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Sample records for target protein expression

  1. Expression of protein-tyrosine phosphatases in the major insulin target tissues

    DEFF Research Database (Denmark)

    Norris, K; Norris, F; Kono, D H

    1997-01-01

    Protein-tyrosine phosphatases (PTPs) are key regulators of the insulin receptor signal transduction pathway. We have performed a detailed analysis of PTP expression in the major human insulin target tissues or cells (liver, adipose tissue, skeletal muscle and endothelial cells). To obtain a repre...

  2. Tuning protein expression using synonymous codon libraries targeted to the 5' mRNA coding region

    DEFF Research Database (Denmark)

    Goltermann, Lise; Borch Jensen, Martin; Bentin, Thomas

    2011-01-01

    intermediate expression levels of green fluorescent protein in Escherichia coli. At least in one case, no apparent effect on protein stability was observed, pointing to RNA level effects as the principal reason for the observed expression differences. Targeting a synonymous codon library to the 5' coding...

  3. ESPRIT: an automated, library-based method for mapping and soluble expression of protein domains from challenging targets.

    Science.gov (United States)

    Yumerefendi, Hayretin; Tarendeau, Franck; Mas, Philippe J; Hart, Darren J

    2010-10-01

    Expression of sufficient quantities of soluble protein for structural biology and other applications is often a very difficult task, especially when multimilligram quantities are required. In order to improve yield, solubility or crystallisability of a protein, it is common to subclone shorter genetic constructs corresponding to single- or multi-domain fragments. However, it is not always clear where domain boundaries are located, especially when working on novel targets with little or no sequence similarity to other proteins. Several methods have been described employing aspects of directed evolution to the recombinant expression of challenging proteins. These combine the construction of a random library of genetic constructs of a target with a screening or selection process to identify solubly expressing protein fragments. Here we review several datasets from the ESPRIT (Expression of Soluble Proteins by Random Incremental Truncation) technology to provide a view on its capabilities. Firstly, we demonstrate how it functions using the well-characterised NF-kappaB p50 transcription factor as a model system. Secondly, application of ESPRIT to the challenging PB2 subunit of influenza polymerase has led to several novel atomic resolution structures; here we present an overview of the screening phase of that project. Thirdly, analysis of the human kinase TBK1 is presented to show how the ESPRIT technology rapidly addresses the compatibility of challenging targets with the Escherichia coli expression system.

  4. Drug-induced regulation of target expression

    DEFF Research Database (Denmark)

    Iskar, Murat; Campillos, Monica; Kuhn, Michael

    2010-01-01

    Drug perturbations of human cells lead to complex responses upon target binding. One of the known mechanisms is a (positive or negative) feedback loop that adjusts the expression level of the respective target protein. To quantify this mechanism systems-wide in an unbiased way, drug......-induced differential expression of drug target mRNA was examined in three cell lines using the Connectivity Map. To overcome various biases in this valuable resource, we have developed a computational normalization and scoring procedure that is applicable to gene expression recording upon heterogeneous drug treatments....... In 1290 drug-target relations, corresponding to 466 drugs acting on 167 drug targets studied, 8% of the targets are subject to regulation at the mRNA level. We confirmed systematically that in particular G-protein coupled receptors, when serving as known targets, are regulated upon drug treatment. We...

  5. Endosialin and Associated Protein Expression in Soft Tissue Sarcomas: A Potential Target for Anti-Endosialin Therapeutic Strategies

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    Daniel J. O’Shannessy

    2016-01-01

    Full Text Available Endosialin (CD248, TEM-1 is expressed in pericytes, tumor vasculature, tumor fibroblasts, and some tumor cells, including sarcomas, with limited normal tissue expression, and appears to play a key role in tumor-stromal interactions, including angiogenesis. Monoclonal antibodies targeting endosialin have entered clinical trials, including soft tissue sarcomas. We evaluated a cohort of 94 soft tissue sarcoma samples to assess the correlation between gene expression and protein expression by immunohistochemistry for endosialin and PDGFR-β, a reported interacting protein, across available diagnoses. Correlations between the expression of endosialin and 13 other genes of interest were also examined. Within cohorts of soft tissue diagnoses assembled by tissue type (liposarcoma, leiomyosarcoma, undifferentiated sarcoma, and other, endosialin expression was significantly correlated with a better outcome. Endosialin expression was highest in liposarcomas and lowest in leiomyosarcomas. A robust correlation between protein and gene expression data for both endosialin and PDGFR-β was observed. Endosialin expression positively correlated with PDGFR-β and heparin sulphate proteoglycan 2 and negatively correlated with carbonic anhydrase IX. Endosialin likely interacts with a network of extracellular and hypoxia activated proteins in sarcomas and other tumor types. Since expression does vary across histologic groups, endosialin may represent a selective target in soft tissue sarcomas.

  6. An array of Escherichia coli clones over-expressing essential proteins: A new strategy of identifying cellular targets of potent antibacterial compounds

    International Nuclear Information System (INIS)

    Xu, H. Howard; Real, Lilian; Bailey, Melissa Wu

    2006-01-01

    With the advancement of high throughput screening, it has become easier and faster to discover hit compounds that inhibit proliferation of bacterial cells. However, development in technologies used to identify cellular targets of potent antibacterial inhibitors has lagged behind. Here, we describe a novel strategy of target identification for antibacterial inhibitors using an array of Escherichia coli clones each over-expressing one essential protein. In a proof-of-concept study, eight essential genes were cloned into pLex5BA vector under the control of an inducible promoter. Over-expression of target proteins was confirmed. For two clones, one over-expressing FabI and the other over-expressing MurA enzymes, the host cells became 17- and 139-fold more resistant to the specific inhibitors triclosan and phosphomycin, respectively, while the susceptibility of other clones towards these inhibitors remained unchanged after induction of gene expression. Target identification via target protein over-expression was demonstrated using both mixed clone and individual clone assay formats

  7. Generation and evaluation of mammalian secreted and membrane protein expression libraries for high-throughput target discovery.

    Science.gov (United States)

    Panavas, Tadas; Lu, Jin; Liu, Xuesong; Winkis, Ann-Marie; Powers, Gordon; Naso, Michael F; Amegadzie, Bernard

    2011-09-01

    Expressed protein libraries are becoming a critical tool for new target discovery in the pharmaceutical industry. In order to get the most meaningful and comprehensive results from protein library screens, it is essential to have library proteins in their native conformation with proper post-translation modifications. This goal is achieved by expressing untagged human proteins in a human cell background. We optimized the transfection and cell culture conditions to maximize protein expression in a 96-well format so that the expression levels were comparable with the levels observed in shake flasks. For detection purposes, we engineered a 'tag after stop codon' system. Depending on the expression conditions, it was possible to express either native or tagged proteins from the same expression vector set. We created a human secretion protein library of 1432 candidates and a small plasma membrane protein set of about 500 candidates. Utilizing the optimized expression conditions, we expressed and analyzed both libraries by SDS-PAGE gel electrophoresis and Western blotting. Two thirds of secreted proteins could be detected by Western-blot analyses; almost half of them were visible on Coomassie stained gels. In this paper, we describe protein expression libraries that can be easily produced in mammalian expression systems in a 96-well format, with one protein expressed per well. The libraries and methods described allow for the development of robust, high-throughput functional screens designed to assay for protein specific functions associated with a relevant disease-specific activity. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Properties of Protein Drug Target Classes

    Science.gov (United States)

    Bull, Simon C.; Doig, Andrew J.

    2015-01-01

    Accurate identification of drug targets is a crucial part of any drug development program. We mined the human proteome to discover properties of proteins that may be important in determining their suitability for pharmaceutical modulation. Data was gathered concerning each protein’s sequence, post-translational modifications, secondary structure, germline variants, expression profile and drug target status. The data was then analysed to determine features for which the target and non-target proteins had significantly different values. This analysis was repeated for subsets of the proteome consisting of all G-protein coupled receptors, ion channels, kinases and proteases, as well as proteins that are implicated in cancer. Machine learning was used to quantify the proteins in each dataset in terms of their potential to serve as a drug target. This was accomplished by first inducing a random forest that could distinguish between its targets and non-targets, and then using the random forest to quantify the drug target likeness of the non-targets. The properties that can best differentiate targets from non-targets were primarily those that are directly related to a protein’s sequence (e.g. secondary structure). Germline variants, expression levels and interactions between proteins had minimal discriminative power. Overall, the best indicators of drug target likeness were found to be the proteins’ hydrophobicities, in vivo half-lives, propensity for being membrane bound and the fraction of non-polar amino acids in their sequences. In terms of predicting potential targets, datasets of proteases, ion channels and cancer proteins were able to induce random forests that were highly capable of distinguishing between targets and non-targets. The non-target proteins predicted to be targets by these random forests comprise the set of the most suitable potential future drug targets, and should therefore be prioritised when building a drug development programme. PMID

  9. Expression and activity analysis of a new fusion protein targeting ovarian cancer cells.

    Science.gov (United States)

    Su, Manman; Chang, Weiqin; Wang, Dingding; Cui, Manhua; Lin, Yang; Wu, Shuying; Xu, Tianmin

    2015-09-01

    The aim of the present study was to develop a new therapeutic drug to improve the prognosis of ovarian cancer patients. Human urokinase-type plasminogen activator (uPA)17-34-kunitz-type protease inhibitor (KPI) eukaryotic expression vector was constructed and recombinant human uPA17-34-KPI (rhuPA17-34-KPI) in P. pastoris was expressed. In the present study, the DNA sequences that encode uPA 17-34 amino acids were created according to the native amino acids sequence and inserted into the KPI-pPICZαC vector, which was constructed. Then, uPA17‑34-KPI-pPICZαC was transformed into P. pastoris X-33, and rhuPA17-34-KPI was expressed by induction of methanol. The bioactivities of a recombinant fusion protein were detected with trypsin inhibition analysis, and the inhibitory effects on the growth of ovarian cancer cells were identified using the TUNEL assay, in vitro wound‑healing assay and Matrigel model analysis. The results of the DNA sequence analysis of the recombinant vector uPA17-34-KPI‑pPICZα demonstrated that the DNA‑encoding human uPA 17-34 amino acids, 285-288 amino acids of amyloid precursor protein (APP) and 1-57 amino acids of KPI were correctly inserted into the pPICZαC vector. Following induction by methonal, the fusion protein with a molecular weight of 8.8 kDa was observed using SDS-PAGE and western blot analysis. RhuPA17-34-KPI was expressed in P. pastoris with a yield of 50 mg/l in a 50-ml tube. The recombinant fusion protein was able to inhibit the activity of trypsin, inhibit growth and induce apoptosis of SKOV3 cells, and inhibit the invasion and metastasis of ovarian cancer cells. By considering uPA17-34 amino acid specific binding uPAR as the targeted part of fusion protein and utilizing the serine protease inhibitor activity of KPI, it was found that the recombinant fusion protein uPA17-34-KPI inhibited the invasion and metastasis of ovarian tumors, and may therefore be regarded as effective in targeted treatment.

  10. Employment of colorimetric enzyme assay for monitoring expression and solubility of GST fusion proteins targeted to inclusion bodies.

    Science.gov (United States)

    Mačinković, Igor S; Abughren, Mohamed; Mrkic, Ivan; Grozdanović, Milica M; Prodanović, Radivoje; Gavrović-Jankulović, Marija

    2013-12-01

    High levels of recombinant protein expression can lead to the formation of insoluble inclusion bodies. These complex aggregates are commonly solubilized in strong denaturants, such as 6-8M urea, although, if possible, solubilization under milder conditions could facilitate subsequent refolding and purification of bioactive proteins. Commercially available GST-tag assays are designed for quantitative measurement of GST activity under native conditions. GST fusion proteins accumulated in inclusion bodies are considered to be undetectable by such assays. In this work, solubilization of recombinantly produced proteins was performed in 4M urea. The activity of rGST was assayed in 2M urea and it was shown that rGST preserves 85% of its activity under such denaturing conditions. A colorimetric GST activity assay with 1-chloro-2, 4-dinitrobenzene (CDNB) was examined for use in rapid detection of expression targeted to inclusion bodies and for the identification of inclusion body proteins which can be solubilized in low concentrations of chaotropic agents. Applicability of the assay was evaluated by tracking protein expression of two GST-fused allergens of biopharmaceutical value in E. coli, GST-Der p 2 and GST-Mus a 5, both targeted to inclusion bodies. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Dissecting the expression relationships between RNA-binding proteins and their cognate targets in eukaryotic post-transcriptional regulatory networks

    Science.gov (United States)

    Nishtala, Sneha; Neelamraju, Yaseswini; Janga, Sarath Chandra

    2016-05-01

    RNA-binding proteins (RBPs) are pivotal in orchestrating several steps in the metabolism of RNA in eukaryotes thereby controlling an extensive network of RBP-RNA interactions. Here, we employed CLIP (cross-linking immunoprecipitation)-seq datasets for 60 human RBPs and RIP-ChIP (RNP immunoprecipitation-microarray) data for 69 yeast RBPs to construct a network of genome-wide RBP- target RNA interactions for each RBP. We show in humans that majority (~78%) of the RBPs are strongly associated with their target transcripts at transcript level while ~95% of the studied RBPs were also found to be strongly associated with expression levels of target transcripts when protein expression levels of RBPs were employed. At transcript level, RBP - RNA interaction data for the yeast genome, exhibited a strong association for 63% of the RBPs, confirming the association to be conserved across large phylogenetic distances. Analysis to uncover the features contributing to these associations revealed the number of target transcripts and length of the selected protein-coding transcript of an RBP at the transcript level while intensity of the CLIP signal, number of RNA-Binding domains, location of the binding site on the transcript, to be significant at the protein level. Our analysis will contribute to improved modelling and prediction of post-transcriptional networks.

  12. Targeting protein-protein interactions for parasite control.

    Directory of Open Access Journals (Sweden)

    Christina M Taylor

    2011-04-01

    Full Text Available Finding new drug targets for pathogenic infections would be of great utility for humanity, as there is a large need to develop new drugs to fight infections due to the developing resistance and side effects of current treatments. Current drug targets for pathogen infections involve only a single protein. However, proteins rarely act in isolation, and the majority of biological processes occur via interactions with other proteins, so protein-protein interactions (PPIs offer a realm of unexplored potential drug targets and are thought to be the next-generation of drug targets. Parasitic worms were chosen for this study because they have deleterious effects on human health, livestock, and plants, costing society billions of dollars annually and many sequenced genomes are available. In this study, we present a computational approach that utilizes whole genomes of 6 parasitic and 1 free-living worm species and 2 hosts. The species were placed in orthologous groups, then binned in species-specific orthologous groups. Proteins that are essential and conserved among species that span a phyla are of greatest value, as they provide foundations for developing broad-control strategies. Two PPI databases were used to find PPIs within the species specific bins. PPIs with unique helminth proteins and helminth proteins with unique features relative to the host, such as indels, were prioritized as drug targets. The PPIs were scored based on RNAi phenotype and homology to the PDB (Protein DataBank. EST data for the various life stages, GO annotation, and druggability were also taken into consideration. Several PPIs emerged from this study as potential drug targets. A few interactions were supported by co-localization of expression in M. incognita (plant parasite and B. malayi (H. sapiens parasite, which have extremely different modes of parasitism. As more genomes of pathogens are sequenced and PPI databases expanded, this methodology will become increasingly

  13. Gene design, cloning and protein-expression methods for high-value targets at the Seattle Structural Genomics Center for Infectious Disease

    International Nuclear Information System (INIS)

    Raymond, Amy; Haffner, Taryn; Ng, Nathan; Lorimer, Don; Staker, Bart; Stewart, Lance

    2011-01-01

    An overview of one salvage strategy for high-value SSGCID targets is given. Any structural genomics endeavor, particularly ambitious ones such as the NIAID-funded Seattle Structural Genomics Center for Infectious Disease (SSGCID) and Center for Structural Genomics of Infectious Disease (CSGID), face technical challenges at all points of the production pipeline. One salvage strategy employed by SSGCID is combined gene engineering and structure-guided construct design to overcome challenges at the levels of protein expression and protein crystallization. Multiple constructs of each target are cloned in parallel using Polymerase Incomplete Primer Extension cloning and small-scale expressions of these are rapidly analyzed by capillary electrophoresis. Using the methods reported here, which have proven particularly useful for high-value targets, otherwise intractable targets can be resolved

  14. Protein-anchoring therapy to target extracellular matrix proteins to their physiological destinations.

    Science.gov (United States)

    Ito, Mikako; Ohno, Kinji

    2018-02-20

    Endplate acetylcholinesterase (AChE) deficiency is a form of congenital myasthenic syndrome (CMS) caused by mutations in COLQ, which encodes collagen Q (ColQ). ColQ is an extracellular matrix (ECM) protein that anchors AChE to the synaptic basal lamina. Biglycan, encoded by BGN, is another ECM protein that binds to the dystrophin-associated protein complex (DAPC) on skeletal muscle, which links the actin cytoskeleton and ECM proteins to stabilize the sarcolemma during repeated muscle contractions. Upregulation of biglycan stabilizes the DPAC. Gene therapy can potentially ameliorate any disease that can be recapitulated in cultured cells. However, the difficulty of tissue-specific and developmental stage-specific regulated expression of transgenes, as well as the difficulty of introducing a transgene into all cells in a specific tissue, prevents us from successfully applying gene therapy to many human diseases. In contrast to intracellular proteins, an ECM protein is anchored to the target tissue via its specific binding affinity for protein(s) expressed on the cell surface within the target tissue. Exploiting this unique feature of ECM proteins, we developed protein-anchoring therapy in which a transgene product expressed even in remote tissues can be delivered and anchored to a target tissue using specific binding signals. We demonstrate the application of protein-anchoring therapy to two disease models. First, intravenous administration of adeno-associated virus (AAV) serotype 8-COLQ to Colq-deficient mice, resulting in specific anchoring of ectopically expressed ColQ-AChE at the NMJ, markedly improved motor functions, synaptic transmission, and the ultrastructure of the neuromuscular junction (NMJ). In the second example, Mdx mice, a model for Duchenne muscular dystrophy, were intravenously injected with AAV8-BGN. The treatment ameliorated motor deficits, mitigated muscle histopathologies, decreased plasma creatine kinase activities, and upregulated expression

  15. High-throughput Cloning and Expression of Integral Membrane Proteins in Escherichia coli

    Science.gov (United States)

    Bruni, Renato

    2014-01-01

    Recently, several structural genomics centers have been established and a remarkable number of three-dimensional structures of soluble proteins have been solved. For membrane proteins, the number of structures solved has been significantly trailing those for their soluble counterparts, not least because over-expression and purification of membrane proteins is a much more arduous process. By using high throughput technologies, a large number of membrane protein targets can be screened simultaneously and a greater number of expression and purification conditions can be employed, leading to a higher probability of successfully determining the structure of membrane proteins. This unit describes the cloning, expression and screening of membrane proteins using high throughput methodologies developed in our laboratory. Basic Protocol 1 deals with the cloning of inserts into expression vectors by ligation-independent cloning. Basic Protocol 2 describes the expression and purification of the target proteins on a miniscale. Lastly, for the targets that express at the miniscale, basic protocols 3 and 4 outline the methods employed for the expression and purification of targets at the midi-scale, as well as a procedure for detergent screening and identification of detergent(s) in which the target protein is stable. PMID:24510647

  16. Expression of membrane targeted aequorin in Xenopus laevis oocytes.

    Science.gov (United States)

    Daguzan, C; Nicolas, M T; Mazars, C; Leclerc, C; Moreau, M

    1995-08-01

    We described here a system for high level of expression of the calcium activated photoprotein aequorin. This protein has been targeted to the plasma membrane of Xenopus oocyte by nuclear microinjection of a plasmid containing a construction of a chimeric cDNA encoding a fusion protein composed of the photoprotein aequorin and the 5-HT1A receptor. The expression of this fusion protein is placed under the control of RSV promoter. Functional photoprotein was reconstituted in the oocyte by incubation with coelenterazine. The amount of photoprotein 24 h after nuclear microinjection of the plasmid was sufficient to trigger a detectable light emission following calcium entry. The efficiency of the expression is correlated with the dose of plasmid injected. Intracytoplasmic injection of the plasmid always failed in photoprotein expression. Targeting of the apoprotein was demonstrated by immunolocalization under confocal microscopy. In our experimental conditions, the apoprotein was always localized at the animal pole above the nucleus. We never observed expression and targeting to the plasma membrane of the vegetal pole. WE suggest that such expression might be of great interest for the study of numerous problems of developmental biology, in which calcium-dependent pathways are involved.

  17. Targeted amino-terminal acetylation of recombinant proteins in E. coli.

    Directory of Open Access Journals (Sweden)

    Matthew Johnson

    2010-12-01

    Full Text Available One major limitation in the expression of eukaryotic proteins in bacteria is an inability to post-translationally modify the expressed protein. Amino-terminal acetylation is one such modification that can be essential for protein function. By co-expressing the fission yeast NatB complex with the target protein in E.coli, we report a simple and widely applicable method for the expression and purification of functional N-terminally acetylated eukaryotic proteins.

  18. A Generic Protocol for Intracellular Expression of Recombinant Proteins in Bacillus subtilis.

    Science.gov (United States)

    Phan, Trang; Huynh, Phuong; Truong, Tuom; Nguyen, Hoang

    2017-01-01

    Bacillus subtilis (B. subtilis) is a potential and attractive host for the production of recombinant proteins. Different expression systems for B. subtilis have been developed recently, and various target proteins have been recombinantly synthesized and purified using this host. In this chapter, we introduce a generic protocol to express a recombinant protein in B. subtilis. It includes protocols for (1) using our typical expression vector (plasmid pHT254) to introduce a target gene, (2) transformation of the target vector into B. subtilis, and (3) evaluation of the actual expression of a recombinant protein.

  19. Differential binding of calmodulin-related proteins to their targets revealed through high-density Arabidopsis protein microarrays

    Science.gov (United States)

    Popescu, Sorina C.; Popescu, George V.; Bachan, Shawn; Zhang, Zimei; Seay, Montrell; Gerstein, Mark; Snyder, Michael; Dinesh-Kumar, S. P.

    2007-01-01

    Calmodulins (CaMs) are the most ubiquitous calcium sensors in eukaryotes. A number of CaM-binding proteins have been identified through classical methods, and many proteins have been predicted to bind CaMs based on their structural homology with known targets. However, multicellular organisms typically contain many CaM-like (CML) proteins, and a global identification of their targets and specificity of interaction is lacking. In an effort to develop a platform for large-scale analysis of proteins in plants we have developed a protein microarray and used it to study the global analysis of CaM/CML interactions. An Arabidopsis thaliana expression collection containing 1,133 ORFs was generated and used to produce proteins with an optimized medium-throughput plant-based expression system. Protein microarrays were prepared and screened with several CaMs/CMLs. A large number of previously known and novel CaM/CML targets were identified, including transcription factors, receptor and intracellular protein kinases, F-box proteins, RNA-binding proteins, and proteins of unknown function. Multiple CaM/CML proteins bound many binding partners, but the majority of targets were specific to one or a few CaMs/CMLs indicating that different CaM family members function through different targets. Based on our analyses, the emergent CaM/CML interactome is more extensive than previously predicted. Our results suggest that calcium functions through distinct CaM/CML proteins to regulate a wide range of targets and cellular activities. PMID:17360592

  20. Urea transporter proteins as targets for small-molecule diuretics.

    Science.gov (United States)

    Esteva-Font, Cristina; Anderson, Marc O; Verkman, Alan S

    2015-02-01

    Conventional diuretics such as furosemide and thiazides target salt transporters in kidney tubules, but urea transporters (UTs) have emerged as alternative targets. UTs are a family of transmembrane channels expressed in a variety of mammalian tissues, in particular the kidney. UT knockout mice and humans with UT mutations exhibit reduced maximal urinary osmolality, demonstrating that UTs are necessary for the concentration of urine. Small-molecule screening has identified potent and selective inhibitors of UT-A, the UT protein expressed in renal tubule epithelial cells, and UT-B, the UT protein expressed in vasa recta endothelial cells. Data from UT knockout mice and from rodents administered UT inhibitors support the diuretic action of UT inhibition. The kidney-specific expression of UT-A1, together with high selectivity of the small-molecule inhibitors, means that off-target effects of such small-molecule drugs should be minimal. This Review summarizes the structure, expression and function of UTs, and looks at the evidence supporting the validity of UTs as targets for the development of salt-sparing diuretics with a unique mechanism of action. UT-targeted inhibitors may be useful alone or in combination with conventional diuretics for therapy of various oedemas and hyponatraemias, potentially including those refractory to treatment with current diuretics.

  1. Recombinant Expression Screening of P. aeruginosa Bacterial Inner Membrane Proteins

    Directory of Open Access Journals (Sweden)

    Jeffery Constance J

    2010-11-01

    Full Text Available Abstract Background Transmembrane proteins (TM proteins make up 25% of all proteins and play key roles in many diseases and normal physiological processes. However, much less is known about their structures and molecular mechanisms than for soluble proteins. Problems in expression, solubilization, purification, and crystallization cause bottlenecks in the characterization of TM proteins. This project addressed the need for improved methods for obtaining sufficient amounts of TM proteins for determining their structures and molecular mechanisms. Results Plasmid clones were obtained that encode eighty-seven transmembrane proteins with varying physical characteristics, for example, the number of predicted transmembrane helices, molecular weight, and grand average hydrophobicity (GRAVY. All the target proteins were from P. aeruginosa, a gram negative bacterial opportunistic pathogen that causes serious lung infections in people with cystic fibrosis. The relative expression levels of the transmembrane proteins were measured under several culture growth conditions. The use of E. coli strains, a T7 promoter, and a 6-histidine C-terminal affinity tag resulted in the expression of 61 out of 87 test proteins (70%. In this study, proteins with a higher grand average hydrophobicity and more transmembrane helices were expressed less well than less hydrophobic proteins with fewer transmembrane helices. Conclusions In this study, factors related to overall hydrophobicity and the number of predicted transmembrane helices correlated with the relative expression levels of the target proteins. Identifying physical characteristics that correlate with protein expression might aid in selecting the "low hanging fruit", or proteins that can be expressed to sufficient levels using an E. coli expression system. The use of other expression strategies or host species might be needed for sufficient levels of expression of transmembrane proteins with other physical

  2. Expression and Chloroplast Targeting of Cholesterol Oxidase in Transgenic Tobacco Plants

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    Corbin, David R.; Grebenok, Robert J.; Ohnmeiss, Thomas E.; Greenplate, John T.; Purcell, John P.

    2001-01-01

    Cholesterol oxidase represents a novel type of insecticidal protein with potent activity against the cotton boll weevil (Anthonomus grandis grandis Boheman). We transformed tobacco (Nicotiana tabacum) plants with the cholesterol oxidase choM gene and expressed cytosolic and chloroplast-targeted versions of the ChoM protein. Transgenic leaf tissues expressing cholesterol oxidase exerted insecticidal activity against boll weevil larvae. Our results indicate that cholesterol oxidase can metabolize phytosterols in vivo when produced cytosolically or when targeted to chloroplasts. The transgenic plants exhibiting cytosolic expression accumulated low levels of saturated sterols known as stanols, and displayed severe developmental aberrations. In contrast, the transgenic plants expressing chloroplast-targeted cholesterol oxidase maintained a greater accumulation of stanols, and appeared phenotypically and developmentally normal. These results are discussed within the context of plant sterol distribution and metabolism. PMID:11457962

  3. Targeting IAP proteins in combination with radiotherapy

    International Nuclear Information System (INIS)

    Fulda, Simone

    2015-01-01

    The efficacy of radiotherapy critically depends on the activation of intrinsic cell death programs in cancer cells. This implies that evasion of cell death, a hallmark of human cancers, can contribute to radioresistance. Therefore, novel strategies to reactivate cell death programs in cancer cells are required in order to overcome resistance to radiotherapy. Since Inhibitor of Apoptosis (IAP) proteins are expressed at high levels in multiple cancers and block cell death induction at a central point, therapeutic targeting of IAP proteins represents a promising approach to potentiate the efficacy of radiotherapy. The current review discusses the concept of targeting IAP proteins in combination with radiotherapy

  4. Expression and purification of toxic anti-breast cancer p28-NRC chimeric protein

    OpenAIRE

    Soleimani, Meysam; Mirmohammad-Sadeghi, Hamid; Sadeghi-Aliabadi, Hojjat; Jahanian-Najafabadi, Ali

    2016-01-01

    Background: Chimeric proteins consisting of a targeting moiety and a cytotoxic moiety are now under intense research focus for targeted therapy of cancer. Here, we report cloning, expression, and purification of such a targeted chimeric protein made up of p28 peptide as both targeting and anticancer moiety fused to NRC peptide as a cytotoxic moiety. However, since the antimicrobial activity of the NRC peptide would intervene expression of the chimeric protein in Escherichia coli, we evaluated...

  5. Protein-protein interactions and cancer: targeting the central dogma.

    Science.gov (United States)

    Garner, Amanda L; Janda, Kim D

    2011-01-01

    Between 40,000 and 200,000 protein-protein interactions have been predicted to exist within the human interactome. As these interactions are of a critical nature in many important cellular functions and their dysregulation is causal of disease, the modulation of these binding events has emerged as a leading, yet difficult therapeutic arena. In particular, the targeting of protein-protein interactions relevant to cancer is of fundamental importance as the tumor-promoting function of several aberrantly expressed proteins in the cancerous state is directly resultant of its ability to interact with a protein-binding partner. Of significance, these protein complexes play a crucial role in each of the steps of the central dogma of molecular biology, the fundamental processes of genetic transmission. With the many important discoveries being made regarding the mechanisms of these genetic process, the identification of new chemical probes are needed to better understand and validate the druggability of protein-protein interactions related to the central dogma. In this review, we provide an overview of current small molecule-based protein-protein interaction inhibitors for each stage of the central dogma: transcription, mRNA splicing and translation. Importantly, through our analysis we have uncovered a lack of necessary probes targeting mRNA splicing and translation, thus, opening up the possibility for expansion of these fields.

  6. Mechanistic target of rapamycin (MTOR) protein expression in the tumor and its microenvironment correlates with more aggressive pathology at cystectomy

    NARCIS (Netherlands)

    Winters, B.R. (Brian R.); Vakar-Lopez, F. (Funda); Brown, L. (Lisha); Montgomery, B. (Bruce); Seiler, R. (Roland); P.C. Black (Peter C.); J.L. Boormans (Joost); Dall′Era, M. (Marc); Davincioni, E. (Elai); Douglas, J. (James); Gibb, E.A. (Ewan A.); B.W. van Rhijn (Bas); M.S. van der Heijden (Michiel); Hsieh, A.C. (Andrew C.); Wright, J.L. (Jonathan L.); Lam, H.-M. (Hung-Ming)

    2018-01-01

    textabstractBackground: The mechanistic target of rapamycin (mTOR) has been implicated in driving tumor biology in multiple malignancies, including urothelial carcinoma (UC). We investigate how mTOR and phosphorylated mTOR (pmTOR) protein expression correlate with chemoresponsiveness in the tumor

  7. A potyvirus vector efficiently targets recombinant proteins to chloroplasts, mitochondria and nuclei in plant cells when expressed at the amino terminus of the polyprotein.

    Science.gov (United States)

    Majer, Eszter; Navarro, José-Antonio; Daròs, José-Antonio

    2015-09-01

    Plant virus-based expression systems allow quick and efficient production of recombinant proteins in plant biofactories. Among them, a system derived from tobacco etch virus (TEV; genus potyvirus) permits coexpression of equimolar amounts of several recombinant proteins. This work analyzed how to target recombinant proteins to different subcellular localizations in the plant cell using this system. We constructed TEV clones in which green fluorescent protein (GFP), with a chloroplast transit peptide (cTP), a nuclear localization signal (NLS) or a mitochondrial targeting peptide (mTP) was expressed either as the most amino-terminal product or embedded in the viral polyprotein. Results showed that cTP and mTP mediated efficient translocation of GFP to the corresponding organelle only when present at the amino terminus of the viral polyprotein. In contrast, the NLS worked efficiently at both positions. Viruses expressing GFP in the amino terminus of the viral polyprotein produced milder symptoms. Untagged GFPs and cTP and NLS tagged amino-terminal GFPs accumulated to higher amounts in infected tissues. Finally, viral progeny from clones with internal GFPs maintained the extra gene better. These observations will help in the design of potyvirus-based vectors able to coexpress several proteins while targeting different subcellular localizations, as required in plant metabolic engineering. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Expression, Delivery and Function of Insecticidal Proteins Expressed by Recombinant Baculoviruses

    Science.gov (United States)

    Kroemer, Jeremy A.; Bonning, Bryony C.; Harrison, Robert L.

    2015-01-01

    Since the development of methods for inserting and expressing genes in baculoviruses, a line of research has focused on developing recombinant baculoviruses that express insecticidal peptides and proteins. These recombinant viruses have been engineered with the goal of improving their pesticidal potential by shortening the time required for infection to kill or incapacitate insect pests and reducing the quantity of crop damage as a consequence. A wide variety of neurotoxic peptides, proteins that regulate insect physiology, degradative enzymes, and other potentially insecticidal proteins have been evaluated for their capacity to reduce the survival time of baculovirus-infected lepidopteran host larvae. Researchers have investigated the factors involved in the efficient expression and delivery of baculovirus-encoded insecticidal peptides and proteins, with much effort dedicated to identifying ideal promoters for driving transcription and signal peptides that mediate secretion of the expressed target protein. Other factors, particularly translational efficiency of transcripts derived from recombinant insecticidal genes and post-translational folding and processing of insecticidal proteins, remain relatively unexplored. The discovery of RNA interference as a gene-specific regulation mechanism offers a new approach for improvement of baculovirus biopesticidal efficacy through genetic modification. PMID:25609310

  9. ANP32B is a nuclear target of henipavirus M proteins.

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    Anja Bauer

    Full Text Available Membrane envelopment and budding of negative strand RNA viruses (NSVs is mainly driven by viral matrix proteins (M. In addition, several M proteins are also known to be involved in host cell manipulation. Knowledge about the cellular targets and detailed molecular mechanisms, however, is poor for many M proteins. For instance, Nipah Virus (NiV M protein trafficking through the nucleus is essential for virus release, but nuclear targets of NiV M remain unknown. To identify cellular interactors of henipavirus M proteins, tagged Hendra Virus (HeV M proteins were expressed and M-containing protein complexes were isolated and analysed. Presence of acidic leucine-rich nuclear phosphoprotein 32 family member B (ANP32B in the complex suggested that this protein represents a direct or indirect interactor of the viral matrix protein. Over-expression of ANP32B led to specific nuclear accumulation of HeV M, providing a functional link between ANP32B and M protein. ANP32B-dependent nuclear accumulation was observed after plasmid-driven expression of HeV and NiV matrix proteins and also in NiV infected cells. The latter indicated that an interaction of henipavirus M protein with ANP32B also occurs in the context of virus replication. From these data we conclude that ANP32B is a nuclear target of henipavirus M that may contribute to virus replication. Potential effects of ANP32B on HeV nuclear shuttling and host cell manipulation by HeV M affecting ANP32B functions in host cell survival and gene expression regulation are discussed.

  10. Evolved Escherichia coli strains for amplified, functional expression of membrane proteins.

    Science.gov (United States)

    Gul, Nadia; Linares, Daniel M; Ho, Franz Y; Poolman, Bert

    2014-01-09

    The major barrier to the physical characterization and structure determination of membrane proteins is low protein yield and/or low functionality in recombinant expression. The enteric bacterium Escherichia coli is the most widely employed organism for producing recombinant proteins. Beside several advantages of this expression host, one major drawback is that the protein of interest does not always adopt its native conformation and may end up in large insoluble aggregates. We describe a robust strategy to increase the likelihood of overexpressing membrane proteins in a functional state. The method involves fusion in tandem of green fluorescent protein and the erythromycin resistance protein (23S ribosomal RNA adenine N-6 methyltransferase, ErmC) to the C-terminus of a target membrane protein. The fluorescence of green fluorescent protein is used to report the folding state of the target protein, whereas ErmC is used to select for increased expression. By gradually increasing the erythromycin concentration of the medium and testing different membrane protein targets, we obtained a number of evolved strains of which four (NG2, NG3, NG5 and NG6) were characterized and their genome was fully sequenced. Strikingly, each of the strains carried a mutation in the hns gene, whose product is involved in genome organization and transcriptional silencing. The degree of expression of (membrane) proteins correlates with the severity of the hns mutation, but cells in which hns was deleted showed an intermediate expression performance. We propose that (partial) removal of the transcriptional silencing mechanism changes the levels of proteins essential for the functional overexpression of membrane proteins. © 2013.

  11. Effect of high fat diet on pulmonary expression of parathyroid hormone-related protein and its downstream targets

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    Learta Oruqaj

    2016-10-01

    Full Text Available Aims: Parathyroid hormone-related protein (PTHrP is involved in lung development and surfactant production. The latter one requires a paracrine interaction between type II alveolar cells and lipofibroblasts in which leptin triggers PTHrP-induced effects. Whether increased plasma leptin levels, as they occur in high fat diet, modify the expression of PTHrP remains unclear. Furthermore, the effect of high fat diet under conditions of forced pulmonary remodelling such as response to post myocardial infarction remains to be defined. Materials and methods: C57 bl/6 mice were randomized to either normal diet or high fat diet at an age of 6 weeks. Seven months later, the mice were euthanized and the lung was removed and frozen in fluid nitrogen until use. Samples were analyzed by real-time RT-PCR and western blot. Leptin deficient mice were used to investigate the effect of leptin on pulmonary expression of PTHrP more directly. A subgroup of mice with and without high fat diet underwent in vivo ischemia (45 min and reperfusion (4 weeks. Finally, experiments were repeated with prolonged high-fat diet. Key findings: High fat diet increased plasma leptin levels by 30.4% and the pulmonary mRNA expression of PTHrP (1,447-fold, PTH-1 receptor (4.21-fold, and PTHrP-downstream targets ADRP (7.54-fold and PPARγ (5.27-fold. Pulmonary PTHrP expression was reduced in leptin deficient mice by 88% indicating leptin dependent regulation. High fat diet further improved changes in pulmonary adaptation caused by ischemia/reperfusion (1.48-fold increased PTH-1 receptor protein expression. These effects were lost during prolonged high fat diet. Significance: This study established that physiological regulation of leptin plasma levels by high fat diet affects the pulmonary PTHrP expression and of PTHrP downstream targets. Modification of pulmonary expression of PTH-1 receptors by high fat diet after myocardial infarction suggests that the identified interaction may

  12. Comprehensive predictions of target proteins based on protein-chemical interaction using virtual screening and experimental verifications.

    Science.gov (United States)

    Kobayashi, Hiroki; Harada, Hiroko; Nakamura, Masaomi; Futamura, Yushi; Ito, Akihiro; Yoshida, Minoru; Iemura, Shun-Ichiro; Shin-Ya, Kazuo; Doi, Takayuki; Takahashi, Takashi; Natsume, Tohru; Imoto, Masaya; Sakakibara, Yasubumi

    2012-04-05

    Identification of the target proteins of bioactive compounds is critical for elucidating the mode of action; however, target identification has been difficult in general, mostly due to the low sensitivity of detection using affinity chromatography followed by CBB staining and MS/MS analysis. We applied our protocol of predicting target proteins combining in silico screening and experimental verification for incednine, which inhibits the anti-apoptotic function of Bcl-xL by an unknown mechanism. One hundred eighty-two target protein candidates were computationally predicted to bind to incednine by the statistical prediction method, and the predictions were verified by in vitro binding of incednine to seven proteins, whose expression can be confirmed in our cell system.As a result, 40% accuracy of the computational predictions was achieved successfully, and we newly found 3 incednine-binding proteins. This study revealed that our proposed protocol of predicting target protein combining in silico screening and experimental verification is useful, and provides new insight into a strategy for identifying target proteins of small molecules.

  13. Comprehensive predictions of target proteins based on protein-chemical interaction using virtual screening and experimental verifications

    Directory of Open Access Journals (Sweden)

    Kobayashi Hiroki

    2012-04-01

    Full Text Available Abstract Background Identification of the target proteins of bioactive compounds is critical for elucidating the mode of action; however, target identification has been difficult in general, mostly due to the low sensitivity of detection using affinity chromatography followed by CBB staining and MS/MS analysis. Results We applied our protocol of predicting target proteins combining in silico screening and experimental verification for incednine, which inhibits the anti-apoptotic function of Bcl-xL by an unknown mechanism. One hundred eighty-two target protein candidates were computationally predicted to bind to incednine by the statistical prediction method, and the predictions were verified by in vitro binding of incednine to seven proteins, whose expression can be confirmed in our cell system. As a result, 40% accuracy of the computational predictions was achieved successfully, and we newly found 3 incednine-binding proteins. Conclusions This study revealed that our proposed protocol of predicting target protein combining in silico screening and experimental verification is useful, and provides new insight into a strategy for identifying target proteins of small molecules.

  14. Restriction of GAGE protein expression to subpopulations of cancer cells is independent of genotype and may limit the use of GAGE proteins as targets for cancer immunotherapy

    DEFF Research Database (Denmark)

    Gjerstorff, M F; Johansen, L E; Nielsen, O

    2006-01-01

    The GAGE cancer testis antigen gene family encodes products that can be recognized by autologous T cells, and GAGE proteins have been suggested as potential targets for cancer immunotherapy. Analysis of GAGE expression in tumours has primarily been performed at the level of gene transcription, wh...

  15. GEC-targeted HO-1 expression reduces proteinuria in glomerular immune injury.

    Science.gov (United States)

    Duann, Pu; Lianos, Elias A

    2009-09-01

    Induction of heme oxygenase (HO)-1 is a key defense mechanism against oxidative stress. Compared with tubules, glomeruli are refractory to HO-1 upregulation in response to injury. This can be a disadvantage as it may be associated with insufficient production of cytoprotective heme-degradation metabolites. We, therefore, explored whether 1) targeted HO-1 expression can be achieved in glomeruli without altering their physiological integrity and 2) this expression reduces proteinuria in immune injury induced by an anti-glomerular basement membrane (GBM) antibody (Ab). We employed a 4.125-kb fragment of a mouse nephrin promoter downstream to which a FLAG-tagged hHO-1 cDNA sequence was inserted and subsequently generated transgenic mice from the FVB/N parental strain. There was a 16-fold higher transgene expression in the kidney than nonspecific background (liver) while the transprotein immunolocalized in glomerular epithelial cells (GEC). There was no change in urinary protein excretion, indicating that GEC-targeted HO-1 expression had no effect on glomerular protein permeability. Urinary protein excretion in transgenic mice with anti-GBM Ab injury (days 3 and 6) was significantly lower compared with wild-type controls. There was no significant change in renal expression levels of profibrotic (TGF-beta1) or anti-inflammatory (IL-10) cytokines in transgenic mice with anti-GBM Ab injury. These observations indicate that GEC-targeted HO-1 expression does not alter glomerular physiological integrity and reduces proteinuria in glomerular immune injury.

  16. Escherichia coli Protein Expression System for Acetylcholine Binding Proteins (AChBPs.

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    Nikita Abraham

    Full Text Available Nicotinic acetylcholine receptors (nAChR are ligand gated ion channels, identified as therapeutic targets for a range of human diseases. Drug design for nAChR related disorders is increasingly using structure-based approaches. Many of these structural insights for therapeutic lead development have been obtained from co-crystal structures of nAChR agonists and antagonists with the acetylcholine binding protein (AChBP. AChBP is a water soluble, structural and functional homolog of the extracellular, ligand-binding domain of nAChRs. Currently, AChBPs are recombinantly expressed in eukaryotic expression systems for structural and biophysical studies. Here, we report the establishment of an Escherichia coli (E. coli expression system that significantly reduces the cost and time of production compared to the existing expression systems. E. coli can efficiently express unglycosylated AChBP for crystallography and makes the expression of isotopically labelled forms feasible for NMR. We used a pHUE vector containing an N-terminal His-tagged ubiquitin fusion protein to facilitate AChBP expression in the soluble fractions, and thus avoid the need to recover protein from inclusion bodies. The purified protein yield obtained from the E. coli expression system is comparable to that obtained from existing AChBP expression systems. E. coli expressed AChBP bound nAChR agonists and antagonists with affinities matching those previously reported. Thus, the E. coli expression system significantly simplifies the expression and purification of functional AChBP for structural and biophysical studies.

  17. 2-Deoxyglucose induces the expression of thioredoxin interacting protein (TXNIP) by increasing O-GlcNAcylation – Implications for targeting the Warburg effect in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Shin Yee; Hagen, Thilo, E-mail: bchth@nus.edu.sg

    2015-10-02

    The high proliferation rate of cancer cells and the microenvironment in the tumor tissue require the reprogramming of tumor cell metabolism. The major mechanism of metabolic reprogramming in cancer cells is the Warburg effect, defined as the preferential utilization of glucose via glycolysis even in the presence of oxygen. Targeting the Warburg effect is considered as a promising therapeutic strategy in cancer therapy. In this regard, the glycolytic inhibitor 2-deoxyglucose (2DG) has been evaluated clinically. 2DG exerts its effect by directly inhibiting glycolysis at the level of hexokinase and phosphoglucoisomerase. In addition, 2DG is also known to induce the expression of thioredoxin interacting protein (TXNIP), a tumor suppressor protein and an important negative regulator of cellular glucose uptake. Hence, characterization of the mechanism through which 2DG regulates TXNIP expression may reveal novel approaches to target the Warburg effect in cancer cells. Therefore, in this study we sought to test various hypotheses for the mechanistic basis of the 2DG dependent TXNIP regulation. We have shown that 2DG induced TXNIP expression is independent of carbohydrate response element mediated transcription. Furthermore, the induction of TXNIP is neither dependent on the ability of 2DG to deplete cellular ATP nor to cause endoplasmic reticulum stress. We found that the 2DG induced TXNIP expression is at least in part dependent on the inhibition of the O-GlcNAcase enzyme and the accumulation of O-GlcNAc modified proteins. These results have implications for the identification of therapeutic targets to increase TXNIP expression in cancer. - Highlights: • 2DG increases TXNIP expression at the mRNA and protein level. • The effect of 2DG on TXNIP is independent of ChoRE mediated transcription. • 2DG induces TXNIP independent of ER stress induction and ATP depletion. • 2DG inhibits OGA and leads to accumulation of O-GlcNAcylated proteins. • The upregulation of

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

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    Duchmann Rainer

    2007-06-01

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

  19. Diversity, expression and mRNA targeting abilities of Argonaute-targeting miRNAs among selected vascular plants.

    Science.gov (United States)

    Jagtap, Soham; Shivaprasad, Padubidri V

    2014-12-02

    Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1 (DCL1) proteins process long ds-like structures to produce micro (mi) RNA duplexes in a stepwise manner. These miRNAs are incorporated into Argonaute (AGO) proteins and influence expression of RNAs that have sequence complementarity with miRNAs. Expression levels of AGOs are greatly regulated by plants in order to minimize unwarranted perturbations using miRNAs to target mRNAs coding for AGOs. AGOs may also have high promoter specificity-sometimes expression of AGO can be limited to just a few cells in a plant. Viral pathogens utilize various means to counter antiviral roles of AGOs including hijacking the host encoded miRNAs to target AGOs. Two host encoded miRNAs namely miR168 and miR403 that target AGOs have been described in the model plant Arabidopsis and such a mechanism is thought to be well conserved across plants because AGO sequences are well conserved. We show that the interaction between AGO mRNAs and miRNAs is species-specific due to the diversity in sequences of two miRNAs that target AGOs, sequence diversity among corresponding target regions in AGO mRNAs and variable expression levels of these miRNAs among vascular plants. We used miRNA sequences from 68 plant species representing 31 plant families for this analysis. Sequences of miR168 and miR403 are not conserved among plant lineages, but surprisingly they differ drastically in their sequence diversity and expression levels even among closely related plants. Variation in miR168 expression among plants correlates well with secondary structures/length of loop sequences of their precursors. Our data indicates a complex AGO targeting interaction among plant lineages due to miRNA sequence diversity and sequences of miRNA targeting regions among AGO mRNAs, thus leading to the assumption that the perturbations by viruses that use host miRNAs to target antiviral AGOs can only be species-specific. We also show

  20. A single point in protein trafficking by Plasmodium falciparum determines the expression of major antigens on the surface of infected erythrocytes targeted by human antibodies.

    Science.gov (United States)

    Chan, Jo-Anne; Howell, Katherine B; Langer, Christine; Maier, Alexander G; Hasang, Wina; Rogerson, Stephen J; Petter, Michaela; Chesson, Joanne; Stanisic, Danielle I; Duffy, Michael F; Cooke, Brian M; Siba, Peter M; Mueller, Ivo; Bull, Peter C; Marsh, Kevin; Fowkes, Freya J I; Beeson, James G

    2016-11-01

    Antibodies to blood-stage antigens of Plasmodium falciparum play a pivotal role in human immunity to malaria. During parasite development, multiple proteins are trafficked from the intracellular parasite to the surface of P. falciparum-infected erythrocytes (IEs). However, the relative importance of different proteins as targets of acquired antibodies, and key pathways involved in trafficking major antigens remain to be clearly defined. We quantified antibodies to surface antigens among children, adults, and pregnant women from different malaria-exposed regions. We quantified the importance of antigens as antibody targets using genetically engineered P. falciparum with modified surface antigen expression. Genetic deletion of the trafficking protein skeleton-binding protein-1 (SBP1), which is involved in trafficking the surface antigen PfEMP1, led to a dramatic reduction in antibody recognition of IEs and the ability of human antibodies to promote opsonic phagocytosis of IEs, a key mechanism of parasite clearance. The great majority of antibody epitopes on the IE surface were SBP1-dependent. This was demonstrated using parasite isolates with different genetic or phenotypic backgrounds, and among antibodies from children, adults, and pregnant women in different populations. Comparisons of antibody reactivity to parasite isolates with SBP1 deletion or inhibited PfEMP1 expression suggest that PfEMP1 is the dominant target of acquired human antibodies, and that other P. falciparum IE surface proteins are minor targets. These results establish SBP1 as part of a critical pathway for the trafficking of major surface antigens targeted by human immunity, and have key implications for vaccine development, and quantifying immunity in populations.

  1. Getting a Handle on Neuropharmacology by Targeting Receptor-Associated Proteins.

    Science.gov (United States)

    Maher, Michael P; Matta, Jose A; Gu, Shenyan; Seierstad, Mark; Bredt, David S

    2017-12-06

    Targeted therapy for neuropsychiatric disorders requires selective modulation of dysfunctional neuronal pathways. Receptors relevant to CNS disorders typically have associated proteins discretely expressed in specific neuronal pathways; these accessory proteins provide a new dimension for drug discovery. Recent studies show that targeting a TARP auxiliary subunit of AMPA receptors selectively modulates neuronal excitability in specific forebrain pathways relevant to epilepsy. Other medicinally important ion channels, gated by glutamate, γ-aminobutyric acid (GABA), and acetylcholine, also have associated proteins, which may be druggable. This emerging pharmacology of receptor-associated proteins provides a new approach for improving drug efficacy while mitigating side effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Use of a protein engineering strategy to overcome limitations in the production of "Difficult to Express" recombinant proteins.

    Science.gov (United States)

    Hussain, Hirra; Fisher, David I; Abbott, W Mark; Roth, Robert G; Dickson, Alan J

    2017-10-01

    Certain recombinant proteins are deemed "difficult to express" in mammalian expression systems requiring significant cell and/or process engineering to abrogate expression bottlenecks. With increasing demand for the production of recombinant proteins in mammalian cells, low protein yields can have significant consequences for industrial processes. To investigate the molecular mechanisms that restrict expression of recombinant proteins, naturally secreted model proteins were analyzed from the tissue inhibitors of metalloproteinase (TIMP) protein family. In particular, TIMP-2 and TIMP-3 were subjected to detailed study. TIMP proteins share significant sequence homology (∼50% identity and ∼70% similarity in amino acid sequence). However, they show marked differences in secretion in mammalian expression systems despite this extensive sequence homology. Using these two proteins as models, this study characterized the molecular mechanisms responsible for poor recombinant protein production. Our results reveal that both TIMP-2 and TIMP-3 are detectable at mRNA and protein level within the cell but only TIMP-2 is secreted effectively into the extracellular medium. Analysis of protein localization and the nature of intracellular protein suggest TIMP-3 is severely limited in its post-translational processing. To overcome this challenge, modification of the TIMP-3 sequence to include a furin protease-cleavable pro-sequence resulted in secretion of the modified TIMP-3 protein, however, incomplete processing was observed. Based on the TIMP-3 data, the protein engineering approach was optimized and successfully applied in combination with cell engineering, the overexpression of furin, to another member of the TIMP protein family (the poorly expressed TIMP-4). Use of the described protein engineering strategy resulted in successful secretion of poorly (TIMP-4) and non-secreted (TIMP-3) targets, and presents a novel strategy to enhance the production of "difficult" recombinant

  3. Effects of immunosuppressive treatment on protein expression in rat kidney

    Directory of Open Access Journals (Sweden)

    Kędzierska K

    2014-09-01

    Full Text Available Karolina Kędzierska,1 Katarzyna Sporniak-Tutak,2 Krzysztof Sindrewicz,2 Joanna Bober,3 Leszek Domański,1 Mirosław Parafiniuk,4 Elżbieta Urasińska,5 Andrzej Ciechanowicz,6 Maciej Domański,1 Tomasz Smektała,2 Marek Masiuk,5 Wiesław Skrzypczak,6 Małgorzata Ożgo,6 Joanna Kabat-Koperska,1 Kazimierz Ciechanowski1 1Department of Nephrology, Transplantology, and Internal Medicine, 2Department of Dental Surgery, 3Department of Medical Chemistry, 4Department of Forensic Medicine, 5Department of Pathomorphology, Pomeranian Medical University, 6Department of Physiology, Cytobiology, and Proteomics, West Pomeranian University of Technology, Szczecin, Poland Abstract: The structural proteins of renal tubular epithelial cells may become a target for the toxic metabolites of immunosuppressants. These metabolites can modify the properties of the proteins, thereby affecting cell function, which is a possible explanation for the mechanism of immunosuppressive agents' toxicity. In our study, we evaluated the effect of two immunosuppressive strategies on protein expression in the kidneys of Wistar rats. Fragments of the rat kidneys were homogenized after cooling in liquid nitrogen and then dissolved in lysis buffer. The protein concentration in the samples was determined using a protein assay kit, and the proteins were separated by two-dimensional electrophoresis. The obtained gels were then stained with Coomassie Brilliant Blue, and their images were analyzed to evaluate differences in protein expression. Identification of selected proteins was then performed using mass spectrometry. We found that the immunosuppressive drugs used in popular regimens induce a series of changes in protein expression in target organs. The expression of proteins involved in drug, glucose, amino acid, and lipid metabolism was pronounced. However, to a lesser extent, we also observed changes in nuclear, structural, and transport proteins' synthesis. Very slight differences

  4. Fragile X mental retardation protein expression in Alzheimer’s disease

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    Abigail J Renoux

    2014-10-01

    Full Text Available The FMR1 protein product, FMRP, is an mRNA binding protein associated with translational inhibition of target transcripts. One FMRP target is the amyloid precursor protein (APP mRNA, and APP levels are elevated in Fmr1 KO mice. Given that elevated APP protein expression can elicit Alzheimer’s disease (AD in patients and model systems, we evaluated whether FMRP expression might be altered in Alzheimer’s autopsy brain samples and mouse models compared to controls. In a double transgenic mouse model of AD (APP/PS1, we found no difference in FMRP expression in aged AD model mice compared to littermate controls. FMRP expression was also similar in AD and control patient frontal cortex and cerebellum samples. Fragile X-associated tremor/ataxia syndrome (FXTAS is an age related neurodegenerative disorder caused by expanded CGG repeats in the 5’UTR of the FMR1 gene. Patients experience cognitive impairment and dementia in addition to motor symptoms. In parallel studies, we measured FMRP expression in cortex and cerebellum from three FXTAS patients and found reduced expression compared to both controls and Alzheimer’s patient brains, consistent with animal models. We also find increased APP levels in cerebellar, but not cortical, samples of FXTAS patients compared to controls. Taken together, these data suggest that a decrease in FMRP expression is unlikely to be a primary contributor to Alzheimer’s disease pathogenesis.

  5. Recombinant expression and purification of a tumor-targeted toxin in Bacillus anthracis

    International Nuclear Information System (INIS)

    Bachran, Christopher; Abdelazim, Suzanne; Fattah, Rasem J.; Liu, Shihui; Leppla, Stephen H.

    2013-01-01

    Highlights: ► Non-infectious and protease-deficient Bacillus anthracis protein expression system. ► Successful expression and purification of a tumor-targeted fusion protein drug. ► Very low endotoxin contamination of purified protein. ► Efficient protein secretion simplifies purification. ► Functional anti-tumor fusion protein purified. -- Abstract: Many recombinant therapeutic proteins are purified from Escherichia coli. While expression in E. coli is easily achieved, some disadvantages such as protein aggregation, formation of inclusion bodies, and contamination of purified proteins with the lipopolysaccharides arise. Lipopolysaccharides have to be removed to prevent inflammatory responses in patients. Use of the Gram-positive Bacillus anthracis as an expression host offers a solution to circumvent these problems. Using the multiple protease-deficient strain BH460, we expressed a fusion of the N-terminal 254 amino acids of anthrax lethal factor (LFn), the N-terminal 389 amino acids of diphtheria toxin (DT389) and human transforming growth factor alpha (TGFα). The resulting fusion protein was constitutively expressed and successfully secreted by B. anthracis into the culture supernatant. Purification was achieved by anion exchange chromatography and proteolytic cleavage removed LFn from the desired fusion protein (DT389 fused to TGFα). The fusion protein showed the intended specific cytotoxicity to epidermal growth factor receptor-expressing human head and neck cancer cells. Final analyses showed low levels of lipopolysaccharides, originating most likely from contamination during the purification process. Thus, the fusion to LFn for protein secretion and expression in B. anthracis BH460 provides an elegant tool to obtain high levels of lipopolysaccharide-free recombinant protein.

  6. AR-v7 protein expression is regulated by protein kinase and phosphatase

    Science.gov (United States)

    Li, Yinan; Xie, Ning; Gleave, Martin E.; Rennie, Paul S.; Dong, Xuesen

    2015-01-01

    Failure of androgen-targeted therapy and progression of castration-resistant prostate cancer (CRPC) are often attributed to sustained expression of the androgen receptor (AR) and its major splice variant, AR-v7. Although the new generation of anti-androgens such as enzalutamide effectively inhibits AR activity, accumulating pre-clinical and clinical evidence indicates that AR-v7 remains constitutively active in driving CRPC progression. However, molecular mechanisms which control AR-v7 protein expression remain unclear. We apply multiple prostate cancer cell models to demonstrate that enzalutamide induces differential activation of protein phosphatase-1 (PP-1) and Akt kinase depending on the gene context of cancer cells. The balance between PP-1 and Akt activation governs AR phosphorylation status and activation of the Mdm2 ubiquitin ligase. Mdm2 recognizes phosphorylated serine 213 of AR-v7, and induces AR-v7 ubiquitination and protein degradation. These findings highlight the decisive roles of PP-1 and Akt for AR-v7 protein expression and activities when AR is functionally blocked. PMID:26378044

  7. Expression proteomics study to determine metallodrug targets and optimal drug combinations.

    Science.gov (United States)

    Lee, Ronald F S; Chernobrovkin, Alexey; Rutishauser, Dorothea; Allardyce, Claire S; Hacker, David; Johnsson, Kai; Zubarev, Roman A; Dyson, Paul J

    2017-05-08

    The emerging technique termed functional identification of target by expression proteomics (FITExP) has been shown to identify the key protein targets of anti-cancer drugs. Here, we use this approach to elucidate the proteins involved in the mechanism of action of two ruthenium(II)-based anti-cancer compounds, RAPTA-T and RAPTA-EA in breast cancer cells, revealing significant differences in the proteins upregulated. RAPTA-T causes upregulation of multiple proteins suggesting a broad mechanism of action involving suppression of both metastasis and tumorigenicity. RAPTA-EA bearing a GST inhibiting ethacrynic acid moiety, causes upregulation of mainly oxidative stress related proteins. The approach used in this work could be applied to the prediction of effective drug combinations to test in cancer chemotherapy clinical trials.

  8. Ndrg2 is a PGC-1α/ERRα target gene that controls protein synthesis and expression of contractile-type genes in C2C12 myotubes.

    Science.gov (United States)

    Foletta, Victoria C; Brown, Erin L; Cho, Yoshitake; Snow, Rod J; Kralli, Anastasia; Russell, Aaron P

    2013-12-01

    The stress-responsive, tumor suppressor N-myc downstream-regulated gene 2 (Ndrg2) is highly expressed in striated muscle. In response to anabolic and catabolic signals, Ndrg2 is suppressed and induced, respectively, in mouse C2C12 myotubes. However, little is known about the mechanisms regulating Ndrg2 expression in muscle, as well as the biological role for Ndrg2 in differentiated myotubes. Here, we show that Ndrg2 is a target of a peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) and estrogen-related receptor alpha (ERRα) transcriptional program and is induced in response to endurance exercise, a physiological stress known also to increase PGC-1α/ERRα activity. Analyses of global gene and protein expression profiles in C2C12 myotubes with reduced levels of NDRG2, suggest that NDRG2 affects muscle growth, contractile properties, MAPK signaling, ion and vesicle transport and oxidative phosphorylation. Indeed, suppression of NDRG2 in myotubes increased protein synthesis and the expression of fast glycolytic myosin heavy chain isoforms, while reducing the expression of embryonic myosin Myh3, other contractile-associated genes and the MAPK p90 RSK1. Conversely, enhanced expression of NDRG2 reduced protein synthesis, and furthermore, partially blocked the increased protein synthesis rates elicited by a constitutively active form of ERRα. In contrast, suppressing or increasing levels of NDRG2 did not affect mRNA expression of genes involved in mitochondrial biogenesis that are regulated by PGC-1α or ERRα. This study shows that in C2C12 myotubes Ndrg2 is a novel PGC-1α/ERRα transcriptional target, which influences protein turnover and the regulation of genes involved in muscle contraction and function. © 2013 Elsevier B.V. All rights reserved.

  9. Generation of TALE nickase-mediated gene-targeted cows expressing human serum albumin in mammary glands.

    Science.gov (United States)

    Luo, Yan; Wang, Yongsheng; Liu, Jun; Cui, Chenchen; Wu, Yongyan; Lan, Hui; Chen, Qi; Liu, Xu; Quan, Fusheng; Guo, Zekun; Zhang, Yong

    2016-02-08

    Targeting exogenous genes at milk protein loci via gene-targeting technology is an ideal strategy for producing large quantities of pharmaceutical proteins. Transcription-activator-like effector (TALE) nucleases (TALENs) are an efficient genome-editing tool. However, the off-target effects may lead to unintended gene mutations. In this study, we constructed TALENs and TALE nickases directed against exon 2 of the bovine β-lactoglobulin (BLG) locus. The nickases can induce a site-specific DNA single-strand break, without inducing double-strand break and nonhomologous end joining mediated gene mutation, and lower cell apoptosis rate than TALENs. After co-transfecting the bovine fetal fibroblasts with human serum albumin (HSA) gene-targeting vector and TALE nickase expression vectors, approximately 4.8% (40/835) of the cell clones contained HSA at BLG locus. Unexpectedly, one homozygous gene-targeted cell clone (1/835, 0.1%) was obtained by targeting both alleles of BLG in a single round of transfection. The recombinant protein mimicking the endogenous BLG was highly expressed and correctly folded in the mammary glands of the targeted cows, and the expression level of HSA was significantly increased in the homozygous targeted cows. Results suggested that the combination of TALE nickase-mediated gene targeting and somatic cell nuclear transfer is a feasible and safe approach in producing gene-targeted livestock.

  10. Recombinant expression and purification of a tumor-targeted toxin in Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Bachran, Christopher; Abdelazim, Suzanne; Fattah, Rasem J.; Liu, Shihui [National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892 (United States); Leppla, Stephen H., E-mail: sleppla@niaid.nih.gov [National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892 (United States)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Non-infectious and protease-deficient Bacillus anthracis protein expression system. Black-Right-Pointing-Pointer Successful expression and purification of a tumor-targeted fusion protein drug. Black-Right-Pointing-Pointer Very low endotoxin contamination of purified protein. Black-Right-Pointing-Pointer Efficient protein secretion simplifies purification. Black-Right-Pointing-Pointer Functional anti-tumor fusion protein purified. -- Abstract: Many recombinant therapeutic proteins are purified from Escherichia coli. While expression in E. coli is easily achieved, some disadvantages such as protein aggregation, formation of inclusion bodies, and contamination of purified proteins with the lipopolysaccharides arise. Lipopolysaccharides have to be removed to prevent inflammatory responses in patients. Use of the Gram-positive Bacillus anthracis as an expression host offers a solution to circumvent these problems. Using the multiple protease-deficient strain BH460, we expressed a fusion of the N-terminal 254 amino acids of anthrax lethal factor (LFn), the N-terminal 389 amino acids of diphtheria toxin (DT389) and human transforming growth factor alpha (TGF{alpha}). The resulting fusion protein was constitutively expressed and successfully secreted by B. anthracis into the culture supernatant. Purification was achieved by anion exchange chromatography and proteolytic cleavage removed LFn from the desired fusion protein (DT389 fused to TGF{alpha}). The fusion protein showed the intended specific cytotoxicity to epidermal growth factor receptor-expressing human head and neck cancer cells. Final analyses showed low levels of lipopolysaccharides, originating most likely from contamination during the purification process. Thus, the fusion to LFn for protein secretion and expression in B. anthracis BH460 provides an elegant tool to obtain high levels of lipopolysaccharide-free recombinant protein.

  11. Protein Drug Targets of Lavandula angustifolia on treatment of Rat Alzheimer's Disease

    Science.gov (United States)

    Zali, Hakimeh; Zamanian-Azodi, Mona; Rezaei Tavirani, Mostafa; Akbar-zadeh Baghban, Alireza

    2015-01-01

    Different treatment strategies of Alzheimer's disease (AD) are being studied for treating or slowing the progression of AD. Many pharmaceutically important regulation systems operate through proteins as drug targets. Here, we investigate the drug target proteins in beta-amyloid (Aβ) injected rat hippocampus treated with Lavandula angustifolia (LA) by proteomics techniques. The reported study showed that lavender extract (LE) improves the spatial performance in AD animal model by diminishing Aβ production in histopathology of hippocampus, so in this study neuroprotective proteins expressed in Aβ injected rats treated with LE were scrutinized. Rats were divided into three groups including normal, Aβ injected, and Aβ injected that was treated with LE. Protein expression profiles of hippocampus tissue were determined by two-dimensional electrophoresis (2DE) method and dysregulated proteins such as Snca, NF-L, Hspa5, Prdx2, Apoa1, and Atp5a1were identified by MALDI-TOF/TOF. KEGG pathway and gene ontology (GO) categories were used by searching DAVID Bioinformatics Resources. All detected protein spots were used to determine predictedinteractions with other proteins in STRING online database. Different isoforms of important protein, Snca that exhibited neuroprotective effects by anti-apoptotic properties were expressed. NF-L involved in the maintenance of neuronal caliber. Hspa5 likewise Prdx2 displays as anti-apoptotic protein that Prdx2 also involved in the neurotrophic effects. Apoa1 has anti-inflammatory activity and Atp5a1, produces ATP from ADP. To sum up, these proteins as potential drug targets were expressed in hippocampus in response to effective components in LA may have therapeutic properties for the treatment of AD and other neurodegenerative diseases. PMID:25561935

  12. Cell-free expression and stable isotope labelling strategies for membrane proteins

    International Nuclear Information System (INIS)

    Sobhanifar, Solmaz; Reckel, Sina; Junge, Friederike; Schwarz, Daniel; Kai, Lei; Karbyshev, Mikhail; Loehr, Frank; Bernhard, Frank; Doetsch, Volker

    2010-01-01

    Membrane proteins are highly underrepresented in the structural data-base and remain one of the most challenging targets for functional and structural elucidation. Their roles in transport and cellular communication, furthermore, often make over-expression toxic to their host, and their hydrophobicity and structural complexity make isolation and reconstitution a complicated task, especially in cases where proteins are targeted to inclusion bodies. The development of cell-free expression systems provides a very interesting alternative to cell-based systems, since it circumvents many problems such as toxicity or necessity for the transportation of the synthesized protein to the membrane, and constitutes the only system that allows for direct production of membrane proteins in membrane-mimetic environments which may be suitable for liquid state NMR measurements. The unique advantages of the cell-free expression system, including strong expression yields as well as the direct incorporation of almost any combination of amino acids with very little metabolic scrambling, has allowed for the development of a wide-array of isotope labelling techniques which facilitate structural investigations of proteins whose spectral congestion and broad line-widths may have earlier rendered them beyond the scope of NMR. Here we explore various labelling strategies in conjunction with cell-free developments, with a particular focus on α-helical transmembrane proteins which benefit most from such methods.

  13. miR-24 and miR-205 expression is dependent on HPV onco-protein expression in keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    McKenna, Declan J., E-mail: dj.mckenna@ulster.ac.uk [Biomedical Sciences Research Institute, University of Ulster, Coleraine, Co. Derry BT52 1SA (United Kingdom); Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Science, Queen' s University Belfast, Belfast BT9 7BL (United Kingdom); Patel, Daksha, E-mail: d.patel@qub.ac.uk [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Science, Queen' s University Belfast, Belfast BT9 7BL (United Kingdom); McCance, Dennis J., E-mail: d.mccance@qub.ac.uk [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Science, Queen' s University Belfast, Belfast BT9 7BL (United Kingdom)

    2014-01-05

    A screen of microRNA (miRNA) expression following differentiation in human foreskin keratinocytes (HFKs) identified changes in several miRNAs, including miR-24 and miR-205. We investigated how expression of Human Papilloma Virus Type-16 (HPV16) onco-proteins E6 and E7 affected expression of miR-24 and miR-205 during proliferation and differentiation of HFKs. We show that the induction of both miR-24 and miR-205 observed during differentiation of HFKs is lost in HFKs expressing E6 and E7. We demonstrate that the effect on miR-205 is due to E7 activity, as miR-205 expression is dependent on pRb expression. Finally, we provide evidence that miR-24 effects in the cell may be due to targeting of cyclin dependent kinase inhibitor p27. In summary, these results indicate that expression of both miR-24 and miR-205 are impacted by E6 and/or E7 expression, which may be one mechanism by which HPV onco-proteins can disrupt the balance between proliferation and differentiation in keratinocytes. - Highlights: • miR-24 and miR-205 are induced during keratinocyte differentiation. • This induction is lost in keratinocytes expressing HPV onco-proteins E6 and E7. • miR-205 is dependent upon pRb expression. • miR-24 targets p27 in cycling keratinocytes.

