Barreira, Luísa; Varela, João

    2018-03-23

    Industrial production of novel microalgal isolates is key to improving the current portfolio of available strains that are able to grow in large-scale production systems for different biotechnological applications, including carbon mitigation. In this context, Tetraselmis sp. CTP4 was successfully scaled up from an agar plate to 35- and 100-m 3 industrial scale tubular photobioreactors (PBR). Growth was performed semi-continuously for 60 days in the autumn-winter season (17 th October - 14 th December). Optimisation of tubular PBR operations showed that improved productivities were obtained at a culture velocity of 0.65-1.35 m s -1 and a pH set-point for CO 2 injection of 8.0. Highest volumetric (0.08 ± 0.01 g L -1 d -1 ) and areal (20.3 ± 3.2 g m -2 d -1 ) biomass productivities were attained in the 100-m 3 PBR compared to those of the 35-m 3 PBR (0.05 ± 0.02 g L -1 d -1 and 13.5 ± 4.3 g m -2 d -1 , respectively). Lipid contents were similar in both PBRs (9-10% of ash free dry weight). CO 2 sequestration was followed in the 100-m 3 PBR, revealing a mean CO 2 mitigation efficiency of 65% and a biomass to carbon ratio of 1.80. Tetraselmis sp. CTP4 is thus a robust candidate for industrial-scale production with promising biomass productivities and photosynthetic efficiencies up to 3.5% of total solar irradiance.

  17. Protein interaction networks by proteome peptide scanning.

    Directory of Open Access Journals (Sweden)

    Christiane Landgraf

    2004-01-01

    Full Text Available A substantial proportion of protein interactions relies on small domains binding to short peptides in the partner proteins. Many of these interactions are relatively low affinity and transient, and they impact on signal transduction. However, neither the number of potential interactions mediated by each domain nor the degree of promiscuity at a whole proteome level has been investigated. We have used a combination of phage display and SPOT synthesis to discover all the peptides in the yeast proteome that have the potential to bind to eight SH3 domains. We first identified the peptides that match a relaxed consensus, as deduced from peptides selected by phage display experiments. Next, we synthesized all the matching peptides at high density on a cellulose membrane, and we probed them directly with the SH3 domains. The domains that we have studied were grouped by this approach into five classes with partially overlapping specificity. Within the classes, however, the domains display a high promiscuity and bind to a large number of common targets with comparable affinity. We estimate that the yeast proteome contains as few as six peptides that bind to the Abp1 SH3 domain with a dissociation constant lower than 100 microM, while it contains as many as 50-80 peptides with corresponding affinity for the SH3 domain of Yfr024c. All the targets of the Abp1 SH3 domain, identified by this approach, bind to the native protein in vivo, as shown by coimmunoprecipitation experiments. Finally, we demonstrate that this strategy can be extended to the analysis of the entire human proteome. We have developed an approach, named WISE (whole interactome scanning experiment, that permits rapid and reliable identification of the partners of any peptide recognition module by peptide scanning of a proteome. Since the SPOT synthesis approach is semiquantitative and provides an approximation of the dissociation constants of the several thousands of interactions that are

  18. Mitogen-activated protein kinase and abscisic acid signal transduction

    NARCIS (Netherlands)

    Heimovaara-Dijkstra, S.; Testerink, C.; Wang, M.

    1998-01-01

    The phytohormone abscisic acid (ABA) is a classical plant hormone, responsible for regulation of abscission, diverse aspects of plant and seed development, stress responses and germination. It was found that ABA signal transduction in plants can involve the activity of type 2C-phosphatases (PP2C),

  19. Molecular methods for the study of signal transduction in plants

    KAUST Repository

    Irving, Helen R.; Gehring, Christoph A

    2013-01-01

    as well as at the systems level where transcriptomics and particularly phosphoproteomics afford a window into complex biological responses. Here we review the role of the cyclic nucleotides cAMP and cGMP in plant signal transduction as well

  20. Cell biology symposium: Membrane trafficking and signal transduction

    Science.gov (United States)

    In general, membrane trafficking is a broad group of processes where proteins and other large molecules are distributed throughout the cell as well as adjacent extracellular spaces. Whereas signal transduction is a process where signals are transmitted through a series of chemical or molecular event...

  1. Olfactory transduction pathways in the Senegalese sole Solea senegalensis.

    Science.gov (United States)

    Velez, Z; Hubbard, P C; Barata, E N; Canário, A V M

    2013-09-01

    This study tested whether differences in sensitivity between the upper and lower olfactory epithelia of Solea senegalensis are associated with different odorant receptors and transduction pathways, using the electro-olfactogram. Receptor mechanisms were assessed by cross-adaptation with amino acids (L-cysteine, L-phenylalanine and 1-methyl-L-tryptophan) and bile acids (taurocholic acid and cholic acid). This suggested that relatively specific receptors exist for 1-methyl-L-tryptophan and L-phenylalanine (food-related odorants) in the lower epithelium, and for taurocholic acid (conspecific-derived odorant) in the upper. Inhibition by U73122 [a phospholipase C (PLC) inhibitor] suggested that olfactory responses to amino acids were mediated mostly, but not entirely, by PLC-mediated transduction (IC50 ; 15-55 nM), whereas bile acid responses were mediated by both PLC and adenylate cyclase-cyclic adenosine monophosphate (AC-cAMP) (using SQ-22536; an AC inhibitor). Simultaneous application of both drugs rarely inhibited responses completely, suggesting possible involvement of non-PLC and non-AC mediated mechanisms. For aromatic amino acids and bile acids, there were differences in the contribution of each transduction pathway (PLC, AC and non-PLC and non-AC) between the two epithelia. These results suggest that differences in sensitivity of the two epithelia are associated with differences in odorant receptors and transduction mechanisms. © 2013 The Fisheries Society of the British Isles.

  2. Protein phosphorylation and its role in archaeal signal transduction

    Science.gov (United States)

    Esser, Dominik; Hoffmann, Lena; Pham, Trong Khoa; Bräsen, Christopher; Qiu, Wen; Wright, Phillip C.; Albers, Sonja-Verena; Siebers, Bettina

    2016-01-01

    Reversible protein phosphorylation is the main mechanism of signal transduction that enables cells to rapidly respond to environmental changes by controlling the functional properties of proteins in response to external stimuli. However, whereas signal transduction is well studied in Eukaryotes and Bacteria, the knowledge in Archaea is still rather scarce. Archaea are special with regard to protein phosphorylation, due to the fact that the two best studied phyla, the Euryarchaeota and Crenarchaeaota, seem to exhibit fundamental differences in regulatory systems. Euryarchaeota (e.g. halophiles, methanogens, thermophiles), like Bacteria and Eukaryotes, rely on bacterial-type two-component signal transduction systems (phosphorylation on His and Asp), as well as on the protein phosphorylation on Ser, Thr and Tyr by Hanks-type protein kinases. Instead, Crenarchaeota (e.g. acidophiles and (hyper)thermophiles) only depend on Hanks-type protein phosphorylation. In this review, the current knowledge of reversible protein phosphorylation in Archaea is presented. It combines results from identified phosphoproteins, biochemical characterization of protein kinases and protein phosphatases as well as target enzymes and first insights into archaeal signal transduction by biochemical, genetic and polyomic studies. PMID:27476079

  3. Expression of SMAD signal transduction molecules in the pancreas

    DEFF Research Database (Denmark)

    Brorson, Michael; Hougaard, D.; Nielsen, Jens Høiriis

    2001-01-01

    Members of the TGF-beta superfamily of cytokines have been implicated in pancreatic cancer, pancreatitis and in regulation and differentiation of pancreatic endocrine and exocrine cells. Different TGF-beta members signal through phosphorylation of different signal transduction proteins, which eve...

  4. Development and validation of novel AAV2 random libraries displaying peptides of diverse lengths and at diverse capsid positions.

    Science.gov (United States)

    Naumer, Matthias; Ying, Ying; Michelfelder, Stefan; Reuter, Antje; Trepel, Martin; Müller, Oliver J; Kleinschmidt, Jürgen A

    2012-05-01

    Libraries based on the insertion of random peptide ligands into the capsid of adeno-associated virus type 2 (AAV2) have been widely used to improve the efficiency and selectivity of the AAV vector system. However, so far only libraries of 7-mer peptide ligands have been inserted at one well-characterized capsid position. Here, we expanded the combinatorial AAV2 display system to a panel of novel AAV libraries, displaying peptides of 5, 7, 12, 19, or 26 amino acids in length at capsid position 588 or displaying 7-mer peptides at position 453, the most prominently exposed region of the viral capsid. Library selections on two unrelated cell types-human coronary artery endothelial cells and rat cardiomyoblasts-revealed the isolation of cell type-characteristic peptides of different lengths mediating strongly improved target-cell transduction, except for the 26-mer peptide ligands. Characterization of vector selectivity by transduction of nontarget cells and comparative gene-transduction analysis using a panel of 44 human tumor cell lines revealed that insertion of different-length peptides allows targeting of distinct cellular receptors for cell entry with similar efficiency, but with different selectivity. The application of such novel AAV2 libraries broadens the spectrum of targetable receptors by capsid-modified AAV vectors and provides the opportunity to choose the best suited targeting ligand for a certain application from a number of different candidates.

  5. Human peptide transporters

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Brodin, Birger; Jørgensen, Flemming Steen

    2002-01-01

    Peptide transporters are epithelial solute carriers. Their functional role has been characterised in the small intestine and proximal tubules, where they are involved in absorption of dietary peptides and peptide reabsorption, respectively. Currently, two peptide transporters, PepT1 and PepT2, wh...

  6. Characterization of sur-2, a Novel Ras-Mediated Signal Transduction Component in C. elegans

    National Research Council Canada - National Science Library

    DesJardins, Edward

    1998-01-01

    ... (oncogenes). A subset of proto-oncogenes comprise the RAS signal transduction pathway. Vulval development in the nematode worm Caenorhabditis elegans is controlled by a RAS signal transduction pathway...

  7. Characterization of sur-2, a Novel Ras-Mediated Signal Transduction Component in C. elegans

    National Research Council Canada - National Science Library

    DesJardins, Edward

    1999-01-01

    ... (oncogenes). A subset of proto-oncogenes comprise the RAS signal transduction pathway. Vulval development in the nematode worm Caenorhabditis elegans is controlled by a RAS signal transduction pathway. C...

  8. Enhancing T cell activation and antiviral protection by introducing the HIV-1 protein transduction domain into a DNA vaccine.

    Science.gov (United States)

    Leifert, J A; Lindencrona, J A; Charo, J; Whitton, J L

    2001-10-10

    Protein transduction domains (PTD), which can transport proteins or peptides across biological membranes, have been identified in several proteins of viral, invertebrate, and vertebrate origin. Here, we evaluate the immunological and biological consequences of including PTD in synthetic peptides and in DNA vaccines that contain CD8(+) T cell epitopes from lymphocytic choriomeningitis virus (LCMV). Synthetic PTD-peptides did not induce detectable CD8(+) T cell responses. However, fusion of an open reading frame encoding a PTD to an epitope minigene caused transfected tissue culture cells to stimulate epitope-specific T cells much more effectively. Kinetic studies indicated that the epitope reached the surface of transfected cells more rapidly and that the number of transfected cells needed to stimulate T cell responses was reduced by 35- to 50-fold when compared to cells transfected with a standard minigene plasmid. The mechanism underlying the effect of PTD linkage is not clear, but transit of the PTD-attached epitope from transfected cells to nontransfected cells (cross presentation) seemed to play, at most, a minimal role. Mice immunized once with the plasmid encoding the PTD-linked epitope showed a markedly accelerated CD8(+) T cell response and, unlike mice immunized with a standard plasmid, were completely protected against a normally lethal LCMV challenge administered only 8 days post-immunization.

  9. Molecular methods for the study of signal transduction in plants

    KAUST Repository

    Irving, Helen R.

    2013-09-03

    Novel and improved analytical methods have led to a rapid increase in our understanding of the molecular mechanism underlying plant signal transduction. Progress has been made both at the level of single-component analysis and in vivo imaging as well as at the systems level where transcriptomics and particularly phosphoproteomics afford a window into complex biological responses. Here we review the role of the cyclic nucleotides cAMP and cGMP in plant signal transduction as well as the discovery and biochemical and biological characterization of an increasing number of complex multi-domain nucleotide cyclases that catalyze the synthesis of cAMP and cGMP from ATP and GTP, respectively. © Springer Science+Business Media New York 2013.

  10. Tuning piezoresistive transduction in nanomechanical resonators by geometrical asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Llobet, J.; Sansa, M.; Lorenzoni, M.; Pérez-Murano, F., E-mail: francesc.perez@csic.es [Institut de Microelectrònica de Barcelona (IMB-CNM CSIC), Campus UAB, 08193 Bellaterra (Spain); Borrisé, X. [Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, 08193 Bellaterra Spain (Spain); San Paulo, A. [Instituto de Microelectrónica de Madrid (IMM-CSIC), 28760 Tres Cantos, Madrid (Spain)

    2015-08-17

    The effect of geometrical asymmetries on the piezoresistive transduction in suspended double clamped beam nanomechanical resonators is investigated. Tapered silicon nano-beams, fabricated using a fast and flexible prototyping method, are employed to determine how the asymmetry affects the transduced piezoresistive signal for different mechanical resonant modes. This effect is attributed to the modulation of the strain in pre-strained double clamped beams, and it is confirmed by means of finite element simulations.

  11. Efficiency of Energy Transduction in a Molecular Chemical Engine

    OpenAIRE

    Sasaki, Kazuo; Kanada, Ryo; Amari, Satoshi

    2006-01-01

    A simple model of the two-state ratchet type is proposed for molecular chemical engines that convert chemical free energy into mechanical work and vice versa. The engine works by catalyzing a chemical reaction and turning a rotor. Analytical expressions are obtained for the dependences of rotation and reaction rates on the concentrations of reactant and product molecules, from which the performance of the engine is analyzed. In particular, the efficiency of energy transduction is discussed in...

  12. Dynamic Testing of Signal Transduction Deregulation During Breast Cancer Initiation

    Science.gov (United States)

    2012-07-01

    Std. Z39.18 Victoria Seewaldt, M.D. Dynamic Testing of Signal Transduction Deregulation During Breast Cancer Initiation Duke University Durham...attomole- zeptomole range. Internal dilution curves insure a high-dynamic calibration range. DU -26 8L DU -26 6L DU -29 5R DU -22 9.2 L DU...3: Nanobiosensor technology is translated to test for pathway deregulation in RPFNA cytology obtained from 10 high-risk women with cytological

  13. State–time spectrum of signal transduction logic models

    International Nuclear Information System (INIS)

    MacNamara, Aidan; Terfve, Camille; Henriques, David; Bernabé, Beatriz Peñalver; Saez-Rodriguez, Julio

    2012-01-01

    Despite the current wealth of high-throughput data, our understanding of signal transduction is still incomplete. Mathematical modeling can be a tool to gain an insight into such processes. Detailed biochemical modeling provides deep understanding, but does not scale well above relatively a few proteins. In contrast, logic modeling can be used where the biochemical knowledge of the system is sparse and, because it is parameter free (or, at most, uses relatively a few parameters), it scales well to large networks that can be derived by manual curation or retrieved from public databases. Here, we present an overview of logic modeling formalisms in the context of training logic models to data, and specifically the different approaches to modeling qualitative to quantitative data (state) and dynamics (time) of signal transduction. We use a toy model of signal transduction to illustrate how different logic formalisms (Boolean, fuzzy logic and differential equations) treat state and time. Different formalisms allow for different features of the data to be captured, at the cost of extra requirements in terms of computational power and data quality and quantity. Through this demonstration, the assumptions behind each formalism are discussed, as well as their advantages and disadvantages and possible future developments. (paper)

  14. Signal Transduction Pathways of TNAP: Molecular Network Analyses.

    Science.gov (United States)

    Négyessy, László; Györffy, Balázs; Hanics, János; Bányai, Mihály; Fonta, Caroline; Bazsó, Fülöp

    2015-01-01

    Despite the growing body of evidence pointing on the involvement of tissue non-specific alkaline phosphatase (TNAP) in brain function and diseases like epilepsy and Alzheimer's disease, our understanding about the role of TNAP in the regulation of neurotransmission is severely limited. The aim of our study was to integrate the fragmented knowledge into a comprehensive view regarding neuronal functions of TNAP using objective tools. As a model we used the signal transduction molecular network of a pyramidal neuron after complementing with TNAP related data and performed the analysis using graph theoretic tools. The analyses show that TNAP is in the crossroad of numerous pathways and therefore is one of the key players of the neuronal signal transduction network. Through many of its connections, most notably with molecules of the purinergic system, TNAP serves as a controller by funnelling signal flow towards a subset of molecules. TNAP also appears as the source of signal to be spread via interactions with molecules involved among others in neurodegeneration. Cluster analyses identified TNAP as part of the second messenger signalling cascade. However, TNAP also forms connections with other functional groups involved in neuronal signal transduction. The results indicate the distinct ways of involvement of TNAP in multiple neuronal functions and diseases.

  15. Microscopic insight into thermodynamics of conformational changes of SAP-SLAM complex in signal transduction cascade

    Science.gov (United States)

    Samanta, Sudipta; Mukherjee, Sanchita

    2017-04-01

    The signalling lymphocytic activation molecule (SLAM) family of receptors, expressed by an array of immune cells, associate with SLAM-associated protein (SAP)-related molecules, composed of single SH2 domain architecture. SAP activates Src-family kinase Fyn after SLAM ligation, resulting in a SLAM-SAP-Fyn complex, where, SAP binds the Fyn SH3 domain that does not involve canonical SH3 or SH2 interactions. This demands insight into this SAP mediated signalling cascade. Thermodynamics of the conformational changes are extracted from the histograms of dihedral angles obtained from the all-atom molecular dynamics simulations of this structurally well characterized SAP-SLAM complex. The results incorporate the binding induced thermodynamic changes of individual amino acid as well as the secondary structural elements of the protein and the solvent. Stabilization of the peptide partially comes through a strong hydrogen bonding network with the protein, while hydrophobic interactions also play a significant role where the peptide inserts itself into a hydrophobic cavity of the protein. SLAM binding widens SAP's second binding site for Fyn, which is the next step in the signal transduction cascade. The higher stabilization and less fluctuation of specific residues of SAP in the Fyn binding site, induced by SAP-SLAM complexation, emerge as the key structural elements to trigger the recognition of SAP by the SH3 domain of Fyn. The thermodynamic quantification of the protein due to complexation not only throws deeper understanding in the established mode of SAP-SLAM interaction but also assists in the recognition of the relevant residues of the protein responsible for alterations in its activity.

  16. Exploring Transduction Mechanisms of Protein Transduction Domains (PTDs in Living Cells Utilizing Single-Quantum Dot Tracking (SQT Technology

    Directory of Open Access Journals (Sweden)

    Yasuhiro Suzuki

    2012-01-01

    Full Text Available Specific protein domains known as protein transduction domains (PTDs can permeate cell membranes and deliver proteins or bioactive materials into living cells. Various approaches have been applied for improving their transduction efficacy. It is, therefore, crucial to clarify the entry mechanisms and to identify the rate-limiting steps. Because of technical limitations for imaging PTD behavior on cells with conventional fluorescent-dyes, how PTDs enter the cells has been a topic of much debate. Utilizing quantum dots (QDs, we recently tracked the behavior of PTD that was derived from HIV-1 Tat (TatP in living cells at the single-molecule level with 7-nm special precision. In this review article, we initially summarize the controversy on TatP entry mechanisms; thereafter, we will focus on our recent findings on single-TatP-QD tracking (SQT, to identify the major sequential steps of intracellular delivery in living cells and to discuss how SQT can easily provide direct information on TatP entry mechanisms. As a primer for SQT study, we also discuss the latest findings on single particle tracking of various molecules on the plasma membrane. Finally, we discuss the problems of QDs and the challenges for the future in utilizing currently available QD probes for SQT. In conclusion, direct identification of the rate-limiting steps of PTD entry with SQT should dramatically improve the methods for enhancing transduction efficiency.

  17. RIG-I self-oligomerization is either dispensable or very transient for signal transduction.

    Directory of Open Access Journals (Sweden)

    Jade Louber

    Full Text Available Effective host defence against viruses depends on the rapid triggering of innate immunity through the induction of a type I interferon (IFN response. To this end, microbe-associated molecular patterns are detected by dedicated receptors. Among them, the RIG-I-like receptors RIG-I and MDA5 activate IFN gene expression upon sensing viral RNA in the cytoplasm. While MDA5 forms long filaments in vitro upon activation, RIG-I is believed to oligomerize after RNA binding in order to transduce a signal. Here, we show that in vitro binding of synthetic RNA mimicking that of Mononegavirales (Ebola, rabies and measles viruses leader sequences to purified RIG-I does not induce RIG-I oligomerization. Furthermore, in cells devoid of endogenous functional RIG-I-like receptors, after activation of exogenous Flag-RIG-I by a 62-mer-5'ppp-dsRNA or by polyinosinic:polycytidylic acid, a dsRNA analogue, or by measles virus infection, anti-Flag immunoprecipitation and specific elution with Flag peptide indicated a monomeric form of RIG-I. Accordingly, when using the Gaussia Luciferase-Based Protein Complementation Assay (PCA, a more sensitive in cellula assay, no RIG-I oligomerization could be detected upon RNA stimulation. Altogether our data indicate that the need for self-oligomerization of RIG-I for signal transduction is either dispensable or very transient.

  18. PeptideAtlas

    Data.gov (United States)

    U.S. Department of Health & Human Services — PeptideAtlas is a multi-organism, publicly accessible compendium of peptides identified in a large set of tandem mass spectrometry proteomics experiments. Mass...

  19. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  20. PH dependent adhesive peptides

    Science.gov (United States)

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  1. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  2. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  3. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  4. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  5. Antimicrobial Peptides in 2014

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2015-03-01

    Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

  6. Accessing Specific Peptide Recognition by Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Li, Ming

    Molecular recognition is at the basis of all processes for life, and plays a central role in many biological processes, such as protein folding, the structural organization of cells and organelles, signal transduction, and the immune response. Hence, my PhD project is entitled “Accessing Specific...... Peptide Recognition by Combinatorial Chemistry”. Molecular recognition is a specific interaction between two or more molecules through noncovalent bonding, such as hydrogen bonding, metal coordination, van der Waals forces, π−π, hydrophobic, or electrostatic interactions. The association involves kinetic....... Combinatorial chemistry was invented in 1980s based on observation of functional aspects of the adaptive immune system. It was employed for drug development and optimization in conjunction with high-throughput synthesis and screening. (chapter 2) Combinatorial chemistry is able to rapidly produce many thousands...

  7. FY1995 transduction method and CAD database systems for integrated design; 1995 nendo transduction ho to CAD database togo sekkei shien system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Transduction method developed by the research coordinator and Prof. Muroga is one of the most popular methods to design large-scale integrated circuits, and thus used by major design tool companies in USA and Japan. The major objectives of the research is to improve capability and utilize its reusable property by combining with CAD databases. Major results of the project is as follows, (1) Improvement of Transduction method : Efficiency, capability and the maximum circuit size are improved. Error compensation method is also improved. (2) Applications to new logic elements : Transduction method is modified to cope with wired logic and FPGAs. (3) CAD databases : One of the major advantages of Transduction methods is 'reusability' of already designed circuits. It is suitable to combine with CAD databases. We design CAD databases suitable for cooperative design using Transduction method. (4) Program development : Programs for Windows95 and developed for distribution. (NEDO)

  8. FY1995 transduction method and CAD database systems for integrated design; 1995 nendo transduction ho to CAD database togo sekkei shien system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Transduction method developed by the research coordinator and Prof. Muroga is one of the most popular methods to design large-scale integrated circuits, and thus used by major design tool companies in USA and Japan. The major objectives of the research is to improve capability and utilize its reusable property by combining with CAD databases. Major results of the project is as follows, (1) Improvement of Transduction method : Efficiency, capability and the maximum circuit size are improved. Error compensation method is also improved. (2) Applications to new logic elements : Transduction method is modified to cope with wired logic and FPGAs. (3) CAD databases : One of the major advantages of Transduction methods is 'reusability' of already designed circuits. It is suitable to combine with CAD databases. We design CAD databases suitable for cooperative design using Transduction method. (4) Program development : Programs for Windows95 and developed for distribution. (NEDO)

  9. Reduced modeling of signal transduction – a modular approach

    Directory of Open Access Journals (Sweden)

    Ederer Michael

    2007-09-01

    Full Text Available Abstract Background Combinatorial complexity is a challenging problem in detailed and mechanistic mathematical modeling of signal transduction. This subject has been discussed intensively and a lot of progress has been made within the last few years. A software tool (BioNetGen was developed which allows an automatic rule-based set-up of mechanistic model equations. In many cases these models can be reduced by an exact domain-oriented lumping technique. However, the resulting models can still consist of a very large number of differential equations. Results We introduce a new reduction technique, which allows building modularized and highly reduced models. Compared to existing approaches further reduction of signal transduction networks is possible. The method also provides a new modularization criterion, which allows to dissect the model into smaller modules that are called layers and can be modeled independently. Hallmarks of the approach are conservation relations within each layer and connection of layers by signal flows instead of mass flows. The reduced model can be formulated directly without previous generation of detailed model equations. It can be understood and interpreted intuitively, as model variables are macroscopic quantities that are converted by rates following simple kinetics. The proposed technique is applicable without using complex mathematical tools and even without detailed knowledge of the mathematical background. However, we provide a detailed mathematical analysis to show performance and limitations of the method. For physiologically relevant parameter domains the transient as well as the stationary errors caused by the reduction are negligible. Conclusion The new layer based reduced modeling method allows building modularized and strongly reduced models of signal transduction networks. Reduced model equations can be directly formulated and are intuitively interpretable. Additionally, the method provides very good

  10. Polybrene inhibits human mesenchymal stem cell proliferation during lentiviral transduction.

    Directory of Open Access Journals (Sweden)

    Paul Lin

    Full Text Available Human mesenchymal stem cells (hMSCs can be engineered to express specific genes, either for their use in cell-based therapies or to track them in vivo over long periods of time. To obtain long-term expression of these genes, a lentivirus- or retrovirus-mediated cell transduction is often used. However, given that the efficiency with these viruses is typically low in primary cells, additives such as polybrene are always used for efficient viral transduction. Unfortunately, as presented here, exposure to polybrene alone at commonly used concentratons (1-8 µg/mL negatively impacts hMSC proliferation in a dose-dependent manner as measured by CyQUANT, EdU incorporation, and cell cycle analysis. This inhibition of proliferation was observable in culture even 3 weeks after exposure. Culturing the cells in the presence of FGF-2, a potent mitogen, did not abrogate this negative effect of polybrene. In fact, the normally sharp increase in hMSC proliferation that occurs during the first days of exposure to FGF-2 was absent at 4 µg/mL or higher concentrations of polybrene. Similarly, the effect of stimulating cell proliferation under simulated hypoxic conditions was also decreased when cells were exposed to polybrene, though overall proliferation rates were higher. The negative influence of polybrene was, however, reduced when the cells were exposed to polybrene for a shorter period of time (6 hr vs 24 hr. Thus, careful evaluation should be done when using polybrene to aid in lentiviral transduction of human MSCs or other primary cells, especially when cell number is critical.

  11. Modeling evolution of crosstalk in noisy signal transduction networks

    Science.gov (United States)

    Tareen, Ammar; Wingreen, Ned S.; Mukhopadhyay, Ranjan

    2018-02-01

    Signal transduction networks can form highly interconnected systems within cells due to crosstalk between constituent pathways. To better understand the evolutionary design principles underlying such networks, we study the evolution of crosstalk for two parallel signaling pathways that arise via gene duplication. We use a sequence-based evolutionary algorithm and evolve the network based on two physically motivated fitness functions related to information transmission. We find that one fitness function leads to a high degree of crosstalk while the other leads to pathway specificity. Our results offer insights on the relationship between network architecture and information transmission for noisy biomolecular networks.

  12. Signal transduction by the major histocompatibility complex class I molecule

    DEFF Research Database (Denmark)

    Pedersen, A E; Skov, Svend; Bregenholt, S

    1999-01-01

    Ligation of cell surface major histocompatibility class I (MHC-I) proteins by antibodies, or by their native counter receptor, the CD8 molecule, mediates transduction of signals into the cells. MHC-I-mediated signaling can lead to both increased and decreased activity of the MHC-I-expressing cell...... and functioning, MHC-I molecules might be of importance for the maintenance of cellular homeostasis not only within the immune system, but also in the interplay between the immune system and other organ systems....

  13. Signaling transduction pathways involved in basophil adhesion and histamine release

    DEFF Research Database (Denmark)

    Sha, Quan; Poulsen, Lars K.; Gerwien, Jens

    2006-01-01

    Little is known about basophil with respect to the different signaling transduction pathways involved in spontaneous, cytokine or anti-IgE induced adhesion and how this compares to IgE-dependent and IgE-independent mediator secretion. The purpose of the present study was to investigate the roles...... of beta1 and beta2 integrins in basophil adhesion as well as hosphatidylinositol 3-kinase (PI3K), src-kinases and extracellular signal regulated kinase (ERK) 1/2 in basophil adhesion and histamine release (HR)....

  14. Analysis and logical modeling of biological signaling transduction networks

    Science.gov (United States)

    Sun, Zhongyao

    The study of network theory and its application span across a multitude of seemingly disparate fields of science and technology: computer science, biology, social science, linguistics, etc. It is the intrinsic similarities embedded in the entities and the way they interact with one another in these systems that link them together. In this dissertation, I present from both the aspect of theoretical analysis and the aspect of application three projects, which primarily focus on signal transduction networks in biology. In these projects, I assembled a network model through extensively perusing literature, performed model-based simulations and validation, analyzed network topology, and proposed a novel network measure. The application of network modeling to the system of stomatal opening in plants revealed a fundamental question about the process that has been left unanswered in decades. The novel measure of the redundancy of signal transduction networks with Boolean dynamics by calculating its maximum node-independent elementary signaling mode set accurately predicts the effect of single node knockout in such signaling processes. The three projects as an organic whole advance the understanding of a real system as well as the behavior of such network models, giving me an opportunity to take a glimpse at the dazzling facets of the immense world of network science.

  15. Signal perception, transduction, and gene expression involved in anthocyanin biosynthesis

    International Nuclear Information System (INIS)

    Mol, J.; Jenkins, G.; Schäfer, E.; Weiss, D.

    1996-01-01

    Anthocyanin pigments provide fruits and flowers with their bright red and blue colors and are induced in vegetative tissues by various signals. The biosynthetic pathway probably represents one of the best‐studied examples of higher plant secondary metabolism. It has attracted much attention of plant geneticists because of the dispensable nature of the compounds it produces. Not unexpectedly, several excellent reviews on anthocyanin biosynthesis have been published over the last 5 years (Dooner et al., 1991; Martin and Gerats, 1993a, 1993b; Koes et al., 1994; Holton and Cornish, 1995). These reviews emphasize the late steps of pigment biosynthesis rather than the early and intermediate events of signal perception and transduction. This review is broader and not only covers the identification of components of the anthocyanin signal perception/transduction networks but also provides a description of our current understanding of how they evoke the responses that they do. Progress has derived from a combination of biochemical, molecular and genetic studies. We discuss a range of relevant research to highlight the different experimental approaches being used and the diverse biological systems under investigation. (author)

  16. Discriminative clustering on manifold for adaptive transductive classification.

    Science.gov (United States)

    Zhang, Zhao; Jia, Lei; Zhang, Min; Li, Bing; Zhang, Li; Li, Fanzhang

    2017-10-01

    In this paper, we mainly propose a novel adaptive transductive label propagation approach by joint discriminative clustering on manifolds for representing and classifying high-dimensional data. Our framework seamlessly combines the unsupervised manifold learning, discriminative clustering and adaptive classification into a unified model. Also, our method incorporates the adaptive graph weight construction with label propagation. Specifically, our method is capable of propagating label information using adaptive weights over low-dimensional manifold features, which is different from most existing studies that usually predict the labels and construct the weights in the original Euclidean space. For transductive classification by our formulation, we first perform the joint discriminative K-means clustering and manifold learning to capture the low-dimensional nonlinear manifolds. Then, we construct the adaptive weights over the learnt manifold features, where the adaptive weights are calculated through performing the joint minimization of the reconstruction errors over features and soft labels so that the graph weights can be joint-optimal for data representation and classification. Using the adaptive weights, we can easily estimate the unknown labels of samples. After that, our method returns the updated weights for further updating the manifold features. Extensive simulations on image classification and segmentation show that our proposed algorithm can deliver the state-of-the-art performance on several public datasets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Fetus Sound Stimulation: Cilia Memristor Effect of Signal Transduction

    Directory of Open Access Journals (Sweden)

    Svetlana Jankovic-Raznatovic

    2014-01-01

    Full Text Available Background. This experimental study evaluates fetal middle cerebral artery (MCA circulation after the defined prenatal acoustical stimulation (PAS and the role of cilia in hearing and memory and could explain signal transduction and memory according to cilia optical-acoustical properties. Methods. PAS was performed twice on 119 no-risk term pregnancies. We analyzed fetal MCA circulation before, after first and second PAS. Results. Analysis of the Pulsatility index basic (PIB and before PAS and Pulsatility index reactive after the first PAS (PIR 1 shows high statistical difference, representing high influence on the brain circulation. Analysis of PIB and Pulsatility index reactive after the second PAS (PIR 2 shows no statistical difference. Cilia as nanoscale structure possess magnetic flux linkage that depends on the amount of charge that has passed between two-terminal variable resistors of cilia. Microtubule resistance, as a function of the current through and voltage across the structure, leads to appearance of cilia memory with the “memristor” property. Conclusion. Acoustical and optical cilia properties play crucial role in hearing and memory processes. We suggest that fetuses are getting used to sound, developing a kind of memory patterns, considering acoustical and electromagnetically waves and involving cilia and microtubules and try to explain signal transduction.

  18. Molecular mechanisms of root gravity sensing and signal transduction.

    Science.gov (United States)

    Strohm, Allison K; Baldwin, Katherine L; Masson, Patrick H

    2012-01-01

    Plants use gravity as a guide to direct their roots down into the soil to anchor themselves and to find resources needed for growth and development. In higher plants, the columella cells of the root tip form the primary site of gravity sensing, and in these cells the sedimentation of dense, starch-filled plastids (amyloplasts) triggers gravity signal transduction. This generates an auxin gradient across the root cap that is transmitted to the elongation zone where it promotes differential cell elongation, allowing the root to direct itself downward. It is still not well understood how amyloplast sedimentation leads to auxin redistribution. Models have been proposed to explain how mechanosensitive ion channels or ligand-receptor interactions could connect these events. Although their roles are still unclear, possible second messengers in this process include protons, Ca(2+), and inositol 1,4,5-triphosphate. Upon gravistimulation, the auxin efflux facilitators PIN3 and PIN7 relocalize to the lower side of the columella cells and mediate auxin redistribution. However, evidence for an auxin-independent secondary mechanism of gravity sensing and signal transduction suggests that this physiological process is quite complex. Furthermore, plants must integrate a variety of environmental cues, resulting in multifaceted relationships between gravitropism and other directional growth responses such as hydro-, photo-, and thigmotropism. Copyright © 2011 Wiley Periodicals, Inc.

  19. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation.

  20. Genetic analysis of gravity signal transduction in roots

    Science.gov (United States)

    Masson, Patrick; Strohm, Allison; Baldwin, Katherine

    To grow downward into the soil, roots use gravity as a guide. Specialized cells, named stato-cytes, enable this directional growth response by perceiving gravity. Located in the columella region of the cap, these cells sense a reorientation of the root within the gravity field through the sedimentation of, and/or tension/pressure exerted by, dense amyloplasts. This process trig-gers a gravity signal transduction pathway that leads to a fast alkalinization of the cytoplasm and a change in the distribution of the plasma membrane-associated auxin-efflux carrier PIN3. The latter protein is uniformly distributed within the plasma membrane on all sides of the cell in vertically oriented roots. However, it quickly accumulates at the bottom side upon gravis-timulation. This process correlates with a preferential transport of auxin to the bottom side of the root cap, resulting in a lateral gradient across the tip. This gradient is then transported to the elongation zone where it promotes differential cellular elongation, resulting in downward curvature. We isolated mutations that affect gravity signal transduction at a step that pre-cedes cytoplasmic alkalinization and/or PIN3 relocalization and lateral auxin transport across the cap. arg1 and arl2 mutations identify a common genetic pathway that is needed for all three gravity-induced processes in the cap statocytes, indicating these genes function early in the pathway. On the other hand, adk1 affects gravity-induced PIN3 relocalization and lateral auxin transport, but it does not interfere with cytoplasmic alkalinization. ARG1 and ARL2 encode J-domain proteins that are associated with membranes of the vesicular trafficking path-way whereas ADK1 encodes adenosine kinase, an enzyme that converts adenosine derived from nucleic acid metabolism and the AdoMet cycle into AMP, thereby alleviating feedback inhibi-tion of this important methyl-donor cycle. Because mutations in ARG1 (and ARL2) do not completely eliminate

  1. Genetic Analysis of Gravity Signal Transduction in Arabidopsis Roots

    Science.gov (United States)

    Masson, Patrick; Strohm, Allison; Barker, Richard; Su, Shih-Heng

    Like most other plant organs, roots use gravity as a directional guide for growth. Specialized cells within the columella region of the root cap (the statocytes) sense the direction of gravity through the sedimentation of starch-filled plastids (amyloplasts). Amyloplast movement and/or pressure on sensitive membranes triggers a gravity signal transduction pathway within these cells, which leads to a fast transcytotic relocalization of plasma-membrane associated auxin-efflux carrier proteins of the PIN family (PIN3 and PIN7) toward the bottom membrane. This leads to a polar transport of auxin toward the bottom flank of the cap. The resulting lateral auxin gradient is then transmitted toward the elongation zones where it triggers a curvature that ultimately leads to a restoration of vertical downward growth. Our laboratory is using strategies derived from genetics and systems biology to elucidate the molecular mechanisms that modulate gravity sensing and signal transduction in the columella cells of the root cap. Our previous research uncovered two J-domain-containing proteins, ARG1 and ARL2, as contributing to this process. Mutations in the corresponding paralogous genes led to alterations of root and hypocotyl gravitropism accompanied by an inability for the statocytes to develop a cytoplasmic alkalinization, relocalize PIN3, and transport auxin laterally, in response to gravistimulation. Both proteins are associated peripherally to membranes belonging to various compartments of the vesicular trafficking pathway, potentially modulating the trafficking of defined proteins between plasma membrane and endosomes. MAR1 and MAR2, on the other end, are distinct proteins of the plastidic outer envelope protein import TOC complex (the transmembrane channel TOC75 and the receptor TOC132, respectively). Mutations in the corresponding genes enhance the gravitropic defects of arg1. Using transformation-rescue experiments with truncated versions of TOC132 (MAR2), we have shown

  2. Budget impact analysis of biosimilar infliximab (CT-P13) for the treatment of rheumatoid arthritis in six Central and Eastern European countries.

    Science.gov (United States)

    Brodszky, Valentin; Baji, Petra; Balogh, Orsolya; Péntek, Márta

    2014-05-01

    The first biosimilar monoclonal antibody (infliximab, CT-P13) was registered by the European Medicines Agency in 2013 for the treatment of several inflammatory conditions including rheumatoid arthritis (RA). Biosimilar infliximab is first being marketed in the Central and Eastern European countries. This paper presents the estimated budget impact of the introduction of biosimilar infliximab in RA over a 3-year time period in six selected countries, namely Bulgaria, the Czech Republic, Hungary, Poland, Romania and Slovakia. A prevalence-based model was constructed for budget impact analysis. Two scenarios were compared to the reference scenario (RSc) where no biosimilar infliximab is available: biosimilar scenario 1 (BSc1), where interchanging the originator infliximab with biosimilar infliximab is disallowed, and only patients who start new biological therapy are allowed to use biosimilar infliximab; as well as biosimilar scenario 2 (BSc2), where interchanging the originator infliximab with biosimilar infliximab is allowed, and 80% of patients treated with originator infliximab are interchanged to biosimilar infliximab. Compared to the RSc, the net savings are estimated to be €15.3 or €20.8 M in BSc1 and BSc2, respectively, over the 3 years. If budget savings were spent on reimbursement of additional biosimilar infliximab treatment, approximately 1,200 or 1,800 more patients could be treated in the six countries within 3 years in the two biosimilar scenarios, respectively. The actual saving is most sensitive to the assumption of the acquisition cost of the biosimilar drug and to the initial number of patients treated with biological therapy. The study focused on one indication (RA) and demonstrated that the introduction of biosimilar infliximab can lead to substantial budget savings in health care budgets. Further savings are expected for other indications where biosimilar medicines are implemented.

  3. Determination of the anomeric specificity of the Escherichia coli CTP:CMP-3-deoxy-D-manno-octulosonate cytidylyltransferase by 13C NMR spectroscopy

    International Nuclear Information System (INIS)

    Kohlbrenner, W.E.; Fesik, S.W.

    1985-01-01

    [99%, 1- 13 C]- and [90%, 2- 13 C]3-deoxy-D-manno-octulosonic acid (KDO) were prepared enzymatically and used to determine the anomeric specificity of the CTP:CMP-3-deoxy-D-manno-octulosonate cytidylyl transferase (CMP-KDO synthetase) by 13 C NMR spectroscopy. Addition of CMP-KDO synthetase to reaction mixtures containing either 1- 13 C- or 2- 13 C-labeled KDO resulted in rapid CMP-KDO formation which was accompanied by a substantial decrease in the 13 C-enriched resonances of the beta-pyranose form of KDO relative to the resonances of other KDO species in solution, demonstrating that the beta-pyranose is the preferred substrate. Concomitant with the production of CMP-KDO was the appearance of peaks at 174.3 and 101.4 ppm when [1- 13 C]- and [2- 13 C]KDO, respectively, were used as substrates. The correspondence of these resonances to the enriched carbons in CMP-KDO was confirmed by the expected 3-bond (3JP,C-1 = 6.9 Hz) and 2-bond coupling (2JP,C-2 = 8.3 Hz) between the labeled carbons and the ketosidically linked phosphoryl group. A large coupling (3J = 5.7 Hz) was observed in proton-coupled spectra of CMP-[1- 13 C]KDO between carbon 1 and the axial proton at carbon 3 of KDO. The magnitude of this coupling constant supports a diaxial relationship between these two groups and, along with chemical shift data, indicates that KDO retains the beta-configuration when linked in CMP-KDO

  4. The targeted transduction of MMP-overexpressing tumor cells by ACPP-HPMA copolymer-coated adenovirus conjugates.

    Directory of Open Access Journals (Sweden)

    Shuhua Li

    Full Text Available We have designed and tested a new way to selectively deliver HPMA polymer-coated adenovirus type 5 (Ad5 particles into matrix metalloproteinase (MMP-overexpressing tumor cells. An activatable cell penetrating peptide (ACPP was designed and attached to the reactive 4-nitrophenoxy groups of HPMA polymers by the C-terminal amino acid (asparagine, N. ACPPs are activatable cell penetrating peptides (CPPs with a linker between polycationic and polyanionic domains, and MMP-mediated cleavage releases the CPP portion and its attached cargo to enable cell entry. Our data indicate that the transport of these HPMA polymer conjugates by a single ACPP molecule to the cytoplasm occurs via a nonendocytotic and concentration-independent process. The uptake was observed to finish within 20 minutes by inverted fluorescence microscopy. In contrast, HPMA polymer-coated Ad5 without ACPPs was internalized solely by endocytosis. The optimal formulation was not affected by the presence of Ad5 neutralizing antibodies during transduction, and ACPP/polymer-coated Ad5 also retained high targeting capability to several MMP-overexpressing tumor cell types. For the first time, ACPP-mediated cytoplasmic delivery of polymer-bound Ad5 to MMP-overexpressing tumor cells was demonstrated. These findings are significant, as they demonstrate the use of a polymer-based system for the targeted delivery into MMP-overexpressing solid tumors and highlight how to overcome major cellular obstacles to achieve intracellular macromolecular delivery.

  5. Staurosporine Increases Lentiviral Vector Transduction Efficiency of Human Hematopoietic Stem and Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Gretchen Lewis

    2018-06-01

    Full Text Available Lentiviral vector (LVV-mediated transduction of human CD34+ hematopoietic stem and progenitor cells (HSPCs holds tremendous promise for the treatment of monogenic hematological diseases. This approach requires the generation of a sufficient proportion of gene-modified cells. We identified staurosporine, a serine/threonine kinase inhibitor, as a small molecule that could be added to the transduction process to increase the proportion of genetically modified HSPCs by overcoming a LVV entry barrier. Staurosporine increased vector copy number (VCN approximately 2-fold when added to mobilized peripheral blood (mPB CD34+ cells prior to transduction. Limited staurosporine treatment did not affect viability of cells post-transduction, and there was no difference in in vitro colony formation compared to vehicle-treated cells. Xenotransplantation studies identified a statistically significant increase in VCN in engrafted human cells in mouse bone marrow at 4 months post-transplantation compared to vehicle-treated cells. Prostaglandin E2 (PGE2 is known to increase transduction efficiency of HSPCs through a different mechanism. Combining staurosporine and PGE2 resulted in further enhancement of transduction efficiency, particularly in short-term HSPCs. The combinatorial use of small molecules, such as staurosporine and PGE2, to enhance LVV transduction of human CD34+ cells is a promising method to improve transduction efficiency and subsequent potential therapeutic benefit of gene therapy drug products. Keywords: lentiviral, HSPC, transduction

  6. Polymerase chain reaction-based detection of myc transduction in feline leukemia virus-infected cats.

    Science.gov (United States)

    Sumi, Ryosuke; Miyake, Ariko; Endo, Taiji; Ohsato, Yoshiharu; Ngo, Minh Ha; Nishigaki, Kazuo

    2018-04-01

    Feline lymphomas are associated with the transduction and activation of cellular proto-oncogenes, such as c-myc, by feline leukemia virus (FeLV). We describe a polymerase chain reaction assay for detection of myc transduction usable in clinical diagnosis. The assay targets c-myc exons 2 and 3, which together result in a FeLV-specific fusion gene following c-myc transduction. When this assay was conducted on FeLV-infected feline tissues submitted for clinical diagnosis of tumors, myc transduction was detected in 14% of T-cell lymphoma/leukemias. This newly established system could become a useful diagnostic tool in veterinary medicine.

  7. In vitro and in vivo delivery of therapeutic proteins using cell penetrating peptides.

    Science.gov (United States)

    Bolhassani, Azam; Jafarzade, Behnaz Sadat; Mardani, Golnaz

    2017-01-01

    The failure of proteins to penetrate mammalian cells or target tumor cells restricts their value as therapeutic tools in a variety of diseases such as cancers. Recently, protein transduction domains (PTDs) or cell penetrating peptides (CPPs) have been shown to promote the delivery of therapeutic proteins or peptides into live cells. The successful delivery of proteins mainly depends on their physicochemical properties. Although, linear cell penetrating peptides are one of the most effective delivery vehicles; but currently, cyclic CPPs has been developed to potently transport bioactive full-length proteins into cells. Up to now, several small protein transduction domains from viral proteins including Tat or VP22 could be fused to other peptides or proteins to entry them in various cell types at a dose-dependent approach. A major disadvantage of PTD-fusion proteins is primary uptake into endosomal vesicles leading to inefficient release of the fusion proteins into the cytosol. Recently, non-covalent complex formation (Chariot) between proteins and CPPs has attracted a special interest to overcome some delivery limitations (e.g., toxicity). Many preclinical and clinical trials of CPP-based delivery are currently under evaluation. Generally, development of more efficient protein transduction domains would significantly increase the potency of protein therapeutics. Moreover, the synergistic or combined effects of CPPs with other delivery systems for protein/peptide drug delivery would promote their therapeutic effects in cancer and other diseases. In this review, we will describe the functions and implications of CPPs for delivering the therapeutic proteins or peptides in preclinical and clinical studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Molecular transduction mechanisms in ACTH-induced grooming

    NARCIS (Netherlands)

    Gispen, W.H.; Colbern, D.; Spruijt, B.M.

    1988-01-01

    Intraventricular administration of ACTH1-24 induces excessive grooming in the rat. Ethogram analysis shows that the peptide does not alter grooming behavior seen in a novel box, but that it prolongs the duration of the grooming bout. Extensive structure-activity studies have been performed which

  9. Peptides in melanoma therapy.

    Science.gov (United States)

    Mocellin, Simone

    2012-01-01

    Peptides derived from tumor associated antigens can be utilized to elicit a therapeutically effective immune response against melanoma in experimental models. However, patient vaccination with peptides - although it is often followed by the induction of melanoma- specific T lymphocytes - is rarely associated with tumor response of clinical relevance. In this review I summarize the principles of peptide design as well as the results so far obtained in the clinical setting while treating cutaneous melanoma by means of this active immunotherapy strategy. I also discuss some immunological and methodological issues that might be helpful for the successful development of peptide-based vaccines.

  10. Antimicrobial Peptides in Reptiles

    Science.gov (United States)

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  11. Simulation and Evaluation of CTP and Secure-CTP Protocols

    Directory of Open Access Journals (Sweden)

    P. Pecho

    2010-04-01

    Full Text Available The paper discusses characteristics and qualities of two routing protocols – Collection Tree Protocol and its secure modification. The original protocol, as well as other protocols for wireless sensors, solves only problems of ra- dio communication and limited resources. Our design of the secure protocol tries to solve also the essential security ob- jectives. For the evaluation of properties of our protocol in large networks, a TOSSIM simulator was used. Our effort was to show the influence of the modification of the routing protocol to its behavior and quality of routing trees. We have proved that adding security into protocol design does not necessarily mean higher demands for data transfer, power consumption or worse protocol efficiency. In the paper, we manifest that security in the protocol may be achieved with low cost and may offer similar performance as the original protocol.

  12. Mechanistic Insights in Ethylene Perception and Signal Transduction1

    Science.gov (United States)

    Ju, Chuanli; Chang, Caren

    2015-01-01

    The gaseous hormone ethylene profoundly affects plant growth, development, and stress responses. Ethylene perception occurs at the endoplasmic reticulum membrane, and signal transduction leads to a transcriptional cascade that initiates diverse responses, often in conjunction with other signals. Recent findings provide a more complete picture of the components and mechanisms in ethylene signaling, now rendering a more dynamic view of this conserved pathway. This includes newly identified protein-protein interactions at the endoplasmic reticulum membrane, as well as the major discoveries that the central regulator ETHYLENE INSENSITIVE2 (EIN2) is the long-sought phosphorylation substrate for the CONSTITUTIVE RESPONSE1 protein kinase, and that cleavage of EIN2 transmits the signal to the nucleus. In the nucleus, hundreds of potential gene targets of the EIN3 master transcription factor have been identified and found to be induced in transcriptional waves, and transcriptional coregulation has been shown to be a mechanism of ethylene cross talk. PMID:26246449

  13. Piezoelectric Multilayer-Stacked Hybrid Actuation/Transduction System

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor)

    2014-01-01

    A novel full piezoelectric multilayer stacked hybrid actuation/transduction system. The system demonstrates significantly-enhanced electromechanical performance by utilizing the cooperative contributions of the electromechanical responses of multilayer stacked negative and positive strain components. Both experimental and theoretical studies indicate that for this system, the displacement is over three times that of a same-sized conventional flextensional actuator/transducer. The system consists of at least 2 layers which include electromechanically active components. The layers are arranged such that when electric power is applied, one layer contracts in a transverse direction while the second layer expands in a transverse direction which is perpendicular to the transverse direction of the first layer. An alternate embodiment includes a third layer. In this embodiment, the outer two layers contract in parallel transverse directions while the middle layer expands in a transverse direction which is perpendicular to the transverse direction of the outer layers.

  14. Influence of Unweighting on Insulin Signal Transduction in Muscle

    Science.gov (United States)

    Tischler, Marc E.

    2002-01-01

    Unweighting of the juvenile soleus muscle is characterized by an increased binding capacity for insulin relative to muscle mass due to sparing of the receptors during atrophy. Although carbohydrate metabolism and protein degradation in the unweighted muscle develop increased sensitivity to insulin in vivo, protein synthesis in vivo and system A amino acid transport in vitro do not appear to develop such an enhanced response. The long-term goal is to identify the precise nature of this apparent resistance in the insulin signal transduction pathway and to consider how reduced weight-bearing may elicit this effect, by evaluating specific components of the insulin signalling pathway. Because the insulin-signalling pathway has components in common with the signal transduction pathway for insulin-like growth factor (IGF-1) and potentially other growth factors, the study could have important implications in the role of weight-bearing function on muscle growth and development. Since the insulin signalling pathway diverges following activation of insulin receptor tyrosine kinase, the immediate specific aims will be to study the receptor tyrosine kinase (IRTK) and those branches, which lead to phosphorylation of insulin receptor substrate-1 (IRS-1) and of Shc protein. To achieve these broader objectives, we will test in situ, by intramuscular injection, the responses of glucose transport, system A amino acid transport and protein synthesis to insulin analogues for which the receptor has either a weaker or much stronger binding affinity compared to insulin. Studies will include: (1) estimation of the ED(sub 50) for each analogue for these three processes; (2) the effect of duration (one to four days) of unweighting on the response of each process to all analogues tested; (3) the effect of unweighting and the analogues on IRTK activity; and (4) the comparative effects of unweighting and analogue binding on the tyrosine phosphorylation of IRTK, IRS-1, and Shc protein.

