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Sample records for renders signal peptides

  1. SPdb – a signal peptide database

    Directory of Open Access Journals (Sweden)

    Tan Tin

    2005-10-01

    Full Text Available Abstract Background The signal peptide plays an important role in protein targeting and protein translocation in both prokaryotic and eukaryotic cells. This transient, short peptide sequence functions like a postal address on an envelope by targeting proteins for secretion or for transfer to specific organelles for further processing. Understanding how signal peptides function is crucial in predicting where proteins are translocated. To support this understanding, we present SPdb signal peptide database http://proline.bic.nus.edu.sg/spdb, a repository of experimentally determined and computationally predicted signal peptides. Results SPdb integrates information from two sources (a Swiss-Prot protein sequence database which is now part of UniProt and (b EMBL nucleotide sequence database. The database update is semi-automated with human checking and verification of the data to ensure the correctness of the data stored. The latest release SPdb release 3.2 contains 18,146 entries of which 2,584 entries are experimentally verified signal sequences; the remaining 15,562 entries are either signal sequences that fail to meet our filtering criteria or entries that contain unverified signal sequences. Conclusion SPdb is a manually curated database constructed to support the understanding and analysis of signal peptides. SPdb tracks the major updates of the two underlying primary databases thereby ensuring that its information remains up-to-date.

  2. Prediction of twin-arginine signal peptides

    DEFF Research Database (Denmark)

    Bendtsen, Jannick Dyrløv; Nielsen, Henrik; Widdick, D.;

    2005-01-01

    peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than...

  3. Peptide pheromone signaling in Streptococcus and Enterococcus.

    Science.gov (United States)

    Cook, Laura C; Federle, Michael J

    2014-05-01

    Intercellular chemical signaling in bacteria, commonly referred to as quorum sensing (QS), relies on the production and detection of compounds known as pheromones to elicit coordinated responses among members of a community. Pheromones produced by Gram-positive bacteria are comprised of small peptides. Based on both peptide structure and sensory system architectures, Gram-positive bacterial signaling pathways may be classified into one of four groups with a defining hallmark: cyclical peptides of the Agr type, peptides that contain Gly-Gly processing motifs, sensory systems of the RNPP family, or the recently characterized Rgg-like regulatory family. The recent discovery that Rgg family members respond to peptide pheromones increases substantially the number of species in which QS is likely a key regulatory component. These pathways control a variety of fundamental behaviors including conjugation, natural competence for transformation, biofilm development, and virulence factor regulation. Overlapping QS pathways found in multiple species and pathways that utilize conserved peptide pheromones provide opportunities for interspecies communication. Here we review pheromone signaling identified in the genera Enterococcus and Streptococcus, providing examples of all four types of pathways.

  4. Peptide pheromone signaling in Streptococcus and Enterococcus

    Science.gov (United States)

    Cook, Laura C.; Federle, Michael J.

    2014-01-01

    Intercellular chemical signaling in bacteria, commonly referred to as quorum sensing (QS), relies on the production and detection of compounds known as pheromones to elicit coordinated responses among members of a community. Pheromones produced by Gram-positive bacteria are comprised of small peptides. Based on both peptide structure and sensory system architectures, Gram-positive bacterial signaling pathways may be classified into one of four groups with a defining hallmark: cyclical peptides of the Agr type, peptides that contain Gly-Gly processing motifs, sensory systems of the RNPP family, or the recently characterized Rgg-like regulatory family. The recent discovery that Rgg family members respond to peptide pheromones increases substantially the number of species in which QS is likely a key regulatory component. These pathways control a variety of fundamental behaviors including conjugation, natural competence for transformation, biofilm development, and virulence factor regulation. Overlapping QS pathways found in multiple species and pathways that utilize conserved peptide pheromones provide opportunities for interspecies communication. Here we review pheromone signaling identified in the genera Enterococcus and Streptococcus, providing examples of all four types of pathways. PMID:24118108

  5. Prediction of signal peptides and signal anchors by a hidden Markovmodel

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Krogh, Anders Stærmose

    1998-01-01

    A hidden Markov model of signal peptides has been developed. It contains submodels for the N-terminal part, the hydrophobic region and the region around the cleavage site. For known signal peptides, the model can be used to assign objective boundaries between these three regions. Applied to our d...... is the poor discrimination between signal peptides and uncleaved signal anchors, but this is substantially improved by the hidden Markov model when expanding it with a very simple signal anchor model....

  6. Prediction of signal peptides and signal anchors by a hidden Markov model

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Nielsen, Henrik

    1998-01-01

    A hidden Markov model of signal peptides has been developed. It contains submodels for the N-terminal part, the hydrophobic region, and the region around the cleavage site. For known signal peptides, the model can be used to assign objective boundaries between these three regions. Applied to our ...... is the poor discrimination between signal peptides and uncleaved signal anchors, but this is substantially improved by the hidden Markov model when expanding it with a very simple signal anchor model....

  7. Signal Processing Implementation and Comparison of Automotive Spatial Sound Rendering Strategies

    Directory of Open Access Journals (Sweden)

    Bai MingsianR

    2009-01-01

    Full Text Available Design and implementation strategies of spatial sound rendering are investigated in this paper for automotive scenarios. Six design methods are implemented for various rendering modes with different number of passengers. Specifically, the downmixing algorithms aimed at balancing the front and back reproductions are developed for the 5.1-channel input. Other five algorithms based on inverse filtering are implemented in two approaches. The first approach utilizes binaural (Head-Related Transfer Functions HRTFs measured in the car interior, whereas the second approach named the point-receiver model targets a point receiver positioned at the center of the passenger's head. The proposed processing algorithms were compared via objective and subjective experiments under various listening conditions. Test data were processed by the multivariate analysis of variance (MANOVA method and the least significant difference (Fisher's LSD method as a post hoc test to justify the statistical significance of the experimental data. The results indicate that inverse filtering algorithms are preferred for the single passenger mode. For the multipassenger mode, however, downmixing algorithms generally outperformed the other processing techniques.

  8. Vigilin interacts with signal peptide peptidase

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    Lu Stephen Hsueh-Jeng

    2012-05-01

    Full Text Available Abstract Background Signal peptide peptidase (SPP, a member of the presenilin-like intra-membrane cleaving aspartyl protease family, migrates on Blue Native (BN gels as 100 kDa, 200 kDa and 450 kDa species. SPP has recently been implicated in other non-proteolytic functions such as retro-translocation of MHC Class I molecules and binding of misfolded proteins in the endoplasmic reticulum (ER. These high molecular weight SPP complexes might contain additional proteins that regulate the proteolytic activity of SPP or support its non-catalytic functions. Results In this study, an unbiased iTRAQ-labeling mass spectrometry approach was used to identify SPP-interacting proteins. We found that vigilin, a ubiquitous multi-KH domain containing cytoplasmic protein involved in RNA binding and protein translation control, selectively enriched with SPP. Vigilin interacted with SPP and both proteins co-localized in restricted intracellular domains near the ER, biochemically co-fractionated and were part of the same 450 kDa complex on BN gels. However, vigilin does not alter the protease activity of SPP, suggesting that the SPP-vigilin interaction might be involved in the non-proteolytic functions of SPP. Conclusions We have identified and validated vigilin as a novel interacting partner of SPP that could play an important role in the non-proteolytic functions of SPP. This data adds further weight to the idea that intramembrane-cleaving aspartyl proteases, such as presenilin and SPPs, could have other functions besides the proteolysis of short membrane stubs.

  9. Role of signal peptides in targeting of proteins in cyanobacteria.

    OpenAIRE

    Mackle, M M; Zilinskas, B A

    1994-01-01

    Proteins of cyanobacteria may be transported across one of two membrane systems: the typical eubacterial cell envelope (consisting of an inner membrane, periplasmic space, and an outer membrane) and the photosynthetic thylakoids. To investigate the role of signal peptides in targeting in cyanobacteria, Synechococcus sp. strain PCC 7942 was transformed with vectors carrying the chloramphenicol acetyltransferase reporter gene fused to coding sequences for one of four different signal peptides. ...

  10. The Chromatin Scaffold Protein SAFB1 Renders Chromatin Permissive for DNA Damage Signaling

    DEFF Research Database (Denmark)

    Altmeyer, Matthias; Toledo Lazaro, Luis Ignacio; Gudjonsson, Thorkell

    2013-01-01

    the chromatin-associated scaffold attachment factor SAFB1 as a component of the DNA damage response and show that SAFB1 cooperates with histone acetylation to allow for efficient γH2AX spreading and genotoxic stress signaling. SAFB1 undergoes a highly dynamic exchange at damaged chromatin in a poly...

  11. Intracellular Peptides as Natural Regulators of Cell Signaling*S⃞

    Science.gov (United States)

    Cunha, Fernanda M.; Berti, Denise A.; Ferreira, Zulma S.; Klitzke, Clécio F.; Markus, Regina P.; Ferro, Emer S.

    2008-01-01

    Protein degradation by the ubiquitin proteasome system releases large amounts of oligopeptides within cells. To investigate possible functions for these intracellularly generated oligopeptides, we fused them to a cationic transactivator peptide sequence using reversible disulfide bonds, introduced them into cells, and analyzed their effect on G protein-coupled receptor (GPCR) signal transduction. A mixture containing four of these peptides (20–80 μm) significantly inhibited the increase in the extracellular acidification response triggered by angiotensin II (ang II) in CHO-S cells transfected with the ang II type 1 receptor (AT1R-CHO-S). Subsequently, either alone or in a mixture, these peptides increased luciferase gene transcription in AT1R CHO-S cells stimulated with ang II and in HEK293 cells treated with isoproterenol. These peptides without transactivator failed to affect GPCR cellular responses. All four functional peptides were shown in vitro to competitively inhibit the degradation of a synthetic substrate by thimet oligopeptidase. Overexpression of thimet oligopeptidase in both CHO-S and HEK293 cells was sufficient to reduce luciferase activation triggered by a specific GPCR agonist. Moreover, using individual peptides as baits in affinity columns, several proteins involved in GPCR signaling were identified, including α-adaptin A and dynamin 1. These results suggest that before their complete degradation, intracellular peptides similar to those generated by proteasomes can actively affect cell signaling, probably representing additional bioactive molecules within cells. PMID:18617518

  12. Intracellular peptides as natural regulators of cell signaling.

    Science.gov (United States)

    Cunha, Fernanda M; Berti, Denise A; Ferreira, Zulma S; Klitzke, Clécio F; Markus, Regina P; Ferro, Emer S

    2008-09-05

    Protein degradation by the ubiquitin proteasome system releases large amounts of oligopeptides within cells. To investigate possible functions for these intracellularly generated oligopeptides, we fused them to a cationic transactivator peptide sequence using reversible disulfide bonds, introduced them into cells, and analyzed their effect on G protein-coupled receptor (GPCR) signal transduction. A mixture containing four of these peptides (20-80 microm) significantly inhibited the increase in the extracellular acidification response triggered by angiotensin II (ang II) in CHO-S cells transfected with the ang II type 1 receptor (AT1R-CHO-S). Subsequently, either alone or in a mixture, these peptides increased luciferase gene transcription in AT1R CHO-S cells stimulated with ang II and in HEK293 cells treated with isoproterenol. These peptides without transactivator failed to affect GPCR cellular responses. All four functional peptides were shown in vitro to competitively inhibit the degradation of a synthetic substrate by thimet oligopeptidase. Overexpression of thimet oligopeptidase in both CHO-S and HEK293 cells was sufficient to reduce luciferase activation triggered by a specific GPCR agonist. Moreover, using individual peptides as baits in affinity columns, several proteins involved in GPCR signaling were identified, including alpha-adaptin A and dynamin 1. These results suggest that before their complete degradation, intracellular peptides similar to those generated by proteasomes can actively affect cell signaling, probably representing additional bioactive molecules within cells.

  13. Commensal-epithelial signaling mediated via formyl peptide receptors.

    Science.gov (United States)

    Wentworth, Christy C; Jones, Rheinallt M; Kwon, Young Man; Nusrat, Asma; Neish, Andrew S

    2010-12-01

    Commensal bacteria and/or their products engender beneficial effects to the mammalian gut, including stimulating physiological cellular turnover and enhancing wound healing, without activating overt inflammation. In the present study, we observed commensal bacteria-mediated activation of the noninflammatory extracellular signal-regulated kinase[ERK]/mitogen-activated protein kinase and Akt signaling pathways in gut epithelial cells and delineated a mechanism for this bacterially activated signaling. All tested strains of commensal bacteria induced ERK phosphorylation without stimulating pro-inflammatory phospho-IκB or pro-apoptotic phospho-c-Jun NH(2)-terminal kinase, with Lactobacillus species being most potent. This pattern of signaling activation was recapitulated using the peptide N-formyl-Met-Leu-Phe, a bacterial product known to stimulate signaling events in mammalian phagocytes. Sensing of N-formyl-Met-Leu-Phe by gut epithelial cells occurs via recently characterized formyl peptide receptors located in the plasma membrane. Both commensal bacteria and N-formyl-Met-Leu-Phe application to the apical surface of polarized gut epithelial cells resulted in specific formyl peptide receptor activation. In addition, pretreatment of model epithelia and murine colon with Boc2 (a specific peptide antagonist) or pertussis toxin (a G(i)-protein inhibitor) abolished commensal-mediated ERK phosphorylation. Taken together, these data show that commensal bacteria specifically activate the ERK/mitogen-activated protein kinase pathway in an formyl peptide receptor-dependent manner, delineating a mechanism by which commensal bacteria contribute to cellular signaling in gut epithelia.

  14. Differential age-dependent import regulation by signal peptides.

    Directory of Open Access Journals (Sweden)

    Yi-Shan Teng

    Full Text Available Gene-specific, age-dependent regulations are common at the transcriptional and translational levels, while protein transport into organelles is generally thought to be constitutive. Here we report a new level of differential age-dependent regulation and show that chloroplast proteins are divided into three age-selective groups: group I proteins have a higher import efficiency into younger chloroplasts, import of group II proteins is nearly independent of chloroplast age, and group III proteins are preferentially imported into older chloroplasts. The age-selective signal is located within the transit peptide of each protein. A group III protein with its transit peptide replaced by a group I transit peptide failed to complement its own mutation. Two consecutive positive charges define the necessary motif in group III signals for older chloroplast preference. We further show that different members of a gene family often belong to different age-selective groups because of sequence differences in their transit peptides. These results indicate that organelle-targeting signal peptides are part of cells' differential age-dependent regulation networks. The sequence diversity of some organelle-targeting peptides is not a result of the lack of selection pressure but has evolved to mediate regulation.

  15. Signal peptides and protein localization prediction

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2005-01-01

    In 1999, the Nobel prize in Physiology or Medicine was awarded to Gunther Blobel “for the discovery that proteins have intrinsic signals that govern their transport and localization in the cell”. Since the subcellular localization of a protein is an important clue to its function...

  16. Quantum rendering

    Science.gov (United States)

    Lanzagorta, Marco O.; Gomez, Richard B.; Uhlmann, Jeffrey K.

    2003-08-01

    In recent years, computer graphics has emerged as a critical component of the scientific and engineering process, and it is recognized as an important computer science research area. Computer graphics are extensively used for a variety of aerospace and defense training systems and by Hollywood's special effects companies. All these applications require the computer graphics systems to produce high quality renderings of extremely large data sets in short periods of time. Much research has been done in "classical computing" toward the development of efficient methods and techniques to reduce the rendering time required for large datasets. Quantum Computing's unique algorithmic features offer the possibility of speeding up some of the known rendering algorithms currently used in computer graphics. In this paper we discuss possible implementations of quantum rendering algorithms. In particular, we concentrate on the implementation of Grover's quantum search algorithm for Z-buffering, ray-tracing, radiosity, and scene management techniques. We also compare the theoretical performance between the classical and quantum versions of the algorithms.

  17. Bioinformatic analysis of the CLE signaling peptide family

    Directory of Open Access Journals (Sweden)

    Weiller Georg F

    2008-01-01

    Full Text Available Abstract Background Plants encode a large number of leucine-rich repeat receptor-like kinases. Legumes encode several LRR-RLK linked to the process of root nodule formation, the ligands of which are unknown. To identify ligands for these receptors, we used a combination of profile hidden Markov models and position-specific iterative BLAST, allowing us to detect new members of the CLV3/ESR (CLE protein family from publicly available sequence databases. Results We identified 114 new members of the CLE protein family from various plant species, as well as five protein sequences containing multiple CLE domains. We were able to cluster the CLE domain proteins into 13 distinct groups based on their pairwise similarities in the primary CLE motif. In addition, we identified secondary motifs that coincide with our sequence clusters. The groupings based on the CLE motifs correlate with known biological functions of CLE signaling peptides and are analogous to groupings based on phylogenetic analysis and ectopic overexpression studies. We tested the biological function of two of the predicted CLE signaling peptides in the legume Medicago truncatula. These peptides inhibit the activity of the root apical and lateral root meristems in a manner consistent with our functional predictions based on other CLE signaling peptides clustering in the same groups. Conclusion Our analysis provides an identification and classification of a large number of novel potential CLE signaling peptides. The additional motifs we found could lead to future discovery of recognition sites for processing peptidases as well as predictions for receptor binding specificity.

  18. Signal peptide hydrophobicity is critical for early stages in protein export by Bacillus subtilis

    NARCIS (Netherlands)

    Zanen, G; Meima, R; Tjalsma, H; Jongbloed, JDH; Westers, H; Oudega, B; Luirink, J; van Dijl, JM; Quax, WJ; Houben, E.N.G.

    2005-01-01

    Signal peptides that direct protein export in Bacillus subtilis are overall more hydrophobic than signal peptides in Escherichia coli. To study the importance of signal peptide hydrophobicity for protein export in both organisms, the alpha-amylase AmyQ was provided with leucine-rich (high hydrophobi

  19. Prediction of lipoprotein signal peptides in Gram-negative bacteria

    DEFF Research Database (Denmark)

    Juncker, Agnieszka; Willenbrock, Hanni; Von Heijne, G.

    2003-01-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor...... was able to predict 96.8% of the lipoproteins correctly with only 0.3% false positives in a set of SPaseI-cleaved, cytoplasmic, and transmembrane proteins. The results obtained were significantly better than those of previously developed methods. Even though Gram-positive lipoprotein signal peptides differ...... from Gram-negatives, the HMM was able to identify 92.9% of the lipoproteins included in a Gram-positive test set. A genome search was carried out for 12 Gram-negative genomes and one Gram-positive genome. The results for Escherichia coli K12 were compared with new experimental data, and the predictions...

  20. Silaffin peptides as a novel signal enhancer for gravimetric biosensors.

    Science.gov (United States)

    Nam, Dong Hyun; Lee, Jeong-O; Sang, Byoung-In; Won, Keehoon; Kim, Yong Hwan

    2013-05-01

    Application of biomimetic silica formation to gravimetric biosensors has been conducted for the first time. As a model system, silaffin peptides fused with green fluorescent protein (GFP) were immobilized on a gold quartz crystal resonator for quartz crystal microbalances using a self-assembled monolayer. When a solution of silicic acid was supplied, silica particles were successfully deposited on the Au surface, resulting in a significant change in resonance frequency (i.e., signal enhancement) with the silaffin-GFP. However, frequency was not altered when bare GFP was used as a control. The novel peptide enhancer is advantageous because it can be readily and quantitatively conjugated with sensing proteins using recombinant DNA technology. As a proof of concept, this study shows that the silaffin domains can be employed as a novel and efficient biomolecular signal enhancer for gravimetric biosensors.

  1. Signal peptide-dependent inhibition of MHC class I heavy chain translation by rhesus cytomegalovirus.

    Science.gov (United States)

    Powers, Colin J; Früh, Klaus

    2008-10-03

    The US2-11 region of human and rhesus cytomegalovirus encodes a conserved family of glycoproteins that inhibit MHC-I assembly with viral peptides, thus preventing cytotoxic T cell recognition. Since HCMV lacking US2-11 is no longer able to block assembly and transport of MHC-I, we examined whether this is also observed for RhCMV lacking the corresponding region. Unexpectedly, recombinant RhCMV lacking US2-11 was still able to inhibit MHC-I expression in infected fibroblasts, suggesting the presence of an additional MHC-I evasion mechanism. Progressive deletion analysis of RhCMV-specific genomic regions revealed that MHC-I expression is fully restored upon additional deletion of rh178. The protein encoded by this RhCMV-specific open reading frame is anchored in the endoplasmic reticulum membrane. In the presence of rh178, RhCMV prevented MHC-I heavy chain (HC) expression, but did not inhibit mRNA transcription or association of HC mRNA with translating ribosomes. Proteasome inhibitors stabilized a HC degradation intermediate in the absence of rh178, but not in its presence, suggesting that rh178 prevents completion of HC translation. This interference was signal sequence-dependent since replacing the signal peptide with that of CD4 or murine HC rendered human HCs resistant to rh178. We have identified an inhibitor of antigen presentation encoded by rhesus cytomegalovirus unique in both its lack of homology to any other known protein and in its mechanism of action. By preventing signal sequence-dependent HC translocation, rh178 acts prior to US2, US3 and US11 which attack MHC-I proteins after protein synthesis is completed. Rh178 is the first viral protein known to interfere at this step of the MHC-I pathway, thus taking advantage of the conserved nature of HC leader peptides, and represents a new mechanism of translational interference.

  2. Computational Analysis of Signal Peptide-Dependent Secreted Proteins in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Computer based software such as the SignalP v3.0, TargetP vl.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in genome of Saccharomyces cerevisiae. The results showed that 163 proteins were the secreted ones containing signal peptides, and they were secreted via Sec pathway. Among the 163 predicted secreted proteins, the signal peptides of 47 secreted proteins included only the H-domain and C-domain, without N-domain, but the signal peptides of other 116 secreted proteins included all the three domains. There were differences in the constitution of signal peptides between the secreted proteins of S. cerevisiae and of Candida albicans, but the length and amino acids types of their signal peptides were similar in general. Few of the same signal peptides occurred in the secreted proteins of S. cerevisiae genome, and the homology could be compared among the secreted proteins with the same signal peptides. The BLAST 2 SEQUENECES and CLUSTAL W were used to align the two protein sequences and multi-protein sequences, respectively. The alignment result indicated that homology of these sequences with the same signal peptide was very highly conservative in amino acid of complete gene. The effect of the signal peptides in S. cerevisia on expression of foreign eukaryotic secreted proteins is discussed in this paper.

  3. CNP signal peptide (CNPsp in patients with cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Jacqui eLee

    2015-06-01

    Full Text Available We have previously reported that signal peptide fragments of C-type natriuretic peptide (CNP are present in the human circulation. Here, we provide the first preliminary assessment of the potential utility of CNP signal peptide (CNPsp measurement in acute cardiovascular disease. Utilising our specific and sensitive immunoassay, we assessed the potential of CNPsp measurement to assist in the identification of acute coronary syndromes in 494 patients presenting consecutively with chest pain. The diagnostic and prognostic potential of CNPsp was assessed in conjunction with a contemporary clinical troponin I assay, an investigational highly sensitive troponin T assay and NT-proBNP measurement. Utility was assessed via receiver operator curve characteristic analysis.CNPsp did not identify patients with myocardial infarction (MI or those with unstable angina, nor did it assist the diagnostic ability of clinical or investigational troponin measurement. CNPsp levels were significantly elevated in patients presenting with atrial fibrillation (P<0.05 and were significantly lower in those with a history of previous MI (P<0.05. CNPsp could identify those at risk of mortality within 1 year (P<0.05 and also could identify those at risk of death or re-infarction within 1 year (P<0.01. This is the first exploratory report describing the potential of CNPsp measurement in acute cardiovascular disease. Whilst CNPsp does not have utility in acute diagnosis, it may have potential in assisting risk prognosis with respect to mortality and re-infarction.

  4. Vasoactive intestinal peptide signaling axis in human leukemia

    Institute of Scientific and Technical Information of China (English)

    Glenn; Paul; Dorsam; Keith; Benton; Jarrett; Failing; Sandeep; Batra

    2011-01-01

    The vasoactive intestinal peptide (VIP) signaling axis constitutes a master "communication coordinator" between cells of the nervous and immune systems.To date,VIP and its two main receptors expressed in T lymphocytes,vasoactive intestinal peptide receptor (VPAC)1 and VPAC2,mediate critical cellular functions regulating adaptive immunity,including arresting CD4 T cells in G 1 of the cell cycle,protection from apoptosis and a potent chemotactic recruiter of T cells to the mucosa associated lymphoid compartment of the gastrointestinal tissues.Since the discovery of VIP in 1970,followed by the cloning of VPAC1 and VPAC2 in the early 1990s,this signaling axis has been associated with common human cancers,including leukemia.This review highlights the present day knowledge of the VIP ligand and its receptor expression profile in T cell leukemia and cell lines.Also,there will be a discussion describing how the anti-leukemic DNA binding transcription factor,Ikaros,regulates VIP receptor expression in primary human CD4 T lymphocytes and T cell lymphoblastic cell lines (e.g.Hut-78).Lastly,future goals will be mentioned that are expected to uncover the role of how the VIP signaling axis contributes to human leukemogenesis,and to establish whether the VIP receptor signature expressed by leukemic blasts can provide therapeutic and/or diagnostic information.

  5. Improved secretion of Candida antarctica lipase B with its native signal peptide in Pichia pastoris.

    Science.gov (United States)

    Vadhana, Ashok Kumar Prasanna; Samuel, Premsingh; Berin, Ronald M; Krishna, Jayachandran; Kamatchi, Kavitha; Meenakshisundaram, Sankaranarayanan

    2013-03-05

    Secretion efficiency of the 85-amino acid Sacchromyces cerevisiae alpha signal peptide and the 25-amino acid Candida antarctica lipase B signal (nsB) peptide were compared. Three reporter proteins used for the study are C. antarctica lipase A (CalA), lipase B (CalB) and hGMCSF. The copy number of recombinant α-CalB and nsB-CalB clones was determined by qPCR and clones with equivalent gene copies were used for comparative analysis. About threefold increased CalB production corresponding to an activity of 480 U ml(-1) was obtained with its native signal peptide, whereas with the alpha signal peptide the maximum activity was 160 U ml(-1). Also, CalB was secreted as a mature protein with native N-terminus when fused to its own signal peptide, while unprocessed CalB with N-terminal extension was detected with the alpha signal peptide. Real time PCR analysis of CalB strains indicated that the difference in protein expression was not at the transcriptional level. The nsB signal sequence was also effective in secreting CalA enzyme and its secretion efficiency was on par with the alpha signal sequence. Further, hGMCSF fused inframe with the nsB signal peptide was also efficiently secreted into the medium. These results indicate that the nsB signal peptide can be a better alternative to alpha signal peptide for heterologous protein expression in Pichia pastoris.

  6. Signal-CF: a subsite-coupled and window-fusing approach for predicting signal peptides.

    Science.gov (United States)

    Chou, Kuo-Chen; Shen, Hong-Bin

    2007-06-01

    We have developed an automated method for predicting signal peptide sequences and their cleavage sites in eukaryotic and bacterial protein sequences. It is a 2-layer predictor: the 1st-layer prediction engine is to identify a query protein as secretory or non-secretory; if it is secretory, the process will be automatically continued with the 2nd-layer prediction engine to further identify the cleavage site of its signal peptide. The new predictor is called Signal-CF, where C stands for "coupling" and F for "fusion", meaning that Signal-CF is formed by incorporating the subsite coupling effects along a protein sequence and by fusing the results derived from many width-different scaled windows through a voting system. Signal-CF is featured by high success prediction rates with short computational time, and hence is particularly useful for the analysis of large-scale datasets. Signal-CF is freely available as a web-server at http://chou.med.harvard.edu/bioinf/Signal-CF/ or http://202.120.37.186/bioinf/Signal-CF/.

  7. Signal peptide-dependent inhibition of MHC class I heavy chain translation by rhesus cytomegalovirus.

    Directory of Open Access Journals (Sweden)

    Colin J Powers

    Full Text Available The US2-11 region of human and rhesus cytomegalovirus encodes a conserved family of glycoproteins that inhibit MHC-I assembly with viral peptides, thus preventing cytotoxic T cell recognition. Since HCMV lacking US2-11 is no longer able to block assembly and transport of MHC-I, we examined whether this is also observed for RhCMV lacking the corresponding region. Unexpectedly, recombinant RhCMV lacking US2-11 was still able to inhibit MHC-I expression in infected fibroblasts, suggesting the presence of an additional MHC-I evasion mechanism. Progressive deletion analysis of RhCMV-specific genomic regions revealed that MHC-I expression is fully restored upon additional deletion of rh178. The protein encoded by this RhCMV-specific open reading frame is anchored in the endoplasmic reticulum membrane. In the presence of rh178, RhCMV prevented MHC-I heavy chain (HC expression, but did not inhibit mRNA transcription or association of HC mRNA with translating ribosomes. Proteasome inhibitors stabilized a HC degradation intermediate in the absence of rh178, but not in its presence, suggesting that rh178 prevents completion of HC translation. This interference was signal sequence-dependent since replacing the signal peptide with that of CD4 or murine HC rendered human HCs resistant to rh178. We have identified an inhibitor of antigen presentation encoded by rhesus cytomegalovirus unique in both its lack of homology to any other known protein and in its mechanism of action. By preventing signal sequence-dependent HC translocation, rh178 acts prior to US2, US3 and US11 which attack MHC-I proteins after protein synthesis is completed. Rh178 is the first viral protein known to interfere at this step of the MHC-I pathway, thus taking advantage of the conserved nature of HC leader peptides, and represents a new mechanism of translational interference.

  8. Optimization of heavy chain and light chain signal peptides for high level expression of therapeutic antibodies in CHO cells.

    Directory of Open Access Journals (Sweden)

    Ryan Haryadi

    Full Text Available Translocation of a nascent protein from the cytosol into the ER mediated by its signal peptide is a critical step in protein secretion. The aim of this work was to develop a platform technology to optimize the signal peptides for high level production of therapeutic antibodies in CHO cells. A database of signal peptides from a large number of human immunoglobulin (Ig heavy chain (HC and kappa light chain (LC was generated. Most of the HC signal peptides contain 19 amino acids which can be divided into three domains and the LC signal peptides contain 22 amino acids. The signal peptides were then clustered according to sequence similarity. Based on the clustering, 8 HC and 2 LC signal peptides were analyzed for their impacts on the production of 5-top selling antibody therapeutics, namely, Herceptin, Avastin, Remicade, Rituxan, and Humira. The best HC and LC signal peptides for producing these 5 antibodies were identified. The optimized signal peptides for Rituxan is 2-fold better compared to its native signal peptides which are available in the public database. Substitution of a single amino acid in the optimized HC signal peptide for Avastin reduced its production significantly. Mass spectrometry analyses revealed that all optimized signal peptides are accurately removed in the mature antibodies. The results presented in this report are particularly important for the production of these 5 antibodies as biosimilar drugs. They also have the potential to be the best signal peptides for the production of new antibodies in CHO cells.

  9. Improved prediction of signal peptides: SignalP 3.0

    DEFF Research Database (Denmark)

    Bendtsen, Jannick Dyrløv; Nielsen, Henrik; von Heijne, G.

    2004-01-01

    P version 2. In version 3, correctness of the cleavage site predictions has increased notably for all three organism groups, eukaryotes, Gram-negative and Gram-positive bacteria. The accuracy of cleavage site prediction has increased in the range 6-17% over the previous version, whereas the signal peptide...... discrimination improvement is mainly due to the elimination of false-positive predictions, as well as the introduction of a new discrimination score for the neural network. The new method has been benchmarked against other available methods. Predictions can be made at the publicly available web server http://www.cbs.dtu.dk/services/SignaIP/....

  10. Novel role for endogenous mitochondrial formylated peptide-driven formyl peptide receptor 1 signalling in acute respiratory distress syndrome.

    Science.gov (United States)

    Dorward, David A; Lucas, Christopher D; Doherty, Mary K; Chapman, Gavin B; Scholefield, Emma J; Conway Morris, Andrew; Felton, Jennifer M; Kipari, Tiina; Humphries, Duncan C; Robb, Calum T; Simpson, A John; Whitfield, Phillip D; Haslett, Christopher; Dhaliwal, Kevin; Rossi, Adriano G

    2017-10-01

    Acute respiratory distress syndrome (ARDS) is an often fatal neutrophil-dominant lung disease. Although influenced by multiple proinflammatory mediators, identification of suitable therapeutic candidates remains elusive. We aimed to delineate the presence of mitochondrial formylated peptides in ARDS and characterise the functional importance of formyl peptide receptor 1 (FPR1) signalling in sterile lung inflammation. Mitochondrial formylated peptides were identified in bronchoalveolar lavage fluid (BALF) and serum of patients with ARDS by liquid chromatography-tandem mass spectrometry. In vitro, human neutrophils were stimulated with mitochondrial formylated peptides and their effects assessed by flow cytometry and chemotaxis assay. Mouse lung injury was induced by mitochondrial formylated peptides or hydrochloric acid. Bone marrow chimeras determined the contribution of myeloid and parenchymal FPR1 to sterile lung inflammation. Mitochondrial formylated peptides were elevated in BALF and serum from patients with ARDS. These peptides drove neutrophil activation and chemotaxis through FPR1-dependent mechanisms in vitro and in vivo. In mouse lung injury, inflammation was attenuated in Fpr1-/- mice, effects recapitulated by a pharmacological FPR1 antagonist even when administered after the onset of injury. FPR1 expression was present in alveolar epithelium and chimeric mice demonstrated that both myeloid and parenchymal FPR1 contributed to lung inflammation. We provide the first definitive evidence of mitochondrial formylated peptides in human disease and demonstrate them to be elevated in ARDS and important in a mouse model of lung injury. This work reveals mitochondrial formylated peptide FPR1 signalling as a key driver of sterile acute lung injury and a potential therapeutic target in ARDS. 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/.

  11. Signal peptide peptidase (SPP) assembles with substrates and misfolded membrane proteins into distinct oligomeric complexes

    Science.gov (United States)

    Schrul, Bianca; Kapp, Katja; Sinning, Irmgard; Dobberstein, Bernhard

    2010-01-01

    SPP (signal peptide peptidase) is an aspartyl intramembrane cleaving protease, which processes a subset of signal peptides, and is linked to the quality control of ER (endoplasmic reticulum) membrane proteins. We analysed SPP interactions with signal peptides and other membrane proteins by co-immunoprecipitation assays. We found that SPP interacts specifically and tightly with a large range of newly synthesized membrane proteins, including signal peptides, preproteins and misfolded membrane proteins, but not with all co-expressed type II membrane proteins. Signal peptides are trapped by the catalytically inactive SPP mutant SPPD/A. Preproteins and misfolded membrane proteins interact with both SPP and the SPPD/A mutant, and are not substrates for SPP-mediated intramembrane proteolysis. Proteins interacting with SPP are found in distinct complexes of different sizes. A signal peptide is mainly trapped in a 200 kDa SPP complex, whereas a preprotein is predominantly found in a 600 kDa SPP complex. A misfolded membrane protein is detected in 200, 400 and 600 kDa SPP complexes. We conclude that SPP not only processes signal peptides, but also collects preproteins and misfolded membrane proteins that are destined for disposal. PMID:20196774

  12. Practical Parallel Rendering

    CERN Document Server

    Chalmers, Alan

    2002-01-01

    Meeting the growing demands for speed and quality in rendering computer graphics images requires new techniques. Practical parallel rendering provides one of the most practical solutions. This book addresses the basic issues of rendering within a parallel or distributed computing environment, and considers the strengths and weaknesses of multiprocessor machines and networked render farms for graphics rendering. Case studies of working applications demonstrate, in detail, practical ways of dealing with complex issues involved in parallel processing.

  13. Prediction of Signal Peptide Cleavage Sites with Subsite-Coupled and Template Matching Fusion Algorithm.

    Science.gov (United States)

    Zhang, Shao-Wu; Zhang, Ting-He; Zhang, Jun-Nan; Huang, Yufei

    2014-03-01

    Fast and effective prediction of signal peptides (SP) and their cleavage sites is of great importance in computational biology. The approaches developed to predict signal peptide can be roughly divided into machine learning based, and sliding windows based. In order to further increase the prediction accuracy and coverage of organism for SP cleavage sites, we propose a novel method for predicting SP cleavage sites called Signal-CTF that utilizes machine learning and sliding windows, and is designed for N-termial secretory proteins in a large variety of organisms including human, animal, plant, virus, bacteria, fungi and archaea. Signal-CTF consists of three distinct elements: (1) a subsite-coupled and regularization function with a scaled window of fixed width that selects a set of candidates of possible secretion-cleavable segment for a query secretory protein; (2) a sum fusion system that integrates the outcomes from aligning the cleavage site template sequence with each of the aforementioned candidates in a scaled window of fixed width to determine the best candidate cleavage sites for the query secretory protein; (3) a voting system that identifies the ultimate signal peptide cleavage site among all possible results derived from using scaled windows of different width. When compared with Signal-3L and SignalP 4.0 predictors, the prediction accuracy of Signal-CTF is 4-12 %, 10-25 % higher than that of Signal-3L for human, animal and eukaryote, and SignalP 4.0 for eukaryota, Gram-positive bacteria and Gram-negative bacteria, respectively. Comparing with PRED-SIGNAL and SignalP 4.0 predictors on the 32 archaea secretory proteins of used in Bagos's paper, the prediction accuracy of Signal-CTF is 12.5 %, 25 % higher than that of PRED-SIGNAL and SignalP 4.0, respectively. The predicting results of several long signal peptides show that the Signal-CTF can better predict cleavage sites for long signal peptides than SignalP, Phobius, Philius, SPOCTOPUS, Signal

  14. Recognition of signal peptide by protein translocation machinery in middle silk gland of silkworm Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    Xiuyang Guo; Yi Zhang; Xue Zhang; Shengpeng Wang; Changde Lu

    2008-01-01

    To investigate the functions of signal peptide in protein secretion in the middle silk gland of silkworm Bombyx mori,a series of recombinant Autographa californica multiple nucleopolyhedroviruses containing enhanced green fluorescent protein (egfp) gene,led by sericin-1 promoter and mutated signal peptide coding sequences,were constructed by region-deletions or single amino acid residue deletions.The recombinant Autographa californica multiple nucleopolyhedroviruses were injected into the hemocoele of newly ecdysed fifth-instar silkworm larvae.The expression and secretion of EGFP in the middle silk gland were examined by fluorescence microscopy and Western blot analysis.Results showed that even with a large part (up to 14 amino acid residues) of the ser-1 signal peptide deleted,the expressed EGFP could still be secreted into the cavity of the silk gland.Western blot analysis showed that shortening of the signal peptide from the C-terminal suppressed the maturation of pro-EGFP to EGFP.When 8 amino acid residues were deleted from the C-terminal of the signal peptide (mutant 13 aa),the secretion of EGFP was incomplete,implicating the importance of proper coupling of the h-region and c-region.The deletion of amino acid residue(s) in the h-region did not affect the secretion of EGFP,indicating that the recognition of signal peptide by translocation machinery was mainly by a structural domain,but not by special amino acid residue(s).Furthermore,the deletion of Arg2 or replacement with Asp in the n-region of the signal peptide did not influence secretion of EGFP,suggesting that a positive charge is not crucial.

  15. Atypical signaling and functional desensitization response of MAS receptor to peptide ligands.

    Science.gov (United States)

    Tirupula, Kalyan C; Desnoyer, Russell; Speth, Robert C; Karnik, Sadashiva S

    2014-01-01

    MAS is a G protein-coupled receptor (GPCR) implicated in multiple physiological processes. Several physiological peptide ligands such as angiotensin-(1-7), angiotensin fragments and neuropeptide FF (NPFF) are reported to act on MAS. Studies of conventional G protein signaling and receptor desensitization upon stimulation of MAS with the peptide ligands are limited so far. Therefore, we systematically analyzed G protein signals activated by the peptide ligands. MAS-selective non-peptide ligands that were previously shown to activate G proteins were used as controls for comparison on a common cell based assay platform. Activation of MAS by the non-peptide agonist (1) increased intracellular calcium and D-myo-inositol-1-phosphate (IP1) levels which are indicative of the activation of classical Gαq-phospholipase C signaling pathways, (2) decreased Gαi mediated cAMP levels and (3) stimulated Gα12-dependent expression of luciferase reporter. In all these assays, MAS exhibited strong constitutive activity that was inhibited by the non-peptide inverse agonist. Further, in the calcium response assay, MAS was resistant to stimulation by a second dose of the non-peptide agonist after the first activation has waned suggesting functional desensitization. In contrast, activation of MAS by the peptide ligand NPFF initiated a rapid rise in intracellular calcium with very weak IP1 accumulation which is unlike classical Gαq-phospholipase C signaling pathway. NPFF only weakly stimulated MAS-mediated activation of Gα12 and Gαi signaling pathways. Furthermore, unlike non-peptide agonist-activated MAS, NPFF-activated MAS could be readily re-stimulated the second time by the agonists. Functional assays with key ligand binding MAS mutants suggest that NPFF and non-peptide ligands bind to overlapping regions. Angiotensin-(1-7) and other angiotensin fragments weakly potentiated an NPFF-like calcium response at non-physiological concentrations (≥100 µM). Overall, our data suggest

  16. The sensing of bacteria: emerging principles for the detection of signal sequences by formyl peptide receptors.

    Science.gov (United States)

    Bufe, Bernd; Zufall, Frank

    2016-06-01

    The ability to detect specific chemical signatures released by bacteria and other microorganisms is a fundamental feature of immune defense against pathogens. There is increasing evidence that chemodetection of such microorganism-associated molecular patterns (MAMPs) occurs at many places in the body including specific sets of chemosensory neurons in the mammalian nose. Formyl peptide receptors (FPRs) are a unique family of G protein-coupled receptors (GPCRs) that can detect the presence of bacteria and function as chemotactic receptors. Here, we highlight the recent discovery of a vast family of natural FPR agonists, the bacterial signal peptides (or signal sequences), thus providing new insight into the molecular mechanisms of bacterial sensing by human and mouse FPRs. Signal peptides in bacteria are formylated, N-terminal protein signatures required for directing the transfer of proteins through the plasma membrane. After their cleavage and release, signal peptides are available for FPR detection and thus provide a previously unrecognized MAMP. With over 170 000 predicted sequences, bacterial signal peptides represent one of the largest families of GPCR ligands and one of the most complex classes of natural activators of the innate immune system. By recognizing a conserved three-dimensional peptide motif, FPRs employ an unusual detection mechanism that combines structural promiscuity with high specificity and sensitivity, thus solving the problem of detecting thousands of distinct sequences yet maintaining selectivity. How signal peptides are released by bacteria and sensed by GPCRs and how these processes shape the responses of other cells and whole organisms represents an important topic for future research.

  17. Peptide nanowires for coordination and signal transduction of peroxidase biosensors to carbon nanotube electrode arrays.

    Science.gov (United States)

    Yeh, J I; Lazareck, A; Kim, J Ho; Xu, J; Du, S

    2007-11-30

    A strategy of metallizing peptides to serve as conduits of electronic signals that bridge between a redox enzyme and a carbon-nanotube electrode has been developed with enhanced results. In conjunction, a protocol to link the biological elements to the tips of carbon nanotubes has been developed to optimize contact and geometry between the redox enzyme and the carbon nanotube electrode array. A peptide nanowire of 33 amino acids, comprised of a leucine zipper motif, was mutated to bind divalent metals, conferring conductivity into the peptide. Reaction between a thiolate of the peptide with the sulfenic acid of the NADH peroxidase enzyme formed a peptide-enzyme assembly that are fully primed to transduce electrons out of the enzyme active site to an electrode. Scanning electron microscopy shows immobilization and linking of the assembly specifically to the tips of carbon nanotube electrodes, as designed. Isothermal titration calorimetry and mass spectrometry indicate a binding stoichiometry of at least three metals bound per peptide strand. Overall, these results highlight the gain that can be achieved when the signal tranducing units of a biosensor are aligned through directed peptide chemistry.

  18. Amplification of single molecule translocation signal using β-strand peptide functionalized nanopores.

    Science.gov (United States)

    Liebes-Peer, Yael; Rapaport, Hanna; Ashkenasy, Nurit

    2014-07-22

    Changes in ionic current flowing through nanopores due to binding or translocation of single biopolymer molecules enable their detection and characterization. It is, however, much more challenging to detect small molecules due to their rapid and small signal signature. Here we demonstrate the use of de novo designed peptides for functionalization of nanopores that enable the detection of a small analytes at the single molecule level. The detection relies on cooperative peptide conformational change that is induced by the binding of the small molecule to a receptor domain on the peptide. This change results in alteration of the nanopore effective diameter and hence induces current perturbation signal. On the basis of this approach, we demonstrate here the detection of diethyl 4-nitrophenyl phosphate (paraoxon), a poisonous organophosphate molecule. Paraoxon binding is induced by the incorporation of the catalytic triad of acetylcholine esterase in the hydrophilic domain of a short amphiphilic peptide and promotes β-sheet assembly of the peptide both in solution and for peptide molecules immobilized on solid surfaces. Nanopores coated with this peptide allowed the detection of paraoxon at the single molecule level revealing two binding arrangements. This unique approach, hence, provides the ability to study interactions of small molecules with the corresponding engineered receptors at the single molecule level. Furthermore, the suggested versatile platform may be used for the development of highly sensitive small analytes sensors.

  19. Stringency of bacterial prolipoprotein signal peptidase (LspA) in recognition of signal peptides - Structure-function correlation.

    Science.gov (United States)

    Sangith, Nikhil; Sankaran, Krishnan

    2017-06-24

    Bacterial lipid modification of proteins is an essential post-translational event committed by Phosphatidylglycerol: prolipoprotein diacylglyceryl transferase (Lgt) by catalysing diacyglyceryl transfer from Phosphatidylglycerol to cysteine present in the characteristic 'lipobox' ([LVI] ((-3)) [ASTVI] ((-2)) [GAS] ((-1)) C ((+1))) of prolipoprotein signal peptides. This is then followed by the cleavage of the signal peptide by lipoprotein-specific signal peptidase (LspA). It had been known for long that threonine at the -1 position allows diacylglyceryl modification by Lgt, but not signal peptide cleavage by LspA. We have addressed this unexplained stringency by computational analysis of the recently published 3D structure of LspA with its competitive inhibitor as well as transition state analogue, globomycin using PyMoL viewing tool and VADAR (Volume, Area, Dihedral Angle Reporter) web server. The propensity to form hydrogen bond (2.9a) between the hydroxyl group of threonine (not possible with serine) and the NH of the lipid-modified cysteine, possible only in the transition state, will prevent the protonation of NH of the leaving peptide and therefore its cleavage. This knowledge could be useful for designing inhibitors of this essential pathway in bacteria or for engineering LspA. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. A Genetic Programming Method for the Identification of Signal Peptides and Prediction of Their Cleavage Sites

    Directory of Open Access Journals (Sweden)

    David Lennartsson

    2004-01-01

    Full Text Available A novel approach to signal peptide identification is presented. We use an evolutionary algorithm for automatic evolution of classification programs, so-called programmatic motifs. The variant of evolutionary algorithm used is called genetic programming where a population of solution candidates in the form of full computer programs is evolved, based on training examples consisting of signal peptide sequences. The method is compared with a previous work using artificial neural network (ANN approaches. Some advantages compared to ANNs are noted. The programmatic motif can perform computational tasks beyond that of feed-forward neural networks and has also other advantages such as readability. The best motif evolved was analyzed and shown to detect the h-region of the signal peptide. A powerful parallel computer cluster was used for the experiment.

  1. Signal Peptide of Potato PinⅡ Enhances the Expression of Cry1Ac in Transgenic Tobacco

    Institute of Scientific and Technical Information of China (English)

    Yun-Jun LIU; Yuan YUAN; Jun ZHENG; Ya-Zhong TAO; Zhi-Gang DONG; Jian-Hua WANG; Guo-Ying WANG

    2004-01-01

    The modified Cry1Ac was expressed in transgenic tobacco plants.To allow secretion of the Cry1Ac protein into the intercellular space,the signal peptide sequence of potato proteinase inhibitor Ⅱ(pinⅡ)was N-terminally fused to the CrylAc encoding region.Expression of Cry1Ac in transgenic tobacco plants was assayed with ELISA.The results showed that pinⅡ signal peptide sequence enhanced the expression of Cry 1 Ac protein and led to the secretion of the Cry 1Ac protein in transgenic tobacco plants.GFP gene was also fused to the signal peptide sequence and transformed to tobacco.The results of fluorescent detection showed that GFP had localized in the apoplast of transgenic plants.

  2. Advantages of combined transmembrane topology and signal peptide prediction--the Phobius web server

    DEFF Research Database (Denmark)

    Käll, Lukas; Krogh, Anders; Sonnhammer, Erik L L

    2007-01-01

    predicted transmembrane topologies overlap. This impairs predictions of 5-10% of the proteome, hence this is an important issue in protein annotation. To address this problem, we previously designed a hidden Markov model, Phobius, that combines transmembrane topology and signal peptide predictions....... The method makes an optimal choice between transmembrane segments and signal peptides, and also allows constrained and homology-enriched predictions. We here present a web interface (http://phobius.cgb.ki.se and http://phobius.binf.ku.dk) to access Phobius. Udgivelsesdato: 2007-Jul...

  3. Biased signaling by peptide agonists of protease activated receptor 2.

    Science.gov (United States)

    Jiang, Yuhong; Yau, Mei-Kwan; Kok, W Mei; Lim, Junxian; Wu, Kai-Chen; Liu, Ligong; Hill, Timothy A; Suen, Jacky Y; Fairlie, David P

    2017-02-07

    Protease activated receptor 2 (PAR2) is associated with metabolism, obesity, inflammatory, respiratory and gastrointestinal disorders, pain, cancer and other diseases. The extracellular N-terminus of PAR2 is a common target for multiple proteases, which cleave it at different sites to generate different N-termini that activate different PAR2-mediated intracellular signaling pathways. There are no synthetic PAR2 ligands that reproduce the same signaling profiles and potencies as proteases. Structure-activity relationships here for 26 compounds spanned a signaling bias over 3 log units, culminating in three small ligands as biased agonist tools for interrogating PAR2 functions. DF253 (2f-LAAAAI-NH2) triggered PAR2-mediated calcium release (EC50 2 μM) but not ERK1/2 phosphorylation (EC50 > 100 μM) in CHO cells transfected with hPAR2. AY77 (Isox-Cha-Chg-NH2) was a more potent calcium-biased agonist (EC50 40 nM, Ca2+; EC50 2 μM, ERK1/2), while its analogue AY254 (Isox-Cha-Chg-A-R-NH2) was an ERK-biased agonist (EC50 2 nM, ERK1/2; EC50 80 nM, Ca2+). Signaling bias led to different functional responses in human colorectal carcinoma cells (HT29). AY254, but not AY77 or DF253, attenuated cytokine-induced caspase 3/8 activation, promoted scratch-wound healing and induced IL-8 secretion, all via PAR2-ERK1/2 signaling. Different ligand components were responsible for different PAR2 signaling and functions, clues that can potentially lead to drugs that modulate different pathway-selective cellular and physiological responses.

  4. The neuroendocrine genome : neuropeptides and related signaling peptides

    NARCIS (Netherlands)

    Burbach, JPH

    2016-01-01

    Neuropeptides are small proteinaceous substances which are produced, stored, and released through the regulated secretory route by neurons and act on neural substrates. They represent the most diverse group of signaling molecules in the nervous system. In mammals there are 200–300 neuropeptides know

  5. The neuroendocrine genome : neuropeptides and related signaling peptides

    NARCIS (Netherlands)

    Burbach, JPH|info:eu-repo/dai/nl/068420404

    2016-01-01

    Neuropeptides are small proteinaceous substances which are produced, stored, and released through the regulated secretory route by neurons and act on neural substrates. They represent the most diverse group of signaling molecules in the nervous system. In mammals there are 200–300 neuropeptides know

  6. Drosophila neprilysins control insulin signaling and food intake via cleavage of regulatory peptides

    DEFF Research Database (Denmark)

    Hallier, Benjamin; Schiemann, Ronja; Cordes, Eva;

    2016-01-01

    Insulin and IGF signaling are critical to numerous developmental and physiological processes, with perturbations being pathognomonic of various diseases, including diabetes. Although the functional roles of the respective signaling pathways have been extensively studied, the control of insulin...... production and release is only partially understood. Herein, we show that in Drosophila expression of insulin-like peptides is regulated by neprilysin activity. Concomitant phenotypes of altered neprilysin expression included impaired food intake, reduced body size, and characteristic changes...

  7. Signal peptide replacements enhance expression and secretion of hepatitis C virus envelope glycoproteins

    Institute of Scientific and Technical Information of China (English)

    Bo Wen; Yao Deng; Jie Guan; Weizheng Yan; Yue Wang; Wenjie Tan; Jimin Gao

    2011-01-01

    A large number of researches focused on glycoproteins E1 and E2 of hepatitis C virus (HCV) aimed at the develop-ment of anti-HCV vaccines and inhibitors. Enhancement of E1/E2 expression and secretion is critical for the charac-terization of these glycoproteins and thus for subunit vaccine development. In this study, we designed and syn-thesized three signal peptide sequences based on onlineprograms SignalP, TargetP, and PSORT, then removed and replaced the signal peptide preceding E1/E2 by over-lapping the polymerase chain reaction method. We assessed the effect of this alteration on E1/E2 expression and secretion in mammalian cells, using western blot analysis, dot blot, and Galanthus nivalis agglutinin iectin capture enzyme immunoassay. Replacing the peptides pre-ceding E1 and E2 with the signal peptides of the tissue plasminogen activator and Gaussia luciferase resulted in maximum enhancement of E1/E2 expression and secretion of E1 in mammalian cells, without altering glycosylation.Such an advance would help to facilitate both the research of E1/E2 biology and the development of an effective HCV subunit vaccine. The strategy used in this study could be applied to the expression and production of other glyco-proteins in mammalian ceil line-based systems.

  8. Structural diversity in twin-arginine signal peptide-binding proteins

    NARCIS (Netherlands)

    Maillard, J.; Spronk, C.A.E.M.; Buchanan, G.; Lyall, V.; Richardson, D.J.; Palmer, T.; Vuister, G.W.; Sargent, F.

    2007-01-01

    The twin-arginine transport (Tat) system is dedicated to the translocation of folded proteins across the bacterial cytoplasmic membrane. Proteins are targeted to the Tat system by signal peptides containing a twin-arginine motif. In Escherichia coli, many Tat substrates bind redox-active cofactors i

  9. Video-based rendering

    CERN Document Server

    Magnor, Marcus A

    2005-01-01

    Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as computer games, special effects, and interactive TV. This book offers an in-depth introduction to video-based rendering, a rapidly developing new interdisciplinary topic employing techniques from computer graphics, computer vision, and telecommunication en

  10. 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

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

    Science.gov (United States)

    Cattaneo, Fabio; Parisi, Melania; Ammendola, Rosario

    2013-01-01

    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 (Prp)106–126, 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 agonists. PMID

  12. A neural network method for identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Engelbrecht, Jacob; Brunak, Søren;

    1997-01-01

    We have developed a new method for the identication of signal peptides and their cleavage sites based on neural networks trained on separate sets of prokaryotic and eukaryotic sequences. The method performs signicantly better than previous prediction schemes, and can easily be applied to genome-w......-wide data sets. Discrimination between cleaved signal peptides and uncleaved N-terminal signal-anchor sequences is also possible, though with lower precision....

  13. High-resolution mass spectrometry driven discovery of peptidic danger signals in insect immunity.

    Science.gov (United States)

    Berisha, Arton; Mukherjee, Krishnendu; Vilcinskas, Andreas; Spengler, Bernhard; Römpp, Andreas

    2013-01-01

    The 'danger model' is an alternative concept for immune response postulating that the immune system reacts to entities that do damage (danger associated molecular patterns, DAMP) and not only to entities that are foreign (pathogen-associated molecular patterns, PAMP) as proposed by classical immunology concepts. In this study we used Galleria mellonella to validate the danger model in insects. Hemolymph of G. mellonella was digested with thermolysin (as a representative for virulence-associated metalloproteinases produced by humanpathogens) followed by chromatographic fractionation. Immune-stimulatory activity was tested by measuring lysozyme activity with the lytic zone assays against Micrococcus luteus cell wall components. Peptides were analyzed by nano-scale liquid chromatography coupled to high-resolution Fourier transform mass spectrometers. Addressing the lack of a genome sequence we complemented the rudimentary NCBI protein database with a recently established transcriptome and de novo sequencing methods for peptide identification. This approach led to identification of 127 peptides, 9 of which were identified in bioactive fractions. Detailed MS/MS experiments in comparison with synthetic analogues confirmed the amino acid sequence of all 9 peptides. To test the potential of these putative danger signals to induce immune responses we injected the synthetic analogues into G. mellonella and monitored the anti-bacterial activity against living Micrococcus luteus. Six out of 9 peptides identified in the bioactive fractions exhibited immune-stimulatory activity when injected. Hence, we provide evidence that small peptides resulting from thermolysin-mediated digestion of hemolymph proteins function as endogenous danger signals which can set the immune system into alarm. Consequently, our study indicates that the danger model also plays a role in insect immunity.

  14. Conservation of capa peptide-induced nitric oxide signalling in Diptera.

    Science.gov (United States)

    Pollock, Valerie P; McGettigan, James; Cabrero, Pablo; Maudlin, Ian M; Dow, Julian A T; Davies, Shireen-A

    2004-11-01

    In D. melanogaster Malpighian (renal) tubules, the capa peptides stimulate production of nitric oxide (NO) and guanosine 3', 5'-cyclic monophosphate (cGMP), resulting in increased fluid transport. The roles of NO synthase (NOS), NO and cGMP in capa peptide signalling were tested in several other insect species of medical relevance within the Diptera (Aedes aegypti, Anopheles stephensi and Glossina morsitans) and in one orthopteran out-group, Schistocerca gregaria. NOS immunoreactivity was detectable by immunocytochemistry in tubules from all species studied. D. melanogaster, A. aegypti and A. stephensi express NOS in only principal cells, whereas G. morsitans and S. gregaria show more general NOS expression in the tubule. Measurement of associated NOS activity (NADPH diaphorase) shows that both D. melanogaster capa-1 and the two capa peptides encoded in the A. gambiae genome, QGLVPFPRVamide (AngCAPA-QGL) and GPTVGLFAFPRVamide (AngCAPA-GPT), all stimulate NOS activity in D. melanogaster, A. aegypti, A. stephensi and G. morsitans tubules but not in S. gregaria. Furthermore, capa-stimulated NOS activity in all the Diptera was inhibited by the NOS inhibitor l-NAME. All capa peptides stimulate an increase in cGMP content across the dipteran species, but not in the orthopteran S. gregaria. Similarly, all capa peptides tested stimulate fluid secretion in D. melanogaster, A. aegypti, A. stephensi and G. morsitans tubules but are either without effect or are inhibitory on S. gregaria. Consistent with these results, the Drosophila capa receptor was shown to be expressed in Drosophila tubules, and its closest Anopheles homologue was shown to be expressed in Anopheles tubules. Thus, we provide the first demonstration of physiological roles for two putative A. gambiae neuropeptides. We also demonstrate neuropeptide modulation of fluid secretion in tsetse tubule for the first time. Finally, we show the generality of capa peptide action, to stimulate NO/cGMP signalling and

  15. Advances in peptidic and peptidomimetic-based approaches to inhibit STAT signaling in human diseases.

    Science.gov (United States)

    Szelag, Malgorzata; Wesoly, Joanna; Bluyssen, Hans A R

    2016-01-01

    STATs promote fundamental cellular processes, marking them as convergence points of many oncogenic and inflammatory pathways. Therefore, aberrant activation of STAT signaling is implicated in a plethora of human diseases, like cancer, inflammation and auto-immunity. Identification of STAT-specific inhibitors is the topic of great practical importance, and various inhibitory strategies are being pursued. An interesting approach includes peptides and peptide-like biopolymers, because they allow the manipulation of STAT signaling without the transfer of genetic material. Phosphopeptides and peptidomimetics directly target STATs by inhibiting dimerization. Despite that a large number of efficient peptide- based STAT3-specific inhibitors have been reported to date, none of them was able to meet the pharmacological requirements to serve as a potent anti-cancer drug. The existing limitations, like metabolic instability and poor cell permeability during in vivo tests, excluded these macromolecules from further clinical development. To overcome these liabilities, in the last five years many advances have been made to develop next generation STAT-specific inhibitors. Here we discuss the pitfalls of current STAT inhibitory strategies and review the progress on the development of peptide-like prodrugs directly targeting STATs. Novel strategies involve screening of high-complexity libraries of random peptides, as specific STAT3 or STAT5 DNA-binding inhibitors, to construct cell permeable peptide aptamers and aptides for cancer therapy. Another new direction is synthesis of negative dominant α-helical mimetics of the STAT3 N-domain, preventing oligomerization on DNA. Moreover, construction of phosphopeptide conjugates with molecules mediating cellular uptake offers new therapeutic possibilities in treatment of cancer, asthma and allergy.

  16. A Role of TDIF Peptide Signaling in Vascular Cell Differentiation is Conserved Among Euphyllophytes.

    Science.gov (United States)

    Hirakawa, Yuki; Bowman, John L

    2015-01-01

    Peptide signals mediate a variety of cell-to-cell communication crucial for plant growth and development. During Arabidopsis thaliana vascular development, a CLE (CLAVATA3/EMBRYO SURROUNDING REGION-related) family peptide hormone, TDIF (tracheary element differentiation inhibitory factor), regulates procambial cell fate by its inhibitory activity on xylem differentiation. To address if this activity is conserved among vascular plants, we performed comparative analyses of TDIF signaling in non-flowering vascular plants (gymnosperms, ferns and lycophytes). We identified orthologs of TDIF/CLE as well as its receptor TDR/PXY (TDIF RECEPTOR/PHLOEM INTERCALATED WITH XYLEM) in Ginkgo biloba, Adiantum aethiopicum, and Selaginella kraussiana by RACE-PCR. The predicted TDIF peptide sequences in seed plants and ferns were identical to that of A. thaliana TDIF. We examined the effects of exogenous CLE peptide-motif sequences of TDIF in these species. We found that liquid culturing of dissected leaves or shoots was useful for examining TDIF activity during vascular development. TDIF treatment suppressed xylem/tracheary element differentiation of procambial cells in G. biloba and A. aethiopicum leaves. In contrast, neither TDIF nor putative endogenous TDIF inhibited xylem differentiation in developing shoots and rhizophores of S. kraussiana. These data suggest that activity of TDIF in vascular development is conserved among extant euphyllophytes. In addition to the conserved function, via liquid culturing of its bulbils, we found a novel inhibitory activity on root growth in the fern Asplenium × lucrosum suggesting lineage-specific co-option of peptide signaling occurred during the evolution of vascular plant organs.

  17. A role of TDIF peptide signaling in vascular cell differentiation is conserved among euphyllophytes

    Directory of Open Access Journals (Sweden)

    Yuki eHirakawa

    2015-11-01

    Full Text Available Peptide signals mediate a variety of cell-to-cell communication crucial for plant growth and development. During Arabidopsis thaliana vascular development, a CLE (CLAVATA3/EMBRYO SURROUNDING REGION-related family peptide hormone, TDIF (tracheary element differentiation inhibitory factor, regulates procambial cell fate by its inhibitory activity on xylem differentiation. To address if this activity is conserved among vascular plants, we performed comparative analyses of TDIF signaling in non-flowering vascular plants (gymnosperms, monilophytes and lycophytes. We identified orthologs of TDIF/CLE as well as its receptor TDR/PXY (TDIF RECEPTOR/PHLOEM INTERCALATED WITH XYLEM in Ginkgo biloba, Adiantum aethiopicum and Selaginella kraussiana by RACE-PCR. The predicted TDIF peptide sequences in seed plants and monilophytes were identical to that of A. thaliana TDIF. We examined the effects of exogenous CLE peptide-motif sequences of TDIF in these species. We found that liquid culturing of dissected leaves or shoots was useful for examining TDIF activity during vascular development. TDIF treatment suppressed xylem/tracheary element differentiation of procambial cells in G. bioloba and A. aethiopicum leaves. In contrast, neither TDIF nor putative endogenous TDIF inhibited xylem differentiation in developing shoots and rhizophores of S. kraussiana. These data suggest that activity of TDIF in vascular development is conserved among extant euphyllophytes. In addition to the conserved function, via liquid culturing of its bulbils, we found a novel inhibitory activity on root growth in the monilophyte Asplenium x lucrosum suggesting lineage-specific co-option of peptide signaling occurred during the evolution of vascular plant organs.

  18. Inhibition of HIV-1 by a peptide ligand of the genomic RNA packaging signal Psi.

    Science.gov (United States)

    Dietz, Julia; Koch, Joachim; Kaur, Ajit; Raja, Chinnappan; Stein, Stefan; Grez, Manuel; Pustowka, Anette; Mensch, Sarah; Ferner, Jan; Möller, Lars; Bannert, Norbert; Tampé, Robert; Divita, Gilles; Mély, Yves; Schwalbe, Harald; Dietrich, Ursula

    2008-05-01

    The interaction of the nucleocapsid NCp7 of the human immunodeficiency virus type 1 (HIV-1) Gag polyprotein with the RNA packaging signal Psi ensures specific encapsidation of the dimeric full length viral genome into nascent virus particles. Being an essential step in the HIV-1 replication cycle, specific genome encapsidation represents a promising target for therapeutic intervention. We previously selected peptides binding to HIV-1 Psi-RNA or stem loops (SL) thereof by phage display. Herein, we describe synthesis of peptide variants of the consensus HWWPWW motif on membrane supports to optimize Psi-RNA binding. The optimized peptide, psi-pepB, was characterized in detail with respect to its conformation and binding properties for the SL3 of the Psi packaging signal by NMR and tryptophan fluorescence quenching. Functional analysis revealed that psi-pepB caused a strong reduction of virus release by infected cells as monitored by reduced transduction efficiencies, capsid p24 antigen levels, and electron microscopy. Thus, this peptide shows antiviral activity and could serve as a lead compound to develop new drugs targeting HIV-1.

  19. Reversal of hyperactive Wnt signaling-dependent adipocyte defects by peptide boronic acids.

    Science.gov (United States)

    Zhang, Tianyi; Hsu, Fu-Ning; Xie, Xiao-Jun; Li, Xiao; Liu, Mengmeng; Gao, Xinsheng; Pei, Xun; Liao, Yang; Du, Wei; Ji, Jun-Yuan

    2017-08-21

    Deregulated Wnt signaling and altered lipid metabolism have been linked to obesity, diabetes, and various cancers, highlighting the importance of identifying inhibitors that can modulate Wnt signaling and aberrant lipid metabolism. We have established a Drosophila model with hyperactivated Wnt signaling caused by partial loss of axin, a key component of the Wnt cascade. The Axin mutant larvae are transparent and have severe adipocyte defects caused by up-regulation of β-catenin transcriptional activities. We demonstrate pharmacologic mitigation of these phenotypes in Axin mutants by identifying bortezomib and additional peptide boronic acids. We show that the suppressive effect of peptide boronic acids on hyperactive Wnt signaling is dependent on α-catenin; the rescue effect is completely abolished with the depletion of α-catenin in adipocytes. These results indicate that rather than targeting the canonical Wnt signaling pathway directly, pharmacologic modulation of β-catenin activity through α-catenin is a potentially attractive approach to attenuating Wnt signaling in vivo.

  20. Cleavage of honeybee prepromelittin by an endoprotease from rat liver microsomes: identification of intact signal peptide.

    Science.gov (United States)

    Mollay, C; Vilas, U; Kreil, G

    1982-01-01

    It has previously been shown that rat liver microsomes contain a proteolytic enzyme that cleaves honeybee prepromelittin to yield promelittin. This enzyme has now been further purified by centrifugation on a sucrose-deoxycholate gradient and then reconstituted into phospholipid vesicles. Incubation of prepromelittin with vesicles in the presence of melittin yields, in addition to promelittin, a hydrophobic peptide. The latter could be isolated by extraction with l-butanol and paper electrophoresis in 30% formic acid and was shown to be intact signal peptide by analysis of peptic fragments and automated Edman degradation. The microsomal enzyme is thus an endoprotease that hydrolyzes prepromelittin exclusively at the pre-pro junction. The precision of this cleavage of an insect preprotein by a rat liver enzyme indicates that we are dealing with the ubiquitous eukaryotic signal peptidase. PMID:7048315

  1. Use of a porous silicon-gold plasmonic nanostructure to enhance serum peptide signals in MALDI-TOF analysis.

    Science.gov (United States)

    Li, Xiao; Tan, Jie; Yu, Jiekai; Feng, Jiandong; Pan, Aiwu; Zheng, Shu; Wu, Jianmin

    2014-11-07

    Small peptides in serum are potential biomarkers for the diagnosis of cancer and other diseases. The identification of peptide biomarkers in human plasma/serum has become an area of high interest in medical research. However, the direct analysis of peptides in serum samples using mass spectrometry is challenging due to the low concentration of peptides and the high abundance of high-molecular-weight proteins in serum, the latter of which causes severe signal suppression. Herein, we reported that porous semiconductor-noble metal hybrid nanostructures can both eliminate the interference from large proteins in serum samples and significantly enhance the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) yields of peptides captured on the nanostructure. Serum peptide fingerprints with high fidelity can be acquired rapidly, and successful discrimination of colorectal cancer patients based on peptide fingerprints is demonstrated.

  2. A Method for Structure–Activity Analysis of Quorum-Sensing Signaling Peptides from Naturally Transformable Streptococci

    Directory of Open Access Journals (Sweden)

    Tian XiaoLin

    2009-06-01

    Full Text Available Abstract Many species of streptococci secrete and use a competence-stimulating peptide (CSP to initiate quorum sensing for induction of genetic competence, bacteriocin production, and other activities. These signaling molecules are small, unmodified peptides that induce powerful strain-specific activity at nano-molar concentrations. This feature has provided an excellent opportunity to explore their structure–function relationships. However, CSP variants have also been identified in many species, and each specifically activates its cognate receptor. How such minor changes dramatically affect the specificity of these peptides remains unclear. Structure–activity analysis of these peptides may provide clues for understanding the specificity of signaling peptide–receptor interactions. Here, we use the Streptococcus mutans CSP as an example to describe methods of analyzing its structure–activity relationship. The methods described here may provide a platform for studying quorum-sensing signaling peptides of other naturally transformable streptococci.