  14. miR-24 and miR-205 expression is dependent on HPV onco-protein expression in keratinocytes

    International Nuclear Information System (INIS)

    McKenna, Declan J.; Patel, Daksha; McCance, Dennis J.

    2014-01-01

    A screen of microRNA (miRNA) expression following differentiation in human foreskin keratinocytes (HFKs) identified changes in several miRNAs, including miR-24 and miR-205. We investigated how expression of Human Papilloma Virus Type-16 (HPV16) onco-proteins E6 and E7 affected expression of miR-24 and miR-205 during proliferation and differentiation of HFKs. We show that the induction of both miR-24 and miR-205 observed during differentiation of HFKs is lost in HFKs expressing E6 and E7. We demonstrate that the effect on miR-205 is due to E7 activity, as miR-205 expression is dependent on pRb expression. Finally, we provide evidence that miR-24 effects in the cell may be due to targeting of cyclin dependent kinase inhibitor p27. In summary, these results indicate that expression of both miR-24 and miR-205 are impacted by E6 and/or E7 expression, which may be one mechanism by which HPV onco-proteins can disrupt the balance between proliferation and differentiation in keratinocytes. - Highlights: • miR-24 and miR-205 are induced during keratinocyte differentiation. • This induction is lost in keratinocytes expressing HPV onco-proteins E6 and E7. • miR-205 is dependent upon pRb expression. • miR-24 targets p27 in cycling keratinocytes

  15. Soluble expression of recombinant proteins in the cytoplasm of Escherichia coli

    DEFF Research Database (Denmark)

    Sørensen, Hans; Mortensen, Kim

    2005-01-01

    Pure, soluble and functional proteins are of high demand in modern biotechnology. Natural protein sources rarely meet the requirements for quantity, ease of isolation or price and hence recombinant technology is often the method of choice. Recombinant cell factories are constantly employed...... molecular tools available. In spite of all these qualities, expression of recombinant proteins with E. coli as the host often results in insoluble and/or nonfunctional proteins. Here we review new approaches to overcome these obstacles by strategies that focus on either controlled expression of target...... for the production of protein preparations bound for downstream purification and processing. Eschericia coli is a frequently used host, since it facilitates protein expression by its relative simplicity, its inexpensive and fast high density cultivation, the well known genetics and the large number of compatible...

  16. Multi-targeted priming for genome-wide gene expression assays

    Directory of Open Access Journals (Sweden)

    Adomas Aleksandra B

    2010-08-01

    Full Text Available Abstract Background Complementary approaches to assaying global gene expression are needed to assess gene expression in regions that are poorly assayed by current methodologies. A key component of nearly all gene expression assays is the reverse transcription of transcribed sequences that has traditionally been performed by priming the poly-A tails on many of the transcribed genes in eukaryotes with oligo-dT, or by priming RNA indiscriminately with random hexamers. We designed an algorithm to find common sequence motifs that were present within most protein-coding genes of Saccharomyces cerevisiae and of Neurospora crassa, but that were not present within their ribosomal RNA or transfer RNA genes. We then experimentally tested whether degenerately priming these motifs with multi-targeted primers improved the accuracy and completeness of transcriptomic assays. Results We discovered two multi-targeted primers that would prime a preponderance of genes in the genomes of Saccharomyces cerevisiae and Neurospora crassa while avoiding priming ribosomal RNA or transfer RNA. Examining the response of Saccharomyces cerevisiae to nitrogen deficiency and profiling Neurospora crassa early sexual development, we demonstrated that using multi-targeted primers in reverse transcription led to superior performance of microarray profiling and next-generation RNA tag sequencing. Priming with multi-targeted primers in addition to oligo-dT resulted in higher sensitivity, a larger number of well-measured genes and greater power to detect differences in gene expression. Conclusions Our results provide the most complete and detailed expression profiles of the yeast nitrogen starvation response and N. crassa early sexual development to date. Furthermore, our multi-targeting priming methodology for genome-wide gene expression assays provides selective targeting of multiple sequences and counter-selection against undesirable sequences, facilitating a more complete and

  17. Protein-protein interaction networks identify targets which rescue the MPP+ cellular model of Parkinson’s disease

    Science.gov (United States)

    Keane, Harriet; Ryan, Brent J.; Jackson, Brendan; Whitmore, Alan; Wade-Martins, Richard

    2015-11-01

    Neurodegenerative diseases are complex multifactorial disorders characterised by the interplay of many dysregulated physiological processes. As an exemplar, Parkinson’s disease (PD) involves multiple perturbed cellular functions, including mitochondrial dysfunction and autophagic dysregulation in preferentially-sensitive dopamine neurons, a selective pathophysiology recapitulated in vitro using the neurotoxin MPP+. Here we explore a network science approach for the selection of therapeutic protein targets in the cellular MPP+ model. We hypothesised that analysis of protein-protein interaction networks modelling MPP+ toxicity could identify proteins critical for mediating MPP+ toxicity. Analysis of protein-protein interaction networks constructed to model the interplay of mitochondrial dysfunction and autophagic dysregulation (key aspects of MPP+ toxicity) enabled us to identify four proteins predicted to be key for MPP+ toxicity (P62, GABARAP, GBRL1 and GBRL2). Combined, but not individual, knockdown of these proteins increased cellular susceptibility to MPP+ toxicity. Conversely, combined, but not individual, over-expression of the network targets provided rescue of MPP+ toxicity associated with the formation of autophagosome-like structures. We also found that modulation of two distinct proteins in the protein-protein interaction network was necessary and sufficient to mitigate neurotoxicity. Together, these findings validate our network science approach to multi-target identification in complex neurological diseases.

  18. EBF factors drive expression of multiple classes of target genes governing neuronal development.

    Science.gov (United States)

    Green, Yangsook S; Vetter, Monica L

    2011-04-30

    Early B cell factor (EBF) family members are transcription factors known to have important roles in several aspects of vertebrate neurogenesis, including commitment, migration and differentiation. Knowledge of how EBF family members contribute to neurogenesis is limited by a lack of detailed understanding of genes that are transcriptionally regulated by these factors. We performed a microarray screen in Xenopus animal caps to search for targets of EBF transcriptional activity, and identified candidate targets with multiple roles, including transcription factors of several classes. We determined that, among the most upregulated candidate genes with expected neuronal functions, most require EBF activity for some or all of their expression, and most have overlapping expression with ebf genes. We also found that the candidate target genes that had the most strongly overlapping expression patterns with ebf genes were predicted to be direct transcriptional targets of EBF transcriptional activity. The identification of candidate targets that are transcription factor genes, including nscl-1, emx1 and aml1, improves our understanding of how EBF proteins participate in the hierarchy of transcription control during neuronal development, and suggests novel mechanisms by which EBF activity promotes migration and differentiation. Other candidate targets, including pcdh8 and kcnk5, expand our knowledge of the types of terminal differentiated neuronal functions that EBF proteins regulate.

  19. Production of soluble mammalian proteins in Escherichia coli: identification of protein features that correlate with successful expression

    Directory of Open Access Journals (Sweden)

    Perera Rajika L

    2004-12-01

    Full Text Available Abstract Background In the search for generic expression strategies for mammalian protein families several bacterial expression vectors were examined for their ability to promote high yields of soluble protein. Proteins studied included cell surface receptors (Ephrins and Eph receptors, CD44, kinases (EGFR-cytoplasmic domain, CDK2 and 4, proteases (MMP1, CASP2, signal transduction proteins (GRB2, RAF1, HRAS and transcription factors (GATA2, Fli1, Trp53, Mdm2, JUN, FOS, MAD, MAX. Over 400 experiments were performed where expression of 30 full-length proteins and protein domains were evaluated with 6 different N-terminal and 8 C-terminal fusion partners. Expression of an additional set of 95 mammalian proteins was also performed to test the conclusions of this study. Results Several protein features correlated with soluble protein expression yield including molecular weight and the number of contiguous hydrophobic residues and low complexity regions. There was no relationship between successful expression and protein pI, grand average of hydropathicity (GRAVY, or sub-cellular location. Only small globular cytoplasmic proteins with an average molecular weight of 23 kDa did not require a solubility enhancing tag for high level soluble expression. Thioredoxin (Trx and maltose binding protein (MBP were the best N-terminal protein fusions to promote soluble expression, but MBP was most effective as a C-terminal fusion. 63 of 95 mammalian proteins expressed at soluble levels of greater than 1 mg/l as N-terminal H10-MBP fusions and those that failed possessed, on average, a higher molecular weight and greater number of contiguous hydrophobic amino acids and low complexity regions. Conclusions By analysis of the protein features identified here, this study will help predict which mammalian proteins and domains can be successfully expressed in E. coli as soluble product and also which are best targeted for a eukaryotic expression system. In some cases

  20. Organ-specific gene expression: the bHLH protein Sage provides tissue specificity to Drosophila FoxA.

    Science.gov (United States)

    Fox, Rebecca M; Vaishnavi, Aria; Maruyama, Rika; Andrew, Deborah J

    2013-05-01

    FoxA transcription factors play major roles in organ-specific gene expression, regulating, for example, glucagon expression in the pancreas, GLUT2 expression in the liver, and tyrosine hydroxylase expression in dopaminergic neurons. Organ-specific gene regulation by FoxA proteins is achieved through cooperative regulation with a broad array of transcription factors with more limited expression domains. Fork head (Fkh), the sole Drosophila FoxA family member, is required for the development of multiple distinct organs, yet little is known regarding how Fkh regulates tissue-specific gene expression. Here, we characterize Sage, a bHLH transcription factor expressed exclusively in the Drosophila salivary gland (SG). We show that Sage is required for late SG survival and normal tube morphology. We find that many Sage targets, identified by microarray analysis, encode SG-specific secreted cargo, transmembrane proteins, and the enzymes that modify these proteins. We show that both Sage and Fkh are required for the expression of Sage target genes, and that co-expression of Sage and Fkh is sufficient to drive target gene expression in multiple cell types. Sage and Fkh drive expression of the bZip transcription factor Senseless (Sens), which boosts expression of Sage-Fkh targets, and Sage, Fkh and Sens colocalize on SG chromosomes. Importantly, expression of Sage-Fkh target genes appears to simply add to the tissue-specific gene expression programs already established in other cell types, and Sage and Fkh cannot alter the fate of most embryonic cell types even when expressed early and continuously.

  1. Characterization and Oral Delivery of Proinsulin-Transferrin Fusion Protein Expressed Using ExpressTec

    Directory of Open Access Journals (Sweden)

    Yu-Sheng Chen

    2018-01-01

    Full Text Available Proinsulin-transferrin fusion protein (ProINS-Tf has been designed and successfully expressed from the mammalian HEK293 cells (HEK-ProINS-Tf. It was found that HEK-ProINS-Tf could be converted into an activated form in the liver. Furthermore, HEK-ProINS-Tf was demonstrated as an extra-long acting insulin analogue with liver-specific insulin action in streptozotocin (STZ-induced type 1 diabetic mice. However, due to the low production yield from transfected HEK293 cells, there are other interesting features, including the oral bioavailability, which have not been fully explored and characterized. To improve the protein production yield, an alternative protein expression system, ExpressTec using transgenic rice (Oryza sativa L., was used. The intact and active rice-derived ProINS-Tf (ExpressTec-ProINS-Tf was successfully expressed from the transgenic rice expression system. Our results suggested that, although the insulin-like bioactivity of ExpressTec-ProINS-Tf was slightly lower in vitro, its potency of in vivo blood glucose control was considerably stronger than that of HEK-ProINS-Tf. The oral delivery studies in type 1 diabetic mice demonstrated a prolonged control of blood glucose to near-normal levels after oral administration of ExpressTec-ProINS-Tf. Results in this report suggest that ExpressTec-ProINS-Tf is a promising insulin analog with advantages including low cost, prolonged and liver targeting effects, and most importantly, oral bioactivity.

  2. Exploiting translational coupling for the selection of cells producing toxic recombinant proteins from expression vectors.

    Science.gov (United States)

    Tagliavia, Marcello; Cuttitta, Angela

    2016-01-01

    High rates of plasmid instability are associated with the use of some expression vectors in Escherichia coli, resulting in the loss of recombinant protein expression. This is due to sequence alterations in vector promoter elements caused by the background expression of the cloned gene, which leads to the selection of fast-growing, plasmid-containing cells that do not express the target protein. This phenomenon, which is worsened when expressing toxic proteins, results in preparations containing very little or no recombinant protein, or even in clone loss; however, no methods to prevent loss of recombinant protein expression are currently available. We have exploited the phenomenon of translational coupling, a mechanism of prokaryotic gene expression regulation, in order to select cells containing plasmids still able to express recombinant proteins. Here we designed an expression vector in which the cloned gene and selection marker are co-expressed. Our approach allowed for the selection of the recombinant protein-expressing cells and proved effective even for clones encoding toxic proteins.

  3. Pericentriolar Targeting of the Mouse Mammary Tumor Virus GAG Protein.

    Directory of Open Access Journals (Sweden)

    Guangzhi Zhang

    Full Text Available The Gag protein of the mouse mammary tumor virus (MMTV is the chief determinant of subcellular targeting. Electron microscopy studies show that MMTV Gag forms capsids within the cytoplasm and assembles as immature particles with MMTV RNA and the Y box binding protein-1, required for centrosome maturation. Other betaretroviruses, such as Mason-Pfizer monkey retrovirus (M-PMV, assemble adjacent to the pericentriolar region because of a cytoplasmic targeting and retention signal in the Matrix protein. Previous studies suggest that the MMTV Matrix protein may also harbor a similar cytoplasmic targeting and retention signal. Herein, we show that a substantial fraction of MMTV Gag localizes to the pericentriolar region. This was observed in HEK293T, HeLa human cell lines and the mouse derived NMuMG mammary gland cells. Moreover, MMTV capsids were observed adjacent to centrioles when expressed from plasmids encoding either MMTV Gag alone, Gag-Pro-Pol or full-length virus. We found that the cytoplasmic targeting and retention signal in the MMTV Matrix protein was sufficient for pericentriolar targeting, whereas mutation of the glutamine to alanine at position 56 (D56/A resulted in plasma membrane localization, similar to previous observations from mutational studies of M-PMV Gag. Furthermore, transmission electron microscopy studies showed that MMTV capsids accumulate around centrioles suggesting that, similar to M-PMV, the pericentriolar region may be a site for MMTV assembly. Together, the data imply that MMTV Gag targets the pericentriolar region as a result of the MMTV cytoplasmic targeting and retention signal, possibly aided by the Y box protein-1 required for the assembly of centrosomal microtubules.

  4. Membrane and inclusion body targeting of lyssavirus matrix proteins.

    Science.gov (United States)

    Pollin, Reiko; Granzow, Harald; Köllner, Bernd; Conzelmann, Karl-Klaus; Finke, Stefan

    2013-02-01

    Lyssavirus matrix proteins (M) support virus budding and have accessory functions that may contribute to host cell manipulation and adaptation to specific hosts. Here, we show that rabies virus (RABV) and European Bat Lyssavirus Type 1 (EBLV-1) M proteins differ in targeting and accumulation at cellular membranes. In contrast to RABV M, EBLV-1 M expressed from authentic EBLV-1 or chimeric RABV accumulated at the Golgi apparatus. Chimeric M proteins revealed that Golgi association depends on the integrity of the entire EBLV-1 M protein. Since RABV and EBLV-1 M differ in the use of cellular membranes for particle formation, differential membrane targeting and transport of M might determine the site of virus production. Moreover, both RABV and EBLV-1 M were for the first time detected within the nucleus and in Negri body-like inclusions bodies. Whereas nuclear M may imply hitherto unknown functions of lyssavirus M in host cell manipulation, the presence of M in inclusion bodies may correlate with regulatory functions of M in virus RNA synthesis. The data strongly support a model in which targeting of lyssavirus M proteins to distinctintracellular sites is a key determinant of diverse features in lyssavirus replication, host adaptation and pathogenesis. © 2012 Blackwell Publishing Ltd.

  5. Accurate microRNA target prediction correlates with protein repression levels

    Directory of Open Access Journals (Sweden)

    Simossis Victor A

    2009-09-01

    Full Text Available Abstract Background MicroRNAs are small endogenously expressed non-coding RNA molecules that regulate target gene expression through translation repression or messenger RNA degradation. MicroRNA regulation is performed through pairing of the microRNA to sites in the messenger RNA of protein coding genes. Since experimental identification of miRNA target genes poses difficulties, computational microRNA target prediction is one of the key means in deciphering the role of microRNAs in development and disease. Results DIANA-microT 3.0 is an algorithm for microRNA target prediction which is based on several parameters calculated individually for each microRNA and combines conserved and non-conserved microRNA recognition elements into a final prediction score, which correlates with protein production fold change. Specifically, for each predicted interaction the program reports a signal to noise ratio and a precision score which can be used as an indication of the false positive rate of the prediction. Conclusion Recently, several computational target prediction programs were benchmarked based on a set of microRNA target genes identified by the pSILAC method. In this assessment DIANA-microT 3.0 was found to achieve the highest precision among the most widely used microRNA target prediction programs reaching approximately 66%. The DIANA-microT 3.0 prediction results are available online in a user friendly web server at http://www.microrna.gr/microT

  6. Dynamic functional modules in co-expressed protein interaction networks of dilated cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Oyang Yen-Jen

    2010-10-01

    Full Text Available Abstract Background Molecular networks represent the backbone of molecular activity within cells and provide opportunities for understanding the mechanism of diseases. While protein-protein interaction data constitute static network maps, integration of condition-specific co-expression information provides clues to the dynamic features of these networks. Dilated cardiomyopathy is a leading cause of heart failure. Although previous studies have identified putative biomarkers or therapeutic targets for heart failure, the underlying molecular mechanism of dilated cardiomyopathy remains unclear. Results We developed a network-based comparative analysis approach that integrates protein-protein interactions with gene expression profiles and biological function annotations to reveal dynamic functional modules under different biological states. We found that hub proteins in condition-specific co-expressed protein interaction networks tended to be differentially expressed between biological states. Applying this method to a cohort of heart failure patients, we identified two functional modules that significantly emerged from the interaction networks. The dynamics of these modules between normal and disease states further suggest a potential molecular model of dilated cardiomyopathy. Conclusions We propose a novel framework to analyze the interaction networks in different biological states. It successfully reveals network modules closely related to heart failure; more importantly, these network dynamics provide new insights into the cause of dilated cardiomyopathy. The revealed molecular modules might be used as potential drug targets and provide new directions for heart failure therapy.

  7. EBF factors drive expression of multiple classes of target genes governing neuronal development

    Directory of Open Access Journals (Sweden)

    Vetter Monica L

    2011-04-01

    Full Text Available Abstract Background Early B cell factor (EBF family members are transcription factors known to have important roles in several aspects of vertebrate neurogenesis, including commitment, migration and differentiation. Knowledge of how EBF family members contribute to neurogenesis is limited by a lack of detailed understanding of genes that are transcriptionally regulated by these factors. Results We performed a microarray screen in Xenopus animal caps to search for targets of EBF transcriptional activity, and identified candidate targets with multiple roles, including transcription factors of several classes. We determined that, among the most upregulated candidate genes with expected neuronal functions, most require EBF activity for some or all of their expression, and most have overlapping expression with ebf genes. We also found that the candidate target genes that had the most strongly overlapping expression patterns with ebf genes were predicted to be direct transcriptional targets of EBF transcriptional activity. Conclusions The identification of candidate targets that are transcription factor genes, including nscl-1, emx1 and aml1, improves our understanding of how EBF proteins participate in the hierarchy of transcription control during neuronal development, and suggests novel mechanisms by which EBF activity promotes migration and differentiation. Other candidate targets, including pcdh8 and kcnk5, expand our knowledge of the types of terminal differentiated neuronal functions that EBF proteins regulate.

  8. Targeting low-density lipoprotein receptors with protein-only nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhikun [Universitat Autònoma de Barcelona, Institut de Biotecnologia i de Biomedicina (Spain); Céspedes, María Virtudes [CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Unzueta, Ugutz [Universitat Autònoma de Barcelona, Institut de Biotecnologia i de Biomedicina (Spain); Álamo, Patricia [CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Pesarrodona, Mireia [Universitat Autònoma de Barcelona, Institut de Biotecnologia i de Biomedicina (Spain); Mangues, Ramón [CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Vázquez, Esther; Villaverde, Antonio, E-mail: antoni.villaverde@uab.cat; Ferrer-Miralles, Neus, E-mail: neus.ferrer@uab.cat [Universitat Autònoma de Barcelona, Institut de Biotecnologia i de Biomedicina (Spain)

    2015-03-15

    Low-density lipoprotein receptors (LDLR) are appealing cell surface targets in drug delivery, as they are expressed in the blood–brain barrier (BBB) endothelium and are able to mediate transcytosis of functionalized drugs for molecular therapies of the central nervous system (CNS). On the other hand, brain-targeted drug delivery is currently limited, among others, by the poor availability of biocompatible vehicles, as most of the nanoparticles under development as drug carriers pose severe toxicity issues. In this context, protein nanoparticles offer functional versatility, easy and cost-effective bioproduction, and full biocompatibility. In this study, we have designed and characterized several chimerical proteins containing different LDLR ligands, regarding their ability to bind and internalize target cells and to self-organize as viral mimetic nanoparticles of about 18 nm in diameter. While the self-assembling of LDLR-binding proteins as nanoparticles positively influences cell penetration in vitro, the nanoparticulate architecture might be not favoring BBB crossing in vivo. These findings are discussed in the context of the use of nanostructured materials as vehicles for the systemic treatment of CNS diseases.

  9. Targeting low-density lipoprotein receptors with protein-only nanoparticles

    International Nuclear Information System (INIS)

    Xu, Zhikun; Céspedes, María Virtudes; Unzueta, Ugutz; Álamo, Patricia; Pesarrodona, Mireia; Mangues, Ramón; Vázquez, Esther; Villaverde, Antonio; Ferrer-Miralles, Neus

    2015-01-01

    Low-density lipoprotein receptors (LDLR) are appealing cell surface targets in drug delivery, as they are expressed in the blood–brain barrier (BBB) endothelium and are able to mediate transcytosis of functionalized drugs for molecular therapies of the central nervous system (CNS). On the other hand, brain-targeted drug delivery is currently limited, among others, by the poor availability of biocompatible vehicles, as most of the nanoparticles under development as drug carriers pose severe toxicity issues. In this context, protein nanoparticles offer functional versatility, easy and cost-effective bioproduction, and full biocompatibility. In this study, we have designed and characterized several chimerical proteins containing different LDLR ligands, regarding their ability to bind and internalize target cells and to self-organize as viral mimetic nanoparticles of about 18 nm in diameter. While the self-assembling of LDLR-binding proteins as nanoparticles positively influences cell penetration in vitro, the nanoparticulate architecture might be not favoring BBB crossing in vivo. These findings are discussed in the context of the use of nanostructured materials as vehicles for the systemic treatment of CNS diseases

  10. A distinct epigenetic signature at targets of a leukemia protein

    Directory of Open Access Journals (Sweden)

    van der Spek Peter

    2007-02-01

    Full Text Available Abstract Background Human myelogenous leukemia characterized by either the non random t(8; 21(q22; q22 or t(16; 21(q24; q22 chromosome translocations differ for both their biological and clinical features. Some of these features could be consequent to differential epigenetic transcriptional deregulation at AML1 targets imposed by AML1-MTG8 and AML1-MTG16, the fusion proteins deriving from the two translocations. Preliminary findings showing that these fusion proteins lead to transcriptional downregulation of AML1 targets, marked by repressive chromatin changes, would support this hypothesis. Here we show that combining conventional global gene expression arrays with the power of bioinformatic genomic survey of AML1-consensus sequences is an effective strategy to identify AML1 targets whose transcription is epigenetically downregulated by the leukemia-associated AML1-MTG16 protein. Results We interrogated mouse gene expression microarrays with probes generated either from 32D cells infected with a retroviral vector carrying AML1-MTG16 and unable of granulocyte differentiation and proliferation in response to the granulocyte colony stimulating factor (G-CSF, or from 32D cells infected with the cognate empty vector. From the analysis of differential gene expression alone (using as criteria a p value 3, we were unable to conclude which of the 37 genes downregulated by AML1-MTG16 were, or not, direct AML1 targets. However, when we applied a bioinformatic approach to search for AML1-consensus sequences in the 10 Kb around the gene transcription start sites, we closed on 17 potential direct AML1 targets. By focusing on the most significantly downregulated genes, we found that both the AML1-consensus and the transcription start site chromatin regions were significantly marked by aberrant repressive histone tail changes. Further, the promoter of one of these genes, containing a CpG island, was aberrantly methylated. Conclusion This study shows that a

  11. Development of immobilized membrane-based affinity columns for use in the online characterization of membrane bound proteins and for targeted affinity isolations

    International Nuclear Information System (INIS)

    Moaddel, Ruin; Wainer, Irving W.

    2006-01-01

    Membranes obtained from cell lines that express or do not express a target membrane bound protein have been immobilized on a silica-based liquid chromatographic support or on the surface of an activated glass capillary. The resulting chromatographic columns have been placed in liquid chromatographic systems and used to characterize the target proteins and to identify small molecules that bind to the target. Membranes containing ligand gated ion channels, G-protein coupled receptors and drug transporters have been prepared and characterized. If a marker ligand has been identified for the target protein, frontal or zonal displacement chromatographic techniques can be used to determine binding affinities (K d values) and non-linear chromatography can be used to assess the association (k on ) and dissociation (k off ) rate constants and the thermodynamics of the binding process. Membrane-based affinity columns have been created using membranes from a cell line that does not express the target protein (control) and the same cell line that expresses the target protein (experimental) after genomic transfection. The resulting columns can be placed in a parallel chromatography system and the differential retention between the control and experimental columns can be used to identify small molecules and protein that bind to the target protein. These applications will be illustrated using columns created using cellular membranes containing nicotinic acetylcholine receptors and the drug transporter P-glycoprotein

  12. Development of immobilized membrane-based affinity columns for use in the online characterization of membrane bound proteins and for targeted affinity isolations

    Energy Technology Data Exchange (ETDEWEB)

    Moaddel, Ruin [Gerontology Research Center, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825 (United States); Wainer, Irving W. [Gerontology Research Center, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825 (United States)]. E-mail: Wainerir@grc.nia.nih.gov

    2006-03-30

    Membranes obtained from cell lines that express or do not express a target membrane bound protein have been immobilized on a silica-based liquid chromatographic support or on the surface of an activated glass capillary. The resulting chromatographic columns have been placed in liquid chromatographic systems and used to characterize the target proteins and to identify small molecules that bind to the target. Membranes containing ligand gated ion channels, G-protein coupled receptors and drug transporters have been prepared and characterized. If a marker ligand has been identified for the target protein, frontal or zonal displacement chromatographic techniques can be used to determine binding affinities (K {sub d} values) and non-linear chromatography can be used to assess the association (k {sub on}) and dissociation (k {sub off}) rate constants and the thermodynamics of the binding process. Membrane-based affinity columns have been created using membranes from a cell line that does not express the target protein (control) and the same cell line that expresses the target protein (experimental) after genomic transfection. The resulting columns can be placed in a parallel chromatography system and the differential retention between the control and experimental columns can be used to identify small molecules and protein that bind to the target protein. These applications will be illustrated using columns created using cellular membranes containing nicotinic acetylcholine receptors and the drug transporter P-glycoprotein.

  13. MicroRNA expression, target genes, and signaling pathways in infants with a ventricular septal defect.

    Science.gov (United States)

    Chai, Hui; Yan, Zhaoyuan; Huang, Ke; Jiang, Yuanqing; Zhang, Lin

    2018-02-01

    This study aimed to systematically investigate the relationship between miRNA expression and the occurrence of ventricular septal defect (VSD), and characterize the miRNA target genes and pathways that can lead to VSD. The miRNAs that were differentially expressed in blood samples from VSD and normal infants were screened and validated by implementing miRNA microarrays and qRT-PCR. The target genes regulated by differentially expressed miRNAs were predicted using three target gene databases. The functions and signaling pathways of the target genes were enriched using the GO database and KEGG database, respectively. The transcription and protein expression of specific target genes in critical pathways were compared in the VSD and normal control groups using qRT-PCR and western blotting, respectively. Compared with the normal control group, the VSD group had 22 differentially expressed miRNAs; 19 were downregulated and three were upregulated. The 10,677 predicted target genes participated in many biological functions related to cardiac development and morphogenesis. Four target genes (mGLUR, Gq, PLC, and PKC) were involved in the PKC pathway and four (ECM, FAK, PI3 K, and PDK1) were involved in the PI3 K-Akt pathway. The transcription and protein expression of these eight target genes were significantly upregulated in the VSD group. The 22 miRNAs that were dysregulated in the VSD group were mainly downregulated, which may result in the dysregulation of several key genes and biological functions related to cardiac development. These effects could also be exerted via the upregulation of eight specific target genes, the subsequent over-activation of the PKC and PI3 K-Akt pathways, and the eventual abnormal cardiac development and VSD.

  14. Optimised 'on demand' protein arraying from DNA by cell free expression with the 'DNA to Protein Array' (DAPA) technology.

    Science.gov (United States)

    Schmidt, Ronny; Cook, Elizabeth A; Kastelic, Damjana; Taussig, Michael J; Stoevesandt, Oda

    2013-08-02

    We have previously described a protein arraying process based on cell free expression from DNA template arrays (DNA Array to Protein Array, DAPA). Here, we have investigated the influence of different array support coatings (Ni-NTA, Epoxy, 3D-Epoxy and Polyethylene glycol methacrylate (PEGMA)). Their optimal combination yields an increased amount of detected protein and an optimised spot morphology on the resulting protein array compared to the previously published protocol. The specificity of protein capture was improved using a tag-specific capture antibody on a protein repellent surface coating. The conditions for protein expression were optimised to yield the maximum amount of protein or the best detection results using specific monoclonal antibodies or a scaffold binder against the expressed targets. The optimised DAPA system was able to increase by threefold the expression of a representative model protein while conserving recognition by a specific antibody. The amount of expressed protein in DAPA was comparable to those of classically spotted protein arrays. Reaction conditions can be tailored to suit the application of interest. DAPA represents a cost effective, easy and convenient way of producing protein arrays on demand. The reported work is expected to facilitate the application of DAPA for personalized medicine and screening purposes. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. SHuffle, a novel Escherichia coli protein expression strain capable of correctly folding disulfide bonded proteins in its cytoplasm

    Directory of Open Access Journals (Sweden)

    Lobstein Julie

    2012-05-01

    Full Text Available Abstract Background Production of correctly disulfide bonded proteins to high yields remains a challenge. Recombinant protein expression in Escherichia coli is the popular choice, especially within the research community. While there is an ever growing demand for new expression strains, few strains are dedicated to post-translational modifications, such as disulfide bond formation. Thus, new protein expression strains must be engineered and the parameters involved in producing disulfide bonded proteins must be understood. Results We have engineered a new E. coli protein expression strain named SHuffle, dedicated to producing correctly disulfide bonded active proteins to high yields within its cytoplasm. This strain is based on the trxB gor suppressor strain SMG96 where its cytoplasmic reductive pathways have been diminished, allowing for the formation of disulfide bonds in the cytoplasm. We have further engineered a major improvement by integrating into its chromosome a signal sequenceless disulfide bond isomerase, DsbC. We probed the redox state of DsbC in the oxidizing cytoplasm and evaluated its role in assisting the formation of correctly folded multi-disulfide bonded proteins. We optimized protein expression conditions, varying temperature, induction conditions, strain background and the co-expression of various helper proteins. We found that temperature has the biggest impact on improving yields and that the E. coli B strain background of this strain was superior to the K12 version. We also discovered that auto-expression of substrate target proteins using this strain resulted in higher yields of active pure protein. Finally, we found that co-expression of mutant thioredoxins and PDI homologs improved yields of various substrate proteins. Conclusions This work is the first extensive characterization of the trxB gor suppressor strain. The results presented should help researchers design the appropriate protein expression conditions using

  16. Targeted repression of AXIN2 and MYC gene expression using designer TALEs

    International Nuclear Information System (INIS)

    Rennoll, Sherri A.; Scott, Samantha A.; Yochum, Gregory S.

    2014-01-01

    Highlights: • We designed TALE–SID fusion proteins to target AXIN2 and MYC. • TALE–SIDs bound the chromosomal AXIN2 and MYC genes and repressed their expression. • TALE–SIDs repress β-catenin S45F -dependent AXIN2 and MYC transcription. - Abstract: Designer TALEs (dTALEs) are chimeric transcription factors that can be engineered to regulate gene expression in mammalian cells. Whether dTALEs can block gene transcription downstream of signal transduction cascades, however, has yet to be fully explored. Here we tested whether dTALEs can be used to target genes whose expression is controlled by Wnt/β-catenin signaling. TALE DNA binding domains were engineered to recognize sequences adjacent to Wnt responsive enhancer elements (WREs) that control expression of axis inhibition protein 2 (AXIN2) and c-MYC (MYC). These custom DNA binding domains were linked to the mSin3A interaction domain (SID) to generate TALE–SID chimeric repressors. The TALE–SIDs repressed luciferase reporter activity, bound their genomic target sites, and repressed AXIN2 and MYC expression in HEK293 cells. We generated a novel HEK293 cell line to determine whether the TALE–SIDs could function downstream of oncogenic Wnt/β-catenin signaling. Treating these cells with doxycycline and tamoxifen stimulates nuclear accumulation of a stabilized form of β-catenin found in a subset of colorectal cancers. The TALE–SIDs repressed AXIN2 and MYC expression in these cells, which suggests that dTALEs could offer an effective therapeutic strategy for the treatment of colorectal cancer

  17. Targeted repression of AXIN2 and MYC gene expression using designer TALEs

    Energy Technology Data Exchange (ETDEWEB)

    Rennoll, Sherri A.; Scott, Samantha A.; Yochum, Gregory S., E-mail: gsy3@psu.edu

    2014-04-18

    Highlights: • We designed TALE–SID fusion proteins to target AXIN2 and MYC. • TALE–SIDs bound the chromosomal AXIN2 and MYC genes and repressed their expression. • TALE–SIDs repress β-catenin{sup S45F}-dependent AXIN2 and MYC transcription. - Abstract: Designer TALEs (dTALEs) are chimeric transcription factors that can be engineered to regulate gene expression in mammalian cells. Whether dTALEs can block gene transcription downstream of signal transduction cascades, however, has yet to be fully explored. Here we tested whether dTALEs can be used to target genes whose expression is controlled by Wnt/β-catenin signaling. TALE DNA binding domains were engineered to recognize sequences adjacent to Wnt responsive enhancer elements (WREs) that control expression of axis inhibition protein 2 (AXIN2) and c-MYC (MYC). These custom DNA binding domains were linked to the mSin3A interaction domain (SID) to generate TALE–SID chimeric repressors. The TALE–SIDs repressed luciferase reporter activity, bound their genomic target sites, and repressed AXIN2 and MYC expression in HEK293 cells. We generated a novel HEK293 cell line to determine whether the TALE–SIDs could function downstream of oncogenic Wnt/β-catenin signaling. Treating these cells with doxycycline and tamoxifen stimulates nuclear accumulation of a stabilized form of β-catenin found in a subset of colorectal cancers. The TALE–SIDs repressed AXIN2 and MYC expression in these cells, which suggests that dTALEs could offer an effective therapeutic strategy for the treatment of colorectal cancer.

  18. Expression of a novel stress-inducible protein, sestrin 2, in rat glomerular parietal epithelial cells

    Science.gov (United States)

    Hamatani, Hiroko; Sakairi, Toru; Takahashi, Satoshi; Watanabe, Mitsuharu; Maeshima, Akito; Ohse, Takamoto; Pippin, Jeffery W.; Shankland, Stuart J.; Nojima, Yoshihisa

    2014-01-01

    Sestrin 2, initially identified as a p53 target protein, accumulates in cells exposed to stress and inhibits mammalian target of rapamycin (mTOR) signaling. In normal rat kidneys, sestrin 2 was selectively expressed in parietal epithelial cells (PECs), identified by the marker protein gene product 9.5. In adriamycin nephropathy, sestrin 2 expression decreased in PECs on day 14, together with increased expression of phosphorylated S6 ribosomal protein (P-S6RP), a downstream target of mTOR. Sestrin 2 expression was markedly decreased on day 42, coinciding with glomerulosclerosis and severe periglomerular fibrosis. In puromycin aminonucleoside nephropathy, decreased sestrin 2 expression, increased P-S6RP expression, and periglomerular fibrosis were observed on day 9, when massive proteinuria developed. These changes were transient and nearly normalized by day 28. In crescentic glomerulonephritis, sestrin 2 expression was not detected in cellular crescents, whereas P-S6RP increased. In conditionally immortalized cultured PECs, the forced downregulation of sestrin 2 by short hairpin RNA resulted in increased expression of P-S6RP and increased apoptosis. These data suggest that sestrin 2 is involved in PEC homeostasis by regulating the activity of mTOR. In addition, sestrin 2 could be a novel marker of PECs, and decreased expression of sestrin 2 might be a marker of PEC injury. PMID:25056347

  19. De-repressing LncRNA-Targeted Genes to Upregulate Gene Expression: Focus on Small Molecule Therapeutics

    Directory of Open Access Journals (Sweden)

    Roya Pedram Fatemi

    2014-01-01

    Full Text Available Non-protein coding RNAs (ncRNAs make up the overwhelming majority of transcripts in the genome and have recently gained attention for their complex regulatory role in cells, including the regulation of protein-coding genes. Furthermore, ncRNAs play an important role in normal development and their expression levels are dysregulated in several diseases. Recently, several long noncoding RNAs (lncRNAs have been shown to alter the epigenetic status of genomic loci and suppress the expression of target genes. This review will present examples of such a mechanism and focus on the potential to target lncRNAs for achieving therapeutic gene upregulation by de-repressing genes that are epigenetically silenced in various diseases. Finally, the potential to target lncRNAs, through their interactions with epigenetic enzymes, using various tools, such as small molecules, viral vectors and antisense oligonucleotides, will be discussed. We suggest that small molecule modulators of a novel class of drug targets, lncRNA-protein interactions, have great potential to treat some cancers, cardiovascular disease, and neurological disorders.

  20. Signatures of RNA binding proteins globally coupled to effective microRNA target sites

    DEFF Research Database (Denmark)

    Jacobsen, Anders; Wen, Jiayu; Marks, Debora S

    2010-01-01

    MicroRNAs (miRNAs) and small interfering RNAs (siRNAs), bound to Argonaute proteins (RISC), destabilize mRNAs through base-pairing with the mRNA. However, the gene expression changes after perturbations of these small RNAs are only partially explained by predicted miRNA/siRNA targeting. Targeting...

  1. Hot-spot analysis for drug discovery targeting protein-protein interactions.

    Science.gov (United States)

    Rosell, Mireia; Fernández-Recio, Juan

    2018-04-01

    Protein-protein interactions are important for biological processes and pathological situations, and are attractive targets for drug discovery. However, rational drug design targeting protein-protein interactions is still highly challenging. Hot-spot residues are seen as the best option to target such interactions, but their identification requires detailed structural and energetic characterization, which is only available for a tiny fraction of protein interactions. Areas covered: In this review, the authors cover a variety of computational methods that have been reported for the energetic analysis of protein-protein interfaces in search of hot-spots, and the structural modeling of protein-protein complexes by docking. This can help to rationalize the discovery of small-molecule inhibitors of protein-protein interfaces of therapeutic interest. Computational analysis and docking can help to locate the interface, molecular dynamics can be used to find suitable cavities, and hot-spot predictions can focus the search for inhibitors of protein-protein interactions. Expert opinion: A major difficulty for applying rational drug design methods to protein-protein interactions is that in the majority of cases the complex structure is not available. Fortunately, computational docking can complement experimental data. An interesting aspect to explore in the future is the integration of these strategies for targeting PPIs with large-scale mutational analysis.

  2. Identification of poly(rC) binding protein 2 (PCBP2) as a target protein of immunosuppressive agent 15-deoxyspergualin

    Energy Technology Data Exchange (ETDEWEB)

    Murahashi, Masataka; Simizu, Siro; Morioka, Masahiko [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Umezawa, Kazuo, E-mail: umezawa@aichi-med-u.ac.jp [Department of Molecular Target Medicine, Aichi Medical University School of Medicine, 1-1 Yazako-Karimata, Nagakute 480-1195 (Japan)

    2016-08-05

    15-Deoxyspergualin (DSG) is an immunosuppressive agent being clinically used. Unlike tacrolimus and cyclosporine A, it does not inhibit the calcineurin pathway, and its mechanism of action and target molecule have not been elucidated. Therefore, we previously prepared biotinylated derivative of DSG (BDSG) to fish up the target protein. In the present research, we identified poly(rC) binding protein 2 (PCBP2) as a DSG-binding protein using this probe. DSG was confirmed to bind to PCBP2 by pull-down assay. Intracellular localization of PCBP2 was changed from the nucleus to the cytoplasm by DSG treatment. DSG inhibited the cell growth, and over-expression of PCBP2 reduced the anti-proliferative activity of DSG. PCBP2 is known to regulate various proteins including STAT1/2. Thus, we found PCBP2 as the first target protein of DSG that can explain the immunosuppressive activity. -- Highlights: •Fifteen-deoxyspergualin (DSG) is an immunosuppressive agent clinically used. •We have identified PCBP2, an RNA-binding protein, as a molecular target of DSG. •Alteration of PCBP2 activity may explain the immunosuppressive activity of DSG.

  3. Mapping a nucleolar targeting sequence of an RNA binding nucleolar protein, Nop25

    International Nuclear Information System (INIS)

    Fujiwara, Takashi; Suzuki, Shunji; Kanno, Motoko; Sugiyama, Hironobu; Takahashi, Hisaaki; Tanaka, Junya

    2006-01-01

    Nop25 is a putative RNA binding nucleolar protein associated with rRNA transcription. The present study was undertaken to determine the mechanism of Nop25 localization in the nucleolus. Deletion experiments of Nop25 amino acid sequence showed Nop25 to contain a nuclear targeting sequence in the N-terminal and a nucleolar targeting sequence in the C-terminal. By expressing derivative peptides from the C-terminal as GFP-fusion proteins in the cells, a lysine and arginine residue-enriched peptide (KRKHPRRAQDSTKKPPSATRTSKTQRRRR) allowed a GFP-fusion protein to be transported and fully retained in the nucleolus. When the peptide was fused with cMyc epitope and expressed in the cells, a cMyc epitope was then detected in the nucleolus. Nop25 did not localize in the nucleolus by deletion of the peptide from Nop25. Furthermore, deletion of a subdomain (KRKHPRRAQ) in the peptide or amino acid substitution of lysine and arginine residues in the subdomain resulted in the loss of Nop25 nucleolar localization. These results suggest that the lysine and arginine residue-enriched peptide is the most prominent nucleolar targeting sequence of Nop25 and that the long stretch of basic residues might play an important role in the nucleolar localization of Nop25. Although Nop25 contained putative SUMOylation, phosphorylation and glycosylation sites, the amino acid substitution in these sites had no effect on the nucleolar localization, thus suggesting that these post-translational modifications did not contribute to the localization of Nop25 in the nucleolus. The treatment of the cells, which expressed a GFP-fusion protein with a nucleolar targeting sequence of Nop25, with RNase A resulted in a complete dislocation of the protein from the nucleolus. These data suggested that the nucleolar targeting sequence might therefore play an important role in the binding of Nop25 to RNA molecules and that the RNA binding of Nop25 might be essential for the nucleolar localization of Nop25

  4. A New Strain Collection for Improved Expression of Outer Membrane Proteins

    Directory of Open Access Journals (Sweden)

    Ina Meuskens

    2017-11-01

    Full Text Available Almost all integral membrane proteins found in the outer membranes of Gram-negative bacteria belong to the transmembrane β-barrel family. These proteins are not only important for nutrient uptake and homeostasis, but are also involved in such processes as adhesion, protein secretion, biofilm formation, and virulence. As surface exposed molecules, outer membrane β-barrel proteins are also potential drug and vaccine targets. High production levels of heterologously expressed proteins are desirable for biochemical and especially structural studies, but over-expression and subsequent purification of membrane proteins, including outer membrane proteins, can be challenging. Here, we present a set of deletion mutants derived from E. coli BL21(DE3 designed for the over-expression of recombinant outer membrane proteins. These strains harbor deletions of four genes encoding abundant β-barrel proteins in the outer membrane (OmpA, OmpC, OmpF, and LamB, both single and in all combinations of double, triple, and quadruple knock-outs. The sequences encoding these outer membrane proteins were deleted completely, leaving only a minimal scar sequence, thus preventing the possibility of genetic reversion. Expression tests in the quadruple mutant strain with four test proteins, including a small outer membrane β-barrel protein and variants thereof as well as two virulence-related autotransporters, showed significantly improved expression and better quality of the produced proteins over the parent strain. Differences in growth behavior and aggregation in the presence of high salt were observed, but these phenomena did not negatively influence the expression in the quadruple mutant strain when handled as we recommend. The strains produced in this study can be used for outer membrane protein production and purification, but are also uniquely useful for labeling experiments for biophysical measurements in the native membrane environment.

  5. Method for Targeted Therapeutic Delivery of Proteins into Cells | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The Protein Expression Laboratory at the National Cancer Institute in Frederick, MD is seeking statements of capability or interest from parties interested in collaborative research to further develop a platform technology for the targeted intra-cellular delivery of proteins using virus-like particles (VLPs).

  6. Hepatitis C virus core protein targets 4E-BP1 expression and phosphorylation and potentiates Myc-induced liver carcinogenesis in transgenic mice.

    Science.gov (United States)

    Abdallah, Cosette; Lejamtel, Charlène; Benzoubir, Nassima; Battaglia, Serena; Sidahmed-Adrar, Nazha; Desterke, Christophe; Lemasson, Matthieu; Rosenberg, Arielle R; Samuel, Didier; Bréchot, Christian; Pflieger, Delphine; Le Naour, François; Bourgeade, Marie-Françoise

    2017-08-22

    Hepatitis C virus (HCV) is a leading cause of liver diseases including the development of hepatocellular carcinoma (HCC). Particularly, core protein has been involved in HCV-related liver pathologies. However, the impact of HCV core on signaling pathways supporting the genesis of HCC remains largely elusive. To decipher the host cell signaling pathways involved in the oncogenic potential of HCV core, a global quantitative phosphoproteomic approach was carried out. This study shed light on novel differentially phosphorylated proteins, in particular several components involved in translation. Among the eukaryotic initiation factors that govern the translational machinery, 4E-BP1 represents a master regulator of protein synthesis that is associated with the development and progression of cancers due to its ability to increase protein expression of oncogenic pathways. Enhanced levels of 4E-BP1 in non-modified and phosphorylated forms were validated in human hepatoma cells and in mouse primary hepatocytes expressing HCV core, in the livers of HCV core transgenic mice as well as in HCV-infected human primary hepatocytes. The contribution of HCV core in carcinogenesis and the status of 4E-BP1 expression and phosphorylation were studied in HCV core/Myc double transgenic mice. HCV core increased the levels of 4E-BP1 expression and phosphorylation and significantly accelerated the onset of Myc-induced tumorigenesis in these double transgenic mice. These results reveal a novel function of HCV core in liver carcinogenesis potentiation. They position 4E-BP1 as a tumor-specific target of HCV core and support the involvement of the 4E-BP1/eIF4E axis in hepatocarcinogenesis.

  7. Effect of Plasmid Design and Type of Integration Event on Recombinant Protein Expression in Pichia pastoris.

    Science.gov (United States)

    Vogl, Thomas; Gebbie, Leigh; Palfreyman, Robin W; Speight, Robert

    2018-03-15

    Pichia pastoris (syn. Komagataella phaffii ) is one of the most common eukaryotic expression systems for heterologous protein production. Expression cassettes are typically integrated in the genome to obtain stable expression strains. In contrast to Saccharomyces cerevisiae , where short overhangs are sufficient to target highly specific integration, long overhangs are more efficient in P. pastoris and ectopic integration of foreign DNA can occur. Here, we aimed to elucidate the influence of ectopic integration by high-throughput screening of >700 transformants and whole-genome sequencing of 27 transformants. Different vector designs and linearization approaches were used to mimic the most common integration events targeted in P. pastoris Fluorescence of an enhanced green fluorescent protein (eGFP) reporter protein was highly uniform among transformants when the expression cassettes were correctly integrated in the targeted locus. Surprisingly, most nonspecifically integrated transformants showed highly uniform expression that was comparable to specific integration, suggesting that nonspecific integration does not necessarily influence expression. However, a few clones (integrated cassettes showed a greater variation spanning a 25-fold range, surpassing specifically integrated reference strains up to 6-fold. High-expression strains showed a correlation between increased gene copy numbers and high reporter protein fluorescence levels. Our results suggest that for comparing expression levels between strains, the integration locus can be neglected as long as a sufficient numbers of transformed strains are compared. For expression optimization of highly expressible proteins, increasing copy number appears to be the dominant positive influence rather than the integration locus, genomic rearrangements, deletions, or single-nucleotide polymorphisms (SNPs). IMPORTANCE Yeasts are commonly used as biotechnological production hosts for proteins and metabolites. In the yeast

  8. High Expression of Cry1Ac Protein in Cotton (Gossypium hirsutum by Combining Independent Transgenic Events that Target the Protein to Cytoplasm and Plastids.

    Directory of Open Access Journals (Sweden)

    Amarjeet Kumar Singh

    Full Text Available Transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1Ac gene (1,848 bp, which was originally characterized from Bacillus thuringiensis subspecies kurstaki strain HD73 that encodes a toxin highly effective against many lepidopteran pests. In Construct I, the cry1Ac gene was cloned under FMVde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. In Construct II, the encoded protein was directed to the plastids using a transit peptide taken from the cotton rbcSIb gene. Genetic transformation experiments with Construct I resulted in a single copy insertion event in which the Cry1Ac protein expression level was 2-2.5 times greater than in the Bacillus thuringiensis cotton event Mon 531, which is currently used in varieties and hybrids grown extensively in India and elsewhere. Another high expression event was selected from transgenics developed with Construct II. The Cry protein expression resulting from this event was observed only in the green plant parts. No transgenic protein expression was observed in the non-green parts, including roots, seeds and non-green floral tissues. Thus, leucoplasts may lack the mechanism to allow entry of a protein tagged with the transit peptide from a protein that is only synthesized in tissues containing mature plastids. Combining the two events through sexual crossing led to near additive levels of the toxin at 4-5 times the level currently used in the field. The two high expression events and their combination will allow for effective resistance management against lepidopteran insect pests, particularly Helicoverpa armigera, using a high dosage strategy.

  9. Potential proteins targeted by let-7f-5p in HeLa cells.

    Science.gov (United States)

    Wang, Yu; Chen, Xiujuan; Zhang, Yi; Song, Jiandong

    2017-07-24

    MicroRNAs are a class of small, endogenous, non-coding RNAs mediating posttranscriptional gene silencing. The current authors hypothesized that let-7f-5p is likely involved in cell invasion and proliferation by regulating the expression of target genes. The current study combined let-7f-5p with iTRAQ to assess its effect on gene expression in HeLa cells. Results indicated that 164 proteins were expressed at different levels in HeLa cells overexpressing let-7f-5p and negative controls and that 172 proteins were expressed at different levels in let-7f-5p-silenced HeLa cells and negative controls. Results indicated that let-7f-5p may suppress insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) in HeLa cells.

  10. Optimization of translation profiles enhances protein expression and solubility.

    Directory of Open Access Journals (Sweden)

    Anne-Katrin Hess

    Full Text Available mRNA is translated with a non-uniform speed that actively coordinates co-translational folding of protein domains. Using structure-based homology we identified the structural domains in epoxide hydrolases (EHs and introduced slow-translating codons to delineate the translation of single domains. These changes in translation speed dramatically improved the solubility of two EHs of metagenomic origin in Escherichia coli. Conversely, the importance of transient attenuation for the folding, and consequently solubility, of EH was evidenced with a member of the EH family from Agrobacterium radiobacter, which partitions in the soluble fraction when expressed in E. coli. Synonymous substitutions of codons shaping the slow-transiting regions to fast-translating codons render this protein insoluble. Furthermore, we show that low protein yield can be enhanced by decreasing the free folding energy of the initial 5'-coding region, which can disrupt mRNA secondary structure and enhance ribosomal loading. This study provides direct experimental evidence that mRNA is not a mere messenger for translation of codons into amino acids but bears an additional layer of information for folding, solubility and expression level of the encoded protein. Furthermore, it provides a general frame on how to modulate and fine-tune gene expression of a target protein.

  11. Targeted recombinant fusion proteins of IFNγ and mimetic IFNγ with PDGFβR bicyclic peptide inhibits liver fibrogenesis in vivo.

    Directory of Open Access Journals (Sweden)

    Ruchi Bansal

    Full Text Available Hepatic stellate cells (HSCs, following transdifferentiation to myofibroblasts plays a key role in liver fibrosis. Therefore, attempts to attenuate this myofibroblastic phenotype would be a promising therapeutic approach. Interferon gamma (IFNγ is a potent anti-fibrotic cytokine, but its pleiotropic receptor expression leading to severe adverse effects has limited its clinical application. Since, activated HSC express high-level of platelet derived growth factor beta receptor (PDGFβR, we investigated the potential of PDGFβR-specific targeting of IFNγ and its signaling peptide that lacks IFNγR binding site (mimetic IFNγ or mimIFNγ in liver fibrosis. We prepared DNA constructs expressing IFNγ, mimIFNγ or BiPPB (PDGFβR-specific bicyclic peptide-IFNγ, BiPPB-mimIFNγ fusion proteins. Both chimeric proteins alongwith IFNγ and mimIFNγ were produced in E.coli. The expressed proteins were purified and analyzed for PDGFβR-specific binding and in vitro effects. Subsequently, these recombinant proteins were investigated for the liver uptake (pSTAT1α signaling pathway, for anti-fibrotic effects and adverse effects (platelet counts in CCl4-induced liver fibrogenesis in mice. The purified HSC-targeted IFNγ and mimIFNγ fusion proteins showed PDGFβR-specific binding and significantly reduced TGFβ-induced collagen-I expression in human HSC (LX2 cells, while mouse IFNγ and mimIFNγ did not show any effect. Conversely, mouse IFNγ and BiPPB-IFNγ induced activation and dose-dependent nitric oxide release in mouse macrophages (express IFNγR while lack PDGFβR, which was not observed with mimIFNγ and BiPPB-mimIFNγ, due to the lack of IFNγR binding sites. In vivo, targeted BiPPB-IFNγ and BiPPB-mimIFNγ significantly activated intrahepatic IFNγ-signaling pathway compared to IFNγ and mimIFNγ suggesting increased liver accumulation. Furthermore, the targeted fusion proteins ameliorated liver fibrogenesis in mice by significantly reducing

  12. Transcript and protein expression profile of PF11_0394, a Plasmodium falciparum protein expressed in salivary gland sporozoites

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    Schlarman Maggie S

    2012-03-01

    Full Text Available Abstract Background Plasmodium falciparum malaria is a significant problem around the world today, thus there is still a need for new control methods to be developed. Because the sporozoite displays dual infectivity for both the mosquito salivary glands and vertebrate host tissue, it is a good target for vaccine development. Methods The P. falciparum gene, PF11_0394, was chosen as a candidate for study due to its potential role in the invasion of host tissues. This gene, which was selected using a data mining approach from PlasmoDB, is expressed both at the transcriptional and protein levels in sporozoites and likely encodes a putative surface protein. Using reverse transcription-polymerase chain reaction (RT-PCR and green fluorescent protein (GFP-trafficking studies, a transcript and protein expression profile of PF11_0394 was determined. Results The PF11_0394 protein has orthologs in other Plasmodium species and Apicomplexans, but none outside of the group Apicomplexa. PF11_0394 transcript was found to be present during both the sporozoite and erythrocytic stages of the parasite life cycle, but no transcript was detected during axenic exoerythrocytic stages. Despite the presence of transcript throughout several life cycle stages, the PF11_0394 protein was only detected in salivary gland sporozoites. Conclusions PF11_0394 appears to be a protein uniquely detected in salivary gland sporozoites. Even though a specific function of PF11_0394 has not been determined in P. falciparum biology, it could be another candidate for a new vaccine.

  13. EGFR and HER2 expression in primary cervical cancers and corresponding lymph node metastases: Implications for targeted radiotherapy

    International Nuclear Information System (INIS)

    Shen, Li; Shui, Yongjie; Wang, Xiaojia; Sheng, Liming; Yang, Zhengyan; Xue, Danfeng; Wei, Qichun

    2008-01-01

    Proteins overexpressed on the surface of tumor cells can be selectively targeted. Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are among the most often targeted proteins. The level and stability of expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target for imaging in nuclear medicine and for various forms of therapy. So far, the expression of EGFR and HER2 has only been determined in primary cervical cancers, and we have not found published data regarding the receptor status in corresponding metastatic lesions. The goal of this study was to evaluate whether any of these receptors are suitable as target for clinical diagnosis and therapy. Expression of EGFR and HER2 was investigated immunohistochemically in both lymph node metastases and corresponding primary cervical cancers (n = 53). HER2 and EGFR expression was scored using HercepTest criteria (0, 1+, 2+ or 3+). EGFR overexpression (2+ or 3+) was found in 64% (35/53) of the primary cervical tumors and 60% (32/53) of the corresponding lymph node metastases. There was a good concordance between the primary tumors and the paired metastases regarding EGFR expression. Only four patients who had 2+ or 3+ in the primary tumors changed to 0 or 1+ in lymph node metastases, and another two cases changed the other way around. None of the primary tumors or the lymph node metastases expressed HER2 protein. The EGFR expression seems to be common and stable during cervical cancer metastasis, which is encouraging for testing of EGFR targeted radiotherapy. HER2 appears to be of poor interest as a potential target in the treatment of cervical cancer

  14. A single peroxisomal targeting signal mediates matrix protein import in diatoms.

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    Nicola H Gonzalez

    Full Text Available Peroxisomes are single membrane bound compartments. They are thought to be present in almost all eukaryotic cells, although the bulk of our knowledge about peroxisomes has been generated from only a handful of model organisms. Peroxisomal matrix proteins are synthesized cytosolically and posttranslationally imported into the peroxisomal matrix. The import is generally thought to be mediated by two different targeting signals. These are respectively recognized by the two import receptor proteins Pex5 and Pex7, which facilitate transport across the peroxisomal membrane. Here, we show the first in vivo localization studies of peroxisomes in a representative organism of the ecologically relevant group of diatoms using fluorescence and transmission electron microscopy. By expression of various homologous and heterologous fusion proteins we demonstrate that targeting of Phaeodactylum tricornutum peroxisomal matrix proteins is mediated only by PTS1 targeting signals, also for proteins that are in other systems imported via a PTS2 mode of action. Additional in silico analyses suggest this surprising finding may also apply to further diatoms. Our data suggest that loss of the PTS2 peroxisomal import signal is not reserved to Caenorhabditis elegans as a single exception, but has also occurred in evolutionary divergent organisms. Obviously, targeting switching from PTS2 to PTS1 across different major eukaryotic groups might have occurred for different reasons. Thus, our findings question the widespread assumption that import of peroxisomal matrix proteins is generally mediated by two different targeting signals. Our results implicate that there apparently must have been an event causing the loss of one targeting signal even in the group of diatoms. Different possibilities are discussed that indicate multiple reasons for the detected targeting switching from PTS2 to PTS1.

  15. Targeted disruption of fibrinogen like protein-1 accelerates hepatocellular carcinoma development

    International Nuclear Information System (INIS)

    Nayeb-Hashemi, Hamed; Desai, Anal; Demchev, Valeriy; Bronson, Roderick T.; Hornick, Jason L.; Cohen, David E.; Ukomadu, Chinweike

    2015-01-01

    Fibrinogen like protein-1 (Fgl1) is a predominantly liver expressed protein that has been implicated as both a hepatoprotectant and a hepatocyte mitogen. Fgl1 expression is decreased in hepatocellular carcinoma (HCC) and its loss correlates with a poorly differentiated phenotype. To better elucidate the role of Fgl1 in hepatocarcinogenesis, we treated mice wild type or null for Fgl1 with diethyl nitrosamine and monitored for incidence of hepatocellular cancer. We find that mice lacking Fgl1 develop HCC at more than twice the rate of wild type mice. We show that hepatocellular cancers from Fgl1 null mice are molecularly distinct from those of the wild type mice. In tumors from Fgl1 null mice there is enhanced activation of Akt and downstream targets of the mammalian target of rapamycin (mTOR). In addition, there is paradoxical up regulation of putative hepatocellular cancer tumor suppressors; tripartite motif-containing protein 35 (Trim35) and tumor necrosis factor super family 10b (Tnfrsf10b). Taken together, these findings suggest that Fgl1 acts as a tumor suppressor in hepatocellular cancer through an Akt dependent mechanism and supports its role as a potential therapeutic target in HCC. - Highlights: • Fgl1 knockout mice (Fgl1KO) are more prone to carcinogen-induced liver cancer compared to wild type (WT) mates. • Tumors from the Fgl1KO are molecularly distinct with enhanced Akt and mTOR activity in comparison with Fgl1WT tumors. • Tumors from the Fgl1KO have enhanced expression of Trim35 and Tnfrsf10b, putative HCC tumor suppressors

  16. Targeted disruption of fibrinogen like protein-1 accelerates hepatocellular carcinoma development

    Energy Technology Data Exchange (ETDEWEB)

    Nayeb-Hashemi, Hamed; Desai, Anal; Demchev, Valeriy [Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine. Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Bronson, Roderick T. [Department of Microbiology and Immunology, Harvard Medical School, Boston, MA 02115 (United States); Hornick, Jason L. [Department of Pathology, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Cohen, David E. [Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine. Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Ukomadu, Chinweike, E-mail: cukomadu@partners.org [Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine. Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States)

    2015-09-18

    Fibrinogen like protein-1 (Fgl1) is a predominantly liver expressed protein that has been implicated as both a hepatoprotectant and a hepatocyte mitogen. Fgl1 expression is decreased in hepatocellular carcinoma (HCC) and its loss correlates with a poorly differentiated phenotype. To better elucidate the role of Fgl1 in hepatocarcinogenesis, we treated mice wild type or null for Fgl1 with diethyl nitrosamine and monitored for incidence of hepatocellular cancer. We find that mice lacking Fgl1 develop HCC at more than twice the rate of wild type mice. We show that hepatocellular cancers from Fgl1 null mice are molecularly distinct from those of the wild type mice. In tumors from Fgl1 null mice there is enhanced activation of Akt and downstream targets of the mammalian target of rapamycin (mTOR). In addition, there is paradoxical up regulation of putative hepatocellular cancer tumor suppressors; tripartite motif-containing protein 35 (Trim35) and tumor necrosis factor super family 10b (Tnfrsf10b). Taken together, these findings suggest that Fgl1 acts as a tumor suppressor in hepatocellular cancer through an Akt dependent mechanism and supports its role as a potential therapeutic target in HCC. - Highlights: • Fgl1 knockout mice (Fgl1KO) are more prone to carcinogen-induced liver cancer compared to wild type (WT) mates. • Tumors from the Fgl1KO are molecularly distinct with enhanced Akt and mTOR activity in comparison with Fgl1WT tumors. • Tumors from the Fgl1KO have enhanced expression of Trim35 and Tnfrsf10b, putative HCC tumor suppressors.

  17. Methyl labeling and TROSY NMR spectroscopy of proteins expressed in the eukaryote Pichia pastoris

    International Nuclear Information System (INIS)

    Clark, Lindsay; Zahm, Jacob A.; Ali, Rustam; Kukula, Maciej; Bian, Liangqiao; Patrie, Steven M.; Gardner, Kevin H.; Rosen, Michael K.; Rosenbaum, Daniel M.

    2015-01-01

    13 C Methyl TROSY NMR spectroscopy has emerged as a powerful method for studying the dynamics of large systems such as macromolecular assemblies and membrane proteins. Specific 13 C labeling of aliphatic methyl groups and perdeuteration has been limited primarily to proteins expressed in E. coli, preventing studies of many eukaryotic proteins of physiological and biomedical significance. We demonstrate the feasibility of efficient 13 C isoleucine δ1-methyl labeling in a deuterated background in an established eukaryotic expression host, Pichia pastoris, and show that this method can be used to label the eukaryotic protein actin, which cannot be expressed in bacteria. This approach will enable NMR studies of previously intractable targets

  18. Tunable Control of an Escherichia coli Expression System for the Overproduction of Membrane Proteins by Titrated Expression of a Mutant lac Repressor.

    Science.gov (United States)

    Kim, Seong Keun; Lee, Dae-Hee; Kim, Oh Cheol; Kim, Jihyun F; Yoon, Sung Ho

    2017-09-15

    Most inducible expression systems suffer from growth defects, leaky basal induction, and inhomogeneous expression levels within a host cell population. These difficulties are most prominent with the overproduction of membrane proteins that are toxic to host cells. Here, we developed an Escherichia coli inducible expression system for membrane protein production based on titrated expression of a mutant lac repressor (mLacI). Performance of the mLacI inducible system was evaluated in conjunction with commonly used lac operator-based expression vectors using a T7 or tac promoter. Remarkably, expression of a target gene can be titrated by the dose-dependent addition of l-rhamnose, and the expression levels were homogeneous in the cell population. The developed system was successfully applied to overexpress three membrane proteins that were otherwise difficult to produce in E. coli. This gene expression control system can be easily applied to a broad range of existing protein expression systems and should be useful in constructing genetic circuits that require precise output signals.

  19. Specific Increase of Protein Levels by Enhancing Translation Using Antisense Oligonucleotides Targeting Upstream Open Frames.

    Science.gov (United States)

    Liang, Xue-Hai; Shen, Wen; Crooke, Stanley T

    2017-01-01

    A number of diseases are caused by low levels of key proteins; therefore, increasing the amount of specific proteins in human bodies is of therapeutic interest. Protein expression is downregulated by some structural or sequence elements present in the 5' UTR of mRNAs, such as upstream open reading frames (uORF). Translation initiation from uORF(s) reduces translation from the downstream primary ORF encoding the main protein product in the same mRNA, leading to a less efficient protein expression. Therefore, it is possible to use antisense oligonucleotides (ASOs) to specifically inhibit translation of the uORF by base-pairing with the uAUG region of the mRNA, redirecting translation machinery to initiate from the primary AUG site. Here we review the recent findings that translation of specific mRNAs can be enhanced using ASOs targeting uORF regions. Appropriately designed and optimized ASOs are highly specific, and they act in a sequence- and position-dependent manner, with very minor off-target effects. Protein levels can be increased using this approach in different types of human and mouse cells, and, importantly, also in mice. Since uORFs are present in around half of human mRNAs, the uORF-targeting ASOs may thus have valuable potential as research tools and as therapeutics to increase the levels of proteins for a variety of genes.

  20. Human Cytomegalovirus Nuclear Egress Proteins Ectopically Expressed in the Heterologous Environment of Plant Cells are Strictly Targeted to the Nuclear Envelope.

    Science.gov (United States)

    Lamm, Christian E; Link, Katrin; Wagner, Sabrina; Milbradt, Jens; Marschall, Manfred; Sonnewald, Uwe

    2016-03-10

    In all eukaryotic cells, the nucleus forms a prominent cellular compartment containing the cell's nuclear genome. Although structurally similar, animal and plant nuclei differ substantially in details of their architecture. One example is the nuclear lamina, a layer of tightly interconnected filament proteins (lamins) underlying the nuclear envelope of metazoans. So far no orthologous lamin genes could be detected in plant genomes and putative lamin-like proteins are only poorly described in plants. To probe for potentially conserved features of metazoan and plant nuclear envelopes, we ectopically expressed the core nuclear egress proteins of human cytomegalovirus pUL50 and pUL53 in plant cells. pUL50 localizes to the inner envelope of metazoan nuclei and recruits the nuclear localized pUL53 to it, forming heterodimers. Upon expression in plant cells, a very similar localization pattern of both proteins could be determined. Notably, pUL50 is specifically targeted to the plant nuclear envelope in a rim-like fashion, a location to which coexpressed pUL53 becomes strictly corecruited from its initial nucleoplasmic distribution. Using pUL50 as bait in a yeast two-hybrid screening, the cytoplasmic re-initiation supporting protein RISP could be identified. Interaction of pUL50 and RISP could be confirmed by coexpression and coimmunoprecipitation in mammalian cells and by confocal laser scanning microscopy in plant cells, demonstrating partial pUL50-RISP colocalization in areas of the nuclear rim and other intracellular compartments. Thus, our study provides strong evidence for conserved structural features of plant and metazoan nuclear envelops and identifies RISP as a potential pUL50-interacting plant protein.