  15. Forward Programming of Cardiac Stem Cells by Homogeneous Transduction with MYOCD plus TBX5.

    Directory of Open Access Journals (Sweden)

    Elisa Belian

    Full Text Available Adult cardiac stem cells (CSCs express many endogenous cardiogenic transcription factors including members of the Gata, Hand, Mef2, and T-box family. Unlike its DNA-binding targets, Myocardin (Myocd-a co-activator not only for serum response factor, but also for Gata4 and Tbx5-is not expressed in CSCs. We hypothesised that its absence was a limiting factor for reprogramming. Here, we sought to investigate the susceptibility of adult mouse Sca1+ side population CSCs to reprogramming by supplementing the triad of GATA4, MEF2C, and TBX5 (GMT, and more specifically by testing the effect of the missing co-activator, Myocd. Exogenous factors were expressed via doxycycline-inducible lentiviral vectors in various combinations. High throughput quantitative RT-PCR was used to test expression of 29 cardiac lineage markers two weeks post-induction. GMT induced more than half the analysed cardiac transcripts. However, no protein was detected for the induced sarcomeric genes Actc1, Myh6, and Myl2. Adding MYOCD to GMT affected only slightly the breadth and level of gene induction, but, importantly, triggered expression of all three proteins examined (α-cardiac actin, atrial natriuretic peptide, sarcomeric myosin heavy chains. MYOCD + TBX was the most effective pairwise combination in this system. In clonal derivatives homogenously expressing MYOCD + TBX at high levels, 93% of cardiac transcripts were up-regulated and all five proteins tested were visualized.(1 GMT induced cardiac genes in CSCs, but not cardiac proteins under the conditions used. (2 Complementing GMT with MYOCD induced cardiac protein expression, indicating a more complete cardiac differentiation program. (3 Homogeneous transduction with MYOCD + TBX5 facilitated the identification of differentiating cells and the validation of this combinatorial reprogramming strategy. Together, these results highlight the pivotal importance of MYOCD in driving CSCs toward a cardiac muscle fate.

  16. Insulin C-peptide test

    Science.gov (United States)

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin the body produces and insulin someone injects ...

  17. Synthesis and Characterization of a Gd-DOTA-D-Permeation Peptide for Magnetic Resonance Relaxation Enhancement of Intracellular Targets

    Directory of Open Access Journals (Sweden)

    Andrew M. Prantner

    2003-10-01

    Full Text Available Many MR contrast agents have been developed and proven effective for extracellular nontargeted applications, but exploitation of intracellular MR contrast agents has been elusive due to the permeability barrier of the plasma membrane. Peptide transduction domains can circumvent this permeability barrier and deliver cargo molecules to the cell interior. Based upon enhanced cellular uptake of permeation peptides with D-amino acid residues, an all-D Tat basic domain peptide was conjugated to DOTA and chelated to gadolinium. Gd-DOTA-D-Tat peptide in serum at room temperature showed a relaxivity of 7.94 ± 0.11 mM−1 sec−1 at 4.7 T. The peptide complex displayed no significant binding to serum proteins, was efficiently internalized by human Jurkat leukemia cells resulting in intracellular T1 relaxation enhancement, and in preliminary T1-weighted MRI experiments, significantly enhanced liver, kidney, and mesenteric signals.

  18. Mechanisms of Insertion of dCTP and dTTP Opposite the DNA Lesion O6-Methyl-2′-deoxyguanosine by Human DNA Polymerase η*

    Science.gov (United States)

    Patra, Amitraj; Zhang, Qianqian; Guengerich, F. Peter; Egli, Martin

    2016-01-01

    O6-Methyl-2′-deoxyguanosine (O6-MeG) is a ubiquitous DNA lesion, formed not only by xenobiotic carcinogens but also by the endogenous methylating agent S-adenosylmethionine. It can introduce mutations during DNA replication, with different DNA polymerases displaying different ratios of correct or incorrect incorporation opposite this nucleoside. Of the “translesion” Y-family human DNA polymerases (hpols), hpol η is most efficient in incorporating equal numbers of correct and incorrect C and T bases. However, the mechanistic basis for this specific yet indiscriminate activity is not known. To explore this question, we report biochemical and structural analysis of the catalytic core of hpol η. Activity assays showed the truncated form displayed similar misincorporation properties as the full-length enzyme, incorporating C and T equally and extending from both. X-ray crystal structures of both dC and dT paired with O6-MeG were solved in both insertion and extension modes. The structures revealed a Watson-Crick-like pairing between O6-MeG and 2"-deoxythymidine-5"-[(α, β)-imido]triphosphate (approximating dT) at both the insertion and extension stages with formation of two H-bonds. Conversely, both the structures with O6- MeG opposite dCTP and dC display sheared configuration of base pairs but to different degrees, with formation of two bifurcated H-bonds and two single H-bonds in the structures trapped in the insertion and extension states, respectively. The structural data are consistent with the observed tendency of hpol η to insert both dC and dT opposite the O6-MeG lesion with similar efficiencies. Comparison of the hpol η active site configurations with either O6-MeG:dC or O6-MeG:dT bound compared with the corresponding situations in structures of complexes of Sulfolobus solfataricus Dpo4, a bypass pol that favors C relative to T by a factor of ∼4, helps rationalize the more error-prone synthesis opposite the lesion by hpol η. PMID:27694439

  19. Coincident resection at both ends of random, γ-induced double-strand breaks requires MRX (MRN, Sae2 (Ctp1, and Mre11-nuclease.

    Directory of Open Access Journals (Sweden)

    James W Westmoreland

    2013-03-01

    Full Text Available Resection is an early step in homology-directed recombinational repair (HDRR of DNA double-strand breaks (DSBs. Resection enables strand invasion as well as reannealing following DNA synthesis across a DSB to assure efficient HDRR. While resection of only one end could result in genome instability, it has not been feasible to address events at both ends of a DSB, or to distinguish 1- versus 2-end resections at random, radiation-induced "dirty" DSBs or even enzyme-induced "clean" DSBs. Previously, we quantitatively addressed resection and the role of Mre11/Rad50/Xrs2 complex (MRX at random DSBs in circular chromosomes within budding yeast based on reduced pulsed-field gel electrophoretic mobility ("PFGE-shift". Here, we extend PFGE analysis to a second dimension and demonstrate unique patterns associated with 0-, 1-, and 2-end resections at DSBs, providing opportunities to examine coincidence of resection. In G2-arrested WT, Δrad51 and Δrad52 cells deficient in late stages of HDRR, resection occurs at both ends of γ-DSBs. However, for radiation-induced and I-SceI-induced DSBs, 1-end resections predominate in MRX (MRN null mutants with or without Ku70. Surprisingly, Sae2 (Ctp1/CtIP and Mre11 nuclease-deficient mutants have similar responses, although there is less impact on repair. Thus, we provide direct molecular characterization of coincident resection at random, radiation-induced DSBs and show that rapid and coincident initiation of resection at γ-DSBs requires MRX, Sae2 protein, and Mre11 nuclease. Structural features of MRX complex are consistent with coincident resection being due to an ability to interact with both DSB ends to directly coordinate resection. Interestingly, coincident resection at clean I-SceI-induced breaks is much less dependent on Mre11 nuclease or Sae2, contrary to a strong dependence on MRX complex, suggesting different roles for these functions at "dirty" and clean DSB ends. These approaches apply to resection at

  20. Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Theilade, M D; Gram, G J; Jensen, P B

    1999-01-01

    of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

  1. Peptide Vaccines for Leishmaniasis

    Directory of Open Access Journals (Sweden)

    Rory C. F. De Brito

    2018-05-01

    Full Text Available Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the disease have become a high priority. Classic vaccines against leishmaniases were based on live or attenuated parasites or their subunits. Nevertheless, the use of whole parasite or their subunits for vaccine production has numerous disadvantages. Therefore, the use of Leishmania peptides to design more specific vaccines against leishmaniases seems promising. Moreover, peptides have several benefits in comparison with other kinds of antigens, for instance, good stability, absence of potentially damaging materials, antigen low complexity, and low-cost to scale up. By contrast, peptides are poor immunogenic alone, and they need to be delivered correctly. In this context, several approaches described in this review are useful to solve these drawbacks. Approaches, such as, peptides in combination with potent adjuvants, cellular vaccinations, adenovirus, polyepitopes, or DNA vaccines have been used to develop peptide-based vaccines. Recent advancements in peptide vaccine design, chimeric, or polypeptide vaccines and nanovaccines based on particles attached or formulated with antigenic components or peptides have been increasingly employed to drive a specific immune response. In this review, we briefly summarize the old, current, and future stands on peptide-based vaccines, describing the disadvantages and benefits associated with them. We also propose possible approaches to overcome the related weaknesses of synthetic vaccines and suggest future guidelines for their development.

  2. Peptide Vaccines for Leishmaniasis.

    Science.gov (United States)

    De Brito, Rory C F; Cardoso, Jamille M De O; Reis, Levi E S; Vieira, Joao F; Mathias, Fernando A S; Roatt, Bruno M; Aguiar-Soares, Rodrigo Dian D O; Ruiz, Jeronimo C; Resende, Daniela de M; Reis, Alexandre B

    2018-01-01

    Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the disease have become a high priority. Classic vaccines against leishmaniases were based on live or attenuated parasites or their subunits. Nevertheless, the use of whole parasite or their subunits for vaccine production has numerous disadvantages. Therefore, the use of Leishmania peptides to design more specific vaccines against leishmaniases seems promising. Moreover, peptides have several benefits in comparison with other kinds of antigens, for instance, good stability, absence of potentially damaging materials, antigen low complexity, and low-cost to scale up. By contrast, peptides are poor immunogenic alone, and they need to be delivered correctly. In this context, several approaches described in this review are useful to solve these drawbacks. Approaches, such as, peptides in combination with potent adjuvants, cellular vaccinations, adenovirus, polyepitopes, or DNA vaccines have been used to develop peptide-based vaccines. Recent advancements in peptide vaccine design, chimeric, or polypeptide vaccines and nanovaccines based on particles attached or formulated with antigenic components or peptides have been increasingly employed to drive a specific immune response. In this review, we briefly summarize the old, current, and future stands on peptide-based vaccines, describing the disadvantages and benefits associated with them. We also propose possible approaches to overcome the related weaknesses of synthetic vaccines and suggest future guidelines for their development.

  3. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from...

  4. Phosphotyrosine biased enrichment of tryptic peptides from cancer cells by combining pY-MIP and TiO2 affinity resins

    DEFF Research Database (Denmark)

    Bllaci, Loreta; Torsetnes, Silje Bøen; Wierzbicka, Celina Katarzyna

    2017-01-01

    Protein phosphorylation at distinct tyrosine residues (pY) is essential for fast, specific and accurate signal transduction in cells. Enrichment of pY-containing peptides derived from phosphoproteins is commonly facilitated by use of immobilized anti-pY antibodies prior to phosphoproteomics analy...

  5. cGMP inhibition of type 3 phosphodiesterase is the major mechanism by which C-type natriuretic peptide activates CFTR in the shark rectal gland

    NARCIS (Netherlands)

    H.R. de Jonge (Hugo); B.C. Tilly (Bernard); B.M. Hogema (Boris); D.J. Pfau (Daniel); C.A. Kelley (Catherine); M.H. Kelley (Megan); A.M. Melita (August); M.T. Morris (Montana); M.S. Viola (Maria); J.N. Forrest Jr. (John)

    2014-01-01

    textabstractThe in vitro perfused rectal gland of the dogfish shark (Squalus acanthias) and filter-grown monolayers of primary cultures of shark rectal gland (SRG) epithelial cells were used to analyze the signal transduction pathway by which C-type natriuretic peptide (CNP) stimulates chloride

  6. Interaction of the protein transduction domain of HIV-1 TAT with heparan sulfate: binding mechanism and thermodynamic parameters.

    Science.gov (United States)

    Ziegler, André; Seelig, Joachim

    2004-01-01

    The positively charged protein transduction domain of the HIV-1 TAT protein (TAT-PTD; residues 47-57 of TAT) rapidly translocates across the plasma membrane of living cells. This property is exploited for the delivery of proteins, drugs, and genes into cells. The mechanism of this translocation is, however, not yet understood. Recent theories for translocation suggest binding of the protein transduction domain (PTD) to extracellular glycosaminoglycans as a possible mechanism. We have studied the binding equilibrium between TAT-PTD and three different glycosaminoglycans with high sensitivity isothermal titration calorimetry and provide the first quantitative thermodynamic description. The polysulfonated macromolecules were found to exhibit multiple identical binding sites for TAT-PTD with only small differences between the three species as far as the thermodynamic parameters are concerned. Heparan sulfate (HS, molecular weight, 14.2 +/- 2 kDa) has 6.3 +/- 1.0 independent binding sites for TAT-PTD which are characterized by a binding constant K0 = (6.0 +/- 0.6) x 10(5) M(-1) and a reaction enthalpy deltaHpep0 = -4.6 +/- 1.0 kcal/mol at 28 degrees C. The binding affinity, deltaGpep0, is determined to equal extent by enthalpic and entropic contributions. The HS-TAT-PTD complex formation entails a positive heat capacity change of deltaCp0 = +135 cal/mol peptide, which is characteristic of a charge neutralization reaction. This is in contrast to hydrophobic binding reactions which display a large negative heat capacity change. The stoichiometry of 6-7 TAT-PTD molecules per HS corresponds to an electric charge neutralization. Light scattering data demonstrate a maximum scattering intensity at this stoichiometric ratio, the intensity of which depends on the order of mixing of the two components. The data suggest cross-linking and/or aggregation of HS-TAT-PTD complexes. Two other glycosaminoglycans, namely heparin and chondroitin sulfate B, were also studied with isothermal

  7. Genetic Analysis of Gravity Signal Transduction in Arabidopsis thaliana Seedlings

    Science.gov (United States)

    Boonsirichai, K.; Harrison, B.; Stanga, J.; Young, L.-S.; Neal, C.; Sabat, G.; Murthy, N.; Harms, A.; Sedbrook, J.; Masson, P.

    The primary roots of Arabidopsis thaliana seedlings respond to gravity stimulation by developing a tip curvature that results from differential cellular elongation on opposite flanks of the elongation zone. This curvature appears modulated by a lateral gradient of auxin that originates in the gravity-perceiving cells (statocytes) of the root cap through an apparent lateral repositioning of a component the auxin efflux carrier complex within these cells (Friml et al, 2002, Nature 415: 806-809). Unfortunately, little is known about the molecular mechanisms that govern early phases of gravity perception and signal transduction within the root-cap statocytes. We have used a molecular genetic approach to uncover some of these mechanisms. Mutations in the Arabidopsis ARG1 and ARL2 genes, which encode J-domain proteins, resulted in specific alterations in root and hypocotyl gravitropism, without pleiotropic phenotypes. Interestingly, ARG1 and ARL2 appear to function in the same genetic pathway. A combination of molecular genetic, biochemical and cell-biological approaches were used to demonstrate that ARG1 functions in early phases of gravity signal transduction within the root and hypocotyl statocytes, and is needed for efficient lateral auxin transport within the cap. The ARG1 protein is associated with components of the secretory and/or endosomal pathways, suggesting its role in the recycling of components of the auxin efflux carrier complex between plasma membrane and endosome (Boonsirichai et al, 2003, Plant Cell 15:2612-2625). Genetic modifiers of arg1-2 were isolated and shown to enhance the gravitropic defect of arg1-2, while resulting in little or no gravitropic defects in a wild type ARG1 background. A slight tendency for arg1-2;mar1-1 and arg1-2;mar2-1 double-mutant organs to display an opposite gravitropic response compared to wild type suggests that all three genes contribute to the interpretation of the gravity-vector information by seedling organs. The

  8. Identification of a mutant α1 Na/K-ATPase that pumps but is defective in signal transduction.

    Science.gov (United States)

    Lai, Fangfang; Madan, Namrata; Ye, Qiqi; Duan, Qiming; Li, Zhichuan; Wang, Shaomeng; Si, Shuyi; Xie, Zijian

    2013-05-10

    It has not been possible to study the pumping and signaling functions of Na/K-ATPase independently in live cells. Both cell-free and cell-based assays indicate that the A420P mutation abolishes the Src regulatory function of Na/K-ATPase. A420P mutant has normal pumping but not signaling function. Identification of Src regulation-null mutants is crucial for addressing physiological role of Na/K-ATPase. The α1 Na/K-ATPase possesses both pumping and signaling functions. However, it has not been possible to study these functions independently in live cells. We have identified a 20-amino acid peptide (Ser-415 to Gln-434) (NaKtide) from the nucleotide binding domain of α1 Na/K-ATPase that binds and inhibits Src in vitro. The N terminus of NaKtide adapts a helical structure. In vitro kinase assays showed that replacement of residues that contain a bulky side chain in the helical structure of NaKtide by alanine abolished the inhibitory effect of the peptide on Src. Similarly, disruption of helical structure by proline replacement, either single or in combination, reduced the inhibitory potency of NaKtide on Src. To identify mutant α1 that retains normal pumping function but is defective in Src regulation, we transfected Na/K-ATPase α1 knockdown PY-17 cells with expression vectors of wild type or mutant α1 carrying Ala to Pro mutations in the region of NaKtide helical structure and generated several stable cell lines. We found that expression of either A416P or A420P or A425P mutant fully restored the α1 content and consequently the pumping capacity of cells. However, in contrast to A416P, either A420P or A425P mutant was incapable of interacting and regulating cellular Src. Consequently, expression of these two mutants caused significant inhibition of ouabain-activated signal transduction and cell growth. Thus we have identified α1 mutant that has normal pumping function but is defective in signal transduction.

  9. Mannotriose regulates learning and memory signal transduction in the hippocampus

    Institute of Scientific and Technical Information of China (English)

    Lina Zhang; Weiwei Dai; Xueli Zhang; Zhangbin Gong; Guoqin Jin

    2013-01-01

    Rehmannia is a commonly used Chinese herb, which improves learning and memory. However, the crucial components of the signal transduction pathway associated with this effect remain elusive. Pri-mary hippocampal neurons were cultured in vitro, insulted with high-concentration (1 × 10-4 mol/L) cor-ticosterone, and treated with 1 × 10-4 mol/L mannotriose. Thiazolyl blue tetrazolium bromide assay and western blot analysis showed that hippocampal neuron survival rates and protein levels of glucocorti-coid receptor, serum and glucocorticoid-regulated protein kinase, and brain-derived neurotrophic factor were al dramatical y decreased after high-concentration corticosterone-induced injury. This effect was reversed by mannotriose, to a similar level as RU38486 and donepezil. Our findings indicate that mannotriose could protect hippocampal neurons from high-concentration corticosterone-induced injury. The mechanism by which this occurred was associated with levels of glucocorticoid receptor protein, serum and glucocorticoid-regulated protein kinase, and brain-derived neurotrophic factor.

  10. The interleukin-4 receptor: signal transduction by a hematopoietin receptor.

    Science.gov (United States)

    Keegan, A D; Pierce, J H

    1994-02-01

    Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3'-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome.

  11. Modulation of signal transduction by tea catechins and related phytochemicals

    International Nuclear Information System (INIS)

    Shimizu, Masahito; Weinstein, I. Bernard

    2005-01-01

    Epidemiologic studies in human populations and experimental studies in rodents provide evidence that green tea and its constituents can inhibit both the development and growth of tumors at a variety of tissue sites. In addition, EGCG, a major biologically active component of green tea, inhibits growth and induces apoptosis in a variety of cancer cell lines. The purpose of this paper is to review evidence that these effects are mediated, at least in part, through inhibition of the activity of specific receptor tyrosine kinases (RTKs) and related downstream pathways of signal transduction. We also review evidence indicating that the antitumor effects of the related polyphenolic phytochemicals resveratrol, genistein, curcumin, and capsaicin are exerted via similar mechanisms. Some of these agents (EGCG, genistein, and curcumin) appear to directly target specific RTKs, and all of these compounds cause inhibition of the activity of the transcription factors AP-1 and NF-κB, thus inhibiting cell proliferation and enhancing apoptosis. Critical areas of future investigation include: (1) identification of the direct molecular target(s) of EGCG and related polyphenolic compounds in cells; (2) the in vivo metabolism and bioavailability of these compounds; (3) the ancillary effects of these compounds on tumor-stromal interactions; (4) the development of synergistic combinations with other antitumor agents to enhance efficacy in cancer prevention and therapy, and also minimize potential toxicities

  12. Structural basis for energy transduction by respiratory alternative complex III.

    Science.gov (United States)

    Sousa, Joana S; Calisto, Filipa; Langer, Julian D; Mills, Deryck J; Refojo, Patrícia N; Teixeira, Miguel; Kühlbrandt, Werner; Vonck, Janet; Pereira, Manuela M

    2018-04-30

    Electron transfer in respiratory chains generates the electrochemical potential that serves as energy source for the cell. Prokaryotes can use a wide range of electron donors and acceptors and may have alternative complexes performing the same catalytic reactions as the mitochondrial complexes. This is the case for the alternative complex III (ACIII), a quinol:cytochrome c/HiPIP oxidoreductase. In order to understand the catalytic mechanism of this respiratory enzyme, we determined the structure of ACIII from Rhodothermus marinus at 3.9 Å resolution by single-particle cryo-electron microscopy. ACIII presents a so-far unique structure, for which we establish the arrangement of the cofactors (four iron-sulfur clusters and six c-type hemes) and propose the location of the quinol-binding site and the presence of two putative proton pathways in the membrane. Altogether, this structure provides insights into a mechanism for energy transduction and introduces ACIII as a redox-driven proton pump.

  13. Signal transduction in cells of the immune system in microgravity

    Directory of Open Access Journals (Sweden)

    Huber Kathrin

    2008-10-01

    Full Text Available Abstract Life on Earth developed in the presence and under the constant influence of gravity. Gravity has been present during the entire evolution, from the first organic molecule to mammals and humans. Modern research revealed clearly that gravity is important, probably indispensable for the function of living systems, from unicellular organisms to men. Thus, gravity research is no more or less a fundamental question about the conditions of life on Earth. Since the first space missions and supported thereafter by a multitude of space and ground-based experiments, it is well known that immune cell function is severely suppressed in microgravity, which renders the cells of the immune system an ideal model organism to investigate the influence of gravity on the cellular and molecular level. Here we review the current knowledge about the question, if and how cellular signal transduction depends on the existence of gravity, with special focus on cells of the immune system. Since immune cell function is fundamental to keep the organism under imnological surveillance during the defence against pathogens, to investigate the effects and possible molecular mechanisms of altered gravity is indispensable for long-term space flights to Earth Moon or Mars. Thus, understanding the impact of gravity on cellular functions on Earth will provide not only important informations about the development of life on Earth, but also for therapeutic and preventive strategies to cope successfully with medical problems during space exploration.

  14. Signal transduction by the platelet-derived growth factor receptor

    International Nuclear Information System (INIS)

    Williams, L.T.; Escobedo, J.A.; Keating, M.T.; Coughlin, S.R.

    1988-01-01

    The mitogenic effects of platelet-derived growth factor (PDGF) are mediated by the PDGF receptor. The mouse PDGF receptor was recently purified on the basis of its ability to become tyrosine phosphorylated in response to the A-B human platelet form of PDGF, and the receptor amino acid sequence was determined from a full-length cDNA clone. Both the human and mouse receptor cDNA sequences have been expressed in Chinese hamster ovary fibroblast (CHO) cells that normally lack PDGF receptors. This paper summarizes recent results using this system to study signal transduction by the PDGF receptor. Some of the findings show that the KI domain of the PDGF receptor plays an important role in the stimulation of DNA synthesis by PDGF. Surprisingly, the kinase insert region is not essential for PDGF stimulation of PtdIns turnover, pH change, increase in cellular calcium, and receptor autophosphorylation. In addition, PDGF stimulates a conformational change in the receptor

  15. Metformin selectively targets redox control of complex I energy transduction

    Directory of Open Access Journals (Sweden)

    Amy R. Cameron

    2018-04-01

    Full Text Available Many guanide-containing drugs are antihyperglycaemic but most exhibit toxicity, to the extent that only the biguanide metformin has enjoyed sustained clinical use. Here, we have isolated unique mitochondrial redox control properties of metformin that are likely to account for this difference. In primary hepatocytes and H4IIE hepatoma cells we found that antihyperglycaemic diguanides DG5-DG10 and the biguanide phenformin were up to 1000-fold more potent than metformin on cell signalling responses, gluconeogenic promoter expression and hepatocyte glucose production. Each drug inhibited cellular oxygen consumption similarly but there were marked differences in other respects. All diguanides and phenformin but not metformin inhibited NADH oxidation in submitochondrial particles, indicative of complex I inhibition, which also corresponded closely with dehydrogenase activity in living cells measured by WST-1. Consistent with these findings, in isolated mitochondria, DG8 but not metformin caused the NADH/NAD+ couple to become more reduced over time and mitochondrial deterioration ensued, suggesting direct inhibition of complex I and mitochondrial toxicity of DG8. In contrast, metformin exerted a selective oxidation of the mitochondrial NADH/NAD+ couple, without triggering mitochondrial deterioration. Together, our results suggest that metformin suppresses energy transduction by selectively inducing a state in complex I where redox and proton transfer domains are no longer efficiently coupled. Keywords: Diabetes, Metformin, Mitochondria, NADH, NAD+

  16. Phosphoproteomics-based systems analysis of signal transduction networks

    Directory of Open Access Journals (Sweden)

    Hiroko eKozuka-Hata

    2012-01-01

    Full Text Available Signal transduction systems coordinate complex cellular information to regulate biological events such as cell proliferation and differentiation. Although the accumulating evidence on widespread association of signaling molecules has revealed essential contribution of phosphorylation-dependent interaction networks to cellular regulation, their dynamic behavior is mostly yet to be analyzed. Recent technological advances regarding mass spectrometry-based quantitative proteomics have enabled us to describe the comprehensive status of phosphorylated molecules in a time-resolved manner. Computational analyses based on the phosphoproteome dynamics accelerate generation of novel methodologies for mathematical analysis of cellular signaling. Phosphoproteomics-based numerical modeling can be used to evaluate regulatory network elements from a statistical point of view. Integration with transcriptome dynamics also uncovers regulatory hubs at the transcriptional level. These omics-based computational methodologies, which have firstly been applied to representative signaling systems such as the epidermal growth factor receptor pathway, have now opened up a gate for systems analysis of signaling networks involved in immune response and cancer.

  17. Signal transduction around thymic stromal lymphopoietin (TSLP in atopic asthma

    Directory of Open Access Journals (Sweden)

    Kuepper Michael

    2008-08-01

    Full Text Available Abstract Thymic stromal lymphopoietin (TSLP, a novel interleukin-7-like cytokine, triggers dendritic cell-mediated inflammatory responses ultimately executed by T helper cells of the Th2 subtype. TSLP emerged as a central player in the development of allergic symptoms, especially in the airways, and is a prime regulatory cytokine at the interface of virus- or antigen-exposed epithelial cells and dendritic cells (DCs. DCs activated by epithelium-derived TSLP can promote naïve CD4+ T cells to adopt a Th2 phenotype, which in turn recruite eosinophilic and basophilic granulocytes as well as mast cells into the airway mucosa. These different cells secrete inflammatory cytokines and chemokines operative in inducing an allergic inflammation and atopic asthma. TSLP is, thus, involved in the control of both an innate and an adaptive immune response. Since TSLP links contact of allergen with the airway epithelium to the onset and maintainance of the asthmatic syndrome, defining the signal transduction underlying TSLP expression and function is of profound interest for a better understandimg of the disease and for the development of new therapeutics.

  18. Defect in radiation signal transduction in ataxia-telangiectasia

    International Nuclear Information System (INIS)

    Lavin, M.F.

    1994-01-01

    Exposure of mammalian cells to ionizing radiation causes a delay in progression through the cycle at several checkpoints. Cells from patients with ataxia-telangiectasia (A-T) ignore these checkpoint controls postirradiation. The tumour suppressor gene product p53 plays a key role at the G 1 /S checkpoint preventing the progression of cells into S phase. The induction of p53 by radiation is reduced and/or delayed in A-T cells, which appears to account for the failure of delay at the G 1 /S checkpoint. We have investigated further this defect in radiation signal transduction in A-T. While the p53 response was defective after radiation, agents that interfered with cell cycle progression such as mimosine, aphidicolin and deprivation of serum led to a normal p53 response in A-T cells. None of these agents caused breaks in DNA, as determined by pulse-field gel electrophoresis, in order to elicit the response. Since this pathway is mediated by protein kinases, we investigated the activity of several of these enzymes in control and A-T cells. Ca +2 -dependent and -independent protein kinase C activities were increased by radiation to the same extent in the two cell types, a variety of serine/threonine protein kinase activities were approximately the same and anti-tyrosine antibodies failed to reveal any differences in protein phosphorylation between A-T and control cells. (author)

  19. Load-induced modulation of signal transduction networks.

    Science.gov (United States)

    Jiang, Peng; Ventura, Alejandra C; Sontag, Eduardo D; Merajver, Sofia D; Ninfa, Alexander J; Del Vecchio, Domitilla

    2011-10-11

    Biological signal transduction networks are commonly viewed as circuits that pass along information--in the process amplifying signals, enhancing sensitivity, or performing other signal-processing tasks--to transcriptional and other components. Here, we report on a "reverse-causality" phenomenon, which we call load-induced modulation. Through a combination of analytical and experimental tools, we discovered that signaling was modulated, in a surprising way, by downstream targets that receive the signal and, in doing so, apply what in physics is called a load. Specifically, we found that non-intuitive changes in response dynamics occurred for a covalent modification cycle when load was present. Loading altered the response time of a system, depending on whether the activity of one of the enzymes was maximal and the other was operating at its minimal rate or whether both enzymes were operating at submaximal rates. These two conditions, which we call "limit regime" and "intermediate regime," were associated with increased or decreased response times, respectively. The bandwidth, the range of frequency in which the system can process information, decreased in the presence of load, suggesting that downstream targets participate in establishing a balance between noise-filtering capabilities and a circuit's ability to process high-frequency stimulation. Nodes in a signaling network are not independent relay devices, but rather are modulated by their downstream targets.

  20. Disruption of Microtubules Post-Virus Entry Enhances Adeno-Associated Virus Vector Transduction

    Science.gov (United States)

    Xiao, Ping-Jie; Mitchell, Angela M.; Huang, Lu; Li, Chengwen; Samulski, R. Jude

    2016-01-01

    Perinuclear retention of viral particles is a poorly understood phenomenon observed during many virus infections. In this study, we investigated whether perinuclear accumulation acts as a barrier to limit recombinant adeno-associated virus (rAAV) transduction. After nocodazole treatment to disrupt microtubules at microtubule-organization center (MT-MTOC) after virus entry, we observed higher rAAV transduction. To elucidate the role of MT-MTOC in rAAV infection and study its underlying mechanisms, we demonstrated that rAAV's perinuclear localization was retained by MT-MTOC with fluorescent analysis, and enhanced rAAV transduction from MT-MTOC disruption was dependent on the rAAV capsid's nuclear import signals. Interestingly, after knocking down RhoA or inhibiting its downstream effectors (ROCK and Actin), MT-MTOC disruption failed to increase rAAV transduction or nuclear entry. These data suggest that enhancement of rAAV transduction is the result of increased trafficking to the nucleus via the RhoA-ROCK-Actin pathway. Ten-fold higher rAAV transduction was also observed by disrupting MT-MTOC in brain, liver, and tumor in vivo. In summary, this study indicates that virus perinuclear accumulation at MT-MTOC is a barrier-limiting parameter for effective rAAV transduction and defines a novel defense mechanism by which host cells restrain viral invasion. PMID:26942476

  1. Microfluidic Transduction Harnesses Mass Transport Principles to Enhance Gene Transfer Efficiency.

    Science.gov (United States)

    Tran, Reginald; Myers, David R; Denning, Gabriela; Shields, Jordan E; Lytle, Allison M; Alrowais, Hommood; Qiu, Yongzhi; Sakurai, Yumiko; Li, William C; Brand, Oliver; Le Doux, Joseph M; Spencer, H Trent; Doering, Christopher B; Lam, Wilbur A

    2017-10-04

    Ex vivo gene therapy using lentiviral vectors (LVs) is a proven approach to treat and potentially cure many hematologic disorders and malignancies but remains stymied by cumbersome, cost-prohibitive, and scale-limited production processes that cannot meet the demands of current clinical protocols for widespread clinical utilization. However, limitations in LV manufacture coupled with inefficient transduction protocols requiring significant excess amounts of vector currently limit widespread implementation. Herein, we describe a microfluidic, mass transport-based approach that overcomes the diffusion limitations of current transduction platforms to enhance LV gene transfer kinetics and efficiency. This novel ex vivo LV transduction platform is flexible in design, easy to use, scalable, and compatible with standard cell transduction reagents and LV preparations. Using hematopoietic cell lines, primary human T cells, primary hematopoietic stem and progenitor cells (HSPCs) of both murine (Sca-1 + ) and human (CD34 + ) origin, microfluidic transduction using clinically processed LVs occurs up to 5-fold faster and requires as little as one-twentieth of LV. As an in vivo validation of the microfluidic-based transduction technology, HSPC gene therapy was performed in hemophilia A mice using limiting amounts of LV. Compared to the standard static well-based transduction protocols, only animals transplanted with microfluidic-transduced cells displayed clotting levels restored to normal. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Diversity-oriented peptide stapling

    DEFF Research Database (Denmark)

    Tran, Thu Phuong; Larsen, Christian Ørnbøl; Røndbjerg, Tobias

    2017-01-01

    as a powerful method for peptide stapling. However, to date CuAAC stapling has not provided a simple method for obtaining peptides that are easily diversified further. In the present study, we report a new diversity-oriented peptide stapling (DOPS) methodology based on CuAAC chemistry. Stapling of peptides...

  3. PNA Peptide chimerae

    DEFF Research Database (Denmark)

    Koch, T.; Næsby, M.; Wittung, P.

    1995-01-01

    Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields....

  4. Origin of anti-tumor activity of the cysteine-containing GO peptides and further optimization of their cytotoxic properties

    Science.gov (United States)

    Tyuryaeva, Irina I.; Lyublinskaya, Olga G.; Podkorytov, Ivan S.; Skrynnikov, Nikolai R.

    2017-01-01

    Antitumor GO peptides have been designed as dimerization inhibitors of prominent oncoprotein mucin 1. In this study we demonstrate that activity of GO peptides is independent of the level of cellular expression of mucin 1. Furthermore, these peptides prove to be broadly cytotoxic, causing cell death also in normal cells such as dermal fibroblasts and endometrial mesenchymal stem cells. To explore molecular mechanism of their cytotoxicity, we have designed and tested a number of new peptide sequences containing the key CxC or CxxC motifs. Of note, these sequences bear no similarity to mucin 1 except that they also contain a pair of proximal cysteines. Several of the new peptides turned out to be significantly more potent than their GO prototypes. The results suggest that cytotoxicity of these peptides stems from their (moderate) activity as disulfide oxidoreductases. It is expected that such peptides, which we have termed DO peptides, are involved in disulfide-dithiol exchange reaction, resulting in formation of adventitious disulfide bridges in cell proteins. In turn, this leads to a partial loss of protein function and rapid onset of apoptosis. We anticipate that coupling DO sequences with tumor-homing transduction domains can create a potentially valuable new class of tumoricidal peptides.

  5. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    Tambet eTeesalu

    2013-08-01

    Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular zip code of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

  6. Graph Regularized Meta-path Based Transductive Regression in Heterogeneous Information Network.

    Science.gov (United States)

    Wan, Mengting; Ouyang, Yunbo; Kaplan, Lance; Han, Jiawei

    2015-01-01

    A number of real-world networks are heterogeneous information networks, which are composed of different types of nodes and links. Numerical prediction in heterogeneous information networks is a challenging but significant area because network based information for unlabeled objects is usually limited to make precise estimations. In this paper, we consider a graph regularized meta-path based transductive regression model ( Grempt ), which combines the principal philosophies of typical graph-based transductive classification methods and transductive regression models designed for homogeneous networks. The computation of our method is time and space efficient and the precision of our model can be verified by numerical experiments.

  7. Peptide aldehyde inhibitors of bacterial peptide deformylases.

    Science.gov (United States)

    Durand, D J; Gordon Green, B; O'Connell, J F; Grant, S K

    1999-07-15

    Bacterial peptide deformylases (PDF, EC 3.5.1.27) are metalloenzymes that cleave the N-formyl groups from N-blocked methionine polypeptides. Peptide aldehydes containing a methional or norleucinal inhibited recombinant peptide deformylase from gram-negative Escherichia coli and gram-positive Bacillus subtilis. The most potent inhibitor was calpeptin, N-CBZ-Leu-norleucinal, which was a competitive inhibitor of the zinc-containing metalloenzymes, E. coli and B. subtilis PDF with Ki values of 26.0 and 55.6 microM, respectively. Cobalt-substituted E. coli and B. subtilis deformylases were also inhibited by these aldehydes with Ki values for calpeptin of 9.5 and 12.4 microM, respectively. Distinct spectral changes were observed upon binding of calpeptin to the Co(II)-deformylases, consistent with the noncovalent binding of the inhibitor rather than the formation of a covalent complex. In contrast, the chelator 1,10-phenanthroline caused the time-dependent inhibition of B. subtilis Co(II)-PDF activity with the loss of the active site metal. The fact that calpeptin was nearly equipotent against deformylases from both gram-negative and gram-positive bacterial sources lends further support to the idea that a single deformylase inhibitor might have broad-spectrum antibacterial activity. Copyright 1999 Academic Press.

  8. Signal transduction through the IL-4 and insulin receptor families.

    Science.gov (United States)

    Wang, L M; Keegan, A; Frankel, M; Paul, W E; Pierce, J H

    1995-07-01

    Activation of tyrosine kinase-containing receptors and intracellular tyrosine kinases by ligand stimulation is known to be crucial for mediating initial and subsequent events involved in mitogenic signal transduction. Receptors for insulin and insulin-like growth factor 1 (IGF-1) contain cytoplasmic tyrosine kinase domains that undergo autophosphorylation upon ligand stimulation. Activation of these receptors also leads to pronounced and rapid tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1) in cells of connective tissue origin. A related substrate, designated 4PS, is similarly phosphorylated by insulin and IGF-1 stimulation in many hematopoietic cell types. IRS-1 and 4PS possess a number of tyrosine phosphorylation sites that are within motifs that bind specific SH2-containing molecules known to be involved in mitogenic signaling such as PI-3 kinase, SHPTP-2 (Syp) and Grb-2. Thus, they appear to act as docking substrates for a variety of signaling molecules. The majority of hematopoietic cytokines bind to receptors that do not possess intrinsic kinase activity, and these receptors have been collectively termed as members of the hematopoietin receptor superfamily. Despite their lack of tyrosine kinase domains, stimulation of these receptors has been demonstrated to activate intracellular kinases leading to tyrosine phosphorylation of multiple substrates. Recent evidence has demonstrated that activation of different members of the Janus family of tyrosine kinases is involved in mediating tyrosine phosphorylation events by specific cytokines. Stimulation of the interleukin 4 (IL-4) receptor, a member of the hematopoietin receptor superfamily, is thought to result in activation of Jak1, Jak3, and/or Fes tyrosine kinases.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Computational study of noise in a large signal transduction network

    Directory of Open Access Journals (Sweden)

    Ruohonen Keijo

    2011-06-01

    Full Text Available Abstract Background Biochemical systems are inherently noisy due to the discrete reaction events that occur in a random manner. Although noise is often perceived as a disturbing factor, the system might actually benefit from it. In order to understand the role of noise better, its quality must be studied in a quantitative manner. Computational analysis and modeling play an essential role in this demanding endeavor. Results We implemented a large nonlinear signal transduction network combining protein kinase C, mitogen-activated protein kinase, phospholipase A2, and β isoform of phospholipase C networks. We simulated the network in 300 different cellular volumes using the exact Gillespie stochastic simulation algorithm and analyzed the results in both the time and frequency domain. In order to perform simulations in a reasonable time, we used modern parallel computing techniques. The analysis revealed that time and frequency domain characteristics depend on the system volume. The simulation results also indicated that there are several kinds of noise processes in the network, all of them representing different kinds of low-frequency fluctuations. In the simulations, the power of noise decreased on all frequencies when the system volume was increased. Conclusions We concluded that basic frequency domain techniques can be applied to the analysis of simulation results produced by the Gillespie stochastic simulation algorithm. This approach is suited not only to the study of fluctuations but also to the study of pure noise processes. Noise seems to have an important role in biochemical systems and its properties can be numerically studied by simulating the reacting system in different cellular volumes. Parallel computing techniques make it possible to run massive simulations in hundreds of volumes and, as a result, accurate statistics can be obtained from computational studies.

  10. Transduction-like gene transfer in the methanogen Methanococcus voltae

    Science.gov (United States)

    Bertani, G.

    1999-01-01

    Strain PS of Methanococcus voltae (a methanogenic, anaerobic archaebacterium) was shown to generate spontaneously 4.4-kbp chromosomal DNA fragments that are fully protected from DNase and that, upon contact with a cell, transform it genetically. This activity, here called VTA (voltae transfer agent), affects all markers tested: three different auxotrophies (histidine, purine, and cobalamin) and resistance to BES (2-bromoethanesulfonate, an inhibitor of methanogenesis). VTA was most effectively prepared by culture filtration. This process disrupted a fraction of the M. voltae cells (which have only an S-layer covering their cytoplasmic membrane). VTA was rapidly inactivated upon storage. VTA particles were present in cultures at concentrations of approximately two per cell. Gene transfer activity varied from a minimum of 2 x 10(-5) (BES resistance) to a maximum of 10(-3) (histidine independence) per donor cell. Very little VTA was found free in culture supernatants. The phenomenon is functionally similar to generalized transduction, but there is no evidence, for the time being, of intrinsically viral (i.e., containing a complete viral genome) particles. Consideration of VTA DNA size makes the existence of such viral particles unlikely. If they exist, they must be relatively few in number;perhaps they differ from VTA particles in size and other properties and thus escaped detection. Digestion of VTA DNA with the AluI restriction enzyme suggests that it is a random sample of the bacterial DNA, except for a 0.9-kbp sequence which is amplified relative to the rest of the bacterial chromosome. A VTA-sized DNA fraction was demonstrated in a few other isolates of M. voltae.

  11. Transduction on Directed Graphs via Absorbing Random Walks.

    Science.gov (United States)

    De, Jaydeep; Zhang, Xiaowei; Lin, Feng; Cheng, Li

    2017-08-11

    In this paper we consider the problem of graph-based transductive classification, and we are particularly interested in the directed graph scenario which is a natural form for many real world applications.Different from existing research efforts that either only deal with undirected graphs or circumvent directionality by means of symmetrization, we propose a novel random walk approach on directed graphs using absorbing Markov chains, which can be regarded as maximizing the accumulated expected number of visits from the unlabeled transient states. Our algorithm is simple, easy to implement, and works with large-scale graphs on binary, multiclass, and multi-label prediction problems. Moreover, it is capable of preserving the graph structure even when the input graph is sparse and changes over time, as well as retaining weak signals presented in the directed edges. We present its intimate connections to a number of existing methods, including graph kernels, graph Laplacian based methods, and interestingly, spanning forest of graphs. Its computational complexity and the generalization error are also studied. Empirically our algorithm is systematically evaluated on a wide range of applications, where it has shown to perform competitively comparing to a suite of state-of-the-art methods. In particular, our algorithm is shown to work exceptionally well with large sparse directed graphs with e.g. millions of nodes and tens of millions of edges, where it significantly outperforms other state-of-the-art methods. In the dynamic graph setting involving insertion or deletion of nodes and edge-weight changes over time, it also allows efficient online updates that produce the same results as of the batch update counterparts.

  12. Radiation-induced adaptive response and intracellular signal transduction pathways

    International Nuclear Information System (INIS)

    Tachibana, Akira

    2009-01-01

    As an essential biological function, cells can sense the radiation even at low dose and respond to it, and which is one of bases of the radiation-induced adaptive response (AR) where effects caused by high dose radiation are reduced by prior exposure to low dose radiation (LDR). Here described are studies of AR in well established m5S cells on the intracellular signal transduction that involves sensing of LDR and transmitting of its signal within the cell network. The first signal for AR yielded by LDR on the cell membrane is exactly unknown though hydrogen peroxide and phorbol ester (PMA) can reportedly cause AR. As PMA activates protein kinase C (PKC) and its inhibitors suppress AR, participation of PKC in AR has been suggested and supported by studies showing PKCα activation by LDR. In addition, p38 mitogen-activated protein kinase (MAPK) is shown to participate in AR by those facts that the enzyme is activated by LDR, a p38 MAPK inhibitor suppresses AR, and PKC inhibitors suppress the enzyme activation, which also suggesting that the signaling from PKC to p38 MAPK can become operative by LDR. However, the possible reverse signaling is also suggested, and thus the activation of positive feedback mechanism is postulated in PKC/p38 MAPK/phospholipase δ1/ PKC pathway. Cells introduced with siRNA against Prkca gene (coding PKCs) produce reduced amount of the enzyme, particularly, of PKCα. In those cells, AR by 5 Gy X-ray is not observed and thereby PKCα is involved in AR. The signaling in AR is only partly elucidated at present as above, and more detailed studies including identification of more PKC subtypes and signaling to DNA repair system are considered necessary. (K.T.)

  13. Second-chance signal transduction explains cooperative flagellar switching.

    Science.gov (United States)

    Zot, Henry G; Hasbun, Javier E; Minh, Nguyen Van

    2012-01-01

    The reversal of flagellar motion (switching) results from the interaction between a switch complex of the flagellar rotor and a torque-generating stationary unit, or stator (motor unit). To explain the steeply cooperative ligand-induced switching, present models propose allosteric interactions between subunits of the rotor, but do not address the possibility of a reaction that stimulates a bidirectional motor unit to reverse direction of torque. During flagellar motion, the binding of a ligand-bound switch complex at the dwell site could excite a motor unit. The probability that another switch complex of the rotor, moving according to steady-state rotation, will reach the same dwell site before that motor unit returns to ground state will be determined by the independent decay rate of the excited-state motor unit. Here, we derive an analytical expression for the energy coupling between a switch complex and a motor unit of the stator complex of a flagellum, and demonstrate that this model accounts for the cooperative switching response without the need for allosteric interactions. The analytical result can be reproduced by simulation when (1) the motion of the rotor delivers a subsequent ligand-bound switch to the excited motor unit, thereby providing the excited motor unit with a second chance to remain excited, and (2) the outputs from multiple independent motor units are constrained to a single all-or-none event. In this proposed model, a motor unit and switch complex represent the components of a mathematically defined signal transduction mechanism in which energy coupling is driven by steady-state and is regulated by stochastic ligand binding. Mathematical derivation of the model shows the analytical function to be a general form of the Hill equation (Hill AV (1910) The possible effects of the aggregation of the molecules of haemoglobin on its dissociation curves. J Physiol 40: iv-vii).

  14. Lipid rafts are required for signal transduction by angiotensin II receptor type 1 in neonatal glomerular mesangial cells

    Energy Technology Data Exchange (ETDEWEB)

    Adebiyi, Adebowale, E-mail: aadebiyi@uthsc.edu; Soni, Hitesh; John, Theresa A.; Yang, Fen

    2014-05-15

    Angiotensin II (ANG-II) receptors (AGTRs) contribute to renal physiology and pathophysiology, but the underlying mechanisms that regulate AGTR function in glomerular mesangium are poorly understood. Here, we show that AGTR1 is the functional AGTR subtype expressed in neonatal pig glomerular mesangial cells (GMCs). Cyclodextrin (CDX)-mediated cholesterol depletion attenuated cell surface AGTR1 protein expression and ANG-II-induced intracellular Ca{sup 2+} ([Ca{sup 2+}]{sub i}) elevation in the cells. The COOH-terminus of porcine AGTR1 contains a caveolin (CAV)-binding motif. However, neonatal GMCs express CAV-1, but not CAV-2 and CAV-3. Colocalization and in situ proximity ligation assay detected an association between endogenous AGTR1 and CAV-1 in the cells. A synthetic peptide corresponding to the CAV-1 scaffolding domain (CSD) sequence also reduced ANG-II-induced [Ca{sup 2+}]{sub i} elevation in the cells. Real-time imaging of cell growth revealed that ANG-II stimulates neonatal GMC proliferation. ANG-II-induced GMC growth was attenuated by EMD 66684, an AGTR1 antagonist; BAPTA, a [Ca{sup 2+}]{sub i} chelator; KN-93, a Ca{sup 2+}/calmodulin-dependent protein kinase II inhibitor; CDX; and a CSD peptide, but not PD 123319, a selective AGTR2 antagonist. Collectively, our data demonstrate [Ca{sup 2+}]{sub i}-dependent proliferative effect of ANG-II and highlight a critical role for lipid raft microdomains in AGTR1-mediated signal transduction in neonatal GMCs. - Highlights: • AGTR1 is the functional AGTR subtype expressed in neonatal mesangial cells. • Endogenous AGTR1 associates with CAV-1 in neonatal mesangial cells. • Lipid raft disruption attenuates cell surface AGTR1 protein expression. • Lipid raft disruption reduces ANG-II-induced [Ca{sup 2+}]{sub i} elevation in neonatal mesangial cells. • Lipid raft disruption inhibits ANG-II-induced neonatal mesangial cell growth.

  15. Lactoferricin B-derived peptides with inhibitory effects on ECE-dependent vasoconstriction.

    Science.gov (United States)

    Fernández-Musoles, Ricardo; López-Díez, José Javier; Torregrosa, Germán; Vallés, Salvador; Alborch, Enrique; Manzanares, Paloma; Salom, Juan B

    2010-10-01

    Endothelin-converting enzyme (ECE), a key peptidase in the endothelin (ET) system, cleaves inactive big ET-1 to produce active ET-1, which binds to ET(A) receptors to exert its vasoconstrictor and pressor effects. ECE inhibition could be beneficial in the treatment of hypertension. In this study, a set of eight lactoferricin B (LfcinB)-derived peptides, previously characterized in our laboratory as angiotensin-converting enzyme (ACE) inhibitory peptides, was examined for their inhibitory effects on ECE. In vitro inhibitory effects on ECE activity were assessed using both the synthetic fluorogenic peptide substrate V (FPS V) and the natural substrate big ET-1. To study vasoactive effects, an ex vivo functional assay was developed using isolated rabbit carotid artery segments. With FPS V, only four LfcinB-derived peptides induced inhibition of ECE activity, whereas the eight peptides showed ECE inhibitory effects with big ET-1 as substrate. Regarding the ex vivo assays, six LfcinB-derived peptides showed inhibition of big ET-1-induced, ECE-dependent vasoconstriction. A positive correlation between the inhibitory effects of LfcinB-derived peptides on ECE activity when using big ET-1 and the inhibitory effects on ECE-dependent vasoconstriction was shown. ECE-independent vasoconstriction induced by ET-1 was not affected, thus discarding effects of LfcinB-derived peptides on ET(A) receptors or intracellular signal transduction mechanisms. In conclusion, a combined in vitro and ex vivo method to assess the effects of potentially antihypertensive peptides on the ET system has been developed and applied to show the inhibitory effects on ECE-dependent vasoconstriction of six LfcinB-derived peptides, five of which were dual vasopeptidase (ACE/ECE) inhibitors. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Theilade, M D; Gram, G J; Jensen, P B

    1999-01-01

    Multidrug resistance (MDR) remains a major problem in the successful treatment of small cell lung cancer (SCLC). New treatment strategies are needed, such as gene therapy specifically targeting the MDR cells in the tumor. Retroviral LacZ gene-containing vectors that were either pseudotyped...... for the gibbon ape leukemia virus (GALV-1) receptor or had specificity for the amphotropic murine leukemia virus (MLV-A) receptor were used for transduction of five SCLC cell lines differing by a range of MDR mechanisms. Transduction efficiencies in these cell lines were compared by calculating the percentage...... of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

  17. Efficient, Broadband and Wide-Angle Hot-Electron Transduction using Metal-Semiconductor Hyperbolic Metamaterials

    KAUST Repository

    Sakhdari, Maryam; Hajizadegan, Mehdi; Farhat, Mohamed; Chen, Pai-Yen

    2016-01-01

    Hot-electron devices are emerging as promising candidates for the transduction of optical radiation into electrical current, as they enable photodetection and solar/infrared energy harvesting at sub-bandgap wavelengths. Nevertheless, poor

  18. [Cellular adhesion signal transduction network of tumor necrosis factor-alpha induced hepatocellular carcinoma cells].

    Science.gov (United States)

    Zheng, Yongchang; Du, Shunda; Xu, Haifeng; Xu, Yiyao; Zhao, Haitao; Chi, Tianyi; Lu, Xin; Sang, Xinting; Mao, Yilei

    2014-11-18

    To systemically explore the cellular adhesion signal transduction network of tumor necrosis factor-alpha (TNF-α)-induced hepatocellular carcinoma cells with bioinformatics tools. Published microarray dataset of TNF-α-induced HepG2, human transcription factor database HTRI and human protein-protein interaction database HPRD were used to construct and analyze the signal transduction network. In the signal transduction network, MYC and SP1 were the key nodes of signaling transduction. Several genes from the network were closely related with cellular adhesion.Epidermal growth factor receptor (EGFR) is a possible key gene of effectively regulating cellular adhesion during the induction of TNF-α. EGFR is a possible key gene for TNF-α-induced metastasis of hepatocellular carcinoma.

  19. Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

    Science.gov (United States)

    Saher, G; Hildt, E

    1999-09-24

    Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

  20. Cavity opto-electromechanical system combining strong electrical actuation with ultrasensitive transduction

    OpenAIRE

    McRae, Terry G.; Lee, Kwan H.; Harris, Glen I.; Knittel, Joachim; Bowen, Warwick P.