  3. Transcriptional Profiling of the Oral Pathogen Streptococcus mutans in Response to Competence Signaling Peptide XIP

    Science.gov (United States)

    Wenderska, Iwona B.; Latos, Andrew; Pruitt, Benjamin; Palmer, Sara; Spatafora, Grace

    2017-01-01

    ABSTRACT In the cariogenic Streptococcus mutans, competence development is regulated by the ComRS signaling system comprised of the ComR regulator and the ComS prepeptide to the competence signaling peptide XIP (ComX-inducing peptide). Aside from competence development, XIP signaling has been demonstrated to regulate cell lysis, and recently, the expression of bacteriocins, small antimicrobial peptides used by bacteria to inhibit closely related species. Our study further explores the effect of XIP signaling on the S. mutans transcriptome. RNA sequencing revealed that XIP induction resulted in a global change in gene expression that was consistent with a stress response. An increase in several membrane-bound regulators, including HdrRM and BrsRM, involved in bacteriocin production, and the VicRKX system, involved in acid tolerance and biofilm formation, was observed. Furthermore, global changes in gene expression corresponded to changes observed during the stringent response to amino acid starvation. Effects were also observed on genes involved in sugar transport and carbon catabolite repression and included the levQRST and levDEFG operons. Finally, our work identified a novel heat shock-responsive intergenic region, encoding a small RNA, with a potential role in competence shutoff. IMPORTANCE Genetic competence provides bacteria with an opportunity to increase genetic diversity or acquire novel traits conferring a survival advantage. In the cariogenic pathogen Streptococcus mutans, DNA transformation is regulated by the competence stimulating peptide XIP (ComX-inducing peptide). The present study utilizes high-throughput RNA sequencing (RNAseq) to provide a greater understanding of how global gene expression patterns change in response to XIP. Overall, our work demonstrates that in S. mutans, XIP signaling induces a response that resembles the stringent response to amino acid starvation. We further identify a novel heat shock-responsive intergenic region with a

  4. Growth-Blocking Peptides As Nutrition-Sensitive Signals for Insulin Secretion and Body Size Regulation.

    Directory of Open Access Journals (Sweden)

    Takashi Koyama

    2016-02-01

    Full Text Available In Drosophila, the fat body, functionally equivalent to the mammalian liver and adipocytes, plays a central role in regulating systemic growth in response to nutrition. The fat body senses intracellular amino acids through Target of Rapamycin (TOR signaling, and produces an unidentified humoral factor(s to regulate insulin-like peptide (ILP synthesis and/or secretion in the insulin-producing cells. Here, we find that two peptides, Growth-Blocking Peptide (GBP1 and CG11395 (GBP2, are produced in the fat body in response to amino acids and TOR signaling. Reducing the expression of GBP1 and GBP2 (GBPs specifically in the fat body results in smaller body size due to reduced growth rate. In addition, we found that GBPs stimulate ILP secretion from the insulin-producing cells, either directly or indirectly, thereby increasing insulin and insulin-like growth factor signaling activity throughout the body. Our findings fill an important gap in our understanding of how the fat body transmits nutritional information to the insulin producing cells to control body size.

  5. Death and Survival in Streptococcus mutans: Differing Outcomes of a Quorum-Sensing Signalling Peptide

    Directory of Open Access Journals (Sweden)

    Vincent eLeung

    2015-10-01

    Full Text Available Bacteria are considered ‘social’ organisms able to communicate with one another using small hormone-like molecules (pheromones in a process called quorum-sensing. These signalling molecules increase in concentration as a function of bacterial cell density. For most human pathogens, quorum-sensing is critical for virulence and biofilm formation, and the opportunity to interfere with bacterial quorum-sensing could provide a sophisticated means for manipulating the composition of pathogenic biofilms, and possibly eradicating the infection. Streptococcus mutans is a well-characterized resident of the dental plaque biofilm, and is the major pathogen of dental caries (tooth decay. In S. mutans, its CSP quorum-sensing signalling peptide does not act as a classical quorum-sensing signal by accumulating passively in proportion to cell density. In fact, particular stresses such as those encountered in the oral cavity, induces the production of the CSP pheromone, suggesting that the pheromone most probably functions as a stress-inducible alarmone by triggering the signalling to the bacterial population to initiate an adaptive response that results in different phenotypic outcomes. This mini-review discusses two different CSP-induced phenotypes, bacterial ‘suicide’ and dormancy, and the underlying mechanisms by which S. mutans utilizes the same quorum-sensing signalling peptide to regulate two opposite phenotypes.

  6. The effect of peptide adsorption on signal linearity and a simple approach to improve reliability of quantification☆

    Science.gov (United States)

    Warwood, Stacey; Byron, Adam; Humphries, Martin J.; Knight, David

    2013-01-01

    Peptide quantification using MS often relies on the comparison of peptide signal intensities between different samples, which is based on the assumption that observed signal intensity has a linear relationship to peptide abundance. A typical proteomics experiment is subject to multiple sources of variance, so we focussed here on properties affecting peptide linearity under simple, well-defined conditions. Peptides from a standard protein digest were analysed by multiple reaction monitoring (MRM) MS to determine peptide linearity over a range of concentrations. We show that many peptides do not display a linear relationship between signal intensity and amount under standard conditions. Increasing the organic content of the sample solvent increased peptide linearity by increasing the accuracy and precision of quantification, which suggests that peptide non-linearity is due to concentration-dependent surface adsorption. Using multiple peptides at various dilutions, we show that peptide non-linearity is related to observed retention time and predicted hydrophobicity. Whereas the effect of adsorption on peptide storage has been investigated previously, here we demonstrate the deleterious effect of peptide adsorption on the quantification of fresh samples, highlight aspects of sample preparation that can minimise the effect, and suggest bioinformatic approaches to enhance the selection of peptides for quantification. Biological significance Accurate quantification is central to many aspects of science, especially those examining dynamic processes or comparing molecular stoichiometries. In biological research, the quantification of proteins is an important yet challenging objective. Large-scale quantification of proteins using MS often depends on the comparison of peptide intensities with only a single-level calibrant (as in stable isotope labelling and absolute quantification approaches) or no calibrants at all (as in label-free approaches). For these approaches to be

  7. Cytosolically expressed PrP GPI-signal peptide interacts with mitochondria.

    Science.gov (United States)

    Guizzunti, Gianni; Zurzolo, Chiara

    2015-01-01

    We previously reported that PrP GPI-anchor signal peptide (GPI-SP) is specifically degraded by the proteasome. Additionally, we showed that the point mutation P238S, responsible for a genetic form of prion diseases, while not affecting the GPI-anchoring process, results in the accumulation of PrP GPI-SP, suggesting the possibility that PrP GPI-anchor signal peptide could play a role in neurodegenerative prion diseases. We now show that PrP GPI-SP, when expressed as a cytosolic peptide, is able to localize to the mitochondria and to induce mitochondrial fragmentation and vacuolarization, followed by loss in mitochondrial membrane potential, ultimately resulting in apoptosis. Our results identify the GPI-SP of PrP as a novel candidate responsible for the impairment in mitochondrial function involved in the synaptic pathology observed in prion diseases, establishing a link between PrP GPI-SP accumulation and neuronal death.

  8. Rendering the Topological Spines

    Energy Technology Data Exchange (ETDEWEB)

    Nieves-Rivera, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-05

    Many tools to analyze and represent high dimensional data already exits yet most of them are not flexible, informative and intuitive enough to help the scientists make the corresponding analysis and predictions, understand the structure and complexity of scientific data, get a complete picture of it and explore a greater number of hypotheses. With this in mind, N-Dimensional Data Analysis and Visualization (ND²AV) is being developed to serve as an interactive visual analysis platform with the purpose of coupling together a number of these existing tools that range from statistics, machine learning, and data mining, with new techniques, in particular with new visualization approaches. My task is to create the rendering and implementation of a new concept called topological spines in order to extend ND²AV's scope. Other existing visualization tools create a representation preserving either the topological properties or the structural (geometric) ones because it is challenging to preserve them both simultaneously. Overcoming such challenge by creating a balance in between them, the topological spines are introduced as a new approach that aims to preserve them both. Its render using OpenGL and C++ and is currently being tested to further on be implemented on ND²AV. In this paper I will present what are the Topological Spines and how they are rendered.

  9. OmpA signal peptide leads to heterogenous secretion of B. subtilis chitosanase enzyme from E. coli expression system.

    Science.gov (United States)

    Pechsrichuang, Phornsiri; Songsiriritthigul, Chomphunuch; Haltrich, Dietmar; Roytrakul, Sittiruk; Namvijtr, Peenida; Bonaparte, Napolean; Yamabhai, Montarop

    2016-01-01

    The production of secreted recombinant proteins from E. coli is pivotal to the biotechnological industry because it reduces the cost of downstream processing. Proteins destined for secretion contain an N-terminal signal peptide that is cleaved by secretion machinery in the plasma membrane. The resulting protein is released in an active mature form. In this study, Bacillus subtilis chitosanase (Csn) was used as a model protein to compare the effect of two signal peptides on the secretion of heterologous recombinant protein. The results showed that the E. coli secretion machinery could recognize both native bacillus and E. coli signal peptides. However, only the native bacillus signal peptide could generate the same N-terminal sequence as in the wild type bacteria. When the recombinant Csn constructs contained the E. coli OmpA signal peptide, the secreted enzymes were heterogeneous, comprising a mixed population of secreted enzymes with different N-terminal sequences. Nevertheless, the E. coli OmpA signal peptide was found to be more efficient for high expression and secretion of bacillus Csn. These findings may be used to help engineer other recombinant proteins for secretory production in E. coli.

  10. Plasmodium falciparum signal peptide peptidase cleaves malaria heat shock protein 101 (HSP101). Implications for gametocytogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, Michael; Russo, Crystal; Li, Xuerong [Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111 (United States); Chishti, Athar H., E-mail: athar.chishti@tufts.edu [Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111 (United States); Sackler School of Graduate Biomedical Sciences, Programs in Physiology, Pharmacology, and Microbiology, Tufts University School of Medicine, Boston, MA 02111 (United States)

    2014-08-08

    Highlights: • PfSPP is an ER resident protease. • PfSPP is expressed both as a monomer and dimer. • The signal peptide of HSP101 is the first known substrate of PfSPP. • Reduced PfSPP activity may significantly affect ER homeostasis. - Abstract: Previously we described the identification of a Plasmodium falciparum signal peptide peptidase (PfSPP) functioning at the blood stage of malaria infection. Our studies also demonstrated that mammalian SPP inhibitors prevent malaria parasite growth at the late-ring/early trophozoite stage of intra-erythrocytic development. Consistent with its role in development, we tested the hypothesis that PfSPP functions at the endoplasmic reticulum of P.falciparum where it cleaves membrane-bound signal peptides generated following the enzyme activity of signal peptidase. The localization of PfSPP to the endoplasmic reticulum was confirmed by immunofluorescence microscopy and immunogold electron microscopy. Biochemical analysis indicated the existence of monomer and dimer forms of PfSPP in the parasite lysate. A comprehensive bioinformatics screen identified several candidate PfSPP substrates in the parasite genome. Using an established transfection based in vivo luminescence assay, malaria heat shock protein 101 (HSP101) was identified as a substrate of PfSPP, and partial inhibition of PfSPP correlated with the emergence of gametocytes. This finding unveils the first known substrate of PfSPP, and provides new perspectives for the function of intra-membrane proteolysis at the erythrocyte stage of malaria parasite life cycle.

  11. 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.

  12. Machine learning approaches for the prediction of signal peptides and otherprotein sorting signals

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Brunak, Søren; von Heijne, Gunnar

    1999-01-01

    Prediction of protein sorting signals from the sequence of amino acids has great importance in the field of proteomics today. Recently,the growth of protein databases, combined with machine learning approaches, such as neural networks and hidden Markov models, havemade it possible to achieve...

  13. Machine learning approaches for the prediction of signal peptides and otherprotein sorting signals

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Brunak, Søren; von Heijne, Gunnar

    1999-01-01

    Prediction of protein sorting signals from the sequence of amino acids has great importance in the field of proteomics today. Recently,the growth of protein databases, combined with machine learning approaches, such as neural networks and hidden Markov models, havemade it possible to achieve...

  14. High Fidelity Haptic Rendering

    CERN Document Server

    Otaduy, Miguel A

    2006-01-01

    The human haptic system, among all senses, provides unique and bidirectional communication between humans and their physical environment. Yet, to date, most human-computer interactive systems have focused primarily on the graphical rendering of visual information and, to a lesser extent, on the display of auditory information. Extending the frontier of visual computing, haptic interfaces, or force feedback devices, have the potential to increase the quality of human-computer interaction by accommodating the sense of touch. They provide an attractive augmentation to visual display and enhance t

  15. The plant natriuretic peptide receptor is a guanylyl cyclase and enables cGMP-dependent signaling

    KAUST Repository

    Turek, Ilona

    2016-03-05

    The functional homologues of vertebrate natriuretic peptides (NPs), the plant natriuretic peptides (PNPs), are a novel class of peptidic hormones that signal via guanosine 3′,5′-cyclic monophosphate (cGMP) and systemically affect plant salt and water balance and responses to biotrophic plant pathogens. Although there is increasing understanding of the complex roles of PNPs in plant responses at the systems level, little is known about the underlying signaling mechanisms. Here we report isolation and identification of a novel Leucine-Rich Repeat (LRR) protein that directly interacts with A. thaliana PNP, AtPNP-A. In vitro binding studies revealed that the Arabidopsis AtPNP-A binds specifically to the LRR protein, termed AtPNP-R1, and the active region of AtPNP-A is sufficient for the interaction to occur. Importantly, the cytosolic part of the AtPNP-R1, much like in some vertebrate NP receptors, harbors a catalytic center diagnostic for guanylyl cyclases and the recombinant AtPNP-R1 is capable of catalyzing the conversion of guanosine triphosphate to cGMP. In addition, we show that AtPNP-A causes rapid increases of cGMP levels in wild type (WT) leaf tissue while this response is significantly reduced in the atpnp-r1 mutants. AtPNP-A also causes cGMP-dependent net water uptake into WT protoplasts, and hence volume increases, whereas responses of the protoplasts from the receptor mutant are impaired. Taken together, our results suggest that the identified LRR protein is an AtPNP-A receptor essential for the PNP-dependent regulation of ion and water homeostasis in plants and that PNP- and vertebrate NP-receptors and their signaling mechanisms share surprising similarities. © 2016 Springer Science+Business Media Dordrecht

  16. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  17. Binaural Rendering in MPEG Surround

    Science.gov (United States)

    Breebaart, Jeroen; Villemoes, Lars; Kjörling, Kristofer

    2008-12-01

    This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial) properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate "binaural parameters" that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  18. Getting something for nothing: Regeneration of peptide signals from apparently exhausted MALDI samples by “waterboarding"

    Science.gov (United States)

    An often cited advantage of MALDI-MS is the ability to archive and reuse sample plates after the initial analysis is complete. However, experience demonstrates that the peptide ion signals decay rapidly as the number of laser shots becomes large. Thus, the signal level obtainable from an archived sa...

  19. TDIF peptide signaling regulates vascular stem cell proliferation via the WOX4 homeobox gene in Arabidopsis.

    Science.gov (United States)

    Hirakawa, Yuki; Kondo, Yuki; Fukuda, Hiroo

    2010-08-01

    The indeterminate nature of plant growth and development depends on the stem cell system found in meristems. The Arabidopsis thaliana vascular meristem includes procambium and cambium. In these tissues, cell-cell signaling, mediated by a ligand-receptor pair made of the TDIF (for tracheary element differentiation inhibitory factor) peptide and the TDR/PXY (for TDIF RECEPTOR/ PHLOEM INTERCALATED WITH XYLEM) membrane protein kinase, promotes proliferation of procambial cells and suppresses their xylem differentiation. Here, we report that a WUSCHEL-related HOMEOBOX gene, WOX4, is a key target of the TDIF signaling pathway. WOX4 is expressed preferentially in the procambium and cambium, and its expression level was upregulated upon application of TDIF in a TDR-dependent manner. Genetic analyses showed that WOX4 is required for promoting the proliferation of procambial/cambial stem cells but not for repressing their commitment to xylem differentiation in response to the TDIF signal. Thus, at least two intracellular signaling pathways that diverge after TDIF recognition by TDR might regulate independently the behavior of vascular stem cells. Detailed observations in loss-of-function mutants revealed that TDIF-TDR-WOX4 signaling plays a crucial role in the maintenance of the vascular meristem organization during secondary growth.

  20. Peptides interfering with protein-protein interactions in the ethylene signaling pathway delay tomato fruit ripening

    Science.gov (United States)

    Bisson, Melanie M. A.; Kessenbrock, Mareike; Müller, Lena; Hofmann, Alexander; Schmitz, Florian; Cristescu, Simona M.; Groth, Georg

    2016-08-01

    The plant hormone ethylene is involved in the regulation of several processes with high importance for agricultural applications, e.g. ripening, aging and senescence. Previous work in our group has identified a small peptide (NOP-1) derived from the nuclear localization signal of the Arabidopsis ethylene regulator ETHYLENE INSENSITIVE-2 (EIN2) C-terminal part as efficient inhibitor of ethylene responses. Here, we show that NOP-1 is also able to efficiently disrupt EIN2-ETR1 complex formation in tomato, indicating that the NOP-1 inhibition mode is conserved across plant species. Surface application of NOP-1 on green tomato fruits delays ripening similar to known inhibitors of ethylene perception (MCP) and ethylene biosynthesis (AVG). Fruits treated with NOP-1 showed similar ethylene production as untreated controls underlining that NOP-1 blocks ethylene signaling by targeting an essential interaction in this pathway, while having no effect on ethylene biosynthesis.

  1. Signal peptide of eosinophil cationic protein upregulates transforming growth factor-alpha expression in human cells.

    Science.gov (United States)

    Chang, Hao-Teng; Kao, Yu-Lin; Wu, Chia-Mao; Fan, Tan-Chi; Lai, Yiu-Kay; Huang, Kai-Ling; Chang, Yuo-Sheng; Tsai, Jaw-Ji; Chang, Margaret Dah-Tsyr

    2007-04-01

    Eosinophil cationic protein (ECP) is a major component of eosinophil granule protein that is used as a clinical bio-marker for asthma and allergic inflammatory diseases. Previously, it has been reported that the signal peptide of human ECP (ECPsp) inhibits the cell growth of Escherichia coli (E. coli) and Pichia pastoris (P. pastoris), but not mammalian A431 cells. The inhibitory effect is due to the lack of human signal peptide peptidase (hSPP), a protease located on the endoplasmic reticulum (ER) membrane, in the lower organisms. In this study, we show that the epidermal growth factor receptor (EGFR) is upregulated by the exogenous ECPsp-eGFP as a result of the increased expression of the transforming growth factor-alpha (TGF-alpha) at both transcriptional and translational levels in A431 and HL-60 clone 15 cell lines. Furthermore, the N-terminus of ECPsp fragment generated by the cleavage of hSPP (ECPspM1-G17) gives rise to over threefold increase of TGF-alpha protein expression, whereas another ECPsp fragment (ECPspL18-A27) and the hSPP-resistant ECPsp (ECPspG17L) do not show similar effect. Our results indicate that the ECPspM1-G17 plays a crucial role in the upregulation of TGF-alpha, suggesting that the ECPsp not only directs the secretion of mature ECP, but also involves in the autocrine system.

  2. Coupling of D2R Short but not D2R Long receptor isoform to the Rho/ROCK signaling pathway renders striatal neurons vulnerable to mutant huntingtin.

    Science.gov (United States)

    Galan-Rodriguez, Beatriz; Martin, Elodie; Brouillet, Emmanuel; Déglon, Nicole; Betuing, Sandrine; Caboche, Jocelyne

    2017-01-01

    Huntington's disease, an inherited neurodegenerative disorder, results from abnormal polyglutamine extension in the N-terminal region of the huntingtin protein. This mutation causes preferential degeneration of striatal projection neurons. We previously demonstrated, in vitro, that dopaminergic D2 receptor stimulation acted in synergy with expanded huntingtin to increase aggregates formation and striatal death through activation of the Rho/ROCK signaling pathway. In vivo, in a lentiviral-mediated model of expanded huntingtin expression in the rat striatum, we found that the D2 antagonist haloperidol protects striatal neurons against expanded huntingtin-mediated toxicity. Two variant transcripts are generated by alternative splicing of the of D2 receptor gene, the D2R-Long and the D2R-Short, which are thought to play different functional roles. We show herein that overexpression of D2R-Short, but not D2R-Long in cell lines is associated with activation of the RhoA/ROCK signaling pathway. In striatal neurons in culture, the selective D2 agonist Quinpirole triggers phosphorylation of cofilin, a downstream effector of ROCK, which is abrogated by siRNAs that knockdown both D2R-Long and D2R-Short, but not by siRNAs targeting D2R-Long alone. Aggregate formation and neuronal death induced by expanded huntingtin, were potentiated by Quinpirole. This D2 agonist-mediated effect was selectively inhibited by the siRNA targeting both D2R-Long and D2R-Short but not D2R-Long alone. Our data provide evidence for a specific coupling of D2R-Short to the RhoA/ROCK/cofilin pathway, and its involvement in striatal vulnerability to expanded huntingtin. A new route for targeting Rho-ROCK signaling in Huntington's disease is unraveled with our findings.

  3. Pilose antler peptide protects osteoblasts from inflammatory and oxidative injury through EGF/EGFR signaling.

    Science.gov (United States)

    Chunhui, Yang; Wenjun, Cai; Hui, Wen; Liquan, Sha; Changwei, Zhao; Tianzhu, Zhang; Wenhai, Zhao

    2017-02-16

    Epidermal growth factor (EGF)/EFG receptor (EGFR) signaling plays an important role in the osteoblastogenesis. The potential effects of pilose antler peptide (PAP) on osteoblast cell damages was investigated in our present study through EGF/EGFR signaling. In MC3T3-E1 osteoblastic cells, PAP treatment significantly inhibited the production of inflammatory cytokines by decreasing the levels of serum proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). PAP treatment also alleviated the oxidative responses as indicated by increased activities of catalase (SOD) and decreased levels of malondialdehyde (MDA). EGF inhibition, by siRNA knockdown, almost abolished PAP-induced osteoblast cytoprotection against inflammation and oxidant stress. Further, our results showed that PAP stimulated the nuclear erythroid factor 2-related factor 2 (Nrf2)2/heme oxygenase-1(HO-1) signaling, and inhibited the activation of uclear factor kappa B (NF-κB) pathway in MC3T3-E1 cells. On the other hand, EGF siRNA knockdown inhibited PAP-induced cytoprotection, which decreased the expression of Nrf-2, HO-1 and increased the level of p-NF-κBp65, p-IκBα in MC3T3-E1 cells. Thus, our research demonstrated that PAP protects osteoblasts from inflammatory and oxidative injury through EGF/EGFR signaling.

  4. T cell receptor (TCR-transgenic CD8 lymphocytes rendered insensitive to transforming growth factor beta (TGFβ signaling mediate superior tumor regression in an animal model of adoptive cell therapy

    Directory of Open Access Journals (Sweden)

    Quatromoni Jon G

    2012-06-01

    Full Text Available Abstract Tumor antigen-reactive T cells must enter into an immunosuppressive tumor microenvironment, continue to produce cytokine and deliver apoptotic death signals to affect tumor regression. Many tumors produce transforming growth factor beta (TGFβ, which inhibits T cell activation, proliferation and cytotoxicity. In a murine model of adoptive cell therapy, we demonstrate that transgenic Pmel-1 CD8 T cells, rendered insensitive to TGFβ by transduction with a TGFβ dominant negative receptor II (DN, were more effective in mediating regression of established B16 melanoma. Smaller numbers of DN Pmel-1 T cells effectively mediated tumor regression and retained the ability to produce interferon-γ in the tumor microenvironment. These results support efforts to incorporate this DN receptor in clinical trials of adoptive cell therapy for cancer.

  5. Human urinary renalase lacks the N-terminal signal peptide crucial for accommodation of its FAD cofactor.

    Science.gov (United States)

    Fedchenko, Valerii I; Buneeva, Olga A; Kopylov, Arthur T; Veselovsky, Alexander V; Zgoda, Victor G; Medvedev, Alexei E

    2015-01-01

    Renalase is a recently discovered secretory protein involved in the regulation of blood pressure. Cells synthesize all known isoforms of human renalase (1 and 2) as flavoproteins. Accommodation of FAD in the renalase protein requires the presence of its N-terminal peptide. However, in secretory proteins, such peptides are usually cleaved during their export from the cell. In the present study, we have isolated human renalase from urinary samples of healthy volunteers and human recombinant renalases 1 and 2 expressed in Escherichia coli cells. In these proteins, we investigated the presence of the renalase N-terminal peptide and the FAD cofactor and performed computer-aided molecular analysis of the renalase crystal structure to evaluate possible consequences of removal of the N-terminal peptide. In contrast to human recombinant renalase isoforms 1 and 2 containing non-covalently bound FAD and clearly detectable N-terminal peptide, renalase purified from human urine lacks both the N-terminal signal peptide and FAD. The computer-aided analysis indicates that the removal of this peptide results in inability of the truncated renalase to bind the FAD cofactor. Thus, our results indicate that human renalase secreted in urine lacks its N-terminal peptide, and therefore catalytic activities of urinary renalase reported in the literature cannot be attributed to FAD-dependent mechanisms. We suggest that FAD-dependent catalytic functions are intrinsic properties of intracellular renalases, whereas extracellular renalases act in FAD- and possibly catalytic-independent manner.

  6. A Comprehensive Immunoreceptor Phosphotyrosine-based Signaling Network Revealed by Reciprocal Protein–Peptide Array Screening*

    Science.gov (United States)

    Liu, Huadong; Li, Lei; Voss, Courtney; Wang, Feng; Liu, Juewen; Li, Shawn Shun-Cheng

    2015-01-01

    Cells of the immune system communicate with their environment through immunoreceptors. These receptors often harbor intracellular tyrosine residues, which, when phosphorylated upon receptor activation, serve as docking sites to recruit downstream signaling proteins containing the Src Homology 2 (SH2) domain. A systematic investigation of interactions between the SH2 domain and the immunoreceptor tyrosine-based regulatory motifs (ITRM), including inhibitory (ITIM), activating (ITAM), or switching (ITSM) motifs, is critical for understanding cellular signal transduction and immune function. Using the B cell inhibitory receptor CD22 as an example, we developed an approach that combines reciprocal or bidirectional phosphopeptide and SH2 domain array screens with in-solution binding assays to identify a comprehensive SH2-CD22 interaction network. Extending this approach to 194 human ITRM sequences and 78 SH2 domains led to the identification of a high-confidence immunoreceptor interactome containing 1137 binary interactions. Besides recapitulating many previously reported interactions, our study uncovered numerous novel interactions. The resulting ITRM-SH2 interactome not only helped to fill many gaps in the immune signaling network, it also allowed us to associate different SH2 domains to distinct immune functions. Detailed analysis of the NK cell ITRM-mediated interactions led to the identification of a network nucleated by the Vav3 and Fyn SH2 domains. We showed further that these SH2 domains have distinct functions in cytotoxicity. The bidirectional protein-peptide array approach described herein may be applied to the numerous other peptide-binding modules to identify potential protein–protein interactions in a systematic and reliable manner. PMID:25907764

  7. A Comprehensive Immunoreceptor Phosphotyrosine-based Signaling Network Revealed by Reciprocal Protein-Peptide Array Screening.

    Science.gov (United States)

    Liu, Huadong; Li, Lei; Voss, Courtney; Wang, Feng; Liu, Juewen; Li, Shawn Shun-Cheng

    2015-07-01

    Cells of the immune system communicate with their environment through immunoreceptors. These receptors often harbor intracellular tyrosine residues, which, when phosphorylated upon receptor activation, serve as docking sites to recruit downstream signaling proteins containing the Src Homology 2 (SH2) domain. A systematic investigation of interactions between the SH2 domain and the immunoreceptor tyrosine-based regulatory motifs (ITRM), including inhibitory (ITIM), activating (ITAM), or switching (ITSM) motifs, is critical for understanding cellular signal transduction and immune function. Using the B cell inhibitory receptor CD22 as an example, we developed an approach that combines reciprocal or bidirectional phosphopeptide and SH2 domain array screens with in-solution binding assays to identify a comprehensive SH2-CD22 interaction network. Extending this approach to 194 human ITRM sequences and 78 SH2 domains led to the identification of a high-confidence immunoreceptor interactome containing 1137 binary interactions. Besides recapitulating many previously reported interactions, our study uncovered numerous novel interactions. The resulting ITRM-SH2 interactome not only helped to fill many gaps in the immune signaling network, it also allowed us to associate different SH2 domains to distinct immune functions. Detailed analysis of the NK cell ITRM-mediated interactions led to the identification of a network nucleated by the Vav3 and Fyn SH2 domains. We showed further that these SH2 domains have distinct functions in cytotoxicity. The bidirectional protein-peptide array approach described herein may be applied to the numerous other peptide-binding modules to identify potential protein-protein interactions in a systematic and reliable manner. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. A common polymorphism renders the luteinizing hormone receptor protein more active by improving signal peptide function and predicts adverse outcome in breast cancer patients

    NARCIS (Netherlands)

    D. Piersma (Djura); P.M.J.J. Berns (Els); M. Verhoef-Post (Miriam); A.G. Uitterlinden (André); I. Braakman (Ineke); H.A.P. Pols (Huib); A.P.N. Themmen (Axel)

    2006-01-01

    textabstractContext: Epidemiological and animal studies indicate a carcinogenic role of estrogens in breast tissue. The pituitary gonadotropin LH is an important regulator of estrogen production in premenopausal women, whereas even in women after menopause, 10-25% of ovarian steroid hormone producti

  9. ARE: Ada Rendering Engine

    Directory of Open Access Journals (Sweden)

    Stefano Penge

    2009-10-01

    Full Text Available E' ormai pratica diffusa, nello sviluppo di applicazioni web, l'utilizzo di template e di potenti template engine per automatizzare la generazione dei contenuti da presentare all'utente. Tuttavia a volte la potenza di tali engine è€ ottenuta mescolando logica e interfaccia, introducendo linguaggi diversi da quelli di descrizione della pagina, o addirittura inventando nuovi linguaggi dedicati.ARE (ADA Rendering Engine è€ pensato per gestire l'intero flusso di creazione del contenuto HTML/XHTML dinamico, la selezione del corretto template, CSS, JavaScript e la produzione dell'output separando completamente logica e interfaccia. I templates utilizzati sono puro HTML senza parti in altri linguaggi, e possono quindi essere gestiti e visualizzati autonomamente. Il codice HTML generato è€ uniforme e parametrizzato.E' composto da due moduli, CORE (Common Output Rendering Engine e ALE (ADA Layout Engine.Il primo (CORE viene utilizzato per la generazione OO degli elementi del DOM ed è pensato per aiutare lo sviluppatore nella produzione di codice valido rispetto al DTD utilizzato. CORE genera automaticamente gli elementi del DOM in base al DTD impostato nella configurazioneIl secondo (ALE viene utilizzato come template engine per selezionare automaticamente in base ad alcuni parametri (modulo, profilo utente, tipologia del nodo, del corso, preferenze di installazione il template HTML, i CSS e i file JavaScript appropriati. ALE permette di usare templates di default e microtemplates ricorsivi per semplificare il lavoro del grafico.I due moduli possono in ogni caso essere utilizzati indipendentemente l'uno dall'altro. E' possibile generare e renderizzare una pagina HTML utilizzando solo CORE oppure inviare gli oggetti CORE al template engine ALE che provvede a renderizzare la pagina HTML. Viceversa è possibile generare HTML senza utilizzare CORE ed inviarlo al template engine ALECORE è alla prima release ed è€ già utilizzato all

  10. Parallel hierarchical radiosity rendering

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  11. Sea modeling and rendering

    Science.gov (United States)

    Cathala, Thierry; Latger, Jean

    2010-10-01

    More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.

  12. Spinal cord interneurons expressing the gastrin releasing peptide receptor convey itch through VGLUT2-mediated signaling.

    Science.gov (United States)

    Aresh, Bejan; Freitag, Fabio B; Perry, Sharn; Blümel, Edda; Lau, Joey; Franck, Marina C M; Lagerström, Malin C

    2017-02-01

    Itch is a sensation that promotes the desire to scratch, which can be evoked by mechanical and chemical stimuli. In the spinal cord, neurons expressing the gastrin releasing peptide receptor (GRPR) have been identified as specific mediators of itch. However, our understanding of the GRPR-population in the spinal cord, and thus how these neurons exercise their functions, is limited. For this purpose, we constructed a Cre line designed to target the GRPR population of neurons (Grpr-Cre). Our analysis revealed that Grpr-Cre cells in the spinal cord are predominantly excitatory interneurons that are found in the dorsal lamina, especially in lamina II-IV. Application of the specific agonist gastrin releasing peptide (GRP) induced spike responses in 43.3% of the patched Grpr-Cre neurons, where the majority of the cells displayed a tonic firing property. Additionally, our analysis showed that the Grpr-Cre population expresses Vglut2 mRNA and mice ablated of Vglut2 in Grpr-Cre cells (Vglut2-lox;Grpr-Cre mice) displayed less spontaneous itch, and attenuated responses to both histaminergic and non-histaminergic agents. We could also show that application of the itch-inducing peptide natriuretic polypeptide b (NPPB) induces calcium influx in a sub-population of Grpr-Cre neurons. To summarize, our data indicate that the Grpr-Cre spinal cord neural population is composed of interneurons that use VGLUT2-mediated signaling for transmitting chemical and spontaneous itch stimuli to the next, currently unknown, neurons in the labeled line of itch.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  13. Impaired cleavage of preproinsulin signal peptide linked to autosomal-dominant diabetes.

    Science.gov (United States)

    Liu, Ming; Lara-Lemus, Roberto; Shan, Shu-ou; Wright, Jordan; Haataja, Leena; Barbetti, Fabrizio; Guo, Huan; Larkin, Dennis; Arvan, Peter

    2012-04-01

    Recently, missense mutations upstream of preproinsulin's signal peptide (SP) cleavage site were reported to cause mutant INS gene-induced diabetes of youth (MIDY). Our objective was to understand the molecular pathogenesis using metabolic labeling and assays of proinsulin export and insulin and C-peptide production to examine the earliest events of insulin biosynthesis, highlighting molecular mechanisms underlying β-cell failure plus a novel strategy that might ameliorate the MIDY syndrome. We find that whereas preproinsulin-A(SP23)S is efficiently cleaved, producing authentic proinsulin and insulin, preproinsulin-A(SP24)D is inefficiently cleaved at an improper site, producing two subpopulations of molecules. Both show impaired oxidative folding and are retained in the endoplasmic reticulum (ER). Preproinsulin-A(SP24)D also blocks ER exit of coexpressed wild-type proinsulin, accounting for its dominant-negative behavior. Upon increased expression of ER-oxidoreductin-1, preproinsulin-A(SP24)D remains blocked but oxidative folding of wild-type proinsulin improves, accelerating its ER export and increasing wild-type insulin production. We conclude that the efficiency of SP cleavage is linked to the oxidation of (pre)proinsulin. In turn, impaired (pre)proinsulin oxidation affects ER export of the mutant as well as that of coexpressed wild-type proinsulin. Improving oxidative folding of wild-type proinsulin may provide a feasible way to rescue insulin production in patients with MIDY.

  14. Evolutionary well-conserved region in the signal peptide of parathyroid hormone-related protein is critical for its dual localization through the regulation of ER translocation.

    Science.gov (United States)

    Amaya, Yoshihiro; Nakai, Toshiki; Miura, Satoshi

    2016-04-01

    Parathyroid hormone-related protein (PTHrP) has two different targeting signals: an N-terminal signal peptide for the endoplasmic reticulum (ER) targeting and an internal nuclear localization signal. The protein not only functions as a secretory protein, but is also found in the nucleus and/or nucleolus under certain conditions. PTHrP signal peptide is less hydrophobic than most signal peptides mainly due to its evolutionarily well-conserved region (QQWS). The substitution of four tandem leucine residues for this conserved region resulted in a significant inhibition of the signal peptide cleavage. At the same time, proportion of nuclear and/or nucleolar localization decreased, probably due to tethering of the protein to the ER membrane by the uncleaved mutant signal peptide. Almost complete cleavage of the signal peptide accompanied by a lack of nuclear/nucleolar localization was achieved by combining the hydrophobic h-region and an optimized sequence of the cleavage site. In addition, mutational modifications of the distribution of charged residues in and around the signal peptide affect its cleavage and/or nuclear/nucleolar localization of the protein. These results indicate that the well-conserved region in the signal peptide plays an essential role in the dual localization of PTHrP through ER targeting and/or the membrane translocation. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  15. Defining a similarity threshold for a functional proteinsequence pattern: The signal peptide cleavage site

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Engelbrecht, Jacob; von Heijne, Gunnar

    1996-01-01

    prediction. We have developed a similar procedure based on pair-wise alignments for sequences with functional sites. We show how a correlation coefficient between sequence similarity and functional homology can be used to compare the efficiency of different similarity measures and choose a nonarbitrary...... threshold value for excluding redundant sequences. The impact of the choice of scoring matrix used in the alignments is examined. We demonstrate that the parameter determining the quality of the correlation is the relative entropy of the matrix, rather than the assumed(PAM or identity) substitution model....... Results are presented for the case of prediction of cleavage sites in signal peptides. By inspection of the false positives, several errors in the database were found. The procedure presented may be used as a general outline for finding a problem-specific similarity measure and threshold value...

  16. Remnant signal peptides on non-exported enzymes: implications for the evolution of prokaryotic respiratory chains.

    Science.gov (United States)

    Ize, Bérengère; Coulthurst, Sarah J; Hatzixanthis, Kostas; Caldelari, Isabelle; Buchanan, Grant; Barclay, Elaine C; Richardson, David J; Palmer, Tracy; Sargent, Frank

    2009-12-01

    The twin-arginine translocation (Tat) pathway is a prokaryotic protein targeting system dedicated to the transmembrane translocation of folded proteins. Substrate proteins are directed to the Tat translocase by signal peptides bearing a conserved SRRxFLK 'twin-arginine' motif. In Escherichia coli, most of the 27 periplasmically located Tat substrates are cofactor-containing respiratory enzymes, and many of these harbour a molybdenum cofactor at their active site. Molybdenum cofactor-containing proteins are not exclusively located in the periplasm, however, with the major respiratory nitrate reductase (NarG) and the biotin sulfoxide reductase (BisC), for example, being located at the cytoplasmic side of the membrane. Interestingly, both NarG and BisC contain 'N-tail' regions that bear some sequence similarity to twin-arginine signal peptides. In this work, we have examined the relationship between the non-exported N-tails and the Tat system. Using a sensitive genetic screen for Tat transport, variant N-tails were identified that displayed Tat transport activity. For the NarG 36-residue N-tail, six amino acid changes were needed to induce transport activity. However, these changes interfered with binding by the NarJ biosynthetic chaperone and impaired biosynthesis of the native enzyme. For the BisC 36-residue N-tail, only five amino acid substitutions were needed to restore Tat transport activity. These modifications also impaired in vivo BisC activity, but it was not possible to identify a biosynthetic chaperone for this enzyme. These data highlight an intimate genetic and evolutionary link between some non-exported redox enzymes and those transported across membranes by the Tat translocation system.

  17. Promotion of Cell Growth and Adhesion of a Peptide Hydrogel Scaffold via mTOR/Cadherin Signaling.

    Science.gov (United States)

    Wei, Guojun; Wang, Liping; Dong, Daming; Teng, Zhaowei; Shi, Zuowei; Wang, Kaifu; An, Gang; Guan, Ying; Han, Bo; Yao, Meng; Xian, Cory J

    2017-02-18

    Understanding neurite outgrowth, orientation, and migration is important for the design of biomaterials that interface with the neural tissue. However, the molecular signaling alternations have not been well elucidated to explain the impact of hydrogels on cell morphology. In our previous studies, a silk fibroin peptide (SF16) hydrogel was found to be an effective matrix for the viability, morphology and proliferation of PC12 rat pheocrhomocytoma cells. We found that PC12 cells in the peptide hydrogel exhibited adhesive morphology compared to those cultured in agarose or collagen. Moreover, we identified that cell adhesion molecules (E- and N-cadherin) controlled by mTOR signaling were highly induced in PC12 cells cultured in the SF16 peptide hydrogel. Our findings suggest that the SF16 peptide might be suitable to be a cell-adhesion material in cell culture or tissue engineering, and mTOR/cadherin signaling is required for the cell adhesion in the SF16-peptide hydrogel. This article is protected by copyright. All rights reserved.

  18. A two-component signal-transduction cascade in Carnobacterium piscicola LV17B : two signaling peptides and one sensor-transmitter

    NARCIS (Netherlands)

    Kleerebezem, M; Kuipers, OP; de Vos, WM; Stiles, ME; Quadri, LEN; Vos, Willem M. de; Stiles, Michael E.; Quadri, Luis E.N.

    2001-01-01

    In the lactic acid bacterium Carnobacterium piscicola LV17B a peptide-pheromone dependent quorum-sensing mode is involved in the regulation of bacteriocin production. Bacteriocin CB2 was identified as an environmental signal that induces bacteriocin production. Here, we demonstrate that a second 24

  19. A two-component signal-transduction cascade in Carnobacterium piscicola LV17B : two signaling peptides and one sensor-transmitter

    NARCIS (Netherlands)

    Kleerebezem, M; Kuipers, OP; de Vos, WM; Stiles, ME; Quadri, LEN; Vos, Willem M. de; Stiles, Michael E.; Quadri, Luis E.N.

    2001-01-01

    In the lactic acid bacterium Carnobacterium piscicola LV17B a peptide-pheromone dependent quorum-sensing mode is involved in the regulation of bacteriocin production. Bacteriocin CB2 was identified as an environmental signal that induces bacteriocin production. Here, we demonstrate that a second 24

  20. 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

  1. Secretory signal peptide modification for optimized antibody-fragment expression-secretion in Leishmania tarentolae

    Directory of Open Access Journals (Sweden)

    Klatt Stephan

    2012-07-01

    Full Text Available Abstract Background Secretory signal peptides (SPs are well-known sequence motifs targeting proteins for translocation across the endoplasmic reticulum membrane. After passing through the secretory pathway, most proteins are secreted to the environment. Here, we describe the modification of an expression vector containing the SP from secreted acid phosphatase 1 (SAP1 of Leishmania mexicana for optimized protein expression-secretion in the eukaryotic parasite Leishmania tarentolae with regard to recombinant antibody fragments. For experimental design the online tool SignalP was used, which predicts the presence and location of SPs and their cleavage sites in polypeptides. To evaluate the signal peptide cleavage site as well as changes of expression, SPs were N-terminally linked to single-chain Fragment variables (scFv’s. The ability of L. tarentolae to express complex eukaryotic proteins with highly diverse post-translational modifications and its easy bacteria-like handling, makes the parasite a promising expression system for secretory proteins. Results We generated four vectors with different SP-sequence modifications based on in-silico analyses with SignalP in respect to cleavage probability and location, named pLTEX-2 to pLTEX-5. To evaluate their functionality, we cloned four individual scFv-fragments into the vectors and transfected all 16 constructs into L. tarentolae. Independently from the expressed scFv, pLTEX-5 derived constructs showed the highest expression rate, followed by pLTEX-4 and pLTEX-2, whereas only low amounts of protein could be obtained from pLTEX-3 clones, indicating dysfunction of the SP. Next, we analysed the SP cleavage sites by Edman degradation. For pLTEX-2, -4, and -5 derived scFv’s, the results corresponded to in-silico predictions, whereas pLTEX-3 derived scFv’s contained one additional amino-acid (AA. Conclusions The obtained results demonstrate the importance of SP-sequence optimization for efficient

  2. Regulation of N-Formyl Peptide Receptor Signaling and Trafficking by Arrestin-Src Kinase Interaction.

    Science.gov (United States)

    Wagener, Brant M; Marjon, Nicole A; Prossnitz, Eric R

    2016-01-01

    Arrestins were originally described as proteins recruited to ligand-activated, phosphorylated G protein-coupled receptors (GPCRs) to attenuate G protein-mediated signaling. It was later revealed that arrestins also mediate GPCR internalization and recruit a number of signaling proteins including, but not limited to, Src family kinases, ERK1/2, and JNK3. GPCR-arrestin binding and trafficking control the spatial and temporal activity of these multi-protein complexes. In previous reports, we concluded that N-formyl peptide receptor (FPR)-mediated apoptosis, which occurs upon receptor stimulation in the absence of arrestins, is associated with FPR accumulation in perinuclear recycling endosomes. Under these conditions, inhibition of Src kinase and ERK1/2 prevented FPR-mediated apoptosis. To better understand the role of Src kinase in this process, in the current study we employed a previously described arrestin-2 (arr2) mutant deficient in Src kinase binding (arr2-P91G/P121E). Unlike wild type arrestin, arr2-P91G/P121E did not inhibit FPR-mediated apoptosis, suggesting that Src binding to arrestin-2 prevents apoptotic signaling. However, in cells expressing this mutant, FPR-mediated apoptosis was still blocked by inhibition of Src kinase activity, suggesting that activation of Src independent of arrestin-2 binding is involved in FPR-mediated apoptosis. Finally, while Src kinase inhibition prevented FPR-mediated-apoptosis in the presence of arr2-P91G/P121E, it did not prevent FPR-arr2-P91G/P121E accumulation in the perinuclear recycling endosome. On the contrary, inhibition of Src kinase activity mediated the accumulation of activated FPR-wild type arrestin-2 in recycling endosomes without initiating FPR-mediated apoptosis. Based on these observations, we conclude that Src kinase has two independent roles following FPR activation that regulate both FPR-arrestin-2 signaling and trafficking.

  3. Regulation of N-Formyl Peptide Receptor Signaling and Trafficking by Arrestin-Src Kinase Interaction.

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    Brant M Wagener

    Full Text Available Arrestins were originally described as proteins recruited to ligand-activated, phosphorylated G protein-coupled receptors (GPCRs to attenuate G protein-mediated signaling. It was later revealed that arrestins also mediate GPCR internalization and recruit a number of signaling proteins including, but not limited to, Src family kinases, ERK1/2, and JNK3. GPCR-arrestin binding and trafficking control the spatial and temporal activity of these multi-protein complexes. In previous reports, we concluded that N-formyl peptide receptor (FPR-mediated apoptosis, which occurs upon receptor stimulation in the absence of arrestins, is associated with FPR accumulation in perinuclear recycling endosomes. Under these conditions, inhibition of Src kinase and ERK1/2 prevented FPR-mediated apoptosis. To better understand the role of Src kinase in this process, in the current study we employed a previously described arrestin-2 (arr2 mutant deficient in Src kinase binding (arr2-P91G/P121E. Unlike wild type arrestin, arr2-P91G/P121E did not inhibit FPR-mediated apoptosis, suggesting that Src binding to arrestin-2 prevents apoptotic signaling. However, in cells expressing this mutant, FPR-mediated apoptosis was still blocked by inhibition of Src kinase activity, suggesting that activation of Src independent of arrestin-2 binding is involved in FPR-mediated apoptosis. Finally, while Src kinase inhibition prevented FPR-mediated-apoptosis in the presence of arr2-P91G/P121E, it did not prevent FPR-arr2-P91G/P121E accumulation in the perinuclear recycling endosome. On the contrary, inhibition of Src kinase activity mediated the accumulation of activated FPR-wild type arrestin-2 in recycling endosomes without initiating FPR-mediated apoptosis. Based on these observations, we conclude that Src kinase has two independent roles following FPR activation that regulate both FPR-arrestin-2 signaling and trafficking.

  4. Identification of a system required for the functional surface localization of sugar binding proteins with class III signal peptides in Sulfolobus solfataricus

    NARCIS (Netherlands)

    Zolghadr, Behnam; Weber, Stefan; Szabo, Zalan; Driessen, Arnold J. M.; Albers, Sonja-Verena

    2007-01-01

    The hyperthermophilic archaeon Sulfolobus solfataricus contains an unusual large number of sugar binding proteins that are synthesized as precursors with a class III signal peptide. Such signal peptides are commonly used to direct archaeal flagellin subunits or bacterial (pseudo)pilins into extracel

  5. Calpain-catalyzed proteolysis of human dUTPase specifically removes the nuclear localization signal peptide.

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    Zoltán Bozóky

    Full Text Available BACKGROUND: Calpain proteases drive intracellular signal transduction via specific proteolysis of multiple substrates upon Ca(2+-induced activation. Recently, dUTPase, an enzyme essential to maintain genomic integrity, was identified as a physiological calpain substrate in Drosophila cells. Here we investigate the potential structural/functional significance of calpain-activated proteolysis of human dUTPase. METHODOLOGY/PRINCIPAL FINDINGS: Limited proteolysis of human dUTPase by mammalian m-calpain was investigated in the presence and absence of cognate ligands of either calpain or dUTPase. Significant proteolysis was observed only in the presence of Ca(II ions, inducing calpain action. The presence or absence of the dUTP-analogue α,β-imido-dUTP did not show any effect on Ca(2+-calpain-induced cleavage of human dUTPase. The catalytic rate constant of dUTPase was unaffected by calpain cleavage. Gel electrophoretic analysis showed that Ca(2+-calpain-induced cleavage of human dUTPase resulted in several distinctly observable dUTPase fragments. Mass spectrometric identification of the calpain-cleaved fragments identified three calpain cleavage sites (between residues (4SE(5; (7TP(8; and (31LS(32. The cleavage between the (31LS(32 peptide bond specifically removes the flexible N-terminal nuclear localization signal, indispensable for cognate localization. CONCLUSIONS/SIGNIFICANCE: Results argue for a mechanism where Ca(2+-calpain may regulate nuclear availability and degradation of dUTPase.

  6. Genome-wide analysis of signal peptide functionality in Lactobacillus plantarum WCFS1

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    Axelsson Lars

    2009-09-01

    Full Text Available Abstract Background Lactobacillus plantarum is a normal, potentially probiotic, inhabitant of the human gastrointestinal (GI tract. The bacterium has great potential as food-grade cell factory and for in situ delivery of biomolecules. Since protein secretion is important both for probiotic activity and in biotechnological applications, we have carried out a genome-wide experimental study of signal peptide (SP functionality. Results We have constructed a library of 76 Sec-type signal peptides from L. plantarum WCFS1 that were predicted to be cleaved by signal peptidase I. SP functionality was studied using staphylococcal nuclease (NucA as a reporter protein. 82% of the SPs gave significant extracellular NucA activity. Levels of secreted NucA varied by a dramatic 1800-fold and this variation was shown not to be the result of different mRNA levels. For the best-performing SPs all produced NucA was detected in the culture supernatant, but the secretion efficiency decreased for the less well performing SPs. Sequence analyses of the SPs and their cognate proteins revealed four properties that correlated positively with SP performance for NucA: high hydrophobicity, the presence of a transmembrane helix predicted by TMHMM, the absence of an anchoring motif in the cognate protein, and the length of the H+C domain. Analysis of a subset of SPs with a lactobacillal amylase (AmyA showed large variation in production levels and secretion efficiencies. Importantly, there was no correlation between SP performance with NucA and the performance with AmyA. Conclusion This is the first comprehensive experimental study showing that predicted SPs in the L. plantarum genome actually are capable of driving protein secretion. The results reveal considerable variation between the SPs that is at least in part dependent on the protein that is secreted. Several SPs stand out as promising candidates for efficient secretion of heterologous proteins in L. plantarum. The

  7. Growth phase and pH influence peptide signaling for competence development in Streptococcus mutans.

    Science.gov (United States)

    Guo, Qiang; Ahn, Sang-Joon; Kaspar, Justin; Zhou, Xuedong; Burne, Robert A

    2014-01-01

    The development of competence by the dental caries pathogen Streptococcus mutans is mediated primarily through the alternative sigma factor ComX (SigX), which is under the control of multiple regulatory systems and activates the expression of genes involved in DNA uptake and recombination. Here we report that the induction of competence and competence gene expression by XIP (sigX-inducing peptide) and CSP (competence-stimulating peptide) is dependent on the growth phase and that environmental pH has a potent effect on the responses to XIP. A dramatic decline in comX and comS expression was observed in mid- and late-exponential-phase cells. XIP-mediated competence development and responses to XIP were optimal around a neutral pH, although mid-exponential-phase cells remained refractory to XIP treatment, and acidified late-exponential-phase cultures were resistant to killing by high concentrations of XIP. Changes in the expression of the genes for the oligopeptide permease (opp), which appears to be responsible for the internalization of XIP, could not entirely account for the behaviors observed. Interestingly, comS and comX expression was highly induced in response to endogenously overproduced XIP or ComS in mid-exponential-phase cells. In contrast to the effects of pH on XIP, competence induction and responses to CSP in complex medium were not affected by pH, although a decreased response to CSP in cells that had exited early-exponential phase was observed. Collectively, these results indicate that competence development may be highly sensitive to microenvironments within oral biofilms and that XIP and CSP signaling in biofilms could be spatially and temporally heterogeneous.

  8. In silico analysis and experimental validation of lipoprotein and novel Tat signal peptides processing in Anabaena sp. PCC7120.

    Science.gov (United States)

    Kumari, Sonika; Chaurasia, Akhilesh Kumar

    2015-12-01

    Signal peptide (SP) plays a pivotal role in protein translocation. Lipoprotein- and twin arginine translocase (Tat) dependent signal peptides were studied in All3087, a homolog of competence protein of Synechocystis PCC6803 and in two putative alkaline phosphatases (ALPs, Alr2234 and Alr4976), respectively. In silico analysis of All3087 is shown to possess the characteristics feature of competence proteins such as helix-hairpin-helix, N and C-terminal HKD endonuclease domain, calcium binding domain and N-terminal lipoprotein signal peptide. The SP recognition-cleavage site in All3087 was predicted (AIA-AC) using SignalP while further in-depth analysis using Pred-Lipo and WebLogo analysis for consensus sequence showed it as IAA-C. Activities of putative ALPs were confirmed by heterologous overexpression, activity assessment and zymogram analysis. ALP activity in Anabaena remains cell bound in log-phase, but during late log/stationary phase, an enhanced ALP activity was detected in extracellular milieu. The enhancement of ALP activity during stationary phase was not only due to inorganic phosphate limitation but also contributed by the presence of novel bipartite Tat-SP. The Tat signal transported the folded active ALPs to the membrane, followed by anchoring into the membrane and successive cleavage enabling transportation of the ALPs to the extracellular milieu, because of bipartite architecture and processing of transit Tat-SP.

  9. Extracellular expression of alkaline phytase in Pichia pastoris: Influence of signal peptides, promoters and growth medium

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    Mimi Yang

    2015-06-01

    Full Text Available Alkaline phytase isolated from pollen grains of Lilium longiflorum (LlALP possesses unique catalytic and thermal stability properties that suggest it has the potential to be used as a feed supplement. However, substantial amounts of active enzymes are needed for animal feed studies and endogenous levels of LlALP in lily pollen are too low to provide the required amounts. Active rLlALP2 (coded by LlAlp2, one of two isoforms of alkaline phytase cDNA identified in lily pollen has been successfully expressed in intracellular compartments of Pichia pastoris, however enzyme yields have been modest (25–30 mg/L and purification of the enzyme has been challenging. Expression of foreign proteins to the extracellular medium of P. pastoris greatly simplifies protein purification because low levels of endogenous proteins are secreted by the yeast. In this paper, we first describe the generation of P. pastoris strains that will secrete rLlALP2 to the extracellular medium. Data presented here indicates that deletion of native signal peptides at the N- and C-termini of rLlALP2 enhanced α-mating factor (α-MF-driven secretion by four-fold; chicken egg white lysozyme signal peptide was ineffective in the extracellular secretion of rLlALP2. Second, we describe our efforts to increase expression levels by employing a constitutive promoter from the glyceraldehyde-3-phosphate dehydrogenase gene (PGAP in place of the strong, tightly controlled promoter of alcohol oxidase 1 gene (PAOX1. PGAP enhanced the extracellular expression levels of rLlALP2 compared to PAOX1. Finally, we report on the optimization of the culture medium to enhance yields of rLlALP2. The strength of PGAP varies depending on the carbon source available for cell growth; secreted expression of rLlALP2 was highest when glycerol was the carbon source. The addition of histidine and Triton X-100 also enhanced extracellular expression. Taken together, the employment of PGAP under optimized culture

  10. Entropy, color, and color rendering.

    Science.gov (United States)

    Price, Luke L A

    2012-12-01

    The Shannon entropy [Bell Syst. Tech J.27, 379 (1948)] of spectral distributions is applied to the problem of color rendering. With this novel approach, calculations for visual white entropy, spectral entropy, and color rendering are proposed, indices that are unreliant on the subjectivity inherent in reference spectra and color samples. The indices are tested against real lamp spectra, showing a simple and robust system for color rendering assessment. The discussion considers potential roles for white entropy in several areas of color theory and psychophysics and nonextensive entropy generalizations of the entropy indices in mathematical color spaces.

  11. The potential of signal peptide peptidase as a therapeutic target for hepatitis C.

    Science.gov (United States)

    Moriishi, Kohji

    2017-09-01

    Chronic infection with hepatitis C virus (HCV) causes liver steatosis, cirrhosis, metabolic syndrome with inflammation, and eventually leads to hepatocellular carcinoma. HCV core protein is a well-known capsid protein and pathogenic factor related to lipid accumulation, type 2 diabetes mellitus, and carcinogenesis. Cleavage of the C-terminal transmembrane region by signal peptide peptidase (SPP) is required for maturation of the core protein. Areas covered: Herein, this review details the general aspects of the structure, lifecycle, pathogenesis, and maturation of the HCV core protein, the function of SPP, and clinically available direct-acting antivirals (DAAs). SPP is classified into a group of GXGD-type intramembrane proteases including presenilin-1, which is a component of γ-secretase complex. Several SPP inhibitors were previously identified from γ-secretase inhibitors, but have not yet been improved based on specificity to SPP. Finally, the author discusses the potential of SPP inhibitors for hepatitis C therapy. Expert opinion: Currently available DAAs therapies are limited because of different viral genotypes and underlying conditions in each patient. DAA-resistant viruses have also been reported. Development of SPP-selective inhibitors may improve current HCV therapies by decreasing in the emergence of DAA-resistant viruses irrespective of viral genotype.

  12. Targeting p35/Cdk5 Signalling via CIP-Peptide Promotes Angiogenesis in Hypoxia

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    Bosutti, Alessandra; Qi, Jie; Pennucci, Roberta; Bolton, David; Matou, Sabine; Ali, Kamela; Tsai, Li-Huei; Krupinski, Jerzy; Petcu, Eugene B.; Montaner, Joan; Al Baradie, Raid; Caccuri, Francesca; Caruso, Arnaldo; Alessandri, Giulio; Kumar, Shant; Rodriguez, Cristina; Martinez-Gonzalez, Jose; Slevin, Mark

    2013-01-01

    Cyclin-dependent kinase-5 (Cdk5) is over-expressed in both neurons and microvessels in hypoxic regions of stroke tissue and has a significant pathological role following hyper-phosphorylation leading to calpain-induced cell death. Here, we have identified a critical role of Cdk5 in cytoskeleton/focal dynamics, wherein its activator, p35, redistributes along actin microfilaments of spreading cells co-localising with p(Tyr15)Cdk5, talin/integrin beta-1 at the lamellipodia in polarising cells. Cdk5 inhibition (roscovitine) resulted in actin-cytoskeleton disorganisation, prevention of protein co-localization and inhibition of movement. Cells expressing Cdk5 (D144N) kinase mutant, were unable to spread, migrate and form tube-like structures or sprouts, while Cdk5 wild-type over-expression showed enhanced motility and angiogenesis in vitro, which was maintained during hypoxia. Gene microarray studies demonstrated myocyte enhancer factor (MEF2C) as a substrate for Cdk5-mediated angiogenesis in vitro. MEF2C showed nuclear co-immunoprecipitation with Cdk5 and almost complete inhibition of differentiation and sprout formation following siRNA knock-down. In hypoxia, insertion of Cdk5/p25-inhibitory peptide (CIP) vector preserved and enhanced in vitro angiogenesis. These results demonstrate the existence of critical and complementary signalling pathways through Cdk5 and p35, and through which coordination is a required factor for successful angiogenesis in sustained hypoxic condition. PMID:24098701

  13. Targeting p35/Cdk5 signalling via CIP-peptide promotes angiogenesis in hypoxia.

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    Alessandra Bosutti

    Full Text Available Cyclin-dependent kinase-5 (Cdk5 is over-expressed in both neurons and microvessels in hypoxic regions of stroke tissue and has a significant pathological role following hyper-phosphorylation leading to calpain-induced cell death. Here, we have identified a critical role of Cdk5 in cytoskeleton/focal dynamics, wherein its activator, p35, redistributes along actin microfilaments of spreading cells co-localising with p(Tyr15Cdk5, talin/integrin beta-1 at the lamellipodia in polarising cells. Cdk5 inhibition (roscovitine resulted in actin-cytoskeleton disorganisation, prevention of protein co-localization and inhibition of movement. Cells expressing Cdk5 (D144N kinase mutant, were unable to spread, migrate and form tube-like structures or sprouts, while Cdk5 wild-type over-expression showed enhanced motility and angiogenesis in vitro, which was maintained during hypoxia. Gene microarray studies demonstrated myocyte enhancer factor (MEF2C as a substrate for Cdk5-mediated angiogenesis in vitro. MEF2C showed nuclear co-immunoprecipitation with Cdk5 and almost complete inhibition of differentiation and sprout formation following siRNA knock-down. In hypoxia, insertion of Cdk5/p25-inhibitory peptide (CIP vector preserved and enhanced in vitro angiogenesis. These results demonstrate the existence of critical and complementary signalling pathways through Cdk5 and p35, and through which coordination is a required factor for successful angiogenesis in sustained hypoxic condition.

  14. Sequence variations of Env signal peptide alleles in different clinical stages of HIV infection.

    Science.gov (United States)

    da Silva, Joaquim Xavier; Franco, Octávio Luiz; Lemos, Mikael Araújo Guimarães; Gondim, Marcos Vinícius Pereira; Prosdocimi, Francisco; Argañaraz, Enrique Roberto

    2011-09-01

    The human immunodeficiency virus has been shown to increase its infectivity throughout the course of infection. This virus selection property has been associated with genome mutations and recombinations among virus variants, causing amino acid residue alterations in important viral proteins. In order to explore the contribution of Env signal peptide (Env-sp) to Env glycoprotein expression and its possible relationship to increased virus infectivity observed at late stages of infection, we characterized Env-sp sequences derived from twelve patients at "early" and "late" stages of HIV infection without antiretroviral therapy use. In spite of the remarkable overall similarity between both stages, we observed the deletion of a sequence of neutral and basic residues at the Env-sp amino terminus in virus from early stage specimens and the insertion of basic residues in the hydrophobic region on late-stage viral isolates. The Env-sp sequence alterations may have viral adaptive functions during HIV infection. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Antagonist properties of Conus parius peptides on N-methyl-D-aspartate receptors and their effects on CREB signaling.

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    Shailaja Kunda

    Full Text Available Three members of a family of small neurotoxic peptides from the venom of Conus parius, conantokins (Con Pr1, Pr2, and Pr3, function as antagonists of N-methyl-D-aspartate receptors (NMDAR. We report structural characterizations of these synthetic peptides, and also demonstrate their antagonistic properties toward ion flow through NMDAR ion channels in primary neurons. ConPr1 and ConPr2 displayed moderate increases in α-helicity after addition of Mg(2+. Native apo-ConPr3 possessed an α-helical conformation, and the helicity increased only slightly on addition of Mg(2+. Additionally, these peptides diminished NMDA/Gly-mediated currents and intracellular Ca(2+ (iCa(2+ influx in mature rat primary hippocampal neurons. Electrophysiological data showed that these peptides displayed slower antagonistic properties toward the NMDAR than conantokins from other species of cone snails, e.g., ConT and ConG. Furthermore, to demonstrate selectivity of the C. parius-derived conantokins towards specific NMDAR subunits, cortical neurons from GluN2A(-/- and GluN2B(-/- mice were utilized. Robust inhibition of NMDAR-mediated stimulation in GluN2A(-/--derived mouse neurons, as compared to those isolated from GluN2B(-/--mouse brains, was observed, suggesting a greater selectivity of these antagonists towards the GluN2B subunit. These C. parius conantokins mildly inhibited NMDAR-induced phosphorylation of CREB at Ser(133, suggesting that the peptides modulated iCa(2+ entry and, thereby, activation of CREB, a transcription factor that is required for maintaining long-term synaptic activity. Our data mechanistically show that while these peptides effectively antagonize NMDAR-directed current and iCa(2+ influx, receptor-coupled CREB signaling is maintained. The consequence of sustained CREB signaling is improved neuronal plasticity and survival during neuropathologies.

  16. Antagonist properties of Conus parius peptides on N-methyl-D-aspartate receptors and their effects on CREB signaling.

    Science.gov (United States)

    Kunda, Shailaja; Cheriyan, John; Hur, Michael; Balsara, Rashna D; Castellino, Francis J

    2013-01-01

    Three members of a family of small neurotoxic peptides from the venom of Conus parius, conantokins (Con) Pr1, Pr2, and Pr3, function as antagonists of N-methyl-D-aspartate receptors (NMDAR). We report structural characterizations of these synthetic peptides, and also demonstrate their antagonistic properties toward ion flow through NMDAR ion channels in primary neurons. ConPr1 and ConPr2 displayed moderate increases in α-helicity after addition of Mg(2+). Native apo-ConPr3 possessed an α-helical conformation, and the helicity increased only slightly on addition of Mg(2+). Additionally, these peptides diminished NMDA/Gly-mediated currents and intracellular Ca(2+) (iCa(2+)) influx in mature rat primary hippocampal neurons. Electrophysiological data showed that these peptides displayed slower antagonistic properties toward the NMDAR than conantokins from other species of cone snails, e.g., ConT and ConG. Furthermore, to demonstrate selectivity of the C. parius-derived conantokins towards specific NMDAR subunits, cortical neurons from GluN2A(-/-) and GluN2B(-/-) mice were utilized. Robust inhibition of NMDAR-mediated stimulation in GluN2A(-/-)-derived mouse neurons, as compared to those isolated from GluN2B(-/-)-mouse brains, was observed, suggesting a greater selectivity of these antagonists towards the GluN2B subunit. These C. parius conantokins mildly inhibited NMDAR-induced phosphorylation of CREB at Ser(133), suggesting that the peptides modulated iCa(2+) entry and, thereby, activation of CREB, a transcription factor that is required for maintaining long-term synaptic activity. Our data mechanistically show that while these peptides effectively antagonize NMDAR-directed current and iCa(2+) influx, receptor-coupled CREB signaling is maintained. The consequence of sustained CREB signaling is improved neuronal plasticity and survival during neuropathologies.

  17. Circulating preproinsulin signal peptide-specific CD8 T cells restricted by the susceptibility molecule HLA-A24 are expanded at onset of type 1 diabetes and kill β-cells.

    Science.gov (United States)

    Kronenberg, Deborah; Knight, Robin R; Estorninho, Megan; Ellis, Richard J; Kester, Michel G; de Ru, Arnoud; Eichmann, Martin; Huang, Guo C; Powrie, Jake; Dayan, Colin M; Skowera, Ania; van Veelen, Peter A; Peakman, Mark

    2012-07-01

    Type 1 diabetes results from T cell-mediated β-cell destruction. The HLA-A*24 class I gene confers significant risk of disease and early onset. We tested the hypothesis that HLA-A24 molecules on islet cells present preproinsulin (PPI) peptide epitopes to CD8 cytotoxic T cells (CTLs). Surrogate β-cell lines secreting proinsulin and expressing HLA-A24 were generated and their peptide ligandome examined by mass spectrometry to discover naturally processed and HLA-A24-presented PPI epitopes. A novel PPI epitope was identified and used to generate HLA-A24 tetramers and examine the frequency of PPI-specific T cells in new-onset HLA-A*24(+) patients and control subjects. We identified a novel naturally processed and HLA-A24-presented PPI signal peptide epitope (PPI(3-11); LWMRLLPLL). HLA-A24 tetramer analysis reveals a significant expansion of PPI(3-11)-specific CD8 T cells in the blood of HLA-A*24(+) recent-onset patients compared with HLA-matched control subjects. Moreover, a patient-derived PPI(3-11)-specific CD8 T-cell clone shows a proinflammatory phenotype and kills surrogate β-cells and human HLA-A*24(+) islet cells in vitro. These results indicate that the type 1 diabetes susceptibility molecule HLA-A24 presents a naturally processed PPI signal peptide epitope. PPI-specific, HLA-A24-restricted CD8 T cells are expanded in patients with recent-onset disease. Human islet cells process and present PPI(3-11), rendering themselves targets for CTL-mediated killing.

  18. A facile reporter system for the experimental identification of twin-arginine translocation (Tat) signal peptides from all kingdoms of life.

    Science.gov (United States)

    Widdick, David A; Eijlander, Robyn T; van Dijl, Jan Maarten; Kuipers, Oscar P; Palmer, Tracy

    2008-01-18

    We have developed a reporter protein system for the experimental verification of twin-arginine signal peptides. This reporter system is based on the Streptomyces coelicolor agarase protein, which is secreted into the growth medium by the twin-arginine translocation (Tat) pathway and whose extracellular activity can be assayed colorimetrically in a semiquantitative manner. Replacement of the native agarase signal peptide with previously characterized twin-arginine signal peptides from other Gram-positive and Gram-negative bacteria resulted in efficient Tat-dependent export of agarase. Candidate twin-arginine signal peptides from archaeal proteins as well as plant thylakoid-targeting sequences were also demonstrated to mediate agarase translocation. A naturally occurring variant signal peptide with an arginine-glutamine motif instead of the consensus di-arginine was additionally recognized as a Tat-targeting sequence by Streptomyces. Application of the agarase assay to previously uncharacterized candidate Tat signal peptides from Bacillus subtilis identified two further probable Tat substrates in this organism. This is the first versatile reporter system for Tat signal peptide identification.

  19. Exposure render: an interactive photo-realistic volume rendering framework.

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    Thomas Kroes

    Full Text Available The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR by integrating a number of visually plausible but often effect-specific rendering techniques, for instance modeling of light occlusion and depth of field. Besides yielding more attractive renderings, especially the more realistic lighting has a positive effect on perceptual tasks. Although these new rendering techniques yield impressive results, they exhibit limitations in terms of their exibility and their performance. Monte Carlo ray tracing (MCRT, coupled with physically based light transport, is the de-facto standard for synthesizing highly realistic images in the graphics domain, although usually not from volumetric data. Due to the stochastic sampling of MCRT algorithms, numerous effects can be achieved in a relatively straight-forward fashion. For this reason, we have developed a practical framework that applies MCRT techniques also to direct volume rendering (DVR. With this work, we demonstrate that a host of realistic effects, including physically based lighting, can be simulated in a generic and flexible fashion, leading to interactive DVR with improved realism. In the hope that this improved approach to DVR will see more use in practice, we have made available our framework under a permissive open source license.