  1. Identification of novel human damage response proteins targeted through yeast orthology.

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    J Peter Svensson

    Full Text Available Studies in Saccharomyces cerevisiae show that many proteins influence cellular survival upon exposure to DNA damaging agents. We hypothesized that human orthologs of these S. cerevisiae proteins would also be required for cellular survival after treatment with DNA damaging agents. For this purpose, human homologs of S. cerevisiae proteins were identified and mapped onto the human protein-protein interaction network. The resulting human network was highly modular and a series of selection rules were implemented to identify 45 candidates for human toxicity-modulating proteins. The corresponding transcripts were targeted by RNA interference in human cells. The cell lines with depleted target expression were challenged with three DNA damaging agents: the alkylating agents MMS and 4-NQO, and the oxidizing agent t-BuOOH. A comparison of the survival revealed that the majority (74% of proteins conferred either sensitivity or resistance. The identified human toxicity-modulating proteins represent a variety of biological functions: autophagy, chromatin modifications, RNA and protein metabolism, and telomere maintenance. Further studies revealed that MMS-induced autophagy increase the survival of cells treated with DNA damaging agents. In summary, we show that damage recovery proteins in humans can be identified through homology to S. cerevisiae and that many of the same pathways are represented among the toxicity modulators.

  2. Arabidopsis mRNA polyadenylation machinery: comprehensive analysis of protein-protein interactions and gene expression profiling

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    Mo Min

    2008-05-01

    extensive protein network was revealed for plant polyadenylation machinery, in which all predicted proteins were found to be connecting to the complex. The gene expression profiles are indicative that specialized sub-complexes may be formed to carry out targeted processing of mRNA in different developmental stages and tissue types. These results offer a roadmap for further functional characterizations of the protein factors, and for building models when testing the genetic contributions of these genes in plant growth and development.

  3. A multiplexed miRNA and transgene expression platform for simultaneous repression and expression of protein coding sequences.

    Science.gov (United States)

    Seyhan, Attila A

    2016-01-01

    Knockdown of single or multiple gene targets by RNA interference (RNAi) is necessary to overcome escape mutants or isoform redundancy. It is also necessary to use multiple RNAi reagents to knockdown multiple targets. It is also desirable to express a transgene or positive regulatory elements and inhibit a target gene in a coordinated fashion. This study reports a flexible multiplexed RNAi and transgene platform using endogenous intronic primary microRNAs (pri-miRNAs) as a scaffold located in the green fluorescent protein (GFP) as a model for any functional transgene. The multiplexed intronic miRNA - GFP transgene platform was designed to co-express multiple small RNAs within the polycistronic cluster from a Pol II promoter at more moderate levels to reduce potential vector toxicity. The native intronic miRNAs are co-transcribed with a precursor GFP mRNA as a single transcript and presumably cleaved out of the precursor-(pre) mRNA by the RNA splicing machinery, spliceosome. The spliced intron with miRNA hairpins will be further processed into mature miRNAs or small interfering RNAs (siRNAs) capable of triggering RNAi effects, while the ligated exons become a mature messenger RNA for the translation of the functional GFP protein. Data show that this approach led to robust RNAi-mediated silencing of multiple Renilla Luciferase (R-Luc)-tagged target genes and coordinated expression of functional GFP from a single transcript in transiently transfected HeLa cells. The results demonstrated that this design facilitates the coordinated expression of all mature miRNAs either as individual miRNAs or as multiple miRNAs and the associated protein. The data suggest that, it is possible to simultaneously deliver multiple negative (miRNA or shRNA) and positive (transgene) regulatory elements. Because many cellular processes require simultaneous repression and activation of downstream pathways, this approach offers a platform technology to achieve that dual manipulation efficiently

  4. R7-binding protein targets the G protein β5/R7-regulator of G protein signaling complex to lipid rafts in neuronal cells and brain

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    Zhang Jian-Hua

    2007-09-01

    Full Text Available Abstract Background Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins, composed of Gα, Gβ, and Gγ subunits, are positioned at the inner face of the plasma membrane and relay signals from activated G protein-coupled cell surface receptors to various signaling pathways. Gβ5 is the most structurally divergent Gβ isoform and forms tight heterodimers with regulator of G protein signalling (RGS proteins of the R7 subfamily (R7-RGS. The subcellular localization of Gβ 5/R7-RGS protein complexes is regulated by the palmitoylation status of the associated R7-binding protein (R7BP, a recently discovered SNARE-like protein. We investigate here whether R7BP controls the targeting of Gβ5/R7-RGS complexes to lipid rafts, cholesterol-rich membrane microdomains where conventional heterotrimeric G proteins and some effector proteins are concentrated in neurons and brain. Results We show that endogenous Gβ5/R7-RGS/R7BP protein complexes are present in native neuron-like PC12 cells and that a fraction is targeted to low-density, detergent-resistant membrane lipid rafts. The buoyant density of endogenous raft-associated Gβ5/R7-RGS protein complexes in PC12 cells was similar to that of lipid rafts containing the palmitoylated marker proteins PSD-95 and LAT, but distinct from that of the membrane microdomain where flotillin was localized. Overexpression of wild-type R7BP, but not its palmitoylation-deficient mutant, greatly enriched the fraction of endogenous Gβ5/R7-RGS protein complexes in the lipid rafts. In HEK-293 cells the palmitoylation status of R7BP also regulated the lipid raft targeting of co-expressed Gβ5/R7-RGS/R7BP proteins. A fraction of endogenous Gβ5/R7-RGS/R7BP complexes was also present in lipid rafts in mouse brain. Conclusion A fraction of Gβ5/R7-RGS/R7BP protein complexes is targeted to low-density, detergent-resistant membrane lipid rafts in PC12 cells and brain. In cultured cells, the palmitoylation status of

  5. Expression, purification and activity determination of the beetle tenebrio molitor antifreeze protein afp84c in escherichia coli

    International Nuclear Information System (INIS)

    Yang, Q.; Feng, H.

    2013-01-01

    Summary: A cDNA encoding antifreeze protein (AFP84c) was cloned by RT-PCR from the larva of the yellow mealworm Tenebrio molitor. The coding fragment of 252 bp encodes a protein of 84 amino acid residues and was fused to the expression vectors pMAL-c2X and pMAL-p2X. The expression plasmids pMAL-c2X-afp84c and pMAL-p2X-afp84c were constructed and transformed into Escherischia coli strains TBI, respectively. Strategy of optimization of induction conditions were used for expression of the highly disulfide-bonded beta-helix-contained protein with the activity of antifreeze in pMALTM expression system. The target fusion protein was released from the cytoplasm and periplasm by sonication and cold osmotic shock procedure respectively. Recombinant AFP84c was purified by amylose affinity column. The purified target protein displayed a single band in SDS-PAGE. Expressed AFP84c exhibits to increase low temperature resistance of bacteria. (author)

  6. Short hairpin RNA-mediated knockdown of protein expression in Entamoeba histolytica

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    Singh Upinder

    2009-02-01

    Full Text Available Abstract Background Entamoeba histolytica is an intestinal protozoan parasite of humans. The genome has been sequenced, but the study of individual gene products has been hampered by the lack of the ability to generate gene knockouts. We chose to test the use of RNA interference to knock down gene expression in Entamoeba histolytica. Results An episomal vector-based system, using the E. histolytica U6 promoter to drive expression of 29-basepair short hairpin RNAs, was developed to target protein-encoding genes in E. histolytica. The short hairpin RNAs successfully knocked down protein levels of all three unrelated genes tested with this system: Igl, the intermediate subunit of the galactose- and N-acetyl-D-galactosamine-inhibitable lectin; the transcription factor URE3-BP; and the membrane binding protein EhC2A. Igl levels were reduced by 72%, URE3-BP by 89%, and EhC2A by 97%. Conclusion Use of the U6 promoter to drive expression of 29-basepair short hairpin RNAs is effective at knocking down protein expression for unrelated genes in Entamoeba histolytica, providing a useful tool for the study of this parasite.

  7. Short hairpin RNA-mediated knockdown of protein expression in Entamoeba histolytica.

    Science.gov (United States)

    Linford, Alicia S; Moreno, Heriberto; Good, Katelyn R; Zhang, Hanbang; Singh, Upinder; Petri, William A

    2009-02-17

    Entamoeba histolytica is an intestinal protozoan parasite of humans. The genome has been sequenced, but the study of individual gene products has been hampered by the lack of the ability to generate gene knockouts. We chose to test the use of RNA interference to knock down gene expression in Entamoeba histolytica. An episomal vector-based system, using the E. histolytica U6 promoter to drive expression of 29-basepair short hairpin RNAs, was developed to target protein-encoding genes in E. histolytica. The short hairpin RNAs successfully knocked down protein levels of all three unrelated genes tested with this system: Igl, the intermediate subunit of the galactose- and N-acetyl-D-galactosamine-inhibitable lectin; the transcription factor URE3-BP; and the membrane binding protein EhC2A. Igl levels were reduced by 72%, URE3-BP by 89%, and EhC2A by 97%. Use of the U6 promoter to drive expression of 29-basepair short hairpin RNAs is effective at knocking down protein expression for unrelated genes in Entamoeba histolytica, providing a useful tool for the study of this parasite.

  8. Intracellular targeting of CD44+ cells with self-assembling, protein only nanoparticles.

    Science.gov (United States)

    Pesarrodona, Mireia; Ferrer-Miralles, Neus; Unzueta, Ugutz; Gener, Petra; Tatkiewicz, Witold; Abasolo, Ibane; Ratera, Imma; Veciana, Jaume; Schwartz, Simó; Villaverde, Antonio; Vazquez, Esther

    2014-10-01

    CD44 is a multifunctional cell surface protein involved in proliferation and differentiation, angiogenesis and signaling. The expression of CD44 is up-regulated in several types of human tumors and particularly in cancer stem cells, representing an appealing target for drug delivery in the treatment of cancer. We have explored here several protein ligands of CD44 for the construction of self-assembling modular proteins designed to bind and internalize target cells. Among five tested ligands, two of them (A5G27 and FNI/II/V) drive the formation of protein-only, ring-shaped nanoparticles of about 14 nm that efficiently bind and penetrate CD44(+) cells by an endosomal route. The potential of these newly designed nanoparticles is evaluated regarding the need of biocompatible nanostructured materials for drug delivery in CD44-linked conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Exosomal protein interactors as emerging therapeutic targets in urothelial bladder cancer

    International Nuclear Information System (INIS)

    Kumari, N.; Saxena, S.; Agrawal, U.

    2015-01-01

    Background: Exosomes are rich sources of biological material (proteins and nucleic acids) secreted by both tumor and normal cells, and found in urine of urinary bladder cancer patients. Objective: The objective of the study was to identify interacting exosomal proteins in bladder cancer for future use in targeted therapy. Methods: The Exocarta database (www.exocarta.org) was mined for urinary bladder cancer specific exosomal proteins. The urinary bladder cancer specific exosomal proteins (n = 248) were analyzed to identify enriched pathways by Onto-tool Pathway Express (http://vortex.cs.wayne.edu/ ontoexpress). Results: Enriched pathways included cellular architecture, motility, cell to cell adhesion, tumorigenesis and metastasis. Proteins in the 9 top-ranked pathways included CTNNA1 (alpha-catenin), CTNNB1 (beta-catenin), VSAP, ITGA4, PAK1, DDR1, CDC42, RHOA, NRAS, RHO, PIK3AR1, MLC1, MMRN1, and CTTNBP2 and network analysis revealed 10 important hub proteins and identified inferred interactor NF2. Conclusions: The importance of identifying interactors is that that they can be used as targets for therapy, for example, using Bevacizumab (avastin - an angiogenesis inhibitor) against NF2 to inhibit protein-protein interactions will inhibit tumor growth and progression by hindering the exosome biogenesis

  10. Classification, expression pattern and comparative analysis of sugarcane expressed sequences tags (ESTs encoding glycine-rich proteins (GRPs

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    Fusaro Adriana

    2001-01-01

    Full Text Available Since the isolation of the first glycine-rich proteins (GRPs in plants a wealth of new GRPs have been identified. The highly specific but diverse expression pattern of grp genes, taken together with the distinct sub-cellular localization of some GRP groups, clearly indicate that these proteins are involved in several independent physiological processes. Notwithstanding the absence of a clear definition of the role of GRPs in plant cells, studies conducted with these proteins have provided new and interesting insights into the molecular biology and cell biology of plants. Complexly regulated promoters and distinct mechanisms for the regulation of gene expression have been demonstrated and new protein targeting pathways, as well as the exportation of GRPs from different cell types have been discovered. These data show that GRPs can be useful as markers and/or models to understand distinct aspects of plant biology. In this paper, the structural and functional features of these proteins in sugarcane (Saccharum officinarum L. are summarized. Since this is the first description of GRPs in sugarcane, special emphasis has been given to the expression pattern of these GRP genes by studying their abundance and prevalence in the different cDNA-libraries of the Sugarcane Expressed Sequence Tag (SUCEST project . The comparison of sugarcane GRPs with GRPs from other species is also discussed.

  11. Therapeutic targeting strategies using endogenous cells and proteins.

    Science.gov (United States)

    Parayath, Neha N; Amiji, Mansoor M

    2017-07-28

    Targeted drug delivery has become extremely important in enhancing efficacy and reducing the toxicity of therapeutics in the treatment of various disease conditions. Current approaches include passive targeting, which relies on naturally occurring differences between healthy and diseased tissues, and active targeting, which utilizes various ligands that can recognize targets expressed preferentially at the diseased site. Clinical translation of these mechanisms faces many challenges including the immunogenic and toxic effects of these non-natural systems. Thus, use of endogenous targeting systems is increasingly gaining momentum. This review is focused on strategies for employing endogenous moieties, which could serve as safe and efficient carriers for targeted drug delivery. The first part of the review involves cells and cellular components as endogenous carriers for therapeutics in multiple disease states, while the second part discusses the use of endogenous plasma components as endogenous carriers. Further understanding of the biological tropism with cells and proteins and the newer generation of delivery strategies that exploits these endogenous approaches promises to provide better solutions for site-specific delivery and could further facilitate clinical translations. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Production of cloned pigs with targeted attenuation of gene expression.

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    Vilceu Bordignon

    Full Text Available The objective of this study was to demonstrate that RNA interference (RNAi and somatic cell nuclear transfer (SCNT technologies can be used to attenuate the expression of specific genes in tissues of swine, a large animal species. Apolipoprotein E (apoE, a secreted glycoprotein known for its major role in lipid and lipoprotein metabolism and transport, was selected as the target gene for this study. Three synthetic small interfering RNAs (siRNA targeting the porcine apoE mRNA were tested in porcine granulosa cells in primary culture and reduced apoE mRNA abundance ranging from 45-82% compared to control cells. The most effective sequence was selected for cloning into a short hairpin RNA (shRNA expression vector under the control of RNA polymerase III (U6 promoter. Stably transfected fetal porcine fibroblast cells were generated and used to produce embryos with in vitro matured porcine oocytes, which were then transferred into the uterus of surrogate gilts. Seven live and one stillborn piglet were born from three gilts that became pregnant. Integration of the shRNA expression vector into the genome of clone piglets was confirmed by PCR and expression of the GFP transgene linked to the expression vector. Analysis showed that apoE protein levels in the liver and plasma of the clone pigs bearing the shRNA expression vector targeting the apoE mRNA was significantly reduced compared to control pigs cloned from non-transfected fibroblasts of the same cell line. These results demonstrate the feasibility of applying RNAi and SCNT technologies for introducing stable genetic modifications in somatic cells for eventual attenuation of gene expression in vivo in large animal species.

  13. Heterogeneity mapping of protein expression in tumors using quantitative immunofluorescence.

    Science.gov (United States)

    Faratian, Dana; Christiansen, Jason; Gustavson, Mark; Jones, Christine; Scott, Christopher; Um, InHwa; Harrison, David J

    2011-10-25

    Morphologic heterogeneity within an individual tumor is well-recognized by histopathologists in surgical practice. While this often takes the form of areas of distinct differentiation into recognized histological subtypes, or different pathological grade, often there are more subtle differences in phenotype which defy accurate classification (Figure 1). Ultimately, since morphology is dictated by the underlying molecular phenotype, areas with visible differences are likely to be accompanied by differences in the expression of proteins which orchestrate cellular function and behavior, and therefore, appearance. The significance of visible and invisible (molecular) heterogeneity for prognosis is unknown, but recent evidence suggests that, at least at the genetic level, heterogeneity exists in the primary tumor(1,2), and some of these sub-clones give rise to metastatic (and therefore lethal) disease. Moreover, some proteins are measured as biomarkers because they are the targets of therapy (for instance ER and HER2 for tamoxifen and trastuzumab (Herceptin), respectively). If these proteins show variable expression within a tumor then therapeutic responses may also be variable. The widely used histopathologic scoring schemes for immunohistochemistry either ignore, or numerically homogenize the quantification of protein expression. Similarly, in destructive techniques, where the tumor samples are homogenized (such as gene expression profiling), quantitative information can be elucidated, but spatial information is lost. Genetic heterogeneity mapping approaches in pancreatic cancer have relied either on generation of a single cell suspension(3), or on macrodissection(4). A recent study has used quantum dots in order to map morphologic and molecular heterogeneity in prostate cancer tissue(5), providing proof of principle that morphology and molecular mapping is feasible, but falling short of quantifying the heterogeneity. Since immunohistochemistry is, at best, only semi

  14. Protein search for multiple targets on DNA

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Martin [Johannes Gutenberg University, Mainz 55122 (Germany); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Kochugaeva, Maria [Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Kolomeisky, Anatoly B., E-mail: tolya@rice.edu [Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005 (United States)

    2015-09-14

    Protein-DNA interactions are crucial for all biological processes. One of the most important fundamental aspects of these interactions is the process of protein searching and recognizing specific binding sites on DNA. A large number of experimental and theoretical investigations have been devoted to uncovering the molecular description of these phenomena, but many aspects of the mechanisms of protein search for the targets on DNA remain not well understood. One of the most intriguing problems is the role of multiple targets in protein search dynamics. Using a recently developed theoretical framework we analyze this question in detail. Our method is based on a discrete-state stochastic approach that takes into account most relevant physical-chemical processes and leads to fully analytical description of all dynamic properties. Specifically, systems with two and three targets have been explicitly investigated. It is found that multiple targets in most cases accelerate the search in comparison with a single target situation. However, the acceleration is not always proportional to the number of targets. Surprisingly, there are even situations when it takes longer to find one of the multiple targets in comparison with the single target. It depends on the spatial position of the targets, distances between them, average scanning lengths of protein molecules on DNA, and the total DNA lengths. Physical-chemical explanations of observed results are presented. Our predictions are compared with experimental observations as well as with results from a continuum theory for the protein search. Extensive Monte Carlo computer simulations fully support our theoretical calculations.

  15. The Drosophila FoxA ortholog Fork head regulates growth and gene expression downstream of Target of rapamycin.

    Directory of Open Access Journals (Sweden)

    Margret H Bülow

    2010-12-01

    Full Text Available Forkhead transcription factors of the FoxO subfamily regulate gene expression programs downstream of the insulin signaling network. It is less clear which proteins mediate transcriptional control exerted by Target of rapamycin (TOR signaling, but recent studies in nematodes suggest a role for FoxA transcription factors downstream of TOR. In this study we present evidence that outlines a similar connection in Drosophila, in which the FoxA protein Fork head (FKH regulates cellular and organismal size downstream of TOR. We find that ectopic expression and targeted knockdown of FKH in larval tissues elicits different size phenotypes depending on nutrient state and TOR signaling levels. FKH overexpression has a negative effect on growth under fed conditions, and this phenotype is not further exacerbated by inhibition of TOR via rapamycin feeding. Under conditions of starvation or low TOR signaling levels, knockdown of FKH attenuates the size reduction associated with these conditions. Subcellular localization of endogenous FKH protein is shifted from predominantly cytoplasmic on a high-protein diet to a pronounced nuclear accumulation in animals with reduced levels of TOR or fed with rapamycin. Two putative FKH target genes, CG6770 and cabut, are transcriptionally induced by rapamycin or FKH expression, and silenced by FKH knockdown. Induction of both target genes in heterozygous TOR mutant animals is suppressed by mutations in fkh. Furthermore, TOR signaling levels and FKH impact on transcription of the dFOXO target gene d4E-BP, implying a point of crosstalk with the insulin pathway. In summary, our observations show that an alteration of FKH levels has an effect on cellular and organismal size, and that FKH function is required for the growth inhibition and target gene induction caused by low TOR signaling levels.

  16. ERG protein expression over time

    DEFF Research Database (Denmark)

    Berg, Kasper Drimer; Brasso, Klaus; Thomsen, Frederik Birkebæk

    2015-01-01

    AIMS: We evaluated the consistency in ERG protein expression from diagnostic specimens through rebiopsies to radical prostatectomies in patients with clinically localised prostate cancer to investigate the validity of ERG status in biopsies. METHODS: ERG expression was assessed by immunohistochem......AIMS: We evaluated the consistency in ERG protein expression from diagnostic specimens through rebiopsies to radical prostatectomies in patients with clinically localised prostate cancer to investigate the validity of ERG status in biopsies. METHODS: ERG expression was assessed...

  17. Identification of Cell Surface Proteins as Potential Immunotherapy Targets in 12 Pediatric Cancers

    Energy Technology Data Exchange (ETDEWEB)

    Orentas, Rimas J. [Immunology Section, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Yang, James J. [Immunology Section, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Oncogenomics Section, Advanced Technology Center, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Gaithersburg, MD (United States); Wen, Xinyu; Wei, Jun S. [Oncogenomics Section, Advanced Technology Center, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Gaithersburg, MD (United States); Mackall, Crystal L. [Immunology Section, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Khan, Javed, E-mail: rimas.orentas@nih.gov [Oncogenomics Section, Advanced Technology Center, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Gaithersburg, MD (United States)

    2012-12-17

    Technological advances now allow us to rapidly produce CARs and other antibody-derived therapeutics targeting cell surface receptors. To maximize the potential of these new technologies, relevant extracellular targets must be identified. The Pediatric Oncology Branch of the NCI curates a freely accessible database of gene expression data for both pediatric cancers and normal tissues, through which we have defined discrete sets of over-expressed transcripts in 12 pediatric cancer subtypes as compared to normal tissues. We coupled gene expression profiles to current annotation databases (i.e., Affymetrix, Gene Ontology, Entrez Gene), in order to categorize transcripts by their sub-cellular location. In this manner we generated a list of potential immune targets expressed on the cell surface, ranked by their difference from normal tissue. Global differences from normal between each of the pediatric tumor types studied varied, indicating that some malignancies expressed transcript sets that were more highly diverged from normal tissues than others. The validity of our approach is seen by our findings for pre-B cell ALL, where targets currently in clinical trials were top-ranked hits (CD19, CD22). For some cancers, reagents already in development could potentially be applied to a new disease class, as exemplified by CD30 expression on sarcomas. Moreover, several potential new targets shared among several pediatric solid tumors are herein identified, such as MCAM (MUC18), metadherin (MTDH), and glypican-2 (GPC2). These targets have been identified at the mRNA level and are yet to be validated at the protein level. The safety of targeting these antigens has yet to be demonstrated and therefore the identified transcripts should be considered preliminary candidates for new CAR and therapeutic antibody targets. Prospective candidate targets will be evaluated by proteomic analysis including Westerns and immunohistochemistry of normal and tumor tissues.

  18. GABARAPL1 antibodies: target one protein, get one free!

    Science.gov (United States)

    Le Grand, Jaclyn Nicole; Chakrama, Fatima Zahra; Seguin-Py, Stéphanie; Fraichard, Annick; Delage-Mourroux, Régis; Jouvenot, Michèle; Risold, Pierre-Yves; Boyer-Guittaut, Michaël

    2011-11-01

    Atg8 is a yeast protein involved in the autophagic process and in particular in the elongation of autophagosomes. In mammals, several orthologs have been identified and are classed into two subfamilies: the LC3 subfamily and the GABARAP subfamily, referred to simply as the LC3 or GABARAP families. GABARAPL1 (GABARAP-like protein 1), one of the proteins belonging to the GABARAP (GABA(A) receptor-associated protein) family, is highly expressed in the central nervous system and implicated in processes such as receptor and vesicle transport as well as autophagy. The proteins that make up the GABARAP family demonstrate conservation of their amino acid sequences and protein structures. In humans, GABARAPL1 shares 86% identity with GABARAP and 61% with GABARAPL2 (GATE-16). The identification of the individual proteins is thus very limited when working in vivo due to a lack of unique peptide sequences from which specific antibodies can be developed. Actually, and to our knowledge, there are no available antibodies on the market that are entirely specific to GABARAPL1 and the same may be true of the anti-GABARAP antibodies. In this study, we sought to examine the specificity of three antibodies targeted against different peptide sequences within GABARAPL1: CHEM-CENT (an antibody raised against a short peptide sequence within the center of the protein), PTG-NTER (an antibody raised against the N-terminus of the protein) and PTG-FL (an antibody raised against the full-length protein). The results described in this article demonstrate the importance of testing antibody specificity under the conditions for which it will be used experimentally, a caution that should be taken when studying the expression of the GABARAP family proteins.

  19. Co-delivery of Cbfa-1-targeting siRNA and SOX9 protein using PLGA nanoparticles to induce chondrogenesis of human mesenchymal stem cells.

    Science.gov (United States)

    Jeon, Su Yeon; Park, Ji Sun; Yang, Han Na; Lim, Hye Jin; Yi, Se Won; Park, Hansoo; Park, Keun-Hong

    2014-09-01

    During stem cell differentiation, various cellular responses occur that are mediated by transcription factors and proteins. This study evaluated the abilities of SOX9, a crucial protein during the early stage of chondrogenesis, and siRNA targeting Cbfa-1, a transcription factor that promotes osteogenesis, to stimulate chondrogenesis. Non-toxic poly-(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. Coomassie blue staining and circular dichroism revealed that the loaded SOX9 protein maintained its stability and bioactivity. These NPs easily entered human mesenchymal stem cells (hMSCs) in vitro and caused them to differentiate into chondrocytes. Markers that are typically expressed in mature chondrocytes were examined. These markers were highly expressed at the mRNA and protein levels in hMSCs treated with PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. By contrast, these cells did not express osteogenesis-related markers. hMSCs were injected into mice following internalization of PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. When the injection site was excised, markers of chondrogenesis were found to be highly expressed at the mRNA and protein levels, similar to the in vitro results. When hMSCs internalized these NPs and were then cultured in vitro or injected into mice, chondrogenesis-related extracellular matrix components were highly expressed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Bcl-2 protein expression is associated with p27 and p53 protein expressions and MIB-1 counts in breast cancer

    International Nuclear Information System (INIS)

    Tsutsui, Shinichi; Yasuda, Kazuhiro; Suzuki, Kosuke; Takeuchi, Hideya; Nishizaki, Takashi; Higashi, Hidefumi; Era, Shoichi

    2006-01-01

    Recent experimental studies have shown that Bcl-2, which has been established as a key player in the control of apoptosis, plays a role in regulating the cell cycle and proliferation. The aim of this study was to investigate the relationship between Bcl-2 and p27 protein expression, p53 protein expression and the proliferation activity as defined by the MIB-1 counts. The prognostic implication of Bcl-2 protein expression in relation to p27 and p53 protein expressions and MIB-1 counts for breast cancer was also evaluated. The immunohistochemical expression of Bcl-2 protein was evaluated in a series of 249 invasive ductal carcinomas of the breast, in which p27 and p53 protein expressions and MIB-1 counts had been determined previously. The Bcl-2 protein expression was found to be decreased in 105 (42%) cases. A decreased Bcl-2 protein expression was significantly correlated with a nuclear grade of III, a negative estrogen receptor, a decreased p27 protein expression, a positive p53 protein expression, positive MIB-1 counts and a positive HER2 protein expression. The incidence of a nuclear grade of III and positive MIB-1 counts increased as the number of abnormal findings of Bcl-2, p27 and p53 protein expressions increased. A univariate analysis indicated a decreased Bcl-2 protein expression to be significantly (p = 0.0089) associated with a worse disease free survival (DFS), while a multivariate analysis indicated the lymph node status and MIB-1 counts to be independently significant prognostic factors for the DFS. The Bcl-2 protein expression has a close correlation with p27 and p53 protein expressions and the proliferation activity determined by MIB-1 counts in invasive ductal carcinoma of the breast. The prognostic value of Bcl-2 as well as p27 and p53 protein expressions was dependent on the proliferation activity in breast cancer

  1. Bcl-2 protein expression is associated with p27 and p53 protein expressions and MIB-1 counts in breast cancer

    Directory of Open Access Journals (Sweden)

    Nishizaki Takashi

    2006-07-01

    Full Text Available Abstract Background Recent experimental studies have shown that Bcl-2, which has been established as a key player in the control of apoptosis, plays a role in regulating the cell cycle and proliferation. The aim of this study was to investigate the relationship between Bcl-2 and p27 protein expression, p53 protein expression and the proliferation activity as defined by the MIB-1 counts. The prognostic implication of Bcl-2 protein expression in relation to p27 and p53 protein expressions and MIB-1 counts for breast cancer was also evaluated. Methods The immunohistochemical expression of Bcl-2 protein was evaluated in a series of 249 invasive ductal carcinomas of the breast, in which p27 and p53 protein expressions and MIB-1 counts had been determined previously. Results The Bcl-2 protein expression was found to be decreased in 105 (42% cases. A decreased Bcl-2 protein expression was significantly correlated with a nuclear grade of III, a negative estrogen receptor, a decreased p27 protein expression, a positive p53 protein expression, positive MIB-1 counts and a positive HER2 protein expression. The incidence of a nuclear grade of III and positive MIB-1 counts increased as the number of abnormal findings of Bcl-2, p27 and p53 protein expressions increased. A univariate analysis indicated a decreased Bcl-2 protein expression to be significantly (p = 0.0089 associated with a worse disease free survival (DFS, while a multivariate analysis indicated the lymph node status and MIB-1 counts to be independently significant prognostic factors for the DFS. Conclusion The Bcl-2 protein expression has a close correlation with p27 and p53 protein expressions and the proliferation activity determined by MIB-1 counts in invasive ductal carcinoma of the breast. The prognostic value of Bcl-2 as well as p27 and p53 protein expressions was dependent on the proliferation activity in breast cancer.

  2. Toxicological relationships between proteins obtained from protein target predictions of large toxicity databases

    International Nuclear Information System (INIS)

    Nigsch, Florian; Mitchell, John B.O.

    2008-01-01

    The combination of models for protein target prediction with large databases containing toxicological information for individual molecules allows the derivation of 'toxiclogical' profiles, i.e., to what extent are molecules of known toxicity predicted to interact with a set of protein targets. To predict protein targets of drug-like and toxic molecules, we built a computational multiclass model using the Winnow algorithm based on a dataset of protein targets derived from the MDL Drug Data Report. A 15-fold Monte Carlo cross-validation using 50% of each class for training, and the remaining 50% for testing, provided an assessment of the accuracy of that model. We retained the 3 top-ranking predictions and found that in 82% of all cases the correct target was predicted within these three predictions. The first prediction was the correct one in almost 70% of cases. A model built on the whole protein target dataset was then used to predict the protein targets for 150 000 molecules from the MDL Toxicity Database. We analysed the frequency of the predictions across the panel of protein targets for experimentally determined toxicity classes of all molecules. This allowed us to identify clusters of proteins related by their toxicological profiles, as well as toxicities that are related. Literature-based evidence is provided for some specific clusters to show the relevance of the relationships identified

  3. Differentially expressed and survival-related proteins of lung adenocarcinoma with bone metastasis.

    Science.gov (United States)

    Yang, Mengdi; Sun, Yi; Sun, Jing; Wang, Zhiyu; Zhou, Yiyi; Yao, Guangyu; Gu, Yifeng; Zhang, Huizhen; Zhao, Hui

    2018-04-01

    Despite recent advances in targeted and immune-based therapies, the poor prognosis of lung adenocarcinoma (LUAD) with bone metastasis (BM) remains a challenge. First, two-dimensional gel electrophoresis (2-DE) was used to identify proteins that were differentially expressed in LUAD with BM, and then matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) was used to identify these proteins. Second, the Cancer Genome Atlas (TCGA) was used to identify mutations in these differentially expressed proteins and Kaplan-Meier plotter (KM Plotter) was used to generate survival curves for the analyzed cases. Immunohistochemistry (IHC) was used to check the expression of proteins in 28 patients with BM and nine patients with LUAD. Lastly, the results were analyzed with respect to clinical features and patient's follow-up. We identified a number of matched proteins from 2-DE. High expression of enolase 1 (ENO1) (HR = 1.67, logrank P = 1.9E-05), ribosomal protein lateral stalk subunit P2 (RPLP2) (HR = 1.77, logrank P = 2.9e-06), and NME/NM23 nucleoside diphosphate kinase 2 (NME1-NME2) (HR = 2.65, logrank P = 3.9E-15) was all significantly associated with poor survival (P < 0.05). Further, ENO1 was upregulated (P = 0.0004) and calcyphosine (CAPS1) was downregulated (P = 5.34E-07) in TCGA LUAD RNA-seq expression data. IHC revealed that prominent ENO1 staining (OR = 7.5, P = 0.034) and low levels of CAPS1 (OR = 0.01, P < 0.0001) staining were associated with BM incidence. Finally, we found that LUAD patients with high expression of ENO1 and RPLP2 had worse overall survival. This is the first instance where the genes ENO1, RPLP2, NME1-NME2 and CAPS1 were associated with disease severity and progression in LUAD patients with BM. Thus, with this study, we have identified potential biomarkers and therapeutic targets for this disease. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  4. Purification of Microbially Expressed Recombinant Proteins via a Dual ELP Split Intein System.

    Science.gov (United States)

    Shi, Changhua; Han, Tzu-Chiang; Wood, David W

    2017-01-01

    Fusions of elastin-like peptide (ELP) purification tags and self-cleaving inteins provide a powerful platform for purifying tagless recombinant proteins without the need for conventional packed-bed columns. A drawback to this method has been premature cleaving of the ELP tag during expression, before the purification procedure can take place. Here we demonstrate a split-intein method, where the self-cleaving intein is divided into two inactive segments during expression and purification. Spontaneous assembly of the purified intein segments then restores self-cleaving activity to deliver the tagless target protein.

  5. Dual localized mitochondrial and nuclear proteins as gene expression regulators in plants?

    Directory of Open Access Journals (Sweden)

    Philippe eGiegé

    2012-09-01

    Full Text Available Mitochondria heavily depend on the coordinated expression of both mitochondrial and nuclear genomes because some of their most significant activities are held by multi-subunit complexes composed of both mitochondrial and nuclear encoded proteins. Thus, precise communication and signaling pathways are believed to exist between the two compartments. Proteins dual localized to both mitochondria and the nucleus make excellent candidates for a potential involvement in the envisaged communication. Here, we review the identified instances of dual localized nucleo-mitochondrial proteins with an emphasis on plant proteins and discuss their functions, which are seemingly mostly related to gene expression regulation. We discuss whether dual localization could be achieved by dual targeting and / or by re-localization and try to apprehend the signals required for the respective processes. Finally, we propose that in some instances, dual localized mitochondrial and nuclear proteins might act as retrograde signaling molecules for mitochondrial biogenesis.

  6. Analysis of disease-associated protein expression using quantitative proteomics—fibulin-5 is expressed in association with hepatic fibrosis.

    Science.gov (United States)

    Bracht, Thilo; Schweinsberg, Vincent; Trippler, Martin; Kohl, Michael; Ahrens, Maike; Padden, Juliet; Naboulsi, Wael; Barkovits, Katalin; Megger, Dominik A; Eisenacher, Martin; Borchers, Christoph H; Schlaak, Jörg F; Hoffmann, Andreas-Claudius; Weber, Frank; Baba, Hideo A; Meyer, Helmut E; Sitek, Barbara

    2015-05-01

    Hepatic fibrosis and cirrhosis are major health problems worldwide. Until now, highly invasive biopsy remains the diagnostic gold standard despite many disadvantages. To develop noninvasive diagnostic assays for the assessment of liver fibrosis, it is urgently necessary to identify molecules that are robustly expressed in association with the disease. We analyzed biopsied tissue samples from 95 patients with HBV/HCV-associated hepatic fibrosis using three different quantification methods. We performed a label-free proteomics discovery study to identify novel disease-associated proteins using a subset of the cohort (n = 27). Subsequently, gene expression data from all available clinical samples were analyzed (n = 77). Finally, we performed a targeted proteomics approach, multiple reaction monitoring (MRM), to verify the disease-associated expression in samples independent from the discovery approach (n = 68). We identified fibulin-5 (FBLN5) as a novel protein expressed in relation to hepatic fibrosis. Furthermore, we confirmed the altered expression of microfibril-associated glycoprotein 4 (MFAP4), lumican (LUM), and collagen alpha-1(XIV) chain (COL14A1) in association to hepatic fibrosis. To our knowledge, no tissue-based quantitative proteomics study for hepatic fibrosis has been performed using a cohort of comparable size. By this means, we add substantial evidence for the disease-related expression of the proteins examined in this study.

  7. Proteomic Identification of Target Proteins of Thiodigalactoside in White Adipose Tissue from Diet-Induced Obese Rats

    Directory of Open Access Journals (Sweden)

    Hilal Ahmad Parray

    2015-06-01

    Full Text Available Previously, galectin-1 (GAL1 was found to be up-regulated in obesity-prone subjects, suggesting that use of a GAL1 inhibitor could be a novel therapeutic approach for treatment of obesity. We evaluated thiodigalactoside (TDG as a potent inhibitor of GAL1 and identified target proteins of TDG by performing comparative proteome analysis of white adipose tissue (WAT from control and TDG-treated rats fed a high fat diet (HFD using two dimensional gel electrophoresis (2-DE combined with MALDI-TOF-MS. Thirty-two spots from a total of 356 matched spots showed differential expression between control and TDG-treated rats, as identified by peptide mass fingerprinting. These proteins were categorized into groups such as carbohydrate metabolism, tricarboxylic acid (TCA cycle, signal transduction, cytoskeletal, and mitochondrial proteins based on functional analysis using Protein Annotation Through Evolutionary Relationship (PANTHER and Database for Annotation, Visualization, Integrated Discovery (DAVID classification. One of the most striking findings of this study was significant changes in Carbonic anhydrase 3 (CA3, Voltage-dependent anion channel 1 (VDAC1, phosphatidylethanolamine-binding protein 1 (PEBP1, annexin A2 (ANXA2 and lactate dehydrogenase A chain (LDHA protein levels between WAT from control and TDG-treated groups. In addition, we confirmed increased expression of thermogenic proteins as well as reduced expression of lipogenic proteins in response to TDG treatment. These results suggest that TDG may effectively prevent obesity, and TDG-responsive proteins can be used as novel target proteins for obesity treatment.

  8. Ectopic expression of the erythrocyte band 3 anion exchange protein, using a new avian retrovirus vector

    DEFF Research Database (Denmark)

    Fuerstenberg, S; Beug, H; Introna, M

    1990-01-01

    into protein. Using the Escherichia coli beta-galactosidase gene cloned into the vector as a test construct, expression of enzyme activity could be detected in 90 to 95% of transfected target cells and in 80 to 85% of subsequently infected cells. In addition, a cDNA encoding the avian erythrocyte band 3 anion...... exchange protein has been expressed from the vector in both chicken embryo fibroblasts and QT6 cells and appears to function as an active, plasma membrane-based anion transporter. The ectopic expression of band 3 protein provides a visual marker for vector function in these cells....

  9. Differential Expression of Proteins Associated with the Hair Follicle Cycle - Proteomics and Bioinformatics Analyses.

    Directory of Open Access Journals (Sweden)

    Lei Wang

    Full Text Available Hair follicle cycling can be divided into the following three stages: anagen, catagen, and telogen. The molecular signals that orchestrate the follicular transition between phases are still unknown. To better understand the detailed protein networks controlling this process, proteomics and bioinformatics analyses were performed to construct comparative protein profiles of mouse skin at specific time points (0, 8, and 20 days. Ninety-five differentially expressed protein spots were identified by MALDI-TOF/TOF as 44 proteins, which were found to change during hair follicle cycle transition. Proteomics analysis revealed that these changes in protein expression are involved in Ca2+-regulated biological processes, migration, and regulation of signal transduction, among other processes. Subsequently, three proteins were selected to validate the reliability of expression patterns using western blotting. Cluster analysis revealed three expression patterns, and each pattern correlated with specific cell processes that occur during the hair cycle. Furthermore, bioinformatics analysis indicated that the differentially expressed proteins impacted multiple biological networks, after which detailed functional analyses were performed. Taken together, the above data may provide insight into the three stages of mouse hair follicle morphogenesis and provide a solid basis for potential therapeutic molecular targets for this hair disease.

  10. TIMP-1 increases expression and phosphorylation of proteins associated with drug resistance in breast cancer cells

    DEFF Research Database (Denmark)

    Hekmat, Omid; Munk, Stephanie; Fogh, Louise

    2013-01-01

    may explain the resistance phenotype to topoisomerase inhibitors that was observed in cells with high TIMP-1 levels. Pathway analysis showed an enrichment of proteins from functional categories such as apoptosis, cell cycle, DNA repair, transcription factors, drug targets and proteins associated......Tissue inhibitor of metalloproteinase 1 (TIMP-1) is a protein with a potential biological role in drug resistance. To elucidate the unknown molecular mechanisms underlying the association between high TIMP-1 levels and increased chemotherapy resistance, we employed SILAC-based quantitative mass...... spectrometry to analyze global proteome and phosphoproteome differences of MCF-7 breast cancer cells expressing high or low levels of TIMP-1. In TIMP-1 high expressing cells, 312 proteins and 452 phosphorylation sites were up-regulated. Among these were the cancer drug targets topoisomerase 1, 2A and 2B, which...

  11. A synthetic arabinose-inducible promoter confers high levels of recombinant protein expression in hyperthermophilic archaeon Sulfolobus islandicus

    DEFF Research Database (Denmark)

    Peng, Nan; Deng, Ling; Mei, Yuxia

    2012-01-01

    Despite major progresses in genetic studies of hyperthermophilic archaea, recombinant protein production in these organisms always suffers from low yields and a robust expression system is still in great demand. Here we report a versatile vector that confers high levels of protein expression...... to remove the peptide tags from expressed recombinant proteins. While pEXA employed an araS promoter for protein expression, pSeSD utilized P(araS-SD), an araS derivative promoter carrying an engineered ribosome-binding site (RBS; a Shine-Dalgarno [SD] sequence). We found that P(araS-SD) directed high...... levels of target gene expression. More strikingly, N-terminal amino acid sequencing of recombinant proteins unraveled that the protein synthesized from pEXA-N-lacS lacked the designed 6×His tag and that translation initiation did not start at the ATG codon of the fusion gene. Instead, it started...

  12. The long N-terminus of the human monocarboxylate transporter 8 is a target of ubiquitin-dependent proteasomal degradation which regulates protein expression and oligomerization capacity.

    Science.gov (United States)

    Zwanziger, Denise; Schmidt, Mathias; Fischer, Jana; Kleinau, Gunnar; Braun, Doreen; Schweizer, Ulrich; Moeller, Lars Christian; Biebermann, Heike; Fuehrer, Dagmar

    2016-10-15

    Monocarboxylate transporter 8 (MCT8) equilibrates thyroid hormones between the extra- and the intracellular sides. MCT8 exists either with a short or a long N-terminus, but potential functional differences between both variants are yet not known. We, therefore, generated MCT8 constructs which are different in N-terminal length: MCT8(1-613), MCT8(25-613), MCT8(49-613) and MCT8(75-613). The M75G substitution prevents translation of MCT8(75-613) and ensures expression of full-length MCT8 protein. The K56G substitution was made to prevent ubiquitinylation. Cell-surface expression, localization and proteasomal degradation were investigated using C-terminally GFP-tagged MCT8 constructs (HEK293 and MDCK1 cells) and oligomerization capacity was determined using N-terminally HA- and C-terminally FLAG-tagged MCT8 constructs (COS7 cells). MCT8(1-613)-GFP showed a lower protein expression than the shorter MCT8(75-613)-GFP protein. The proteasome inhibitor lactacystin increased MCT8(1-613)-GFP protein amount, suggesting proteasomal degradation of MCT8 with the long N-terminus. Ubiquitin conjugation of MCT8(1-613)-GFP was found by immuno-precipitation. A diminished ubiquitin conjugation caused by K56G substitution resulted in increased MCT8(1-613)-GFP protein expression. Sandwich ELISA was performed to investigate if the bands at higher molecular weight observed in Western blot analysis are due to MCT8 oligomerization, which was indeed shown. Our data imply a role of the long N-terminus of MCT8 as target of ubiquitin-dependent proteasomal degradation affecting MCT8 amount and subsequently oligomerization capacity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Unfolded Protein Response (UPR Regulator Cib1 Controls Expression of Genes Encoding Secreted Virulence Factors in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Martin Hampel

    Full Text Available The unfolded protein response (UPR, a conserved eukaryotic signaling pathway to ensure protein homeostasis in the endoplasmic reticulum (ER, coordinates biotrophic development in the corn smut fungus Ustilago maydis. Exact timing of UPR activation is required for virulence and presumably connected to the elevated expression of secreted effector proteins during infection of the host plant Zea mays. In the baker's yeast Saccharomyces cerevisiae, expression of UPR target genes is induced upon binding of the central regulator Hac1 to unfolded protein response elements (UPREs in their promoters. While a role of the UPR in effector secretion has been described previously, we investigated a potential UPR-dependent regulation of genes encoding secreted effector proteins. In silico prediction of UPREs in promoter regions identified the previously characterized effector genes pit2 and tin1-1, as bona fide UPR target genes. Furthermore, direct binding of the Hac1-homolog Cib1 to the UPRE containing promoter fragments of both genes was confirmed by quantitative chromatin immunoprecipitation (qChIP analysis. Targeted deletion of the UPRE abolished Cib1-dependent expression of pit2 and significantly affected virulence. Furthermore, ER stress strongly increased Pit2 expression and secretion. This study expands the role of the UPR as a signal hub in fungal virulence and illustrates, how biotrophic fungi can coordinate cellular physiology, development and regulation of secreted virulence factors.

  14. Wongabel Rhabdovirus Accessory Protein U3 Targets the SWI/SNF Chromatin Remodeling Complex

    Science.gov (United States)

    Joubert, D. Albert; Rodriguez-Andres, Julio; Monaghan, Paul; Cummins, Michelle; McKinstry, William J.; Paradkar, Prasad N.; Moseley, Gregory W.

    2014-01-01

    ABSTRACT Wongabel virus (WONV) is an arthropod-borne rhabdovirus that infects birds. It is one of the growing array of rhabdoviruses with complex genomes that encode multiple accessory proteins of unknown function. In addition to the five canonical rhabdovirus structural protein genes (N, P, M, G, and L), the 13.2-kb negative-sense single-stranded RNA (ssRNA) WONV genome contains five uncharacterized accessory genes, one overlapping the N gene (Nx or U4), three located between the P and M genes (U1 to U3), and a fifth one overlapping the G gene (Gx or U5). Here we show that WONV U3 is expressed during infection in insect and mammalian cells and is required for efficient viral replication. A yeast two-hybrid screen against a mosquito cell cDNA library identified that WONV U3 interacts with the 83-amino-acid (aa) C-terminal domain of SNF5, a component of the SWI/SNF chromatin remodeling complex. The interaction was confirmed by affinity chromatography, and nuclear colocalization was established by confocal microscopy. Gene expression studies showed that SNF5 transcripts are upregulated during infection of mosquito cells with WONV, as well as West Nile virus (Flaviviridae) and bovine ephemeral fever virus (Rhabdoviridae), and that SNF5 knockdown results in increased WONV replication. WONV U3 also inhibits SNF5-regulated expression of the cytokine gene CSF1. The data suggest that WONV U3 targets the SWI/SNF complex to block the host response to infection. IMPORTANCE The rhabdoviruses comprise a large family of RNA viruses infecting plants, vertebrates, and invertebrates. In addition to the major structural proteins (N, P, M, G, and L), many rhabdoviruses encode a diverse array of accessory proteins of largely unknown function. Understanding the role of these proteins may reveal much about host-pathogen interactions in infected cells. Here we examine accessory protein U3 of Wongabel virus, an arthropod-borne rhabdovirus that infects birds. We show that U3 enters the

  15. Phaseolin expression in tobacco chloroplast reveals an autoregulatory mechanism in heterologous protein translation.

    Science.gov (United States)

    De Marchis, Francesca; Bellucci, Michele; Pompa, Andrea

    2016-02-01

    Plastid DNA engineering is a well-established research area of plant biotechnology, and plastid transgenes often give high expression levels. However, it is still almost impossible to predict the accumulation rate of heterologous protein in transplastomic plants, and there are many cases of unsuccessful transgene expression. Chloroplasts regulate their proteome at the post-transcriptional level, mainly through translation control. One of the mechanisms to modulate the translation has been described in plant chloroplasts for the chloroplast-encoded subunits of multiprotein complexes, and the autoregulation of the translation initiation of these subunits depends on the availability of their assembly partners [control by epistasy of synthesis (CES)]. In Chlamydomonas reinhardtii, autoregulation of endogenous proteins recruited in the assembly of functional complexes has also been reported. In this study, we revealed a self-regulation mechanism triggered by the accumulation of a soluble recombinant protein, phaseolin, in the stroma of chloroplast-transformed tobacco plants. Immunoblotting experiments showed that phaseolin could avoid this self-regulation mechanism when targeted to the thylakoids in transplastomic plants. To inhibit the thylakoid-targeted phaseolin translation as well, this protein was expressed in the presence of a nuclear version of the phaseolin gene with a transit peptide. Pulse-chase and polysome analysis revealed that phaseolin mRNA translation on plastid ribosomes was repressed due to the accumulation in the stroma of the same soluble polypeptide imported from the cytosol. We suggest that translation autoregulation in chloroplast is not limited to heteromeric protein subunits but also involves at least some of the foreign soluble recombinant proteins, leading to the inhibition of plastome-encoded transgene expression in chloroplast. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  16. Ubiquitin fusion expression and tissue-dependent targeting of hG-CSF in transgenic tobacco

    Science.gov (United States)

    2011-01-01

    Background Human granulocyte colony-stimulating factor (hG-CSF) is an important human cytokine which has been widely used in oncology and infection protection. To satisfy clinical needs, expression of recombinant hG-CSF has been studied in several organisms, including rice cell suspension culture and transient expression in tobacco leaves, but there was no published report on its expression in stably transformed plants which can serve as a more economical expression platform with potential industrial application. Results In this study, hG-CSF expression was investigated in transgenic tobacco leaves and seeds in which the accumulation of hG-CSF could be enhanced through fusion with ubiquitin by up to 7 fold in leaves and 2 fold in seeds, leading to an accumulation level of 2.5 mg/g total soluble protein (TSP) in leaves and 1.3 mg/g TSP in seeds, relative to hG-CSF expressed without a fusion partner. Immunoblot analysis showed that ubiquitin was processed from the final protein product, and ubiquitination was up-regulated in all transgenic plants analyzed. Driven by CaMV 35S promoter and phaseolin signal peptide, hG-CSF was observed to be secreted into apoplast in leaves but deposited in protein storage vacuole (PSV) in seeds, indicating that targeting of the hG-CSF was tissue-dependent in transgenic tobacco. Bioactivity assay showed that hG-CSF expressed in both seeds and leaves was bioactive to support the proliferation of NFS-60 cells. Conclusions In this study, the expression of bioactive hG-CSF in transgenic plants was improved through ubiquitin fusion strategy, demonstrating that protein expression can be enhanced in both plant leaves and seeds through fusion with ubiquitin and providing a typical case of tissue-dependent expression of recombinant protein in transgenic plants. PMID:21985646

  17. Drosophila photoreceptor axon guidance and targeting requires the dreadlocks SH2/SH3 adapter protein.

    Science.gov (United States)

    Garrity, P A; Rao, Y; Salecker, I; McGlade, J; Pawson, T; Zipursky, S L

    1996-05-31

    Mutations in the Drosophila gene dreadlocks (dock) disrupt photoreceptor cell (R cell) axon guidance and targeting. Genetic mosaic analysis and cell-type-specific expression of dock transgenes demonstrate dock is required in R cells for proper innervation. Dock protein contains one SH2 and three SH3 domains, implicating it in tyrosine kinase signaling, and is highly related to the human proto-oncogene Nck. Dock expression is detected in R cell growth cones in the target region. We propose Dock transmits signals in the growth cone in response to guidance and targeting cues. These findings provide an important step for dissection of signaling pathways regulating growth cone motility.

  18. WRKY proteins: signaling and regulation of expression during abiotic stress responses.

    Science.gov (United States)

    Banerjee, Aditya; Roychoudhury, Aryadeep

    2015-01-01

    WRKY proteins are emerging players in plant signaling and have been thoroughly reported to play important roles in plants under biotic stress like pathogen attack. However, recent advances in this field do reveal the enormous significance of these proteins in eliciting responses induced by abiotic stresses. WRKY proteins act as major transcription factors, either as positive or negative regulators. Specific WRKY factors which help in the expression of a cluster of stress-responsive genes are being targeted and genetically modified to induce improved abiotic stress tolerance in plants. The knowledge regarding the signaling cascade leading to the activation of the WRKY proteins, their interaction with other proteins of the signaling pathway, and the downstream genes activated by them are altogether vital for justified targeting of the WRKY genes. WRKY proteins have also been considered to generate tolerance against multiple abiotic stresses with possible roles in mediating a cross talk between abiotic and biotic stress responses. In this review, we have reckoned the diverse signaling pattern and biological functions of WRKY proteins throughout the plant kingdom along with the growing prospects in this field of research.

  19. Nuclear Expression of a Mitochondrial DNA Gene: Mitochondrial Targeting of Allotopically Expressed Mutant ATP6 in Transgenic Mice

    Directory of Open Access Journals (Sweden)

    David A. Dunn

    2012-01-01

    Full Text Available Nuclear encoding of mitochondrial DNA transgenes followed by mitochondrial targeting of the expressed proteins (allotopic expression; AE represents a potentially powerful strategy for creating animal models of mtDNA disease. Mice were created that allotopically express either a mutant (A6M or wildtype (A6W mt-Atp6 transgene. Compared to non-transgenic controls, A6M mice displayed neuromuscular and motor deficiencies (wire hang, pole, and balance beam analyses; P0.05. This study illustrates a mouse model capable of circumventing in vivo mitochondrial mutations. Moreover, it provides evidence supporting AE as a tool for mtDNA disease research with implications in development of DNA-based therapeutics.

  20. Screening and large-scale expression of membrane proteins in mammalian cells for structural studies.

    Science.gov (United States)

    Goehring, April; Lee, Chia-Hsueh; Wang, Kevin H; Michel, Jennifer Carlisle; Claxton, Derek P; Baconguis, Isabelle; Althoff, Thorsten; Fischer, Suzanne; Garcia, K Christopher; Gouaux, Eric

    2014-11-01

    Structural, biochemical and biophysical studies of eukaryotic membrane proteins are often hampered by difficulties in overexpression of the candidate molecule. Baculovirus transduction of mammalian cells (BacMam), although a powerful method to heterologously express membrane proteins, can be cumbersome for screening and expression of multiple constructs. We therefore developed plasmid Eric Gouaux (pEG) BacMam, a vector optimized for use in screening assays, as well as for efficient production of baculovirus and robust expression of the target protein. In this protocol, we show how to use small-scale transient transfection and fluorescence-detection size-exclusion chromatography (FSEC) experiments using a GFP-His8-tagged candidate protein to screen for monodispersity and expression level. Once promising candidates are identified, we describe how to generate baculovirus, transduce HEK293S GnTI(-) (N-acetylglucosaminyltransferase I-negative) cells in suspension culture and overexpress the candidate protein. We have used these methods to prepare pure samples of chicken acid-sensing ion channel 1a (cASIC1) and Caenorhabditis elegans glutamate-gated chloride channel (GluCl) for X-ray crystallography, demonstrating how to rapidly and efficiently screen hundreds of constructs and accomplish large-scale expression in 4-6 weeks.

  1. Germ Cell Proteins in Melanoma: Prognosis, Diagnosis, Treatment, and Theories on Expression

    International Nuclear Information System (INIS)

    Rosa, A. M.; Dabas, N.; Byrnes, D. M.; Eller, M. S.; Grichnik, J. M.; Grichnik, J M.; Grichnik, J M.

    2012-01-01

    Germ cell protein expression in melanoma has been shown to correlate with malignancy, severity of disease and to serve as an immunologic target for therapy. However, very little is known about the role that germ cell proteins play in cancer development. Unique germ cell pathways include those involved in immortalization, genetic evolution, and energy metabolism. There is an ever increasing recognition that within tumors there is a subpopulation of cells with stem-cell-like characteristics that play a role in driving tumor genesis. Stem cell and germ cell biology is intertwined. Given the enormous potential and known expression of germ cell proteins in melanoma, it is possible that they represent a largely untapped resource that may play a fundamental role in tumor development and progression. The purpose of this paper is to provide an update on the current value of germ cell protein expression in melanoma diagnosis, prognosis, and therapy, as well as to review critical germ cell pathways and discuss the potential roles these pathways may play in malignant transformation

  2. MirZ: an integrated microRNA expression atlas and target prediction resource.

    Science.gov (United States)

    Hausser, Jean; Berninger, Philipp; Rodak, Christoph; Jantscher, Yvonne; Wirth, Stefan; Zavolan, Mihaela

    2009-07-01

    MicroRNAs (miRNAs) are short RNAs that act as guides for the degradation and translational repression of protein-coding mRNAs. A large body of work showed that miRNAs are involved in the regulation of a broad range of biological functions, from development to cardiac and immune system function, to metabolism, to cancer. For most of the over 500 miRNAs that are encoded in the human genome the functions still remain to be uncovered. Identifying miRNAs whose expression changes between cell types or between normal and pathological conditions is an important step towards characterizing their function as is the prediction of mRNAs that could be targeted by these miRNAs. To provide the community the possibility of exploring interactively miRNA expression patterns and the candidate targets of miRNAs in an integrated environment, we developed the MirZ web server, which is accessible at www.mirz.unibas.ch. The server provides experimental and computational biologists with statistical analysis and data mining tools operating on up-to-date databases of sequencing-based miRNA expression profiles and of predicted miRNA target sites in species ranging from Caenorhabditis elegans to Homo sapiens.

  3. Protein Kinase CK2 Expression Predicts Relapse Survival in ERα Dependent Breast Cancer, and Modulates ERα Expression in Vitro

    Directory of Open Access Journals (Sweden)

    Marlon D. Williams

    2015-12-01

    Full Text Available The heterotetrameric protein kinase CK2 has been associated with oncogenic transformation, and our previous studies have shown that it may affect estrogenic signaling. Here, we investigate the role of the protein kinase CK2 in regulating ERα (estrogen receptor α signaling in breast cancer. We determined the correlation of CK2α expression with relapse free breast cancer patient survival utilizing Kaplan Meier Plotter (kmplot.com/analysis/ to mine breast cancer microarrays repositories. Patients were stratified according to ERα status, histological grade, and hormonal therapy. Luciferase reporter assays and flow cytometry were implemented to determine the impact of CK2 inhibition on ERE-mediated gene expression and expression of ERα protein. CK2α expression is associated with shorter relapse free survival among ERα (+ patients with grade 1 or 2 tumors, as well as among those patients receiving hormonal therapy. Biochemical inhibition of CK2 activity results in increased ER-transactivation as well as increased expression among ERα (+ and ERα (− breast cancer cell lines. These findings suggest that CK2 may contribute to estrogen-independent cell proliferation and breast tumor progression, and may potentially serve as a biomarker and pharmacological target in breast cancer.

  4. Modifying a standard method allows simultaneous extraction of RNA and protein, enabling detection of enzymes in the rat retina with low expressions and protein levels.

    Science.gov (United States)

    Agardh, Elisabet; Gustavsson, Carin; Hagert, Per; Nilsson, Marie; Agardh, Carl-David

    2006-02-01

    The aim of the study was to evaluate messenger RNA and protein expression in limited amounts of tissue with low protein content. The Chomczynski method was used for simultaneous extraction of RNA, and protein was modified in the protein isolation step. Template mass and cycling time for the complementary DNA synthesis step of real-time reverse transcription-polymerase chain reaction (RT-PCR) for analysis of catalase, copper/zinc superoxide dismutase, manganese superoxide dismutase, the catalytic subunit of glutamylcysteine ligase, glutathione peroxidase 1, and the endogenous control cyclophilin B (CypB) were optimized before PCR. Polymerase chain reaction accuracy and efficacy were demonstrated by calculating the regression (R2) values of the separate amplification curves. Appropriate antibodies, blocking buffers, and running conditions were established for Western blot, and protein detection and multiplex assays with CypB were performed for each target. During the extraction procedure, the protein phase was dissolved in a modified washing buffer containing 0.1% sodium dodecyl sulfate, followed by ultrafiltration. Enzyme expression on real-time RT-PCR was accomplished with high reliability and reproducibility (R2, 0.990-0.999), and all enzymes except for glutathione peroxidase 1 were detectable in individual retinas on Western blot. Western blot multiplexing with CypB was possible for all targets. In conclusion, connecting gene expression directly to protein levels in the individual rat retina was possible by simultaneous extraction of RNA and protein. Real-time RT-PCR and Western blot allowed accurate detection of retinal protein expressions and levels.

  5. Efficient cellular solid-state NMR of membrane proteins by targeted protein labeling

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Lindsay A. [University of Oxford, Oxford Particle Imaging Centre, The Wellcome Trust Centre for Human Genetics, Division of Structural Biology, Nuffield Department of Medicine (United Kingdom); Daniëls, Mark; Cruijsen, Elwin A. W. van der; Folkers, Gert E.; Baldus, Marc, E-mail: m.baldus@uu.nl [Utrecht University, NMR Spectroscopy, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research (Netherlands)

    2015-06-15

    Solid-state NMR spectroscopy (ssNMR) has made significant progress towards the study of membrane proteins in their native cellular membranes. However, reduced spectroscopic sensitivity and high background signal levels can complicate these experiments. Here, we describe a method for ssNMR to specifically label a single protein by repressing endogenous protein expression with rifampicin. Our results demonstrate that treatment of E. coli with rifampicin during induction of recombinant membrane protein expression reduces background signals for different expression levels and improves sensitivity in cellular membrane samples. Further, the method reduces the amount of time and resources needed to produce membrane protein samples, enabling new strategies for studying challenging membrane proteins by ssNMR.

  6. Efficient cellular solid-state NMR of membrane proteins by targeted protein labeling

    International Nuclear Information System (INIS)

    Baker, Lindsay A.; Daniëls, Mark; Cruijsen, Elwin A. W. van der; Folkers, Gert E.; Baldus, Marc

    2015-01-01

    Solid-state NMR spectroscopy (ssNMR) has made significant progress towards the study of membrane proteins in their native cellular membranes. However, reduced spectroscopic sensitivity and high background signal levels can complicate these experiments. Here, we describe a method for ssNMR to specifically label a single protein by repressing endogenous protein expression with rifampicin. Our results demonstrate that treatment of E. coli with rifampicin during induction of recombinant membrane protein expression reduces background signals for different expression levels and improves sensitivity in cellular membrane samples. Further, the method reduces the amount of time and resources needed to produce membrane protein samples, enabling new strategies for studying challenging membrane proteins by ssNMR

  7. A novel mosquito ubiquitin targets viral envelope protein for degradation and reduces virion production during dengue virus infection.

    Science.gov (United States)

    Troupin, Andrea; Londono-Renteria, Berlin; Conway, Michael J; Cloherty, Erin; Jameson, Samuel; Higgs, Stephen; Vanlandingham, Dana L; Fikrig, Erol; Colpitts, Tonya M

    2016-09-01

    Dengue virus (DENV) is a mosquito-borne flavivirus that causes significant human disease and mortality in the tropics and subtropics. By examining the effects of virus infection on gene expression, and interactions between virus and vector, new targets for prevention of infection and novel treatments may be identified in mosquitoes. We previously performed a microarray analysis of the Aedes aegypti transcriptome during infection with DENV and found that mosquito ubiquitin protein Ub3881 (AAEL003881) was specifically and highly down-regulated. Ubiquitin proteins have multiple functions in insects, including marking proteins for proteasomal degradation, regulating apoptosis and mediating innate immune signaling. We used qRT-PCR to quantify gene expression and infection, and RNAi to reduce Ub3881 expression. Mosquitoes were infected with DENV through blood feeding. We transfected DENV protein expression constructs to examine the effect of Ub3881 on protein degradation. We used site-directed mutagenesis and transfection to determine what amino acids are involved in Ub3881-mediated protein degradation. Immunofluorescence, Co-immunoprecipitation and Western blotting were used to examine protein interactions and co-localization. The overexpression of Ub3881, but not related ubiquitin proteins, decreased DENV infection in mosquito cells and live Ae. aegypti. The Ub3881 protein was demonstrated to be involved in DENV envelope protein degradation and reduce the number of infectious virions released. We conclude that Ub3881 has several antiviral functions in the mosquito, including specific viral protein degradation. Our data highlights Ub3881 as a target for future DENV prevention strategies in the mosquito transmission vector. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Identification of target genes of transcription factor activator protein 2 gamma in breast cancer cells

    International Nuclear Information System (INIS)

    Ailan, He; Shuanglin, Xiang; Xiangwen, Xiao; Daolong, Ren; Lu, Gan; Xiaofeng, Ding; Xi, Qiao; Xingwang, Hu; Rushi, Liu; Jian, Zhang

    2009-01-01

    Activator protein 2 gamma (AP-2γ) is a member of the transcription factor activator protein-2 (AP-2) family, which is developmentally regulated and plays a role in human neoplasia. AP-2γ has been found to be overexpressed in most breast cancers, and have a dual role to inhibit tumor initiation and promote tumor progression afterwards during mammary tumorigensis. To identify the gene targets that mediate its effects, we performed chromatin immunoprecipitation (ChIP) to isolate AP-2γ binding sites on genomic DNA from human breast cancer cell line MDA-MB-453. 20 novel DNA fragments proximal to potential AP-2γ targets were obtained. They are categorized into functional groups of carcinogenesis, metabolism and others. A combination of sequence analysis, reporter gene assays, quantitative real-time PCR, electrophoretic gel mobility shift assays and immunoblot analysis further confirmed the four AP-2γ target genes in carcinogenesis group: ErbB2, CDH2, HPSE and IGSF11. Our results were consistent with the previous reports that ErbB2 was the target gene of AP-2γ. Decreased expression and overexpression of AP-2γ in human breast cancer cells significantly altered the expression of these four genes, indicating that AP-2γ directly regulates them. This suggested that AP-2γ can coordinate the expression of a network of genes, involving in carcinogenesis, especially in breast cancer. They could serve as therapeutic targets against breast cancers in the future

  9. Specific DNA-binding proteins and DNA sequences involved in steroid hormone regulation of gene expression

    International Nuclear Information System (INIS)

    Spelsberg, T.; Hora, J.; Horton, M.; Goldberger, A.; Littlefield, B.; Seelke, R.; Toyoda, H.

    1987-01-01

    Steroid hormones circulate in the blood and are taken by target cells via complexes with intracellular binding proteins termed receptors, that are hormone and tissue specific. Each receptor binds it specific steroid with very high affinity, having an equilibrium dissociation constant (K/sub d/) in the range of 10 -9 to 10 -10 M. Once bound by their specific steroid hormones, the steroid receptors undergo a conformational change which allows them to bind with high affinity to sites on chromatin, termed nuclear acceptor sites. There are estimated 5,000 to 10,000 of these sites expressed with an equal number not expressed (''masked'') in intact chromatin. The result of the binding to nuclear acceptor sites is an alteration of gene transcription or, in some cases, gene expression as measured by the changing levels of specific RNAs and proteins in that target tissue. Each steroid regulates specific effects on the RNA and protein profiles. The chronology of the above mechanism of action after injection of radiolabelled steroid as is follows: Steroid-receptor complex formation (1 minute), nuclear acceptor sites (2 minutes), effects on RNA synthesis (10 to 30 minutes), and finally the changing protein profiles via changes in protein synthesis and protein turnover (1 to 6 hours). Thus steroid receptors represent one of the first identified intracellular gene regulation proteins. The receptor molecules themselves are regulated by the presence or absence of the steroid molecule

  10. Sperm protein 17 is expressed in human nervous system tumours

    International Nuclear Information System (INIS)

    Grizzi, Fabio; Baena, Riccardo Rodriguez y; Dioguardi, Nicola; Chiriva-Internati, Maurizio; Gaetani, Paolo; Franceschini, Barbara; Di Ieva, Antonio; Colombo, Piergiuseppe; Ceva-Grimaldi, Giorgia; Bollati, Angelo; Frezza, Eldo E; Cobos, E

    2006-01-01

    Human sperm protein 17 (Sp17) is a highly conserved protein that was originally isolated from a rabbit epididymal sperm membrane and testis membrane pellet. It has recently been included in the cancer/testis (CT) antigen family, and shown to be expressed in multiple myeloma and ovarian cancer. We investigated its immunolocalisation in specimens of nervous system (NS) malignancies, in order to establish its usefulness as a target for tumour-vaccine strategies. The expression of Sp17 was assessed by means of a standardised immunohistochemical procedure [(mAb/antigen) MF1/Sp17] in formalin-fixed and paraffin embedded surgical specimens of NS malignancies, including 28 neuroectodermal primary tumours (6 astrocytomas, 16 glioblastoma multiforme, 5 oligodendrogliomas, and 1 ependymoma), 25 meningeal tumours, and five peripheral nerve sheath tumours (4 schwannomas, and 1 neurofibroma),. A number of neuroectodermal (21%) and meningeal tumours (4%) were found heterogeneously immunopositive for Sp17. None of the peripheral nerve sheath tumours was immunopositive for Sp17. The expression pattern was heterogeneous in all of the positive samples, and did not correlate with the degree of malignancy. The frequency of expression and non-uniform cell distribution of Sp17 suggest that it cannot be used as a unique immunotherapeutic target in NS cancer. However, our results do show the immunolocalisation of Sp17 in a proportion of NS tumour cells, but not in their non-pathological counterparts. The emerging complex function of Sp17 makes further studies necessary to clarify the link between it and immunopositive cells

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

    Science.gov (United States)

    Barron, Daniel A; Moberg, Kenneth

    2016-03-14

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

  12. Targeting the Anti-Apoptotic Protein c-FLIP for Cancer Therapy

    International Nuclear Information System (INIS)

    Safa, Ahmad R.; Pollok, Karen E.