    2010-01-01

    A cavity opto-electromechanical system is reported which combines the ultrasensitive transduction of cavity optomechanical systems with the electrical actuation of nanoelectromechanical systems. Ultrasensitive mechanical transduction is achieved via opto-mechanical coupling. Electrical gradient forces as large as 0.40 $\\mu$N are realized, facilitating strong actuation with ultralow dissipation. A scanning probe microscope is implemented, capable of characterizing the mechanical modes. The int...

  1. Polyploidization without mitosis improves in vivo liver transduction with lentiviral vectors.

    Science.gov (United States)

    Pichard, Virginie; Couton, Dominique; Desdouets, Chantal; Ferry, Nicolas

    2013-02-01

    Lentiviral vectors are efficient gene delivery vehicles for therapeutic and research applications. In contrast to oncoretroviral vectors, they are able to infect most nonproliferating cells. In the liver, induction of cell proliferation dramatically improved hepatocyte transduction using all types of retroviral vectors. However, the precise relationship between hepatocyte division and transduction efficiency has not been determined yet. Here we compared gene transfer efficiency in the liver after in vivo injection of recombinant lentiviral or Moloney murine leukemia viral (MoMuLV) vectors in hepatectomized rats treated or not with retrorsine, an alkaloid that blocks hepatocyte division and induces megalocytosis. Partial hepatectomy alone resulted in a similar increase in hepatocyte transduction using either vector. In retrorsine-treated and partially hepatectomized rats, transduction with MoMuLV vectors dropped dramatically. In contrast, we observed that retrorsine treatment combined with partial hepatectomy increased lentiviral transduction to higher levels than hepatectomy alone. Analysis of nuclear ploidy in single cells showed that a high level of transduction was associated with polyploidization. In conclusion, endoreplication could be exploited to improve the efficiency of liver-directed lentiviral gene therapy.

  2. Evidence that membrane transduction of oligoarginine does not require vesicle formation

    International Nuclear Information System (INIS)

    Zaro, Jennica L.; Shen Weichiang

    2005-01-01

    The involvement of vesicular formation processes in the membrane transduction and nuclear transport of oligoarginine is currently a subject of controversy. In this report, a novel quantitative method which allows for the selective measurement of membrane transduction excluding concurrent endocytosis was used to determine the effects of temperature, endosomal acidification, endosomolysis, and several known inhibitors of endocytic pathways on the internalization of oligoarginine. The results show that, unlike endocytosis, transduction of oligoarginine was not affected by incubation at 16 deg. C as compared to the 37 deg. C control, and was only partially inhibited at 4 deg. C incubation. Additionally, membrane transduction was not inhibited to the same extent as endocytosis following treatment with ammonium chloride, hypertonic medium, amiloride, or filipin. The endosomolytic activity of oligoarginine was investigated by examining the leakage of FITC-dextran into the cytosolic compartment, which was not higher in the presence of oligoarginine. Furthermore, ammonium chloride showed no effect on the nuclear transport of oligoarginine. The data presented in this report indicate that membrane transduction is likely to occur at the plasma membrane without the formation of membrane vesicles, and the nuclear localization involves membrane transduction, rather than endocytosis of oligoarginine

  3. Peptide Integrated Optics.

    Science.gov (United States)

    Handelman, Amir; Lapshina, Nadezda; Apter, Boris; Rosenman, Gil

    2018-02-01

    Bio-nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light-guiding components. In this work, an advanced concept of integrated bio-optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding. Developed new technology combining bottom-up controlled deposition of peptide planar wafers of a large area and top-down focus ion beam lithography provides direct fabrication of peptide optical integrated circuits. Finding a deep modification of peptide optical properties by reconformation of biological secondary structure from native phase to β-sheet architecture is followed by the appearance of visible fluorescence and unexpected transition from a native passive optical waveguiding to an active one. Original biocompatibility, switchable regimes of waveguiding, and multifunctional nonlinear optical properties make these new peptide planar optical materials attractive for application in emerging technology of lab-on-biochips, combining biomedical photonic and electronic circuits toward medical diagnosis, light-activated therapy, and health monitoring. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    James P. Tam

    2015-11-01

    Full Text Available Plant antimicrobial peptides (AMPs have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic, lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms.

  5. Squalestatin alters the intracellular trafficking of a neurotoxic prion peptide

    Directory of Open Access Journals (Sweden)

    Williams Alun

    2007-11-01

    Full Text Available Abstract Background Neurotoxic peptides derived from the protease-resistant core of the prion protein are used to model the pathogenesis of prion diseases. The current study characterised the ingestion, internalization and intracellular trafficking of a neurotoxic peptide containing amino acids 105–132 of the murine prion protein (MoPrP105-132 in neuroblastoma cells and primary cortical neurons. Results Fluorescence microscopy and cell fractionation techniques showed that MoPrP105-132 co-localised with lipid raft markers (cholera toxin and caveolin-1 and trafficked intracellularly within lipid rafts. This trafficking followed a non-classical endosomal pathway delivering peptide to the Golgi and ER, avoiding classical endosomal trafficking via early endosomes to lysosomes. Fluorescence resonance energy transfer analysis demonstrated close interactions of MoPrP105-132 with cytoplasmic phospholipase A2 (cPLA2 and cyclo-oxygenase-1 (COX-1, enzymes implicated in the neurotoxicity of prions. Treatment with squalestatin reduced neuronal cholesterol levels and caused the redistribution of MoPrP105-132 out of lipid rafts. In squalestatin-treated cells, MoPrP105-132 was rerouted away from the Golgi/ER into degradative lysosomes. Squalestatin treatment also reduced the association between MoPrP105-132 and cPLA2/COX-1. Conclusion As the observed shift in peptide trafficking was accompanied by increased cell survival these studies suggest that the neurotoxicity of this PrP peptide is dependent on trafficking to specific organelles where it activates specific signal transduction pathways.

  6. Full Piezoelectric Multilayer-Stacked Hybrid Actuation/Transduction Systems

    Science.gov (United States)

    Su, Ji; Jiang, Xiaoning; Zu, Tian-Bing

    2011-01-01

    The Stacked HYBATS (Hybrid Actuation/Transduction system) demonstrates significantly enhanced electromechanical performance by using the cooperative contributions of the electromechanical responses of multilayer, stacked negative strain components and positive strain components. Both experimental and theoretical studies indicate that, for Stacked HYBATS, the displacement is over three times that of a same-sized conventional flextensional actuator/transducer. The coupled resonance mode between positive strain and negative strain components of Stacked HYBATS is much stronger than the resonance of a single element actuation only when the effective lengths of the two kinds of elements match each other. Compared with the previously invented hybrid actuation system (HYBAS), the multilayer Stacked HYBATS can be designed to provide high mechanical load capability, low voltage driving, and a highly effective piezoelectric constant. The negative strain component will contract, and the positive strain component will expand in the length directions when an electric field is applied on the device. The interaction between the two elements makes an enhanced motion along the Z direction for Stacked-HYBATS. In order to dominate the dynamic length of Stacked-HYBATS by the negative strain component, the area of the cross-section for the negative strain component will be much larger than the total cross-section areas of the two positive strain components. The transverse strain is negative and longitudinal strain positive in inorganic materials, such as ceramics/single crystals. Different piezoelectric multilayer stack configurations can make a piezoelectric ceramic/single-crystal multilayer stack exhibit negative strain or positive strain at a certain direction without increasing the applied voltage. The difference of this innovation from the HYBAS is that all the elements can be made from one-of-a-kind materials. Stacked HYBATS can provide an extremely effective piezoelectric

  7. The dynamic basis of energy transduction in enzymes.

    Science.gov (United States)

    Somogyi, B; Welch, G R; Damjanovich, S

    1984-09-06

    The most important idea underlying our treatment herein is the unity of the enzyme molecule and the medium. Appreciation of this relationship is vital, if enzymology is to graduate from its present reductionistic status to a more holistic posture. Enzymes are biological entities firstly, and isolated objects of physicochemical analysis secondly. Perhaps the most crucial 'biological lesson', particularly apropos of enzymes in intermediary metabolism, concerns the 'cytosociology' of enzyme action in vivo [94,128]. The natural habitat of many enzymes in the living cell is far different from that in bulk aqueous solution in vitro. In order to obtain a real grasp of the nature of enzyme function, one must ultimately couch enzymology in concepts emerging from contemporary cell biology [95]. Notwithstanding, analysis precedes synthesis; and one must needs begin with the individual enzyme molecule. The trenchant efforts of the physical chemist and the organic chemist have produced a wealth of information on the nature of the binding and catalytic events at the enzyme active site. While it is not yet possible to explain precisely the complete sequence of events in the catalytic process, nevertheless, the basic mechanisms by which enzymes effect catalysis (i.e., reduce activation energy) now seem apparent [81,129]. The new frontier is to be found, in exploring the dynamic role of the protein matrix [17]. Not only does the protein provide the 3-D scaffolding for active-site processes, but, more importantly, it serves as the local solvent for the bound chemical subsystem. Thus, the dynamical aspects of enzyme catalysis (for thermally based systems) must arise from the fluctuational properties of the protein molecule. This notion is the common denominator in all of the models in subsection IIC. It is the anisotropic nature of this fluctuational behavior, which would characterize the energy-transduction phenomenon leading to localized catalytic events at the active-site. In

  8. Signal transduction, receptors, mediators and genes: younger than ever - the 13th meeting of the Signal Transduction Society focused on aging and immunology

    Directory of Open Access Journals (Sweden)

    Klotz Lars-Oliver

    2010-02-01

    Full Text Available Abstract The 13th meeting of the Signal Transduction Society was held in Weimar, from October 28 to 30, 2009. Special focus of the 2009 conference was "Aging and Senescence", which was co-organized by the SFB 728 "Environmentally-Induced Aging Processes" of the University of Düsseldorf and the study group 'Signal Transduction' of the German Society for Cell Biology (DGZ. In addition, several other areas of signal transduction research were covered and supported by different consortia associated with the Signal Transduction Society including the long-term associated study groups of the German Society for Immunology and the Society for Biochemistry and Molecular Biology, and for instance the SFB/Transregio 52 "Transcriptional Programming of Individual T Cell Subsets" located in Würzburg, Mainz and Berlin. The different research areas that were introduced by outstanding keynote speakers attracted more than 250 scientists, showing the timeliness and relevance of the interdisciplinary concept and exchange of knowledge during the three days of the scientific program. This report gives an overview of the presentations of the conference.

  9. Acylation of Therapeutic Peptides

    DEFF Research Database (Denmark)

    Trier, Sofie; Henriksen, Jonas Rosager; Jensen, Simon Bjerregaard

    ) , which promotes intestinal growth and is used to treat bowel disorders such as inflammatory bowel diseases and short bowel syndrome, and the 32 amino acid salmon calcitonin (sCT), which lowers blood calcium and is employed in the treatment of post-menopausal osteoporosis and hypercalcemia. The two...... peptides are similar in size and structure, but oppositely charged at physiological pH. Both peptides were acylated with linear acyl chains of systematically increasing length, where sCT was furthermore acylated at two different positions on the peptide backbone. For GLP-2, we found that increasing acyl...... remained optimal overall. The results indicate that rational acylation of GLP-2 can increase its in vitro intestinal absorption, alone or in combination with permeation enhancers, and are consistent with the initial project hypothesis. For sCT, an unpredicted effect of acylation largely superseded...

  10. Integration tests of prototype LVL1 calorimeter trigger CP/JEP ROD and LVL2 trigger Region-of-Interest Builder. Also visible in the photo are two further racks containing the demonstrator prototypes of the LVL1 CTP and the MUCTPI.

    CERN Multimedia

    Gee, N

    2001-01-01

    Integration tests of prototype LVL1 calorimeter trigger CP/JEP ROD and LVL2 trigger Region-of-Interest Builder. Also visible in the photo are two further racks containing the demonstrator prototypes of the LVL1 CTP and the MUCTPI.

  11. How Y-Family DNA polymerase IV is more accurate than Dpo4 at dCTP insertion opposite an N2-dG adduct of benzo[a]pyrene.

    Science.gov (United States)

    Sholder, Gabriel; Creech, Amanda; Loechler, Edward L

    2015-11-01

    To bypass DNA damage, cells have Y-Family DNA polymerases (DNAPs). One Y-Family-class includes DNAP κ and DNAP IV, which accurately insert dCTP opposite N(2)-dG adducts, including from the carcinogen benzo[a]pyrene (BP). Another class includes DNAP η and DNAP V, which insert accurately opposite UV-damage, but inaccurately opposite BP-N(2)-dG. To investigate structural differences between Y-Family-classes, regions are swapped between DNAP IV (a κ/IV-class-member) and Dpo4 (a η/V-class-member); the kinetic consequences are evaluated via primer-extension studies with a BP-N(2)-dG-containing template. Four key structural elements are revealed. (1) Y-Family DNAPs have discreet non-covalent contacts between their little finger-domain (LF-Domain) and their catalytic core-domain (CC-Domain), which we call "non-covalent bridges" (NCBs). Arg37 and Arg38 in DNAP IV's CC-Domain near the active site form a non-covalent bridge (AS-NCB) by interacting with Glu251 and Asp252, respectively, in DNAP IV's LF-Domain. Without these interactions dATP/dGTP/dTTP misinsertions increase. DNAP IV's AS-NCB suppresses misinsertions better than Dpo4's equivalent AS-NCB. (2) DNAP IV also suppresses dATP/dGTP/dTTP misinsertions via a second non-covalent bridge, which is ∼8Å from the active site (Distal-NCB). Dpo4 has no Distal-NCB, rendering it inferior at dATP/dGTP/dTTP suppression. (3) dCTP insertion is facilitated by the larger minor groove opening near the active site in DNAP IV versus Dpo4, which is sensible given that Watson/Crick-like [dCTP:BP-N(2)-dG] pairing requires the BP-moiety to be in the minor groove. (4) Compared to Dpo4, DNAP IV has a smaller major groove opening, which suppresses dGTP misinsertion, implying BP-N(2)-dG bulk in the major groove during Hoogsteen syn-adduct-dG:dGTP pairing. In summary, DNAP IV has a large minor groove opening to enhance dCTP insertion, a plugged major groove opening to suppress dGTP misinsertion, and two non-covalent bridges (near and distal

  12. Inhibition of peptide aggregation by means of enzymatic phosphorylation

    Directory of Open Access Journals (Sweden)

    Kristin Folmert

    2016-11-01

    Full Text Available As is the case in numerous natural processes, enzymatic phosphorylation can be used in the laboratory to influence the conformational populations of proteins. In nature, this information is used for signal transduction or energy transfer, but has also been shown to play an important role in many diseases like tauopathies or diabetes. With the goal of determining the effect of phosphorylation on amyloid fibril formation, we designed a model peptide which combines structural characteristics of α-helical coiled-coils and β-sheets in one sequence. This peptide undergoes a conformational transition from soluble structures into insoluble amyloid fibrils over time and under physiological conditions and contains a recognition motif for PKA (cAMP-dependent protein kinase that enables enzymatic phosphorylation. We have analyzed the pathway of amyloid formation and the influence of enzymatic phosphorylation on the different states along the conformational transition from random-coil to β-sheet-rich oligomers to protofilaments and on to insoluble amyloid fibrils, and we found a remarkable directing effect from β-sheet-rich structures to unfolded structures in the initial growth phase, in which small oligomers and protofilaments prevail if the peptide is phosphorylated.

  13. Therapeutic HIV Peptide Vaccine

    DEFF Research Database (Denmark)

    Fomsgaard, Anders

    2015-01-01

    Therapeutic vaccines aim to control chronic HIV infection and eliminate the need for lifelong antiretroviral therapy (ART). Therapeutic HIV vaccine is being pursued as part of a functional cure for HIV/AIDS. We have outlined a basic protocol for inducing new T cell immunity during chronic HIV-1...... infection directed to subdominant conserved HIV-1 epitopes restricted to frequent HLA supertypes. The rationale for selecting HIV peptides and adjuvants are provided. Peptide subunit vaccines are regarded as safe due to the simplicity, quality, purity, and low toxicity. The caveat is reduced immunogenicity...

  14. Descriptors for antimicrobial peptides

    DEFF Research Database (Denmark)

    Jenssen, Håvard

    2011-01-01

    of these are currently being used in quantitative structure--activity relationship (QSAR) studies for AMP optimization. Additionally, some key commercial computational tools are discussed, and both successful and less successful studies are referenced, illustrating some of the challenges facing AMP scientists. Through...... examples of different peptide QSAR studies, this review highlights some of the missing links and illuminates some of the questions that would be interesting to challenge in a more systematic fashion. Expert opinion: Computer-aided peptide QSAR using molecular descriptors may provide the necessary edge...

  15. Single Amino Acid Modification of Adeno-Associated Virus Capsid Changes Transduction and Humoral Immune Profiles

    Science.gov (United States)

    Diprimio, Nina; Bowles, Dawn E.; Hirsch, Matthew L.; Monahan, Paul E.; Asokan, Aravind; Rabinowitz, Joseph; Agbandje-McKenna, Mavis

    2012-01-01

    Adeno-associated virus (AAV) vectors have the potential to promote long-term gene expression. Unfortunately, humoral immunity restricts patient treatment and in addition provides an obstacle to the potential option of vector readministration. In this study, we describe a comprehensive characterization of the neutralizing antibody (NAb) response to AAV type 1 (AAV1) through AAV5 both in vitro and in vivo. These results demonstrated that NAbs generated from one AAV type are unable to neutralize the transduction of other types. We extended this observation by demonstrating that a rationally engineered, muscle-tropic AAV2 mutant containing 5 amino acid substitutions from AAV1 displayed a NAb profile different from those of parental AAV2 and AAV1. Here we found that a single insertion of Thr from AAV1 into AAV2 capsid at residue 265 preserved high muscle transduction, while also changing the immune profile. To better understand the role of Thr insertion at position 265, we replaced all 20 amino acids and evaluated both muscle transduction and the NAb response. Of these variants, 8 mutants induced higher muscle transduction than AAV2. Additionally, three classes of capsid NAb immune profile were defined based on the ability to inhibit transduction from AAV2 or mutants. While no relationship was found between transduction, amino acid properties, and NAb titer or its cross-reactivity, these studies map a critical capsid motif involved in all steps of AAV infectivity. Our results suggest that AAV types can be utilized not only as templates to generate mutants with enhanced transduction efficiency but also as substrates for repeat administration. PMID:22593151

  16. Antimicrobial Peptides: An Introduction.

    Science.gov (United States)

    Haney, Evan F; Mansour, Sarah C; Hancock, Robert E W

    2017-01-01

    The "golden era" of antibiotic discovery has long passed, but the need for new antibiotics has never been greater due to the emerging threat of antibiotic resistance. This urgency to develop new antibiotics has motivated researchers to find new methods to combat pathogenic microorganisms resulting in a surge of research focused around antimicrobial peptides (AMPs; also termed host defense peptides) and their potential as therapeutics. During the past few decades, more than 2000 AMPs have been identified from a diverse range of organisms (animals, fungi, plants, and bacteria). While these AMPs share a number of common features and a limited number of structural motifs; their sequences, activities, and targets differ considerably. In addition to their antimicrobial effects, AMPs can also exhibit immunomodulatory, anti-biofilm, and anticancer activities. These diverse functions have spurred tremendous interest in research aimed at understanding the activity of AMPs, and various protocols have been described to assess different aspects of AMP function including screening and evaluating the activities of natural and synthetic AMPs, measuring interactions with membranes, optimizing peptide function, and scaling up peptide production. Here, we provide a general overview of AMPs and introduce some of the methodologies that have been used to advance AMP research.

  17. Genetic incorporation of the protein transduction domain of Tat into Ad5 fiber enhances gene transfer efficacy

    Directory of Open Access Journals (Sweden)

    Siegal Gene P

    2007-10-01

    Full Text Available Abstract Background Human adenovirus serotype 5 (Ad5 has been widely explored as a gene delivery vector for a variety of diseases. Many target cells, however, express low levels of Ad5 native receptor, the Coxsackie-Adenovirus Receptor (CAR, and thus are resistant to Ad5 infection. The Protein Transduction Domain of the HIV Tat protein, namely PTDtat, has been shown to mediate protein transduction in a wide range of cells. We hypothesize that re-targeting Ad5 vector via the PTDtat motif would improve the efficacy of Ad5-mediated gene delivery. Results In this study, we genetically incorporated the PTDtat motif into the knob domain of Ad5 fiber, and rescued the resultant viral vector, Ad5.PTDtat. Our data showed the modification did not interfere with Ad5 binding to its native receptor CAR, suggesting Ad5 infection via the CAR pathway is retained. In addition, we found that Ad5.PTDtat exhibited enhanced gene transfer efficacy in all of the cell lines that we have tested, which included both low-CAR and high-CAR decorated cells. Competitive inhibition assays suggested the enhanced infectivity of Ad5.PTDtat was mediated by binding of the positively charged PTDtat peptide to the negatively charged epitopes on the cells' surface. Furthermore, we investigated in vivo gene delivery efficacy of Ad5.PTDtat using subcutaneous tumor models established with U118MG glioma cells, and found that Ad5.PTDtat exhibited enhanced gene transfer efficacy compared to unmodified Ad5 vector as analyzed by a non-invasive fluorescence imaging technique. Conclusion Genetic incorporation of the PTDtat motif into Ad5 fiber allowed Ad5 vectors to infect cells via an alternative PTDtat targeting motif while retaining the native CAR-mediated infection pathway. The enhanced infectivity was demonstrated in both cultured cells and in in vivo tumor models. Taken together, our study identifies a novel tropism expanded Ad5 vector that may be useful for clinical gene therapy

  18. A peptide export-import control circuit modulating bacterial development regulates protein phosphatases of the phosphorelay.

    Science.gov (United States)

    Perego, M

    1997-08-05

    The phosphorelay signal transduction system activates developmental transcription in sporulation of Bacillus subtilis by phosphorylation of aspartyl residues of the Spo0F and Spo0A response regulators. The phosphorylation level of these response regulators is determined by the opposing activities of protein kinases and protein aspartate phosphatases that interpret positive and negative signals for development in a signal integration circuit. The RapA protein aspartate phosphatase of the phosphorelay is regulated by a peptide that directly inhibits its activity. This peptide is proteolytically processed from an inactive pre-inhibitor protein encoded in the phrA gene. The pre-inhibitor is cleaved by the protein export apparatus to a putative pro-inhibitor that is further processed to the active inhibitor peptide and internalized by the oligopeptide permease. This export-import circuit is postulated to be a mechanism for timing phosphatase activity where the processing enzymes regulate the rate of formation of the active inhibitor. The processing events may, in turn, be controlled by a regulatory hierarchy. Chromosome sequencing has revealed several other phosphatase-prepeptide gene pairs in B. subtilis, suggesting that the use of this mechanism may be widespread in signal transduction.

  19. MRP-1/CD9 gene transduction regulates the actin cytoskeleton through the downregulation of WAVE2.

    Science.gov (United States)

    Huang, C-L; Ueno, M; Liu, D; Masuya, D; Nakano, J; Yokomise, H; Nakagawa, T; Miyake, M

    2006-10-19

    Motility-related protein-1 (MRP-1/CD9) is involved in cell motility. We studied the change in the actin cytoskeleton, and the expression of actin-related protein (Arp) 2 and Arp3 and the Wiskott-Aldrich syndrome protein (WASP) family according to MRP-1/CD9 gene transduction into HT1080 cells. The frequency of cells with lamellipodia was significantly lower in MRP-1/CD9-transfected HT1080 cells than in control HT1080 cells (PMRP-1/CD9 gene transduction affected the subcellular localization of Arp2 and Arp3 proteins. Furthermore, MRP-1/CD9 gene transduction induced a downregulation of WAVE2 expression (PMRP-1/CD9 monoclonal antibody inhibited downregulation of WAVE2 in MRP-1/CD9-transfected HT1080 cells (PMRP-1/CD9 gene transduction. Furthermore, downregulation of WAVE2 by transfection of WAVE2-specific small interfering RNA (siRNA) mimicked the morphological effects of MRP-1/CD9 gene transduction and suppressed cell motility. However, transfection of each siRNA for Wnt1, Wnt2b1 or Wnt5a did not affect WAVE2 expression. Transfection of WAVE2-specific siRNA also did not affect expressions of these Wnts. These results indicate that MRP-1/CD9 regulates the actin cytoskeleton by downregulating of the WAVE2, through the Wnt-independent signal pathway.

  20. Discovery of intramolecular signal transduction network based on a new protein dynamics model of energy dissipation.

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Ma

    Full Text Available A novel approach to reveal intramolecular signal transduction network is proposed in this work. To this end, a new algorithm of network construction is developed, which is based on a new protein dynamics model of energy dissipation. A key feature of this approach is that direction information is specified after inferring protein residue-residue interaction network involved in the process of signal transduction. This enables fundamental analysis of the regulation hierarchy and identification of regulation hubs of the signaling network. A well-studied allosteric enzyme, E. coli aspartokinase III, is used as a model system to demonstrate the new method. Comparison with experimental results shows that the new approach is able to predict all the sites that have been experimentally proved to desensitize allosteric regulation of the enzyme. In addition, the signal transduction network shows a clear preference for specific structural regions, secondary structural types and residue conservation. Occurrence of super-hubs in the network indicates that allosteric regulation tends to gather residues with high connection ability to collectively facilitate the signaling process. Furthermore, a new parameter of propagation coefficient is defined to determine the propagation capability of residues within a signal transduction network. In conclusion, the new approach is useful for fundamental understanding of the process of intramolecular signal transduction and thus has significant impact on rational design of novel allosteric proteins.

  1. Rapid lentiviral transduction preserves the engraftment potential of Fanca(-/-) hematopoietic stem cells.

    Science.gov (United States)

    Müller, Lars U W; Milsom, Michael D; Kim, Mi-Ok; Schambach, Axel; Schuesler, Todd; Williams, David A

    2008-06-01

    Fanconi anemia (FA) is a rare recessive syndrome, characterized by congenital anomalies, bone marrow failure, and predisposition to cancer. Two earlier clinical trials utilizing gamma-retroviral vectors for the transduction of autologous FA hematopoietic stem cells (HSCs) required extensive in vitro manipulation and failed to achieve detectable long-term engraftment of transduced HSCs. As a strategy for minimizing ex vivo manipulation, we investigated the use of a "rapid" lentiviral transduction protocol in a murine Fanca(-/-) model. Importantly, while this and most murine models of FA fail to completely mimic the human hematopoietic phenotype, we observed a high incidence of HSC transplant engraftment failure and low donor chimerism after conventional transduction (CT) of Fanca(-/-) donor cells. In contrast, rapid transduction (RT) of Fanca(-/-) HSCs preserved engraftment to the level achieved in wild-type cells, resulting in long-term multilineage engraftment of gene-modified cells. We also demonstrate the correction of the characteristic hypersensitivity of FA cells against the cross-linking agent mitomycin C (MMC), and provide evidence for the advantage of using pharmacoselection as a means of further increasing gene-modified cells after RT. Collectively, these data support the use of rapid lentiviral transduction for gene therapy in FA.

  2. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis

    Directory of Open Access Journals (Sweden)

    Gareth W. Fearnley

    2016-05-01

    Full Text Available Vascular endothelial growth factor A (VEGF-A binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A–VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor–ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145 promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes.

  3. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis.

    Science.gov (United States)

    Fearnley, Gareth W; Smith, Gina A; Abdul-Zani, Izma; Yuldasheva, Nadira; Mughal, Nadeem A; Homer-Vanniasinkam, Shervanthi; Kearney, Mark T; Zachary, Ian C; Tomlinson, Darren C; Harrison, Michael A; Wheatcroft, Stephen B; Ponnambalam, Sreenivasan

    2016-05-15

    Vascular endothelial growth factor A (VEGF-A) binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A-VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor-ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145) promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes. © 2016. Published by The Company of Biologists Ltd.

  4. [Distiller Yeasts Producing Antibacterial Peptides].

    Science.gov (United States)

    Klyachko, E V; Morozkina, E V; Zaitchik, B Ts; Benevolensky, S V

    2015-01-01

    A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.

  5. Cloning of a two-component signal transduction system of Xanthomonas campestris pv. phaseoli var. fuscans strain BXPF65

    DEFF Research Database (Denmark)

    Chan, JWYF; Maynard, Scott; Goodwin, PH

    1998-01-01

    A putative two-component signal transduction system was amplified and cloned from the plant pathogenic bacterium Xanthomonas campestris pv. phaseoli var. fuscans isolate BXPF65. The 620 bp amplified fragment was sequenced and analyzed with the BLAST Enhanced Alignment Utility (BEAUTY). BEAUTY...... that the putative histidine kinase has homology with conserved “transmitter” domains of sensor proteins in two-component signal transduction systems. RFLP analysis using the putative signal transduction system showed polymorphisms among the strains....

  6. The homeodomain derived peptide Penetratin induces curvature of fluid membrane domains.

    Directory of Open Access Journals (Sweden)

    Antonin Lamazière

    Full Text Available BACKGROUND: Protein membrane transduction domains that are able to cross the plasma membrane are present in several transcription factors, such as the homeodomain proteins and the viral proteins such as Tat of HIV-1. Their discovery resulted in both new concepts on the cell communication during development, and the conception of cell penetrating peptide vectors for internalisation of active molecules into cells. A promising cell penetrating peptide is Penetratin, which crosses the cell membranes by a receptor and metabolic energy-independent mechanism. Recent works have claimed that Penetratin and similar peptides are internalized by endocytosis, but other endocytosis-independent mechanisms have been proposed. Endosomes or plasma membranes crossing mechanisms are not well understood. Previously, we have shown that basic peptides induce membrane invaginations suggesting a new mechanism for uptake, "physical endocytosis". METHODOLOGY/PRINCIPAL FINDINGS: Herein, we investigate the role of membrane lipid phases on Penetratin induced membrane deformations (liquid ordered such as in "raft" microdomains versus disordered fluid "non-raft" domains in membrane models. Experimental data show that zwitterionic lipid headgroups take part in the interaction with Penetratin suggesting that the external leaflet lipids of cells plasma membrane are competent for peptide interaction in the absence of net negative charges. NMR and X-ray diffraction data show that the membrane perturbations (tubulation and vesiculation are associated with an increase in membrane negative curvature. These effects on curvature were observed in the liquid disordered but not in the liquid ordered (raft-like membrane domains. CONCLUSIONS/SIGNIFICANCE: The better understanding of the internalisation mechanisms of protein transduction domains will help both the understanding of the mechanisms of cell communication and the development of potential therapeutic molecular vectors. Here we

  7. Ligand-regulated peptide aptamers.

    Science.gov (United States)

    Miller, Russell A

    2009-01-01

    The peptide aptamer approach employs high-throughput selection to identify members of a randomized peptide library displayed from a scaffold protein by virtue of their interaction with a target molecule. Extending this approach, we have developed a peptide aptamer scaffold protein that can impart small-molecule control over the aptamer-target interaction. This ligand-regulated peptide (LiRP) scaffold, consisting of the protein domains FKBP12, FRB, and GST, binds to the cell-permeable small-molecule rapamycin and the binding of this molecule can prevent the interaction of the randomizable linker region connecting FKBP12 with FRB. Here we present a detailed protocol for the creation of a peptide aptamer plasmid library, selection of peptide aptamers using the LiRP scaffold in a yeast two-hybrid system, and the screening of those peptide aptamers for a ligand-regulated interaction.

  8. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...... peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well....... An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

  9. Radiolabelled peptides for oncological diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Laverman, Peter; Boerman, Otto C.; Oyen, Wim J.G. [Radboud University Nijmegen Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands); Sosabowski, Jane K. [Queen Mary University of London, Centre for Molecular Oncology, Barts Cancer Institute, London (United Kingdom)

    2012-02-15

    Radiolabelled receptor-binding peptides targeting receptors (over)expressed on tumour cells are widely under investigation for tumour diagnosis and therapy. The concept of using radiolabelled receptor-binding peptides to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. The {sup 111}In-labelled somatostatin analogue octreotide (OctreoScan trademark) is the most successful radiopeptide for tumour imaging, and was the first to be approved for diagnostic use. Based on the success of these studies, other receptor-targeting peptides such as cholecystokinin/gastrin analogues, glucagon-like peptide-1, bombesin (BN), chemokine receptor CXCR4 targeting peptides, and RGD peptides are currently under development or undergoing clinical trials. In this review, we discuss some of these peptides and their analogues, with regard to their potential for radionuclide imaging of tumours. (orig.)

  10. Information Thermodynamics of the Cell Signal Transduction as a Szilard Engine

    Directory of Open Access Journals (Sweden)

    Tatsuaki Tsuruyama

    2018-03-01

    Full Text Available A cell signaling system is in a non-equilibrium state, and it includes multistep biochemical signaling cascades (BSCs, which involve phosphorylation of signaling molecules, such as mitogen-activated protein kinase (MAPK pathways. In this study, the author considered signal transduction description using information thermodynamic theory. The ideal BSCs can be considered one type of the Szilard engine, and the presumed feedback controller, Maxwell’s demon, can extract the work during signal transduction. In this model, the mutual entropy and chemical potential of the signal molecules can be redefined by the extracted chemical work in a mechanicochemical model, Szilard engine, of BSC. In conclusion, signal transduction is computable using the information thermodynamic method.

  11. Notch2 transduction by feline leukemia virus in a naturally infected cat.

    Science.gov (United States)

    Watanabe, Shinya; Ito, Jumpei; Baba, Takuya; Hiratsuka, Takahiro; Kuse, Kyohei; Ochi, Haruyo; Anai, Yukari; Hisasue, Masaharu; Tsujimoto, Hajime; Nishigaki, Kazuo

    2014-04-01

    Feline leukemia virus (FeLV) induces neoplastic and nonneoplastic diseases in cats. The transduction of cellular genes by FeLV is sometimes observed and associated with neoplastic diseases including lymphoma and sarcoma. Here, we report the first natural case of feline Notch2 transduction by FeLV in an infected cat with multicentric lymphoma and hypercalcemia. We cloned recombinant FeLVs harboring Notch2 in the env gene. Notch2 was able to activate expression of a reporter gene, similar to what was previously reported in cats with experimental FeLV-induced thymic lymphoma. Our findings suggest that the transduction of Notch2 strongly correlates with FeLV-induced lymphoma.

  12. Effects of pergolide mesylate on transduction efficiency of PEP-1-catalase protein

    International Nuclear Information System (INIS)

    Sohn, Eun Jeong; Kim, Dae Won; Kim, Young Nam; Kim, So Mi; Lim, Soon Sung; Kang, Tae-Cheon; Kwon, Hyeok Yil; Kim, Duk-Soo; Cho, Sung-Woo; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Hwang, Hyun Sook; Choi, Soo Young

    2011-01-01

    Research highlights: → We studied effects of pergolide mesylate (PM) on in vitro and in vivo transduction of PEP-1-catalase. → PEP-1-catatase inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation. → PM enhanced the transduction of PEP-1-catalase into HaCaT cells and skin tissue. → PM increased anti-inflammatory activity of PEP-1-catalase. → PM stimulated therapeutic action of anti-oxidant enzyme catalase in oxidative-related diseases. -- Abstract: The low transduction efficiency of various proteins is an obstacle to their therapeutic application. However, protein transduction domains (PTDs) are well-known for a highly effective tool for exogenous protein delivery to cells. We examined the effects of pergolide mesylate (PM) on the transduction of PEP-1-catalase into HaCaT human keratinocytes and mice skin and on the anti-inflammatory activity of PEP-1-catatase against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation using Western blot and histological analysis. PM enhanced the time- and dose-dependent transduction of PEP-1-catalase into HaCaT cells without affecting the cellular toxicity. In a mouse edema model, PEP-1-catalase inhibited the increased expressions of inflammatory mediators and cytokines such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1β, and tumor necrosis factor-α induced by TPA. On the other hand, PM alone failed to exert any significant anti-inflammatory effects. However, the anti-inflammatory effect of co-treatment with PEP-1-catalase and PM was more potent than that of PEP-1-catalase alone. Our results indicate that PM may enhance the delivery of PTDs fusion therapeutic proteins to target cells and tissues and has potential to increase their therapeutic effects of such drugs against various diseases.

  13. Effects of pergolide mesylate on transduction efficiency of PEP-1-catalase protein

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Eun Jeong; Kim, Dae Won; Kim, Young Nam; Kim, So Mi [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Lim, Soon Sung [Department of Food Science and Nutrition and RIC Center, Hallym University, Chunchon 200-702 (Korea, Republic of); Kang, Tae-Cheon [Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Kwon, Hyeok Yil [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Kim, Duk-Soo [Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan-Si 330-090 (Korea, Republic of); Cho, Sung-Woo [Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Hwang, Hyun Sook, E-mail: wazzup@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Choi, Soo Young, E-mail: sychoi@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)

    2011-03-18

    Research highlights: {yields} We studied effects of pergolide mesylate (PM) on in vitro and in vivo transduction of PEP-1-catalase. {yields} PEP-1-catatase inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation. {yields} PM enhanced the transduction of PEP-1-catalase into HaCaT cells and skin tissue. {yields} PM increased anti-inflammatory activity of PEP-1-catalase. {yields} PM stimulated therapeutic action of anti-oxidant enzyme catalase in oxidative-related diseases. -- Abstract: The low transduction efficiency of various proteins is an obstacle to their therapeutic application. However, protein transduction domains (PTDs) are well-known for a highly effective tool for exogenous protein delivery to cells. We examined the effects of pergolide mesylate (PM) on the transduction of PEP-1-catalase into HaCaT human keratinocytes and mice skin and on the anti-inflammatory activity of PEP-1-catatase against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation using Western blot and histological analysis. PM enhanced the time- and dose-dependent transduction of PEP-1-catalase into HaCaT cells without affecting the cellular toxicity. In a mouse edema model, PEP-1-catalase inhibited the increased expressions of inflammatory mediators and cytokines such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1{beta}, and tumor necrosis factor-{alpha} induced by TPA. On the other hand, PM alone failed to exert any significant anti-inflammatory effects. However, the anti-inflammatory effect of co-treatment with PEP-1-catalase and PM was more potent than that of PEP-1-catalase alone. Our results indicate that PM may enhance the delivery of PTDs fusion therapeutic proteins to target cells and tissues and has potential to increase their therapeutic effects of such drugs against various diseases.

  14. Antimicrobial Peptides (AMPs

    Directory of Open Access Journals (Sweden)

    Mehrzad Sadredinamin

    2016-04-01

    Full Text Available Antimicrobial peptides (AMPs are extensive group of molecules that produced by variety tissues of invertebrate, plants, and animal species which play an important role in their immunity response. AMPs have different classifications such as; biosynthetic machines, biological sources, biological functions, molecular properties, covalent bonding patterns, three dimensional structures, and molecular targets.These molecules have multidimensional properties including antimicrobial activity, antiviral activity, antifungal activity, anti-parasite activity, biofilm control, antitumor activity, mitogens activity and linking innate to adaptive immunity that making them promising agents for therapeutic drugs. In spite of this advantage of AMPs, their clinical developments have some limitation for commercial development. But some of AMPs are under clinical trials for the therapeutic purpose such as diabetic foot ulcers, different bacterial infections and tissue damage. In this review, we emphasized on the source, structure, multidimensional properties, limitation and therapeutic applications of various antimicrobial peptides.

  15. Cancer classification through filtering progressive transductive support vector machine based on gene expression data

    Science.gov (United States)

    Lu, Xinguo; Chen, Dan

    2017-08-01

    Traditional supervised classifiers neglect a large amount of data which not have sufficient follow-up information, only work with labeled data. Consequently, the small sample size limits the advancement of design appropriate classifier. In this paper, a transductive learning method which combined with the filtering strategy in transductive framework and progressive labeling strategy is addressed. The progressive labeling strategy does not need to consider the distribution of labeled samples to evaluate the distribution of unlabeled samples, can effective solve the problem of evaluate the proportion of positive and negative samples in work set. Our experiment result demonstrate that the proposed technique have great potential in cancer prediction based on gene expression.

  16. Deciphering complex dynamics of water counteraction around secondary structural elements of allosteric protein complex: Case study of SAP-SLAM system in signal transduction cascade.

    Science.gov (United States)

    Samanta, Sudipta; Mukherjee, Sanchita

    2018-01-28

    The first hydration shell of a protein exhibits heterogeneous behavior owing to several attributes, majorly local polarity and structural flexibility as revealed by solvation dynamics of secondary structural elements. We attempt to recognize the change in complex water counteraction generated due to substantial alteration in flexibility during protein complex formation. The investigation is carried out with the signaling lymphocytic activation molecule (SLAM) family of receptors, expressed by an array of immune cells, and interacting with SLAM-associated protein (SAP), composed of one SH2 domain. All atom molecular dynamics simulations are employed to the aqueous solutions of free SAP and SLAM-peptide bound SAP. We observed that water dynamics around different secondary structural elements became highly affected as well as nicely correlated with the SLAM-peptide induced change in structural rigidity obtained by thermodynamic quantification. A few instances of contradictory dynamic features of water to the change in structural flexibility are explained by means of occluded polar residues by the peptide. For βD, EFloop, and BGloop, both structural flexibility and solvent accessibility of the residues confirm the obvious contribution. Most importantly, we have quantified enhanced restriction in water dynamics around the second Fyn-binding site of the SAP due to SAP-SLAM complexation, even prior to the presence of Fyn. This observation leads to a novel argument that SLAM induced more restricted water molecules could offer more water entropic contribution during the subsequent Fyn binding and provide enhanced stability to the SAP-Fyn complex in the signaling cascade. Finally, SLAM induced water counteraction around the second binding site of the SAP sheds light on the allosteric property of the SAP, which becomes an integral part of the underlying signal transduction mechanism.

  17. Deciphering complex dynamics of water counteraction around secondary structural elements of allosteric protein complex: Case study of SAP-SLAM system in signal transduction cascade

    Science.gov (United States)

    Samanta, Sudipta; Mukherjee, Sanchita

    2018-01-01

    The first hydration shell of a protein exhibits heterogeneous behavior owing to several attributes, majorly local polarity and structural flexibility as revealed by solvation dynamics of secondary structural elements. We attempt to recognize the change in complex water counteraction generated due to substantial alteration in flexibility during protein complex formation. The investigation is carried out with the signaling lymphocytic activation molecule (SLAM) family of receptors, expressed by an array of immune cells, and interacting with SLAM-associated protein (SAP), composed of one SH2 domain. All atom molecular dynamics simulations are employed to the aqueous solutions of free SAP and SLAM-peptide bound SAP. We observed that water dynamics around different secondary structural elements became highly affected as well as nicely correlated with the SLAM-peptide induced change in structural rigidity obtained by thermodynamic quantification. A few instances of contradictory dynamic features of water to the change in structural flexibility are explained by means of occluded polar residues by the peptide. For βD, EFloop, and BGloop, both structural flexibility and solvent accessibility of the residues confirm the obvious contribution. Most importantly, we have quantified enhanced restriction in water dynamics around the second Fyn-binding site of the SAP due to SAP-SLAM complexation, even prior to the presence of Fyn. This observation leads to a novel argument that SLAM induced more restricted water molecules could offer more water entropic contribution during the subsequent Fyn binding and provide enhanced stability to the SAP-Fyn complex in the signaling cascade. Finally, SLAM induced water counteraction around the second binding site of the SAP sheds light on the allosteric property of the SAP, which becomes an integral part of the underlying signal transduction mechanism.

  18. Therapeutic peptides for cancer therapy. Part II - cell cycle inhibitory peptides and apoptosis-inducing peptides.

    Science.gov (United States)

    Raucher, Drazen; Moktan, Shama; Massodi, Iqbal; Bidwell, Gene L

    2009-10-01

    Therapeutic peptides have great potential as anticancer agents owing to their ease of rational design and target specificity. However, their utility in vivo is limited by low stability and poor tumor penetration. The authors review the development of peptide inhibitors with potential for cancer therapy. Peptides that arrest the cell cycle by mimicking CDK inhibitors or induce apoptosis directly are discussed. The authors searched Medline for articles concerning the development of therapeutic peptides and their delivery. Inhibition of cancer cell proliferation directly using peptides that arrest the cell cycle or induce apoptosis is a promising strategy. Peptides can be designed that interact very specifically with cyclins and/or cyclin-dependent kinases and with members of apoptotic cascades. Use of these peptides is not limited by their design, as a rational approach to peptide design is much less challenging than the design of small molecule inhibitors of specific protein-protein interactions. However, the limitations of peptide therapy lie in the poor pharmacokinetic properties of these large, often charged molecules. Therefore, overcoming the drug delivery hurdles could open the door for effective peptide therapy, thus making an entirely new class of molecules useful as anticancer drugs.

  19. Characterization of adenoviral transduction profile in prostate cancer cells and normal prostate tissue.

    Science.gov (United States)

    Ai, Jianzhong; Tai, Phillip W L; Lu, Yi; Li, Jia; Ma, Hong; Su, Qin; Wei, Qiang; Li, Hong; Gao, Guangping

    2017-09-01

    Prostate diseases are common in males worldwide with high morbidity. Gene therapy is an attractive therapeutic strategy for prostate diseases, however, it is currently underdeveloped. As well known, adeno virus (Ad) is the most widely used gene therapy vector. The aims of this study are to explore transduction efficiency of Ad in prostate cancer cells and normal prostate tissue, thus further providing guidance for future prostate pathophysiological studies and therapeutic development of prostate diseases. We produced Ad expressing enhanced green fluorescence protein (EGFP), and characterized the transduction efficiency of Ad in both human and mouse prostate cancer cell lines in vitro, as well as prostate tumor xenograft, and wild-type mouse prostate tissue in vivo. Ad transduction efficiency was determined by EGFP fluorescence using microscopy and flow cytometry. Cell type-specific transduction was examined by immunofluorescence staining of cell markers. Our data showed that Ad efficiently transduced human and mouse prostate cancer cells in vitro in a dose dependent manner. Following intratumoral and intraprostate injection, Ad could efficiently transduce prostate tumor xenograft and the major prostatic cell types in vivo, respectively. Our findings suggest that Ad can efficiently transduce prostate tumor cells in vitro as well as xenograft and normal prostate tissue in vivo, and further indicate that Ad could be a potentially powerful toolbox for future gene therapy of prostate diseases. © 2017 Wiley Periodicals, Inc.

  20. Regulation of autophagy by amino acids and MTOR-dependent signal transduction

    NARCIS (Netherlands)

    Meijer, Alfred J.; Lorin, Séverine; Blommaart, Edward F.; Codogno, Patrice

    2015-01-01

    Amino acids not only participate in intermediary metabolism but also stimulate insulin-mechanistic target of rapamycin (MTOR)-mediated signal transduction which controls the major metabolic pathways. Among these is the pathway of autophagy which takes care of the degradation of long-lived proteins

  1. Beacon Editor: Capturing Signal Transduction Pathways Using the Systems Biology Graphical Notation Activity Flow Language.

    Science.gov (United States)

    Elmarakeby, Haitham; Arefiyan, Mostafa; Myers, Elijah; Li, Song; Grene, Ruth; Heath, Lenwood S

    2017-12-01

    The Beacon Editor is a cross-platform desktop application for the creation and modification of signal transduction pathways using the Systems Biology Graphical Notation Activity Flow (SBGN-AF) language. Prompted by biologists' requests for enhancements, the Beacon Editor includes numerous powerful features for the benefit of creation and presentation.

  2. Effects of matrine on JAK-STAT signaling transduction pathways in ...

    African Journals Online (AJOL)

    The current study aims to investigate the effects of matrine on the JAK-STAT signaling transduction pathways in bleomycin (BLM)-induced pulmonary fibrosis (PF) and to explore its action mechanism. A total of 72 male C57BL/6 mice were randomized into the control, model, and treatment groups. PF models were ...

  3. Signal transduction events in aluminum-induced cell death in tomato suspension cells

    NARCIS (Netherlands)

    Iakimova, E.T.; Kapchina-Toteva, V.M.; Woltering, E.J.

    2007-01-01

    In this study, some of the signal transduction events involved in AlCl3-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 ¿M AlCl3 showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation.

  4. Sensory cilia and integration of signal transduction in human health and disease

    DEFF Research Database (Denmark)

    Christensen, Søren T; Pedersen, Lotte B; Schneider, Linda

    2007-01-01

    The primary cilium is a hallmark of mammalian tissue cells. Recent research has shown that these organelles display unique sets of selected signal transduction modules including receptors, ion channels, effector proteins and transcription factors that relay chemical and physical stimuli from the ...

  5. CRISPR-cas-mediated phage resistance enhances horizontal gene transfer by transduction

    NARCIS (Netherlands)

    Watson, Bridget N.J.; Staals, Raymond H.J.; Fineran, Peter C.

    2018-01-01

    A powerful contributor to prokaryotic evolution is horizontal gene transfer (HGT) through transformation, conjugation, and transduction, which can be advantageous, neutral, or detrimental to fitness. Bacteria and archaea control HGT and phage infection through CRISPR-Cas (clustered regularly

  6. Efficient transduction of neurons using Ross River glycoprotein-pseudotyped lentiviral vectors

    DEFF Research Database (Denmark)

    Jakobsson, J; Nielsen, T Tolstrup; Staflin, K

    2006-01-01

    , including the possibility to establish stable producer cell lines. After injection of RRV-LV expressing green fluorescent protein into different structures in the rat brain we found efficient transduction of both neurons and glial cells. By using two cell-type-specific promoters, neuron-specific enolase...

  7. The role of Ryk and Ror receptor tyrosine kinases in Wnt signal transduction

    NARCIS (Netherlands)

    Green, J.; Nusse, R.; van Amerongen, R.

    2014-01-01

    Receptor tyrosine kinases of the Ryk and Ror families were initially classified as orphan receptors because their ligands were unknown. They are now known to contain functional extracellular Wnt-binding domains and are implicated in Wnt-signal transduction in multiple species. Although their

  8. Semi-Supervised Transductive Hot Spot Predictor Working on Multiple Assumptions

    KAUST Repository

    Wang, Jim Jing-Yan; Almasri, Islam; Shi, Yuexiang; Gao, Xin

    2014-01-01

    of the transductive semi-supervised algorithms takes all the three semisupervised assumptions, i.e., smoothness, cluster and manifold assumptions, together into account during learning. In this paper, we propose a novel semi-supervised method for hot spot residue

  9. Intrapulmonary Versus Nasal Transduction of Murine Airways With GP64-pseudotyped Viral Vectors

    Directory of Open Access Journals (Sweden)

    Mayumi Oakland

    2013-01-01

    Full Text Available Persistent viral vector-mediated transgene expression in the airways requires delivery to cells with progenitor capacity and avoidance of immune responses. Previously, we observed that GP64-pseudotyped feline immunodeficiency virus (FIV-mediated gene transfer was more efficient in the nasal airways than the large airways of the murine lung. We hypothesized that in vivo gene transfer was limited by immunological and physiological barriers in the murine intrapulmonary airways. Here, we systematically investigate multiple potential barriers to lentiviral gene transfer in the airways of mice. We show that GP64-FIV vector transduced primary cultures of well-differentiated murine nasal epithelia with greater efficiency than primary cultures of murine tracheal epithelia. We further demonstrate that neutrophils, type I interferon (IFN responses, as well as T and B lymphocytes are not the major factors limiting the transduction of murine conducting airways. In addition, we observed better transduction of GP64-pseudotyped vesicular stomatitis virus (VSV in the nasal epithelia compared with the intrapulmonary airways in mice. VSVG glycoprotein pseudotyped VSV transduced intrapulmonary epithelia with similar efficiency as nasal epithelia. Our results suggest that the differential transduction efficiency of nasal versus intrapulmonary airways by FIV vector is not a result of immunological barriers or surface area, but rather differential expression of cellular factors specific for FIV vector transduction.

  10. Integration of adeno-associated virus vectors in CD34+ human hematopoietic progenitor cells after transduction.

    Science.gov (United States)

    Fisher-Adams, G; Wong, K K; Podsakoff, G; Forman, S J; Chatterjee, S

    1996-07-15

    Gene transfer vectors based on adeno-associated virus (AAV) appear promising because of their high transduction frequencies regardless of cell cycle status and ability to integrate into chromosomal DNA. We tested AAV-mediated gene transfer into a panel of human bone marrow or umbilical cord-derived CD34+ hematopoietic progenitor cells, using vectors encoding several transgenes under the control of viral and cellular promoters. Gene transfer was evaluated by (1) chromosomal integration of vector sequences and (2) analysis of transgene expression. Southern hybridization and fluorescence in situ hybridization analysis of transduced CD34 genomic DNA showed the presence of integrated vector sequences in chromosomal DNA in a portion of transduced cells and showed that integrated vector sequences were replicated along with cellular DNA during mitosis. Transgene expression in transduced CD34 cells in suspension cultures and in myeloid colonies differentiating in vitro from transduced CD34 cells approximated that predicted by the multiplicity of transduction. This was true in CD34 cells from different donors, regardless of the transgene or selective pressure. Comparisons of CD34 cell transduction either before or after cytokine stimulation showed similar gene transfer frequencies. Our findings suggest that AAV transduction of CD34+ hematopoietic progenitor cells is efficient, can lead to stable integration in a population of transduced cells, and may therefore provide the basis for safe and efficient ex vivo gene therapy of the hematopoietic system.

  11. FASEB summer research conference on signal transduction in plants. Final report, June 16, 1996--June 21, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Lomax, T.L.; Quatrano, R.S.

    1996-12-31

    This is the program from the second FASEB conference on Signal Transduction in Plants. Topic areas included the following: environmental signaling; perception and transduction of light signals; signaling in plant microbe interactions; signaling in plant pathogen interactions; cell, cell communication; cytoskeleton, plasma membrane, and cellwall continuum; signaling molecules in plant growth and development I and II. A list of participants is included.