  20. Targeted Mass Spectrometry Approach Enabled Discovery of O-Glycosylated Insulin and Related Signaling Peptides in Mouse and Human Pancreatic Islets.

    Science.gov (United States)

    Yu, Qing; Canales, Alejandra; Glover, Matthew S; Das, Rahul; Shi, Xudong; Liu, Yang; Keller, Mark P; Attie, Alan D; Li, Lingjun

    2017-08-07

    O-Linked glycosylation often involves the covalent attachment of sugar moieties to the hydroxyl group of serine or threonine on proteins/peptides. Despite growing interest in glycoproteins, little attention has been directed to glycosylated signaling peptides, largely due to lack of enabling analytical tools. Here we explore the occurrence of naturally O-linked glycosylation on the signaling peptides extracted from mouse and human pancreatic islets using mass spectrometry (MS). A novel targeted MS-based method is developed to increase the likelihood of capturing these modified signaling peptides and to provide improved sequence coverage and accurate glycosite localization, enabling the first large-scale discovery of O-glycosylation on signaling peptides. Several glycosylated signaling peptides with multiple glycoforms are identified, including the first report of glycosylated insulin-B chain and insulin-C peptide and BigLEN. This discovery may reveal potential novel functions as glycosylation could influence their conformation and biostability. Given the importance of insulin and its related peptide hormones and previous studies of glycosylated insulin analogues, this natural glycosylation may provide important insights into diabetes research and therapeutic treatments.

  1. Solution structure and peptide binding of the PTB domain from the AIDA1 postsynaptic signaling scaffolding protein.

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    Ekaterina Smirnova

    Full Text Available AIDA1 links persistent chemical signaling events occurring at the neuronal synapse with global changes in gene expression. Consistent with its role as a scaffolding protein, AIDA1 is composed of several protein-protein interaction domains. Here we report the NMR structure of the carboxy terminally located phosphotyrosine binding domain (PTB that is common to all AIDA1 splice variants. A comprehensive survey of peptides identified a consensus sequence around an NxxY motif that is shared by a number of related neuronal signaling proteins. Using peptide arrays and fluorescence based assays, we determined that the AIDA1 PTB domain binds amyloid protein precursor (APP in a similar manner to the X11/Mint PTB domain, albeit at reduced affinity (∼10 µM that may allow AIDA1 to effectively sample APP, as well as other protein partners in a variety of cellular contexts.

  2. Extreme variations in the ratios of non-synonymous to synonymous nucleotide substitution rates in signal peptide evolution.

    Science.gov (United States)

    Garcia-Maroto, F; Castagnaro, A; Sanchez de la Hoz, P; Maraña, C; Carbonero, P; García-Olmedo, F

    1991-08-05

    Nucleotide sequences encoding signal peptides from the precursors of alpha-amylase/trypsin inhibitors from cereals are homologous to those corresponding to the precursors of thaumatin II and of plastocyanins. Non-synonymous (KA) and synonymous (KS) rates of nucleotide substitutions have been calculated for all possible binary combinations. Extreme variation in KA/KS ratios has been observed; from the 0.167 average found within the plastocyanin family to an average of 1.90 calculated for the inhibitors/thaumatin II transition. A similar calculation has been carried out for the signal peptide sequences of thionins, which are unrelated to those of the alpha-amylase/trypsin inhibitor family, and an average KA/KS of 0.12 has been obtained. This variation can be largely explained in terms of an empirical index of stability related to amino acid composition and seems to be independent of functional constraints.

  3. Amelogenin signal peptide mutation: Correlation between mutations in the amelogenin gene (AMGX) and manifestations of X-linked amelogenesis imperfecta

    Energy Technology Data Exchange (ETDEWEB)

    Lagerstroem-Fermer, M.; Nilsson, M.; Pettersson, U. [Univ. of Uppsala (Sweden)] [and others

    1995-03-01

    Formation of tooth enamel is a poorly understood biological process. In this study the authors describe a 9-bp deletion in exon 2 of the amelogenin gene (AMGX) causing X-linked hypoplastic amelogenesis imperfecta, a disease characterized by defective enamel. The mutation results in the loss of 3 amino acids and exchange of 1 in the signal peptide of the amelogenin protein. This deletion in the signal peptide probably interferes with translocation of the amelogenin protein during synthesis, resulting in the thin enamel observed in affected members of the family. The authors compare this mutation to a previously reported mutation in the amelogenin gene that causes a different disease phenotype. The study illustrates that molecular analysis can help explain the various manifestations of a tooth disorder and thereby provide insights into the mechanisms of tooth enamel formation. 16 refs., 2 figs., 1 tab.

  4. Baculovirus display of single chain antibody (scFv using a novel signal peptide

    Directory of Open Access Journals (Sweden)

    Gonzalez Gaëlle

    2010-11-01

    vector resulted in baculoviral progeny displaying scFvE2/p17. The function required for BV envelope incorporation was carried by the N-terminal octadecapeptide of scFvE2/p17, which acted as a signal peptide for BV display. Fusion of this peptide to the N-terminus of scFv molecules of interest could be applied as a general method for BV-display of scFv in a GP64- and VSV-G-independent manner.

  5. Enhanced endothelium-dependent vasodilation in subjects with Proline7 substitution in the signal peptide of neuropeptide Y.

    Science.gov (United States)

    Järvisalo, Mikko J; Jartti, Laura; Karvonen, Matti K; Pesonen, Ullamari; Koulu, Markku; Marniemi, Jukka; Hammar, Niklas; Kaprio, Jaakko; Paakkunainen, Ulla; Simell, Olli; Raitakari, Olli T; Rönnemaa, Tapani

    2003-04-01

    Neuropeptide Y (NPY) is a molecule that may have both vasoconstrictive and vasodilatory actions. A common polymorphism in the human NPY gene that results in the Leucine7 to Proline7 substitution (Leu7Pro) in the signal peptide part of the NPY was recently identified. This substitution has been associated with elevated serum cholesterol levels and with slightly accelerated progression rate of carotid intima-media thickness, thus suggesting increased risk of atherosclerosis in carriers of Pro7 substitution. Recent data also indicate that subjects with Pro7 substitution may have increased endothelial release of NPY. This study was undertaken to elucidate the effects of Leu7Pro polymorphism on arterial endothelial function. We measured flow-mediated endothelial-dependent dilatation (FMD) of the brachial artery in two separate populations: in 152 middle-aged men and in 95 prepubertal children. In both study populations, subjects with Pro7 substitution had 48-52% higher FMD compared with subjects having the wildtype (Leu7/Leu7) signal peptide sequence. We conclude that Pro7 substitution in signal peptide of the NPY is associated with enhanced endothelial-dependent vasodilation. Prospective studies are needed to determine whether Pro7 substitution is associated with increased or decreased risk of cardiovascular morbidity and mortality.

  6. An essential signal peptide peptidase identified in an RNAi screen of serine peptidases of Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Catherine X Moss

    Full Text Available The serine peptidases of Trypanosoma brucei have been viewed as potential drug targets. In particular, the S9 prolyl oligopeptidase subfamily is thought to be a good avenue for drug discovery. This is based on the finding that some S9 peptidases are secreted and active in the mammalian bloodstream, and that they are a class of enzyme against which drugs have successfully been developed. We collated a list of all serine peptidases in T. brucei, identifying 20 serine peptidase genes, of which nine are S9 peptidases. We screened all 20 serine peptidases by RNAi to determine which, if any, are essential for bloodstream form T. brucei survival. All S9 serine peptidases were dispensable for parasite survival in vitro, even when pairs of similar genes, coding for oligopeptidase B or prolyl oligopeptidase, were targeted simultaneously. We also found no effect on parasite survival in an animal host when the S9 peptidases oligopeptidase B, prolyl oligopeptidase or dipeptidyl peptidase 8 were targeted. The only serine peptidase to emerge from the RNAi screen as essential was a putative type-I signal peptide peptidase (SPP1. This gene was essential for parasite survival both in vitro and in vivo. The growth defect conferred by RNAi depletion of SPP1 was rescued by expression of a functional peptidase from an RNAi resistant SPP1 gene. However, expression of catalytically inactive SPP1 was unable to rescue cells from the SPP1 depleted phenotype, demonstrating that SPP1 serine peptidase activity is necessary for T. brucei survival.

  7. Signal peptide discrimination and cleavage site identification using SVM and NN.

    Science.gov (United States)

    Kazemian, H B; Yusuf, S A; White, K

    2014-02-01

    About 15% of all proteins in a genome contain a signal peptide (SP) sequence, at the N-terminus, that targets the protein to intracellular secretory pathways. Once the protein is targeted correctly in the cell, the SP is cleaved, releasing the mature protein. Accurate prediction of the presence of these short amino-acid SP chains is crucial for modelling the topology of membrane proteins, since SP sequences can be confused with transmembrane domains due to similar composition of hydrophobic amino acids. This paper presents a cascaded Support Vector Machine (SVM)-Neural Network (NN) classification methodology for SP discrimination and cleavage site identification. The proposed method utilises a dual phase classification approach using SVM as a primary classifier to discriminate SP sequences from Non-SP. The methodology further employs NNs to predict the most suitable cleavage site candidates. In phase one, a SVM classification utilises hydrophobic propensities as a primary feature vector extraction using symmetric sliding window amino-acid sequence analysis for discrimination of SP and Non-SP. In phase two, a NN classification uses asymmetric sliding window sequence analysis for prediction of cleavage site identification. The proposed SVM-NN method was tested using Uni-Prot non-redundant datasets of eukaryotic and prokaryotic proteins with SP and Non-SP N-termini. Computer simulation results demonstrate an overall accuracy of 0.90 for SP and Non-SP discrimination based on Matthews Correlation Coefficient (MCC) tests using SVM. For SP cleavage site prediction, the overall accuracy is 91.5% based on cross-validation tests using the novel SVM-NN model.

  8. GROWTH OF STREPTOCOCCUS MUTANS IN BIOFILMS ALTERS PEPTIDE SIGNALING AT THE SUB-POPULATION LEVEL

    Directory of Open Access Journals (Sweden)

    Robert Colquhoun Shields

    2016-07-01

    Full Text Available Streptococcus mutans activates multiple cellular processes in response to the formation of a complex between comX-inducing peptide (XIP and the ComR transcriptional regulator. Bulk phase and microfluidic experiments previously revealed that ComR-dependent activation of comX is altered by pH and by carbohydrate source. Biofilm formation is a major factor in bacterial survival and virulence in the oral cavity. Here, we sought to determine the response of S. mutans biofilm cells to XIP during different stages of biofilm maturation. Using flow cytometry and confocal microscopy, we showed that exogenous addition of XIP to early biofilms resulted in robust comX activation. However, as the biofilms matured, increasing amounts of XIP were required to activate comX expression. Single-cell analysis demonstrated that the entire population was responding to XIP with activation of comX in early biofilms, but only a sub-population was responding in mature biofilms. The sub-population response of mature biofilms was retained when the cells were dispersed and then treated with XIP. The proportion and intensity of the bi-modal response of mature biofilm cells was altered in mutants lacking the Type II toxins MazF and RelE, or in a strain lacking the (pppGpp synthase/hydrolase RelA. Thus, competence signaling is markedly altered in cells growing in mature biofilms, and pathways that control cell death and growth/survival decisions modulate activation of comX expression in these sessile populations.

  9. Growth of Streptococcus mutans in Biofilms Alters Peptide Signaling at the Sub-population Level

    Science.gov (United States)

    Shields, Robert C.; Burne, Robert A.

    2016-01-01

    Streptococcus mutans activates multiple cellular processes in response to the formation of a complex between comX-inducing peptide (XIP) and the ComR transcriptional regulator. Bulk phase and microfluidic experiments previously revealed that ComR-dependent activation of comX is altered by pH and by carbohydrate source. Biofilm formation is a major factor in bacterial survival and virulence in the oral cavity. Here, we sought to determine the response of S. mutans biofilm cells to XIP during different stages of biofilm maturation. Using flow cytometry and confocal microscopy, we showed that exogenous addition of XIP to early biofilms resulted in robust comX activation. However, as the biofilms matured, increasing amounts of XIP were required to activate comX expression. Single-cell analysis demonstrated that the entire population was responding to XIP with activation of comX in early biofilms, but only a sub-population was responding in mature biofilms. The sub-population response of mature biofilms was retained when the cells were dispersed and then treated with XIP. The proportion and intensity of the bi-modal response of mature biofilm cells was altered in mutants lacking the Type II toxins MazF and RelE, or in a strain lacking the (p)ppGpp synthase/hydrolase RelA. Thus, competence signaling is markedly altered in cells growing in mature biofilms, and pathways that control cell death and growth/survival decisions modulate activation of comX expression in these sessile populations. PMID:27471495

  10. Amino Acid-Dependent Attenuation of Toll-like Receptor Signaling by Peptide-Gold Nanoparticle Hybrids.

    Science.gov (United States)

    Yang, Hong; Fung, Shan-Yu; Xu, Shuyun; Sutherland, Darren P; Kollmann, Tobias R; Liu, Mingyao; Turvey, Stuart E

    2015-07-28

    Manipulation of immune responsiveness using nanodevices provides a potential approach to treat human diseases. Toll-like receptor (TLR) signaling plays a central role in the pathophysiology of many acute and chronic human inflammatory diseases, and pharmacological regulation of TLR responses is anticipated to be beneficial in many of these inflammatory conditions. Here we describe the discovery of a unique class of peptide-gold nanoparticle hybrids that exhibit a broad inhibitory activity on TLR signaling, inhibiting signaling through TLRs 2, 3, 4, and 5. As exemplified using TLR4, the nanoparticles were found to inhibit both arms of TLR4 signaling cascade triggered by the prototypical ligand, lipopolysaccharide (LPS). Through structure-activity relationship studies, we identified the key chemical components of the hybrids that contribute to their immunomodulatory activity. Specifically, the hydrophobicity and aromatic ring structure of the amino acids on the peptides were essential for modulating TLR4 responses. This work enhances our fundamental understanding of the role of nanoparticle surface chemistry in regulating innate immune signaling, and identifies specific nanoparticle hybrids that may represent a unique class of anti-inflammatory therapeutics for human inflammatory diseases.

  11. RenderMan design principles

    Science.gov (United States)

    Apodaca, Tony; Porter, Tom

    1989-01-01

    The two worlds of interactive graphics and realistic graphics have remained separate. Fast graphics hardware runs simple algorithms and generates simple looking images. Photorealistic image synthesis software runs slowly on large expensive computers. The time has come for these two branches of computer graphics to merge. The speed and expense of graphics hardware is no longer the barrier to the wide acceptance of photorealism. There is every reason to believe that high quality image synthesis will become a standard capability of every graphics machine, from superworkstation to personal computer. The significant barrier has been the lack of a common language, an agreed-upon set of terms and conditions, for 3-D modeling systems to talk to 3-D rendering systems for computing an accurate rendition of that scene. Pixar has introduced RenderMan to serve as that common language. RenderMan, specifically the extensibility it offers in shading calculations, is discussed.

  12. Exposure Render: An Interactive Photo-Realistic Volume Rendering Framework

    NARCIS (Netherlands)

    Kroes, T.; Post, F.H.; Botha, C.P.

    2012-01-01

    The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR) by i

  13. Signaling Pathways Involved in Renal Oxidative Injury: Role of the Vasoactive Peptides and the Renal Dopaminergic System

    Directory of Open Access Journals (Sweden)

    N. L. Rukavina Mikusic

    2014-01-01

    Full Text Available The physiological hydroelectrolytic balance and the redox steady state in the kidney are accomplished by an intricate interaction between signals from extrarenal and intrarenal sources and between antinatriuretic and natriuretic factors. Angiotensin II, atrial natriuretic peptide and intrarenal dopamine play a pivotal role in this interactive network. The balance between endogenous antioxidant agents like the renal dopaminergic system and atrial natriuretic peptide, by one side, and the prooxidant effect of the renin angiotensin system, by the other side, contributes to ensuring the normal function of the kidney. Different pathological scenarios, as nephrotic syndrome and hypertension, where renal sodium excretion is altered, are associated with an impaired interaction between two natriuretic systems as the renal dopaminergic system and atrial natriuretic peptide that may be involved in the pathogenesis of renal diseases. The aim of this review is to update and comment the most recent evidences about the intracellular pathways involved in the relationship between endogenous antioxidant agents like the renal dopaminergic system and atrial natriuretic peptide and the prooxidant effect of the renin angiotensin system in the pathogenesis of renal inflammation.

  14. Overcoming the Refractory Expression of Secreted Recombinant Proteins in Mammalian Cells through Modification of the Signal Peptide and Adjacent Amino Acids.

    Directory of Open Access Journals (Sweden)

    Gülin Güler-Gane

    Full Text Available The expression and subsequent purification of mammalian recombinant proteins is of critical importance to many areas of biological science. To maintain the appropriate tertiary structure and post-translational modifications of such proteins, transient mammalian expression systems are often adopted. The successful utilisation of these systems is, however, not always forthcoming and some recombinant proteins prove refractory to expression in mammalian hosts. In this study we focussed on the role of different N-terminal signal peptides and residues immediately downstream, in influencing the level of secreted recombinant protein obtained from suspension HEK293 cells. Using secreted alkaline phosphatase (SEAP as a model protein, we identified that the +1/+2 downstream residues flanking a heterologous signal peptide significantly affect secreted levels. By incorporating these findings we conducted a comparison of different signal peptide sequences and identified the most productive as secrecon, a computationally-designed sequence. Importantly, in the context of the secrecon signal peptide and SEAP, we also demonstrated a clear preference for specific amino acid residues at the +1 position (e.g. alanine, and a detrimental effect of others (cysteine, proline, tyrosine and glutamine. When proteins that naturally contain these "undesirable" residues at the +1 position were expressed with their native signal peptide, the heterologous secrecon signal peptide, or secrecon with an additional alanine at the +1 or +1 and +2 position, the level of expression differed significantly and in an unpredictable manner. For each protein, however, at least one of the panel of signal peptide/adjacent amino acid combinations enabled successful recombinant expression. In this study, we highlight the important interplay between a signal peptide and its adjacent amino acids in enabling protein expression, and we describe a strategy that could enable recombinant proteins that

  15. Identification of putative insulin-like peptides and components of insulin signaling pathways in parasitic platyhelminths by the use of genome-wide screening.

    Science.gov (United States)

    Wang, Shuai; Luo, Xuenong; Zhang, Shaohua; Yin, Cai; Dou, Yongxi; Cai, Xuepeng

    2014-02-01

    No endogenous insulin-like peptides in parasitic flatworms have been reported. Insulin receptors from flukes and tapeworms have been shown to interact directly with the host-derived insulin molecule, which suggests the exploitation of host-derived insulin. In this study, a strategy of genome-wide searches followed by comprehensive analyses of strictly conserved features of the insulin family was used to demonstrate the presence of putative insulin-like peptides in the genomes of six tapeworms and two flukes. In addition, whole insulin signaling pathways were annotated on a genome-wide scale. Two putative insulin-like peptide genes in each genome of tapeworms and one insulin-like peptide gene in each genome of flukes were identified. The comprehensive analyses revealed that all of these peptides showed the common features shared by other members of the insulin family, and the phylogenetic analysis implied a putative gene duplication event in the Cestoda during the evolution of insulin-like peptide genes. The quantitative expression analysis and immunolocalization results suggested a putative role of these peptides in reproduction. Entire sets of major components of the classic insulin signaling pathway were successfully identified, suggesting that this pathway in parasitic flatworms might also regulate many other important biological activities. We believe that the identification of the insulin-like peptides gives us a better understanding of the insulin signaling pathway in these parasites, as well as host-parasite interactions.

  16. Single-Step Affinity Purification of ERK Signaling Complexes Using the Streptavidin-Binding Peptide (SBP) Tag.

    Science.gov (United States)

    Yang, Liu; Veraksa, Alexey

    2017-01-01

    Elucidation of biological functions of signaling proteins is facilitated by studying their protein-protein interaction networks. Affinity purification combined with mass spectrometry (AP-MS) has become a favorite method to study protein complexes. Here we describe a procedure for single-step purification of ERK (Rolled) and associated proteins from Drosophila cultured cells. The use of the streptavidin-binding peptide (SBP) tag allows for a highly efficient isolation of native ERK signaling complexes, which are suitable for subsequent analysis by mass spectrometry. Our analysis of the ERK interactome has identified both known and novel signaling components. This method can be easily adapted for SBP-based purification of protein complexes in any expression system.

  17. Truncated Glucagon-like Peptide-1 and Exendin-4 α-Conotoxin pl14a Peptide Chimeras Maintain Potency and α-Helicity and Reveal Interactions Vital for cAMP Signaling in Vitro.

    Science.gov (United States)

    Swedberg, Joakim E; Schroeder, Christina I; Mitchell, Justin M; Fairlie, David P; Edmonds, David J; Griffith, David A; Ruggeri, Roger B; Derksen, David R; Loria, Paula M; Price, David A; Liras, Spiros; Craik, David J

    2016-07-22

    Glucagon-like peptide-1 (GLP-1) signaling through the glucagon-like peptide 1 receptor (GLP-1R) is a key regulator of normal glucose metabolism, and exogenous GLP-1R agonist therapy is a promising avenue for the treatment of type 2 diabetes mellitus. To date, the development of therapeutic GLP-1R agonists has focused on producing drugs with an extended serum half-life. This has been achieved by engineering synthetic analogs of GLP-1 or the more stable exogenous GLP-1R agonist exendin-4 (Ex-4). These synthetic peptide hormones share the overall structure of GLP-1 and Ex-4, with a C-terminal helical segment and a flexible N-terminal tail. Although numerous studies have investigated the molecular determinants underpinning GLP-1 and Ex-4 binding and signaling through the GLP-1R, these have primarily focused on the length and composition of the N-terminal tail or on how to modulate the helicity of the full-length peptides. Here, we investigate the effect of C-terminal truncation in GLP-1 and Ex-4 on the cAMP pathway. To ensure helical C-terminal regions in the truncated peptides, we produced a series of chimeric peptides combining the N-terminal portion of GLP-1 or Ex-4 and the C-terminal segment of the helix-promoting peptide α-conotoxin pl14a. The helicity and structures of the chimeric peptides were confirmed using circular dichroism and NMR, respectively. We found no direct correlation between the fractional helicity and potency in signaling via the cAMP pathway. Rather, the most important feature for efficient receptor binding and signaling was the C-terminal helical segment (residues 22-27) directing the binding of Phe(22) into a hydrophobic pocket on the GLP-1R.

  18. Inhibition of Raf/MAPK signaling in Xenopus oocyte extracts by Raf-1-specific peptides.

    Science.gov (United States)

    Radziwill, G; Steinhusen, U; Aitken, A; Moelling, K

    1996-10-01

    Raf-1 is an upstream element of the mitogen-activated protein kinase (MAPK) pathway which leads to cell proliferation and differentiation. In this study Raf-1 derived peptides comprising the conserved amino acid residues Arg89 and Ser259, involved in binding of activated Ras and 14-3-3 proteins, respectively, were shown to interfere with MAPK activation in extracts from immature Xenopus oocytes. Lipids prepared from oocyte extracts can stimulate MAPK in a Ras- and protein kinase C-independent manner. This lipid-induced MAPK activation is blocked by a Raf-1 derived peptide comprising Ser259.

  19. Atrial natriuretic peptide signal pathway upregulated in stomach of streptozotocin-induced diabetic mice

    Institute of Scientific and Technical Information of China (English)

    Young-Chul; Kim

    2010-01-01

    AIM:To investigate atrial natriuretic peptide(ANP) secretion from gastric mucosa and the relationship between the ANP/natriuretic peptide receptor type A (NPR-A)pathway and diabetic gastroparesis. METHODS:Male imprinting control region(ICR)mice (4 wk old)were divided into two groups:control mice, and streptozotocin-induced diabetic mice.Eight weeks after injection,spontaneous gastric contraction was recorded by using physiography in control and streptozotocin-induced diabetic mice.The ANP-positive cells in ...

  20. REVIEW: Role of cyclic AMP signaling in the production and function of the incretin hormone glucagon-like peptide-1

    Science.gov (United States)

    Yu, Zhiwen; Jin, Tianru

    2008-01-01

    Pancreatic cells express the proglucagon gene (gcg) and thereby produce the peptide hormone glucagon, which stimulates hepatic glucose production and thereby increases blood glucose levels. The same gcg gene is also expressed in the intestinal endocrine L cells and certain neural cells in the brain. In the gut, gcg expression leads to the production of glucagon-like peptide-1 (GLP-1). This incretin hormone stimulates insulin secretion when blood glucose level is high. In addition, GLP-1 stimulates pancreatic cell proliferation, inhibits cell apoptosis, and has been utilized in the trans-differentiation of insulin producing cells. Today, a long-term effective GLP-1 receptor agonist has been developed as a drug in treating diabetes and potentially other metabolic disorders. Extensive investigations have shown that the expression of gcg and the production of GLP-1 can be activated by the elevation of the second messenger cyclic AMP (cAMP). Recent studies suggest that in addition to protein kinase A (PKA), exchange protein activated by cAMP (Epac), another effector of cAMP signaling, and the crosstalk between PKA and Wnt signaling pathway, are also involved in cAMP-stimulated gcg expression and GLP-1 production. Furthermore, functions of GLP-1 in pancreatic cells are mainly mediated by cAMP-PKA, cAMP-Epac and Wnt signaling pathways as well.

  1. The signal peptide anchors apolipoprotein M in plasma lipoproteins and prevents rapid clearance of apolipoprotein M from plasma

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Ahnström, Josefin; Axler, Olof

    2008-01-01

    Lipoproteins consist of lipids solubilized by apolipoproteins. The lipid-binding structural motifs of apolipoproteins include amphipathic alpha-helixes and beta-sheets. Plasma apolipoprotein (apo) M lacks an external amphipathic motif but, nevertheless, is exclusively associated with lipoproteins......M(Q22A)-Tg mice (transgenic mice)) and compared them with mice expressing wild-type human apoM (apoM-Tg mice). The substitution of the amino acid glutamine 22 with alanine in apoM(Q22A) results in secretion of human apoM without a signal peptide. The human apoM mRNA level in liver and the amount...

  2. Transcriptional regulation and signal-peptide-dependent secretion of exolevanase (LsdB) in the endophyte Gluconacetobacter diazotrophicus.

    Science.gov (United States)

    Menéndez, Carmen; Banguela, Alexander; Caballero-Mellado, Jesús; Hernández, Lázaro

    2009-03-01

    Gluconacetobacter diazotrophicus utilizes plant sucrose with a constitutively expressed levansucrase (LsdA), producing extracellular levan, which may be degraded under energetically unfavored conditions. Reverse transcriptase-PCR analysis revealed that lsdA and the downstream exolevanase gene (lsdB) form an operon. lsdB transcription was induced during growth with low fructose concentrations (0.44 to 33 mM) and repressed by glucose. Transport of LsdB to the periplasm involved N-terminal signal peptide cleavage. Type II secretion mutants failed to transfer LsdB across the outer membrane, impeding levan hydrolysis.

  3. Signal peptide homology between the sweet protein thaumatin II and unrelated cereal alpha-amylase/trypsin inhibitors.

    Science.gov (United States)

    Lázaro, A; Rodriguez-Palenzuela, P; Maraña, C; Carbonero, P; Garcia-Olmedo, F

    1988-10-24

    A cDNA clone (pUP-23) corresponding to a member of a protein family that includes inhibitors of trypsin and of heterologous alpha-amylases has been selected from a library derived from developing barley endosperm and its sequence has been determined. A stretch of 95 nucleotides that included the signal peptide and the first 8 residues of the mature protein was found to be homologous to an exactly equivalent region of the nucleotide sequence encoding the sweet protein thaumatin II. Evolutionary implications of this finding are discussed.

  4. Transcriptional Regulation and Signal-Peptide-Dependent Secretion of Exolevanase (LsdB) in the Endophyte Gluconacetobacter diazotrophicus▿

    Science.gov (United States)

    Menéndez, Carmen; Banguela, Alexander; Caballero-Mellado, Jesús; Hernández, Lázaro

    2009-01-01

    Gluconacetobacter diazotrophicus utilizes plant sucrose with a constitutively expressed levansucrase (LsdA), producing extracellular levan, which may be degraded under energetically unfavored conditions. Reverse transcriptase-PCR analysis revealed that lsdA and the downstream exolevanase gene (lsdB) form an operon. lsdB transcription was induced during growth with low fructose concentrations (0.44 to 33 mM) and repressed by glucose. Transport of LsdB to the periplasm involved N-terminal signal peptide cleavage. Type II secretion mutants failed to transfer LsdB across the outer membrane, impeding levan hydrolysis. PMID:19139238

  5. Interfering with DNA Damage Signals: Radiosensitizing Prostate Cancer Using Small Peptides

    Science.gov (United States)

    2009-05-01

    change of basal cell cycle distribution is detected (data not shown). These observations suggest that the THM-fusion peptides have minimal cytotoxicity...mec hanism inv olving ATM and dCK on the syn ergistic eff ect of nucleos ide analogues with radiotherapy. Manuscript in preparation. 24. Xi

  6. Systemic inflammatory response syndrome following burns is mediated by brain natriuretic peptide/natriuretic peptide A receptor-induced shock factor 1 signaling pathway.

    Science.gov (United States)

    Xu, Yang-Cheng; Luo, Cheng-Qun; Li, Xiong

    2016-10-01

    The aim of this study was to determine whether systemic inflammatory response syndrome (SIRS) in burn patients is mediated by the brain natriuretic peptide (BNP)/natriuretic peptide A receptor (NPRA)-induced heat shock factor 1 (HSF-1) signalling pathway. Mononuclear cells (MNCs) that were isolated from patients with burn injuries and SIRS mouse models and a RAW264.7 cell line were treated with normal serum or serum obtained from animals with burn injuries. In parallel, small hairpin RNAs (shRNAs) against BNP or NPRA were transfected in both cell types. Western blotting (WB) and enzyme-linked immunosorbent assay (ELISA) were used to detect protein expression and inflammatory factor levels, respectively. We found that interleukin (IL)-12, tumour necrosis factor (TNF)-α, C-reactive protein (CRP), and BNP levels were increased and IL-10 levels were decreased in the plasma and MNCs in vivo in the animal model of SIRS. Additionally, NPRA was upregulated, whereas HSF-1 was downregulated in monocytes in vivo. Treatment of RAW264.7 cells with burn serum or BNP induced IL-12, TNF-α, and CRP secretion as well as HSF-1 expression. Finally, silencing BNP with shRNA interrupted the effect of burn serum on RAW264.7 cells, and silencing NPRA blocked burn serum- and BNP-mediated changes in RAW264.7 cells. These results suggest that the interaction of NPRA with BNP secreted from circulatory MNCs as well as mononuclear macrophages leads to inflammation via HSF-1 during SIRS development following serious burn injury.

  7. Amyloid β Peptide Enhances RANKL-Induced Osteoclast Activation through NF-κB, ERK, and Calcium Oscillation Signaling

    Directory of Open Access Journals (Sweden)

    Shangfu Li

    2016-10-01

    Full Text Available Osteoporosis and Alzheimer’s disease (AD are common chronic degenerative disorders which are strongly associated with advanced age. We have previously demonstrated that amyloid beta peptide (Aβ, one of the pathological hallmarks of AD, accumulated abnormally in osteoporotic bone specimens in addition to having an activation effect on osteoclast (Bone 2014,61:164-75. However, the underlying molecular mechanisms remain unclear. Activation of NF-κB, extracellular signal-regulated kinase (ERK phosphorylates, and calcium oscillation signaling pathways by receptor activator NF-κB ligand (RANKL plays a pivotal role in osteoclast activation. Targeting this signaling to modulate osteoclast function has been a promising strategy for osteoclast-related diseases. In this study, we investigated the effects of Aβ on RANKL-induced osteoclast signaling pathways in vitro. In mouse bone marrow monocytes (BMMs, Aβ exerted no effect on RANKL-induced osteoclastogenesis but promoted osteoclastic bone resorption. In molecular levels, Aβ enhanced NF-κB activity and IκB-α degradation, activated ERK phosphorylation and stimulated calcium oscillation, thus leading to upregulation of NFAT-c1 expression during osteoclast activation. Taken together, our data demonstrate that Aβ enhances RANKL-induced osteoclast activation through IκB-α degradation, ERK phosphorylation, and calcium oscillation signaling pathways and that Aβ may be a promising agent in the treatment of osteoclast-related disease such as osteoporosis.

  8. Glucagon-like peptide-1 and cholecystokinin production and signaling in the pancreatic islet as an adaptive response to obesity.

    Science.gov (United States)

    Linnemann, Amelia K; Davis, Dawn Belt

    2016-04-01

    Precise control of blood glucose is dependent on adequate β-cell mass and function. Thus, reductions in β-cell mass and function lead to insufficient insulin production to meet demand, and result in diabetes. Recent evidence suggests that paracrine signaling in the islet might be important in obesity, and disruption of this signaling could play a role in the pathogenesis of diabetes. For example, we recently discovered a novel islet incretin axis where glucagon-like peptide-1 regulates β-cell production of another classic gut hormone, cholecystokinin. This axis is stimulated by obesity, and plays a role in enhancing β-cell survival. In the present review, we place our observations in the wider context of the literature on incretin regulation in the islet, and discuss the potential for therapeutic targeting of these pathways.

  9. Extensive sequence turnover of the signal peptides of members of the GDF/BMP family: exploring their evolutionary landscape

    Directory of Open Access Journals (Sweden)

    Veitia Reiner A

    2009-07-01

    Full Text Available Abstract We show that the predicted signal peptide (SP sequences of the secreted factors GDF9, BMP15 and AMH are well conserved in mammals but dramatic divergence is noticed for more distant orthologs. Interestingly, bioinformatic predictions show that the divergent protein segments do encode SPs. Thus, such SPs have undergone extensive sequence turnover with full preservation of functionality. This can be explained by a pervasive accumulation of neutral and compensatory mutations. An exploration of the potential evolutionary landscape of some SPs is presented. Some of these signal sequences highlight an apparent paradox: they are encoded, by definition, by orthologous DNA segments but they are, given their striking divergence, examples of what can be called functional convergence. Reviewers: This article was reviewed by Fyodor Kondrashov and Eugene V. Koonin.

  10. Somatostatin signaling system as an ancestral mechanism: Myoregulatory activity of an Allatostatin-C peptide in Hydra.

    Science.gov (United States)

    Alzugaray, María Eugenia; Hernández-Martínez, Salvador; Ronderos, Jorge Rafael

    2016-08-01

    The coordination of physiological processes requires precise communication between cells. Cellular interactions allow cells to be functionally related, facilitating the maintaining of homeostasis. Neuropeptides functioning as intercellular signals are widely distributed in Metazoa. It is assumed that neuropeptides were the first intercellular transmitters, appearing early during the evolution. In Cnidarians, neuropeptides are mainly involved in neurotransmission, acting directly or indirectly on epithelial muscle cells, and thereby controlling coordinated movements. Allatostatins are a group of chemically unrelated neuropeptides that were originally characterized based on their ability to inhibit juvenil hormone synthesis in insects. Allatostatin-C has pleiotropic functions, acting as myoregulator in several insects. In these studies, we analyzed the myoregulatory effect of Aedes aegypti Allatostatin-C in Hydra sp., a member of the phylum Cnidaria. Allatostatin-C peptide conjugated with Qdots revealed specifically distributed cell populations that respond to the peptide in different regions of hydroids. In vivo physiological assays using Allatostatin-C showed that the peptide induced changes in shape and length in tentacles, peduncle and gastrovascular cavity. The observed changes were dose and time dependent suggesting the physiological nature of the response. Furthermore, at highest doses, Allatostatin-C induced peristaltic movements of the gastrovascular cavity resembling those that occur during feeding. In silico search of putative Allatostatin-C receptors in Cnidaria showed that genomes predict the existence of proteins of the somatostatin/Allatostatin-C receptors family. Altogether, these results suggest that Allatostatin-C has myoregulatory activity in Hydra sp, playing a role in the control of coordinated movements during feeding, indicating that Allatostatin-C/Somatostatin based signaling might be an ancestral mechanism.

  11. Evolutionary divergence of the plant elicitor peptides (Peps) and their receptors: interfamily incompatibility of perception but compatibility of downstream signalling

    KAUST Repository

    Lori, M.

    2015-05-22

    Plant elicitor peptides (Peps) are potent inducers of pattern-triggered immunity and amplify the immune response against diverse pathogens. Peps have been discovered and studied extensively in Arabidopsis and only recently orthologs in maize were also identified and characterized in more detail. Here, the presence of PROPEPs, the Pep precursors, and PEPRs, the Pep receptors, was investigated within the plant kingdom. PROPEPs and PEPRs were identified in most sequenced species of the angiosperms. The conservation and compatibility of the Pep-PEPR-system was analysed by using plants of two distantly related dicot families, Brassicaceae and Solanaceae, and a representative family of monocot plants, the Poaceae. All three plant families contain important crop plants, including maize, rice, tomato, potato, and canola. Peps were not recognized by species outside of their plant family of origin, apparently because of a divergence of the Pep sequences. Three family-specific Pep motifs were defined and the integration of such a motif into the Pep sequence of an unrelated Pep enabled its perception. Transient transformation of Nicotiana benthamiana with the coding sequences of the AtPEPR1 and ZmPEPR1a led to the recognition of Pep peptides of Brassicaceae or Poaceae origin, respectively, and to the proper activation of downstream signalling. It was concluded that signalling machinery downstream of the PEPRs is highly conserved whereas the leucine-rich repeat domains of the PEPRs co-evolved with the Peps, leading to distinct motifs and, with it, interfamily incompatibility.

  12. Integration of reward signalling and appetite regulating peptide systems in the control of food-cue responses.

    Science.gov (United States)

    Reichelt, A C; Westbrook, R F; Morris, M J

    2015-11-01

    Understanding the neurobiological substrates that encode learning about food-associated cues and how those signals are modulated is of great clinical importance especially in light of the worldwide obesity problem. Inappropriate or maladaptive responses to food-associated cues can promote over-consumption, leading to excessive energy intake and weight gain. Chronic exposure to foods rich in fat and sugar alters the reinforcing value of foods and weakens inhibitory neural control, triggering learned, but maladaptive, associations between environmental cues and food rewards. Thus, responses to food-associated cues can promote cravings and food-seeking by activating mesocorticolimbic dopamine neurocircuitry, and exert physiological effects including salivation. These responses may be analogous to the cravings experienced by abstaining drug addicts that can trigger relapse into drug self-administration. Preventing cue-triggered eating may therefore reduce the over-consumption seen in obesity and binge-eating disorder. In this review we discuss recent research examining how cues associated with palatable foods can promote reward-based feeding behaviours and the potential involvement of appetite-regulating peptides including leptin, ghrelin, orexin and melanin concentrating hormone. These peptide signals interface with mesolimbic dopaminergic regions including the ventral tegmental area to modulate reactivity to cues associated with palatable foods. Thus, a novel target for anti-obesity therapeutics is to reduce non-homeostatic, reward driven eating behaviour, which can be triggered by environmental cues associated with highly palatable, fat and sugar rich foods.

  13. Integration of reward signalling and appetite regulating peptide systems in the control of food‐cue responses

    Science.gov (United States)

    Westbrook, R F; Morris, M J

    2015-01-01

    Understanding the neurobiological substrates that encode learning about food‐associated cues and how those signals are modulated is of great clinical importance especially in light of the worldwide obesity problem. Inappropriate or maladaptive responses to food‐associated cues can promote over‐consumption, leading to excessive energy intake and weight gain. Chronic exposure to foods rich in fat and sugar alters the reinforcing value of foods and weakens inhibitory neural control, triggering learned, but maladaptive, associations between environmental cues and food rewards. Thus, responses to food‐associated cues can promote cravings and food‐seeking by activating mesocorticolimbic dopamine neurocircuitry, and exert physiological effects including salivation. These responses may be analogous to the cravings experienced by abstaining drug addicts that can trigger relapse into drug self‐administration. Preventing cue‐triggered eating may therefore reduce the over‐consumption seen in obesity and binge‐eating disorder. In this review we discuss recent research examining how cues associated with palatable foods can promote reward‐based feeding behaviours and the potential involvement of appetite‐regulating peptides including leptin, ghrelin, orexin and melanin concentrating hormone. These peptide signals interface with mesolimbic dopaminergic regions including the ventral tegmental area to modulate reactivity to cues associated with palatable foods. Thus, a novel target for anti‐obesity therapeutics is to reduce non‐homeostatic, reward driven eating behaviour, which can be triggered by environmental cues associated with highly palatable, fat and sugar rich foods. PMID:26403657

  14. GPU Pro advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2010-01-01

    This book covers essential tools and techniques for programming the graphics processing unit. Brought to you by Wolfgang Engel and the same team of editors who made the ShaderX series a success, this volume covers advanced rendering techniques, engine design, GPGPU techniques, related mathematical techniques, and game postmortems. A special emphasis is placed on handheld programming to account for the increased importance of graphics on mobile devices, especially the iPhone and iPod touch.Example programs and source code can be downloaded from the book's CRC Press web page. 

  15. Porcine glucagon-like peptide-2: structure, signaling, metabolism and effects

    DEFF Research Database (Denmark)

    Pedersen, Nis Borbye; Hjøllund, Karina Rahr; Johnsen, Anders H

    2007-01-01

    Mass spectrometry of HPLC-purified porcine glucagon-like peptide-2 (pGLP-2)(1) revealed a 35 amino acid sequence with C-terminal Ser and Leu, in contrast to the 33 amino acids of human, cow, rat and mouse GLP-2. Synthetic pGLP-2 stimulated cAMP-production in COS-7 cells expressing human GLP-2 (h...

  16. Antibody constant region peptides can display immunomodulatory activity through activation of the Dectin-1 signalling pathway.

    Directory of Open Access Journals (Sweden)

    Elena Gabrielli

    Full Text Available We previously reported that a synthetic peptide with sequence identical to a CDR of a mouse monoclonal antibody specific for difucosyl human blood group A exerted an immunomodulatory activity on murine macrophages. It was therapeutic against systemic candidiasis without possessing direct candidacidal properties. Here we demonstrate that a selected peptide, N10K, putatively deriving from the enzymatic cleavage of the constant region (Fc of human IgG(1, is able to induce IL-6 secretion and pIkB-α activation. More importantly, it causes an up-regulation of Dectin-1 expression. This leads to an increased activation of β-glucan-induced pSyk, CARD9 and pIkB-α, and an increase in the production of pro-inflammatory cytokines such as IL-6, IL-12, IL-1β and TNF-α. The increased activation of this pathway coincides with an augmented phagocytosis of non opsonized Candida albicans cells by monocytes. The findings suggest that some Fc-peptides, potentially deriving from the proteolysis of immunoglobulins, may cause an unexpected immunoregulation in a way reminiscent of innate immunity molecules.

  17. Self-assembled N-cadherin mimetic peptide hydrogels promote the chondrogenesis of mesenchymal stem cells through inhibition of canonical Wnt/β-catenin signaling.

    Science.gov (United States)

    Li, Rui; Xu, Jianbin; Wong, Dexter Siu Hong; Li, Jinming; Zhao, Pengchao; Bian, Liming

    2017-11-01

    N-cadherin, a transmembrane protein and major component of adherens junction, mediates cell-cell interactions and intracellular signaling that are important to the regulation of cell behaviors and organ development. Previous studies have identified mimetic peptides that possess similar bioactivity as that of N-cadherin, which promotes chondrogenesis of human mesenchymal stem cells (hMSCs); however, the molecular mechanism remains unknown. In this study, we combined the N-cadherin mimetic peptide (HAVDI) with the self-assembling KLD-12 peptide: the resultant peptide is capable of self-assembling into hydrogels functionalized with N-cadherin peptide in phosphate-buffered saline (PBS) at 37 °C. Encapsulation of hMSCs in these hydrogels showed enhanced expression of chondrogenic marker genes and deposition of cartilage specific extracellular matrix rich in proteoglycan and Type II Collagen compared to control hydrogels, with a scrambled-sequence peptide after 14 days of chondrogenic culture. Furthermore, western blot showed a significantly higher expression of active glycogen synthase kinase-3β (GSK-3β), which phosphorylates β-catenin and facilitates ubiquitin-mediated degradation, as well as a lower expression of β-catenin and LEF1 in the N-cadherin peptide hydrogels versus controls. Immunofluorescence staining revealed significantly less nuclear localization of β-catenin in N-cadherin mimetic peptide hydrogels. Our findings suggest that N-cadherin peptide hydrogels suppress canonical Wnt signaling in hMSCs by reducing β-catenin nuclear translocation and the associated transcriptional activity of β-catenin/LEF-1/TCF complex, thereby enhancing the chondrogenesis of hMSCs. Our biomimetic self-assembled peptide hydrogels can serve as a tailorable and versatile three-dimensional culture platform to investigate the effect of biofunctionalization on stem cell behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Real-time trafficking and signaling of the glucagon-like peptide-1 receptor

    DEFF Research Database (Denmark)

    Roed, Sarah Noerklit; Wismann, Pernille; Underwood, Christina Rye

    2014-01-01

    . A fundamental mechanism controlling the signaling capacity of GPCRs is the post-endocytic trafficking of receptors between recycling and degradative fates. Here, we combined microscopy with novel real-time assays to monitor both receptor trafficking and signaling in living cells. We find that the human GLP-1R...

  19. Isolation of Positive Modulator of Glucagon-like Peptide-1 Signaling from Trigonella foenum-graecum (Fenugreek) Seed.

    Science.gov (United States)

    King, Klim; Lin, Nai-Pin; Cheng, Yu-Hong; Chen, Gao-Hui; Chein, Rong-Jie

    2015-10-23

    The glucagon-like peptide-1 receptor (GLP-1R) is expressed in many tissues and has been implicated in diverse physiological functions, such as energy homeostasis and cognition. GLP-1 analogs are approved for treatment of type 2 diabetes and are undergoing clinical trials for other disorders, including neurodegenerative diseases. GLP-1 analog therapies maintain chronically high plasma levels of the analog and can lead to loss of spatiotemporal control of GLP-1R activation. To avoid adverse effects associated with current therapies, we characterized positive modulators of GLP-1R signaling. We screened extracts from edible plants using an intracellular cAMP biosensor and GLP-1R endocytosis assays. Ethanol extracts from fenugreek seeds enhanced GLP-1 signaling. These seeds have previously been found to reduce glucose and glycated hemoglobin levels in humans. An active compound (N55) with a new N-linoleoyl-2-amino-γ-butyrolactone structure was purified from fenugreek seeds. N55 promoted GLP-1-dependent cAMP production and GLP-1R endocytosis in a dose-dependent and saturable manner. N55 specifically enhanced GLP-1 potency more than 40-fold, but not that of exendin 4, to stimulate cAMP production. In contrast to the current allosteric modulators that bind to GLP-1R, N55 binds to GLP-1 peptide and facilitates trypsin-mediated GLP-1 inactivation. These findings identify a new class of modulators of GLP-1R signaling and suggest that GLP-1 might be a viable target for drug discovery. Our results also highlight a feasible approach for screening bioactive activity of plant extracts.

  20. Leucine 7-proline 7 polymorphism in the signal peptide of neuropeptide Y is not a risk factor for exudative age-related macular degeneration.

    Science.gov (United States)

    Kaarniranta, Kai; Holopainen, Juha M; Karvonen, Matti K; Koulu, Markku; Kallio, Jaana; Pesonen, Ullamari; Teräsvirta, Markku; Uusitalo, Hannu; Immonen, Ilkka

    2007-03-01

    Because of the regulatory role of neuropeptide Y (NPY) in angiogenesis, we set out to determine the presence of the leucine 7-proline 7 (Leu7Pro) polymorphism in exudative age-related macular degeneration (AMD) patients and to analyse its implications. Genotype analysis of the Leu7Pro polymorphism in the signal peptide region of the human prepro-NPY was performed in blood samples from exudative AMD patients (n = 240) and control subjects (n = 79). In all, 11% of exudative AMD patients and 14% of control subjects exhibited the NPY signal peptide Leu7Pro polymorphism. There were no statistically significant differences in Leu7Pro polymorphism frequency between the exudative AMD and control cases, as analysed by Fisher's exact two-sided test. Leu7Pro polymorphism in the signal peptide region of the human prepro-NPY is not a risk factor for exudative AMD.

  1. Pituitary adenylate cyclase activating peptide (PACAP participates in adipogenesis by activating ERK signaling pathway.

    Directory of Open Access Journals (Sweden)

    Tatjana Arsenijevic

    Full Text Available Pituitary adenylate cyclase activating peptide (PACAP belongs to the secretin/glucagon/vasoactive intestinal peptide (VIP family. Its action can be mediated by three different receptor subtypes: PAC1, which has exclusive affinity for PACAP, and VPAC1 and VPAC2 which have equal affinity for PACAP and VIP. We showed that all three receptors are expressed in 3T3-L1 cells throughout their differentiation into adipocytes. We established the activity of these receptors by cAMP accumulation upon induction by PACAP. Together with insulin and dexamethasone, PACAP induced adipogenesis in 3T3-L1 cell line. PACAP increased cAMP production within 15 min upon stimulation and targeted the expression and phosphorylation of MAPK (ERK1/2, strengthened by the ERK1/2 phosphorylation being partially or completely abolished by different combinations of PACAP receptors antagonists. We therefore speculate that ERK1/2 activation is crucial for the activation of CCAAT/enhancer- binding protein β (C/EBPβ.

  2. 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...... agonist properties and in their ability to modulate ghrelin signaling. A receptor model is presented wherein ghrelin normally only activates one receptor subunit in a dimer and where the smaller nonendogenous agonists bind in the other subunit to act both as coagonists and as either neutral (MK-677...

  3. Arabidopsis thaliana resistance to fusarium oxysporum 2 implicates tyrosine-sulfated peptide signaling in susceptibility and resistance to root infection.

    Directory of Open Access Journals (Sweden)

    Yunping Shen

    2013-05-01

    Full Text Available In the plant Arabidopsis thaliana, multiple quantitative trait loci (QTLs, including RFO2, account for the strong resistance of accession Columbia-0 (Col-0 and relative susceptibility of Taynuilt-0 (Ty-0 to the vascular wilt fungus Fusarium oxysporum forma specialis matthioli. We find that RFO2 corresponds to diversity in receptor-like protein (RLP genes. In Col-0, there is a tandem pair of RLP genes: RFO2/At1g17250 confers resistance while RLP2 does not. In Ty-0, the highly diverged RFO2 locus has one RLP gene conferring weaker resistance. While the endogenous RFO2 makes a modest contribution to resistance, transgenic RFO2 provides strong pathogen-specific resistance. The extracellular leucine-rich repeats (eLRRs in RFO2 and RLP2 are interchangeable for resistance and remarkably similar to eLRRs in the receptor-like kinase PSY1R, which perceives tyrosine-sulfated peptide PSY1. Reduced infection in psy1r and mutants of related phytosulfokine (PSK receptor genes PSKR1 and PSKR2 shows that tyrosine-sulfated peptide signaling promotes susceptibility. The related eLRRs in RFO2 and PSY1R are not interchangeable; and expression of the RLP nPcR, in which eLRRs in RFO2 are replaced with eLRRs in PSY1R, results in constitutive resistance. Counterintuitively, PSY1 signaling suppresses nPcR because psy1r nPcR is lethal. The fact that PSK signaling does not similarly affect nPcR argues that PSY1 signaling directly downregulates the expression of nPcR. Our results support a speculative but intriguing model to explain RFO2's role in resistance. We propose that F. oxysporum produces an effector that inhibits the normal negative feedback regulation of PSY1R, which stabilizes PSY1 signaling and induces susceptibility. However, RFO2, acting as a decoy receptor for PSY1R, is also stabilized by the effector and instead induces host immunity. Overall, the quantitative resistance of RFO2 is reminiscent of the better-studied monogenic resistance traits.

  4. Bacterial expression, correct membrane targeting and functional folding of the HIV-1 membrane protein Vpu using a periplasmic signal peptide.

    Science.gov (United States)

    Deb, Arpan; Johnson, William A; Kline, Alexander P; Scott, Boston J; Meador, Lydia R; Srinivas, Dustin; Martin-Garcia, Jose M; Dörner, Katerina; Borges, Chad R; Misra, Rajeev; Hogue, Brenda G; Fromme, Petra; Mor, Tsafrir S

    2017-01-01

    Viral protein U (Vpu) is a type-III integral membrane protein encoded by Human Immunodeficiency Virus-1 (HIV- 1). It is expressed in infected host cells and plays several roles in viral progeny escape from infected cells, including down-regulation of CD4 receptors. But key structure/function questions remain regarding the mechanisms by which the Vpu protein contributes to HIV-1 pathogenesis. Here we describe expression of Vpu in bacteria, its purification and characterization. We report the successful expression of PelB-Vpu in Escherichia coli using the leader peptide pectate lyase B (PelB) from Erwinia carotovora. The protein was detergent extractable and could be isolated in a very pure form. We demonstrate that the PelB signal peptide successfully targets Vpu to the cell membranes and inserts it as a type I membrane protein. PelB-Vpu was biophysically characterized by circular dichroism and dynamic light scattering experiments and was shown to be an excellent candidate for elucidating structural models.

  5. Bacterial expression, correct membrane targeting and functional folding of the HIV-1 membrane protein Vpu using a periplasmic signal peptide

    Science.gov (United States)

    Deb, Arpan; Johnson, William A.; Kline, Alexander P.; Scott, Boston J.; Meador, Lydia R.; Srinivas, Dustin; Martin-Garcia, Jose M.; Dörner, Katerina; Borges, Chad R.; Misra, Rajeev; Hogue, Brenda G.; Fromme, Petra

    2017-01-01

    Viral protein U (Vpu) is a type-III integral membrane protein encoded by Human Immunodeficiency Virus-1 (HIV- 1). It is expressed in infected host cells and plays several roles in viral progeny escape from infected cells, including down-regulation of CD4 receptors. But key structure/function questions remain regarding the mechanisms by which the Vpu protein contributes to HIV-1 pathogenesis. Here we describe expression of Vpu in bacteria, its purification and characterization. We report the successful expression of PelB-Vpu in Escherichia coli using the leader peptide pectate lyase B (PelB) from Erwinia carotovora. The protein was detergent extractable and could be isolated in a very pure form. We demonstrate that the PelB signal peptide successfully targets Vpu to the cell membranes and inserts it as a type I membrane protein. PelB-Vpu was biophysically characterized by circular dichroism and dynamic light scattering experiments and was shown to be an excellent candidate for elucidating structural models. PMID:28225803

  6. Metal-chelating plastic MALDI (pMALDI) chips for the enhancement of phosphorylated-peptide/protein signals.

    Science.gov (United States)

    Ibañez, Alfredo J; Muck, Alexander; Svatos, Ales

    2007-09-01

    A disposable polymeric pMALDI array with a universal metal cation-chelatable surface for pretreatment/signal enhancement of phosphoproteins and/or phosphopeptides in complex samples was developed. Acrylic acid N-hydroxysuccinimide ester and methyl methacrylate monomers were copolymerized in thin layer molds in a 1:13.3 molar ratio and subsequently treated with Nalpha,Nalpha-bis(carboxymethyl)-l-lysine to obtain a structured planar MALDI array. The prepared NTA pMALDI chip array was activated with metal cations (e.g., Ga(III), Ni(II)), and the selectivities for phosphopeptides (e.g., trypsin-digested alpha-casein (alpha-Cas), and phospho-angiotensin II (p-Ang)) were evaluated using MALDI-TOF/MS. The highest selectivity for proteins was observed for the Ni(II)-NTA chip. The p-Ang was enriched in the presence of BSA tryptic peptides ca. 5 times and represented the major peak after sample adsorption/washing on Ga(III)-NTA chip. The performance of the Ga(III)-chip, tested on alpha-Cas tryptic digest, is fully comparable to commercial systems. Additionally, higher MW peptides and limited methionine oxidation were observed with the chip. A combination of selective absorption of phosphoproteins on Ni(II)-chips and the further enrichment of digested phosphopeptides on the Ga(III)-chip can prove to be very useful for fast identification of unknown proteins using MALDI-TOF/MS.

  7. Partial deficiency of thyroxine-binding globulin-Allentown is due to a mutation in the signal peptide.

    Science.gov (United States)

    Fingerhut, Anja; Reutrakul, Sirimon; Knuedeler, Sebastian D; Moeller, Lars C; Greenlee, Carol; Refetoff, Samuel; Janssen, Onno E

    2004-05-01

    We present an unusual variant of T(4)-binding globulin (TBG) found in a family from Allentown, Pennsylvania (TBG-AT). The heterozygous proposita presented serum total T(4) and TBG levels ranging from low to normal. TBG gene sequencing revealed a C-to-T substitution in codon -2 (CAC to TAC) leading to the substitution of the normal histidine by a tyrosine within the signal peptide. No mutation within the mature peptide was found. Allele-specific PCR confirmed the H(-2)Y mutation in the propositas mother and son. T(4)-binding analysis of TBG in serum from the proposita and son showed normal affinity but reduced capacity when compared with the unaffected father. Heat stability and isoelectric focusing of TBG-AT were normal. In vitro expression of a recombinant TBG-AT in Xenopus oocytes revealed a diminished secretory efficiency and confirmed the normal binding affinity and heat stability of the small amount of secreted TBG-AT. This study has defined impaired cotranslational processing as a hitherto unrecognized cause of hereditary TBG deficiency.

  8. Real-time graphics rendering engine

    CERN Document Server

    Bao, Hujun

    2011-01-01

    ""Real-Time Graphics Rendering Engine"" reveals the software architecture of the modern real-time 3D graphics rendering engine and the relevant technologies based on the authors' experience developing this high-performance, real-time system. The relevant knowledge about real-time graphics rendering such as the rendering pipeline, the visual appearance and shading and lighting models are also introduced. This book is intended to offer well-founded guidance for researchers and developers who are interested in building their own rendering engines. Hujun Bao is a professor at the State Key Lab of

  9. Hardware Accelerated Point Rendering of Isosurfaces

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2003-01-01

    an approximate technique for point scaling using distance attenuation which makes it possible to render points stored in display lists or vertex arrays. This enables us to render points quickly using OpenGL. Our comparisons show that point generation is significantly faster than triangle generation...... and that the advantage of rendering points as opposed to triangles increases with the size and complexity of the volumes. To gauge the visual quality of future hardware accelerated point rendering schemes, we have implemented a software based point rendering method and compare the quality to both MC and our OpenGL based...

  10. Role of Notch-1 signaling pathway in PC12 cell apoptosis induced by amyloid beta-peptide (25-35)

    Institute of Scientific and Technical Information of China (English)

    Huimin Liang; Yaozhou Zhang; Xiaoyan Shi; Tianxiang Wei; Jiyu Lou

    2014-01-01

    Recent studies have demonstrated that Notch-1 expression is increased in the hippocampus of Alzheimer’s disease patients. We speculate that Notch-1 signaling may be involved in PC12 cell apoptosis induced by amyloid beta-peptide (25-35) (Aβ25-35). In the present study, PC12 cells were cultured with different doses (0, 0.1, 1.0, 10 and 100 nmol/L) of N-[N-(3,5-Dilfuorophen-acetyl)-L-alanyl]-S-phenylglycine t-butyl ester, a Notch-1 signaling pathway inhibitor, for 30 minutes. Then cultured cells were induced with Aβ25-35 for 48 hours. Pretreatment of PC12 cells with high doses of N-[N-(3,5-Dilfuorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (> 10 nmol/L) prolonged the survival of PC12 cells after Aβ25-35 induction, decreased the expression of apoptosis-related proteins caspase-3, -8, -9, increased the activity of oxidative stress-related su-peroxide dismutase and catalase, inhibited the production of active oxygen, and reduced nuclear factor kappa B expression. This study indicates that the Notch-1 signaling pathway plays a pivotal role in Aβ25-35-induced PC12 apoptosis.

  11. Hindbrain leptin and glucagon-like-peptide-1 receptor signaling interact to suppress food intake in an additive manner.

    Science.gov (United States)

    Zhao, S; Kanoski, S E; Yan, J; Grill, H J; Hayes, M R

    2012-12-01

    The physiological control of feeding behavior involves modulation of the intake inhibitory effects of gastrointestinal satiation signaling via endogenous hindbrain leptin receptor (LepR) and glucagon-like-peptide-1 receptor (GLP-1R) activation. Using a variety of dose-combinations of hindbrain delivered (4th intracerebroventricular; i.c.v.) leptin and the GLP-1R agonist exendin-4, experiments demonstrate that hindbrain LepR and GLP-1R signaling interact to control food intake and body weight in an additive manner. In addition, the maximum intake suppressive response that could be achieved by 4th i.c.v. leptin alone in non-obese rats (∼33%) was shown to be further suppressed when exendin-4 was co-administered. Importantly, it was determined that the interaction between hindbrain LepR signaling and GLP-1R signaling is relevant to endogenous food intake control, as hindbrain GLP-1R blockade by the selective antagonist exendin-(9-39) attenuated the intake inhibitory effects of hindbrain leptin delivery. Collectively, the findings reported here show that hindbrain LepR and GLP-1R activation interact in at least an additive manner to control food intake and body weight. As evidence is accumulating that combination pharmacotherapies offer greater sustained food intake and body weight suppression in obese individuals when compared with mono-drug therapies or lifestyle modifications alone, these findings highlight the need for further examination of combined central nervous system GLP-1R and LepR signaling as a potential drug target for obesity treatment.

  12. [Low prevalence of the Leu7/Pro polymorphism in the signal peptide of preproneuropeptide Y in the Spanish Mediterranean population].

    Science.gov (United States)

    Portolés, Olga; Sorlí, José Vicente; González, José Ignacio; Ruiz de la Fuente, Salvador; Ramírez, Judith Begoña; Corella, Dolores

    2003-03-15

    A common Leu7Pro polymorphism in the signal peptide of neuropeptide Y has been associated with increased plasma cholesterol and accelerated atherosclerosis in the Finnish population. A cross-sectional design was carried out in 1,000 individuals from the Mediterranean Spanish population to estimate its prevalence. Two independently collected samples consisting of 486 subjects (sample 1) and 514 subjects (sample 2) were studied. The Leu7Pro polymorphism was determined. We found only one individual carrying the Leu7Pro variant (0.1%). The allele frequency of the Pro7 allele was extremely low: 0.005 (95% CI,0.0001-0.0015). This low prevalence suggests that the Pro7 allele is not one of the genetic determinant factors affecting obesity, plasma lipids or alcoholism in this population.

  13. Opposing effects of dietary protein and sugar regulate a transcriptional target of Drosophila insulin-like peptide signaling.

    Science.gov (United States)

    Buch, Susanne; Melcher, Christoph; Bauer, Matthias; Katzenberger, Joerg; Pankratz, Michael J

    2008-04-01

    Specific neurosecretory cells of the Drosophila brain express insulin-like peptides (dilps), which regulate growth, glucose homeostasis, and aging. Through microarray analysis of flies in which the insulin-producing cells (IPCs) were ablated, we identified a target gene, target of brain insulin (tobi), that encodes an evolutionarily conserved alpha-glucosidase. Flies with lowered tobi levels are viable, whereas tobi overexpression causes severe growth defects and a decrease in body glycogen. Interestingly, tobi expression is increased by dietary protein and decreased by dietary sugar. This pattern is reminiscent of mammalian glucagon secretion, which is increased by protein intake and decreased by sugar intake, suggesting that tobi is regulated by a glucagon analog. tobi expression is also eliminated upon ablation of neuroendocrine cells that produce adipokinetic hormone (AKH), an analog of glucagon. tobi is thus a target of the insulin- and glucagon-like signaling system that responds oppositely to dietary protein and sugar.

  14. Cluster parallel rendering based on encoded mesh

    Institute of Scientific and Technical Information of China (English)

    QIN Ai-hong; XIONG Hua; PENG Hao-yu; LIU Zhen; SHI Jiao-ying

    2006-01-01

    Use of compressed mesh in parallel rendering architecture is still an unexplored area, the main challenge of which is to partition and sort the encoded mesh in compression-domain. This paper presents a mesh compression scheme PRMC (Parallel Rendering based Mesh Compression) supplying encoded meshes that can be partitioned and sorted in parallel rendering system even in encoded-domain. First, we segment the mesh into submeshes and clip the submeshes' boundary into Runs, and then piecewise compress the submeshes and Runs respectively. With the help of several auxiliary index tables, compressed submeshes and Runs can serve as rendering primitives in parallel rendering system. Based on PRMC, we design and implement a parallel rendering architecture. Compared with uncompressed representation, experimental results showed that PRMC meshes applied in cluster parallel rendering system can dramatically reduce the communication requirement.

  15. Protection of cardiomyocytes from the hypoxia-mediated injury by a peptide targeting the activator of G-protein signaling 8.

    Directory of Open Access Journals (Sweden)

    Motohiko Sato

    Full Text Available Signaling via heterotrimeric G-protein is involved in the development of human diseases including ischemia-reperfusion injury of the heart. We previously identified an ischemia-inducible G-protein activator, activator of G-protein signaling 8 (AGS8, which regulates Gβγ signaling and plays a key role in the hypoxia-induced apoptosis of cardiomyocytes. Here, we attempted to intervene in the AGS8-Gβγ signaling process and protect cardiomyocytes from hypoxia-induced apoptosis with a peptide that disrupted the AGS8-Gβγ interaction. Synthesized AGS8-peptides, with amino acid sequences based on those of the Gβγ-binding domain of AGS8, successfully inhibited the association of AGS8 with Gβγ. The AGS8-peptide effectively blocked hypoxia-induced apoptosis of cardiomyocytes, as determined by DNA end-labeling and an increase in cleaved caspase-3. AGS8-peptide also inhibited the change in localization/permeability of channel protein connexin 43, which was mediated by AGS8-Gβγ under hypoxia. Small compounds that inhibit a wide range of Gβγ signals caused deleterious effects in cardiomyocytes. In contrast, AGS8-peptide did not cause cell damage under normoxia, suggesting an advantage inherent in targeted disruption of the AGS8-Gβγ signaling pathway. These data indicate a pivotal role for the interaction of AGS8 with Gβγ in hypoxia-induced apoptosis of cardiomyocytes, and suggest that targeted disruption of the AGS8-Gβγ signal provides a novel approach for protecting the myocardium against ischemic injury.

  16. Protection of cardiomyocytes from the hypoxia-mediated injury by a peptide targeting the activator of G-protein signaling 8.

    Science.gov (United States)

    Sato, Motohiko; Hiraoka, Masahiro; Suzuki, Hiroko; Sakima, Miho; Mamun, Abdullah Al; Yamane, Yukiko; Fujita, Takayuki; Yokoyama, Utako; Okumura, Satoshi; Ishikawa, Yoshihiro

    2014-01-01

    Signaling via heterotrimeric G-protein is involved in the development of human diseases including ischemia-reperfusion injury of the heart. We previously identified an ischemia-inducible G-protein activator, activator of G-protein signaling 8 (AGS8), which regulates Gβγ signaling and plays a key role in the hypoxia-induced apoptosis of cardiomyocytes. Here, we attempted to intervene in the AGS8-Gβγ signaling process and protect cardiomyocytes from hypoxia-induced apoptosis with a peptide that disrupted the AGS8-Gβγ interaction. Synthesized AGS8-peptides, with amino acid sequences based on those of the Gβγ-binding domain of AGS8, successfully inhibited the association of AGS8 with Gβγ. The AGS8-peptide effectively blocked hypoxia-induced apoptosis of cardiomyocytes, as determined by DNA end-labeling and an increase in cleaved caspase-3. AGS8-peptide also inhibited the change in localization/permeability of channel protein connexin 43, which was mediated by AGS8-Gβγ under hypoxia. Small compounds that inhibit a wide range of Gβγ signals caused deleterious effects in cardiomyocytes. In contrast, AGS8-peptide did not cause cell damage under normoxia, suggesting an advantage inherent in targeted disruption of the AGS8-Gβγ signaling pathway. These data indicate a pivotal role for the interaction of AGS8 with Gβγ in hypoxia-induced apoptosis of cardiomyocytes, and suggest that targeted disruption of the AGS8-Gβγ signal provides a novel approach for protecting the myocardium against ischemic injury.

  17. Satiety signalling histaminergic system and brain-gut peptides in regulation of food intake in rats with portocaval anastomosis.

    Science.gov (United States)

    Fogel, W A; Stasiak, A; Lewinski, A; Maksymowicz, M; Jochem, J

    2008-08-01

    Brain histamine plays a regulatory role in feeding behaviour, acting as an inhibitory modulator. Portocaval anastomosis (PCA) is associated with cerebral aminergic systems alterations, including high histamine accumulation and release from neurons. Despite that, the rats with PCA eat significantly more, their body mass being lower than sham-operated animals. To disclose underlying regulatory mechanisms, food intake was measured before and after treatment with antagonists of histamine H(1) and H(2), orexin type 1 (OX(1)) and cannabinoid type 1 (CB(1)) receptors in adult male Lewis rats 6 months following the end-to-side PCA or sham operation. Hypothalamic concentrations of orexin A and histamine as well as serum concentrations of leptin, insulin and cholecystokinin (CCK) were analysed. PCA rats with body mass lower by 30%, have consumed more feed and water 150% and 200%, respectively. The modifying effects of pyrilamine, ranitidine, SB 334867 and rimonabant were less pronounced in PCA compared with sham-operated rats. Hypothalamic orexin A and histamine concentrations were higher in PCA rats than in the control group with intact portocaval system. In PCA rats, serum concentrations of CCK were higher, leptin concentrations lower, while there were no differences between the groups in insulin levels. In conclusion, the adaptive mechanisms efficiently render PCA rats less sensitive to peripheral and central anorexigenic signals. Orexin A appears to be involved in the counteracting mechanisms preventing further body mass loss in PCA rats.

  18. Efficient production of active chicken avidin using a bacterial signal peptide in Escherichia coli

    OpenAIRE

    Hytönen, Vesa P.; Laitinen, Olli H.; Airenne, Tomi T.; Kidron, Heidi; Meltola, Niko J.; Porkka, Eevaleena J.; Hörhä, Jarno; Paldanius, Tiina; Määttä, Juha A. E.; Nordlund, Henri R.; Johnson, Mark S.; Salminen, Tiina A.; Airenne, Kari J.; Ylä-Herttuala, Seppo; Kulomaa, Markku S.