    2011-01-01

    Cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor and critical anti-apoptotic regulator that inhibits tumor necrosis factor-alpha (TNF-alpha), Fas-L, and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as well as chemotherapy-triggered apoptosis in malignant cells. c-FLIP is expressed as long (c-FLIP L ), short (c-FLIP S ), and c-FLIP R splice variants in human cells. c-FLIP binds to FADD and/or caspase-8 or -10 in a ligand-dependent and-independent fashion, which in turn prevents death-inducing signaling complex (DISC) formation and subsequent activation of the caspase cascade. Moreover, c-FLIP L and c-FLIP S are known to have multifunctional roles in various signaling pathways, as well as activating and/or upregulating several cytoprotective signaling molecules. Upregulation of c-FLIP has been found in various tumor types, and its downregulation has been shown to restore apoptosis triggered by cytokines and various chemotherapeutic agents. Hence, c-FLIP is an important target for cancer therapy. For example, small interfering RNAs (siRNAs) that specifically knockdown the expression of c-FLIP L in diverse human cancer cell lines augmented TRAIL-induced DISC recruitment and increased the efficacy of chemotherapeutic agents, thereby enhancing effector caspase stimulation and apoptosis. Moreover, small molecules causing degradation of c-FLIP as well as decreasing mRNA and protein levels of c-FLIP L and c-FLIP S splice variants have been found, and efforts are underway to develop other c-FLIP-targeted cancer therapies. This review focuses on (1) the functional role of c-FLIP splice variants in preventing apoptosis and inducing cytokine and drug resistance; (2) the molecular mechanisms that regulate c-FLIP expression; and (3) strategies to inhibit c-FLIP expression and function

  13. Targeting protein kinases to reverse multidrug resistance in sarcoma.

    Science.gov (United States)

    Chen, Hua; Shen, Jacson; Choy, Edwin; Hornicek, Francis J; Duan, Zhenfeng

    2016-02-01

    Sarcomas are a group of cancers that arise from transformed cells of mesenchymal origin. They can be classified into over 50 subtypes, accounting for approximately 1% of adult and 15% of pediatric cancers. Wide surgical resection, radiotherapy, and chemotherapy are the most common treatments for the majority of sarcomas. Among these therapies, chemotherapy can palliate symptoms and prolong life for some sarcoma patients. However, sarcoma cells can have intrinsic or acquired resistance after treatment with chemotherapeutics drugs, leading to the development of multidrug resistance (MDR). MDR attenuates the efficacy of anticancer drugs and results in treatment failure for sarcomas. Therefore, overcoming MDR is an unmet need for sarcoma therapy. Certain protein kinases demonstrate aberrant expression and/or activity in sarcoma cells, which have been found to be involved in the regulation of sarcoma cell progression, such as cell cycle, apoptosis, and survival. Inhibiting these protein kinases may not only decrease the proliferation and growth of sarcoma cells, but also reverse their resistance to chemotherapeutic drugs to subsequently reduce the doses of anticancer drugs and decrease drug side-effects. The discovery of novel strategies targeting protein kinases opens a door to a new area of sarcoma research and provides insight into the mechanisms of MDR in chemotherapy. This review will focus on the recent studies in targeting protein kinase to reverse chemotherapeutic drug resistance in sarcoma. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. The predictive nature of transcript expression levels on protein expression in adult human brain.

    Science.gov (United States)

    Bauernfeind, Amy L; Babbitt, Courtney C

    2017-04-24

    Next generation sequencing methods are the gold standard for evaluating expression of the transcriptome. When determining the biological implications of such studies, the assumption is often made that transcript expression levels correspond to protein levels in a meaningful way. However, the strength of the overall correlation between transcript and protein expression is inconsistent, particularly in brain samples. Following high-throughput transcriptomic (RNA-Seq) and proteomic (liquid chromatography coupled with tandem mass spectrometry) analyses of adult human brain samples, we compared the correlation in the expression of transcripts and proteins that support various biological processes, molecular functions, and that are located in different areas of the cell. Although most categories of transcripts have extremely weak predictive value for the expression of their associated proteins (R 2 values of < 10%), transcripts coding for protein kinases and membrane-associated proteins, including those that are part of receptors or ion transporters, are among those that are most predictive of downstream protein expression levels. The predictive value of transcript expression for corresponding proteins is variable in human brain samples, reflecting the complex regulation of protein expression. However, we found that transcriptomic analyses are appropriate for assessing the expression levels of certain classes of proteins, including those that modify proteins, such as kinases and phosphatases, regulate metabolic and synaptic activity, or are associated with a cellular membrane. These findings can be used to guide the interpretation of gene expression results from primate brain samples.

  15. Astrocyte-targeted expression of IL-6 protects the CNS against a focal brain injury

    DEFF Research Database (Denmark)

    Penkowa, Milena; Giralt, Mercedes; Lago, Natalia

    2003-01-01

    significantly increased up to but not including 20 dpl in the GFAP-IL6 mice. Oxidative stress as well as apoptotic cell death was significantly decreased throughout the time period studied in the GFAP-IL6 mice compared to controls. This could be linked to the altered inflammatory response as well......The effect of CNS-targeted IL-6 gene expression has been thoroughly investigated in the otherwise nonperturbed brain but not following brain injury. Here we examined the impact of astrocyte-targeted IL-6 production in a traumatic brain injury (cryolesion) model using GFAP-IL6 transgenic mice...... as to the transgenic IL-6-induced increase of the antioxidant, neuroprotective proteins metallothionein-I + II. These results indicate that although in the brain the chronic astrocyte-targeted expression of IL-6 spontaneously induces an inflammatory response causing significant damage, during an acute...

  16. Culture medium, gas atmosphere and MAPK inhibition affect regulation of RNA-binding protein targets during mouse preimplantation development.

    Science.gov (United States)

    Calder, Michele D; Watson, Patricia H; Watson, Andrew J

    2011-11-01

    During oogenesis, mammalian oocytes accumulate maternal mRNAs that support the embryo until embryonic genome activation. RNA-binding proteins (RBP) may regulate the stability and turnover of maternal and embryonic mRNAs. We hypothesised that varying embryo culture conditions, such as culture medium, oxygen tension and MAPK inhibition, affects regulation of RBPs and their targets during preimplantation development. STAU1, ELAVL1, KHSRP and ZFP36 proteins and mRNAs were detected throughout mouse preimplantation development, whereas Elavl2 mRNA decreased after the two-cell stage. Potential target mRNAs of RBP regulation, Gclc, Slc2a1 and Slc7a1 were detected during mouse preimplantation development. Gclc mRNA was significantly elevated in embryos cultured in Whitten's medium compared with embryos cultured in KSOMaa, and Gclc mRNA was elevated under high-oxygen conditions. Inhibition of the p38 MAPK pathway reduced Slc7a1 mRNA expression while inhibition of ERK increased Slc2a1 mRNA expression. The half-lives of the potential RBP mRNA targets are not regulated in parallel; Slc2a1 mRNA displayed the longest half-life. Our results indicate that mRNAs and proteins encoding five RBPs are present during preimplantation development and more importantly, demonstrate that expression of RBP target mRNAs are regulated by culture medium, gas atmosphere and MAPK pathways.

  17. Molecular design and nanoparticle-mediated intracellular delivery of functional proteins to target cellular pathways

    Science.gov (United States)

    Shah, Dhiral Ashwin

    Intracellular delivery of specific proteins and peptides represents a novel method to influence stem cells for gain-of-function and loss-of-function. Signaling control is vital in stem cells, wherein intricate control of and interplay among critical pathways directs the fate of these cells into either self-renewal or differentiation. The most common route to manipulate cellular function involves the introduction of genetic material such as full-length genes and shRNA into the cell to generate (or prevent formation of) the target protein, and thereby ultimately alter cell function. However, viral-mediated gene delivery may result in relatively slow expression of proteins and prevalence of oncogene insertion into the cell, which can alter cell function in an unpredictable fashion, and non-viral delivery may lead to low efficiency of genetic delivery. For example, the latter case plagues the generation of induced pluripotent stem cells (iPSCs) and hinders their use for in vivo applications. Alternatively, introducing proteins into cells that specifically recognize and influence target proteins, can result in immediate deactivation or activation of key signaling pathways within the cell. In this work, we demonstrate the cellular delivery of functional proteins attached to hydrophobically modified silica (SiNP) nanoparticles to manipulate specifically targeted cell signaling proteins. In the Wnt signaling pathway, we have targeted the phosphorylation activity of glycogen synthase kinase-3beta (GSK-3beta) by designing a chimeric protein and delivering it in neural stem cells. Confocal imaging indicates that the SiNP-chimeric protein conjugates were efficiently delivered to the cytosol of human embryonic kidney cells and rat neural stem cells, presumably via endocytosis. This uptake impacted the Wnt signaling cascade, indicated by the elevation of beta-catenin levels, and increased transcription of Wnt target genes, such as c-MYC. The results presented here suggest that

  18. Functional redundancy and/or ongoing pseudogenization among F-box protein genes expressed in Arabidopsis male gametophyte.

    Science.gov (United States)

    Ikram, Sobia; Durandet, Monique; Vesa, Simona; Pereira, Serge; Guerche, Philippe; Bonhomme, Sandrine

    2014-06-01

    F-box protein genes family is one of the largest gene families in plants, with almost 700 predicted genes in the model plant Arabidopsis. F-box proteins are key components of the ubiquitin proteasome system that allows targeted protein degradation. Transcriptome analyses indicate that half of these F-box protein genes are found expressed in microspore and/or pollen, i.e., during male gametogenesis. To assess the role of F-box protein genes during this crucial developmental step, we selected 34 F-box protein genes recorded as highly and specifically expressed in pollen and isolated corresponding insertion mutants. We checked the expression level of each selected gene by RT-PCR and confirmed pollen expression for 25 genes, but specific expression for only 10 of the 34 F-box protein genes. In addition, we tested the expression level of selected F-box protein genes in 24 mutant lines and showed that 11 of them were null mutants. Transmission analysis of the mutations to the progeny showed that none of the single mutations was gametophytic lethal. These unaffected transmission efficiencies suggested leaky mutations or functional redundancy among F-box protein genes. Cytological observation of the gametophytes in the mutants confirmed these results. Combinations of mutations in F-box protein genes from the same subfamily did not lead to transmission defect either, further highlighting functional redundancy and/or a high proportion of pseudogenes among these F-box protein genes.

  19. Benzo[a]pyrene treatment leads to changes in nuclear protein expression and alternative splicing

    Energy Technology Data Exchange (ETDEWEB)

    Yan Chunlan; Wu Wei [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Li Haiyan [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Huzhou Maternity and Child Care Hospital, Huzhou, Zhejiang 313000 (China); Zhang Guanglin [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Duerksen-Hughes, Penelope J. [Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354 (United States); Zhu Xinqiang, E-mail: zhuxq@zju.edu.cn [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Yang Jun, E-mail: gastate@zju.edu.cn [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Zhejiang-California International Nanosystems Institute, Hangzhou, Zhejiang 310029 (China)

    2010-04-01

    Benzo[a]pyrene (BaP) is a potent pro-carcinogen generated from the combustion of fossil fuel and cigarette smoke. Previously, using a proteomic approach, we have shown that BaP can induce changes in the expression of many cellular proteins, including transcription regulators. In the present study, using a similar approach, we examined the nuclear protein response to BaP in HeLa cells and found that BaP treatment caused expression changes in many nuclear proteins. Twenty-four of these proteins were successfully identified, several of which are involved in the alternative splicing of mRNA, DNA replication, recombination, and repair. The changed expression levels were further confirmed by immunoblot analysis using specific antibodies for two proteins, Lamin A and mitotic checkpoint protein Bub3. The nuclear localization of these two proteins was also confirmed by confocal microscopy. To determine whether alternative splicing was activated following BaP treatment, we examined Fas and CD44, two genes previously shown to be targets of alternative splicing in respond to DNA damage. While no significant activation of alternative splicing was observed for Fas, CD44 splicing variants were found after BaP treatment. Together, these data show that DNA damage induces dramatic changes in nuclear protein expression, and that alternative splicing might be involved in the cellular response to DNA damage.

  20. Endothelial Protein C–Targeting Liposomes Show Enhanced Uptake and Improved Therapeutic Efficacy in Human Retinal Endothelial Cells

    DEFF Research Database (Denmark)

    Arta, Anthoula; Eriksen, Anne Z.; Melander, Fredrik

    2018-01-01

    PURPOSE. To determine whether human retinal endothelial cells (HRECs) express the endothelial cell protein C receptor (EPCR) and to realize its potential as a targeting moiety by developing novel single and dual corticosteroid–loaded functionalized liposomes that exhibit both enhanced uptake by H...... of cell tube formations in contrast to nontargeting liposomes. CONCLUSIONS. We show that HRECs express EPCR and this receptor could be a promising nanomedicine target in ocular diseases where the endothelial barrier of the retina is compromised....

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  2. Changes in Hepatic TRβ Protein Expression, Lipogenic Gene Expression, and Long-Chain Acylcarnitine Levels During Chronic Hyperthyroidism and Triiodothyronine Withdrawal in a Mouse Model.

    Science.gov (United States)

    Ohba, Kenji; Sinha, Rohit Anthony; Singh, Brijesh Kumar; Iannucci, Liliana Felicia; Zhou, Jin; Kovalik, Jean-Paul; Liao, Xiao-Hui; Refetoff, Samuel; Sng, Judy Chia Ghee; Leow, Melvin Khee-Shing; Yen, Paul Michael

    2017-06-01

    Thyroid hormone (TH) has important roles in regulating hepatic metabolism. It was previously reported that most hepatic genes activated by a single triiodothyronine (T3) injection became desensitized after multiple injections, and that approximately 10% of target genes did not return to basal expression levels after T3 withdrawal, despite normalization of serum TH and thyrotropin (TSH) levels. To determine the possible mechanism(s) for desensitization and incomplete recovery of hepatic target gene transcription and their effects on metabolism, mRNA and/or protein expression levels of key regulators of TH action were measured, as well as metabolomic changes after chronic T3 treatment and withdrawal. Adult male mice were treated with daily injections of T3 (20 μg/100 g body weight) for 14 days followed by the cessation of T3 for 10 days. Livers were harvested at 6 hours, 24 hours, and 14 days after the first T3 injection, and at 10 days after withdrawal, and then analyzed by quantitative reverse transcription polymerase chain reaction, Western blotting, and metabolomics. Although TH receptor (TRα and TRβ) mRNAs decreased slightly after chronic T3 treatment, only TRβ protein decreased before returning to basal expression level after withdrawal. The expression of other regulators of TH action was unchanged. TRβ protein expression was also decreased in adult male monocarboxylate transporter-8 (Mct8)-knockout mice, an in vivo model of chronic intrahepatic hyperthyroidism. Previously, increased hepatic long-chain acylcarnitine levels were found after acute TH treatment. However, in this study, long-chain acylcarnitine levels were unchanged after chronic T3, and paradoxically increased after T3 withdrawal. Pathway analyses of the previous microarray results showed upregulation of lipogenic genes after acute T3 treatment and withdrawal. Phosphorylation of acetyl-CoA carboxylase also decreased after T3 withdrawal. Decreased hepatic TRβ protein expression occurred

  3. Expression and purification of sea raven type II antifreeze protein from Drosophila melanogaster S2 cells.

    Science.gov (United States)

    Scotter, Andrew J; Kuntz, Douglas A; Saul, Michelle; Graham, Laurie A; Davies, Peter L; Rose, David R

    2006-06-01

    We present a system for the expression and purification of recombinant sea raven type II antifreeze protein, a cysteine-rich, C-type lectin-like globular protein that has proved to be a difficult target for recombinant expression and purification. The cDNAs encoding the pro- and mature forms of the sea raven protein were cloned into a modified pMT Drosophila expression vector. These constructs produced N-terminally His(6)-tagged pro- and mature forms of the type II antifreeze protein under the control of a metallothionein promoter when transfected into Drosophila melanogaster S2 cells. Upon induction of stable cell lines the two proteins were expressed at high levels and secreted into the medium. The proteins were then purified from the cell medium in a simple and rapid protocol using immobilized metal affinity chromatography and specific protease cleavage by tobacco etch virus protease. The proteins demonstrated antifreeze activity indistinguishable from that of wild-type sea raven antifreeze protein purified from serum as illustrated by ice affinity purification, ice crystal morphology, and their ability to inhibit ice crystal growth. This expression and purification system gave yields of 95 mg/L of fully active mature sea raven type II AFP and 9.6 mg/L of the proprotein. This surpasses all previous attempts to express this protein in Escherichia coli, baculovirus-infected fall armyworm cells and Pichia pastoris and will provide sufficient protein for structural analysis.

  4. Control of Secreted Protein Gene Expression and the Mammalian Secretome by the Metabolic Regulator PGC-1α.

    Science.gov (United States)

    Minsky, Neri; Roeder, Robert G

    2017-01-06

    Secreted proteins serve pivotal roles in the development of multicellular organisms, acting as structural matrix, extracellular enzymes, and signal molecules. However, how the secretome is regulated remains incompletely understood. Here we demonstrate, unexpectedly, that peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), a critical transcriptional co-activator of metabolic gene expression, functions to down-regulate the expression of diverse genes encoding secreted molecules and extracellular matrix components to modulate the secretome. Using cell lines, primary cells, and mice, we show that both endogenous and exogenous PGC-1α down-regulate the expression of numerous genes encoding secreted molecules. Mechanistically, results obtained using mRNA stability measurements as well as intronic RNA expression analysis are consistent with a transcriptional effect of PGC-1α on the expression of genes encoding secreted proteins. Interestingly, PGC-1α requires the central heat shock response regulator heat shock factor protein 1 (HSF1) to affect some of its targets, and both factors co-reside on several target genes encoding secreted molecules in cells. Finally, using a mass spectrometric analysis of secreted proteins, we demonstrate that PGC-1α modulates the secretome of mouse embryonic fibroblasts. Our results define a link between a key pathway controlling metabolic regulation and the regulation of the mammalian secretome. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Efficient protein production method for NMR using soluble protein tags with cold shock expression vector

    International Nuclear Information System (INIS)

    Hayashi, Kokoro; Kojima, Chojiro

    2010-01-01

    The E. coli protein expression system is one of the most useful methods employed for NMR sample preparation. However, the production of some recombinant proteins in E. coli is often hampered by difficulties such as low expression level and low solubility. To address these problems, a modified cold-shock expression system containing a glutathione S-transferase (GST) tag, the pCold-GST system, was investigated. The pCold-GST system successfully expressed 9 out of 10 proteins that otherwise could not be expressed using a conventional E. coli expression system. Here, we applied the pCold-GST system to 84 proteins and 78 proteins were successfully expressed in the soluble fraction. Three other cold-shock expression systems containing a maltose binding protein tag (pCold-MBP), protein G B1 domain tag (pCold-GB1) or thioredoxin tag (pCold-Trx) were also developed to improve the yield. Additionally, we show that a C-terminal proline tag, which is invisible in 1 H- 15 N HSQC spectra, inhibits protein degradation and increases the final yield of unstable proteins. The purified proteins were amenable to NMR analyses. These data suggest that pCold expression systems combined with soluble protein tags can be utilized to improve the expression and purification of various proteins for NMR analysis.

  6. The protein micro-crystallography beamlines for targeted protein research program

    International Nuclear Information System (INIS)

    Hirata, Kunio; Yamamoto, Masaki; Matsugaki, Naohiro; Wakatsuki, Soichi

    2010-01-01

    In order to collect proper diffraction data from outstanding micro-crystals, a brand-new data collection system should be designed to provide high signal-to noise ratio in diffraction images. SPring-8 and KEK-PF are currently developing two micro-beam beamlines for Targeted Proteins Research Program by MEXT of Japan. The program aims to reveal the structure and function of proteins that are difficult to solve but have great importance in both academic research and industrial application. At SPring-8, a new 1-micron beam beamline for protein micro-crystallography, RIKEN Targeted Proteins Beamline (BL32XU), is developed. At KEK-PF a new low energy micro-beam beamline, BL-1A, is dedicated for SAD micro-crystallography. The two beamlines will start operation in the end of 2010. The present status of the research and development for protein micro-crystallography will be presented. (author)

  7. The group A streptococcal collagen-like protein 1, Scl1, mediates biofilm formation by targeting the EDA-containing variant of cellular fibronectin expressed in wounded tissue

    Science.gov (United States)

    Oliver-Kozup, Heaven; Martin, Karen H.; Schwegler-Berry, Diane; Green, Brett J.; Betts, Courtney; Shinde, Arti V.; Van De Water, Livingston; Lukomski, Slawomir

    2012-01-01

    Summary Wounds are known to serve as portals of entry for group A Streptococcus (GAS). Subsequent tissue colonization is mediated by interactions between GAS surface proteins and host extracellular matrix components. We recently reported that the streptococcal collagen-like protein-1, Scl1, selectively binds the cellular form of fibronectin (cFn) and also contributes to GAS biofilm formation on abiotic surfaces. One structural feature of cFn, which is predominantly expressed in response to tissue injury, is the presence of a spliced variant containing extra domain A (EDA/EIIIA). We now report that GAS biofilm formation is mediated by the Scl1 interaction with EDA-containing cFn. Recombinant Scl1 proteins that bound cFn also bound recombinant EDA within the C-C′ loop region recognized by the α9β1 integrin. The extracellular 2-D matrix derived from human dermal fibroblasts supports GAS adherence and biofilm formation. Altogether, this work identifies and characterizes a novel molecular mechanism by which GAS utilizes Scl1 to specifically target an extracellular matrix component that is predominantly expressed at the site of injury in order to secure host tissue colonization. PMID:23217101

  8. Purification-Free, Target-Selective Immobilization of a Protein from Cell Lysates.

    Science.gov (United States)

    Cha, Jaehyun; Kwon, Inchan

    2018-02-27

    Protein immobilization has been widely used for laboratory experiments and industrial processes. Preparation of a recombinant protein for immobilization usually requires laborious and expensive purification steps. Here, a novel purification-free, target-selective immobilization technique of a protein from cell lysates is reported. Purification steps are skipped by immobilizing a target protein containing a clickable non-natural amino acid (p-azidophenylalanine) in cell lysates onto alkyne-functionalized solid supports via bioorthogonal azide-alkyne cycloaddition. In order to achieve a target protein-selective immobilization, p-azidophenylalanine was introduced into an exogenous target protein, but not into endogenous non-target proteins using host cells with amber codon-free genomic DNAs. Immobilization of superfolder fluorescent protein (sfGFP) from cell lysates is as efficient as that of the purified sfGFP. Using two fluorescent proteins (sfGFP and mCherry), the authors also demonstrated that the target proteins are immobilized with a minimal immobilization of non-target proteins (target-selective immobilization). © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. mRNA secondary structure at start AUG codon is a key limiting factor for human protein expression in Escherichia coli

    International Nuclear Information System (INIS)

    Zhang Weici; Xiao Weihua; Wei Haiming; Zhang Jian; Tian Zhigang

    2006-01-01

    Codon usage and thermodynamic optimization of the 5'-end of mRNA have been applied to improve the efficiency of human protein production in Escherichia coli. However, high level expression of human protein in E. coli is still a challenge that virtually depends upon each individual target genes. Using human interleukin 10 (huIL-10) and interferon α (huIFN-α) coding sequences, we systematically analyzed the influence of several major factors on expression of human protein in E. coli. The results from huIL-10 and reinforced by huIFN-α showed that exposing AUG initiator codon from base-paired structure within mRNA itself significantly improved the translation of target protein, which resulted in a 10-fold higher protein expression than the wild-type genes. It was also noted that translation process was not affected by the retained short-range stem-loop structure at Shine-Dalgarno (SD) sequences. On the other hand, codon-optimized constructs of huIL-10 showed unimproved levels of protein expression, on the contrary, led to a remarkable RNA degradation. Our study demonstrates that exposure of AUG initiator codon from long-range intra-strand secondary structure at 5'-end of mRNA may be used as a general strategy for human protein production in E. coli

  10. Differentially expressed proteins on postoperative 3

    Directory of Open Access Journals (Sweden)

    Jialili Ainuer

    2011-04-01

    Full Text Available 【Abstract】Objectives: Surgical repair of Achilles tendon (AT rupture should immediately be followed by active tendon mobilization. The optimal time as to when the mobilization should begin is important yet controversial. Early kinesitherapy leads to reduced rehabilitation period. However, an insight into the detailed mechanism of this process has not been gained. Proteomic technique can be used to separate and purify the proteins by differential expression profile which is related to the function of different proteins, but research in the area of proteomic analysis of AT 3 days after repair has not been studied so far. Methods: Forty-seven New Zealand white rabbits were randomized into 3 groups. Group A (immobilization group, n=16 received postoperative cast immobilization; Group B (early motion group, n=16 received early active motion treatments immediately following the repair of AT rupture from tenotomy. Another 15 rabbits served as control group (Group C. The AT samples were prepared 3 days following the microsurgery. The proteins were separated employing twodimensional polyacrylamide gel electrophoresis (2D-PAGE. PDQuest software version 8.0 was used to identify differentially expressed proteins, followed by peptide mass fingerprint (PMF and tandem mass spectrum analysis, using the National Center for Biotechnology Information (NCBI protein database retrieval and then for bioinformatics analysis. Results: A mean of 446.33, 436.33 and 462.67 protein spots on Achilles tendon samples of 13 rabbits in Group A, 14 rabbits in Group B and 13 rabbits in Group C were successfully detected in the 2D-PAGE. There were 40, 36 and 79 unique proteins in Groups A, B and C respectively. Some differentially expressed proteins were enzyme with the gel, matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS. We successfully identified 9 and 11 different proteins in Groups A and B, such as GAPDH, phosphoglycerate kinase 1

  11. Methylation status and protein expression of RASSF1A in breast cancer patients.

    Science.gov (United States)

    Hagrass, Hoda A; Pasha, Heba F; Shaheen, Mohamed A; Abdel Bary, Eman H; Kassem, Rasha

    2014-01-01

    Recently genetics and epigenetics alterations have been found to be characteristic of malignancy and hence can be used as targets for detection of neoplasia. RAS association domain family protein 1A (RASSF1A) gene hypermethylation has been a subject of interest in recent researches on cancer breast patients. The aim of the present study was to evaluate whether RASSF1A methylation status and RASSF1A protein expression are associated with the major clinico-pathological parameters. One hundred and twenty breast cancer Egyptian patients and 100-control subjects diagnosed with benign lesions of the breast were enrolled in this study. We evaluated RASSF1A methylation status in tissue and serum samples using Methyl specific PCR together with RASSF1A protein expression in tissues by immunohistochemistry. Results were studied in relation to known prognostic clinicopathological features in breast cancer. Frequency of RASSF1A methylation in tissues and serum were 70 and 63.3 % respectively and RASSF1A protein expression showed frequency of 46.7 %. There was an association between RASSF1A methylation in tissues, serum and loss of protein expression in tissues with invasive carcinoma, advanced stage breast cancer, L.N. metastasis, ER/PR and HER2 negativity. RASSF1A methylation in serum showed high degree of concordance with methylation in tissues (Kappa = 0.851, P < 0.001). RASSF1A hypermethylation in tissues and serum and its protein expression may be a valid, reliable and sensitive tool for detection and follow up of breast cancer patients.

  12. Efficient protein production method for NMR using soluble protein tags with cold shock expression vector

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Kokoro [Fujifilm Corporation, Analysis Technology Center (Japan); Kojima, Chojiro, E-mail: kojima@protein.osaka-u.ac.j [Nara Institute of Science and Technology (NAIST), Graduate School of Biological Sciences (Japan)

    2010-11-15

    The E. coli protein expression system is one of the most useful methods employed for NMR sample preparation. However, the production of some recombinant proteins in E. coli is often hampered by difficulties such as low expression level and low solubility. To address these problems, a modified cold-shock expression system containing a glutathione S-transferase (GST) tag, the pCold-GST system, was investigated. The pCold-GST system successfully expressed 9 out of 10 proteins that otherwise could not be expressed using a conventional E. coli expression system. Here, we applied the pCold-GST system to 84 proteins and 78 proteins were successfully expressed in the soluble fraction. Three other cold-shock expression systems containing a maltose binding protein tag (pCold-MBP), protein G B1 domain tag (pCold-GB1) or thioredoxin tag (pCold-Trx) were also developed to improve the yield. Additionally, we show that a C-terminal proline tag, which is invisible in {sup 1}H-{sup 15}N HSQC spectra, inhibits protein degradation and increases the final yield of unstable proteins. The purified proteins were amenable to NMR analyses. These data suggest that pCold expression systems combined with soluble protein tags can be utilized to improve the expression and purification of various proteins for NMR analysis.

  13. Protective Effects of Scutellarin on Human Cardiac Microvascular Endothelial Cells against Hypoxia-Reoxygenation Injury and Its Possible Target-Related Proteins.

    Science.gov (United States)

    Shi, Meina; Liu, Yingting; Feng, Lixing; Cui, Yingbo; Chen, Yajuan; Wang, Peng; Wu, Wenjuan; Chen, Chen; Liu, Xuan; Yang, Weimin

    2015-01-01

    Scutellarin (SCU) is one of the main components of traditional Chinese medicine plant Erigeron breviscapus (Vant.) Hand.-Mazz. In this paper, we studied the protective effects of SCU on human cardiac microvascular endothelial cells (HCMECs) against hypoxia-reoxygenation (HR) injury and its possible target-related proteins. Results of MTT assay showed that pretreatment of SCU at doses of 1, 5, and 10 μM for 2 h could significantly inhibit the decrease in cell viability of HCMECs induced by HR injury. Subcellular fractions of cells treated with vehicle control, 1 μM SCU, HR injury, or 1 μM SCU + HR injury were separated by ultracentrifugation. The protein expression profiles of cytoplasm and membrane/nuclei fractions were checked using protein two-dimensional electrophoresis (2-DE). Proteins differentially expressed between control and SCU-treated group, control and HR group, or HR and SCU + HR group were identified using mass spectrometry (MS/MS). Possible interaction network of these target-related proteins was predicted using bioinformatic analysis. The influence of SCU on the expression levels of these proteins was confirmed using Western blotting assay. The results indicated that proteins such as p27BBP protein (EIF6), heat shock 60 kDa protein 1 (HSPD1), and chaperonin containing TCP1 subunit 6A isoform (CCT6A) might play important roles in the effects of SCU.

  14. MicroRNA miR-328 regulates zonation morphogenesis by targeting CD44 expression.

    Science.gov (United States)

    Wang, Chia-Hui; Lee, Daniel Y; Deng, Zhaoqun; Jeyapalan, Zina; Lee, Shao-Chen; Kahai, Shireen; Lu, Wei-Yang; Zhang, Yaou; Yang, Burton B

    2008-06-18

    Morphogenesis is crucial to initiate physiological development and tumor invasion. Here we show that a microRNA controls zonation morphogenesis by targeting hyaluronan receptor CD44. We have developed a novel system to study microRNA functions by generating constructs expressing pre-miRNAs and mature miRNAs. Using this system, we have demonstrated that expression of miR-328 reduced cell adhesion, aggregation, and migration, and regulated formation of capillary structure. Protein analysis indicated that miR-328 repressed CD44 expression. Activities of luciferase constructs harboring the target site in CD44, but not the one containing mutation, were repressed by miR-328. Zonation morphogenesis appeared in cells transfected by miR-328: miR-328-transfected cells were present on the surface of zonating structures while the control cells stayed in the middle. MiR-328-mediated CD44 actions was validated by anti-CD44 antibody, hyaluronidase, CD44 siRNA, and CD44 expression constructs. In vivo experiments showed that CD44-silencing cells appeared as layers on the surfaces of nodules or zonating structures. Immuno-histochemistry also exhibited CD44-negative cells on the surface layers of normal rat livers and the internal zones of Portal veins. Our results demonstrate that miR-328 targets CD44, which is essential in regulating zonation morphogenesis: silencing of CD44 expression is essential in sealing the zonation structures to facilitate their extension and to inhibit complex expansion.

  15. MicroRNA miR-328 regulates zonation morphogenesis by targeting CD44 expression.

    Directory of Open Access Journals (Sweden)

    Chia-Hui Wang

    Full Text Available Morphogenesis is crucial to initiate physiological development and tumor invasion. Here we show that a microRNA controls zonation morphogenesis by targeting hyaluronan receptor CD44. We have developed a novel system to study microRNA functions by generating constructs expressing pre-miRNAs and mature miRNAs. Using this system, we have demonstrated that expression of miR-328 reduced cell adhesion, aggregation, and migration, and regulated formation of capillary structure. Protein analysis indicated that miR-328 repressed CD44 expression. Activities of luciferase constructs harboring the target site in CD44, but not the one containing mutation, were repressed by miR-328. Zonation morphogenesis appeared in cells transfected by miR-328: miR-328-transfected cells were present on the surface of zonating structures while the control cells stayed in the middle. MiR-328-mediated CD44 actions was validated by anti-CD44 antibody, hyaluronidase, CD44 siRNA, and CD44 expression constructs. In vivo experiments showed that CD44-silencing cells appeared as layers on the surfaces of nodules or zonating structures. Immuno-histochemistry also exhibited CD44-negative cells on the surface layers of normal rat livers and the internal zones of Portal veins. Our results demonstrate that miR-328 targets CD44, which is essential in regulating zonation morphogenesis: silencing of CD44 expression is essential in sealing the zonation structures to facilitate their extension and to inhibit complex expansion.

  16. Identification of α(1,6)fucosylated proteins differentially expressed in human colorectal cancer

    International Nuclear Information System (INIS)

    Muinelo-Romay, Laura; Villar-Portela, Susana; Cuevas, Elisa; Gil-Martín, Emilio; Fernández-Briera, Almudena

    2011-01-01

    A universal hallmark of cancer cells is the change in their glycosylation phenotype. One of the most frequent alterations in the normal glycosylation pattern observed during carcinogenesis is the enhancement of α(1,6)linked fucose residues of glycoproteins, due to the up-regulation of the α(1,6)fucosyltransferase activity. Our previous results demonstrated the specific alteration of this enzyme activity and expression in colorectal cancer, suggesting its implication in tumour development and progression. In the current work we combined a LCA-affinity chromatography with SDS-PAGE and mass spectrometry in order to identify α(1,6)fucosylated proteins differentially expressed in colorectal cancer. This strategy allowed the identification of a group of α(1,6)fucosylated proteins candidates to be involved in CRC malignancy. The majority of the identified proteins take part in cell signaling and interaction processes as well as in modulation of the immunological response. Likewise, we confirmed the increased expression of GRP94 in colorectal cancer tissue and the significant down-regulation of the IgGFcBP expression in tumour cells. All these results validate the importance of core-fucosylated proteins profile analysis to understand the mechanisms which promote cancer onset and progression and to discover new tumour markers or therapeutic targets

  17. When less becomes more : Optimization of protein expression in HEK293-EBNA1 cells using plasmid titration - A case study for NLRs

    NARCIS (Netherlands)

    Halff, Els F.; Versteeg, Marian; Brondijk, T. Harma C; Huizinga, Eric G.

    2014-01-01

    Transient transfection of the human HEK293-EBNA1 cell line using polyethyleneimine is widely adopted for recombinant protein production. Whereas high expression of many targets is achieved, purification yields of some highly expressed proteins remain low due to aggregation. We hypothesized that for

  18. Small interfering RNA targeted to stem-loop II of the 5' untranslated region effectively inhibits expression of six HCV genotypes

    Directory of Open Access Journals (Sweden)

    Dash Srikanta

    2006-11-01

    Full Text Available Abstract Background The antiviral action of interferon alpha targets the 5' untranslated region (UTR used by hepatitis C virus (HCV to translate protein by an internal ribosome entry site (IRES mechanism. Although this sequence is highly conserved among different clinical strains, approximately half of chronically infected hepatitis C patients do not respond to interferon therapy. Therefore, development of small interfering RNA (siRNA targeted to the 5'UTR to inhibit IRES mediated translation may represent an alternative approach that could circumvent the problem of interferon resistance. Results Four different plasmid constructs were prepared for intracellular delivery of siRNAs targeting the stem loop II-III of HCV 5' UTR. The effect of siRNA production on IRES mediated translation was investigated using chimeric clones between the gene for green fluorescence protein (GFP and IRES sequences of six different HCV genotypes. The siRNA targeted to stem loop II effectively mediated degradation of HCV IRES mRNA and inhibited GFP expression in the case of six different HCV genotypes, where as siRNAs targeted to stem loop III did not. Furthermore, intracytoplasmic expression of siRNA into transfected Huh-7 cells efficiently degraded HCV genomic RNA and inhibited core protein expression from infectious full-length infectious clones HCV 1a and HCV 1b strains. Conclusion These in vitro studies suggest that siRNA targeted to stem-loop II is highly effective inhibiting IRES mediated translation of the major genotypes of HCV. Stem-loop II siRNA may be a good target for developing an intracellular immunization strategy based antiviral therapy to inhibit hepatitis C virus strains that are not inhibited by interferon.

  19. 4EBP-Dependent Signaling Supports West Nile Virus Growth and Protein Expression.

    Science.gov (United States)

    Shives, Katherine D; Massey, Aaron R; May, Nicholas A; Morrison, Thomas E; Beckham, J David

    2016-10-18

    West Nile virus (WNV) is a (+) sense, single-stranded RNA virus in the Flavivirus genus. WNV RNA possesses an m7 GpppN m 5' cap with 2'- O -methylation that mimics host mRNAs preventing innate immune detection and allowing the virus to translate its RNA genome through the utilization of cap-dependent translation initiation effectors in a wide variety of host species. Our prior work established the requirement of the host mammalian target of rapamycin complex 1 (mTORC1) for optimal WNV growth and protein expression; yet, the roles of the downstream effectors of mTORC1 in WNV translation are unknown. In this study, we utilize gene deletion mutants in the ribosomal protein kinase called S6 kinase (S6K) and eukaryotic translation initiation factor 4E-binding protein (4EBP) pathways downstream of mTORC1 to define the role of mTOR-dependent translation initiation signals in WNV gene expression and growth. We now show that WNV growth and protein expression are dependent on mTORC1 mediated-regulation of the eukaryotic translation initiation factor 4E-binding protein/eukaryotic translation initiation factor 4E-binding protein (4EBP/eIF4E) interaction and eukaryotic initiation factor 4F (eIF4F) complex formation to support viral growth and viral protein expression. We also show that the canonical signals of mTORC1 activation including ribosomal protein s6 (rpS6) and S6K phosphorylation are not required for WNV growth in these same conditions. Our data suggest that the mTORC1/4EBP/eIF4E signaling axis is activated to support the translation of the WNV genome.

  20. 4EBP-Dependent Signaling Supports West Nile Virus Growth and Protein Expression

    Directory of Open Access Journals (Sweden)

    Katherine D. Shives

    2016-10-01

    Full Text Available West Nile virus (WNV is a (+ sense, single-stranded RNA virus in the Flavivirus genus. WNV RNA possesses an m7GpppNm 5′ cap with 2′-O-methylation that mimics host mRNAs preventing innate immune detection and allowing the virus to translate its RNA genome through the utilization of cap-dependent translation initiation effectors in a wide variety of host species. Our prior work established the requirement of the host mammalian target of rapamycin complex 1 (mTORC1 for optimal WNV growth and protein expression; yet, the roles of the downstream effectors of mTORC1 in WNV translation are unknown. In this study, we utilize gene deletion mutants in the ribosomal protein kinase called S6 kinase (S6K and eukaryotic translation initiation factor 4E-binding protein (4EBP pathways downstream of mTORC1 to define the role of mTOR-dependent translation initiation signals in WNV gene expression and growth. We now show that WNV growth and protein expression are dependent on mTORC1 mediated-regulation of the eukaryotic translation initiation factor 4E-binding protein/eukaryotic translation initiation factor 4E-binding protein (4EBP/eIF4E interaction and eukaryotic initiation factor 4F (eIF4F complex formation to support viral growth and viral protein expression. We also show that the canonical signals of mTORC1 activation including ribosomal protein s6 (rpS6 and S6K phosphorylation are not required for WNV growth in these same conditions. Our data suggest that the mTORC1/4EBP/eIF4E signaling axis is activated to support the translation of the WNV genome.

  1. Differentially expressed proteins among normal cervix, cervical intraepithelial neoplasia and cervical squamous cell carcinoma.

    Science.gov (United States)

    Zhao, Q; He, Y; Wang, X-L; Zhang, Y-X; Wu, Y-M

    2015-08-01

    positive expression rate was 70.0 % in normal cervix, 73.3 % in CIN and 60.0 % in CSCC tissues, without significant difference among them (P = 0.758). PKM2 was mainly expressed in the cell nuclei, and its positive expression rate was 100.0 % in normal cervix, 93.3 % in CIN and 75.0 % in CSCC tissues, showing a difference close to statistical significance (P = 0.059) among them. There are differentially expressed proteins among normal cervix, CIN and CSCC. S100A9, eEF1A1 and PKM2 may become candidate markers for early diagnosis of cervical cancer and new targets for therapy. It also provides a basis for further studies of the mechanism for CIN developing to CSCC.

  2. Characteristics of functional enrichment and gene expression level of human putative transcriptional target genes.

    Science.gov (United States)

    Osato, Naoki

    2018-01-19

    enrichments were related to the cellular functions. The normalized number of functional enrichments of human putative transcriptional target genes changed according to the criteria of enhancer-promoter assignments and correlated with the median expression level of the target genes. These analyses and characters of human putative transcriptional target genes would be useful to examine the criteria of enhancer-promoter assignments and to predict the novel mechanisms and factors such as DNA binding proteins and DNA sequences of enhancer-promoter interactions.

  3. Sex-Specificity of Mineralocorticoid Target Gene Expression during Renal Development, and Long-Term Consequences

    Science.gov (United States)

    Dumeige, Laurence; Storey, Caroline; Decourtye, Lyvianne; Nehlich, Melanie; Lhadj, Christophe; Viengchareun, Say; Kappeler, Laurent; Lombès, Marc; Martinerie, Laetitia

    2017-01-01

    Sex differences have been identified in various biological processes, including hypertension. The mineralocorticoid signaling pathway is an important contributor to early arterial hypertension, however its sex-specific expression has been scarcely studied, particularly with respect to the kidney. Basal systolic blood pressure (SBP) and heart rate (HR) were measured in adult male and female mice. Renal gene expression studies of major players of mineralocorticoid signaling were performed at different developmental stages in male and female mice using reverse transcription quantitative PCR (RT-qPCR), and were compared to those of the same genes in the lung, another mineralocorticoid epithelial target tissue that regulates ion exchange and electrolyte balance. The role of sex hormones in the regulation of these genes was also investigated in differentiated KC3AC1 renal cells. Additionally, renal expression of the 11 β-hydroxysteroid dehydrogenase type 2 (11βHSD2) protein, a regulator of mineralocorticoid specificity, was measured by immunoblotting and its activity was indirectly assessed in the plasma using liquid-chromatography coupled to mass spectrometry in tandem (LC-MSMS) method. SBP and HR were found to be significantly lower in females compared to males. This was accompanied by a sex- and tissue-specific expression profile throughout renal development of the mineralocorticoid target genes serum and glucocorticoid-regulated kinase 1 (Sgk1) and glucocorticoid-induced leucine zipper protein (Gilz), together with Hsd11b2, Finally, the implication of sex hormones in this sex-specific expression profile was demonstrated in vitro, most notably for Gilz mRNA expression. We demonstrate a tissue-specific, sex-dependent and developmentally-regulated pattern of expression of the mineralocorticoid pathway that could have important implications in physiology and pathology. PMID:28230786

  4. Protein-protein interactions: an application of Tus-Ter mediated protein microarray system.

    Science.gov (United States)

    Sitaraman, Kalavathy; Chatterjee, Deb K

    2011-01-01

    In this chapter, we present a novel, cost-effective microarray strategy that utilizes expression-ready plasmid DNAs to generate protein arrays on-demand and its use to validate protein-protein interactions. These expression plasmids were constructed in such a way so as to serve a dual purpose of synthesizing the protein of interest as well as capturing the synthesized protein. The microarray system is based on the high affinity binding of Escherichia coli "Tus" protein to "Ter," a 20 bp DNA sequence involved in the regulation of DNA replication. The protein expression is carried out in a cell-free protein synthesis system, with rabbit reticulocyte lysates, and the target proteins are detected either by labeled incorporated tag specific or by gene-specific antibodies. This microarray system has been successfully used for the detection of protein-protein interaction because both the target protein and the query protein can be transcribed and translated simultaneously in the microarray slides. The utility of this system for detecting protein-protein interaction is demonstrated by a few well-known examples: Jun/Fos, FRB/FKBP12, p53/MDM2, and CDK4/p16. In all these cases, the presence of protein complexes resulted in the localization of fluorophores at the specific sites of the immobilized target plasmids. Interestingly, during our interactions studies we also detected a previously unknown interaction between CDK2 and p16. Thus, this Tus-Ter based system of protein microarray can be used for the validation of known protein interactions as well as for identifying new protein-protein interactions. In addition, it can be used to examine and identify targets of nucleic acid-protein, ligand-receptor, enzyme-substrate, and drug-protein interactions.

  5. Expression, Localization of SUMO-1, and Analyses of Potential SUMOylated Proteins in Bubalus bubalis Spermatozoa.

    Science.gov (United States)

    Brohi, Rahim Dad; Wang, Li; Hassine, Najla Ben; Cao, Jing; Talpur, Hira Sajjad; Wu, Di; Huang, Chun-Jie; Rehman, Zia-Ur; Bhattarai, Dinesh; Huo, Li-Jun

    2017-01-01

    Mature spermatozoa have highly condensed DNA that is essentially silent both transcriptionally and translationally. Therefore, post translational modifications are very important for regulating sperm motility, morphology, and for male fertility in general. Protein sumoylation was recently demonstrated in human and rodent spermatozoa, with potential consequences for sperm motility and DNA integrity. We examined the expression and localization of small ubiquitin-related modifier-1 (SUMO-1) in the sperm of water buffalo ( Bubalus bubalis ) using immunofluorescence analysis. We confirmed the expression of SUMO-1 in the acrosome. We further found that SUMO-1 was lost if the acrosome reaction was induced by calcium ionophore A23187. Proteins modified or conjugated by SUMO-1 in water buffalo sperm were pulled down and analyzed by mass spectrometry. Sixty proteins were identified, including proteins important for sperm morphology and motility, such as relaxin receptors and cytoskeletal proteins, including tubulin chains, actins, and dyneins. Forty-six proteins were predicted as potential sumoylation targets. The expression of SUMO-1 in the acrosome region of water buffalo sperm and the identification of potentially SUMOylated proteins important for sperm function implicates sumoylation as a crucial PTM related to sperm function.

  6. Expression, Localization of SUMO-1, and Analyses of Potential SUMOylated Proteins in Bubalus bubalis Spermatozoa

    Directory of Open Access Journals (Sweden)

    Rahim Dad Brohi

    2017-06-01

    Full Text Available Mature spermatozoa have highly condensed DNA that is essentially silent both transcriptionally and translationally. Therefore, post translational modifications are very important for regulating sperm motility, morphology, and for male fertility in general. Protein sumoylation was recently demonstrated in human and rodent spermatozoa, with potential consequences for sperm motility and DNA integrity. We examined the expression and localization of small ubiquitin-related modifier-1 (SUMO-1 in the sperm of water buffalo (Bubalus bubalis using immunofluorescence analysis. We confirmed the expression of SUMO-1 in the acrosome. We further found that SUMO-1 was lost if the acrosome reaction was induced by calcium ionophore A23187. Proteins modified or conjugated by SUMO-1 in water buffalo sperm were pulled down and analyzed by mass spectrometry. Sixty proteins were identified, including proteins important for sperm morphology and motility, such as relaxin receptors and cytoskeletal proteins, including tubulin chains, actins, and dyneins. Forty-six proteins were predicted as potential sumoylation targets. The expression of SUMO-1 in the acrosome region of water buffalo sperm and the identification of potentially SUMOylated proteins important for sperm function implicates sumoylation as a crucial PTM related to sperm function.

  7. Proteolysis targeting peptide (PROTAP) strategy for protein ubiquitination and degradation.

    Science.gov (United States)

    Zheng, Jing; Tan, Chunyan; Xue, Pengcheng; Cao, Jiakun; Liu, Feng; Tan, Ying; Jiang, Yuyang

    2016-02-19

    Ubiquitination proteasome pathway (UPP) is the most important and selective way to degrade proteins in vivo. Here, a novel proteolysis targeting peptide (PROTAP) strategy, composed of a target protein binding peptide, a linker and a ubiquitin E3 ligase recognition peptide, was designed to recruit both target protein and E3 ligase and then induce polyubiquitination and degradation of the target protein through UPP. In our study, the PROTAP strategy was proved to be a general method with high specificity using Bcl-xL protein as model target in vitro and in cells, which indicates that the strategy has great potential for in vivo application. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Regulation of SUMO2 Target Proteins by the Proteasome in Human Cells Exposed to Replication Stress

    DEFF Research Database (Denmark)

    Bursomanno, Sara; McGouran, Joanna F; Kessler, Benedikt M

    2015-01-01

    In human cells, SUMO2 is predominantly conjugated to target proteins in response to cellular stress. Previous studies suggested that proteins conjugated to SUMO2, but not to SUMO1, could be regulated by the ubiquitin-mediated proteasome system. Hence, we set out to understand the role...... of the proteasome in determining the fate of proteins conjugated to SUMO2 when cells are treated with DNA replication stress conditions. We conducted a quantitative proteomic analysis in a U2OS cell line stably expressing SUMO2(Q87R) tagged with StrepHA in the presence or absence of epoxomicin (EPOX), a proteasome...... inhibitor. We identified subgroups of putative SUMO2 targets that were either degraded or stabilized by EPOX upon SUMO2 conjugation in response to replication stress. Interestingly, the subgroup of proteins degraded upon SUMO2 conjugation was enriched in proteins playing roles in DNA damage repair...

  9. Protein interactions in genome maintenance as novel antibacterial targets.

    Directory of Open Access Journals (Sweden)

    Aimee H Marceau

    Full Text Available Antibacterial compounds typically act by directly inhibiting essential bacterial enzyme activities. Although this general mechanism of action has fueled traditional antibiotic discovery efforts for decades, new antibiotic development has not kept pace with the emergence of drug resistant bacterial strains. These limitations have severely restricted the therapeutic tools available for treating bacterial infections. Here we test an alternative antibacterial lead-compound identification strategy in which essential protein-protein interactions are targeted rather than enzymatic activities. Bacterial single-stranded DNA-binding proteins (SSBs form conserved protein interaction "hubs" that are essential for recruiting many DNA replication, recombination, and repair proteins to SSB/DNA nucleoprotein substrates. Three small molecules that block SSB/protein interactions are shown to have antibacterial activity against diverse bacterial species. Consistent with a model in which the compounds target multiple SSB/protein interactions, treatment of Bacillus subtilis cultures with the compounds leads to rapid inhibition of DNA replication and recombination, and ultimately to cell death. The compounds also have unanticipated effects on protein synthesis that could be due to a previously unknown role for SSB/protein interactions in translation or to off-target effects. Our results highlight the potential of targeting protein-protein interactions, particularly those that mediate genome maintenance, as a powerful approach for identifying new antibacterial compounds.

  10. Lack of A-factor production induces the expression of nutrient scavenging and stress-related proteins in Streptomyces griseus.

    Science.gov (United States)

    Birkó, Zsuzsanna; Swiatek, Magdalena; Szájli, Emília; Medzihradszky, Katalin F; Vijgenboom, Erik; Penyige, András; Keseru, Judit; van Wezel, Gilles P; Biró, Sándor

    2009-10-01

    The small gamma-butyrolactone A-factor is an important autoregulatory signaling molecule for the soil-inhabiting streptomycetes. Starvation is a major trigger for development, and nutrients are provided by degradation of the vegetative mycelium via a process of programmed cell death, reusing proteins, nucleic acids, and cell wall material. The A-factor regulon includes many extracellular hydrolases. Here we show via proteomics analysis that many nutrient-scavenging and stress-related proteins were overexpressed in an A-factor non-producing mutant of Streptomyces griseus B-2682. Transcript analysis showed that this is primarily due to differential transcription of the target genes during early development. The targets include proteins relating to nutrient stress and environmental stress and an orthologue of the Bacillus sporulation control protein Spo0M. The enhanced expression of these proteins underlines the stress that is generated by the absence of A-factor. Wild-type developmental gene expression was restored to the A-factor non-producing mutant by the signaling protein Factor C in line with our earlier observation that Factor C triggers A-factor production.

  11. WWOX protein expression varies among ovarian carcinoma histotypes and correlates with less favorable outcome

    International Nuclear Information System (INIS)

    Nunez, María I; Mills, Gordon B; Aldaz, C Marcelo; Rosen, Daniel G; Ludes-Meyers, John H; Abba, Martín C; Kil, Hyunsuk; Page, Robert; Klein-Szanto, Andres JP; Godwin, Andrew K; Liu, Jinsong

    2005-01-01

    The putative tumor suppressor WWOX gene spans the common chromosomal fragile site 16D (FRA16D) at chromosome area 16q23.3-24.1. This region is a frequent target for loss of heterozygosity and chromosomal rearrangement in ovarian, breast, hepatocellular, prostate carcinomas and other neoplasias. The goal of these studies was to evaluate WWOX protein expression levels in ovarian carcinomas to determine if they correlated with clinico-pathological parameters, thus providing additional support for WWOX functioning as a tumor suppressor. We performed WWOX protein expression analyses by means of immunobloting and immunohistochemistry on normal ovaries and specific human ovarian carcinoma Tissue Microarrays (n = 444). Univariate analysis of clinical-pathological parameters based on WWOX staining was determined by χ 2 test with Yates' correction. The basic significance level was fixed at p < 0.05. Immunoblotting analysis from normal ovarian samples demonstrated consistently strong WWOX expression while 37% ovarian carcinomas showed reduced or undetectable WWOX protein expression levels. The immunohistochemistry of normal human ovarian tissue sections confirmed strong WWOX expression in ovarian surface epithelial cells and in epithelial inclusion cysts within the cortex. Out of 444 ovarian carcinoma samples analyzed 30% of tumors showed lack of or barely detectable WWOX expression. The remaining ovarian carcinomas (70%) stained moderately to strongly positive for this protein. The two histotypes showing significant loss of WWOX expression were of the Mucinous (70%) and Clear Cell (42%) types. Reduced WWOX expression demonstrated a significant association with clinical Stage IV (FIGO) (p = 0.007), negative Progesterone Receptor (PR) status (p = 0.008) and shorter overall survival (p = 0.03). These data indicate that WWOX protein expression is highly variable among ovarian carcinoma histotypes. It was also observed that subsets of ovarian tumors demonstrated loss of

  12. Increase in DNA vaccine efficacy by virosome delivery and co-expression of a cytolytic protein.

    Science.gov (United States)

    Gargett, Tessa; Grubor-Bauk, Branka; Miller, Darren; Garrod, Tamsin; Yu, Stanley; Wesselingh, Steve; Suhrbier, Andreas; Gowans, Eric J

    2014-06-01

    The potential of DNA vaccines has not been realised due to suboptimal delivery, poor antigen expression and the lack of localised inflammation, essential for antigen presentation and an effective immune response to the immunogen. Initially, we examined the delivery of a DNA vaccine encoding a model antigen, luciferase (LUC), to the respiratory tract of mice by encapsulation in a virosome. Virosomes that incorporated influenza virus haemagglutinin effectively delivered DNA to cells in the mouse respiratory tract and resulted in antigen expression and systemic and mucosal immune responses to the immunogen after an intranasal (IN) prime/intradermal (ID) boost regimen, whereas a multidose ID regimen only generated systemic immunity. We also examined systemic immune responses to LUC after ID vaccination with a DNA vaccine, which also encoded one of the several cytolytic or toxic proteins. Although the herpes simplex virus thymidine kinase, in the presence of the prodrug, ganciclovir, resulted in cell death, this failed to increase the humoral or cell-mediated immune responses. In contrast, the co-expression of LUC with the rotavirus non-structural protein 4 (NSP4) protein or a mutant form of mouse perforin, proteins which are directly cytolytic, resulted in increased LUC-specific humoral and cell-mediated immunity. On the other hand, co-expression of LUC with diphtheria toxin subunit A or overexpression of perforin or NSP4 resulted in a lower level of immunity. In summary, the efficacy of DNA vaccines can be improved by targeted IN delivery of DNA or by the induction of cell death in vaccine-targeted cells after ID delivery.

  13. Targeted Delivery of Protein Drugs by Nanocarriers

    Directory of Open Access Journals (Sweden)

    Antonella Battisti

    2010-03-01

    Full Text Available Recent advances in biotechnology demonstrate that peptides and proteins are the basis of a new generation of drugs. However, the transportation of protein drugs in the body is limited by their high molecular weight, which prevents the crossing of tissue barriers, and by their short lifetime due to immuno response and enzymatic degradation. Moreover, the ability to selectively deliver drugs to target organs, tissues or cells is a major challenge in the treatment of several human diseases, including cancer. Indeed, targeted delivery can be much more efficient than systemic application, while improving bioavailability and limiting undesirable side effects. This review describes how the use of targeted nanocarriers such as nanoparticles and liposomes can improve the pharmacokinetic properties of protein drugs, thus increasing their safety and maximizing the therapeutic effect.

  14. Expression Profile of Stress-responsive Arabidopsis thaliana miRNAs and their Target Genes in Response to Inoculation with Pectobacterium carotovorum subsp. carotovorum.

    Science.gov (United States)

    Djami-Tchatchou, A T; Ntushelo, K

    2017-01-01

    Pectobacterium carotovorum subsp. carotovorum (Pcc) is a soft rot bacterium which upon entry into the plant macerates plant tissues by producing plant cell wall degrading enzymes. It has a wide host range which includes carrot, potato, tomato, leafy greens, squash and other cucurbits, onion, green peppers and cassava. During plant-microbe interactions, one of the ways of plant response to pathogen infection is through the small RNA silencing mechanism. Under pathogen attack the plant utilizes microRNAs to regulate gene expression by means of mediating gene silencing at transcriptional and post-transcriptional level. This study aims to assess for the first time, the expression profile of some stress-responsive miRNA and differential expression pattern of their target genes in Arabidopsis thaliana inoculated with Pcc. Leaves of five weeks old Arabidopsis thaliana plants were infected with Pcc and the quantitative real time-PCR, was used to investigate after 0, 24, 48 and 72 h post infection, the expression profiling of the stress-responsive miRNAs which include: miR156, miR159, miR169, miR393, miR396 miR398, miR399 and miR408 along with their target genes which include: Squamosa promoter-binding-like protein, myb domain protein 101, nuclear factor Y subunit A8, concanavalin A-like lectin protein kinase, growth regulating factor 4, copper superoxide dismutase, ubiquitin-protein ligase and plantacyanin respectively. The findings showed that the overexpression of 6 miRNAs at 24, 48 and 72 h after infection resulted in the repression of their target genes and the expression of 2 miRNAs didn't affect their target genes. These results provide the first indication of the miRNAs role in response to the infection of Pcc in A. thaliana and open new vistas for a better understanding of miRNA regulation of plant response to Pcc.

  15. Elevated expression of ribosomal protein genes L37, RPP-1, and S2 in the presence of mutant p53.

    Science.gov (United States)

    Loging, W T; Reisman, D

    1999-11-01

    The wild-type p53 protein is a DNA-binding transcription factor that activates genes such as p21, MDM2, GADD45, and Bax that are required for the regulation of cell cycle progression or apoptosis in response to DNA damage. Mutant forms of p53, which are transforming oncogenes and are expressed at high levels in tumor cells, generally have a reduced binding affinity for the consensus DNA sequence. Interestingly, some p53 mutants that are no longer effective at binding to the consensus DNA sequence and transactivating promoters containing this target site have acquired the ability to transform cells in culture, in part through their ability to transactivate promoters of a number of genes that are not targets of the wild-type protein. Certain p53 mutants are therefore considered to be gain-of-function mutants and appear to be promoting proliferation or transforming cells through their ability to alter the expression of novel sets of genes. Our goal is to identify genes that have altered expression in the presence of a specific mutant p53 (Arg to Trp mutation at codon 248) protein. Through examining differential gene expression in cells devoid of p53 expression and in cells that express high levels of mutant p53 protein, we have identified three ribosomal protein genes that have elevated expression in response to mutant p53. Consistent with these findings, the overexpression of a number of ribosomal protein genes in human tumors and evidence for their contribution to oncogenic transformation have been reported previously, although the mechanism leading to this overexpression has remained elusive. We show results that indicate that expression of these specific ribosomal protein genes is increased in the presence of the R248W p53 mutant, which provides a mechanism for their overexpression in human tumors.

  16. Identification of unique expression signatures and therapeutic targets in esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Yan Wusheng

    2012-01-01

    Full Text Available Abstract Background Esophageal squamous cell carcinoma (ESCC, the predominant histological subtype of esophageal cancer, is characterized by high mortality. Previous work identified important mRNA expression differences between normal and tumor cells; however, to date there are limited ex vivo studies examining expression changes occurring during normal esophageal squamous cell differentiation versus those associated with tumorigenesis. In this study, we used a unique tissue microdissection strategy and microarrays to measure gene expression profiles associated with cell differentiation versus tumorigenesis in twelve cases of patient-matched normal basal squamous epithelial cells (NB, normal differentiated squamous epithelium (ND, and squamous cell cancer. Class comparison and pathway analysis were used to compare NB versus tumor in a search for unique therapeutic targets. Results As a first step towards this goal, gene expression profiles and pathways were evaluated. Overall, ND expression patterns were markedly different from NB and tumor; whereas, tumor and NB were more closely related. Tumor showed a general decrease in differentially expressed genes relative to NB as opposed to ND that exhibited the opposite trend. FSH and IgG networks were most highly dysregulated in normal differentiation and tumorigenesis, respectively. DNA repair pathways were generally elevated in NB and tumor relative to ND indicating involvement in both normal and pathological growth. PDGF signaling pathway and 12 individual genes unique to the tumor/NB comparison were identified as therapeutic targets, and 10 associated ESCC gene-drug pairs were identified. We further examined the protein expression level and the distribution patterns of four genes: ODC1, POSTN, ASPA and IGF2BP3. Ultimately, three genes (ODC1, POSTN, ASPA were verified to be dysregulated in the same pattern at both the mRNA and protein levels. Conclusions These data reveal insight into genes and

  17. Expression of a truncated ATHB17 protein in maize increases ear weight at silking.

    Directory of Open Access Journals (Sweden)

    Elena A Rice

    Full Text Available ATHB17 (AT2G01430 is an Arabidopsis gene encoding a member of the α-subclass of the homeodomain leucine zipper class II (HD-Zip II family of transcription factors. The ATHB17 monomer contains four domains common to all class II HD-Zip proteins: a putative repression domain adjacent to a homeodomain, leucine zipper, and carboxy terminal domain. However, it also possesses a unique N-terminus not present in other members of the family. In this study we demonstrate that the unique 73 amino acid N-terminus is involved in regulation of cellular localization of ATHB17. The ATHB17 protein is shown to function as a transcriptional repressor and an EAR-like motif is identified within the putative repression domain of ATHB17. Transformation of maize with an ATHB17 expression construct leads to the expression of ATHB17Δ113, a truncated protein lacking the first 113 amino acids which encodes a significant portion of the repression domain. Because ATHB17Δ113 lacks the repression domain, the protein cannot directly affect the transcription of its target genes. ATHB17Δ113 can homodimerize, form heterodimers with maize endogenous HD-Zip II proteins, and bind to target DNA sequences; thus, ATHB17Δ113 may interfere with HD-Zip II mediated transcriptional activity via a dominant negative mechanism. We provide evidence that maize HD-Zip II proteins function as transcriptional repressors and that ATHB17Δ113 relieves this HD-Zip II mediated transcriptional repression activity. Expression of ATHB17Δ113 in maize leads to increased ear size at silking and, therefore, may enhance sink potential. We hypothesize that this phenotype could be a result of modulation of endogenous HD-Zip II pathways in maize.

  18. Expression of a truncated ATHB17 protein in maize increases ear weight at silking.

    Science.gov (United States)

    Rice, Elena A; Khandelwal, Abha; Creelman, Robert A; Griffith, Cara; Ahrens, Jeffrey E; Taylor, J Philip; Murphy, Lesley R; Manjunath, Siva; Thompson, Rebecca L; Lingard, Matthew J; Back, Stephanie L; Larue, Huachun; Brayton, Bonnie R; Burek, Amanda J; Tiwari, Shiv; Adam, Luc; Morrell, James A; Caldo, Rico A; Huai, Qing; Kouadio, Jean-Louis K; Kuehn, Rosemarie; Sant, Anagha M; Wingbermuehle, William J; Sala, Rodrigo; Foster, Matt; Kinser, Josh D; Mohanty, Radha; Jiang, Dongming; Ziegler, Todd E; Huang, Mingya G; Kuriakose, Saritha V; Skottke, Kyle; Repetti, Peter P; Reuber, T Lynne; Ruff, Thomas G; Petracek, Marie E; Loida, Paul J

    2014-01-01

    ATHB17 (AT2G01430) is an Arabidopsis gene encoding a member of the α-subclass of the homeodomain leucine zipper class II (HD-Zip II) family of transcription factors. The ATHB17 monomer contains four domains common to all class II HD-Zip proteins: a putative repression domain adjacent to a homeodomain, leucine zipper, and carboxy terminal domain. However, it also possesses a unique N-terminus not present in other members of the family. In this study we demonstrate that the unique 73 amino acid N-terminus is involved in regulation of cellular localization of ATHB17. The ATHB17 protein is shown to function as a transcriptional repressor and an EAR-like motif is identified within the putative repression domain of ATHB17. Transformation of maize with an ATHB17 expression construct leads to the expression of ATHB17Δ113, a truncated protein lacking the first 113 amino acids which encodes a significant portion of the repression domain. Because ATHB17Δ113 lacks the repression domain, the protein cannot directly affect the transcription of its target genes. ATHB17Δ113 can homodimerize, form heterodimers with maize endogenous HD-Zip II proteins, and bind to target DNA sequences; thus, ATHB17Δ113 may interfere with HD-Zip II mediated transcriptional activity via a dominant negative mechanism. We provide evidence that maize HD-Zip II proteins function as transcriptional repressors and that ATHB17Δ113 relieves this HD-Zip II mediated transcriptional repression activity. Expression of ATHB17Δ113 in maize leads to increased ear size at silking and, therefore, may enhance sink potential. We hypothesize that this phenotype could be a result of modulation of endogenous HD-Zip II pathways in maize.

  19. Expression of a Truncated ATHB17 Protein in Maize Increases Ear Weight at Silking

    Science.gov (United States)

    Creelman, Robert A.; Griffith, Cara; Ahrens, Jeffrey E.; Taylor, J. Philip; Murphy, Lesley R.; Manjunath, Siva; Thompson, Rebecca L.; Lingard, Matthew J.; Back, Stephanie L.; Larue, Huachun; Brayton, Bonnie R.; Burek, Amanda J.; Tiwari, Shiv; Adam, Luc; Morrell, James A.; Caldo, Rico A.; Huai, Qing; Kouadio, Jean-Louis K.; Kuehn, Rosemarie; Sant, Anagha M.; Wingbermuehle, William J.; Sala, Rodrigo; Foster, Matt; Kinser, Josh D.; Mohanty, Radha; Jiang, Dongming; Ziegler, Todd E.; Huang, Mingya G.; Kuriakose, Saritha V.; Skottke, Kyle; Repetti, Peter P.; Reuber, T. Lynne; Ruff, Thomas G.; Petracek, Marie E.; Loida, Paul J.

    2014-01-01

    ATHB17 (AT2G01430) is an Arabidopsis gene encoding a member of the α-subclass of the homeodomain leucine zipper class II (HD-Zip II) family of transcription factors. The ATHB17 monomer contains four domains common to all class II HD-Zip proteins: a putative repression domain adjacent to a homeodomain, leucine zipper, and carboxy terminal domain. However, it also possesses a unique N-terminus not present in other members of the family. In this study we demonstrate that the unique 73 amino acid N-terminus is involved in regulation of cellular localization of ATHB17. The ATHB17 protein is shown to function as a transcriptional repressor and an EAR-like motif is identified within the putative repression domain of ATHB17. Transformation of maize with an ATHB17 expression construct leads to the expression of ATHB17Δ113, a truncated protein lacking the first 113 amino acids which encodes a significant portion of the repression domain. Because ATHB17Δ113 lacks the repression domain, the protein cannot directly affect the transcription of its target genes. ATHB17Δ113 can homodimerize, form heterodimers with maize endogenous HD-Zip II proteins, and bind to target DNA sequences; thus, ATHB17Δ113 may interfere with HD-Zip II mediated transcriptional activity via a dominant negative mechanism. We provide evidence that maize HD-Zip II proteins function as transcriptional repressors and that ATHB17Δ113 relieves this HD-Zip II mediated transcriptional repression activity. Expression of ATHB17Δ113 in maize leads to increased ear size at silking and, therefore, may enhance sink potential. We hypothesize that this phenotype could be a result of modulation of endogenous HD-Zip II pathways in maize. PMID:24736658

  20. Sperm protein 17 is highly expressed in endometrial and cervical cancers

    International Nuclear Information System (INIS)

    Li, Fang-qiu; Liu, Qun; Han, Yan-ling; Wu, Bo; Yin, Hong-lin

    2010-01-01

    Sperm protein 17 (Sp17) is a highly conserved mammalian protein in the testis and spermatozoa and has been characterized as a tumor-associated antigen in a variety of human malignancies. Many studies have examined the role of Sp17 in tumorigenesis and the migration of malignant cells. It has been proposed as a useful target for tumor-vaccine strategies and a novel marker to define tumor subsets and predict drug response. This study aimed to investigate the expression of Sp17 in endometrial and cervical cancer specimens, its possible correlation with the pathological characteristics, and its value in the diagnosis and immunotherapy of the related cancers. The monoclonal antibodies against human Sp17 were produced as reagents for the analysis and immunohistochemistry was used to study two major kinds of paraffin-embedded gynecological cancer specimens, including 50 cases of endometrial cancer (44 adenous and 6 adenosquamous) and 31 cases of cervical cancer (15 adenous and 16 squamous). Normal peripheral endometrial and cervical tissues were used as controls. Sp17 was found in 66% (33/50) of the patients with endometrial cancer and 61% (19/31) of those with cervical cancer. Its expression was found in a heterogeneous pattern in the cancer tissues. The expression was not correlated with the histological subtype and grade of malignancy, but the staining patterns were different in endometrial and cervical cancers. The hyperplastic glands were positive for Sp17 in the normal peripheral endometrial and cervical tissues in 10% (8/81) of the patients. Sp17 is highly expressed in human endometrial and cervical cancers in a heterogeneous pattern. Although the expression frequency of Sp17 is not correlated with the histological subtype, the staining pattern may help to define endometrial and cervical cancers. Sp17 targeted immunotherapy of tumors needs more accurate validation

  1. Protective Effects of Scutellarin on Human Cardiac Microvascular Endothelial Cells against Hypoxia-Reoxygenation Injury and Its Possible Target-Related Proteins

    Directory of Open Access Journals (Sweden)

    Meina Shi

    2015-01-01

    Full Text Available Scutellarin (SCU is one of the main components of traditional Chinese medicine plant Erigeron breviscapus (Vant. Hand.-Mazz. In this paper, we studied the protective effects of SCU on human cardiac microvascular endothelial cells (HCMECs against hypoxia-reoxygenation (HR injury and its possible target-related proteins. Results of MTT assay showed that pretreatment of SCU at doses of 1, 5, and 10 μM for 2 h could significantly inhibit the decrease in cell viability of HCMECs induced by HR injury. Subcellular fractions of cells treated with vehicle control, 1 μM SCU, HR injury, or 1 μM SCU + HR injury were separated by ultracentrifugation. The protein expression profiles of cytoplasm and membrane/nuclei fractions were checked using protein two-dimensional electrophoresis (2-DE. Proteins differentially expressed between control and SCU-treated group, control and HR group, or HR and SCU + HR group were identified using mass spectrometry (MS/MS. Possible interaction network of these target-related proteins was predicted using bioinformatic analysis. The influence of SCU on the expression levels of these proteins was confirmed using Western blotting assay. The results indicated that proteins such as p27BBP protein (EIF6, heat shock 60 kDa protein 1 (HSPD1, and chaperonin containing TCP1 subunit 6A isoform (CCT6A might play important roles in the effects of SCU.