  12. Structure-function relationships of Na+, K+, ATP, or Mg2+ binding and energy transduction in Na,K-ATPase

    DEFF Research Database (Denmark)

    Jorgensen, Peter L.; Pedersen, Per Amstrup

    2000-01-01

    Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction......Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction...

  13. Solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Jensen, Knud Jørgen

    2013-01-01

    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective.......This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....

  14. Improving Peptide Applications Using Nanotechnology.

    Science.gov (United States)

    Narayanaswamy, Radhika; Wang, Tao; Torchilin, Vladimir P

    2016-01-01

    Peptides are being successfully used in various fields including therapy and drug delivery. With advancement in nanotechnology and targeted delivery carrier systems, suitable modification of peptides has enabled achievement of many desirable goals over-riding some of the major disadvantages associated with the delivery of peptides in vivo. Conjugation or physical encapsulation of peptides to various nanocarriers, such as liposomes, micelles and solid-lipid nanoparticles, has improved their in vivo performance multi-fold. The amenability of peptides to modification in chemistry and functionalization with suitable nanocarriers are very relevant aspects in their use and have led to the use of 'smart' nanoparticles with suitable linker chemistries that favor peptide targeting or release at the desired sites, minimizing off-target effects. This review focuses on how nanotechnology has been used to improve the number of peptide applications. The paper also focuses on the chemistry behind peptide conjugation to nanocarriers, the commonly employed linker chemistries and the several improvements that have already been achieved in the areas of peptide use with the help of nanotechnology.

  15. Anti-apoptotic peptides protect against radiation-induced cell death

    International Nuclear Information System (INIS)

    McConnell, Kevin W.; Muenzer, Jared T.; Chang, Kathy C.; Davis, Chris G.; McDunn, Jonathan E.; Coopersmith, Craig M.; Hilliard, Carolyn A.; Hotchkiss, Richard S.; Grigsby, Perry W.; Hunt, Clayton R.

    2007-01-01

    The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15 Gy radiation. In mice exposed to 5 Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues

  16. Anticancer peptides from bacteria

    Directory of Open Access Journals (Sweden)

    Tomasz M. Karpiński

    2013-08-01

    Full Text Available Cancer is a leading cause of death in the world. The rapid development of medicine and pharmacology allows to create new and effective anticancer drugs. Among modern anticancer drugs are bacterial proteins. Until now has been shown anticancer activity among others azurin and exotoxin A from Pseudomonas aeruginosa, Pep27anal2 from Streptococcus pneumoniae, diphtheria toxin from Corynebacterium diphtheriae, and recently discovered Entap from Enterococcus sp. The study presents the current data regarding the properties, action and anticancer activity of listed peptides.

  17. Enrichment of human hematopoietic stem/progenitor cells facilitates transduction for stem cell gene therapy.

    Science.gov (United States)

    Baldwin, Kismet; Urbinati, Fabrizia; Romero, Zulema; Campo-Fernandez, Beatriz; Kaufman, Michael L; Cooper, Aaron R; Masiuk, Katelyn; Hollis, Roger P; Kohn, Donald B

    2015-05-01

    Autologous hematopoietic stem cell (HSC) gene therapy for sickle cell disease has the potential to treat this illness without the major immunological complications associated with allogeneic transplantation. However, transduction efficiency by β-globin lentiviral vectors using CD34-enriched cell populations is suboptimal and large vector production batches may be needed for clinical trials. Transducing a cell population more enriched for HSC could greatly reduce vector needs and, potentially, increase transduction efficiency. CD34(+) /CD38(-) cells, comprising ∼1%-3% of all CD34(+) cells, were isolated from healthy cord blood CD34(+) cells by fluorescence-activated cell sorting and transduced with a lentiviral vector expressing an antisickling form of beta-globin (CCL-β(AS3) -FB). Isolated CD34(+) /CD38(-) cells were able to generate progeny over an extended period of long-term culture (LTC) compared to the CD34(+) cells and required up to 40-fold less vector for transduction compared to bulk CD34(+) preparations containing an equivalent number of CD34(+) /CD38(-) cells. Transduction of isolated CD34(+) /CD38(-) cells was comparable to CD34(+) cells measured by quantitative PCR at day 14 with reduced vector needs, and average vector copy/cell remained higher over time for LTC initiated from CD34(+) /38(-) cells. Following in vitro erythroid differentiation, HBBAS3 mRNA expression was similar in cultures derived from CD34(+) /CD38(-) cells or unfractionated CD34(+) cells. In vivo studies showed equivalent engraftment of transduced CD34(+) /CD38(-) cells when transplanted in competition with 100-fold more CD34(+) /CD38(+) cells. This work provides initial evidence for the beneficial effects from isolating human CD34(+) /CD38(-) cells to use significantly less vector and potentially improve transduction for HSC gene therapy. © 2015 AlphaMed Press.

  18. Urodilatin, a natriuretic peptide with clinical implications.

    Science.gov (United States)

    Meyer, M; Richter, R; Forssmann, W G

    1998-02-21

    Natriuretic peptides (NP) constitute hormonal systems of great clinical impact. This report deals with Urodilatin (URO), a renal natriuretic peptide type A. From the gene of NP type A, a message for the preprohormone is transcribed in heart and kidney. The cardiac prohormone CDD/ANP-1-126 is synthesized in the heart atrium and processed during exocytosis forming the circulating hormone CDD/ANP-99-126. URO (CDD/ANP 95-126) is a product from the same gene, but differentially processed in the kidney and detected only in urine. Physiologically, URO acts in a paracrine fashion. After release from distal tubular kidney cells into the tubular lumen, URO binds to luminal receptors (NPR-A) in the collecting duct resulting in a cGMP-dependent signal transduction. cGMP generation is followed by an interaction with the amiloriode-sensitive sodium channel which induces diuresis and natriuresis. In this way, URO physiologically regulates fluid balance and sodium homeostasis. Moreover, URO excretion and natriuresis are in turn dependent on several physiological states, such as directly by sodium homeostasis. Pharmacologically, URO at low dose administered intravenously shows a strong diuretic and natriuretic effect and a low hypotensive effect. Renal, pulmonary, and cardiovascular effects evoked by pharmacological doses indicate that URO is a putative drug for several related diseases. Clinical trials show promising results for various clinical indications. However, the reduction in hemodialysis/hemofiltration in patients suffering from ARF following heart and liver transplantation, derived from preliminary trials recruiting a small number of patients, was not confirmed by a multicenter phase II study. In contrast, data for the prophylactic use of URO in this clinical setting suggest a better outcome for the patients. Furthermore, treatment of asthmatic patients showed a convincingly beneficial effect of URO on pulmonary function. Patients with congestive heart failure may also

  19. Distinct Signaling Cascades Elicited by Different Formyl Peptide Receptor 2 (FPR2 Agonists

    Directory of Open Access Journals (Sweden)

    Fabio Cattaneo

    2013-04-01

    Full Text Available The formyl peptide receptor 2 (FPR2 is a remarkably versatile transmembrane protein belonging to the G-protein coupled receptor (GPCR family. FPR2 is activated by an array of ligands, which include structurally unrelated lipids and peptide/proteins agonists, resulting in different intracellular responses in a ligand-specific fashion. In addition to the anti-inflammatory lipid, lipoxin A4, several other endogenous agonists also bind FPR2, including serum amyloid A, glucocorticoid-induced annexin 1, urokinase and its receptor, suggesting that the activation of FPR2 may result in potent pro- or anti-inflammatory responses. Other endogenous ligands, also present in biological samples, include resolvins, amyloidogenic proteins, such as beta amyloid (Aβ-42 and prion protein (Prp106–126, the neuroprotective peptide, humanin, antibacterial peptides, annexin 1-derived peptides, chemokine variants, the neuropeptides, vasoactive intestinal peptide (VIP and pituitary adenylate cyclase activating polypeptide (PACAP-27, and mitochondrial peptides. Upon activation, intracellular domains of FPR2 mediate signaling to G-proteins, which trigger several agonist-dependent signal transduction pathways, including activation of phospholipase C (PLC, protein kinase C (PKC isoforms, the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt pathway, the mitogen-activated protein kinase (MAPK pathway, p38MAPK, as well as the phosphorylation of cytosolic tyrosine kinases, tyrosine kinase receptor transactivation, phosphorylation and nuclear translocation of regulatory transcriptional factors, release of calcium and production of oxidants. FPR2 is an attractive therapeutic target, because of its involvement in a range of normal physiological processes and pathological diseases. Here, we review and discuss the most significant findings on the intracellular pathways and on the cross-communication between FPR2 and tyrosine kinase receptors triggered by different FPR2

  20. Enhancing gene delivery of adeno-associated viruses by cell-permeable peptides

    Directory of Open Access Journals (Sweden)

    Yarong Liu

    2014-01-01

    Full Text Available Adeno-associated virus type 2 (AAV2 is considered a promising gene delivery vector and has been extensively applied in several disease models; however, inefficient transduction in various cells and tissues has limited its widespread application in many areas of gene therapy. In this study, we have developed a general, but efficient, strategy to enhance viral transduction, both in vitro and in vivo, by incubating viral particles with cell-permeable peptides (CPPs. We show that CPPs increase internalization of viral particles into cells by facilitating both energy-independent and energy-dependent endocytosis. Moreover, CPPs can significantly enhance the endosomal escape process of viral particles, thus enhancing viral transduction to those cells that have exhibited very low permissiveness to AAV2 infection as a result of impaired intracellular viral processing. We also demonstrated that this approach could be applicable to other AAV serotypes. Thus, the membrane-penetrating ability of CPPs enables us to generate an efficient method for enhanced gene delivery of AAV vectors, potentially facilitating its applicability to human gene therapy.

  1. Structure, synthesis, and activity of dermaseptin b, a novel vertebrate defensive peptide from frog skin: relationship with adenoregulin.

    Science.gov (United States)

    Mor, A; Amiche, M; Nicolas, P

    1994-05-31

    A novel antimicrobial peptide, designated dermaseptin b, was isolated from the skin of the arboreal frog Phyllomedusa bicolor. This 27-residue peptide amide is basic, containing 3 lysine residues that punctuate an alternating hydrophobic and hydrophilic sequence. In helix-inducing solvent, dermaseptin b adopts an amphipathic alpha-helical conformation that most closely resembles class L amphipathic helixes, with all lysine residues on the polar face of the helix. The peptide exhibits growth inhibition activity in vitro against a broad spectrum of pathogenic microorganisms including yeast and bacteria as well as various filamentous fungi that are responsible for severe opportunistic infections accompanying acquired immunodeficiency syndrome and the use of immunosuppressive agents. Maximized pairwise sequence alignment of dermaseptin b and dermaseptin s, a 34-residue antimicrobial peptide previously isolated from Phyllomedusa sauvagii, reveals 81% amino acid identity. No other significant similarity was found between dermaseptin b and any prokaryotic or eukaryotic protein, but similarity was found with adenoregulin (38% amino acid postional identity), a 33-residue peptide that enhances binding of agonists to the A1 adenosine receptor. The synthetic replicates of dermaseptin b and adenoregulin displayed similar but nonidentical spectra of antimicrobial activity, and both peptides were devoid of lytic effect on mammalian cells. Accordingly, the observation that adenoregulin enhances binding of agonists to the adenosine receptor may in fact be a consequence of its ability to alter the structure of biological membranes and to produce signal transduction via interactions with the lipid bilayer, bypassing cell surface receptor interactions.

  2. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    Zegers, N.D.

    1995-01-01

    Synthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps that lead to the

  3. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    N.D. Zegers (Netty)

    1995-01-01

    textabstractSynthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps

  4. Peptide radiopharmaceuticals in nuclear medicine

    International Nuclear Information System (INIS)

    Blok, D.; Vermeij, P.; Feitsma, R.I.J.; Pauwels, E.J.K.

    1999-01-01

    This article reviews the labelling of peptides that are recognised to be of interest for nuclear medicine or are the subject of ongoing nuclear medicine research. Applications and approaches to the labelling of peptide radiopharmaceuticals are discussed, and drawbacks in their development considered. (orig.)

  5. Cell-Penetrating Peptide as a Means of Directing the Differentiation of Induced-Pluripotent Stem Cells.

    Science.gov (United States)

    Kaitsuka, Taku; Tomizawa, Kazuhito

    2015-11-06

    Protein transduction using cell-penetrating peptides (CPPs) is useful for the delivery of large protein molecules, including some transcription factors. This method is safer than gene transfection methods with a viral vector because there is no risk of genomic integration of the exogenous DNA. Recently, this method was reported as a means for the induction of induced pluripotent stem (iPS) cells, directing the differentiation into specific cell types and supporting gene editing/correction. Furthermore, we developed a direct differentiation method to obtain a pancreatic lineage from mouse and human pluripotent stem cells via the protein transduction of three transcription factors, Pdx1, NeuroD, and MafA. Here, we discuss the possibility of using CPPs as a means of directing the differentiation of iPS cells and other stem cell technologies.

  6. Cell-Penetrating Peptide as a Means of Directing the Differentiation of Induced-Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Taku Kaitsuka

    2015-11-01

    Full Text Available Protein transduction using cell-penetrating peptides (CPPs is useful for the delivery of large protein molecules, including some transcription factors. This method is safer than gene transfection methods with a viral vector because there is no risk of genomic integration of the exogenous DNA. Recently, this method was reported as a means for the induction of induced pluripotent stem (iPS cells, directing the differentiation into specific cell types and supporting gene editing/correction. Furthermore, we developed a direct differentiation method to obtain a pancreatic lineage from mouse and human pluripotent stem cells via the protein transduction of three transcription factors, Pdx1, NeuroD, and MafA. Here, we discuss the possibility of using CPPs as a means of directing the differentiation of iPS cells and other stem cell technologies.

  7. The Equine PeptideAtlas

    DEFF Research Database (Denmark)

    Bundgaard, Louise; Jacobsen, Stine; Sørensen, Mette Aamand

    2014-01-01

    Progress in MS-based methods for veterinary research and diagnostics is lagging behind compared to the human research, and proteome data of domestic animals is still not well represented in open source data repositories. This is particularly true for the equine species. Here we present a first...... Equine PeptideAtlas encompassing high-resolution tandem MS analyses of 51 samples representing a selection of equine tissues and body fluids from healthy and diseased animals. The raw data were processed through the Trans-Proteomic Pipeline to yield high quality identification of proteins and peptides....... The current release comprises 24 131 distinct peptides representing 2636 canonical proteins observed at false discovery rates of 0.2% at the peptide level and 1.4% at the protein level. Data from the Equine PeptideAtlas are available for experimental planning, validation of new datasets, and as a proteomic...

  8. Vascular targeting with peptide libraries

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, R. [La Jolla Cancer Research Center The Burnham Inst., La Jolla CA (United States)

    1999-06-01

    The authors have developed an 'in vivo' selection system in which phage capable of selective homing to different tissues are recovered from a phage display peptide library following intravenous administration. Using this strategy, they have isolate several organ and tumor-homing peptides. They have shown that each of those peptides binds of different receptors that are selectively expressed on the vasculature of the target tissue. The tumor-homing peptides bind to receptors that are up regulated in tumor angiogenic vasculature. Targeted delivery of doxorubicin to angiogenic vasculature using these peptides in animals models decrease toxicity and increased the therapeutic efficacy of the drug. Vascular targeting may facilitate the development of other treatment strategies that rely on inhibition of angio genesis and lead to advances to extend the potential for targeting of drugs, genes and radionuclides in the context of many diseases.

  9. Natriuretic peptides and cerebral hemodynamics

    DEFF Research Database (Denmark)

    Guo, Song; Barringer, Filippa; Zois, Nora Elisabeth

    2014-01-01

    Natriuretic peptides have emerged as important diagnostic and prognostic tools for cardiovascular disease. Plasma measurement of the bioactive peptides as well as precursor-derived fragments is a sensitive tool in assessing heart failure. In heart failure, the peptides are used as treatment...... in decompensated disease. In contrast, their biological effects on the cerebral hemodynamics are poorly understood. In this mini-review, we summarize the hemodynamic effects of the natriuretic peptides with a focus on the cerebral hemodynamics. In addition, we will discuss its potential implications in diseases...... where alteration of the cerebral hemodynamics plays a role such as migraine and acute brain injury including stroke. We conclude that a possible role of the peptides is feasible as evaluated from animal and in vitro studies, but more research is needed in humans to determine the precise response...

  10. Maize Bioactive Peptides against Cancer

    Science.gov (United States)

    Díaz-Gómez, Jorge L.; Castorena-Torres, Fabiola; Preciado-Ortiz, Ricardo E.; García-Lara, Silverio

    2017-06-01

    Cancer is one of the main chronic degenerative diseases worldwide. In recent years, consumption of whole-grain cereals and their derived food products has been associated with reduction risks of various types of cancer. Cereals main biomolecules includes proteins, peptides, and amino acids present in different quantities within the grain. The nutraceutical properties associated with peptides exerts biological functions that promote health and prevent this disease. In this review, we report the current status and advances on maize peptides regarding bioactive properties that have been reported such as antioxidant, antihypertensive, hepatoprotective, and anti-tumour activities. We also highlighted its biological potential through which maize bioactive peptides exert anti-cancer activity. Finally, we analyse and emphasize the possible areas of application for maize peptides.

  11. Structural Basis of Rap Phosphatase Inhibition by Phr Peptides

    Science.gov (United States)

    Gallego del Sol, Francisca; Marina, Alberto

    2013-01-01

    Two-component systems, composed of a sensor histidine kinase and an effector response regulator (RR), are the main signal transduction devices in bacteria. In Bacillus, the Rap protein family modulates complex signaling processes mediated by two-component systems, such as competence, sporulation, or biofilm formation, by inhibiting the RR components involved in these pathways. Despite the high degree of sequence homology, Rap proteins exert their activity by two completely different mechanisms of action: inducing RR dephosphorylation or blocking RR binding to its target promoter. However the regulatory mechanism involving Rap proteins is even more complex since Rap activity is antagonized by specific signaling peptides (Phr) through a mechanism that remains unknown at the molecular level. Using X-ray analyses, we determined the structure of RapF, the anti-activator of competence RR ComA, alone and in complex with its regulatory peptide PhrF. The structural and functional data presented herein reveal that peptide PhrF blocks the RapF-ComA interaction through an allosteric mechanism. PhrF accommodates in the C-terminal tetratricopeptide repeat domain of RapF by inducing its constriction, a conformational change propagated by a pronounced rotation to the N-terminal ComA-binding domain. This movement partially disrupts the ComA binding site by triggering the ComA disassociation, whose interaction with RapF is also sterically impaired in the PhrF-induced conformation of RapF. Sequence analyses of the Rap proteins, guided by the RapF-PhrF structure, unveil the molecular basis of Phr recognition and discrimination, allowing us to relax the Phr specificity of RapF by a single residue change. PMID:23526880

  12. Hepatoma targeting peptide conjugated bio-reducible polymer complexed with oncolytic adenovirus for cancer gene therapy.

    Science.gov (United States)

    Choi, Joung-Woo; Kim, Hyun Ah; Nam, Kihoon; Na, Youjin; Yun, Chae-Ok; Kim, SungWan

    2015-12-28

    Despite adenovirus (Ad) vector's numerous advantages for cancer gene therapy, such as high ability of endosomal escape, efficient nuclear entry mechanism, and high transduction, and therapeutic efficacy, tumor specific targeting and antiviral immune response still remain as a critical challenge in clinical setting. To overcome these obstacles and achieve cancer-specific targeting, we constructed tumor targeting bioreducible polymer, an arginine grafted bio-reducible polymer (ABP)-PEG-HCBP1, by conjugating PEGylated ABP with HCBP1 peptides which has high affinity and selectivity towards hepatoma. The ABP-PEG-HCBP1-conjugated replication incompetent GFP-expressing ad, (Ad/GFP)-ABP-PEG-HCBP1, showed a hepatoma cancer specific uptake and transduction compared to either naked Ad/GFP or Ad/GFP-ABP. Competition assays demonstrated that Ad/GFP-ABP-PEG-HCBP1-mediated transduction was specifically inhibited by HCBP1 peptide rather than coxsackie and adenovirus receptor specific antibody. In addition, ABP-PEG-HCBP1 can protect biological activity of Ad against serum, and considerably reduced both innate and adaptive immune response against Ad. shMet-expressing oncolytic Ad (oAd; RdB/shMet) complexed with ABP-PEG-HCBP1 delivered oAd efficiently into hepatoma cancer cells. The oAd/ABP-PEG-HCBP1 demonstrated enhanced cancer cell killing efficacy in comparison to oAd/ABP complex. Furthermore, Huh7 and HT1080 cancer cells treated with oAd/shMet-ABP-PEG-HCBP1 complex had significantly decreased Met and VEGF expression in hepatoma cancer, but not in non-hepatoma cancer. In sum, these results suggest that HCBP1-conjugated bioreducible polymer could be used to deliver oncolytic Ad safely and efficiently to treat hepatoma. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Purification and use of E. coli peptide deformylase for peptide deprotection in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia; Sonke, Theo; Quaedflieg, Peter J.; Janssen, Dick B.

    Peptide deformylases (PDFs) catalyze the removal of the formyl group from the N-terminal methionine residue in nascent polypeptide chains in prokaryotes. Its deformylation activity makes PDF an attractive candidate for the biocatalytic deprotection of formylated peptides that are used in

  14. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Handan [Institute; Department; Samaeekia, Ravand [Institute; Department; Schnorenberg, Mathew R. [Institute; Department; Medical; Sasmal, Dibyendu K. [Institute; Huang, Jun [Institute; Tirrell, Matthew V. [Institute; Institute; LaBelle, James L. [Department

    2017-08-24

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  15. DMPD: Signal transduction pathways mediated by the interaction of CpG DNA withToll-like receptor 9. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14751759 Signal transduction pathways mediated by the interaction of CpG DNA withTo...;16(1):17-22. (.png) (.svg) (.html) (.csml) Show Signal transduction pathways mediated by the interaction of... CpG DNA withToll-like receptor 9. PubmedID 14751759 Title Signal transduction pathways media

  16. Primary cilia modulate Ihh signal transduction in response to hydrostatic loading of growth plate chondrocytes.

    Science.gov (United States)

    Shao, Yvonne Y; Wang, Lai; Welter, Jean F; Ballock, R Tracy

    2012-01-01

    Indian hedgehog (Ihh) is a key component of the regulatory apparatus governing chondrocyte proliferation and differentiation in the growth plate. Recent studies have demonstrated that the primary cilium is the site of Ihh signaling within the cell, and that primary cilia are essential for bone and cartilage formation. Primary cilia are also postulated to act as mechanosensory organelles that transduce mechanical forces acting on the cell into biological signals. In this study, we used a hydrostatic compression system to examine Ihh signal transduction under the influence of mechanical load. Our results demonstrate that hydrostatic compression increased both Ihh gene expression and Ihh-responsive Gli-luciferase activity. These increases were aborted by disrupting the primary cilia structure with chloral hydrate. These results suggest that growth plate chondrocytes respond to hydrostatic loading by increasing Ihh signaling, and that the primary cilium is required for this mechano-biological signal transduction to occur. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Experimental demonstration of high fidelity entanglement distribution over decoherence channels via qubit transduction.

    Science.gov (United States)

    Lim, Hyang-Tag; Hong, Kang-Hee; Kim, Yoon-Ho

    2015-10-21

    Quantum coherence and entanglement, which are essential resources for quantum information, are often degraded and lost due to decoherence. Here, we report a proof-of-principle experimental demonstration of high fidelity entanglement distribution over decoherence channels via qubit transduction. By unitarily switching the initial qubit encoding to another, which is insensitive to particular forms of decoherence, we have demonstrated that it is possible to avoid the effect of decoherence completely. In particular, we demonstrate high-fidelity distribution of photonic polarization entanglement over quantum channels with two types of decoherence, amplitude damping and polarization-mode dispersion, via qubit transduction between polarization qubits and dual-rail qubits. These results represent a significant breakthrough in quantum communication over decoherence channels as the protocol is input-state independent, requires no ancillary photons and symmetries, and has near-unity success probability.

  18. Systematic Prediction of Scaffold Proteins Reveals New Design Principles in Scaffold-Mediated Signal Transduction

    Science.gov (United States)

    Hu, Jianfei; Neiswinger, Johnathan; Zhang, Jin; Zhu, Heng; Qian, Jiang

    2015-01-01

    Scaffold proteins play a crucial role in facilitating signal transduction in eukaryotes by bringing together multiple signaling components. In this study, we performed a systematic analysis of scaffold proteins in signal transduction by integrating protein-protein interaction and kinase-substrate relationship networks. We predicted 212 scaffold proteins that are involved in 605 distinct signaling pathways. The computational prediction was validated using a protein microarray-based approach. The predicted scaffold proteins showed several interesting characteristics, as we expected from the functionality of scaffold proteins. We found that the scaffold proteins are likely to interact with each other, which is consistent with previous finding that scaffold proteins tend to form homodimers and heterodimers. Interestingly, a single scaffold protein can be involved in multiple signaling pathways by interacting with other scaffold protein partners. Furthermore, we propose two possible regulatory mechanisms by which the activity of scaffold proteins is coordinated with their associated pathways through phosphorylation process. PMID:26393507

  19. Lipid rafts generate digital-like signal transduction in cell plasma membranes.

    Science.gov (United States)

    Suzuki, Kenichi G N

    2012-06-01

    Lipid rafts are meso-scale (5-200 nm) cell membrane domains where signaling molecules assemble and function. However, due to their dynamic nature, it has been difficult to unravel the mechanism of signal transduction in lipid rafts. Recent advanced imaging techniques have revealed that signaling molecules are frequently, but transiently, recruited to rafts with the aid of protein-protein, protein-lipid, and/or lipid-lipid interactions. Individual signaling molecules within the raft are activated only for a short period of time. Immobilization of signaling molecules by cytoskeletal actin filaments and scaffold proteins may facilitate more efficient signal transmission from rafts. In this review, current opinions of how the transient nature of molecular interactions in rafts generates digital-like signal transduction in cell membranes, and the benefits this phenomenon provides, are discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Primary Cilia Modulate IHH Signal Transduction in Response to Hydrostatic Loading of Growth Plate Chondrocytes

    Science.gov (United States)

    Shao, Y, Yvonne Y.; Wang, Lai; Welter, J, Jean F.; Ballock, R. Tracy

    2011-01-01

    Indian Hedgehog (Ihh) is a key component of the regulatory apparatus governing chondrocyte proliferation and differentiation in the growth plate. Recent studies have demonstrated that the primary cilium is the site of Ihh signaling within the cell, and that primary cilia are essential for bone and cartilage formation. Primary cilia are also postulated to act as mechanosensory organelles that transduce mechanical forces acting on the cell into biological signals. In this study, we used a hydrostatic compression system to examine Ihh signal transduction under the influence of mechanical load. Our results demonstrate that hydrostatic compression increased both Ihh gene expression and Ihh-responsive Gli-luciferase activity. These increases were aborted by disrupting the primary cilia structure with chloral hydrate. These results suggest that growth plate chondrocytes respond to hydrostatic loading by increasing Ihh signaling, and that the primary cilium is required for this mechano-biological signal transduction to occur. PMID:21930256

  1. Effect of insulin resistance on intracellular signal transduction of vessels in diabetic

    International Nuclear Information System (INIS)

    Cen Rongguang; Wei Shaoying; Mo Xingju

    2003-01-01

    To investigate the relationship between the insulin resistance (IR) and the intracellular signal transduction of vessels, changes in fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG), total cholesterol (TC), inositol triphosphate (IP 3 ), protein kinase C(PKC) and intracellular total calcium concentration in 31 diabetic patients were compared with those of 39 normal controls. The levels of FBG, FINS, TG and TC in diabetic patients were significantly higher than those of normal controls (P 3 and PKC in diabetic patients were significantly lower than those of normal controls (P<0.01). The results suggest that there is a causal relation between insulin resistance and abnormalities of cellular calcium metabolism and intracellular signal transduction of vessels

  2. Adeno-associated viral vector transduction of human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Stender, Stefan; Murphy, Mary; O'Brien, Tim

    2007-01-01

    Mesenchymal stem cells (MSCs) have received considerable attention in the emerging field of regenerative medicine. One aspect of MSC research focuses on genetically modifying the cells with the aim of enhancing their regenerative potential. Adeno-associated virus (AAV) holds promise as a vector...... in human MSCs and to assess whether AAV transduction affects MSC multipotentiality. The results indicated that human MSCs could indeed be transiently transduced in vitro by the AAV2 vector with efficiencies of up to 65%. The percentage of GFP-positive cells peaked at 4 days post-transduction and declined...... rapidly towards 0% after day 8. The level of transgene expression in the GFP-positive population increased 4-fold over a 10,000 fold viral dose increase. This dose-response contrasted with the 200-fold increase observed in similarly transduced 293-cells, indicating a relatively restricted transgene...

  3. TRANSDUCTION OF BACILLUS LICHENIFORMIS AND BACILLUS SUBTILIS BY EACH OF TWO PHAGES1

    Science.gov (United States)

    Taylor, Martha J.; Thorne, Curtis B.

    1963-01-01

    Taylor, Martha J. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.) and Curtis B. Thorne. Transduction of Bacillus licheniformis and Bacillus subtilis by each of two phages. J. Bacteriol. 86:452–461. 1963.—A second transducing bacteriophage, designated SP-15, was isolated from the same soil-sample culture filtrate that supplied the Bacillus subtilis transducing phage, SP-10, reported earlier from this laboratory. SP-10 and SP-15 differ serologically and in several other respects, but share the ability to propagate on B. subtilis W-23-Sr (streptomycin-resistant) and B. licheniformis ATCC 9945a, and to mediate general transduction in either species when propagated homologously. Attempts to transduce between the species have failed. SP-10 forms plaques readily on both W-23-Sr and 9945a; SP-15 forms minute plaques on W-23-Sr and has shown no evidence of any lytic activity on 9945a. Maximal recoveries of prototrophic colonies from mixtures of SP-10 with auxotrophs of either W-23-Sr or 9945a were obtained only when excess phage was neutralized by post-transduction treatment with specific phage antiserum. Such treatment was not necessary for maximal recovery of transductants effected by SP-15. Unlike SP-10, SP-15 propagated on W-23-Sr did not transduce B. subtilis 168 (indole−). SP-15 transduced B. licheniformis more efficiently than did SP-10. Neither phage was able to transduce B. licheniformis as efficiently as it transduced B. subtilis. The differing influences of multiplicity of infection were compared for the two phages in both species. PMID:14066421

  4. Mechanism of active transport: free energy dissipation and free energy transduction.

    OpenAIRE

    Tanford, C

    1982-01-01

    The thermodynamic pathway for "chemiosmotic" free energy transduction in active transport is discussed with an ATP-driven Ca2+ pump as an illustrative example. Two innovations are made in the analysis. (i) Free energy dissipated as heat is rigorously excluded from overall free energy bookkeeping by focusing on the dynamic equilibrium state of the chemiosmotic process. (ii) Separate chemical potential terms for free energy donor and transported ions are used to keep track of the thermodynamic ...

  5. Tapping of Love waves in an isotropic surface waveguide by surface-to-bulk wave transduction.

    Science.gov (United States)

    Tuan, H.-S.; Chang, C.-P.

    1972-01-01

    A theoretical study of tapping a Love wave in an isotropic microacoustic surface waveguide is given. The surface Love wave is tapped by partial transduction into a bulk wave at a discontinuity. It is shown that, by careful design of the discontinuity, the converted bulk wave power and the radiation pattern may be controlled. General formulas are derived for the calculation of these important characteristics from a relatively general surface contour deformation.

  6. Efficient biotechnological approach for lentiviral transduction of induced pluripotent stem cells.

    Science.gov (United States)

    Zare, Mehrak; Soleimani, Masoud; Mohammadian, Mozhdeh; Akbarzadeh, Abolfazl; Havasi, Parvaneh; Zarghami, Nosratollah

    2016-01-01

    Induced pluripotent stem (iPS) cells are generated from differentiated adult somatic cells by reprogramming them. Unlimited self-renewal, and the potential to differentiate into any cell type, make iPS cells very promising candidates for basic and clinical research. Furthermore, iPS cells can be genetically manipulated for use as therapeutic tools. DNA can be introduced into iPS cells, using lentiviral vectors, which represent a helpful choice for efficient transduction and stable integration of transgenes. In this study, we compare two methods of lentiviral transduction of iPS cells, namely, the suspension method and the hanging drop method. In contrast to the conventional suspension method, in the hanging drop method, embryoid body (EB) formation and transduction occur concurrently. The iPS cells were cultured to form EBs, and then transduced with lentiviruses, using the conventional suspension method and the hanging drop method, to express miR-128 and green fluorescent protein (GFP). The number of transduced cells were assessed by fluorescent microscopy and flow cytometry. MTT assay and real-time PCR were performed to determine the cell viability and transgene expression, respectively. Morphologically, GFP+ cells were more detectable in the hanging drop method, and this finding was quantified by flow cytometric analysis. According to the results of the MTT assay, cell viability was considerably higher in the hanging drop method, and real-time PCR represented a higher relative expression of miR-128 in the iPS cells introduced with lentiviruses in drops. Altogether, it seems that lentiviral transduction of challenging iPS cells using the hanging drop method offers a suitable and sufficient strategy in their gene transfer, with less toxicity than the conventional suspension method.

  7. Signal transduction by normal isoforms and W mutant variants of the Kit receptor tyrosine kinase.

    OpenAIRE

    Reith, A D; Ellis, C; Lyman, S D; Anderson, D M; Williams, D E; Bernstein, A; Pawson, T

    1991-01-01

    Germline mutations at the Dominant White Spotting (W) and Steel (Sl) loci have provided conclusive genetic evidence that c-kit mediated signal transduction pathways are essential for normal mouse development. We have analysed the interactions of normal and mutant W/c-kit gene products with cytoplasmic signalling proteins, using transient c-kit expression assays in COS cells. In addition to the previously identified c-kit gene product (Kit+), a second normal Kit isoform (KitA+) containing an i...

  8. Role of Glycolytic Intermediates in Global Regulation and Signal Transduction. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Liao, J.C.

    2000-05-08

    The goal of this project is to determine the role of glycolytic intermediates in regulation of cell physiology. It is known that many glycolytic intermediates are involved in regulation of enzyme activities at the kinetic level. However, little is known regarding the role of these metabolites in global regulation and signal transduction. This project aims to investigate the role of glycolytic intermediates in the regulation of gene expression.

  9. Enhanced transduction of photonic crystal dye lasers for gas sensing via swelling polymer film

    DEFF Research Database (Denmark)

    Smith, Cameron; Lind, Johan Ulrik; Christiansen, Mads Brøkner

    2011-01-01

    We present the enhanced transduction of a photonic crystal dye laser for gas sensing via deposition of an additional swelling polymer film. Device operation involves swelling of the polymer film during exposure to specific gases, leading to a change in total effective refractive index. Experimental...... in its application to other intracavity-based detection schemes to enable gas sensing. © 2011 Optical Society of America....

  10. Recombinant adeno-associated virus: efficient transduction of the rat VMH and clearance from blood.

    Directory of Open Access Journals (Sweden)

    Margriet A van Gestel

    Full Text Available To promote the efficient and safe application of adeno-associated virus (AAV vectors as a gene transfer tool in the central nervous system (CNS, transduction efficiency and clearance were studied for serotypes commonly used to transfect distinct areas of the brain. As AAV2 was shown to transduce only small volumes in several brain regions, this study compares the transduction efficiency of three AAV pseudotyped vectors, namely AAV2/1, AAV2/5 and AAV2/8, in the ventromedial nucleus of the hypothalamus (VMH. No difference was found between AAV2/1 and AAV2/5 in transduction efficiency. Both AAV2/1 and AAV2/5 achieved a higher transduction rate than AAV2/8. One hour after virus administration to the brain, no viral particles could be traced in blood, indicating that no or negligible numbers of virions crossed the blood-brain barrier. In order to investigate survival of AAV in blood, clearance was determined following systemic AAV administration. The half-life of AAV2/1, AAV2/2, AAV2/5 and AAV2/8 was calculated by determining virus clearance rates from blood after systemic injection. The half-life of AAV2/2 was 4.2 minutes, which was significantly lower than the half-lives of AAV2/1, AAV2/5 and AAV2/8. With a half-life of more than 11 hours, AAV2/8 particles remained detectable in blood significantly longer than AAV2/5. We conclude that application of AAV in the CNS is relatively safe as no AAV particles are detectable in blood after injection into the brain. With a half-life of 1.67 hours of AAV2/5, a systemic injection with 1×109 genomic copies of AAV would be fully cleared from blood after 2 days.

  11. The Drosophila rolled locus encodes a MAP kinase required in the sevenless signal transduction pathway.

    OpenAIRE

    Biggs, W H; Zavitz, K H; Dickson, B; van der Straten, A; Brunner, D; Hafen, E; Zipursky, S L

    1994-01-01

    Mitogen-activated protein (MAP) kinases have been proposed to play a critical role in receptor tyrosine kinase (RTK)-mediated signal transduction pathways. Although genetic and biochemical studies of RTK pathways in Caenorhabditis elegans, Drosophila melanogaster and mammals have revealed remarkable similarities, a genetic requirement for MAP kinases in RTK signaling has not been established. During retinal development in Drosophila, the sevenless (Sev) RTK is required for development of the ...

  12. Radiopharmaceutical development of radiolabelled peptides

    Energy Technology Data Exchange (ETDEWEB)

    Fani, Melpomeni; Maecke, Helmut R. [University Hospital Freiburg, Department of Nuclear Medicine, Freiburg (Germany)

    2012-02-15

    Receptor targeting with radiolabelled peptides has become very important in nuclear medicine and oncology in the past few years. The overexpression of many peptide receptors in numerous cancers, compared to their relatively low density in physiological organs, represents the molecular basis for in vivo imaging and targeted radionuclide therapy with radiolabelled peptide-based probes. The prototypes are analogs of somatostatin which are routinely used in the clinic. More recent developments include somatostatin analogs with a broader receptor subtype profile or with antagonistic properties. Many other peptide families such as bombesin, cholecystokinin/gastrin, glucagon-like peptide-1 (GLP-1)/exendin, arginine-glycine-aspartic acid (RGD) etc. have been explored during the last few years and quite a number of potential radiolabelled probes have been derived from them. On the other hand, a variety of strategies and optimized protocols for efficient labelling of peptides with clinically relevant radionuclides such as {sup 99m}Tc, M{sup 3+} radiometals ({sup 111}In, {sup 86/90}Y, {sup 177}Lu, {sup 67/68}Ga), {sup 64/67}Cu, {sup 18}F or radioisotopes of iodine have been developed. The labelling approaches include direct labelling, the use of bifunctional chelators or prosthetic groups. The choice of the labelling approach is driven by the nature and the chemical properties of the radionuclide. Additionally, chemical strategies, including modification of the amino acid sequence and introduction of linkers/spacers with different characteristics, have been explored for the improvement of the overall performance of the radiopeptides, e.g. metabolic stability and pharmacokinetics. Herein, we discuss the development of peptides as radiopharmaceuticals starting from the choice of the labelling method and the conditions to the design and optimization of the peptide probe, as well as some recent developments, focusing on a selected list of peptide families, including somatostatin

  13. Presence of Ca2+-dependent K+ channels in chemosensory cilia support a role in odor transduction.

    Science.gov (United States)

    Delgado, Ricardo; Saavedra, M Veronica; Schmachtenberg, Oliver; Sierralta, Jimena; Bacigalupo, Juan

    2003-09-01

    Olfactory receptor neurons (ORNs) respond to odorants with changes in the action potential firing rate. Excitatory responses, consisting of firing increases, are mediated by a cyclic AMP cascade that leads to the activation of cationic nonselective cyclic nucleotide-gated (CNG) channels and Ca2+-dependent Cl- (ClCa) channels. This process takes place in the olfactory cilia, where all protein components of this cascade are confined. ORNs from various vertebrate species have also been shown to generate inhibitory odor responses, expressed as decreases in action potential discharges. Odor inhibition appears to rely on Ca2+-dependent K+ (KCa) channels, but the underlying transduction mechanism remains unknown. If these channels are involved in odor transduction, they are expected to be present in the olfactory cilia. We found that a specific antibody against a large conductance KCa recognized a protein of approximately 116 kDa in Western blots of purified rat olfactory ciliary membranes. Moreover, the antibody labeled ORN cilia in isolated ORNs from rat and toad (Caudiverbera caudiverbera). In addition, single-channel recordings from inside-out membrane patches excised from toad chemosensory cilia showed the presence of 4 different types of KCa channels, with unitary conductances of 210, 60, 12, and 29 and 60 pS, high K+-selectivity, and Ca2+ sensitivities in the low micromolar range. Our work demonstrates the presence of K+ channels in the ORN cilia and supports their participation in odor transduction.

  14. Decision Aggregation in Distributed Classification by a Transductive Extension of Maximum Entropy/Improved Iterative Scaling

    Directory of Open Access Journals (Sweden)

    George Kesidis

    2008-06-01

    Full Text Available In many ensemble classification paradigms, the function which combines local/base classifier decisions is learned in a supervised fashion. Such methods require common labeled training examples across the classifier ensemble. However, in some scenarios, where an ensemble solution is necessitated, common labeled data may not exist: (i legacy/proprietary classifiers, and (ii spatially distributed and/or multiple modality sensors. In such cases, it is standard to apply fixed (untrained decision aggregation such as voting, averaging, or naive Bayes rules. In recent work, an alternative transductive learning strategy was proposed. There, decisions on test samples were chosen aiming to satisfy constraints measured by each local classifier. This approach was shown to reliably correct for class prior mismatch and to robustly account for classifier dependencies. Significant gains in accuracy over fixed aggregation rules were demonstrated. There are two main limitations of that work. First, feasibility of the constraints was not guaranteed. Second, heuristic learning was applied. Here, we overcome these problems via a transductive extension of maximum entropy/improved iterative scaling for aggregation in distributed classification. This method is shown to achieve improved decision accuracy over the earlier transductive approach and fixed rules on a number of UC Irvine datasets.

  15. A Biosensor for Urea from Succinimide-Modified Acrylic Microspheres Based on Reflectance Transduction

    Directory of Open Access Journals (Sweden)

    Musa Ahmad

    2011-08-01

    Full Text Available New acrylic microspheres were synthesised by photopolymerisation where the succinimide functional group was incorporated during the microsphere preparation. An optical biosensor for urea based on reflectance transduction with a large linear response range to urea was successfully developed using this material. The biosensor utilized succinimide-modified acrylic microspheres immobilized with a Nile blue chromoionophore (ETH 5294 for optical detection and urease enzyme was immobilized on the surface of the microspheres via the succinimide groups. No leaching of the enzyme or chromoionophore was observed. Hydrolysis of the urea by urease changes the pH and leads to a color change of the immobilized chromoionophore. When the color change was monitored by reflectance spectrophotometry, the linear response range of the biosensor to urea was from 0.01 to 1,000 mM (R2 = 0.97 with a limit of detection of 9.97 mM. The biosensor response showed good reproducibility (relative standard deviation = 1.43%, n = 5 with no interference by major cations such as Na+, K+, NH4+ and Mg2+. The use of reflectance as a transduction method led to a large linear response range that is better than that of many urea biosensors based on other optical transduction methods.

  16. Adeno-associated virus vector-mediated transduction in the cat brain.

    Science.gov (United States)

    Vite, Charles H; Passini, Marco A; Haskins, Mark E; Wolfe, John H

    2003-10-01

    Adeno-associated virus (AAV) vectors are capable of delivering a therapeutic gene to the mouse brain that can result in long-term and widespread protein production. However, the human infant brain is more than 1000 times larger than the mouse brain, which will make the treatment of global neurometabolic disorders in children more difficult. In this study, we evaluated the ability of three AAV serotypes (1,2, and 5) to transduce cells in the cat brain as a model of a large mammalian brain. The human lysosomal enzyme beta-glucuronidase (GUSB) was used as a reporter gene, because it can be distinguished from feline GUSB by heat stability. The vectors were injected into the cerebral cortex, caudate nucleus, thalamus, corona radiata, internal capsule, and centrum semiovale of 8-week-old cats. The brains were evaluated for gene expression using in situ hybridization and enzyme histochemistry 10 weeks after surgery. The AAV2 vector was capable of transducing cells in the gray matter, while the AAV1 vector resulted in greater transduction of the gray matter than AAV2 as well as transduction of the white matter. AAV5 did not result in detectable transduction in the cat brain.

  17. Influence of arsenate and arsenite on signal transduction pathways: an update

    Energy Technology Data Exchange (ETDEWEB)

    Druwe, Ingrid L.; Vaillancourt, Richard R. [The University of Arizona College of Pharmacy, Department of Pharmacology and Toxicology, Tucson, AZ (United States)

    2010-08-15

    Arsenic has been a recognized contaminant and toxicant, as well as a medicinal compound throughout human history. Populations throughout the world are exposed to arsenic and these exposures have been associated with a number of human cancers. Not much is known about the role of arsenic as a human carcinogen and more recently its role in non-cancerous diseases, such as cardiovascular disease, hypertension and diabetes mellitus have been uncovered. The health effects associated with arsenic are numerous and the association between arsenic exposure and human disease has intensified the search for molecular mechanisms that describe the biological activity of arsenic in humans and leads to the aforementioned disease states. Arsenic poses a human health risk due in part to the regulation of cellular signal transduction pathways and over the last few decades, some cellular mechanisms that account for arsenic toxicity, as well as, signal transduction pathways have been discovered. However, given the ubiquitous nature of arsenic in the environment, making sense of all the data remains a challenge. This review will focus on our knowledge of signal transduction pathways that are regulated by arsenic. (orig.)

  18. Progestins alter photo-transduction cascade and circadian rhythm network in eyes of zebrafish (Danio rerio)

    Science.gov (United States)

    Zhao, Yanbin; Fent, Karl

    2016-02-01

    Environmental progestins are implicated in endocrine disruption in vertebrates. Additional targets that may be affected in organisms are poorly known. Here we report that progesterone (P4) and drospirenone (DRS) interfere with the photo-transduction cascade and circadian rhythm network in the eyes of zebrafish. Breeding pairs of adult zebrafish were exposed to P4 and DRS for 21 days with different measured concentrations of 7-742 ng/L and 99-13´650 ng/L, respectively. Of totally 10 key photo-transduction cascade genes analyzed, transcriptional levels of most were significantly up-regulated, or normal down-regulation was attenuated. Similarly, for some circadian rhythm genes, dose-dependent transcriptional alterations were also observed in the totally 33 genes analyzed. Significant alterations occurred even at environmental relevant levels of 7 ng/L P4. Different patterns were observed for these transcriptional alterations, of which, the nfil3 family displayed most significant changes. Furthermore, we demonstrate the importance of sampling time for the determination and interpretation of gene expression data, and put forward recommendations for sampling strategies to avoid false interpretations. Our results suggest that photo-transduction signals and circadian rhythm are potential targets for progestins. Further studies are required to assess alterations on the protein level, on physiology and behavior, as well as on implications in mammals.

  19. Peptide-LNA oligonucleotide conjugates

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Hansen, Lykke Haastrup; Vester, Birte

    2013-01-01

    properties, peptides were introduced into oligonucleotides via a 2'-alkyne-2'-amino-LNA scaffold. Derivatives of methionine- and leucine-enkephalins were chosen as model peptides of mixed amino acid content, which were singly and doubly incorporated into LNA/DNA strands using highly efficient copper......(i)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" chemistry. DNA/RNA target binding affinity and selectivity of the resulting POCs were improved in comparison to LNA/DNA mixmers and unmodified DNA controls. This clearly demonstrates that internal attachment of peptides to oligonucleotides can significantly...

  20. New vasoactive peptides in cirrhosis

    DEFF Research Database (Denmark)

    Kimer, Nina; Goetze, Jens Peter; Bendtsen, Flemming

    2014-01-01

    BACKGROUND: Patients with cirrhosis have substantial circulatory imbalance between vasoconstrictive and vasodilating forces. The study of circulatory vasoactive peptides may provide important pathophysiological information. This study aimed to assess concentrations, organ extraction and relations...... to haemodynamic changes in the pro-peptides copeptin, proadrenomedullin and pro-atrial natriuretic peptide (proANP) in patients with cirrhosis. MATERIALS AND METHODS: Fifty-four cirrhotic patients and 15 controls were characterized haemodynamically during a liver vein catheterization. Copeptin, proadrenomedullin...... pressure (R=0·32, P0·31, Ppeptide is elevated in cirrhosis. Copeptin, proadrenomedullin and proANP are related to portal pressure and seem associated with systemic haemodynamics. These propeptides may...

  1. Characterization of synthetic peptides by mass spectrometry

    DEFF Research Database (Denmark)

    Prabhala, Bala Krishna; Mirza, Osman Asghar; Højrup, Peter

    2015-01-01

    Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI......-TOF-MS and LC-MS of synthetic peptides....

  2. Inconsistent Transduction

    DEFF Research Database (Denmark)

    Højlund, Marie Koldkjær; Riis, Morten S.

    2017-01-01

    The growing integration of sounding art as research practice in academia is a part of the “practice turn” in humanities and social sciences, where artistic practices and artefacts themselves become a form of academic inquiry. As the process of creating art represents a valid research method...... at “not-knowing” or “not-yet-knowing” within artistic research encompassing the unexpected, the spontaneous and involuntary. We argue that the implicit human-centred perspective present in these alternative understandings of knowledge production in artistic research prevents us from fully engaging...... with the objects in question on their own premises. Therefore, tuning into the “not-knowing” requires expanding the perspective to encompass non-human forms of knowledge incorporated through an object-oriented ontological line of thinking. By switching the focus from the human perspective to that of the objects...

  3. Marine Peptides: Bioactivities and Applications

    Directory of Open Access Journals (Sweden)

    Randy Chi Fai Cheung

    2015-06-01

    Full Text Available Peptides are important bioactive natural products which are present in many marine species. These marine peptides have high potential nutraceutical and medicinal values because of their broad spectra of bioactivities. Their antimicrobial, antiviral, antitumor, antioxidative, cardioprotective (antihypertensive, antiatherosclerotic and anticoagulant, immunomodulatory, analgesic, anxiolytic anti-diabetic, appetite suppressing and neuroprotective activities have attracted the attention of the pharmaceutical industry, which attempts to design them for use in the treatment or prevention of various diseases. Some marine peptides or their derivatives have high commercial values and had reached the pharmaceutical and nutraceutical markets. A large number of them are already in different phases of the clinical and preclinical pipeline. This review highlights the recent research in marine peptides and the trends and prospects for the future, with special emphasis on nutraceutical and pharmaceutical development into marketed products.

  4. Cardioprotective peptides from marine sources.

    Science.gov (United States)

    Harnedy, Padraigín A; FitzGerald, Richard J

    2013-05-01

    Elevated blood pressure or hypertension is one of the fastest growing health problems worldwide. Although the etiology of essential hypertension has a genetic component, dietary factors play an important role. With the high costs and adverse side-effects associated with synthetic antihypertensive drugs and the awareness of the link between diet and health there has been increased focus on identification of food components that may contribute to cardiovascular health. In recent years special interest has been paid to the cardioprotective activity of peptides derived from food proteins including marine proteins. These peptides are latent within the sequence of the parent protein and only become active when released by proteolytic digestion during gastrointestinal digestion or through food processing. Current data on antihypertensive activity of marine-derived protein hydrolysates/peptides in animal and human studies is reviewed herein. Furthermore, products containing protein hydrolysates/peptides from marine origin with antihypertensive effects are discussed.

  5. Antimicrobial peptides from Capsicum sp.

    African Journals Online (AJOL)

    ajl yemi

    2011-12-30

    Dec 30, 2011 ... Key words: Antimicrobial peptides, Capsicum sp, Capsicum chinense, chili pepper, agronomical options, ..... of this human activity is resumed by the simple phrase: produce .... It will be interesting to scale the AMPs extraction.

  6. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Hansen, Paul Robert; Houen, Gunnar

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies...... are powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

  7. Gastro-Resistant Insulin Receptor-Binding Peptide from Momordica charantia Improved the Glucose Tolerance in Streptozotocin-Induced Diabetic Mice via Insulin Receptor Signaling Pathway.

    Science.gov (United States)

    Lo, Hsin-Yi; Li, Chia-Cheng; Chen, Feng-Yuan; Chen, Jaw-Chyun; Hsiang, Chien-Yun; Ho, Tin-Yun

    2017-10-25

    Momordica charantia is a commonly used food and has been used for the management of diabetes. Our previous study has identified an insulin receptor (IR)-binding protein (mcIRBP) from Momordica charantia. Here we identified the gastro-resistant hypoglycemic bioactive peptides from protease-digested mcIRBP. By in vitro digestion and IR kinase activity assay, we found that a 9-amino-acid-residue peptide, mcIRBP-9, was a gastro-resistant peptide that enhanced IR kinase activities. mcIRBP-9 activated IR signaling transduction pathway, which resulted in the phosphorylation of IR, the translocation of glucose transporter 4, and the uptake of glucose in cells. Intraperitoneal and oral administration of mcIRBP-9 stimulated the glucose clearance by 30.91 ± 0.39% and 32.09 ± 0.38%, respectively, in streptozotocin-induced diabetic mice. Moreover, a pilot study showed that daily ingestion of mcIRBP-9 for 30 days decreased the fasting blood glucose levels and glycated hemoglobin (HbA1c) levels by 23.62 ± 6.14% and 24.06 ± 1.53%, respectively. In conclusion, mcIRBP-9 is a unique gastro-resistant bioactive peptide generated after the digestion of mcIRBP. Furthermore, oral administration of mcIRBP-9 improves both the glucose tolerance and the HbA1c levels in diabetic mice via targeting IR signaling transduction pathway.