    2004-01-01

    Chicken avidin is a highly popular tool with countless applications in the life sciences. In the present study, an efficient method for producing avidin protein in the periplasmic space of Escherichia coli in the active form is described. Avidin was produced by replacing the native signal sequence of the protein with a bacterial OmpA secretion signal. The yield after a single 2-iminobiotin–agarose affinity purification step was approx. 10 mg/l of virtually pure avidin. Purified avidin had 3.7...

  19. 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.

  20. CGRP-RCP, a novel protein required for signal transduction at calcitonin gene-related peptide and adrenomedullin receptors.

    Science.gov (United States)

    Evans, B N; Rosenblatt, M I; Mnayer, L O; Oliver, K R; Dickerson, I M

    2000-10-06

    It is becoming clear that receptors that initiate signal transduction by interacting with G-proteins do not function as monomers, but often require accessory proteins for function. Some of these accessory proteins are chaperones, required for correct transport of the receptor to the cell surface, but the function of many accessory proteins remains unknown. We determined the role of an accessory protein for the receptor for calcitonin gene-related peptide (CGRP), a potent vasodilator neuropeptide. We have previously shown that this accessory protein, the CGRP-receptor component protein (RCP), is expressed in CGRP responsive tissues and that RCP protein expression correlates with the biological efficacy of CGRP in vivo. However, the function of RCP has remained elusive. In this study stable cell lines were made that express antisense RCP RNA, and CGRP- and adrenomedullin-mediated signal transduction were greatly reduced. However, the loss of RCP did not effect CGRP binding or receptor density, indicating that RCP did not behave as a chaperone but was instead coupling the CGRP receptor to downstream effectors. A candidate CGRP receptor named calcitonin receptor-like receptor (CRLR) has been identified, and in this study RCP co-immunoprecipitated with CRLR indicating that these two proteins interact directly. Since CGRP and adrenomedullin can both signal through CRLR, which has been previously shown to require a chaperone protein for function, we now propose that a functional CGRP or adrenomedullin receptor consists of at least three proteins: the receptor (CRLR), the chaperone protein (RAMP), and RCP that couples the receptor to the cellular signal transduction pathway.

  1. Conventional Matrices Loaded Onto a Graphene Layer Enhances MALDI-TOF/TOF Signal: Its Application to Improve Detection of Phosphorylated Peptides

    Science.gov (United States)

    Rodríguez, Carlos E.; Palacios, Javier; Fajardo, Ignacio; Urdiales, José Luis; Le Guével, Xavier; Lozano, José; Sánchez-Jiménez, Francisca

    2016-02-01

    This is the first study where graphene is used as a MALDI adjuvant in combination with the traditional matrix α-cyano-4-hydroxycinnamic acid (CHCA) to improve the signal intensity of peptide samples. Use of this amended matrix not only leads to increased signals but also to a higher number of peaks detected in complex samples. Additionally, the use of graphene has a stabilizing effect that can also be exploited to improve the detection of easily cleavable molecules.

  2. A facile reporter system for the experimental identification of twin-arginine translocation (Tat) signal peptides from all kingdoms of life

    NARCIS (Netherlands)

    Widdick, David A.; Eijlander, Robyn T.; van Dijl, Jan Maarten; Kuipers, Oscar P.; Palmer, Tracy

    2008-01-01

    We have developed a reporter protein system for the experimental verification of twin-arginine signal peptides. This reporter system is based on the Streptomyces coelicolor agarase protein, which is secreted into the growth medium by the twin-arginine translocation (Tat) pathway and whose extracellu

  3. The Escherichia coli TatABC system and a Bacillus subtilis TatAC-type system recognise three distinct targeting determinants in twin-arginine signal peptides

    NARCIS (Netherlands)

    Mendel, Sharon; McCarthy, Andrew; Barnett, James P.; Eijlander, Robyn T.; Nenninger, Anja; Kuipers, Oscar P.; Robinson, Colin

    2008-01-01

    The Tat system transports folded proteins across bacterial and thylakoid membranes. In Gram-negative organisms, it is encoded by tatABC genes and the system recognizes substrates bearing signal peptides with a conserved twin-arginine motif. Most Gram-positive organisms lack a tatB gene, indicating m

  4. Expression pattern of the alpha-kafirin promoter coupled with a signal peptide from Sorghum bicolor L. Moench.

    Science.gov (United States)

    Ahmad, Norazlina; Sant, Rajnesh; Bokan, Milovan; Steadman, Kathryn J; Godwin, Ian D

    2012-01-01

    Regulatory sequences with endosperm specificity are essential for foreign gene expression in the desired tissue for both grain quality improvement and molecular pharming. In this study, promoters of seed storage α-kafirin genes coupled with signal sequence (ss) were isolated from Sorghum bicolor L. Moench genomic DNA by PCR. The α-kafirin promoter (α-kaf) contains endosperm specificity-determining motifs, prolamin-box, the O2-box 1, CATC, and TATA boxes required for α-kafirin gene expression in sorghum seeds. The constructs pMB-Ubi-gfp and pMB-kaf-gfp were microprojectile bombarded into various sorghum and sweet corn explants. GFP expression was detected on all explants using the Ubi promoter but only in seeds for the α-kaf promoter. This shows that the α-kaf promoter isolated was functional and demonstrated seed-specific GFP expression. The constructs pMB-Ubi-ss-gfp and pMB-kaf-ss-gfp were also bombarded into the same explants. Detection of GFP expression showed that the signal peptide (SP)::GFP fusion can assemble and fold properly, preserving the fluorescent properties of GFP.

  5. Expression Pattern of the Alpha-Kafirin Promoter Coupled with a Signal Peptide from Sorghum bicolor L. Moench

    Directory of Open Access Journals (Sweden)

    Norazlina Ahmad

    2012-01-01

    Full Text Available Regulatory sequences with endosperm specificity are essential for foreign gene expression in the desired tissue for both grain quality improvement and molecular pharming. In this study, promoters of seed storage α-kafirin genes coupled with signal sequence (ss were isolated from Sorghum bicolor L. Moench genomic DNA by PCR. The α-kafirin promoter (α-kaf contains endosperm specificity-determining motifs, prolamin-box, the O2-box 1, CATC, and TATA boxes required for α-kafirin gene expression in sorghum seeds. The constructs pMB-Ubi-gfp and pMB-kaf-gfp were microprojectile bombarded into various sorghum and sweet corn explants. GFP expression was detected on all explants using the Ubi promoter but only in seeds for the α-kaf promoter. This shows that the α-kaf promoter isolated was functional and demonstrated seed-specific GFP expression. The constructs pMB-Ubi-ss-gfp and pMB-kaf-ss-gfp were also bombarded into the same explants. Detection of GFP expression showed that the signal peptide (SP::GFP fusion can assemble and fold properly, preserving the fluorescent properties of GFP.

  6. The role of proteolytic processing and the stable signal peptide in expression of the Old World arenavirus envelope glycoprotein ectodomain

    Energy Technology Data Exchange (ETDEWEB)

    Burri, Dominique J.; Pasquato, Antonella; Ramos da Palma, Joel [Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011 (Switzerland); Igonet, Sebastien; Oldstone, Michael B.A. [Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037 (United States); Kunz, Stefan, E-mail: Stefan.Kunz@chuv.ch [Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011 (Switzerland)

    2013-02-05

    Maturation of the arenavirus GP precursor (GPC) involves proteolytic processing by cellular signal peptidase and the proprotein convertase subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P), yielding a tripartite complex comprised of a stable signal peptide (SSP), the receptor-binding GP1, and the fusion-active transmembrane GP2. Here we investigated the roles of SKI-1/S1P processing and SSP in the biosynthesis of the recombinant GP ectodomains of lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV). When expressed in mammalian cells, the LCMV and LASV GP ectodomains underwent processing by SKI-1/S1P, followed by dissociation of GP1 from GP2. The GP2 ectodomain spontaneously formed trimers as revealed by chemical cross-linking. The endogenous SSP, known to be crucial for maturation and transport of full-length arenavirus GPC was dispensable for processing and secretion of the soluble GP ectodomain, suggesting a specific role of SSP in the stable prefusion conformation and transport of full-length GPC.

  7. Expression pattern of sonic hedgehog signaling and calcitonin gene-related peptide in the socket healing process after tooth extraction.

    Science.gov (United States)

    Pang, Pai; Shimo, Tsuyoshi; Takada, Hiroyuki; Matsumoto, Kenichi; Yoshioka, Norie; Ibaragi, Soichiro; Sasaki, Akira

    2015-11-06

    Sonic Hedgehog (SHH), a neural development inducer, plays a significant role in the bone healing process. Calcitonin gene-related peptide (CGRP), a neuropeptide marker of sensory nerves, has been demonstrated to affect bone formation. The roles of SHH signaling and CGRP-positive sensory nerves in the alveolar bone formation process have been unknown. Here we examined the expression patterns of SHH signaling and CGRP in mouse socket by immunohistochemistry and immunofluorescence analysis. We found that the expression level of SHH peaked at day 3 and was then decreased at 5 days after tooth extraction. CGRP, PTCH1 and GLI2 were each expressed in a similar pattern with their highest expression levels at day 5 and day 7 after tooth extraction. CGRP and GLI2 were co-expressed in some inflammatory cells and bone forming cells. In some areas, CGRP-positive neurons expressed GLI2. In conclusion, SHH may affect alveolar bone healing by interacting with CGRP-positive sensory neurons and thus regulate the socket's healing process after tooth extraction.

  8. Rendering Caustics on Non-Lambertian Surfaces

    DEFF Research Database (Denmark)

    Jensen, Henrik Wann

    1997-01-01

    This paper presents a new technique for rendering caustics on non-Lambertian surfaces. The method is based on an extension of the photon map which removes previous restrictions limiting the usage to Lambertian surfaces. We add information about the incoming direction to the photons and this allow...... reduces the rendering time. We have used the method to render caustics on surfaces with reflectance functions varying from Lambertian to glossy specular....

  9. Building Interstellar's black hole: the gravitational renderer

    OpenAIRE

    James, Oliver; Dieckmann, Sylvan; Pabst, Simon; Roberts, Paul-George H.; Thorne, Kip S.

    2015-01-01

    Interstellar is the first feature film to attempt depicting a black hole as it would actually be seen by somebody nearby. A close collaboration between the production's Scientific Advisor and the Visual Effects team led to the development of a new renderer, DNGR (Double Negative Gravitational Renderer) which uses novel techniques for rendering in curved space-time. Following the completion of the movie, the code was adapted for scientific research, leading to new insights into gravitational l...

  10. Image Based Rendering under Varying Illumination

    Institute of Scientific and Technical Information of China (English)

    Wang Chengfeng (王城峰); Hu Zhanyi

    2003-01-01

    A new approach for photorealistic rendering of a class of objects at arbitrary illumination is presented. The approach of the authors relies entirely on image based rendering techniques. A scheme is utilized for re-illumination of objects based on linear combination of low dimensional image representations. The minimum rendering condition of technique of the authors is three sample images under varying illumination of a reference object and a single input image of an interested object. Important properties of this approach are its simplicity, robustness and speediness. Experimental results validate the proposed rendering approach.

  11. RenderToolbox3: MATLAB tools that facilitate physically based stimulus rendering for vision research.

    Science.gov (United States)

    Heasly, Benjamin S; Cottaris, Nicolas P; Lichtman, Daniel P; Xiao, Bei; Brainard, David H

    2014-02-07

    RenderToolbox3 provides MATLAB utilities and prescribes a workflow that should be useful to researchers who want to employ graphics in the study of vision and perhaps in other endeavors as well. In particular, RenderToolbox3 facilitates rendering scene families in which various scene attributes and renderer behaviors are manipulated parametrically, enables spectral specification of object reflectance and illuminant spectra, enables the use of physically based material specifications, helps validate renderer output, and converts renderer output to physical units of radiance. This paper describes the design and functionality of the toolbox and discusses several examples that demonstrate its use. We have designed RenderToolbox3 to be portable across computer hardware and operating systems and to be free and open source (except for MATLAB itself). RenderToolbox3 is available at https://github.com/DavidBrainard/RenderToolbox3.

  12. A Nascent Peptide Signal Responsive to Endogenous Levels of Polyamines Acts to Stimulate Regulatory Frameshifting on Antizyme mRNA*

    Science.gov (United States)

    Yordanova, Martina M.; Wu, Cheng; Andreev, Dmitry E.; Sachs, Matthew S.; Atkins, John F.

    2015-01-01

    The protein antizyme is a negative regulator of cellular polyamine concentrations from yeast to mammals. Synthesis of functional antizyme requires programmed +1 ribosomal frameshifting at the 3′ end of the first of two partially overlapping ORFs. The frameshift is the sensor and effector in an autoregulatory circuit. Except for Saccharomyces cerevisiae antizyme mRNA, the frameshift site alone only supports low levels of frameshifting. The high levels usually observed depend on the presence of cis-acting stimulatory elements located 5′ and 3′ of the frameshift site. Antizyme genes from different evolutionary branches have evolved different stimulatory elements. Prior and new multiple alignments of fungal antizyme mRNA sequences from the Agaricomycetes class of Basidiomycota show a distinct pattern of conservation 5′ of the frameshift site consistent with a function at the amino acid level. As shown here when tested in Schizosaccharomyces pombe and mammalian HEK293T cells, the 5′ part of this conserved sequence acts at the nascent peptide level to stimulate the frameshifting, without involving stalling detectable by toe-printing. However, the peptide is only part of the signal. The 3′ part of the stimulator functions largely independently and acts at least mostly at the nucleotide level. When polyamine levels were varied, the stimulatory effect was seen to be especially responsive in the endogenous polyamine concentration range, and this effect may be more general. A conserved RNA secondary structure 3′ of the frameshift site has weaker stimulatory and polyamine sensitizing effects on frameshifting. PMID:25998126

  13. A Nascent Peptide Signal Responsive to Endogenous Levels of Polyamines Acts to Stimulate Regulatory Frameshifting on Antizyme mRNA.

    Science.gov (United States)

    Yordanova, Martina M; Wu, Cheng; Andreev, Dmitry E; Sachs, Matthew S; Atkins, John F

    2015-07-17

    The protein antizyme is a negative regulator of cellular polyamine concentrations from yeast to mammals. Synthesis of functional antizyme requires programmed +1 ribosomal frameshifting at the 3' end of the first of two partially overlapping ORFs. The frameshift is the sensor and effector in an autoregulatory circuit. Except for Saccharomyces cerevisiae antizyme mRNA, the frameshift site alone only supports low levels of frameshifting. The high levels usually observed depend on the presence of cis-acting stimulatory elements located 5' and 3' of the frameshift site. Antizyme genes from different evolutionary branches have evolved different stimulatory elements. Prior and new multiple alignments of fungal antizyme mRNA sequences from the Agaricomycetes class of Basidiomycota show a distinct pattern of conservation 5' of the frameshift site consistent with a function at the amino acid level. As shown here when tested in Schizosaccharomyces pombe and mammalian HEK293T cells, the 5' part of this conserved sequence acts at the nascent peptide level to stimulate the frameshifting, without involving stalling detectable by toe-printing. However, the peptide is only part of the signal. The 3' part of the stimulator functions largely independently and acts at least mostly at the nucleotide level. When polyamine levels were varied, the stimulatory effect was seen to be especially responsive in the endogenous polyamine concentration range, and this effect may be more general. A conserved RNA secondary structure 3' of the frameshift site has weaker stimulatory and polyamine sensitizing effects on frameshifting. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. SKPDT is a signaling peptide that stimulates sporulation and cry1Aa expression in Bacillus thuringiensis but not in Bacillus subtilis.

    Science.gov (United States)

    Aceves-Diez, Angel E; Robles-Burgueño, Refugio; de la Torre, Mayra

    2007-08-01

    We have identified and characterized in the supernatant of the transition phase of Bacillus thuringiensis var. kurstaki the peptide SKPDT. This peptide was previously identified by in silico analysis by Pottathil and Lazazzera (Front Biosci 8:32-45 2003) as a putative signaling peptide (NprRB) of the Phr family in B. thuringiensis. The chemically synthesized NprRB did not affect the growth kinetics of B. thuringiensis var. kurstaki but stimulated the sporulation, spore release, and transcription of cry1Aa when added to cultures during the transition phase. In fact, when the peptide (100 nM) was added to a culture in transition phase, the transcription of cry1Aa was stimulated almost threefold, mainly from the late promoter BtII, which requires the late-stage sporulation-specific transcription factor sigma (K). On the other hand, NprRB did not have any effect on B. subtilis. Thus, SKPDT seems to be a signaling peptide specific for B. thuringiensis.

  15. Targeting Yes-associated Protein with Evolved Peptide Aptamers to Disrupt TGF-β Signaling Pathway: Therapeutic Implication for Bone Tumor.

    Science.gov (United States)

    Ji, Wei-Ping; Dong, Yang

    2015-11-01

    The binding of transcription coactivator Yes-associated protein (YAP) to Smad transcription factors is an important event in activating transforming growth factor-β (TGF-β) signaling pathway, which is involved in the tumorigenicity and metastasis of bone tumor. Design of peptide aptamers to disrupt YAPSmad interaction has been established as a promising approach for bone tumor therapy. Here, an evolution strategy was used to optimize Smad-derived peptides for high potency binding to YAP WW2 domain, resulting in an improved peptide population, from which those high-scoring candidates were characterized rigorously using molecular dynamics (MD) simulations and interaction free energy calculations. With the computational protocol we were able to generate a number of potential domain binders, which were then substantiated by using fluorescence spectroscopy assay. Subsequently, the complex structure of YAP WW2 domain with a high-affinity peptide was modeled and examined in detail, which was then used to guide structure-based peptide optimization to obtain several strong domain binders. Structural and energetic analysis revealed that electrostatic complementarity is primarily responsible for domainpeptide recognition, while other nonbonded interactions such as hydrogen bonding and salt bridges can contribute significantly to the recognition specificity.

  16. A cardiac pathway of cyclic GMP-independent signaling of guanylyl cyclase A, the receptor for atrial natriuretic peptide

    Science.gov (United States)

    Klaiber, Michael; Dankworth, Beatrice; Kruse, Martin; Hartmann, Michael; Nikolaev, Viacheslav O.; Yang, Ruey-Bing; Völker, Katharina; Gaßner, Birgit; Oberwinkler, Heike; Feil, Robert; Freichel, Marc; Groschner, Klaus; Skryabin, Boris V.; Frantz, Stefan; Birnbaumer, Lutz; Pongs, Olaf; Kuhn, Michaela

    2011-01-01

    Cardiac atrial natriuretic peptide (ANP) regulates arterial blood pressure, moderates cardiomyocyte growth, and stimulates angiogenesis and metabolism. ANP binds to the transmembrane guanylyl cyclase (GC) receptor, GC-A, to exert its diverse functions. This process involves a cGMP-dependent signaling pathway preventing pathological [Ca2+]i increases in myocytes. In chronic cardiac hypertrophy, however, ANP levels are markedly increased and GC-A/cGMP responses to ANP are blunted due to receptor desensitization. Here we show that, in this situation, ANP binding to GC-A stimulates a unique cGMP-independent signaling pathway in cardiac myocytes, resulting in pathologically elevated intracellular Ca2+ levels. This pathway involves the activation of Ca2+‐permeable transient receptor potential canonical 3/6 (TRPC3/C6) cation channels by GC-A, which forms a stable complex with TRPC3/C6 channels. Our results indicate that the resulting cation influx activates voltage-dependent L-type Ca2+ channels and ultimately increases myocyte Ca2+i levels. These observations reveal a dual role of the ANP/GC-A–signaling pathway in the regulation of cardiac myocyte Ca2+i homeostasis. Under physiological conditions, activation of a cGMP-dependent pathway moderates the Ca2+i-enhancing action of hypertrophic factors such as angiotensin II. By contrast, a cGMP-independent pathway predominates under pathophysiological conditions when GC-A is desensitized by high ANP levels. The concomitant rise in [Ca2+]i might increase the propensity to cardiac hypertrophy and arrhythmias. PMID:22027011

  17. Efficient production of active chicken avidin using a bacterial signal peptide in Escherichia coli.

    Science.gov (United States)

    Hytönen, Vesa P; Laitinen, Olli H; Airenne, Tomi T; Kidron, Heidi; Meltola, Niko J; Porkka, Eevaleena J; Hörhä, Jarno; Paldanius, Tiina; Määttä, Juha A E; Nordlund, Henri R; Johnson, Mark S; Salminen, Tiina A; Airenne, Kari J; Ylä-Herttuala, Seppo; Kulomaa, Markku S

    2004-12-01

    Chicken avidin is a highly popular tool with countless applications in the life sciences. In the present study, an efficient method for producing avidin protein in the periplasmic space of Escherichia coli in the active form is described. Avidin was produced by replacing the native signal sequence of the protein with a bacterial OmpA secretion signal. The yield after a single 2-iminobiotin-agarose affinity purification step was approx. 10 mg/l of virtually pure avidin. Purified avidin had 3.7 free biotin-binding sites per tetramer and showed the same biotin-binding affinity and thermal stability as egg-white avidin. Avidin crystallized under various conditions, which will enable X-ray crystallographic studies. Avidin produced in E. coli lacks the carbohydrate chains of chicken avidin and the absence of glycosylation should decrease the non-specific binding that avidin exhibits towards many materials [Rosebrough and Hartley (1996) J. Nucl. Med. 37, 1380-1384]. The present method provides a feasible and inexpensive alternative for the production of recombinant avidin, avidin mutants and avidin fusion proteins for novel avidin-biotin technology applications.

  18. Myristoylation of the Arenavirus Envelope Glycoprotein Stable Signal Peptide Is Critical for Membrane Fusion but Dispensable for Virion Morphogenesis

    Science.gov (United States)

    York, Joanne

    2016-01-01

    ABSTRACT Arenaviruses are responsible for severe and often fatal hemorrhagic disease. In the absence of effective antiviral therapies and vaccines, these viruses pose serious threats to public health and biodefense. Arenaviruses enter the host cell by fusion of the viral and endosomal membranes, a process mediated by the virus envelope glycoprotein GPC. Unlike other class I viral fusion proteins, GPC retains its stable signal peptide (SSP) as an essential third subunit in the mature complex. SSP spans the membrane twice and is myristoylated at its cytoplasmic N terminus. Mutations that abolish SSP myristoylation have been shown to reduce pH-induced cell-cell fusion activity of ectopically expressed GPC to ∼20% of wild-type levels. In order to examine the role of SSP myristoylation in the context of the intact virus, we used reverse genetics to generate Junín viruses (Candid #1 isolate) in which the critical glycine-2 residue in SSP was either replaced by alanine (G2A) or deleted (ΔG2). These mutant viruses produced smaller foci of infection in Vero cells and showed an ∼5-fold reduction in specific infectivity, commensurate with the defect in cell-cell fusion. However, virus assembly and GPC incorporation into budded virions were unaffected. Our findings suggest that the myristate moiety is cryptically disposed in the prefusion GPC complex and may function late in the fusion process to promote merging of the viral and cellular membranes. IMPORTANCE Hemorrhagic fever arenaviruses pose significant threats to public health and biodefense. Arenavirus entry into the host cell is promoted by the virus envelope glycoprotein GPC. Unlike other viral envelope glycoproteins, GPC contains a myristoylated stable signal peptide (SSP) as an essential third subunit. Myristoylation has been shown to be important for the membrane fusion activity of recombinantly expressed GPC. Here, we use reverse genetics to study the role of SSP myristoylation in the context of the intact

  19. Signal peptide peptidase (SPP dimer formation as assessed by fluorescence lifetime imaging microscopy (FLIM in intact cells

    Directory of Open Access Journals (Sweden)

    Nyborg Andrew C

    2006-11-01

    Full Text Available Abstract Background Signal peptide peptidase (SPP is an intramembrane cleaving protease identified by its cleavage of several type II membrane signal peptides. Conservation of intramembrane active site residues demonstrates that SPP, SPP family members, and presenilins (PSs make up a family of intramembrane cleaving proteases. Because SPP appears to function without additional protein cofactors, the study of SPP may provide structural insights into the mechanism of intramembrane proteolysis by this biomedically important family of proteins. Previous studies have shown that SPP isolated from cells appears to be a homodimer, but some evidence exists that in vitro SPP may be active as a monomer. We have conducted additional experiments to determine if SPP exists as a monomer or dimer in vivo. Results Fluorescence lifetime imaging microscopy (FLIM can be is used to determine intra- or intermolecular interactions by fluorescently labeling epitopes on one or two different molecules. If the donor and acceptor fluorophores are less than 10 nm apart, the donor fluorophore lifetime shortens proportionally to the distance between the fluorophores. In this study, we used two types of fluorescence energy transfer (FRET pairs; cyan fluorescent protein (CFP with yellow fluorescent protein (YFP or Alexa 488 with Cy3 to differentially label the NH2- or COOH-termini of SPP molecules. A cell based SPP activity assay was used to show that all tagged SPP proteins are proteolytically active. Using FLIM we were able to show that the donor fluorophore lifetime of the CFP tagged SPP construct in living cells significantly decreases when either a NH2- or COOH-terminally YFP tagged SPP construct is co-transfected, indicating close proximity between two different SPP molecules. These data were then confirmed in cell lines stably co-expressing V5- and FLAG-tagged SPP constructs. Conclusion Our FLIM data strongly suggest dimer formation between two separate SPP proteins

  20. Prolonged signaling at the parathyroid hormone receptor by peptide ligands targeted to a specific receptor conformation.

    Science.gov (United States)

    Okazaki, Makoto; Ferrandon, Sebastien; Vilardaga, Jean-Pierre; Bouxsein, Mary L; Potts, John T; Gardella, Thomas J

    2008-10-28

    The parathyroid hormone receptor (PTHR) is a class B G protein-coupled receptor that plays critical roles in bone and mineral ion metabolism. Ligand binding to the PTHR involves interactions to both the amino-terminal extracellular (N) domain, and transmembrane/extracellular loop, or juxtamembrane (J) regions of the receptor. Recently, we found that PTH(1-34), but not PTH-related protein, PTHrP(1-36), or M-PTH(1-14) (M = Ala/Aib(1),Aib(3),Gln(10),Har(11),Ala(12),Trp(14),Arg(19)), binds to the PTHR in a largely GTPgammaS-resistant fashion, suggesting selective binding to a novel, high-affinity conformation (R(0)), distinct from the GTPgammaS-sensitive conformation (RG). We examined the effects in vitro and in vivo of introducing the M substitutions, which enhance interaction to the J domain, into PTH analogs extended C-terminally to incorporate residues involved in the N domain interaction. As compared with PTH(1-34), M-PTH(1-28) and M-PTH(1-34) bound to R(0) with higher affinity, produced more sustained cAMP responses in cells, formed more stable complexes with the PTHR in FRET and subcellular localization assays, and induced more prolonged calcemic and phosphate responses in mice. Moreover, after 2 weeks of daily injection in mice, M-PTH(1-34) induced larger increases in trabecular bone volume and greater increases in cortical bone turnover, than did PTH(1-34). Thus, the putative R(0) PTHR conformation can form highly stable complexes with certain PTH ligand analogs and thereby mediate surprisingly prolonged signaling responses in bone and/or kidney PTH target cells. Controlling, via ligand analog design, the selectivity with which a PTH ligand binds to R(0), versus RG, may be a strategy for optimizing signaling duration time, and hence therapeutic efficacy, of PTHR agonist ligands.

  1. Image Based Rendering and Virtual Reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

  2. Physically based rendering: from theory to implementation

    National Research Council Canada - National Science Library

    Pharr, Matt; Humphreys, Greg, Ph. D

    2010-01-01

    ... rendering algorithm variations. This book is not only a textbook for students, but also a useful reference book for practitioners in the field. The second edition has been extended with sections on Metropolis light transport, subsurface scattering, precomputed light transport, and more. Per Christensen Senior Software Developer, RenderMan Products,...

  3. Image Based Rendering and Virtual Reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

  4. Moisture movements in render on brick wall

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Munch, Thomas Astrup; Thorsen, Peter Schjørmann

    2003-01-01

    A three-layer render on brick wall used for building facades is studied in the laboratory. The vertical render surface is held in contact with water for 24 hours simulating driving rain while it is measured with non-destructive X-ray equipment every hour in order to follow the moisture front...... through the render and into the brick. The test specimen is placed between the source and the detector. The test specimens are all scanned before they are exposed to water. In that way the loss of counts from the dry scan to the wet scan qualitatively shows the presence of water. The results show nearly...... no penetration of water through the render and into the brick, and the results are independent of the start condition of the test specimens. Also drying experiments are performed. The results show a small difference in the rate of drying, in favour of the bricks without render....

  5. Physically based rendering from theory to implementation

    CERN Document Server

    Pharr, Matt

    2010-01-01

    "Physically Based Rendering, 2nd Edition" describes both the mathematical theory behind a modern photorealistic rendering system as well as its practical implementation. A method - known as 'literate programming'- combines human-readable documentation and source code into a single reference that is specifically designed to aid comprehension. The result is a stunning achievement in graphics education. Through the ideas and software in this book, you will learn to design and employ a full-featured rendering system for creating stunning imagery. This book features new sections on subsurface scattering, Metropolis light transport, precomputed light transport, multispectral rendering, and much more. It includes a companion site complete with source code for the rendering system described in the book, with support for Windows, OS X, and Linux. Code and text are tightly woven together through a unique indexing feature that lists each function, variable, and method on the page that they are first described.

  6. Optimization-Based Wearable Tactile Rendering.

    Science.gov (United States)

    Perez, Alvaro G; Lobo, Daniel; Chinello, Francesco; Cirio, Gabriel; Malvezzi, Monica; San Martin, Jose; Prattichizzo, Domenico; Otaduy, Miguel A

    2016-10-20

    Novel wearable tactile interfaces offer the possibility to simulate tactile interactions with virtual environments directly on our skin. But, unlike kinesthetic interfaces, for which haptic rendering is a well explored problem, they pose new questions about the formulation of the rendering problem. In this work, we propose a formulation of tactile rendering as an optimization problem, which is general for a large family of tactile interfaces. Based on an accurate simulation of contact between a finger model and the virtual environment, we pose tactile rendering as the optimization of the device configuration, such that the contact surface between the device and the actual finger matches as close as possible the contact surface in the virtual environment. We describe the optimization formulation in general terms, and we also demonstrate its implementation on a thimble-like wearable device. We validate the tactile rendering formulation by analyzing its force error, and we show that it outperforms other approaches.

  7. Gastrin-releasing peptide signaling plays a limited and subtle role in amygdala physiology and aversive memory.

    Science.gov (United States)

    Chaperon, Frederique; Fendt, Markus; Kelly, Peter H; Lingenhoehl, Kurt; Mosbacher, Johannes; Olpe, Hans-Rudolf; Schmid, Peter; Sturchler, Christine; McAllister, Kevin H; van der Putten, P Herman; Gee, Christine E

    2012-01-01

    Links between synaptic plasticity in the lateral amygdala (LA) and Pavlovian fear learning are well established. Neuropeptides including gastrin-releasing peptide (GRP) can modulate LA function. GRP increases inhibition in the LA and mice lacking the GRP receptor (GRPR KO) show more pronounced and persistent fear after single-trial associative learning. Here, we confirmed these initial findings and examined whether they extrapolate to more aspects of amygdala physiology and to other forms of aversive associative learning. GRP application in brain slices from wildtype but not GRPR KO mice increased spontaneous inhibitory activity in LA pyramidal neurons. In amygdala slices from GRPR KO mice, GRP did not increase inhibitory activity. In comparison to wildtype, short- but not long-term plasticity was increased in the cortico-lateral amygdala (LA) pathway of GRPR KO amygdala slices, whereas no changes were detected in the thalamo-LA pathway. In addition, GRPR KO mice showed enhanced fear evoked by single-trial conditioning and reduced spontaneous firing of neurons in the central nucleus of the amygdala (CeA). Altogether, these results are consistent with a potentially important modulatory role of GRP/GRPR signaling in the amygdala. However, administration of GRP or the GRPR antagonist (D-Phe(6), Leu-NHEt(13), des-Met(14))-Bombesin (6-14) did not affect amygdala LTP in brain slices, nor did they affect the expression of conditioned fear following intra-amygdala administration. GRPR KO mice also failed to show differences in fear expression and extinction after multiple-trial fear conditioning, and there were no differences in conditioned taste aversion or gustatory neophobia. Collectively, our data indicate that GRP/GRPR signaling modulates amygdala physiology in a paradigm-specific fashion that likely is insufficient to generate therapeutic effects across amygdala-dependent disorders.

  8. Gastrin-releasing peptide signaling plays a limited and subtle role in amygdala physiology and aversive memory.

    Directory of Open Access Journals (Sweden)

    Frederique Chaperon

    Full Text Available Links between synaptic plasticity in the lateral amygdala (LA and Pavlovian fear learning are well established. Neuropeptides including gastrin-releasing peptide (GRP can modulate LA function. GRP increases inhibition in the LA and mice lacking the GRP receptor (GRPR KO show more pronounced and persistent fear after single-trial associative learning. Here, we confirmed these initial findings and examined whether they extrapolate to more aspects of amygdala physiology and to other forms of aversive associative learning. GRP application in brain slices from wildtype but not GRPR KO mice increased spontaneous inhibitory activity in LA pyramidal neurons. In amygdala slices from GRPR KO mice, GRP did not increase inhibitory activity. In comparison to wildtype, short- but not long-term plasticity was increased in the cortico-lateral amygdala (LA pathway of GRPR KO amygdala slices, whereas no changes were detected in the thalamo-LA pathway. In addition, GRPR KO mice showed enhanced fear evoked by single-trial conditioning and reduced spontaneous firing of neurons in the central nucleus of the amygdala (CeA. Altogether, these results are consistent with a potentially important modulatory role of GRP/GRPR signaling in the amygdala. However, administration of GRP or the GRPR antagonist (D-Phe(6, Leu-NHEt(13, des-Met(14-Bombesin (6-14 did not affect amygdala LTP in brain slices, nor did they affect the expression of conditioned fear following intra-amygdala administration. GRPR KO mice also failed to show differences in fear expression and extinction after multiple-trial fear conditioning, and there were no differences in conditioned taste aversion or gustatory neophobia. Collectively, our data indicate that GRP/GRPR signaling modulates amygdala physiology in a paradigm-specific fashion that likely is insufficient to generate therapeutic effects across amygdala-dependent disorders.

  9. Construction of a novel secretion expression system guided by native signal peptide of PhoD in Zymomonas mobilis.

    Science.gov (United States)

    Wu, Bo; He, Ming-Xiong; Feng, Hong; Shui, Zong-Xia; Tang, Xiao-Yu; Hu, Qi-Chun; Zhang, Yi-Zheng

    2014-01-01

    In the current study, three native signal peptides (SPs) from PhoC, PhoD, and ZMO0331were investigated and compared to construct novel secretion expression systems in Zymomonas mobilis. The secretion expression of target protein, α-amylase from Bacillus amyloliquefaciens (BAA), guided by PhoD's SP resulted in more hydrolysis of starch than that by the other two SPs. Extracellular and intracellular α-amylase activities of the strain containing PhoD's SP were also higher than the other two strains containing PhoC or ZMO0331's SP. In addition, the evidence by alcohol dehydrogenase activity assay further confirmed that the starch hydrolysis was resulted from the secretion expression of BAA rather than the breakage of cells. Our results indicated that the SP of PhoD is able to serve as a promising candidate to assist secretion expression of heterogeneous genes in Z. mobilis. This will contribute to development of engineered Z. mobilis strains converting starch into ethanol.

  10. Dissection of the role of the stable signal peptide of the arenavirus envelope glycoprotein in membrane fusion.

    Science.gov (United States)

    Messina, Emily L; York, Joanne; Nunberg, Jack H

    2012-06-01

    The arenavirus envelope glycoprotein (GPC) retains a stable signal peptide (SSP) as an essential subunit in the mature complex. The 58-amino-acid residue SSP comprises two membrane-spanning hydrophobic regions separated by a short ectodomain loop that interacts with the G2 fusion subunit to promote pH-dependent membrane fusion. Small-molecule compounds that target this unique SSP-G2 interaction prevent arenavirus entry and infection. The interaction between SSP and G2 is sensitive to the phylogenetic distance between New World (Junín) and Old World (Lassa) arenaviruses. For example, heterotypic GPC complexes are unable to support virion entry. In this report, we demonstrate that the hybrid GPC complexes are properly assembled, proteolytically cleaved, and transported to the cell surface but are specifically defective in their membrane fusion activity. Chimeric SSP constructs reveal that this incompatibility is localized to the first transmembrane segment of SSP (TM1). Genetic changes in TM1 also affect sensitivity to small-molecule fusion inhibitors, generating resistance in some cases and inhibitor dependence in others. Our studies suggest that interactions of SSP TM1 with the transmembrane domain of G2 may be important for GPC-mediated membrane fusion and its inhibition.

  11. A mutation in signal peptide of rat resistin gene inhibits differentiation of 3T3-L1 preadipocytes

    Institute of Scientific and Technical Information of China (English)

    Xi-rong GUO; Hai-xia GONG; Yan-qin GAO; Li FEI; Yu-hui NI; Rong-hua CHEN

    2004-01-01

    AIM: To detect the resistin expression of white adipose tissue in diet-induced obese (DIO) versus diet-resistant (DR) rats, and to investigate the relationship of mutated resistin and 3T3-L1 preadipocytes differentiation. METHODS:RT-PCR and Western Blot were used to detect gene/protein expression. 3T3-L1 cells were cultured, transfected,and induced to differentiation using 0.5 mmol/L 3-isobutyl-1-methyxanthine (MIX), 1 mg/L insulin, and 1μmol/Ldexamethasone. Oil red O staining was applied to detect the degree of preadipocytes differentiation. RESULTS:Expression of resistin mRNA was upregulated in DIO rats and downregulated in DR rats. However, the expression levels varied greatly within the groups. Sequencing of the resistin genes from DIO and DR rats revealed a Leu9Val (C25G) missense mutation within the signal peptide in one DR rat. The mutant resistin inhibited preadipocyte differentiation. Local experiments and Western blotting with tagged resistin fusion proteins identified both mutant and wild type proteins in the cytoplasm and secreted into the culture medium. Computer predictions using the Proscan and Subloc programs revealed four putative phosphorylation sites and a possible leucine zipper motif within the rat resistin protein. CONCLUSION: Resistin-increased differentiation may be inhibited by the mutationcontaining precursor protein, or by the mutant non-secretory resistin isoform.

  12. The Antidiabetic Mechanisms of Polyphenols Related to Increased Glucagon-Like Peptide-1 (GLP1 and Insulin Signaling

    Directory of Open Access Journals (Sweden)

    J. Abraham Domínguez Avila

    2017-05-01

    Full Text Available Type-2 diabetes mellitus (T2DM is an endocrine disease related to impaired/absent insulin signaling. Dietary habits can either promote or mitigate the onset and severity of T2DM. Diets rich in fruits and vegetables have been correlated with a decreased incidence of T2DM, apparently due to their high polyphenol content. Polyphenols are compounds of plant origin with several documented bioactivities related to health promotion. The present review describes the antidiabetic effects of polyphenols, specifically related to the secretion and effects of insulin and glucagon-like peptide 1 (GLP1, an enteric hormone that stimulates postprandial insulin secretion. The evidence suggests that polyphenols from various sources stimulate L-cells to secrete GLP1, increase its half-life by inhibiting dipeptidyl peptidase-4 (DPP4, stimulate β-cells to secrete insulin and stimulate the peripheral response to insulin, increasing the overall effects of the GLP1-insulin axis. The glucose-lowering potential of polyphenols has been evidenced in various acute and chronic models of healthy and diabetic organisms. Some polyphenols appear to exert their effects similarly to pharmaceutical antidiabetics; thus, rigorous clinical trials are needed to fully validate this claim. The broad diversity of polyphenols has not allowed for entirely describing their mechanisms of action, but the evidence advocates for their regular consumption.

  13. Zfp521 is a target gene and key effector of parathyroid hormone-related peptide signaling in growth plate chondrocytes.

    Science.gov (United States)

    Correa, Diego; Hesse, Eric; Seriwatanachai, Dutmanee; Kiviranta, Riku; Saito, Hiroaki; Yamana, Kei; Neff, Lynn; Atfi, Azeddine; Coillard, Lucie; Sitara, Despina; Maeda, Yukiko; Warming, Soren; Jenkins, Nancy A; Copeland, Neal G; Horne, William C; Lanske, Beate; Baron, Roland

    2010-10-19

    In the growth plate, the interplay between parathyroid hormone-related peptide (PTHrP) and Indian hedgehog (Ihh) signaling tightly regulates chondrocyte proliferation and differentiation during longitudinal bone growth. We found that PTHrP increases the expression of Zfp521, a zinc finger transcriptional coregulator, in prehypertrophic chondrocytes. Mice with chondrocyte-targeted deletion of Zfp521 resembled PTHrP(-/-) and chondrocyte-specific PTHR1(-/-) mice, with decreased chondrocyte proliferation, early hypertrophic transition, and reduced growth plate thickness. Deleting Zfp521 increased expression of Runx2 and Runx2 target genes, and decreased Cyclin D1 and Bcl-2 expression while increasing Caspase-3 activation and apoptosis. Zfp521 associated with Runx2 in chondrocytes, antagonizing its activity via an HDAC4-dependent mechanism. PTHrP failed to upregulate Cyclin D1 and to antagonize Runx2, Ihh, and collagen X expression when Zfp521 was absent. Thus, Zfp521 is an important PTHrP target gene that regulates growth plate chondrocyte proliferation and differentiation.

  14. PCNA-interacting peptides reduce Akt phosphorylation and TLR-mediated cytokine secretion suggesting a role of PCNA in cellular signaling.

    Science.gov (United States)

    Olaisen, Camilla; Müller, Rebekka; Nedal, Aina; Otterlei, Marit

    2015-07-01

    Proliferating cell nuclear antigen (PCNA), commonly known as a nuclear protein essential for regulation of DNA replication, DNA repair, and epigenetics, has recently been associated with multiple cytosolic functions. Many proteins containing one of the two known PCNA-interacting motifs, the AlkB homologue 2 PCNA interacting motif (APIM) and the PCNA-interacting peptide (PIP)-box, are considered to be mainly cytosolic. APIM is found in more than 20 kinases and/or associated proteins including several direct or indirect members of the mitogen-activated protein kinase (MAPK) and PI3K/Akt pathways. Mass spectrometry analysis of PCNA-pull downs verified that many cytosolic proteins involved in the MAPK and PI3K/Akt pathways are in complex with PCNA. Furthermore, treatment of cells with a PCNA-interacting APIM-containing peptide (APIM-peptide) reduced Akt phosphorylation in human peripheral blood monocytes and a human keratinocyte cell line (HaCaT). Additionally, the APIM-peptide strongly reduced the cytokine secretion from monocytes stimulated with toll like receptor (TLR) ligands and potentiated the effects of MAPK and PI3K/Akt inhibitors. Interestingly, the protein level of the APIM-containing PKR/RIG-1 activator protein (PACT) was initially strongly reduced in HaCaT cells stimulated with APIM-peptide in combination with the TLR ligand polyinosinic-polycytidylic acid (polyIC). Our results suggest that PCNA has a platform role in cytosol affecting cellular signaling.

  15. 3D Rendering - Techniques and Challenges

    Directory of Open Access Journals (Sweden)

    Ekta Walia

    2010-04-01

    Full Text Available Computer generated images and animations are getting more and more common. They are used in many different contexts such as movies,mobiles, medical visualization, architectural visualization and CAD. Advanced ways of describing surface and light source properties are important to ensure that artists are able to create realistic and stylish looking images. Even when using advanced rendering algorithms such as ray tracing, time required for shading may contribute towards a large part of the image creation time. Therefore both performance and flexibility is important in a rendering system. This paper gives a comparative study of various 3D Rendering techniques and their challenges in a complete and systematic manner.

  16. Genetic evidence for a tight cooperation of TatB and TatC during productive recognition of twin-arginine (Tat signal peptides in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Frank Lausberg

    Full Text Available The twin arginine translocation (Tat pathway transports folded proteins across the cytoplasmic membrane of bacteria. Tat signal peptides contain a consensus motif (S/T-R-R-X-F-L-K that is thought to play a crucial role in substrate recognition by the Tat translocase. Replacement of the phenylalanine at the +2 consensus position in the signal peptide of a Tat-specific reporter protein (TorA-MalE by aspartate blocked export of the corresponding TorA(D(+2-MalE precursor, indicating that this mutation prevents a productive binding of the TorA(D(+2 signal peptide to the Tat translocase. Mutations were identified in the extreme amino-terminal regions of TatB and TatC that synergistically suppressed the export defect of TorA(D(+2-MalE when present in pairwise or triple combinations. The observed synergistic suppression activities were even more pronounced in the restoration of membrane translocation of another export-defective precursor, TorA(KQ-MalE, in which the conserved twin arginine residues had been replaced by lysine-glutamine. Collectively, these findings indicate that the extreme amino-terminal regions of TatB and TatC cooperate tightly during recognition and productive binding of Tat-dependent precursor proteins and, furthermore, that TatB and TatC are both involved in the formation of a specific signal peptide binding site that reaches out as far as the end of the TatB transmembrane segment.

  17. FAST CROWD RENDERING IN COMPUTER GAMES

    Directory of Open Access Journals (Sweden)

    Kaya OĞUZ

    2010-06-01

    Full Text Available Computer games, with the speed advancements of graphical processors, are coming closer to the quality of cinema industry. Contrary to offline rendering of the scenes in a motion picture, computer games should be able to render at 30 frames per second. Therefore, CPU and memory performance are sought by using various techniques. This paper is about using instancing feature of contemporary graphical processors along with level of detail techniques which has been in use for a very long time. Using instancing, 15,000 instances were successfully rendered at 30 frames per second using a very low %10 CPU usage. The application can render 40,000 instances at 13 frames per second.

  18. Visibility-Aware Direct Volume Rendering

    Institute of Scientific and Technical Information of China (English)

    Wai-Ho Mak; Yingcai Wu; Ming-Yuen Chan; Huamin Qu

    2011-01-01

    Direct volume rendering (DVR) is a powerful visualization technique which allows users to effectively explore and study volumetric datasets. Different transparency settings can be flexibly assigned to different structures such that some valuable information can be revealed in direct volume rendered images (DVRIs). However, end-users often feel that some risks are always associated with DVR because they do not know whether any important information is missing from the transparent regions of DVRIs. In this paper, we investigate how to semi-automatically generate a set of DVRIs and also an animation which can reveal information missed in the original DVRIs and meanwhile satisfy some image quality criteria such as coherence. A complete framework is developed to tackle various problems related to the generation and quality evaluation of visibility-aware DVRIs and animations. Our technique can reduce the risk of using direct volume rendering and thus boost the confidence of users in volume rendering systems.

  19. ARC Code TI: SLAB Spatial Audio Renderer

    Data.gov (United States)

    National Aeronautics and Space Administration — SLAB is a software-based, real-time virtual acoustic environment rendering system being developed as a tool for the study of spatial hearing. SLAB is designed to...

  20. Layered Textures for Image-Based Rendering

    Institute of Scientific and Technical Information of China (English)

    en-Cheng Wang; ui-Yu Li; in Zheng; n-Hua Wu

    2004-01-01

    An extension to texture mapping is given in this paper for improving the efficiency of image-based rendering. For a depth image with an orthogonal displacement at each pixel, it is decomposed by the displacement into a series of layered textures (LTs) with each one having the same displacement for all its texels. Meanwhile,some texels of the layered textures are interpolated for obtaining a continuous 3D approximation of the model represented in the depth image. Thus, the plane-to-plane texture mapping can be used to map these layered textures to produce novel views and the advantages can be obtained as follows: accelerating the rendering speed,supporting the 3D surface details and view motion parallax, and avoiding the expensive task of hole-filling in the rendering stage. Experimental results show the new method can produce high-quality images and run faster than many famous image-based rendering techniques.

  1. Composed Scattering Model for Direct Volume Rendering

    Institute of Scientific and Technical Information of China (English)

    蔡文立; 石教英

    1996-01-01

    Based on the equation of transfer in transport theory of optical physics,a new volume rendering model,called composed scattering model(CSM),is presented.In calculating the scattering term of the equation,it is decomposed into volume scattering intensity and surface scattering intensity,and they are composed with the boundary detection operator as the weight function.This proposed model differs from the most current volume rendering models in the aspect that in CSM segmentation and illumination intensity calculation are taken as two coherent parts while in existing models they are regarded as two separate ones.This model has been applied to the direct volume rendering of 3D data sets obtained by CT and MRI.The resultant images show not only rich details but also clear boundary surfaces.CSM is demonstrated to be an accurate volume rendering model suitable for CT and MRI data sets.

  2. GUANYLYL CYCLASE/NATRIURETIC PEPTIDES RECEPTOR-A SIGNALING ANTAGONIZES PHOSPHOINOSITIDE HYDROLYSIS, Ca2+ RELEASE, AND ACTIVATION OF PROTEIN KINASE C

    Directory of Open Access Journals (Sweden)

    Kailash N Pandey

    2014-08-01

    Full Text Available Thus far, three related natriuretic peptides (NPs and three distinct sub-types of cognate NP receptors have been identified and characterized based on the specific ligand binding affinities, guanylyl cyclase activity, and generation of intracellular cGMP. Atrial and brain natriuretic peptides (ANP and BNP specifically bind and activate guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA, and C-type natriuretic peptide (CNP shows specificity to activate guanylyl cyclase/natriuretic peptide receptor-B (GC-B/NPRB. All three NPs bind to natriuretic peptide receptor-C (NPRC, which is also known as clearance or silent receptor. The NPRA is considered the principal biologically active receptor of NP family; however, the molecular signaling mechanisms of NP receptors are not well understood. The activation of NPRA and NPRB produces the intracellular second messenger cGMP, which serves as the major signaling molecule of all three NPs. The activation of NPRB in response to CNP also produces the intracellular cGMP; however, at lower magnitude than that of NPRA, which is activated by ANP and BNP. In addition to enhanced accumulation of intracellular cGMP in response to all three NPs, the levels of cAMP, Ca2+ and inositol triphosphate (IP3 have also been reported to be altered in different cells and tissue types. Interestingly, ANP has been found to lower the concentrations of cAMP, Ca2+, and IP3; however, NPRC has been proposed to increase the levels of these metabolic signaling molecules. The mechanistic studies of decreased and/or increased levels of cAMP, Ca2+, and IP3 in response to NPs and their receptors have not yet been clearly established. This review focuses on the signaling mechanisms of ANP/NPRA and their biological effects involving an increased level of intracellular accumulation of cGMP and a decreased level of cAMP, Ca2+, and IP3 in different cells and tissue systems.

  3. The glucagon-like peptide-1 analogue exendin-4 reverses impaired intracellular Ca(2+) signalling in steatotic hepatocytes.

    Science.gov (United States)

    Ali, Eunüs S; Hua, Jin; Wilson, Claire H; Tallis, George A; Zhou, Fiona H; Rychkov, Grigori Y; Barritt, Greg J

    2016-09-01

    The release of Ca(2+) from the endoplasmic reticulum (ER) and subsequent replenishment of ER Ca(2+) by Ca(2+) entry through store-operated Ca(2+) channels (SOCE) play critical roles in the regulation of liver metabolism by adrenaline, glucagon and other hormones. Both ER Ca(2+) release and Ca(2+) entry are severely inhibited in steatotic hepatocytes. Exendin-4, a slowly-metabolised glucagon-like peptide-1 (GLP-1) analogue, is known to reduce liver glucose output and liver lipid, but the mechanisms involved are not well understood. The aim of this study was to determine whether exendin-4 alters intracellular Ca(2+) homeostasis in steatotic hepatocytes, and to evaluate the mechanisms involved. Exendin-4 completely reversed lipid-induced inhibition of SOCE in steatotic liver cells, but did not reverse lipid-induced inhibition of ER Ca(2+) release. The action of exendin-4 on Ca(2+) entry was rapid in onset and was mimicked by GLP-1 or dibutyryl cyclic AMP. In steatotic liver cells, exendin-4 caused a rapid decrease in lipid (half time 6.5min), inhibited the accumulation of lipid in liver cells incubated in the presence of palmitate plus the SOCE inhibitor BTP-2, and enhanced the formation of cyclic AMP. Hormone-stimulated accumulation of extracellular glucose in glycogen replete steatotic liver cells was inhibited compared to that in non-steatotic cells, and this effect of lipid was reversed by exendin-4. It is concluded that, in steatotic hepatocytes, exendin-4 reverses the lipid-induced inhibition of SOCE leading to restoration of hormone-regulated cytoplasmic Ca(2+) signalling. The mechanism may involve GLP-1 receptors, cyclic AMP, lipolysis, decreased diacylglycerol and decreased activity of protein kinase C.

  4. Involvement of formyl peptide receptors in receptor for advanced glycation end products (RAGE - and amyloid beta 1-42-induced signal transduction in glial cells

    Directory of Open Access Journals (Sweden)

    Slowik Alexander

    2012-11-01

    Full Text Available Abstract Background Recent studies suggest that the chemotactic G-protein-coupled-receptor (GPCR formyl-peptide-receptor-like-1 (FPRL1 and the receptor-for-advanced-glycation-end-products (RAGE play an important role in the inflammatory response involved in neurodegenerative disorders such as Alzheimer’s disease (AD. Therefore, the expression and co-localisation of mouse formyl peptide receptor (mFPR 1 and 2 as well as RAGE in an APP/PS1 transgenic mouse model using immunofluorescence and real-time RT-PCR were analysed. The involvement of rat or human FPR1/FPRL1 (corresponds to mFPR1/2 and RAGE in amyloid-β 1–42 (Aβ1-42-induced signalling were investigated by extracellular signal regulated kinase 1/2 (ERK1/2 phosphorylation. Furthermore, the cAMP level in primary rat glial cells (microglia and astrocytes and transfected HEK 293 cells was measured. Formyl peptide receptors and RAGE were inhibited by a small synthetic antagonist WRW4 and an inactive receptor variant delta-RAGE, lacking the intracytoplasmatic domains. Results We demonstrated a strong increase of mFPR1/2 and RAGE expression in the cortex and hippocampus of APP/PS1 transgenic mice co-localised to the glial cells. In addition, the Aβ1-42-induced signal transduction is dependant on FPRL1, but also on FPR1. For the first time, we have shown a functional interaction between FPRL1/FPR1 and RAGE in RAGE ligands S100B- or AGE-mediated signalling by ERK1/2 phosphorylation and cAMP level measurement. In addition a possible physical interaction between FPRL1 as well as FPR1 and RAGE was shown with co-immunoprecipitation and fluorescence microscopy. Conclusions The results suggest that both formyl peptide receptors play an essential role in Aβ1-42-induced signal transduction in glial cells. The interaction with RAGE could explain the broad ligand spectrum of formyl peptide receptors and their important role for inflammation and the host defence against infections.

  5. Involvement of formyl peptide receptors in receptor for advanced glycation end products (RAGE)--and amyloid beta 1-42-induced signal transduction in glial cells.

    Science.gov (United States)

    Slowik, Alexander; Merres, Julika; Elfgen, Anne; Jansen, Sandra; Mohr, Fabian; Wruck, Christoph J; Pufe, Thomas; Brandenburg, Lars-Ove

    2012-11-20

    Recent studies suggest that the chemotactic G-protein-coupled-receptor (GPCR) formyl-peptide-receptor-like-1 (FPRL1) and the receptor-for-advanced-glycation-end-products (RAGE) play an important role in the inflammatory response involved in neurodegenerative disorders such as Alzheimer's disease (AD).Therefore, the expression and co-localisation of mouse formyl peptide receptor (mFPR) 1 and 2 as well as RAGE in an APP/PS1 transgenic mouse model using immunofluorescence and real-time RT-PCR were analysed. The involvement of rat or human FPR1/FPRL1 (corresponds to mFPR1/2) and RAGE in amyloid-β 1-42 (Aβ1-42)-induced signalling were investigated by extracellular signal regulated kinase 1/2 (ERK1/2) phosphorylation. Furthermore, the cAMP level in primary rat glial cells (microglia and astrocytes) and transfected HEK 293 cells was measured. Formyl peptide receptors and RAGE were inhibited by a small synthetic antagonist WRW4 and an inactive receptor variant delta-RAGE, lacking the intracytoplasmatic domains. We demonstrated a strong increase of mFPR1/2 and RAGE expression in the cortex and hippocampus of APP/PS1 transgenic mice co-localised to the glial cells. In addition, the Aβ1-42-induced signal transduction is dependant on FPRL1, but also on FPR1. For the first time, we have shown a functional interaction between FPRL1/FPR1 and RAGE in RAGE ligands S100B- or AGE-mediated signalling by ERK1/2 phosphorylation and cAMP level measurement. In addition a possible physical interaction between FPRL1 as well as FPR1 and RAGE was shown with co-immunoprecipitation and fluorescence microscopy. The results suggest that both formyl peptide receptors play an essential role in Aβ1-42-induced signal transduction in glial cells. The interaction with RAGE could explain the broad ligand spectrum of formyl peptide receptors and their important role for inflammation and the host defence against infections.

  6. Involvement of formyl peptide receptors in receptor for advanced glycation end products (RAGE) - and amyloid beta 1-42-induced signal transduction in glial cells

    Science.gov (United States)

    2012-01-01

    Background Recent studies suggest that the chemotactic G-protein-coupled-receptor (GPCR) formyl-peptide-receptor-like-1 (FPRL1) and the receptor-for-advanced-glycation-end-products (RAGE) play an important role in the inflammatory response involved in neurodegenerative disorders such as Alzheimer’s disease (AD). Therefore, the expression and co-localisation of mouse formyl peptide receptor (mFPR) 1 and 2 as well as RAGE in an APP/PS1 transgenic mouse model using immunofluorescence and real-time RT-PCR were analysed. The involvement of rat or human FPR1/FPRL1 (corresponds to mFPR1/2) and RAGE in amyloid-β 1–42 (Aβ1-42)-induced signalling were investigated by extracellular signal regulated kinase 1/2 (ERK1/2) phosphorylation. Furthermore, the cAMP level in primary rat glial cells (microglia and astrocytes) and transfected HEK 293 cells was measured. Formyl peptide receptors and RAGE were inhibited by a small synthetic antagonist WRW4 and an inactive receptor variant delta-RAGE, lacking the intracytoplasmatic domains. Results We demonstrated a strong increase of mFPR1/2 and RAGE expression in the cortex and hippocampus of APP/PS1 transgenic mice co-localised to the glial cells. In addition, the Aβ1-42-induced signal transduction is dependant on FPRL1, but also on FPR1. For the first time, we have shown a functional interaction between FPRL1/FPR1 and RAGE in RAGE ligands S100B- or AGE-mediated signalling by ERK1/2 phosphorylation and cAMP level measurement. In addition a possible physical interaction between FPRL1 as well as FPR1 and RAGE was shown with co-immunoprecipitation and fluorescence microscopy. Conclusions The results suggest that both formyl peptide receptors play an essential role in Aβ1-42-induced signal transduction in glial cells. The interaction with RAGE could explain the broad ligand spectrum of formyl peptide receptors and their important role for inflammation and the host defence against infections. PMID:23164356

  7. Insulin production and signaling in renal tubules of Drosophila is under control of tachykinin-related peptide and regulates stress resistance.

    Directory of Open Access Journals (Sweden)

    Jeannette A E Söderberg

    Full Text Available The insulin-signaling pathway is evolutionarily conserved in animals and regulates growth, reproduction, metabolic homeostasis, stress resistance and life span. In Drosophila seven insulin-like peptides (DILP1-7 are known, some of which are produced in the brain, others in fat body or intestine. Here we show that DILP5 is expressed in principal cells of the renal tubules of Drosophila and affects survival at stress. Renal (Malpighian tubules regulate water and ion homeostasis, but also play roles in immune responses and oxidative stress. We investigated the control of DILP5 signaling in the renal tubules by Drosophila tachykinin peptide (DTK and its receptor DTKR during desiccative, nutritional and oxidative stress. The DILP5 levels in principal cells of the tubules are affected by stress and manipulations of DTKR expression in the same cells. Targeted knockdown of DTKR, DILP5 and the insulin receptor dInR in principal cells or mutation of Dilp5 resulted in increased survival at either stress, whereas over-expression of these components produced the opposite phenotype. Thus, stress seems to induce hormonal release of DTK that acts on the renal tubules to regulate DILP5 signaling. Manipulations of S6 kinase and superoxide dismutase (SOD2 in principal cells also affect survival at stress, suggesting that DILP5 acts locally on tubules, possibly in oxidative stress regulation. Our findings are the first to demonstrate DILP signaling originating in the renal tubules and that this signaling is under control of stress-induced release of peptide hormone.

  8. A peptide targeting an interaction interface disrupts the dopamine D1-D2 receptor heteromer to block signaling and function in vitro and in vivo: effective selective antagonism

    Science.gov (United States)

    Hasbi, Ahmed; Perreault, Melissa L.; Shen, Maurice Y. F.; Zhang, Lucia; To, Ryan; Fan, Theresa; Nguyen, Tuan; Ji, Xiaodong; O'Dowd, Brian F.; George, Susan R.

    2014-01-01

    Although the dopamine D1-D2 receptor heteromer has emerging physiological relevance and a postulated role in different neuropsychiatric disorders, such as drug addiction, depression, and schizophrenia, there is a need for pharmacological tools that selectively target such receptor complexes in order to analyze their biological and pathophysiological functions. Since no selective antagonists for the D1-D2 heteromer are available, serial deletions and point mutations were used to precisely identify the amino acids involved in an interaction interface between the receptors, residing within the carboxyl tail of the D1 receptor that interacted with the D2 receptor to form the D1-D2 receptor heteromer. It was determined that D1 receptor carboxyl tail residues 404Glu and 405Glu were critical in mediating the interaction with the D2 receptor. Isolated mutation of these residues in the D1 receptor resulted in the loss of agonist activation of the calcium signaling pathway mediated through the D1-D2 receptor heteromer. The physical interaction between the D1 and D2 receptor could be disrupted, as shown by coimmunoprecipitation and BRET analysis, by a small peptide generated from the D1 receptor sequence that contained these amino acids, leading to a switch in G-protein affinities and loss of calcium signaling, resulting in the inhibition of D1-D2 heteromer function. The use of the D1-D2 heteromer-disrupting peptide in vivo revealed a pathophysiological role for the D1-D2 heteromer in the modulation of behavioral despair. This peptide may represent a novel pharmacological tool with potential therapeutic benefits in depression treatment.—Hasbi, A., Perreault, M. L., Shen, M. Y. F., Zhang, L., To, R., Fan, T., Nguyen, T., Ji, X., O'Dowd, B. F., George, S. R. A peptide targeting an interaction interface disrupts the dopamine D1-D2 receptor heteromer to block signaling and function in vitro and in vivo: effective selective antagonism. PMID:25063849

  9. Blocking protein phosphatase 2A signaling prevents endothelial-to-mesenchymal transition and renal fibrosis: a peptide-based drug therapy

    Science.gov (United States)

    Deng, Yuanjun; Guo, Yanyan; Liu, Ping; Zeng, Rui; Ning, Yong; Pei, Guangchang; Li, Yueqiang; Chen, Meixue; Guo, Shuiming; Li, Xiaoqing; Han, Min; Xu, Gang

    2016-01-01

    Endothelial-to-mesenchymal transition (EndMT) contributes to the emergence of fibroblasts and plays a significant role in renal interstitial fibrosis. Protein phosphatase 2A (PP2A) is a major serine/threonine protein phosphatase in eukaryotic cells and regulates many signaling pathways. However, the significance of PP2A in EndMT is poorly understood. In present study, the role of PP2A in EndMT was evaluated. We demonstrated that PP2A activated in endothelial cells (EC) during their EndMT phenotype acquisition and in the mouse model of obstructive nephropathy (i.e., UUO). Inhibition of PP2A activity by its specific inhibitor prevented EC undergoing EndMT. Importantly, PP2A activation was dependent on tyrosine nitration at 127 in the catalytic subunit of PP2A (PP2Ac). Our renal-protective strategy was to block tyrosine127 nitration to inhibit PP2A activation by using a mimic peptide derived from PP2Ac conjugating a cell penetrating peptide (CPP: TAT), termed TAT-Y127WT. Pretreatment withTAT-Y127WT was able to prevent TGF-β1-induced EndMT. Administration of the peptide to UUO mice significantly ameliorated renal EndMT level, with preserved density of peritubular capillaries and reduction in extracellular matrix deposition. Taken together, these results suggest that inhibiting PP2Ac nitration using a mimic peptide is a potential preventive strategy for EndMT in renal fibrosis.

  10. Amyloid-β peptides act as allosteric modulators of cholinergic signalling through formation of soluble BAβACs.

    Science.gov (United States)

    Kumar, Rajnish; Nordberg, Agneta; Darreh-Shori, Taher

    2016-01-01

    Amyloid-β peptides, through highly sophisticated enzymatic machinery, are universally produced and released in an action potential synchronized manner into the interstitial fluids in the brain. Yet no native functions are attributed to amyloid-β. The amyloid-β hypothesis ascribes just neurotoxicity properties through build-up of soluble homomeric amyloid-β oligomers or fibrillar deposits. Apolipoprotein-ε4 (APOE4) allele is the only confirmed genetic risk factor of sporadic Alzheimer's disease; once more it is unclear how it increases the risk of Alzheimer's disease. Similarly, central cholinergic signalling is affected selectively and early in the Alzheimer's disease brain, again why cholinergic neurons show this sensitivity is still unclear. However, the three main known Alzheimer's disease risk factors, advancing age, female gender and APOE4, have been linked to a high apolipoprotein-E and accumulation of the acetylcholine degrading enzyme, butyrylcholinesterase in cerebrospinal fluids of patients. Furthermore, numerous reports indicate that amyloid-β interacts with butyrylcholinesterase and apolipoprotein-E. We have proposed that this interaction leads to formation of soluble ultrareactive acetylcholine-hydrolyzing complexes termed BAβACs, to adjust at demand both synaptic and extracellular acetylcholine signalling. This hypothesis predicted presence of acetylcholine-synthesizing enzyme, choline acetyltransferase in extracellular fluids to allow maintenance of equilibrium between breakdown and synthesis of acetylcholine through continuous in situ syntheses. A recent proof-of-concept study led to the discovery of this enzyme in the human extracellular fluids. We report here that apolipoprotein-E, in particular ε4 isoprotein acts as one of the strongest endogenous anti-amyloid-β fibrillization agents reported in the literature. At biological concentrations, apolipoprotein-E prevented amyloid-β fibrillization for at least 65 h. We show that amyloid

  11. Rendering and Compositing Infrastructure Improvements to VisIt for Insitu Rendering

    Energy Technology Data Exchange (ETDEWEB)

    Loring, Burlen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ruebel, Oliver [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-01-28

    Compared to posthoc rendering, insitu rendering often generates larger numbers of images, as a result rendering performance and scalability are critical in the insitu setting. In this work we present improvements to VisIt's rendering and compositing infrastructure that deliver increased performance and scalability in both posthoc and insitu settings. We added the capability for alpha blend compositing and use it with ordered compositing when datasets have disjoint block domain decomposition to optimize the rendering of transparent geometry. We also made improvements that increase overall efficiency by reducing communication and data movement and have addressed a number of performance issues. We structured our code to take advantage of SIMD parallelization and use threads to overlap communication and compositing. We tested our improvements on a 20 core workstation using 8 cores to render geometry generated from a $256^3$ cosmology dataset and on a Cray XC31 using 512 cores to render geometry generated from a $2000^2 \\times 800$ plasma dataset. Our results show that ordered compositing provides a speed up of up to $4 \\times$ over the current sort first strategy. The other improvements resulted in modest speed up with one notable exception where we achieve up to $40 \\times$ speed up of rendering and compositing of opaque geometry when both opaque and transparent geometry are rendered together. We also investigated the use of depth peeling, but found that the implementation provided by VTK is substantially slower,both with and without GPU acceleration, than a local camera order sort.

  12. Brain Image Representation and Rendering: A Survey

    Directory of Open Access Journals (Sweden)

    Mudassar Raza

    2012-09-01

    Full Text Available Brain image representation and rendering processes are basically used for evaluation, development and investigation consent experimental examination and formation of brain images of a variety of modalities that includes the major brain types like MEG, EEG, PET, MRI, CT or microscopy. So, there is a need to conduct a study to review the existing work in this area. This paper provides a review of different existing techniques and methods regarding the brain image representation and rendering. Image Rendering is the method of generating an image by means of a model, through computer programs. The basic purpose of brain image representation and rendering processes is to analyze the brain images precisely in order to effectively diagnose and examine the diseases and problems. The basic objective of this study is to evaluate and discuss different techniques and approaches proposed in order to handle different brain imaging types. The paper provides a short overview of different methods, in the form of advantages and limitations, presented in the prospect of brain image representation and rendering along with their sub categories proposed by different authors.

  13. Equalizer: a scalable parallel rendering framework.

    Science.gov (United States)

    Eilemann, Stefan; Makhinya, Maxim; Pajarola, Renato

    2009-01-01

    Continuing improvements in CPU and GPU performances as well as increasing multi-core processor and cluster-based parallelism demand for flexible and scalable parallel rendering solutions that can exploit multipipe hardware accelerated graphics. In fact, to achieve interactive visualization, scalable rendering systems are essential to cope with the rapid growth of data sets. However, parallel rendering systems are non-trivial to develop and often only application specific implementations have been proposed. The task of developing a scalable parallel rendering framework is even more difficult if it should be generic to support various types of data and visualization applications, and at the same time work efficiently on a cluster with distributed graphics cards. In this paper we introduce a novel system called Equalizer, a toolkit for scalable parallel rendering based on OpenGL which provides an application programming interface (API) to develop scalable graphics applications for a wide range of systems ranging from large distributed visualization clusters and multi-processor multipipe graphics systems to single-processor single-pipe desktop machines. We describe the system architecture, the basic API, discuss its advantages over previous approaches, present example configurations and usage scenarios as well as scalability results.

  14. Standardized rendering from IR surveillance motion imagery

    Science.gov (United States)

    Prokoski, F. J.

    2014-06-01

    Government agencies, including defense and law enforcement, increasingly make use of video from surveillance systems and camera phones owned by non-government entities.Making advanced and standardized motion imaging technology available to private and commercial users at cost-effective prices would benefit all parties. In particular, incorporating thermal infrared into commercial surveillance systems offers substantial benefits beyond night vision capability. Face rendering is a process to facilitate exploitation of thermal infrared surveillance imagery from the general area of a crime scene, to assist investigations with and without cooperating eyewitnesses. Face rendering automatically generates greyscale representations similar to police artist sketches for faces in surveillance imagery collected from proximate locations and times to a crime under investigation. Near-realtime generation of face renderings can provide law enforcement with an investigation tool to assess witness memory and credibility, and integrate reports from multiple eyewitnesses, Renderings can be quickly disseminated through social media to warn of a person who may pose an immediate threat, and to solicit the public's help in identifying possible suspects and witnesses. Renderings are pose-standardized so as to not divulge the presence and location of eyewitnesses and surveillance cameras. Incorporation of thermal infrared imaging into commercial surveillance systems will significantly improve system performance, and reduce manual review times, at an incremental cost that will continue to decrease. Benefits to criminal justice would include improved reliability of eyewitness testimony and improved accuracy of distinguishing among minority groups in eyewitness and surveillance identifications.