  2. Purification method for recombinant proteins based on a fusion between the target protein and the C-terminus of calmodulin

    Science.gov (United States)

    Schauer-Vukasinovic, Vesna; Deo, Sapna K.; Daunert, Sylvia

    2002-01-01

    Calmodulin (CaM) was used as an affinity tail to facilitate the purification of the green fluorescent protein (GFP), which was used as a model target protein. The protein GFP was fused to the C-terminus of CaM, and a factor Xa cleavage site was introduced between the two proteins. A CaM-GFP fusion protein was expressed in E. coli and purified on a phenothiazine-derivatized silica column. CaM binds to the phenothiazine on the column in a Ca(2+)-dependent fashion and it was, therefore, used as an affinity tail for the purification of GFP. The fusion protein bound to the affinity column was then subjected to a proteolytic digestion with factor Xa. Pure GFP was eluted with a Ca(2+)-containing buffer, while CaM was eluted later with a buffer containing the Ca(2+)-chelating agent EGTA. The purity of the isolated GFP was verified by SDS-PAGE, and the fluorescence properties of the purified GFP were characterized.

  3. A secretory system for bacterial production of high-profile protein targets

    DEFF Research Database (Denmark)

    Kotzsch, Alexander; Vernet, Erik; Hammarström, Martin

    2011-01-01

    Escherichia coli represents a robust, inexpensive expression host for the production of recombinant proteins. However, one major limitation is that certain protein classes do not express well in a biologically relevant form using standard expression approaches in the cytoplasm of E. coli. To impr......Escherichia coli represents a robust, inexpensive expression host for the production of recombinant proteins. However, one major limitation is that certain protein classes do not express well in a biologically relevant form using standard expression approaches in the cytoplasm of E. coli...... membrane protein F (OmpF) and osmotically inducible protein Y (OsmY). Based on the results of this initial study, we carried out an extended expression screen employing the OsmY fusion and multiple constructs of a more diverse set of human proteins. Using this high-throughput compatible system, we clearly...

  4. Abnormal expression of leiomyoma cytoskeletal proteins involved in cell migration.

    Science.gov (United States)

    Ura, Blendi; Scrimin, Federica; Arrigoni, Giorgio; Athanasakis, Emmanouil; Aloisio, Michelangelo; Monasta, Lorenzo; Ricci, Giuseppe

    2016-05-01

    Uterine leiomyomas are monoclonal tumors. Several factors are involved in the neoplastic transformation of the myometrium. In our study we focused on dysregulated cytoskeletal proteins in the leiomyoma as compared to the myometrium. Paired tissue samples of ten leiomyomas and adjacent myometria were obtained and analyzed by two‑dimensional gel electrophoresis (2-DE). Mass spectrometry was used for protein identification, and western blotting for 2-DE data validation. The values of ten cytoskeletal proteins were found to be significantly different: eight proteins were upregulated in the leiomyoma and two proteins were downregulated. Three of the upregulated proteins (myosin regulatory light polypeptide 9, four and a half LIM domains protein 1 and LIM and SH3 domain protein 1) are involved in cell migration, while downregulated protein transgelin is involved in replicative senescence. Myosin regulatory light polypeptide 9 (MYL9) was further validated by western blotting because it is considered to be a cell migration marker in several cancers and could play a key role in leiomyoma development. Our data demonstrate significant alterations in the expression of cytoskeletal proteins involved in leiomyoma growth. A better understanding of the involvement of cytoskeletal proteins in leiomyoma pathogenesis may contribute to the identification of new therapeutic targets and the development of new pharmacological approaches.

  5. Ovarian cancer treatment with a tumor-targeting and gene expression-controllable lipoplex

    OpenAIRE

    He, Zhi-Yao; Deng, Feng; Wei, Xia-Wei; Ma, Cui-Cui; Luo, Min; Zhang, Ping; Sang, Ya-Xiong; Liang, Xiao; Liu, Li; Qin, Han-Xiao; Shen, Ya-Li; Liu, Ting; Liu, Yan-Tong; Wang, Wei; Wen, Yan-Jun

    2016-01-01

    Overexpression of folate receptor alpha (FR?) and high telomerase activity are considered to be the characteristics of ovarian cancers. In this study, we developed FR?-targeted lipoplexes loaded with an hTERT promoter-regulated plasmid that encodes a matrix protein (MP) of the vesicular stomatitis virus, F-LP/pMP(2.5), for application in ovarian cancer treatment. We first characterized the pharmaceutical properties of F-LP/pMP(2.5). The efficient expression of the MP-driven hTERT promoter in ...

  6. Free fatty acids-sensing G protein-coupled receptors in drug targeting and therapeutics.

    Science.gov (United States)

    Yonezawa, Tomo; Kurata, Riho; Yoshida, Kaori; Murayama, Masanori A; Cui, Xiaofeng; Hasegawa, Akihiko

    2013-01-01

    G protein-coupled receptor (GPCR) (also known as seven-transmembrane domain receptor) superfamily represents the largest protein family in the human genome. These receptors respond to various physiological ligands such as photons, odors, pheromones, hormones, ions, and small molecules including amines, amino acids to large peptides and steroids. Thus, GPCRs are involved in many diseases and the target of around half of all conventional drugs. The physiological roles of free fatty acids (FFAs), in particular, long-chain FFAs, are important for the development of many metabolic disease including obesity, diabetes, and atherosclerosis. In the past half decade, deorphanization of several GPCRs has revealed that GPR40, GPR41, GPR43, GPR84 and GPR120 sense concentration of extracellular FFAs with various carbon chain lengths. GPR40 and GPR120 are activated by medium- and long-chain FFAs. GPR84 is activated by medium- chain, but not long-chain, FFAs. GPR41 and GPR43 are activated by short-chain FFAs. GPR40 is highly expressed in pancreatic beta cells and plays a crucial role in FFAs-induced insulin secretion. GPR120 is mainly expressed in enteroendocrine cells and plays an important role for FFAs-induced glucagon-like peptide-1. GPR43 is abundant in leukocytes and adipose tissue, whilst GPR41 is highly expressed in adipose tissue, the pancreas and leukocytes. GPR84 is expressed in leukocytes and monocyte/macrophage. This review aims to shed light on the physiological roles and development of drugs targeting these receptors.

  7. Cell-Free Systems Based on CHO Cell Lysates: Optimization Strategies, Synthesis of "Difficult-to-Express" Proteins and Future Perspectives.

    Directory of Open Access Journals (Sweden)

    Lena Thoring

    Full Text Available Nowadays, biotechnological processes play a pivotal role in target protein production. In this context, Chinese Hamster Ovary (CHO cells are one of the most prominent cell lines for the expression of recombinant proteins and revealed as a safe host for nearly 40 years. Nevertheless, the major bottleneck of common in vivo protein expression platforms becomes obvious when looking at the production of so called "difficult-to-express" proteins. This class of proteins comprises in particular several ion channels and multipass membrane proteins as well as cytotoxic proteins. To enhance the production of "difficult-to-express" proteins, alternative technologies were developed, mainly based on translationally active cell lysates. These so called "cell-free" protein synthesis systems enable an efficient production of different classes of proteins. Eukaryotic cell-free systems harboring endogenous microsomal structures for the synthesis of functional membrane proteins and posttranslationally modified proteins are of particular interest for future applications. Therefore, we present current developments in cell-free protein synthesis based on translationally active CHO cell extracts, underlining the high potential of this platform. We present novel results highlighting the optimization of protein yields, the synthesis of various "difficult-to-express" proteins and the cotranslational incorporation of non-standard amino acids, which was exemplarily demonstrated by residue specific labeling of the glycoprotein Erythropoietin and the multimeric membrane protein KCSA.

  8. A proteomic screen reveals the mitochondrial outer membrane protein Mdm34p as an essential target of the F-box protein Mdm30p.

    Science.gov (United States)

    Ota, Kazuhisa; Kito, Keiji; Okada, Satoshi; Ito, Takashi

    2008-10-01

    Ubiquitination plays various critical roles in eukaryotic cellular regulation and is mediated by a cascade of enzymes including ubiquitin protein ligase (E3). The Skp1-Cullin-F-box protein complex comprises the largest E3 family, in each member of which a unique F-box protein binds its targets to define substrate specificity. Although genome sequencing uncovers a growing number of F-box proteins, most of them have remained as "orphans" because of the difficulties in identification of their substrates. To address this issue, we tested a quantitative proteomic approach by combining the stable isotope labeling by amino acids in cell culture (SILAC), parallel affinity purification (PAP) that we had developed for efficient enrichment of ubiquitinated proteins, and mass spectrometry (MS). We applied this SILAC-PAP-MS approach to compare ubiquitinated proteins between yeast cells with and without over-expressed Mdm30p, an F-box protein implicated in mitochondrial morphology. Consequently, we identified the mitochondrial outer membrane protein Mdm34p as a target of Mdm30p. Furthermore, we found that mitochondrial defects induced by deletion of MDM30 are not only recapitulated by a mutant Mdm34p defective in interaction with Mdm30p but alleviated by ubiquitination-mimicking forms of Mdm34p. These results indicate that Mdm34p is a physiologically important target of Mdm30p.

  9. Human Sterol Regulatory Element-Binding Protein 1a Contributes Significantly to Hepatic Lipogenic Gene Expression

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    Andreas Bitter

    2015-01-01

    Full Text Available Background/Aims: Sterol regulatory element-binding protein (SREBP 1, the master regulator of lipogenesis, was shown to be associated with non-alcoholic fatty liver disease, which is attributed to its major isoform SREBP1c. Based on studies in mice, the minor isoform SREBP1a is regarded as negligible for hepatic lipogenesis. This study aims to elucidate the expression and functional role of SREBP1a in human liver. Methods: mRNA expression of both isoforms was quantified in cohorts of human livers and primary human hepatocytes. Hepatocytes were treated with PF-429242 to inhibit the proteolytic activation of SREBP precursor protein. SREBP1a-specifc and pan-SREBP1 knock-down were performed by transfection of respective siRNAs. Lipogenic SREBP-target gene expression was analyzed by real-time RT-PCR. Results: In human liver, SREBP1a accounts for up to half of the total SREBP1 pool. Treatment with PF-429242 indicated SREBP-dependent auto-regulation of SREBP1a, which however was much weaker than of SREBP1c. SREBP1a-specifc knock-down also reduced significantly the expression of SREBP1c and of SREBP-target genes. Regarding most SREBP-target genes, simultaneous knock-down of both isoforms resulted in effects of only similar extent as SREBP1a-specific knock-down. Conclusion: We here showed that SREBP1a is significantly contributing to the human hepatic SREBP1 pool and has a share in human hepatic lipogenic gene expression.

  10. Monoubiquitination of Tob/BTG family proteins competes with degradation-targeting polyubiquitination

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Toru, E-mail: toru@ims.u-tokyo.ac.jp [Division of Oncology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Kim, Minsoo [Division of Bacterial Infection, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Kozuka-Hata, Hiroko [Medical Proteomics Laboratory, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Watanabe, Masato [Department of Medical Genome Science, School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562 (Japan); Oyama, Masaaki [Medical Proteomics Laboratory, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Tsumoto, Kouhei [Medical Proteomics Laboratory, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Department of Medical Genome Science, School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8562 (Japan); Yamamoto, Tadashi, E-mail: tyamamot@ims.u-tokyo.ac.jp [Division of Oncology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Cell Signal Unit, Okinawa Institute of Science and Technology, 1919-1 Onna-son, Kunigami, Okinawa 904-0412 (Japan)

    2011-05-27

    Highlights: {yields} Tob/BTG family proteins are monoubiquitinated in the absence of E3s in vitro. {yields} Monoubiquitination sites of Tob are identified by mass spectrometry. {yields} The monoubiquitination event correlates with lower levels of polyubiquitination. -- Abstract: Tob belongs to the anti-proliferative Tob/BTG protein family. The expression level of Tob family proteins is strictly regulated both transcriptionally and through post-translational modification. Ubiquitin (Ub)/proteosome-dependent degradation of Tob family proteins is critical in controlling cell cycle progression and DNA damage responses. Various Ub ligases (E3s) are responsible for degradation of Tob protein. Here, we show that Tob family proteins undergo monoubiquitination even in the absence of E3s in vitro. Determination of the ubiquitination site(s) in Tob by mass spectrometric analysis revealed that two lysine residues (Lys48 and Lys63) located in Tob/BTG homology domain are ubiquitinated. A mutant Tob, in which both Lys48 and Lys63 are substituted with alanine, is more strongly polyubiquitinated than wild-type Tob in vivo. These data suggest that monoubiquitination of Tob family proteins confers resistance against polyubiquitination, which targets proteins for degradation. The strategy for regulating the stability of Tob family proteins suggests a novel role for monoubiquitination.

  11. Monoubiquitination of Tob/BTG family proteins competes with degradation-targeting polyubiquitination

    International Nuclear Information System (INIS)

    Suzuki, Toru; Kim, Minsoo; Kozuka-Hata, Hiroko; Watanabe, Masato; Oyama, Masaaki; Tsumoto, Kouhei; Yamamoto, Tadashi

    2011-01-01

    Highlights: → Tob/BTG family proteins are monoubiquitinated in the absence of E3s in vitro. → Monoubiquitination sites of Tob are identified by mass spectrometry. → The monoubiquitination event correlates with lower levels of polyubiquitination. -- Abstract: Tob belongs to the anti-proliferative Tob/BTG protein family. The expression level of Tob family proteins is strictly regulated both transcriptionally and through post-translational modification. Ubiquitin (Ub)/proteosome-dependent degradation of Tob family proteins is critical in controlling cell cycle progression and DNA damage responses. Various Ub ligases (E3s) are responsible for degradation of Tob protein. Here, we show that Tob family proteins undergo monoubiquitination even in the absence of E3s in vitro. Determination of the ubiquitination site(s) in Tob by mass spectrometric analysis revealed that two lysine residues (Lys48 and Lys63) located in Tob/BTG homology domain are ubiquitinated. A mutant Tob, in which both Lys48 and Lys63 are substituted with alanine, is more strongly polyubiquitinated than wild-type Tob in vivo. These data suggest that monoubiquitination of Tob family proteins confers resistance against polyubiquitination, which targets proteins for degradation. The strategy for regulating the stability of Tob family proteins suggests a novel role for monoubiquitination.

  12. Filling and mining the reactive metabolite target protein database.

    Science.gov (United States)

    Hanzlik, Robert P; Fang, Jianwen; Koen, Yakov M

    2009-04-15

    The post-translational modification of proteins is a well-known endogenous mechanism for regulating protein function and activity. Cellular proteins are also susceptible to post-translational modification by xenobiotic agents that possess, or whose metabolites possess, significant electrophilic character. Such non-physiological modifications to endogenous proteins are sometimes benign, but in other cases they are strongly associated with, and are presumed to cause, lethal cytotoxic consequences via necrosis and/or apoptosis. The Reactive Metabolite Target Protein Database (TPDB) is a searchable, freely web-accessible (http://tpdb.medchem.ku.edu:8080/protein_database/) resource that attempts to provide a comprehensive, up-to-date listing of known reactive metabolite target proteins. In this report we characterize the TPDB by reviewing briefly how the information it contains came to be known. We also compare its information to that provided by other types of "-omics" studies relevant to toxicology, and we illustrate how bioinformatic analysis of target proteins may help to elucidate mechanisms of cytotoxic responses to reactive metabolites.

  13. MicroRNA-338 inhibits growth, invasion and metastasis of gastric cancer by targeting NRP1 expression.

    Directory of Open Access Journals (Sweden)

    Yang Peng

    Full Text Available NRP1 as multifunctional non-tyrosine-kinase receptors play critical roles in tumor progression. MicroRNAs (miRNAs are an important class of pervasive genes that are involved in a variety of biological functions, particularly cancer. It remains unclear whether miRNAs can regulate the expression of NRP1. The goal of this study was to identify miRNAs that could inhibit the growth, invasion and metastasis of gastric cancer by targeting NRP1 expression. We found that miR-338 expression was reduced in gastric cancer cell lines and in gastric cancer tissues. Moreover, we found that miR-338 inhibited gastric cancer cell migration, invasion, proliferation and promoted apoptosis by targeting NRP1 expression. As an upstream regulator of NRP1, miR-338 directly targets NRP1. The forced expression of miR-338 inhibited the phosphorylation of Erk1/2, P38 MAPK and Akt; however, the expression of phosphorylated Erk1/2, P38 MAPK and Akt was restored by the overexpression of NRP1. In AGS cells infected with miR-338 or transfected with SiNRP1, the protein levels of fibronectin, vimentin, N-cadherin and SNAIL were decreased, but the expression of E-cadherin was increased. The expression of mesenchymal markers in miR-338-expressing cells was restored to normal levels by the restoration of NRP1 expression. In vivo, miR-338 also decreased tumor growth and suppressed D-MVA by targeting NRP1. Therefore, we conclude that miR-338 acts as a novel tumor suppressor gene in gastric cancer. miR-338 can decrease migratory, invasive, proliferative and apoptotic behaviors, as well as gastric cancer EMT, by attenuating the expression of NRP1.

  14. PDTD: a web-accessible protein database for drug target identification

    Directory of Open Access Journals (Sweden)

    Gao Zhenting

    2008-02-01

    Full Text Available Abstract Background Target identification is important for modern drug discovery. With the advances in the development of molecular docking, potential binding proteins may be discovered by docking a small molecule to a repository of proteins with three-dimensional (3D structures. To complete this task, a reverse docking program and a drug target database with 3D structures are necessary. To this end, we have developed a web server tool, TarFisDock (Target Fishing Docking http://www.dddc.ac.cn/tarfisdock, which has been used widely by others. Recently, we have constructed a protein target database, Potential Drug Target Database (PDTD, and have integrated PDTD with TarFisDock. This combination aims to assist target identification and validation. Description PDTD is a web-accessible protein database for in silico target identification. It currently contains >1100 protein entries with 3D structures presented in the Protein Data Bank. The data are extracted from the literatures and several online databases such as TTD, DrugBank and Thomson Pharma. The database covers diverse information of >830 known or potential drug targets, including protein and active sites structures in both PDB and mol2 formats, related diseases, biological functions as well as associated regulating (signaling pathways. Each target is categorized by both nosology and biochemical function. PDTD supports keyword search function, such as PDB ID, target name, and disease name. Data set generated by PDTD can be viewed with the plug-in of molecular visualization tools and also can be downloaded freely. Remarkably, PDTD is specially designed for target identification. In conjunction with TarFisDock, PDTD can be used to identify binding proteins for small molecules. The results can be downloaded in the form of mol2 file with the binding pose of the probe compound and a list of potential binding targets according to their ranking scores. Conclusion PDTD serves as a comprehensive and

  15. Differences in IGF-axis protein expression and survival among multiethnic breast cancer patients

    International Nuclear Information System (INIS)

    Hernandez, Brenda Y; Wilkens, Lynne R; Le Marchand, Loïc; Horio, David; Chong, Clayton D; Loo, Lenora W M

    2015-01-01

    There is limited knowledge about the biological basis of racial/ethnic disparities in breast cancer outcomes. Aberrations in IGF signaling induced by obesity and other factors may contribute to these disparities. This study examines the expression profiles of the insulin-like growth factor (IGF)-axis proteins and the association with breast cancer survival across a multiethnic population. We examined the expression profiles of the IGF1, IGF1R, IGFBP2 (IGF-binding proteins), and IGFBP3 proteins in breast tumor tissue and their relationships with all-cause and breast cancer-specific survival up to 17 years postdiagnosis in a multiethnic series of 358 patients in Hawaii, USA. Native Hawaiians, Caucasians, and Japanese were compared. Covariates included demographic and clinical factors and ER/PR/HER2 (estrogen receptor/progesterone receptor/human epidermal growth factor receptor-2) status. In Native Hawaiian patients, IGFBP2 and IGFBP3 expression were each independently associated with overall and breast cancer mortality (IGFB2: HR mort = 10.96, 95% CI: 2.18–55.19 and HR mort = 35.75, 95% CI: 3.64–350.95, respectively; IGFBP3: HR mort = 5.16, 95% CI: 1.27–20.94 and HR mort = 8.60, 95% CI: 1.84–40.15, respectively). IGF1R expression was also positively associated with all-cause mortality in Native Hawaiians. No association of IGF-axis protein expression and survival was observed in Japanese or Caucasian patients. The interaction of race/ethnicity and IGFBP3 expression on mortality risk was significant. IGF-axis proteins may have variable influence on breast cancer progression across different racial/ethnic groups. Expression of binding proteins and receptors in breast tumors may influence survival in breast cancer patients by inducing aberrations in IGF signaling and/or through IGF-independent mechanisms. Additional studies to evaluate the role of the IGF-axis in breast cancer are critical to improve targeted breast cancer treatment strategies

  16. Identification of membrane-associated proteins with pathogenic potential expressed by Corynebacterium pseudotuberculosis grown in animal serum.

    Science.gov (United States)

    Raynal, José Tadeu; Bastos, Bruno Lopes; Vilas-Boas, Priscilla Carolinne Bagano; Sousa, Thiago de Jesus; Costa-Silva, Marcos; de Sá, Maria da Conceição Aquino; Portela, Ricardo Wagner; Moura-Costa, Lília Ferreira; Azevedo, Vasco; Meyer, Roberto

    2018-01-25

    Previous works defining antigens that might be used as vaccine targets against Corynebacterium pseudotuberculosis, which is the causative agent of sheep and goat caseous lymphadenitis, have focused on secreted proteins produced in a chemically defined culture media. Considering that such antigens might not reflect the repertoire of proteins expressed during infection conditions, this experiment aimed to investigate the membrane-associated proteins with pathogenic potential expressed by C. pseudotuberculosis grown directly in animal serum. Its membrane-associated proteins have been extracted using an organic solvent enrichment methodology, followed by LC-MS/MS and bioinformatics analysis for protein identification and classification. The results revealed 22 membrane-associated proteins characterized as potentially pathogenic. An interaction network analysis indicated that the four potentially pathogenic proteins ciuA, fagA, OppA4 and OppCD were biologically connected within two distinct network pathways, which were both associated with the ABC Transporters KEGG pathway. These results suggest that C. pseudotuberculosis pathogenesis might be associated with the transport and uptake of nutrients; other seven identified potentially pathogenic membrane proteins also suggest that pathogenesis might involve events of bacterial resistance and adhesion. The proteins herein reported potentially reflect part of the protein repertoire expressed during real infection conditions and might be tested as vaccine antigens.

  17. Targeting Mycobacterium tuberculosis nucleoid-associated protein HU with structure-based inhibitors

    Science.gov (United States)

    Bhowmick, Tuhin; Ghosh, Soumitra; Dixit, Karuna; Ganesan, Varsha; Ramagopal, Udupi A.; Dey, Debayan; Sarma, Siddhartha P.; Ramakumar, Suryanarayanarao; Nagaraja, Valakunja

    2014-06-01

    The nucleoid-associated protein HU plays an important role in maintenance of chromosomal architecture and in global regulation of DNA transactions in bacteria. Although HU is essential for growth in Mycobacterium tuberculosis (Mtb), there have been no reported attempts to perturb HU function with small molecules. Here we report the crystal structure of the N-terminal domain of HU from Mtb. We identify a core region within the HU-DNA interface that can be targeted using stilbene derivatives. These small molecules specifically inhibit HU-DNA binding, disrupt nucleoid architecture and reduce Mtb growth. The stilbene inhibitors induce gene expression changes in Mtb that resemble those induced by HU deficiency. Our results indicate that HU is a potential target for the development of therapies against tuberculosis.

  18. Virtual target screening to rapidly identify potential protein targets of natural products in drug discovery

    Directory of Open Access Journals (Sweden)

    Yuri Pevzner

    2014-05-01

    Full Text Available Inherent biological viability and diversity of natural products make them a potentially rich source for new therapeutics. However, identification of bioactive compounds with desired therapeutic effects and identification of their protein targets is a laborious, expensive process. Extracts from organism samples may show desired activity in phenotypic assays but specific bioactive compounds must be isolated through further separation methods and protein targets must be identified by more specific phenotypic and in vitro experimental assays. Still, questions remain as to whether all relevant protein targets for a compound have been identified. The desire is to understand breadth of purposing for the compound to maximize its use and intellectual property, and to avoid further development of compounds with insurmountable adverse effects. Previously we developed a Virtual Target Screening system that computationally screens one or more compounds against a collection of virtual protein structures. By scoring each compound-protein interaction, we can compare against averaged scores of synthetic drug-like compounds to determine if a particular protein would be a potential target of a compound of interest. Here we provide examples of natural products screened through our system as we assess advantages and shortcomings of our current system in regards to natural product drug discovery.

  19. Virtual target screening to rapidly identify potential protein targets of natural products in drug discovery

    Directory of Open Access Journals (Sweden)

    Yuri Pevzner

    2015-08-01

    Full Text Available Inherent biological viability and diversity of natural products make them a potentially rich source for new therapeutics. However, identification of bioactive compounds with desired therapeutic effects and identification of their protein targets is a laborious, expensive process. Extracts from organism samples may show desired activity in phenotypic assays but specific bioactive compounds must be isolated through further separation methods and protein targets must be identified by more specific phenotypic and in vitro experimental assays. Still, questions remain as to whether all relevant protein targets for a compound have been identified. The desire is to understand breadth of purposing for the compound to maximize its use and intellectual property, and to avoid further development of compounds with insurmountable adverse effects. Previously we developed a Virtual Target Screening system that computationally screens one or more compounds against a collection of virtual protein structures. By scoring each compound-protein interaction, we can compare against averaged scores of synthetic drug-like compounds to determine if a particular protein would be a potential target of a compound of interest. Here we provide examples of natural products screened through our system as we assess advantages and shortcomings of our current system in regards to natural product drug discovery.

  20. Determination of Six Transmembrane Protein of Prostate 2 Gene Expression and Intracellular Localization in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Bora İrer

    2017-12-01

    Full Text Available Objective: In this study, we aimed to determine the relationship between the RNA and protein expression profile of six transmembrane protein of prostate 2 (STAMP2 gene and androgen and the intracellular localization of STAMP2. Materials and Methods: RNA and protein were obtained from androgen treated lymph node carcinoma of the prostate (LNCaP cells, untreated LNCaP cells, DU145 cells with no androgen receptor, and STAMP2 transfected COS-7 cells. The expression profile of STAMP2 gene and the effect of androgenes on the expression was shown in RNA and protein levels by using Northern and Western blotting methods. In addition, intracellular localization of the naturally synthesized STAMP2 protein and the transfected STAMP2 protein in COS-7 cells after androgen administration in both LNCaP cells was determined by immunofluorescence microscopy. Results: We found that the RNA and protein expression of STAMP2 gene in LNCaP cells are regulated by androgenes, the power of expression is increased with the duration of androgen treatment and there is no STAMP2 expression in DU145 cells which has no androgen receptor. As a result of the immunofluorescence microscopy study we observed that STAMP2 protein was localized at golgi complex and cell membrane. Conclusion: In conclusion, we have demonstrated that STAMP2 may play an important role in the pathogenesis of the prostate cancer and in the androgen-dependent androgen-independent staging of prostate cancer. In addition, STAMP2 protein, which is localized in the intracellular golgi complex and cell membrane, may be a new target molecule for prostate cancer diagnosis and treatment.

  1. Predictable tuning of protein expression in bacteria

    DEFF Research Database (Denmark)

    Bonde, Mads; Pedersen, Margit; Klausen, Michael Schantz

    2016-01-01

    We comprehensively assessed the contribution of the Shine-Dalgarno sequence to protein expression and used the data to develop EMOPEC (Empirical Model and Oligos for Protein Expression Changes; http://emopec.biosustain.dtu.dk). EMOPEC is a free tool that makes it possible to modulate the expressi...

  2. Protein Expression Analyses at the Single Cell Level

    Directory of Open Access Journals (Sweden)

    Masae Ohno

    2014-09-01

    Full Text Available The central dogma of molecular biology explains how genetic information is converted into its end product, proteins, which are responsible for the phenotypic state of the cell. Along with the protein type, the phenotypic state depends on the protein copy number. Therefore, quantification of the protein expression in a single cell is critical for quantitative characterization of the phenotypic states. Protein expression is typically a dynamic and stochastic phenomenon that cannot be well described by standard experimental methods. As an alternative, fluorescence imaging is being explored for the study of protein expression, because of its high sensitivity and high throughput. Here we review key recent progresses in fluorescence imaging-based methods and discuss their application to proteome analysis at the single cell level.

  3. Expression of RIZ1 protein (Retinoblastoma-interacting zinc-finger protein 1) in prostate cancer epithelial cells changes with cancer grade progression and is modulated in vitro by DHT and E2.

    Science.gov (United States)

    Rossi, Valentina; Staibano, Stefania; Abbondanza, Ciro; Pasquali, Daniela; De Rosa, Caterina; Mascolo, Massimo; Bellastella, Giuseppe; Visconti, Daniela; De Bellis, Annamaria; Moncharmont, Bruno; De Rosa, Gaetano; Puca, Giovanni Alfredo; Bellastella, Antonio; Sinisi, Antonio Agostino

    2009-12-01

    The nuclear protein methyl-transferase Retinoblastoma-interacting zinc-finger protein 1 (RIZ1) is considered to be a downstream effector of estrogen action in target tissues. Silencing of RIZ1 expression is common in many tumors. We analyzed RIZ1 expression in normal and malignant prostate tissue and evaluated whether estradiol (E2) or dihydrotestosterone (DHT) treatment modulated RIZ1 in cultured prostate epithelial cells (PEC). Moreover, we studied the possible involvement of RIZ1 in estrogen action on the EPN prostate cell line, constitutively expressing both estrogen receptor (ER)-alpha and beta. RIZ1 protein, found in the nucleus of normal PECs by immunohistochemistry, was progressively lost in cancer tissues as the Gleason score increased and was only detected in the cytoplasmic compartment. RIZ1 transcript levels, as assayed by semi-quantitative RT-PCR in primary PEC cultures, were significantly reduced in cancer cells (P DHT treatment significantly increased RIZ1 transcript and protein levels (P DHT or E2 treatment in vitro. Furthermore, the E2 effects on ER-expressing prostate cells involve RIZ1, which confirms a possible role for ER-mediated pathways in a non-classic E(2)-target tissue.

  4. Nutlin-3 down-regulates retinoblastoma protein expression and inhibits muscle cell differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Erica M. [Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 (United States); Niu, MengMeng; Bergholz, Johann [Center of Growth, Metabolism and Aging, College of Life Sciences, Sichuan University, Chengdu, 610014 China (China); Jim Xiao, Zhi-Xiong, E-mail: jxiao@bu.edu [Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 (United States); Center of Growth, Metabolism and Aging, College of Life Sciences, Sichuan University, Chengdu, 610014 China (China)

    2015-05-29

    The p53 tumor suppressor gene plays a critical role in regulation of proliferation, cell death and differentiation. The MDM2 oncoprotein is a major negative regulator for p53 by binding to and targeting p53 for proteasome-mediated degradation. The small molecule inhibitor, nutlin-3, disrupts MDM2-p53 interaction resulting in stabilization and activation of p53 protein. We have previously shown that nutlin-3 activates p53, leading to MDM2 accumulation as concomitant of reduced retinoblastoma (Rb) protein stability. It is well known that Rb is important in muscle development and myoblast differentiation and that rhabdomyosarcoma (RMS), or cancer of the skeletal muscle, typically harbors MDM2 amplification. In this study, we show that nutlin-3 inhibited myoblast proliferation and effectively prevented myoblast differentiation, as evidenced by lack of expression of muscle differentiation markers including myogenin and myosin heavy chain (MyHC), as well as a failure to form multinucleated myotubes, which were associated with dramatic increases in MDM2 expression and decrease in Rb protein levels. These results indicate that nutlin-3 can effectively inhibit muscle cell differentiation. - Highlights: • Nutlin-3 inhibits myoblast proliferation and prevents differentiation into myotubes. • Nutlin-3 increases MDM2 expression and down-regulates Rb protein levels. • This study has implication in nutlin-3 treatment of rhabdomyosarcomas.

  5. Roles of silkworm endoplasmic reticulum chaperones in the secretion of recombinant proteins expressed by baculovirus system.

    Science.gov (United States)

    Imai, Saki; Kusakabe, Takahiro; Xu, Jian; Li, Zhiqing; Shirai, Shintaro; Mon, Hiroaki; Morokuma, Daisuke; Lee, Jae Man

    2015-11-01

    Baculovirus expression vector system (BEVS) is widely used for production of recombinant eukaryotic proteins in insect larvae or cultured cells. BEVS has advantages over bacterial expression system in producing post-translationally modified secreted proteins. However, for some unknown reason, it is very difficult for insects to secrete sufficiently for certain proteins of interest. To understand the reasons why insect cells fail to secrete some kinds of recombinant proteins, we here employed three mammalian proteins as targets, EPO, HGF, and Wnt3A, with different secretion levels in BEVS and investigated their mRNA transcriptions from the viral genome, subcellular localizations, and interactions with silkworm ER chaperones. Moreover, we observed that no significantly influence on the secretion amounts of all three proteins when depleting or overexpressing most endogenous ER chaperone genes in cultured silkworm cells. However, among all detected ER chaperones, the depletion of BiP severely decreased the recombinant protein secretion in BEVS, indicating the possible central role of Bip in silkworm secretion pathway.

  6. FOXO1 is a direct target of EWS-Fli1 oncogenic fusion protein in Ewing's sarcoma cells

    International Nuclear Information System (INIS)

    Yang, Liu; Hu, Hsien-Ming; Zielinska-Kwiatkowska, Anna; Chansky, Howard A.

    2010-01-01

    Research highlights: → Inducible and reversible siRNA knockdown of an oncogenic fusion protein such as EWS-Fli1 is feasible and more advantageous than other siRNA methods. → The tumor suppressor gene FOXO1 is a new EWS-Fli1 target. → While trans-activators are known for the FOXO1 gene, there has been no report on negative regulators of FOXO1 transcription. → This study provides first evidence that the EWS-Fli1 oncogenic fusion protein can function as a transcriptional repressor of the FOXO1 gene. -- Abstract: Ewing's family tumors are characterized by a specific t(11;22) chromosomal translocation that results in the formation of EWS-Fli1 oncogenic fusion protein. To investigate the effects of EWS-Fli1 on gene expression, we carried out DNA microarray analysis after specific knockdown of EWS-Fli1 through transfection of synthetic siRNAs. EWS-Fli1 knockdown increased expression of genes such as DKK1 and p57 that are known to be repressed by EWS-Fli1 fusion protein. Among other potential EWS-Fli1 targets identified by our microarray analysis, we have focused on the FOXO1 gene since it encodes a potential tumor suppressor and has not been previously reported in Ewing's cells. To better understand how EWS-Fli1 affects FOXO1 expression, we have established a doxycycline-inducible siRNA system to achieve stable and reversible knockdown of EWS-Fli1 in Ewing's sarcoma cells. Here we show that FOXO1 expression in Ewing's cells has an inverse relationship with EWS-Fli1 protein level, and FOXO1 promoter activity is increased after doxycycline-induced EWS-Fli1 knockdown. In addition, we have found that direct binding of EWS-Fli1 to FOXO1 promoter is attenuated after doxycycline-induced siRNA knockdown of the fusion protein. Together, these results suggest that suppression of FOXO1 function by EWS-Fli1 fusion protein may contribute to cellular transformation in Ewing's family tumors.

  7. Bioinformatic analysis of xenobiotic reactive metabolite target proteins and their interacting partners

    Directory of Open Access Journals (Sweden)

    Hanzlik Robert P

    2009-06-01

    Full Text Available Abstract Background Protein covalent binding by reactive metabolites of drugs, chemicals and natural products can lead to acute cytotoxicity. Recent rapid progress in reactive metabolite target protein identification has shown that adduction is surprisingly selective and inspired the hope that analysis of target proteins might reveal protein factors that differentiate target- vs. non-target proteins and illuminate mechanisms connecting covalent binding to cytotoxicity. Results Sorting 171 known reactive metabolite target proteins revealed a number of GO categories and KEGG pathways to be significantly enriched in targets, but in most cases the classes were too large, and the "percent coverage" too small, to allow meaningful conclusions about mechanisms of toxicity. However, a similar analysis of the directlyinteracting partners of 28 common targets of multiple reactive metabolites revealed highly significant enrichments in terms likely to be highly relevant to cytotoxicity (e.g., MAP kinase pathways, apoptosis, response to unfolded protein. Machine learning was used to rank the contribution of 211 computed protein features to determining protein susceptibility to adduction. Protein lysine (but not cysteine content and protein instability index (i.e., rate of turnover in vivo were among the features most important to determining susceptibility. Conclusion As yet there is no good explanation for why some low-abundance proteins become heavily adducted while some abundant proteins become only lightly adducted in vivo. Analyzing the directly interacting partners of target proteins appears to yield greater insight into mechanisms of toxicity than analyzing target proteins per se. The insights provided can readily be formulated as hypotheses to test in future experimental studies.

  8. Targeting of OSBP-related protein 3 (ORP3) to endoplasmic reticulum and plasma membrane is controlled by multiple determinants

    International Nuclear Information System (INIS)

    Lehto, Markku; Hynynen, Riikka; Karjalainen, Katja; Kuismanen, Esa; Hyvaerinen, Kati; Olkkonen, Vesa M.

    2005-01-01

    The intracellular targeting determinants of oxysterol binding protein (OSBP)-related protein 3 (ORP3) were studied using a series of truncated and point mutated constructs. The pleckstrin homology (PH) domain of ORP3 binds the phosphoinositide-3-kinase (PI3K) products, PI(3,4)P 2 and PI(3,4,5)P 3 . A functional PH domain and flanking sequences are crucial for the plasma membrane (PM) targeting of ORP3. The endoplasmic reticulum (ER) targeting of ORP3 is regulated the by a FFAT motif (EFFDAxE), which mediates interaction with VAMP-associated protein (VAP)-A. The targeting function of the FFAT motif dominates over that of the PH domain. In addition, the exon 10/11 region modulates interaction of ORP3 with the ER and the nuclear membrane. Analysis of a chimeric ORP3:OSBP protein suggests that ligand binding by the C-terminal domain of OSBP induces allosteric changes that activate the N-terminal targeting modules of ORP3. Notably, over-expression of ORP3 together with VAP-A induces stacked ER membrane structures also known as organized smooth ER (OSER). Moreover, lipid starvation promotes formation of dilated peripheral ER (DPER) structures dependent on the ORP3 protein. Based on the present data, we introduce a model for the inter-relationships of the functional domains of ORP3 in the membrane targeting of the protein

  9. Coculture of Bifidobacterium longum and Bifidobacterium breve alters their protein expression profiles and enzymatic activities.

    Science.gov (United States)

    Ruiz, Lorena; Sánchez, Borja; de Los Reyes-Gavilán, Clara G; Gueimonde, Miguel; Margolles, Abelardo

    2009-07-31

    Some strains of the genus Bifidobacterium are probiotic bacteria commonly added to functional dairy products. The influence of coculturing Bifidobacterium longum NCIMB8809 and Bifidobacterium breve NCIMB8807 on their physiology was studied. 2DE separation of protein extracts, coupled to MS protein analysis allowed the identification of 16 proteins whose expression drastically changed when cells were grown in compartmentalized coculture, compared to monoculture. These included ribosomal proteins and proteins involved in carbohydrate metabolism, gene regulation, cell envelope biogenesis and transport processes. Significant changes in some glycoside-hydrolysing activities (beta-d-xylopyranosidase, alpha-l-arabinofuranosidase and beta-d-glucopyranosidase) were also detected. Furthermore, qRT-PCR experiments using as targets the B. breve genes clgR (transcriptional regulator) clpP1, clpP2 and clpC (chaperone- and protease-encoding genes positively regulated by clgR) supported the proteomic results, the four genes displaying a higher expression level in coculture. This study provides new insights to understand the communication among Bifidobacterium species.

  10. Identification of BAG3 target proteins in anaplastic thyroid cancer cells by proteomic analysis.

    Science.gov (United States)

    Galdiero, Francesca; Bello, Anna Maria; Spina, Anna; Capiluongo, Anna; Liuu, Sophie; De Marco, Margot; Rosati, Alessandra; Capunzo, Mario; Napolitano, Maria; Vuttariello, Emilia; Monaco, Mario; Califano, Daniela; Turco, Maria Caterina; Chiappetta, Gennaro; Vinh, Joëlle; Chiappetta, Giovanni

    2018-01-30

    BAG3 protein is an apoptosis inhibitor and is highly expressed in Anaplastic Thyroid Cancer. We investigated the entire set of proteins modulated by BAG3 silencing in the human anaplastic thyroid 8505C cancer cells by using the Stable-Isotope Labeling by Amino acids in Cell culture strategy combined with mass spectrometry analysis. By this approach we identified 37 up-regulated and 54 down-regulated proteins in BAG3-silenced cells. Many of these proteins are reportedly involved in tumor progression, invasiveness and resistance to therapies. We focused our attention on an oncogenic protein, CAV1, and a tumor suppressor protein, SERPINB2, that had not previously been reported to be modulated by BAG3. Their expression levels in BAG3-silenced cells were confirmed by qRT-PCR and western blot analyses, disclosing two novel targets of BAG3 pro-tumor activity. We also examined the dataset of proteins obtained by the quantitative proteomics analysis using two tools, Downstream Effect Analysis and Upstream Regulator Analysis of the Ingenuity Pathways Analysis software. Our analyses confirm the association of the proteome profile observed in BAG3-silenced cells with an increase in cell survival and a decrease in cell proliferation and invasion, and highlight the possible involvement of four tumor suppressor miRNAs and TP53/63 proteins in BAG3 activity.

  11. Bcmimp1, a Botrytis cinerea gene transiently expressed in planta, encodes a mitochondrial protein

    Directory of Open Access Journals (Sweden)

    David eBenito-Pescador

    2016-02-01

    Full Text Available Botrytis cinerea is a widespread necrotrophic fungus which infects more than 200 plant species. In an attempt to characterize the physiological status of the fungus in planta and to identify genetic factors contributing to its ability to infect the host cells, a differential gene expression analysis during the interaction B. cinerea-tomato was carried out. Gene Bcmimp1 codes for a mRNA detected by differential display in the course of this analysis. During the interaction with the host, it shows a transient expression pattern with maximal expression levels during the colonization and maceration of the infected tissues. Bioinformatic analysis suggested that BCMIMP1 is an integral membrane protein located in the mitochondrial inner membrane. Co-localization experiments with a BCMIMP1-GFP fusion protein confirmed that the protein is targeted to the mitochondria. ΔBcmimp1 mutants do not show obvious phenotypic differences during saprophytic growth and their infection ability was unaltered as compared to the wild-type. Interestingly, the mutants produced increased levels of ROS, likely as a consequence of disturbed mitochondrial function. Although Bcmimp1 expression is enhanced in planta it cannot be considered a pathogenicity factor.

  12. The scaffold protein RACK1 is a target of endocrine disrupting chemicals (EDCs) with important implication in immunity

    Energy Technology Data Exchange (ETDEWEB)

    Buoso, Erica; Galasso, Marilisa; Ronfani, Melania [Dipartimento di Scienze del Farmaco, Università degli Studi di Pavia, Viale Taramelli 12/14, 27100 Pavia (Italy); Papale, Angela; Galbiati, Valentina [Laboratory of Toxicology, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano (Italy); Eberini, Ivano [Laboratorio di Biochimica e Biofisica Computazionale, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan (Italy); Marinovich, Marina [Laboratory of Toxicology, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano (Italy); Racchi, Marco [Dipartimento di Scienze del Farmaco, Università degli Studi di Pavia, Viale Taramelli 12/14, 27100 Pavia (Italy); Corsini, Emanuela, E-mail: emanuela.corsini@unimi.it [Laboratory of Toxicology, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano (Italy)

    2017-06-15

    We recently demonstrated the existence of a complex hormonal balance between steroid hormones in the control of RACK1 (Receptor for Activated C Kinase 1) expression and immune activation, suggesting that this scaffold protein may also be targeted by endocrine disrupting chemicals (EDCs). As a proof of concept, we investigated the effect of the doping agent nandrolone, an androgen receptor (AR) agonist, and of p,p′DDT (dichlorodiphenyltrichloroethane) and its main metabolite p,p′DDE (dichlorodiphenyldichloroethylene), a weak and strong AR antagonist, respectively, on RACK1 expression and innate immune response. In analogy to endogenous androgens, nandrolone induced a dose-related increase in RACK1 transcriptional activity and protein expression, resulting in increased LPS-induced IL-8 and TNF-α production and proliferation in THP-1 cells. Conversely, p,p′DDT and p,p′DDE significantly decrease RACK1 expression, LPS-induced cytokine production and CD86 expression; with p,p′DDE exerting a stronger repressor effect than p,p′DDT, consistent with its stronger AR antagonistic effect. These results indicate that RACK1 could be a relevant target of EDCs, responding in opposite ways to agonist or antagonist of AR, representing a bridge between the endocrine system and the innate immune system. - Highlights: • RACK1 expression can be induced by AR agonists with a consequent enhancement of the response to LPS. • RACK1 can be negatively modulated by the AR antagonists DDT and its main metabolite p,p′DDE. • RACK1 can be a relevant target of EDCs, representing a bridge between the endocrine system and the immune system.

  13. Differential Protein Expressions in Virus-Infected and Uninfected Trichomonas vaginalis.

    Science.gov (United States)

    He, Ding; Pengtao, Gong; Ju, Yang; Jianhua, Li; He, Li; Guocai, Zhang; Xichen, Zhang

    2017-04-01

    Protozoan viruses may influence the function and pathogenicity of the protozoa. Trichomonas vaginalis is a parasitic protozoan that could contain a double stranded RNA (dsRNA) virus, T. vaginalis virus (TVV). However, there are few reports on the properties of the virus. To further determine variations in protein expression of T. vaginalis , we detected 2 strains of T. vaginalis ; the virus-infected (V + ) and uninfected (V - ) isolates to examine differentially expressed proteins upon TVV infection. Using a stable isotope N-terminal labeling strategy (iTRAQ) on soluble fractions to analyze proteomes, we identified 293 proteins, of which 50 were altered in V + compared with V - isolates. The results showed that the expression of 29 proteins was increased, and 21 proteins decreased in V + isolates. These differentially expressed proteins can be classified into 4 categories: ribosomal proteins, metabolic enzymes, heat shock proteins, and putative uncharacterized proteins. Quantitative PCR was used to detect 4 metabolic processes proteins: glycogen phosphorylase, malate dehydrogenase, triosephosphate isomerase, and glucose-6-phosphate isomerase, which were differentially expressed in V + and V - isolates. Our findings suggest that mRNA levels of these genes were consistent with protein expression levels. This study was the first which analyzed protein expression variations upon TVV infection. These observations will provide a basis for future studies concerning the possible roles of these proteins in host-parasite interactions.

  14. Modulation of brassinosteroid-regulated gene expression by jumonji domain-containing proteins ELF6 and REF6 in Arabidopsis

    OpenAIRE

    Yu, Xiaofei; Li, Li; Li, Lei; Guo, Michelle; Chory, Joanne; Yin, Yanhai

    2008-01-01

    Plant steroid hormones, brassinosteroids (BRs), are of great importance for plant growth and development. BRs signal through a cell surface receptor kinase, BRI1, and a GSK3-like kinase, BIN2, to regulate the BES1/BZR1 family of transcription factors, which directly bind to target gene promoters to activate or repress gene expression and mediate BR responses. To understand how BES1 regulates target gene expression, we identified two BES1-interacting proteins, ELF6 (early flowering 6) and its ...

  15. Built-in adjuvanticity of genetically and protein-engineered chimeric molecules for targeting of influenza A peptide epitopes.

    Science.gov (United States)

    Kerekov, Nikola S; Ivanova, Iva I; Mihaylova, Nikolina M; Nikolova, Maria; Prechl, Jozsef; Tchorbanov, Andrey I

    2014-10-01

    Highly purified, subunit, or synthetic viral antigens are known to be weakly immunogenic and potentate only the antibody, rather than cell-mediated immune responses. An alternative approach for inducing protective immunity with small viral peptides would be the direct targeting of viral epitopes to the immunocompetent cells by DNA vaccines encoding antibody fragments specific to activating cell surface co-receptor molecules. Here, we are exploring as a new genetic vaccine, a DNA chimeric molecule encoding a T and B cell epitope-containing influenza A virus hemagglutinin peptide joined to sequences encoding a single-chain variable fragment antibody fragment specific for the costimulatory B cell complement receptors 1 and 2. This recombinant DNA molecule was inserted into eukaryotic expression vector and used as a naked DNA vaccine in WT and CR1/2 KO mice. The intramuscular administration of the DNA construct resulted in the in vivo expression of an immunogenic chimeric protein, which cross-links cell surface receptors on influenza-specific B cells. The DNA vaccination was followed by prime-boosting with the protein-engineered replica of the DNA construct, thus delivering an activation intracellular signal. Immunization with an expression vector containing the described construct and boosting with the protein chimera induced a strong anti-influenza cytotoxic response, modulation of cytokine profile, and a weak antibody response in Balb/c mice. The same immunization scheme did not result in generation of influenza-specific response in mice lacking the target receptor, underlining the molecular adjuvant effect of receptor targeting.

  16. Immunohistochemical evaluation of molecular radiotherapy target expression in neuroblastoma tissue

    Energy Technology Data Exchange (ETDEWEB)

    Gains, Jennifer E.; Gaze, Mark N. [University College London Hospitals NHS Foundation Trust, Department of Oncology, London (United Kingdom); Sebire, Neil J. [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Pathology, London (United Kingdom); Moroz, Veronica; Wheatley, Keith [University of Birmingham, Cancer Research UK Clinical Trials Unit, Birmingham (United Kingdom)

    2018-03-15

    Neuroblastoma may be treated with molecular radiotherapy, {sup 131}I meta-Iodobenzylguanidine and {sup 177}Lu Lutetium DOTATATE, directed at distinct molecular targets: Noradrenaline Transporter Molecule (NAT) and Somatostatin Receptor (SSTR2), respectively. This study used immunohistochemistry to evaluate target expression in archival neuroblastoma tissue, to determine whether it might facilitate clinical use of molecular radiotherapy. Tissue bank samples of formalin fixed paraffin embedded neuroblastoma tissue from patients for whom clinical outcome data were available were sectioned and stained with haematoxylin and eosin, and monoclonal antibodies directed against NAT and SSTR2. Sections were examined blinded to clinical information and scored for the percentage and intensity of tumour cells stained. These data were analysed in conjunction with clinical data. Tissue from 75 patients was examined. Target expression scores varied widely between patients: NAT median 45%, inter-quartile range 25% - 65%; and SSTR2 median 55%, interquartile range 30% - 80%; and in some cases heterogeneity of expression between different parts of a tumour was observed. A weak positive correlation was observed between the expression scores of the different targets: correlation coefficient = 0.23, p = 0.05. MYCN amplified tumours had lower SSTR2 scores: mean difference 23% confidence interval 8% - 39%, p < 0.01. Survival did not differ by scores. As expression of both targets is variable and heterogeneous, imaging assessment of both may yield more clinical information than either alone. The clinical value of immunohistochemical assessment of target expression requires prospective evaluation. Variable target expression within a patient may contribute to treatment failure. (orig.)

  17. Interaction Research on the Antiviral Molecule Dufulin Targeting on Southern Rice Black Streaked Dwarf Virus P9-1 Nonstructural Protein

    Directory of Open Access Journals (Sweden)

    Zhenchao Wang

    2015-03-01

    Full Text Available ern rice black streaked dwarf virus (SRBSDV causes severe harm to rice production. Unfortunately, studies on effective antiviral drugs against SRBSDV and interaction mechanism of antiviral molecule targeting on SRBSDV have not been reported. This study found dufulin (DFL, an ideal anti-SRBSDV molecule, and investigated the interactions of DFL targeting on the nonstructural protein P9-1. The biological sequence information and bonding characterization of DFL to four kinds of P9-1 protein were described with fluorescence titration (FT and microscale thermophoresis (MST assays. The sequence analysis indicated that P9-1 had highly-conserved C- and N-terminal amino acid residues and a hypervariable region that differed from 131 aa to 160 aa. Consequently, wild-type (WT-His-P9-1, 23 C-terminal residues truncated (TR-ΔC23-His-P9-1, 6 N-terminal residues truncated (TR-ΔN6-His-P9-1, and Ser138 site-directed (MU-138-His-P9-1 mutant proteins were expressed. The FT and MST assay results indicated that DFL bounded to WT-His-P9-1 with micromole affinity and the 23 C-terminal amino acids were the potential targeting site. This system, which combines a complete sequence analysis, mutant protein expression, and binding action evaluating system, could further advance the understanding of the interaction abilities between antiviral drugs and their targets.

  18. Expression of androgen-binding protein (ABP) in human cardiac myocytes.

    Science.gov (United States)

    Schock, H W; Herbert, Z; Sigusch, H; Figulla, H R; Jirikowski, G F; Lotze, U

    2006-04-01

    Cardiomyocytes are known to be androgen targets. Changing systemic steroid levels are thought to be linked to various cardiac ailments, including dilated cardiomyopathy (DCM). The mode of action of gonadal steroid hormones on the human heart is unknown to date. In the present study, we used high-resolution immunocytochemistry on semithin sections (1 microm thick), IN SITU hybridization, and mass spectrometry to investigate the expression of androgen-binding protein (ABP) in human myocardial biopsies taken from male patients with DCM. We observed distinct cytoplasmic ABP immunoreactivity in a fraction of the myocytes. IN SITU hybridization with synthetic oligonucleotide probes revealed specific hybridization signals in these cells. A portion of the ABP-positive cells contained immunostaining for androgen receptor. With SELDI TOF mass spectrometry of affinity purified tissue extracts of human myocardium, we confirmed the presence of a 50 kDa protein similar to ABP. Our observations provide evidence of an intrinsic expression of ABP in human heart. ABP may be secreted from myocytes in a paracrine manner perhaps to influence the bioavailabity of gonadal steroids in myocardium.

  19. Quantitative analysis of differentially expressed saliva proteins in human immunodeficiency virus type 1 (HIV-1) infected individuals

    International Nuclear Information System (INIS)

    Zhang, Nawei; Zhang, Zhenyu; Feng, Shan; Wang, Qingtao; Malamud, Daniel; Deng, Haiteng

    2013-01-01

    Highlights: ► A high-throughput method for profiling and quantification of the differentially expressed proteins in saliva samples was developed. ► Identified that DMBT1, S100A7, S100A8, S100A9 and alpha defensin were up-regulated in saliva from HIV-1 seropositive patients. ► Established analytical strategies are translatable to the clinical setting. -- Abstract: In the present study, we have established a new methodology to analyze saliva proteins from HIV-1-seropositive patients before highly active antiretroviral therapy (HAART) and seronegative controls. A total of 593 and 601 proteins were identified in the pooled saliva samples from 5 HIV-1 subjects and 5 controls, respectively. Forty-one proteins were found to be differentially expressed. Bioinformatic analysis of differentially expressed salivary proteins showed an increase of antimicrobial proteins and decrease of protease inhibitors upon HIV-1 infection. To validate some of these differentially expressed proteins, a high-throughput quantitation method was established to determine concentrations of 10 salivary proteins in 40 individual saliva samples from 20 seropositive patients before HAART and 20 seronegative subjects. This method was based on limited protein separation within the zone of the stacking gel of the 1D SDS PAGE and using isotope-coded synthetic peptides as internal standards. The results demonstrated that a combination of protein profiling and targeted quantitation is an efficient method to identify and validate differentially expressed salivary proteins. Expression levels of members of the calcium-binding S100 protein family and deleted in malignant brain tumors 1 protein (DMBT1) were up-regulated while that of Mucin 5B was down-regulated in HIV-1 seropositive saliva samples, which may provide new perspectives for monitoring HIV-infection and understanding the mechanism of HIV-1 infectivity

  20. Quantitative analysis of differentially expressed saliva proteins in human immunodeficiency virus type 1 (HIV-1) infected individuals

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Nawei; Zhang, Zhenyu [Beijing Chaoyang Hospital Affiliated Capital Medical University, Beijing (China); Feng, Shan [MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing (China); Wang, Qingtao [Beijing Chaoyang Hospital Affiliated Capital Medical University, Beijing (China); Malamud, Daniel [NYU College of Dentistry, 345 East 24th Street, New York, NY 10010 (United States); Deng, Haiteng, E-mail: dht@mail.tsinghua.edu.cn [MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing (China)

    2013-04-24

    Highlights: ► A high-throughput method for profiling and quantification of the differentially expressed proteins in saliva samples was developed. ► Identified that DMBT1, S100A7, S100A8, S100A9 and alpha defensin were up-regulated in saliva from HIV-1 seropositive patients. ► Established analytical strategies are translatable to the clinical setting. -- Abstract: In the present study, we have established a new methodology to analyze saliva proteins from HIV-1-seropositive patients before highly active antiretroviral therapy (HAART) and seronegative controls. A total of 593 and 601 proteins were identified in the pooled saliva samples from 5 HIV-1 subjects and 5 controls, respectively. Forty-one proteins were found to be differentially expressed. Bioinformatic analysis of differentially expressed salivary proteins showed an increase of antimicrobial proteins and decrease of protease inhibitors upon HIV-1 infection. To validate some of these differentially expressed proteins, a high-throughput quantitation method was established to determine concentrations of 10 salivary proteins in 40 individual saliva samples from 20 seropositive patients before HAART and 20 seronegative subjects. This method was based on limited protein separation within the zone of the stacking gel of the 1D SDS PAGE and using isotope-coded synthetic peptides as internal standards. The results demonstrated that a combination of protein profiling and targeted quantitation is an efficient method to identify and validate differentially expressed salivary proteins. Expression levels of members of the calcium-binding S100 protein family and deleted in malignant brain tumors 1 protein (DMBT1) were up-regulated while that of Mucin 5B was down-regulated in HIV-1 seropositive saliva samples, which may provide new perspectives for monitoring HIV-infection and understanding the mechanism of HIV-1 infectivity.

  1. Identification and target prediction of miRNAs specifically expressed in rat neural tissue

    Directory of Open Access Journals (Sweden)

    Tu Kang

    2009-05-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are a large group of RNAs that play important roles in regulating gene expression and protein translation. Several studies have indicated that some miRNAs are specifically expressed in human, mouse and zebrafish tissues. For example, miR-1 and miR-133 are specifically expressed in muscles. Tissue-specific miRNAs may have particular functions. Although previous studies have reported the presence of human, mouse and zebrafish tissue-specific miRNAs, there have been no detailed reports of rat tissue-specific miRNAs. In this study, Home-made rat miRNA microarrays which established in our previous study were used to investigate rat neural tissue-specific miRNAs, and mapped their target genes in rat tissues. This study will provide information for the functional analysis of these miRNAs. Results In order to obtain as complete a picture of specific miRNA expression in rat neural tissues as possible, customized miRNA microarrays with 152 selected miRNAs from miRBase were used to detect miRNA expression in 14 rat tissues. After a general clustering analysis, 14 rat tissues could be clearly classified into neural and non-neural tissues based on the obtained expression profiles with p values Conclusion Our work provides a global view of rat neural tissue-specific miRNA profiles and a target map of miRNAs, which is expected to contribute to future investigations of miRNA regulatory mechanisms in neural systems.

  2. Mucosal Immunogenicity of Genetically Modified Lactobacillus acidophilus Expressing an HIV-1 Epitope within the Surface Layer Protein.

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    Akinobu Kajikawa

    Full Text Available Surface layer proteins of probiotic lactobacilli are theoretically efficient epitope-displaying scaffolds for oral vaccine delivery due to their high expression levels and surface localization. In this study, we constructed genetically modified Lactobacillus acidophilus strains expressing the membrane proximal external region (MPER from human immunodeficiency virus type 1 (HIV-1 within the context of the major S-layer protein, SlpA. Intragastric immunization of mice with the recombinants induced MPER-specific and S-layer protein-specific antibodies in serum and mucosal secretions. Moreover, analysis of systemic SlpA-specific cytokines revealed that the responses appeared to be Th1 and Th17 dominant. These findings demonstrated the potential use of the Lactobacillus S-layer protein for development of oral vaccines targeting specific peptides.

  3. Constructs for the expression of repeating triple-helical protein domains

    International Nuclear Information System (INIS)

    Peng, Yong Y; Werkmeister, Jerome A; Vaughan, Paul R; Ramshaw, John A M

    2009-01-01

    The development of novel scaffolds will be an important aspect in future success of tissue engineering. Scaffolds will preferably contain information that directs the cellular content of constructs so that the new tissue that is formed is closely aligned in structure, composition and function to the target natural tissue. One way of approaching this will be the development of novel protein-based constructs that contain one or more repeats of functional elements derived from various proteins. In the present case, we describe a strategy to make synthetic, recombinant triple-helical constructs that contain repeat segments of biologically relevant domains. Copies of a DNA fragment prepared by PCR from human type III collagen have been inserted in a co-linear contiguous fashion into the yeast expression vector YEpFlag-1, using sequential addition between selected restriction sites. Constructs containing 1, 2 and 3 repeats were designed to maintain the (Gly-X-Y) repeat, which is essential for the formation of an extended triple helix. All constructs gave expressed protein, with the best being the 3-repeat construct which was readily secreted. This material had the expected composition and N-terminal sequence. Incubation of the product at low temperature led to triple-helix formation, shown by reaction with a conformation dependent monoclonal antibody.

  4. Constructs for the expression of repeating triple-helical protein domains

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yong Y; Werkmeister, Jerome A; Vaughan, Paul R; Ramshaw, John A M, E-mail: jerome.werkmeister@csiro.a [CSIRO Molecular and Health Technologies, Bag 10, Clayton South, VIC 3169 (Australia)

    2009-02-15

    The development of novel scaffolds will be an important aspect in future success of tissue engineering. Scaffolds will preferably contain information that directs the cellular content of constructs so that the new tissue that is formed is closely aligned in structure, composition and function to the target natural tissue. One way of approaching this will be the development of novel protein-based constructs that contain one or more repeats of functional elements derived from various proteins. In the present case, we describe a strategy to make synthetic, recombinant triple-helical constructs that contain repeat segments of biologically relevant domains. Copies of a DNA fragment prepared by PCR from human type III collagen have been inserted in a co-linear contiguous fashion into the yeast expression vector YEpFlag-1, using sequential addition between selected restriction sites. Constructs containing 1, 2 and 3 repeats were designed to maintain the (Gly-X-Y) repeat, which is essential for the formation of an extended triple helix. All constructs gave expressed protein, with the best being the 3-repeat construct which was readily secreted. This material had the expected composition and N-terminal sequence. Incubation of the product at low temperature led to triple-helix formation, shown by reaction with a conformation dependent monoclonal antibody.

  5. Expression and localization of a novel phosducin-like protein from amphioxus Branchiostoma belcheri

    Science.gov (United States)

    Saren, Gaowa; Zhao, Yonggang

    2009-05-01

    A full length amphioxus cDNA, encoding a novel phosducin-like protein ( Amphi-PhLP), was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open reading frame (ORF) of 241 amino acids, with a predicted molecular mass of approximately 28 kDa. In situ hybridization histochemistry revealed a tissue-specific expression pattern of Amphi-PhLP with the high levels in the ovary, and at a lower level in the hind gut and testis, hepatic caecum, gill, endostyle, and epipharyngeal groove, while it was absent in the muscle, neural tube and notochord. In the Chinese Hamster Ovary (CHO) cells transfected with the expression plasmid pEGFP-N1/ Amphi-PhLP, the fusion protein was targeted in the cytoplasm of CHO cells, suggesting that Amphi-PhLP is a cytosolic protein. This work may provide a framework for further understanding of the physiological function of Amphi-PhLP in B. belcheri.

  6. Knockdown of Pokemon protein expression inhibits hepatocellular carcinoma cell proliferation by suppression of AKT activity.

    Science.gov (United States)

    Zhu, Xiaosan; Dai, Yichen; Chen, Zhangxin; Xie, Junpei; Zeng, Wei; Lin, Yuanyuan

    2013-01-01

    Overexpression of Pokemon, which is an erythroid myeloid ontogenic factor protein, occurs in different cancers, including hepatocellular carcinoma (HCC). Pokemon is also reported to have an oncogenic activity in various human cancers. This study investigated the effect of Pokemon knockdown on the regulation of HCC growth. POK shRNA suppressed the expression of Pokemon protein in HepG2 cells compared to the negative control vector-transfected HCC cells. Pokemon knockdown also reduced HCC cell viability and enhanced cisplatin-induced apoptosis in HCC cells. AKT activation and the expression of various cell cycle-related genes were inhibited following Pokemon knockdown. These data demonstrate that Pokemon may play a role in HCC progression, suggesting that inhibition of Pokemon expression using Pokemon shRNA should be further evaluated as a novel target for the control of HCC.

  7. Comprehensive reanalysis of transcription factor knockout expression data in Saccharomyces cerevisiae reveals many new targets.

    Science.gov (United States)

    Reimand, Jüri; Vaquerizas, Juan M; Todd, Annabel E; Vilo, Jaak; Luscombe, Nicholas M

    2010-08-01

    Transcription factor (TF) perturbation experiments give valuable insights into gene regulation. Genome-scale evidence from microarray measurements may be used to identify regulatory interactions between TFs and targets. Recently, Hu and colleagues published a comprehensive study covering 269 TF knockout mutants for the yeast Saccharomyces cerevisiae. However, the information that can be extracted from this valuable dataset is limited by the method employed to process the microarray data. Here, we present a reanalysis of the original data using improved statistical techniques freely available from the BioConductor project. We identify over 100,000 differentially expressed genes-nine times the total reported by Hu et al. We validate the biological significance of these genes by assessing their functions, the occurrence of upstream TF-binding sites, and the prevalence of protein-protein interactions. The reanalysed dataset outperforms the original across all measures, indicating that we have uncovered a vastly expanded list of relevant targets. In summary, this work presents a high-quality reanalysis that maximizes the information contained in the Hu et al. compendium. The dataset is available from ArrayExpress (accession: E-MTAB-109) and it will be invaluable to any scientist interested in the yeast transcriptional regulatory system.

  8. Expression of multidrug resistance proteins in retinoblastoma

    Directory of Open Access Journals (Sweden)

    Swati Shukla

    2017-11-01

    Full Text Available AIM: To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance. METHODS: Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy (PCNC were also prepared. Their chemosensitivity to chemotherapeutic agents (vincristine, etoposide and carboplatin were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells. RESULTS: Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein (P-gp was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1 (Mrp-1 expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associated protein (Lrp was observed in the drug resistant Y79 cells as well as in PCNC. CONCLUSION: Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy.

  9. Expression of multidrug resistance proteins in retinoblastoma.

    Science.gov (United States)

    Shukla, Swati; Srivastava, Arpna; Kumar, Sunil; Singh, Usha; Goswami, Sandeep; Chawla, Bhavna; Bajaj, Mandeep Singh; Kashyap, Seema; Kaur, Jasbir

    2017-01-01

    To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance. Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy (PCNC) were also prepared. Their chemosensitivity to chemotherapeutic agents (vincristine, etoposide and carboplatin) were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells. Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein (P-gp) was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1 (Mrp-1) expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associated protein (Lrp) was observed in the drug resistant Y79 cells as well as in PCNC. Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy.