  8. Peptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Bachovchin, W.W.; Unkefer, C.J.

    1994-12-01

    Advances in magnetic resonance and vibrational spectroscopy make it possible to derive detailed structural information about biomolecular structures in solution. These techniques are critically dependent on the availability of labeled compounds. For example, NMR techniques used today to derive peptide and protein structures require uniformity {sup 13}C-and {sup 15}N-labeled samples that are derived biosynthetically from (U-6-{sup 13}C) glucose. These experiments are possible now because, during the 1970s, the National Stable Isotope Resource developed algal methods for producing (U-6-{sup 13}C) glucose. If NMR techniques are to be used to study larger proteins, we will need sophisticated labelling patterns in amino acids that employ a combination of {sup 2}H, {sup 13}C, and {sup 15}N labeling. The availability of these specifically labeled amino acids requires a renewed investment in new methods for chemical synthesis of labeled amino acids. The development of new magnetic resonance or vibrational techniques to elucidate biomolecular structure will be seriously impeded if we do not see rapid progress in labeling technology. Investment in labeling chemistry is as important as investment in the development of advanced spectroscopic tools.

  9. Matrix-assisted peptide synthesis on nanoparticles.

    Science.gov (United States)

    Khandadash, Raz; Machtey, Victoria; Weiss, Aryeh; Byk, Gerardo

    2014-09-01

    We report a new method for multistep peptide synthesis on polymeric nanoparticles of differing sizes. Polymeric nanoparticles were functionalized via their temporary embedment into a magnetic inorganic matrix that allows multistep peptide synthesis. The matrix is removed at the end of the process for obtaining nanoparticles functionalized with peptides. The matrix-assisted synthesis on nanoparticles was proved by generating various biologically relevant peptides. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  10. Material Binding Peptides for Nanotechnology

    Directory of Open Access Journals (Sweden)

    Urartu Ozgur Safak Seker

    2011-02-01

    Full Text Available Remarkable progress has been made to date in the discovery of material binding peptides and their utilization in nanotechnology, which has brought new challenges and opportunities. Nowadays phage display is a versatile tool, important for the selection of ligands for proteins and peptides. This combinatorial approach has also been adapted over the past decade to select material-specific peptides. Screening and selection of such phage displayed material binding peptides has attracted great interest, in particular because of their use in nanotechnology. Phage display selected peptides are either synthesized independently or expressed on phage coat protein. Selected phage particles are subsequently utilized in the synthesis of nanoparticles, in the assembly of nanostructures on inorganic surfaces, and oriented protein immobilization as fusion partners of proteins. In this paper, we present an overview on the research conducted on this area. In this review we not only focus on the selection process, but also on molecular binding characterization and utilization of peptides as molecular linkers, molecular assemblers and material synthesizers.

  11. Towards a clinically relevant lentiviral transduction protocol for primary human CD34 hematopoietic stem/progenitor cells.

    Directory of Open Access Journals (Sweden)

    Michelle Millington

    2009-07-01

    Full Text Available Hematopoietic stem cells (HSC, in particular mobilized peripheral blood stem cells, represent an attractive target for cell and gene therapy. Efficient gene delivery into these target cells without compromising self-renewal and multi-potency is crucial for the success of gene therapy. We investigated factors involved in the ex vivo transduction of CD34(+ HSCs in order to develop a clinically relevant transduction protocol for gene delivery. Specifically sought was a protocol that allows for efficient transduction with minimal ex vivo manipulation without serum or other reagents of animal origin.Using commercially available G-CSF mobilized peripheral blood (PB CD34(+ cells as the most clinically relevant target, we systematically examined factors including the use of serum, cytokine combinations, pre-stimulation time, multiplicity of infection (MOI, transduction duration and the use of spinoculation and/or retronectin. A self-inactivating lentiviral vector (SIN-LV carrying enhanced green fluorescent protein (GFP was used as the gene delivery vehicle. HSCs were monitored for transduction efficiency, surface marker expression and cellular function. We were able to demonstrate that efficient gene transduction can be achieved with minimal ex vivo manipulation while maintaining the cellular function of transduced HSCs without serum or other reagents of animal origin.This study helps to better define factors relevant towards developing a standard clinical protocol for the delivery of SIN-LV into CD34(+ cells.

  12. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    International Nuclear Information System (INIS)

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-01-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs

  13. Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor-Derived Peptides for Regulation of Mast Cell Degranulation.

    Science.gov (United States)

    Yang, Yoosoo; Kong, Byoungjae; Jung, Younghoon; Park, Joon-Bum; Oh, Jung-Mi; Hwang, Jaesung; Cho, Jae Youl; Kweon, Dae-Hyuk

    2018-01-01

    Vesicle-associated V-soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and target membrane-associated T-SNAREs (syntaxin 4 and SNAP-23) assemble into a core trans -SNARE complex that mediates membrane fusion during mast cell degranulation. This complex plays pivotal roles at various stages of exocytosis from the initial priming step to fusion pore opening and expansion, finally resulting in the release of the vesicle contents. In this study, peptides with the sequences of various SNARE motifs were investigated for their potential inhibitory effects against SNARE complex formation and mast cell degranulation. The peptides with the sequences of the N-terminal regions of vesicle-associated membrane protein 2 (VAMP2) and VAMP8 were found to reduce mast cell degranulation by inhibiting SNARE complex formation. The fusion of protein transduction domains to the N-terminal of each peptide enabled the internalization of the fusion peptides into the cells equally as efficiently as cell permeabilization by streptolysin-O without any loss of their inhibitory activities. Distinct subsets of mast cell granules could be selectively regulated by the N-terminal-mimicking peptides derived from VAMP2 and VAMP8, and they effectively decreased the symptoms of atopic dermatitis in mouse models. These results suggest that the cell membrane fusion machinery may represent a therapeutic target for atopic dermatitis.

  14. Flanking signal and mature peptide residues influence signal peptide cleavage

    Directory of Open Access Journals (Sweden)

    Ranganathan Shoba

    2008-12-01

    Full Text Available Abstract Background Signal peptides (SPs mediate the targeting of secretory precursor proteins to the correct subcellular compartments in prokaryotes and eukaryotes. Identifying these transient peptides is crucial to the medical, food and beverage and biotechnology industries yet our understanding of these peptides remains limited. This paper examines the most common type of signal peptides cleavable by the endoprotease signal peptidase I (SPase I, and the residues flanking the cleavage sites of three groups of signal peptide sequences, namely (i eukaryotes (Euk (ii Gram-positive (Gram+ bacteria, and (iii Gram-negative (Gram- bacteria. Results In this study, 2352 secretory peptide sequences from a variety of organisms with amino-terminal SPs are extracted from the manually curated SPdb database for analysis based on physicochemical properties such as pI, aliphatic index, GRAVY score, hydrophobicity, net charge and position-specific residue preferences. Our findings show that the three groups share several similarities in general, but they display distinctive features upon examination in terms of their amino acid compositions and frequencies, and various physico-chemical properties. Thus, analysis or prediction of their sequences should be separated and treated as distinct groups. Conclusion We conclude that the peptide segment recognized by SPase I extends to the start of the mature protein to a limited extent, upon our survey of the amino acid residues surrounding the cleavage processing site. These flanking residues possibly influence the cleavage processing and contribute to non-canonical cleavage sites. Our findings are applicable in defining more accurate prediction tools for recognition and identification of cleavage site of SPs.

  15. Peptides and Anti-peptide Antibodies for Small and Medium Scale Peptide and Anti-peptide Affinity Microarrays: Antigenic Peptide Selection, Immobilization, and Processing.

    Science.gov (United States)

    Zhang, Fan; Briones, Andrea; Soloviev, Mikhail

    2016-01-01

    This chapter describes the principles of selection of antigenic peptides for the development of anti-peptide antibodies for use in microarray-based multiplex affinity assays and also with mass-spectrometry detection. The methods described here are mostly applicable to small to medium scale arrays. Although the same principles of peptide selection would be suitable for larger scale arrays (with 100+ features) the actual informatics software and printing methods may well be different. Because of the sheer number of proteins/peptides to be processed and analyzed dedicated software capable of processing all the proteins and an enterprise level array robotics may be necessary for larger scale efforts. This report aims to provide practical advice to those who develop or use arrays with up to ~100 different peptide or protein features.

  16. Automated solid-phase peptide synthesis to obtain therapeutic peptides

    Directory of Open Access Journals (Sweden)

    Veronika Mäde

    2014-05-01

    Full Text Available The great versatility and the inherent high affinities of peptides for their respective targets have led to tremendous progress for therapeutic applications in the last years. In order to increase the drugability of these frequently unstable and rapidly cleared molecules, chemical modifications are of great interest. Automated solid-phase peptide synthesis (SPPS offers a suitable technology to produce chemically engineered peptides. This review concentrates on the application of SPPS by Fmoc/t-Bu protecting-group strategy, which is most commonly used. Critical issues and suggestions for the synthesis are covered. The development of automated methods from conventional to essentially improved microwave-assisted instruments is discussed. In order to improve pharmacokinetic properties of peptides, lipidation and PEGylation are described as covalent conjugation methods, which can be applied by a combination of automated and manual synthesis approaches. The synthesis and application of SPPS is described for neuropeptide Y receptor analogs as an example for bioactive hormones. The applied strategies represent innovative and potent methods for the development of novel peptide drug candidates that can be manufactured with optimized automated synthesis technologies.

  17. What peptides these deltorphins be.

    Science.gov (United States)

    Lazarus, L H; Bryant, S D; Cooper, P S; Salvadori, S

    1999-02-01

    The deltorphins are a class of highly selective delta-opioid heptapeptides from the skin of the Amazonian frogs Phyllomedusa sauvagei and P. bicolor. The first of these fascinating peptides came to light in 1987 by cloning of the cDNA of from frog skins, while the other members of this family were identified either by cDNA or isolation of the peptides. The distinctive feature of deltorphins is the presence of a naturally occurring D-enantiomer at the second position in their common N-terminal sequence, Tyr-D-Xaa-Phe, comparable to dermorphin, which is the prototype of a group of mu-selective opioids from the same source. The D-amino acid and the anionic residues, either Glu or Asp, as well as their unique amino acid compositions are responsible for the remarkable biostability, high delta-receptor affinity, bioactivity and peptide conformation. This review summarizes a decade of research from many laboratories that defined which residues and substituents in the deltorphins interact with the delta-receptor and characterized pharmacological and physiological activities in vitro and in vivo. It begins with a historical description of the topic and presents general schema for the synthesis of peptide analogues of deltorphins A, B and C as a means to document the methods employed in producing a myriad of analogues. Structure activity studies of the peptides and their pharmacological activities in vitro are detailed in abundantly tabulated data. A brief compendium of the current level of knowledge of the delta-receptor assists the reader to appreciate the rationale for the design of these analogues. Discussion of the conformation of these peptides addresses how structure leads to further hypotheses regarding ligand receptor interaction. The review ends with a broad discussion of the potential applications of these peptides in clinical and therapeutic settings.

  18. Sequencing Cyclic Peptides by Multistage Mass Spectrometry

    Science.gov (United States)

    Mohimani, Hosein; Yang, Yu-Liang; Liu, Wei-Ting; Hsieh, Pei-Wen; Dorrestein, Pieter C.; Pevzner, Pavel A.

    2012-01-01

    Some of the most effective antibiotics (e.g., Vancomycin and Daptomycin) are cyclic peptides produced by non-ribosomal biosynthetic pathways. While hundreds of biomedically important cyclic peptides have been sequenced, the computational techniques for sequencing cyclic peptides are still in their infancy. Previous methods for sequencing peptide antibiotics and other cyclic peptides are based on Nuclear Magnetic Resonance spectroscopy, and require large amount (miligrams) of purified materials that, for most compounds, are not possible to obtain. Recently, development of mass spectrometry based methods has provided some hope for accurate sequencing of cyclic peptides using picograms of materials. In this paper we develop a method for sequencing of cyclic peptides by multistage mass spectrometry, and show its advantages over single stage mass spectrometry. The method is tested on known and new cyclic peptides from Bacillus brevis, Dianthus superbus and Streptomyces griseus, as well as a new family of cyclic peptides produced by marine bacteria. PMID:21751357

  19. Cyclic peptide therapeutics: past, present and future.

    Science.gov (United States)

    Zorzi, Alessandro; Deyle, Kaycie; Heinis, Christian

    2017-06-01

    Cyclic peptides combine several favorable properties such as good binding affinity, target selectivity and low toxicity that make them an attractive modality for the development of therapeutics. Over 40 cyclic peptide drugs are currently in clinical use and around one new cyclic peptide drug enters the market every year on average. The vast majority of clinically approved cyclic peptides are derived from natural products, such as antimicrobials or human peptide hormones. New powerful techniques based on rational design and in vitro evolution have enabled the de novo development of cyclic peptide ligands to targets for which nature does not offer solutions. A look at the cyclic peptides currently under clinical evaluation shows that several have been developed using such techniques. This new source for cyclic peptide ligands introduces a freshness to the field, and it is likely that de novo developed cyclic peptides will be in clinical use in the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Semi-Supervised Transductive Hot Spot Predictor Working on Multiple Assumptions

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-05-23

    Protein-protein interactions are critically dependent on just a few residues (“hot spots”) at the interfaces. Hot spots make a dominant contribution to the binding free energy and if mutated they can disrupt the interaction. As mutagenesis studies require significant experimental efforts, there exists a need for accurate and reliable computational hot spot prediction methods. Compared to the supervised hot spot prediction algorithms, the semi-supervised prediction methods can take into consideration both the labeled and unlabeled residues in the dataset during the prediction procedure. The transductive support vector machine has been utilized for this task and demonstrated a better prediction performance. To the best of our knowledge, however, none of the transductive semi-supervised algorithms takes all the three semisupervised assumptions, i.e., smoothness, cluster and manifold assumptions, together into account during learning. In this paper, we propose a novel semi-supervised method for hot spot residue prediction, by considering all the three semisupervised assumptions using nonlinear models. Our algorithm, IterPropMCS, works in an iterative manner. In each iteration, the algorithm first propagates the labels of the labeled residues to the unlabeled ones, along the shortest path between them on a graph, assuming that they lie on a nonlinear manifold. Then it selects the most confident residues as the labeled ones for the next iteration, according to the cluster and smoothness criteria, which is implemented by a nonlinear density estimator. Experiments on a benchmark dataset, using protein structure-based features, demonstrate that our approach is effective in predicting hot spots and compares favorably to other available methods. The results also show that our method outperforms the state-of-the-art transductive learning methods.

  1. Rice PLASTOCHRON genes regulate leaf maturation downstream of the gibberellin signal transduction pathway.

    Science.gov (United States)

    Mimura, Manaki; Nagato, Yasuo; Itoh, Jun-Ichi

    2012-05-01

    Rice PLASTOCHRON 1 (PLA1) and PLA2 genes regulate leaf maturation and plastochron, and their loss-of-function mutants exhibit small organs and rapid leaf emergence. They encode a cytochrome P450 protein CYP78A11 and an RNA-binding protein, respectively. Their homologs in Arabidopsis and maize are also associated with plant development/organ size. Despite the importance of PLA genes in plant development, their molecular functions remain unknown. Here, we investigated how PLA1 and PLA2 genes are related to phytohormones. We found that gibberellin (GA) is the major phytohormone that promotes PLA1 and PLA2 expression. GA induced PLA1 and PLA2 expression, and conversely the GA-inhibitor uniconazole suppressed PLA1 and PLA2 expression. In pla1-4 and pla2-1 seedlings, expression levels of GA biosynthesis genes and the signal transduction gene were similar to those in wild-type seedlings. GA treatment slightly down-regulated the GA biosynthesis gene GA20ox2 and up-regulated the GA-catabolizing gene GA2ox4, whereas the GA biosynthesis inhibitor uniconazole up-regulated GA20ox2 and down-regulated GA2ox4 both in wild-type and pla mutants, suggesting that the GA feedback mechanism is not impaired in pla1 and pla2. To reveal how GA signal transduction affects the expression of PLA1 and PLA2, PLA expression in GA-signaling mutants was examined. In GA-insensitive mutant, gid1 and less-sensitive mutant, Slr1-d1, PLA1 and PLA2 expression was down-regulated. On the other hand, the expression levels of PLA1 and PLA2 were highly enhanced in a GA-constitutive-active mutant, slr1-1, causing ectopic overexpression. These results indicate that both PLA1 and PLA2 act downstream of the GA signal transduction pathway to regulate leaf development.

  2. Unrestricted Hepatocyte Transduction with Adeno-Associated Virus Serotype 8 Vectors in Mice

    Science.gov (United States)

    Nakai, Hiroyuki; Fuess, Sally; Storm, Theresa A.; Muramatsu, Shin-ichi; Nara, Yuko; Kay, Mark A.

    2005-01-01

    Recombinant adeno-associated virus (rAAV) vectors can mediate long-term stable transduction in various target tissues. However, with rAAV serotype 2 (rAAV2) vectors, liver transduction is confined to only a small portion of hepatocytes even after administration of extremely high vector doses. In order to investigate whether rAAV vectors of other serotypes exhibit similar restricted liver transduction, we performed a dose-response study by injecting mice with β-galactosidase-expressing rAAV1 and rAAV8 vectors via the portal vein. The rAAV1 vector showed a blunted dose-response similar to that of rAAV2 at high doses, while the rAAV8 vector dose-response remained unchanged at any dose and ultimately could transduce all the hepatocytes at a dose of 7.2 × 1012 vector genomes/mouse without toxicity. This indicates that all hepatocytes have the ability to process incoming single-stranded vector genomes into duplex DNA. A single tail vein injection of the rAAV8 vector was as efficient as portal vein injection at any dose. In addition, intravascular administration of the rAAV8 vector at a high dose transduced all the skeletal muscles throughout the body, including the diaphragm, the entire cardiac muscle, and substantial numbers of cells in the pancreas, smooth muscles, and brain. Thus, rAAV8 is a robust vector for gene transfer to the liver and provides a promising research tool for delivering genes to various target organs. In addition, the rAAV8 vector may offer a potential therapeutic agent for various diseases affecting nonhepatic tissues, but great caution is required for vector spillover and tight control of tissue-specific gene expression. PMID:15596817

  3. Transfer functions for protein signal transduction: application to a model of striatal neural plasticity.

    Directory of Open Access Journals (Sweden)

    Gabriele Scheler

    Full Text Available We present a novel formulation for biochemical reaction networks in the context of protein signal transduction. The model consists of input-output transfer functions, which are derived from differential equations, using stable equilibria. We select a set of "source" species, which are interpreted as input signals. Signals are transmitted to all other species in the system (the "target" species with a specific delay and with a specific transmission strength. The delay is computed as the maximal reaction time until a stable equilibrium for the target species is reached, in the context of all other reactions in the system. The transmission strength is the concentration change of the target species. The computed input-output transfer functions can be stored in a matrix, fitted with parameters, and even recalled to build dynamical models on the basis of state changes. By separating the temporal and the magnitudinal domain we can greatly simplify the computational model, circumventing typical problems of complex dynamical systems. The transfer function transformation of biochemical reaction systems can be applied to mass-action kinetic models of signal transduction. The paper shows that this approach yields significant novel insights while remaining a fully testable and executable dynamical model for signal transduction. In particular we can deconstruct the complex system into local transfer functions between individual species. As an example, we examine modularity and signal integration using a published model of striatal neural plasticity. The modularizations that emerge correspond to a known biological distinction between calcium-dependent and cAMP-dependent pathways. Remarkably, we found that overall interconnectedness depends on the magnitude of inputs, with higher connectivity at low input concentrations and significant modularization at moderate to high input concentrations. This general result, which directly follows from the properties of

  4. IGF-1 signaling mediated cell-specific skeletal mechano-transduction.

    Science.gov (United States)

    Tian, Faming; Wang, Yongmei; Bikle, Daniel D

    2018-02-01

    Mechanical loading preserves bone mass and stimulates bone formation, whereas skeletal unloading leads to bone loss. In addition to osteocytes, which are considered the primary sensor of mechanical load, osteoblasts, and bone specific mesenchymal stem cells also are involved. The skeletal response to mechanical signals is a complex process regulated by multiple signaling pathways including that of insulin-like growth factor-1 (IGF-1). Conditional osteocyte deletion of IGF-1 ablates the osteogenic response to mechanical loading. Similarly, osteocyte IGF-1 receptor (IGF-1R) expression is necessary for reloading-induced periosteal bone formation. Transgenic overexpression of IGF-1 in osteoblasts results in enhanced responsiveness to in vivo mechanical loading in mice, a response which is eliminated by osteoblastic conditional disruption of IGF-1 in vivo. Bone marrow derived stem cells (BMSC) from unloaded bone fail to respond to IGF-1 in vitro. IGF-1R is required for the transduction of a mechanical stimulus to downstream effectors, transduction which is lost when the IGF-1R is deleted. Although the molecular mechanisms are not yet fully elucidated, the IGF signaling pathway and its interactions with potentially interlinked signaling cascades involving integrins, the estrogen receptor, and wnt/β-catenin play an important role in regulating adaptive response of cancer bone cells to mechanical stimuli. In this review, we discuss recent advances investigating how IGF-1 and other interlinked molecules and signaling pathways regulate skeletal mechano-transduction involving different bone cells, providing an overview of the IGF-1 signaling mediated cell-specific response to mechanical stimuli. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:576-583, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. Resting lymphocyte transduction with measles virus glycoprotein pseudotyped lentiviral vectors relies on CD46 and SLAM

    International Nuclear Information System (INIS)

    Zhou Qi; Schneider, Irene C.; Gallet, Manuela; Kneissl, Sabrina; Buchholz, Christian J.

    2011-01-01

    The measles virus (MV) glycoproteins hemagglutinin (H) and fusion (F) were recently shown to mediate transduction of resting lymphocytes by lentiviral vectors. MV vaccine strains use CD46 or signaling lymphocyte activation molecule (SLAM) as receptor for cell entry. A panel of H protein mutants derived from vaccine strain or wild-type MVs that lost or gained CD46 or SLAM receptor usage were investigated for their ability to mediate gene transfer into unstimulated T lymphocytes. The results demonstrate that CD46 is sufficient for efficient vector particle association with unstimulated lymphocytes. For stable gene transfer into these cells, however, both MV receptors were found to be essential.

  6. Phenomenally High Transduction Air/gas Transducers for Practical Non-Contact Ultrasonic Applications

    Science.gov (United States)

    Bhardwaj, Mahesh C.

    2009-03-01

    Based on novel acoustic impedance matching layers and high coupling piezoelectric materials this paper describes exceptionally high air/gas transduction ultrasonic transducers. By providing applications oriented performance of these transducers we also usher in the era of much desired Non-Contact Ultrasound (NCU) testing and analysis of a wide range of materials including early stage formation of materials such as uncured composite prepregs, green ceramics and powder metals, plastics, elastomers, porous, hygroscopic, chemically bonded and other materials. Besides quality control, ultimately NCU offers timely opportunities for cost-effective materials production, energy savings, and environment protection.

  7. Role and regulation of 90 kDa ribosomal S6 kinase (RSK) in signal transduction

    DEFF Research Database (Denmark)

    Frödin, M; Gammeltoft, S

    1999-01-01

    ), which were among the first substrates of ERK to be discovered and which has proven to be a ubiquitous and versatile mediator of ERK signal transduction. RSK is composed of two functional kinase domains that are activated in a sequential manner by a series of phosphorylations. Recently, a family of RSK......-related kinases that are activated by ERK as well as p38 MAPK were discovered and named mitogen- and stress-activated protein kinases (MSK). A number of cellular functions of RSK have been proposed. (1) Regulation of gene expression via association and phosphorylation of transcriptional regulators including c...

  8. Transductive and matched-pair machine learning for difficult target detection problems

    Science.gov (United States)

    Theiler, James

    2014-06-01

    This paper will describe the application of two non-traditional kinds of machine learning (transductive machine learning and the more recently proposed matched-pair machine learning) to the target detection problem. The approach combines explicit domain knowledge to model the target signal with a more agnostic machine-learning approach to characterize the background. The concept is illustrated with simulated data from an elliptically-contoured background distribution, on which a subpixel target of known spectral signature but unknown spatial extent has been implanted.

  9. A neural cell adhesion molecule-derived peptide reduces neuropathological signs and cognitive impairment induced by Abeta25-35

    DEFF Research Database (Denmark)

    Klementiev, B; Novikova, T; Novitskaya, V

    2007-01-01

    death and brain atrophy in response to Abeta25-35. Finally, the Abeta25-35-administration led to a reduced short-term memory as determined by the social recognition test. A synthetic peptide termed FGL derived from the neural cell adhesion molecule (NCAM) was able to prevent or, if already manifest......, strongly reduce all investigated signs of Abeta25-35-induced neuropathology and cognitive impairment. The FGL peptide was recently demonstrated to be able to cross the blood-brain-barrier. Accordingly, we found that the beneficial effects of FGL were achieved not only by intracisternal, but also...... and cognitive impairment involves the modulation of intracellular signal-transduction mediated through GSK3beta....

  10. Peptide Vaccine: Progress and Challenges

    Directory of Open Access Journals (Sweden)

    Weidang Li

    2014-07-01

    Full Text Available Conventional vaccine strategies have been highly efficacious for several decades in reducing mortality and morbidity due to infectious diseases. The bane of conventional vaccines, such as those that include whole organisms or large proteins, appear to be the inclusion of unnecessary antigenic load that, not only contributes little to the protective immune response, but complicates the situation by inducing allergenic and/or reactogenic responses. Peptide vaccines are an attractive alternative strategy that relies on usage of short peptide fragments to engineer the induction of highly targeted immune responses, consequently avoiding allergenic and/or reactogenic sequences. Conversely, peptide vaccines used in isolation are often weakly immunogenic and require particulate carriers for delivery and adjuvanting. In this article, we discuss the specific advantages and considerations in targeted induction of immune responses by peptide vaccines and progresses in the development of such vaccines against various diseases. Additionally, we also discuss the development of particulate carrier strategies and the inherent challenges with regard to safety when combining such technologies with peptide vaccines.

  11. Double-Stranded Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2001-01-01

    A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker.......A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  12. Genetic induction of the gastrin releasing peptide receptor on tumor cells for radiolabeled peptide binding

    International Nuclear Information System (INIS)

    Raben, David; Stackhouse, Murray; Buchsbaum, Donald J.; Mikheeva, Galeena; Khazaeli, M.B.; McLean, Stephanie; Kirkman, Richard; Krasnykh, Victor; Curiel, David T.

    1996-01-01

    Purpose/Objective: To improve upon existing radioimmunotherapy (RAIT) approaches, we have devised a strategy to genetically induce high levels of new membrane-associated receptors on human cancer cells targetable by radiolabeled peptides. In this context, we report successful adenoviral-mediated transduction of tumor cells to express the murine gastrin releasing peptide receptor (mGRPr) as demonstrated by 125 I-labeled bombesin binding. Materials and Methods: To demonstrate the feasibility of our strategy and to provide rapid proof of principle, we constructed a plasmid encoding the mGRPr gene. We cloned the mGRPr gene into the adenoviral shuttle vector pACMVpLpARS+ (F. Graham). We then utilized the methodology of adenovirus-polylysine-mediated transfection (AdpLmGRPr) to accomplish transient gene expression of mGRPr in two human cancer cell lines including A427 non-small cell lung cancer cells and HeLa cervical cancer cells. Murine GRPr expression was then measured by a live-cell binding assay using 125 I-labeled bombesin. In order to develop this strategy further, it was necessary to construct a vector that would be more efficient for in vivo transduction. In this regard, we constructed a recombinant adenoviral vector (AdCMVGRPr) encoding the mGRPr under the control of the CMV promoter based on in vivo homologous recombination methods. The recombinant shuttle vector containing mGRPr was co-transfected with the adenoviral rescue plasmid pJM17 into the E1A trans complementing cell line 293 allowing for derivation of replication-incompetent, recombinant adenoviral vector. Individual plaques were isolated and subjected to two further rounds of plaque purification. The identity of the virus was confirmed at each step by PCR employing primers for mGRPr. The absence of wild-type adenovirus was confirmed by PCR using primers to the adenoviral E1A gene. SKOV3.ip1 human ovarian cancer cells and MDA-MB-231 human breast cancer cells were transduced in vitro with AdCMVGRPr at

  13. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    The role of proteins as very effective immunogens for the generation of antibodies is indisputable. Nevertheless, cases in which protein usage for antibody production is not feasible or convenient compelled the creation of a powerful alternative consisting of synthetic peptides. Synthetic peptides...... can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery....... To better understand the underlying mechanisms of antibody-antigen interaction here we present a pipeline developed by us to structurally classify immunoglobulin antigen binding sites and to infer key sequence residues and other variables that have a prominent role in each structural class....

  14. Self-assembling peptide semiconductors

    Science.gov (United States)

    Tao, Kai; Makam, Pandeeswar; Aizen, Ruth; Gazit, Ehud

    2017-01-01

    Semiconductors are central to the modern electronics and optics industries. Conventional semiconductive materials bear inherent limitations, especially in emerging fields such as interfacing with biological systems and bottom-up fabrication. A promising candidate for bioinspired and durable nanoscale semiconductors is the family of self-assembled nanostructures comprising short peptides. The highly ordered and directional intermolecular π-π interactions and hydrogen-bonding network allow the formation of quantum confined structures within the peptide self-assemblies, thus decreasing the band gaps of the superstructures into semiconductor regions. As a result of the diverse architectures and ease of modification of peptide self-assemblies, their semiconductivity can be readily tuned, doped, and functionalized. Therefore, this family of electroactive supramolecular materials may bridge the gap between the inorganic semiconductor world and biological systems. PMID:29146781

  15. Antimicrobial Peptide Production and Purification.

    Science.gov (United States)

    Suda, Srinivas; Field, Des; Barron, Niall

    2017-01-01

    Antimicrobial peptides (AMPs) are natural defense compounds which are synthesized as ribosomal gene-encoded pre-peptides and produced by all living organisms. AMPs are small peptides, usually cationic and typically have hydrophobic residues which interact with cell membranes and have either a narrow or broad spectrum of biological activity. AMPs are isolated from the natural host or heterologously expressed in other hosts such as Escherichia coli. The proto-typical lantibiotic Nisin is a widely used AMP that is produced by the food-grade organism Lactococcus lactis. Although AMP production and purification procedures require optimization for individual AMPs, the Nisin production and purification protocol outlined in this chapter can be easily applied with minor modifications for the production and purification of other lantibiotics or AMPs. While Nisin is produced and secreted into the supernatant, steps to recover Nisin from both cell-free supernatant and cell pellet are outlined in detail.

  16. Delivery systems for antimicrobial peptides

    DEFF Research Database (Denmark)

    Nordström, Randi; Malmsten, Martin

    2017-01-01

    Due to rapidly increasing resistance development against conventional antibiotics, finding novel approaches for the treatment of infections has emerged as a key health issue. Antimicrobial peptides (AMPs) have attracted interest in this context, and there is by now a considerable literature...... on the identification such peptides, as well as on their optimization to reach potent antimicrobial and anti-inflammatory effects at simultaneously low toxicity against human cells. In comparison, delivery systems for antimicrobial peptides have attracted considerably less interest. However, such delivery systems...... are likely to play a key role in the development of potent and safe AMP-based therapeutics, e.g., through reducing chemical or biological degradation of AMPs either in the formulation or after administration, by reducing adverse side-effects, by controlling AMP release rate, by promoting biofilm penetration...

  17. Radioactive labelling of peptidic hormones

    International Nuclear Information System (INIS)

    Fromageot, P.; Pradelles, P.; Morgat, J.L.; Levine, H.

    1976-01-01

    The labelling of peptidic hormones requires stability, specificity and sensitivity of the label. Introduction of a radioactive atome is one way to satisfy these criteria. Several processes have been described to prepare radioactive TRF: synthesis of the peptide with labelled aminoacids or introduction of the label into the hormone. In that approach, tritium can be substituted in the imidazole ring, via precursors activating the proper carbon. Monoiodo TRF leads essentially to tritium labelling of the 5 positions whereas monoazo TRF allows the preparation of 3 H TRF labelled in the 2 positions. Di-substituted TRF leads to labelling into the 2 and 5 carbons. Labelled analogs of TRF can be prepared with labelled iodine; further developments of peptide labelling, will be presented. In particular, the homolytic scission of the C-iodine, bond by photochemical activation. The nascent carbon radical can be stabilized by a tritiated scavenger. This approach eliminates the use of heavy metal catalysts

  18. The Pig PeptideAtlas

    DEFF Research Database (Denmark)

    Hesselager, Marianne Overgaard; Codrea, Marius; Sun, Zhi

    2016-01-01

    Biological research of Sus scrofa, the domestic pig, is of immediate relevance for food production sciences, and for developing pig as a model organism for human biomedical research. Publicly available data repositories play a fundamental role for all biological sciences, and protein data...... repositories are in particular essential for the successful development of new proteomic methods. Cumulative proteome data repositories, including the PeptideAtlas, provide the means for targeted proteomics, system-wide observations, and cross-species observational studies, but pigs have so far been...... underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within...

  19. Two-Component Signal Transduction System SaeRS Positively Regulates Staphylococcus epidermidis Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Qiang Lou

    2014-01-01

    Full Text Available Staphylococcus epidermidis, which is a causative pathogen of nosocomial infection, expresses its virulent traits such as biofilm and autolysis regulated by two-component signal transduction system SaeRS. In this study, we performed a proteomic analysis of differences in expression between the S. epidermidis 1457 wild-type and saeRS mutant to identify candidates regulated by saeRS using two-dimensional gel electrophoresis (2-DE combined with matrix-assisted laser desorption/lonization mass spectrometry (MALDI-TOF-MS. Of 55 identified proteins that significantly differed in expression between the two strains, 15 were upregulated and 40 were downregulated. The downregulated proteins included enzymes related to glycolysis and TCA cycle, suggesting that glucose is not properly utilized in S. epidermidis when saeRS was deleted. The study will be helpful for treatment of S. epidermidis infection from the viewpoint of metabolic modulation dependent on two-component signal transduction system SaeRS.

  20. Gibberellin biosynthesis and signal transduction is essential for internode elongation in deepwater rice.

    Science.gov (United States)

    Ayano, Madoka; Kani, Takahiro; Kojima, Mikiko; Sakakibara, Hitoshi; Kitaoka, Takuya; Kuroha, Takeshi; Angeles-Shim, Rosalyn B; Kitano, Hidemi; Nagai, Keisuke; Ashikari, Motoyuki

    2014-10-01

    Under flooded conditions, the leaves and internodes of deepwater rice can elongate above the water surface to capture oxygen and prevent drowning. Our previous studies showed that three major quantitative trait loci (QTL) regulate deepwater-dependent internode elongation in deepwater rice. In this study, we investigated the age-dependent internode elongation in deepwater rice. We also investigated the relationship between deepwater-dependent internode elongation and the phytohormone gibberellin (GA) by physiological and genetic approach using a QTL pyramiding line (NIL-1 + 3 + 12). Deepwater rice did not show internode elongation before the sixth leaf stage under deepwater condition. Additionally, deepwater-dependent internode elongation occurred on the sixth and seventh internodes during the sixth leaf stage. These results indicate that deepwater rice could not start internode elongation until the sixth leaf stage. Ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS) method for the phytohormone contents showed a deepwater-dependent GA1 and GA4 accumulation in deepwater rice. Additionally, a GA inhibitor abolished deepwater-dependent internode elongation in deepwater rice. On the contrary, GA feeding mimicked internode elongation under ordinary growth conditions. However, mutations in GA biosynthesis and signal transduction genes blocked deepwater-dependent internode elongation. These data suggested that GA biosynthesis and signal transduction are essential for deepwater-dependent internode elongation in deepwater rice. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  1. Analysis of signal transduction in cell-free extracts and rafts of Xenopus eggs.

    Science.gov (United States)

    Tokmakov, Alexander A; Iwasaki, Tetsushi; Sato, Ken-Ichi; Fukami, Yasuo

    2010-05-01

    Intracellular signaling during egg activation/fertilization has been extensively studied using intact eggs, which can be manipulated by microinjection of different mRNAs, proteins, or chemical drugs. Furthermore, egg extracts, which retain high CSF activity (CSF-arrested extracts), were developed for studying fertilization/activation signal transduction, which have significant advantages as a model system. The addition of calcium to CSF-arrested extracts initiates a plethora of signaling events that take place during egg activation. Hence, the signaling downstream of calcium mobilization has been successfully studied in the egg extracts. Moreover, despite disruption of membrane-associated signaling compartments and ordered compartmentalization during extract preparation, CSF-arrested extracts can be successfully used to study early signaling events, which occur upstream of calcium release during egg activation/fertilization. In combination with the CSF-arrested extracts, activated egg rafts can reproduce some events of egg activation, including PLCgamma activation, IP3 production, transient calcium release, MAPK inactivation, and meiotic exit. This becomes possible due to complementation of the sperm-induced egg activation signaling machinery present in the rafts with the components of signal transduction system localized in the extracts. Herein, we describe protocols for studying molecular mechanisms of egg fertilization/activation using cell-free extracts and membrane rafts prepared from metaphase-arrested Xenopus eggs.

  2. Effect of saw palmetto extract on PI3K cell signaling transduction in human glioma.

    Science.gov (United States)

    Yang, Yang; Hui, Lv; Yuqin, Che; Jie, Li; Shuai, Hou; Tiezhu, Zhou; Wei, Wang

    2014-08-01

    Saw palmetto extract can induce the apoptosis of prostate cancer cells. The aim of the present study was to investigate the effect of saw palmetto extract on the phosphatidylinositol 3-kinase (PI3K)/Akt signaling transduction pathway in human glioma U87 and U251 cell lines. Suspensions of U87 and U251 cells in a logarithmic growth phase were seeded into six-well plates at a density of 10 4 cells/well. In the experimental group, 1 μl/ml saw palmetto extract was added, while the control group was cultured without a drug for 24 h. The expression levels of PI3K, B-cell lymphoma-extra large (Bcl-xL) and p53 were evaluated through western blot analysis. In the experimental group, the U87 and U251 cells exhibited a lower expression level of PI3K protein as compared with the control group (t=6.849; Psaw palmetto extract induces glioma cell growth arrest and apoptosis via decreasing PI3K/Akt signal transduction.

  3. A functional TOC complex contributes to gravity signal transduction in Arabidopsis.

    Science.gov (United States)

    Strohm, Allison K; Barrett-Wilt, Greg A; Masson, Patrick H

    2014-01-01

    Although plastid sedimentation has long been recognized as important for a plant's perception of gravity, it was recently shown that plastids play an additional function in gravitropism. The Translocon at the Outer envelope membrane of Chloroplasts (TOC) complex transports nuclear-encoded proteins into plastids, and a receptor of this complex, Toc132, was previously hypothesized to contribute to gravitropism either by directly functioning as a gravity signal transducer or by indirectly mediating the plastid localization of a gravity signal transducer. Here we show that mutations in multiple genes encoding TOC complex components affect gravitropism in a genetically sensitized background and that the cytoplasmic acidic domain of Toc132 is not required for its involvement in this process. Furthermore, mutations in TOC132 enhance the gravitropic defect of a mutant whose amyloplasts lack starch. Finally, we show that the levels of several nuclear-encoded root proteins are altered in toc132 mutants. These data suggest that the TOC complex indirectly mediates gravity signal transduction in Arabidopsis and support the idea that plastids are involved in gravitropism not only through their ability to sediment but also as part of the signal transduction mechanism.

  4. Ubiquitination of basal VEGFR2 regulates signal transduction and endothelial function

    Directory of Open Access Journals (Sweden)

    Gina A. Smith

    2017-10-01

    Full Text Available Cell surface receptors can undergo recycling or proteolysis but the cellular decision-making events that sort between these pathways remain poorly defined. Vascular endothelial growth factor A (VEGF-A and vascular endothelial growth factor receptor 2 (VEGFR2 regulate signal transduction and angiogenesis, but how signaling and proteolysis is regulated is not well understood. Here, we provide evidence that a pathway requiring the E1 ubiquitin-activating enzyme UBA1 controls basal VEGFR2 levels, hence metering plasma membrane receptor availability for the VEGF-A-regulated endothelial cell response. VEGFR2 undergoes VEGF-A-independent constitutive degradation via a UBA1-dependent ubiquitin-linked pathway. Depletion of UBA1 increased VEGFR2 recycling from endosome-to-plasma membrane and decreased proteolysis. Increased membrane receptor availability after UBA1 depletion elevated VEGF-A-stimulated activation of key signaling enzymes such as PLCγ1 and ERK1/2. Although UBA1 depletion caused an overall decrease in endothelial cell proliferation, surviving cells showed greater VEGF-A-stimulated responses such as cell migration and tubulogenesis. Our study now suggests that a ubiquitin-linked pathway regulates the balance between receptor recycling and degradation which in turn impacts on the intensity and duration of VEGF-A-stimulated signal transduction and the endothelial response.

  5. Subsumed complexity: abiogenesis as a by-product of complex energy transduction

    Science.gov (United States)

    Adam, Z. R.; Zubarev, D.; Aono, M.; Cleaves, H. James

    2017-11-01

    The origins of life bring into stark relief the inadequacy of our current synthesis of thermodynamic, chemical, physical and information theory to predict the conditions under which complex, living states of organic matter can arise. Origins research has traditionally proceeded under an array of implicit or explicit guiding principles in lieu of a universal formalism for abiogenesis. Within the framework of a new guiding principle for prebiotic chemistry called subsumed complexity, organic compounds are viewed as by-products of energy transduction phenomena at different scales (subatomic, atomic, molecular and polymeric) that retain energy in the form of bonds that inhibit energy from reaching the ground state. There is evidence for an emergent level of complexity that is overlooked in most conceptualizations of abiogenesis that arises from populations of compounds formed from atomic energy input. We posit that different forms of energy input can exhibit different degrees of dissipation complexity within an identical chemical medium. By extension, the maximum capacity for organic chemical complexification across molecular and macromolecular scales subsumes, rather than emerges from, the underlying complexity of energy transduction processes that drive their production and modification. This article is part of the themed issue 'Reconceptualizing the origins of life'.

  6. New insights into the organization of plasma membrane and its role in signal transduction.

    Science.gov (United States)

    Suzuki, Kenichi G N

    2015-01-01

    Plasma membranes have heterogeneous structures for efficient signal transduction, required to perform cell functions. Recent evidence indicates that the heterogeneous structures are produced by (1) compartmentalization by actin-based membrane skeleton, (2) raft domains, (3) receptor-receptor interactions, and (4) the binding of receptors to cytoskeletal proteins. This chapter provides an overview of recent studies on diffusion, clustering, raft association, actin binding, and signal transduction of membrane receptors, especially glycosylphosphatidylinositol (GPI)-anchored receptors. Studies on diffusion of GPI-anchored receptors suggest that rafts may be small and/or short-lived in plasma membranes. In steady state conditions, GPI-anchored receptors form transient homodimers, which may represent the "standby state" for the stable homodimers and oligomers upon ligation. Furthermore, It is proposed that upon ligation, the binding of GPI-anchored receptor clusters to cytoskeletal actin filaments produces a platform for downstream signaling, and that the pulse-like signaling easily maintains the stability of the overall signaling activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Evidence for some signal transduction elements involved in UV-light-dependent responses in parsley protoplasts

    International Nuclear Information System (INIS)

    Frohnmeyer, H.; Bowler, C.; Schäfer, E.

    1997-01-01

    The signalling pathways used by UV-light are largely unknown. Using protoplasts from a heterotrophic parsley (Petroselinum crispum L.) cell culture that exclusively respond to UV-B light between 300 and 350 nm with a fast induction of genes encoding flavonoid biosynthetic enzymes, information was obtained about the UV-light signal transduction pathway for chalcone synthase (CHS) and phenylalanine ammonia-lyase (PAL) gene expression. Pharmacological effectors which influence intracellular calcium levels, calmodulin and the activity of serine/threonine kinases also changed the UV-light-dependent expression of these genes. This evaluation indicated the participation of these components on the UV-B-mediated signal transduction cascade to CHS. In contrast, neither membrane-permeable cyclic GMP nor the tyrosine kinase inhibitor genistein affected CHS or PAL expression. Similar results were obtained in protoplasts, which have been transiently transformed with CHS-promoter/GUS (β-glucuronidase) reporter fusion constructs. The involvement of calcium and calmodulin was further indicated in a cell-free light-responsive in vitro transcription system from evacuolated parsley protoplasts. In conclusion, there is evidence now that components of the UV-light-dependent pathway leading to the CHS-promoter are different from the previously characterized cGMP-dependent pathway to CHS utilized by phytochrome in soybean (Glycine max) and tomato seedlings (Lycopersicon esculentum). (author)

  8. Ubiquitination of basal VEGFR2 regulates signal transduction and endothelial function.

    Science.gov (United States)

    Smith, Gina A; Fearnley, Gareth W; Abdul-Zani, Izma; Wheatcroft, Stephen B; Tomlinson, Darren C; Harrison, Michael A; Ponnambalam, Sreenivasan

    2017-10-15

    Cell surface receptors can undergo recycling or proteolysis but the cellular decision-making events that sort between these pathways remain poorly defined. Vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) regulate signal transduction and angiogenesis, but how signaling and proteolysis is regulated is not well understood. Here, we provide evidence that a pathway requiring the E1 ubiquitin-activating enzyme UBA1 controls basal VEGFR2 levels, hence metering plasma membrane receptor availability for the VEGF-A-regulated endothelial cell response. VEGFR2 undergoes VEGF-A-independent constitutive degradation via a UBA1-dependent ubiquitin-linked pathway. Depletion of UBA1 increased VEGFR2 recycling from endosome-to-plasma membrane and decreased proteolysis. Increased membrane receptor availability after UBA1 depletion elevated VEGF-A-stimulated activation of key signaling enzymes such as PLCγ1 and ERK1/2. Although UBA1 depletion caused an overall decrease in endothelial cell proliferation, surviving cells showed greater VEGF-A-stimulated responses such as cell migration and tubulogenesis. Our study now suggests that a ubiquitin-linked pathway regulates the balance between receptor recycling and degradation which in turn impacts on the intensity and duration of VEGF-A-stimulated signal transduction and the endothelial response. © 2017. Published by The Company of Biologists Ltd.

  9. Rab11-FIP3 Regulation of Lck Endosomal Traffic Controls TCR Signal Transduction.

    Science.gov (United States)

    Bouchet, Jérôme; Del Río-Iñiguez, Iratxe; Vázquez-Chávez, Elena; Lasserre, Rémi; Agüera-González, Sonia; Cuche, Céline; McCaffrey, Mary W; Di Bartolo, Vincenzo; Alcover, Andrés

    2017-04-01

    The role of endosomes in receptor signal transduction is a long-standing question, which remains largely unanswered. The T cell Ag receptor and various components of its proximal signaling machinery are associated with distinct endosomal compartments, but how endosomal traffic affects T cell signaling remains ill-defined. In this article, we demonstrate in human T cells that the subcellular localization and function of the protein tyrosine kinase Lck depends on the Rab11 effector FIP3 (Rab11 family interacting protein-3). FIP3 overexpression or silencing and its ability to interact with Rab11 modify Lck subcellular localization and its delivery to the immunological synapse. Importantly, FIP3-dependent Lck localization controls early TCR signaling events, such as tyrosine phosphorylation of TCRζ, ZAP70, and LAT and intracellular calcium concentration, as well as IL-2 gene expression. Interestingly, FIP3 controls both steady-state and poststimulation phosphotyrosine and calcium levels. Finally, our findings indicate that FIP3 modulates TCR-CD3 cell surface expression via the regulation of steady-state Lck-mediated TCRζ phosphorylation, which in turn controls TCRζ protein levels. This may influence long-term T cell activation in response to TCR-CD3 stimulation. Therefore, our data underscore the importance of finely regulated endosomal traffic in TCR signal transduction and T cell activation leading to IL-2 production. Copyright © 2017 by The American Association of Immunologists, Inc.

  10. Signal transduction meets vesicle traffic: the software and hardware of GLUT4 translocation.

    Science.gov (United States)

    Klip, Amira; Sun, Yi; Chiu, Tim Ting; Foley, Kevin P

    2014-05-15

    Skeletal muscle is the major tissue disposing of dietary glucose, a function regulated by insulin-elicited signals that impart mobilization of GLUT4 glucose transporters to the plasma membrane. This phenomenon, also central to adipocyte biology, has been the subject of intense and productive research for decades. We focus on muscle cell studies scrutinizing insulin signals and vesicle traffic in a spatiotemporal manner. Using the analogy of an integrated circuit to approach the intersection between signal transduction and vesicle mobilization, we identify signaling relays ("software") that engage structural/mechanical elements ("hardware") to enact the rapid mobilization and incorporation of GLUT4 into the cell surface. We emphasize how insulin signal transduction switches from tyrosine through lipid and serine phosphorylation down to activation of small G proteins of the Rab and Rho families, describe key negative regulation step of Rab GTPases through the GTPase-activating protein activity of the Akt substrate of 160 kDa (AS160), and focus on the mechanical effectors engaged by Rabs 8A and 10 (the molecular motor myosin Va), and the Rho GTPase Rac1 (actin filament branching and severing through Arp2/3 and cofilin). Finally, we illustrate how actin filaments interact with myosin 1c and α-Actinin4 to promote vesicle tethering as preamble to fusion with the membrane. Copyright © 2014 the American Physiological Society.

  11. Targeted genome editing by lentiviral protein transduction of zinc-finger and TAL-effector nucleases.

    Science.gov (United States)

    Cai, Yujia; Bak, Rasmus O; Mikkelsen, Jacob Giehm

    2014-04-24

    Future therapeutic use of engineered site-directed nucleases, like zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), relies on safe and effective means of delivering nucleases to cells. In this study, we adapt lentiviral vectors as carriers of designer nuclease proteins, providing efficient targeted gene disruption in vector-treated cell lines and primary cells. By co-packaging pairs of ZFN proteins with donor RNA in 'all-in-one' lentiviral particles, we co-deliver ZFN proteins and the donor template for homology-directed repair leading to targeted DNA insertion and gene correction. Comparative studies of ZFN activity in a predetermined target locus and a known nearby off-target locus demonstrate reduced off-target activity after ZFN protein transduction relative to conventional delivery approaches. Additionally, TALEN proteins are added to the repertoire of custom-designed nucleases that can be delivered by protein transduction. Altogether, our findings generate a new platform for genome engineering based on efficient and potentially safer delivery of programmable nucleases.DOI: http://dx.doi.org/10.7554/eLife.01911.001. Copyright © 2014, Cai et al.

  12. Repair of damage induced by ultraviolet radiation in mutator T-1 Escherichia coli transductants

    International Nuclear Information System (INIS)

    Sideropoulos, A.S.; Greenberg, J.; Warren, G.

    1975-01-01

    To ascertain whether a relationship commonly exists between azide resistance, ultraviolet (uv) resistance, and the mutator property (mut T-1), we performed uv survival and mutation frequency determinations with and without caffeine (2.571 mM) in nonmutator azide resistant (azi/sup r/) and phage mediated mut T-1 transductants of Escherichia coli K-12, B/r, B/r T-, Bs-1, and Bs-8. The strains constructed were assumed to be ''co-isogenic'' except for the mutator factor. The frequency of mutation to streptomycin resistance (str/sup r/) was relatively constant and approximated 2 x 10- 7 . Transductants carrying the azide marker with or without the mut T-1 gene had the same level of uv survival as the parent with the same mutator phenotype. Dark repair of the prelethal uv lesion is equally caffeine sensitive in the nonmutator and mutator HCR+ strains. Our results indicated that the mut T-1 strains possess an efficient dark repair system for uv damage and that the mechanism of mut T-1 action is independent of uv dark repair processes. (auth)

  13. Progression in sensing cardiac troponin biomarker charge transductions on semiconducting nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Fathil, M.F.M., E-mail: faris.fathil@gmail.com [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Md Arshad, M.K., E-mail: mohd.khairuddin@unimap.edu.my [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); School of Microelectronic Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Ruslinda, A.R., E-mail: ruslinda@unimap.edu.my [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Nuzaihan, M.N.M., E-mail: m.nuzaihan@unimap.edu.my [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Gopinath, Subash C.B., E-mail: subash@unimap.edu.my [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); School of Bioprocess Engineering, Universiti Malaysia Perlis, 02600, Arau, Perlis (Malaysia); Adzhri, R., E-mail: adzhri@gmail.com [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Hashim, U., E-mail: uda@unimap.edu.my [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); School of Microelectronic Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia)

    2016-09-07

    A real-time ability to interpret the interaction between targeted biomolecules and the surface of semiconductors (metal transducers) into readable electrical signals, without biomolecular modification involving fluorescence dyes, redox enzymes, and radioactive labels, created by label-free biosensors has been extensively researched. Field-effect transistor (FET)- and capacitor-based biosensors are among the diverse electrical charge biosensing architectures that have drawn much attention for having charge transduction; thus, enabling the early and rapid diagnosis of the appropriate cardiac biomarkers at lower concentrations. These semiconducting material-based transducers are very suitable to be integrated with portable electronic devices for future online collection, transmission, reception, analysis, and reporting. This overview elucidates and clarifies two major electrical label-free systems (FET- and capacitor-based biosensors) with cardiac troponin (cTn) biomarker-mediated charge transduction for acute myocardial infarction (AMI) diagnosis. Advances in these systems are highlighted by their progression in bridging the laboratory and industry; the foremost technologies have made the transition from benchtop to bedside and beyond. - Highlights: • The progression of cardiac troponin detection from past to future are presented. • Electrical label-free biosensors for cardiac troponin are discussed. • The discussion focused on field-effect transistor-and capacitor-based devices. • Surface functionalization, sensitivity, and innovation of devices are highlighted. • They presented high sensitivity and specificity of real-time AMI determination.