  15. Signal peptide-independent secretory expression and characterization of pullulanase from a newly isolated Klebsiella variicola SHN-1 in Escherichia coli.

    Science.gov (United States)

    Chen, Wen-Bo; Nie, Yao; Xu, Yan

    2013-01-01

    A strain with the power to produce extracellular pullulanase was obtained from the sample taken from a flour mill. By sequencing its 16S rDNA, the isolate was identified as Klebsiella variicola SHN-1. When the gene encoding pullulanase, containing the N-terminal signal sequence, was cloned into Escherichia coli BL21 (DE3), extracellular activity was detected up to 10 U/ml, a higher level compared with the results in published literature. Subsequently, the recombinant pullulanase was purified and characterized. The main end product from pullulan hydrolyzed by recombinant pullulanase was determined as maltotriose with HPLC, and hence, the recombinant pullulanase was identified as type I pullulanase, which could be efficiently employed in starch processing to produce maltotriose with higher purity and even to evaluate the purity of pullulan. To investigate the effect of signal peptide on secretion of the recombinant enzyme, the signal sequence was removed from the constructed vector. However, secretion of pullulanase in E. coli was not influenced, which was seldom reported previously. By localizing the distribution of pullulanase on subcellular fractions, the secretion of recombinant pullulanase in E. coli BL21 (DE3) was confirmed, even from the expression system of nonsecretory type without the assistance of signal peptide.

  16. Adaptive Rendering Based on Visual Acuity Equations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new method of adaptable rendering for interaction in Virtual Environment(VE) through different visual acuity equations is proposed. An acuity factor equation of luminance vision is first given. Secondly, five equations which calculate the visual acuity through visual acuity factors are presented, and adaptive rendering strategy based on different visual acuity equations is given. The VE system may select one of them on the basis of the host's load, hereby select LOD for each model which would be rendered. A coarser LOD is selected where the visual acuity is lower, and a better LOD is used where it is higher. This method is tested through experiments and the experimental results show that it is effective.

  17. Rendering Falling Leaves on Graphics Hardware

    Directory of Open Access Journals (Sweden)

    Marcos Balsa

    2008-04-01

    Full Text Available There is a growing interest in simulating natural phenomena in computer graphics applications. Animating natural scenes in real time is one of the most challenging problems due to the inherent complexity of their structure, formed by millions of geometric entities, and the interactions that happen within. An example of natural scenario that is needed for games or simulation programs are forests. Forests are difficult to render because the huge amount of geometric entities and the large amount of detail to be represented. Moreover, the interactions between the objects (grass, leaves and external forces such as wind are complex to model. In this paper we concentrate in the rendering of falling leaves at low cost. We present a technique that exploits graphics hardware in order to render thousands of leaves with different falling paths in real time and low memory requirements.

  18. Toll recognition signal activates oenocytoid cell lysis via a crosstalk between plasmatocyte-spreading peptide and eicosanoids in response to a fungal infection.

    Science.gov (United States)

    Park, Jung-A; Kim, Yonggyun

    2012-10-01

    Plasmatocyte-spreading peptide (PSP) activates hemocyte-spreading behavior in response to various microbial pathogens. Its homolog, growth-blocking peptide, has several functions that activate immune cells and induce oenocytoid cell lysis (OCL). OCL is required for release of prophenoloxidase from oenocytoids in the beet armyworm, Spodoptera exigua. Injection of PSP to S. exigua larvae significantly induced in vivo OCL and resulted in significant increase of phenoloxidase (PO) activity. A fungal infection induced PSP expression and also significantly increased OCL. RNA interference (RNAi) of PSP expression significantly suppressed OCL induction and subsequently inhibited PO activation. Interestingly, an addition of dexamethasone (a specific phospholipase A₂ inhibitor) inhibited the PSP activity to induce OCL. Toll signal pathway was associated with PSP action on inducing OCL because RNAi of Toll expression suppressed PSP expression and subsequent OCL induction. However, an addition of PSP to the larvae under RNAi of Toll expression rescued the progress of OCL.

  19. Blender cycles lighting and rendering cookbook

    CERN Document Server

    Iraci, Bernardo

    2013-01-01

    An in-depth guide full of step-by-step recipes to explore the concepts behind the usage of Cycles. Packed with illustrations, and lots of tips and tricks; the easy-to-understand nature of the book will help the reader understand even the most complex concepts with ease.If you are a digital artist who already knows your way around Blender, and you want to learn about the new Cycles' rendering engine, this is the book for you. Even experts will be able to pick up new tips and tricks to make the most of the rendering capabilities of Cycles.

  20. Volume Rendering for Curvilinear and Unstructured Grids

    Energy Technology Data Exchange (ETDEWEB)

    Max, N; Williams, P; Silva, C; Cook, R

    2003-03-05

    We discuss two volume rendering methods developed at Lawrence Livermore National Laboratory. The first, cell projection, renders the polygons in the projection of each cell. It requires a global visibility sort in order to composite the cells in back to front order, and we discuss several different algorithms for this sort. The second method uses regularly spaced slice planes perpendicular to the X, Y, or Z axes, which slice the cells into polygons. Both methods are supplemented with anti-aliasing techniques to deal with small cells that might fall between pixel samples or slice planes, and both have been parallelized.

  1. GPU Pro 5 advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2014-01-01

    In GPU Pro5: Advanced Rendering Techniques, section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Michal Valient, Wessam Bahnassi, and Marius Bjorge have once again assembled a high-quality collection of cutting-edge techniques for advanced graphics processing unit (GPU) programming. Divided into six sections, the book covers rendering, lighting, effects in image space, mobile devices, 3D engine design, and compute. It explores rasterization of liquids, ray tracing of art assets that would otherwise be used in a rasterized engine, physically based area lights, volumetric light

  2. Digital color acquisition, perception, coding and rendering

    CERN Document Server

    Fernandez-Maloigne, Christine; Macaire, Ludovic

    2013-01-01

    In this book the authors identify the basic concepts and recent advances in the acquisition, perception, coding and rendering of color. The fundamental aspects related to the science of colorimetry in relation to physiology (the human visual system) are addressed, as are constancy and color appearance. It also addresses the more technical aspects related to sensors and the color management screen. Particular attention is paid to the notion of color rendering in computer graphics. Beyond color, the authors also look at coding, compression, protection and quality of color images and videos.

  3. Haptic rendering for simulation of fine manipulation

    CERN Document Server

    Wang, Dangxiao; Zhang, Yuru

    2014-01-01

    This book introduces the latest progress in six degrees of freedom (6-DoF) haptic rendering with the focus on a new approach for simulating force/torque feedback in performing tasks that require dexterous manipulation skills. One of the major challenges in 6-DoF haptic rendering is to resolve the conflict between high speed and high fidelity requirements, especially in simulating a tool interacting with both rigid and deformable objects in a narrow space and with fine features. The book presents a configuration-based optimization approach to tackle this challenge. Addressing a key issue in man

  4. Conservation of the abscission signaling peptide IDA during Angiosperm evolution: withstanding genome duplications and gain and loss of the receptors HAE/HSL2

    Directory of Open Access Journals (Sweden)

    Ida M. Stø

    2015-10-01

    Full Text Available The peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA, which signals through the leucine-rich repeat receptor-like kinases HAESA (HAE and HAESA-LIKE2 (HSL2, controls different cell separation events in Arabidopsis thaliana. We hypothesize the involvement of this signaling module in abscission processes in other plant species even though they may shed other organs than A. thaliana. As the first step towards testing this hypothesis from an evolutionarily perspective we have identified genes encoding putative orthologues of IDA and its receptors by BLAST searches of publically available protein, nucleotide and genome databases for angiosperms. Genes encoding IDA or IDA-LIKE (IDL peptides and HSL proteins were found in all investigated species, which were selected as to represent each angiosperm order with available genomic sequences. The 12 amino acids representing the bioactive peptide in A. thaliana have virtually been unchanged throughout the evolution of the angiosperms; however, the number of IDL and HSL genes varies between different orders and species. The phylogenetic analyses suggest that IDA, HSL2 and the related HSL1 gene, were present in the species that gave rise to the angiosperms. HAE has arisen from HSL1 after a genome duplication that took place after the monocot - eudicots split. HSL1 has also independently been duplicated in the monocots, while HSL2 has been lost in gingers (Zingiberales and grasses (Poales. IDA has been duplicated in eudicots to give rise to functionally divergent IDL peptides. We postulate that the high number of IDL homologs present in the core eudicots is a result of multiple whole genome duplications. We substantiate the involvement of IDA and HAE/HSL2 homologs in abscission by providing gene expression data of different organ separation events from various species.

  5. The signal peptide-like segment of hpaXm is required for its association to the cell wall in transgenic tobacco plants

    Science.gov (United States)

    Li, Le; Miao, Weiguo; Liu, Wenbo; Zhang, Shujian

    2017-01-01

    Harpins, encoded by hrp (hypersensitive response and pathogenicity) genes of Gram-negative plant pathogens, are elicitors of hypersensitive response (HR). HpaXm is a novel harpin-like protein described from cotton leaf blight bacteria, Xanthomonas citri subsp. malvacearum—a synonym of X. campestris pv. malvacearum (Smith 1901–1978). A putative signal peptide (1-MNSLNTQIGANSSFL-15) of hpaXm was predicted in the nitroxyl-terminal (N-terminal)by SignalP (SignalP 3.0 server). Here, we explored the function of the N-terminal leader peptide like segment of hpaXm using transgenic tobacco (Nicotiana tabacum cv. Xanthi nc.). Transgenic tobacco lines expressing the full-length hpaXm and the signal peptide-like segment-deleted mutant hpaXmΔLP were developed using transformation mediated by Agrobacterium tumefaciens. The target genes were confirmed integrated into the tobacco genomes and expressed normally. Using immune colloidal-gold detection technique, hpaXm protein was found to be transferred to the cytoplasm, the cell membrane, and organelles such as chloroplasts, mitochondria, and nucleus, as well as the cell wall. However, the deletion mutant hpaXmΔLP expressed in transgenic tobacco was found unable to cross the membrane to reach the cell wall. Additionally, soluble proteins extracted from plants transformed with hpaXm and hpaXmΔLP were bio-active. Defensive micro-HR induced by the transgene expression of hpaXm and hpaXmΔLP were observed on transgenic tobacco leaves. Disease resistance bioassays to tobacco mosaic virus (TMV) showed that tobacco plants transformed with hpaXm and with hpaXmΔLP exhibited enhanced resistance to TMV. In summary, the N-terminal signal peptide-like segment (1–45 bp) in hpaXm sequence is not necessary for transgene expression, bioactivity of hpaXm and resistance to TMV in transgenic tobacco, but is required for the protein to be translocated to the cell wall. PMID:28141855

  6. Intra- and Interspecies Signaling between Streptococcus salivarius and Streptococcus pyogenes Mediated by SalA and SalA1 Lantibiotic Peptides

    Science.gov (United States)

    Upton, M.; Tagg, J. R.; Wescombe, P.; Jenkinson, H. F.

    2001-01-01

    Streptococcus salivarius 20P3 produces a 22-amino-acid residue lantibiotic, designated salivaricin A (SalA), that inhibits the growth of a range of streptococci, including all strains of Streptococcus pyogenes. Lantibiotic production is associated with the sal genetic locus comprising salA, the lantibiotic structural gene; salBCTX genes encoding peptide modification and export machinery proteins; and salYKR genes encoding a putative immunity protein and two-component sensor-regulator system. Insertional inactivation of salB in S. salivarius 20P3 resulted in abrogation of SalA peptide production, of immunity to SalA, and of salA transcription. Addition of exogenous SalA peptide to salB mutant cultures induced dose-dependent expression of salA mRNA (0.2 kb), demonstrating that SalA production was normally autoregulated. Inactivation of salR encoding the response regulator of the SalKR two-component system led to reduced production of, and immunity to, SalA. The sal genetic locus was also present in S. pyogenes SF370 (M type 1), but because of a deletion across the salBCT genes, the corresponding lantibiotic peptide, designated SalA1, was not produced. However, in S. pyogenes T11 (M type 4) the sal locus gene complement was apparently complete, and active SalA1 peptide was synthesized. Exogenously added SalA1 peptide from S. pyogenes T11 induced salA1 transcription in S. pyogenes SF370 and in an isogenic S. pyogenes T11 salB mutant and salA transcription in S. salivarius 20P3 salB. Thus, SalA and SalA1 are examples of streptococcal lantibiotics whose production is autoregulated. These peptides act as intra- and interspecies signaling molecules, modulating lantibiotic production and possibly influencing streptococcal population ecology in the oral cavity. PMID:11395456

  7. Spatial sound rendering of a playing xylophone for the telepresence application

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Hoffmann, Pablo F.

    2013-01-01

    xylophone sound rendering is proposed. The recorded signal is processed in order to define multiple virtual sources which are spatially distributed for the auditory width representation of the virtual xylophone. The results of the analyzed recording and rendering techniques are compared in terms...... played at the student's location is required at the teacher’s site. This paper presents a comparison of different recording techniques for a spatial xylophone sound rendering, focusing on the horizontal width of the xylophone auditory image. The directivity pattern of the xylophone was measured...

  8. An example of quantum imaging: rendering an object undetectable

    CERN Document Server

    Ataman, Stefan

    2016-01-01

    In this paper we propose and analyse a Gedankenexperiment involving three non-linear crystals and two objects inserted in the idler beams. We show that, besides the behaviour that can be extrapolated from previous experiments involving two crystals and one object, we are able to predict a new effect: under certain circumstances, one of the objects can be rendered undetectable to any single detection rate on the signal photons with discarded idler photons. This effect could find applications in future developments of quantum imaging techniques.

  9. An example of quantum imaging: rendering an object undetectable

    Science.gov (United States)

    Ataman, Stefan

    2016-06-01

    In this paper we propose and analyse a Gedankenexperiment involving three non-linear crystals and two objects inserted in the idler beams. We show that, besides the behaviour that can be extrapolated from previous experiments involving two crystals and one object, we are able to predict a new effect: under certain circumstances, one of the objects can be rendered undetectable to any single detection rate on the signal photons with discarded idler photons. This effect could find applications in future developments of quantum imaging techniques.

  10. The Arabidopsis thaliana natriuretic peptide AtPNP-A is a systemic regulator of leaf dark respiration and signals via the phloem

    KAUST Repository

    Ruzvidzo, Oziniel

    2011-09-01

    Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. Here we show that a recombinant Arabidopsis thaliana PNP (AtPNP-A) rapidly increased the rate of dark respiration in treated leaves after 5 min. In addition, we observed increases in lower leaves, and with a lag time of 10 min, the effect spread to the upper leaves and subsequently (after 15 min) to the opposite leaves. This response signature is indicative of phloem mobility of the signal, a hypothesis that was further strengthened by the fact that cold girdling, which affects phloem but not xylem or apoplastic processes, delayed the long distance AtPNP-A effect. We conclude that locally applied AtPNP-A can induce a phloem-mobile signal that rapidly modifies plant homeostasis in distal parts. © 2011 Elsevier GmbH.

  11. The Arabidopsis thaliana natriuretic peptide AtPNP-A is a systemic regulator of leaf dark respiration and signals via the phloem.

    Science.gov (United States)

    Ruzvidzo, Oziniel; Donaldson, Lara; Valentine, Alex; Gehring, Chris

    2011-09-15

    Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. Here we show that a recombinant Arabidopsis thaliana PNP (AtPNP-A) rapidly increased the rate of dark respiration in treated leaves after 5 min. In addition, we observed increases in lower leaves, and with a lag time of 10 min, the effect spread to the upper leaves and subsequently (after 15 min) to the opposite leaves. This response signature is indicative of phloem mobility of the signal, a hypothesis that was further strengthened by the fact that cold girdling, which affects phloem but not xylem or apoplastic processes, delayed the long distance AtPNP-A effect. We conclude that locally applied AtPNP-A can induce a phloem-mobile signal that rapidly modifies plant homeostasis in distal parts. Copyright © 2011 Elsevier GmbH. All rights reserved.

  12. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  13. Haptic rendering for dental training system

    Institute of Scientific and Technical Information of China (English)

    WANG DangXiao; ZHANG YuRu; WANG Yong; L(U) PeiJun; ZHOU RenGe; ZHOU WanLin

    2009-01-01

    Immersion and Interaction are two key features of virtual reality systems,which are especially important for medical applications.Based on the requirement of motor skill training in dental surgery,haptic rendering method based on triangle model is investigated in this paper.Multi-rate haptic rendering architecture is proposed to solve the contradiction between fidelity and efficiency requirements.Realtime collision detection algorithm based on spatial partition and time coherence is utilized to enable fast contact determination.Proxy-based collision response algorithm is proposed to compute surface contact point.Cutting force model based on piecewise contact transition model is proposed for dental drilling simulation during tooth preparation.Velocity-driven levels of detail hapUc rendering algorithm is proposed to maintain high update rate for complex scenes with a large number of triangles.Hapticvisual collocated dental training prototype is established using half-mirror solution.Typical dental operations have been realized Including dental caries exploration,detection of boundary within dental crose-section plane,and dental drilling during tooth preparation.The haptic rendering method is a fundamental technology to improve Immersion and interaction of virtual reality training systems,which is useful not only in dental training,but also in other surgical training systems.

  14. ProteinShader: illustrative rendering of macromolecules

    Directory of Open Access Journals (Sweden)

    Weber Joseph R

    2009-03-01

    Full Text Available Abstract Background Cartoon-style illustrative renderings of proteins can help clarify structural features that are obscured by space filling or balls and sticks style models, and recent advances in programmable graphics cards offer many new opportunities for improving illustrative renderings. Results The ProteinShader program, a new tool for macromolecular visualization, uses information from Protein Data Bank files to produce illustrative renderings of proteins that approximate what an artist might create by hand using pen and ink. A combination of Hermite and spherical linear interpolation is used to draw smooth, gradually rotating three-dimensional tubes and ribbons with a repeating pattern of texture coordinates, which allows the application of texture mapping, real-time halftoning, and smooth edge lines. This free platform-independent open-source program is written primarily in Java, but also makes extensive use of the OpenGL Shading Language to modify the graphics pipeline. Conclusion By programming to the graphics processor unit, ProteinShader is able to produce high quality images and illustrative rendering effects in real-time. The main feature that distinguishes ProteinShader from other free molecular visualization tools is its use of texture mapping techniques that allow two-dimensional images to be mapped onto the curved three-dimensional surfaces of ribbons and tubes with minimum distortion of the images.

  15. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  16. Signal peptide cleavage is essential for surface expression of a regulatory T cell surface protein, leucine rich repeat containing 32 (LRRC32

    Directory of Open Access Journals (Sweden)

    Sugiyama Hideaki

    2011-05-01

    Full Text Available Abstract Background Elevated numbers of regulatory T cells (Tregs have been implicated in certain cancers. Depletion of Tregs has been shown to increase anti-tumor immunity. Tregs also play a critical role in the suppression of autoimmune responses. The study of Tregs has been hampered by a lack of adequate surface markers. Leucine Rich Repeat Containing 32 (LRRC32, also known as Glycoprotein A Repetitions Predominant (GARP, has been postulated as a novel surface marker of activated Tregs. However, there is limited information regarding the processing of LRRC32 or the regulatory phenotype and functional activity of Tregs expressing LRRC32. Results Using naturally-occurring freshly isolated Tregs, we demonstrate that low levels of LRRC32 are present intracellularly prior to activation and that freshly isolated LRRC32+ Tregs are distinct from LRRC32- Tregs with respect to the expression of surface CD62L. Using LRRC32 transfectants of HEK cells, we demonstrate that the N-terminus of LRRC32 is cleaved prior to expression of the protein at the cell surface. Furthermore, we demonstrate using a construct containing a deleted putative signal peptide region that the presence of a signal peptide region is critical to cell surface expression of LRRC32. Finally, mixed lymphocyte assays demonstrate that LRRC32+ Tregs are more potent suppressors than LRRC32- Tregs. Conclusions A cleaved signal peptide site in LRRC32 is necessary for surface localization of native LRRC32 following activation of naturally-occurring freshly-isolated regulatory T cells. LRRC32 expression appears to alter the surface expression of activation markers of T cells such as CD62L. LRRC32 surface expression may be useful as a marker that selects for more potent Treg populations. In summary, understanding the processing and expression of LRRC32 may provide insight into the mechanism of action of Tregs and the refinement of immunotherapeutic strategies aimed at targeting these cells.

  17. Signal peptide of FadA adhesin from Fusobacterium nucleatum plays a novel structural role by regulating the filament's length and width

    OpenAIRE

    2011-01-01

    FadA, a novel adhesin of periodontal pathogen Fusobacterium nucleatum is composed of two forms, pre-FadA and mature FadA (mFadA), constituting the functional FadA complex (FadAc). By electron microscopy, we observed that mFadA formed uniformly long and thin filaments, while FadAc formed heterogeneous filaments of varying lengths and widths, as well as “knots”. Mutants in signal peptide or in the non-alpha helical loop retaining heterogeneous structures had binding activity while those forming...

  18. Oxyntomodulin differentially affects glucagon-like peptide-1 receptor beta-arrestin recruitment and signaling through Galpha(s)

    DEFF Research Database (Denmark)

    Jorgensen, Rasmus; Kubale, Valentina; Vrecl, Milka

    2007-01-01

    The glucagon-like peptide (GLP)-1 receptor is a promising target for the treatment of type 2 diabetes and obesity, and there is great interest in characterizing the pharmacology of the GLP-1 receptor and its ligands. In the present report, we have applied bioluminescence resonance energy transfer...

  19. Targeting the Nrf2 Signaling Pathway in the Retina With a Gene-Delivered Secretable and Cell-Penetrating Peptide.

    Science.gov (United States)

    Ildefonso, Cristhian J; Jaime, Henrique; Brown, Emily E; Iwata, Ryo L; Ahmed, Chulbul M; Massengill, Michael T; Biswal, Manas R; Boye, Shannon E; Hauswirth, William W; Ash, John D; Li, Qiuhong; Lewin, Alfred S

    2016-02-01

    Oxidative stress has been linked to several ocular diseases, initiating an inflammatory response that increases tissue injury. The Nrf2 transcription factor regulates expression of antioxidant genes and is tightly regulated by Kelch-Like ECH-Associated Protein 1 (Keap-1). We evaluate the antioxidant and anti-inflammatory properties of an adeno-associated virus (AAV) vector delivering an Nrf2-derived peptide that binds Keap-1. The sequence of the Nrf2 peptide was fused to a cell-penetrating peptide (Tat-peptide) sequence (TatNrf2mer). The effects of lentiviral-delivered TatNrf2mer were studied in vitro. Transcript (quantitative [q] RT-PCR) and protein levels (ELISA and immunofluorescence) were quantified. Cell viability was measured by MTT and Cell Titer assays. The AAV vectors were packaged with the TatNrf2mer fused to secretable green fluorescent protein (GFP) under the control of the small chicken β actin promoter. The protective effects of this vector were evaluated in a model of RPE oxidative injury and in a mouse model of uveitis after intravitreal injection. Expression of TatNrf2mer peptide induced antioxidant gene expression, blocked IL-1β secretion, and protected cells from oxidative injury. In mice, TatNrf2mer expression partially protected photoreceptor function based on ERG responses and optical coherence tomography measurements in the sodium iodate (NaIO3) model. Furthermore, sGFP-TatNrf2mer expression decreased IL-1β and IL-6 in the NaIO3-treated mice, and resulted in a 54% decrease in the number of inflammatory cells in the vitreous body of the endotoxin-induced uveitis mouse model. The intravitreally delivered AAV-TatNrf2mer has antioxidant and anti-inflammatory effects in widely-used models of ocular injury, suggesting it also could be useful in ocular diseases associated with oxidative stress and inflammasome activation.

  20. Negative Energy Balance Blocks Neural and Behavioral Responses to Acute Stress by “Silencing” Central Glucagon-Like Peptide 1 Signaling in Rats

    Science.gov (United States)

    Maniscalco, James W.; Zheng, Huiyuan; Gordon, Patrick J.

    2015-01-01

    , reduces or blocks the ability of acute stress to activate hindbrain neurons that are immunoreactive for either prolactin-releasing peptide or glucagon-like peptide 1, and attenuates the activation of their stress-sensitive projection targets in the limbic forebrain. In nonfasted rats, central antagonism of glucagon-like peptide 1 receptors partially mimics the effect of an overnight fast by blocking the ability of acute stress to inhibit food intake, and by attenuating stress-induced activation of hindbrain and limbic forebrain neurons. We propose that caloric restriction attenuates behavioral and physiological responses to acute stress by “silencing” central glucagon-like peptide 1 signaling pathways. PMID:26224855

  1. RAY TRACING RENDER MENGGUNAKAN FRAGMENT ANTI ALIASING

    Directory of Open Access Journals (Sweden)

    Febriliyan Samopa

    2008-07-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Rendering is generating surface and three-dimensional effects on an object displayed on a monitor screen. Ray tracing as a rendering method that traces ray for each image pixel has a drawback, that is, aliasing (jaggies effect. There are some methods for executing anti aliasing. One of those methods is OGSS (Ordered Grid Super Sampling. OGSS is able to perform aliasing well. However, this method requires more computation time since sampling of all pixels in the image will be increased. Fragment Anti Aliasing (FAA is a new alternative method that can cope with the drawback. FAA will check the image when performing rendering to a scene. Jaggies effect is only happened at curve and gradient object. Therefore, only this part of object that will experience sampling magnification. After this sampling magnification and the pixel values are computed, then downsample is performed to retrieve the original pixel values. Experimental results show that the software can implement ray tracing well in order to form images, and it can implement FAA and OGSS technique to perform anti aliasing. In general, rendering using FAA is faster than using OGSS

  2. PI3K p110α/Akt signaling negatively regulates secretion of the intestinal peptide neurotensin through interference of granule transport.

    Science.gov (United States)

    Li, Jing; Song, Jun; Cassidy, Margaret G; Rychahou, Piotr; Starr, Marlene E; Liu, Jianyu; Li, Xin; Epperly, Garretson; Weiss, Heidi L; Townsend, Courtney M; Gao, Tianyan; Evers, B Mark

    2012-08-01

    Neurotensin (NT), an intestinal peptide secreted from N cells in the small bowel, regulates a variety of physiological functions of the gastrointestinal tract, including secretion, gut motility, and intestinal growth. The class IA phosphatidylinositol 3-kinase (PI3K) family, which comprised of p110 catalytic (α, β and δ) and p85 regulatory subunits, has been implicated in the regulation of hormone secretion from endocrine cells. However, the underlying mechanisms remain poorly understood. In particular, the role of PI3K in intestinal peptide secretion is not known. Here, we show that PI3K catalytic subunit, p110α, negatively regulates NT secretion in vitro and in vivo. We demonstrate that inhibition of p110α, but not p110β, induces NT release in BON, a human endocrine cell line, which expresses NT mRNA and produces NT peptide in a manner analogous to N cells, and QGP-1, a pancreatic endocrine cell line that produces NT peptide. In contrast, overexpression of p110α decreases NT secretion. Consistently, p110α-inhibition increases plasma NT levels in mice. To further delineate the mechanisms contributing to this effect, we demonstrate that inhibition of p110α increases NT granule trafficking by up-regulating α-tubulin acetylation; NT secretion is prevented by overexpression of HDAC6, an α-tubulin deacetylase. Moreover, ras-related protein Rab27A (a small G protein) and kinase D-interacting substrate of 220 kDa (Kidins220), which are associated with NT granules, play a negative and positive role, respectively, in p110α-inhibition-induced NT secretion. Our findings identify the critical role and novel mechanisms for the PI3K signaling pathway in the control of intestinal hormone granule transport and release.

  3. A peptide targeting an interaction interface disrupts the dopamine D1-D2 receptor heteromer to block signaling and function in vitro and in vivo: effective selective antagonism.

    Science.gov (United States)

    Hasbi, Ahmed; Perreault, Melissa L; Shen, Maurice Y F; Zhang, Lucia; To, Ryan; Fan, Theresa; Nguyen, Tuan; Ji, Xiaodong; O'Dowd, Brian F; George, Susan R

    2014-11-01

    Although the dopamine D1-D2 receptor heteromer has emerging physiological relevance and a postulated role in different neuropsychiatric disorders, such as drug addiction, depression, and schizophrenia, there is a need for pharmacological tools that selectively target such receptor complexes in order to analyze their biological and pathophysiological functions. Since no selective antagonists for the D1-D2 heteromer are available, serial deletions and point mutations were used to precisely identify the amino acids involved in an interaction interface between the receptors, residing within the carboxyl tail of the D1 receptor that interacted with the D2 receptor to form the D1-D2 receptor heteromer. It was determined that D1 receptor carboxyl tail residues (404)Glu and (405)Glu were critical in mediating the interaction with the D2 receptor. Isolated mutation of these residues in the D1 receptor resulted in the loss of agonist activation of the calcium signaling pathway mediated through the D1-D2 receptor heteromer. The physical interaction between the D1 and D2 receptor could be disrupted, as shown by coimmunoprecipitation and BRET analysis, by a small peptide generated from the D1 receptor sequence that contained these amino acids, leading to a switch in G-protein affinities and loss of calcium signaling, resulting in the inhibition of D1-D2 heteromer function. The use of the D1-D2 heteromer-disrupting peptide in vivo revealed a pathophysiological role for the D1-D2 heteromer in the modulation of behavioral despair. This peptide may represent a novel pharmacological tool with potential therapeutic benefits in depression treatment. © FASEB.

  4. Diversity of insulin-like peptide signaling system proteins in Calanus finmarchicus (Crustacea; Copepoda) - Possible contributors to seasonal pre-adult diapause.

    Science.gov (United States)

    Christie, Andrew E; Roncalli, Vittoria; Lenz, Petra H

    2016-09-15

    Calanus finmarchicus, an abundant calanoid copepod in the North Atlantic Ocean, is both a major grazer on phytoplankton and an important forage species for invertebrate and vertebrate predators. One component of the life history of C. finmarchicus is the overwintering dormancy of sub-adults, a feature key for the annual recruitment of this species in early spring. While little is known about the control of dormancy in C. finmarchicus, one hypothesis is that it is an insect-like diapause, where the endocrine system is a key regulator. One group of hormones implicated in the control of insect diapause is the insulin-like peptides (ILPs). Here, C. finmarchicus transcriptomic data were used to predict ILP signaling pathway proteins. Four ILP precursors were identified, each possessing a distinct A- and B-chain peptide; these peptides are predicted to form bioactive heterodimers via inter-chain disulfide bridging. Two ILP receptors, which likely represent splice variants of a common gene, were identified. Three insulin-degrading enzymes were also discovered, as were proteins encoding the transcription factor FOXO, a downstream target of ILP that has been implicated in the regulation of insect diapause, and insulin receptor substrate, a protein putatively linking the ILP receptor and FOXO. RNA-Seq data suggest that some C. finmarchicus insulin pathway transcripts are differentially expressed across development. As in insects, the ILP signaling system may be involved in controlling C. finmarchicus' organism-environment interactions (e.g., regulation of seasonal sub-adult diapause), a hypothesis that can now be investigated using these data.

  5. A novel missense mutation in the signal peptide of the human POMC gene: a possible additional link between early-onset type 2 diabetes and obesity.

    Science.gov (United States)

    Mencarelli, Monica; Zulian, Alessandra; Cancello, Raffaella; Alberti, Luisella; Gilardini, Luisa; Di Blasio, Anna Maria; Invitti, Cecilia

    2012-12-01

    Rare mutations in several genes have a critical role in the control of homeostatic mechanisms such as food-intake, energy balance and glucose metabolism. In this study, we performed a mutational screening in a 58-year-old woman presenting early-onset type 2 diabetes and central obesity. The entire coding regions of MC4R, MC3R, HNF1A, GCK and POMC (pro-opiomelanocortin) genes were analyzed by direct sequencing. A new missense mutation was identified within the POMC gene signal peptide sequence, resulting in a heterozygous substitution of an arginine for a glycine at codon 15 (p.A15G) that was excluded in 300 healthy normal weight controls. The mutation segregated in the family and was associated with overweight, type 2 diabetes, hypertension and coronary heart disease in the carriers. Functional studies demonstrated that POMC protein was not detectable in β-TC3 cells transfected with A15G-POMC vector as well as in their culture media, despite POMC mRNA levels were comparable for amount and stability to those of wild-type-transfected cells. In silico RNA folding prediction indicated that the mutation gives rise to a different RNA secondary structure, suggesting that it might affect translation and protein synthesis. To the best of our knowledge, this is the first report addressing the functional consequences of a mutation in the signal peptide of POMC. These findings further support the hypothesis that POMC-derived peptides might have a role in the control of peripheral glucose metabolism and suggest that disruption of central POMC secretion might represent an additional link between type 2 diabetes and obesity.

  6. CodY Regulates the Activity of the Virulence Quorum Sensor PlcR by Controlling the Import of the Signaling Peptide PapR in Bacillus thuringiensis

    Science.gov (United States)

    Slamti, Leyla; Lemy, Christelle; Henry, Céline; Guillot, Alain; Huillet, Eugénie; Lereclus, Didier

    2016-01-01

    In Gram-positive bacteria, cell–cell communication mainly relies on cytoplasmic sensors of the RNPP family. Activity of these regulators depends on their binding to secreted signaling peptides that are imported into the cell. These quorum sensing regulators control important biological functions in bacteria of the Bacillus cereus group, such as virulence and necrotrophism. The RNPP quorum sensor PlcR, in complex with its cognate signaling peptide PapR, is the main regulator of virulence in B. cereus and Bacillus thuringiensis (Bt). Recent reports have shown that the global stationary phase regulator CodY, involved in adaptation to nutritional limitation, is required for the expression of virulence genes belonging to the PlcR regulon. However, the mechanism underlying this regulation was not described. Using genetics and proteomics approaches, we showed that CodY regulates the expression of the virulence genes through the import of PapR. We report that CodY positively controls the production of the proteins that compose the oligopeptide permease OppABCDF, and of several other Opp-like proteins. It was previously shown that the pore components of this oligopeptide permease, OppBCDF, were required for the import of PapR. However, the role of OppA, the substrate-binding protein (SBP), was not investigated. Here, we demonstrated that OppA is not the only SBP involved in the recognition of PapR, and that several other OppA-like proteins can allow the import of this peptide. Altogether, these data complete our model of quorum sensing during the lifecycle of Bt and indicate that RNPPs integrate environmental conditions, as well as cell density, to coordinate the behavior of the bacteria throughout growth. PMID:26779156

  7. Automatic Image-Based Pencil Sketch Rendering

    Institute of Scientific and Technical Information of China (English)

    王进; 鲍虎军; 周伟华; 彭群生; 徐迎庆

    2002-01-01

    This paper presents an automatic image-based approach for converting greyscale images to pencil sketches, in which strokes follow the image features. The algorithm first extracts a dense direction field automatically using Logical/Linear operators which embody the drawing mechanism. Next, a reconstruction approach based on a sampling-and-interpolation scheme is introduced to generate stroke paths from the direction field. Finally, pencil strokes are rendered along the specified paths with consideration of image tone and artificial illumination.As an important application, the technique is applied to render portraits from images with little user interaction. The experimental results demonstrate that the approach can automatically achieve compelling pencil sketches from reference images.

  8. Anti-Aliased Rendering of Water Surface

    Institute of Scientific and Technical Information of China (English)

    Xue-Ying Qin; Eihachiro Nakamae; Wei Hua; Yasuo Nagai; Qun-Sheng Peng

    2004-01-01

    Water surface is one of the most important components of landscape scenes. When rendering spacious far from the viewpoint. This is because water surface consists of stochastic water waves which are usually modeled by periodic bump mapping. The incident rays on the water surface are actually scattered by the bumped waves,pattern, we estimate this solid angle of reflected rays and trace these rays. An image-based accelerating method is adopted so that the contribution of each reflected ray can be quickly obtained without elaborate intersection calculation. We also demonstrate anti-aliased shadows of sunlight and skylight on the water surface. Both the rendered images and animations show excellent effects on the water surface of a reservoir.

  9. The fusion protein signal-peptide-coding region of canine distemper virus: a useful tool for phylogenetic reconstruction and lineage identification.

    Directory of Open Access Journals (Sweden)

    Nicolás Sarute

    Full Text Available Canine distemper virus (CDV; Paramyxoviridae, Morbillivirus is the etiologic agent of a multisystemic infectious disease affecting all terrestrial carnivore families with high incidence and mortality in domestic dogs. Sequence analysis of the hemagglutinin (H gene has been widely employed to characterize field strains, permitting the identification of nine CDV lineages worldwide. Recently, it has been established that the sequences of the fusion protein signal-peptide (Fsp coding region are extremely variable, suggesting that analysis of its sequence might be useful for strain characterization studies. However, the divergence of Fsp sequences among worldwide strains and its phylogenetic resolution has not yet been evaluated. We constructed datasets containing the Fsp-coding region and H gene sequences of the same strains belonging to eight CDV lineages. Both datasets were used to evaluate their phylogenetic resolution. The phylogenetic analysis revealed that both datasets clustered the same strains into eight different branches, corresponding to CDV lineages. The inter-lineage amino acid divergence was fourfold greater for the Fsp peptide than for the H protein. The likelihood mapping revealed that both datasets display strong phylogenetic signals in the region of well-resolved topologies. These features indicate that Fsp-coding region sequence analysis is suitable for evolutionary studies as it allows for straightforward identification of CDV lineages.

  10. Topical administration of a suppressor of cytokine signaling-1 (SOCS1) mimetic peptide inhibits ocular inflammation and mitigates ocular pathology during mouse uveitis.

    Science.gov (United States)

    He, Chang; Yu, Cheng-Rong; Sun, Lin; Mahdi, Rashid M; Larkin, Joseph; Egwuagu, Charles E

    2015-08-01

    Uveitis is a diverse group of potentially sight-threatening intraocular inflammatory diseases and pathology derives from sustained production of pro-inflammatory cytokines in the optical axis. Although topical or systemic steroids are effective therapies, their adverse effects preclude prolonged usage and are impetus for seeking alternative immunosuppressive agents, particularly for patients with refractory uveitis. In this study, we synthesized a 16 amino acid membrane-penetrating lipophilic suppressor of cytokine signaling 1 peptide (SOCS1-KIR) that inhibits JAK/STAT signaling pathways and show that it suppresses and ameliorates experimental autoimmune uveitis (EAU), the mouse model of human uveitis. Fundus images, histological and optical coherence tomography analysis of eyes showed significant suppression of clinical disease, with average clinical score of 0.5 compared to 2.0 observed in control mice treated with scrambled peptide. We further show that SOCS1-KIR conferred protection from ocular pathology by inhibiting the expansion of pathogenic Th17 cells and inhibiting trafficking of inflammatory cells into the neuroretina during EAU. Dark-adapted scotopic and photopic electroretinograms further reveal that SOCS1-KIR prevented decrement of retinal function, underscoring potential neuroprotective effects of SOCS1-KIR in uveitis. Importantly, SOCS1-KIR is non-toxic, suggesting that topical administration of SOCS1-Mimetics can be exploited as a non-invasive treatment for uveitis and for limiting cytokine-mediated pathology in other ocular inflammatory diseases including scleritis.

  11. Optimization techniques for computationally expensive rendering algorithms

    OpenAIRE

    Navarro Gil, Fernando; Gutiérrez Pérez, Diego; Serón Arbeloa, Francisco José

    2012-01-01

    Realistic rendering in computer graphics simulates the interactions of light and surfaces. While many accurate models for surface reflection and lighting, including solid surfaces and participating media have been described; most of them rely on intensive computation. Common practices such as adding constraints and assumptions can increase performance. However, they may compromise the quality of the resulting images or the variety of phenomena that can be accurately represented. In this thesi...

  12. Trandermal Peptides for Large Molecule Delivery

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ A research team, led by Prof. WEN Longping from the University of Science and Technology of China under CAS,has successfully screened out a trandermal peptide, using biotechnology. The new peptide is able to deliver insulin into human body through skin, rendering an immediate therapeutic effect. The finding was published in the March 27 issue of the journal Natural Biotechnology.

  13. Visualization of Medpor implants using surface rendering

    Institute of Scientific and Technical Information of China (English)

    WANG Meng; GUI Lai; LIU Xiao-jing

    2011-01-01

    Background The Medpor surgical implant is one of the easiest implants in clinical practice, especially in craniomaxillofacial surgery. It is often used as a bone substitute material for the repair of skull defects and facial deformities. The Medpor implant has several advantages but its use is limited because it is radiolucent in both direct radiography and conventional computed tomography, causing serious problems with visualization.Methods In this study, a new technique for visualizing Medpor implants was evaluated in 10 patients who had undergone facial reconstruction using the material. Continuous volume scans were made using a 16-channel tomographic scanner and 3D reconstruction software was used to create surface renderings. The threshold values for surface renderings of the implant ranged from -70 HU to -20 HU, with bone as the default.Results The shape of the implants and the spatial relationship between bone and implant could both be displayed.Conclusion Surface rendering can allow successful visualization of Medpor implants in the body.

  14. Calcitonin gene-related peptide promotes the expression of osteoblastic genes and activates the WNT signal transduction pathway in bone marrow stromal stem cells

    Science.gov (United States)

    ZHOU, RI; YUAN, ZHI; LIU, JIERONG; LIU, JIAN

    2016-01-01

    Calcitonin gene-related peptide (CGRP) is known to induce osteoblastic differentiation and alkaline phosphatase activity in bone marrow stromal stem cells (BMSCs). However, it has remained elusive whether this effect is mediated by CGRP receptors directly or whether other signaling pathways are involved. The present study assessed the possible involvement of the Wnt/β-catenin signaling pathway in the activation of CGRP signaling during the differentiation of BMSCs. First, the differentiation of BMSCs was induced in vitro and the expression of CGRP receptors was examined by western blot analysis. The effects of exogenous CGRP and LiCl, a stimulator of the Wnt/β-catenin signaling pathway, on the osteoblastic differentiation of BMSCs were assessed; furthermore, the expression of mRNA and proteins involved in the Wnt/β-catenin signaling pathway was assessed using quantitative PCR and western blot analyses. The results revealed that CGRP receptors were expressed throughout the differentiation of BMSCs, at days 7 and 14. Incubation with CGRP and LiCl led to the upregulation of the expression of osteoblastic genes associated with the Wnt/β-catenin pathway, including the mRNA of c-myc, cyclin D1, Lef1, Tcf7 and β-catenin as well as β-catenin protein. However, the upregulation of these genes and β-catenin protein was inhibited by CGRP receptor antagonist or secreted frizzled-related protein, an antagonist of the Wnt/β-catenin pathway. The results of the present study therefore suggested that the Wnt/β-catenin signaling pathway may be involved in CGRP- and LiCl-promoted osteoblastic differentiation of BMSCs. PMID:27082317

  15. Secretion of Recombinant Proteins in Mammalian Cells Directed by Growth Hormone Signal Peptide%生长激素信号肽可诱导重组蛋白外分泌表达

    Institute of Scientific and Technical Information of China (English)

    张志谦; 李金萍; 胡颖

    2005-01-01

    Signal peptide capable of efficiently directing many protein secretion in mammalian cells is one ot the key elements in recombinant protein production, gene therapy and the development of DNA vaccines. In order to explore the possibility of rat growth hormone signal peptide as such an element, a new vector based on the mammalian expression vector pcDNA3 was constructed by employing rat growth hormone (rGH) signal peptide as leading sequence, followed by multiple cloning sites, the myc epitope-tag and 6 × his purification tag in the expression cassette. The vector was validated by successfully expressing and secretion of chick MMP-2 Cterminal PEX domain, a potential angiogenesis inhibitor, and tandem peptide repeats of myc epitope-tag in COS-7 cells. These results suggest that rat growth hormone signal peptide is effective in the mediation of recombinant protein expression and secretion, and this vector provides a new tool for universal cloning and secretion of exogenous proteins in mammalian cells.

  16. GPU Pro 4 advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2013-01-01

    GPU Pro4: Advanced Rendering Techniques presents ready-to-use ideas and procedures that can help solve many of your day-to-day graphics programming challenges. Focusing on interactive media and games, the book covers up-to-date methods producing real-time graphics. Section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Michal Valient, Wessam Bahnassi, and Sebastien St-Laurent have once again assembled a high-quality collection of cutting-edge techniques for advanced graphics processing unit (GPU) programming. Divided into six sections, the book begins with discussions on the abi

  17. Haptic rendering foundations, algorithms, and applications

    CERN Document Server

    Lin, Ming C

    2008-01-01

    For a long time, human beings have dreamed of a virtual world where it is possible to interact with synthetic entities as if they were real. It has been shown that the ability to touch virtual objects increases the sense of presence in virtual environments. This book provides an authoritative overview of state-of-theart haptic rendering algorithms and their applications. The authors examine various approaches and techniques for designing touch-enabled interfaces for a number of applications, including medical training, model design, and maintainability analysis for virtual prototyping, scienti

  18. GPU PRO 3 Advanced rendering techniques

    CERN Document Server

    Engel, Wolfgang

    2012-01-01

    GPU Pro3, the third volume in the GPU Pro book series, offers practical tips and techniques for creating real-time graphics that are useful to beginners and seasoned game and graphics programmers alike. Section editors Wolfgang Engel, Christopher Oat, Carsten Dachsbacher, Wessam Bahnassi, and Sebastien St-Laurent have once again brought together a high-quality collection of cutting-edge techniques for advanced GPU programming. With contributions by more than 50 experts, GPU Pro3: Advanced Rendering Techniques covers battle-tested tips and tricks for creating interesting geometry, realistic sha

  19. Defects of organization in rendering medical aid

    Directory of Open Access Journals (Sweden)

    Shavkat Islamov

    2010-09-01

    Full Text Available The defects of organization at the medical institution mean disturbance of rules, norms and order of rendering of medical aid. The number of organization defects in Uzbekistan increased from 20.42%, in 1999 to 25.46% in 2001 with gradual decrease to 19.9% in 2003 and 16.66%, in 2006 and gradual increase to 21.95% and 28.28% (P<0.05 in 2005 and 2008. Among the groups of essential defects of organization there were following: disturbance of transportation rules, lack of dispensary care, shortcomings in keeping medical documentation.

  20. The antimicrobial peptide snakin-2 is upregulated in the defense response of tomatoes (Solanum lycopersicum) as part of the jasmonate-dependent signaling pathway.

    Science.gov (United States)

    Herbel, Vera; Sieber-Frank, Julia; Wink, Michael

    2017-01-01

    Antimicrobial peptides (AMPs) are produced by all living organisms and play an important role in innate immunity because they are readily available and non-specific against invading pathogenic microorganisms. Snakin-2 (SN2) from tomato is a short, cationic peptide that forms lethal pores in biomembranes of microbes. In plant cells, SN2 is produced as a prepeptide with a signal sequence for ER targeting and an acidic region to decrease toxicity in the producing organism. Gene expression analysis by qRT-PCR in tomato plants demonstrated that SN2 is constitutively expressed, mostly in leaves and flowers. After fungal infection, wounding, or external application of phytohormones (such as methyl jasmonate, MeJa) operating in the JA-dependent defense response, a systemic reaction with an elevated expression of the SN2 gene is triggered in all parts of tomato plants. Abiotic stress factors like extreme temperatures or dehydration do not affect SN2 expression. Upon wounding, the expression of SN2 and LoxD are strongly enhanced in tomato fruits. Furthermore, we provide evidence that the protein level of bioactive SN2 is also increased upon application of methyl jasmonate in tomato seedlings. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. A Multiresolution Image Cache for Volume Rendering

    Energy Technology Data Exchange (ETDEWEB)

    LaMar, E; Pascucci, V

    2003-02-27

    The authors discuss the techniques and implementation details of the shared-memory image caching system for volume visualization and iso-surface rendering. One of the goals of the system is to decouple image generation from image display. This is done by maintaining a set of impostors for interactive display while the production of the impostor imagery is performed by a set of parallel, background processes. The system introduces a caching basis that is free of the gap/overlap artifacts of earlier caching techniques. instead of placing impostors at fixed, pre-defined positions in world space, the technique is to adaptively place impostors relative to the camera viewpoint. The positions translate with the camera but stay aligned to the data; i.e., the positions translate, but do not rotate, with the camera. The viewing transformation is factored into a translation transformation and a rotation transformation. The impostor imagery is generated using just the translation transformation and visible impostors are displayed using just the rotation transformation. Displayed image quality is improved by increasing the number of impostors and the frequency that impostors are re-rendering is improved by decreasing the number of impostors.

  2. Rendering of 3D Dynamic Virtual Environments

    CERN Document Server

    Catanese, Salvatore; Fiumara, Giacomo; Pagano, Francesco

    2011-01-01

    In this paper we present a framework for the rendering of dynamic 3D virtual environments which can be integrated in the development of videogames. It includes methods to manage sounds and particle effects, paged static geometries, the support of a physics engine and various input systems. It has been designed with a modular structure to allow future expansions. We exploited some open-source state-of-the-art components such as OGRE, PhysX, ParticleUniverse, etc.; all of them have been properly integrated to obtain peculiar physical and environmental effects. The stand-alone version of the application is fully compatible with Direct3D and OpenGL APIs and adopts OpenAL APIs to manage audio cards. Concluding, we devised a showcase demo which reproduces a dynamic 3D environment, including some particular effects: the alternation of day and night infuencing the lighting of the scene, the rendering of terrain, water and vegetation, the reproduction of sounds and atmospheric agents.

  3. Annexin A1 released from apoptotic cells acts through formyl peptide receptors to dampen inflammatory monocyte activation via JAK/STAT/SOCS signalling

    Science.gov (United States)

    Pupjalis, Danute; Goetsch, Julia; Kottas, Diane J; Gerke, Volker; Rescher, Ursula

    2011-01-01

    The immunosuppressive effects of apoptotic cells involve inhibition of pro-inflammatory cytokine release and establishment of an anti-inflammatory cytokine profile, thus limiting the degree of inflammation and promoting resolution. We report here that this is in part mediated by the release of the anti-inflammatory mediator annexin A1 from apoptotic cells and the functional activation of annexin A1 receptors of the formyl peptide receptor (FPR) family on target cells. Supernatants from apoptotic neutrophils or the annexin A1 peptidomimetic Ac2-26 significantly reduced IL-6 signalling and the release of TNF-α from endotoxin-challenged monocytes. Ac2-26 activated STAT3 in a JAK-dependent manner, resulting in upregulated SOCS3 levels, and depletion of SOCS3 reversed the Ac2-26-mediated inhibition of IL-6 signalling. This identifies annexin A1 as part of the anti-inflammatory pattern of apoptotic cells and links the activation of FPRs to established signalling pathways triggering anti-inflammatory responses. PMID:21254404

  4. Cutting Edge: LL-37-Mediated Formyl Peptide Receptor-2 Signaling in Follicular Dendritic Cells Contributes to B Cell Activation in Peyer's Patch Germinal Centers.

    Science.gov (United States)

    Kim, Sae-Hae; Kim, Yu Na; Jang, Yong-Suk

    2017-01-15

    Peyer's patches (PPs) are the major mucosal immune-inductive site, and germinal centers (GCs) in PPs determine the quality of the Abs produced. PP GCs are continuously induced by the gut microbiota, and their maintenance contributes to the induction of strong IgA responses to Ags. In this study, we investigated the role of formyl peptide receptor (FPR)-mediated signaling in the maintenance of PP GCs, because FPRs recognize the microbiota and initiate an innate immune response by chemotaxis. We found that follicular dendritic cells (FDCs), a key organizer of B cell follicles and GCs in mucosal immunity, express Fpr2. Additionally, Fpr2-mediated signaling in PP FDCs promoted Cxcl13 and B cell activating factor expression, as well as B cell proliferation and activation. Therefore, we suggest that Fpr2-mediated signaling in FDCs plays a key role in GC maintenance in PPs and results in an Ag-specific IgA response in the gut mucosal immune compartment. Copyright © 2017 by The American Association of Immunologists, Inc.

  5. A peptide from Porphyra yezoensis stimulates the proliferation of IEC-6 cells by activating the insulin-like growth factor I receptor signaling pathway.

    Science.gov (United States)

    Lee, Min-Kyeong; Kim, In-Hye; Choi, Youn-Hee; Nam, Taek-Jeong

    2015-02-01

    Porphyra yezoensis (P. yezoensis) is the most noteworthy red alga and is mainly consumed in China, Japan and Korea. In the present study, the effects of a P. yezoensis peptide (PY‑PE) on cell proliferation and the associated signaling pathways were examined in IEC‑6 rat intestinal epithelial cells. First, the MTS assay showed that PY‑PE induced cell proliferation in a dose‑dependent manner. Subsequently, the mechanism behind the proliferative activity induced by PY‑PE was determined. The insulin‑like growth factor‑I receptor (IGF‑IR) signaling pathway was the main focus as it plays an important role in the regulation of cell growth and proliferation. PY‑PE increased the protein and mRNA expression of IGF‑IR, insulin receptor substrate‑1, Shc and PY‑99. In addition, PY‑PE stimulated extracellular signal‑regulated kinase phosphorylation and phosphatidylinositol 3‑kinase/Akt activation but inhibited p38 and c‑Jun N‑terminal kinase phosphorylation. Furthermore, PY‑PE treatment increased protein and mRNA expression levels of activator protein‑1, which regulates cell proliferation and survival, in the nuclear fraction. These results have significant implications for understanding the role of cell proliferation signaling pathways in intestinal epithelial cells.

  6. β-Arrestin 1’s Interaction with TC45 Attenuates Stat signaling by dephosphorylating Stat to inhibit antimicrobial peptide expression

    Science.gov (United States)

    Sun, Jie-Jie; Yang, Hui-Ting; Niu, Guo-Juan; Feng, Xiao-Wu; Lan, Jiang-Feng; Zhao, Xiao-Fan; Wang, Jin-Xing

    2016-01-01

    Impaired phosphatase activity leads to the persistent activation of signal transducers and activators of transcription (Stat). In mammals, Stat family members are often phosphorylated or dephosphorylated by the same enzymes. To date, only one Stat similar to mammalian Stat5a/b has been found in crustaceans and there have been few studies in Stat signal regulation in crustaceans. Here, we report that β-arrestin1 interacts with TC45 (45-kDa form of T cell protein tyrosine phosphatase) in the nucleus to attenuate Stat signaling by promoting dephosphorylation of Stat. Initially, we showed that Stat translocates into the nucleus to induce antimicrobial peptide (AMP) expression after bacterial infection. βArr1 enters the nucleus of hemocytes and recruits TC45 to form the βarr1-TC45-Stat complex, which dephosphorylates Stat efficiently. The interaction of TC45 with Stat decreased and Stat phosphorylation increased in βarr1-silenced shrimp (Marsupenaeus japonicus) after challenge with Vibrio anguillarum. βArr1 directly interacts with Stat in nucleus and accelerates Stat dephosphorylation by recruiting TC45 after V. anguillarum challenge. Further study showed that βarr1 and TC45 also affect AMP expression, which is regulated by Stat. Therefore, βarr1 and TC45 are involved in the anti-V. anguillarum immune response by regulating Stat activity negatively to decrease AMP expression in shrimp. PMID:27782165

  7. One pot synthesis of highly luminescent polyethylene glycol anchored carbon dots functionalized with a nuclear localization signal peptide for cell nucleus imaging.

    Science.gov (United States)

    Yang, Lei; Jiang, Weihua; Qiu, Lipeng; Jiang, Xuewei; Zuo, Daiying; Wang, Dongkai; Yang, Li

    2015-04-14

    Strong blue fluorescent polyethylene glycol (PEG) anchored carbon nitride dots (CDs@PEG) with a high quantum yield (QY) of 75.8% have been synthesized by a one step hydrothermal treatment. CDs with a diameter of ca. 6 nm are well dispersed in water and present a graphite-like structure. Photoluminescence (PL) studies reveal that CDs display excitation-dependent behavior and are stable under various test conditions. Based on the as-prepared CDs, we designed novel cell nucleus targeting imaging carbon dots functionalized with a nuclear localization signal (NLS) peptide. The favourable biocompatibilities of CDs and NLS modified CDs (NLS-CDs) are confirmed by in vitro cytotoxicity assays. Importantly, intracellular localization experiments in MCF7 and A549 cells demonstrate that NLS-CDs could be internalized in the nucleus and show blue light, which indicates that CDs may serve as cell nucleus imaging probes.

  8. Topical peptides as cosmeceuticals

    Directory of Open Access Journals (Sweden)

    Varadraj Vasant Pai

    2017-01-01

    Full Text Available Peptides are known to have diverse biological roles, most prominently as signaling/regulatory molecules in a broad variety of physiological processes including defense, immunity, stress, growth, homeostasis and reproduction. These aspects have been used in the field of dermatology and cosmetology to produce short, stable and synthetic peptides for extracellular matrix synthesis, pigmentation, innate immunity and inflammation. The evolution of peptides over the century, which started with the discovery of penicillin, has now extended to their usage as cosmeceuticals in recent years. Cosmeceutical peptides may act as signal modulators of the extracellular matrix component, as structural peptides, carrier peptides and neurotransmitter function modulators. Transdermal delivery of peptides can be made more effective by penetration enhancers, chemical modification or encapsulation of peptides. The advantages of using peptides as cosmeceuticals include their involvement in many physiological functions of the skin, their selectivity, their lack of immunogenicity and absence of premarket regulatory requirements for their use. However, there are disadvantages: clinical evidence for efficacy is often weak, absorption may be poor due to low lipophilicity, high molecular weight and binding to other ingredients, and prices can be quite high.

  9. Chimeras of mature pediocin PA-1 fused to the signal peptide of enterocin P permits the cloning, production, and expression of pediocin PA-1 in Lactococcus lactis.

    Science.gov (United States)

    Martín, María; Gutiérrez, Jorge; Criado, Raquel; Herranz, Carmen; Cintas, Luis M; Hernández, Pablo E

    2007-12-01

    Chimeras of pediocin PA-1 (PedA-1), a bacteriocin produced by Pediococcus acidilactici PLBH9, fused to the signal peptide of enterocin P (EntP), a sec-dependent bacteriocin produced by Enterococcus faecium P13, permitted the production of PedA-1 in Lactococcus lactis. Chimeric genes encoding the EntP signal peptide (SP(entP)) fused to mature PedA-1 (pedA), with or without its immunity gene (pedB), were cloned into the expression vector pMG36c to generate the recombinant plasmids pMPP9 (SP(entP):pedA) and pMPP14i (SP(entP):pedA + pedB). Transformation of competent L. lactis subsp. lactis IL1403, L. lactis subsp. cremoris NZ9000, and L. lactis subsp. lactis DPC5598 with the recombinant plasmids has permitted the detection and quantitation of PedA-1 and the coproduction of nisin A and PedA-1 in supernatants of producer cells with specific anti-PedA-1 antibodies and a noncompetitive indirect enzyme-linked immunosorbent assay. Recombinant L. lactis hosts carrying pMPP9 or pMPP14i displayed antimicrobial activity, suggesting that mature PedA-1 fused to SP(EntP) is the minimum requirement for the synthesis, processing, and secretion of biologically active PedA-1 in L. lactis. However, the production and antimicrobial activity of the PedA-1 produced by L. lactis was lower than that produced by the P. acidilactici control strains.

  10. Signal transduction by the formyl peptide receptor. Studies using chimeric receptors and site-directed mutagenesis define a novel domain for interaction with G-proteins.

    Science.gov (United States)

    Amatruda, T T; Dragas-Graonic, S; Holmes, R; Perez, H D

    1995-11-24

    The binding of small peptide ligands to high affinity chemoattractant receptors on the surface of neutrophils and monocytes leads to activation of heterotrimeric G-proteins, stimulation of phosphatidylinositol-phospholipase C (PI-PLC), and subsequently to the inflammatory response. It was recently shown (Amatruda, T. T., Gerard, N. P., Gerard, C., and Simon, M. I. (1993) J. Biol. Chem. 268, 10139-10144) that the receptor for the chemoattractant peptide C5a specifically interacts with G alpha 16, a G-protein alpha subunit of the Gq class, to trigger ligand-dependent stimulation of PI-PLC in transfected cells. In order to further characterize this chemoattractant peptide signal transduction pathway, we transfected cDNAs encoding the formylmethionylleucylphenylalanine receptor (fMLPR) into COS cells and measured the production of inositol phosphates. Ligand-dependent activation of PI-PLC was seen in COS cells transfected with the fMLPR and G alpha 16 and stimulated with fMLP but not in cells transfected with receptor alone or with receptor plus G alpha q. Chimeric receptors in which the N-terminal extracellular domain, the second intracellular domain, or the intracellular C-terminal tail of the fMLP receptor was replaced with C5a receptor domains (Perez, H. D., Holmes, R., Vilander, L. R., Adams, R. R., Manzana, W., Jolley, D., and Andrews, W. H. (1993) J. Biol. Chem. 268, 2292-2295) were capable of ligand-dependent activation of PI-PLC when co-transfected with G alpha 16. A chimeric receptor exchanging the first intracellular domain of the fMLPR was constitutively activated, stimulating PI-PLC in the absence of ligand. Constitutive activation of PI-PLC, to a level 233% of that seen in cells transfected with wild-type fMLP receptors, was dependent on G alpha 16. Site-directed mutagenesis of the first intracellular domain of the fMLPR (amino acids 54-62) reveals this to be a domain necessary for ligand-dependent activation of G alpha 16. These results suggest that

  11. Tissue-specific transcription start sites and alternative splicing of the parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor gene: a new PTH/PTHrP receptor splice variant that lacks the signal peptide.

    Science.gov (United States)

    Joun, H; Lanske, B; Karperien, M; Qian, F; Defize, L; Abou-Samra, A

    1997-04-01

    The PTH/PTHrP receptor gene is expressed in bone and kidney as well as in many other tissues. Using primer extension followed by rapid cloning of amplified complementary DNA ends, we have isolated new PTH/PTHrP receptor complementary DNAs with different splicing patterns and have characterized a new upstream transcription start site. Three 5' nontranslated exons, U3, U2 and U1, located 4.8, 2.5, and 1.2 kb upstream of the exon that encodes the putative signal peptide of the classical receptor (exon S), have been characterized. Four types of splicing patterns were recognized. Type I splicing pattern is transcribed from exon U1 and is spliced to exons S and E1; this pattern was found in most tissues tested. Types II, III, and IV splicing patterns are transcribed from exon U3 and have a restricted tissue distribution. Type II splice pattern, containing exons U3, U2, and S and type III splicing pattern, containing exon U3, U2, and E1 (skipping exon S), was found only in kidney. Type IV splice pattern, containing exon U3 and S was found both in kidney and ovary. Because the type III splice variant skips exon S, translation of this splice variant initiates at a different AUG codon. The type III splice variant was weakly expressed on the cell surface of COS-7 cells, as assessed by double antibody binding assay, and no detectable ligand binding was observed on intact cells. The type III splice variant, however, increased cAMP accumulation in COS-7 cells when challenged with PTH(1-34), PTH(1-84) and hPTHrP(1-36) with EC50s that are similar to those observed in COS-7 cells expressing the type I variant but with a maximum stimulation that was lower than that observed in COS-7 cells expressing the type I variant. These data indicate low levels of cell surface expression of the type III splice variant. Treatment of COS-7 cells with tunicamycin decreased the size of the type I splice variant from a broad band of 85 kDa to a compact band of about 60 kDa. The type III splice

  12. Photon Differential Splatting for Rendering Caustics

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Schjøth, Lars; Erleben, Kenny;

    2014-01-01

    We present a photon splatting technique which reduces noise and blur in the rendering of caustics. Blurring of illumination edges is an inherent problem in photon splatting, as each photon is unaware of its neighbours when being splatted. This means that the splat size is usually based...... on heuristics rather than knowledge of the local flux density. We use photon differentials to determine the size and shape of the splats such that we achieve adaptive anisotropic flux density estimation in photon splatting. As compared to previous work that uses photon differentials, we present the first method...... where no photons or beams or differentials need to be stored in a map. We also present improvements in the theory of photon differentials, which give more accurate results and a faster implementation. Our technique has good potential for GPU acceleration, and we limit the number of parameters requiring...

  13. Immersive volume rendering of blood vessels

    Science.gov (United States)

    Long, Gregory; Kim, Han Suk; Marsden, Alison; Bazilevs, Yuri; Schulze, Jürgen P.

    2012-03-01

    In this paper, we present a novel method of visualizing flow in blood vessels. Our approach reads unstructured tetrahedral data, resamples it, and uses slice based 3D texture volume rendering. Due to the sparse structure of blood vessels, we utilize an octree to efficiently store the resampled data by discarding empty regions of the volume. We use animation to convey time series data, wireframe surface to give structure, and utilize the StarCAVE, a 3D virtual reality environment, to add a fully immersive element to the visualization. Our tool has great value in interdisciplinary work, helping scientists collaborate with clinicians, by improving the understanding of blood flow simulations. Full immersion in the flow field allows for a more intuitive understanding of the flow phenomena, and can be a great help to medical experts for treatment planning.

  14. Constructing And Rendering Vectorised Photographic Images

    Directory of Open Access Journals (Sweden)

    P. J. Willis

    2013-06-01

    Full Text Available We address the problem of representing captured images in the continuous mathematical space more usually associated with certain forms of drawn ('vector' images. Such an image is resolution-independent so can be used as a master for varying resolution-specific formats. We briefly describe the main features of a vectorising codec for photographic images, whose significance is that drawing programs can access images and image components as first-class vector objects. This paper focuses on the problem of rendering from the isochromic contour form of a vectorised image and demonstrates a new fill algorithm which could also be used in drawing generally. The fill method is described in terms of level set diffusion equations for clarity. Finally we show that image warping is both simplified and enhanced in the vector form and that we can demonstrate real histogram equalisation with genuinely rectangular histograms straightforwardly.

  15. The proliferative effects of Pyropia yezoensis peptide on IEC-6 cells are mediated through the epidermal growth factor receptor signaling pathway.

    Science.gov (United States)

    Lee, Min-Kyeong; Kim, In-Hye; Choi, Youn-Hee; Choi, Jeong-Wook; Kim, Young-Min; Nam, Taek-Jeong

    2015-04-01

    For a number of years, seaweed has been used as a functional food in Asian countries, particularly in Korea, Japan and China. Pyropia yezoensis is a marine red alga that has potentially beneficial biological activities. In this study, we examined the mechanisms through which a Pyropia yezoensis peptide [PYP1 (1-20)] induces the proliferation of IEC-6 cells, a rat intestinal epithelial cell line, and the involvement of the epidermal growth factor receptor (EGFR) signaling pathway. First, cell viability assay revealed that PYP1 (1-20) induced cell proliferation in a concentration-dependent manner. Subsequently, we examined the mechanisms responsible for this induction of proliferation induced by PYP1 (1-20). EGFR is widely expressed in mammalian epithelial tissues, and the binding of this ligand affects a variety of cell physiological parameters, such as cell growth and proliferation. PYP1 (1-20) increased the expression of EGFR, Shc, growth factor receptor-bound protein 2 (Grb2) and son of sevenless (SOS). EGFR also induced the activation of the Ras signaling pathway through Raf, MEK and extracellular signal-regulated kinase (ERK) phosphorylation. In addition, cell cycle analysis revealed the expression of cell cycle-related proteins. The results demonstrated an increased number of cells in the G1 phase and an enhanced cell proliferation. In addition, the upregulation of cyclin D, cyclin E, Cdk2, Cdk4 and Cdk6 was observed accompanied by a decreased in p21 and p27 expression. These findings suggest that PYP1 (1-20) stimulates the proliferation of rat IEC-6 cells by activating the EGFR signaling pathway. Therefore, PYP1 (1-20) may be a potential source for the development of bio-functional foods which promotes the proliferation of intestinal epithelial cells.

  16. Glucagon-like peptide-1 induced signaling and insulin secretion do not drive fuel and energy metabolism in primary rodent pancreatic beta-cells.

    Directory of Open Access Journals (Sweden)

    Marie-Line Peyot

    Full Text Available BACKGROUND: Glucagon like peptide-1 (GLP-1 and its analogue exendin-4 (Ex-4 enhance glucose stimulated insulin secretion (GSIS and activate various signaling pathways in pancreatic beta-cells, in particular cAMP, Ca(2+ and protein kinase-B (PKB/Akt. In many cells these signals activate intermediary metabolism. However, it is not clear whether the acute amplification of GSIS by GLP-1 involves in part metabolic alterations and the production of metabolic coupling factors. METHODOLOGY/PRINICIPAL FINDINGS: GLP-1 or Ex-4 at high glucose caused release (approximately 20% of the total rat islet insulin content over 1 h. While both GLP-1 and Ex-4 markedly potentiated GSIS in isolated rat and mouse islets, neither had an effect on beta-cell fuel and energy metabolism over a 5 min to 3 h time period. GLP-1 activated PKB without changing glucose usage and oxidation, fatty acid oxidation, lipolysis or esterification into various lipids in rat islets. Ex-4 caused a rise in [Ca(2+](i and cAMP but did not enhance energy utilization, as neither oxygen consumption nor mitochondrial ATP levels were altered. CONCLUSIONS/SIGNIFICANCE: The results indicate that GLP-1 barely affects beta-cell intermediary metabolism and that metabolic signaling does not significantly contribute to GLP-1 potentiation of GSIS. The data also indicate that insulin secretion is a minor energy consuming process in the beta-cell, and that the beta-cell is different from most cell types in that its metabolic activation appears to be primarily governed by a "push" (fuel substrate driven process, rather than a "pull" mechanism secondary to enhanced insulin release as well as to Ca(2+, cAMP and PKB signaling.