  10. Expression of multidrug resistance proteins in retinoblastoma

    Science.gov (United States)

    Shukla, Swati; Srivastava, Arpna; Kumar, Sunil; Singh, Usha; Goswami, Sandeep; Chawla, Bhavna; Bajaj, Mandeep Singh; Kashyap, Seema; Kaur, Jasbir

    2017-01-01

    AIM To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance. METHODS Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy (PCNC) were also prepared. Their chemosensitivity to chemotherapeutic agents (vincristine, etoposide and carboplatin) were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells. RESULTS Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein (P-gp) was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1 (Mrp-1) expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associated protein (Lrp) was observed in the drug resistant Y79 cells as well as in PCNC. CONCLUSION Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy. PMID:29181307

  11. Nucleic acid programmable protein array a just-in-time multiplexed protein expression and purification platform.

    Science.gov (United States)

    Qiu, Ji; LaBaer, Joshua

    2011-01-01

    Systematic study of proteins requires the availability of thousands of proteins in functional format. However, traditional recombinant protein expression and purification methods have many drawbacks for such study at the proteome level. We have developed an innovative in situ protein expression and capture system, namely NAPPA (nucleic acid programmable protein array), where C-terminal tagged proteins are expressed using an in vitro expression system and efficiently captured/purified by antitag antibodies coprinted at each spot. The NAPPA technology presented in this chapter enable researchers to produce and display fresh proteins just in time in a multiplexed high-throughput fashion and utilize them for various downstream biochemical researches of interest. This platform could revolutionize the field of functional proteomics with it ability to produce thousands of spatially separated proteins in high density with narrow dynamic rand of protein concentrations, reproducibly and functionally. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. FGFR Family Members Protein Expression as Prognostic Markers in Oral Cavity and Oropharyngeal Squamous Cell Carcinoma

    NARCIS (Netherlands)

    Koole, Koos; Clausen, Martijn J. A. M.; van Es, Robert J. J.; van Kempen, Pauline M. W.; Melchers, Lieuwe J.; Koole, Ron; Langendijk, Johannes A.; van Diest, Paul J.; Roodenburg, Jan L. N.; Schuuring, Ed; Willems, Stefan M.

    Introduction Fibroblast growth factor receptor family member proteins (FGFR1-4) have been identified as promising novel therapeutic targets and prognostic markers in a wide spectrum of solid tumors. The present study investigates the expression and prognostic value of four FGFR family member

  13. Task-dependent neural bases of perceiving emotionally expressive targets

    Directory of Open Access Journals (Sweden)

    Jamil eZaki

    2012-08-01

    Full Text Available Social cognition is fundamentally interpersonal: individuals’ behavior and dispositions critically affect their interaction partners’ information processing. However, cognitive neuroscience studies, partially because of methodological constraints, have remained largely perceiver-centric: focusing on the abilities, motivations, and goals of social perceivers while largely ignoring interpersonal effects. Here, we address this knowledge gap by examining the neural bases of perceiving emotionally expressive and inexpressive social targets. Sixteen perceivers were scanned using fMRI while they watched targets discussing emotional autobiographical events. Perceivers continuously rated each target’s emotional state or eye-gaze direction. The effects of targets’ emotional expressivity on perceiver’s brain activity depended on task set: when perceivers explicitly attended to targets’ emotions, expressivity predicted activity in neural structures—including medial prefrontal and posterior cingulate cortex—associated with drawing inferences about mental states. When perceivers instead attended to targets’ eye-gaze, target expressivity predicted activity in regions—including somatosensory cortex, fusiform gyrus, and motor cortex—associated with monitoring sensorimotor states and biological motion. These findings suggest that expressive targets affect information processing in manner that depends on perceivers’ goals. More broadly, these data provide an early step towards understanding the neural bases of interpersonal social cognition.

  14. A family of E. coli expression vectors for laboratory scale and high throughput soluble protein production

    Directory of Open Access Journals (Sweden)

    Bottomley Stephen P

    2006-03-01

    Full Text Available Abstract Background In the past few years, both automated and manual high-throughput protein expression and purification has become an accessible means to rapidly screen and produce soluble proteins for structural and functional studies. However, many of the commercial vectors encoding different solubility tags require different cloning and purification steps for each vector, considerably slowing down expression screening. We have developed a set of E. coli expression vectors with different solubility tags that allow for parallel cloning from a single PCR product and can be purified using the same protocol. Results The set of E. coli expression vectors, encode for either a hexa-histidine tag or the three most commonly used solubility tags (GST, MBP, NusA and all with an N-terminal hexa-histidine sequence. The result is two-fold: the His-tag facilitates purification by immobilised metal affinity chromatography, whilst the fusion domains act primarily as solubility aids during expression, in addition to providing an optional purification step. We have also incorporated a TEV recognition sequence following the solubility tag domain, which allows for highly specific cleavage (using TEV protease of the fusion protein to yield native protein. These vectors are also designed for ligation-independent cloning and they possess a high-level expressing T7 promoter, which is suitable for auto-induction. To validate our vector system, we have cloned four different genes and also one gene into all four vectors and used small-scale expression and purification techniques. We demonstrate that the vectors are capable of high levels of expression and that efficient screening of new proteins can be readily achieved at the laboratory level. Conclusion The result is a set of four rationally designed vectors, which can be used for streamlined cloning, expression and purification of target proteins in the laboratory and have the potential for being adaptable to a high

  15. TRPM4 protein expression in prostate cancer

    DEFF Research Database (Denmark)

    Berg, Kasper Drimer; Soldini, Davide; Jung, Maria

    2016-01-01

    BACKGROUND: Transient receptor potential cation channel, subfamily M, member 4 (TRPM4) messenger RNA (mRNA) has been shown to be upregulated in prostate cancer (PCa) and might be a new promising tissue biomarker. We evaluated TRPM4 protein expression and correlated the expression level.......79-2.62; p = 0.01-0.03 for the two observers) when compared to patients with a lower staining intensity. CONCLUSIONS: TRPM4 protein expression is widely expressed in benign and cancerous prostate tissue, with highest staining intensities found in PCa. Overexpression of TRPM4 in PCa (combination of high...

  16. LeCPK1, a Calcium-Dependent Protein Kinase from Tomato. Plasma Membrane Targeting and Biochemical Characterization1

    Science.gov (United States)

    Rutschmann, Frank; Stalder, Urs; Piotrowski, Markus; Oecking, Claudia; Schaller, Andreas

    2002-01-01

    The cDNA of LeCPK1, a calcium-dependent protein kinase, was cloned from tomato (Lycopersicon esculentum Mill.). LeCPK1 was expressed in Escherichia coli and purified from bacterial extracts. The recombinant protein was shown to be a functional protein kinase using a synthetic peptide as the substrate (syntide-2, Km = 85 μm). Autophosphorylation of LeCPK1 was observed on threonine and serine residues, one of which was identified as serine-439. Kinase activity was shown to be Ca2+ dependent and required the C-terminal, calmodulin-like domain of LeCPK1. Two classes of high- and low-affinity Ca2+-binding sites were observed, exhibiting dissociation constants of 0.6 and 55 μm, respectively. LeCPK1 was found to phosphorylate the regulatory C-terminal domain of the plasma membrane H+-ATPase in vitro. A potential role in the regulation of proton pump activity is corroborated by the apparent colocalization of the plasma membrane H+-ATPase and LeCPK1 in vivo. Upon transient expression in suspension-cultured cells, a C-terminal fusion of LeCPK1 with the green fluorescent protein was targeted to the plasma membrane. Myristoylation of the LeCPK1 N terminus was found to be required for plasma membrane targeting. PMID:12011347

  17. Hepatitis B virus induces cell proliferation via HBx-induced microRNA-21 in hepatocellular carcinoma by targeting programmed cell death protein4 (PDCD4 and phosphatase and tensin homologue (PTEN.

    Directory of Open Access Journals (Sweden)

    Preeti Damania

    Full Text Available Hepatitis B viral infection-induced hepatocellular carcinoma is one of the major problems in the developing countries. One of the HBV proteins, HBx, modulates the host cell machinery via several mechanisms. In this study we hypothesized that HBV enhances cell proliferation via HBx-induced microRNA-21 in hepatocellular carcinoma. HBx gene was over-expressed, and miRNA-21 expression and cell proliferation were measured in Huh 7 and Hep G2 cells. miRNA-21 was over-expressed in these cells, cell proliferation and the target proteins were analyzed. To confirm the role of miRNA-21 in HBx-induced proliferation, Hep G 2.2.1.5 cells (a cell line that expresses HBV stably were used for miRNA-21 inhibition studies. HBx over-expression enhanced proliferation (3.7- and 4.5-fold increase; n = 3; p<0.01 and miRNA-21 expression (24- and 36-fold increase, normalized with 5S rRNA; p<0.001 in Huh 7 and Hep G2 cells respectively. HBx also resulted in the inhibition of miRNA-21 target proteins, PDCD4 and PTEN. miRNA-21 resulted in a significant increase in proliferation (2- and 2.3-fold increase over control cells; p<0.05 in Huh 7 and Hep G2 cells respectively and decreased target proteins, PDCD4 and PTEN expression. Anti-miR-21 resulted in a significant decrease in proliferation (p<0.05 and increased miRNA-21 target protein expression. We conclude that HBV infection enhances cell proliferation, at least in part, via HBx-induced miRNA-21 expression during hepatocellular carcinoma progression.

  18. Isotopomer distributions in amino acids from a highly expressed protein as a proxy for those from total protein

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, Afshan; Shaikh, Afshan S.; Tang, Yinjie; Mukhopadhyay, Aindrila; Keasling, Jay D.

    2008-06-27

    {sup 13}C-based metabolic flux analysis provides valuable information about bacterial physiology. Though many biological processes rely on the synergistic functions of microbial communities, study of individual organisms in a mixed culture using existing flux analysis methods is difficult. Isotopomer-based flux analysis typically relies on hydrolyzed amino acids from a homogeneous biomass. Thus metabolic flux analysis of a given organism in a mixed culture requires its separation from the mixed culture. Swift and efficient cell separation is difficult and a major hurdle for isotopomer-based flux analysis of mixed cultures. Here we demonstrate the use of a single highly-expressed protein to analyze the isotopomer distribution of amino acids from one organism. Using the model organism E. coli expressing a plasmid-borne, his-tagged Green Fluorescent Protein (GFP), we show that induction of GFP does not affect E. coli growth kinetics or the isotopomer distribution in nine key metabolites. Further, the isotopomer labeling patterns of amino acids derived from purified GFP and total cell protein are indistinguishable, indicating that amino acids from a purified protein can be used to infer metabolic fluxes of targeted organisms in a mixed culture. This study provides the foundation to extend isotopomer-based flux analysis to study metabolism of individual strains in microbial communities.

  19. Direct and indirect targets of the E2A-PBX1 leukemia-specific fusion protein.

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    Christofer Diakos

    Full Text Available E2A-PBX1 is expressed as a result of the t(1;19 chromosomal translocation in nearly 5% of cases of childhood acute lymphoblastic leukemia. The E2A-PBX1 chimeric transcription factor contains the N-terminal transactivation domain of E2A (TCF3 fused to the C-terminal DNA-binding homeodomain of PBX1. While there is no doubt of its oncogenic potential, the mechanisms of E2A-PBX1-mediated pre-B cell transformation and the nature of direct E2A-PBX1 target genes and pathways remain largely unknown. Herein we used chromatin immunoprecipitation assays (ChIP-chip to identify direct targets of E2A-PBX1, and we used gene expression arrays of siRNA E2A-PBX1-silenced cells to evaluate changes in expression induced by the fusion protein. Combined ChIP-chip and expression data analysis gave rise to direct and functional targets of E2A-PBX1. Further we observe that the set of ChIP-chip identified E2A-PBX1 targets show a collective down-regulation trend in the E2A-PBX1 silenced samples compared to controls suggesting an activating role of this fusion transcription factor. Our data suggest that the expression of the E2A-PBX1 fusion gene interferes with key regulatory pathways and functions of hematopoietic biology. Among these are members of the WNT and apoptosis/cell cycle control pathways, and thus may comprise an essential driving force for the propagation and maintenance of the leukemic phenotype. These findings may also provide evidence of potentially attractive therapeutic targets.

  20. Direct and indirect targets of the E2A-PBX1 leukemia-specific fusion protein.

    Science.gov (United States)

    Diakos, Christofer; Xiao, Yuanyuan; Zheng, Shichun; Kager, Leo; Dworzak, Michael; Wiemels, Joseph L

    2014-01-01

    E2A-PBX1 is expressed as a result of the t(1;19) chromosomal translocation in nearly 5% of cases of childhood acute lymphoblastic leukemia. The E2A-PBX1 chimeric transcription factor contains the N-terminal transactivation domain of E2A (TCF3) fused to the C-terminal DNA-binding homeodomain of PBX1. While there is no doubt of its oncogenic potential, the mechanisms of E2A-PBX1-mediated pre-B cell transformation and the nature of direct E2A-PBX1 target genes and pathways remain largely unknown. Herein we used chromatin immunoprecipitation assays (ChIP-chip) to identify direct targets of E2A-PBX1, and we used gene expression arrays of siRNA E2A-PBX1-silenced cells to evaluate changes in expression induced by the fusion protein. Combined ChIP-chip and expression data analysis gave rise to direct and functional targets of E2A-PBX1. Further we observe that the set of ChIP-chip identified E2A-PBX1 targets show a collective down-regulation trend in the E2A-PBX1 silenced samples compared to controls suggesting an activating role of this fusion transcription factor. Our data suggest that the expression of the E2A-PBX1 fusion gene interferes with key regulatory pathways and functions of hematopoietic biology. Among these are members of the WNT and apoptosis/cell cycle control pathways, and thus may comprise an essential driving force for the propagation and maintenance of the leukemic phenotype. These findings may also provide evidence of potentially attractive therapeutic targets.

  1. Collagen targeting using multivalent protein-functionalized dendrimers

    NARCIS (Netherlands)

    Breurken, M.; Lempens, E.H.M.; Temming, R.P.; Helms, B.A.; Meijer, E.W.; Merkx, M.

    2011-01-01

    Collagen is an attractive marker for tissue remodeling in a variety of common disease processes. Here we report the preparation of protein dendrimers as multivalent collagen targeting ligands by native chemical ligation of the collagen binding protein CNA35 to cysteine-functionalized dendritic

  2. Evolutionary conservation of nuclear and nucleolar targeting sequences in yeast ribosomal protein S6A

    International Nuclear Information System (INIS)

    Lipsius, Edgar; Walter, Korden; Leicher, Torsten; Phlippen, Wolfgang; Bisotti, Marc-Angelo; Kruppa, Joachim

    2005-01-01

    Over 1 billion years ago, the animal kingdom diverged from the fungi. Nevertheless, a high sequence homology of 62% exists between human ribosomal protein S6 and S6A of Saccharomyces cerevisiae. To investigate whether this similarity in primary structure is mirrored in corresponding functional protein domains, the nuclear and nucleolar targeting signals were delineated in yeast S6A and compared to the known human S6 signals. The complete sequence of S6A and cDNA fragments was fused to the 5'-end of the LacZ gene, the constructs were transiently expressed in COS cells, and the subcellular localization of the fusion proteins was detected by indirect immunofluorescence. One bipartite and two monopartite nuclear localization signals as well as two nucleolar binding domains were identified in yeast S6A, which are located at homologous regions in human S6 protein. Remarkably, the number, nature, and position of these targeting signals have been conserved, albeit their amino acid sequences have presumably undergone a process of co-evolution with their corresponding rRNAs

  3. Parts Characterization for Tunable Protein Expression

    DEFF Research Database (Denmark)

    Klausen, Michael Schantz; Sommer, Morten Otto Alexander

    2018-01-01

    Flow-seq combines flexible genome engineering methods with flow cytometry-based cell sorting and deep DNA sequencing to enable comprehensive interrogation of genotype to phenotype relationships. One application is to study the effect of specific regulatory elements on protein expression. Construc......Flow-seq combines flexible genome engineering methods with flow cytometry-based cell sorting and deep DNA sequencing to enable comprehensive interrogation of genotype to phenotype relationships. One application is to study the effect of specific regulatory elements on protein expression...

  4. Differential Protein Expression in Congenital and Acquired Cholesteatomas.

    Directory of Open Access Journals (Sweden)

    Seung-Ho Shin

    Full Text Available Congenital cholesteatomas are epithelial lesions that present as an epithelial pearl behind an intact eardrum. Congenital and acquired cholesteatomas progress quite differently from each other and progress patterns can provide clues about the unique origin and pathogenesis of the abnormality. However, the exact pathogenic mechanisms by which cholesteatomas develop remain unknown. In this study, key proteins that directly affect cholesteatoma pathogenesis are investigated with proteomics and immunohistochemistry. Congenital cholesteatoma matrices and retroauricular skin were harvested during surgery in 4 patients diagnosed with a congenital cholesteatoma. Tissue was also harvested from the retraction pocket in an additional 2 patients during middle ear surgery. We performed 2-dimensional (2D electrophoresis to detect and analyze spots that are expressed only in congenital cholesteatoma and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS to separate proteins by molecular weight. Protein expression was confirmed by immunohistochemical staining. The image analysis of 2D electrophoresis showed that 4 congenital cholesteatoma samples had very similar protein expression patterns and that 127 spots were exclusively expressed in congenital cholesteatomas. Of these 127 spots, 10 major spots revealed the presence of titin, forkhead transcription activator homolog (FKH 5-3, plectin 1, keratin 10, and leucine zipper protein 5 by MALDI-TOF/MS analysis. Immunohistochemical staining showed that FKH 5-3 and titin were expressed in congenital cholesteatoma matrices, but not in acquired cholesteatomas. Our study shows that protein expression patterns are completely different in congenital cholesteatomas, acquired cholesteatomas, and skin. Moreover, non-epithelial proteins, including FKH 5-3 and titin, were unexpectedly expressed in congenital cholesteatoma tissue. Our data indicates that congenital cholesteatoma origins

  5. An amplified promoter system for targeted expression of calcium indicator proteins in the cerebellar cortex

    Directory of Open Access Journals (Sweden)

    Bernd eKuhn

    2012-07-01

    Full Text Available Recording of identified neuronal network activity using genetically encoded calcium indicators (GECIs requires labeling that is cell type-specific and bright enough for the detection of functional signals. However, specificity and strong expression are often not achievable using the same promoter. Here we present a combinatorial approach for targeted expression and single-cell-level quantification in which a weak promoter is used to drive trans-amplification under a strong general promoter. We demonstrated this approach using recombinant adeno-associated viruses (rAAVs to deliver the sequence of the GECI D3cpv in the mouse cerebellar cortex. Direct expression under the human synapsin promoter (hSYN led to high levels of expression (50-100 µM in five interneuron types of the cerebellar cortex but not in Purkinje cells (PCs (≤10 μM, yielding sufficient contrast to allow functional signals to be recorded from somata and processes in awake animals using two-photon microscopy. When the hSYN promoter was used to drive expression of the tetracycline transactivator (tTA, a second rAAV containing the bidirectional TET promoter (Ptetbi could drive strong D3cpv expression in PCs (10-300 µM, enough to allow reliable complex spike detection in the dendritic arbor. An amplified approach should be of use in monitoring neural processing in selected cell types and boosting expression of optogenetic probes. Additionally, we overcome cell toxicity associated with rAAV injection and/or local GECI overexpression by combining the virus injection with systemic pre-injection of hyperosmotic D-mannitol, and by this double the time window for functional imaging.

  6. Evolution, diversification and expression of KNOX proteins in plants

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    Jie eGao

    2015-10-01

    Full Text Available The KNOX (KNOTTED1-like homeobox transcription factors play a pivotal role in leaf and meristem development. The majority of these proteins are characterized by the KNOX1, KNOX2, ELK and homeobox domains whereas the proteins of the KNATM family contain only the KNOX domains. We carried out an extensive inventory of these proteins and here report on a total of 394 KNOX proteins from 48 species. The land plant proteins fall into two classes (I and II as previously shown where the class I family seems to be most closely related to the green algae homologs. The KNATM proteins are restricted to Eudicots and some species have multiple paralogs of this protein. Certain plants are characterized by a significant increase in the number of KNOX paralogs; one example is Glycine max. Through the analysis of public gene expression data we show that the class II proteins of this plant have a relatively broad expression specificity as compared to class I proteins, consistent with previous studies of other plants. In G. max, class I protein are mainly distributed in axis tissues and KNATM paralogs are overall poorly expressed; highest expression is in the early plumular axis. Overall, analysis of gene expression in G. max demonstrates clearly that the expansion in gene number is associated with functional diversification.

  7. Role of alpha-crystallin, early-secreted antigenic target 6-kDa protein and culture filtrate protein 10 as novel diagnostic markers in osteoarticular tuberculosis

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    Nazia Rizvi

    2016-07-01

    Full Text Available Osteoarticular tuberculosis constitutes about 3% of all tuberculosis cases. Early and accurate diagnosis of tuberculosis is a challenging problem especially in the case of osteoarticular tuberculosis owing to the lower number of bacilli. However, an accurate and timely diagnosis of the disease results in an improved efficacy of the given treatment. Besides the limitations of conventional methods, nowadays molecular diagnostic techniques have emerged as a major breakthrough for the early diagnosis of tuberculosis with high sensitivity and specificity. Alpha-crystallin is a dominantly expressed protein responsible for the long viability of the pathogen during the latent phase under certain stress conditions such as hypoxia and nitric oxide stress. Two other proteins—early secreted antigenic target-6 and culture filtrate protein-10—show high expression in the active infective phase of Mycobacterium tuberculosis. In this article, we focus on the different proteins expressed dominantly in latent/active tuberculosis, and which may be further used as prognostic biomarkers for diagnosing tuberculosis, both in latent and active phases.

  8. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Pavlikova, Nela, E-mail: nela.pavlikova@lf3.cuni.cz [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Smetana, Pavel [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Halada, Petr [Laboratory of Molecular Structure Characterization, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Kovar, Jan [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic)

    2015-10-15

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  9. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    International Nuclear Information System (INIS)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-01-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  10. Akt/FOXO3a signaling modulates the endothelial stress response through regulation of heat shock protein 70 expression.

    Science.gov (United States)

    Kim, Hyo-Soo; Skurk, Carsten; Maatz, Henrike; Shiojima, Ichiro; Ivashchenko, Yuri; Yoon, Suk-Won; Park, Young-Bae; Walsh, Kenneth

    2005-06-01

    To identify new antiapoptotic targets of the PI3K-Akt signaling pathway in endothelial cells, adenovirus-mediated Akt1 gene transfer and oligonucleotide microarrays were used to examine Akt-regulated transcripts. DNA microarray analysis revealed that HSP70 expression underwent the greatest fold activation of 12,532 transcripts examined in human umbilical vein endothelial cells (HUVEC) transduced with constitutively active Akt1. Akt1 gene transfer increased HSP70 transcript expression by 24.8-fold as determined by quantitative PCR and promoted a dose-dependent up-regulation of HSP70 protein as determined by Western immunoblot analysis. Gene transfer of FOXO3a, a downstream target of Akt in endothelial cells, significantly suppressed both basal and stress-induced HSP70 protein expression. FOXO3a induced caspase-9-dependent apoptosis in HUVEC, and cotransduction with Ad-HSP70 rescued endothelial cells from FOXO3a-induced apoptosis under basal and stress conditions. Our results identify HSP70 as a new antiapoptotic target of Akt-FOXO3a signaling in endothelial cells that controls viability through modulation of the stress-induced intrinsic cell death pathway.

  11. RNA Binding Protein RBM38 Regulates Expression of the 11-Kilodalton Protein of Parvovirus B19, Which Facilitates Viral DNA Replication.

    Science.gov (United States)

    Ganaie, Safder S; Chen, Aaron Yun; Huang, Chun; Xu, Peng; Kleiboeker, Steve; Du, Aifang; Qiu, Jianming

    2018-04-15

    receptors and coreceptors on the cell surface but also on the intracellular host factors that support B19V replication. Our present study shows that B19V uses a host factor, RNA binding motif protein 38 (RBM38), for the processing of its pre-mRNA during virus replication. Specifically, RBM38 interacts with the intronic splicing enhancer 2 (ISE2) element of B19V pre-mRNA and promotes 11-kDa protein expression, thereby regulating the 11-kDa protein-mediated augmentation of B19V replication. The identification of this novel host-pathogen interaction will provide mechanistic insights into B19V replication and aid in finding new targets for anti-B19V therapeutics. Copyright © 2018 American Society for Microbiology.

  12. Optimized Mitochondrial Targeting of Proteins Encoded by Modified mRNAs Rescues Cells Harboring Mutations in mtATP6

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    Randall Marcelo Chin

    2018-03-01

    Full Text Available Summary: Mitochondrial disease may be caused by mutations in the protein-coding genes of the mitochondrial genome. A promising strategy for treating such diseases is allotopic expression—the translation of wild-type copies of these proteins in the cytosol, with subsequent translocation into the mitochondria, resulting in rescue of mitochondrial function. In this paper, we develop an automated, quantitative, and unbiased screening platform to evaluate protein localization and mitochondrial morphology. This platform was used to compare 31 mitochondrial targeting sequences and 15 3′ UTRs in their ability to localize up to 9 allotopically expressed proteins to the mitochondria and their subsequent impact on mitochondrial morphology. Taking these two factors together, we synthesized chemically modified mRNAs that encode for an optimized allotopic expression construct for mtATP6. These mRNAs were able to functionally rescue a cell line harboring the 8993T > G point mutation in the mtATP6 gene. : Allotopic expression of proteins normally encoded by mtDNA is a promising therapy for mitochondrial disease. Chin et al. use an unbiased and high-content imaging-based screening platform to optimize allotopic expression. Modified mRNAs encoding for the optimized allotopic expression constructs rescued the respiration and growth of mtATP6-deficient cells. Keywords: mitochondria, mitochondrial disease, mRNA, modified mRNA, ATP6, allotopic expression, rare disease, gene therapy, screening, high content imaging

  13. Arabidopsis EMB1990 Encoding a Plastid-Targeted YlmG Protein Is Required for Chloroplast Biogenesis and Embryo Development

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    Hongyu Chen

    2018-02-01

    Full Text Available In higher plants, embryo development originated from fertilized egg cell is the first step of the life cycle. The chloroplast participates in many essential metabolic pathways, and its function is highly associated with embryo development. However, the mechanisms and relevant genetic components by which the chloroplast functions in embryogenesis are largely uncharacterized. In this paper, we describe the Arabidopsis EMB1990 gene, encoding a plastid-targeted YlmG protein which is required for chloroplast biogenesis and embryo development. Loss of the EMB1990/YLMG1-1 resulted in albino seeds containing abortive embryos, and the morphological development of homozygous emb1990 embryos was disrupted after the globular stage. Our results showed that EMB1990/YLMG1-1 was expressed in the primordia and adaxial region of cotyledon during embryogenesis, and the encoded protein was targeted to the chloroplast. TEM observation of cellular ultrastructure showed that chloroplast biogenesis was impaired in emb1990 embryo cells. Expression of certain plastid genes was also affected in the loss-of-function mutants, including genes encoding core protein complex subunits located in the thylakoid membrane. Moreover, the tissue-specific genes of embryo development were misexpressed in emb1990 mutant, including genes known to delineate cell fate decisions in the SAM (shoot apical meristem, cotyledon and hypophysis. Taken together, we propose that the nuclear-encoded YLMG1-1 is targeted to the chloroplast and required for normal plastid gene expression. Hence, YLMG1-1 plays a critical role in Arabidopsis embryogenesis through participating in chloroplast biogenesis.

  14. MAGE-C2/CT10 protein expression is an independent predictor of recurrence in prostate cancer.

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    Lotta von Boehmer

    Full Text Available The cancer-testis (CT family of antigens is expressed in a variety of malignant neoplasms. In most cases, no CT antigen is found in normal tissues, except in testis, making them ideal targets for cancer immunotherapy. A comprehensive analysis of CT antigen expression has not yet been reported in prostate cancer. MAGE-C2/CT-10 is a novel CT antigen. The objective of this study was to analyze extent and prognostic significance of MAGE-C2/CT10 protein expression in prostate cancer. 348 prostate carcinomas from consecutive radical prostatectomies, 29 castration-refractory prostate cancer, 46 metastases, and 45 benign hyperplasias were immunohistochemically analyzed for MAGE-C2/CT10 expression using tissue microarrays. Nuclear MAGE-C2/CT10 expression was identified in only 3.3% primary prostate carcinomas. MAGE-C2/CT10 protein expression was significantly more frequent in metastatic (16.3% positivity and castration-resistant prostate cancer (17% positivity; p<0.001. Nuclear MAGE-C2/CT10 expression was identified as predictor of biochemical recurrence after radical prostatectomy (p = 0.015, which was independent of preoperative PSA, Gleason score, tumor stage, and surgical margin status in multivariate analysis (p<0.05. MAGE-C2/CT10 expression in prostate cancer correlates with the degree of malignancy and indicates a higher risk for biochemical recurrence after radical prostatectomy. Further, the results suggest MAGE-C2/CT10 as a potential target for adjuvant and palliative immunotherapy in patients with prostate cancer.

  15. Conformational targeting of fibrillar polyglutamine proteins in live cells escalates aggregation and cytotoxicity.

    Directory of Open Access Journals (Sweden)

    Erik Kvam

    2009-05-01

    Full Text Available Misfolding- and aggregation-prone proteins underlying Parkinson's, Huntington's and Machado-Joseph diseases, namely alpha-synuclein, huntingtin, and ataxin-3 respectively, adopt numerous intracellular conformations during pathogenesis, including globular intermediates and insoluble amyloid-like fibrils. Such conformational diversity has complicated research into amyloid-associated intracellular dysfunction and neurodegeneration. To this end, recombinant single-chain Fv antibodies (scFvs are compelling molecular tools that can be selected against specific protein conformations, and expressed inside cells as intrabodies, for investigative and therapeutic purposes.Using atomic force microscopy (AFM and live-cell fluorescence microscopy, we report that a human scFv selected against the fibrillar form of alpha-synuclein targets isomorphic conformations of misfolded polyglutamine proteins. When expressed in the cytoplasm of striatal cells, this conformation-specific intrabody co-localizes with intracellular aggregates of misfolded ataxin-3 and a pathological fragment of huntingtin, and enhances the aggregation propensity of both disease-linked polyglutamine proteins. Using this intrabody as a tool for modulating the kinetics of amyloidogenesis, we show that escalating aggregate formation of a pathologic huntingtin fragment is not cytoprotective in striatal cells, but rather heightens oxidative stress and cell death as detected by flow cytometry. Instead, cellular protection is achieved by suppressing aggregation using a previously described intrabody that binds to the amyloidogenic N-terminus of huntingtin. Analogous cytotoxic results are observed following conformational targeting of normal or polyglutamine-expanded human ataxin-3, which partially aggregate through non-polyglutamine domains.These findings validate that the rate of aggregation modulates polyglutamine-mediated intracellular dysfunction, and caution that molecules designed to

  16. Protein-Protein Interactions of Viroporins in Coronaviruses and Paramyxoviruses: New Targets for Antivirals?

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    Jaume Torres

    2015-06-01

    Full Text Available Viroporins are members of a rapidly growing family of channel-forming small polypeptides found in viruses. The present review will be focused on recent structural and protein-protein interaction information involving two viroporins found in enveloped viruses that target the respiratory tract; (i the envelope protein in coronaviruses and (ii the small hydrophobic protein in paramyxoviruses. Deletion of these two viroporins leads to viral attenuation in vivo, whereas data from cell culture shows involvement in the regulation of stress and inflammation. The channel activity and structure of some representative members of these viroporins have been recently characterized in some detail. In addition, searches for protein-protein interactions using yeast-two hybrid techniques have shed light on possible functional roles for their exposed cytoplasmic domains. A deeper analysis of these interactions should not only provide a more complete overview of the multiple functions of these viroporins, but also suggest novel strategies that target protein-protein interactions as much needed antivirals. These should complement current efforts to block viroporin channel activity.

  17. Alternative splicing affects the targeting sequence of peroxisome proteins in Arabidopsis.

    Science.gov (United States)

    An, Chuanjing; Gao, Yuefang; Li, Jinyu; Liu, Xiaomin; Gao, Fuli; Gao, Hongbo

    2017-07-01

    A systematic analysis of the Arabidopsis genome in combination with localization experiments indicates that alternative splicing affects the peroxisomal targeting sequence of at least 71 genes in Arabidopsis. Peroxisomes are ubiquitous eukaryotic cellular organelles that play a key role in diverse metabolic functions. All peroxisome proteins are encoded by nuclear genes and target to peroxisomes mainly through two types of targeting signals: peroxisomal targeting signal type 1 (PTS1) and PTS2. Alternative splicing (AS) is a process occurring in all eukaryotes by which a single pre-mRNA can generate multiple mRNA variants, often encoding proteins with functional differences. However, the effects of AS on the PTS1 or PTS2 and the targeting of the protein were rarely studied, especially in plants. Here, we systematically analyzed the genome of Arabidopsis, and found that the C-terminal targeting sequence PTS1 of 66 genes and the N-terminal targeting sequence PTS2 of 5 genes are affected by AS. Experimental determination of the targeting of selected protein isoforms further demonstrated that AS at both the 5' and 3' region of a gene can affect the inclusion of PTS2 and PTS1, respectively. This work underscores the importance of AS on the global regulation of peroxisome protein targeting.

  18. Evaluation of miRNA-196a2 and apoptosis-related target genes: ANXA1, DFFA and PDCD4 expression in gastrointestinal cancer patients: A pilot study

    Science.gov (United States)

    Toraih, Eman A.; Ibrahiem, Afaf; Abdeldayem, Hala; Mohamed, Amany O.; Abdel-Daim, Mohamed M.

    2017-01-01

    Previous reports have suggested the significant association of miRNAs aberrant expression with tumor initiation, progression and metastasis in cancer, including gastrointestinal (GI) cancers. The current preliminary study aimed to evaluate the relative expression levels of miR-196a2 and three of its selected apoptosis-related targets; ANXA1, DFFA and PDCD4 in a sample of GI cancer patients. Quantitative real-time PCR for miR-196a2 and its selected mRNA targets, as well as immunohistochemical assay for annexin A1 protein expression were detected in 58 tissues with different GI cancer samples. In addition, correlation with the clinicopathological features and in silico network analysis of the selected molecular markers were analyzed. Stratified analyses by cancer site revealed elevated levels of miR-196a2 and low expression of the selected target genes. Annexin protein expression was positively correlated with its gene expression profile. In colorectal cancer, miR-196a over-expression was negatively correlated with annexin A1 protein expression (r = -0.738, p < 0.001), and both were indicators of unfavorable prognosis in terms of poor differentiation, larger tumor size, and advanced clinical stage. Taken together, aberrant expression of miR-196a2 and the selected apoptosis-related biomarkers might be involved in GI cancer development and progression and could have potential diagnostic and prognostic roles in these types of cancer; particularly colorectal cancer, provided the results experimentally validated and confirmed in larger multi-center studies. PMID:29091952

  19. The proteome response to amyloid protein expression in vivo.

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    Ricardo A Gomes

    Full Text Available Protein misfolding disorders such as Alzheimer, Parkinson and transthyretin amyloidosis are characterized by the formation of protein amyloid deposits. Although the nature and location of the aggregated proteins varies between different diseases, they all share similar molecular pathways of protein unfolding, aggregation and amyloid deposition. Most effects of these proteins are likely to occur at the proteome level, a virtually unexplored reality. To investigate the effects of an amyloid protein expression on the cellular proteome, we created a yeast expression system using human transthyretin (TTR as a model amyloidogenic protein. We used Saccharomyces cerevisiae, a living test tube, to express native TTR (non-amyloidogenic and the amyloidogenic TTR variant L55P, the later forming aggregates when expressed in yeast. Differential proteome changes were quantitatively analyzed by 2D-differential in gel electrophoresis (2D-DIGE. We show that the expression of the amyloidogenic TTR-L55P causes a metabolic shift towards energy production, increased superoxide dismutase expression as well as of several molecular chaperones involved in protein refolding. Among these chaperones, members of the HSP70 family and the peptidyl-prolyl-cis-trans isomerase (PPIase were identified. The latter is highly relevant considering that it was previously found to be a TTR interacting partner in the plasma of ATTR patients but not in healthy or asymptomatic subjects. The small ubiquitin-like modifier (SUMO expression is also increased. Our findings suggest that refolding and degradation pathways are activated, causing an increased demand of energetic resources, thus the metabolic shift. Additionally, oxidative stress appears to be a consequence of the amyloidogenic process, posing an enhanced threat to cell survival.

  20. Targeted Diazotransfer Reagents Enable Selective Modification of Proteins with Azides.

    Science.gov (United States)

    Lohse, Jonas; Swier, Lotteke J Y M; Oudshoorn, Ruben C; Médard, Guillaume; Kuster, Bernhard; Slotboom, Dirk-Jan; Witte, Martin D

    2017-04-19

    In chemical biology, azides are used to chemically manipulate target structures in a bioorthogonal manner for a plethora of applications ranging from target identification to the synthesis of homogeneously modified protein conjugates. While a variety of methods have been established to introduce the azido group into recombinant proteins, a method that directly converts specific amino groups in endogenous proteins is lacking. Here, we report the first biotin-tethered diazotransfer reagent DtBio and demonstrate that it selectively modifies the model proteins streptavidin and avidin and the membrane protein BioY on cell surface. The reagent converts amines in the proximity of the binding pocket to azides and leaves the remaining amino groups in streptavidin untouched. Reagents of this novel class will find use in target identification as well as the selective functionalization and bioorthogonal protection of proteins.

  1. Arabidopsis Tic40 expression in tobacco chloroplasts results in massive proliferation of the inner envelope membrane and upregulation of associated proteins.

    Science.gov (United States)

    Singh, Nameirakpam Dolendro; Li, Ming; Lee, Sueng-Bum; Schnell, Danny; Daniell, Henry

    2008-12-01

    The chloroplast inner envelope membrane (IM) plays essential roles in lipid synthesis, metabolite transport, and cellular signaling in plants. We have targeted a model nucleus-encoded IM protein from Arabidopsis thaliana, pre-Tic40-His, by relocating its expression from the nucleus to the chloroplast genome. Pre-Tic40-His was properly targeted, processed, and inserted. It attained correct topology and was folded and assembled into a TIC complex, where it accounted for up to 15% of the total chloroplast protein. These results confirm the existence of a novel pathway for protein targeting to the IM. Tic40-His overexpression resulted in a massive proliferation of the IM (up to 19 layers in electron micrographs) without significant effects on plant growth or reproduction. Consistent with IM proliferation, the expression levels of other endogenous IM proteins (IEP37, PPT, Tic110) were significantly (10-fold) upregulated but those of outer envelope membrane (Toc159), stromal (hsp93, cpn60), or thylakoid (LHCP, OE23) proteins were not increased, suggesting retrograde signal transduction between chloroplast and nuclear genomes to increase lipid and protein components for accommodation of increased accumulation of Tic40. This study opens the door for understanding the regulation of membrane biogenesis within the organelle and the utilization of transgenic chloroplasts as bioreactors for hyperaccumulation of membrane proteins for biotechnological applications.

  2. Small molecule PGC-1α1 protein stabilizers induce adipocyte Ucp1 expression and uncoupled mitochondrial respiration

    Directory of Open Access Journals (Sweden)

    A.T. Pettersson-Klein

    2018-03-01

    Full Text Available Objective: The peroxisome proliferator-activated receptor-γ coactivator-1α1 (PGC-1α1 regulates genes involved in energy metabolism. Increasing adipose tissue energy expenditure through PGC-1α1 activation is potentially beneficial for systemic metabolism. Pharmacological PGC-1α1 activators could be valuable tools in the fight against obesity and metabolic disease. Finding such compounds has been challenging partly because PGC-1α1 is a transcriptional coactivator with no known ligand-binding properties. While, PGC-1α1 activation is regulated by several mechanisms, protein stabilization is a crucial limiting step due to its short half-life under unstimulated conditions. Methods: We designed a cell-based high-throughput screening system to identify PGC-1α1 protein stabilizers. Positive hits were tested for their ability to induce endogenous PGC-1α1 protein accumulation and activate target gene expression in brown adipocytes. Select compounds were analyzed for their effects on global gene expression and cellular respiration in adipocytes. Results: Among 7,040 compounds screened, we highlight four small molecules with high activity as measured by: PGC-1α1 protein accumulation, target gene expression, and uncoupled mitochondrial respiration in brown adipocytes. Conclusions: We identify compounds that induce PGC-1α1 protein accumulation and show that this increases uncoupled respiration in brown adipocytes. This screening platform establishes the foundation for a new class of therapeutics with potential use in obesity and associated disorders. Keywords: Small molecule screening, PGC-1a, PGC-1alpha, PGC-1alpha1, Protein stabilization, UCP1, Mitochondrial respiration, Brown adipose tissue

  3. Ligand Binding Domain Protein in Tetracycline-Inducible Expression

    African Journals Online (AJOL)

    Purpose: To investigate tetracycline-inducible expression system for producing clinically usable, highquality liver X receptor ligand-binding domain recombinant protein. Methods: In this study, we have expressed and purified the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a tetracycline ...

  4. Stimulation of Protein Expression Through the Harmonic Resonance of Frequency-Specific Music.

    Science.gov (United States)

    Orhan, Ibrahim Y; Gulbahar, Burak A

    2016-12-01

    The use of specific frequencies for specific individual amino acids may increase the potential energy of protein molecules in the medium [1]. The resonance would also increase the movement of particles in the cytosol, increasing the collisions necessary for the conduction of protein expression. The clash of two waves that share frequencies will exhibit an increase in energy through an increase in amplitude [2]. The increase in energy would in turn increase the number of collisions forming the tRNA-amino acid, increasing the amino acid acquiry for ribosomes to improve intracellular efficiency in gene expression. To test the hypothesis, Red Fluorescent Protein (RFP) in transformated BL-21 strains of E. coli and p53 protein of MCF-7 were examined after exposure to sounds of specific frequencies. Through the exposure of the experimental systems to a sequence of sounds that match the frequencies of specific amino acids, the levels of RFP exhibition respective to the control groups in the bacterial medium increased two-fold in terms of RFU. The experiments that targeted the p53 protein with the 'music' showed a decrease in the cell prevalence in the MCF-7 type breast cancer cells by 28%, by decreasing the speed of tumour formation. Exposure to 'music' that was designed through assigning a musical note for every single one of the twenty unique amino acids, produced both an analytical and a visible shift in protein synthesis, making it as potential tool for reducing procedural time uptake.

  5. Loss of the Caenorhabditis elegans pocket protein LIN-35 reveals MuvB's innate function as the repressor of DREAM target genes.

    Directory of Open Access Journals (Sweden)

    Paul D Goetsch

    2017-11-01

    Full Text Available The DREAM (Dp/Retinoblastoma(Rb-like/E2F/MuvB transcriptional repressor complex acts as a gatekeeper of the mammalian cell cycle by establishing and maintaining cellular quiescence. How DREAM's three functional components, the E2F-DP heterodimer, the Rb-like pocket protein, and the MuvB subcomplex, form and function at target gene promoters remains unknown. The current model invokes that the pocket protein links E2F-DP and MuvB and is essential for gene repression. We tested this model by assessing how the conserved yet less redundant DREAM system in Caenorhabditis elegans is affected by absence of the sole C. elegans pocket protein LIN-35. Using a LIN-35 protein null mutant, we analyzed the assembly of E2F-DP and MuvB at promoters that are bound by DREAM and the level of expression of those "DREAM target genes" in embryos. We report that LIN-35 indeed mediates the association of E2F-DP and MuvB, a function that stabilizes DREAM subunit occupancy at target genes. In the absence of LIN-35, the occupancy of E2F-DP and MuvB at most DREAM target genes decreases dramatically and many of those genes become upregulated. The retention of E2F-DP and MuvB at some target gene promoters in lin-35 null embryos allowed us to test their contribution to DREAM target gene repression. Depletion of MuvB, but not E2F-DP, in the sensitized lin-35 null background caused further upregulation of DREAM target genes. We conclude that the pocket protein functions primarily to support MuvB-mediated repression of DREAM targets and that transcriptional repression is the innate function of the evolutionarily conserved MuvB complex. Our findings provide important insights into how mammalian DREAM assembly and disassembly may regulate gene expression and the cell cycle.

  6. Novel treatment option for MUC16-positive malignancies with the targeted TRAIL-based fusion protein Meso-TR3

    International Nuclear Information System (INIS)

    Garg, Gunjal; Spitzer, Dirk; Gibbs, Jesse; Belt, Brian; Powell, Matthew A; Mutch, David G; Goedegebuure, Peter; Collins, Lynne; Piwnica-Worms, David; Hawkins, William G

    2014-01-01

    The targeted delivery of cancer therapeutics represents an ongoing challenge in the field of drug development. TRAIL is a promising cancer drug but its activity profile could benefit from a cancer-selective delivery mechanism, which would reduce potential side effects and increase treatment efficiencies. We recently developed the novel TRAIL-based drug platform TR3, a genetically fused trimer with the capacity for further molecular modifications such as the addition of tumor-directed targeting moieties. MUC16 (CA125) is a well characterized biomarker in several human malignancies including ovarian, pancreatic and breast cancer. Mesothelin is known to interact with MUC16 with high affinity. In order to deliver TR3 selectively to MUC16-expressing cancers, we investigated the possibility of targeted TR3 delivery employing the high affinity mesothelin/MUC16 ligand/receptor interaction. Using genetic engineering, we designed the novel cancer drug Meso-TR3, a fusion protein between native mesothelin and TR3. The recombinant proteins were produced with mammalian HEK293T cells. Meso-TR3 was characterized for binding selectivity and killing efficacy against MUC16-positive cancer cells and controls that lack MUC16 expression. Drug efficacy experiments were performed in vitro and in vivo employing an intraperitoneal xenograft mouse model of ovarian cancer. Similar to soluble mesothelin itself, the strong MUC16 binding property was retained in the Meso-TR3 fusion protein. The high affinity ligand/receptor interaction was associated with a selective accumulation of the cancer drug on MUC16-expressing cancer targets and directly correlated with increased killing activity in vitro and in a xenograft mouse model of ovarian cancer. The relevance of the mesothelin/MUC16 interaction for attaching Meso-TR3 to the cancer cells was verified by competitive blocking experiments using soluble mesothelin. Mechanistic studies using soluble DR5-Fc and caspase blocking assays confirmed

  7. [Expression of c-jun protein after experimental rat brain concussion].

    Science.gov (United States)

    Wang, Feng; Li, Yong-hong

    2010-02-01

    To observe e-jun protein expression after rat brain concussion and explore the forensic pathologic markers following brain concussion. Fifty-five rats were randomly divided into brain concussion group and control group. The expression of c-jun protein was observed by immunohistochemistry. There were weak positive expression of c-jun protein in control group. In brain concussion group, however, some neutrons showed positive expression of c-jun protein at 15 min after brain concussion, and reach to the peak at 3 h after brain concussion. The research results suggest that detection of c-jun protein could be a marker to determine brain concussion and estimate injury time after brain concussion.

  8. Plant pathology: monitoring a pathogen-targeted host protein.

    Science.gov (United States)

    Ellis, Jeff; Dodds, Peter

    2003-05-13

    A plant protein RIN4 is targeted and modified by bacterial pathogens as part of the disease process. At least two host resistance proteins monitor this pathogen interference and trigger the plant's defence responses.

  9. Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks

    Science.gov (United States)

    2012-09-21

    Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks Paulo Shakarian1*, J. Kenneth Wickiser2 1 Paulo Shakarian...significantly attacked. Citation: Shakarian P, Wickiser JK (2012) Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks...to 00-00-2012 4. TITLE AND SUBTITLE Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks 5a. CONTRACT NUMBER 5b

  10. Expression analysis of G Protein-Coupled Receptors in mouse macrophages.

    Science.gov (United States)

    Lattin, Jane E; Schroder, Kate; Su, Andrew I; Walker, John R; Zhang, Jie; Wiltshire, Tim; Saijo, Kaoru; Glass, Christopher K; Hume, David A; Kellie, Stuart; Sweet, Matthew J

    2008-04-29

    Monocytes and macrophages express an extensive repertoire of G Protein-Coupled Receptors (GPCRs) that regulate inflammation and immunity. In this study we performed a systematic micro-array analysis of GPCR expression in primary mouse macrophages to identify family members that are either enriched in macrophages compared to a panel of other cell types, or are regulated by an inflammatory stimulus, the bacterial product lipopolysaccharide (LPS). Several members of the P2RY family had striking expression patterns in macrophages; P2ry6 mRNA was essentially expressed in a macrophage-specific fashion, whilst P2ry1 and P2ry5 mRNA levels were strongly down-regulated by LPS. Expression of several other GPCRs was either restricted to macrophages (e.g. Gpr84) or to both macrophages and neural tissues (e.g. P2ry12, Gpr85). The GPCR repertoire expressed by bone marrow-derived macrophages and thioglycollate-elicited peritoneal macrophages had some commonality, but there were also several GPCRs preferentially expressed by either cell population. The constitutive or regulated expression in macrophages of several GPCRs identified in this study has not previously been described. Future studies on such GPCRs and their agonists are likely to provide important insights into macrophage biology, as well as novel inflammatory pathways that could be future targets for drug discovery.

  11. Recombinant protein production data after expression in the bacterium Escherichia coli

    Directory of Open Access Journals (Sweden)

    J. Enrique Cantu-Bustos

    2016-06-01

    Full Text Available Fusion proteins have become essential for the expression and purification of recombinant proteins in Escherichia coli. The metal-binding protein CusF has shown several features that make it an attractive fusion protein and affinity tag: "Expression and purification of recombinant proteins in Escherichia coli tagged with the metal-binding protein CusF" (Cantu-Bustos et al., 2016 [1]. Here we present accompanying data from protein expression experiments; we tested different protein tags, temperatures, expression times, cellular compartments, and concentrations of inducer in order to obtain soluble protein and low formation of inclusion bodies. Additionally, we present data from the purification of the green fluorescent protein (GFP tagged with CusF, using Ag(I metal affinity chromatography.

  12. Genomes2Drugs: identifies target proteins and lead drugs from proteome data.

    LENUS (Irish Health Repository)

    Toomey, David

    2009-01-01

    BACKGROUND: Genome sequencing and bioinformatics have provided the full hypothetical proteome of many pathogenic organisms. Advances in microarray and mass spectrometry have also yielded large output datasets of possible target proteins\\/genes. However, the challenge remains to identify new targets for drug discovery from this wealth of information. Further analysis includes bioinformatics and\\/or molecular biology tools to validate the findings. This is time consuming and expensive, and could fail to yield novel drugs if protein purification and crystallography is impossible. To pre-empt this, a researcher may want to rapidly filter the output datasets for proteins that show good homology to proteins that have already been structurally characterised or proteins that are already targets for known drugs. Critically, those researchers developing novel antibiotics need to select out the proteins that show close homology to any human proteins, as future inhibitors are likely to cross-react with the host protein, causing off-target toxicity effects later in clinical trials. METHODOLOGY\\/PRINCIPAL FINDINGS: To solve many of these issues, we have developed a free online resource called Genomes2Drugs which ranks sequences to identify proteins that are (i) homologous to previously crystallized proteins or (ii) targets of known drugs, but are (iii) not homologous to human proteins. When tested using the Plasmodium falciparum malarial genome the program correctly enriched the ranked list of proteins with known drug target proteins. CONCLUSIONS\\/SIGNIFICANCE: Genomes2Drugs rapidly identifies proteins that are likely to succeed in drug discovery pipelines. This free online resource helps in the identification of potential drug targets. Importantly, the program further highlights proteins that are likely to be inhibited by FDA-approved drugs. These drugs can then be rapidly moved into Phase IV clinical studies under \\'change-of-application\\' patents.

  13. Genomes2Drugs: identifies target proteins and lead drugs from proteome data.

    Directory of Open Access Journals (Sweden)

    David Toomey

    Full Text Available BACKGROUND: Genome sequencing and bioinformatics have provided the full hypothetical proteome of many pathogenic organisms. Advances in microarray and mass spectrometry have also yielded large output datasets of possible target proteins/genes. However, the challenge remains to identify new targets for drug discovery from this wealth of information. Further analysis includes bioinformatics and/or molecular biology tools to validate the findings. This is time consuming and expensive, and could fail to yield novel drugs if protein purification and crystallography is impossible. To pre-empt this, a researcher may want to rapidly filter the output datasets for proteins that show good homology to proteins that have already been structurally characterised or proteins that are already targets for known drugs. Critically, those researchers developing novel antibiotics need to select out the proteins that show close homology to any human proteins, as future inhibitors are likely to cross-react with the host protein, causing off-target toxicity effects later in clinical trials. METHODOLOGY/PRINCIPAL FINDINGS: To solve many of these issues, we have developed a free online resource called Genomes2Drugs which ranks sequences to identify proteins that are (i homologous to previously crystallized proteins or (ii targets of known drugs, but are (iii not homologous to human proteins. When tested using the Plasmodium falciparum malarial genome the program correctly enriched the ranked list of proteins with known drug target proteins. CONCLUSIONS/SIGNIFICANCE: Genomes2Drugs rapidly identifies proteins that are likely to succeed in drug discovery pipelines. This free online resource helps in the identification of potential drug targets. Importantly, the program further highlights proteins that are likely to be inhibited by FDA-approved drugs. These drugs can then be rapidly moved into Phase IV clinical studies under 'change-of-application' patents.

  14. The reactive metabolite target protein database (TPDB)--a web-accessible resource.

    Science.gov (United States)

    Hanzlik, Robert P; Koen, Yakov M; Theertham, Bhargav; Dong, Yinghua; Fang, Jianwen

    2007-03-16

    The toxic effects of many simple organic compounds stem from their biotransformation to chemically reactive metabolites which bind covalently to cellular proteins. To understand the mechanisms of cytotoxic responses it may be important to know which proteins become adducted and whether some may be common targets of multiple toxins. The literature of this field is widely scattered but expanding rapidly, suggesting the need for a comprehensive, searchable database of reactive metabolite target proteins. The Reactive Metabolite Target Protein Database (TPDB) is a comprehensive, curated, searchable, documented compilation of publicly available information on the protein targets of reactive metabolites of 18 well-studied chemicals and drugs of known toxicity. TPDB software enables i) string searches for author names and proteins names/synonyms, ii) more complex searches by selecting chemical compound, animal species, target tissue and protein names/synonyms from pull-down menus, and iii) commonality searches over multiple chemicals. Tabulated search results provide information, references and links to other databases. The TPDB is a unique on-line compilation of information on the covalent modification of cellular proteins by reactive metabolites of chemicals and drugs. Its comprehensiveness and searchability should facilitate the elucidation of mechanisms of reactive metabolite toxicity. The database is freely available at http://tpdb.medchem.ku.edu/tpdb.html.

  15. MicroRNA-147b regulates vascular endothelial barrier function by targeting ADAM15 expression.

    Directory of Open Access Journals (Sweden)

    Victor Chatterjee

    Full Text Available A disintegrin and metalloproteinase15 (ADAM15 has been shown to be upregulated and mediate endothelial hyperpermeability during inflammation and sepsis. This molecule contains multiple functional domains with the ability to modulate diverse cellular processes including cell adhesion, extracellular matrix degradation, and ectodomain shedding of transmembrane proteins. These characteristics make ADAM15 an attractive therapeutic target in various diseases. The lack of pharmacological inhibitors specific to ADAM15 prompted our efforts to identify biological or molecular tools to alter its expression for further studying its function and therapeutic implications. The goal of this study was to determine if ADAM15-targeting microRNAs altered ADAM15-induced endothelial barrier dysfunction during septic challenge by bacterial lipopolysaccharide (LPS. An in silico analysis followed by luciferase reporter assay in human vascular endothelial cells identified miR-147b with the ability to target the 3' UTR of ADAM15. Transfection with a miR-147b mimic led to decreased total, as well as cell surface expression of ADAM15 in endothelial cells, while miR-147b antagomir produced an opposite effect. Functionally, LPS-induced endothelial barrier dysfunction, evidenced by a reduction in transendothelial electric resistance and increase in albumin flux across endothelial monolayers, was attenuated in cells treated with miR-147b mimics. In contrast, miR-147b antagomir exerted a permeability-increasing effect in vascular endothelial cells similar to that caused by LPS. Taken together, these data suggest the potential role of miR147b in regulating endothelial barrier function by targeting ADAM15 expression.

  16. Determinants for membrane association and permeabilization of the coxsackievirus 2B protein and the identification of the Golgi complex as the target organelle.

    Science.gov (United States)

    de Jong, Arjan S; Wessels, Els; Dijkman, Henri B P M; Galama, Jochem M D; Melchers, Willem J G; Willems, Peter H G M; van Kuppeveld, Frank J M

    2003-01-10

    The 2B protein of enterovirus is responsible for the alterations in the permeability of secretory membranes and the plasma membrane in infected cells. The structural requirements for the membrane association and the subcellular localization of this essential virus protein, however, have not been defined. Here, we provide evidence that the 2B protein is an integral membrane protein in vivo that is predominantly localized at the Golgi complex upon individual expression. Addition of organelle-specific targeting signals to the 2B protein revealed that the Golgi localization is an absolute prerequisite for the ability of the protein to modify plasma membrane permeability. Expression of deletion mutants and heterologous proteins containing specific domains of the 2B protein demonstrated that each of the two hydrophobic regions could mediate membrane binding individually. However, the presence of both hydrophobic regions was required for the correct membrane association, efficient Golgi targeting, and the membrane-permeabilizing activity of the 2B protein, suggesting that the two hydrophobic regions are cooperatively involved in the formation of a membrane-integral complex. The formation of membrane-integral pores by the 2B protein in the Golgi complex and the possible mechanism by which a Golgi-localized virus protein modifies plasma membrane permeability are discussed.

  17. Application of encoded library technology (ELT) to a protein-protein interaction target: discovery of a potent class of integrin lymphocyte function-associated antigen 1 (LFA-1) antagonists.

    Science.gov (United States)

    Kollmann, Christopher S; Bai, Xiaopeng; Tsai, Ching-Hsuan; Yang, Hongfang; Lind, Kenneth E; Skinner, Steven R; Zhu, Zhengrong; Israel, David I; Cuozzo, John W; Morgan, Barry A; Yuki, Koichi; Xie, Can; Springer, Timothy A; Shimaoka, Motomu; Evindar, Ghotas

    2014-04-01

    The inhibition of protein-protein interactions remains a challenge for traditional small molecule drug discovery. Here we describe the use of DNA-encoded library technology for the discovery of small molecules that are potent inhibitors of the interaction between lymphocyte function-associated antigen 1 and its ligand intercellular adhesion molecule 1. A DNA-encoded library with a potential complexity of 4.1 billion compounds was exposed to the I-domain of the target protein and the bound ligands were affinity selected, yielding an enriched small-molecule hit family. Compounds representing this family were synthesized without their DNA encoding moiety and found to inhibit the lymphocyte function-associated antigen 1/intercellular adhesion molecule-1 interaction with submicromolar potency in both ELISA and cell adhesion assays. Re-synthesized compounds conjugated to DNA or a fluorophore were demonstrated to bind to cells expressing the target protein. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Targeting HSP90 and monoclonal protein trafficking modulates the unfolded protein response, chaperone regulation and apoptosis in myeloma cells

    International Nuclear Information System (INIS)

    Born, E J; Hartman, S V; Holstein, S A

    2013-01-01

    Multiple myeloma is characterized by the production of substantial quantities of monoclonal protein. We have previously demonstrated that select inhibitors of the isoprenoid biosynthetic pathway (IBP) induce apoptosis of myeloma cells via inhibition of Rab geranylgeranylation, leading to disruption of monoclonal protein trafficking and induction of the unfolded protein response (UPR) pathway. Heat-shock protein 90 (HSP90) inhibitors disrupt protein folding and are currently under clinical investigation in myeloma. The effects of combining IBP and HSP90 inhibitors on cell death, monoclonal protein trafficking, the UPR and chaperone regulation were investigated in monoclonal protein-producing cells. An enhanced induction of cell death was observed following treatment with IBP and HSP90 inhibitors, which occurred through both ER stress and non-ER stress pathways. The HSP90 inhibitor 17-AAG abrogated the effects of the IBP inhibitors on intracellular monoclonal protein levels and localization as well as induction of the UPR in myeloma cells. Disparate effects on chaperone expression were observed in myeloma vs amyloid light chain cells. Here we demonstrate that the novel strategy of targeting MP trafficking in concert with HSP90 enhances myeloma cell death via a complex modulation of ER stress, UPR, and cell death pathways

  19. Protein and Peptide in Drug Targeting and its Therapeutic Approach

    Directory of Open Access Journals (Sweden)

    Raj K. Keservani

    2015-09-01

    Full Text Available Aim: The main aim of this review article is to provide information like advantages of protein and peptides via different routes of drug administration, targeted to a particular site and its implication in drug delivery system. Methods: To that aim, from the web sites of PubMed, HCAplus, Thomson, and Registry were used as the main sources to perform the search for the most significant research articles published on the subject. The information was then carefully analyzed, highlighting the most important results in the development of protein and peptide drug targeting as well as its therapeutic activity. Results: In recent years many researchers use protein and peptide as a target site of drug by a different delivery system. Proteins and peptides are used as specific and effective therapeutic agents, due to instability and side effects their use is complicated. Protein kinases are important regulators of most, if not all, biological processes. Abnormal activity of proteins and peptides has been implicated in many human diseases, such as diabetes, cancer and neurodegenerative disorders. Conclusions: It is concluded that the protein and peptide were used in drug targeting to specific site and also used in different diseased states like cancer, diabetes, immunomodulating, neurodegenerative effects and antimicrobial activity.

  20. Targeting and Assembly of Components of the TOC Protein Import Complex at the Chloroplast Outer Envelope Membrane

    Directory of Open Access Journals (Sweden)

    Lynn G.L. Richardson

    2014-06-01

    Full Text Available The translocon at the outer envelope membrane of chloroplasts (TOC initiates the import of thousands of nuclear encoded preproteins required for chloroplast biogenesis and function. The multimeric TOC complex contains two GTP-regulated receptors, Toc34 and Toc159, which recognize the transit peptides of preproteins and initiate protein import through a β–barrel membrane channel, Toc75. Different isoforms of Toc34 and Toc159 assemble with Toc75 to form structurally and functionally diverse translocons, and the composition and levels of TOC translocons is required for the import of specific subsets of coordinately expressed proteins during plant growth and development. Consequently, the proper assembly of the TOC complexes is key to ensuring organelle homeostasis. This review will focus on our current knowledge of the targeting and assembly of TOC components to form functional translocons at the outer membrane. Our analyses reveal that the targeting of TOC components involves elements common to the targeting of other outer membrane proteins, but also include unique features that appear to have evolved to specifically facilitate assembly of the import apparatus.

  1. Targeting and assembly of components of the TOC protein import complex at the chloroplast outer envelope membrane.

    Science.gov (United States)

    Richardson, Lynn G L; Paila, Yamuna D; Siman, Steven R; Chen, Yi; Smith, Matthew D; Schnell, Danny J

    2014-01-01

    The translocon at the outer envelope membrane of chloroplasts (TOC) initiates the import of thousands of nuclear encoded preproteins required for chloroplast biogenesis and function. The multimeric TOC complex contains two GTP-regulated receptors, Toc34 and Toc159, which recognize the transit peptides of preproteins and initiate protein import through a β-barrel membrane channel, Toc75. Different isoforms of Toc34 and Toc159 assemble with Toc75 to form structurally and functionally diverse translocons, and the composition and levels of TOC translocons is required for the import of specific subsets of coordinately expressed proteins during plant growth and development. Consequently, the proper assembly of the TOC complexes is key to ensuring organelle homeostasis. This review will focus on our current knowledge of the targeting and assembly of TOC components to form functional translocons at the outer membrane. Our analyses reveal that the targeting of TOC components involves elements common to the targeting of other outer membrane proteins, but also include unique features that appear to have evolved to specifically facilitate assembly of the import apparatus.

  2. Recent progress in the development of protein-protein interaction inhibitors targeting androgen receptor-coactivator binding in prostate cancer.

    Science.gov (United States)

    Biron, Eric; Bédard, François

    2016-07-01

    The androgen receptor (AR) is a key regulator for the growth, differentiation and survival of prostate cancer cells. Identified as a primary target for the treatment of prostate cancer, many therapeutic strategies have been developed to attenuate AR signaling in prostate cancer cells. While frontline androgen-deprivation therapies targeting either the production or action of androgens usually yield favorable responses in prostate cancer patients, a significant number acquire treatment resistance. Known as the castration-resistant prostate cancer (CRPC), the treatment options are limited for this advanced stage. It has been shown that AR signaling is restored in CRPC due to many aberrant mechanisms such as AR mutations, amplification or expression of constitutively active splice-variants. Coregulator recruitment is a crucial regulatory step in AR signaling and the direct blockade of coactivator binding to AR offers the opportunity to develop therapeutic agents that would remain effective in prostate cancer cells resistant to conventional endocrine therapies. Structural analyses of the AR have identified key surfaces involved in protein-protein interaction with coregulators that have been recently used to design and develop promising AR-coactivator binding inhibitors. In this review we will discuss the design and development of small-molecule inhibitors targeting the AR-coactivator interactions for the treatment of prostate cancer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Antagonism pattern detection between microRNA and target expression in Ewing's sarcoma.

    Directory of Open Access Journals (Sweden)

    Loredana Martignetti

    Full Text Available MicroRNAs (miRNAs have emerged as fundamental regulators that silence gene expression at the post-transcriptional and translational levels. The identification of their targets is a major challenge to elucidate the regulated biological processes. The overall effect of miRNA is reflected on target mRNA expression, suggesting the design of new investigative methods based on high-throughput experimental data such as miRNA and transcriptome profiles. We propose a novel statistical measure of non-linear dependence between miRNA and mRNA expression, in order to infer miRNA-target interactions. This approach, which we name antagonism pattern detection, is based on the statistical recognition of a triangular-shaped pattern in miRNA-target expression profiles. This pattern is observed in miRNA-target expression measurements since their simultaneously elevated expression is statistically under-represented in the case of miRNA silencing effect. The proposed method enables miRNA target prediction to strongly rely on cellular context and physiological conditions reflected by expression data. The procedure has been assessed on synthetic datasets and tested on a set of real positive controls. Then it has been applied to analyze expression data from Ewing's sarcoma patients. The antagonism relationship is evaluated as a good indicator of real miRNA-target biological interaction. The predicted targets are consistently enriched for miRNA binding site motifs in their 3'UTR. Moreover, we reveal sets of predicted targets for each miRNA sharing important biological function. The procedure allows us to infer crucial miRNA regulators and their potential targets in Ewing's sarcoma disease. It can be considered as a valid statistical approach to discover new insights in the miRNA regulatory mechanisms.

  4. Protein targeting to glycogen is a master regulator of glycogen synthesis in astrocytes

    KAUST Repository

    Ruchti, E.

    2016-10-08

    The storage and use of glycogen, the main energy reserve in the brain, is a metabolic feature of astrocytes. Glycogen synthesis is regulated by Protein Targeting to Glycogen (PTG), a member of specific glycogen-binding subunits of protein phosphatase-1 (PPP1). It positively regulates glycogen synthesis through de-phosphorylation of both glycogen synthase (activation) and glycogen phosphorylase (inactivation). In cultured astrocytes, PTG mRNA levels were previously shown to be enhanced by the neurotransmitter noradrenaline. To achieve further insight into the role of PTG in the regulation of astrocytic glycogen, its levels of expression were manipulated in primary cultures of mouse cortical astrocytes using adenovirus-mediated overexpression of tagged-PTG or siRNA to downregulate its expression. Infection of astrocytes with adenovirus led to a strong increase in PTG expression and was associated with massive glycogen accumulation (>100 fold), demonstrating that increased PTG expression is sufficient to induce glycogen synthesis and accumulation. In contrast, siRNA-mediated downregulation of PTG resulted in a 2-fold decrease in glycogen levels. Interestingly, PTG downregulation strongly impaired long-term astrocytic glycogen synthesis induced by insulin or noradrenaline. Finally, these effects of PTG downregulation on glycogen metabolism could also be observed in cultured astrocytes isolated from PTG-KO mice. Collectively, these observations point to a major role of PTG in the regulation of glycogen synthesis in astrocytes and indicate that conditions leading to changes in PTG expression will directly impact glycogen levels in this cell type.

  5. Comparative Proteomic Analysis Provides insight into the Key Proteins as Possible Targets Involved in Aspirin Inhibiting Biofilm Formation of Staphylococcus xylosus

    Directory of Open Access Journals (Sweden)

    Chang-Geng Xu

    2017-08-01

    Full Text Available Staphylococcus xylosus is an opportunistic pathogen that causes infection in humans and cow mastitis. And S. xylosus possesses a strong ability to form biofilms in vitro. As biofilm formation facilitates resistance to antimicrobial agents, the discovery of new medicinal properties for classic drugs is highly desired. Aspirin, which is the most common active component of non-steroidal anti-inflammatory compounds, affects the biofilm-forming capacity of various bacterial species. We have found that aspirin effectively inhibits biofilm formation of S. xylosus by Crystal violet (CV staining and scanning electron microscopy analyses. The present study sought to elucidate possible targets of aspirin in suppressing S. xylosus biofilm formation. Based on an isobaric tag for relative and absolute quantitation (iTRAQ fold-change of >1.2 or <0.8 (P-value < 0.05, 178 differentially expressed proteins, 111 down-regulated and 67 up-regulated, were identified after application of aspirin to cells at a 1/2 minimal inhibitory concentration. Gene ontology analysis indicated enrichment in metabolic processes for the majority of the differentially expressed proteins. We then used the Kyoto Encyclopedia of Genes and Genomes (KEGG pathway database to analyze a large number of differentially expressed proteins and identified genes involved in biosynthesis of amino acids pathway, carbon metabolism (pentose phosphate and glycolytic pathways, tricarboxylic acid cycle and nitrogen metabolism (histidine metabolism. These novel proteins represent candidate targets in aspirin-mediated inhibition of S. xylosus biofilm formation at sub-MIC levels. The findings lay the foundation for further studies to identify potential aspirin targets.