  14. Novel Formulations for Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2014-10-01

    Full Text Available Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy.

  15. Peptides and the new endocrinology

    Science.gov (United States)

    Schwyzer, Robert

    1982-01-01

    The discovery of regulatory peptides common to the nervous and the endocrine systems (brain, gut, and skin) has brought about a revolution in our concepts of endocrinology and neurology. We are beginning to understand some of the complex interrelationships between soma and psyche that might, someday, be important for an integrated treatment of diseases. Examples of the actions of certain peptides in the periphery and in the central nervous system are given, and their biosynthesis and molecular anatomy as carriers for information are discussed.

  16. Novel Formulations for Antimicrobial Peptides

    Science.gov (United States)

    Carmona-Ribeiro, Ana Maria; Carrasco, Letícia Dias de Melo

    2014-01-01

    Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy. PMID:25302615

  17. The application of multiple biophysical cues to engineer functional neocartilage for treatment of osteoarthritis. Part II: signal transduction.

    Science.gov (United States)

    Brady, Mariea A; Waldman, Stephen D; Ethier, C Ross

    2015-02-01

    The unique mechanoelectrochemical environment of cartilage has motivated researchers to investigate the effect of multiple biophysical cues, including mechanical, magnetic, and electrical stimulation, on chondrocyte biology. It is well established that biophysical stimuli promote chondrocyte proliferation, differentiation, and maturation within "biological windows" of defined dose parameters, including mode, frequency, magnitude, and duration of stimuli (see companion review Part I: Cellular Response). However, the underlying molecular mechanisms and signal transduction pathways activated in response to multiple biophysical stimuli remain to be elucidated. Understanding the mechanisms of biophysical signal transduction will deepen knowledge of tissue organogenesis, remodeling, and regeneration and aiding in the treatment of pathologies such as osteoarthritis. Further, this knowledge will provide the tissue engineer with a potent toolset to manipulate and control cell fate and subsequently develop functional replacement cartilage. The aim of this article is to review chondrocyte signal transduction pathways in response to mechanical, magnetic, and electrical cues. Signal transduction does not occur along a single pathway; rather a number of parallel pathways appear to be activated, with calcium signaling apparently common to all three types of stimuli, though there are different modes of activation. Current tissue engineering strategies, such as the development of "smart" functionalized biomaterials that enable the delivery of growth factors or integration of conjugated nanoparticles, may further benefit from targeting known signal transduction pathways in combination with external biophysical cues.

  18. Dendroaspis natriuretic peptide binds to the natriuretic peptide clearance receptor

    International Nuclear Information System (INIS)

    Johns, Douglas G.; Ao, Zhaohui; Heidrich, Bradley J.; Hunsberger, Gerald E.; Graham, Taylor; Payne, Lisa; Elshourbagy, Nabil; Lu, Quinn; Aiyar, Nambi; Douglas, Stephen A.

    2007-01-01

    Dendroaspis natriuretic peptide (DNP) is a newly-described natriuretic peptide which lowers blood pressure via vasodilation. The natriuretic peptide clearance receptor (NPR-C) removes natriuretic peptides from the circulation, but whether DNP interacts with human NPR-C directly is unknown. The purpose of this study was to test the hypothesis that DNP binds to NPR-C. ANP, BNP, CNP, and the NPR-C ligands AP-811 and cANP(4-23) displaced [ 125 I]-ANP from NPR-C with pM-to-nM K i values. DNP displaced [ 125 I]-ANP from NPR-C with nM potency, which represents the first direct demonstration of binding of DNP to human NPR-C. DNP showed high pM affinity for the GC-A receptor and no affinity for GC-B (K i > 1000 nM). DNP was nearly 10-fold more potent than ANP at stimulating cGMP production in GC-A expressing cells. Blockade of NPR-C might represent a novel therapeutic approach in augmenting the known beneficial actions of DNP in cardiovascular diseases such as hypertension and heart failure

  19. Toxins and antimicrobial peptides: interactions with membranes

    Science.gov (United States)

    Schlamadinger, Diana E.; Gable, Jonathan E.; Kim, Judy E.

    2009-08-01

    The innate immunity to pathogenic invasion of organisms in the plant and animal kingdoms relies upon cationic antimicrobial peptides (AMPs) as the first line of defense. In addition to these natural peptide antibiotics, similar cationic peptides, such as the bee venom toxin melittin, act as nonspecific toxins. Molecular details of AMP and peptide toxin action are not known, but the universal function of these peptides to disrupt cell membranes of pathogenic bacteria (AMPs) or a diverse set of eukaryotes and prokaryotes (melittin) is widely accepted. Here, we have utilized spectroscopic techniques to elucidate peptide-membrane interactions of alpha-helical human and mouse AMPs of the cathelicidin family as well as the peptide toxin melittin. The activity of these natural peptides and their engineered analogs was studied on eukaryotic and prokaryotic membrane mimics consisting of resistant pathogens.

  20. Histidine-Containing Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2000-01-01

    Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics.......Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics....

  1. Streptavidin-binding peptides and uses thereof

    Science.gov (United States)

    Szostak, Jack W. (Inventor); Wilson, David S. (Inventor); Keefe, Anthony D. (Inventor)

    2006-01-01

    The invention provides peptides with high affinity for streptavidin. These peptides may be expressed as part of fusion proteins to facilitate the detection, quantitation, and purification of proteins of interest.

  2. Biomedical Applications of Self-Assembling Peptides

    NARCIS (Netherlands)

    Radmalekshahi, Mazda; Lempsink, Ludwijn; Amidi, Maryam; Hennink, Wim E.; Mastrobattista, Enrico

    2016-01-01

    Self-assembling peptides have gained increasing attention as versatile molecules to generate diverse supramolecular structures with tunable functionality. Because of the possibility to integrate a wide range of functional domains into self-assembling peptides including cell attachment sequences,

  3. Computer-Aided Design of Antimicrobial Peptides

    DEFF Research Database (Denmark)

    Fjell, Christopher D.; Hancock, Robert E.W.; Jenssen, Håvard

    2010-01-01

    in antimicrobial activity. Consequently, the majority of peptides put into clinical trials have failed at some point, underlining the importance of a thorough peptide optimization. An important tool in peptide design and optimization is quantitative structure-activity relationship (QSAR) analysis, correlating...... chemical parameters with biological activities of the peptide, using statistical methods. In this review we will discuss two different in silico strategies of computer-aided antibacterial peptide design, a linear correlation model build as an extension of traditional principal component analysis (PCA......) and a non-linear artificial neural network model. Studies on structurally diverse peptides, have concluded that the PCA derived model are able to guide the antibacterial peptide design in a meaningful way, however requiring rather a high homology between the peptides in the test-set and the in silico...

  4. Characterization of cyclic peptides containing disulfide bonds

    OpenAIRE

    Johnson, Mindy; Liu, Mingtao; Struble, Elaine; Hettiarachchi, Kanthi

    2015-01-01

    Unlike linear peptides, analysis of cyclic peptides containing disulfide bonds is not straightforward and demands indirect methods to achieve a rigorous proof of structure. Three peptides that belong to this category, p-Cl-Phe-DPDPE, DPDPE, and CTOP, were analyzed and the results are presented in this paper. The great potential of two dimensional NMR and ESI tandem mass spectrometry was harnessed during the course of peptide characterizations. A new RP-HPLC method for the analysis of trifluor...

  5. Development and use of engineered peptide deformylase in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia

    2012-01-01

    Deze thesis beschrijft het onderzoek naar potentieel van het gebruik van het peptide deformylase (PDF) in chemo enzymatische peptide synthese. PDF is geschikt voor selective N terminale deformylatie van bepaalde N-formyl-peptides zonder gelijktijdige hydrolyse van de peptide binding. Door de

  6. Oxidative Modification of Tryptophan-Containing Peptides

    DEFF Research Database (Denmark)

    Petersen, Jonas; Christensen, Pia Katrine; Nielsen, Mathias T

    2018-01-01

    We herein present a broadly useful method for the chemoselective modification of a wide range of tryptophan-containing peptides. Exposing a tryptophan-containing peptide to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) resulted in a selective cyclodehydration between the peptide backbone...

  7. Synthetic Procedures for Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  8. Intracellular delivery of cell-penetrating peptide-transcriptional factor fusion protein and its role in selective osteogenesis

    Science.gov (United States)

    Suh, Jin Sook; Lee, Jue Yeon; Choi, Yoon Jung; You, Hyung Keun; Hong, Seong-Doo; Chung, Chong Pyoung; Park, Yoon Jeong

    2014-01-01

    Protein-transduction technology has been attempted to deliver macromolecular materials, including protein, nucleic acids, and polymeric drugs, for either diagnosis or therapeutic purposes. Herein, fusion protein composed of an arginine-rich cell-penetrating peptide, termed low-molecular-weight protamine (LMWP), and a transcriptional coactivator with a PDZ-binding motif (TAZ) protein was prepared and applied in combination with biomaterials to increase bone-forming capacity. TAZ has been recently identified as a specific osteogenic stimulating transcriptional coactivator in human mesenchymal stem cell (hMSC) differentiation, while simultaneously blocking adipogenic differentiation. However, TAZ by itself cannot penetrate the cells, and thus needs a transfection tool for translocalization. The LMWP-TAZ fusion proteins were efficiently translocalized into the cytosol of hMSCs. The hMSCs treated with cell-penetrating LMWP-TAZ exhibited increased expression of osteoblastic genes and protein, producing significantly higher quantities of mineralized matrix compared to free TAZ. In contrast, adipogenic differentiation of the hMSCs was blocked by treatment of LMWP-TAZ fusion protein, as reflected by reduced marker-protein expression, adipocyte fatty acid-binding protein 2, and peroxisome proliferator-activated receptor-γ messenger ribonucleic acid levels. LMWP-TAZ was applied in alginate gel for the purpose of localization and controlled release. The LMWP-TAZ fusion protein-loaded alginate gel matrix significantly increased bone formation in rabbit calvarial defects compared with alginate gel matrix mixed with free TAZ protein. The protein transduction of TAZ fused with cell-penetrating LMWP peptide was able selectively to stimulate osteogenesis in vitro and in vivo. Taken together, this fusion protein-transduction technology for osteogenic protein can thus be applied in combination with biomaterials for tissue regeneration and controlled release for tissue

  9. FLT3 ligand preserves the uncommitted CD34+CD38- progenitor cells during cytokine prestimulation for retroviral transduction

    DEFF Research Database (Denmark)

    Nielsen, S D; Husemoen, L L; Sørensen, T U

    2000-01-01

    for transduction of CD34+ cells. The effect of cytokine prestimulation on transduction efficiency and the population of uncommitted CD34+CD38- cells was determined. CD34+ cells harvested from umbilical cord blood were kept in suspension cultures and stimulated with combinations of the cytokines stem cell factor......Before stem cell gene therapy can be considered for clinical applications, problems regarding cytokine prestimulation remain to be solved. In this study, a retroviral vector carrying the genes for the enhanced version of green fluorescent protein (EGFP) and neomycin resistance (neo(r)) was used...... in a higher percentage of cells than the EGFP gene, but there seemed to be a positive correlation between expression of the two genes. The effect of cytokine prestimulation was therefore monitored using EGFP as marker for transduction. When SCF was compared to SCF in combination with more potent cytokines...

  10. Binding Mode of Insulin Receptor and Agonist Peptide

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Insulin is a protein hormone secreted by pancreatic β cells. One of its main functions is to keep the balance of glucose inside the body by regulating the absorption and metabolism of glucose in the periphery tissue, as well as the production and storage of hepatic glycogen. The insulin receptor is a transmembrane glycoprotein in which two α subunits with a molecular weight of 135 kD and twoβ subunits with a molecular weight of 95 kD are joined by a disulfide bond to form a β-α-α-β structure. The extracellular α subunit, especially, its three domains near the N-terminal are partially responsible for signal transduction or ligand-binding, as indicated by the experiments. The extracellular α subunits are involved in binding the ligands. The experimental results indicate that the three domains of the N-terminal of the α subunits are the main determinative parts of the insulin receptor to bind the insulin or mimetic peptide.We employed the extracellular domain (PDBID: 1IGR) of the insulin-like growth factor-1 receptor (IGF-1 R ) as the template to simulate and optimize the spatial structures of the three domains in the extracellular domain of the insulin receptor, which includes 468 residues. The work was accomplished by making use of the homology program in the Insight Ⅱ package on an Origin3800 server. The docking calculations of the insulin receptor obtained by homology with hexapeptides were carried out by means of the program Affinity. The analysis indicated that there were hydrogen bonding, and electrostatic and hydrophobic effects in the docking complex of the insulin receptor with hexapeptides.Moreover, we described the spatial orientation of a mimetic peptide with agonist activity in the docking complex. We obtained a rough model of binding of DLAPSQ or STIVYS with the insulin receptor, which provides the powerful theoretical support for designing the minimal insulin mimetic peptide with agonist activity, making it possible to develop oral small

  11. Expression of the synaptic exocytosis-regulating molecule complexin 2 in taste buds and its participation in peripheral taste transduction.

    Science.gov (United States)

    Kurokawa, Azusa; Narukawa, Masataka; Ohmoto, Makoto; Yoshimoto, Joto; Abe, Keiko; Misaka, Takumi

    2015-06-01

    Taste information from type III taste cells to gustatory neurons is thought to be transmitted via synapses. However, the molecular mechanisms underlying taste transduction through this pathway have not been fully elucidated. In this study, to identify molecules that participate in synaptic taste transduction, we investigated whether complexins (Cplxs), which play roles in regulating membrane fusion in synaptic vesicle exocytosis, were expressed in taste bud cells. Among four Cplx isoforms, strong expression of Cplx2 mRNA was detected in type III taste cells. To investigate the function of CPLX2 in taste transduction, we observed taste responses in CPLX2-knockout mice. When assessed with electrophysiological and behavioral assays, taste responses to some sour stimuli in CPLX2-knockout mice were significantly lower than those in wild-type mice. These results suggested that CPLX2 participated in synaptic taste transduction from type III taste cells to gustatory neurons. A part of taste information is thought to be transmitted via synapses. However, the molecular mechanisms have not been fully elucidated. To identify molecules that participate in synaptic taste transduction, we investigated complexins (Cplxs) expression in taste bud cells. Strong expression of Cplx2 mRNA was detected in taste bud cells. Furthermore, taste responses to some sour stimuli in CPLX2- knockout mice were significantly lower than those in wild-type mice. These suggested that CPLX2 participated in synaptic taste transduction. © 2015 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of The International Society for Neurochemistry.

  12. Mechanism of Cancer Growth Suppression of Alpha-Fetoprotein Derived Growth Inhibitory Peptides (GIP): Comparison of GIP-34 versus GIP-8 (AFPep). Updates and Prospects

    Energy Technology Data Exchange (ETDEWEB)

    Mizejewski, Gerald J. [Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201 (United States)

    2011-06-20

    The Alpha-fetoprotein (AFP) derived Growth Inhibitory Peptide (GIP) is a 34-amino acid segment of the full-length human AFP molecule that inhibits tumor growth and metastasis. The GIP-34 and its carboxy-terminal 8-mer segment, termed GIP-8, were found to be effective as anti-cancer therapeutic peptides against nine different human cancer types. Following the uptake of GIP-34 and GIP-8 into the cell cytoplasm, each follows slightly different signal transduction cascades en route to inhibitory pathways of tumor cell growth and proliferation. The parallel mechanisms of action of GIP-34 versus GIP-8 are demonstrated to involve interference of signaling transduction cascades that ultimately result in: (1) cell cycle S-phase/G2-phase arrest; (2) prevention of cyclin inhibitor degradation; (3) protection of p53 from inactivation by phosphorylation; and (4) blockage of K{sup +} ion channels opened by estradiol and epidermal growth factor (EGF). The overall mechanisms of action of both peptides are discussed in light of their differing modes of cell attachment and uptake fortified by RNA microarray analysis and electrophysiologic measurements of cell membrane conductance and resistance. As a chemotherapeutic adjunct, the GIPs could potentially aid in alleviating the negative side effects of: (1) tamoxifen resistance, uterine hyperplasia/cancer, and blood clotting; (2) Herceptin antibody resistance and cardiac (arrest) arrhythmias; and (3) doxorubicin's bystander cell toxicity.

  13. Cell Penetrating Capacity and Internalization Mechanisms Used by the Synthetic Peptide CIGB-552 and Its Relationship with Tumor Cell Line Sensitivity.

    Science.gov (United States)

    Astrada, Soledad; Fernández Massó, Julio Raúl; Vallespí, Maribel G; Bollati-Fogolín, Mariela

    2018-03-30

    CIGB-552 is a twenty-amino-acid novel synthetic peptide that has proven to be effective in reducing tumor size and increasing lifespan in tumor-bearing mice. Such capability is conferred by its cell-penetrating peptide character, which allows it to enter cells and elicit a pro-apoptotic effect through its major mediator, COMMD1 protein. Cell-penetrating peptides are able to use different internalization mechanisms, such as endocytosis or direct transduction through the plasma membrane. Although CIGB-552 cytotoxicity has been evaluated in several non-tumor- and tumor-derived cell lines, no data regarding the relationship between cell line sensitivity, cell penetrating capacity, the internalization mechanisms involved, COMMD1 expression levels, or its subcellular localization has yet been produced. Here, we present the results obtained from a comparative analysis of CIGB-552 sensitivity, internalization capacity and the mechanisms involved in three human tumor-derived cell lines from different origins: mammary gland, colon and lung (MCF-7, HT-29 and H460, respectively). Furthermore, cell surface markers relevant for internalization processes such as phosphatidylserine, as well as CIGB-552 target COMMD1 expression/localization, were also evaluated. We found that both endocytosis and transduction are involved in CIGB-552 internalization in the three cell lines evaluated. However, CIGB-552 incorporation efficiency and contribution of each mechanism is cell-line dependent. Finally, sensitivity was directly correlated with high internalization capacity in those cell lines where endocytosis had a major contribution on CIGB-552 internalization.

  14. Rotavirus NSP4114-135 peptide has no direct, specific effect on chloride transport in rabbit brush-border membrane

    Directory of Open Access Journals (Sweden)

    Vasseur Monique

    2006-11-01

    Full Text Available Abstract The direct effect of the rotavirus NSP4114-135 and Norovirus NV464-483 peptides on 36Cl uptake was studied by using villus cell brush border membrane (BBM isolated from young rabbits. Both peptides inhibited the Cl-/H+ symport activity about equally and partially. The interaction involved one peptide-binding site per carrier unit. Whereas in vitro NSP4114-135 caused nonspecific inhibition of the Cl-/H+ symporter, the situation in vivo is different. Because rotavirus infection in young rabbits accelerated both Cl- influx and Cl- efflux rates across villi BBM without stimulating Cl- transport in crypt BBM, we conclude that the NSP4114-135 peptide, which causes diarrhea in young rodents, did not have any direct, specific effect on either intestinal absorption or secretion of chloride. The lack of direct effect of NSP4 on chloride transport strengthens the hypothesis that NSP4 would trigger signal transduction pathways to enhance net chloride secretion at the onset of rotavirus diarrhea.

  15. Coating with spermine-pullulan polymer enhances adenoviral transduction of mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Wan L

    2016-12-01

    coating could enhance adenoviral transduction of MSCs without detectable cytotoxicity or effects on differentiation. Our results argue in favor of the potentiality of the SP-coated Adv as a prototype vector for efficient and safe transduction of MSCs. Keywords: mesenchymal stem cells, adenovirus vectors, spermine-pullulan, polymer, gene transduction

  16. Efficient Generation of Functional Hepatocytes From Human Embryonic Stem Cells and Induced Pluripotent Stem Cells by HNF4α Transduction

    OpenAIRE

    Takayama, Kazuo; Inamura, Mitsuru; Kawabata, Kenji; Katayama, Kazufumi; Higuchi, Maiko; Tashiro, Katsuhisa; Nonaka, Aki; Sakurai, Fuminori; Hayakawa, Takao; Kusuda Furue, Miho; Mizuguchi, Hiroyuki

    2012-01-01

    Hepatocyte-like cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are expected to be a useful source of cells drug discovery. Although we recently reported that hepatic commitment is promoted by transduction of SOX17 and HEX into human ESC- and iPSC-derived cells, these hepatocyte-like cells were not sufficiently mature for drug screening. To promote hepatic maturation, we utilized transduction of the hepatocyte nuclear factor 4α (HNF4α) gene, which is kn...

  17. Insect Peptides - Perspectives in Human Diseases Treatment.

    Science.gov (United States)

    Chowanski, Szymon; Adamski, Zbigniew; Lubawy, Jan; Marciniak, Pawel; Pacholska-Bogalska, Joanna; Slocinska, Malgorzata; Spochacz, Marta; Szymczak, Monika; Urbanski, Arkadiusz; Walkowiak-Nowicka, Karolina; Rosinski, Grzegorz

    2017-01-01

    Insects are the largest and the most widely distributed group of animals in the world. Their diversity is a source of incredible variety of different mechanisms of life processes regulation. There are many agents that regulate immunology, reproduction, growth and development or metabolism. Hence, it seems that insects may be a source of numerous substances useful in human diseases treatment. Especially important in the regulation of insect physiology are peptides, like neuropeptides, peptide hormones or antimicrobial peptides. There are two main aspects where they can be helpful, 1) Peptides isolated from insects may become potential drugs in therapy of different diseases, 2) A lot of insect peptide hormones show structural or functional homology to mammalian peptide hormones and the comparative studies may give a new look on human disorders. In our review we focused on three group of insect derived peptides: 1) immune-active peptides, 2) peptide hormones and 3) peptides present in venoms. In our review we try to show the considerable potential of insect peptides in searching for new solutions for mammalian diseases treatment. We summarise the knowledge about properties of insect peptides against different virulent agents, anti-inflammatory or anti-nociceptive properties as well as compare insect and mammalian/vertebrate peptide endocrine system to indicate usefulness of knowledge about insect peptide hormones in drug design. The field of possible using of insect delivered peptide to therapy of various human diseases is still not sufficiently explored. Undoubtedly, more attention should be paid to insects due to searching new drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Peptides: Production, bioactivity, functionality, and applications

    DEFF Research Database (Denmark)

    Hajfathalian, Mona; Ghelichi, Sakhi; García Moreno, Pedro Jesús

    2017-01-01

    Production of peptides with various effects from proteins of different sources continues to receive academic attention. Researchers of different disciplines are putting increasing efforts to produce bioactive and functional peptides from different sources such as plants, animals, and food industry...... by-products. The aim of this review is to introduce production methods of hydrolysates and peptides and provide a comprehensive overview of their bioactivity in terms of their effects on immune, cardiovascular, nervous, and gastrointestinal systems. Moreover, functional and antioxidant properties...... of hydrolysates and isolated peptides are reviewed. Finally, industrial and commercial applications of bioactive peptides including their use in nutrition and production of pharmaceuticals and nutraceuticals are discussed....

  19. Improved intracellular delivery of glucocerebrosidase mediated by the HIV-1 TAT protein transduction domain

    International Nuclear Information System (INIS)

    Lee, Kyun Oh; Luu, Nga; Kaneski, Christine R.; Schiffmann, Raphael; Brady, Roscoe O.; Murray, Gary J.

    2005-01-01

    Enzyme replacement therapy (ERT) for Gaucher disease designed to target glucocerebrosidase (GC) to macrophages via mannose-specific endocytosis is very effective in reversing hepatosplenomegaly, and normalizing hematologic parameters but is less effective in improving bone and lung involvement and ineffective in brain. Recombinant GCs containing an in-frame fusion to the HIV-1 trans-activator protein transduction domain (TAT) were expressed in eukaryotic cells in order to obtain active, normally glycosylated GC fusion proteins for enzyme uptake studies. Despite the absence of mannose-specific endocytic receptors on the plasma membranes of various fibroblasts, the recombinant GCs with C-terminal TAT fusions were readily internalized by these cells. Immunofluorescent confocal microscopy demonstrated the recombinant TAT-fusion proteins with a mixed endosomal and lysosomal localization. Thus, TAT-modified GCs represent a novel strategy for a new generation of therapeutic enzymes for ERT for Gaucher disease

  20. Electro-Optomechanical Transduction & Quantum Hard-Sphere Model for Dissipative Rydberg-EIT Media

    DEFF Research Database (Denmark)

    Zeuthen, Emil

    by two key parameters, the signal transfer efficiency and added noise temperature. In terms of these, we may evaluate its performance in various tasks ranging from classical signal detection to quantum state conversion between, e.g., superconducting circuitry and traveling optical signals. Having...... transduction functionality into the well-established framework of electrical engineering, thereby facilitating its implementation in potential applications such as nuclear magnetic resonance imaging and radio astronomy. We consider such optomechanical sensing of weak electrical signals and discuss how...... in a cold, optically dense cloud with light fields propagating under the condition of electromagnetically induced transparency (EIT). This can lead to strong and non-linear dissipative dynamics at the quantum level that prevent slow-light polaritons from coexisting within a blockade radius of one another...

  1. Comprehensive analysis of signal transduction in three-dimensional ECM-based tumor cell cultures

    Directory of Open Access Journals (Sweden)

    Iris Eke

    2015-11-01

    Full Text Available Analysis of signal transduction and protein phosphorylation is fundamental to understand physiological and pathological cell behavior as well as identification of novel therapeutic targets. Despite the fact that more physiological three-dimensional cell culture assays are increasingly used, particularly proteomics and phosphoproteomics remain challenging due to easy, robust and reproducible sample preparation. Here, we present an easy-to-perform, reliable and time-efficient method for the production of 3D cell lysates without compromising cell adhesion before cell lysis. The samples can be used for Western blotting as well as phosphoproteome array technology. This technique would be of interest for researchers working in all fields of biology and drug development.

  2. Development of a Modular Magnetostrictive Transducer for Torsional Guided Wave Transduction in a Cylindrical Structure

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seung Hyun; Park, Jae Ha; Kwon, Hyu Sang; Ahn, Bong Young; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2009-10-15

    Cylindrical structures such as pipes and shafts are widely used in various industrial facilities. Recently, researches on magnetostrictive transduction of torsional waves have been actively reported for the nondestructive evaluation of those cylindrical structures. However, the existing magnetostrictive patch transducer has somewhat inconvenient and time. Consuming process like patch bonding to a structure since it should employ a magnetostrictive patch having strong magnetostriction. To overcome these limitations of the existing transducer, in this work, we develop a novel modular magnetostrictive transducer to generate and measure torsional waves to inspect a cylindrical structure. The proposed transducer can be applied as viscous liquid coupling with shear couplant or dry coupling without coupling media instead of patch bonding to a structure. We describe a detailed structure of the modular transducer and conduct some experiments to verify its performance

  3. Development of a Modular Magnetostrictive Transducer for Torsional Guided Wave Transduction in a Cylindrical Structure

    International Nuclear Information System (INIS)

    Cho, Seung Hyun; Park, Jae Ha; Kwon, Hyu Sang; Ahn, Bong Young; Lee, Seung Seok

    2009-01-01

    Cylindrical structures such as pipes and shafts are widely used in various industrial facilities. Recently, researches on magnetostrictive transduction of torsional waves have been actively reported for the nondestructive evaluation of those cylindrical structures. However, the existing magnetostrictive patch transducer has somewhat inconvenient and time. Consuming process like patch bonding to a structure since it should employ a magnetostrictive patch having strong magnetostriction. To overcome these limitations of the existing transducer, in this work, we develop a novel modular magnetostrictive transducer to generate and measure torsional waves to inspect a cylindrical structure. The proposed transducer can be applied as viscous liquid coupling with shear couplant or dry coupling without coupling media instead of patch bonding to a structure. We describe a detailed structure of the modular transducer and conduct some experiments to verify its performance

  4. Arm-in-Arm Response Regulator Dimers Promote Intermolecular Signal Transduction

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Anna W.; Satyshur, Kenneth A.; Morales, Neydis Moreno; Forest, Katrina T. (UW)

    2016-02-01

    ABSTRACT

    Bacteriophytochrome photoreceptors (BphPs) and their cognate response regulators make up two-component signal transduction systems which direct bacteria to mount phenotypic responses to changes in environmental light quality. Most of these systems utilize single-domain response regulators to transduce signals through unknown pathways and mechanisms. Here we describe the photocycle and autophosphorylation kinetics of RtBphP1, a red light-regulated histidine kinase from the desert bacteriumRamlibacter tataouinensis. RtBphP1 undergoes red to far-red photoconversion with rapid thermal reversion to the dark state. RtBphP1 is autophosphorylated in the dark; this activity is inhibited under red light. The RtBphP1 cognate response regulator, theR. tataouinensisbacteriophytochrome response regulator (RtBRR), and a homolog, AtBRR fromAgrobacterium tumefaciens, crystallize unexpectedly as arm-in-arm dimers, reliant on a conserved hydrophobic motif, hFWAhL (where h is a hydrophobic M, V, L, or I residue). RtBRR and AtBRR dimerize distinctly from four structurally characterized phytochrome response regulators found in photosynthetic organisms and from all other receiver domain homodimers in the Protein Data Bank. A unique cacodylate-zinc-histidine tag metal organic framework yielded single-wavelength anomalous diffraction phases and may be of general interest. Examination of the effect of the BRR stoichiometry on signal transduction showed that phosphorylated RtBRR is accumulated more efficiently than the engineered monomeric RtBRR (RtBRRmon) in phosphotransfer reactions. Thus, we conclude that arm-in-arm dimers are a relevant signaling intermediate in this class of two-component regulatory systems.

  5. Regulation of autophagy by amino acids and MTOR-dependent signal transduction.

    Science.gov (United States)

    Meijer, Alfred J; Lorin, Séverine; Blommaart, Edward F; Codogno, Patrice

    2015-10-01

    Amino acids not only participate in intermediary metabolism but also stimulate insulin-mechanistic target of rapamycin (MTOR)-mediated signal transduction which controls the major metabolic pathways. Among these is the pathway of autophagy which takes care of the degradation of long-lived proteins and of the elimination of damaged or functionally redundant organelles. Proper functioning of this process is essential for cell survival. Dysregulation of autophagy has been implicated in the etiology of several pathologies. The history of the studies on the interrelationship between amino acids, MTOR signaling and autophagy is the subject of this review. The mechanisms responsible for the stimulation of MTOR-mediated signaling, and the inhibition of autophagy, by amino acids have been studied intensively in the past but are still not completely clarified. Recent developments in this field are discussed.

  6. Expression of cDNAs in human Natural Killer cell lines by retroviral transduction.

    Science.gov (United States)

    Miah, S M Shahjahan; Campbell, Kerry S

    2010-01-01

    Human NK-like cell lines are difficult to transfect using standard mammalian expression vectors and conventional transfection protocols, but they are susceptible to retroviral transduction as a means to introduce cDNAs. Our laboratory has exploited this technique to study a number of receptors in human NK cell lines. The method utilizes a bicistronic retroviral vector that co-expresses either drug resistance or enhanced green fluorescent protein (EGFP) in parallel with the gene of interest. After a single infection with recombinant retrovirus, transduced NK cells can be sorted for expression of EGFP or the transduced cell surface marker. Alternatively, cells expressing the transduced cDNAs can be selected for by treatment with neomycin, puromycin, or hygromycin. Using this method, the sorted/selected cells uniformly express the gene of interest and the expression is stable for many weeks of culture.

  7. Effect of the opioid methionine enkephalinamide on signal transduction in human T-lymphocytes

    DEFF Research Database (Denmark)

    Sørensen, A N; Claesson, Mogens Helweg

    1998-01-01

    T cell receptor (TCR/CD3) induced fluctuations in intracellular free ionizied calcium, [Ca2+]i, was analysed in the human T leukemia cell clone, Jurkat, cultured in the presence of the opioid methionine enkephalinamide (Met-Enk) in titrated concentrations (10[-7] to 10[-15] M) or saline (PBS....... Moreover, the levels of [Ca2+]i in this particular fraction were lower than control levels prior to ligation of the TCR/CD3 complex. The data support the idea that signal transduction in T cells can be influenced by endogenous opioid. The data therefore give credit to the evolving hypothesis...... of a functional relationship between the neuroendocrine system and the immune system....

  8. Practical considerations of image analysis and quantification of signal transduction IHC staining.

    Science.gov (United States)

    Grunkin, Michael; Raundahl, Jakob; Foged, Niels T

    2011-01-01

    The dramatic increase in computer processing power in combination with the availability of high-quality digital cameras during the last 10 years has fertilized the grounds for quantitative microscopy based on digital image analysis. With the present introduction of robust scanners for whole slide imaging in both research and routine, the benefits of automation and objectivity in the analysis of tissue sections will be even more obvious. For in situ studies of signal transduction, the combination of tissue microarrays, immunohistochemistry, digital imaging, and quantitative image analysis will be central operations. However, immunohistochemistry is a multistep procedure including a lot of technical pitfalls leading to intra- and interlaboratory variability of its outcome. The resulting variations in staining intensity and disruption of original morphology are an extra challenge for the image analysis software, which therefore preferably should be dedicated to the detection and quantification of histomorphometrical end points.

  9. Creating and analyzing pathway and protein interaction compendia for modelling signal transduction networks

    Directory of Open Access Journals (Sweden)

    Kirouac Daniel C

    2012-05-01

    Full Text Available Abstract Background Understanding the information-processing capabilities of signal transduction networks, how those networks are disrupted in disease, and rationally designing therapies to manipulate diseased states require systematic and accurate reconstruction of network topology. Data on networks central to human physiology, such as the inflammatory signalling networks analyzed here, are found in a multiplicity of on-line resources of pathway and interactome databases (Cancer CellMap, GeneGo, KEGG, NCI-Pathway Interactome Database (NCI-PID, PANTHER, Reactome, I2D, and STRING. We sought to determine whether these databases contain overlapping information and whether they can be used to construct high reliability prior knowledge networks for subsequent modeling of experimental data. Results We have assembled an ensemble network from multiple on-line sources representing a significant portion of all machine-readable and reconcilable human knowledge on proteins and protein interactions involved in inflammation. This ensemble network has many features expected of complex signalling networks assembled from high-throughput data: a power law distribution of both node degree and edge annotations, and topological features of a “bow tie” architecture in which diverse pathways converge on a highly conserved set of enzymatic cascades focused around PI3K/AKT, MAPK/ERK, JAK/STAT, NFκB, and apoptotic signaling. Individual pathways exhibit “fuzzy” modularity that is statistically significant but still involving a majority of “cross-talk” interactions. However, we find that the most widely used pathway databases are highly inconsistent with respect to the actual constituents and interactions in this network. Using a set of growth factor signalling networks as examples (epidermal growth factor, transforming growth factor-beta, tumor necrosis factor, and wingless, we find a multiplicity of network topologies in which receptors couple to downstream

  10. A composite approach boosts transduction coefficients of piezoceramics for energy harvesting

    Science.gov (United States)

    Yu, Xiaole; Hou, Yudong; Zheng, Mupeng; Zhao, Haiyan; Zhu, Mankang

    2018-03-01

    Piezoelectric energy harvesting is a hotspot in the field of new energy, the core goal of which is to prepare piezoceramics with a high transduction coefficient (d33×g33). The traditional solid-solution design strategy usually causes the same variation trend of d33 and ɛr, resulting in a low d33×g33 value. In this work, a composite design strategy was proposed that uses PZN-PZT/ZnAl2O4 as an example. By introducing ZnAl2O4, which is nonferroelectric with low ɛr, to the PZN-PZT piezoelectric matrix, ɛr decreased rapidly while d33 remained relatively stable. This behavior was ascribed to the increase of Q33 caused by an interfacial effect facilitating the formation of micro-domain structure.

  11. A composite approach boosts transduction coefficients of piezoceramics for energy harvesting

    Directory of Open Access Journals (Sweden)

    Xiaole Yu

    2018-03-01

    Full Text Available Piezoelectric energy harvesting is a hotspot in the field of new energy, the core goal of which is to prepare piezoceramics with a high transduction coefficient (d33×g33. The traditional solid–solution design strategy usually causes the same variation trend of d33 and εr, resulting in a low d33×g33 value. In this work, a composite design strategy was proposed that uses PZN–PZT/ZnAl2O4 as an example. By introducing ZnAl2O4, which is nonferroelectric with low εr, to the PZN–PZT piezoelectric matrix, εr decreased rapidly while d33 remained relatively stable. This behavior was ascribed to the increase of Q33 caused by an interfacial effect facilitating the formation of micro-domain structure.

  12. Transduction of Repetitive Mechanical Stimuli by Piezo1 and Piezo2 Ion Channels

    Directory of Open Access Journals (Sweden)

    Amanda H. Lewis

    2017-06-01

    Full Text Available Several cell types experience repetitive mechanical stimuli, including vein endothelial cells during pulsating blood flow, inner ear hair cells upon sound exposure, and skin cells and their innervating dorsal root ganglion (DRG neurons when sweeping across a textured surface or touching a vibrating object. While mechanosensitive Piezo ion channels have been clearly implicated in sensing static touch, their roles in transducing repetitive stimulations are less clear. Here, we perform electrophysiological recordings of heterologously expressed mouse Piezo1 and Piezo2 responding to repetitive mechanical stimulations. We find that both channels function as pronounced frequency filters whose transduction efficiencies vary with stimulus frequency, waveform, and duration. We then use numerical simulations and human disease-related point mutations to demonstrate that channel inactivation is the molecular mechanism underlying frequency filtering and further show that frequency filtering is conserved in rapidly adapting mouse DRG neurons. Our results give insight into the potential contributions of Piezos in transducing repetitive mechanical stimuli.

  13. Efficient, Broadband and Wide-Angle Hot-Electron Transduction using Metal-Semiconductor Hyperbolic Metamaterials

    KAUST Repository

    Sakhdari, Maryam

    2016-05-20

    Hot-electron devices are emerging as promising candidates for the transduction of optical radiation into electrical current, as they enable photodetection and solar/infrared energy harvesting at sub-bandgap wavelengths. Nevertheless, poor photoconversion quantum yields and low bandwidth pose fundamental challenge to fascinating applications of hot-electron optoelectronics. Based on a novel hyperbolic metamaterial (HMM) structure, we theoretically propose a vertically-integrated hot-electron device that can efficiently couple plasmonic excitations into electron flows, with an external quantum efficiency approaching the physical limit. Further, this metamaterial-based device can have a broadband and omnidirectional response at infrared and visible wavelengths. We believe that these findings may shed some light on designing practical devices for energy-efficient photodetection and energy harvesting beyond the bandgap spectral limit.

  14. A bead-based western for high-throughput cellular signal transduction analyses

    Science.gov (United States)

    Treindl, Fridolin; Ruprecht, Benjamin; Beiter, Yvonne; Schultz, Silke; Döttinger, Anette; Staebler, Annette; Joos, Thomas O.; Kling, Simon; Poetz, Oliver; Fehm, Tanja; Neubauer, Hans; Kuster, Bernhard; Templin, Markus F.

    2016-01-01

    Dissecting cellular signalling requires the analysis of large number of proteins. The DigiWest approach we describe here transfers the western blot to a bead-based microarray platform. By combining gel-based protein separation with immobilization on microspheres, hundreds of replicas of the initial blot are created, thus enabling the comprehensive analysis of limited material, such as cells collected by laser capture microdissection, and extending traditional western blotting to reach proteomic scales. The combination of molecular weight resolution, sensitivity and signal linearity on an automated platform enables the rapid quantification of hundreds of specific proteins and protein modifications in complex samples. This high-throughput western blot approach allowed us to identify and characterize alterations in cellular signal transduction that occur during the development of resistance to the kinase inhibitor Lapatinib, revealing major changes in the activation state of Ephrin-mediated signalling and a central role for p53-controlled processes. PMID:27659302

  15. Modulators of Stomatal Lineage Signal Transduction Alter Membrane Contact Sites and Reveal Specialization among ERECTA Kinases.

    Science.gov (United States)

    Ho, Chin-Min Kimmy; Paciorek, Tomasz; Abrash, Emily; Bergmann, Dominique C

    2016-08-22

    Signal transduction from a cell's surface to its interior requires dedicated signaling elements and a cellular environment conducive to signal propagation. Plant development, defense, and homeostasis rely on plasma membrane receptor-like kinases to perceive endogenous and environmental signals, but little is known about their immediate downstream targets and signaling modifiers. Using genetics, biochemistry, and live-cell imaging, we show that the VAP-RELATED SUPPRESSOR OF TMM (VST) family is required for ERECTA-mediated signaling in growth and cell-fate determination and reveal a role for ERECTA-LIKE2 in modulating signaling by its sister kinases. We show that VSTs are peripheral plasma membrane proteins that can form complexes with integral ER-membrane proteins, thereby potentially influencing the organization of the membrane milieu to promote efficient and differential signaling from the ERECTA-family members to their downstream intracellular targets. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Auxin apical control of the auxin polar transport and its oscillation - a suggested cellular transduction mechanism

    Directory of Open Access Journals (Sweden)

    Tomasz J. Wodzicki

    2014-01-01

    Full Text Available The proposed hypothesis concerns the transduction of auxin molecular signals arriving from the apoplast at the plasma membrane or recognized by the proteineous receptors of the responding cell, to the concentration gradients oscillating in the supracellular space, associated usually with the specific plant growth and differentiation. Acting as an agonist from outside the target cell auxin stimulates in this cell: (1 the liberation of auxin from the cytosolic pool of its conjugates directly into the basipetal efflux; (2 the synthesis of new auxin which restores the cytosolic reserve of auxin conjugates. The functioning of such a system may be effective in a series of processes initiated by the changing concentration of cytosolic calcium. The hypothesis suggests a molecular mechanism for the development and effective operation of the morphogenetic field in the supracellular space of the plant body, such as the field resulting from auxin waves discovered in cambium.

  17. Drawing a Transductive Ecosophy in Process: Technological Arts, Residual Matter, Associated Milieus

    Directory of Open Access Journals (Sweden)

    Gisèle Trudel

    2015-06-01

    Full Text Available Drawing a Transductive Ecosophy in Process: Technological Arts, Residual Matter, Associated Milieus by Gisèle Trudel. NANO: New American Notes Online, Issue 7: The Aesthetics of Trash - nanocrit.com. This text examines the tetralogy of media artworks about residual matter produced by Ælab between 2008 and 2014. Taking its own title as a diagram (Deleuze and Guattari Mille Plateaux, it charts and builds on the processes of these artworks, elucidating their relations to materiality, philosophy and technicity. Technological research-creation becomes in these instances a transdisciplinary aesthetic act, emerging from an ecology of practices that combine humans, non-humans and waste matter in an effort to increase attentiveness in actions.

  18. Localization of phosphatidylinositol signaling components in rat taste cells: Role in bitter taste transduction

    International Nuclear Information System (INIS)

    Hwang, P.M.; Verma, A.; Bredt, D.S.; Snyder, S.H.

    1990-01-01

    To assess the role of phosphatidylinositol turnover in taste transduction we have visualized, in rat tongue, ATP-dependent endoplasmic reticular accumulation of 45 Ca 2+ , inositol 1,4,5-trisphosphate receptor binding sites, and phosphatidylinositol turnover monitored by autoradiography of [ 3 H]cytidine diphosphate diacylglycerol formed from [ 3 H]cytidine. Accumulated 45 Ca 2+ , inositol 1,4,5-trisphosphate receptors, and phosphatidylinositol turnover are selectively localized to apical areas of the taste buds of circumvallate papillae, which are associated with bitter taste. Further evidence for a role of phosphatidylinositol turnover in bitter taste is our observation of a rapid, selective increase in mass levels of inositol 1,4,5-trisphosphate elicited by low concentrations of denatonium, a potently bitter tastant

  19. CD4 expression on EL4 cells as an epiphenomenon of retroviral transduction and selection.

    Science.gov (United States)

    Logan, Grant J; Spinoulas, Afroditi; Alexander, Stephen I; Smythe, Jason A; Alexander, Ian E

    2004-04-01

    The EL4 murine tumour cell line, isolated from a chemically induced lymphoma over 50 years ago, has been extensively exploited in immunological research. The conclusions drawn from many of these studies have been based on the presumption that EL4 cells maintain a stable phenotype during experimental manipulation. To the contrary, we have observed 100-fold greater expression of cell surface CD4 (CD4(high)) on a subpopulation of EL4 cells following retroviral transduction and G418 selection when compared with unmodified populations. Although the mechanism responsible for this effect remains to be elucidated, the unexpected expression of CD4, a molecule that functions as both a coreceptor with the T-cell receptor and ligand for the pro-inflammatory cytokine IL-16, has the potential to influence experimental outcomes. Upregulation of CD4 should be excluded when EL4 cells are utilized in experiments requiring a consistent immuno-phenotype.

  20. Downstream reporter gene imaging for signal transduction pathway of dopamine type 2 receptor

    International Nuclear Information System (INIS)

    Le, Uyenchi N.; Min, Jung Joon; Moon, Sung Min; Bom, Hee Seung

    2004-01-01

    The Dopamine 2 receptor (D2R) signal pathway regulates gene expression by phosphorylation of proteins including cAMP reponse element-binding protein (CREB), a transcription factor. In this study, we developed a reporter strategy using the GAL4 fusion CREB to assess the phosphorylation of CREB, one of the targets of the D2R signal transduction pathway. We used three plasmids: GAL4 fusion transactivator (pCMV-CREB), firefly luciferase reporter with GAL4 binding sites (pG5-FLUC), and D2R plasmid (pCMV-D2R). Group 1 293T cells were transiently transfected with pCMV-CREB and pG5-FLUC, and group 2 cells were transfected with all three plasmids. Transfected cells were stimulated with different concentrations of dopamine (0-200 M). For animal studies, group 1 and 2 cells (1x10 6 ) were subcutaneously injected on the left and right thigh of six nude mice, respectively. Dopamine stimiulation was performed with intraperitoneal injection of L-DOPA incombination with carbidopa, a peripheral DOPA decarboxylase inhibitor. Bioluminescence optical imaging studies were performed before and after L-DOPA injection. In cell culture studies, group 1 cells showed strong luciferase activity which implies direct activation of the signaling pathway due to growth factors contained in culture medium. Group 2 cells showed strong luciferase activity and a further increase after administration of dopamine. In animal studies, group 1 and 2 cells showed bioluminescence signal before L-DOPA injection, but signal from group 2 cells significantly increased 12 h after L-DOPA injection. The signal from group 1 cells disappeared thereafter, but group 2 cells continued to show signal until 36 h of L-DOPA injection. This study demonstrates imaging of the D2R signal transduction pathway and should be useful for noninvasive imaging of downstream effects of G-coupled protein pathways

  1. Anagrelide represses GATA-1 and FOG-1 expression without interfering with thrombopoietin receptor signal transduction.

    Science.gov (United States)

    Ahluwalia, M; Donovan, H; Singh, N; Butcher, L; Erusalimsky, J D

    2010-10-01

     Anagrelide is a selective inhibitor of megakaryocytopoiesis used to treat thrombocytosis in patients with chronic myeloproliferative disorders. The effectiveness of anagrelide in lowering platelet counts is firmly established, but its primary mechanism of action remains elusive.  Here, we have evaluated whether anagrelide interferes with the major signal transduction cascades stimulated by thrombopoietin in the hematopoietic cell line UT-7/mpl and in cultured CD34(+) -derived human hematopoietic cells. In addition, we have used quantitative mRNA expression analysis to assess whether the drug affects the levels of known transcription factors that control megakaryocytopoiesis.  In UT-7/mpl cells, anagrelide (1μm) did not interfere with MPL-mediated signaling as monitored by its lack of effect on JAK2 phosphorylation. Similarly, the drug did not affect the phosphorylation of STAT3, ERK1/2 or AKT in either UT-7/mpl cells or primary hematopoietic cells. In contrast, during thrombopoietin-induced megakaryocytic differentiation of normal hematopoietic cultures, anagrelide (0.3μm) reduced the rise in the mRNA levels of the transcription factors GATA-1 and FOG-1 as well as those of the downstream genes encoding FLI-1, NF-E2, glycoprotein IIb and MPL. However, the drug showed no effect on GATA-2 or RUNX-1 mRNA expression. Furthermore, anagrelide did not diminish the rise in GATA-1 and FOG-1 expression during erythropoietin-stimulated erythroid differentiation. Cilostamide, an exclusive and equipotent phosphodiesterase III (PDEIII) inhibitor, did not alter the expression of these genes.  Anagrelide suppresses megakaryocytopoiesis by reducing the expression levels of GATA-1 and FOG-1 via a PDEIII-independent mechanism that is differentiation context-specific and does not involve inhibition of MPL-mediated early signal transduction events. © 2010 International Society on Thrombosis and Haemostasis.

  2. MMP-1/PAR-1 signal transduction axis and its prognostic impact in esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Hong-hua Peng

    2012-01-01

    Full Text Available The matrix metalloprotease-1 (MMP-1/protease-activated receptor-1 (PAR-1 signal transduction axis plays an important role in tumorigenesis. To explore the expression and prognostic value of MMP-1 and PAR-1 in esophageal squamous cell carcinoma (ESCC, we evaluated the expression of two proteins in resected specimens from 85 patients with ESCC by immunohistochemistry. Sixty-two (72.9% and 58 (68.2% tumors were MMP-1- and PAR-1-positive, respectively, while no significant staining was observed in normal esophageal squamous epithelium. MMP-1 and PAR-1 overexpression was significantly associated with tumor node metastasis (TNM stage and regional lymph node involvement. Patients with MMP-1- and PAR-1-positive tumors, respectively, had poorer disease-free survival (DFS than those with negative ESCC (P = 0.002 and 0.003, respectively. Univariate analysis showed a significant relationship between TNM stage [hazard ratio (HR = 2.836, 95% confidence interval (CI = 1.866-4.308], regional lymph node involvement (HR = 2.955, 95%CI = 1.713-5.068, MMP-1 expression (HR = 2.669, 95%CI = 1.229-6.127, and PAR-1 expression (HR = 1.762, 95%CI = 1.156-2.883 and DFS. Multivariate analysis including the above four parameters identified TNM stage (HR = 2.035, 95%CI = 1.167-3.681, MMP-1 expression (HR = 2.109, 95%CI = 1.293-3.279, and PAR-1 expression (HR = 1.967, 95%CI = 1.256-2.881 as independent and significant prognostic factors for DFS. Our data suggest for the first time that MMP-1 and PAR-1 were both overexpressed in ESCC and are novel predictors of poor patient prognosis after curative resection. The MMP-1/PAR-1 signal transduction axis might be a new therapeutic target for future therapies tailored against ESCC.

  3. Dual functional extracellular recording using a light-addressable potentiometric sensor for bitter signal transduction.

    Science.gov (United States)

    Du, Liping; Wang, Jian; Chen, Wei; Zhao, Luhang; Wu, Chunsheng; Wang, Ping

    2018-08-31

    This paper presents a dual functional extracellular recording biosensor based on a light-addressable potentiometric sensor (LAPS). The design and fabrication of this biosensor make it possible to record both extracellular membrane potential changes and ATP release from a single taste bud cell for the first time. For detecting ATP release, LAPS chip was functionalized with ATP-sensitive DNA aptamer by covalent immobilization. Taste bud cells isolated from rat were cultured on LAPS surface. When the desired single taste bud cell was illuminated by modulated light, ATP release from single taste bud cells can be measured by recording the shifts of bias voltage-photocurrent curves (I-V curves) when the LAPS chip is working in discrete mode. On the other hand, extracellular membrane potential changes can be monitored by recording the fluctuation of LAPS photocurrent when the LAPS chip is working in continuous mode. The results show this biosensor can effectively record the enhancive effect of the bitter substance and inhibitory effect of the carbenoxolone (CBX) on the extracellular membrane potential changes and ATP release of single taste bud cells. In addition, the inhibitory effect of CBX also confirms LAPS extracellular recordings are originated from bitter signal transduction. It is proved this biosensor is suitable for extracellular recording of ATP release and membrane potential changes of single taste bud cells. It is suggested this biosensor could be applied to investigating taste signal transduction at the single-cell level as well as applied to other types of cells which have similar functions to taste bud cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Immunophilin ligands demonstrate common features of signal transduction leading to exocytosis or transcription.