  17. Apoptosis induced by Aβ25-35 peptide is Ca(2+) -IP3 signaling-dependent in murine astrocytes.

    Science.gov (United States)

    Oseki, K T; Monteforte, P T; Pereira, G J S; Hirata, H; Ureshino, R P; Bincoletto, C; Hsu, Y-T; Smaili, S S

    2014-08-01

    Although the accumulation of the neurotoxic peptide β-amyloid (Aβ) in the central nervous system is a hallmark of Alzheimer's disease, whether Aβ acts in astrocytes is unclear, and downstream functional consequences have yet to be defined. Here, we show that cytosolic Ca(2+) dysregulation, induced by a neurotoxic fragment (Aβ25-35), caused apoptosis in a concentration-dependent manner, leading to cytoplasmic Ca(2+) mobilization from extra- and intracellular sources, mainly from the endoplasmic reticulum (ER) via IP3 receptor activation. This mechanism was related to Aβ-mediated apoptosis by the intrinsic pathway because the expression of pro-apoptotic Bax was accompanied by its translocation in cells transfected with GFP-Bax. Aβ-mediated apoptosis was reduced by BAPTA-AM, a fast Ca(2+) chelator, indicating that an increase in intracellular Ca(2+) was involved in cell death. Interestingly, the Bax translocation was dependent on Ca(2+) mobilization from IP3 receptors because pre-incubation with xestospongin C, a selective IP3 receptor inhibitor, abolished this response. Taken together, these results provide evidence that Aβ dysregulation of Ca(2+) homeostasis induces ER depletion of Ca(2+) stores and leads to apoptosis; this mechanism plays a significant role in Aβ apoptotic cell death and might be a new target for neurodegeneration treatments.

  18. A peptide antagonist of CD28 signaling attenuates toxic shock and necrotizing soft-tissue infection induced by Streptococcus pyogenes.

    Science.gov (United States)

    Ramachandran, Girish; Tulapurkar, Mohan E; Harris, Kristina M; Arad, Gila; Shirvan, Anat; Shemesh, Ronen; Detolla, Louis J; Benazzi, Cinzia; Opal, Steven M; Kaempfer, Raymond; Cross, Alan S

    2013-06-15

    Staphylococcus aureus and group A Streptococcus pyogenes (GAS) express superantigen (SAg) exotoxin proteins capable of inducing lethal shock. To induce toxicity, SAgs must bind not only to the major histocompatibility complex II molecule of antigen-presenting cells and the variable β chain of the T-cell receptor but also to the dimer interface of the T-cell costimulatory receptor CD28. Here, we show that the CD28-mimetic peptide AB103 (originally designated "p2TA") protects mice from lethal challenge with streptococcal exotoxin A, as well as from lethal GAS bacterial infection in a murine model of necrotizing soft-tissue infection. Administration of a single dose of AB103 increased survival when given up to 5 hours after infection, reduced inflammatory cytokine expression and bacterial burden at the site of infection, and improved muscle inflammation in a dose-dependent manner, without compromising cellular and humoral immunity. Thus, AB103 merits further investigation as a potential therapeutic in SAg-mediated necrotizing soft-tissue infection.

  19. Amyloid β peptide directly impairs pineal gland melatonin synthesis and melatonin receptor signaling through the ERK pathway.

    Science.gov (United States)

    Cecon, Erika; Chen, Min; Marçola, Marina; Fernandes, Pedro A C; Jockers, Ralf; Markus, Regina P

    2015-06-01

    Melatonin is the hormone produced by the pineal gland known to regulate physiologic rhythms and to display immunomodulatory and neuroprotective properties. It has been reported that Alzheimer disease patients show impaired melatonin production and altered expression of the 2 G protein-coupled melatonin receptors (MTRs), MT₁ and MT₂, but the underlying mechanisms are not known. Here we evaluated whether this dysfunction of the melatonergic system is directly caused by amyloid β peptides (Aβ(1-40) and Aβ(1-42)). Aβ treatment of rat pineal glands elicited an inflammatory response within the gland, evidenced by the up-regulation of 52 inflammatory genes, and decreased the production of melatonin up to 75% compared to vehicle-treated glands. Blocking NF-κB activity prevented this effect. Exposure of HEK293 cells stably expressing recombinant MT₁ or MT₂ receptors to Aβ lead to a 40% reduction in [(125)I]iodomelatonin binding to MT₁. ERK1/2 activation triggered by MTRs, but not by the β₂-adrenergic receptor, was markedly impaired by Aβ in HEK293 transfected cells, as well as in primary rat endothelial cells expressing endogenous MTRs. Our data reveal the melatonergic system as a new target of Aβ, opening new perspectives to Alzheimer disease diagnosis and therapeutic intervention.

  20. Resolution-independent surface rendering using programmable graphics hardware

    Science.gov (United States)

    Loop, Charles T.; Blinn, James Frederick

    2008-12-16

    Surfaces defined by a Bezier tetrahedron, and in particular quadric surfaces, are rendered on programmable graphics hardware. Pixels are rendered through triangular sides of the tetrahedra and locations on the shapes, as well as surface normals for lighting evaluations, are computed using pixel shader computations. Additionally, vertex shaders are used to aid interpolation over a small number of values as input to the pixel shaders. Through this, rendering of the surfaces is performed independently of viewing resolution, allowing for advanced level-of-detail management. By individually rendering tetrahedrally-defined surfaces which together form complex shapes, the complex shapes can be rendered in their entirety.

  1. Soybean nodule-enhanced CLE peptides in roots act as signals in GmNARK-mediated nodulation suppression.

    Science.gov (United States)

    Lim, Chae Woo; Lee, Young Woo; Hwang, Cheol Ho

    2011-09-01

    The number of nodules formed in the roots of leguminous plants is systemically controlled by autoregulation of nodulation (AON). This study characterized two of the CLAVATA3/endosperm-surrounding region (CLE) genes involved in AON signal transduction. The GmRIC1 and GmRIC2 genes initiated expression solely in the roots at approximately 3 days after inoculation (DAI) with Nod factor-producing rhizobia, corresponding to the time point of AON, and the expression was up-regulated by cytokinins. Levels of GmRIC1 and GmRIC2 gene expression were much higher in the supernodulation mutant, SS2-2, than in wild-type (WT) soybeans during nodule development, even after initiation of nitrogen fixation. At 3 DAI, GmRIC2 was induced in the cells of the pericycle and the outer cortex, which undergo cell division to form nodule primordia and spreads from the central region to the whole nodule as it develops. Overexpression of GmRIC1 and GmRIC2 strongly suppressed the nodulation of WT roots as well as transgenic hairy roots in a GmNARK-dependent manner. This systemic suppression of nodulation was caused by the secretion of two CLE proteins into the extracellular space. Double grafting between WT and SS2-2 soybeans showed that signal Q is larger in SS2-2 than in WT roots during nodulation. The results of this study suggest that GmRIC1 and GmRIC2 are good candidates for root-derived signal Q in AON signal transduction.

  2. Design and construction of novel molecular conjugates for signal amplification (I): conjugation of multiple horseradish peroxidase molecules to immunoglobulin via primary amines on lysine peptide chains.

    Science.gov (United States)

    Dhawan, Subhash

    2002-12-01

    Immunoconjugates are widely used for indirect detection of analytes (such as antibodies or antigens) in a variety of immunoassays. However, the availability of functional groups such as primary amines or free sulfhydryls in an immunoglobulin molecule is the limiting factor for optimal conjugation and, therefore, determines the sensitivity of an assay. In the present study, an N-terminal bromoacetylated 20 amino acid peptide containing 20 lysine residues was conjugated to N-succinimidyl-S-acetylthioacetate (SATA)-modified IgG or free sulfhydryl groups on 2-mercaptoethylamine (2-MEA)-reduced IgG molecules via a thioether (S[bond]CH(2)CONH) linkage to introduce multiple reactive primary amines per IgG. These primary amines were then covalently coupled with maleimide-activated horseradish peroxidase (HRP). The poly-HRP-antibody conjugates thus generated demonstrated greater than 15-fold signal amplification upon reaction with orthophenyldiamine substrate. The poly-HRP-antibody conjugates efficiently detected human immunodeficiency virus (HIV)-1 antibodies in plasma specimens with significantly higher sensitivity than conventionally prepared HRP-antibody conjugates in an HIV-1 solid-phase enzyme immunoassay and Western blot analysis. The signal amplification techniques reported here could have the potential for development of highly sensitive immunodiagnostic assay systems.

  3. Efficient and Effective Volume Visualization with Enhanced Isosurface Rendering

    CERN Document Server

    Yang, Fei; Tian, Jie

    2012-01-01

    Compared with full volume rendering, isosurface rendering has several well recognized advantages in efficiency and accuracy. However, standard isosurface rendering has some limitations in effectiveness. First, it uses a monotone colored approach and can only visualize the geometry features of an isosurface. The lack of the capability to illustrate the material property and the internal structures behind an isosurface has been a big limitation of this method in applications. Another limitation of isosurface rendering is the difficulty to reveal physically meaningful structures, which are hidden in one or multiple isosurfaces. As such, the application requirements of extract and recombine structures of interest can not be implemented effectively with isosurface rendering. In this work, we develop an enhanced isosurface rendering technique to improve the effectiveness while maintaining the performance efficiency of the standard isosurface rendering. First, an isosurface color enhancement method is proposed to il...

  4. Acoustic Holographic Rendering with Two-dimensional Metamaterial-based Passive Phased Array

    Science.gov (United States)

    Xie, Yangbo; Shen, Chen; Wang, Wenqi; Li, Junfei; Suo, Dingjie; Popa, Bogdan-Ioan; Jing, Yun; Cummer, Steven A.

    2016-01-01

    Acoustic holographic rendering in complete analogy with optical holography are useful for various applications, ranging from multi-focal lensing, multiplexed sensing and synthesizing three-dimensional complex sound fields. Conventional approaches rely on a large number of active transducers and phase shifting circuits. In this paper we show that by using passive metamaterials as subwavelength pixels, holographic rendering can be achieved without cumbersome circuitry and with only a single transducer, thus significantly reducing system complexity. Such metamaterial-based holograms can serve as versatile platforms for various advanced acoustic wave manipulation and signal modulation, leading to new possibilities in acoustic sensing, energy deposition and medical diagnostic imaging. PMID:27739472

  5. Regulation of hypothalamic signaling by tuberoinfundibular peptide of 39 residues is critical for the response to cold: a novel peptidergic mechanism of thermoregulation.

    Science.gov (United States)

    Dimitrov, Eugene L; Kim, Yoon Yi; Usdin, Ted B

    2011-12-07

    Euthermia is critical for mammalian homeostasis. Circuits within the preoptic hypothalamus regulate temperature, with fine control exerted via descending GABAergic inhibition of presympathetic motor neurons that control brown adipose tissue (BAT) thermogenesis and cutaneous vascular tone. The thermoregulatory role of hypothalamic excitatory neurons is less clear. Here we report peptidergic regulation of preoptic glutamatergic neurons that contributes to temperature regulation. Tuberoinfundibular peptide of 39 residues (TIP39) is a ligand for the parathyroid hormone 2 receptor (PTH2R). Both peptide and receptor are abundant in the preoptic hypothalamus. Based on PTH2R and vesicular glutamate transporter 2 (VGlut2) immunolabeling in animals with retrograde tracer injection, PTH2R-containing glutamatergic fibers are presynaptic to neurons projecting from the median preoptic nucleus (MnPO) to the dorsomedial hypothalamus. Transneuronal retrograde pathway tracing with pseudorabies virus revealed connectivity between MnPO VGlut2 and PTH2R neurons and BAT. MnPO injection of TIP39 increased body temperature by 2°C for several hours. Mice lacking TIP39 signaling, either because of PTH2R-null mutation or brain delivery of a PTH2R antagonist had impaired heat production upon cold exposure, but no change in basal temperature and no impairment in response to a hot environment. Thus, TIP39 appears to act on PTH2Rs present on MnPO glutamatergic terminals to regulate their activation of projection neurons and subsequent sympathetic BAT activation. This excitatory mechanism of heat production appears to be activated on demand, during cold exposure, and parallels the tonic inhibitory GABAergic control of body temperature.

  6. A novel peptide derived from human pancreatitis-associated protein inhibits inflammation in vivo and in vitro and blocks NF-kappa B signaling pathway.

    Directory of Open Access Journals (Sweden)

    Xiaolu Yang

    Full Text Available BACKGROUND: Pancreatitis-associated protein (PAP is a pancreatic secretory protein belongs to the group VII of C-type lectin family. Emerging evidence suggests that PAP plays a protective effect in inflammatory diseases. In the present study, we newly identified a 16-amino-acid peptide (named PAPep derived from C-type lectin-like domain (CTLD of human PAP with potent anti-inflammatory activity using both in vivo and in vitro assays. METHODOLOGY/PRINCIPAL FINDINGS: We assessed the anti-inflammatory effect of PAPep on endotoxin-induced uveitis (EIU in rats and demonstrated that intravitreal pretreatment of PAPep concentration-dependently attenuated clinical manifestation of EIU rats, reduced protein leakage and cell infiltration into the aqueous humor (AqH, suppressed tumor necrosis factor (TNF-α, interleukin (IL-6, intercellular adhesion molecule-1 (ICAM-1 and monocyte chemoattractant protein (MCP-1 production in ocular tissues, and improved histopathologic manifestation of EIU. Furthermore, PAPep suppressed the LPS-induced mRNA expression of TNF-α and IL-6 in RAW 264.7 cells, inhibited protein expression of ICAM-1 in TNF-α-stimulated human umbilical vein endothelial cells (HUVECs as well as U937 cells adhesion to HUVECs. Western blot analysis in ocular tissues and different cell lines revealed that the possible mechanism for this anti-inflammatory effect of PAPep may depend on its ability to inhibit the activation of NF-kB signaling pathway. CONCLUSIONS/SIGNIFICANCE: Our studies provide the first evidence that the sequence of PAPep is within the critically active region for the anti-inflammatory function of PAP and the peptide may be a promising candidate for the management of ocular inflammatory diseases.

  7. The shrimp IKK-NF-κB signaling pathway regulates antimicrobial peptide expression and may be subverted by white spot syndrome virus to facilitate viral gene expression.

    Science.gov (United States)

    Wang, Pei-Hui; Gu, Zhi-Hua; Wan, Ding-Hui; Liu, Bo-Du; Huang, Xian-De; Weng, Shao-Ping; Yu, Xiao-Qiang; He, Jian-Guo

    2013-09-01

    The IκB kinases IKKα and IKKβ and the IKK-related kinases TANK-binding kinase 1 (TBK1) and IKKε are the master regulators of the NF-κB signaling pathway. Although this pathway has been extensively studied in mammals, less attention has been paid in crustaceans, which have significant economic value. Here, we report the cloning and functional studies of two IKK homologs, LvIKKβ and LvIKKε, from Pacific white shrimp, Litopenaeus vannamei. LvIKKβ and LvIKKε mRNAs are widely expressed in different tissues and are responsive to white spot syndrome virus (WSSV) infection. When overexpressed in Drosophila S2 cells, LvIKKβ but not LvIKKε activates the promoters of NF-κB pathway-controlled antimicrobial peptide genes (AMPs), such as the Penaeidins (PENs). In HEK 293T cells, both LvIKKβ and LvIKKε activate an NF-κB reporter. The silencing of LvIKKβ or LvIKKε using double-stranded RNA (dsRNA)-mediated RNA interference (RNAi) decreases the expression of L. vannamei AMPs, including PENs, lysozyme and crustins. Intriguingly, LvIKKβ- or LvIKKε-silenced L. vannamei are resistant to WSSV infection. We hypothesized that successful infection with WSSV requires the activation of the IKK-NF-κB signaling pathway to modulate viral gene expression. We constructed luciferase reporters for 147 WSSV genes. By screening, we found that the WSV051, WSV059, WSV069, WSV083, WSV090, WSV107, WSV244, WSV303, WSV371 and WSV445 promoters can be activated by LvIKKβ or LvIKKε in Drosophila S2 cells. Taken together, our results reveal that LvIKKβ and LvIKKε may participate in the regulation of shrimp AMPs and that WSSV may subvert the L. vannamei IKK-NF-κB signaling pathway to facilitate viral gene expression.

  8. Dynamic Resolution in GPU-Accelerated Volume Rendering to Autostereoscopic Multiview Lenticular Displays

    Directory of Open Access Journals (Sweden)

    Daniel Ruijters

    2008-09-01

    Full Text Available The generation of multiview stereoscopic images of large volume rendered data demands an enormous amount of calculations. We propose a method for hardware accelerated volume rendering of medical data sets to multiview lenticular displays, offering interactive manipulation throughout. The method is based on buffering GPU-accelerated direct volume rendered visualizations of the individual views from their respective focal spot positions, and composing the output signal for the multiview lenticular screen in a second pass. This compositing phase is facilitated by the fact that the view assignment per subpixel is static, and therefore can be precomputed. We decoupled the resolution of the individual views from the resolution of the composited signal, and adjust the resolution on-the-fly, depending on the available processing resources, in order to maintain interactive refresh rates. The optimal resolution for the volume rendered views is determined by means of an analysis of the lattice of the output signal for the lenticular screen in the Fourier domain.

  9. Direct volume rendering methods for cell structures.

    Science.gov (United States)

    Martišek, Dalibor; Martišek, Karel

    2012-01-01

    The study of the complicated architecture of cell space structures is an important problem in biology and medical research. Optical cuts of cells produced by confocal microscopes enable two-dimensional (2D) and three-dimensional (3D) reconstructions of observed cells. This paper discuses new possibilities for direct volume rendering of these data. We often encounter 16 or more bit images in confocal microscopy of cells. Most of the information contained in these images is unsubstantial for the human vision. Therefore, it is necessary to use mathematical algorithms for visualization of such images. Present software tools as OpenGL or DirectX run quickly in graphic station with special graphic cards, run very unsatisfactory on PC without these cards and outputs are usually poor for real data. These tools are black boxes for a common user and make it impossible to correct and improve them. With the method proposed, more parameters of the environment can be set, making it possible to apply 3D filters to set the output image sharpness in relation to the noise. The quality of the output is incomparable to the earlier described methods and is worth increasing the computing time. We would like to offer mathematical methods of 3D scalar data visualization describing new algorithms that run on standard PCs very well.

  10. Secretory expression of thermostable alkaline protease from Bacillus stearothermophilus FI by using native signal peptide and α-factor secretion signal in Pichia pastoris.

    Science.gov (United States)

    Latiffi, Amaliawati Ahmad; Salleh, Abu Bakar; Rahman, Raja Noor Zaliha Raja Abd; Oslan, Siti Nurbaya; Basri, Mahiran

    2013-01-01

    The thermostable alkaline protease from Bacillus stearothermophilus F1 has high potential for industrial applications, and attempt to produce the enzyme in yeast for higher yield was undertaken. Secretory expression of F1 protease through yeast system could improve enzyme's capability, thus simplifying the purification steps. Mature and full genes of F1 protease were cloned into Pichia pastoris expression vectors (pGAPZαB and pPICZαB) and transformed into P. pastoris strains (GS115 and SMD1168H) via electroporation method. Recombinant F1 protease under regulation constitutive GAP promoter revealed that the highest expression was achieved after 72 h cultivation. While inducible AOX promoter showed that 0.5% (v/v) methanol was the best to induce expression. It was proven that constitutive expression strategy was better than inducible system. The α-secretion signal from the plasmid demonstrated higher secretory expression level of F1 protease as compared to native Open Reading Frame (ORF) in GS115 strain (GE6GS). Production medium YPTD was found to be the best for F1 protease expression with the highest yield of 4.13 U/mL. The protein was expressed as His-tagged fusion protein with a size about 34 kDa.

  11. Spatial sound rendering of a playing xylophone for the telepresence application

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Hoffmann, Pablo F.

    2013-01-01

    and spatial properties of the sound field created by a xylophone as a distributed sound source were analyzed. Xylophone recordings were performed using different microphone configurations: one and two-channel recording setups are implemented. One-channel recording technique with binaural synthesis for spatial...... played at the student's location is required at the teacher’s site. This paper presents a comparison of different recording techniques for a spatial xylophone sound rendering, focusing on the horizontal width of the xylophone auditory image. The directivity pattern of the xylophone was measured...... xylophone sound rendering is proposed. The recorded signal is processed in order to define multiple virtual sources which are spatially distributed for the auditory width representation of the virtual xylophone. The results of the analyzed recording and rendering techniques are compared in terms...

  12. The effects of orbital spaceflight on bone histomorphometry and messenger ribonucleic acid levels for bone matrix proteins and skeletal signaling peptides in ovariectomized growing rats

    Science.gov (United States)

    Cavolina, J. M.; Evans, G. L.; Harris, S. A.; Zhang, M.; Westerlind, K. C.; Turner, R. T.

    1997-01-01

    A 14-day orbital spaceflight was performed using ovariectomized Fisher 344 rats to determine the combined effects of estrogen deficiency and near weightlessness on tibia radial bone growth and cancellous bone turnover. Twelve ovariectomized rats with established cancellous osteopenia were flown aboard the space shuttle Columbia (STS-62). Thirty ovariectomized rats were housed on earth as ground controls: 12 in animal enclosure modules, 12 in vivarium cages, and 6 killed the day of launch for baseline measurements. An additional 18 ovary-intact rats were housed in vivarium cages as ground controls: 8 rats were killed as baseline controls and the remaining 10 rats were killed 14 days later. Ovariectomy increased periosteal bone formation at the tibia-fibula synostosis; cancellous bone resorption and formation in the secondary spongiosa of the proximal tibial metaphysis; and messenger RNA (mRNA) levels for the prepro-alpha2(1) subunit of type 1 collagen, osteocalcin, transforming growth factor-beta, and insulin-like growth factor I in the contralateral proximal tibial metaphysis and for the collagen subunit in periosteum pooled from tibiae and femora and decreased cancellous bone area. Compared to ovariectomized weight-bearing rats, the flight group experienced decreases in periosteal bone formation, collagen subunit mRNA levels, and cancellous bone area. The flight rats had a small decrease in the cancellous mineral apposition rate, but no change in the calculated bone formation rate. Also, spaceflight had no effect on cancellous osteoblast and osteoclast perimeters or on mRNA levels for bone matrix proteins and signaling peptides. On the other hand, spaceflight resulted in an increase in bone resorption, as ascertained from the diminished retention of a preflight fluorochrome label. This latter finding suggests that osteoclast activity was increased. In a follow-up ground-based experiment, unilateral sciatic neurotomy of ovariectomized rats resulted in cancellous

  13. Interaction of synthetic peptide corresponding to signal sequence of glucitol permease of Escherichia Coli and its analogue with liposomes

    Institute of Scientific and Technical Information of China (English)

    王庆达; 崔大敷; 林其谁

    1996-01-01

    The N-terminal signal sequence of glucitol pcrmease of Escherichia Coli (Gut22) and its analogue (Gut22Ana) were synthesized. The analogue had a Pro residue substituting for the His at the 7th position of Gut22 and a Val residue substituting for the Glu at the 10th position. The intrinsic fluorescence emission spectra indicated that the binding of Gut22 with lipid bilayer was much stronger than that of Gut22Ana. The leakage experiments with calcein-loaded liposomes showed that Gut22 strongly perturbed lipid bilayers while Gut22Ana did not. The apparent partition constant of Gut22 for partitioning into phosphatidylserine/phosphatidylcholine bilayers was measured; the effect of membrane potential on the interaction of Gut22 with lipid bilayers was studied and the conformation changes of Gut22 and Gut22Ana upon interacting with liposomes were studied by the method of circular dichroism analysis.

  14. HDlive rendering images of the fetal stomach: a preliminary report.

    Science.gov (United States)

    Inubashiri, Eisuke; Abe, Kiyotaka; Watanabe, Yukio; Akutagawa, Noriyuki; Kuroki, Katumaru; Sugawara, Masaki; Maeda, Nobuhiko; Minami, Kunihiro; Nomura, Yasuhiro

    2015-01-01

    This study aimed to show reconstruction of the fetal stomach using the HDlive rendering mode in ultrasound. Seventeen healthy singleton fetuses at 18-34 weeks' gestational age were observed using the HDlive rendering mode of ultrasound in utero. In all of the fetuses, we identified specific spatial structures, including macroscopic anatomical features (e.g., the pyrous, cardia, fundus, and great curvature) of the fetal stomach, using the HDlive rendering mode. In particular, HDlive rendering images showed remarkably fine details that appeared as if they were being viewed under an endoscope, with visible rugal folds after 27 weeks' gestational age. Our study suggests that the HDlive rendering mode can be used as an additional method for evaluating the fetal stomach. The HDlive rendering mode shows detailed 3D structural images and anatomically realistic images of the fetal stomach. This technique may be effective in prenatal diagnosis for examining detailed information of fetal organs.

  15. Treatment of mice with the suppressor of cytokine signaling-1 mimetic peptide, tyrosine kinase inhibitor peptide, prevents development of the acute form of experimental allergic encephalomyelitis and induces stable remission in the chronic relapsing/remitting form.

    Science.gov (United States)

    Mujtaba, Mustafa G; Flowers, Lawrence O; Patel, Chintak B; Patel, Ravi A; Haider, Mohammad I; Johnson, Howard M

    2005-10-15

    We have previously characterized a novel tyrosine kinase inhibitor peptide (Tkip) that is a mimetic of suppressor of cytokine signaling 1 (SOCS-1) and inhibits JAK2 phosphorylation of the transcription factor STAT1alpha. We show in this study that Tkip protects mice against experimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis. Mice are immunized with myelin basic protein (MBP) for induction of disease. Tkip (63 mug) administered every other day suppressed the development of acute EAE in 75% of New Zealand White (NZW) mice. Furthermore, Tkip completely protected SJL/J mice, which where induced to get the relapsing/remitting form of EAE, against relapses compared with control groups in which >70% of the mice relapsed after primary incidence of disease. Protection of mice by Tkip was similar to that seen with the type I IFN, IFN-tau. Protection of mice correlated with lower MBP Ab titers in Tkip-treated groups as well as suppression of MBP-induced proliferation of splenocytes taken from EAE-afflicted mice. Cessation of Tkip and IFN-tau administration resulted in SJL/J mice relapsing back into disease. Prolonged treatment of mice with Tkip produced no evidence of cellular toxicity or weight loss. Consistent with its JAK2 inhibitory function, Tkip also inhibited the activity of the inflammatory cytokine TNF-alpha, which uses the STAT1alpha transcription factor. The data presented in this study show that Tkip, like the type I IFN, IFN-tau, inhibits both the autoreactive cellular and humoral responses in EAE and ameliorates both the acute and chronic relapsing/remitting forms of EAE.

  16. Curcumin Improves Amyloid β-Peptide (1-42 Induced Spatial Memory Deficits through BDNF-ERK Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    Full Text Available Curcumin, the most active component of turmeric, has various beneficial properties, such as antioxidant, anti-inflammatory, and antitumor effects. Previous studies have suggested that curcumin reduces the levels of amyloid and oxidized proteins and prevents memory deficits and thus is beneficial to patients with Alzheimer's disease (AD. However, the molecular mechanisms underlying curcumin's effect on cognitive functions are not well-understood. In the present study, we examined the working memory and spatial reference memory in rats that received a ventricular injection of amyloid-β1-42 (Aβ1-42, representing a rodent model of Alzheimer's disease (AD. The rats treated with Aβ1-42 exhibited obvious cognitive deficits in behavioral tasks. Chronic (seven consecutive days, once per day but not acute (once a day curcumin treatments (50, 100, and 200 mg/kg improved the cognitive functions in a dose-dependent manner. In addition, the beneficial effect of curcumin is accompanied by increased BDNF levels and elevated levels of phosphorylated ERK in the hippocampus. Furthermore, the cognition enhancement effect of curcumin could be mimicked by the overexpression of BDNF in the hippocampus and blocked by either bilateral hippocampal injections with lentiviruses that express BDNF shRNA or a microinjection of ERK inhibitor. These findings suggest that chronic curcumin ameliorates AD-related cognitive deficits and that upregulated BDNF-ERK signaling in the hippocampus may underlie the cognitive improvement produced by curcumin.

  17. cGMP and NHR signaling co-regulate expression of insulin-like peptides and developmental activation of infective larvae in Strongyloides stercoralis.

    Science.gov (United States)

    Stoltzfus, Jonathan D; Bart, Stephen M; Lok, James B

    2014-07-01

    The infectious form of the parasitic nematode Strongyloides stercoralis is a developmentally arrested third-stage larva (L3i), which is morphologically similar to the developmentally arrested dauer larva in the free-living nematode Caenorhabditis elegans. We hypothesize that the molecular pathways regulating C. elegans dauer development also control L3i arrest and activation in S. stercoralis. This study aimed to determine the factors that regulate L3i activation, with a focus on G protein-coupled receptor-mediated regulation of cyclic guanosine monophosphate (cGMP) pathway signaling, including its modulation of the insulin/IGF-1-like signaling (IIS) pathway. We found that application of the membrane-permeable cGMP analog 8-bromo-cGMP potently activated development of S. stercoralis L3i, as measured by resumption of feeding, with 85.1 ± 2.2% of L3i feeding in 200 µM 8-bromo-cGMP in comparison to 0.6 ± 0.3% in the buffer diluent. Utilizing RNAseq, we examined L3i stimulated with DMEM, 8-bromo-cGMP, or the DAF-12 nuclear hormone receptor (NHR) ligand Δ7-dafachronic acid (DA)--a signaling pathway downstream of IIS in C. elegans. L3i stimulated with 8-bromo-cGMP up-regulated transcripts of the putative agonistic insulin-like peptide (ILP) -encoding genes Ss-ilp-1 (20-fold) and Ss-ilp-6 (11-fold) in comparison to controls without stimulation. Surprisingly, we found that Δ7-DA similarly modulated transcript levels of ILP-encoding genes. Using the phosphatidylinositol-4,5-bisphosphate 3-kinase inhibitor LY294002, we demonstrated that 400 nM Δ7-DA-mediated activation (93.3 ± 1.1% L3i feeding) can be blocked using this IIS inhibitor at 100 µM (7.6 ± 1.6% L3i feeding). To determine the tissues where promoters of ILP-encoding genes are active, we expressed promoter::egfp reporter constructs in transgenic S. stercoralis post-free-living larvae. Ss-ilp-1 and Ss-ilp-6 promoters are active in the hypodermis and neurons and the Ss-ilp-7 promoter is active in the intestine

  18. Ca2+ signaling by plant Arabidopsis thaliana Pep peptides depends on AtPepR1, a receptor with guanylyl cyclase activity, and cGMP-activated Ca2+ channels.

    Science.gov (United States)

    Qi, Zhi; Verma, Rajeev; Gehring, Chris; Yamaguchi, Yube; Zhao, Yichen; Ryan, Clarence A; Berkowitz, Gerald A

    2010-12-01

    A family of peptide signaling molecules (AtPeps) and their plasma membrane receptor AtPepR1 are known to act in pathogen-defense signaling cascades in plants. Little is currently known about the molecular mechanisms that link these signaling peptides and their receptor, a leucine-rich repeat receptor-like kinase, to downstream pathogen-defense responses. We identify some cellular activities of these molecules that provide the context for a model for their action in signaling cascades. AtPeps activate plasma membrane inwardly conducting Ca(2+) permeable channels in mesophyll cells, resulting in cytosolic Ca(2+) elevation. This activity is dependent on their receptor as well as a cyclic nucleotide-gated channel (CNGC2). We also show that the leucine-rich repeat receptor-like kinase receptor AtPepR1 has guanylyl cyclase activity, generating cGMP from GTP, and that cGMP can activate CNGC2-dependent cytosolic Ca(2+) elevation. AtPep-dependent expression of pathogen-defense genes (PDF1.2, MPK3, and WRKY33) is mediated by the Ca(2+) signaling pathway associated with AtPep peptides and their receptor. The work presented here indicates that extracellular AtPeps, which can act as danger-associated molecular patterns, signal by interaction with their receptor, AtPepR1, a plasma membrane protein that can generate cGMP. Downstream from AtPep and AtPepR1 in a signaling cascade, the cGMP-activated channel CNGC2 is involved in AtPep- and AtPepR1-dependent inward Ca(2+) conductance and resulting cytosolic Ca(2+) elevation. The signaling cascade initiated by AtPeps leads to expression of pathogen-defense genes in a Ca(2+)-dependent manner.

  19. Ca 2+ signaling by plant Arabidopsis thaliana Pep peptides depends on AtPepR1, a receptor with guanylyl cyclase activity, and cGMP-activated Ca 2+ channels

    KAUST Repository

    Qia, Zhi

    2010-11-18

    A family of peptide signaling molecules (AtPeps) and their plasma membrane receptor AtPepR1 are known to act in pathogendefense signaling cascades in plants. Little is currently known about the molecular mechanisms that link these signaling peptides and their receptor, a leucine-rich repeat receptor-like kinase, to downstream pathogen-defense responses. We identify some cellular activities of these molecules that provide the context for a model for their action in signaling cascades. AtPeps activate plasma membrane inwardly conducting Ca 2+ permeable channels in mesophyll cells, resulting in cytosolic Ca 2+ elevation. This activity is dependent on their receptor as well as a cyclic nucleotide-gated channel (CNGC2). We also show that the leucine-rich repeat receptor- like kinase receptor AtPepR1 has guanylyl cyclase activity, generating cGMP from GTP, and that cGMP can activate CNGC2- dependent cytosolic Ca 2+ elevation. AtPep-dependent expression of pathogen-defense genes (PDF1.2, MPK3, and WRKY33) is mediated by the Ca 2+ signaling pathway associated with AtPep peptides and their receptor. The work presented here indicates that extracellular AtPeps, which can act as danger-associated molecular patterns, signal by interaction with their receptor, AtPepR1, a plasma membrane protein that can generate cGMP. Downstream from AtPep and AtPepR1 in a signaling cascade, the cGMP-activated channel CNGC2 is involved in AtPep- and AtPepR1-dependent inward Ca 2+ conductance and resulting cytosolic Ca 2+ elevation. The signaling cascade initiated by AtPeps leads to expression of pathogen- defense genes in a Ca 2+-dependent manner.

  20. Fast combinative volume rendering by indexed data structure

    Institute of Scientific and Technical Information of China (English)

    孙文武; 王文成; 吴恩华

    2001-01-01

    It is beneficial to study the interesting contents in a data set by combining and rendering variouscontents of the data. In this regard, an indexed data structure is proposed to facilitate the reorganization of data so that the contents of the data can be combined conveniently and only the selected contents in the data are processed for rendering. Based on the structure, the cells of different contents can be queued up easily so that the volume rendering can be conducted more accurately and quickly. Experimental results show that the indexed data structure is very efficient in improving combinative volume rendering.

  1. Early intraplatelet signaling enhances the release of human platelet PAR-1 and -4 amino-terminal peptides in response to thrombin.

    Science.gov (United States)

    Ofosu, Frederick A; Dewar, Lori; Song, Yingqi; Cedrone, Aisha C; Hortelano, Gonzalo; Craven, Sharon J

    2009-02-24

    Activation of washed human platelets initiated with alpha-thrombin, SFLLRN, or AYPGKF invariably results in the generation of PAR-1-(1-41) and PAR-4-(1-47). PAR-1-(1-41) and PAR-4-(1-47) are amino-terminal peptides generated when PAR-1 and -4 are cleaved in their first extracellular domains after R(41) and R(47), respectively, to expose the tethered ligand domains of PAR-1 and -4. Since soybean trypsin inhibitor decreases generation of PAR-1-(1-41) and PAR-4-(1-47) and other platelet aggregation-related responses to these three agonists, but does not inactivate alpha-thrombin, a platelet trypsin-like proteinase apparently activates PAR-1 and -4 to propagate PAR-dependent platelet responses. This study identified the signaling pathways implicated in the generation of the platelet proteinase that in turn produces PAR-1-(1-41) and PAR-4-(1-47), to thereby drive the subsequent PAR-dependent platelet aggregation-related responses to alpha-thrombin, SFLLRN, or AYPGKF. Only inhibitors of signaling enzymes that prevented ATP release (forskolin, PGE(1), or BIMI-1) prevented or delayed the generation of PAR-1-(1-41) and PAR-4-(1-47) in response to all three agonists. SBTI prevented platelet aggregation initiated by alpha-thrombin, SFLLRN, or AYPGKF but did so less effectively when it was added 10 s after each agonist. Thus, the platelet-derived proteinase acts within 10 s of each agonist addition to generate PAR-1-(1-41) and PAR-4-(1-47). Furthermore, alpha-thrombin may not effectively catalyze PAR-1-(1-41) and PAR-4-(1-47) generation. We propose that unidentified ATP-dependent phosphorylation reactions catalyzed by PKC help to generate the platelet-derived proteinase that propagates human platelet PAR-1 and -4 activation by the three agonists.

  2. Activation of calcitonin gene-related peptide signaling through the prostaglandin E2-EP1/EP2/EP4 receptor pathway in synovium of knee osteoarthritis patients.

    Science.gov (United States)

    Minatani, Atsushi; Uchida, Kentaro; Inoue, Gen; Takano, Shotaro; Aikawa, Jun; Miyagi, Masayuki; Fujimaki, Hisako; Iwase, Dai; Onuma, Kenji; Matsumoto, Toshihide; Takaso, Masashi

    2016-10-17

    Calcitonin gene-related peptide (CGRP) is a 37-amino-acid vasodilatory neuropeptide that binds to receptor activity-modifying protein 1 (RAMP1) and the calcitonin receptor-like receptor (CLR). Clinical and preclinical evidence suggests that CGRP is associated with hip and knee joint pain; however, the regulation mechanisms of CGRP/CGRP receptor signaling in synovial tissue are not fully understood. Synovial tissues were harvested from 43 participants with radiographic knee osteoarthritis (OA; unilateral Kellgren/Lawrence (K/L) grades 3-4) during total knee arthroplasty. Correlationships between the mRNA expression levels of CGRP and those of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and cycloxygenase-2 (COX-2) were evaluated using real-time PCR analysis of total RNA extracted from the collected synovial tissues. To investigate the factors controlling the regulation of CGRP and CGRP receptor expression, cultured synovial cells were stimulated with TNF-α, IL-1β, IL-6, and prostaglandin E2 (PGE2) and were also treated with PGE2 receptor (EP) agonist. CGRP and COX-2 localized in the synovial lining layer. Expression of COX-2 positively correlated with CGRP mRNA expression in the synovial tissue of OA patients. The gene expression of CGRP and RAMP1 increased significantly in synovial cells exogenously treated with PGE2 compared to untreated control cells. In cultured synovial cells, CGRP gene expression increased significantly following EP4 agonist treatment, whereas RAMP1 gene expression increased significantly in the presence of exogenously added EP1 and EP2 agonists. PGE2 appears to regulate CGRP/CGRP receptor signaling through the EP receptor in the synovium of knee OA patients.

  3. Insulin/IGF signaling in Drosophila and other insects: factors that regulate production, release and post-release action of the insulin-like peptides.

    Science.gov (United States)

    Nässel, Dick R; Vanden Broeck, Jozef

    2016-01-01

    Insulin, insulin-like growth factors (IGFs) and insulin-like peptides (ILPs) are important regulators of metabolism, growth, reproduction and lifespan, and mechanisms of insulin/IGF signaling (IIS) have been well conserved over evolution. In insects, between one and 38 ILPs have been identified in each species. Relatively few insect species have been investigated in depth with respect to ILP functions, and therefore we focus mainly on the well-studied fruitfly Drosophila melanogaster. In Drosophila eight ILPs (DILP1-8), but only two receptors (dInR and Lgr3) are known. DILP2, 3 and 5 are produced by a set of neurosecretory cells (IPCs) in the brain and their biosynthesis and release are controlled by a number of mechanisms differing between larvae and adults. Adult IPCs display cell-autonomous sensing of circulating glucose, coupled to evolutionarily conserved mechanisms for DILP release. The glucose-mediated DILP secretion is modulated by neurotransmitters and neuropeptides, as well as by factors released from the intestine and adipocytes. Larval IPCs, however, are indirectly regulated by glucose-sensing endocrine cells producing adipokinetic hormone, or by circulating factors from the intestine and fat body. Furthermore, IIS is situated within a complex physiological regulatory network that also encompasses the lipophilic hormones, 20-hydroxyecdysone and juvenile hormone. After release from IPCs, the ILP action can be modulated by circulating proteins that act either as protective carriers (binding proteins), or competitive inhibitors. Some of these proteins appear to have additional functions that are independent of ILPs. Taken together, the signaling with multiple ILPs is under complex control, ensuring tightly regulated IIS in the organism.

  4. Suppressor of cytokine signaling 2 (SOCS2) negatively regulates the expression of antimicrobial peptides by affecting the Stat transcriptional activity in shrimp Marsupenaeus japonicus.

    Science.gov (United States)

    Sun, Jie-Jie; Lan, Jiang-Feng; Xu, Ji-Dong; Niu, Guo-Juan; Wang, Jin-Xing

    2016-09-01

    The suppressor of cytokine signaling (SOCS) family is a kind of negative regulators in the Janus kinase/signal transducer and activator of transcription (Jak/Stat) pathway in mammals and Drosophila. In kuruma shrimp, Marsupenaeus japonicus, SOCS2 is identified and its expression can be stimulated by peptidoglycan and polycytidylic acid. However, if SOCS2 participates in regulating Jak/Stat pathway in shrimp still needs further study. In this study, SOCS2 with Src homology 2 domain and SOCS box was identified in kuruma shrimp, M. japonicus. SOCS2 existed in hemocytes, heart, hepatopancreas, gills, stomach, and intestine, the expression of SOCS2 was upregulated significantly in the hemocytes and intestine of shrimp challenged with Vibrio anguillarum at 6 h. To analyze SOCS2 function in shrimp immunity, bacterial clearance and survival rate were analyzed after knockdown of SOCS2 in shrimp challenged with V. anguillarum. Results showed that bacterial clearance increased, and the survival rate improved significantly comparing with controls. The SOCS2 was expressed in Escherichia coli and the recombinant SOCS2 was injected into shrimp, and Stat phosphorylation and translocation were analyzed. The result showed that "overexpression" of SOCS2 declined Stat phosphorylation level and inhibited Stat translocation into the nucleus. After knockdown of SOCS2 in shrimp prior to V. anguillarum infection, the expression level of antimicrobial peptides, including anti-lipopolysaccharide factors C1, C2 and D1, and Crustin I was upregulated significantly, and the expression of the AMPs was declined after recombinant SOCS2 injection. The SOCS2 expression was also decreased in Stat-knockdown shrimp challenged by V. anguillarum at 6 and 12 h. Therefore, SOCS2 negatively regulates the AMP expression by inhibiting Stat phosphorylation and translocation into nucleus in shrimp, meanwhile, SOCS2 expression was also regulated by Jak/Stat pathway.

  5. Reverse genetics generation of chimeric infectious Junin/Lassa virus is dependent on interaction of homologous glycoprotein stable signal peptide and G2 cytoplasmic domains.

    Science.gov (United States)

    Albariño, César G; Bird, Brian H; Chakrabarti, Ayan K; Dodd, Kimberly A; White, David M; Bergeron, Eric; Shrivastava-Ranjan, Punya; Nichol, Stuart T

    2011-01-01

    The Arenaviridae are a diverse and globally distributed collection of viruses that are maintained primarily by rodent reservoirs. Junin virus (JUNV) and Lassa virus (LASV) can both cause significant outbreaks of severe and often fatal human disease throughout their respective areas of endemicity. In an effort to improve upon the existing live attenuated JUNV Candid1 vaccine, we generated a genetically homogenous stock of this virus from cDNA copies of the virus S and L segments by using a reverse genetics system. Further, these cDNAs were used in combination with LASV cDNAs to successfully generate two recombinant Candid1 JUNV/LASV chimeric viruses (via envelope glycoprotein [GPC] exchange). It was found that while the GPC extravirion domains were readily exchangeable, homologous stable signal peptide (SSP) and G2 transmembrane and cytoplasmic tail domains were essential for correct GPC maturation and production of infectious chimeric viruses. The switching of the JUNV and LASV G1/G2 ectodomains within the Candid1 vaccine background did not alter the attenuated phenotype of the vaccine strain in a lethal mouse model. These recombinant chimeric viruses shed light on the fundamental requirements of arenavirus GPC maturation and may serve as a strategy for the development of bivalent JUNV and LASV vaccine candidates.

  6. An intact signal peptide on dengue virus E protein enhances immunogenicity for CD8(+) T cells and antibody when expressed from modified vaccinia Ankara.

    Science.gov (United States)

    Quinan, Bárbara R; Flesch, Inge E A; Pinho, Tânia M G; Coelho, Fabiana M; Tscharke, David C; da Fonseca, Flávio G

    2014-05-23

    Dengue is a global public health concern and this is aggravated by a lack of vaccines or antiviral therapies. Despite the well-known role of CD8(+) T cells in the immunopathogenesis of Dengue virus (DENV), only recent studies have highlighted the importance of this arm of the immune response in protection against the disease. Thus, the majority of DENV vaccine candidates are designed to achieve protective titers of neutralizing antibodies, with less regard for cellular responses. Here, we used a mouse model to investigate CD8(+) T cell and humoral responses to a set of potential DENV vaccines based on recombinant modified vaccinia virus Ankara (rMVA). To enable this study, we identified two CD8(+) T cell epitopes in the DENV-3 E protein in C57BL/6 mice. Using these we found that all the rMVA vaccines elicited DENV-specific CD8(+) T cells that were cytotoxic in vivo and polyfunctional in vitro. Moreover, vaccines expressing the E protein with an intact signal peptide sequence elicited more DENV-specific CD8(+) T cells than those expressing E proteins in the cytoplasm. Significantly, it was these same ER-targeted E protein vaccines that elicited antibody responses. Our results support the further development of rMVA vaccines expressing DENV E proteins and add to the tools available for dengue vaccine development.

  7. A twin arginine signal peptide and the pH gradient trigger reversible assembly of the thylakoid [Delta]pH/Tat translocase.

    Science.gov (United States)

    Mori, Hiroki; Cline, Kenneth

    2002-04-15

    The thylakoid DeltapH-dependent/Tat pathway is a novel system with the remarkable ability to transport tightly folded precursor proteins using a transmembrane DeltapH as the sole energy source. Three known components of the transport machinery exist in two distinct subcomplexes. A cpTatC-Hcf106 complex serves as precursor receptor and a Tha4 complex is required after precursor recognition. Here we report that Tha4 assembles with cpTatC-Hcf106 during the translocation step. Interactions among components were examined by chemical cross-linking of intact thylakoids followed by immunoprecipitation and immunoblotting. cpTatC and Hcf106 were consistently associated under all conditions tested. In contrast, Tha4 was only associated with cpTatC and Hcf106 in the presence of a functional precursor and the DeltapH. Interestingly, a synthetic signal peptide could replace intact precursor in triggering assembly. The association of all three components was transient and dissipated upon the completion of protein translocation. Such an assembly-disassembly cycle could explain how the DeltapH/Tat system can assemble translocases to accommodate folded proteins of varied size. It also explains in part how the system can exist in the membrane without compromising its ion and proton permeability barrier.

  8. A conserved type IV pilin signal peptide H-domain is critical for the post-translational regulation of flagella-dependent motility.

    Science.gov (United States)

    Esquivel, Rianne N; Pohlschroder, Mechthild

    2014-08-01

    In many bacteria and archaea, type IV pili facilitate surface adhesion, the initial step in biofilm formation. Haloferax volcanii has a specific set of adhesion pilins (PilA1-A6) that, although diverse, contain an absolutely conserved signal peptide hydrophobic (H) domain. Data presented here demonstrate that these pilins (PilA1-A6) also play an important role in regulating flagella-dependent motility, which allows cells to rapidly transition between planktonic and sessile states. Cells lacking adhesion pilins exhibit a severe motility defect, however, expression of any one of the adhesion pilins in trans can rescue the motility and adhesion. Conversely, while deleting pilB3-C3, genes required for PilA pilus biosynthesis, results in cells lacking pili and having an adhesion defect, it does not affect motility, indicating that motility regulation requires the presence of pilins, but not assembled pili. Mutagenesis studies revealed that the pilin-dependent motility regulatory mechanism does not require the diverse C-terminal region of the PilA pilins but specifically involves the conserved H-domain. This novel post-translational regulatory mechanism, which employs components that promote biofilm formation to inhibit motility, can provide a rapid response to changing environmental conditions. A model for this regulatory mechanism, which may also be present in other prokaryotes, is discussed.

  9. Mouse Mammary Tumor Virus Signal Peptide Uses a Novel p97-Dependent and Derlin-Independent Retrotranslocation Mechanism To Escape Proteasomal Degradation

    Directory of Open Access Journals (Sweden)

    Hyewon Byun

    2017-03-01

    Full Text Available Multiple pathogens, including viruses and bacteria, manipulate endoplasmic reticulum-associated degradation (ERAD to avoid the host immune response and promote their replication. The betaretrovirus mouse mammary tumor virus (MMTV encodes Rem, which is a precursor protein that is cleaved into a 98-amino-acid signal peptide (SP and a C-terminal protein (Rem-CT. SP uses retrotranslocation for ER membrane extraction and yet avoids ERAD by an unknown mechanism to enter the nucleus and function as a Rev-like protein. To determine how SP escapes ERAD, we used a ubiquitin-activated interaction trap (UBAIT screen to trap and identify transient protein interactions with SP, including the ERAD-associated p97 ATPase, but not E3 ligases or Derlin proteins linked to retrotranslocation, polyubiquitylation, and proteasomal degradation of extracted proteins. A dominant negative p97 ATPase inhibited both Rem and SP function. Immunoprecipitation experiments indicated that Rem, but not SP, is polyubiquitylated. Using both yeast and mammalian expression systems, linkage of a ubiquitin-like domain (UbL to SP or Rem induced degradation by the proteasome, whereas SP was stable in the absence of the UbL. ERAD-associated Derlin proteins were not required for SP activity. Together, these results suggested that Rem uses a novel p97-dependent, Derlin-independent retrotranslocation mechanism distinct from other pathogens to avoid SP ubiquitylation and proteasomal degradation.

  10. Functional phytohemagglutinin (PHA) and Galanthus nivalis agglutinin (GNA) expressed in Pichia pastoris correct N-terminal processing and secretion of heterologous proteins expressed using the PHA-E signal peptide.

    Science.gov (United States)

    Raemaekers, R J; de Muro, L; Gatehouse, J A; Fordham-Skelton, A P

    1999-10-01

    Phytohemagglutinin (Phaseolus vulgaris agglutinin; PHA; E- and L-forms) and snowdrop lectin (Galanthus nivalis agglutinin; GNA) were expressed in Pichia pastoris using native signal peptides, or the Saccharomyces alpha-factor preprosequence, to direct proteins into the secretory pathway. PHA and GNA were present as soluble, functional proteins in culture supernatants when expressed from constructs containing the alpha-factor preprosequence. The recombinant lectins, purified by affinity chromatography, agglutinated rabbit erythrocytes at concentrations similar to the respective native lectins. However, incomplete processing of the signal sequence resulted in PHA-E, PHA-L and GNA with heterogenous N-termini, with the majority of the protein containing N-terminal extensions derived from the alpha-factor prosequence. Polypeptides in which most of the alpha-factor prosequence was present were also glycosylated. Inclusion of Glu-Ala repeats at the C-terminal end of the alpha-factor preprosequence led to efficient processing N-terminal to the Glu-Ala sequence, but inefficient removal of the repeats themselves, resulting in polypeptides with heterogenous N-termini still containing N-terminal extensions. In contrast, PHA expressed with the native signal peptide was secreted, correctly processed, and also fully functional. No expression of GNA from a construct containing the native GNA signal peptide was observed. The PHA-E signal peptide directed correct processing and secretion of both GNA and green fluorescent protein (GFP) when used in expression constructs, and is suggested to have general utility for synthesis of correctly processed proteins in Pichia.

  11. An essential role for (pppGpp in the integration of stress tolerance, peptide signaling and competence development in Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Justin Kaspar

    2016-07-01

    Full Text Available The microbes that inhabit the human oral cavity are subjected to constant fluctuations in their environment. To overcome these challenges and gain a competitive advantage, oral streptococci employ numerous adaptive strategies, many of which appear to be intertwined with the development of genetic competence. Here, we demonstrate that the regulatory circuits that control development of competence in Streptococcus mutans, a primary etiological agent of human dental caries, are integrated with key stress tolerance pathways by the molecular alarmone (pppGpp. We first observed that the growth of a strain that does not produce (pppGpp (ΔrelAPQ, (pppGpp0 is not sensitive to growth inhibition by comX inducing peptide (XIP, unlike the wild-type strain UA159, even though XIP-dependent activation of the alternative sigma factor comX by the ComRS pathway is not impaired in the (pppGpp0 strain. Overexpression of a (pppGpp synthase gene (relP in the (pppGpp0 mutant restored growth inhibition by XIP. We also demonstrate that exposure to micromolar concentrations of XIP elicited changes in (pppGpp accumulation in UA159. Loss of the RelA/SpoT homolog (RSH enzyme, RelA, lead to higher basal levels of (pppGpp accumulation, but to decreased sensitivity to XIP and to decreases in comR promoter activity and ComX protein levels. By introducing single amino acid substitutions into the RelA enzyme, the hydrolase activity of the enzyme was shown to be crucial for full com gene induction and transformation by XIP. Finally, loss of relA resulted in phenotypic changes to ΔrcrR mutants, highlighted by restoration of transformation and ComX protein production in the otherwise non-transformable ΔrcrR-NP mutant. Thus, RelA activity and its influence on (ppGpp pools appears to modulate competence signaling and development through RcrRPQ and the peptide effectors encoded within rcrQ. Collectively, this study provides new insights into the molecular mechanisms that integrate

  12. An Essential Role for (p)ppGpp in the Integration of Stress Tolerance, Peptide Signaling, and Competence Development in Streptococcus mutans.

    Science.gov (United States)

    Kaspar, Justin; Kim, Jeong N; Ahn, Sang-Joon; Burne, Robert A

    2016-01-01

    The microbes that inhabit the human oral cavity are subjected to constant fluctuations in their environment. To overcome these challenges and gain a competitive advantage, oral streptococci employ numerous adaptive strategies, many of which appear to be intertwined with the development of genetic competence. Here, we demonstrate that the regulatory circuits that control development of competence in Streptococcus mutans, a primary etiological agent of human dental caries, are integrated with key stress tolerance pathways by the molecular alarmone (p)ppGpp. We first observed that the growth of a strain that does not produce (p)ppGpp (ΔrelAPQ, (p)ppGpp(0)) is not sensitive to growth inhibition by comX inducing peptide (XIP), unlike the wild-type strain UA159, even though XIP-dependent activation of the alternative sigma factor comX by the ComRS pathway is not impaired in the (p)ppGpp(0) strain. Overexpression of a (p)ppGpp synthase gene (relP) in the (p)ppGpp(0) mutant restored growth inhibition by XIP. We also demonstrate that exposure to micromolar concentrations of XIP elicited changes in (p)ppGpp accumulation in UA159. Loss of the RelA/SpoT homolog (RSH) enzyme, RelA, lead to higher basal levels of (p)ppGpp accumulation, but to decreased sensitivity to XIP and to decreases in comR promoter activity and ComX protein levels. By introducing single amino acid substitutions into the RelA enzyme, the hydrolase activity of the enzyme was shown to be crucial for full com gene induction and transformation by XIP. Finally, loss of relA resulted in phenotypic changes to ΔrcrR mutants, highlighted by restoration of transformation and ComX protein production in the otherwise non-transformable ΔrcrR-NP mutant. Thus, RelA activity and its influence on (p)ppGpp pools appears to modulate competence signaling and development through RcrRPQ and the peptide effectors encoded within rcrQ. Collectively, this study provides new insights into the molecular mechanisms that integrate

  13. Elucidating the Specificity Determinants of the AtxE2 Lasso Peptide Isopeptidase*

    OpenAIRE

    Maksimov, Mikhail O.; Koos, Joseph D.; Zong, Chuhan; Lisko, Bozhena; Link, A. James

    2015-01-01

    Lasso peptide isopeptidase is an enzyme that specifically hydrolyzes the isopeptide bond of lasso peptides, rendering these peptides linear. To carry out a detailed structure-activity analysis of the lasso peptide isopeptidase AtxE2 from Asticcacaulis excentricus, we solved NMR structures of its substrates astexin-2 and astexin-3. Using in vitro enzyme assays, we show that the C-terminal tail portion of these peptides is dispensable with regards to isopeptidase activity. A collection of astex...

  14. Realistic Real-Time Outdoor Rendering in Augmented Reality

    Science.gov (United States)

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems. PMID:25268480

  15. Realistic real-time outdoor rendering in augmented reality.

    Science.gov (United States)

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  16. Method of producing hydrogen, and rendering a contaminated biomass inert

    Science.gov (United States)

    Bingham, Dennis N [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID

    2010-02-23

    A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

  17. Realistic real-time outdoor rendering in augmented reality.

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    Full Text Available Realistic rendering techniques of outdoor Augmented Reality (AR has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps. Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  18. 7 CFR 54.15 - Advance information concerning service rendered.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 54.15... Service § 54.15 Advance information concerning service rendered. Upon request of any applicant, all or any... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED)...

  19. Local and Global Illumination in the Volume Rendering Integral

    Energy Technology Data Exchange (ETDEWEB)

    Max, N; Chen, M

    2005-10-21

    This article is intended as an update of the major survey by Max [1] on optical models for direct volume rendering. It provides a brief overview of the subject scope covered by [1], and brings recent developments, such as new shadow algorithms and refraction rendering, into the perspective. In particular, we examine three fundamentals aspects of direct volume rendering, namely the volume rendering integral, local illumination models and global illumination models, in a wavelength-independent manner. We review the developments on spectral volume rendering, in which visible light are considered as a form of electromagnetic radiation, optical models are implemented in conjunction with representations of spectral power distribution. This survey can provide a basis for, and encourage, new efforts for developing and using complex illumination models to achieve better realism and perception through optical correctness.

  20. Research of global illumination algorithms rendering in glossy scene

    Institute of Scientific and Technical Information of China (English)

    BAI Shuangxue; ZHANG Qiang; ZHOU Dongsheng

    2012-01-01

    In computer graphic (CG), illumination rendering generated realistic effect at virtual scene is amazing. Not only plausible lighting effect is to show the relative position between of the objects, but also to reflect the material of visual appearance of the vir- tual objects. The diffuse-scene rendering reflectance credibility has gradually matured. Global illumination rendering method for the glossy material is still a challenge for the CG research. Because of the shiny materials is highly energy reflection between the com- plex light paths. Whether we trace glossy reflection paths, or use of one-reflection or multi-reflection approximate above complex il- lumination transmission is a difficult working. This paper we gather some commonly used global illumination algorithms recently year and its extension glossy scene improvements. And we introduce the limitation of classical algorithms rendering glossy scene and some extended solution. Finally, we will summarize the illumination rendering for specular scene, there are still some open prob- lems.

  1. Perception-based transparency optimization for direct volume rendering.

    Science.gov (United States)

    Chan, Ming-Yuen; Wu, Yingcai; Mak, Wai-Ho; Chen, Wei; Qu, Huamin

    2009-01-01

    The semi-transparent nature of direct volume rendered images is useful to depict layered structures in a volume. However, obtaining a semi-transparent result with the layers clearly revealed is difficult and may involve tedious adjustment on opacity and other rendering parameters. Furthermore, the visual quality of layers also depends on various perceptual factors. In this paper, we propose an auto-correction method for enhancing the perceived quality of the semi-transparent layers in direct volume rendered images. We introduce a suite of new measures based on psychological principles to evaluate the perceptual quality of transparent structures in the rendered images. By optimizing rendering parameters within an adaptive and intuitive user interaction process, the quality of the images is enhanced such that specific user requirements can be met. Experimental results on various datasets demonstrate the effectiveness and robustness of our method.

  2. A Volume Rendering Algorithm for Sequential 2D Medical Images

    Institute of Scientific and Technical Information of China (English)

    吕忆松; 陈亚珠

    2002-01-01

    Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics.To help physicians fully understand deep-seated human organs and focuses(e.g.a tumour)as 3D structures.in this paper,we present a modified volume rendering algorithm to render volumetric data,Using this method.the projection images of structures of interest from different viewing directions can be obtained satisfactorily.By rotating the light source and the observer eyepoint,this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time.Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.

  3. Kefir peptides prevent high-fructose corn syrup-induced non-alcoholic fatty liver disease in a murine model by modulation of inflammation and the JAK2 signaling pathway.

    Science.gov (United States)

    Chen, H L; Tsai, T C; Tsai, Y C; Liao, J W; Yen, C C; Chen, C M

    2016-12-12

    of fatty liver by activating JAK2 signal transduction through the JAK2/STAT3 and JAK2/AMPK pathways in the high-fructose-induced fatty liver animal model. Therefore, kefir peptides may have the potential for clinical application for the prevention or treatment of clinical metabolic syndrome.

  4. HLA-E: strong association with beta2-microglobulin and surface expression in the absence of HLA class I signal sequence-derived peptides.

    Science.gov (United States)

    Lo Monaco, Elisa; Sibilio, Leonardo; Melucci, Elisa; Tremante, Elisa; Suchànek, Miloslav; Horejsi, Vaclav; Martayan, Aline; Giacomini, Patrizio

    2008-10-15

    The nonclassical class I HLA-E molecule folds in the presence of peptide ligands donated by the signal sequences of permissive class I HLA alleles, with the aid of TAP and tapasin. To identify HLA-E-specific Abs, four monoclonals of the previously described MEM series were screened by isoelectric focusing (IEF) blot and immunoprecipitation/IEF on >30 single-allele class I transfectants and HLA-homozygous B lymphoid cells coexpressing HLA-E and HLA-A, -B, -C, -F, or -G. Despite their HLA-E-restricted reactivity patterns (MEM-E/02 in IEF blot; MEM-E/07 and MEM-E/08 in immunoprecipitation), all of the MEM Abs unexpectedly reacted with beta(2)-microglobulin (beta(2)m)-free and denatured (but not beta(2)m-associated and folded) HLA-E H chains. Remarkably, other HLA-E-restricted Abs were also reactive with free H chains. Immunodepletion, in vitro assembly, flow cytometry, and three distinct surface-labeling methods, including a modified (conformation-independent) biotin-labeling assay, revealed the coexistence of HLA-E conformers with unusual and drastically antithetic features. MEM-reactive conformers were thermally unstable and poorly surface expressed, as expected, whereas beta(2)m-associated conformers were either unstable and weakly reactive with the prototypic conformational Ab W6/32, or exceptionally stable and strongly reactive with Abs to beta(2)m even in cells lacking permissive alleles (721.221), TAP (T2), or tapasin (721.220). Noncanonical, immature (endoglycosidase H-sensitive) HLA-E glycoforms were surface expressed in these cells, whereas mature glycoforms were exclusively expressed (and at much lower levels) in cells carrying permissive alleles. Thus, HLA-E is a good, and not a poor, beta(2)m assembler, and TAP/tapasin-assisted ligand donation is only one, and possibly not even the major, pathway leading to its stabilization and surface expression.

  5. Signal peptide peptidase-mediated nuclear localization of heme oxygenase-1 promotes cancer cell proliferation and invasion independent of its enzymatic activity.

    Science.gov (United States)

    Hsu, F-F; Yeh, C-T; Sun, Y-J; Chiang, M-T; Lan, W-M; Li, F-A; Lee, W-H; Chau, L-Y

    2015-04-30

    Heme oxygenase-1 (HO-1) is a heme-degrading enzyme anchored in the endoplasmic reticulum by a carboxyl-terminal transmembrane segment (TMS). HO-1 is highly expressed in various cancers and its nuclear localization is associated with the progression of some cancers. Nevertheless, the mechanism underlying HO-1 nuclear translocation and its pathological significance remain elusive. Here we show that the signal peptide peptidase (SPP) catalyzes the intramembrane cleavage of HO-1. Coexpression of HO-1 with wild-type SPP, but not a dominant-negative SPP, promoted the nuclear localization of HO-1 in cells. Mass spectrometry analysis of cytosolic HO-1 isolated from HeLa cells overexpressing HO-1 and SPP revealed two adjacent intramembrane cleavage sites located after S275 and F276 within the TMS. Mutations of S275F276 to A275L276 significantly hindered SPP-mediated HO-1 cleavage and nuclear localization. Nuclear HO-1 was detected in A549 and DU145 cancer cell lines expressing high levels of endogenous HO-1 and SPP. SPP knockdown or inhibition significantly reduced nuclear HO-1 localization in A549 and DU145 cells. The positive nuclear HO-1 stain was also evident in lung cancer tissues expressing high levels of HO-1 and SPP. Overexpression of a truncated HO-1 (t-HO-1) lacking the TMS in HeLa and H1299 cells promoted cell proliferation and migration/invasion. The effect of t-HO-1 was not affected by a mutation in the catalytic site. However, blockade of t-HO-1 nuclear localization abolished t-HO-1-mediated effect. The tumorigenic effect of t-HO-1 was also demonstrated in the mouse model. These findings disclose that SPP-mediated intramembrane cleavage of HO-1 promotes HO-1 nuclear localization and cancer progression independent of HO-1 enzymatic activity.

  6. Can signal peptide-CUB-EGF domain-containing protein (SCUBE) levels be a marker of angiogenesis in patients with psoriasis?

    Science.gov (United States)

    Capkin, Arzu Aydın; Demir, Selim; Mentese, Ahmet; Bulut, Çağlar; Ayar, Ahmet

    2017-04-01

    Angiogenesis is an important process being involved in the pathogenesis of psoriasis and promises new potential parameter for diagnosis and screening of treatment. This study investigated the levels of signal peptide-CUB-EGF (epidermal growth factor-like protein) family domain-containing protein (SCUBE) 1 and 3. Potential value as a novel marker of angiogenesis in patients with psoriasis is also evaluated by assessing possible relation of SCUBE-1 and 3 with disease activity in conjunction with vascular endothelial growth factor (VEGF) levels, as an established marker of angiogenesis. Forty-eight patients with psoriasis (aged >18 years) and 48 age- and gender-matched healthy controls were included. Detailed information was obtained through history and physical examination. Psoriasis area and severity index (PASI) scores were calculated. Blood SCUBE 1 and 3, and VEGF levels were measured by enzyme-linked immunosorbent assay. The mean PASI score of the patients was 6.7 ± 4.1. Patients' serum SCUBE 1 and 3 and VEGF levels were significantly higher than those of the controls (P = 0.001). The sensitivity and specificity were calculated as 83 and 62% for the 0.67 ng/ml cut-off level of SCUBE 1, and 63 and 71% for the 2.57 ng/ml cut-off level of SCUBE 3, respectively. A cut-off VEGF level of 310 ng/mL predicted the presence of psoriasis with a sensitivity of 50% and specificity of 77%. The results of this pioneering study indicate that SCUBE protein family appears to have a probable role in the pathogenesis and angiogenesis development in psoriasis and SCUBE 1 and 3 may be novel markers of angiogenesis in psoriasis.

  7. Effect of calcitonin gene related peptide regulated nuclear factor kappa B signal transduction on c-kit+ cardiac stem cells in hypoxia state

    Directory of Open Access Journals (Sweden)

    Xian-ping LONG

    2015-11-01

    Full Text Available Objective To investigate the effects of calcitonin gene-related peptide (CGRP on the apoptosis of c-kit+ cardiac stem cells in hypoxia. Methods Ischemia and hypoxia models of c-kit+ cardiac stem cells were reproduced in vitro. The models were divided into hypoxia+CGRP group, hypoxia+CGRP8-37 (antagonist of CGRP group, hypoxia control group, normal oxygen group, and hypoxia+BAY11-7082 [antagonist of nuclear factor kappa B (NF-κB] group. NF-κB translocation after hypoxia was detected by immunofluorescence, and NF-κB channel proteins were determined with Western blotting. The NF-κB translocation and the expression of NF-κB channel proteins after CGRP intervention were detected, and the cell apoptosis rate after intervention was determined with flow cytometry in each group. Results Under hypoxia the NF-κB signal pathway was activated, and nuclear translocation occurred in NF-κBP65 (red fluorescence. Compared with hypoxia control group, the expressions of NF-κB related proteins such as P-I-κB, NF-κBP65 and NF-κBP50 decreased obviously (P<0.05. Compared with the hypoxia+CGRP group, the expressions of NF-κB related proteins increased significantly (P<0.05 as mentioned above in hypoxia+CGRP8-37 group. Both the early and late apoptotic rates declined in hypoxia+CGRP group compared with that of hypoxia control group (P<0.05, however, the early apoptotic rate increased markedly in hypoxia+CGRP8-37 group as compared with that of hypoxia+CGRP group (P<0.05. Conclusion Under hypoxia, CGRP may regulate the NF-κB signal pathway, and at the same time suppress the apoptosis of c-kit+ cardiac stem cells. DOI: 10.11855/j.issn.0577-7402.2015.10.03

  8. Antitumor Peptides from Marine Organisms

    Directory of Open Access Journals (Sweden)

    Mi Sun

    2011-10-01

    Full Text Available The biodiversity of the marine environment and the associated chemical diversity constitute a practically unlimited resource of new antitumor agents in the field of the development of marine bioactive substances. In this review, the progress on studies of antitumor peptides from marine sources is provided. The biological properties and mechanisms of action of different marine peptides are described; information about their molecular diversity is also presented. Novel peptides that induce apoptosis signal pathway, affect the tubulin-microtubule equilibrium and inhibit angiogenesis are presented in association with their pharmacological properties. It is intended to provide useful information for further research in the fields of marine antitumor peptides.

  9. Multiresolution maximum intensity volume rendering by morphological adjunction pyramids

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D

  10. Multiresolution Maximum Intensity Volume Rendering by Morphological Adjunction Pyramids

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2001-01-01

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D

  11. Foggy Scene Rendering Based on Transmission Map Estimation

    Directory of Open Access Journals (Sweden)

    Fan Guo

    2014-01-01

    Full Text Available Realistic rendering of foggy scene is important in game development and virtual reality. Traditional methods have many parameters to control or require a long time to compute, and they are usually limited to depicting a homogeneous fog without considering the foggy scene with heterogeneous fog. In this paper, a new rendering method based on transmission map estimation is proposed. We first generate perlin noise image as the density distribution texture of heterogeneous fog. Then we estimate the transmission map using the Markov random field (MRF model and the bilateral filter. Finally, virtual foggy scene is realistically rendered with the generated perlin noise image and the transmission map according to the atmospheric scattering model. Experimental results show that the rendered results of our approach are quite satisfactory.

  12. Comparison of Morphological Pyramids for Multiresolution MIP Volume Rendering

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2002-01-01

    We recently proposed a multiresolution representation for maximum intensity projection (MIP) volume rendering based on morphological adjunction pyramids which allow progressive refinement and have the property of perfect reconstruction. In this algorithm the pyramidal analysis and synthesis

  13. Experiencing "Macbeth": From Text Rendering to Multicultural Performance.

    Science.gov (United States)

    Reisin, Gail

    1993-01-01

    Shows how one teacher used innovative methods in teaching William Shakespeare's "Macbeth." Outlines student assignments including text renderings, rewriting a scene from the play, and creating a multicultural scrapbook for the play. (HB)

  14. View compensated compression of volume rendered images for remote visualization.

    Science.gov (United States)

    Lalgudi, Hariharan G; Marcellin, Michael W; Bilgin, Ali; Oh, Han; Nadar, Mariappan S

    2009-07-01

    Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images from a server, based on viewpoint requests from a client. For constrained server-client bandwidth, an efficient compression scheme is vital for transmitting high quality rendered images. In this paper, we present a new view compensation scheme that utilizes the geometric relationship between viewpoints to exploit the correlation between successive rendered images. The proposed method obviates motion estimation between rendered images, enabling significant reduction to the complexity of a compressor. Additionally, the view compensation scheme, in conjunction with JPEG2000 performs better than AVC, the state of the art video compression standard.