  6. Antisense RNA Controls LRP1 Sense Transcript Expression through Interaction with a Chromatin-Associated Protein, HMGB2

    Directory of Open Access Journals (Sweden)

    Yasunari Yamanaka

    2015-05-01

    Full Text Available Long non-coding RNAs (lncRNAs, including natural antisense transcripts (NATs, are expressed more extensively than previously anticipated and have widespread roles in regulating gene expression. Nevertheless, the molecular mechanisms of action of the majority of NATs remain largely unknown. Here, we identify a NAT of low-density lipoprotein receptor-related protein 1 (Lrp1, referred to as Lrp1-AS, that negatively regulates Lrp1 expression. We show that Lrp1-AS directly binds to high-mobility group box 2 (Hmgb2 and inhibits the activity of Hmgb2 to enhance Srebp1a-dependent transcription of Lrp1. Short oligonucleotides targeting Lrp1-AS inhibit the interaction of antisense transcript and Hmgb2 protein and increase Lrp1 expression by enhancing Hmgb2 activity. Quantitative RT-PCR analysis of brain tissue samples from Alzheimer’s disease patients and aged-matched controls revealed upregulation of LRP1-AS and downregulation of LRP1. Our data suggest a regulatory mechanism whereby a NAT interacts with a ubiquitous chromatin-associated protein to modulate its activity in a locus-specific fashion.

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

    Directory of Open Access Journals (Sweden)

    Jackson Champer

    2016-01-01

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

  8. Targeting tumor-initiating cells: Eliminating anabolic cancer stem cells with inhibitors of protein synthesis or by mimicking caloric restriction

    Science.gov (United States)

    Lamb, Rebecca; Harrison, Hannah; Smith, Duncan L.; Townsend, Paul A.; Jackson, Thomas; Ozsvari, Bela; Martinez-Outschoorn, Ubaldo E.; Pestell, Richard G.; Howell, Anthony; Lisanti, Michael P.; Sotgia, Federica

    2015-01-01

    We have used an unbiased proteomic profiling strategy to identify new potential therapeutic targets in tumor-initiating cells (TICs), a.k.a., cancer stem cells (CSCs). Towards this end, the proteomes of mammospheres from two breast cancer cell lines were directly compared to attached monolayer cells. This allowed us to identify proteins that were highly over-expressed in CSCs and/or progenitor cells. We focused on ribosomal proteins and protein folding chaperones, since they were markedly over-expressed in mammospheres. Overall, we identified >80 molecules specifically associated with protein synthesis that were commonly upregulated in mammospheres. Most of these proteins were also transcriptionally upregulated in human breast cancer cells in vivo, providing evidence for their potential clinical relevance. As such, increased mRNA translation could provide a novel mechanism for enhancing the proliferative clonal expansion of TICs. The proteomic findings were functionally validated using known inhibitors of protein synthesis, via three independent approaches. For example, puromycin (which mimics the structure of tRNAs and competitively inhibits protein synthesis) preferentially targeted CSCs in both mammospheres and monolayer cultures, and was ~10-fold more potent for eradicating TICs, than “bulk” cancer cells. In addition, rapamycin, which inhibits mTOR and hence protein synthesis, was very effective at reducing mammosphere formation, at nanomolar concentrations. Finally, mammosphere formation was also markedly inhibited by methionine restriction, which mimics the positive effects of caloric restriction in cultured cells. Remarkably, mammosphere formation was >18-fold more sensitive to methionine restriction and replacement, as directly compared to monolayer cell proliferation. Methionine is absolutely required for protein synthesis, since every protein sequence starts with a methionine residue. Thus, the proliferation and survival of CSCs is very sensitive to

  9. Enhanced green fluorescent protein is a nearly ideal long-term expression tracer for hematopoietic stem cells, whereas DsRed-express fluorescent protein is not.

    Science.gov (United States)

    Tao, Wen; Evans, Barbara-Graham; Yao, Jing; Cooper, Scott; Cornetta, Kenneth; Ballas, Christopher B; Hangoc, Giao; Broxmeyer, Hal E

    2007-03-01

    Validated gene transfer and expression tracers are essential for elucidating functions of mammalian genes. Here, we have determined the suitability and unintended side effects of enhanced green fluorescent protein (EGFP) and DsRed-Express fluorescent protein as expression tracers in long-term hematopoietic stem cells (HSCs). Retrovirally transduced mouse bone marrow cells expressing either EGFP or DsRed-Express in single or mixed dual-color cell populations were clearly discerned by flow cytometry and fluorescence microscopy. The results from in vivo competitive repopulation assays demonstrated that EGFP-expressing HSCs were maintained nearly throughout the lifespan of the transplanted mice and retained long-term multilineage repopulating potential. All mice assessed at 15 months post-transplantation were EGFP positive, and, on average, 24% total peripheral white blood cells expressed EGFP. Most EGFP-expressing recipient mice lived at least 22 months. In contrast, Discosoma sp. red fluorescent protein (DsRed)-expressing donor cells dramatically declined in transplant-recipient mice over time, particularly in the competitive setting, in which mixed EGFP- and DsRed-expressing cells were cotransplanted. Moreover, under in vitro culture condition favoring preservation of HSCs, purified EGFP-expressing cells grew robustly, whereas DsRed-expressing cells did not. Therefore, EGFP has no detectable deteriorative effects on HSCs, and is nearly an ideal long-term expression tracer for hematopoietic cells; however, DsRed-Express fluorescent protein is not suitable for these cells.

  10. Targeting protein-protein interaction between MLL1 and reciprocal proteins for leukemia therapy.

    Science.gov (United States)

    Wang, Zhi-Hui; Li, Dong-Dong; Chen, Wei-Lin; You, Qi-Dong; Guo, Xiao-Ke

    2018-01-15

    The mixed lineage leukemia protein-1 (MLL1), as a lysine methyltransferase, predominantly regulates the methylation of histone H3 lysine 4 (H3K4) and functions in hematopoietic stem cell (HSC) self-renewal. MLL1 gene fuses with partner genes that results in the generation of MLL1 fusion proteins (MLL1-FPs), which are frequently detected in acute leukemia. In the progress of leukemogenesis, a great deal of proteins cooperate with MLL1 to form multiprotein complexes serving for the dysregulation of H3K4 methylation, the overexpression of homeobox (HOX) cluster genes, and the consequent generation of leukemia. Hence, disrupting the interactions between MLL1 and the reciprocal proteins has been considered to be a new treatment strategy for leukemia. Here, we reviewed potential protein-protein interactions (PPIs) between MLL1 and its reciprocal proteins, and summarized the inhibitors to target MLL1 PPIs. The druggability of MLL1 PPIs for leukemia were also discussed. Copyright © 2017. Published by Elsevier Ltd.

  11. Acute myeloid leukaemia: expression of MYC protein and its association with cytogenetic risk profile and overall survival.

    Science.gov (United States)

    Mughal, Muhammad Kashif; Akhter, Ariz; Street, Lesley; Pournazari, Payam; Shabani-Rad, Meer-Taher; Mansoor, Adnan

    2017-09-01

    Acute myeloid leukaemia (AML) is a clinically aggressive disease with marked genetic heterogeneity. Cytogenetic abnormalities provide the basis for risk stratification into clinically favourable, intermediate, and unfavourable groups. There are additional genetic mutations, which further influence the prognosis of patients with AML. Most of these result in molecular aberrations whose downstream target is MYC. It is therefore logical to study the relationship between MYC protein expression and cytogenetic risk groups. We studied MYC expression by immunohistochemistry in a large cohort (n = 199) of AML patients and correlated these results with cytogenetic risk profile and overall survival (OS). We illustrated differential expression of MYC protein across various cytogenetic risk groups (p = 0.03). Highest expression of MYC was noted in AML patients with favourable cytogenetic risk group. In univariate analysis, MYC expression showed significant negative influence of OS in favourable and intermediate cytogenetic risk group (p = 0.001). Interestingly, MYC expression had a protective effect in the unfavourable cytogenetic risk group. In multivariate analysis, while age and cytogenetic risk group were significant factors influencing survival, MYC expression by immunohistochemistry methods also showed some marginal impact (p = 0.069). In conclusion, we have identified differential expression of MYC protein in relation to cytogenetic risk groups in AML patients and documented its possible impact on OS in favourable and intermediate cytogenetic risk groups. These preliminary observations mandate additional studies to further investigate the routine clinical use of MYC protein expression in AML risk stratification. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Controlled expression of nif and isc iron-sulfur protein maturation components reveals target specificity and limited functional replacement between the two systems.

    Science.gov (United States)

    Dos Santos, Patricia C; Johnson, Deborah C; Ragle, Brook E; Unciuleac, Mihaela-Carmen; Dean, Dennis R

    2007-04-01

    The nitrogen-fixing organism Azotobacter vinelandii contains at least two systems that catalyze formation of [Fe-S] clusters. One of these systems is encoded by nif genes, whose products supply [Fe-S] clusters required for maturation of nitrogenase. The other system is encoded by isc genes, whose products are required for maturation of [Fe-S] proteins that participate in general metabolic processes. The two systems are similar in that they include an enzyme for the mobilization of sulfur (NifS or IscS) and an assembly scaffold (NifU or IscU) upon which [Fe-S] clusters are formed. Normal cellular levels of the Nif system, which supplies [Fe-S] clusters for the maturation of nitrogenase, cannot also supply [Fe-S] clusters for the maturation of other cellular [Fe-S] proteins. Conversely, when produced at the normal physiological levels, the Isc system cannot supply [Fe-S] clusters for the maturation of nitrogenase. In the present work we found that such target specificity for IscU can be overcome by elevated production of NifU. We also found that NifU, when expressed at normal levels, is able to partially replace the function of IscU if cells are cultured under low-oxygen-availability conditions. In contrast to the situation with IscU, we could not establish conditions in which the function of IscS could be replaced by NifS. We also found that elevated expression of the Isc components, as a result of deletion of the regulatory iscR gene, improved the capacity for nitrogen-fixing growth of strains deficient in either NifU or NifS.

  13. Activation of Fetal γ-globin Gene Expression via Direct Protein Delivery of Synthetic Zinc-finger DNA-Binding Domains

    Directory of Open Access Journals (Sweden)

    Mir A Hossain

    2016-01-01

    Full Text Available Reactivation of γ-globin expression has been shown to ameliorate disease phenotypes associated with mutations in the adult β-globin gene, including sickle cell disease. Specific mutations in the promoter of the γ-globin genes are known to prevent repression of the genes in the adult and thus lead to hereditary persistence of fetal hemoglobin. One such hereditary persistence of fetal hemoglobin is associated with a sequence located 567 bp upstream of the Gγ-globin gene which assembles a GATA-containing repressor complex. We generated two synthetic zinc-finger DNA-binding domains (ZF-DBDs targeting this sequence. The -567Gγ ZF-DBDs associated with high affinity and specificity with the target site in the γ-globin gene promoter. We delivered the -567Gγ ZF-DBDs directly to primary erythroid cells. Exposure of these cells to the recombinant -567Gγ ZF-DBDs led to increased expression of the γ-globin gene. Direct protein delivery of ZF-DBDs that compete with transcription regulatory proteins will have broad implications for modulating gene expression in analytical or therapeutic settings.

  14. Hypoxia targeted bifunctional suicide gene expression enhances radiotherapy in vitro and in vivo

    International Nuclear Information System (INIS)

    Sun, Xiaorong; Xing, Ligang; Deng, Xuelong; Hsiao, Hung Tsung; Manami, Akiko; Koutcher, Jason A.; Clifton Ling, C.; Li, Gloria C.

    2012-01-01

    Purpose: To investigate whether hypoxia targeted bifunctional suicide gene expression-cytosine deaminase (CD) and uracil phosphoribosyltransferase (UPRT) with 5-FC treatments can enhance radiotherapy. Materials and methods: Stable transfectants of R3327-AT cells were established which express a triple-fusion-gene: CD, UPRT and monomoric DsRed (mDsRed) controlled by a hypoxia inducible promoter. Hypoxia-induced expression/function of CDUPRTmDsRed was verified by western blot, flow cytometry, fluorescent microscopy, and cytotoxicity assay of 5-FU and 5-FC. Tumor-bearing mice were treated with 5-FC and local radiation. Tumor volume was monitored and compared with those treated with 5-FC or radiation alone. In addition, the CDUPRTmDsRed distribution in hypoxic regions of tumor sections was visualized with fluorescent microscopy. Results: Hypoxic induction of CDUPRTmDsRed protein correlated with increased sensitivity to 5-FC and 5-FU. Significant radiosensitization effects were detected after 5-FC treatments under hypoxic conditions. In the tumor xenografts, the distribution of CDUPRTmDsRed expression visualized with fluorescence microscopy was co-localized with the hypoxia marker pimonidazole positive staining cells. Furthermore, administration of 5-FC to mice in combination with local irradiation resulted in significant tumor regression, as in comparison with 5-FC or radiation treatments alone. Conclusions: Our data suggest that the hypoxia-inducible CDUPRT/5-FC gene therapy strategy has the ability to specifically target hypoxic cancer cells and significantly improve the tumor control in combination with radiotherapy.

  15. Two different protein expression profiles of oral squamous cell carcinoma analyzed by immunoprecipitation high-performance liquid chromatography.

    Science.gov (United States)

    Kim, Soung Min; Jeong, Dasul; Kim, Min Keun; Lee, Sang Shin; Lee, Suk Keun

    2017-08-08

    , while the increased trends of cellular proliferation and survival in the protein profile of SCC-2 were implicative of its rapid growing tumor mass and early lymph node metastasis. These analyses of the essential oncogenic protein expression profiles in OSCC provide important information for genetic counseling or customized gene therapy in cancer treatment. Therefore, protein expression profile analysis through IP-HPLC is helpful not only for the molecular genetic diagnosis of cancer but also in identifying target molecules for customized gene therapy in near future.

  16. Mycobacterium tuberculosis HspX/EsxS Fusion Protein: Gene Cloning, Protein Expression, and Purification in Escherichia coli.

    Science.gov (United States)

    Khademi, Farzad; Yousefi-Avarvand, Arshid; Derakhshan, Mohammad; Meshkat, Zahra; Tafaghodi, Mohsen; Ghazvini, Kiarash; Aryan, Ehsan; Sankian, Mojtaba

    2017-10-01

    The purpose of this study was to clone, express, and purify a novel multidomain fusion protein of Micobacterium tuberculosis (Mtb) in a prokaryotic system. An hspX/esxS gene construct was synthesized and ligated into a pGH plasmid, E. coli TOP10 cells were transformed, and the vector was purified. The vector containing the construct and pET-21b (+) plasmid were digested with the same enzymes and the construct was ligated into pET-21b (+). The accuracy of cloning was confirmed by colony PCR and sequencing. E. coli BL21 cells were transformed with the pET-21b (+)/hspX/esxS expression vector and protein expression was evaluated. Finally, the expressed fusion protein was purified on a Ni-IDA column and verified by SDS-PAGE and western blotting. The hspX/esxS gene construct was inserted into pET-21b (+) and recombinant protein expression was induced with IPTG in E. coli BL21 cells. Various concentrations of IPTG were tested to determine the optimum concentration for expression induction. The recombinant protein was expressed in insoluble inclusion bodies. Three molar guanidine HCl was used to solubilize the insoluble protein. An HspX/EsxS Mtb fusion protein was expressed in E. coli and the recombinant protein was purified. After immunological analysis, the HspX/EsxS fusion protein might be an anti-tuberculosis vaccine candidate in future clinical trial studies.

  17. Late phase cell cycle proteins in Alzheimer’s disease: a possible target for therapy?

    KAUST Repository

    Bajic, Vladan

    2017-02-22

    Alzheimer’s disease (AD) is represented by neuronal loss and this loss is correlated to a constant state of neuronal instability induced by intrinsic and extrinsic factors. In this paper data is presented regarding the possible roles of late phase cell cycle proteins in normal and affected neurons with the goal that understanding the mechanisms involved in the regulation of these proteins may represent a novel strategy for AD treatment. The results demonstrate a relative differential pattern of expression of certain proteins (APC/C, Mad1 and Mad2, Bub R1, Bub1, CDK 11, cohesin subunit Rad 21 and astrin) in the AD brain versus age matched controls, and it is suggested that targeting these proteins might translate into potential treatments for AD. Although the data presented here is of some interest, the ability to translate such information into clinical applications is often a challenge.

  18. Late phase cell cycle proteins in Alzheimer’s disease: a possible target for therapy?

    KAUST Repository

    Bajic, Vladan; B. Bajic, Vladimir; Zivkovic, Lada; Arendt, Thomas; Perry, George; Spremo-Potparevic, Biljana

    2017-01-01

    Alzheimer’s disease (AD) is represented by neuronal loss and this loss is correlated to a constant state of neuronal instability induced by intrinsic and extrinsic factors. In this paper data is presented regarding the possible roles of late phase cell cycle proteins in normal and affected neurons with the goal that understanding the mechanisms involved in the regulation of these proteins may represent a novel strategy for AD treatment. The results demonstrate a relative differential pattern of expression of certain proteins (APC/C, Mad1 and Mad2, Bub R1, Bub1, CDK 11, cohesin subunit Rad 21 and astrin) in the AD brain versus age matched controls, and it is suggested that targeting these proteins might translate into potential treatments for AD. Although the data presented here is of some interest, the ability to translate such information into clinical applications is often a challenge.

  19. Comparative differential gene expression analysis of nucleus-encoded proteins for Rafflesia cantleyi against Arabidopsis thaliana

    Science.gov (United States)

    Ng, Siuk-Mun; Lee, Xin-Wei; Wan, Kiew-Lian; Firdaus-Raih, Mohd

    2015-09-01

    Regulation of functional nucleus-encoded proteins targeting the plastidial functions was comparatively studied for a plant parasite, Rafflesia cantleyi versus a photosynthetic plant, Arabidopsis thaliana. This study involved two species of different feeding modes and different developmental stages. A total of 30 nucleus-encoded proteins were found to be differentially-regulated during two stages in the parasite; whereas 17 nucleus-encoded proteins were differentially-expressed during two developmental stages in Arabidopsis thaliana. One notable finding observed for the two plants was the identification of genes involved in the regulation of photosynthesis-related processes where these processes, as expected, seem to be present only in the autotroph.

  20. The Polerovirus F box protein P0 targets ARGONAUTE1 to suppress RNA silencing.

    Science.gov (United States)

    Bortolamiol, Diane; Pazhouhandeh, Maghsoud; Marrocco, Katia; Genschik, Pascal; Ziegler-Graff, Véronique

    2007-09-18

    Plants employ post-transcriptional gene silencing (PTGS) as an antiviral defense response. In this mechanism, viral-derived small RNAs are incorporated into the RNA-induced silencing complex (RISC) to guide degradation of the corresponding viral RNAs. ARGONAUTE1 (AGO1) is a key component of RISC: it carries the RNA slicer activity. As a counter-defense, viruses have evolved various proteins that suppress PTGS. Recently, we showed that the Polerovirus P0 protein carries an F box motif required to form an SCF-like complex, which is also essential for P0's silencing suppressor function. Here, we investigate the molecular mechanism by which P0 impairs PTGS. First we show that P0's expression does not affect the biogenesis of primary siRNAs in an inverted repeat-PTGS assay, but it does affect their activity. Moreover, P0's expression in transformed Arabidopsis plants leads to various developmental abnormalities reminiscent of mutants affected in miRNA pathways, which is accompanied by enhanced levels of several miRNA-target transcripts, suggesting that P0 acts at the level of RISC. Interestingly, ectopic expression of P0 triggered AGO1 protein decay in planta. Finally, we provide evidence that P0 physically interacts with AGO1. Based on these results, we propose that P0 hijacks the host SCF machinery to modulate gene silencing by destabilizing AGO1.

  1. Overexpression of pucC improves the heterologous protein expression level in a Rhodobacter sphaeroides expression system.

    Science.gov (United States)

    Cheng, L; Chen, G; Ding, G; Zhao, Z; Dong, T; Hu, Z

    2015-04-27

    The Rhodobacter sphaeroides system has been used to express membrane proteins. However, its low yield has substantially limited its application. In order to promote the protein expression capability of this system, the pucC gene, which plays a crucial role in assembling the R. sphaeroides light-harvesting 2 complex (LH2), was overexpressed. To build a pucC overexpression strain, a pucC overexpression vector was constructed and transformed into R. sphaeroides CQU68. The overexpression efficiency was evaluated by quantitative real-time polymerase chain reaction. A well-used reporter β-glucuronidase (GUS) was fusion-expressed with LH2 to evaluate the heterologous protein expression level. As a result, the cell culture and protein in the pucC overexpression strain showed much higher typical spectral absorption peaks at 800 and 850 nm compared with the non-overexpression strain, suggesting a higher expression level of LH2-GUS fusion protein in the pucC overexpression strain. This result was further confirmed by Western blot, which also showed a much higher level of heterologous protein expression in the pucC overexpression strain. We further compared GUS activity in pucC overexpression and non-overexpression strains, the results of which showed that GUS activity in the pucC overexpression strain was approximately ten-fold that in the non-overexpression strain. These results demonstrate that overexpressed pucC can promote heterologous protein expression levels in R. sphaeroides.

  2. Identification of Achaete-scute complex-like 1 (ASCL1) target genes and evaluation of DKK1 and TPH1 expression in pancreatic endocrine tumours

    International Nuclear Information System (INIS)

    Johansson, Térèse A; Westin, Gunnar; Skogseid, Britt

    2009-01-01

    ASCL1 role in pancreatic endocrine tumourigenesis has not been established. Recently it was suggested that ASCL1 negatively controls expression of the Wnt signalling antagonist DKK1. Notch signalling regulates expression of TPH1, the rate limiting enzyme in the biosyntesis of serotonin. Understanding the development and proliferation of pancreatic endocrine tumours (PETs) is essential for the development of new therapies. ASCL1 target genes in the pancreatic endocrine tumour cell line BON1 were identified by RNA interference and microarray expression analysis. Protein expressions of selected target genes in PETs were evaluated by immunohistochemistry. 158 annotated ASCL1 target genes were identified in BON1 cells, among them DKK1 and TPH1 that were negatively regulated by ASCL1. An inverse relation of ASCL1 to DKK1 protein expression was observed for 15 out of 22 tumours (68%). Nine tumours displayed low ASCL1/high DKK1 and six tumours high ASCL1/low DKK1 expression. Remaining PETs showed high ASCL1/high DKK1 (n = 4) or low ASCL1/low DKK1 (n = 3) expression. Nine of twelve analysed PETs (75%) showed TPH1 expression with no relation to ASCL1. A number of genes with potential importance for PET tumourigenesis have been identified. ASCL1 negatively regulated the Wnt signalling antagonist DKK1, and TPH1 expression in BON1 cells. In concordance with these findings DKK1 showed an inverse relation to ASCL1 expression in a subset of PETs, which may affect growth control by the Wnt signalling pathway

  3. Complement inhibitory proteins expression in placentas of thrombophilic women Complement inhibitory proteins expression in placentas of thrombophilic women

    Directory of Open Access Journals (Sweden)

    Przemysław Krzysztof Wirstlein

    2012-10-01

    Full Text Available Factors controlling complement activation appear to exert a protective effect on pregnancy. This is
    particularly important in women with thrombophilia. The aim of this study was to determine the transcript and
    protein levels of complement decay-accelerating factor (DAF and membrane cofactor protein (MCP in the
    placentas of women with acquired and inherited thrombophilia. Also, we assessed immunohistochemistry staining
    of inhibitors of the complement cascade, DAF and MCP proteins, in the placentas of thrombophilic women.
    Placentas were collected from eight women with inherited thrombophilia and ten with acquired thrombophilia.
    The levels of DAF and MCP transcripts were evaluated by qPCR, the protein level was evaluated by Western
    blot. We observed a higher transcript (p < 0.05 and protein (p < 0.001 levels of DAF and MCP in the placentas
    of thrombophilic women than in the control group. DAF and MCP were localized on villous syncytiotrophoblast
    membranes, but the assessment of staining in all groups did not differ. The observed higher expression level of
    proteins that control activation of complement control proteins is only seemingly contradictory to the changes
    observed for example in the antiphospholipid syndrome. However, given the hitherto known biochemical changes
    associated with thrombophilia, a mechanism in which increased expression of DAF and MCP in the placentas is
    an effect of proinflammatory cytokines, which accompanies thrombophilia, is probable.Factors controlling complement activation appear to exert a protective effect on pregnancy. This is
    particularly important in women with thrombophilia. The aim of this study was to determine the transcript and
    protein levels of complement decay-accelerating factor (DAF and membrane cofactor protein (MCP in the
    placentas of women with acquired and inherited thrombophilia. Also, we assessed immunohistochemistry

  4. Expression of the lysosomal-associated membrane protein-1 (LAMP-1) in astrocytomas

    DEFF Research Database (Denmark)

    Jensen, Stine S; Aaberg-Jessen, Charlotte; Christensen, Karina G

    2013-01-01

    Targeting of lysosomes is a novel therapeutic anti-cancer strategy for killing the otherwise apoptosis-resistant cancer cells. Such strategies are urgently needed for treatment of brain tumors, especially the glioblastoma, which is the most frequent and most malignant type. The aim of the present...... study was to investigate the presence of lysosomes in astrocytic brain tumors focussing also on the therapy resistant tumor stem cells. Expression of the lysosomal marker LAMP-1 (lysosomal-associated membrane protein-1) was investigated by immunohistochemistry in 112 formalin fixed paraffin embedded...... in the individual tumor grades. LAMP-1/GFAP showed pronounced co-expression and LAMP-1/CD133 was co-expressed as well suggesting that tumor cells including the proposed tumor stem cells contain lysosomes. The results suggest that high amounts of lysosomes are present in glioblastomas and in the proposed tumor stem...

  5. Molecular characterization and expression analysis of chloroplast protein import components in tomato (Solanum lycopersicum.

    Directory of Open Access Journals (Sweden)

    Jianmin Yan

    Full Text Available The translocon at the outer envelope membrane of chloroplasts (Toc mediates the recognition and initial import into the organelle of thousands of nucleus-encoded proteins. These proteins are translated in the cytosol as precursor proteins with cleavable amino-terminal targeting sequences called transit peptides. The majority of the known Toc components that mediate chloroplast protein import were originally identified in pea, and more recently have been studied most extensively in Arabidopsis. With the completion of the tomato genome sequencing project, it is now possible to identify putative homologues of the chloroplast import components in tomato. In the work reported here, the Toc GTPase cDNAs from tomato were identified, cloned and analyzed. The analysis revealed that there are four Toc159 homologues (slToc159-1, -2, -3 and -4 and two Toc34 homologues (slToc34-1 and -2 in tomato, and it was shown that tomato Toc159 and Toc34 homologues share high sequence similarity with the comparable import apparatus components from Arabidopsis and pea. Thus, tomato is a valid model for further study of this system. The expression level of Toc complex components was also investigated in different tissues during tomato development. The two tomato Toc34 homologues are expressed at higher levels in non-photosynthetic tissues, whereas, the expression of two tomato Toc159 homologues, slToc159-1 and slToc159-4, were higher in photosynthetic tissues, and the expression patterns of slToc159-2 was not significantly different in photosynthetic and non-photosynthetic tissues, and slToc159-3 expression was limited to a few select tissues.

  6. Oral Administration of Recombinant Saccharomyces boulardii Expressing Ovalbumin-CPE Fusion Protein Induces Antibody Response in Mice.

    Science.gov (United States)

    Bagherpour, Ghasem; Ghasemi, Hosnie; Zand, Bahare; Zarei, Najmeh; Roohvand, Farzin; Ardakani, Esmat M; Azizi, Mohammad; Khalaj, Vahid

    2018-01-01

    Saccharomyces boulardii , a subspecies of Saccharomyces cerevisiae , is a well-known eukaryotic probiotic with many benefits for human health. In the present study, a recombinant strain of S. boulardii was prepared to use as a potential oral vaccine delivery vehicle. In this sense, a ura3 auxotroph strain of S. boulardii CNCM I-745 (known as S. cerevisiae HANSEN CBS 5926, Yomogi ® ) was generated using CRISPR/Cas9 methodology. Then a gene construct encoding a highly immunogenic protein, ovalbumin (OVA), was prepared and transformed into the ura3 - S. boulardii . To facilitate the transport of the recombinant immunogen across the intestinal barrier, a claudin-targeting sequence from Clostridium perfringens enterotoxin (CPE) was added to the C-terminus of the expression cassette. The recombinant S. boulardii strain expressing the OVA-CPE fusion protein was then administered orally to a group of mice, and serum IgG and fecal IgA levels were evaluated by ELISA. Our results demonstrated that anti-OVA IgG in serum significantly increased in test group ( P boulardii or PBS), and the fecal IgA titer was significantly higher in test group ( P boulardii strain expressing the similar construct lacking C-terminal CPE was also administered orally. The result showed an increased level of serum IgG in group receiving yeasts expressing the CPE negative construct compared to control groups; however, the fecal IgA levels did not increase significantly. In conclusion, our findings indicated that the yeast S. boulardii , as a delivery vehicle with possible immunomodulatory effects, and c-CPE, as a targeting tag, synergistically assist to stimulate systemic and local immunity. This proposed recombinant S. boulardii system might be useful in the expression of other antigenic peptides, making it as a promising tool for oral delivery of vaccines or therapeutic proteins.

  7. Plastoglobules: a new address for targeting recombinant proteins in the chloroplast

    Directory of Open Access Journals (Sweden)

    Kessler Felix

    2007-01-01

    Full Text Available Abstract Background The potential of transgenic plants for cost-effective production of pharmaceutical molecules is now becoming apparent. Plants have the advantage over established fermentation systems (bacterial, yeast or animal cell cultures to circumvent the risk of pathogen contamination, to be amenable to large scaling up and to necessitate only established farming procedures. Chloroplasts have proven a useful cellular compartment for protein accumulation owing to their large size and number, as well as the possibility for organellar transformation. They therefore represent the targeting destination of choice for recombinant proteins in leaf crops such as tobacco. Extraction and purification of recombinant proteins from leaf material contribute to a large extent to the production costs. Developing new strategies facilitating these processes is therefore necessary. Results Here, we evaluated plastoglobule lipoprotein particles as a new subchloroplastic destination for recombinant proteins. The yellow fluorescent protein as a trackable cargo was targeted to plastoglobules when fused to plastoglobulin 34 (PGL34 as the carrier. Similar to adipocyte differentiation related protein (ADRP in animal cells, most of the protein sequence of PGL34 was necessary for targeting to lipid bodies. The recombinant protein was efficiently enriched in plastoglobules isolated by simple flotation centrifugation. The viability of plants overproducing the recombinant protein was not affected, indicating that plastoglobule targeting did not significantly impair photosynthesis or sugar metabolism. Conclusion Our data identify plastoglobules as a new targeting destination for recombinant protein in leaf crops. The wide-spread presence of plastoglobules and plastoglobulins in crop species promises applications comparable to those of transgenic oilbody-oleosin technology in molecular farming.

  8. Molecular Targets for Targeted Radionuclide Therapy

    International Nuclear Information System (INIS)

    Mather, S.J.

    2009-01-01

    Molecular targeted radionuclide cancer therapy is becoming of increasing importance, especially for disseminated diseases. Systemic chemotherapies often lack selectivity while targeted radionuclide therapy has important advantages as the radioactive cytotoxic unit of the targeting vector is specifically directed to the cancer, sparing normal tissues. The principle strategy to improve cancer selectivity is to couple therapeutic agents to tumour-targeting vectors. In targeted radionuclide therapy (TRT), the cytotoxic portion of the conjugates normally contains a therapeutic radiometal immobilised by a bifunctional chelator. The aim is therefore to use as ligand-targeted therapeutics vectors coupled to Auger-, alpha- and/or beta-emitting radionuclides. An advantage of using radiation instead of chemotherapeutics as the cytotoxic agent is the so called 'crossfire effect'. This allows sterilisation of tumour cells that are not directly targeted due to heterogeneity in target molecule expression or inhomogeneous vector delivery. However, before the targeting ligands can be selected, the target molecule on the tumour has to be selected. It should be uniquely expressed, or at least highly overexpressed, on or in the target cells relative to normal tissues. The target should be easily accessible for ligand delivery and should not be shed or down- regulated after ligand binding. An important property of a receptor (or antigen) is its potential to be internalized upon binding of the ligand. This provides an active uptake mechanism and allows the therapeutic agent to be trapped within the tumour cells. Molecular targets of current interest include: Receptors: G-protein coupled receptors are overexpressed on many major human tumours. The prototype of these receptors are somatostatin receptors which show very high density in neuroendocrine tumours, but there are many other most interesting receptors to be applied for TRT. The targeting ligands for these receptors are

  9. Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins

    International Nuclear Information System (INIS)

    Teutschbein, Janka; Haydn, Johannes M; Samans, Birgit; Krause, Michael; Eilers, Martin; Schartl, Manfred; Meierjohann, Svenja

    2010-01-01

    Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase) triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1), early growth response 1 (Egr1), osteopontin (Opn), insulin-like growth factor binding protein 3 (Igfbp3), dual-specificity phosphatase 4 (Dusp4), and tumor-associated antigen L6 (Taal6). Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute new possible molecular players in melanoma development

  10. Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins

    Directory of Open Access Journals (Sweden)

    Krause Michael

    2010-07-01

    Full Text Available Abstract Background Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Methods Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Results Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1, early growth response 1 (Egr1, osteopontin (Opn, insulin-like growth factor binding protein 3 (Igfbp3, dual-specificity phosphatase 4 (Dusp4, and tumor-associated antigen L6 (Taal6. Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Conclusion Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute

  11. Targeting protein biotinylation enhances tuberculosis chemotherapy.

    Science.gov (United States)

    Tiwari, Divya; Park, Sae Woong; Essawy, Maram M; Dawadi, Surendra; Mason, Alan; Nandakumar, Madhumitha; Zimmerman, Matthew; Mina, Marizel; Ho, Hsin Pin; Engelhart, Curtis A; Ioerger, Thomas; Sacchettini, James C; Rhee, Kyu; Ehrt, Sabine; Aldrich, Courtney C; Dartois, Véronique; Schnappinger, Dirk

    2018-04-25

    Successful drug treatment for tuberculosis (TB) depends on the unique contributions of its component drugs. Drug resistance poses a threat to the efficacy of individual drugs and the regimens to which they contribute. Biologically and chemically validated targets capable of replacing individual components of current TB chemotherapy are a major unmet need in TB drug development. We demonstrate that chemical inhibition of the bacterial biotin protein ligase (BPL) with the inhibitor Bio-AMS (5'-[ N -(d-biotinoyl)sulfamoyl]amino-5'-deoxyadenosine) killed Mycobacterium tuberculosis ( Mtb ), the bacterial pathogen causing TB. We also show that genetic silencing of BPL eliminated the pathogen efficiently from mice during acute and chronic infection with Mtb Partial chemical inactivation of BPL increased the potency of two first-line drugs, rifampicin and ethambutol, and genetic interference with protein biotinylation accelerated clearance of Mtb from mouse lungs and spleens by rifampicin. These studies validate BPL as a potential drug target that could serve as an alternate frontline target in the development of new drugs against Mtb . Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  12. Heat-shock protein 40 is the key farnesylation target in meristem size control, abscisic acid signaling, and drought resistance.

    Science.gov (United States)

    Barghetti, Andrea; Sjögren, Lars; Floris, Maïna; Paredes, Esther Botterweg; Wenkel, Stephan; Brodersen, Peter

    2017-11-15

    Protein farnesylation is central to molecular cell biology. In plants, protein farnesyl transferase mutants are pleiotropic and exhibit defective meristem organization, hypersensitivity to the hormone abscisic acid, and increased drought resistance. The precise functions of protein farnesylation in plants remain incompletely understood because few relevant farnesylated targets have been identified. Here, we show that defective farnesylation of a single factor-heat-shock protein 40 (HSP40), encoded by the J2 and J3 genes-is sufficient to confer ABA hypersensitivity, drought resistance, late flowering, and enlarged meristems, indicating that altered function of chaperone client proteins underlies most farnesyl transferase mutant phenotypes. We also show that expression of an abiotic stress-related microRNA (miRNA) regulon controlled by the transcription factor SPL7 requires HSP40 farnesylation. Expression of a truncated SPL7 form mimicking its activated proteolysis fragment of the membrane-bound SPL7 precursor partially restores accumulation of SPL7-dependent miRNAs in farnesyl transferase mutants. These results implicate the pathway directing SPL7 activation from its membrane-bound precursor as an important target of farnesylated HSP40, consistent with our demonstration that HSP40 farnesylation facilitates its membrane association. The results also suggest that altered gene regulation via select miRNAs contributes to abiotic stress-related phenotypes of farnesyl transferase mutants. © 2017 Barghetti et al.; Published by Cold Spring Harbor Laboratory Press.

  13. Ectopic Expression of Testis Germ Cell Proteins in Cancer and Its Potential Role in Genomic Instability

    Directory of Open Access Journals (Sweden)

    Aaraby Yoheswaran Nielsen

    2016-06-01

    Full Text Available Genomic instability is a hallmark of human cancer and an enabling factor for the genetic alterations that drive cancer development. The processes involved in genomic instability resemble those of meiosis, where genetic material is interchanged between homologous chromosomes. In most types of human cancer, epigenetic changes, including hypomethylation of gene promoters, lead to the ectopic expression of a large number of proteins normally restricted to the germ cells of the testis. Due to the similarities between meiosis and genomic instability, it has been proposed that activation of meiotic programs may drive genomic instability in cancer cells. Some germ cell proteins with ectopic expression in cancer cells indeed seem to promote genomic instability, while others reduce polyploidy and maintain mitotic fidelity. Furthermore, oncogenic germ cell proteins may indirectly contribute to genomic instability through induction of replication stress, similar to classic oncogenes. Thus, current evidence suggests that testis germ cell proteins are implicated in cancer development by regulating genomic instability during tumorigenesis, and these proteins therefore represent promising targets for novel therapeutic strategies.

  14. Overcoming chemotherapy drug resistance by targeting inhibitors of apoptosis proteins (IAPs).

    Science.gov (United States)

    Rathore, Rama; McCallum, Jennifer E; Varghese, Elizabeth; Florea, Ana-Maria; Büsselberg, Dietrich

    2017-07-01

    Inhibitors of apoptosis (IAPs) are a family of proteins that play a significant role in the control of programmed cell death (PCD). PCD is essential to maintain healthy cell turnover within tissue but also to fight disease or infection. Uninhibited, IAPs can suppress apoptosis and promote cell cycle progression. Therefore, it is unsurprising that cancer cells demonstrate significantly elevated expression levels of IAPs, resulting in improved cell survival, enhanced tumor growth and subsequent metastasis. Therapies to target IAPs in cancer has garnered substantial scientific interest and as resistance to anti-cancer agents becomes more prevalent, targeting IAPs has become an increasingly attractive strategy to re-sensitize cancer cells to chemotherapies, antibody based-therapies and TRAIL therapy. Antagonism strategies to modulate the actions of XIAP, cIAP1/2 and survivin are the central focus of current research and this review highlights advances within this field with particular emphasis upon the development and specificity of second mitochondria-derived activator of caspase (SMAC) mimetics (synthetic analogs of endogenously expressed inhibitors of IAPs SMAC/DIABLO). While we highlight the potential of SMAC mimetics as effective single agent or combinatory therapies to treat cancer we also discuss the likely clinical implications of resistance to SMAC mimetic therapy, occasionally observed in cancer cell lines.

  15. Genetics coupled to quantitative intact proteomics links heritable aphid and endosymbiont protein expression to circulative polerovirus transmission.

    Science.gov (United States)

    Cilia, M; Tamborindeguy, C; Fish, T; Howe, K; Thannhauser, T W; Gray, S

    2011-03-01

    Yellow dwarf viruses in the family Luteoviridae, which are the causal agents of yellow dwarf disease in cereal crops, are each transmitted most efficiently by different species of aphids in a circulative manner that requires the virus to interact with a multitude of aphid proteins. Aphid proteins differentially expressed in F2 Schizaphis graminum genotypes segregating for the ability to transmit Cereal yellow dwarf virus-RPV (CYDV-RPV) were identified using two-dimensional difference gel electrophoresis (DIGE) coupled to either matrix-assisted laser desorption ionization-tandem mass spectrometry or online nanoscale liquid chromatography coupled to electrospray tandem mass spectrometry. A total of 50 protein spots, containing aphid proteins and proteins from the aphid's obligate and maternally inherited bacterial endosymbiont, Buchnera, were identified as differentially expressed between transmission-competent and refractive aphids. Surprisingly, in virus transmission-competent F2 genotypes, the isoelectric points of the Buchnera proteins did not match those in the maternal Buchnera proteome as expected, but instead they aligned with the Buchnera proteome of the transmission-competent paternal parent. Among the aphid proteins identified, many were involved in energy metabolism, membrane trafficking, lipid signaling, and the cytoskeleton. At least eight aphid proteins were expressed as heritable, isoelectric point isoform pairs, one derived from each parental lineage. In the F2 genotypes, the expression of aphid protein isoforms derived from the competent parental lineage aligned with the virus transmission phenotype with high precision. Thus, these isoforms are candidate biomarkers for CYDV-RPV transmission in S. graminum. Our combined genetic and DIGE approach also made it possible to predict where several of the proteins may be expressed in refractive aphids with different barriers to transmission. Twelve proteins were predicted to act in the hindgut of the aphid

  16. Expression of a truncated receptor protein tyrosine phosphatase kappa in the brain of an adult transgenic mouse

    DEFF Research Database (Denmark)

    Shen, P; Canoll, P D; Sap, J

    1999-01-01

    processes such as axonal growth and target recognition, as has been demonstrated for certain Drosophila RPTPs. The brain distribution of RPTP-kappa-expressing cells has not been determined, however. In a gene-trap mouse model with a beta-gal+neo (beta-geo) insertion in the endogenous RPTP-kappa gene......-6596]. Nevertheless, since the transgene's expression is driven by the endogenous RPTP-kappa promoter, distribution of the truncated RPTP-kappa/beta-geo fusion protein should reflect the regional and cellular expression of wild-type RPTP-kappa, and thus may identify sites where RPTP-kappa is important. Towards...... that goal, we have used this mouse model to map the distribution of the truncated RPTP-kappa/beta-geo fusion protein in the adult mouse brain using beta-galactosidase as a marker enzyme. Visualization of the beta-galactosidase activity revealed a non-random pattern of expression, and identified cells...

  17. A Bystander Mechanism Explains the Specific Phenotype of a Broadly Expressed Misfolded Protein.

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    Lauren Klabonski

    2016-12-01

    Full Text Available Misfolded proteins in transgenic models of conformational diseases interfere with proteostasis machinery and compromise the function of many structurally and functionally unrelated metastable proteins. This collateral damage to cellular proteins has been termed 'bystander' mechanism. How a single misfolded protein overwhelms the proteostasis, and how broadly-expressed mutant proteins cause cell type-selective phenotypes in disease are open questions. We tested the gain-of-function mechanism of a R37C folding mutation in an endogenous IGF-like C.elegans protein DAF-28. DAF-28(R37C is broadly expressed, but only causes dysfunction in one specific neuron, ASI, leading to a distinct developmental phenotype. We find that this phenotype is caused by selective disruption of normal biogenesis of an unrelated endogenous protein, DAF-7/TGF-β. The combined deficiency of DAF-28 and DAF-7 biogenesis, but not of DAF-28 alone, explains the gain-of-function phenotype-deficient pro-growth signaling by the ASI neuron. Using functional, fluorescently-tagged protein, we find that, in animals with mutant DAF-28/IGF, the wild-type DAF-7/TGF-β is mislocalized to and accumulates in the proximal axon of the ASI neuron. Activation of two different branches of the unfolded protein response can modulate both the developmental phenotype and DAF-7 mislocalization in DAF-28(R37C animals, but appear to act through divergent mechanisms. Our finding that bystander targeting of TGF-β explains the phenotype caused by a folding mutation in an IGF-like protein suggests that, in conformational diseases, bystander misfolding may specify the distinct phenotypes caused by different folding mutations.

  18. Expression, purification, characterization and subcellular localization of the goose parvovirus rep1 protein.

    Science.gov (United States)

    Chen, Zongyan; Li, Chuanfeng; Peng, Gaojing; Liu, Guangqing

    2013-07-01

    The goose parvovirus (GPV) Rep1 protein is both essential for viral replication and a potential target for GPV diagnosis, but its protein characterization and intracellular localization is not clear. We constructed a recombinant plasmid, pET28a/GPV-Rep1, and expressed the Rep1 gene in BL21 (DE3) Escherichia coli. A protein approximately 75 kDa in size was obtained from lysates of E. coli cells expressing the recombinant plasmid. SDS-PAGE analysis showed that after induction with 0.6 mM isopropyl β-D-thiogalactosidase (IPTG) at 30°C for 5 h, the Rep1 protein was highly overexpressed. Two methods used to purify proteins, a salinity-gradient elution and Ni-NTA affinity chromatography, were performed. The amount of Rep1 protein obtained by Ni-NTA affinity chromatography was 41.23 mg, while 119.9 mg of Rep1 protein was obtained by a salinity-gradient elution from a 1 L E. coli BL21 (DE3) culture. An immunogenicity analysis showed that the protein could significantly elicit a specific antibody response in immunized goslings compared to control groups. Antibody titers peaked to 1:5120 (optical density (OD) 450 = 3.9) on day 28 after immunization but had mean titers of 1:10,240 (OD450 = 4.2) in gosling groups immunized with a commercially available GPV-attenuated vaccine strain. Experiments examining subcellular localization showed that the Rep1 protein appeared to associate predominantly with the nuclear membrane, especially during later times of infection. This work provides a basis for biochemical and structural studies on the GPV Rep1 protein.

  19. Genome-wide screens for expressed hypothetical proteins

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Durhuus, Jon Ambæk; Rasmussen, Lene Juel

    2012-01-01

    A hypothetical protein (HP) is defined as a protein that is predicted to be expressed from an open reading frame, but for which there is no experimental evidence of translation. HPs constitute a substantial fraction of proteomes of human as well as of other organisms. With the general belief that...... that the majority of HPs are the product of pseudogenes, it is essential to have a tool with the ability of pinpointing the minority of HPs with a high probability of being expressed....

  20. Protein kinase B/Akt1 inhibits autophagy by down-regulating UVRAG expression

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Wonseok; Ju, Ji-hyun; Lee, Kyung-min; Nam, KeeSoo; Oh, Sunhwa [Department of Life Science, College of Natural Science, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Shin, Incheol, E-mail: incheol@hanyang.ac.kr [Department of Life Science, College of Natural Science, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

    2013-02-01

    Autophagy, or autophagocytosis, is a selective intracellular degradative process involving the cell's own lysosomal apparatus. An essential component in cell development, homeostasis, repair and resistance to stress, autophagy may result in either cell death or survival. The targeted region of the cell is sequestered within a membrane structure, the autophagosome, for regulation of the catabolic process. A key factor in both autophagosome formation and autophagosome maturation is a protein encoded by the ultraviolet irradiation resistance-associated gene (UVRAG). Conversely, the serine/threonine-specific protein kinase B (PKB, also known as Akt), which regulates survival in various cancers, inhibits autophagy through mTOR activation. We found that Akt1 may also directly inhibit autophagy by down-regulating UVRAG both in a 293T transient transfection system and breast cancer cells stably expressing Akt1. The UVRAG with mutations at putative Akt1-phosphorylation sites were still inhibited by Akt1, and dominant-negative Akt1 also inhibited UVRAG expression, suggesting that Akt1 down-regulates UVRAG by a kinase activity-independent mechanism. We showed that Akt1 overexpression in MDA-MB-231 breast cancer cells down-regulated UVRAG transcription. Cells over-expressing Akt1 were more resistant than control cells to ultraviolet light-induced autophagy and exhibited the associated reduction in cell viability. Levels of the autophagosome indicator protein LC3B-II and mRFP-GFP-LC3 were reduced in cells that over-expressing Akt1. Inhibiting Akt1 by siRNA or reintroducing UVRAG gene rescued the level of LC3B-II in UV-irradiation. Altogether, these data suggest that Akt1 may inhibit autophagy by decreasing UVRAG expression, which also sensitizes cancer cells to UV irradiation.

  1. The LIKE system, a novel protein expression toolbox for Bacillus subtilis based on the liaI promoter

    Science.gov (United States)

    2012-01-01

    Background Bacillus subtilis is a very important Gram-positive model organism of high biotechnological relevance, which is widely used as a host for the production of both secreted and cytoplasmic proteins. We developed a novel and efficient expression system, based on the liaI promoter (PliaI) from B. subtilis, which is under control of the LiaRS antibiotic-inducible two-component system. In the absence of a stimulus, this promoter is kept tightly inactive. Upon induction by cell wall antibiotics, it shows an over 100-fold increase in activity within 10 min. Results Based on these traits of PliaI, we developed a novel LiaRS-controlled gene expression system for B. subtilis (the “LIKE" system). Two expression vectors, the integrative pLIKE-int and the replicative pLIKE-rep, were constructed. To enhance the performance of the PliaI-derived system, site-directed mutagenesis was employed to optimize the ribosome binding site and alter its spacing to the initiation codon used for the translational fusion. The impact of these genetic modifications on protein production yield was measured using GFP as a model protein. Moreover, a number of tailored B. subtilis expression strains containing different markerless chromosomal deletions of the liaIH region were constructed to circumvent undesired protein production, enhance the positive autoregulation of the LiaRS system and thereby increase target gene expression strength from the PliaI promoter. Conclusions The LIKE protein expression system is a novel protein expression system, which offers a number of advantages over existing systems. Its major advantages are (i) a tightly switched-off promoter during exponential growth in the absence of a stimulus, (ii) a concentration-dependent activation of PliaI in the presence of suitable inducers, (iii) a very fast but transient response with a very high dynamic range of over 100-fold (up to 1,000-fold) induction, (iv) a choice from a range of well-defined, commercially available

  2. Protein expression analysis of inflammation-related colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    Yasui Yumiko

    2009-01-01

    Full Text Available Background: Chronic inflammation is a risk factor for colorectal cancer (CRC development. The aim of this study was to determine the differences in protein expression between CRC and the surrounding nontumorous colonic tissues in the mice that received azoxymethane (AOM and dextran sodium sulfate (DSS using a proteomic analysis. Materials and Methods: Male ICR mice were given a single intraperitoneal injection of AOM (10 mg/kg body weight, followed by 2% (w/v DSS in their drinking water for seven days, starting one week after the AOM injection. Colonic adenocarcinoma developed after 20 weeks and a proteomics analysis based on two-dimensional gel electrophoresis and ultraflex TOF/TOF mass spectrometry was conducted in the cancerous and nontumorous tissue specimens. Results: The proteomic analysis revealed 21 differentially expressed proteins in the cancerous tissues in comparison to the nontumorous tissues. There were five markedly increased proteins (beta-tropomyosin, tropomyosin 1 alpha isoform b, S100 calcium binding protein A9, and an unknown protein and 16 markedly decreased proteins (Car1 proteins, selenium-binding protein 1, HMG-CoA synthase, thioredoxin 1, 1 Cys peroxiredoxin protein 2, Fcgbp protein, Cytochrome c oxidase, subunit Va, ETHE1 protein, and 7 unknown proteins. Conclusions: There were 21 differentially expressed proteins in the cancerous tissues of the mice that received AOM and DSS. Their functions include metabolism, the antioxidant system, oxidative stress, mucin production, and inflammation. These findings may provide new insights into the mechanisms of inflammation-related colon carcinogenesis and the establishment of novel therapies and preventative strategies to treat carcinogenesis in the inflamed colon.

  3. Exploring off-targets and off-systems for adverse drug reactions via chemical-protein interactome--clozapine-induced agranulocytosis as a case study.

    Directory of Open Access Journals (Sweden)

    Lun Yang

    2011-03-01

    Full Text Available In the era of personalized medical practice, understanding the genetic basis of patient-specific adverse drug reaction (ADR is a major challenge. Clozapine provides effective treatments for schizophrenia but its usage is limited because of life-threatening agranulocytosis. A recent high impact study showed the necessity of moving clozapine to a first line drug, thus identifying the biomarkers for drug-induced agranulocytosis has become important. Here we report a methodology termed as antithesis chemical-protein interactome (CPI, which utilizes the docking method to mimic the differences in the drug-protein interactions across a panel of human proteins. Using this method, we identified HSPA1A, a known susceptibility gene for CIA, to be the off-target of clozapine. Furthermore, the mRNA expression of HSPA1A-related genes (off-target associated systems was also found to be differentially expressed in clozapine treated leukemia cell line. Apart from identifying the CIA causal genes we identified several novel candidate genes which could be responsible for agranulocytosis. Proteins related to reactive oxygen clearance system, such as oxidoreductases and glutathione metabolite enzymes, were significantly enriched in the antithesis CPI. This methodology conducted a multi-dimensional analysis of drugs' perturbation to the biological system, investigating both the off-targets and the associated off-systems to explore the molecular basis of an adverse event or the new uses for old drugs.

  4. Differential Expression of FosB Proteins and Potential Target Genes in Select Brain Regions of Addiction and Depression Patients.

    Directory of Open Access Journals (Sweden)

    Paula A Gajewski

    Full Text Available Chronic exposure to stress or drugs of abuse has been linked to altered gene expression throughout the body, and changes in gene expression in discrete brain regions are thought to underlie many psychiatric diseases, including major depressive disorder and drug addiction. Preclinical models of these disorders have provided evidence for mechanisms of this altered gene expression, including transcription factors, but evidence supporting a role for these factors in human patients has been slow to emerge. The transcription factor ΔFosB is induced in the prefrontal cortex (PFC and hippocampus (HPC of rodents in response to stress or cocaine, and its expression in these regions is thought to regulate their "top down" control of reward circuitry, including the nucleus accumbens (NAc. Here, we use biochemistry to examine the expression of the FosB family of transcription factors and their potential gene targets in PFC and HPC postmortem samples from depressed patients and cocaine addicts. We demonstrate that ΔFosB and other FosB isoforms are downregulated in the HPC but not the PFC in the brains of both depressed and addicted individuals. Further, we show that potential ΔFosB transcriptional targets, including GluA2, are also downregulated in the HPC but not PFC of cocaine addicts. Thus, we provide the first evidence of FosB gene expression in human HPC and PFC in these psychiatric disorders, and in light of recent findings demonstrating the critical role of HPC ΔFosB in rodent models of learning and memory, these data suggest that reduced ΔFosB in HPC could potentially underlie cognitive deficits accompanying chronic cocaine abuse or depression.

  5. Activation of p44/42 in Human Natural Killer Cells Decreases Cell-surface Protein Expression: Relationship to Tributyltin-induced alterations of protein expression

    Science.gov (United States)

    Dudimah, Fred D.; Abraha, Abraham; Wang, Xiaofei; Whalen, Margaret M.

    2010-01-01

    Tributyltin (TBT) activates the mitogen activated protein kinase (MAPK), p44/42 in human natural killer (NK) cells. TBT also reduces NK cytotoxic function and decreases the expression of several NK-cell proteins. To understand the role that p44/42 activation plays in TBT-induced loss of NK cell function, we have investigated how selective activation of p44/42 by phorbol 12-myristate 13-acetate (PMA) affects NK cells. Previously we showed that PMA caused losses of lytic function similar to those seen with TBT exposures. Here we examined activation of p44/42 in the regulation of NK-cell protein expression and how this regulation may explain the protein expression changes seen with TBT exposures. NK cells exposed to PMA were examined for levels of cell-surface proteins, granzyme mRNA, and perforin mRNA expression. The expression of CD11a, CD16, CD18, and CD56 were reduced, perforin mRNA levels were unchanged and granzyme mRNA levels were increased. To verify that activation of p44/42 was responsible for the alterations seen in CD11a, CD16, CD18, and CD56 with PMA, NK cells were treated with the p44/42 pathway inhibitor (PD98059) prior to PMA exposures. In the presence of PD98059, PMA caused no decreases in the expression of the cell-surface proteins. Results of these studies indicate that the activation of p44/42 may lead to the loss of NK cell cytotoxic function by decreasing the expression of CD11a, CD16, CD18, and CD56. Further, activation of p44/42 appears to be at least in part responsible for the TBT-induced decreases in expression of CD16, CD18, and CD56. PMID:20883105

  6. The RNA-binding protein PCBP2 facilitates gastric carcinoma growth by targeting miR-34a

    International Nuclear Information System (INIS)

    Hu, Cheng-En; Liu, Yong-Chao; Zhang, Hui-Dong; Huang, Guang-Jian

    2014-01-01

    Highlights: • PCBP2 is overexpressed in human gastric cancer. • PCBP2 high expression predicts poor survival. • PCBP2 regulates gastric cancer growth in vitro and in vivo. • PCBP2 regulates gastric cancer apoptosis by targeting miR-34a. - Abstract: Gastric carcinoma is the fourth most common cancer worldwide, with a high rate of death and low 5-year survival rate. However, the mechanism underling gastric cancer is still not fully understood. Here in the present study, we identify the RNA-binding protein PCBP2 as an oncogenic protein in human gastric carcinoma. Our results show that PCBP2 is up-regulated in human gastric cancer tissues compared to adjacent normal tissues, and that high level of PCBP2 predicts poor overall and disease-free survival. Knockdown of PCBP2 in gastric cancer cells inhibits cell proliferation and colony formation in vitro, whereas opposing results are obtained when PCBP2 is overexpressed. Our in vivo subcutaneous xenograft results also show that PCBP2 can critically regulate gastric cancer cell growth. In addition, we find that PCBP2-depletion induces apoptosis in gastric cancer cells via up-regulating expression of pro-apoptotic proteins and down-regulating anti-apoptotic proteins. Mechanically, we identify that miR-34a as a target of PCBP2, and that miR-34a is critically essential for the function of PCBP2. In summary, PCBP2 promotes gastric carcinoma development by regulating the level of miR-34a

  7. Cloning, Expression and Purification of the Recombinant HIV-1 Tat-Nef Fusion Protein in Prokaryotic Expression System

    Directory of Open Access Journals (Sweden)

    Somayeh Kadkhodayan

    2016-07-01

    Full Text Available Abstract Background: Nef is one of the HIV-1 critical proteins, because it is essential for viral replication and AIDS disease progression and induction of immune response against it can partially inhibit viral infection. Moreover, a domain of the HIV-1 Trans-Activator of Transcription (Tat, 48-60 aa could act as a cell penetrating peptide (CPP. In current study, cloning and expression of Tat-Nef fusion protein was performed in E. coli for the first time. The protein expression was confirmed by western blot analysis and was purified using reverse staining method. Materials and Methods: In this experimental study, primarily, cloning of Tat-Nef fusion gene was done in pGEX6p2 expression vector. Then, the expression of Tat-Nef recombinat protein in E.coli BL21 (DE3 strain was performed by using IPTG inducer. The protein expression was confirmed by SDS-PAGE and western blotting using anti-Nef monoclonal antibody. Then, the recombinant fusion protein was purified from gel using reverse staining method. Results: The results of PCR analysis and enzyme digestion showed a clear band of ~ 726 bp in agarose gel indicating the correct Tat-Nef fusion cloning in pGEX6p2 prokaryotic expression vector. In addition, a 54 kDa band of Tat-Nef on SDS-PAGE revealed Tat-Nef protein expression that western blot analysis using anti-Nef monoclonal antibody confirmed it. Conclusion: The purified Tat-Nef recombinant fusion protein will be used as an antigen for protein vaccine design against HIV infection.

  8. Anti-EGFR-iRGD recombinant protein conjugated silk fibroin nanoparticles for enhanced tumor targeting and antitumor efficiency

    Directory of Open Access Journals (Sweden)

    Bian X

    2016-05-01

    Full Text Available Xinyu Bian,* Puyuan Wu,* Huizi Sha, Hanqing Qian, Qing Wang, Lei Cheng, Yang Yang, Mi Yang, Baorui LiuComprehensive Cancer Center of Drum-Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute of Nanjing University, Nanjing, People’s Republic of China*These authors contributed equally to this workAbstract: In this study, we report a novel kind of targeting with paclitaxel (PTX-loaded silk fibroin nanoparticles conjugated with iRGD–EGFR nanobody recombinant protein (anti-EGFR-iRGD. The new nanoparticles (called A-PTX-SF-NPs were prepared using the carbodiimide-mediated coupling procedure and their characteristics were evaluated. The cellular cytotoxicity and cellular uptake of A-PTX-SF-NPs were also investigated. The results in vivo suggested that NPs conjugated with the recombinant protein exhibited more targeting and anti-neoplastic property in cells with high EGFR expression. In the in vivo antitumor efficacy assay, the A-PTX-SF-NPs group showed slower tumor growth and smaller tumor volumes than PTX-SF-NPs in a HeLa xenograft mouse model. A real-time near-infrared fluorescence imaging study showed that A-PTX-SF-NPs could target the tumor more effectively. These results suggest that the anticancer activity and tumor targeting of A-PTX-SF-NPs were superior to those of PTX-SF-NPs and may have the potential to be used for targeted delivery for tumor therapies. Keywords: EGFR, nanobody, iRGD, recombinant protein, targeting drug carriers, antitumor efficiency

  9. Robust expression of a bioactive mammalian protein in chlamydomonas chloroplast

    Science.gov (United States)

    Mayfield, Stephen P.

    2010-03-16

    Methods and compositions are disclosed to engineer chloroplast comprising heterologous mammalian genes via a direct replacement of chloroplast Photosystem II (PSII) reaction center protein coding regions to achieve expression of recombinant protein above 5% of total protein. When algae is used, algal expressed protein is produced predominantly as a soluble protein where the functional activity of the peptide is intact. As the host algae is edible, production of biologics in this organism for oral delivery or proteins/peptides, especially gut active proteins, without purification is disclosed.

  10. Optimization of the Expression of DT386-BR2 Fusion Protein in Escherichia coli using Response Surface Methodology.

    Science.gov (United States)

    Shafiee, Fatemeh; Rabbani, Mohammad; Jahanian-Najafabadi, Ali

    2017-01-01

    The aim of this study was to determine the best condition for the production of DT386-BR2 fusion protein, an immunotoxin consisting of catalytic and translocation domains of diphtheria toxin fused to BR2, a cancer specific cell penetrating peptide, for targeted eradication of cancer cells, in terms of the host, cultivation condition, and culture medium. Recombinant pET28a vector containing the codons optimized for the expression of the DT386-BR2 gene was transformed to different strains of Escherichia coli ( E. coli BL21 DE3, E. coli Rosetta DE3 and E. coli Rosetta-gami 2 DE3), followed by the induction of expression using 1 mM IPTG. Then, the strain with the highest ability to produce recombinant protein was selected and used to determine the best expression condition using response surface methodology (RSM). Finally, the best culture medium was selected. Densitometry analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the expressed fusion protein showed that E. coli Rosetta DE3 produced the highest amounts of the recombinant fusion protein when quantified by 1 mg/ml bovine serum albumin (178.07 μg/ml). Results of RSM also showed the best condition for the production of the recombinant fusion protein was induction with 1 mM IPTG for 2 h at 37°C. Finally, it was established that terrific broth could produce higher amounts of the fusion protein when compared to other culture media. In this study, we expressed the recombinant DT386-BR2 fusion protein in large amounts by optimizing the expression host, cultivation condition, and culture medium. This fusion protein will be subjected to purification and evaluation of its cytotoxic effects in future studies.

  11. Optimization of the Expression of DT386-BR2 Fusion Protein in Escherichia coli using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Fatemeh Shafiee

    2017-01-01

    Full Text Available Background: The aim of this study was to determine the best condition for the production of DT386-BR2 fusion protein, an immunotoxin consisting of catalytic and translocation domains of diphtheria toxin fused to BR2, a cancer specific cell penetrating peptide, for targeted eradication of cancer cells, in terms of the host, cultivation condition, and culture medium. Materials and Methods: Recombinant pET28a vector containing the codons optimized for the expression of the DT386-BR2 gene was transformed to different strains of Escherichia coli (E. coli BL21 DE3, E. coli Rosetta DE3 and E. coli Rosetta-gami 2 DE3, followed by the induction of expression using 1 mM IPTG. Then, the strain with the highest ability to produce recombinant protein was selected and used to determine the best expression condition using response surface methodology (RSM. Finally, the best culture medium was selected. Results: Densitometry analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the expressed fusion protein showed that E. coli Rosetta DE3 produced the highest amounts of the recombinant fusion protein when quantified by 1 mg/ml bovine serum albumin (178.07 μg/ml. Results of RSM also showed the best condition for the production of the recombinant fusion protein was induction with 1 mM IPTG for 2 h at 37°C. Finally, it was established that terrific broth could produce higher amounts of the fusion protein when compared to other culture media. Conclusion: In this study, we expressed the recombinant DT386-BR2 fusion protein in large amounts by optimizing the expression host, cultivation condition, and culture medium. This fusion protein will be subjected to purification and evaluation of its cytotoxic effects in future studies.

  12. The E1A proteins of all six human adenovirus subgroups target the p300/CBP acetyltransferases and the SAGA transcriptional regulatory complex

    International Nuclear Information System (INIS)

    Shuen, Michael; Avvakumov, Nikita; Torchia, Joe; Mymryk, Joe S.

    2003-01-01

    The N-terminal/conserved region 1 (CR1) portion of the human adenovirus (Ad) 5 E1A protein was previously shown to inhibit growth in the simple eukaryote Saccharomyces cerevisiae. We now demonstrate that the corresponding regions of the E1A proteins of Ad3,-4,-9,-12, and -40, which represent the remaining five Ad subgroups, also inhibit yeast growth. These results suggest that the E1A proteins of all six human Ad subgroups share a common cellular target(s) conserved in yeast. Growth inhibition induced by either full-length or the N-terminal/CR1 portion of Ad5 E1A was relieved by coexpression of the E1A binding portions of the mammalian p300, CBP, and pCAF acetyltransferases. Similarly, growth inhibition by the N-terminal/CR1 portions of the other Ad E1A proteins was suppressed by expression of the same regions of CBP or pCAF known to bind Ad5 E1A. The physical interaction of each of the different Ad E1A proteins with CBP, p300, and pCAF was confirmed in vitro. Furthermore, deletion of the gene encoding yGcn5, the yeast homolog of pCAF and a subunit of the SAGA transcriptional regulatory complex, restored growth in yeast expressing each of the different Ad E1A proteins. This indicates that the SAGA complex is a conserved target of all Ad E1A proteins. Our results demonstrate for the first time that the p300, CBP, and pCAF acetyltransferases are common targets for the E1A proteins of all six human Ad subgroups, highlighting the importance of these interactions for E1A function

  13. Expression of multiple proteins in transgenic plants

    Science.gov (United States)

    Vierstra, Richard D.; Walker, Joseph M.

    2002-01-01

    A method is disclosed for the production of multiple proteins in transgenic plants. A DNA construct for introduction into plants includes a provision to express a fusion protein of two proteins of interest joined by a linking domain including plant ubiquitin. When the fusion protein is produced in the cells of a transgenic plant transformed with the DNA construction, native enzymes present in plant cells cleave the fusion protein to release both proteins of interest into the cells of the transgenic plant. Since the proteins are produced from the same fusion protein, the initial quantities of the proteins in the cells of the plant are approximately equal.

  14. Protease-activatable collagen targeting based on protein cyclization

    NARCIS (Netherlands)

    Breurken, M.; Lempens, E.H.M.; Merkx, M.

    2010-01-01

    Threading collagen through a protein needle: The collagen-binding protein CNA35 operates by wrapping itself around the collagen triple helix. By connecting the N and C termini through an MMP recognition sequence, a dual-specific MMP-sensitive collagen-targeting ligand is obtained that can be used

  15. F-box protein FBXL2 targets cyclin D2 for ubiquitination and degradation to inhibit leukemic cell proliferation

    Science.gov (United States)

    Chen, Bill B.; Glasser, Jennifer R.; Coon, Tiffany A.; Zou, Chunbin; Miller, Hannah L.; Fenton, Moon; McDyer, John F.; Boyiadzis, Michael

    2012-01-01

    Hematologic maligancies exhibit a growth advantage by up-regulation of components within the molecular apparatus involved in cell-cycle progression. The SCF (Skip-Cullin1-F-box protein) E3 ligase family provides homeostatic feedback control of cell division by mediating ubiquitination and degradation of cell-cycle proteins. By screening several previously undescribed E3 ligase components, we describe the behavior of a relatively new SCF subunit, termed FBXL2, that ubiquitinates and destabilizes cyclin D2 protein leading to G0 phase arrest and apoptosis in leukemic and B-lymphoblastoid cell lines. FBXL2 expression was strongly suppressed, and yet cyclin D2 protein levels were robustly expressed in acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) patient samples. Depletion of endogenous FBXL2 stabilized cyclin D2 levels, whereas ectopically expressed FBXL2 decreased cyclin D2 lifespan. FBXL2 did not bind a phosphodegron within its substrate, which is typical of other F-box proteins, but uniquely targeted a calmodulin-binding signature within cyclin D2 to facilitate its polyubiquitination. Calmodulin competes with the F-box protein for access to this motif where it bound and protected cyclin D2 from FBXL2. Calmodulin reversed FBXL2-induced G0 phase arrest and attenuated FBXL2-induced apoptosis of lymphoblastoid cells. These results suggest an antiproliferative effect of SCFFBXL2 in lymphoproliferative malignancies. PMID:22323446

  16. Chromatin-regulating proteins as targets for cancer therapy

    International Nuclear Information System (INIS)

    Oike, Takahiro; Ogiwara, Hideaki; Kohno, Takashi; Amornwichet, Napapat; Nakano, Takashi

    2014-01-01

    Chromatin-regulating proteins represent a large class of novel targets for cancer therapy. In the context of radiotherapy, acetylation and deacetylation of histones by histone acetyltransferases (HATs) and histone deacetylases (HDACs) play important roles in the repair of DNA double-strand breaks generated by ionizing irradiation, and are therefore attractive targets for radiosensitization. Small-molecule inhibitors of HATs (garcinol, anacardic acid and curcumin) and HDACs (vorinostat, sodium butyrate and valproic acid) have been shown to sensitize cancer cells to ionizing irradiation in preclinical models, and some of these molecules are being tested in clinical trials, either alone or in combination with radiotherapy. Meanwhile, recent large-scale genome analyses have identified frequent mutations in genes encoding chromatin-regulating proteins, especially in those encoding subunits of the SWI/SNF chromatin-remodeling complex, in various human cancers. These observations have driven researchers toward development of targeted therapies against cancers carrying these mutations. DOT1L inhibition in MLL-rearranged leukemia, EZH2 inhibition in EZH2-mutant or MLL-rearranged hematologic malignancies and SNF5-deficient tumors, BRD4 inhibition in various hematologic malignancies, and BRM inhibition in BRG1-deficient tumors have demonstrated promising anti-tumor effects in preclinical models, and these strategies are currently awaiting clinical application. Overall, the data collected so far suggest that targeting chromatin-regulating proteins is a promising strategy for tomorrow's cancer therapy, including radiotherapy and molecularly targeted chemotherapy. (author)

  17. Pairwise protein expression classifier for candidate biomarker discovery for early detection of human disease prognosis

    Directory of Open Access Journals (Sweden)

    Kaur Parminder

    2012-08-01

    Full Text Available Abstract Background An approach to molecular classification based on the comparative expression of protein pairs is presented. The method overcomes some of the present limitations in using peptide intensity data for class prediction for problems such as the detection of a disease, disease prognosis, or for predicting treatment response. Data analysis is particularly challenging in these situations due to sample size (typically tens being much smaller than the large number of peptides (typically thousands. Methods based upon high dimensional statistical models, machine learning or other complex classifiers generate decisions which may be very accurate but can be complex and difficult to interpret in simple or biologically meaningful terms. A classification scheme, called ProtPair, is presented that generates simple decision rules leading to accurate classification which is based on measurement of very few proteins and requires only relative expression values, providing specific targeted hypotheses suitable for straightforward validation. Results ProtPair has been tested against clinical data from 21 patients following a bone marrow transplant, 13 of which progress to idiopathic pneumonia syndrome (IPS. The approach combines multiple peptide pairs originating from the same set of proteins, with each unique peptide pair providing an independent measure of discriminatory power. The prediction rate of the ProtPair for IPS study as measured by leave-one-out CV is 69.1%, which can be very beneficial for clinical diagnosis as it may flag patients in need of closer monitoring. The “top ranked” proteins provided by ProtPair are known to be associated with the biological processes and pathways intimately associated with known IPS biology based on mouse models. Conclusions An approach to biomarker discovery, called ProtPair, is presented. ProtPair is based on the differential expression of pairs of peptides and the associated proteins. Using mass

  18. Expression and Activation of Horseradish Peroxidase-Protein A/G Fusion Protein in Silkworm Larvae for Diagnostic Purposes.