    Science.gov (United States)

    Hultsch, T; Albers, M W; Schreiber, S L; Hohman, R J

    1991-01-01

    Investigations of the actions and interactions of the immunophilin ligands FK506, cyclosporin A (CsA), rapamycin, and 506BD suggest that complexes of FK506 with an FK506-binding protein or of CsA with a cyclophilin (CsA-binding protein) inhibit the T-cell receptor-mediated signal transduction that results in the transcription of interleukin 2. Now we report an identical spectrum of activities of FK506, CsA, rapamycin, and 506BD on IgE receptor-mediated signal transduction that results in exocytosis of secretory granules from the rat basophilic leukemia cell line RBL-2H3, a mast cell model. Both FK506 and CsA inhibit receptor-mediated exocytosis (CsA IC50 = 200 nM; FK506 IC50 = 2 nM) without affecting early receptor-associated events (hydrolysis of phosphatidylinositol, synthesis and release of eicosanoids, uptake of Ca2+). In contrast, rapamycin and 506BD, which share common structural elements with FK506, by themselves have no effect on IgE receptor-mediated exocytosis. Both compounds, however, prevent inhibition by FK506 but not by CsA. Affinity chromatography with FK506, CsA, and rapamycin matrices indicates that the same set of immunophilins present in RBL-2H3 cells have been found in Jurkat T cells and calf thymus; however, the relative amounts of these proteins differ in the two cell types. These results suggest the existence of a common step in cytoplasmic signaling in T cells and mast cells that may be part of a general signaling mechanism. Images PMID:1712484

  5. Human HOXA5 homeodomain enhances protein transduction and its application to vascular inflammation

    International Nuclear Information System (INIS)

    Lee, Ji Young; Park, Kyoung sook; Cho, Eun Jung; Joo, Hee Kyoung; Lee, Sang Ki; Lee, Sang Do; Park, Jin Bong; Chang, Seok Jong; Jeon, Byeong Hwa

    2011-01-01

    Highlights: → We have developed an E. coli protein expression vector including human specific gene sequences for protein cellular delivery. → The plasmid was generated by ligation the nucleotides 770-817 of the homeobox A5 mRNA sequence. → HOXA5-APE1/Ref-1 inhibited TNF-alpha-induced monocyte adhesion to endothelial cells. → Human HOXA5-PTD vector provides a powerful research tools for uncovering cellular functions of proteins or for the generation of human PTD-containing proteins. -- Abstract: Cellular protein delivery is an emerging technique by which exogenous recombinant proteins are delivered into mammalian cells across the membrane. We have developed an Escherichia coli expression vector including human specific gene sequences for protein cellular delivery. The plasmid was generated by ligation the nucleotides 770-817 of the homeobox A5 mRNA sequence which was matched with protein transduction domain (PTD) of homeodomain protein A5 (HOXA5) into pET expression vector. The cellular uptake of HOXA5-PTD-EGFP was detected in 1 min and its transduction reached a maximum at 1 h within cell lysates. The cellular uptake of HOXA5-EGFP at 37 o C was greater than in 4 o C. For study for the functional role of human HOXA5-PTD, we purified HOXA5-APE1/Ref-1 and applied it on monocyte adhesion. Pretreatment with HOXA5-APE1/Ref-1 (100 nM) inhibited TNF-α-induced monocyte adhesion to endothelial cells, compared with HOXA5-EGFP. Taken together, our data suggested that human HOXA5-PTD vector provides a powerful research tools for uncovering cellular functions of proteins or for the generation of human PTD-containing proteins.

  6. Multiple signal transduction pathways in okadaic acid induced apoptosis in HeLa cells

    International Nuclear Information System (INIS)

    Jayaraj, R.; Gupta, Nimesh; Rao, P.V. Lakshmana

    2009-01-01

    Okadaic acid (OA) is the major component of diarrhetic shell fish poisoning toxins and a potent inhibitor of protein phosphatase 1 and 2A. We investigated the signal transduction pathways involved in OA induced cell death in HeLa cells. OA induced cytotoxicity and apoptosis at IC50 of 100 nM. OA treatment resulted in time dependent increase in reactive oxygen species and depleted intracellular glutathione levels. Loss of mitochondrial membrane permeability led to translocation of bax, cytochrome-c and AIF from mitochondria to cytosol. The cells under fluorescence microscope showed typical apoptotic morphology with condensed chromatin, and nuclear fragmentation. We investigated the mitochondrial-mediated caspase cascade. The time dependent activation and cleavage of of bax, caspases-8, 10, 9, 3 and 7 was observed in Western blot analysis. In addition to caspase-dependent pathway AIF mediated caspase-independent pathway was involved in OA mediated cell death. OA also caused time dependent inhibition of protein phosphatase 2A activity and phosphorylation of p38 and p42/44 MAP kinases. Inhibitor studies with Ac-DEVO-CHO and Z-VAD-FMK could not prevent the phosphorylation of p38 and p42/44 MAP kinases. Our experiments with caspase inhibitors Ac-DEVD-CHO, Z-IETD-FMK and Z-VAD-FMK inhibited capsase-3, 8 cleavages but did not prevent OA-induced apoptosis and DNA fragmentation. Similarly, pretreatment with cyclosporin-A and N-acetylcysteine could not prevent the DNA fragmentation. In summary, the results of our study show that OA induces multiple signal transduction pathways acting either independently or simultaneously leading to apoptosis

  7. Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway.

    Science.gov (United States)

    Sato, Yukuto; Hashiguchi, Yasuyuki; Nishida, Mutsumi

    2009-02-20

    Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization) and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization). Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 3.1.4.17) 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8-9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT) pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our analyses imply that an increase in gene product sometimes

  8. Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway

    Directory of Open Access Journals (Sweden)

    Nishida Mutsumi

    2009-02-01

    Full Text Available Abstract Background Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization. Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. Results We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 3.1.4.17 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8–9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. Conclusion The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our

  9. MMP-1/PAR-1 signal transduction axis and its prognostic impact in esophageal squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Hong-hua; Zhang, Xi; Cao, Pei-guo [Department of Oncology, the Third Xiangya Hospital, Central South University, Changsha, Hunan Province (China)

    2011-11-18

    The matrix metalloprotease-1 (MMP-1)/protease-activated receptor-1 (PAR-1) signal transduction axis plays an important role in tumorigenesis. To explore the expression and prognostic value of MMP-1 and PAR-1 in esophageal squamous cell carcinoma (ESCC), we evaluated the expression of two proteins in resected specimens from 85 patients with ESCC by immunohistochemistry. Sixty-two (72.9%) and 58 (68.2%) tumors were MMP-1- and PAR-1-positive, respectively, while no significant staining was observed in normal esophageal squamous epithelium. MMP-1 and PAR-1 overexpression was significantly associated with tumor node metastasis (TNM) stage and regional lymph node involvement. Patients with MMP-1- and PAR-1-positive tumors, respectively, had poorer disease-free survival (DFS) than those with negative ESCC (P = 0.002 and 0.003, respectively). Univariate analysis showed a significant relationship between TNM stage [hazard ratio (HR) = 2.836, 95% confidence interval (CI) = 1.866-4.308], regional lymph node involvement (HR = 2.955, 95%CI = 1.713-5.068), MMP-1 expression (HR = 2.669, 95%CI = 1.229-6.127), and PAR-1 expression (HR = 1.762, 95%CI = 1.156-2.883) and DFS. Multivariate analysis including the above four parameters identified TNM stage (HR = 2.035, 95%CI = 1.167-3.681), MMP-1 expression (HR = 2.109, 95%CI = 1.293-3.279), and PAR-1 expression (HR = 1.967, 95%CI = 1.256-2.881) as independent and significant prognostic factors for DFS. Our data suggest for the first time that MMP-1 and PAR-1 were both overexpressed in ESCC and are novel predictors of poor patient prognosis after curative resection. The MMP-1/PAR-1 signal transduction axis might be a new therapeutic target for future therapies tailored against ESCC.

  10. Optimization of Liquid DiElectroPhoresis (LDEP Digital Microfluidic Transduction for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Hiroyuki Fujita

    2011-06-01

    Full Text Available Digital microfluidic has recently been under intensive study, as an effective method to carry out liquid manipulation in Lab-On-a-Chip (LOC systems. Among droplet actuation forces, ElectroWetting on Dielectric (EWOD and Liquid DiElectroPhoresis (LDEP are powerful tools, used in many LOC platforms. Such digital microfluidic transductions do not require integration of complex mechanical components such as pumps and valves to perform the fluidic operations. However, although LDEP has been proved to be efficient to carry and manipulate biological components in insulating liquids, this microfluidic transduction requires several hundreds of volts at relatively high frequencies (kHz to MHz. With the purpose to develop integrated microsystems µ-TAS (Micro Total Analysis System or Point of Care systems, the goal here is to reduce such high actuation voltage, the power consumption, though using standard dielectric materials. This paper gives key rules to determine the best tradeoff between liquid manipulation efficiency, low-power consumption and robustness of microsystems using LDEP actuation. This study leans on an electromechanical model to describe liquid manipulation that is applied to an experimental setup, and provides precise quantification of both actuation voltage Vth and frequency fc thresholds between EWOD and LDEP regimes. In particular, several parameters will be investigated to quantify Vth and fc, such as the influence of the chip materials, the electrodes size and the device configurations. Compared to current studies in the field, significant reduction of both Vth and fc is achieved by optimization of the aforementioned parameters.

  11. Natriuretic peptides in cardiometabolic regulation and disease

    DEFF Research Database (Denmark)

    Zois, Nora E; Bartels, Emil D; Hunter, Ingrid

    2014-01-01

    decade. Dysregulation of the natriuretic peptide system has been associated with obesity, glucose intolerance, type 2 diabetes mellitus, and essential hypertension. Moreover, the natriuretic peptides have been implicated in the protection against atherosclerosis, thrombosis, and myocardial ischaemia. All...... these conditions can coexist and potentially lead to heart failure, a syndrome associated with a functional natriuretic peptide deficiency despite high circulating concentrations of immunoreactive peptides. Therefore, dysregulation of the natriuretic peptide system, a 'natriuretic handicap', might be an important...... factor in the initiation and progression of metabolic dysfunction and its accompanying cardiovascular complications. This Review provides a summary of the natriuretic peptide system and its involvement in these cardiometabolic conditions. We propose that these peptides might have an integrating role...

  12. GLP-1 secretion is stimulated by 1,10-phenanthroline via colocalized T2R5 signal transduction in human enteroendocrine L cell

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jiyoung; Kim, Ki-Suk; Kim, Kang-Hoon; Lee, In-Seung; Jeong, Hyeon-soo; Kim, Yumi; Jang, Hyeung-Jin, E-mail: hjjang@khu.ac.kr

    2015-12-04

    Glucagon-like peptide-1 (GLP-1) hormone is known to regulate blood glucose by an insulinotropic effect and increases proliferation as and also prevents apoptosis of pancreatic β cells. We know that GLP-1 is secreted by nutrients such as fatty acids and sweet compounds but also bitter compounds via stimulation of G-protein coupled receptors (GPCRs) in the gut. Among these, bitter compounds are multiply-contained in phytochemicals or artificial materials and perceived as ligands of various bitter taste receptors. We hypothesized that GLP-1 hormone is secreted through stimulation of a single bitter taste receptor by 1,10-phenanthroline which is known agonist of taste receptor type 2 member 5 (T2R5). To prove this hypothesis, we used the representatively well-known 1,10-phenanthroline as ligand of single receptor and evaluated the existence of T2R5 by double-labeling immunofluorescence and then 1,10-phenanthroline is able to secrete GLP-1 hormone through stimulation of T2R5 in human enteroendocrine cells. Consequently, we verify that GLP-1 hormone is colocalized with T2R5 in the human duodenum and ileum tissue and is secreted by 1,10-phenanthroline via T2R5 signal transduction in differentiated human enteroendocrine L cells. - Highlights: • Taste receptor type 2 member 5 (T2R5) is colocalized with GLP-1 hormone in human enteroendocrine cells. • GLP-1 secretion is stimulated by 1,10-phenanthroline via stimulation of T2R5. • Inhibition of the bitter taste pathway reduce GLP-1 secretion.

  13. GLP-1 secretion is stimulated by 1,10-phenanthroline via colocalized T2R5 signal transduction in human enteroendocrine L cell

    International Nuclear Information System (INIS)

    Park, Jiyoung; Kim, Ki-Suk; Kim, Kang-Hoon; Lee, In-Seung; Jeong, Hyeon-soo; Kim, Yumi; Jang, Hyeung-Jin

    2015-01-01

    Glucagon-like peptide-1 (GLP-1) hormone is known to regulate blood glucose by an insulinotropic effect and increases proliferation as and also prevents apoptosis of pancreatic β cells. We know that GLP-1 is secreted by nutrients such as fatty acids and sweet compounds but also bitter compounds via stimulation of G-protein coupled receptors (GPCRs) in the gut. Among these, bitter compounds are multiply-contained in phytochemicals or artificial materials and perceived as ligands of various bitter taste receptors. We hypothesized that GLP-1 hormone is secreted through stimulation of a single bitter taste receptor by 1,10-phenanthroline which is known agonist of taste receptor type 2 member 5 (T2R5). To prove this hypothesis, we used the representatively well-known 1,10-phenanthroline as ligand of single receptor and evaluated the existence of T2R5 by double-labeling immunofluorescence and then 1,10-phenanthroline is able to secrete GLP-1 hormone through stimulation of T2R5 in human enteroendocrine cells. Consequently, we verify that GLP-1 hormone is colocalized with T2R5 in the human duodenum and ileum tissue and is secreted by 1,10-phenanthroline via T2R5 signal transduction in differentiated human enteroendocrine L cells. - Highlights: • Taste receptor type 2 member 5 (T2R5) is colocalized with GLP-1 hormone in human enteroendocrine cells. • GLP-1 secretion is stimulated by 1,10-phenanthroline via stimulation of T2R5. • Inhibition of the bitter taste pathway reduce GLP-1 secretion.

  14. Structure, signaling mechanism and regulation of the natriuretic peptide receptor guanylate cyclase.

    Energy Technology Data Exchange (ETDEWEB)

    Misono, K. S.; Philo, J. S.; Arakawa, T.; Ogata, C. M.; Qiu, Y.; Ogawa, H.; Young, H. S. (Biosciences Division); (Univ. of Nevada); (Alliance Protein Labs.)

    2011-06-01

    Atrial natriuretic peptide (ANP) and the homologous B-type natriuretic peptide are cardiac hormones that dilate blood vessels and stimulate natriuresis and diuresis, thereby lowering blood pressure and blood volume. ANP and B-type natriuretic peptide counterbalance the actions of the renin-angiotensin-aldosterone and neurohormonal systems, and play a central role in cardiovascular regulation. These activities are mediated by natriuretic peptide receptor-A (NPRA), a single transmembrane segment, guanylyl cyclase (GC)-linked receptor that occurs as a homodimer. Here, we present an overview of the structure, possible chloride-mediated regulation and signaling mechanism of NPRA and other receptor GCs. Earlier, we determined the crystal structures of the NPRA extracellular domain with and without bound ANP. Their structural comparison has revealed a novel ANP-induced rotation mechanism occurring in the juxtamembrane region that apparently triggers transmembrane signal transduction. More recently, the crystal structures of the dimerized catalytic domain of green algae GC Cyg12 and that of cyanobacterium GC Cya2 have been reported. These structures closely resemble that of the adenylyl cyclase catalytic domain, consisting of a C1 and C2 subdomain heterodimer. Adenylyl cyclase is activated by binding of G{sub s}{alpha} to C2 and the ensuing 7{sup o} rotation of C1 around an axis parallel to the central cleft, thereby inducing the heterodimer to adopt a catalytically active conformation. We speculate that, in NPRA, the ANP-induced rotation of the juxtamembrane domains, transmitted across the transmembrane helices, may induce a similar rotation in each of the dimerized GC catalytic domains, leading to the stimulation of the GC catalytic activity.

  15. Analysis of peptide uptake and location of root hair-promoting peptide accumulation in plant roots.

    Science.gov (United States)

    Matsumiya, Yoshiki; Taniguchi, Rikiya; Kubo, Motoki

    2012-03-01

    Peptide uptake by plant roots from degraded soybean-meal products was analyzed in Brassica rapa and Solanum lycopersicum. B. rapa absorbed about 40% of the initial water volume, whereas peptide concentration was decreased by 75% after 24 h. Analysis by reversed-phase HPLC showed that number of peptides was absorbed by the roots during soaking in degraded soybean-meal products for 24 h. Carboxyfluorescein-labeled root hair-promoting peptide was synthesized, and its localization, movement, and accumulation in roots were investigated. The peptide appeared to be absorbed by root hairs and then moved to trichoblasts. Furthermore, the peptide was moved from trichoblasts to atrichoblasts after 24 h. The peptide was accumulated in epidermal cells, suggesting that the peptide may have a function in both trichoblasts and atrichoblasts. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.

  16. Taylor Dispersion Analysis as a promising tool for assessment of peptide-peptide interactions.

    Science.gov (United States)

    Høgstedt, Ulrich B; Schwach, Grégoire; van de Weert, Marco; Østergaard, Jesper

    2016-10-10

    Protein-protein and peptide-peptide (self-)interactions are of key importance in understanding the physiochemical behavior of proteins and peptides in solution. However, due to the small size of peptide molecules, characterization of these interactions is more challenging than for proteins. In this work, we show that protein-protein and peptide-peptide interactions can advantageously be investigated by measurement of the diffusion coefficient using Taylor Dispersion Analysis. Through comparison to Dynamic Light Scattering it was shown that Taylor Dispersion Analysis is well suited for the characterization of protein-protein interactions of solutions of α-lactalbumin and human serum albumin. The peptide-peptide interactions of three selected peptides were then investigated in a concentration range spanning from 0.5mg/ml up to 80mg/ml using Taylor Dispersion Analysis. The peptide-peptide interactions determination indicated that multibody interactions significantly affect the PPIs at concentration levels above 25mg/ml for the two charged peptides. Relative viscosity measurements, performed using the capillary based setup applied for Taylor Dispersion Analysis, showed that the viscosity of the peptide solutions increased with concentration. Our results indicate that a viscosity difference between run buffer and sample in Taylor Dispersion Analysis may result in overestimation of the measured diffusion coefficient. Thus, Taylor Dispersion Analysis provides a practical, but as yet primarily qualitative, approach to assessment of the colloidal stability of both peptide and protein formulations. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Radio peptide imaging and therapy

    International Nuclear Information System (INIS)

    Buscombe, Jonh

    1997-01-01

    Full text. The concept of the magic bullet retains its attraction to us. If only we could take a drug or radioisotope and inject this intravenously and then will attach to the target cancer. This may allow imaging if labelled with a radio pharmaceutical or possibly even effective therapy. Initially work was started using antibodies of mouse origin. These have shown some utility in targeting tumors but there are problems in that these are essentially non-human proteins, often derived from mice. This leads to the formation of antibodies against that antibody so that repeat administrations lead to reduced efficacy and possibly may carry a risk anaphylaxis for the patient. Two different methods have evolved to deal with this situation. Either make antibodies more human or use smaller fragments, so that they are less likely to cause allergic reactions. The second method is to try and use a synthetic peptide. This will contain a series of amino acids which recognize a certain cell receptor. For example the somatostatin analogue Octreotide is an 8 amino acid peptide which has the same biological actions as natural somatostatin but an increased plasma half life. To this is added a linker a good example being DTPA and then radioisotope for example In-111. There we can have the complex In-111-DTPA-Octreotide which can be used to image somatostatin receptors in vivo. The main advantage over antibodies is that the cost production is less and many different variation of peptides for a particular receptor can be manufactured and assessed to find which is the optimal agent tumour imaging at a fraction of the cost of antibody production. There are two main approaches. Firstly to take a natural peptide hormone such as insulin or VIP and label by a simple method such as iodination with I-123. A group in Vienna have done it and shown good uptake of I-123 Insulin in primary hepatomas and of I-123 VIP in pancreatic cancers. Many natural peptide hormones however have a short plasma half

  18. Cyclic phosphopeptides for interference with Grb2 SH2 domain signal transduction prepared by ring-closing metathesis and phosphorylation

    NARCIS (Netherlands)

    Dekker, Frank J; de Mol, Nico J; Fischer, Marcel J E; Kemmink, Johan; Liskamp, Rob M J; Dekker, Frank

    2003-01-01

    Cyclic phosphopeptides were prepared using ring-closing metathesis followed by phosphorylation. These cyclic phosphopeptides were designed to interact with the SH2 domain of Grb2, which is a signal transduction protein of importance as a target for antiproliferative drug development. Binding of

  19. Inquiry into Chemotherapy-Induced P53 Activation in Cancer Cells as a Model for Teaching Signal Transduction

    Science.gov (United States)

    Srougi, Melissa C.; Carson, Susan

    2013-01-01

    Intracellular and extracellular communication is conducted through an intricate and interwoven network of signal transduction pathways. The mechanisms for how cells speak with one another are of significant biological importance to both basic and industrial scientists from a number of different disciplines. We have therefore developed and…

  20. Functional conservation between Schizosaccharomyces pombe ste8 and Saccharomyces cerevisiae STE11 protein kinases in yeast signal transduction

    DEFF Research Database (Denmark)

    Styrkársdóttir, U; Egel, R; Nielsen, O

    1992-01-01

    in signal transduction in budding yeast. Expression of the S. cerevisiae STE11 gene in S. pombe ste8 mutants restores the ability to transcribe mat1-Pm in response to pheromone. Also, such cells become capable of conjugation and sporulation. When mat1-Pm is artifically expressed from a heterologous promoter...

  1. Kinetics in Signal Transduction Pathways Involving Promiscuous Oligomerizing Receptors Can Be Determined by Receptor Specificity : Apoptosis Induction by TRAIL

    NARCIS (Netherlands)

    Szegezdi, Eva; van der Sloot, Almer M.; Mahalingam, Devalingam; O'Leary, Lynda; Cool, Robbert H.; Munoz, Ines G.; Montoya, Guillermo; Quax, Wim J.; de Jong, Steven; Samali, Afshin; Serrano, Luis

    Here we show by computer modeling that kinetics and outcome of signal transduction in case of hetero-oligomerizing receptors of a promiscuous ligand largely depend on the relative amounts of its receptors. Promiscuous ligands can trigger the formation of nonproductive receptor complexes, which slows

  2. DMPD: Gram-negative endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 1916089 Gram-negative endotoxin: an extraordinary lipid with profound effects oneuk...ep;5(12):2652-60. (.png) (.svg) (.html) (.csml) Show Gram-negative endotoxin: an extraordinary lipid with profound effects...tive endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. Authors Raetz

  3. The cellular response to vascular endothelial growth factors requires co-ordinated signal transduction, trafficking and proteolysis.

    Science.gov (United States)

    Smith, Gina A; Fearnley, Gareth W; Tomlinson, Darren C; Harrison, Michael A; Ponnambalam, Sreenivasan

    2015-08-18

    VEGFs (vascular endothelial growth factors) are a family of conserved disulfide-linked soluble secretory glycoproteins found in higher eukaryotes. VEGFs mediate a wide range of responses in different tissues including metabolic homoeostasis, cell proliferation, migration and tubulogenesis. Such responses are initiated by VEGF binding to soluble and membrane-bound VEGFRs (VEGF receptor tyrosine kinases) and co-receptors. VEGF and receptor splice isoform diversity further enhances complexity of membrane protein assembly and function in signal transduction pathways that control multiple cellular responses. Different signal transduction pathways are simultaneously activated by VEGFR-VEGF complexes with membrane trafficking along the endosome-lysosome network further modulating signal output from multiple enzymatic events associated with such pathways. Balancing VEGFR-VEGF signal transduction with trafficking and proteolysis is essential in controlling the intensity and duration of different intracellular signalling events. Dysfunction in VEGF-regulated signal transduction is important in chronic disease states including cancer, atherosclerosis and blindness. This family of growth factors and receptors is an important model system for understanding human disease pathology and developing new therapeutics for treating such ailments. © 2015 Authors.

  4. The effect of the inner-hair-cell mediated transduction on the shape of neural tuning curves

    Science.gov (United States)

    Altoè, Alessandro; Pulkki, Ville; Verhulst, Sarah

    2018-05-01

    The inner hair cells of the mammalian cochlea transform the vibrations of their stereocilia into releases of neurotransmitter at the ribbon synapses, thereby controlling the activity of the afferent auditory fibers. The mechanical-to-neural transduction is a highly nonlinear process and it introduces differences between the frequency-tuning of the stereocilia and that of the afferent fibers. Using a computational model of the inner hair cell that is based on in vitro data, we estimated that smaller vibrations of the stereocilia are necessary to drive the afferent fibers above threshold at low (≤0.5 kHz) than at high (≥4 kHz) driving frequencies. In the base of the cochlea, the transduction process affects the low-frequency tails of neural tuning curves. In particular, it introduces differences between the frequency-tuning of the stereocilia and that of the auditory fibers resembling those between basilar membrane velocity and auditory fibers tuning curves in the chinchilla base. For units with a characteristic frequency between 1 and 4 kHz, the transduction process yields shallower neural than stereocilia tuning curves as the characteristic frequency decreases. This study proposes that transduction contributes to the progressive broadening of neural tuning curves from the base to the apex.

  5. Peptide-targeted polymer cancerostatics

    Czech Academy of Sciences Publication Activity Database

    Böhmová, Eliška; Pola, Robert

    2016-01-01

    Roč. 65, Suppl. 2 (2016), S153-S164 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : HPMA copolymers * tumor targeting * peptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.461, year: 2016 http://www.biomed.cas.cz/physiolres/pdf/65%20Suppl%202/65_S153.pdf

  6. Photosystem Inspired Peptide Hybrid Catalysts

    Science.gov (United States)

    2017-06-07

    materials defined at the molecular level. We propose a novel way to make hybrid catalyst composed of inorganic nanomaterials and peptides. The...Distribution approved for public release. AF Office Of Scientific Research (AFOSR)/ IOA Arlington, Virginia 22203 Air Force Research Laboratory Air...ORGANIZATION NAME(S) AND ADDRESS(ES) SEOUL NATIONAL UNIVERSITY SNUR&DB FOUNDATION RESEARCH PARK CENTER SEOUL, 151742 KR 8. PERFORMING ORGANIZATION REPORT

  7. Peptide stabilized amphotericin B nanodisks

    Science.gov (United States)

    Tufteland, Megan; Pesavento, Joseph B.; Bermingham, Rachelle L.; Hoeprich, Paul D.; Ryan, Robert O.

    2007-01-01

    Nanometer scale apolipoprotein A-I stabilized phospholipid disk complexes (nanodisks; ND) have been formulated with the polyene antibiotic amphotericin B (AMB). The present studies were designed to evaluate if a peptide can substitute for the function of the apolipoprotein component of ND with respect to particle formation and stability. An 18-residue synthetic amphipathic α-helical peptide, termed 4F (Ac-D-W-F-K-A-F-Y-D-K-V-A-E-K-F-K-E-A-F-NH2), solubilized vesicles comprised of egg phosphatidylcholine (egg PC), dipentadecanoyl PC or dimyristoylphosphatidylcholine (DMPC) at rates greater than or equal to solubilization rates observed with human apolipoprotein A-I (apoA-I; 243 amino acids). Characterization studies revealed that interaction with DMPC induced a near doubling of 4F tryptophan fluorescence emission quantum yield (excitation 280 nm) and a ~7 nm blue shift in emission wavelength maximum. Inclusion of AMB in the vesicle substrate resulted in formation of 4F AMB-ND. Spectra of AMB containing particles revealed the antibiotic is a highly effective quencher of 4F tryptophan fluorescence emission, giving rise to a Ksv = 7.7 × 104. Negative stain electron microscopy revealed that AMB-ND prepared with 4F possessed a disk shaped morphology similar to ND prepared without AMB or prepared with apoA-I. In yeast and pathogenic fungi growth inhibition assays, 4F AMB-ND was as effective as apoA-I AMB-ND. The data indicate that AMB-ND generated using an amphipathic peptide in lieu of apoA-I form a discrete population of particles that possess potent biological activity. Given their intrinsic versatility, peptides may be preferred for scale up and clinical application of AMB-ND. PMID:17293004

  8. Biopharmaceuticals: From peptide to drug

    Science.gov (United States)

    Hannappel, Margarete

    2017-08-01

    Biologics are therapeutic proteins or peptides that are produced by means of biological processes within living organisms and cells. They are highly specific molecules and play a crucial role as therapeutics for the treatment of severe and chronic diseases (e.g. cancer, rheumatoid arthritis, diabetes, autoimmune disorders). The development of new biologics and biologics-based drugs gains more and more importance in the fight against various diseases. A short overview on biotherapeutical drug development is given. Cone snails are a large group of poisonous, predatory sea snails with more than 700 species. They use a very powerful venom which rapidly inactivates and paralyzes their prey. Most bioactive venom components are small peptides (conotoxins, conopeptides) which are precisely directed towards a specific target (e.g. ion channel, receptors). Due to their small size, their precision and speed of action, naturally occurring cone snail venom peptides represent an attractive source for the identification and design of novel biological drug entities. The Jagna cone snail project is an encouraging initiative to map the ecological variety of cone snails around the island of Bohol (Philippines) and to conserve the biological information for potential future application.

  9. Coffee, hunger, and peptide YY.

    Science.gov (United States)

    Greenberg, James A; Geliebter, Allan

    2012-06-01

    There is evidence from several empirical studies suggesting that coffee may help people control body weight. Our objective was to assess the effects of caffeine, caffeinated coffee, and decaffeinated coffee, both alone and in combination with 75 g of glucose, on perceived hunger and satiety and related peptides. We conducted a placebo-controlled single-blinded randomized 4-way crossover trial. Eleven healthy male volunteers (mean age, 23.5 ± 5.7 years; mean BMI, 23.6 ± 4.2 kg/m(2)) ingested 1 of 3 test beverages (caffeine in water, caffeinated coffee, or decaffeinated coffee) or placebo (water), and 60 minutes later they ingested the glucose. Eight times during each laboratory visit, hunger and satiety were assessed by visual analog scales, and blood samples were drawn to measure 3 endogenous peptides associated with hunger and satiety: ghrelin, peptide YY (PYY), and leptin. Compared to placebo, decaffeinated coffee yielded significantly lower hunger during the whole 180-minute study period and higher plasma PYY for the first 90 minutes (p hunger or PYY. Caffeinated coffee showed a pattern between that of decaffeinated coffee and caffeine in water. These findings suggest that one or more noncaffeine ingredients in coffee may have the potential to decrease body weight. Glucose ingestion did not change the effects of the beverages. Our randomized human trial showed that decaffeinated coffee can acutely decrease hunger and increase the satiety hormone PYY.

  10. [The role of Smads and related transcription factors in the signal transduction of bone morphogenetic protein inducing bone formation].

    Science.gov (United States)

    Xu, Xiao-liang; Dai, Ke-rong; Tang, Ting-ting

    2003-09-01

    To clarify the mechanisms of the signal transduction of bone morphogenetic proteins (BMPs) inducing bone formation and to provide theoretical basis for basic and applying research of BMPs. We looked up the literature of the role of Smads and related transcription factors in the signal transduction of BMPs inducing bone formation. The signal transduction processes of BMPs included: 1. BMPs combined with type II and type I receptors; 2. the type I receptor phosphorylated Smads; and 3. Smads entered the cell nucleus, interacted with transcription factors and influenced the transcription of related proteins. Smads could be divided into receptor-regulated Smads (R-Smads: Smad1, Smad2, Smad3, Smad5, Smad8 and Smad9), common-mediator Smad (co-Smad: Smad4), and inhibitory Smads (I-Smads: Smad6 and Smad7). Smad1, Smad5, Smad8, and probable Smad9 were involved in the signal transduction of BMPs. Multiple kinases, such as focal adhesion kinase (FAK), Ras-extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K), and Akt serine/threonine kinase were related to Smads signal transduction. Smad1 and Smad5 related with transcription factors included core binding factor A1 (CBFA1), smad-interacting protein 1 (SIP1), ornithine decarboxylase antizyme (OAZ), activating protein-1 (AP-1), xenopus ventralizing homeobox protein-2 (Xvent-2), sandostatin (Ski), antiproliferative proteins (Tob), and homeodomain-containing transcriptian factor-8 (Hoxc-8), et al. CBFA1 could interact with Smad1, Smad2, Smad3, and Smad5, so it was involved in TGF-beta and BMP-2 signal transduction, and played an important role in the bone formation. Cleidocranial dysplasia (CCD) was thought to be caused by heterozygous mutations in CBFA1. The CBFA1 knockout mice showed no osteogenesis and had maturational disturbance of chondrocytes. Smads and related transcription factors, especially Smad1, Smad5, Smad8 and CBFA1, play an important role in the signal transduction of BMPs inducing bone

  11. Synthetic peptide vaccines: palmitoylation of peptide antigens by a thioester bond increases immunogenicity

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many...... or an amide bond. It was found that these S-palmitoylated peptides were much more immunogenic than N-palmitoylated peptides and at least similar to KLH-conjugated peptides with respect to appearance and magnitude of induced antibodies (canine parvovirus) or immunocastration effect (gonadotropin...

  12. Chemical Methods for Peptide and Protein Production

    Directory of Open Access Journals (Sweden)

    Istvan Toth

    2013-04-01

    Full Text Available Since the invention of solid phase synthetic methods by Merrifield in 1963, the number of research groups focusing on peptide synthesis has grown exponentially. However, the original step-by-step synthesis had limitations: the purity of the final product decreased with the number of coupling steps. After the development of Boc and Fmoc protecting groups, novel amino acid protecting groups and new techniques were introduced to provide high quality and quantity peptide products. Fragment condensation was a popular method for peptide production in the 1980s, but unfortunately the rate of racemization and reaction difficulties proved less than ideal. Kent and co-workers revolutionized peptide coupling by introducing the chemoselective reaction of unprotected peptides, called native chemical ligation. Subsequently, research has focused on the development of novel ligating techniques including the famous click reaction, ligation of peptide hydrazides, and the recently reported a-ketoacid-hydroxylamine ligations with 5-oxaproline. Several companies have been formed all over the world to prepare high quality Good Manufacturing Practice peptide products on a multi-kilogram scale. This review describes the advances in peptide chemistry including the variety of synthetic peptide methods currently available and the broad application of peptides in medicinal chemistry.

  13. Chemical methods for peptide and protein production.

    Science.gov (United States)

    Chandrudu, Saranya; Simerska, Pavla; Toth, Istvan

    2013-04-12

    Since the invention of solid phase synthetic methods by Merrifield in 1963, the number of research groups focusing on peptide synthesis has grown exponentially. However, the original step-by-step synthesis had limitations: the purity of the final product decreased with the number of coupling steps. After the development of Boc and Fmoc protecting groups, novel amino acid protecting groups and new techniques were introduced to provide high quality and quantity peptide products. Fragment condensation was a popular method for peptide production in the 1980s, but unfortunately the rate of racemization and reaction difficulties proved less than ideal. Kent and co-workers revolutionized peptide coupling by introducing the chemoselective reaction of unprotected peptides, called native chemical ligation. Subsequently, research has focused on the development of novel ligating techniques including the famous click reaction, ligation of peptide hydrazides, and the recently reported α-ketoacid-hydroxylamine ligations with 5-oxaproline. Several companies have been formed all over the world to prepare high quality Good Manufacturing Practice peptide products on a multi-kilogram scale. This review describes the advances in peptide chemistry including the variety of synthetic peptide methods currently available and the broad application of peptides in medicinal chemistry.

  14. Immunocytochemical evidence for co-expression of Type III IP3 receptor with signaling components of bitter taste transduction

    Directory of Open Access Journals (Sweden)

    Kinnamon Sue C

    2001-04-01

    Full Text Available Abstract Background Taste receptor cells are responsible for transducing chemical stimuli into electrical signals that lead to the sense of taste. An important second messenger in taste transduction is IP3, which is involved in both bitter and sweet transduction pathways. Several components of the bitter transduction pathway have been identified, including the T2R/TRB taste receptors, phospholipase C β2, and the G protein subunits α-gustducin, β3, and γ13. However, the identity of the IP3 receptor subtype in this pathway is not known. In the present study we used immunocytochemistry on rodent taste tissue to identify the IP3 receptors expressed in taste cells and to examine taste bud expression patterns for IP3R3. Results Antibodies against Type I, II, and III IP3 receptors were tested on sections of rat and mouse circumvallate papillae. Robust cytoplasmic labeling for the Type III IP3 receptor (IP3R3 was found in a large subset of taste cells in both species. In contrast, little or no immunoreactivity was seen with antibodies against the Type I or Type II IP3 receptors. To investigate the potential role of IP3R3 in bitter taste transduction, we used double-label immunocytochemistry to determine whether IP3R3 is expressed in the same subset of cells expressing other bitter signaling components. IP3R3 immunoreactive taste cells were also immunoreactive for PLCβ2 and γ13. Alpha-gustducin immunoreactivity was present in a subset of IP3R3, PLCβ2, and γ13 positive cells. Conclusions IP3R3 is the dominant form of the IP3 receptor expressed in taste cells and our data suggest it plays an important role in bitter taste transduction.

  15. Human Antimicrobial Peptides and Proteins

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2014-05-01

    Full Text Available As the key components of innate immunity, human host defense antimicrobial peptides and proteins (AMPs play a critical role in warding off invading microbial pathogens. In addition, AMPs can possess other biological functions such as apoptosis, wound healing, and immune modulation. This article provides an overview on the identification, activity, 3D structure, and mechanism of action of human AMPs selected from the antimicrobial peptide database. Over 100 such peptides have been identified from a variety of tissues and epithelial surfaces, including skin, eyes, ears, mouths, gut, immune, nervous and urinary systems. These peptides vary from 10 to 150 amino acids with a net charge between −3 and +20 and a hydrophobic content below 60%. The sequence diversity enables human AMPs to adopt various 3D structures and to attack pathogens by different mechanisms. While α-defensin HD-6 can self-assemble on the bacterial surface into nanonets to entangle bacteria, both HNP-1 and β-defensin hBD-3 are able to block cell wall biosynthesis by binding to lipid II. Lysozyme is well-characterized to cleave bacterial cell wall polysaccharides but can also kill bacteria by a non-catalytic mechanism. The two hydrophobic domains in the long amphipathic α-helix of human cathelicidin LL-37 lays the basis for binding and disrupting the curved anionic bacterial membrane surfaces by forming pores or via the carpet model. Furthermore, dermcidin may serve as ion channel by forming a long helix-bundle structure. In addition, the C-type lectin RegIIIα can initially recognize bacterial peptidoglycans followed by pore formation in the membrane. Finally, histatin 5 and GAPDH(2-32 can enter microbial cells to exert their effects. It appears that granulysin enters cells and kills intracellular pathogens with the aid of pore-forming perforin. This arsenal of human defense proteins not only keeps us healthy but also inspires the development of a new generation of personalized

  16. Signal Sensing and Transduction by Histidine Kinases as Unveiled through Studies on a Temperature Sensor.

    Science.gov (United States)

    Abriata, Luciano A; Albanesi, Daniela; Dal Peraro, Matteo; de Mendoza, Diego

    2017-06-20

    Histidine kinases (HK) are the sensory proteins of two-component systems, responsible for a large fraction of bacterial responses to stimuli and environmental changes. Prototypical HKs are membrane-bound proteins that phosphorylate cognate response regulator proteins in the cytoplasm upon signal detection in the membrane or periplasm. HKs stand as potential drug targets but also constitute fascinating systems for studying proteins at work, specifically regarding the chemistry and mechanics of signal detection, transduction through the membrane, and regulation of catalytic outputs. In this Account, we focus on Bacillus subtilis DesK, a membrane-bound HK part of a two-component system that maintains appropriate membrane fluidity at low growth temperatures. Unlike most HKs, DesK has no extracytoplasmic signal-sensing domains; instead, sensing is carried out by 10 transmembrane helices (coming from two protomers) arranged in an unknown structure. The fifth transmembrane helix from each protomer connects, without any of the intermediate domains found in other HKs, into the dimerization and histidine phosphotransfer (DHp) domain located in the cytoplasm, which is followed by the ATP-binding domains (ABD). Throughout the years, genetic, biochemical, structural, and computational studies on wild-type, mutant, and truncated versions of DesK allowed us to dissect several aspects of DesK's functioning, pushing forward a more general understanding of its own structure/function relationships as well as those of other HKs. We have shown that the sensing mechanism is rooted in temperature-dependent membrane properties, most likely a combination of thickness, fluidity, and water permeability, and we have proposed possible mechanisms by which DesK senses these properties and transduces the signals. X-ray structures and computational models have revealed structural features of TM and cytoplasmic regions in DesK's kinase- and phosphatase-competent states. Biochemical and genetic

  17. Intracellular delivery of cell-penetrating peptide-transcriptional factor fusion protein and its role in selective osteogenesis

    Directory of Open Access Journals (Sweden)

    Suh JS

    2014-03-01

    Full Text Available Jin Sook Suh,1,* Jue Yeon Lee,2,* Yoon Jung Choi,1 Hyung Keun You,3 Seong-Doo Hong,4 Chong Pyoung Chung,2 Yoon Jeong Park1,2 1Dental Regenerative Biotechnology, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 2Central Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC, Seoul, 3Department of Periodontology, College of Dentistry, Wonkwang University, Iksan, 4Department of Oral Pathology, School of Dentistry, Seoul National University, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: Protein-transduction technology has been attempted to deliver macromolecular materials, including protein, nucleic acids, and polymeric drugs, for either diagnosis or therapeutic purposes. Herein, fusion protein composed of an arginine-rich cell-penetrating peptide, termed low-molecular-weight protamine (LMWP, and a transcriptional coactivator with a PDZ-binding motif (TAZ protein was prepared and applied in combination with biomaterials to increase bone-forming capacity. TAZ has been recently identified as a specific osteogenic stimulating transcriptional coactivator in human mesenchymal stem cell (hMSC differentiation, while simultaneously blocking adipogenic differentiation. However, TAZ by itself cannot penetrate the cells, and thus needs a transfection tool for translocalization. The LMWP-TAZ fusion proteins were efficiently translocalized into the cytosol of hMSCs. The hMSCs treated with cell-penetrating LMWP-TAZ exhibited increased expression of osteoblastic genes and protein, producing significantly higher quantities of mineralized matrix compared to free TAZ. In contrast, adipogenic differentiation of the hMSCs was blocked by treatment of LMWP-TAZ fusion protein, as reflected by reduced marker-protein expression, adipocyte fatty acid-binding protein 2, and peroxisome proliferator-activated receptor-γ messenger ribonucleic acid levels. LMWP-TAZ was applied in

  18. Synthesis of peptide .alpha.-thioesters

    Science.gov (United States)

    Camarero, Julio A [Livermore, CA; Mitchell, Alexander R [Livermore, CA; De Yoreo, James J [Clayton, CA

    2008-08-19

    Disclosed herein is a new method for the solid phase peptide synthesis (SPPS) of C-terminal peptide .alpha. thioesters using Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazine linker, which is totally stable to conditions required for Fmoc-SPPS. When the peptide synthesis has been completed, activation of the linker is achieved by mild oxidation. The oxidation step converts the acyl-hydrazine group into a highly reactive acyl-diazene intermediate which reacts with an .alpha.-amino acid alkylthioester (H-AA-SR) to yield the corresponding peptide .alpha.-thioester in good yield. A variety of peptide thioesters, cyclic peptides and a fully functional Src homology 3 (SH3) protein domain have been successfully prepared.

  19. Peptide YY receptors in the brain

    International Nuclear Information System (INIS)

    Inui, A.; Oya, M.; Okita, M.

    1988-01-01

    Radiolabelled ligand binding studies demonstrated that specific receptors for peptide YY are present in the porcine as well as the canine brains. Peptide YY was bound to brain tissue membranes via high-affinity (dissociation constant, 1.39 X 10(-10)M) and low-affinity (dissociation constant, 3.72 X 10(-8)M) components. The binding sites showed a high specificity for peptide YY and neuropeptide Y, but not for pancreatic polypeptide or structurally unrelated peptides. The specific activity of peptide YY binding was highest in the hippocampus, followed by the pituitary gland, the hypothalamus, and the amygdala of the porcine brain, this pattern being similarly observed in the canine brain. The results suggest that peptide YY and neuropeptide Y may regulate the function of these regions of the brain through interaction with a common receptor site

  20. The human endolymphatic sac expresses natriuretic peptides

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Kirkeby, Svend; Vikeså, Jonas

    2017-01-01

    : Several natriuretic peptides were found expressed significantly in the ES, including uroguanylin and brain natriuretic peptide, but also peptides regulating vascular tone, including adrenomedullin 2. In addition, both neurophysin and oxytocin (OXT) were found significantly expressed. All peptides were...... verified by immunohistochemistry. CONCLUSION: The present data support the hypothesis that the human ES may have an endocrine/paracrine capacity through expression of several peptides with potent natriuretic activity. Furthermore, the ES may influence the hypothalamo-pituitary-adrenal axis and may regulate...... vasopressin receptors and aquaporin-2 channels in the inner ear via OXT expression. We hypothesize that the ES is likely to regulate inner ear endolymphatic homeostasis, possibly through secretion of several peptides, but it may also influence systemic and/or intracranial blood pressure through direct...

  1. Potent peptidic fusion inhibitors of influenza virus

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Rameshwar U.; Juraszek, Jarek; Brandenburg, Boerries; Buyck, Christophe; Schepens, Wim B. G.; Kesteleyn, Bart; Stoops, Bart; Vreeken, Rob J.; Vermond, Jan; Goutier, Wouter; Tang, Chan; Vogels, Ronald; Friesen, Robert H. E.; Goudsmit, Jaap; van Dongen, Maria J. P.; Wilson, Ian A.

    2017-09-28

    Influenza therapeutics with new targets and mechanisms of action are urgently needed to combat potential pandemics, emerging viruses, and constantly mutating strains in circulation. We report here on the design and structural characterization of potent peptidic inhibitors of influenza hemagglutinin. The peptide design was based on complementarity-determining region loops of human broadly neutralizing antibodies against the hemagglutinin (FI6v3 and CR9114). The optimized peptides exhibit nanomolar affinity and neutralization against influenza A group 1 viruses, including the 2009 H1N1 pandemic and avian H5N1 strains. The peptide inhibitors bind to the highly conserved stem epitope and block the low pH–induced conformational rearrangements associated with membrane fusion. These peptidic compounds and their advantageous biological properties should accelerate the development of new small molecule– and peptide-based therapeutics against influenza virus.

  2. Designing anticancer peptides by constructive machine learning.

    Science.gov (United States)

    Grisoni, Francesca; Neuhaus, Claudia; Gabernet, Gisela; Müller, Alex; Hiss, Jan; Schneider, Gisbert

    2018-04-21

    Constructive machine learning enables the automated generation of novel chemical structures without the need for explicit molecular design rules. This study presents the experimental application of such a generative model to design membranolytic anticancer peptides (ACPs) de novo. A recurrent neural network with long short-term memory cells was trained on alpha-helical cationic amphipathic peptide sequences and then fine-tuned with 26 known ACPs. This optimized model was used to generate unique and novel amino acid sequences. Twelve of the peptides were synthesized and tested for their activity on MCF7 human breast adenocarcinoma cells and selectivity against human erythrocytes. Ten of these peptides were active against cancer cells. Six of the active peptides killed MCF7 cancer cells without affecting human erythrocytes with at least threefold selectivity. These results advocate constructive machine learning for the automated design of peptides with desired biological activities. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Sonoporation-mediated transduction of siRNA ameliorated experimental arthritis using 3 MHz pulsed ultrasound.

    Science.gov (United States)

    Inoue, Hiroaki; Arai, Yuji; Kishida, Tsunao; Shin-Ya, Masaharu; Terauchi, Ryu; Nakagawa, Shuji; Saito, Masazumi; Tsuchida, Shinji; Inoue, Atsuo; Shirai, Toshiharu; Fujiwara, Hiroyoshi; Mazda, Osam; Kubo, Toshikazu

    2014-03-01

    The goal of this feasibility study was to examine whether sonoporation assisted transduction of siRNA could be used to ameliorate arthritis locally. If successful, such approach could provide an alternative treatment for the patients that have or gradually develop adverse response to chemical drugs. Tumor necrosis factor alpha (TNF-α) produced by synovial fibroblasts has an important role in the pathology of rheumatoid arthritis, inducing inflammation and bone destruction. In this study, we injected a mixture of microbubbles and siRNA targeting TNF-α (siTNF) into the articular joints of rats, and transduced siTNF into synovial tissue by exposure to a collimated ultrasound beam, applied through a probe 6mm in diameter with an input frequency of 3.0 MHz, an output intensity of 2.0 W/cm(2) (spatial average temporary peak; SATP), a pulse duty ratio of 50%, and a duration of 1 min. Sonoporation increased skin temperature from 26.8 °C to 27.3 °C, but there were no adverse effect such as burns. The mean level of TNF-α expression in siTNF-treated knee joints was 55% of those in controls. Delivery of siTNF into the knee joints every 3 days (i.e., 7, 10, 13, and 16 days after immunization) by in vivo sonoporation significantly reduced paw swelling on days 20-23 after immunization. Radiographic scores in the siTNF group were 56% of those in the CIA group and 61% of those in the siNeg group. Histological examination showed that the number of TNF-α positive cells was significantly lower in areas of pannus invasion into the ankle joints of siTNF- than of siNeg-treated rats. These results indicate that transduction of siTNF into articular synovium using sonoporation may be an effective local therapy for arthritis. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Use of galerina marginata genes and proteins for peptide production

    Science.gov (United States)

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2018-04-03

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  5. Use of Galerina marginata genes and proteins for peptide production

    Energy Technology Data Exchange (ETDEWEB)

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2017-03-21

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  6. Highly selective enrichment of phosphorylated peptides from peptide mixtures using titanium dioxide microcolumns

    DEFF Research Database (Denmark)

    Larsen, Martin Røssel; Thingholm, Tine E; Jensen, Ole N

    2005-01-01

    based on TiO2microcolumns and peptide loading in 2,5-dihydroxybenzoic acid (DHB). The effect of DHB was a very efficient reduction in the binding of nonphosphorylated peptides to TiO2 while retaining its high binding affinity for phosphorylated peptides. Thus, inclusion of DHB dramatically increased...... the selectivity of the enrichment of phosphorylated peptides by TiO2. We demonstrated that this new procedure was more selective for binding phosphorylated peptides than IMAC using MALDI mass spectrometry. In addition, we showed that LC-ESI-MSMS was biased toward monophosphorylated peptides, whereas MALDI MS...... was not. Other substituted aromatic carboxylic acids were also capable of specifically reducing binding of nonphosphorylated peptides, whereas phosphoric acid reduced binding of both phosphorylated and nonphosphorylated peptides. A putative mechanism for this intriguing effect is presented....

  7. Production of peptide antisera specific for mouse and rat proinsulin C-peptide 2

    DEFF Research Database (Denmark)

    Blume, N; Madsen, O D; Kofod, Hans

    1990-01-01

    for antibody binding to the immunizing antigen. Antisera to C-peptide 2, stained islet beta-cells on mouse and rat, but not monkey pancreas sections in immunocytochemical analysis. Preabsorption to the synthetic C-peptide 2, but not the synthetic mouse and rat C-peptide 1 abolished staining. In conclusion we......Mice and rats have two functional non-allelic insulin genes. By using a synthetic peptide representing a common sequence in mouse and rat C-peptide 2 as antigen, we have produced rabbit antisera specific for an epitope which is not present in mouse or rat C-peptide 1. Long-term immunization did...... not seem to increase the end point titre as tested in direct ELISA. The specificity of the antiserum was determined by competitive ELISA and histochemistry on pancreas sections. Only the synthetic C-peptide 2, but not the homologous synthetic C-peptide 1 from mouse and rat competed efficiently in ELISA...

  8. A novel chimeric peptide with antimicrobial activity.

    Science.gov (United States)

    Alaybeyoglu, Begum; Akbulut, Berna Sariyar; Ozkirimli, Elif

    2015-04-01

    Beta-lactamase-mediated bacterial drug resistance exacerbates the prognosis of infectious diseases, which are sometimes treated with co-administration of beta-lactam type antibiotics and beta-lactamase inhibitors. Antimicrobial peptides are promising broad-spectrum alternatives to conventional antibiotics in this era of evolving bacterial resistance. Peptides based on the Ala46-Tyr51 beta-hairpin loop of beta-lactamase inhibitory protein (BLIP) have been previously shown to inhibit beta-lactamase. Here, our goal was to modify this peptide for improved beta-lactamase inhibition and cellular uptake. Motivated by the cell-penetrating pVEC sequence, which includes a hydrophobic stretch at its N-terminus, our approach involved the addition of LLIIL residues to the inhibitory peptide N-terminus to facilitate uptake. Activity measurements of the peptide based on the 45-53 loop of BLIP for enhanced inhibition verified that the peptide was a competitive beta-lactamase inhibitor with a K(i) value of 58 μM. Incubation of beta-lactam-resistant cells with peptide decreased the number of viable cells, while it had no effect on beta-lactamase-free cells, indicating that this peptide had antimicrobial activity via beta-lactamase inhibition. To elucidate the molecular mechanism by which this peptide moves across the membrane, steered molecular dynamics simulations were carried out. We propose that addition of hydrophobic residues to the N-terminus of the peptide affords a promising strategy in the design of novel antimicrobial peptides not only against beta-lactamase but also for other intracellular targets. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  9. Antimicrobial Peptides, Infections and the Skin Barrier

    DEFF Research Database (Denmark)

    Clausen, Maja Lisa; Agner, Tove

    2016-01-01

    The skin serves as a strong barrier protecting us from invading pathogens and harmful organisms. An important part of this barrier comes from antimicrobial peptides (AMPs), which are small peptides expressed abundantly in the skin. AMPs are produced in the deeper layers of the epidermis and trans......The skin serves as a strong barrier protecting us from invading pathogens and harmful organisms. An important part of this barrier comes from antimicrobial peptides (AMPs), which are small peptides expressed abundantly in the skin. AMPs are produced in the deeper layers of the epidermis...

  10. GE11 Peptide as an Active Targeting Agent in Antitumor Therapy: A Minireview

    Directory of Open Access Journals (Sweden)

    Ida Genta

    2017-12-01

    Full Text Available A lot of solid tumors are characterized by uncontrolled signal transduction triggered by receptors related to cellular growth. The targeting of these cell receptors with antitumor drugs is essential to improve chemotherapy efficacy. This can be achieved by conjugation of an active targeting agent to the polymer portion of a colloidal drug delivery system loaded with an antitumor drug. The goal of this minireview is to report and discuss some recent results in epidermal growth factor receptor targeting by the GE11 peptide combined with colloidal drug delivery systems as smart carriers for antitumor drugs. The minireview chapters will focus on explaining and discussing: (i Epidermal growth factor receptor (EGFR structures and functions; (ii GE11 structure and biologic activity; (iii examples of GE11 conjugation and GE11-conjugated drug delivery systems. The rationale is to contribute in gathering information on the topic of active targeting to tumors. A case study is introduced, involving research on tumor cell targeting by the GE11 peptide combined with polymer nanoparticles.