  15. High-quality multi-resolution volume rendering in medicine

    Institute of Scientific and Technical Information of China (English)

    XIE Kai; YANG Jie; LI Xiao-liang

    2007-01-01

    In order to perform a high-quality interactive rendering of large medical data sets on a single off-theshelf PC, a LOD selection algorithm for multi-resolution volume rendering using 3D texture mapping is presented, which uses an adaptive scheme that renders the volume in a region-of-interest at a high resolution and the volume away from this region at lower resolutions. The algorithm is based on several important criteria, and rendering is done adaptively by selecting high-resolution cells close to a center of attention and low-resolution cells away from this area. In addition, our hierarchical level-of-detail representation guarantees consistent interpolation between different resolution levels. Experiments have been applied to a number of large medical data and have produced high quality images at interactive frame rates using standard PC hardware.

  16. Factors affecting extension workers in their rendering of effective ...

    African Journals Online (AJOL)

    Factors affecting extension workers in their rendering of effective service to pre ... the objective of achieving sustainable livelihoods for the poor and commonages. ... marketing and management to adequately service the land reform programs.

  17. does knowledge influence their attitude and comfort in rendering care?

    African Journals Online (AJOL)

    kemrilib

    Physicians and AIDS care: does knowledge influence their attitude and comfort in rendering ... experience, age and being a consultant or a senior resident influenced attitude, while male ..... having or not having children, prior instructions on ...

  18. Accelerating Monte Carlo Renderers by Ray Histogram Fusion

    Directory of Open Access Journals (Sweden)

    Mauricio Delbracio

    2015-03-01

    Full Text Available This paper details the recently introduced Ray Histogram Fusion (RHF filter for accelerating Monte Carlo renderers [M. Delbracio et al., Boosting Monte Carlo Rendering by Ray Histogram Fusion, ACM Transactions on Graphics, 33 (2014]. In this filter, each pixel in the image is characterized by the colors of the rays that reach its surface. Pixels are compared using a statistical distance on the associated ray color distributions. Based on this distance, it decides whether two pixels can share their rays or not. The RHF filter is consistent: as the number of samples increases, more evidence is required to average two pixels. The algorithm provides a significant gain in PSNR, or equivalently accelerates the rendering process by using many fewer Monte Carlo samples without observable bias. Since the RHF filter depends only on the Monte Carlo samples color values, it can be naturally combined with all rendering effects.

  19. Diverse CLE peptides from cyst nematode species

    Science.gov (United States)

    Plant CLAVATA3/ESR (CLE)-like peptides play diverse roles in plant growth and development including maintenance of the stem cell population in the root meristem. Small secreted peptides sharing similarity to plant CLE signaling peptides have been isolated from several cyst nematode species including...

  20. A parallel architecture for interactively rendering scattering and refraction effects.

    Science.gov (United States)

    Bernabei, Daniele; Hakke-Patil, Ajit; Banterle, Francesco; Di Benedetto, Marco; Ganovelli, Fabio; Pattanaik, Sumanta; Scopigno, Roberto

    2012-01-01

    A new method for interactive rendering of complex lighting effects combines two algorithms. The first performs accurate ray tracing in heterogeneous refractive media to compute high-frequency phenomena. The second applies lattice-Boltzmann lighting to account for low-frequency multiple-scattering effects. The two algorithms execute in parallel on modern graphics hardware. This article includes a video animation of the authors' real-time algorithm rendering a variety of scenes.

  1. Wavelet subdivision methods gems for rendering curves and surfaces

    CERN Document Server

    Chui, Charles

    2010-01-01

    OVERVIEW Curve representation and drawing Free-form parametric curves From subdivision to basis functions Wavelet subdivision and editing Surface subdivision BASIS FUNCTIONS FOR CURVE REPRESENTATION Refinability and scaling functions Generation of smooth basis functions Cardinal B-splines Stable bases for integer-shift spaces Splines and polynomial reproduction CURVE SUBDIVISION SCHEMES Subdivision matrices and stencils B-spline subdivision schemes Closed curve rendering Open curve rendering BASIS FUNCTIONS GENERATED BY SUBDIVISION MATRICES Subdivision operators The up-sampling convolution ope

  2. Predicting Secretory Proteins with SignalP

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2017-01-01

    SignalP is the currently most widely used program for prediction of signal peptides from amino acid sequences. Proteins with signal peptides are targeted to the secretory pathway, but are not necessarily secreted. After a brief introduction to the biology of signal peptides and the history...

  3. A Sort-Last Rendering System over an Optical Backplane

    Directory of Open Access Journals (Sweden)

    Yasuhiro Kirihata

    2005-06-01

    Full Text Available Sort-Last is a computer graphics technique for rendering extremely large data sets on clusters of computers. Sort-Last works by dividing the data set into even-sized chunks for parallel rendering and then composing the images to form the final result. Since sort-last rendering requires the movement of large amounts of image data among cluster nodes, the network interconnecting the nodes becomes a major bottleneck. In this paper, we describe a sort-last rendering system implemented on a cluster of computers whose nodes are connected by an all-optical switch. The rendering system introduces the notion of the Photonic Computing Engine, a computing system built dynamically by using the optical switch to create dedicated network connections among cluster nodes. The sort-last volume rendering algorithm was implemented on the Photonic Computing Engine, and its performance is evaluated. Prelimi- nary experiments show that performance is affected by the image composition time and average payload size. In an attempt to stabilize the performance of the system, we have designed a flow control mechanism that uses feedback messages to dynamically adjust the data flow rate within the computing engine.

  4. Remote volume rendering pipeline for mHealth applications

    Science.gov (United States)

    Gutenko, Ievgeniia; Petkov, Kaloian; Papadopoulos, Charilaos; Zhao, Xin; Park, Ji Hwan; Kaufman, Arie; Cha, Ronald

    2014-03-01

    We introduce a novel remote volume rendering pipeline for medical visualization targeted for mHealth (mobile health) applications. The necessity of such a pipeline stems from the large size of the medical imaging data produced by current CT and MRI scanners with respect to the complexity of the volumetric rendering algorithms. For example, the resolution of typical CT Angiography (CTA) data easily reaches 512^3 voxels and can exceed 6 gigabytes in size by spanning over the time domain while capturing a beating heart. This explosion in data size makes data transfers to mobile devices challenging, and even when the transfer problem is resolved the rendering performance of the device still remains a bottleneck. To deal with this issue, we propose a thin-client architecture, where the entirety of the data resides on a remote server where the image is rendered and then streamed to the client mobile device. We utilize the display and interaction capabilities of the mobile device, while performing interactive volume rendering on a server capable of handling large datasets. Specifically, upon user interaction the volume is rendered on the server and encoded into an H.264 video stream. H.264 is ubiquitously hardware accelerated, resulting in faster compression and lower power requirements. The choice of low-latency CPU- and GPU-based encoders is particularly important in enabling the interactive nature of our system. We demonstrate a prototype of our framework using various medical datasets on commodity tablet devices.

  5. Fast DRR splat rendering using common consumer graphics hardware.

    Science.gov (United States)

    Spoerk, Jakob; Bergmann, Helmar; Wanschitz, Felix; Dong, Shuo; Birkfellner, Wolfgang

    2007-11-01

    Digitally rendered radiographs (DRR) are a vital part of various medical image processing applications such as 2D/3D registration for patient pose determination in image-guided radiotherapy procedures. This paper presents a technique to accelerate DRR creation by using conventional graphics hardware for the rendering process. DRR computation itself is done by an efficient volume rendering method named wobbled splatting. For programming the graphics hardware, NVIDIAs C for Graphics (Cg) is used. The description of an algorithm used for rendering DRRs on the graphics hardware is presented, together with a benchmark comparing this technique to a CPU-based wobbled splatting program. Results show a reduction of rendering time by about 70%-90% depending on the amount of data. For instance, rendering a volume of 2 x 10(6) voxels is feasible at an update rate of 38 Hz compared to 6 Hz on a common Intel-based PC using the graphics processing unit (GPU) of a conventional graphics adapter. In addition, wobbled splatting using graphics hardware for DRR computation provides higher resolution DRRs with comparable image quality due to special processing characteristics of the GPU. We conclude that DRR generation on common graphics hardware using the freely available Cg environment is a major step toward 2D/3D registration in clinical routine.

  6. Small-Molecule Fusion Inhibitors Bind the pH-Sensing Stable Signal Peptide-GP2 Subunit Interface of the Lassa Virus Envelope Glycoprotein

    Science.gov (United States)

    Shankar, Sundaresh; Whitby, Landon R.; Casquilho-Gray, Hedi E.; York, Joanne; Boger, Dale L.

    2016-01-01

    ABSTRACT Arenavirus species are responsible for severe life-threatening hemorrhagic fevers in western Africa and South America. Without effective antiviral therapies or vaccines, these viruses pose serious public health and biodefense concerns. Chemically distinct small-molecule inhibitors of arenavirus entry have recently been identified and shown to act on the arenavirus envelope glycoprotein (GPC) to prevent membrane fusion. In the tripartite GPC complex, pH-dependent membrane fusion is triggered through a poorly understood interaction between the stable signal peptide (SSP) and the transmembrane fusion subunit GP2, and our genetic studies have suggested that these small-molecule inhibitors act at this interface to antagonize fusion activation. Here, we have designed and synthesized photoaffinity derivatives of the 4-acyl-1,6-dialkylpiperazin-2-one class of fusion inhibitors and demonstrate specific labeling of both the SSP and GP2 subunits in a native-like Lassa virus (LASV) GPC trimer expressed in insect cells. Photoaddition is competed by the parental inhibitor and other chemically distinct compounds active against LASV, but not those specific to New World arenaviruses. These studies provide direct physical evidence that these inhibitors bind at the SSP-GP2 interface. We also find that GPC containing the uncleaved GP1-GP2 precursor is not susceptible to photo-cross-linking, suggesting that proteolytic maturation is accompanied by conformational changes at this site. Detailed mapping of residues modified by the photoaffinity adducts may provide insight to guide the further development of these promising lead compounds as potential therapeutic agents to treat Lassa hemorrhagic fever. IMPORTANCE Hemorrhagic fever arenaviruses cause lethal infections in humans and, in the absence of licensed vaccines or specific antiviral therapies, are recognized to pose significant threats to public health and biodefense. Lead small-molecule inhibitors that target the

  7. Intracellular peptides: From discovery to function

    Directory of Open Access Journals (Sweden)

    Emer S. Ferro

    2014-06-01

    Full Text Available Peptidomics techniques have identified hundreds of peptides that are derived from proteins present mainly in the cytosol, mitochondria, and/or nucleus; these are termed intracellular peptides to distinguish them from secretory pathway peptides that function primarily outside of the cell. The proteasome and thimet oligopeptidase participate in the production and metabolism of intracellular peptides. Many of the intracellular peptides are common among mouse tissues and human cell lines analyzed and likely to perform a variety of functions within cells. Demonstrated functions include the modulation of signal transduction, mitochondrial stress, and development; additional functions will likely be found for intracellular peptides.

  8. Enhancement of peptide immunogenicity by linear polymerization.

    Science.gov (United States)

    Borras-Cuesta, F; Fedon, Y; Petit-Camurdan, A

    1988-02-01

    The effect of linear homopolymerization on the immunogenicity of synthetic peptides was studied using either haptenic peptides (representing amino acid sequences 103-115 and 133-147 of bovine rotavirus major protein) or immunogenic peptides TD-103-115 and TD-133-147 which were constructed by co-linear synthesis of the former peptides and an amino acid sequence representing a determinant recognized by T helper cells (TD). It was found that the two haptenic peptides were rendered immunogenic by linear homopolymerization. Moreover, homopolymerization also enhanced the immunogenicity of TD-103-115 but not that of TD-133-147. In the three cases where polymerization enhanced immunogenicity, a reinforced amphipathic pattern was predicted in the neighborhood of the junction of the monomers. The possibility that polymerization might have generated a new T cell determinant is discussed.

  9. An innovative calibration based integral photography rendering algorithm for medical application and its evaluation.

    Science.gov (United States)

    Chen, Guowen; Zhang, Xinran; Fan, Zhencheng; Liao, Hongen

    2015-01-01

    Autostereoscopic has long been proposed to fulfill medical display in image-guided surgery and clinical education to provide more intuitive position information of clinical interest zone thus improving surgery safety and accuracy. As one category of flexible autostereoscopic 3D display, computer generated integral photography (CGIP) has been studied in medical application by many researches for its convenience and cost-efficiency. However, IP still suffers from inaccurate light field reconstruction, which limits its practicality in surgery. In this paper, we propose and apply a flexible fish-eye model based micro lens array (MLA) distortion calibration method and pre-distorted retracing rendering algorithm to render elemental image array (EIA) of CGIP. Furthermore, we also evaluate light field of the proposed algorithm in depth cue, and signal noise ratio of IP images by phantom experiment.

  10. [C-peptide physiological effects].

    Science.gov (United States)

    Shpakov, A O; Granstrem, O K

    2013-02-01

    In the recent years there were numerous evidences that C-peptide, which was previously considered as a product of insulin biosynthesis, is one of the key regulators of physiological processes. C-peptide via heterotrimeric G(i/o) protein-coupled receptors activates a wide range of intracellular effector proteins and transcription factors and, thus, controls the inflammatory and neurotrophic processes, pain sensitivity, cognitive function, macro- and microcirculation, glomerular filtration. These effects of C-peptide are mainly expressed in its absolute or relative deficiency occurred in type 1 diabetes mellitus and they are less pronounced when the level of C-peptide is close to normal. Replacement therapy with C-peptide prevents many complications of type 1 diabetes, such as atherosclerosis, diabetic peripheral neuropathy, and nephropathy. C-peptide interacts with the insulin hexamer complexes and induces their dissociation and, as a result, regulates the functional activity of the insulin signaling system. At the same time, C-peptide at the concentrations above physiological may demonstrate pro-inflammatory effects on the endothelial cells and cause atherosclerotic changes in the vessels, which should be considered in the study of pathogenic mechanisms of complications of type 2 diabetes mellitus, where the level of C peptide is increased, as well as in the development of approaches for C-peptide application in clinic. This review is devoted contemporary achievements and unsolved problems in the study of C-peptide, as an important regulator of physiological and biochemical processes.

  11. Adaptive image contrast enhancement algorithm for point-based rendering

    Science.gov (United States)

    Xu, Shaoping; Liu, Xiaoping P.

    2015-03-01

    Surgical simulation is a major application in computer graphics and virtual reality, and most of the existing work indicates that interactive real-time cutting simulation of soft tissue is a fundamental but challenging research problem in virtual surgery simulation systems. More specifically, it is difficult to achieve a fast enough graphic update rate (at least 30 Hz) on commodity PC hardware by utilizing traditional triangle-based rendering algorithms. In recent years, point-based rendering (PBR) has been shown to offer the potential to outperform the traditional triangle-based rendering in speed when it is applied to highly complex soft tissue cutting models. Nevertheless, the PBR algorithms are still limited in visual quality due to inherent contrast distortion. We propose an adaptive image contrast enhancement algorithm as a postprocessing module for PBR, providing high visual rendering quality as well as acceptable rendering efficiency. Our approach is based on a perceptible image quality technique with automatic parameter selection, resulting in a visual quality comparable to existing conventional PBR algorithms. Experimental results show that our adaptive image contrast enhancement algorithm produces encouraging results both visually and numerically compared to representative algorithms, and experiments conducted on the latest hardware demonstrate that the proposed PBR framework with the postprocessing module is superior to the conventional PBR algorithm and that the proposed contrast enhancement algorithm can be utilized in (or compatible with) various variants of the conventional PBR algorithm.

  12. Bioactive Peptides

    Directory of Open Access Journals (Sweden)

    Eric Banan-Mwine Daliri

    2017-04-01

    Full Text Available The increased consumer awareness of the health promoting effects of functional foods and nutraceuticals is the driving force of the functional food and nutraceutical market. Bioactive peptides are known for their high tissue affinity, specificity and efficiency in promoting health. For this reason, the search for food-derived bioactive peptides has increased exponentially. Over the years, many potential bioactive peptides from food have been documented; yet, obstacles such as the need to establish optimal conditions for industrial scale production and the absence of well-designed clinical trials to provide robust evidence for proving health claims continue to exist. Other important factors such as the possibility of allergenicity, cytotoxicity and the stability of the peptides during gastrointestinal digestion would need to be addressed. This review discusses our current knowledge on the health effects of food-derived bioactive peptides, their processing methods and challenges in their development.

  13. Bioactive Peptides.

    Science.gov (United States)

    Daliri, Eric Banan-Mwine; Oh, Deog H; Lee, Byong H

    2017-04-26

    The increased consumer awareness of the health promoting effects of functional foods and nutraceuticals is the driving force of the functional food and nutraceutical market. Bioactive peptides are known for their high tissue affinity, specificity and efficiency in promoting health. For this reason, the search for food-derived bioactive peptides has increased exponentially. Over the years, many potential bioactive peptides from food have been documented; yet, obstacles such as the need to establish optimal conditions for industrial scale production and the absence of well-designed clinical trials to provide robust evidence for proving health claims continue to exist. Other important factors such as the possibility of allergenicity, cytotoxicity and the stability of the peptides during gastrointestinal digestion would need to be addressed. This review discusses our current knowledge on the health effects of food-derived bioactive peptides, their processing methods and challenges in their development.

  14. Prorenin and renin-induced extracellular signal-regulated kinase 1/2 activation in monocytes is not blocked by aliskiren or the handle-region peptide

    NARCIS (Netherlands)

    S. Feldt (Sandra); W.W. Batenburg (Wendy); I. Mazak (Istvan); U. Maschke (Ulrike); M. Wellner (Maren); H. Kvakan (Heda); R. Dechend (Ralf); A. Fiebeler (Anette); C. Burckle (Celine); A. Contrepas (Aurelie); A.H.J. Danser (Jan); M. Bader (Michael); G. Nguyen (Genevieve); F.C. Luft (Friedrich); D. Müller (Dominik)

    2008-01-01

    textabstractThe recently cloned (pro)renin receptor [(P)RR] mediates renin-stimulated cellular effects by activating mitogen-activated protein kinases and promotes nonproteolytic prorenin activation. In vivo, (P)RR is said to be blocked with a peptide consisting of 10 amino acids from the prorenin p

  15. Clustered deep shadow maps for integrated polyhedral and volume rendering

    KAUST Repository

    Bornik, Alexander

    2012-01-01

    This paper presents a hardware-accelerated approach for shadow computation in scenes containing both complex volumetric objects and polyhedral models. Our system is the first hardware accelerated complete implementation of deep shadow maps, which unifies the computation of volumetric and geometric shadows. Up to now such unified computation was limited to software-only rendering . Previous hardware accelerated techniques can handle only geometric or only volumetric scenes - both resulting in the loss of important properties of the original concept. Our approach supports interactive rendering of polyhedrally bounded volumetric objects on the GPU based on ray casting. The ray casting can be conveniently used for both the shadow map computation and the rendering. We show how anti-aliased high-quality shadows are feasible in scenes composed of multiple overlapping translucent objects, and how sparse scenes can be handled efficiently using clustered deep shadow maps. © 2012 Springer-Verlag.

  16. Real-Time Rendering of Teeth with No Preprocessing

    DEFF Research Database (Denmark)

    Larsen, Christian Thode; Frisvad, Jeppe Revall; Jensen, Peter Dahl Ejby

    2012-01-01

    We present a technique for real-time rendering of teeth with no need for computational or artistic preprocessing. Teeth constitute a translucent material consisting of several layers; a highly scattering material (dentine) beneath a semitransparent layer (enamel) with a transparent coating (saliva......). In this study we examine how light interacts with this multilayered structure. In the past, rendering of teeth has mostly been done using image-based texturing or volumetric scans. We work with surface scans and have therefore developed a simple way of estimating layer thicknesses. We use scattering properties...... based on measurements reported in the optics literature, and we compare rendered results qualitatively to images of ceramic teeth created by denturists....

  17. [A hybrid volume rendering method using general hardware].

    Science.gov (United States)

    Li, Bin; Tian, Lianfang; Chen, Ping; Mao, Zongyuan

    2008-06-01

    In order to improve the effect and efficiency of the reconstructed image after hybrid volume rendering of different kinds of volume data from medical sequential slices or polygonal models, we propose a hybrid volume rendering method based on Shear-Warp with economical hardware. First, the hybrid volume data are pre-processed by Z-Buffer method and RLE (Run-Length Encoded) data structure. Then, during the process of compositing intermediate image, a resampling method based on the dual-interpolation and the intermediate slice interpolation methods is used to improve the efficiency and the effect. Finally, the reconstructed image is rendered by the texture-mapping technology of OpenGL. Experiments demonstrate the good performance of the proposed method.

  18. Universal Rendering Mechanism Supporting Dual-Mode Presentation

    Institute of Scientific and Technical Information of China (English)

    徐鹏; 杨文军; 王克宏

    2003-01-01

    XML is a standard for the exchange of business data that is completely platform and vendor neutral. Because XML data comes in many forms, one of the most important technologies needed for XML applications is the ability to convert the data into visible renderings. This paper focuses on the rendering of XML/XSL documents into a readable and printable format by means of a platform-independent process that enables high-quality printing of the product. This paper introduces the core components in the data rendering engine, the X2P server and different levels of object abstraction. The design pattern and the complete formatting and representation of the XSL stylesheet into different types of output formats in the X2P server are also given. The results show that the X2P sever simultaneously constructs the formatting object tree and the area tree in a very efficient design that saves execution time and memory.

  19. Virtual try-on through image-based rendering.

    Science.gov (United States)

    Hauswiesner, Stefan; Straka, Matthias; Reitmayr, Gerhard

    2013-09-01

    Virtual try-on applications have become popular because they allow users to watch themselves wearing different clothes without the effort of changing them physically. This helps users to make quick buying decisions and, thus, improves the sales efficiency of retailers. Previous solutions usually involve motion capture, 3D reconstruction or modeling, which are time consuming and not robust for all body poses. Our method avoids these steps by combining image-based renderings of the user and previously recorded garments. It transfers the appearance of a garment recorded from one user to another by matching input and recorded frames, image-based visual hull rendering, and online registration methods. Using images of real garments allows for a realistic rendering quality with high performance. It is suitable for a wide range of clothes and complex appearances, allows arbitrary viewing angles, and requires only little manual input. Our system is particularly useful for virtual try-on applications as well as interactive games.

  20. Efficient rendering of breaking waves using MPS method

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; ZHENG Yao; CHEN Chun; FUJIMOTO Tadahiro; CHIBA Norishige

    2006-01-01

    This paper proposes an approach for rendering breaking waves out of large-scale ofparticle-based simulation. Moving particle semi-implicit (MPS) is used to solve the governing equation, and 2D simulation is expanded to 3D representation by giving motion variation using fractional Brownian motion (fBm). The waterbody surface is reconstructed from the outlines of 2D simulation. The splashing effect is computed according to the properties of the particles. Realistic features of the wave are rendered on GPU, including the reflective and refractive effect and the effect of splash. Experiments showed that the proposed method can simulate large scale breaking waves efficiently.

  1. Beaming teaching application: recording techniques for spatial xylophone sound rendering

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Olesen, Søren Krarup;

    2012-01-01

    BEAMING is a telepresence research project aiming at providing a multimodal interaction between two or more participants located at distant locations. One of the BEAMING applications allows a distant teacher to give a xylophone playing lecture to the students. Therefore, rendering of the xylophone...... played at student's location is required at teacher's site. This paper presents a comparison of different recording techniques for a spatial xylophone sound rendering. Directivity pattern of the xylophone was measured and spatial properties of the sound field created by a xylophone as a distributed sound...

  2. Chromium Renderserver: Scalable and Open Source Remote RenderingInfrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Brian; Ahern, Sean; Bethel, E. Wes; Brugger, Eric; Cook,Rich; Daniel, Jamison; Lewis, Ken; Owen, Jens; Southard, Dale

    2007-12-01

    Chromium Renderserver (CRRS) is software infrastructure thatprovides the ability for one or more users to run and view image outputfrom unmodified, interactive OpenGL and X11 applications on a remote,parallel computational platform equipped with graphics hardwareaccelerators via industry-standard Layer 7 network protocolsand clientviewers. The new contributions of this work include a solution to theproblem of synchronizing X11 and OpenGL command streams, remote deliveryof parallel hardware-accelerated rendering, and a performance analysis ofseveral different optimizations that are generally applicable to avariety of rendering architectures. CRRSis fully operational, Open Sourcesoftware.

  3. Depth of Field Effects for Interactive Direct Volume Rendering

    KAUST Repository

    Schott, Mathias

    2011-06-01

    In this paper, a method for interactive direct volume rendering is proposed for computing depth of field effects, which previously were shown to aid observers in depth and size perception of synthetically generated images. The presented technique extends those benefits to volume rendering visualizations of 3D scalar fields from CT/MRI scanners or numerical simulations. It is based on incremental filtering and as such does not depend on any precomputation, thus allowing interactive explorations of volumetric data sets via on-the-fly editing of the shading model parameters or (multi-dimensional) transfer functions. © 2011 The Author(s).

  4. Morphological study of transpterional-insula approach using volume rendering.

    Science.gov (United States)

    Jia, Linpei; Su, Lue; Sun, Wei; Wang, Lina; Yao, Jihang; Li, Youqiong; Luo, Qi

    2012-11-01

    This study describes the measurements of inferior circular insular sulcus (ICIS) and the shortest distance from ICIS to the temporal horn and determines the position of the incision, which does less harm to the temporal stem in the transpterional-insula approach using volume-rendering technique. Results of the research showed that one-third point over the anterior side of ICIS may be the ideal penetration point during operation. And there is no difference between 2 hemispheres (P ICIS from other Chinese researches demonstrated that volume rendering is a reliable method in insular research that enables mass measurements.

  5. The contribution of serotonin 5-HT2C and melanocortin-4 receptors to the satiety signaling of glucagon-like peptide 1 and liraglutide, a glucagon-like peptide 1 receptor agonist, in mice.

    Science.gov (United States)

    Nonogaki, Katsunori; Suzuki, Marina; Sanuki, Marin; Wakameda, Mamoru; Tamari, Tomohiro

    2011-07-29

    Glucagon-like peptide 1 (GLP-1), an insulinotropic gastrointestinal peptide produced mainly from intestinal endocrine L-cells, and liraglutide, a GLP-1 receptor (GLP-1R) agonist, induce satiety. The serotonin 5-HT2C receptor (5-HT2CR) and melanoroctin-4 receptor (MC4R) are involved in the regulation of food intake. Here we show that systemic administration of GLP-1 (50 and 200μg/kg)-induced anorexia was blunted in mice with a 5HT2CR null mutation, and was attenuated in mice with a heterozygous MC4R mutation. On the other hand, systemic administration of liraglutide (50 and 100μg/kg) suppressed food intake in mice lacking 5-HT2CR, mice with a heterozygous mutation of MC4R and wild-type mice matched for age. Moreover, once-daily consecutive intraperitoneal administration of liraglutide (100μg/kg) over 3days significantly suppressed daily food intake and body weight in mice with a heterozygous mutation of MC4R as well as wild-type mice. These findings suggest that GLP-1 and liraglutide induce anorexia via different central pathways.

  6. Catapult mechanism renders the chaperone action of Hsp70 unidirectional.

    Science.gov (United States)

    Gisler, S M; Pierpaoli, E V; Christen, P

    1998-06-19

    Molecular chaperones of the Hsp70 type promote the folding and membrane translocation of proteins. The interaction of Hsp70s with polypeptides is linked to ATP binding and hydrolysis. We formed complexes of seven different fluorescence-labeled peptides with DnaK, the Hsp70 homolog of Escherichia coli, and determined the rate of peptide release under two different sets of conditions. (1) Upon addition of ATP to nucleotide-free peptide.DnaK complexes, all tested peptides were released with similar rate constants (2.2 s-1 to 6.7 s-1). (2) In the binding equilibrium of peptide and ATP-liganded DnaK, the dissociation followed one or two-step reactions, depending on the amino acid sequence of the peptide. For the monophasic reactions, the dissociation rate constants diverged by four orders of magnitude from 0.0004 s-1 to 5.7 s-1; for the biphasic reactions, the rate constants of the second, slower isomerization step were in the range from 0.3 s-1 to 0.0005 s-1. The release of the different peptides in case (1) is 1.4 to 14,000 times faster than in case (2). Apparently, binding of ATP induces a transient state of the chaperone which ejects target peptides before the final state of ATP-liganded DnaK is reached. This "catapult" mechanism provides the chaperone cycle with a mode of peptide release that does not correspond with the reverse of peptide binding. By allowing the conformation of the outgoing polypeptide to differ from that of the incoming polypeptide, a futile cycle with respect to conformational work exerted on the target protein is obviated.

  7. Reactivation of Gαi-coupled formyl peptide receptors is inhibited by Gαq-selective inhibitors when induced by signals generated by the platelet-activating factor receptor.

    Science.gov (United States)

    Holdfeldt, André; Dahlstrand Rudin, Agnes; Gabl, Michael; Rajabkhani, Zahra; König, Gabriele M; Kostenis, Evi; Dahlgren, Claes; Forsman, Huamei

    2017-09-01

    Formyl peptide receptor (FPR)-desensitized neutrophils display increased production/release of superoxide (O2(-)) when activated by platelet-activating factor (PAF), a priming of the response achieved through a unique receptor crosstalk mechanism. The aim of this study was to determine the effect of an inhibitor selective for small, heterotrimeric G proteins belonging to the Gαq subclass on that receptor crosstalk. We show that signals generated by FPRs and the PAF receptor (PAFR) induce activation of the neutrophil O2(-), producing NADPH-oxidase, and that response was sensitive to Gαq inhibition in cells activated by PAF, but no inhibition was obtained in cells activated by FPR agonists. Signaling in naive neutrophils is terminated fairly rapidly, and the receptors become homologously desensitized. The downstream sensitivity to Gαq inhibition in desensitized cells displaying increased production/release of O2(-) through the PAFR receptor crosstalk mechanism also comprised the reactivation of the FPRs, and the activation signals were redirected from the PAFR to the desensitized/reactivated FPRs. The Gαq-dependent activation signals generated by the PAFRs activate the Gαi-coupled FPRs, a receptor crosstalk that represents a novel pathway by which G protein-coupled receptors can be regulated and signaling can be turned on and off. © Society for Leukocyte Biology.

  8. 昆虫中类胰岛素肽保守的信号系统和生理学功能%The Conserved Signaling Pathways and Physiological Functions of Insulin-Like Peptides in Insects

    Institute of Scientific and Technical Information of China (English)

    吴琦; 赵宏媛; 文铁桥

    2004-01-01

    Insulin is one of the most extensively studied protein hormones, and its structure and function have been elucidated in manyvertebrate species, ranging from human to fish. Insulin-like peptides (ILPs) also have been found and characterized in different invertebrates, including nematodes, mollusks and insects. However, insect ILPs turned out to be a structurally diverse group encoded by large multi-gene families that are expressed in the brain and other tissues and serve functions different from vertebrate insulin. Recentphysiological and genetic studies have revealed that, in different insect species, the conserved insulin signaling pathway plays a key role in the regulation of a variety of fundamental processes, such as metabolism, growth, reproduction and aging. Here, the structures, distributions, conserved signaling pathways, and physiological functions of insect ILPs are reviewed in detail.

  9. Dynamic real-time 4D cardiac MDCT image display using GPU-accelerated volume rendering.

    Science.gov (United States)

    Zhang, Qi; Eagleson, Roy; Peters, Terry M

    2009-09-01

    Intraoperative cardiac monitoring, accurate preoperative diagnosis, and surgical planning are important components of minimally-invasive cardiac therapy. Retrospective, electrocardiographically (ECG) gated, multidetector computed tomographical (MDCT), four-dimensional (3D + time), real-time, cardiac image visualization is an important tool for the surgeon in such procedure, particularly if the dynamic volumetric image can be registered to, and fused with the actual patient anatomy. The addition of stereoscopic imaging provides a more intuitive environment by adding binocular vision and depth cues to structures within the beating heart. In this paper, we describe the design and implementation of a comprehensive stereoscopic 4D cardiac image visualization and manipulation platform, based on the opacity density radiation model, which exploits the power of modern graphics processing units (GPUs) in the rendering pipeline. In addition, we present a new algorithm to synchronize the phases of the dynamic heart to clinical ECG signals, and to calculate and compensate for latencies in the visualization pipeline. A dynamic multiresolution display is implemented to enable the interactive selection and emphasis of volume of interest (VOI) within the entire contextual cardiac volume and to enhance performance, and a novel color and opacity adjustment algorithm is designed to increase the uniformity of the rendered multiresolution image of heart. Our system provides a visualization environment superior to noninteractive software-based implementations, but with a rendering speed that is comparable to traditional, but inferior quality, volume rendering approaches based on texture mapping. This retrospective ECG-gated dynamic cardiac display system can provide real-time feedback regarding the suspected pathology, function, and structural defects, as well as anatomical information such as chamber volume and morphology.

  10. A Leu7Pro mutation in the signal peptide of platelet glycoprotein (GP)IX in a case of Bernard-Soulier syndrome abolishes surface expression of the GPIb-V-IX complex.

    Science.gov (United States)

    Lanza, François; De La Salle, Corinne; Baas, Marie-Jeanne; Schwartz, Agnès; Boval, Bernadette; Cazenave, Jean-Pierre; Caen, Jacques P

    2002-07-01

    This paper describes the molecular defect of the second case of Bernard-Soulier syndrome, initially reported in 1957. Analysis of the patient's platelets by flow cytometry and Western blotting failed to detect surface expression of any of the four subunits of the glycoprotein (GP)Ib-V-IX complex and revealed small amounts of intracellular GPIbalpha, GPIbbeta and GPV but no GPIX. DNA sequencing revealed a novel missense mutation in the GPIX gene which replaced Leu (CTG) by Pro (CCG) at position 7 of the signal peptide. This mutation is, to date, the only known example of a leader sequence defect in Bernard-Soulier syndrome. The change occurred in a prototypic alpha-helical hydrophobic core region, typically enriched in leucine and devoid of proline residues. Co-transfection of GPIXPro7 with normal GPIbalpha and GPIbbeta into Chinese hamster ovary cells reproduced the platelet phenotype, resulting in no detectable GPIX, low intracellular levels of GPIbalpha and GPIbbeta, and an absence of surface expression. This mutation presumably leads to an abnormal conformation and, hence, incorrect insertion of GPIX into the endoplasmic reticulum and/or to defective signal peptide cleavage, both of which are required for correct transport to the cell membrane. This provides further evidence for a critical role of GPIX in controlling biosynthesis of the GPIb-IX complex.

  11. Remote parallel rendering for high-resolution tiled display walls

    KAUST Repository

    Nachbaur, Daniel

    2014-11-01

    © 2014 IEEE. We present a complete, robust and simple to use hardware and software stack delivering remote parallel rendering of complex geometrical and volumetric models to high resolution tiled display walls in a production environment. We describe the setup and configuration, present preliminary benchmarks showing interactive framerates, and describe our contributions for a seamless integration of all the software components.

  12. Light Field Rendering for Head Mounted Displays using Pixel Reprojection

    DEFF Research Database (Denmark)

    Hansen, Anne Juhler; Kraus, Martin; Klein, Jákup

    2017-01-01

    of the information of the different images is redundant, we use pixel reprojection from the corner cameras to compute the remaining images in the light field. We compare the reprojected images with directly rendered images in a user test. In most cases, the users were unable to distinguish the images. In extreme...

  13. An experiment on the color rendering of different light sources

    Science.gov (United States)

    Fumagalli, Simonetta; Bonanomi, Cristian; Rizzi, Alessandro

    2013-02-01

    The color rendering index (CRI) of a light source attempts to measure how much the color appearance of objects is preserved when they are illuminated by the given light source. This problem is of great importance for various industrial and scientific fields, such as lighting architecture, design, ergonomics, etc. Usually a light source is specified through the Correlated Color Temperature or CCT. However two (or more) light sources with the same CCT but different spectral power distribution can exist. Therefore color samples viewed under two light sources with equal CCTs can appear different. Hence, the need for a method to assess the quality of a given illuminant in relation to color. Recently CRI has had a renewed interest because of the new LED-based lighting systems. They usually have a color rendering index rather low, but good preservation of color appearance and a pleasant visual appearance (visual appeal). Various attempts to develop a new color rendering index have been done so far, but still research is working for a better one. This article describes an experiment performed by human observers concerning the appearance preservation of color under some light sources, comparing it with a range of available color rendering indices.

  14. Interacting with Stroke-Based Rendering on a Wall Display

    NARCIS (Netherlands)

    Grubert, Jens; Hanckock, Mark; Carpendale, Sheelagh; Tse, Edward; Isenberg, Tobias

    2007-01-01

    We introduce two new interaction techniques for creating and interacting with non-photorealistic images using stroke-based rendering. We provide bimanual control of a large interactive canvas through both remote pointing and direct touch. Remote pointing allows people to sit and interact at a distan

  15. Selection of plasters and renders for salt laden masonry substrates

    NARCIS (Netherlands)

    Groot, C.; Hees, R.P.J. van; Wijffels, T.J.

    2009-01-01

    The choice of a repair plaster or render by architects often appears to be the result of fortuitous circumstances, such as prior experience with a plaster or a recommendation by a producer. Seldom is the choice based on a sound assessment of the state of the building and the wall that is to be repai

  16. Depth-Dependent Halos : Illustrative Rendering of Dense Line Data

    NARCIS (Netherlands)

    Everts, Maarten H.; Bekker, Henk; Roerdink, Jos B.T.M.; Isenberg, Tobias

    2009-01-01

    We present a technique for the illustrative rendering of 3D line data at interactive frame rates. We create depth-dependent halos around lines to emphasize tight line bundles while less structured lines are de-emphasized. Moreover, the depth-dependent halos combined with depth cueing via line width

  17. Virtual Environment of Real Sport Hall and Analyzing Rendering Quality

    Directory of Open Access Journals (Sweden)

    Filip Popovski

    2015-02-01

    Full Text Available Here is presented virtual environment of a real sport hall created in Quest3D VR Edition. All analyzes of the rendering quality, techniques of interaction and performance of the system in real time are presented. We made critical analysis on all of these techniques on different machines and have excellent results.

  18. Interacting with Stroke-Based Rendering on a Wall Display

    NARCIS (Netherlands)

    Grubert, Jens; Hanckock, Mark; Carpendale, Sheelagh; Tse, Edward; Isenberg, Tobias

    2007-01-01

    We introduce two new interaction techniques for creating and interacting with non-photorealistic images using stroke-based rendering. We provide bimanual control of a large interactive canvas through both remote pointing and direct touch. Remote pointing allows people to sit and interact at a

  19. 7 CFR 54.1016 - Advance information concerning service rendered.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 54..., Processing, and Packaging of Livestock and Poultry Products § 54.1016 Advance information concerning service... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE...

  20. 7 CFR 53.17 - Advance information concerning service rendered.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Advance information concerning service rendered. 53.17... (CONTINUED) LIVESTOCK (GRADING, CERTIFICATION, AND STANDARDS) Regulations Service § 53.17 Advance information... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED)...

  1. Fast Rendering of Realistic Virtual Character in Game Scene

    Directory of Open Access Journals (Sweden)

    Mengzhao Yang

    2013-07-01

    Full Text Available Human skin is made up of multiple translucent layers and rendering of skin appearance usually acquire complex modeling and massive calculation. In some practical applications such as 3D game development, we not only approximate the realistic looking skin but also develop efficient method to implement easily for meeting needs of real-time rendering. In this study, we solve the problem of wrap lighting and introduce a surface details approximation method to give realistic rendering of virtual character. Our method considers that different thicknesses of geometry on the skin surface can result in different scattering degree of incident light and so pre-calculate the diffuse falloff into a look-up texture. Also, we notice that scattering is strongly color dependent and small bumps are common on the skin surface and so pre-soften the finer details on the skin surface according to the R/G/B channel. At last, we linearly interpolate the diffuse lighting with different scattering degree from the look-up texture sampled with the curvature and NdotL. Experiment results show that the proposed approach yields realistic virtual character and obtains high frames per second in real-time rendering.

  2. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jürgen P.

    2012-03-01

    We present a new approach for how multiple users\\' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users\\' head positions and orientations. © 2012 IEEE.

  3. Structure–function analysis of the GmRIC1 signal peptide and CLE domain required for nodulation control in soybean

    Science.gov (United States)

    Reid, Dugald E.; Li, Dongxue; Gresshoff, Peter M.

    2013-01-01

    Legumes control the nitrogen-fixing root nodule symbiosis in response to external and internal stimuli, such as nitrate, and via systemic autoregulation of nodulation (AON). Overexpression of the CLV3/ESR-related (CLE) pre-propeptide-encoding genes GmNIC1 (nitrate-induced and acting locally) and GmRIC1 (Bradyrhizobium-induced and acting systemically) suppresses soybean nodulation dependent on the activity of the nodulation autoregulation receptor kinase (GmNARK). This nodule inhibition response was used to assess the relative importance of key structural components within and around the CLE domain sequences of these genes. Using a site-directed mutagenesis approach, mutants were produced at each amino acid within the CLE domain (RLAPEGPDPHHN) of GmRIC1. This approach identified the Arg1, Ala3, Pro4, Gly6, Pro7, Asp8, His11, and Asn12 residues as critical to GmRIC1 nodulation suppression activity (NSA). In contrast, none of the mutations in conserved residues outside of the CLE domain showed compromised NSA. Chimeric genes derived from combinations of GmRIC1 and GmNIC1 domains were used to determine the role of each pre-propeptide domain in NSA differences that exist between the two peptides. It was found that the transit peptide and CLE peptide regions of GmRIC1 significantly enhanced activity of GmNIC1. In contrast, the comparable GmNIC1 domains reduced the NSA of GmRIC1. Identification of these critical residues and domains provides a better understanding of how these hormone-like peptides function in plant development and regulation. PMID:23386683

  4. Structure-function analysis of the GmRIC1 signal peptide and CLE domain required for nodulation control in soybean.

    Science.gov (United States)

    Reid, Dugald E; Li, Dongxue; Ferguson, Brett J; Gresshoff, Peter M

    2013-04-01

    Legumes control the nitrogen-fixing root nodule symbiosis in response to external and internal stimuli, such as nitrate, and via systemic autoregulation of nodulation (AON). Overexpression of the CLV3/ESR-related (CLE) pre-propeptide-encoding genes GmNIC1 (nitrate-induced and acting locally) and GmRIC1 (Bradyrhizobium-induced and acting systemically) suppresses soybean nodulation dependent on the activity of the nodulation autoregulation receptor kinase (GmNARK). This nodule inhibition response was used to assess the relative importance of key structural components within and around the CLE domain sequences of these genes. Using a site-directed mutagenesis approach, mutants were produced at each amino acid within the CLE domain (RLAPEGPDPHHN) of GmRIC1. This approach identified the Arg1, Ala3, Pro4, Gly6, Pro7, Asp8, His11, and Asn12 residues as critical to GmRIC1 nodulation suppression activity (NSA). In contrast, none of the mutations in conserved residues outside of the CLE domain showed compromised NSA. Chimeric genes derived from combinations of GmRIC1 and GmNIC1 domains were used to determine the role of each pre-propeptide domain in NSA differences that exist between the two peptides. It was found that the transit peptide and CLE peptide regions of GmRIC1 significantly enhanced activity of GmNIC1. In contrast, the comparable GmNIC1 domains reduced the NSA of GmRIC1. Identification of these critical residues and domains provides a better understanding of how these hormone-like peptides function in plant development and regulation.

  5. Peptide identification

    Science.gov (United States)

    Jarman, Kristin H [Richland, WA; Cannon, William R [Richland, WA; Jarman, Kenneth D [Richland, WA; Heredia-Langner, Alejandro [Richland, WA

    2011-07-12

    Peptides are identified from a list of candidates using collision-induced dissociation tandem mass spectrometry data. A probabilistic model for the occurrence of spectral peaks corresponding to frequently observed partial peptide fragment ions is applied. As part of the identification procedure, a probability score is produced that indicates the likelihood of any given candidate being the correct match. The statistical significance of the score is known without necessarily having reference to the actual identity of the peptide. In one form of the invention, a genetic algorithm is applied to candidate peptides using an objective function that takes into account the number of shifted peaks appearing in the candidate spectrum relative to the test spectrum.

  6. Exploring Protein-Peptide Binding Specificity through Computational Peptide Screening.

    Directory of Open Access Journals (Sweden)

    Arnab Bhattacherjee

    2013-10-01

    Full Text Available The binding of short disordered peptide stretches to globular protein domains is important for a wide range of cellular processes, including signal transduction, protein transport, and immune response. The often promiscuous nature of these interactions and the conformational flexibility of the peptide chain, sometimes even when bound, make the binding specificity of this type of protein interaction a challenge to understand. Here we develop and test a Monte Carlo-based procedure for calculating protein-peptide binding thermodynamics for many sequences in a single run. The method explores both peptide sequence and conformational space simultaneously by simulating a joint probability distribution which, in particular, makes searching through peptide sequence space computationally efficient. To test our method, we apply it to 3 different peptide-binding protein domains and test its ability to capture the experimentally determined specificity profiles. Insight into the molecular underpinnings of the observed specificities is obtained by analyzing the peptide conformational ensembles of a large number of binding-competent sequences. We also explore the possibility of using our method to discover new peptide-binding pockets on protein structures.

  7. An amphipathic alpha-helix in the prodomain of cocaine and amphetamine regulated transcript peptide precursor serves as its sorting signal to the regulated secretory pathway.

    Directory of Open Access Journals (Sweden)

    Elías H Blanco

    Full Text Available Cocaine and Amphetamine Regulated Transcript (CART peptides are anorexigenic neuropeptides. The L34F mutation in human CART peptide precursor (proCART has been linked to obesity (Yanik et al. Endocrinology 147: 39, 2006. Decrease in CART peptide levels in individuals carrying the L34F mutation was attributed to proCART subcellular missorting. We studied proCART features required to enter the regulated secretory pathway. The subcellular localization and the secretion mode of monomeric EGFP fused to the full-length or truncated forms of human proCART transiently transfected in PC12 cells were analyzed. Our results showed that the N-terminal 1-41 fragment of proCART was necessary and sufficient to sort proCART to the regulated secretory pathway. In silico modeling predicted an alpha-helix structure located between residues 24-37 of proCART. Helical wheel projection of proCART alpha-helix showed an amphipathic configuration. The L34F mutation does not modify the amphipathicity of proCART alpha-helix and consistently proCARTL34F was efficiently sorted to the regulated secretory pathway. However, four additional mutations to proCARTL34F that reduced its alpha-helix amphipathicity resulted in the missorting of the mutated proCART toward the constitutive secretory pathway. These findings show that an amphipathic alpha-helix is a key cis-structure for the proCART sorting mechanism. In addition, our results indicate that the association between L34F mutation and obesity is not explained by proCART missorting.

  8. 9 CFR 315.1 - Carcasses and parts passed for cooking; rendering into lard or tallow.

    Science.gov (United States)

    2010-01-01

    ...; rendering into lard or tallow. 315.1 Section 315.1 Animals and Animal Products FOOD SAFETY AND INSPECTION... PARTS PASSED FOR COOKING § 315.1 Carcasses and parts passed for cooking; rendering into lard or tallow... subchapter or rendered into tallow, provided such rendering is done in the following manner: (a) When...

  9. Realistic Haptic Rendering of Interacting Deformable Objects in Virtual Environments

    CERN Document Server

    Duriez, Christian; Kheddar, Abderrahmane; Andriot, Claude

    2008-01-01

    A new computer haptics algorithm to be used in general interactive manipulations of deformable virtual objects is presented. In multimodal interactive simulations, haptic feedback computation often comes from contact forces. Subsequently, the fidelity of haptic rendering depends significantly on contact space modeling. Contact and friction laws between deformable models are often simplified in up to date methods. They do not allow a "realistic" rendering of the subtleties of contact space physical phenomena (such as slip and stick effects due to friction or mechanical coupling between contacts). In this paper, we use Signorini's contact law and Coulomb's friction law as a computer haptics basis. Real-time performance is made possible thanks to a linearization of the behavior in the contact space, formulated as the so-called Delassus operator, and iteratively solved by a Gauss-Seidel type algorithm. Dynamic deformation uses corotational global formulation to obtain the Delassus operator in which the mass and s...

  10. Hybrid fur rendering: combining volumetric fur with explicit hair strands

    DEFF Research Database (Denmark)

    Andersen, Tobias Grønbeck; Falster, Viggo; Frisvad, Jeppe Revall

    2016-01-01

    Hair is typically modeled and rendered using either explicitly defined hair strand geometry or a volume texture of hair densities. Taken each on their own, these two hair representations have difficulties in the case of animal fur as it consists of very dense and thin undercoat hairs in combination...... with coarse guard hairs. Explicit hair strand geometry is not well-suited for the undercoat hairs, while volume textures are not well-suited for the guard hairs. To efficiently model and render both guard hairs and undercoat hairs, we present a hybrid technique that combines rasterization of explicitly...... defined guard hairs with ray marching of a prismatic shell volume with dynamic resolution. The latter is the key to practical combination of the two techniques, and it also enables a high degree of detail in the undercoat. We demonstrate that our hybrid technique creates a more detailed and soft fur...

  11. Chromium Renderserver: scalable and open remote rendering infrastructure.

    Science.gov (United States)

    Paul, Brian; Ahern, Sean; Bethel, E Wes; Brugger, Eric; Cook, Rich; Daniel, Jamison; Lewis, Ken; Owen, Jens; Southard, Dale

    2008-01-01

    Chromium Renderserver (CRRS) is software infrastructure that provides the ability for one or more users to run and view image output from unmodified, interactive OpenGL and X11 applications on a remote, parallel computational platform equipped with graphics hardware accelerators via industry-standard Layer 7 network protocols and client viewers. The new contributions of this work include a solution to the problem of synchronizing X11 and OpenGL command streams, remote delivery of parallel hardware accelerated rendering, and a performance analysis of several different optimizations that are generally applicable to a variety of rendering architectures. CRRS is fully operational, Open Source software. imagery and sending it to a remote viewer.

  12. Hybrid fur rendering: combining volumetric fur with explicit hair strands

    DEFF Research Database (Denmark)

    Andersen, Tobias Grønbeck; Falster, Viggo; Frisvad, Jeppe Revall

    2016-01-01

    Hair is typically modeled and rendered using either explicitly defined hair strand geometry or a volume texture of hair densities. Taken each on their own, these two hair representations have difficulties in the case of animal fur as it consists of very dense and thin undercoat hairs in combination...... with coarse guard hairs. Explicit hair strand geometry is not well-suited for the undercoat hairs, while volume textures are not well-suited for the guard hairs. To efficiently model and render both guard hairs and undercoat hairs, we present a hybrid technique that combines rasterization of explicitly...... defined guard hairs with ray marching of a prismatic shell volume with dynamic resolution. The latter is the key to practical combination of the two techniques, and it also enables a high degree of detail in the undercoat. We demonstrate that our hybrid technique creates a more detailed and soft fur...

  13. Tactile display for virtual 3D shape rendering

    CERN Document Server

    Mansutti, Alessandro; Bordegoni, Monica; Cugini, Umberto

    2017-01-01

    This book describes a novel system for the simultaneous visual and tactile rendering of product shapes which allows designers to simultaneously touch and see new product shapes during the conceptual phase of product development. This system offers important advantages, including potential cost and time savings, compared with the standard product design process in which digital 3D models and physical prototypes are often repeatedly modified until an optimal design is achieved. The system consists of a tactile display that is able to represent, within a real environment, the shape of a product. Designers can explore the rendered surface by touching curves lying on the product shape, selecting those curves that can be considered style features and evaluating their aesthetic quality. In order to physically represent these selected curves, a flexible surface is modeled by means of servo-actuated modules controlling a physical deforming strip. The tactile display is designed so as to be portable, low cost, modular,...

  14. Binaural technology for e.g. rendering auditory virtual environments

    DEFF Research Database (Denmark)

    Hammershøi, Dorte

    2008-01-01

    , helped mediate the understanding that if the transfer functions could be mastered, then important dimensions of the auditory percept could also be controlled. He early understood the potential of using the HRTFs and numerical sound transmission analysis programs for rendering auditory virtual...... environments. Jens Blauert participated in many European cooperation projects exploring  this field (and others), among other the SCATIS project addressing the auditory-tactile dimensions in the absence of visual information....

  15. Haptic Rendering Techniques for Non-Physical, Command Decision Support

    Science.gov (United States)

    2004-04-01

    tactile and haptic rendering techniques. BACKGROUND Usually visualizing battlefield implies maps, computer screens filled with information and perhaps 3...Traditional 2-D Screens 3-D stereo glasses HMD CAVE Audio Haptics Level 1, 2 3 …..Fusion - Estimates INTEL SATELLITE RAW DATA Transforms...sensory modes of data presentation Haptics Tactile 8-14 Virtual Lexicon Haptic feedback The sensation of weight or resistance in a virtual world. (from

  16. Rendering Optical Effects Based on Spectra Representation in Complex Scenes

    OpenAIRE

    Dong, Weiming

    2006-01-01

    http://www.springerlink.com/; Rendering the structural color of natural objects or modern industrial products in the 3D environment is not possible with RGB-based graphics platforms and software and very time consuming, even with the most efficient spectra representation based methods previously proposed. Our framework allows computing full spectra light object interactions only when it is needed, i.e. for the part of the scene that requires simulating special spectra sensitive phenomena. Ach...

  17. Anisotropic 3D texture synthesis with application to volume rendering

    DEFF Research Database (Denmark)

    Laursen, Lasse Farnung; Ersbøll, Bjarne Kjær; Bærentzen, Jakob Andreas

    2011-01-01

    We present a novel approach to improving volume rendering by using synthesized textures in combination with a custom transfer function. First, we use existing knowledge to synthesize anisotropic solid textures to fit our volumetric data. As input to the synthesis method, we acquire high quality....... This method is applied to a high quality visualization of a pig carcass, where samples of meat, bone, and fat have been used to produce the anisotropic 3D textures....

  18. Glucagon-like peptide 1 interacts with ghrelin and leptin to regulate glucose metabolism and food intake through vagal afferent neuron signaling.

    Science.gov (United States)

    Ronveaux, Charlotte C; Tomé, Daniel; Raybould, Helen E

    2015-04-01

    Emerging evidence has suggested a possible physiologic role for peripheral glucagon-like peptide 1 (GLP-1) in regulating glucose metabolism and food intake. The likely site of action of GLP-1 is on vagal afferent neurons (VANs). The vagal afferent pathway is the major neural pathway by which information about ingested nutrients reaches the central nervous system and influences feeding behavior. Peripheral GLP-1 acts on VANs to inhibit food intake. The mechanism of the GLP-1 receptor (GLP-1R) is unlike other gut-derived receptors; GLP-1Rs change their cellular localization according to feeding status rather than their protein concentrations. It is possible that several gut peptides are involved in mediating GLP-1R translocation. The mechanism of peripheral GLP-1R translocation still needs to be elucidated. We review data supporting the role of peripheral GLP-1 acting on VANs in influencing glucose homeostasis and feeding behavior. We highlight evidence demonstrating that GLP-1 interacts with ghrelin and leptin to induce satiation. Our aim was to understand the mechanism of peripheral GLP-1 in the development of noninvasive antiobesity treatments.

  19. Capturing, processing, and rendering real-world scenes

    Science.gov (United States)

    Nyland, Lars S.; Lastra, Anselmo A.; McAllister, David K.; Popescu, Voicu; McCue, Chris; Fuchs, Henry

    2000-12-01

    While photographs vividly capture a scene from a single viewpoint, it is our goal to capture a scene in such a way that a viewer can freely move to any viewpoint, just as he or she would in an actual scene. We have built a prototype system to quickly digitize a scene using a laser rangefinder and a high-resolution digital camera that accurately captures a panorama of high-resolution range and color information. With real-world scenes, we have provided data to fuel research in many area, including representation, registration, data fusion, polygonization, rendering, simplification, and reillumination. The real-world scene data can be used for many purposes, including immersive environments, immersive training, re-engineering and engineering verification, renovation, crime-scene and accident capture and reconstruction, archaeology and historic preservation, sports and entertainment, surveillance, remote tourism and remote sales. We will describe our acquisition system, the necessary processing to merge data from the multiple input devices and positions. We will also describe high quality rendering using the data we have collected. Issues about specific rendering accelerators and algorithms will also be presented. We will conclude by describing future uses and methods of collection for real- world scene data.

  20. Real-time rendering of optical effects using spatial convolution

    Science.gov (United States)

    Rokita, Przemyslaw

    1998-03-01

    Simulation of special effects such as: defocus effect, depth-of-field effect, raindrops or water film falling on the windshield, may be very useful in visual simulators and in all computer graphics applications that need realistic images of outdoor scenery. Those effects are especially important in rendering poor visibility conditions in flight and driving simulators, but can also be applied, for example, in composing computer graphics and video sequences- -i.e. in Augmented Reality systems. This paper proposes a new approach to the rendering of those optical effects by iterative adaptive filtering using spatial convolution. The advantage of this solution is that the adaptive convolution can be done in real-time by existing hardware. Optical effects mentioned above can be introduced into the image computed using conventional camera model by applying to the intensity of each pixel the convolution filter having an appropriate point spread function. The algorithms described in this paper can be easily implemented int the visualization pipeline--the final effect may be obtained by iterative filtering using a single hardware convolution filter or with the pipeline composed of identical 3 X 3 filters placed as the stages of this pipeline. Another advantage of the proposed solution is that the extension based on proposed algorithm can be added to the existing rendering systems as a final stage of the visualization pipeline.

  1. High Performance GPU-Based Fourier Volume Rendering.

    Science.gov (United States)

    Abdellah, Marwan; Eldeib, Ayman; Sharawi, Amr

    2015-01-01

    Fourier volume rendering (FVR) is a significant visualization technique that has been used widely in digital radiography. As a result of its (N (2)log⁡N) time complexity, it provides a faster alternative to spatial domain volume rendering algorithms that are (N (3)) computationally complex. Relying on the Fourier projection-slice theorem, this technique operates on the spectral representation of a 3D volume instead of processing its spatial representation to generate attenuation-only projections that look like X-ray radiographs. Due to the rapid evolution of its underlying architecture, the graphics processing unit (GPU) became an attractive competent platform that can deliver giant computational raw power compared to the central processing unit (CPU) on a per-dollar-basis. The introduction of the compute unified device architecture (CUDA) technology enables embarrassingly-parallel algorithms to run efficiently on CUDA-capable GPU architectures. In this work, a high performance GPU-accelerated implementation of the FVR pipeline on CUDA-enabled GPUs is presented. This proposed implementation can achieve a speed-up of 117x compared to a single-threaded hybrid implementation that uses the CPU and GPU together by taking advantage of executing the rendering pipeline entirely on recent GPU architectures.

  2. High Performance GPU-Based Fourier Volume Rendering

    Directory of Open Access Journals (Sweden)

    Marwan Abdellah

    2015-01-01

    Full Text Available Fourier volume rendering (FVR is a significant visualization technique that has been used widely in digital radiography. As a result of its O(N2log⁡N time complexity, it provides a faster alternative to spatial domain volume rendering algorithms that are O(N3 computationally complex. Relying on the Fourier projection-slice theorem, this technique operates on the spectral representation of a 3D volume instead of processing its spatial representation to generate attenuation-only projections that look like X-ray radiographs. Due to the rapid evolution of its underlying architecture, the graphics processing unit (GPU became an attractive competent platform that can deliver giant computational raw power compared to the central processing unit (CPU on a per-dollar-basis. The introduction of the compute unified device architecture (CUDA technology enables embarrassingly-parallel algorithms to run efficiently on CUDA-capable GPU architectures. In this work, a high performance GPU-accelerated implementation of the FVR pipeline on CUDA-enabled GPUs is presented. This proposed implementation can achieve a speed-up of 117x compared to a single-threaded hybrid implementation that uses the CPU and GPU together by taking advantage of executing the rendering pipeline entirely on recent GPU architectures.

  3. High dynamic range (HDR) virtual bronchoscopy rendering for video tracking

    Science.gov (United States)

    Popa, Teo; Choi, Jae

    2007-03-01

    In this paper, we present the design and implementation of a new rendering method based on high dynamic range (HDR) lighting and exposure control. This rendering method is applied to create video images for a 3D virtual bronchoscopy system. One of the main optical parameters of a bronchoscope's camera is the sensor exposure. The exposure adjustment is needed since the dynamic range of most digital video cameras is narrower than the high dynamic range of real scenes. The dynamic range of a camera is defined as the ratio of the brightest point of an image to the darkest point of the same image where details are present. In a video camera exposure is controlled by shutter speed and the lens aperture. To create the virtual bronchoscopic images, we first rendered a raw image in absolute units (luminance); then, we simulated exposure by mapping the computed values to the values appropriate for video-acquired images using a tone mapping operator. We generated several images with HDR and others with low dynamic range (LDR), and then compared their quality by applying them to a 2D/3D video-based tracking system. We conclude that images with HDR are closer to real bronchoscopy images than those with LDR, and thus, that HDR lighting can improve the accuracy of image-based tracking.

  4. Partition of biocides between water and inorganic phases of renders with organic binder

    DEFF Research Database (Denmark)

    Urbanczyk, Michal M; Bollmann, Ulla E; Bester, Kai

    2016-01-01

    , the partition of biocides between water and inorganic phases of render with organic binder was investigated. The partition constants of carbendazim, diuron, iodocarb, isoproturon, cybutryn (irgarol), octylisothiazolinone, terbutryn, and tebuconazole towards minerals typically used in renders, e.g. barite...... with render-water distribution constants of two artificially made renders showed that the distribution constants can be estimated based on partition constants of compounds for individual components of the render....

  5. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bingyu [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Luo, Qing, E-mail: qing.luo@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Mao, Xinjian [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Xu, Baiyao [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Yang, Li [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Ju, Yang [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Song, Guanbin, E-mail: song@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2014-03-10

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the

  6. Dual regulation of the parathyroid hormone (PTH)/PTH-related peptide receptor signaling by protein kinase C and beta-arrestins.

    Science.gov (United States)

    Castro, Marián; Dicker, Frank; Vilardaga, Jean-Pierre; Krasel, Cornelius; Bernhardt, Manfred; Lohse, Martin J

    2002-10-01

    We examined here the role of second messenger-dependent kinases and beta-arrestins in short-term regulation of the PTH receptor (PTHR) signaling. The inhibition of protein kinase C (PKC) in COS-7 cells transiently expressing PTHR, led to an approximately 2-fold increase in PTH-stimulated inositol phosphate (IP) and cAMP production. The inhibition of protein kinase A increased cAMP production 1.5-fold without affecting IP signaling. The effects of PKC inhibition on PTHR-mediated G(q) signaling were strongly decreased for a carboxy-terminally truncated PTHR (T480) that is phosphorylation deficient. PKC inhibition was associated with a decrease in agonist-stimulated PTHR phosphorylation and internalization without blocking PTH-dependent mobilization of beta-arrestin2 to the plasma membrane. Overexpression of beta-arrestins strongly decreased the PTHR-mediated IP signal, whereas cAMP production was impaired to a much lower extent. The regulation of PTH-stimulated signals by beta-arrestins was impaired for the truncated T480 receptor. Our data reveal mechanisms at, and distal to, the receptor regulating PTHR-mediated signaling pathways by second messenger-dependent kinases. We conclude that regulation of PTHR-mediated signaling by PKC and beta-arrestins are separable phenomena that both involve the carboxy terminus of the receptor. A major role for PKC and beta-arrestins in preferential regulation of PTHR-mediated G(q) signaling by independent mechanisms at the receptor level was established.

  7. The first salamander defensin antimicrobial peptide.

    Directory of Open Access Journals (Sweden)

    Ping Meng

    Full Text Available Antimicrobial peptides have been widely identified from amphibian skins except salamanders. A novel antimicrobial peptide (CFBD was isolated and characterized from skin secretions of the salamander, Cynops fudingensis. The cDNA encoding CFBD precursor was cloned from the skin cDNA library of C. fudingensis. The precursor was composed of three domains: signal peptide of 17 residues, mature peptide of 41 residues and intervening propeptide of 3 residues. There are six cysteines in the sequence of mature CFBD peptide, which possibly form three disulfide-bridges. CFBD showed antimicrobial activities against Staphylococcus aureus, Bacillus subtilis, Candida albicans and Escherichia coli. This peptide could be classified into family of β-defensin based on its sequence similarity with β-defensins from other vertebrates. Evolution analysis indicated that CFBD was close to fish β-defensin. As far as we know, CFBD is the first β-defensin antimicrobial peptide from salamanders.

  8. C-Peptide Test

    Science.gov (United States)

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities C-peptide Share this page: Was this page helpful? Also known as: Insulin C-peptide; Connecting Peptide Insulin; Proinsulin C-peptide Formal ...

  9. LFP-20, a porcine lactoferrin peptide, ameliorates LPS-induced inflammation via the MyD88/NF-κB and MyD88/MAPK signaling pathways.

    Science.gov (United States)

    Zong, Xin; Song, Deguang; Wang, Tenghao; Xia, Xi; Hu, Wangyang; Han, Feifei; Wang, Yizhen

    2015-10-01

    LFP-20 is one of the 20 amino acid anti-microbial peptides identified in the N terminus of porcine lactoferrin. Apart from its extensively studied direct anti-bacterial activity, its potential as an activator of immune-related cellular functions is unknown. Therefore, this study investigated its anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated pig alveolar macrophages in vitro and systemic inflammation in an in vivo mouse model. We found that the inhibitory effects of LFP-20 on production of pro-inflammatory cytokines were independent of its LPS-binding activity. However, they were associated with NF-κB and MAPK-dependent signaling. Furthermore, LFP-20 might directly influence MyD88 levels to block its interaction with NF-κB and MAPK-dependent signaling molecules that might alter LPS-mediated inflammatory responses in activated macrophages. Taken together, our data indicated that LFP-20 prevents the LPS-induced inflammatory response by inhibiting MyD88/NF-κB and MyD88/MAPK signaling pathways, and sheds light on the potential use of LFP-20 in the therapy of LPS-mediated sepsis.

  10. Nucleotide sequence and expression of relaxin-like gonad-stimulating peptide gene in starfish Asterina pectinifera.

    Science.gov (United States)

    Haraguchi, Shogo; Ikeda, Narumi; Abe, Michiko; Tsutsui, Kazuyoshi; Mita, Masatoshi

    2016-02-01

    Starfish gonad-stimulating substance (GSS) is the only known invertebrate peptide hormone responsible for final gamete maturation, rendering it functionally analogous to gonadotropins in vertebrates. Because GSS belongs to the relaxin-like peptide family, we propose renaming for starfish gonadotropic hormone as relaxin-like gonad-stimulating peptide (RGP). This study examined the primary structure and expression regulation of the RGP gene in starfish Asterina pectinifera. RGP consisted of 3896 base pairs (bp) divided over two exons, exon 1 of 208 bp and exon 2 of 2277 bp, and one intron of 1411 bp. Promoter sequences, CAAT and TATA boxes, were present in the 5'-upstream region of the coding DNA sequence of RGP. The transcript was 2485 bases (b) in length. The AAUAAA polyadenylation signal was found in 3'-untranslated region over 2kb away from the stop codon. This showed that only 14% of the RGP mRNA was translated into the peptide, because a size of the open-reading frame was 351 b. Furthermore, an analysis by using real-time quantitative PCR with specific primers for RGP showed that mRNA of RGP was expressed at high levels in the radial nerves. Expression was also observed in the cardiac stomachs, although the level was low, and trace levels were detected in the gonads, pyloric caeca and tube feet. This result suggests that the RGP gene is transcribed mainly in the radial nerves of A. pectinifera.

  11. NCAM-mimetic, FGL peptide, restores disrupted fibroblast growth factor receptor (FGFR) phosphorylation and FGFR mediated signaling in neural cell adhesion molecule (NCAM)-deficient mice

    DEFF Research Database (Denmark)

    Aonurm-Helm, Anu; Berezin, Vladimir; Bock, Elisabeth;

    2010-01-01

    Neural cell adhesion molecule (NCAM) is a membrane-bound glycoprotein expressed on the surface of neuronal and glial cells. Previous in vitro studies have demonstrated that NCAM promotes neuronal functions largely via three main interaction partners: the fibroblast growth factor receptor (FGFR...... compared the levels of phosphorylation of FGFR1, Src kinase Fyn, Raf1 kinase, MAP kinases, Akt kinase and calcium/calmodulin-dependent kinases II and IV (CaMKII and CaMKIV) in the hippocampus of NCAM knockout mice to their wild-type littermates. The data of our study show that mice constitutively deficient...... in all isoforms of NCAM have decreased basal phosphorylation levels of FGFR1 and CaMKII and CaMKIV. Furthermore, NCAM-mimetic, FGL peptide, is found to be able to restore FGFR1, CaMKII and CaMKIV phosphorylation levels and thereby mimic the interactions of NCAM at this receptor in NCAM deficient mice...

  12. A pilot study examining the relationship among Crohn disease activity, glucagon-like peptide-2 signalling and intestinal function in pediatric patients

    DEFF Research Database (Denmark)

    Sigalet, David L; Kravarusic, Dragan; Butzner, Decker

    2013-01-01

      BACKGROUND⁄/OBJECTIVES: The relationship between the enteroendocrine hormone glucagon-like peptide 2 (GLP-2) and intestinal inflammation is unclear. GLP-2 promotes mucosal growth, decreases permeability and reduces inflammation in the intestine; physiological stimulation of GLP-2 release...... of the small intestine) with a disease activity index >150. Fasting and postprandial GLP-2 levels and quantitative urinary recovery of orally administered 3-O-methyl-glucose (active transport) and lactulose⁄mannitol (passive) were quantified during the acute and remission phases. RESULTS: Seven patients (mean...... normalized with disease remission. The change in the lactulose⁄mannitol ratio was due to both reduced lactulose and increased mannitol absorption. CONCLUSIONS: These findings suggest that pediatric patients with acute ileal CD have decreased postprandial GLP-2 release, reduced glucose absorption...