  11. Antioxidant activity of yoghurt peptides: Part 2 – Characterisationof peptide fractions

    DEFF Research Database (Denmark)

    Farvin, Sabeena; Baron, Caroline; Nielsen, Nina Skall

    2010-01-01

    the peptides identified contained at least one proline residue. Some of the identified peptides included the hydrophobic amino acid residues Val or Leu at the N-terminus and Pro, His or Tyr in the amino acid sequence, which is characteristic of antioxidant peptides. In addition, the yoghurt contained...

  12. Connecting peptide (c-peptide) and the duration of diabetes mellitus ...

    African Journals Online (AJOL)

    Objective: C-peptide is derived from proinsulin and it is secreted in equimolar concentration with insulin. Plasma C-peptide is more stable than insulin and it provides an indirect measure of insulin secretory reserve and beta cell function. To determine relationship between C-peptide and duration of diabetes mellitus, age, ...

  13. Radiometallating antibodies and autoantigenic peptides

    International Nuclear Information System (INIS)

    Mercer-Smith, J.A.; Lewis, D.; Cole, D.A.; Newmyer, S.L.; Schulte, L.D.; Mixon, P.L.; Schreyer, S.A.; Burns, T.P.; Roberts, J.C.; Figard, S.D.; McCormick, D.J.; Lennon, V.A.; Hayashi, M.; Lavallee, D.K.

    1991-01-01

    We have developed methods to radiolabel large molecules, using porphyrins as bifunctional chelating agents for radiometals. The porphyrins are substituted with an N- benzyl group to activate them for radiometallation under mild reaction conditions. Porphyrins that have one functional group for covalent attachment to other molecules cannot cause crosslinking. We have examined the labeling chemistry for antibodies and have developed methods to label smaller biologically active molecules, such as autoantigenic peptides (fragments of the acetylcholine receptor), which are pertinent to myasthenia gravis research. The methods of covalent attachment of these bifunctional chelating agents to large molecules, the radiometallation chemistry, and biological characterization of the radiolabeled compounds will be discussed

  14. Atrial natriuretic peptides in plasma

    DEFF Research Database (Denmark)

    Goetze, Jens Peter; Hansen, Lasse H; Terzic, Dijana

    2014-01-01

    Measurement of cardiac natriuretic peptides in plasma has gained a diagnostic role in the assessment of heart failure. Plasma measurement is though hampered by the marked instability of the hormones, which has led to the development of analyses that target N-terminal fragments from the prohormone....... These fragments are stable in plasma and represent surrogate markers of the actual natriuretic hormone. Post-translational processing of the precursors, however, is revealing itself to be a complex event with new information still being reported on proteolysis, covalent modifications, and amino acid...

  15. Atrial natriuretic peptides in plasma

    DEFF Research Database (Denmark)

    Goetze, Jens P; Holst Hansen, Lasse; Terzic, Dijana

    2015-01-01

    Measurement of cardiac natriuretic peptides in plasma has gained a diagnostic role in the assessment of heart failure. Plasma measurement is though hampered by the marked instability of the hormones, which has led to the development of analyses that target N-terminal fragments from the prohormone....... These fragments are stable in plasma and represent surrogate markers of the actual natriuretic hormone. Post-translational processing of the precursors, however, is revealing itself to be a complex event with new information still being reported on proteolysis, covalent modifications, and amino acid...

  16. Synthesis of radioiodinated labeled peptides

    International Nuclear Information System (INIS)

    Matloobi, M.; Rafii, H.; Beigi, D.; Khalaj, A.; Kamali-Dehghan, M.

    2003-01-01

    Optimization of radioiodination of peptides is covered by both a direct method in which a constituent tyrosine residue is labeled and indirect method by using an iodinated derivative (SIB) of N succinimidyl 3-(tri-n-butylstannyl) benzoate (ATE) as the intermediate. Radioiodination of IgG and FMLF were performed by direct method using Chloramine-T as an oxidant but since Formyl-Methyl-Leucyl-Phenylalanine, FMLF, does not lend itself for direct radioiodination we performed labeling of FMLF by indirect method via radioiodined SIB at different pH. (author)

  17. Development of a CMOS MEMS pressure sensor with a mechanical force-displacement transduction structure

    International Nuclear Information System (INIS)

    Cheng, Chao-Lin; Chang, Heng-Chung; Fang, Weileun; Chang, Chun-I

    2015-01-01

    This study presents a capacitive pressure sensor with a mechanical force-displacement transduction structure based on the commercially available standard CMOS process (the TSMC 0.18 μm 1P6M CMOS process). The pressure sensor has a deformable diaphragm to support a movable plate with an embedded sensing electrode. As the diaphragm is deformed by the ambient pressure, the movable plate and its embedded sensing electrode are displaced. Thus, the pressure is detected from the capacitance change between the movable and fixed electrodes. The undeformed movable electrode will increase the effective sensing area between the sensing electrodes, thereby improving the sensitivity. Experimental results show that the proposed pressure sensor with a force-displacement transducer will increase the sensitivity by 126% within the 20 kPa–300 kPa absolute pressure range. Moreover, this study extends the design to add pillars inside the pressure sensor to further increase its sensing area as well as sensitivity. A sensitivity improvement of 117% is also demonstrated for a pressure sensor with an enlarged sensing electrode (the overlap area is increased two fold). (paper)

  18. Non Linear Programming (NLP) formulation for quantitative modeling of protein signal transduction pathways.

    Science.gov (United States)

    Mitsos, Alexander; Melas, Ioannis N; Morris, Melody K; Saez-Rodriguez, Julio; Lauffenburger, Douglas A; Alexopoulos, Leonidas G

    2012-01-01

    Modeling of signal transduction pathways plays a major role in understanding cells' function and predicting cellular response. Mathematical formalisms based on a logic formalism are relatively simple but can describe how signals propagate from one protein to the next and have led to the construction of models that simulate the cells response to environmental or other perturbations. Constrained fuzzy logic was recently introduced to train models to cell specific data to result in quantitative pathway models of the specific cellular behavior. There are two major issues in this pathway optimization: i) excessive CPU time requirements and ii) loosely constrained optimization problem due to lack of data with respect to large signaling pathways. Herein, we address both issues: the former by reformulating the pathway optimization as a regular nonlinear optimization problem; and the latter by enhanced algorithms to pre/post-process the signaling network to remove parts that cannot be identified given the experimental conditions. As a case study, we tackle the construction of cell type specific pathways in normal and transformed hepatocytes using medium and large-scale functional phosphoproteomic datasets. The proposed Non Linear Programming (NLP) formulation allows for fast optimization of signaling topologies by combining the versatile nature of logic modeling with state of the art optimization algorithms.

  19. Construction and Deciphering of Human Phosphorylation-Mediated Signaling Transduction Networks.

    Science.gov (United States)

    Zhang, Menghuan; Li, Hong; He, Ying; Sun, Han; Xia, Li; Wang, Lishun; Sun, Bo; Ma, Liangxiao; Zhang, Guoqing; Li, Jing; Li, Yixue; Xie, Lu

    2015-07-02

    Protein phosphorylation is the most abundant reversible covalent modification. Human protein kinases participate in almost all biological pathways, and approximately half of the kinases are associated with disease. PhoSigNet was designed to store and display human phosphorylation-mediated signal transduction networks, with additional information related to cancer. It contains 11 976 experimentally validated directed edges and 216 871 phosphorylation sites. Moreover, 3491 differentially expressed proteins in human cancer from dbDEPC, 18 907 human cancer variation sites from CanProVar, and 388 hyperphosphorylation sites from PhosphoSitePlus were collected as annotation information. Compared with other phosphorylation-related databases, PhoSigNet not only takes the kinase-substrate regulatory relationship pairs into account, but also extends regulatory relationships up- and downstream (e.g., from ligand to receptor, from G protein to kinase, and from transcription factor to targets). Furthermore, PhoSigNet allows the user to investigate the impact of phosphorylation modifications on cancer. By using one set of in-house time series phosphoproteomics data, the reconstruction of a conditional and dynamic phosphorylation-mediated signaling network was exemplified. We expect PhoSigNet to be a useful database and analysis platform benefiting both proteomics and cancer studies.

  20. Non Linear Programming (NLP formulation for quantitative modeling of protein signal transduction pathways.

    Directory of Open Access Journals (Sweden)

    Alexander Mitsos

    Full Text Available Modeling of signal transduction pathways plays a major role in understanding cells' function and predicting cellular response. Mathematical formalisms based on a logic formalism are relatively simple but can describe how signals propagate from one protein to the next and have led to the construction of models that simulate the cells response to environmental or other perturbations. Constrained fuzzy logic was recently introduced to train models to cell specific data to result in quantitative pathway models of the specific cellular behavior. There are two major issues in this pathway optimization: i excessive CPU time requirements and ii loosely constrained optimization problem due to lack of data with respect to large signaling pathways. Herein, we address both issues: the former by reformulating the pathway optimization as a regular nonlinear optimization problem; and the latter by enhanced algorithms to pre/post-process the signaling network to remove parts that cannot be identified given the experimental conditions. As a case study, we tackle the construction of cell type specific pathways in normal and transformed hepatocytes using medium and large-scale functional phosphoproteomic datasets. The proposed Non Linear Programming (NLP formulation allows for fast optimization of signaling topologies by combining the versatile nature of logic modeling with state of the art optimization algorithms.

  1. Calcium specificity signaling mechanisms in abscisic acid signal transduction in Arabidopsis guard cells

    Science.gov (United States)

    Brandt, Benjamin; Munemasa, Shintaro; Wang, Cun; Nguyen, Desiree; Yong, Taiming; Yang, Paul G; Poretsky, Elly; Belknap, Thomas F; Waadt, Rainer; Alemán, Fernando; Schroeder, Julian I

    2015-01-01

    A central question is how specificity in cellular responses to the eukaryotic second messenger Ca2+ is achieved. Plant guard cells, that form stomatal pores for gas exchange, provide a powerful system for in depth investigation of Ca2+-signaling specificity in plants. In intact guard cells, abscisic acid (ABA) enhances (primes) the Ca2+-sensitivity of downstream signaling events that result in activation of S-type anion channels during stomatal closure, providing a specificity mechanism in Ca2+-signaling. However, the underlying genetic and biochemical mechanisms remain unknown. Here we show impairment of ABA signal transduction in stomata of calcium-dependent protein kinase quadruple mutant plants. Interestingly, protein phosphatase 2Cs prevent non-specific Ca2+-signaling. Moreover, we demonstrate an unexpected interdependence of the Ca2+-dependent and Ca2+-independent ABA-signaling branches and the in planta requirement of simultaneous phosphorylation at two key phosphorylation sites in SLAC1. We identify novel mechanisms ensuring specificity and robustness within stomatal Ca2+-signaling on a cellular, genetic, and biochemical level. DOI: http://dx.doi.org/10.7554/eLife.03599.001 PMID:26192964

  2. Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades

    Directory of Open Access Journals (Sweden)

    MÔNICA R.M. VIANNA

    2000-09-01

    Full Text Available Since William James (1890 first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has been whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into the hippocampus and related brain areas after one-trial avoidance learning can effectively cancel short-term memory without affecting long-term memory formation. This shows that short-term memory and long-term memory involve separate mechanisms and are independently processed. Other treatments, however, influence both memory types similarly, suggesting links between both at the receptor and at the post-receptor level, which should not be surprising as they both deal with nearly the same sensorimotor representations. This review examines recent advances in short- and long-term memory mechanisms based on the effect of intra-hippocampal infusion of drugs acting upon neurotransmitter and signal transduction systems on both memory types.

  3. Dynamic behavior of ultra large graphene-based membranes using electrothermal transduction

    Science.gov (United States)

    Al-mashaal, A. K.; Wood, G. S.; Torin, A.; Mastropaolo, E.; Newton, M. J.; Cheung, R.

    2017-12-01

    This letter reports an experimental study of an electrothermal actuator made from an ultra-large graphene-based bilayer thin film with a diameter to thickness aspect ratio of ˜10 000. Suspended thin films consisting of multilayer graphene and 350-500 nm-thick Poly(methyl methacrylate) have been transferred over circular cavities with a diameter of 3.5 mm. The use of bilayer materials with different mechanical and thermal properties results in thin film structures that can be induced to vibrate mechanically under the electrothermal transduction mechanism. The dynamic response of the bilayer has been investigated electrothermally by driving the structures with a combination of alternating current and direct current actuation voltages ( Va c and Vd c) and characterizing their resonant frequencies. It has been found that the bilayer thin film structure behaves as a membrane. In addition, the actuation configurations affect not only the amplitude of vibration but also the tuning of the resonant frequency of the vibrating membranes. The existence of Joule heating-induced tension lowers the mechanical stiffness of the membrane and hence shifts the resonant frequency downwards by -108187 ppm. A resonant frequency of 3.26 kHz with a vibration amplitude of 4.34 nm has been achieved for 350 nm-thick membranes under actuation voltages of 1 V of Va c and 8 V of Vd c.

  4. Molecular machinery of signal transduction and cell cycle regulation in Plasmodium.

    Science.gov (United States)

    Koyama, Fernanda C; Chakrabarti, Debopam; Garcia, Célia R S

    2009-05-01

    The regulation of the Plasmodium cell cycle is not understood. Although the Plasmodium falciparum genome is completely sequenced, about 60% of the predicted proteins share little or no sequence similarity with other eukaryotes. This feature impairs the identification of important proteins participating in the regulation of the cell cycle. There are several open questions that concern cell cycle progression in malaria parasites, including the mechanism by which multiple nuclear divisions is controlled and how the cell cycle is managed in all phases of their complex life cycle. Cell cycle synchrony of the parasite population within the host, as well as the circadian rhythm of proliferation, are striking features of some Plasmodium species, the molecular basis of which remains to be elucidated. In this review we discuss the role of indole-related molecules as signals that modulate the cell cycle in Plasmodium and other eukaryotes, and we also consider the possible role of kinases in the signal transduction and in the responses it triggers.

  5. Combination of adenovirus and cross-linked low molecular weight PEI improves efficiency of gene transduction

    International Nuclear Information System (INIS)

    Han Jianfeng; Zhao Dong; Zhong Zhirong; Zhang Zhirong; Gong Tao; Sun Xun

    2010-01-01

    Recombinant adenovirus (Ad)-mediated gene therapy is an exciting novel strategy in cancer treatment. However, poor infection efficiency with coxsackievirus and adenovirus receptor (CAR) down-regulated cancer cell lines is one of the major challenges for its practical and extensive application. As an alternative method of viral gene delivery, a non-viral carrier using cationic materials could compensate for the limitation of adenovirus. In our study, adenovectors were complexed with a new synthetic polymer PEI-DEG-bis-NPC (PDN) based on polyethylenimine (PEI), and then the properties of the vehicle were characterized by measurement of size distribution, zeta potential and transmission electron microscopy (TEM). Enhancement of gene transduction by Ad/PDN complexes was observed in both CAR-overexpressing cell lines (A549) and CAR-lacking cell lines (MDCK, CHO, LLC), as a result of facilitating binding and cell uptake of adenoviral particles by the cationic component. Ad/PDN complexes also promoted the inhibition of tumor growth in vivo and prolonged the survival time of tumor-bearing mice. These data suggest that a combination of viral and non-viral gene delivery methods may offer a new approach to successful cancer gene therapy.

  6. The effect of BAPTA and 4AP in scala media on transduction and cochlear gain.

    Science.gov (United States)

    Sellick, P M; Robertson, D; Patuzzi, R

    2006-01-01

    We have injected by iontophoresis 4-amino-pyridine, a K+ channel blocker and BAPTA, (a Ca++ chelator), into scala media of the first three turns of the guinea pig cochlea. We measured the reduction in outer hair cell (OHC) receptor current, as indicated by cochlear microphonic measured in scala media evoked by a 207 Hz tone, and compared this with the elevation of the cochlear action potential (CAP) threshold. We found that in the basal turn, for frequencies between 12 and 21 kHz, CAP threshold was elevated by about 30 dB, while in the second turn, at the 3 kHz place, the maximum elevation was 15 dB. In the third turn, iontophoresis of 4AP and BAPTA reduced CM by similar amounts to that in the basal and second turn, but caused negligible elevation of CAP threshold. We conclude that the gain of the cochlear amplifier is maximal for basal turn frequencies, is halved at 3 kHz, and is reduced to close to one for frequencies below 1 kHz (no active gain). The effect of 4AP and BAPTA on neural threshold and the receptor current represented by CM may be explained by their action on OHC transduction without the involvement of IHCs.

  7. Scraping through the ice: uncovering the role of TRPM8 in cold transduction

    Science.gov (United States)

    McCoy, Daniel D.; Knowlton, Wendy M.

    2011-01-01

    The proper detection of environmental temperatures is essential for the optimal growth and survival of organisms of all shapes and phyla, yet only recently have the molecular mechanisms for temperature sensing been elucidated. The discovery of temperature-sensitive ion channels of the transient receptor potential (TRP) superfamily has been pivotal in explaining how temperatures are sensed in vivo, and here we will focus on the lone member of this cohort, TRPM8, which has been unequivocally shown to be cold sensitive. TRPM8 is expressed in somatosensory neurons that innervate peripheral tissues such as the skin and oral cavity, and recent genetic evidence has shown it to be the principal transducer of cool and cold stimuli. It is remarkable that this one channel, unlike other thermosensitive TRP channels, is associated with both innocuous and noxious temperature transduction, as well as cold hypersensitivity during injury and, paradoxically, cold-mediated analgesia. With ongoing research, the field is getting closer to answering a number of fundamental questions regarding this channel, including the cellular mechanisms of TRPM8 modulation, the molecular context of TRPM8 expression, as well as the full extent of the role of TRPM8 in cold signaling in vivo. These findings will further our understanding of basic thermotransduction and sensory coding, and may have important implications for treatments for acute and chronic pain. PMID:21411765

  8. Dyslipidemia modulates Müller glial sensing and transduction of ambient information

    Directory of Open Access Journals (Sweden)

    Monika Lakk

    2018-01-01

    Full Text Available Unesterified cholesterol controls the fluidity, permeability and electrical properties of eukaryotic cell membranes. Consequently, cholesterol levels in the retina and the brain are tightly regulated whereas depletion or oversupply caused by diet or heredity contribute to neurodegenerative diseases and vision loss. Astroglia play a central role in the biosynthesis, uptake and transport of cholesterol and also drive inflammatory signaling under hypercholesterolemic conditions associated with high-fat diet (diabetes and neurodegenerative disease. A growing body of evidence shows that unesterified membrane cholesterol modulates the ability of glia to sense and transduce ambient information. Cholesterol-dependence of Müller glia - which function as retinal sentinels for metabolic, mechanical, osmotic and inflammatory signals - is mediated in part by transient receptor potential V4 (TRPV4 channels. Cholesterol supplementation facilitates, whereas depletion suppresses, TRPV4-mediated transduction of temperature and lipid agonists in Müller cells. Acute effects of cholesterol supplementation/depletion on plasma membrane ion channels and calcium homeostasis differ markedly from the effects of chronic dyslipidemia, possibly due to differential modulation of modality-dependent energy barriers associated with the functionality of polymodal channels embedded within lipid rafts. Understanding of cholesterol-dependence of TRP channels is thus providing insight into dyslipidemic pathologies associated with diabetic retinopathy, glaucoma and macular degeneration.

  9. Immortalization of chicken preadipocytes by retroviral transduction of chicken TERT and TR

    Science.gov (United States)

    Wang, Wei; Zhang, Tianmu; Wu, Chunyan; Wang, Shanshan; Wang, Yuxiang; Wang, Ning

    2017-01-01

    The chicken is an important agricultural animal and model for developmental biology, immunology and virology. Excess fat accumulation continues to be a serious problem for the chicken industry. However, chicken adipogenesis and obesity have not been well investigated, because no chicken preadipocyte cell lines have been generated thus far. Here, we successfully generated two immortalized chicken preadipocyte cell lines through transduction of either chicken telomerase reverse transcriptase (chTERT) alone or in combination with chicken telomerase RNA (chTR). Both of these cell lines have survived >100 population doublings in vitro, display high telomerase activity and have no sign of replicative senescence. Similar to primary chicken preadipocytes, these two cell lines display a fibroblast-like morphology, retain the capacity to differentiate into adipocytes, and do not display any signs of malignant transformation. Isoenzyme analysis and PCR-based analysis confirmed that these two cell lines are of chicken origin and are free from inter-species contamination. To our knowledge, this is the first report demonstrating the generation of immortal chicken cells by introduction of chTERT and chTR. Our established chicken preadipocyte cell lines show great promise as an in vitro model for the investigation of chicken adipogenesis, lipid metabolism, and obesity and its related diseases, and our results also provide clues for immortalizing other avian cell types. PMID:28486516

  10. Information theory and signal transduction systems: from molecular information processing to network inference.

    Science.gov (United States)

    Mc Mahon, Siobhan S; Sim, Aaron; Filippi, Sarah; Johnson, Robert; Liepe, Juliane; Smith, Dominic; Stumpf, Michael P H

    2014-11-01

    Sensing and responding to the environment are two essential functions that all biological organisms need to master for survival and successful reproduction. Developmental processes are marshalled by a diverse set of signalling and control systems, ranging from systems with simple chemical inputs and outputs to complex molecular and cellular networks with non-linear dynamics. Information theory provides a powerful and convenient framework in which such systems can be studied; but it also provides the means to reconstruct the structure and dynamics of molecular interaction networks underlying physiological and developmental processes. Here we supply a brief description of its basic concepts and introduce some useful tools for systems and developmental biologists. Along with a brief but thorough theoretical primer, we demonstrate the wide applicability and biological application-specific nuances by way of different illustrative vignettes. In particular, we focus on the characterisation of biological information processing efficiency, examining cell-fate decision making processes, gene regulatory network reconstruction, and efficient signal transduction experimental design. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Isolation of ionospheres from ion transport systems and their role in energy transduction

    Energy Technology Data Exchange (ETDEWEB)

    Shamoo, A E; Goldstein, D A

    1977-01-01

    In the past twenty-five years cell membrane transport has been studied from the point of view of kinetics and the biochemical correlation of enzyme function with that of transport. Artificial lipid bilayers have been used as a model for cell membrane transport. Antibiotics, such as valinomycin have also been studied as models of ion-transport mediators. Much effort has been invested on the study of model compounds as the possible molecular bases of transport. Information derived from the study of model systems throughout the years has been valuable and worthwhile. However, if the aim is to elucidate the mechanism of cell membrane transport, the time has come to merge the two lines of research into one and to shift emphasis from the study of model systems to the study of isolated transport machine components before and after reconstitution of its components into model membranes. These studies should be augmented at all times with the biochemical correlates of the transport proteins. A review is presented of the new avenues employed to elucidate the molecular mechanism of active transport. The new avenues are those of isolation of ion-transport mediators (ionophores) from membrane transport proteins. Reconstitution of ionophores and the various membrane transport proteins into artificial systems such as bilayers and vesicles presents a powerful tool to elucidate the molecular mechanism of active transport. More importantly, the new approach provides the first glimpse of evidence for a reasonable investigation of energy transduction from ATP hydrolysis to transport of an ion.

  12. Enhanced transduction and replication of RGD-fiber modified adenovirus in primary T cells.

    Directory of Open Access Journals (Sweden)

    Sadhak Sengupta

    2011-03-01

    Full Text Available Adenoviruses are often used as vehicles to mediate gene delivery for therapeutic purposes, but their research scope in hematological cells remains limited due to a narrow choice of host cells that express the adenoviral receptor (CAR. T cells, which are attractive targets for gene therapy of numerous diseases, remain resistant to adenoviral infection because of the absence of CAR expression. Here, we demonstrate that this resistance can be overcome when murine or human T cells are transduced with an adenovirus incorporating the RGD-fiber modification (Ad-RGD.A luciferase-expressing replication-deficient Ad-RGD infected 3-fold higher number of activated primary T cells than an adenovirus lacking the RGD-fiber modification in vitro. Infection with replication-competent Ad-RGD virus also caused increased cell cycling, higher E1A copy number and enriched hexon antigen expression in both human and murine T cells. Transduction with oncolytic Ad-RGD also resulted in higher titers of progeny virus and enhanced the killing of T cells. In vivo, 35-45% of splenic T cells were transduced by Ad-RGD.Collectively, our results prove that a fiber modified Ad-RGD successfully transduces and replicates in primary T cells of both murine and human origin.

  13. Signal transduction by VEGF receptors in regulation of angiogenesis and lymphangiogenesis

    International Nuclear Information System (INIS)

    Shibuya, Masabumi; Claesson-Welsh, Lena

    2006-01-01

    The VEGF/VPF (vascular endothelial growth factor/vascular permeability factor) ligands and receptors are crucial regulators of vasculogenesis, angiogenesis, lymphangiogenesis and vascular permeability in vertebrates. VEGF-A, the prototype VEGF ligand, binds and activates two tyrosine kinase receptors: VEGFR1 (Flt-1) and VEGFR2 (KDR/Flk-1). VEGFR1, which occurs in transmembrane and soluble forms, negatively regulates vasculogenesis and angiogenesis during early embryogenesis, but it also acts as a positive regulator of angiogenesis and inflammatory responses, playing a role in several human diseases such as rheumatoid arthritis and cancer. The soluble VEGFR1 is overexpressed in placenta in preeclampsia patients. VEGFR2 has critical functions in physiological and pathological angiogenesis through distinct signal transduction pathways regulating proliferation and migration of endothelial cells. VEGFR3, a receptor for the lymphatic growth factors VEGF-C and VEGF-D, but not for VEGF-A, regulates vascular and lymphatic endothelial cell function during embryogenesis. Loss-of-function variants of VEGFR3 have been identified in lymphedema. Formation of tumor lymphatics may be stimulated by tumor-produced VEGF-C, allowing increased spread of tumor metastases through the lymphatics. Mapping the signaling system of these important receptors may provide the knowledge necessary to suppress specific signaling pathways in major human diseases

  14. Herbaspirillum seropedicae signal transduction protein PII is structurally similar to the enteric GlnK.

    Science.gov (United States)

    Machado Benelli, Elaine; Buck, Martin; Polikarpov, Igor; Maltempi de Souza, Emanuel; Cruz, Leonardo M; Pedrosa, Fábio O

    2002-07-01

    PII-like proteins are signal transduction proteins found in bacteria, archaea and eukaryotes. They mediate a variety of cellular responses. A second PII-like protein, called GlnK, has been found in several organisms. In the diazotroph Herbaspirillum seropedicae, PII protein is involved in sensing nitrogen levels and controlling nitrogen fixation genes. In this work, the crystal structure of the unliganded H. seropedicae PII was solved by X-ray diffraction. H. seropedicae PII has a Gly residue, Gly108 preceding Pro109 and the main-chain forms a beta turn. The glycine at position 108 allows a bend in the C-terminal main-chain, thereby modifying the surface of the cleft between monomers and potentially changing function. The structure suggests that the C-terminal region of PII proteins may be involved in specificity of function, and nonenteric diazotrophs are found to have the C-terminal consensus XGXDAX(107-112). We are also proposing binding sites for ATP and 2-oxoglutarate based on the structural alignment of PII with PII-ATP/GlnK-ATP, 5-carboxymethyl-2-hydroxymuconate isomerase and 4-oxalocrotonate tautomerase bound to the inhibitor 2-oxo-3-pentynoate.

  15. Adaptation to Environmental Stimuli within the Host: Two-Component Signal Transduction Systems of Mycobacterium tuberculosis

    Science.gov (United States)

    Bretl, Daniel J.; Demetriadou, Chrystalla; Zahrt, Thomas C.

    2011-01-01

    Summary: Pathogenic microorganisms encounter a variety of environmental stresses following infection of their respective hosts. Mycobacterium tuberculosis, the etiological agent of tuberculosis, is an unusual bacterial pathogen in that it is able to establish lifelong infections in individuals within granulomatous lesions that are formed following a productive immune response. Adaptation to this highly dynamic environment is thought to be mediated primarily through transcriptional reprogramming initiated in response to recognition of stimuli, including low-oxygen tension, nutrient depletion, reactive oxygen and nitrogen species, altered pH, toxic lipid moieties, cell wall/cell membrane-perturbing agents, and other environmental cues. To survive continued exposure to these potentially adverse factors, M. tuberculosis encodes a variety of regulatory factors, including 11 complete two-component signal transduction systems (TCSSs) and several orphaned response regulators (RRs) and sensor kinases (SKs). This report reviews our current knowledge of the TCSSs present in M. tuberculosis. In particular, we discuss the biochemical and functional characteristics of individual RRs and SKs, the environmental stimuli regulating their activation, the regulons controlled by the various TCSSs, and the known or postulated role(s) of individual TCSSs in the context of M. tuberculosis physiology and/or pathogenesis. PMID:22126994

  16. The condensed chromatin fiber: an allosteric chemo-mechanical machine for signal transduction and genome processing

    International Nuclear Information System (INIS)

    Lesne, Annick; Victor, Jean–Marc; Bécavin, Christophe

    2012-01-01

    Allostery is a key concept of molecular biology which refers to the control of an enzyme activity by an effector molecule binding the enzyme at another site rather than the active site (allos = other in Greek). We revisit here allostery in the context of chromatin and argue that allosteric principles underlie and explain the functional architecture required for spacetime coordination of gene expression at all scales from DNA to the whole chromosome. We further suggest that this functional architecture is provided by the chromatin fiber itself. The structural, mechanical and topological features of the chromatin fiber endow chromosomes with a tunable signal transduction from specific (or nonspecific) effectors to specific (or nonspecific) active sites. Mechanical constraints can travel along the fiber all the better since the fiber is more compact and regular, which speaks in favor of the actual existence of the (so-called 30 nm) chromatin fiber. Chromatin fiber allostery reconciles both the physical and biochemical approaches of chromatin. We illustrate this view with two supporting specific examples. Moreover, from a methodological point of view, we suggest that the notion of chromatin fiber allostery is particularly relevant for systemic approaches. Finally we discuss the evolutionary power of allostery in the context of chromatin and its relation to modularity. (perspective)

  17. An agent-based model of signal transduction in bacterial chemotaxis.

    Directory of Open Access Journals (Sweden)

    Jameson Miller

    2010-05-01

    Full Text Available We report the application of agent-based modeling to examine the signal transduction network and receptor arrays for chemotaxis in Escherichia coli, which are responsible for regulating swimming behavior in response to environmental stimuli. Agent-based modeling is a stochastic and bottom-up approach, where individual components of the modeled system are explicitly represented, and bulk properties emerge from their movement and interactions. We present the Chemoscape model: a collection of agents representing both fixed membrane-embedded and mobile cytoplasmic proteins, each governed by a set of rules representing knowledge or hypotheses about their function. When the agents were placed in a simulated cellular space and then allowed to move and interact stochastically, the model exhibited many properties similar to the biological system including adaptation, high signal gain, and wide dynamic range. We found the agent based modeling approach to be both powerful and intuitive for testing hypotheses about biological properties such as self-assembly, the non-linear dynamics that occur through cooperative protein interactions, and non-uniform distributions of proteins in the cell. We applied the model to explore the role of receptor type, geometry and cooperativity in the signal gain and dynamic range of the chemotactic response to environmental stimuli. The model provided substantial qualitative evidence that the dynamic range of chemotactic response can be traced to both the heterogeneity of receptor types present, and the modulation of their cooperativity by their methylation state.

  18. Immortalization of chicken preadipocytes by retroviral transduction of chicken TERT and TR.

    Directory of Open Access Journals (Sweden)

    Wei Wang

    Full Text Available The chicken is an important agricultural animal and model for developmental biology, immunology and virology. Excess fat accumulation continues to be a serious problem for the chicken industry. However, chicken adipogenesis and obesity have not been well investigated, because no chicken preadipocyte cell lines have been generated thus far. Here, we successfully generated two immortalized chicken preadipocyte cell lines through transduction of either chicken telomerase reverse transcriptase (chTERT alone or in combination with chicken telomerase RNA (chTR. Both of these cell lines have survived >100 population doublings in vitro, display high telomerase activity and have no sign of replicative senescence. Similar to primary chicken preadipocytes, these two cell lines display a fibroblast-like morphology, retain the capacity to differentiate into adipocytes, and do not display any signs of malignant transformation. Isoenzyme analysis and PCR-based analysis confirmed that these two cell lines are of chicken origin and are free from inter-species contamination. To our knowledge, this is the first report demonstrating the generation of immortal chicken cells by introduction of chTERT and chTR. Our established chicken preadipocyte cell lines show great promise as an in vitro model for the investigation of chicken adipogenesis, lipid metabolism, and obesity and its related diseases, and our results also provide clues for immortalizing other avian cell types.

  19. Loss of CIB2 Causes Profound Hearing Loss and Abolishes Mechanoelectrical Transduction in Mice

    Directory of Open Access Journals (Sweden)

    Yanfei Wang

    2017-12-01

    Full Text Available Calcium and integrin-binding protein 2 (CIB2 belongs to a protein family with four known members, CIB1 through CIB4, which are characterized by multiple calcium-binding EF-hand domains. Among the family members, the Cib1 and Cib2 genes are expressed in mouse cochlear hair cells, and mutations in the human CIB2 gene have been associated with nonsyndromic deafness DFNB48 and syndromic deafness USH1J. To further explore the function of CIB1 and CIB2 in hearing, we established Cib1 and Cib2 knockout mice using the clustered regularly interspaced short palindromic repeat (CRISPR-associated Cas9 nuclease (CRISPR/Cas9 genome editing technique. We found that loss of CIB1 protein does not affect auditory function, whereas loss of CIB2 protein causes profound hearing loss in mice. Further investigation revealed that hair cell stereocilia development is affected in Cib2 knockout mice. Noticeably, loss of CIB2 abolishes mechanoelectrical transduction (MET currents in auditory hair cells. In conclusion, we show here that although both CIB1 and CIB2 are readily detected in the cochlea, only loss of CIB2 results in profound hearing loss, and that CIB2 is essential for auditory hair cell MET.

  20. The condensed chromatin fiber: an allosteric chemo-mechanical machine for signal transduction and genome processing

    Science.gov (United States)

    Lesne, Annick; Bécavin, Christophe; Victor, Jean–Marc

    2012-02-01

    Allostery is a key concept of molecular biology which refers to the control of an enzyme activity by an effector molecule binding the enzyme at another site rather than the active site (allos = other in Greek). We revisit here allostery in the context of chromatin and argue that allosteric principles underlie and explain the functional architecture required for spacetime coordination of gene expression at all scales from DNA to the whole chromosome. We further suggest that this functional architecture is provided by the chromatin fiber itself. The structural, mechanical and topological features of the chromatin fiber endow chromosomes with a tunable signal transduction from specific (or nonspecific) effectors to specific (or nonspecific) active sites. Mechanical constraints can travel along the fiber all the better since the fiber is more compact and regular, which speaks in favor of the actual existence of the (so-called 30 nm) chromatin fiber. Chromatin fiber allostery reconciles both the physical and biochemical approaches of chromatin. We illustrate this view with two supporting specific examples. Moreover, from a methodological point of view, we suggest that the notion of chromatin fiber allostery is particularly relevant for systemic approaches. Finally we discuss the evolutionary power of allostery in the context of chromatin and its relation to modularity.

  1. Signal perception, transduction, and response in gravity resistance. Another graviresponse in plants

    Science.gov (United States)

    Hoson, T.; Saito, Y.; Soga, K.; Wakabayashi, K.

    Resistance to the gravitational force is a serious problem that plants have had to solve to survive on land. Mechanical resistance to the pull of gravity is thus a principal graviresponse in plants, comparable to gravitropism. Nevertheless, only limited information has been obtained for this gravity response. We have examined the mechanism of gravity-induced mechanical resistance using hypergravity conditions produced by centrifugation. As a result, we have clarified the outline of the sequence of events leading to the development of mechanical resistance. The gravity signal may be perceived by mechanoreceptors (mechanosensitive ion channels) on the plasma membrane and it appears that amyloplast sedimentation in statocytes is not involved. Transformation and transduction of the perceived signal may be mediated by the structural or physiological continuum of microtubule-cell membrane-cell wall. As the final step in the development of mechanical resistance, plants construct a tough body by increasing cell wall rigidity. The increase in cell wall rigidity is brought about by modification of the metabolism of certain wall constituents and modification of the cell wall environment, especially pH. We need to clarify the details of each step by future space and ground-based experiments.

  2. An agent-based model of signal transduction in bacterial chemotaxis.

    Science.gov (United States)

    Miller, Jameson; Parker, Miles; Bourret, Robert B; Giddings, Morgan C

    2010-05-13

    We report the application of agent-based modeling to examine the signal transduction network and receptor arrays for chemotaxis in Escherichia coli, which are responsible for regulating swimming behavior in response to environmental stimuli. Agent-based modeling is a stochastic and bottom-up approach, where individual components of the modeled system are explicitly represented, and bulk properties emerge from their movement and interactions. We present the Chemoscape model: a collection of agents representing both fixed membrane-embedded and mobile cytoplasmic proteins, each governed by a set of rules representing knowledge or hypotheses about their function. When the agents were placed in a simulated cellular space and then allowed to move and interact stochastically, the model exhibited many properties similar to the biological system including adaptation, high signal gain, and wide dynamic range. We found the agent based modeling approach to be both powerful and intuitive for testing hypotheses about biological properties such as self-assembly, the non-linear dynamics that occur through cooperative protein interactions, and non-uniform distributions of proteins in the cell. We applied the model to explore the role of receptor type, geometry and cooperativity in the signal gain and dynamic range of the chemotactic response to environmental stimuli. The model provided substantial qualitative evidence that the dynamic range of chemotactic response can be traced to both the heterogeneity of receptor types present, and the modulation of their cooperativity by their methylation state.

  3. Standard practice for guided wave testing of above ground steel pipework using piezoelectric effect transduction

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This practice provides a procedure for the use of guided wave testing (GWT), also previously known as long range ultrasonic testing (LRUT) or guided wave ultrasonic testing (GWUT). 1.2 GWT utilizes ultrasonic guided waves, sent in the axial direction of the pipe, to non-destructively test pipes for defects or other features by detecting changes in the cross-section and/or stiffness of the pipe. 1.3 GWT is a screening tool. The method does not provide a direct measurement of wall thickness or the exact dimensions of defects/defected area; an estimate of the defect severity however can be provided. 1.4 This practice is intended for use with tubular carbon steel or low-alloy steel products having Nominal Pipe size (NPS) 2 to 48 corresponding to 60.3 to 1219.2 mm (2.375 to 48 in.) outer diameter, and wall thickness between 3.81 and 25.4 mm (0.15 and 1 in.). 1.5 This practice covers GWT using piezoelectric transduction technology. 1.6 This practice only applies to GWT of basic pipe configuration. This inc...

  4. Nitric oxide agents impair insulin-mediated signal transduction in rat skeletal muscle

    Directory of Open Access Journals (Sweden)

    Ragoobirsingh Dalip

    2006-05-01

    Full Text Available Abstract Background Evidence demonstrates that exogenously administered nitric oxide (NO can induce insulin resistance in skeletal muscle. We have investigated the modulatory effects of two NO donors, S-nitroso-N-acetyl-D, L-penicillamine (SNAP and S-nitrosoglutathione (GSNO on the early events in insulin signaling in rat skeletal myocytes. Results Skeletal muscle cells from 6–8 week old Sprague-Dawley rats were treated with SNAP or GSNO (25 ng/ml in the presence or absence of glucose (25 mM and insulin (100 nM. Cellular insulin receptor-β levels and tyrosine phosphorylation in IRS-1 were significantly reduced, while serine phosphorylation in IRS-1 was significantly increased in these cells, when compared to the insulin-stimulated control. Reversal to near normal levels was achieved using the NO scavenger, 2-(4-carboxyphenyl-4, 4, 5, 5-tetramethylimidazoline-1-oxyl 3-oxide (carboxy-PTIO. Conclusion These data suggest that NO is a potent modulator of insulin-mediated signal transduction and may play a significant role in the pathogenesis of type 2 diabetes mellitus.

  5. Experimental and theoretical investigation of an impact vibration harvester with triboelectric transduction

    Science.gov (United States)

    Ibrahim, Alwathiqbellah; Ramini, Abdallah; Towfighian, Shahrzad

    2018-03-01

    There has been remarkable interest in triboelectric mechanisms because of their high efficiency, wide availability, and low-cost generation of sustainable power. Using impact vibrations, we introduce piece-wise stiffness to the system to enlarge frequency bandwidth. The triboelectric layers consist of Aluminum, which also serves as an electrode, and Polydimethylsiloxane (PDMS) with micro semi-cylindrical patterns. At the bottom of the PDMS layer, there is another Al electrode. The layers are sandwiched between the center mass of a clamped-clamped beam and its base. The center mass enhances the impact force on the triboelectric layers subjected to external vibrations. Upon impact, alternating current, caused by the contact electrification and electrostatic induction, flows between the Al electrodes. Because of the impact, the equivalent stiffness of the structure increases and as a result, the frequency bandwidth gets wider. The output voltage and power reach as large as 5.5 V, 15 μW, respectively at 0.8 g vibrational amplitude. In addition, we report how the surface charge density increases with the excitation levels. The analysis delineates the interactions between impact vibrations and triboelectric transductions. The ability of the system to achieve wider bandwidth paves the way for efficient triboelectric vibrational energy harvesters.

  6. Effect of a Fusion Peptide by Covalent Conjugation of a Mitochondrial Cell-Penetrating Peptide and a Glutathione Analog Peptide

    Directory of Open Access Journals (Sweden)

    Carmine Pasquale Cerrato

    2017-06-01

    Full Text Available Previously, we designed and synthesized a library of mitochondrial antioxidative cell-penetrating peptides (mtCPPs superior to the parent peptide, SS31, to protect mitochondria from oxidative damage. A library of antioxidative glutathione analogs called glutathione peptides (UPFs, exceptional in hydroxyl radical elimination compared with glutathione, were also designed and synthesized. Here, a follow-up study is described, investigating the effects of the most promising members from both libraries on reactive oxidative species scavenging ability. None of the peptides influenced cell viability at the concentrations used. Fluorescence microscopy studies showed that the fluorescein-mtCPP1-UPF25 (mtgCPP internalized into cells, and spectrofluorometric analysis determined the presence and extent of peptide into different cell compartments. mtgCPP has superior antioxidative activity compared with mtCPP1 and UPF25 against H2O2 insult, preventing ROS formation by 2- and 3-fold, respectively. Moreover, we neither observed effects on mitochondrial membrane potential nor production of ATP. These data indicate that mtgCPP is targeting mitochondria, protecting them from oxidative damage, while also being present in the cytosol. Our hypothesis is based on a synergistic effect resulting from the fused peptide. The mitochondrial peptide segment is targeting mitochondria, whereas the glutathione analog peptide segment is active in the cytosol, resulting in increased scavenging ability.

  7. peptide

    Indian Academy of Sciences (India)

    Prakash

    effects can be observed under certain conditions but these are not always .... of proteins with amyloid characteristics in muscle (Jayaraman et al. 2008) ... not enhance the growth of dangerous fibrils generated at pH. 7.4. ..... The lower chart shows Aβ(25-35) aggregation kinetics during the first 4 min of monitoring. Results are ...

  8. Peptide hormones and lung cancer.

    Science.gov (United States)

    Moody, T W

    2006-03-01

    Several peptide hormones have been identified which alter the proliferation of lung cancer. Small cell lung cancer (SCLC), which is a neuroendocrine cancer, produces and secretes gastrin releasing peptide (GRP), neurotensin (NT) and adrenomedullin (AM) as autocrine growth factors. GRP, NT and AM bind to G-protein coupled receptors causing phosphatidylinositol turnover or elevated cAMP in SCLC cells. Addition of GRP, NT or AM to SCLC cells causes altered expression of nuclear oncogenes, such as c-fos, and stimulation of growth. Antagonists have been developed for GRP, NT and AM receptors which function as cytostatic agents and inhibit SCLC growth. Growth factor antagonists, such as the NT1 receptor antagonist SR48692, facilitate the ability of chemotherapeutic drugs to kill lung cancer cells. It remains to be determined if GRP, NT and AM receptors will served as molecular targets, for development of new therapies for the treatment of SCLC patients. Non-small cell lung cancer (NSCLC) cells also have a high density of GRP, NT, AM and epidermal growth factor (EGF) receptors. Several NSCLC patients with EGF receptor mutations respond to gefitinib, a tyrosine kinase inhibitor. Gefitinib relieves NSCLC symptoms, maintaining stable disease in patients who are not eligible for systemic chemotherapy. It is important to develop new therapeutic approaches using translational research techniques for the treatment of lung cancer patients.

  9. Synthetic mimics of antimicrobial peptides.

    Science.gov (United States)

    Som, Abhigyan; Vemparala, Satyavani; Ivanov, Ivaylo; Tew, Gregory N

    2008-01-01

    Infectious diseases and antibiotic resistance are now considered the most imperative global healthcare problem. In the search for new treatments, host defense, or antimicrobial, peptides have attracted considerable attention due to their various unique properties; however, attempts to develop in vivo therapies have been severely limited. Efforts to develop synthetic mimics of antimicrobial peptides (SMAMPs) have increased significantly in the last decade, and this review will focus primarily on the structural evolution of SMAMPs and their membrane activity. This review will attempt to make a bridge between the design of SMAMPs and the fundamentals of SMAMP-membrane interactions. In discussions regarding the membrane interaction of SMAMPs, close attention will be paid to the lipid composition of the bilayer. Despite many years of study, the exact conformational aspects responsible for the high selectivity of these AMPs and SMAMPs toward bacterial cells over mammalian cells are still not fully understood. The ability to design SMAMPs that are potently antimicrobial, yet nontoxic to mammalian cells has been demonstrated with a variety of molecular scaffolds. Initial animal studies show very good tissue distribution along with more than a 4-log reduction in bacterial counts. The results on SMAMPs are not only extremely promising for novel antibiotics, but also provide an optimistic picture for the greater challenge of general proteomimetics.

  10. Driving engineering of novel antimicrobial peptides from simulations of peptide-micelle interactions

    DEFF Research Database (Denmark)

    Khandelia, Himanshu; Langham, Allison A; Kaznessis, Yiannis N

    2006-01-01

    Simulations of antimicrobial peptides in membrane mimics can provide the high resolution, atomistic picture that is necessary to decipher which sequence and structure components are responsible for activity and toxicity. With such detailed insight, engineering new sequences that are active but non...... peptides and their interaction with membrane mimics. In this article, we discuss the promise and the challenges of widely used models and detail our recent work on peptide-micelle simulations as an attractive alternative to peptide-bilayer simulations. We detail our results with two large structural...... classes of peptides, helical and beta-sheet and demonstrate how simulations can assist in engineering of novel antimicrobials with therapeutic potential....

  11. Peptide-tagged proteins in aqueous two-phase systems

    OpenAIRE

    Nilsson, Anna

    2002-01-01

    This thesis deals with proteins containing peptide tags for improved partitioning in aqueous two-phase systems. Qualitatively the peptide-tagged protein partitioning could be predicted from peptide data, i.e. partitioning trends found for peptides were also found for the peptide-tagged proteins. However, full effect of the tag as expected from peptide partitioning was not found in the tagged protein. When alkyl-ethylene oxide surfactant was included in a two-polymer system, almost full effect...

  12. Topical Peptide Treatments with Effective Anti-Aging Results

    OpenAIRE

    Silke Karin Schagen

    2017-01-01

    In the last two decades, many new peptides have been developed, and new knowledge on how peptides improve the skin has been uncovered. The spectrum of peptides in the field of cosmetics is continuously growing. This review summarizes some of the effective data on cosmeceutical peptides that work against intrinsic and extrinsic aging. Some peptides have been proven in their efficacy through clinical skin trials. Well-known and documented peptides like copper tripeptide are still under research...

  13. Prediction of twin-arginine signal peptides

    DEFF Research Database (Denmark)

    Bendtsen, Jannick Dyrløv; Nielsen, Henrik; Widdick, D.

    2005-01-01

    expressions, whereas hydrophobicity discrimination of Tat- and Sec- signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/....

  14. Double quick, double click reversible peptide "stapling".

    Science.gov (United States)

    Grison, Claire M; Burslem, George M; Miles, Jennifer A; Pilsl, Ludwig K A; Yeo, David J; Imani, Zeynab; Warriner, Stuart L; Webb, Michael E; Wilson, Andrew J

    2017-07-01

    The development of constrained peptides for inhibition of protein-protein interactions is an emerging strategy in chemical biology and drug discovery. This manuscript introduces a versatile, rapid and reversible approach to constrain peptides in a bioactive helical conformation using BID and RNase S peptides as models. Dibromomaleimide is used to constrain BID and RNase S peptide sequence variants bearing cysteine (Cys) or homocysteine ( h Cys) amino acids spaced at i and i + 4 positions by double substitution. The constraint can be readily removed by displacement of the maleimide using excess thiol. This new constraining methodology results in enhanced α-helical conformation (BID and RNase S peptide) as demonstrated by circular dichroism and molecular dynamics simulations, resistance to proteolysis (BID) as demonstrated by trypsin proteolysis experiments and retained or enhanced potency of inhibition for Bcl-2 family protein-protein interactions (BID), or greater capability to restore the hydrolytic activity of the RNAse S protein (RNase S peptide). Finally, use of a dibromomaleimide functionalized with an alkyne permits further divergent functionalization through alkyne-azide cycloaddition chemistry on the constrained peptide with fluorescein, oligoethylene glycol or biotin groups to facilitate biophysical and cellular analyses. Hence this methodology may extend the scope and accessibility of peptide stapling.

  15. Protein identification by peptide mass fingerprinting

    DEFF Research Database (Denmark)

    Hjernø, Karin

    2007-01-01

      Peptide mass fingerprinting is an effective way of identifying, e.g., gel-separated proteins, by matching experimentally obtained peptide mass data against large databases. However, several factors are known to influence the quality of the resulting matches, such as proteins contaminating the s...

  16. Peptide Mass Fingerprinting of Egg White Proteins

    Science.gov (United States)

    Alty, Lisa T.; LaRiviere, Frederick J.

    2016-01-01

    Use of advanced mass spectrometry techniques in the undergraduate setting has burgeoned in the past decade. However, relatively few undergraduate experiments examine the proteomics tools of protein digestion, peptide accurate mass determination, and database searching, also known as peptide mass fingerprinting. In this experiment, biochemistry…

  17. Practical use of natriuretic peptide measurement

    DEFF Research Database (Denmark)

    Husby, Simon; Lind, Bent; Goetze, Jens P

    2012-01-01

    To elucidate the knowledge regarding B-type natriuretic peptide (BNP)/N-terminal proBNP (NT-proBNP) measurement among doctors using this biomarker.......To elucidate the knowledge regarding B-type natriuretic peptide (BNP)/N-terminal proBNP (NT-proBNP) measurement among doctors using this biomarker....

  18. Novel peptide-based protease inhibitors

    DEFF Research Database (Denmark)

    Roodbeen, Renée

    of novel peptide-based protease inhibitors, efforts were made towards improved methods for peptide synthesis. The coupling of Fmoc-amino acids onto N-methylated peptidyl resins was investigated. These couplings can be low yielding and the effect of the use of microwave heating combined with the coupling...

  19. Benefits of gene transduction of granulocyte macrophage colony-stimulating factor in cancer vaccine using genetically modified dendritic cells.

    Science.gov (United States)

    Ojima, Toshiyasu; Iwahashi, Makoto; Nakamura, Masaki; Matsuda, Kenji; Nakamori, Mikihito; Ueda, Kentaro; Naka, Teiji; Katsuda, Masahiro; Miyazawa, Motoki; Yamaue, Hiroki

    2007-10-01

    Granulocyte macrophage colony-stimulating factor (GM-CSF) is a key cytokine for the generation and stimulation of dendritic cells (DCs), and it may also play a pivotal role in promoting the survival of DCs. In this study, the feasibility of creating a cancer vaccine using DCs adenovirally transduced with the carcinoembryonic antigen (CEA) gene and the GM-CSF gene was examined. In addition, the effect of the co-transduction of GM-CSF gene on the lifespan of these genetically modified DCs was determined. A cytotoxic assay using peripheral blood mononuclear cell (PBMC)-derived cytotoxic T lymphocytes (CTLs) was performed in a 4-h 51Cr release assay. The apoptosis of DCs was examined by TdT-mediated dUTP-FITC nick end labeling (TUNEL) assay. CEA-specific CTLs were generated from PBMCs stimulated with genetically modified DCs expressing CEA. The cytotoxicity of these CTLs was augmented by co-transduction of DCs with the GM-CSF gene. Co-transduction of the GM-CSF gene into DCs inhibited apoptosis of these DCs themselves via up-regulation of Bcl-x(L) expression, leading to the extension of the lifespan of these DCs. Furthermore, the transduction of the GM-CSF gene into DCs also suppressed the incidence of apoptosis of DCs induced by transforming growth factor-beta1 (TGFbeta-1). Immunotherapy using these genetically modified DCs may therefore be useful with several advantages as follows: i) adenoviral toxicity to DCs can be reduced; ii) the lifespan of vaccinated DCs can be prolonged; and iii) GM-CSF may protect DCs from apoptosis induced by tumor-derived TGFbeta-1 in the regional lymph nodes.

  20. DMPD: When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18631453 When signaling pathways collide: positive and negative regulation of toll-...uction. PubmedID 18631453 Title When signaling pathways collide: positive and neg...l) Show When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transd...likereceptor signal transduction. O'Neill LA. Immunity. 2008 Jul 18;29(1):12-20. (.png) (.svg) (.html) (.csm