  13. Elucidating the Specificity Determinants of the AtxE2 Lasso Peptide Isopeptidase.

    Science.gov (United States)

    Maksimov, Mikhail O; Koos, Joseph D; Zong, Chuhan; Lisko, Bozhena; Link, A James

    2015-12-25

    Lasso peptide isopeptidase is an enzyme that specifically hydrolyzes the isopeptide bond of lasso peptides, rendering these peptides linear. To carry out a detailed structure-activity analysis of the lasso peptide isopeptidase AtxE2 from Asticcacaulis excentricus, we solved NMR structures of its substrates astexin-2 and astexin-3. Using in vitro enzyme assays, we show that the C-terminal tail portion of these peptides is dispensable with regards to isopeptidase activity. A collection of astexin-2 and astexin-3 variants with alanine substitutions at each position within the ring and the loop was constructed, and we showed that all of these peptides except for one were cleaved by the isopeptidase. Thus, much like the lasso peptide biosynthetic enzymes, lasso peptide isopeptidase has broad substrate specificity. Quantitative analysis of the cleavage reactions indicated that alanine substitutions in loop positions of these peptides led to reduced cleavage, suggesting that the loop is serving as a recognition element for the isopeptidase.

  14. Effects of glyceryl trinitrate and calcitonin-gene-related peptide on BOLD signal and arterial diameter –methodological studies by fMRI and MRA

    DEFF Research Database (Denmark)

    Asghar, Mohammed Sohail; Ashina, Messoud

    2013-01-01

    of measuring task-related hemodynamic changes. Pharmacological substances that induce hemodynamic changes can therefore potentially alter the BOLD-signal that in turn falsely can be interpreted as changes in neuronal activity. It is therefore important to characterize possible effects of a pharmacological......Over the last decades MRI has proved to be very useful in the field of drug development and discovery. Pharmacological MRI (phMRI) explores the interaction between brain physiology, neuronal activity and drugs[1]. The BOLD-signal is an indirect method to investigate brain activity by way...

  15. Characterization, tissue distribution and regulation by fasting of the agouti family of peptides in the sea bass (Dicentrarchus labrax).

    Science.gov (United States)

    Agulleiro, Maria Josep; Cortés, Raúl; Leal, Esther; Ríos, Diana; Sánchez, Elisa; Cerdá-Reverter, José Miguel

    2014-09-01

    The melanocortin system is one of the most complex hormonal systems in vertebrates. Atypically, the signaling of melanocortin receptors is regulated by the binding of endogenous antagonists, named agouti-signaling protein (ASIP) and agouti-related protein (AGRP). Teleost specific genome duplication (TSGD) rendered new gene copies in teleost fish and up to four different genes of the agouti family of peptides have been characterized. In this paper, molecular cloning was used to characterize mRNA of the agouti family of peptides in sea bass. Four different genes were identified: AGRP1, ASIP1, AGRP2 and ASIP2. The AGRP1 gene is mainly expressed in the brain whereas ASIP1 is mainly expressed in the ventral skin. Both ASIP2 and AGRP2 are expressed in the brain and the pineal gland but also in some peripheral tissues. Immunocytochemical studies demonstrated that AGRP1 is exclusively expressed within the lateral tuberal nucleus, the homologue of the mammalian arcuate nucleus in fish. Long-term fasting (8-29 days) increased the hypothalamic expression of AGRP1 but depressed AGRP2 expression (15-29 days). In contrast, the hypothalamic expression of ASIP2 was upregulated during short-term fasting suggesting that this peptide could be involved in the short term regulation of food intake in the sea bass.

  16. A survey on hair modeling: styling, simulation, and rendering.

    Science.gov (United States)

    Ward, Kelly; Bertails, Florence; Kim, Tae-Yong; Marschner, Stephen R; Cani, Marie-Paule; Lin, Ming C

    2007-01-01

    Realistic hair modeling is a fundamental part of creating virtual humans in computer graphics. This paper surveys the state of the art in the major topics of hair modeling: hairstyling, hair simulation, and hair rendering. Because of the difficult, often unsolved problems that arise in all these areas, a broad diversity of approaches are used, each with strengths that make it appropriate for particular applications. We discuss each of these major topics in turn, presenting the unique challenges facing each area and describing solutions that have been presented over the years to handle these complex issues. Finally, we outline some of the remaining computational challenges in hair modeling.

  17. Interactive View-Dependent Rendering of Large Isosurfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gregorski, B; Duchaineau, M; Lindstrom, P; Pascucci, V; Joy, K I

    2002-11-19

    We present an algorithm for interactively extracting and rendering isosurfaces of large volume datasets in a view-dependent fashion. A recursive tetrahedral mesh refinement scheme, based on longest edge bisection, is used to hierarchically decompose the data into a multiresolution structure. This data structure allows fast extraction of arbitrary isosurfaces to within user specified view-dependent error bounds. A data layout scheme based on hierarchical space filling curves provides access to the data in a cache coherent manner that follows the data access pattern indicated by the mesh refinement.

  18. Software System for Vocal Rendering of Printed Documents

    Directory of Open Access Journals (Sweden)

    Marian DARDALA

    2008-01-01

    Full Text Available The objective of this paper is to present a software system architecture developed to render the printed documents in a vocal form. On the other hand, in the paper are described the software solutions that exist as software components and are necessary for documents processing as well as for multimedia device controlling used by the system. The usefulness of this system is for people with visual disabilities that can access the contents of documents without that they be printed in Braille system or to exist in an audio form.

  19. Horse-shoe lung-rediscovered via volume rendered images

    Directory of Open Access Journals (Sweden)

    Alpa Bharati

    2013-01-01

    Full Text Available Horseshoe lung, usually associated with pulmonary venolobar syndrome, is a rare congenital anomaly involving the fusion of the postero-basal segments of the right and left lungs across the midline. The fused segment or the isthmus lies posterior to the pericardium and anterior to the aorta.The associated pulmonary venolobar syndrome involves anomalous systemic arterial supply and anomlaous systemic venous drainage of the right lung. With the advent of MDCT imaging, we can diagnose this rare condition as well all its associated anomalies non-invasively. Volume-rendered techniques greatly simplify the complex anatomy and provide easy understanding of the same.

  20. Partitioning of biocides between water and inorganic phases of render

    DEFF Research Database (Denmark)

    Urbanczyk, Michal; Bollmann, Ulla E.; Bester, Kai

    The use of biocides as additives for building materials has gained importance in recent years. These biocides are, e.g., applied to renders and paints to prevent them from microbial spoilage. However, these biocides can leach out into the environment. In order to better understand this leaching...... compared. The partitioning constants for calcium carbonate varied between 0.1 (isoproturon) and 1.1 (iodocarb) and 84.6 (dichlorooctylisothiazolinone), respectively. The results for barite, kaolinite and mica were in a similar range and usually the compounds with high partitioning constants for one mineral...

  1. Practical rendering and computation with Direct3D 11

    CERN Document Server

    Zink, Jason; Hoxley, Jack

    2011-01-01

    Practical Rendering and Computation with Direct3D 11 packs in documentation and in-depth coverage of basic and high-level concepts related to using Direct 3D 11 and is a top pick for any serious programming collection. … perfect for a wide range of users. Any interested in computation and multicore models will find this packed with examples and technical applications.-Midwest Book Review, October 2011The authors have generously provided us with an optimal blend of concepts and philosophy, illustrative figures to clarify the more difficult points, and source code fragments to make the ideas con

  2. IGF-1R peptide vaccines/mimics inhibit the growth of BxPC3 and JIMT-1 cancer cells and exhibit synergistic antitumor effects with HER-1 and HER-2 peptides.

    Science.gov (United States)

    Foy, Kevin Chu; Miller, Megan J; Overholser, Jay; Donnelly, Siobhan M; Nahta, Rita; Kaumaya, Pravin Tp

    2014-11-01

    The insulin-like growth factor-1 receptor (IGF-1R) plays a crucial role in cellular growth, proliferation, transformation, and inhibition of apoptosis. A myriad of human cancer types have been shown to overexpress IGF-1R, including breast and pancreatic adenocarcinoma. IGF-1R signaling interferes with numerous receptor pathways, rendering tumor cells resistant to chemotherapy, anti-hormonal therapy, and epidermal growth factor receptor (EGFR, also known as HER-1) and v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2, (ERBB2, best known as HER-2) -targeted therapies. Targeting the IGF:IGF-1R axis with innovative peptide inhibitors and vaccine antibodies thus represents a promising therapeutic strategy to overcome drug resistance and to provide new avenues for individualized and combinatorial treatment strategies. In this study, we designed, synthesized, and characterized several B-cell epitopes from the IGF-1:IGF-1R axis. The chimeric peptide epitopes were highly immunogenic in outbred rabbits, eliciting high levels of peptide vaccine antibodies. The IGF-1R peptide antibodies and peptide mimics inhibited cell proliferation and receptor phosphorylation, induced apoptosis and antibody-dependent cellular cytotoxicity (ADCC), and significantly inhibited tumor growth in the transplantable BxPC-3 pancreatic and JIMT-1 breast cancer models. Our results showed that the peptides and antibodies targeting residues 56-81 and 233-251 are potential therapeutic and vaccine candidates for the treatment of IGF-1R-expressing cancers, including those that are resistant to the HER-2-targeted antibody, trastuzumab. Additionally, we found additive antitumor effects for the combination treatment of the IGF-1R 56-81 epitope with HER-1-418 and HER-2-597 epitopes. Treatment with the IGF-1R/HER-1 or IGF-1R/HER-2 combination inhibited proliferation, invasion, and receptor phosphorylation, and induced apoptosis and ADCC, to a greater degree than single agents.

  3. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  4. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering.

    Science.gov (United States)

    Sicat, Ronell; Krüger, Jens; Möller, Torsten; Hadwiger, Markus

    2014-12-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  5. Fast polyhedral cell sorting for interactive rendering of unstructured grids

    Energy Technology Data Exchange (ETDEWEB)

    Combra, J; Klosowski, J T; Max, N; Silva, C T; Williams, P L

    1998-10-30

    Direct volume rendering based on projective methods works by projecting, in visibility order, the polyhedral cells of a mesh onto the image plane, and incrementally compositing the cell's color and opacity into the final image. Crucial to this method is the computation of a visibility ordering of the cells. If the mesh is ''well-behaved'' (acyclic and convex), then the MPVO method of Williams provides a very fast sorting algorithm; however, this method only computes an approximate ordering in general datasets, resulting in visual artifacts when rendered. A recent method of Silva et al. removed the assumption that the mesh is convex, by means of a sweep algorithm used in conjunction with the MPVO method; their algorithm is substantially faster than previous exact methods for general meshes. In this paper we propose a new technique, which we call BSP-XMPVO, which is based on a fast and simple way of using binary space partitions on the boundary elements of the mesh to augment the ordering produced by MPVO. Our results are shown to be orders of magnitude better than previous exact methods of sorting cells.

  6. Non-Photorealistic Rendering in Chinese Painting of Animals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A set of algorithms is proposed in this paper to automatically transform 3D animal models to Chinese painting style. Inspired by real painting process in Chinese painting of animals, we divide the whole rendering process into two parts: borderline stroke making and interior shading. In borderline stroke making process we first find 3D model silhouettes in real-time depending on the viewing direction of a user. After retrieving silhouette information from all model edges, a stroke linking mechanism is applied to link these independent edges into a long stroke. Finally we grow a plain thin silhouette line to a stylus stroke with various widths at each control point and a 2D brush model is combined with it to simulate a Chinese painting stroke. In the interior shading pipeline, three stages are used to convert a Gouraud-shading image to a Chinese painting style image: color quantization, ink diffusion and box filtering. The color quantization stage assigns all pixels in an image into four color levels and each level represents a color layer in a Chinese painting. Ink diffusion stage is used to transfer inks and water between different levels and to grow areas in an irregular way. The box filtering stage blurs sharp borders between different levels to embellish the appearance of final interior shading image. In addition to automatic rendering, an interactive Chinese painting system which is equipped with friendly input devices can be also combined to generate more artistic Chinese painting images manually.

  7. Protein and mineral characterisation of rendered meat and bone meal.

    Science.gov (United States)

    Buckley, M; Penkman, K E H; Wess, T J; Reaney, S; Collins, M J

    2012-10-01

    We report the characterisation of meat and bone meal (MBM) standards (Set B-EFPRA) derived from cattle, sheep, pig and chicken, each rendered at four different temperatures (133, 137, 141 and 145 °C). The standards, prepared for an EU programme STRATFEED (to develop new methodologies for the detection and quantification of illegal addition of mammalian tissues in feeding stuffs), have been widely circulated and used to assess a range of methods for identification of the species composition of MBM. The overall state of mineral alteration and protein preservation as a function of temperature was monitored using small angle X-ray diffraction (SAXS), amino acid composition and racemization analyses. Progressive increases in protein damage and mineral alteration in chicken and cattle standards was observed. In the case of sheep and pig, there was greater damage to the proteins and alteration of the minerals at the lowest treatment temperature (133 °C), suggesting that the thermal treatments must have been compromised in some way. This problem has probably impacted upon the numerous studies which tested methods against these heat treatments. We use protein mass spectrometric methods to explore if thermostable proteins could be used to identify rendered MBM. In more thermally altered samples, so-called 'thermostable' proteins such as osteocalcin which has been proposed as a ideal target to speciate MBM were no longer detectable, but the structural protein type I collagen could be used to differentiate all four species, even in the most thermally altered samples.

  8. A-raf and B-raf are dispensable for normal endochondral bone development, and parathyroid hormone-related peptide suppresses extracellular signal-regulated kinase activation in hypertrophic chondrocytes.

    Science.gov (United States)

    Provot, Sylvain; Nachtrab, Gregory; Paruch, Jennifer; Chen, Adele Pin; Silva, Alcino; Kronenberg, Henry M

    2008-01-01

    Parathyroid hormone-related peptide (PTHrP) and the parathyroid hormone-PTHrP receptor increase chondrocyte proliferation and delay chondrocyte maturation in endochondral bone development at least partly through cyclic AMP (cAMP)-dependent signaling pathways. Because data suggest that the ability of cAMP to stimulate cell proliferation involves the mitogen-activated protein kinase kinase kinase B-Raf, we hypothesized that B-Raf might mediate the proliferative action of PTHrP in chondrocytes. Though B-Raf is expressed in proliferative chondrocytes, its conditional removal from cartilage did not affect chondrocyte proliferation and maturation or PTHrP-induced chondrocyte proliferation and PTHrP-delayed maturation. Similar results were obtained by conditionally removing B-Raf from osteoblasts. Because A-raf and B-raf are expressed similarly in cartilage, we speculated that they may fulfill redundant functions in this tissue. Surprisingly, mice with chondrocytes deficient in both A-Raf and B-Raf exhibited normal endochondral bone development. Activated extracellular signal-regulated kinase (ERK) was detected primarily in hypertrophic chondrocytes, where C-raf is expressed, and the suppression of ERK activation in these cells by PTHrP or a MEK inhibitor coincided with a delay in chondrocyte maturation. Taken together, these results demonstrate that B-Raf and A-Raf are dispensable for endochondral bone development and they indicate that the main role of ERK in cartilage is to stimulate not cell proliferation, but rather chondrocyte maturation.

  9. Peptide arrays for screening cancer specific peptides.

    Science.gov (United States)

    Ahmed, Sahar; Mathews, Anu Stella; Byeon, Nara; Lavasanifar, Afsaneh; Kaur, Kamaljit

    2010-09-15

    In this paper, we describe a novel method to screen peptides for specific recognition by cancer cells. Seventy peptides were synthesized on a cellulose membrane in an array format, and a direct method to study the peptide-whole cell interaction was developed. The relative binding affinity of the cells for different peptides with respect to a lead 12-mer p160 peptide, identified by phage display, was evaluated using the CyQUANT fluorescence of the bound cells. Screening allowed identification of at least five new peptides that displayed higher affinity (up to 3-fold) for MDA-MB-435 and MCF-7 human cancer cells compared to the p160 peptide. These peptides showed very little binding to the control (noncancerous) human umbilical vein endothelial cells (HUVECs). Three of these peptides were synthesized separately and labeled with fluorescein isothiocyanate (FITC) to study their uptake and interaction with the cancer and control cells using confocal laser scanning microscopy and flow cytometry. The results confirmed the high and specific affinity of an 11-mer peptide 11 (RGDPAYQGRFL) and a 10-mer peptide 18 (WXEAAYQRFL) for the cancer cells versus HUVECs. Peptide 11 binds different receptors on target cancer cells as its sequence contains multiple recognition motifs, whereas peptide 18 binds mainly to the putative p160 receptor. The peptide array-whole cell binding assay reported here is a complementary method to phage display for further screening and optimization of cancer targeting peptides for cancer therapy and diagnosis.

  10. A pilot study examining the relationship among Crohn disease activity, glucagon-like peptide-2 signalling and intestinal function in pediatric patients

    Science.gov (United States)

    Sigalet, David L; Kravarusic, Dragan; Butzner, Decker; Hartmann, Bolette; Holst, Jens J; Meddings, Jon

    2013-01-01

    BACKGROUND/OBJECTIVES: The relationship between the enteroendocrine hormone glucagon-like peptide 2 (GLP-2) and intestinal inflammation is unclear. GLP-2 promotes mucosal growth, decreases permeability and reduces inflammation in the intestine; physiological stimulation of GLP-2 release is triggered by nutrient contact. The authors hypothesized that ileal Crohn disease (CD) affects GLP-2 release. METHODS: With ethics board approval, pediatric patients hospitalized with CD were studied; controls were recruited from local schools. Inclusion criteria were endoscopy-confirmed CD (primarily of the small intestine) with a disease activity index >150. Fasting and post-prandial GLP-2 levels and quantitative urinary recovery of orally administered 3-O-methyl-glucose (active transport) and lactulose/mannitol (passive) were quantified during the acute and remission phases. RESULTS: Seven patients (mean [± SD] age 15.3±1.3 years) and 10 controls (10.3±1.6 years) were studied. In patients with active disease, fasting levels of GLP-2 remained stable but postprandial levels were reduced. Patients with active disease exhibited reduced glucose absorption and increased lactulose/mannitol recovery; all normalized with disease remission. The change in the lactulose/mannitol ratio was due to both reduced lactulose and increased mannitol absorption. CONCLUSIONS: These findings suggest that pediatric patients with acute ileal CD have decreased postprandial GLP-2 release, reduced glucose absorption and increased intestinal permeability. Healing of CD resulted in normalization of postprandial GLP-2 release and mucosal functioning (nutrient absorption and permeability), the latter due to an increase in mucosal surface area. These findings have implications for the use of GLP-2 and feeding strategies as a therapy in CD patients; further studies of the effects of inflammation and the GLP-2 axis are recommended. PMID:24106731

  11. Rendering graphene supports hydrophilic with non-covalent aromatic functionalization for transmission electron microscopy

    Science.gov (United States)

    Pantelic, Radosav S.; Fu, Wangyang; Schoenenberger, Christian; Stahlberg, Henning

    2014-03-01

    Amorphous carbon films have been routinely used to enhance the preparation of frozen-hydrated samples for transmission electron microscopy (TEM), either in retaining protein concentration, providing mechanical stability or dissipating sample charge. However, strong background signal from the amorphous carbon support obstructs that of the sample, and the insulating properties of thin amorphous carbon films preclude any efficiency in dispersing charge. Graphene addresses the limitations of amorphous carbon. Graphene is a crystalline material with virtually no phase or amplitude contrast and unparalleled, high electrical carrier mobility. However, the hydrophobic properties of graphene have prevented its routine application in Cryo-TEM. This Letter reports a method for rendering graphene TEM supports hydrophilic—a convenient approach maintaining graphene's structural and electrical properties based on non-covalent, aromatic functionalization.

  12. Rendering Intelligence at Physical Layer for Smart Addressing and Multiple Access

    DEFF Research Database (Denmark)

    Sanyal, Rajarshi; Prasad, Ramjee; Cianca, Ernestina

    2010-01-01

    The primary objective of this work is to propose a technique of wireless communication, where we render intelligence to the physical layer. We aim to realize a physical layer that can take part in some processes which is otherwise confined to higher layer signalling activities, like for example...... addressing of a node. For a typical closed user group type of network, we propose a multiple access mechanism and network topology which will not only eliminate the need of intelligent core network equipments in the network area , but to use this intelligent physical layer to directly reach any node over...... the air interface in the coverage area. This system is presence agnostic, hence the network is not aware of the exact location of the mobile node in the network area. So the mobility management process is not to be seen here. Also the network does not follow any cellular topology. This paper addresses...

  13. Rendering graphene supports hydrophilic with non-covalent aromatic functionalization for transmission electron microscopy

    CERN Document Server

    Pantelic, Radosav S; Schoenenberger, Christian; Stahlberg, Henning

    2014-01-01

    Amorphous carbon films have been routinely used to enhance the preparation of frozen-hydrated transmission electron microscopy (TEM) samples, either in retaining protein concentration, providing mechanical stability or dissipating sample charge. However, strong background signal from the amorphous carbon support obstructs that of the sample, and the insulating properties of amorphous carbon films preclude any efficiency in dispersing charge. Graphene addresses the limitations of amorphous carbon. Graphene is a crystalline material with virtually no phase or amplitude contrast and unparalleled, high electrical carrier mobility. However, the hydrophobic properties of graphene have prevented its routine application in Cryo-TEM. This letter reports a method for rendering graphene TEM supports hydrophilic - a convenient approach maintaining graphene's structural and electrical properties based on non-covalent, aromatic functionalization.

  14. A peptide antagonist disrupts NK cell inhibitory synapse formation.

    Science.gov (United States)

    Borhis, Gwenoline; Ahmed, Parvin S; Mbiribindi, Bérénice; Naiyer, Mohammed M; Davis, Daniel M; Purbhoo, Marco A; Khakoo, Salim I

    2013-03-15

    Productive engagement of MHC class I by inhibitory NK cell receptors depends on the peptide bound by the MHC class I molecule. Peptide:MHC complexes that bind weakly to killer cell Ig-like receptors (KIRs) can antagonize the inhibition mediated by high-affinity peptide:MHC complexes and cause NK cell activation. We show that low-affinity peptide:MHC complexes stall inhibitory signaling at the step of Src homology protein tyrosine phosphatase 1 recruitment and do not go on to form the KIR microclusters induced by high-affinity peptide:MHC, which are associated with Vav dephosphorylation and downstream signaling. Furthermore, the low-affinity peptide:MHC complexes prevented the formation of KIR microclusters by high-affinity peptide:MHC. Thus, peptide antagonism of NK cells is an active phenomenon of inhibitory synapse disruption.

  15. The role of BDNF/TrkB signaling in acute amphetamine-induced locomotor activity and opioid peptide gene expression in the rat dorsal striatum

    Directory of Open Access Journals (Sweden)

    Jacqueline F McGinty

    2011-07-01

    Full Text Available Exposure to psychostimulants increases brain-derived neurotrophic factor (BDNF mRNA and protein levels in the cerebral cortex and subcortical structures. Because BDNF is co-localized with dopamine and glutamate in afferents to the striatum of rats, it may be co-released with those neurotransmitters upon stimulation. Further, there may be an interaction between the intracellular signaling cascades activated by dopamine, glutamate, and TrkB receptors in medium spiny striatal neurons. In the present study, the effect of acute amphetamine administration on TrkB phosphorylation (p-TrkB, as an indirect indicator of activation, and striatal gene expression, was evaluated. In Experiment 1, 15 minutes or 2 hours after a single saline or amphetamine (2.5 mg/kg, i.p. injection, the caudate-putamen (CPu, nucleus accumbens (NAc, and dorsomedial prefrontal cortex (dmPFC were extracted and processed for phospho (p-TrkB immunoreactivity. Immunoprecipitation analyses indicated that neither the tyrosine phosphorylation (p-Tyr or autophosphorylation sites of TrkB (706 were changed in NAc, CPu, or dmPFC 15 min after amphetamine administration. In contrast, p-Tyr and the PLCγ phosphorylation site of TrkB (816 were increased in the NAc and CPu 2 hrs after amphetamine. In Experiment 2, intra-striatal infusion of the tyrosine kinase inhibitor, K252a, increased amphetamine-induced vertical activity but not total distance traveled. In addition, K252a inhibited amphetamine -induced preprodynorphin, but not preproenkephalin, mRNA expression in the striatum. These data indicate that acute amphetamine administration induces p-TrkB activation and signaling in a time- and brain region-dependent manner and that TrkB/BDNF signaling plays an important role in amphetamine-induced behavior and striatal gene expression.

  16. Excellent color rendering indexes of multi-package white LEDs.

    Science.gov (United States)

    Oh, Ji Hye; Yang, Su Ji; Sung, Yeon-Goog; Do, Y R

    2012-08-27

    This study introduces multi-package white light-emitting diodes (LEDs) system with the ability to realize high luminous efficacy and an excellent color rendering index (CRI, R a) using the R B,M A B,M G B,M C B (R B,M A B,M G B,M denoted as a long-pass dichroic filter (LPDF)-capped, monochromatic red, amber and green phosphor converted-LED (pc-LED) pumped by a blue LED chip, and C B denoted as a cyan and blue mixed pc-LED pumped by a blue LED) system. The luminous efficacy and color rendering index (CRI) of multi-package white LED systems are compared while changing the concentration of the cyan phosphor used in the paste of a cyan-blue LED package and the driving current of individual LEDs in multi-package white LEDs at correlated color temperatures (CCTs) ranging from 6,500 K (cold white) to 2,700 K (warm white) using a set of eight CCTs as specified by the American National Standards Institute (ANSI) standard number C78.377-2008. A R B,M A B,M G B,M C B white LED system provides high luminous efficacy (≥ 96 lm/W) and a color rendering index (≥ 91) encompassing the complete CCT range. We also compare the optical properties of the R B,M A B,M G B,M C B system with those of the R B,M A B,M G B,M B and RAGB (red, amber, green, and blue semiconductor-type narrow-spectrum-band LEDs) systems. It can be expected that the cyan color added to a blue LED in multi-package white LEDs based on LPDF-capped, phosphor-converted monochromatic LEDs will meet the needs of the high-quality, highly efficient, full-color white LED lighting market in the near future.

  17. Targeting the Eph System with Peptides and Peptide Conjugates.

    Science.gov (United States)

    Riedl, Stefan J; Pasquale, Elena B

    2015-01-01

    Eph receptor tyrosine kinases and ephrin ligands constitute an important cell communication system that controls development, tissue homeostasis and many pathological processes. Various Eph receptors/ephrins are present in essentially all cell types and their expression is often dysregulated by injury and disease. Thus, the 14 Eph receptors are attracting increasing attention as a major class of potential drug targets. In particular, agents that bind to the extracellular ephrin-binding pocket of these receptors show promise for medical applications. This pocket comprises a broad and shallow groove surrounded by several flexible loops, which makes peptides particularly suitable to target it with high affinity and selectivity. Accordingly, a number of peptides that bind to Eph receptors with micromolar affinity have been identified using phage display and other approaches. These peptides are generally antagonists that inhibit ephrin binding and Eph receptor/ ephrin signaling, but some are agonists mimicking ephrin-induced Eph receptor activation. Importantly, some of the peptides are exquisitely selective for single Eph receptors. Most identified peptides are linear, but recently the considerable advantages of cyclic scaffolds have been recognized, particularly in light of potential optimization towards drug leads. To date, peptide improvements have yielded derivatives with low nanomolar Eph receptor binding affinity, high resistance to plasma proteases and/or long in vivo half-life, exemplifying the merits of peptides for Eph receptor targeting. Besides their modulation of Eph receptor/ephrin function, peptides can also serve to deliver conjugated imaging and therapeutic agents or various types of nanoparticles to tumors and other diseased tissues presenting target Eph receptors.

  18. Genetic mechanisms of scorpion venom peptide diversification.

    Science.gov (United States)

    Zhijian, Cao; Feng, Luo; Yingliang, Wu; Xin, Mao; Wenxin, Li

    2006-03-01

    The diversity of scorpion venom peptides is well shown by the presence of about 400 such polypeptides with or without disulfide bonds. Scorpion toxins with disulfide bonds present a variety of sequence features and pharmacological functions by affecting different ion channels, while the venom peptides without disulfide bonds represent a new subfamily, having much lower sequence homology among each other and different functions (e.g. bradykinin-potentiating, antimicrobial, molecular cell signal initiating and immune modulating). Interestingly, all scorpion venom peptides with divergent functions may have evolved from a common ancestor gene. Over the lengthy evolutionary time, the diversification of scorpion venom peptides evolved through polymorphism, duplication, trans-splicing, or alternative splicing at the gene level. In order to completely clarify the diversity of scorpion toxins and toxin-like peptides, toxinomics (genomics and proteomics of scorpion toxins and toxin-like peptides) are expected to greatly advance in the near future.

  19. A small peptide modeled after the NRAGE repeat domain inhibits XIAP-TAB1-TAK1 signaling for NF-κB activation and apoptosis in P19 cells.

    Directory of Open Access Journals (Sweden)

    Jennifer A Rochira

    Full Text Available In normal growth and development, apoptosis is necessary to shape the central nervous system and to eliminate excess neurons which are not required for innervation. In some diseases, however, apoptosis can be either overactive as in some neurodegenerative disorders or severely attenuated as in the spread of certain cancers. Bone morphogenetic proteins (BMPs transmit signals for regulating cell growth, differentiation, and apoptosis. Responding to BMP receptors stimulated from BMP ligands, neurotrophin receptor-mediated MAGE homolog (NRAGE binds and functions with the XIAP-TAK1-TAB1 complex to activate p38(MAPK and induces apoptosis in cortical neural progenitors. NRAGE contains a unique repeat domain that is only found in human, mouse, and rat homologs that we theorize is pivotal in its BMP MAPK role. Previously, we showed that deletion of the repeat domain inhibits apoptosis, p38(MAPK phosphorylation, and caspase-3 cleavage in P19 neural progenitor cells. We also showed that the XIAP-TAB1-TAK1 complex is dependent on NRAGE for IKK-α/β phosphorylation and NF-κB activation. XIAP is a major inhibitor of caspases, the main executioners of apoptosis. Although it has been shown previously that NRAGE binds to the RING domain of XIAP, it has not been determined which NRAGE domain binds to XIAP. Here, we used fluorescence resonance energy transfer (FRET to determine that there is a strong likelihood of a direct interaction between NRAGE and XIAP occurring at NRAGE's unique repeat domain which we also attribute to be the domain responsible for downstream signaling of NF-κB and activating IKK subunits. From these results, we designed a small peptide modeled after the NRAGE repeat domain which we have determined inhibits NF-κB activation and apoptosis in P19 cells. These intriguing results illustrate that the paradigm of the NRAGE repeat domain may hold promising therapeutic strategies in developing pharmaceutical solutions for combating harmful

  20. 9 CFR 319.703 - Rendered animal fat or mixture thereof.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Rendered animal fat or mixture thereof... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Fats, Oils, Shortenings § 319.703 Rendered animal fat or mixture thereof. “Rendered Animal Fat,” or any mixture of...

  1. Phospholipase C signaling via the parathyroid hormone (PTH)/PTH-related peptide receptor is essential for normal bone responses to PTH.

    Science.gov (United States)

    Guo, Jun; Liu, Minlin; Yang, Dehong; Bouxsein, Mary L; Thomas, Clare C; Schipani, Ernestina; Bringhurst, F Richard; Kronenberg, Henry M

    2010-08-01

    We have previously shown that differentiation of hypertrophic chondrocytes is delayed in mice expressing a mutated PTH/PTHrP receptor (PTHR) (called DSEL here) that stimulates adenylyl cyclase normally but fails to activate phospholipase C (PLC). To better understand the role of PLC signaling via the PTHR in skeletal and mineral homeostasis, we examined these mice fed a normal or calcium-deficient diet. On a standard diet, DSEL mice displayed a modest decrease in bone mass. Remarkably, when fed a low-calcium diet or infused with PTH, DSEL mice exhibited strikingly curtailed peritrabecular stromal cell responses and attenuated new bone formation when compared with Wt mice. Attenuated in vitro colony formation was also observed in bone marrow cells derived from DSEL mice fed a low-calcium diet. Furthermore, PTH stimulated proliferation and increased mRNAs encoding cyclin D1 in primary osteoblasts derived from Wt but not from DSEL mice. Our data indicate that PLC signaling through the PTHR is required for skeletal homeostasis.

  2. Efficient Unbiased Rendering using Enlightened Local Path Sampling

    DEFF Research Database (Denmark)

    Kristensen, Anders Wang

    . The downside to using these algorithms is that they can be slow to converge. Due to the nature of Monte Carlo methods, the results are random variables subject to variance. This manifests itself as noise in the images, which can only be reduced by generating more samples. The reason these methods are slow...... is because of a lack of eeffective methods of importance sampling. Most global illumination algorithms are based on local path sampling, which is essentially a recipe for constructing random walks. Using this procedure paths are built based on information given explicitly as part of scene description......, such as the location of the light sources or cameras, or the re flection models at each point. In this work we explore new methods of importance sampling paths. Our idea is to analyze the scene before rendering and compute various statistics that we use to improve importance sampling. The first of these are adjoint...

  3. Real-time Flame Rendering with GPU and CUDA

    Directory of Open Access Journals (Sweden)

    Wei Wei

    2011-02-01

    Full Text Available This paper proposes a method of flame simulation based on Lagrange process and chemical composition, which was non-grid and the problems associated with there grids were overcome. The turbulence movement of flame was described by Lagrange process and chemical composition was added into flame simulation which increased the authenticity of flame. For real-time applications, this paper simplified the EMST model. GPU-based particle system combined with OpenGL VBO and PBO unique technology was used to accelerate finally, the speed of vertex and pixel data interaction between CPU and GPU increased two orders of magnitude, frame rate of rendering increased by 30%, which achieved fast dynamic flame real-time simulation. For further real-time applications, this paper presented a strategy to implement flame simulation with CUDA on GPU, which achieved a speed up to 2.5 times the previous implementation.

  4. Latency in Distributed Acquisition and Rendering for Telepresence Systems.

    Science.gov (United States)

    Ohl, Stephan; Willert, Malte; Staadt, Oliver

    2015-12-01

    Telepresence systems use 3D techniques to create a more natural human-centered communication over long distances. This work concentrates on the analysis of latency in telepresence systems where acquisition and rendering are distributed. Keeping latency low is important to immerse users in the virtual environment. To better understand latency problems and to identify the source of such latency, we focus on the decomposition of system latency into sub-latencies. We contribute a model of latency and show how it can be used to estimate latencies in a complex telepresence dataflow network. To compare the estimates with real latencies in our prototype, we modify two common latency measurement methods. This presented methodology enables the developer to optimize the design, find implementation issues and gain deeper knowledge about specific sources of latency.

  5. Distributed Dimensonality-Based Rendering of LIDAR Point Clouds

    Science.gov (United States)

    Brédif, M.; Vallet, B.; Ferrand, B.

    2015-08-01

    Mobile Mapping Systems (MMS) are now commonly acquiring lidar scans of urban environments for an increasing number of applications such as 3D reconstruction and mapping, urban planning, urban furniture monitoring, practicability assessment for persons with reduced mobility (PRM)... MMS acquisitions are usually huge enough to incur a usability bottleneck for the increasing number of non-expert user that are not trained to process and visualize these huge datasets through specific softwares. A vast majority of their current need is for a simple 2D visualization that is both legible on screen and printable on a static 2D medium, while still conveying the understanding of the 3D scene and minimizing the disturbance of the lidar acquisition geometry (such as lidar shadows). The users that motivated this research are, by law, bound to precisely georeference underground networks for which they currently have schematics with no or poor absolute georeferencing. A solution that may fit their needs is thus a 2D visualization of the MMS dataset that they could easily interpret and on which they could accurately match features with their user datasets they would like to georeference. Our main contribution is two-fold. First, we propose a 3D point cloud stylization for 2D static visualization that leverages a Principal Component Analysis (PCA)-like local geometry analysis. By skipping the usual and error-prone estimation of a ground elevation, this rendering is thus robust to non-flat areas and has no hard-to-tune parameters such as height thresholds. Second, we implemented the corresponding rendering pipeline so that it can scale up to arbitrary large datasets by leveraging the Spark framework and its Resilient Distributed Dataset (RDD) and Dataframe abstractions.

  6. On-the-Fly Decompression and Rendering of Multiresolution Terrain

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, P; Cohen, J D

    2009-04-02

    We present a streaming geometry compression codec for multiresolution, uniformly-gridded, triangular terrain patches that supports very fast decompression. Our method is based on linear prediction and residual coding for lossless compression of the full-resolution data. As simplified patches on coarser levels in the hierarchy already incur some data loss, we optionally allow further quantization for more lossy compression. The quantization levels are adaptive on a per-patch basis, while still permitting seamless, adaptive tessellations of the terrain. Our geometry compression on such a hierarchy achieves compression ratios of 3:1 to 12:1. Our scheme is not only suitable for fast decompression on the CPU, but also for parallel decoding on the GPU with peak throughput over 2 billion triangles per second. Each terrain patch is independently decompressed on the fly from a variable-rate bitstream by a GPU geometry program with no branches or conditionals. Thus we can store the geometry compressed on the GPU, reducing storage and bandwidth requirements throughout the system. In our rendering approach, only compressed bitstreams and the decoded height values in the view-dependent 'cut' are explicitly stored on the GPU. Normal vectors are computed in a streaming fashion, and remaining geometry and texture coordinates, as well as mesh connectivity, are shared and re-used for all patches. We demonstrate and evaluate our algorithms on a small prototype system in which all compressed geometry fits in the GPU memory and decompression occurs on the fly every rendering frame without any cache maintenance.

  7. Technologies Render Views of Earth for Virtual Navigation

    Science.gov (United States)

    2012-01-01

    On a December night in 1995, 159 passengers and crewmembers died when American Airlines Flight 965 flew into the side of a mountain while in route to Cali, Colombia. A key factor in the tragedy: The pilots had lost situational awareness in the dark, unfamiliar terrain. They had no idea the plane was approaching a mountain until the ground proximity warning system sounded an alarm only seconds before impact. The accident was of the kind most common at the time CFIT, or controlled flight into terrain says Trey Arthur, research aerospace engineer in the Crew Systems and Aviation Operations Branch at NASA s Langley Research Center. In situations such as bad weather, fog, or nighttime flights, pilots would rely on airspeed, altitude, and other readings to get an accurate sense of location. Miscalculations and rapidly changing conditions could contribute to a fully functioning, in-control airplane flying into the ground. To improve aviation safety by enhancing pilots situational awareness even in poor visibility, NASA began exploring the possibilities of synthetic vision creating a graphical display of the outside terrain on a screen inside the cockpit. How do you display a mountain in the cockpit? You have to have a graphics-powered computer, a terrain database you can render, and an accurate navigation solution, says Arthur. In the mid-1990s, developing GPS technology offered a means for determining an aircraft s position in space with high accuracy, Arthur explains. As the necessary technologies to enable synthetic vision emerged, NASA turned to an industry partner to develop the terrain graphical engine and database for creating the virtual rendering of the outside environment.

  8. Valence Parity Renders z•-Type Ions Chemically Distinct

    OpenAIRE

    Hubler, Shane L.; Jue, April; Keith, Jason; McAlister, Graeme C.; Craciun, Gheorghe; Coon, Joshua J.

    2008-01-01

    Here we report that the odd electron z•-type ions formed by the electron-based peptide dissociation methods (electron capture or transfer, ECD or ETD) have distinctive chemical compositions from other common product ion types. Specifically, b-, c-, and y-type ions have an odd number of atoms with an odd valence (e.g., N and H), while z•-type ions contain an even number of atoms with an odd valence. This tenet, referred to as the valence parity rule, mandates that no c-type ion shall have the ...

  9. Effective Design of Multifunctional Peptides by Combining Compatible Functions.

    Science.gov (United States)

    Diener, Christian; Garza Ramos Martínez, Georgina; Moreno Blas, Daniel; Castillo González, David A; Corzo, Gerardo; Castro-Obregon, Susana; Del Rio, Gabriel

    2016-04-01

    Multifunctionality is a common trait of many natural proteins and peptides, yet the rules to generate such multifunctionality remain unclear. We propose that the rules defining some protein/peptide functions are compatible. To explore this hypothesis, we trained a computational method to predict cell-penetrating peptides at the sequence level and learned that antimicrobial peptides and DNA-binding proteins are compatible with the rules of our predictor. Based on this finding, we expected that designing peptides for CPP activity may render AMP and DNA-binding activities. To test this prediction, we designed peptides that embedded two independent functional domains (nuclear localization and yeast pheromone activity), linked by optimizing their composition to fit the rules characterizing cell-penetrating peptides. These peptides presented effective cell penetration, DNA-binding, pheromone and antimicrobial activities, thus confirming the effectiveness of our computational approach to design multifunctional peptides with potential therapeutic uses. Our computational implementation is available at http://bis.ifc.unam.mx/en/software/dcf.

  10. Fatty acid conjugation enhances the activities of antimicrobial peptides.

    Science.gov (United States)

    Li, Zhining; Yuan, Penghui; Xing, Meng; He, Zhumei; Dong, Chuanfu; Cao, Yongchang; Liu, Qiuyun

    2013-04-01

    Antimicrobial peptides are small molecules that play a crucial role in innate immunity in multi-cellular organisms, and usually expressed and secreted constantly at basal levels to prevent infection, but local production can be augmented upon an infection. The clock is ticking as rising antibiotic abuse has led to the emergence of many drug resistance bacteria. Due to their broad spectrum antibiotic and antifungal activities as well as anti-viral and anti-tumor activities, efforts are being made to develop antimicrobial peptides into future microbial agents. This article describes some of the recent patents on antimicrobial peptides with fatty acid conjugation. Potency and selectivity of antimicrobial peptide can be modulated with fatty acid tails of variable length. Interaction between membranes and antimicrobial peptides was affected by fatty acid conjugation. At concentrations above the critical miscelle concentration (CMC), propensity of solution selfassembly hampered binding of the peptide to cell membranes. Overall, fatty acid conjugation has enhanced the activities of antimicrobial peptides, and occasionally it rendered inactive antimicrobial peptides to be bioactive. Antimicrobial peptides can not only be used as medicine but also as food additives.

  11. Curcumin Ameliorates the Reduction Effect of PGE2 on Fibrillar β-Amyloid Peptide (1-42-Induced Microglial Phagocytosis through the Inhibition of EP2-PKA Signaling in N9 Microglial Cells.

    Directory of Open Access Journals (Sweden)

    Gen-Lin He

    Full Text Available Inflammatory activation of microglia and β amyloid (Aβ deposition are considered to work both independently and synergistically to contribute to the increased risk of Alzheimer's disease (AD. Recent studies indicate that long-term use of phenolic compounds provides protection against AD, primarily due to their anti-inflammatory actions. We previously suggested that phenolic compound curcumin ameliorated phagocytosis possibly through its anti-inflammatory effects rather than direct regulation of phagocytic function in electromagnetic field-exposed N9 microglial cells (N9 cells. Here, we explored the prostaglandin-E2 (PGE2-related signaling pathway that involved in curcumin-mediated phagocytosis in fibrillar β-amyloid peptide (1-42 (fAβ42-stimulated N9 cells. Treatment with fAβ42 increased phagocytosis of fluorescent-labeled latex beads in N9 cells. This increase was attenuated in a dose-dependent manner by endogenous and exogenous PGE2, as well as a selective EP2 or protein kinase A (PKA agonist, but not by an EP4 agonist. We also found that an antagonist of EP2, but not EP4, abolished the reduction effect of PGE2 on fAβ42-induced microglial phagocytosis. Additionally, the increased expression of endogenous PGE2, EP2, and cyclic adenosine monophosphate (AMP, and activation of vasodilator-stimulated phosphoprotein, cyclic AMP responsive element-binding protein, and PKA were depressed by curcumin administration. This reduction led to the amelioration of the phagocytic abilities of PGE2-stimulated N9 cells. Taken together, these data suggested that curcumin restored the attenuating effect of PGE2 on fAβ42-induced microglial phagocytosis via a signaling mechanism involving EP2 and PKA. Moreover, due to its immune modulatory effects, curcumin may be a promising pharmacological candidate for neurodegenerative diseases.

  12. NCAM Mimetic Peptides: An Update

    DEFF Research Database (Denmark)

    Berezin, Vladimir; Bock, Elisabeth

    2008-01-01

    pharmacological tools interfering with NCAM functions. Recent progress in our understanding of the structural basis of NCAM-mediated cell adhesion and signaling has allowed a structure-based design of NCAM mimetic peptides. Using this approach a number of peptides termed P2, P1-B, P-3-DE and P-3-G, whose...... sequences contain one or several NCAM homophilic binding sites involved in NCAM binding to itself, have been identified. By means of NMR titration analysis and molecular modeling a number of peptides derived from NCAM and targeting NCAM heterophilic ligands such as the fibroblast growth factor receptor...... in vitro and in vivo, making them attractive pharmacological tools suitable for drug development for the treatment of neurodegenerative disorders and impaired memory....

  13. [Effect of vasoactive intestinal peptide on defecation and VIP-cAMP-PKA-AQP3 signaling pathway 
in rats with constipation].

    Science.gov (United States)

    Zhou, Yongxue; Wang, Yujin; Zhang, Hong; Yan, Shuguang; Wang, Bin; Xie, Pei

    2016-11-28

    目的:观察血管活性肠肽(vasoactive intestinal peptide,VIP)对便秘大鼠肠道水液代谢、环磷酸腺苷-蛋白激酶A信号通路(cyclic AMP protein kinase A signaling pathway,cAMP-PKA)和水通道蛋白3(water channel protein 3,AQP3)的影响,探讨VIP治疗便秘的作用及机制。方法:45只健康成年Sprague-Dawley大鼠随机分为空白对照组、模型组、模型+
VIP组。给药4周后,墨汁灌胃法检测大鼠首粒黑便排出时间;根据大鼠粪便干湿重计算粪便含水率;HE染色观察各组大鼠结肠组织形态学变化;Western 印迹检测各组大鼠结肠组织中 VIP和AQP3蛋白表达水平;定量即时聚合酶链锁反应(quantitative real time polymerase chain reaction,qPCR)检测各组大鼠结肠组织中cAMP,PKA和AQP3 mRNA的表达水平。结果:与空白对照组比较,模型组大鼠首粒黑便出现时间延长,粪便含水率明显减少(均PCAMP,PKA和AQP3 mRNA相对表达水平升高(均PcAMP-PKA-AQP3信号通路有关。.

  14. Peptide insertions in domain 4 of hbeta(c), the shared signalling receptor subunit for GM-CSF, IL3 and IL5, induce ligand-independent activation.

    Science.gov (United States)

    Jones, K L; Bagley, C J; Butcher, C; Barry, S C; Vadas, M A; D'Andrea, R J

    2001-06-21

    A mutant form of the common beta-subunit of the GM-CSF, interleukin-3 (IL3) and IL5 receptors is activated by a 37 residue duplicated segment which includes the WSXWS motif and an adjacent, highly conserved, aliphatic/basic element. Haemopoietic expression of this mutant, hbeta(c)FIDelta, in mice leads to myeloproliferative disease. To examine the mechanism of activation of this mutant we targetted the two conserved motifs in each repeat for mutagenesis. Here we show that this mutant exhibits constitutive activity in BaF-B03 cells in the presence of mouse or human GM-CSF receptor alpha-subunit (GMRalpha) and this activity is disrupted by mutations of the conserved motifs in the first repeat. In the presence of these mutations the receptor reverts to an alternative conformation which retains responsiveness to human IL3 in a CTLL cell line co-expressing the human IL3 receptor alpha-subunit (hIL3Ralpha). Remarkably, the activated conformation is maintained in the presence of substitutions, deletions or replacement of the second repeat. This suggests that activation occurs due to insertion of extra sequence after the WSXWS motif and is not dependent on the length or specific sequence of the insertion. Thus hbeta(c) displays an ability to fold into functional receptor conformations given insertion of up to 37 residues in the membrane-proximal region. Constitutive activation most likely results from a specific conformational change which alters a dormant, inactive receptor complex, permitting functional association with GMRalpha and ligand-independent mitogenic signalling.

  15. Age, Health and Attractiveness Perception of Virtual (Rendered) Human Hair.

    Science.gov (United States)

    Fink, Bernhard; Hufschmidt, Carla; Hirn, Thomas; Will, Susanne; McKelvey, Graham; Lankhof, John

    2016-01-01

    The social significance of physical appearance and beauty has been documented in many studies. It is known that even subtle manipulations of facial morphology and skin condition can alter people's perception of a person's age, health and attractiveness. While the variation in facial morphology and skin condition cues has been studied quite extensively, comparably little is known on the effect of hair on social perception. This has been partly caused by the technical difficulty of creating appropriate stimuli for investigations of people's response to systematic variation of certain hair characteristics, such as color and style, while keeping other features constant. Here, we present a modeling approach to the investigation of human hair perception using computer-generated, virtual (rendered) human hair. In three experiments, we manipulated hair diameter (Experiment 1), hair density (Experiment 2), and hair style (Experiment 3) of human (female) head hair and studied perceptions of age, health and attractiveness. Our results show that even subtle changes in these features have an impact on hair perception. We discuss our findings with reference to previous studies on condition-dependent quality cues in women that influence human social perception, thereby suggesting that hair is a salient feature of human physical appearance, which contributes to the perception of beauty.

  16. VITRAIL: Acquisition, Modeling, and Rendering of Stained Glass.

    Science.gov (United States)

    Thanikachalam, Niranjan; Baboulaz, Loic; Prandoni, Paolo; Trumpler, Stefan; Wolf, Sophie; Vetterli, Martin

    2016-10-01

    Stained glass windows are designed to reveal their powerful artistry under diverse and time-varying lighting conditions; virtual relighting of stained glass, therefore, represents an exceptional tool for the appreciation of this age old art form. However, as opposed to most other artifacts, stained glass windows are extremely difficult if not impossible to analyze using controlled illumination because of their size and position. In this paper, we present novel methods built upon image based priors to perform virtual relighting of stained glass artwork by acquiring the actual light transport properties of a given artifact. In a preprocessing step, we build a material-dependent dictionary for light transport by studying the scattering properties of glass samples in a laboratory setup. We can now use the dictionary to recover a light transport matrix in two ways: under controlled illuminations the dictionary constitutes a sparsifying basis for a compressive sensing acquisition, while in the case of uncontrolled illuminations the dictionary is used to perform sparse regularization. The proposed basis preserves volume impurities and we show that the retrieved light transport matrix is heterogeneous, as in the case of real world objects. We present the rendering results of several stained glass artifacts, including the Rose Window of the Cathedral of Lausanne, digitized using the presented methods.

  17. Moisture Transfer through Facades Covered with Organic Binder Renders

    Directory of Open Access Journals (Sweden)

    Carmen DICO

    2013-07-01

    Full Text Available Year after year we witness the negative effect of water over buildings, caused by direct or indirect actions. This situation is obvious in case of old, historical building, subjected to this aggression for a long period of time, but new buildings are also affected. Moisture in building materials causes not only structural damage, but also reduces the thermal insulation capacity of building components.Materials like plasters or paints have been used historically for a long period of time, fulfilling two basics functions: Decoration and Protection. The most acute demands are made on exterior plasters, as they, besides being an important decorative element for the facade, must perform two different functions simultaneously: protect the substrate against weathering and moisture without sealing, providing it a certain ability to “breathe” (Heilen, 2005. In order to accomplish this aim, the first step is to understand the hygrothermal behavior of coating and substrate and define the fundamental principles of moisture transfer; According to Künzel’s Facade Protection Theory, two material properties play the most important role: Water absorption and Vapor permeability.In the context of recently adoption (2009 of the “harmonized” European standard EN 15824 – „Specifications for external renders and internal plasters based on organic binders”, this paper deals extensively with the interaction of the two mentioned above properties for the coating materials, covered by EN 15824.

  18. Light field rendering with omni-directional camera

    Science.gov (United States)

    Todoroki, Hiroshi; Saito, Hideo

    2003-06-01

    This paper presents an approach to capture visual appearance of a real environment such as an interior of a room. We propose the method for generating arbitrary viewpoint images by building light field with the omni-directional camera, which can capture the wide circumferences. Omni-directional camera used in this technique is a special camera with the hyperbolic mirror in the upper part of a camera, so that we can capture luminosity in the environment in the range of 360 degree of circumferences in one image. We apply the light field method, which is one technique of Image-Based-Rendering(IBR), for generating the arbitrary viewpoint images. The light field is a kind of the database that records the luminosity information in the object space. We employ the omni-directional camera for constructing the light field, so that we can collect many view direction images in the light field. Thus our method allows the user to explore the wide scene, that can acheive realistic representation of virtual enviroment. For demonstating the proposed method, we capture image sequence in our lab's interior environment with an omni-directional camera, and succesfully generate arbitray viewpoint images for virual tour of the environment.

  19. WikiPrints: rendering enterprise Wiki content for printing

    Science.gov (United States)

    Berkner, Kathrin

    2010-02-01

    Wikis have become a tool of choice for collaborative, informative communication. In contrast to the immense Wikipedia, that serves as a reference web site and typically covers only one topic per web page, enterprise wikis are often used as project management tools and contain several closely related pages authored by members of one project. In that scenario it is useful to print closely related content for review or teaching purposes. In this paper we propose a novel technique for rendering enterprise wiki content for printing called WikiPrints, that creates a linearized version of wiki content formatted as a mixture between web layout and conventional document layout suitable for printing. Compared to existing print options for wiki content, Wikiprints automatically selects content from different wiki pages given user preferences and usage scenarios. Meta data such as content authors or time of content editing are considered. A preview of the linearized content is shown to the user and an interface for making manual formatting changes provided.

  20. Age, Health and Attractiveness Perception of Virtual (Rendered) Human Hair

    Science.gov (United States)

    Fink, Bernhard; Hufschmidt, Carla; Hirn, Thomas; Will, Susanne; McKelvey, Graham; Lankhof, John

    2016-01-01

    The social significance of physical appearance and beauty has been documented in many studies. It is known that even subtle manipulations of facial morphology and skin condition can alter people’s perception of a person’s age, health and attractiveness. While the variation in facial morphology and skin condition cues has been studied quite extensively, comparably little is known on the effect of hair on social perception. This has been partly caused by the technical difficulty of creating appropriate stimuli for investigations of people’s response to systematic variation of certain hair characteristics, such as color and style, while keeping other features constant. Here, we present a modeling approach to the investigation of human hair perception using computer-generated, virtual (rendered) human hair. In three experiments, we manipulated hair diameter (Experiment 1), hair density (Experiment 2), and hair style (Experiment 3) of human (female) head hair and studied perceptions of age, health and attractiveness. Our results show that even subtle changes in these features have an impact on hair perception. We discuss our findings with reference to previous studies on condition-dependent quality cues in women that influence human social perception, thereby suggesting that hair is a salient feature of human physical appearance, which contributes to the perception of beauty. PMID:28066276

  1. Differentiation renders susceptibility to excitotoxicity in HT22 neurons

    Institute of Scientific and Technical Information of China (English)

    Minchao He; Jun Liu; Shaowu Cheng; Yigang Xing; William Z Suo

    2013-01-01

    HT22 is an immortalized mouse hippocampal neuronal cell line that does not express cholinergic and glutamate receptors like mature hippocampal neurons in vivo. This in part prevents its use as a model for mature hippocampal neurons in memory-related studies. We now report that HT22 cells were appropriately induced to differentiate and possess properties similar to those of mature hippocampal neurons in vivo, such as becoming more glutamate-receptive and excitatory. Results showed that sensitivity of HT22 cells to glutamate-induced toxicity changed dramatically when comparing undifferentiated with differentiated cells, with the half-effective concentration for differentiated cells reducing approximately two orders of magnitude. Moreover, glutamate-induced toxicity in differentiated cells, but not undifferentiated cells, was inhibited by the N-methyl-D- aspartate receptor antagonists MK-801 and memantine. Evidently, differentiated HT22 cells expressed N-methyl-D-aspartate receptors, while undifferentiated cells did not. Our experimental findings indicated that differentiation is important for immortalized cell lines to render post-mitotic neuronal properties, and that differentiated HT22 neurons represent a better model of hippocampal neurons than undifferentiated cells.

  2. 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...

  3. 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...

  4. New light field camera based on physical based rendering tracing

    Science.gov (United States)

    Chung, Ming-Han; Chang, Shan-Ching; Lee, Chih-Kung

    2014-03-01

    Even though light field technology was first invented more than 50 years ago, it did not gain popularity due to the limitation imposed by the computation technology. With the rapid advancement of computer technology over the last decade, the limitation has been uplifted and the light field technology quickly returns to the spotlight of the research stage. In this paper, PBRT (Physical Based Rendering Tracing) was introduced to overcome the limitation of using traditional optical simulation approach to study the light field camera technology. More specifically, traditional optical simulation approach can only present light energy distribution but typically lack the capability to present the pictures in realistic scenes. By using PBRT, which was developed to create virtual scenes, 4D light field information was obtained to conduct initial data analysis and calculation. This PBRT approach was also used to explore the light field data calculation potential in creating realistic photos. Furthermore, we integrated the optical experimental measurement results with PBRT in order to place the real measurement results into the virtually created scenes. In other words, our approach provided us with a way to establish a link of virtual scene with the real measurement results. Several images developed based on the above-mentioned approaches were analyzed and discussed to verify the pros and cons of the newly developed PBRT based light field camera technology. It will be shown that this newly developed light field camera approach can circumvent the loss of spatial resolution associated with adopting a micro-lens array in front of the image sensors. Detailed operational constraint, performance metrics, computation resources needed, etc. associated with this newly developed light field camera technique were presented in detail.

  5. Biologically Active and Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    Carlos E. Salas

    2015-01-01

    Full Text Available Bioactive peptides are part of an innate response elicited by most living forms. In plants, they are produced ubiquitously in roots, seeds, flowers, stems, and leaves, highlighting their physiological importance. While most of the bioactive peptides produced in plants possess microbicide properties, there is evidence that they are also involved in cellular signaling. Structurally, there is an overall similarity when comparing them with those derived from animal or insect sources. The biological action of bioactive peptides initiates with the binding to the target membrane followed in most cases by membrane permeabilization and rupture. Here we present an overview of what is currently known about bioactive peptides from plants, focusing on their antimicrobial activity and their role in the plant signaling network and offering perspectives on their potential application.

  6. Sexual communication via peptide and protein pheromones.

    Science.gov (United States)

    Touhara, Kazushige

    2008-12-01

    Pheromones are specific substances utilized by various organisms for intraspecific communication about sex, strain, or species. Although pheromones in terrestrial animals tend to be volatile airborne chemicals, large non-volatile molecules such as peptides and proteins are also utilized for sociosexual communication. Peptide pheromones are recognized by specific receptors expressed in the vertebrate vomeronasal organ that comprises a unique chemosensory system. The information is sent to the hypothalamic area wherein the signal is further integrated, leading to various pheromonal outputs. In this review, current knowledge on the structure and function of peptide and protein pheromones in vertebrates as well as the mechanisms underlying receptor-mediated signal processing will be summarized. The present review will also discuss why, from chemical and ecological points of view, peptide pheromones evolved.

  7. Design and Implementation of an Application. Programming Interface for Volume Rendering

    OpenAIRE

    Selldin, Håkan

    2002-01-01

    To efficiently examine volumetric data sets from CT or MRI scans good volume rendering applications are needed. This thesis describes the design and implementation of an application programming interface (API) to be used when developing volume-rendering applications. A complete application programming interface has been designed. The interface is designed so that it makes writing application programs containing volume rendering fast and easy. The interface also makes created application progr...

  8. Steric-electronic effects in malarial peptides inducing sterile immunity

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Vranich, Armando [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia); Patarroyo, Manuel E., E-mail: mepatarr@mail.com [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia); Universidad Nacional de Colombia, Bogota (Colombia)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer Is it evident that the residues position are relevant regarding of {phi} angular value. Black-Right-Pointing-Pointer The geometry considered for detailing the alterations undergone by HABPs. Black-Right-Pointing-Pointer The inter planar interactions ruled by clashes between the atoms making them up. -- Abstract: Conserved Plasmodium falciparum high activity binding peptides' (HABPs) most relevant proteins involved in malaria parasite invasion are immunologically silent; critical binding residues must therefore be specifically replaced to render them highly immunogenic and protection-inducing. Such changes have a tremendous impact on these peptides' steric-electronic effects, such as modifications to peptide length peptide bonds and electronic orbitals' disposition, to allow a better fit into immune system MHCII molecules and better interaction with the TCR which might account for the final immunological outcome.

  9. Influence of rendering methods on yield and quality of chicken fat recovered from broiler skin

    Directory of Open Access Journals (Sweden)

    Liang-Kun Lin

    2017-06-01

    Full Text Available Objective In order to utilize fat from broiler byproducts efficiently, it is necessary to develop an appropriate rendering procedure and establish quality information for the rendered fat. A study was therefore undertaken to evaluate the influence of rendering methods on the amounts and general properties of the fat recovered from broiler skin. Methods The yield and quality of the broiler skin fat rendered through high and lower energy microwave rendering (3.6 W/g for 10 min and 2.4 W/g for 10 min for high power microwave rendering (HPMR and high power microwave rendering (LPMR, respectively, oven baking (OB, at 180°C for 40 min, and water cooking (WC, boiling for 40 min were compared. Results Microwave-rendered skin exhibited the highest yields and fat recovery rates, followed by OB, and WC fats (p<0.05. HPMR fat had the highest L*, a*, and b* values, whereas WC fat had the highest moisture content, acid values, and thiobarbituric acid (TBA values (p<0.05. There was no significant difference in the acid value, peroxide value, and TBA values between HPMR and LPMR fats. Conclusion Microwave rendering at a power level of 3.6 W/g for 10 min is suggested base on the yield and quality of chicken fat.

  10. Performance Assessment of Three Rendering Engines in 3D Computer Graphics Software

    Directory of Open Access Journals (Sweden)

    Žan Vidmar

    2015-03-01

    Full Text Available The aim of the research was the determination of testing conditions and visual and numerical evaluation of renderings made with three different rendering engines in Maya software, which is widely used for educational and computer art purposes. In the theoretical part the overview of light phenomena and their simulation in virtual space is presented. This is followed by a detailed presentation of the main rendering methods and the results and limitations of their applications to 3D objects. At the end of the theoretical part the importance of a proper testing scene and especially the role of Cornell box are explained. In the experimental part the terms and conditions as well as hardware and software used for the research are presented. This is followed by a description of the procedures, where we focused on the rendering quality and time, which enabled the comparison of settings of different render engines and determination of conditions for further rendering of testing scenes. The experimental part continued with rendering a variety of simple virtual scenes including Cornell box and virtual object with different materials and colours. Apart from visual evaluation, which was the starting point for comparison of renderings, a procedure for numerical estimation and colour deviations of renderings using the selected regions of interest in the final images is presented.

  11. Real-time volume rendering of digital medical images on an iOS device

    Science.gov (United States)

    Noon, Christian; Holub, Joseph; Winer, Eliot

    2013-03-01

    Performing high quality 3D visualizations on mobile devices, while tantalizingly close in many areas, is still a quite difficult task. This is especially true for 3D volume rendering of digital medical images. Allowing this would empower medical personnel a powerful tool to diagnose and treat patients and train the next generation of physicians. This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing. An interactive volume renderer was designed and developed with several new features including dynamic modification of render resolutions, an incremental render loop, a shader-based clipping algorithm to support OpenGL ES 2.0, and an internal backface culling algorithm for properly sorting rendered geometry with alpha blending. The application was developed using several application programming interfaces (APIs) such as OpenSceneGraph (OSG) as the primary graphics renderer coupled with iOS Cocoa Touch for user interaction, and DCMTK for DICOM I/O. The developed application rendered volume datasets over 450 slices up to 50-60 frames per second, depending on the specific model of the iOS device. All rendering is done locally on the device so no Internet connection is required.

  12. The Leu7Pro polymorphism of the signal peptide of neuropeptide Y (NPY) gene is associated with increased levels of inflammatory markers preceding vascular complications in patients with type 2 diabetes.

    Science.gov (United States)

    Jaakkola, U; Kakko, T; Seppälä, H; Vainio-Jylhä, E; Vahlberg, T; Raitakari, O T; Kallio, J

    2010-12-01

    The Leucine7 to Proline7 (Leu7Pro) polymorphism of the signal peptide of neuropeptide Y (NPY) increases risk for vascular complications in diabetes. Diabetes is associated with low-grade inflammation, which has an important role in the development of atherosclerosis. Currently, we followed diabetes patients to investigate, if the Pro7 allele is associated with the inflammation related to atherosclerosis. In the 5-year follow-up, the genotyped, pair-matched type 2 diabetes patients (12 with the Pro7 allele and 19 without) were investigated using non-invasive ultrasound based methods to measure the development of atherosclerosis (intima media thickness=IMT) and endothelium-dependent (FMD) and -independent nitrate-mediated (NMD) vasodilatation. The development of diabetic complications was followed annually, and the concentrations of inflammatory markers and NPY in plasma were determined. Patients with the Pro7 had increased U-albumin/creatinine (p=0.037), E-selectin (p=0.016), fasting insulin (p=0.011) and HOMA index (p=0.013) but decreased serum amyloid P concentrations (p=0.021). Furthermore, men with the Pro7 had increased CRP (p=0.010) and NPY (p=0.026) concentrations. IMT and FMD were similar in all patients, however, NMD decreased more during the follow-up in the patients with the Pro7 (p=0.002). NPY correlated positively with bIMT [r 0.04 (SE 0.02), p=0.007] and E-selectin negatively with FMD [r -0.05 (S.E 0.02), p=0.039]. Diabetes patients with the Pro7 allele display increased levels of inflammatory molecules and NPY in blood, preceding vascular wall thickening and impaired endothelial dilatation, especially in male patients. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. Vaccination against Experimental Allergic Encephalomyelitis with T Cell Receptor Peptides

    Science.gov (United States)

    Howell, Mark D.; Winters, Steven T.; Olee, Tsaiwei; Powell, Henry C.; Carlo, Dennis J.; Brostoff, Steven W.

    1989-11-01

    Experimental allergic encephalomyelitis (EAE) is an autoimmune disease of the central nervous system mediated by CD4+ T cells reactive with myelin basic protein (MBP). Rats were rendered resistant to the induction of EAE by vaccination with synthetic peptides corresponding to idiotypic determinants of the β chain VDJ region and Jα regions of the T cell receptor (TCR) that are conserved among encephalitogenic T cells. These findings demonstrate the utility of TCR peptide vaccination for modulating the activity of autoreactive T cells and represent a general therapeutic approach for T cell--mediated pathogenesis.

  14. Peptides and Food Intake

    Science.gov (United States)

    Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

  15. Valence parity renders z(*)-type ions chemically distinct.

    Science.gov (United States)

    Hubler, Shane L; Jue, April; Keith, Jason; McAlister, Graeme C; Craciun, Gheorghe; Coon, Joshua J

    2008-05-21

    Here we report that the odd electron z (*) -type ions formed by the electron-based peptide dissociation methods (electron capture or transfer, ECD or ETD) have distinctive chemical compositions from other common product ion types. Specifically, b-, c-, and y-type ions have an odd number of atoms with an odd valence (e.g., N and H), while z (*)-type ions contain an even number of atoms with an odd valence. This tenet, referred to as the valence parity rule, mandates that no c-type ion shall have the same chemical composition, and by extension mass, as a z (*) -type ion. By experiment we demonstrate that nearly half of all observed c- and z (*) -type product ions resulting from 226 ETD product ion spectra can be assigned to a single, correct, chemical composition and ion type by simple inspection of the m/ z peaks. The assignments provide (1) a platform to directly determine amino acid composition, (2) an input for database search algorithms, or (3) a basis for de novo sequence analysis.

  16. Protected aminooxyprolines for expedited library synthesis: application to Tsg101-directed proline-oxime containing peptides.

    Science.gov (United States)

    Liu, Fa; Stephen, Andrew G; Fisher, Robert J; Burke, Terrence R

    2008-02-01

    The stereoselective synthesis of aminooxy-containing proline analogues bearing Fmoc/Boc or Fmoc/Mtt protection that renders them suitable for incorporation into peptides using Fmoc protocols is reported. Acid-catalyzed unmasking at the completion of peptide synthesis yields free aminooxy-functionalities for oxime formation through reaction with libraries of aldehydes. This allows post solid-phase diversification strategies that may facilitate structure-activity relationship studies.

  17. 31 CFR 515.548 - Services rendered by Cuba to United States aircraft.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Services rendered by Cuba to United... REGULATIONS Licenses, Authorizations, and Statements of Licensing Policy § 515.548 Services rendered by Cuba to United States aircraft. Specific licenses are issued for payment to Cuba of charges for services...

  18. Frequency domain volume rendering by the wavelet X-ray transform

    NARCIS (Netherlands)

    Westenberg, Michel A.; Roerdink, Jos B.T.M.

    2000-01-01

    We describe a wavelet-based X-ray rendering method in the frequency domain with a smaller time complexity than wavelet splatting. Standard Fourier volume rendering is summarized and interpolation and accuracy issues are briefly discussed. We review the implementation of the fast wavelet transform in

  19. Evaluation of voxel-based rendering of high resolution surface descriptions

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Olesen, Søren Krarup; Markovic, Milos

    2014-01-01

    responses by having more “distinct” representations of the individual reflections. When rendered audible, such descriptions will lead to a sound quality that can best be described as “canned”. For the rendering of real rooms, as e.g. in "teletransporting", this problem may be addressed by using high...

  20. Hardware Implementation of an Automatic Rendering Tone Mapping Algorithm for a Wide Dynamic Range Display

    Directory of Open Access Journals (Sweden)

    Orly Yadid-Pecht

    2013-10-01

    Full Text Available Tone mapping algorithms are used to adapt captured wide dynamic range (WDR scenes to the limited dynamic range of available display devices. Although there are several tone mapping algorithms available, most of them require manual tuning of their rendering parameters. In addition, the high complexities of some of these algorithms make it difficult to implement efficient real-time hardware systems. In this work, a real-time hardware implementation of an exponent-based tone mapping algorithm is presented. The algorithm performs a mixture of both global and local compression on colored WDR images. An automatic parameter selector has been proposed for the tone mapping algorithm in order to achieve good tone-mapped images without manual reconfiguration of the algorithm for each WDR image. Both algorithms are described in Verilog and synthesized for a field programmable gate array (FPGA. The hardware architecture employs a combination of parallelism and system pipelining, so as to achieve a high performance in power consumption, hardware resources usage and processing speed. Results show that the hardware architecture produces images of good visual quality that can be compared to software-based tone mapping algorithms. High peak signal-to-noise ratio (PSNR and structural similarity (SSIM scores were obtained when the results were compared with output images obtained from software simulations using MATLAB.