    Science.gov (United States)

    Xxxx, Patmawati; Minamihata, Kosuke; Tatsuke, Tsuneyuki; Lee, Jae Man; Kusakabe, Takahiro; Kamiya, Noriho

    2018-06-01

    Recombinant protein production can create artificial proteins with desired functions by introducing genetic modifications to the target proteins. Horseradish peroxidase (HRP) has been used extensively as a reporter enzyme in biotechnological applications; however, recombinant production of HRP has not been very successful, hampering the utilization of HRP with genetic modifications. A fusion protein comprising an antibody binding protein and HRP will be an ideal bio-probe for high-quality HRP-based diagnostic systems. A HRP-protein A/G fusion protein (HRP-pAG) is designed and its production in silkworm (Bombyx mori) is evaluated for the first time. HRP-pAG is expressed in a soluble apo form, and is activated successfully by incubating with hemin. The activated HRP-pAG is used directly for ELISA experiments and retains its activity over 20 days at 4 °C. Moreover, HRP-pAG is modified with biotin by the microbial transglutaminase (MTG) reaction. The biotinylated HRP-pAG is conjugated with streptavidin to form a HRP-pAG multimer and the multimeric HRP-pAG produced higher signals in the ELISA system than monomeric HRP-pAG. The successful production of recombinant HRP in silkworm will contribute to creating novel HRP-based bioconjugates as well as further functionalization of HRP by applying enzymatic post-translational modifications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Mice with GFAP-targeted loss of neurofibromin demonstrate increased axonal MET expression with aging.

    Science.gov (United States)

    Su, Weiping; Xing, Rubing; Guha, Abhijit; Gutmann, David H; Sherman, Larry S

    2007-05-01

    Neurofibromatosis 1 (NF1) is a common genetic disease that predisposes patients to peripheral nerve tumors and central nervous system (CNS) abnormalities including low-grade astrocytomas and cognitive disabilities. Using mice with glial fibrillary acidic protein (GFAP)-targeted Nf1 loss (Nf1(GFAP)CKO mice), we found that Nf1(-/-) astrocytes proliferate faster and are more invasive than wild-type astrocytes. In light of our previous finding that aberrant expression of the MET receptor tyrosine kinase contributes to the invasiveness of human NF1-associated malignant peripheral nerve sheath tumors, we sought to determine whether MET expression is aberrant in the brains of Nf1 mutant mice. We found that Nf1(-/-) astrocytes express slightly more MET than wild-type cells in vitro, but do not express elevated MET in situ. However, fiber tracts containing myelinated axons in the hippocampus, midbrain, cerebral cortex, and cerebellum express higher than normal levels of MET in older (> or =6 months) Nf1(GFAP)CKO mice. Both Nf1(GFAP)CKO and wild-type astrocytes induced MET expression in neurites of wild-type hippocampal neurons in vitro, suggesting that astrocyte-derived signals may induce MET in Nf1 mutant mice. Because the Nf1 gene product functions as a RAS GTPase, we examined MET expression in the brains of mice with GFAP-targeted constitutively active forms of RAS. MET was elevated in axonal fiber tracts in mice with active K-RAS but not H-RAS. Collectively, these data suggest that loss of Nf1 in either astrocytes or GFAP(+) neural progenitor cells results in increased axonal MET expression, which may contribute to the CNS abnormalities in children and adults with NF1. (c) 2007 Wiley-Liss, Inc.

  20. High-level transient expression of recombinant protein in lettuce.

    Science.gov (United States)

    Joh, Lawrence D; Wroblewski, Tadeusz; Ewing, Nicholas N; VanderGheynst, Jean S

    2005-09-30

    Transient expression following agroinfiltration of plant tissue was investigated as a system for producing recombinant protein. As a model system, Agrobacterium tumefaciens containing the beta-glucuronidase (GUS) gene was vacuum infiltrated into lettuce leaf disks. Infiltration with a suspension of 10(9) colony forming units/mL followed by incubation for 72 h at 22 degrees C in continuous darkness produced a maximum of 0.16% GUS protein based on dry tissue or 1.1% GUS protein based on total soluble protein. This compares favorably to expression levels for commercially manufactured GUS protein from transgenic corn seeds. A. tumefaciens culture medium pH between 5.6 and 7.0 and surfactant concentrations lettuce to produce GUS protein more rapidly, but final levels did not exceed the GUS production in leaves incubated in continuous darkness after 72 h at 22 degrees C. The kinetics of GUS expression during incubation in continuous light and dark were represented well using a logistic model, with rate constants of 0.30 and 0.29/h, respectively. To semi-quantitatively measure the GUS expression in large numbers of leaf disks, a photometric enhancement of the standard histochemical staining method was developed. A linear relationship with an R2 value of 0.90 was determined between log10 (% leaf darkness) versus log10 (GUS activity). Although variability in expression level was observed, agroinfiltration appears to be a promising technology that could potentially be scaled up to produce high-value recombinant proteins in planta. Copyright 2005 Wiley Periodicals, Inc

  1. Suppression of leaky expression of adenovirus genes by insertion of microRNA-targeted sequences in the replication-incompetent adenovirus vector genome

    Directory of Open Access Journals (Sweden)

    Kahori Shimizu

    2014-01-01

    Full Text Available Leaky expression of adenovirus (Ad genes occurs following transduction with a conventional replication-incompetent Ad vector, leading to an induction of cellular immunity against Ad proteins and Ad protein-induced toxicity, especially in the late phase following administration. To suppress the leaky expression of Ad genes, we developed novel Ad vectors by incorporating four tandem copies of sequences with perfect complementarity to miR-122a or miR-142-3p into the 3′-untranslated region (UTR of the E2A, E4, or pIX gene, which were mainly expressed from the Ad vector genome after transduction. These Ad vectors easily grew to high titers comparable to those of a conventional Ad vector in conventional 293 cells. The leaky expression of these Ad genes in mouse organs was significantly suppressed by 2- to 100-fold, compared with a conventional Ad vector, by insertion of the miRNA-targeted sequences. Notably, the Ad vector carrying the miR-122a–targeted sequences into the 3′-UTR of the E4 gene expressed higher and longer-term transgene expression and more than 20-fold lower levels of all the Ad early and late genes examined in the liver than a conventional Ad vector. miR-122a–mediated suppression of the E4 gene expression in the liver significantly reduced the hepatotoxicity which an Ad vector causes via both adaptive and non-adaptive immune responses.

  2. Characterization of the Expression of the RNA Binding Protein eIF4G1 and Its Clinicopathological Correlation with Serous Ovarian Cancer.

    Directory of Open Access Journals (Sweden)

    Lanfang Li

    Full Text Available Ovarian cancer is the most lethal type of malignant tumor in gynecological cancers and is associated with a high percentage of late diagnosis and chemotherapy resistance. Thus, it is urgent to identify a tumor marker or a molecular target that allows early detection and effective treatment. RNA-binding proteins (RBPs are crucial in various cellular processes at the post-transcriptional level. The eukaryotic translation initiation factor 4 gamma, 1(eIF4G1, an RNA-binding protein, facilitates the recruitment of mRNA to the ribosome, which is a rate-limiting step during the initiation phase of protein synthesis. However, little is known regarding the characteristics of eIF4G1 expression and its clinical significance in ovarian cancer. Therefore, we propose to investigate the expression and clinicopathological significance of eIF4G1 in ovarian cancer patients.We performed Real-time PCR in 40 fresh serous ovarian cancer tissues and 27 normal ovarian surface epithelial cell specimens to assess eIF4G1mRNA expression. Immunohistochemistry (IHC was used to examine the expression of eIF4G1 at the protein level in 134 patients with serous ovarian cancer and 18 normal ovarian tissues. Statistical analysis was conducted to determine the correlation of the eIF4G1 protein levels with the clinicopathological characteristics and prognosis in ovarian cancer.The expression of eIF4G1 was upregulated in serous ovarian cancer tissues at both the mRNA (P = 0.0375 and the protein (P = 0.0007 levels. The eIF4G1 expression was significantly correlated with the clinical tumor stage (P = 0.0004 and omentum metastasis (P = 0.024. Moreover, patients with low eIF4G1 protein expression had a longer overall survival time (P = 0.026.These data revealed that eIF4G1 is markedly expressed in serous ovarian cancer and that upregulation of the eIF4G1 protein expression is significantly associated with an advanced tumor stage. Besides, the patients with lower expression of eIF4G1 tend

  3. Multiplexed expression and screening for recombinant protein production in mammalian cells

    Directory of Open Access Journals (Sweden)

    McCafferty John

    2006-12-01

    Full Text Available Abstract Background A variety of approaches to understanding protein structure and function require production of recombinant protein. Mammalian based expression systems have advantages over bacterial systems for certain classes of protein but can be slower and more laborious. Thus the availability of a simple system for production and rapid screening of constructs or conditions for mammalian expression would be of great benefit. To this end we have coupled an efficient recombinant protein production system based on transient transfection in HEK-293 EBNA1 (HEK-293E suspension cells with a dot blot method allowing pre-screening of proteins expressed in cells in a high throughput manner. Results A nested PCR approach was used to clone 21 extracellular domains of mouse receptors as CD4 fusions within a mammalian GATEWAY expression vector system. Following transient transfection, HEK-293E cells grown in 2 ml cultures in 24-deep well blocks showed similar growth kinetics, viability and recombinant protein expression profiles, to those grown in 50 ml shake flask cultures as judged by western blotting. Following optimisation, fluorescent dot blot analysis of transfection supernatants was shown to be a rapid method for analysing protein expression yielding similar results as western blot analysis. Addition of urea enhanced the binding of glycoproteins to a nitrocellulose membrane. A good correlation was observed between the results of a plate based small scale transient transfection dot blot pre-screen and successful purification of proteins expressed at the 50 ml scale. Conclusion The combination of small scale multi-well plate culture and dot blotting described here will allow the multiplex analysis of different mammalian expression experiments enabling a faster identification of high yield expression constructs or conditions prior to large scale protein production. The methods for parallel GATEWAY cloning and expression of multiple constructs in cell

  4. Trichohyalin-like 1 protein, a member of fused S100 proteins, is expressed in normal and pathologic human skin

    Energy Technology Data Exchange (ETDEWEB)

    Yamakoshi, Takako [Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama 930-0194 (Japan); Makino, Teruhiko, E-mail: tmakino@med.u-toyama.ac.jp [Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama 930-0194 (Japan); Ur Rehman, Mati; Yoshihisa, Yoko [Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama 930-0194 (Japan); Sugimori, Michiya [Department of Integrative Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama 930-0194 (Japan); Shimizu, Tadamichi, E-mail: shimizut@med.u-toyama.ac.jp [Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama 930-0194 (Japan)

    2013-03-01

    Highlights: ► Trichohyalin-like 1 protein is a member of the fused-type S100 protein gene family. ► Specific antibodies against the C-terminus of the TCHHL1 protein were generated. ► TCHHL1 proteins were expressed in the basal layer of the normal epidermis. ► TCHHL1 proteins were strongly expressed in tumor nests of BCC and SCC. ► The expression of TCHHL1 proteins increased in epidermis of psoriasis vulgaris. - Abstract: Trichohyalin-like 1 (TCHHL1) protein is a novel member of the fused-type S100 protein gene family. The deduced amino acid sequence of TCHHL1 contains an EF-hand domain in the N-terminus, one trans-membrane domain and a nuclear localization signal. We generated specific antibodies against the C-terminus of the TCHHL1 protein and examined the expression of TCHHL1 proteins in normal and pathological human skin. An immunohistochemical study showed that TCHHL1 proteins were expressed in the basal layer of the normal epidermis. In addition, signals of TCHHL1 proteins were observed around the nuclei of cultured growing keratinocytes. Accordingly, TCHHL1 mRNA has been detected in normal skin and cultured growing keratinocytes. Furthermore, TCHHL1 proteins were strongly expressed in the peripheral areas of tumor nests in basal cell carcinomas and squamous cell carcinomas. A dramatic increase in the number of Ki67 positive cells was observed in TCHHL1-expressing areas. The expression of TCHHL1 proteins also increased in non-cancerous hyperproliferative epidermal tissues such as those of psoriasis vulgaris and lichen planus. These findings highlight the possibility that TCHHL1 proteins are expressed in growing keratinocytes of the epidermis and might be associated with the proliferation of keratinocytes.

  5. Trichohyalin-like 1 protein, a member of fused S100 proteins, is expressed in normal and pathologic human skin

    International Nuclear Information System (INIS)

    Yamakoshi, Takako; Makino, Teruhiko; Ur Rehman, Mati; Yoshihisa, Yoko; Sugimori, Michiya; Shimizu, Tadamichi

    2013-01-01

    Highlights: ► Trichohyalin-like 1 protein is a member of the fused-type S100 protein gene family. ► Specific antibodies against the C-terminus of the TCHHL1 protein were generated. ► TCHHL1 proteins were expressed in the basal layer of the normal epidermis. ► TCHHL1 proteins were strongly expressed in tumor nests of BCC and SCC. ► The expression of TCHHL1 proteins increased in epidermis of psoriasis vulgaris. - Abstract: Trichohyalin-like 1 (TCHHL1) protein is a novel member of the fused-type S100 protein gene family. The deduced amino acid sequence of TCHHL1 contains an EF-hand domain in the N-terminus, one trans-membrane domain and a nuclear localization signal. We generated specific antibodies against the C-terminus of the TCHHL1 protein and examined the expression of TCHHL1 proteins in normal and pathological human skin. An immunohistochemical study showed that TCHHL1 proteins were expressed in the basal layer of the normal epidermis. In addition, signals of TCHHL1 proteins were observed around the nuclei of cultured growing keratinocytes. Accordingly, TCHHL1 mRNA has been detected in normal skin and cultured growing keratinocytes. Furthermore, TCHHL1 proteins were strongly expressed in the peripheral areas of tumor nests in basal cell carcinomas and squamous cell carcinomas. A dramatic increase in the number of Ki67 positive cells was observed in TCHHL1-expressing areas. The expression of TCHHL1 proteins also increased in non-cancerous hyperproliferative epidermal tissues such as those of psoriasis vulgaris and lichen planus. These findings highlight the possibility that TCHHL1 proteins are expressed in growing keratinocytes of the epidermis and might be associated with the proliferation of keratinocytes

  6. The new pLAI (lux regulon based auto-inducible expression system for recombinant protein production in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Nocadello Salvatore

    2012-01-01

    Full Text Available Abstract Background After many years of intensive research, it is generally assumed that no universal expression system can exist for high-level production of a given recombinant protein. Among the different expression systems, the inducible systems are the most popular for their tight regulation. However, induction is in many cases less favorable due to the high cost and/or toxicity of inducers, incompatibilities with industrial scale-up or detrimental growth conditions. Expression systems using autoinduction (or self-induction prove to be extremely versatile allowing growth and induction of recombinant proteins without the need to monitor cell density or add inducer. Unfortunately, almost all the actual auto inducible expression systems need endogenous or induced metabolic changes during the growth to trigger induction, both frequently linked to detrimental condition to cell growth. In this context, we use a simple modular approach for a cell density-based genetic regulation in order to assemble an autoinducible recombinant protein expression system in E. coli. Result The newly designed pLAI expression system places the expression of recombinant proteins in Escherichia coli under control of the regulatory genes of the lux regulon of Vibrio fischeri's Quorum Sensing (QS system. The pLAI system allows a tight regulation of the recombinant gene allowing a negligible basal expression and expression only at high cell density. Sequence optimization of regulative genes of QS of V. fischeri for expression in E. coli upgraded the system to high level expression. Moreover, partition of regulative genes between the plasmid and the host genome and introduction of a molecular safety lock permitted tighter control of gene expression. Conclusion Coupling gene expression to cell density using cell-to-cell communication provides a promising approach for recombinant protein production. The system allows the control of expression of the target recombinant gene

  7. Expression of RNA virus proteins by RNA polymerase II dependent expression plasmids is hindered at multiple steps

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    Überla Klaus

    2007-06-01

    Full Text Available Abstract Background Proteins of human and animal viruses are frequently expressed from RNA polymerase II dependent expression cassettes to study protein function and to develop gene-based vaccines. Initial attempts to express the G protein of vesicular stomatitis virus (VSV and the F protein of respiratory syncytial virus (RSV by eukaryotic promoters revealed restrictions at several steps of gene expression. Results Insertion of an intron flanked by exonic sequences 5'-terminal to the open reading frames (ORF of VSV-G and RSV-F led to detectable cytoplasmic mRNA levels of both genes. While the exonic sequences were sufficient to stabilise the VSV-G mRNA, cytoplasmic mRNA levels of RSV-F were dependent on the presence of a functional intron. Cytoplasmic VSV-G mRNA levels led to readily detectable levels of VSV-G protein, whereas RSV-F protein expression remained undetectable. However, RSV-F expression was observed after mutating two of four consensus sites for polyadenylation present in the RSV-F ORF. Expression levels could be further enhanced by codon optimisation. Conclusion Insufficient cytoplasmic mRNA levels and premature polyadenylation prevent expression of RSV-F by RNA polymerase II dependent expression plasmids. Since RSV replicates in the cytoplasm, the presence of premature polyadenylation sites and elements leading to nuclear instability should not interfere with RSV-F expression during virus replication. The molecular mechanisms responsible for the destabilisation of the RSV-F and VSV-G mRNAs and the different requirements for their rescue by insertion of an intron remain to be defined.

  8. Targeted proteomics as a tool for porcine acute phase proteins measurements

    DEFF Research Database (Denmark)

    Marco-Ramell, Anna; Bassols, Anna; Bislev, Stine Lønnerup

    2013-01-01

    . Selected reaction monitoring (SRM), a targeted quantitative proteomic technique, may be used as an alternative to commercial kits for the measurement and validation of target proteins. Acute phase proteins (APPs) are widely recognized inflammation and infection biomarkers (Eckersall, 2010...

  9. Differential expression of centrosomal proteins at different stages of human glioma

    International Nuclear Information System (INIS)

    Loh, Joon-Khim; Lieu, Ann-Shung; Chou, Chia-Hua; Lin, Fang-Yi; Wu, Chia-Hung; Howng, Sheng-Long; Chio, Chung-Ching; Hong, Yi-Ren

    2010-01-01

    High-grade gliomas have poor prognosis, requiring aggressive treatment. The aim of this study is to explore mitotic and centrosomal dysregulation in gliomas, which may provide novel targets for treatment. A case-control study was performed using 34 resected gliomas, which were separated into low- and high-grade groups. Normal human brain tissue was used as a control. Using immunohistochemical analysis, immunofluorescent microscopy, and RT-PCR, detection of centrins 1 and 2, γ-tubulin, hNinein, Aurora A, and Aurora B, expression was performed. Analysis of the GBM8401 glioma cell line was also undertaken to complement the in vivo studies. In high-grade gliomas, the cells had greater than two very brightly staining centrioles within large, atypical nuclei, and moderate-to-strong Aurora A staining. Comparing with normal human brain tissue, most of the mRNAs expression in gliomas for centrosomal structural proteins, including centrin 3, γ-tubulin, and hNinein isoforms 1, 2, 5 and 6, Aurora A and Aurora B were elevated. The significant different expression was observed between high- and low-grade glioma in both γ-tubulin and Aurora A mRNA s. In the high-grade glioma group, 78.6% of the samples had higher than normal expression of γ-tubulin mRNA, which was significantly higher than in the low-grade glioma group (18.2%, p < 0.05). Markers for mitotic dysregulation, such as supernumerary centrosomes and altered expression of centrosome-related mRNA and proteins were more frequently detected in higher grade gliomas. Therefore, these results are clinically useful for glioma staging as well as the development of novel treatments strategies

  10. Differential expression of centrosomal proteins at different stages of human glioma

    Directory of Open Access Journals (Sweden)

    Lin Fang-Yi

    2010-06-01

    Full Text Available Abstract Background High-grade gliomas have poor prognosis, requiring aggressive treatment. The aim of this study is to explore mitotic and centrosomal dysregulation in gliomas, which may provide novel targets for treatment. Methods A case-control study was performed using 34 resected gliomas, which were separated into low- and high-grade groups. Normal human brain tissue was used as a control. Using immunohistochemical analysis, immunofluorescent microscopy, and RT-PCR, detection of centrins 1 and 2, γ-tubulin, hNinein, Aurora A, and Aurora B, expression was performed. Analysis of the GBM8401 glioma cell line was also undertaken to complement the in vivo studies. Results In high-grade gliomas, the cells had greater than two very brightly staining centrioles within large, atypical nuclei, and moderate-to-strong Aurora A staining. Comparing with normal human brain tissue, most of the mRNAs expression in gliomas for centrosomal structural proteins, including centrin 3, γ-tubulin, and hNinein isoforms 1, 2, 5 and 6, Aurora A and Aurora B were elevated. The significant different expression was observed between high- and low-grade glioma in both γ-tubulin and Aurora A mRNA s. In the high-grade glioma group, 78.6% of the samples had higher than normal expression of γ-tubulin mRNA, which was significantly higher than in the low-grade glioma group (18.2%, p Conclusions Markers for mitotic dysregulation, such as supernumerary centrosomes and altered expression of centrosome-related mRNA and proteins were more frequently detected in higher grade gliomas. Therefore, these results are clinically useful for glioma staging as well as the development of novel treatments strategies.

  11. Expression and affinity purification of recombinant proteins from plants

    Science.gov (United States)

    Desai, Urvee A.; Sur, Gargi; Daunert, Sylvia; Babbitt, Ruth; Li, Qingshun

    2002-01-01

    With recent advances in plant biotechnology, transgenic plants have been targeted as an inexpensive means for the mass production of proteins for biopharmaceutical and industrial uses. However, the current plant purification techniques lack a generally applicable, economic, large-scale strategy. In this study, we demonstrate the purification of a model protein, beta-glucuronidase (GUS), by employing the protein calmodulin (CaM) as an affinity tag. In the proposed system, CaM is fused to GUS. In the presence of calcium, the calmodulin fusion protein binds specifically to a phenothiazine-modified surface of an affinity column. When calcium is removed with a complexing agent, e.g., EDTA, calmodulin undergoes a conformational change allowing the dissociation of the calmodulin-phenothiazine complex and, therefore, permitting the elution of the GUS-CaM fusion protein. The advantages of this approach are the fast, efficient, and economical isolation of the target protein under mild elution conditions, thus preserving the activity of the target protein. Two types of transformation methods were used in this study, namely, the Agrobacterium-mediated system and the viral-vector-mediated transformation system. Copyright 2002 Elsevier Science (USA).

  12. High-level expression of soluble recombinant proteins in Escherichia coli using an HE-maltotriose-binding protein fusion tag.

    Science.gov (United States)

    Han, Yingqian; Guo, Wanying; Su, Bingqian; Guo, Yujie; Wang, Jiang; Chu, Beibei; Yang, Guoyu

    2018-02-01

    Recombinant proteins are commonly expressed in prokaryotic expression systems for large-scale production. The use of genetically engineered affinity and solubility enhancing fusion proteins has increased greatly in recent years, and there now exists a considerable repertoire of these that can be used to enhance the expression, stability, solubility, folding, and purification of their fusion partner. Here, a modified histidine tag (HE) used as an affinity tag was employed together with a truncated maltotriose-binding protein (MBP; consisting of residues 59-433) from Pyrococcus furiosus as a solubility enhancing tag accompanying a tobacco etch virus protease-recognition site for protein expression and purification in Escherichia coli. Various proteins tagged at the N-terminus with HE-MBP(Pyr) were expressed in E. coli BL21(DE3) cells to determine expression and solubility relative to those tagged with His6-MBP or His6-MBP(Pyr). Furthermore, four HE-MBP(Pyr)-fused proteins were purified by immobilized metal affinity chromatography to assess the affinity of HE with immobilized Ni 2+ . Our results showed that HE-MBP(Pyr) represents an attractive fusion protein allowing high levels of soluble expression and purification of recombinant protein in E. coli. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Frame-Insensitive Expression Cloning of Fluorescent Protein from Scolionema suvaense

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    Yuki Horiuchi

    2018-01-01

    Full Text Available Expression cloning from cDNA is an important technique for acquiring genes encoding novel fluorescent proteins. However, the probability of in-frame cDNA insertion following the first start codon of the vector is normally only 1/3, which is a cause of low cloning efficiency. To overcome this issue, we developed a new expression plasmid vector, pRSET-TriEX, in which transcriptional slippage was induced by introducing a DNA sequence of (dT14 next to the first start codon of pRSET. The effectiveness of frame-insensitive cloning was validated by inserting the gene encoding eGFP with all three possible frames to the vector. After transformation with one of these plasmids, E. coli cells expressed eGFP with no significant difference in the expression level. The pRSET-TriEX vector was then used for expression cloning of a novel fluorescent protein from Scolionema suvaense. We screened 3658 E. coli colonies transformed with pRSET-TriEX containing Scolionema suvaense cDNA, and found one colony expressing a novel green fluorescent protein, ScSuFP. The highest score in protein sequence similarity was 42% with the chain c of multi-domain green fluorescent protein like protein “ember” from Anthoathecata sp. Variations in the N- and/or C-terminal sequence of ScSuFP compared to other fluorescent proteins indicate that the expression cloning, rather than the sequence similarity-based methods, was crucial for acquiring the gene encoding ScSuFP. The absorption maximum was at 498 nm, with an extinction efficiency of 1.17 × 105 M−1·cm−1. The emission maximum was at 511 nm and the fluorescence quantum yield was determined to be 0.6. Pseudo-native gel electrophoresis showed that the protein forms obligatory homodimers.

  14. Novel Strategy to Control Transgene Expression Mediated by a Sendai Virus-Based Vector Using a Nonstructural C Protein and Endogenous MicroRNAs.

    Directory of Open Access Journals (Sweden)

    Masayuki Sano

    Full Text Available Tissue-specific control of gene expression is an invaluable tool for studying various biological processes and medical applications. Efficient regulatory systems have been utilized to control transgene expression in various types of DNA viral or integrating viral vectors. However, existing regulatory systems are difficult to transfer into negative-strand RNA virus vector platforms because of significant differences in their transcriptional machineries. In this study, we developed a novel strategy for regulating transgene expression mediated by a cytoplasmic RNA vector based on a replication-defective and persistent Sendai virus (SeVdp. Because of the capacity of Sendai virus (SeV nonstructural C proteins to specifically inhibit viral RNA synthesis, overexpression of C protein significantly reduced transgene expression mediated by SeVdp vectors. We found that SeV C overexpression concomitantly reduced SeVdp mRNA levels and genomic RNA synthesis. To control C expression, target sequences for an endogenous microRNA were incorporated into the 3' untranslated region of the C genes. Incorporation of target sequences for miR-21 into the SeVdp vector restored transgene expression in HeLa cells by decreasing C expression. Furthermore, the SeVdp vector containing target sequences for let-7a enabled cell-specific control of transgene expression in human fibroblasts and induced pluripotent stem cells. Our findings demonstrate that SeV C can be used as an effective regulator for controlling transgene expression. This strategy will contribute to efficient and less toxic SeVdp-mediated gene transfer in various biological applications.

  15. Expression of the Argonaute protein PiwiL2 and piRNAs in adult mouse mesenchymal stem cells

    International Nuclear Information System (INIS)

    Wu, Qiuling; Ma, Qi; Shehadeh, Lina A.; Wilson, Amber; Xia, Linghui; Yu, Hong; Webster, Keith A.

    2010-01-01

    Piwi (P-element-induced wimpy testis) first discovered in Drosophila is a member of the Argonaute family of micro-RNA binding proteins with essential roles in germ-cell development. The murine homologue of PiwiL2, also known as Mili is selectively expressed in the testes, and mice bearing targeted mutations of the PiwiL2 gene are male-sterile. PiwiL2 proteins are thought to protect the germ line genome by suppressing retrotransposons, stabilizing heterochromatin structure, and regulating target genes during meiosis and mitosis. Here, we report that PiwiL2 and associated piRNAs (piRs) may play similar roles in adult mouse mesenchymal stem cells. We found that PiwiL2 is expressed in the cytoplasm of metaphase mesenchymal stem cells from the bone marrow of adult and aged mice. Knockdown of PiwiL2 with a specific siRNA enhanced cell proliferation, significantly increased the number of cells in G1/S and G2/M cell cycle phases and was associated with increased expression of cell cycle genes CCND1, CDK8, microtubule regulation genes, and decreased expression of tumor suppressors Cables 1, LATS, and Cxxc4. The results suggest broader roles for Piwi in genome surveillance beyond the germ line and a possible role in regulating the cell cycle of mesenchymal stem cells.

  16. Expression of the Argonaute protein PiwiL2 and piRNAs in adult mouse mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiuling; Ma, Qi; Shehadeh, Lina A.; Wilson, Amber; Xia, Linghui; Yu, Hong [Department of Molecular and Cellular Pharmacology, Vascular Biology Institute, University of Miami Miller School of Medicine, Miami, FL 33136 (United States); Webster, Keith A., E-mail: kwebster@med.miami.edu [Department of Molecular and Cellular Pharmacology, Vascular Biology Institute, University of Miami Miller School of Medicine, Miami, FL 33136 (United States)

    2010-06-11

    Piwi (P-element-induced wimpy testis) first discovered in Drosophila is a member of the Argonaute family of micro-RNA binding proteins with essential roles in germ-cell development. The murine homologue of PiwiL2, also known as Mili is selectively expressed in the testes, and mice bearing targeted mutations of the PiwiL2 gene are male-sterile. PiwiL2 proteins are thought to protect the germ line genome by suppressing retrotransposons, stabilizing heterochromatin structure, and regulating target genes during meiosis and mitosis. Here, we report that PiwiL2 and associated piRNAs (piRs) may play similar roles in adult mouse mesenchymal stem cells. We found that PiwiL2 is expressed in the cytoplasm of metaphase mesenchymal stem cells from the bone marrow of adult and aged mice. Knockdown of PiwiL2 with a specific siRNA enhanced cell proliferation, significantly increased the number of cells in G1/S and G2/M cell cycle phases and was associated with increased expression of cell cycle genes CCND1, CDK8, microtubule regulation genes, and decreased expression of tumor suppressors Cables 1, LATS, and Cxxc4. The results suggest broader roles for Piwi in genome surveillance beyond the germ line and a possible role in regulating the cell cycle of mesenchymal stem cells.

  17. Plasma Membrane Targeting of Protocadherin 15 Is Regulated by the Golgi-Associated Chaperone Protein PIST

    Directory of Open Access Journals (Sweden)

    Hongyun Nie

    2016-01-01

    Full Text Available Protocadherin 15 (PCDH15 is a core component of hair cell tip-links and crucial for proper function of inner ear hair cells. Mutations of PCDH15 gene cause syndromic and nonsyndromic hearing loss. At present, the regulatory mechanisms responsible for the intracellular transportation of PCDH15 largely remain unknown. Here we show that PIST, a Golgi-associated, PDZ domain-containing protein, interacts with PCDH15. The interaction is mediated by the PDZ domain of PIST and the C-terminal PDZ domain-binding interface (PBI of PCDH15. Through this interaction, PIST retains PCDH15 in the trans-Golgi network (TGN and reduces the membrane expression of PCDH15. We have previously showed that PIST regulates the membrane expression of another tip-link component, cadherin 23 (CDH23. Taken together, our finding suggests that PIST regulates the intracellular trafficking and membrane targeting of the tip-link proteins CDH23 and PCDH15.

  18. Receptor-like protein-tyrosine phosphatase alpha specifically inhibits insulin-increased prolactin gene expression

    DEFF Research Database (Denmark)

    Jacob, K K; Sap, J; Stanley, F M

    1998-01-01

    A physiologically relevant response to insulin, stimulation of prolactin promoter activity in GH4 pituitary cells, was used as an assay to study the specificity of protein-tyrosine phosphatase function. Receptor-like protein-tyrosine phosphatase alpha (RPTPalpha) blocks the effect of insulin...... is specific by two criteria. A number of potential RPTPalpha targets were ruled out by finding (a) that they are not affected or (b) that they are not on the pathway to insulin-increased prolactin-CAT activity. The negative effect of RPTPalpha on insulin activation of the prolactin promoter is not due...... to reduced phosphorylation or kinase activity of the insulin receptor or to reduced phosphorylation of insulin receptor substrate-1 or Shc. Inhibitor studies suggest that insulin-increased prolactin gene expression is mediated by a Ras-like GTPase but is not mitogen-activated protein kinase dependent...

  19. Genetics Coupled to Quantitative Intact Proteomics Links Heritable Aphid and Endosymbiont Protein Expression to Circulative Polerovirus Transmission▿ †

    Science.gov (United States)

    Cilia, M.; Tamborindeguy, C.; Fish, T.; Howe, K.; Thannhauser, T. W.; Gray, S.

    2011-01-01

    Yellow dwarf viruses in the family Luteoviridae, which are the causal agents of yellow dwarf disease in cereal crops, are each transmitted most efficiently by different species of aphids in a circulative manner that requires the virus to interact with a multitude of aphid proteins. Aphid proteins differentially expressed in F2 Schizaphis graminum genotypes segregating for the ability to transmit Cereal yellow dwarf virus-RPV (CYDV-RPV) were identified using two-dimensional difference gel electrophoresis (DIGE) coupled to either matrix-assisted laser desorption ionization-tandem mass spectrometry or online nanoscale liquid chromatography coupled to electrospray tandem mass spectrometry. A total of 50 protein spots, containing aphid proteins and proteins from the aphid's obligate and maternally inherited bacterial endosymbiont, Buchnera, were identified as differentially expressed between transmission-competent and refractive aphids. Surprisingly, in virus transmission-competent F2 genotypes, the isoelectric points of the Buchnera proteins did not match those in the maternal Buchnera proteome as expected, but instead they aligned with the Buchnera proteome of the transmission-competent paternal parent. Among the aphid proteins identified, many were involved in energy metabolism, membrane trafficking, lipid signaling, and the cytoskeleton. At least eight aphid proteins were expressed as heritable, isoelectric point isoform pairs, one derived from each parental lineage. In the F2 genotypes, the expression of aphid protein isoforms derived from the competent parental lineage aligned with the virus transmission phenotype with high precision. Thus, these isoforms are candidate biomarkers for CYDV-RPV transmission in S. graminum. Our combined genetic and DIGE approach also made it possible to predict where several of the proteins may be expressed in refractive aphids with different barriers to transmission. Twelve proteins were predicted to act in the hindgut of the aphid

  20. Construction of Lactococcus lactis expressing secreted and anchored Eimeria tenella 3-1E protein and comparison of protective immunity against homologous challenge.

    Science.gov (United States)

    Ma, Chunli; Zhang, Lili; Gao, Mingyang; Ma, Dexing

    2017-07-01

    Two novel plasmids pTX8048-SP-Δ3-1E and pTX8048-SP-NAΔ3-1E-CWA were constructed. The plasmids were respectively electrotransformed into L. lactis NZ9000 to generate strain of L. lactis/pTX8048-SP-Δ3-1E in which 3-1E protein was expressed in secretion, and L. lactis/pTX8048-SP-NAΔ3-1E-CWA on which 3-1E protein was covalently anchored to the surface of bacteria cells. The expression of target proteins were examined by Western blot. The live lactococci expressing secreted 3-1E protein, anchored 3-1E protein, and cytoplasmic 3-1E protein was administered orally to chickens respectively, and the protective immunity and efficacy were compared by animal experiment. The results showed oral immunization to chickens with recombinant lactococci expressing anchored 3-1E protein elicited high 3-1E-specific serum IgG, increased high proportion of CD4 + and CD8α + cells in spleen, alleviated average lesion score in cecum, decreased the oocyst output per chicken compared to lactococci expressing cytoplasmic or secreted 3-1E protein. Taken together, these findings indicated the surface anchored Eimeria protein displayed by L. lacits can induce protective immunity and partial protection against homologous infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Effect of 17-allylamino-17-demethoxygeldanamycin (17-AAG) on Akt protein expression is more effective in head and neck cancer cell lineages that retain PTEN protein expression.

    Science.gov (United States)

    Pontes, Flávia Sirotheau C; Pontes, Hélder A R; de Souza, Lucas L; de Jesus, Adriana S; Joaquim, Andrea M C; Miyahara, Ligia A N; Fonseca, Felipe P; Pinto Junior, Décio S

    2018-03-01

    The aim of this study was to evaluate the expression of Akt, PTEN, Mdm2 and p53 proteins in three different head and neck squamous cell carcinoma (HNSCC) cell lines (HN6, HN19 and HN30), all of them treated with epidermal growth factor (EGF) and 17-allylamino-17-demethoxygeldanamycin (17-AAG), an inhibitor of Hsp90 protein. Immunofluorescence and western blot were performed in order to analyze the location and quantification, respectively, of proteins under the action 17-AAG and EGF. Treatment with EGF resulted in increased levels of Akt, PTEN and p53 in all cell lineages. The expression of Mdm2 was constant in HN30 and HN6 lineages, while in HN19 showed slightly decreased expression. Under the action 17-AAG, in HN6 and HN19, the expression of PTEN and p53 proteins was suppressed, while Akt and Mdm2 expression was reduced. Finally, in the HN30 cell lineage were absolute absence of expression of Akt, Mdm2 and p53 and decreased expression of PTEN. These data allow us to speculate on the particular utility of 17-AAG for HNSCC treatment through the inhibition of Akt protein expression, especially in the cases that retain the expression of PTEN protein. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Segmental isotope labeling of proteins for NMR structural study using a protein S tag for higher expression and solubility

    International Nuclear Information System (INIS)

    Kobayashi, Hiroshi; Swapna, G. V. T.; Wu, Kuen-Phon; Afinogenova, Yuliya; Conover, Kenith; Mao, Binchen; Montelione, Gaetano T.; Inouye, Masayori

    2012-01-01

    A common obstacle to NMR studies of proteins is sample preparation. In many cases, proteins targeted for NMR studies are poorly expressed and/or expressed in insoluble forms. Here, we describe a novel approach to overcome these problems. In the protein S tag-intein (PSTI) technology, two tandem 92-residue N-terminal domains of protein S (PrS 2 ) from Myxococcus xanthus is fused at the N-terminal end of a protein to enhance its expression and solubility. Using intein technology, the isotope-labeled PrS 2 -tag is replaced with non-isotope labeled PrS 2 -tag, silencing the NMR signals from PrS 2 -tag in isotope-filtered 1 H-detected NMR experiments. This method was applied to the E. coli ribosome binding factor A (RbfA), which aggregates and precipitates in the absence of a solubilization tag unless the C-terminal 25-residue segment is deleted (RbfAΔ25). Using the PrS 2 -tag, full-length well-behaved RbfA samples could be successfully prepared for NMR studies. PrS 2 (non-labeled)-tagged RbfA (isotope-labeled) was produced with the use of the intein approach. The well-resolved TROSY-HSQC spectrum of full-length PrS 2 -tagged RbfA superimposes with the TROSY-HSQC spectrum of RbfAΔ25, indicating that PrS 2 -tag does not affect the structure of the protein to which it is fused. Using a smaller PrS-tag, consisting of a single N-terminal domain of protein S, triple resonance experiments were performed, and most of the backbone 1 H, 15 N and 13 C resonance assignments for full-length E. coli RbfA were determined. Analysis of these chemical shift data with the Chemical Shift Index and heteronuclear 1 H– 15 N NOE measurements reveal the dynamic nature of the C-terminal segment of the full-length RbfA protein, which could not be inferred using the truncated RbfAΔ25 construct. CS-Rosetta calculations also demonstrate that the core structure of full-length RbfA is similar to that of the RbfAΔ25 construct.

  3. Nanoscale mapping and organization analysis of target proteins on cancer cells from B-cell lymphoma patients

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mi [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiao, Xiubin [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China); Liu, Lianqing, E-mail: lqliu@sia.cn [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xi, Ning, E-mail: xin@egr.msu.edu [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China); Wang, Yuechao; Dong, Zaili [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, Weijing, E-mail: zhangwj3072@163.com [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)

    2013-11-01

    CD20, a membrane protein highly expressed on most B-cell lymphomas, is an effective target demonstrated in clinical practice for treating B-cell non-Hodgkin's lymphoma (NHL). Rituximab is a monoclonal antibody against CD20. In this work, we applied atomic force microscopy (AFM) to map the nanoscale distribution of CD20 molecules on the surface of cancer cells from clinical B-cell NHL patients under the assistance of ROR1 fluorescence recognition (ROR1 is a specific cell surface marker exclusively expressed on cancer cells). First, the ROR1 fluorescence labeling experiments showed that ROR1 was expressed on cancer cells from B-cell lymphoma patients, but not on normal cells from healthy volunteers. Next, under the guidance of ROR1 fluorescence, the rituximab-conjugated AFM tips were moved to cancer cells to image the cellular morphologies and detect the CD20-rituximab interactions on the cell surfaces. The distribution maps of CD20 on cancer cells were constructed by obtaining arrays of (16×16) force curves in local areas (500×500 nm{sup 2}) on the cell surfaces. The experimental results provide a new approach to directly investigate the nanoscale distribution of target protein on single clinical cancer cells. - Highlights: • Cancer cells were recognized from healthy cells by ROR1 fluorescence labeling. • The nanoscale distribution of CD20 on cancer cells was characterized. • The distribution of CD20 was non-uniform on the surface of cancer cells.

  4. Tax Protein-induced Expression of Antiapoptotic Bfl-1 Protein Contributes to Survival of Human T-cell Leukemia Virus Type 1 (HTLV-1)-infected T-cells*♦

    Science.gov (United States)

    Macaire, Héloïse; Riquet, Aurélien; Moncollin, Vincent; Biémont-Trescol, Marie-Claude; Duc Dodon, Madeleine; Hermine, Olivier; Debaud, Anne-Laure; Mahieux, Renaud; Mesnard, Jean-Michel; Pierre, Marlène; Gazzolo, Louis; Bonnefoy, Nathalie; Valentin, Hélène

    2012-01-01

    Human T lymphotropic virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma (ATLL). ATLL is a severe malignancy with no effective treatment. HTLV-1 regulatory proteins Tax and HTLV-1 basic leucine zipper factor (HBZ) play a major role in ATLL development, by interfering with cellular functions such as CD4+ T-cell survival. In this study, we observed that the expression of Bfl-1, an antiapoptotic protein of the Bcl-2 family, is restricted to HTLV-1-infected T-cell lines and to T-cells expressing both Tax and HBZ proteins. We showed that Tax-induced bfl-1 transcription through the canonical NF-κB pathway. Moreover, we demonstrated that Tax cooperated with c-Jun or JunD, but not JunB, transcription factors of the AP-1 family to stimulate bfl-1 gene activation. By contrast, HBZ inhibited c-Jun-induced bfl-1 gene activation, whereas it increased JunD-induced bfl-1 gene activation. We identified one NF-κB, targeted by RelA, c-Rel, RelB, p105/p50, and p100/p52, and two AP-1, targeted by both c-Jun and JunD, binding sites in the bfl-1 promoter of T-cells expressing both Tax and HBZ. Analyzing the potential role of antiapoptotic Bcl-2 proteins in HTLV-1-infected T-cell survival, we demonstrated that these cells are differentially sensitive to silencing of Bfl-1, Bcl-xL, and Bcl-2. Indeed, both Bfl-1 and Bcl-xL knockdowns decreased the survival of HTLV-1-infected T-cell lines, although no cell death was observed after Bcl-2 knockdown. Furthermore, we demonstrated that Bfl-1 knockdown sensitizes HTLV-1-infected T-cells to ABT-737 or etoposide treatment. Our results directly implicate Bfl-1 and Bcl-xL in HTLV-1-infected T-cell survival and suggest that both Bfl-1 and Bcl-xL represent potential therapeutic targets for ATLL treatment. PMID:22553204

  5. Impact of High-Level Expression of Heterologous Protein on Lactococcus lactis Host.

    Science.gov (United States)

    Kim, Mina; Jin, Yerin; An, Hyun-Joo; Kim, Jaehan

    2017-07-28

    The impact of overproduction of a heterologous protein on the metabolic system of host Lactococcus lactis was investigated. The protein expression profiles of L. lactis IL1403 containing two near-identical plasmids that expressed high- and low-level of the green fluorescent protein (GFP) were examined via shotgun proteomics. Analysis of the two strains via high-throughput LC-MS/MS proteomics identified the expression of 294 proteins. The relative amount of each protein in the proteome of both strains was determined by label-free quantification using the spectral counting method. Although expression level of most proteins were similar, several significant alterations in metabolic network were identified in the high GFP-producing strain. These changes include alterations in the pyruvate fermentation pathway, oxidative pentose phosphate pathway, and de novo synthesis pathway for pyrimidine RNA. Expression of enzymes for the synthesis of dTDP-rhamnose and N -acetylglucosamine from glucose was suppressed in the high GFP strain. In addition, enzymes involved in the amino acid synthesis or interconversion pathway were downregulated. The most noticeable changes in the high GFP-producing strain were a 3.4-fold increase in the expression of stress response and chaperone proteins and increase of caseinolytic peptidase family proteins. Characterization of these host expression changes witnessed during overexpression of GFP was might suggested the metabolic requirements and networks that may limit protein expression, and will aid in the future development of lactococcal hosts to produce more heterologous protein.

  6. Efflux protein expression in human stem cell-derived retinal pigment epithelial cells.

    Directory of Open Access Journals (Sweden)

    Kati Juuti-Uusitalo

    Full Text Available Retinal pigment epithelial (RPE cells in the back of the eye nourish photoreceptor cells and form a selective barrier that influences drug transport from the blood to the photoreceptor cells. At the molecular level, ATP-dependent efflux transporters have a major role in drug delivery in human RPE. In this study, we assessed the relative expression of several ATP-dependent efflux transporter genes (MRP1, -2, -3, -4, -5, -6, p-gp, and BCRP, the protein expression and localization of MRP1, MRP4, and MRP5, and the functionality of MRP1 efflux pumps at different maturation stages of undifferentiated human embryonic stem cells (hESC and RPE derived from the hESC (hESC-RPE. Our findings revealed that the gene expression of ATP-dependent efflux transporters MRP1, -3, -4, -5, and p-gp fluctuated during hESC-RPE maturation from undifferentiated hESC to fusiform, epithelioid, and finally to cobblestone hESC-RPE. Epithelioid hESC-RPE had the highest expression of MRP1, -3, -4, and P-gp, whereas the most mature cobblestone hESC-RPE had the highest expression of MRP5 and MRP6. These findings indicate that a similar efflux protein profile is shared between hESC-RPE and the human RPE cell line, ARPE-19, and suggest that hESC-RPE cells are suitable in vitro RPE models for drug transport studies. Embryonic stem cell model might provide a novel tool to study retinal cell differentiation, mechanisms of RPE-derived diseases, drug testing and targeted drug therapy.

  7. Identification of Protein Targets of 12/15-Lipoxygenase-Derived Lipid Electrophiles in Mouse Peritoneal Macrophages Using Omega-Alkynyl Fatty Acid.

    Science.gov (United States)

    Isobe, Yosuke; Kawashima, Yusuke; Ishihara, Tomoaki; Watanabe, Kenji; Ohara, Osamu; Arita, Makoto

    2018-04-20

    The 12/15-lipoxygenase (12/15-LOX) enzyme introduces peroxyl groups, in a position-specific manner, into polyunsaturated fatty acids to form various kinds of bioactive lipid metabolites, including lipid-derived electrophiles (LDE). The resident peritoneal macrophage is the site of highest 12/15-LOX expression in the mouse. However, the role of the enzyme in the regulation of resident macrophages is not fully understood. Here, we describe a chemoproteomic method to identify the targets of enzymatically generated LDE. By treating mouse peritoneal macrophages with omega-alkynyl arachidonic acid (aAA), we identified a series of proteins adducted by LDE generated through a 12/15-LOX catalyzed reaction. Pathway analysis revealed a dramatic enrichment of proteins involved in energy metabolism and found that glycolytic flux and mitochondrial respiration were significantly affected by the expression of 12/15-LOX. Our findings thus highlight the utility of chemoproteomics using aAA for identifying intracellular targets of enzymatically generated LDE.

  8. Differential Targeting of Hsp70 Heat Shock Proteins HSPA6 and HSPA1A with Components of a Protein Disaggregation/Refolding Machine in Differentiated Human Neuronal Cells following Thermal Stress

    Directory of Open Access Journals (Sweden)

    Ian R. Brown

    2017-04-01

    Full Text Available Heat shock proteins (Hsps co-operate in multi-protein machines that counter protein misfolding and aggregation and involve DNAJ (Hsp40, HSPA (Hsp70, and HSPH (Hsp105α. The HSPA family is a multigene family composed of inducible and constitutively expressed members. Inducible HSPA6 (Hsp70B' is found in the human genome but not in the genomes of mouse and rat. To advance knowledge of this little studied HSPA member, the targeting of HSPA6 to stress-sensitive neuronal sites with components of a disaggregation/refolding machine was investigated following thermal stress. HSPA6 targeted the periphery of nuclear speckles (perispeckles that have been characterized as sites of transcription. However, HSPA6 did not co-localize at perispeckles with DNAJB1 (Hsp40-1 or HSPH1 (Hsp105α. At 3 h after heat shock, HSPA6 co-localized with these members of the disaggregation/refolding machine at the granular component (GC of the nucleolus. Inducible HSPA1A (Hsp70-1 and constitutively expressed HSPA8 (Hsc70 co-localized at nuclear speckles with components of the machine immediately after heat shock, and at the GC layer of the nucleolus at 1 h with DNAJA1 and BAG-1. These results suggest that HSPA6 exhibits targeting features that are not apparent for HSPA1A and HSPA8.

  9. Fos and jun proteins are specifically expressed during differentiation of human keratinocytes.

    Science.gov (United States)

    Mehic, Denis; Bakiri, Latifa; Ghannadan, Minoo; Wagner, Erwin F; Tschachler, Erwin

    2005-01-01

    Activator protein 1 (AP-1) proteins play key roles in the regulation of cell proliferation and differentiation. In this study we investigated the expression of Fos and Jun proteins in different models of terminal differentiation of human keratinocytes and in skin from psoriasis patients. All Jun and Fos proteins, with the exception of FosB, were efficiently expressed in keratinocytes in monolayer cultures. In contrast, in normal epidermis as well as in organotypic epidermal cultures, the expression pattern of AP-1 proteins was dependent on the differentiation stage. Fos proteins were readily detected in nuclei of keratinocytes of basal and suprabasal layers. JunB and JunD were expressed in all layers of normal epidermis. Interestingly, expression of c-Jun started suprabasally, then disappeared and became detectable again in distinct cells of the outermost granular layer directly at the transition zone to the stratum corneum. In psoriatic epidermis, c-Jun expression was prominent in both hyperproliferating basal and suprabasal keratinocytes, whereas c-Fos expression was unchanged. These data indicate that AP-1 proteins are expressed in a highly specific manner during terminal differentiation of keratinocytes and that the enhanced expression of c-Jun in basal and suprabasal keratinocytes might contribute to the pathogenesis of psoriasis.

  10. The HIV-1 Tat protein modulates CD4 expression in human T cells through the induction of miR-222.

    Science.gov (United States)

    Orecchini, Elisa; Doria, Margherita; Michienzi, Alessandro; Giuliani, Erica; Vassena, Lia; Ciafrè, Silvia Anna; Farace, Maria Giulia; Galardi, Silvia

    2014-01-01

    Several cellular microRNAs show substantial changes in expression during HIV-1 infection and their active role in the viral life cycle is progressively emerging. In the present study, we found that HIV-1 infection of Jurkat T cells significantly induces the expression of miR-222. We show that this induction depends on HIV-1 Tat protein, which is able to increase the transcriptional activity of NFkB on miR-222 promoter. Moreover, we demonstrate that miR-222 directly targets CD4, a key receptor for HIV-1, thus reducing its expression. We propose that Tat, by inducing miR-222 expression, complements the CD4 downregulation activity exerted by other viral proteins (i.e., Nef, Vpu, and Env), and we suggest that this represents a novel mechanism through which HIV-1 efficiently represses CD4 expression in infected cells.

  11. Downregulation of ATM Gene and Protein Expression in Canine Mammary Tumors.

    Science.gov (United States)

    Raposo-Ferreira, T M M; Bueno, R C; Terra, E M; Avante, M L; Tinucci-Costa, M; Carvalho, M; Cassali, G D; Linde, S D; Rogatto, S R; Laufer-Amorim, R

    2016-11-01

    The ataxia telangiectasia mutated (ATM) gene encodes a protein associated with DNA damage repair and maintenance of genomic integrity. In women, ATM transcript and protein downregulation have been reported in sporadic breast carcinomas, and the absence of ATM protein expression has been associated with poor prognosis. The aim of this study was to evaluate ATM gene and protein expression in canine mammary tumors and their association with clinical outcome. ATM gene and protein expression was evaluated by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry, respectively, in normal mammary gland samples (n = 10), benign mammary tumors (n = 11), nonmetastatic mammary carcinomas (n = 19), and metastatic mammary carcinomas (n = 11). Lower ATM transcript levels were detected in benign mammary tumors and carcinomas compared with normal mammary glands (P = .011). Similarly, lower ATM protein expression was observed in benign tumors (P = .0003), nonmetastatic mammary carcinomas (P ATM gene or protein levels were detected among benign tumors and nonmetastatic and metastatic mammary carcinomas (P > .05). The levels of ATM gene or protein expression were not significantly associated with clinical and pathological features or with survival. Similar to human breast cancer, the data in this study suggest that ATM gene and protein downregulation is involved in canine mammary gland tumorigenesis. © The Author(s) 2016.

  12. The reactive metabolite target protein database (TPDB – a web-accessible resource

    Directory of Open Access Journals (Sweden)

    Dong Yinghua

    2007-03-01

    Full Text Available Abstract Background The toxic effects of many simple organic compounds stem from their biotransformation to chemically reactive metabolites which bind covalently to cellular proteins. To understand the mechanisms of cytotoxic responses it may be important to know which proteins become adducted and whether some may be common targets of multiple toxins. The literature of this field is widely scattered but expanding rapidly, suggesting the need for a comprehensive, searchable database of reactive metabolite target proteins. Description The Reactive Metabolite Target Protein Database (TPDB is a comprehensive, curated, searchable, documented compilation of publicly available information on the protein targets of reactive metabolites of 18 well-studied chemicals and drugs of known toxicity. TPDB software enables i string searches for author names and proteins names/synonyms, ii more complex searches by selecting chemical compound, animal species, target tissue and protein names/synonyms from pull-down menus, and iii commonality searches over multiple chemicals. Tabulated search results provide information, references and links to other databases. Conclusion The TPDB is a unique on-line compilation of information on the covalent modification of cellular proteins by reactive metabolites of chemicals and drugs. Its comprehensiveness and searchability should facilitate the elucidation of mechanisms of reactive metabolite toxicity. The database is freely available at http://tpdb.medchem.ku.edu/tpdb.html

  13. Orally active-targeted drug delivery systems for proteins and peptides.

    Science.gov (United States)

    Li, Xiuying; Yu, Miaorong; Fan, Weiwei; Gan, Yong; Hovgaard, Lars; Yang, Mingshi

    2014-09-01

    In the past decade, extensive efforts have been devoted to designing 'active targeted' drug delivery systems (ATDDS) to improve oral absorption of proteins and peptides. Such ATDDS enhance cellular internalization and permeability of proteins and peptides via molecular recognition processes such as ligand-receptor or antigen-antibody interaction, and thus enhance drug absorption. This review focuses on recent advances with orally ATDDS, including ligand-protein conjugates, recombinant ligand-protein fusion proteins and ligand-modified carriers. In addition to traditional intestinal active transport systems of substrates and their corresponding receptors, transporters and carriers, new targets such as intercellular adhesion molecule-1 and β-integrin are also discussed. ATDDS can improve oral absorption of proteins and peptides. However, currently, no clinical studies on ATDDS for proteins and peptides are underway, perhaps due to the complexity and limited knowledge of transport mechanisms. Therefore, more research is warranted to optimize ATDDS efficiency.

  14. Differential effect of CLK SR Kinases on HIV-1 gene expression: potential novel targets for therapy

    Directory of Open Access Journals (Sweden)

    Dobson Wendy

    2011-06-01

    Full Text Available Abstract Background RNA processing plays a critical role in the replication of HIV-1, regulated in part through the action of host SR proteins. To explore the impact of modulating SR protein activity on virus replication, the effect of increasing or inhibiting the activity of the Cdc2-like kinase (CLK family of SR protein kinases on HIV-1 expression and RNA processing was examined. Results Despite their high homology, increasing individual CLK expression had distinct effects on HIV-1, CLK1 enhancing Gag production while CLK2 inhibited the virus. Parallel studies on the anti-HIV-1 activity of CLK inhibitors revealed a similar discrepant effect on HIV-1 expression. TG003, an inhibitor of CLK1, 2 and 4, had no effect on viral Gag synthesis while chlorhexidine, a CLK2, 3 and 4 inhibitor, blocked virus production. Chlorhexidine treatment altered viral RNA processing, decreasing levels of unspliced and single spliced viral RNAs, and reduced Rev accumulation. Subsequent experiments in the context of HIV-1 replication in PBMCs confirmed the capacity of chlorhexidine to suppress virus replication. Conclusions Together, these findings establish that HIV-1 RNA processing can be targeted to suppress virus replication as demonstrated by manipulating individual CLK function and identified chlorhexidine as a lead compound in the development of novel anti-viral therapies.

  15. Uncoupling Protein 2: A Key Player and a Potential Therapeutic Target in Vascular Diseases

    Directory of Open Access Journals (Sweden)

    Giorgia Pierelli

    2017-01-01

    Full Text Available Uncoupling protein 2 (UCP2 is an inner mitochondrial membrane protein that belongs to the uncoupling protein family and plays an important role in lowering mitochondrial membrane potential and dissipating metabolic energy with prevention of oxidative stress accumulation. In the present article, we will review the evidence that UCP2, as a consequence of its roles within the mitochondria, represents a critical player in the predisposition to vascular disease development in both animal models and in humans, particularly in relation to obesity, diabetes, and hypertension. The deletion of the UCP2 gene contributes to atherosclerosis lesion development in the knockout mice, also showing significantly shorter lifespan. The UCP2 gene downregulation is a key determinant of higher predisposition to renal and cerebrovascular damage in an animal model of spontaneous hypertension and stroke. In contrast, UCP2 overexpression improves both hyperglycemia- and high-salt diet-induced endothelial dysfunction and ameliorates hypertensive target organ damage in SHRSP. Moreover, drugs (fenofibrate and sitagliptin and several vegetable compounds (extracts from Brassicaceae, berberine, curcumin, and capsaicin are able to induce UCP2 expression level and to exert beneficial effects on the occurrence of vascular damage. As a consequence, UCP2 becomes an interesting therapeutic target for the treatment of common human vascular diseases.

  16. Expression analysis of miRNA and target mRNAs in esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Meng, X.R. [Oncology Department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou (China); Lu, P. [Gastrointestinal Surgery Department, People' s Hospital of Zhengzhou, Zhengzhou (China); Mei, J.Z.; Liu, G.J. [Medical Oncology Department, People' s Hospital of Zhengzhou, Zhengzhou (China); Fan, Q.X. [Oncology Department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou (China)

    2014-08-01

    We aimed to investigate miRNAs and related mRNAs through a network-based approach in order to learn the crucial role that they play in the biological processes of esophageal cancer. Esophageal squamous-cell carcinoma (ESCC) and adenocarcinoma (EAC)-related miRNA and gene expression data were downloaded from the Gene Expression Omnibus database, and differentially expressed miRNAs and genes were selected. Target genes of differentially expressed miRNAs were predicted and their regulatory networks were constructed. Differentially expressed miRNA analysis selected four miRNAs associated with EAC and ESCC, among which hsa-miR-21 and hsa-miR-202 were shared by both diseases. hsa-miR-202 was reported for the first time to be associated with esophageal cancer in the present study. Differentially expressed miRNA target genes were mainly involved in cancer-related and signal-transduction pathways. Functional categories of these target genes were related to transcriptional regulation. The results may indicate potential target miRNAs and genes for future investigations of esophageal cancer.

  17. The centrosome protein NEDD1 as a potential pharmacological target to induce cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Etievant Chantal

    2009-02-01

    Full Text Available Abstract Background NEDD1 is a protein that binds to the gamma-tubulin ring complex, a multiprotein complex at the centrosome and at the mitotic spindle that mediates the nucleation of microtubules. Results We show that NEDD1 is expressed at comparable levels in a variety of tumor-derived cell lines and untransformed cells. We demonstrate that silencing of NEDD1 expression by treatment with siRNA has differential effects on cells, depending on their status of p53 expression: p53-positive cells arrest in G1, whereas p53-negative cells arrest in mitosis with predominantly aberrant monopolar spindles. However, both p53-positive and -negative cells arrest in mitosis if treated with low doses of siRNA against NEDD1 combined with low doses of the inhibitor BI2536 against the mitotic kinase Plk1. Simultaneous reduction of NEDD1 levels and inhibition of Plk1 act in a synergistic manner, by potentiating the anti-mitotic activity of each treatment. Conclusion We propose that NEDD1 may be a promising target for controlling cell proliferation, in particular if targeted in combination with Plk1 inhibitors.

  18. Transient Expression and Cellular Localization of Recombinant Proteins in Cultured Insect Cells.

    Science.gov (United States)

    Fabrick, Jeffrey A; Hull, J Joe

    2017-04-20

    Heterologous protein expression systems are used for the production of recombinant proteins, the interpretation of cellular trafficking/localization, and the determination of the biochemical function of proteins at the sub-organismal level. Although baculovirus expression systems are increasingly used for protein production in numerous biotechnological, pharmaceutical, and industrial applications, nonlytic systems that do not involve viral infection have clear benefits but are often overlooked and underutilized. Here, we describe a method for generating nonlytic expression vectors and transient recombinant protein expression. This protocol allows for the efficient cellular localization of recombinant proteins and can be used to rapidly discern protein trafficking within the cell. We show the expression of four recombinant proteins in a commercially available insect cell line, including two aquaporin proteins from the insect Bemisia tabaci, as well as subcellular marker proteins specific for the cell plasma membrane and for intracellular lysosomes. All recombinant proteins were produced as chimeras with fluorescent protein markers at their carboxyl termini, which allows for the direct detection of the recombinant proteins. The double transfection of cells with plasmids harboring constructs for the genes of interest and a known subcellular marker allows for live cell imaging and improved validation of cellular protein localization.

  19. In situ protein expression in tumour spheres: development of an immunostaining protocol for confocal microscopy

    International Nuclear Information System (INIS)

    Weiswald, Louis-Bastien; Guinebretière, Jean-Marc; Richon, Sophie; Bellet, Dominique; Saubaméa, Bruno; Dangles-Marie, Virginie

    2010-01-01

    Multicellular tumour sphere models have been shown to closely mimic phenotype characteristics of in vivo solid tumours, or to allow in vitro propagation of cancer stem cells (CSCs). CSCs are usually characterized by the expression of specific membrane markers using flow cytometry (FC) after enzymatic dissociation. Consequently, the spatial location of positive cells within spheres is not documented. Confocal microscopy is the best technique for the imaging of thick biological specimens after multi-labelling but suffers from poor antibody penetration. Thus, we describe here a new protocol for in situ confocal imaging of protein expression in intact spheroids. Protein expression in whole spheroids (150 μm in diameter) from two human colon cancer cell lines, HT29 and CT320X6, has been investigated with confocal immunostaining, then compared with profiles obtained through paraffin immunohistochemistry (pIHC) and FC. Target antigens, relevant for colon cancer and with different expression patterns, have been studied. We first demonstrate that our procedure overcomes the well-known problem of antibody penetration in compact structures by performing immunostaining of EpCAM, a membrane protein expressed by all cells within our spheroids. EpCAM expression is detected in all cells, even the deepest ones. Likewise, antibody access is confirmed with CK20 and CD44 immunostaining. Confocal imaging shows that 100% of cells express β-catenin, mainly present in the plasma membrane with also cytoplasmic and nuclear staining, in agreement with FC and pIHC data. pIHC and confocal imaging show similar CA 19-9 cytoplasmic and membranar expression profile in a cell subpopulation. CA 19-9 + cell count confirms confocal imaging as a highly sensitive method (75%, 62% and 51%, for FC, confocal imaging and pIHC, respectively). Finally, confocal imaging reveals that the weak expression of CD133, a putative colon CSC marker, is restricted to the luminal cell surface of colorectal cancer acini

  20. Inhibition of iridovirus protein synthesis and virus replication by antisense morpholino oligonucleotides targeted to the major capsid protein, the 18 kDa immediate-early protein, and a viral homolog of RNA polymerase II

    International Nuclear Information System (INIS)

    Sample, Robert; Bryan, Locke; Long, Scott; Majji, Sai; Hoskins, Glenn; Sinning, Allan; Olivier, Jake; Chinchar, V. Gregory

    2007-01-01

    Frog virus 3 (FV3) is a large DNA virus that encodes ∼ 100 proteins. Although the general features of FV3 replication are known, the specific roles that most viral proteins play in the virus life cycle have not yet been elucidated. To address the question of viral gene function, antisense morpholino oligonucleotides (asMOs) were used to transiently knock-down expression of specific viral genes and thus infer their role in virus replication. We designed asMOs directed against the major capsid protein (MCP), an 18 kDa immediate-early protein (18K) that was thought to be a viral regulatory protein, and the viral homologue of the largest subunit of RNA polymerase II (vPol-IIα). All three asMOs successfully inhibited translation of the targeted protein, and two of the three asMOs resulted in marked phenotypic changes. Knock-down of the MCP resulted in a marked reduction in viral titer without a corresponding drop in the synthesis of other late viral proteins. Transmission electron microscopy (TEM) showed that in cells treated with the anti-MCP MO assembly sites were devoid of viral particles and contained numerous aberrant structures. In contrast, inhibition of 18K synthesis did not block virion formation, suggesting that the 18K protein was not essential for replication of FV3 in fathead minnow (FHM) cells. Finally, consistent with the view that late viral gene expression is catalyzed by a virus-encoded or virus-modified Pol-II-like protein, knock-down of vPol-IIα triggered a global decline in late gene expression and virus yields without affecting the synthesis of early viral genes. Collectively, these results demonstrate the utility of using asMOs to elucidate the function of FV3 proteins

  1. Sialotranscriptomics of Rhipicephalus zambeziensis reveals intricate expression profiles of secretory proteins and suggests tight temporal transcriptional regulation during blood-feeding.

    Science.gov (United States)

    de Castro, Minique Hilda; de Klerk, Daniel; Pienaar, Ronel; Rees, D Jasper G; Mans, Ben J

    2017-08-10

    Ticks secrete a diverse mixture of secretory proteins into the host to evade its immune response and facilitate blood-feeding, making secretory proteins attractive targets for the production of recombinant anti-tick vaccines. The largely neglected tick species, Rhipicephalus zambeziensis, is an efficient vector of Theileria parva in southern Africa but its available sequence information is limited. Next generation sequencing has advanced sequence availability for ticks in recent years and has assisted the characterisation of secretory proteins. This study focused on the de novo assembly and annotation of the salivary gland transcriptome of R. zambeziensis and the temporal expression of secretory protein transcripts in female and male ticks, before the onset of feeding and during early and late feeding. The sialotranscriptome of R. zambeziensis yielded 23,631 transcripts from which 13,584 non-redundant proteins were predicted. Eighty-six percent of these contained a predicted start and stop codon and were estimated to be putatively full-length proteins. A fifth (2569) of the predicted proteins were annotated as putative secretory proteins and explained 52% of the expression in the transcriptome. Expression analyses revealed that 2832 transcripts were differentially expressed among feeding time points and 1209 between the tick sexes. The expression analyses further indicated that 57% of the annotated secretory protein transcripts were differentially expressed. Dynamic expression profiles of secretory protein transcripts were observed during feeding of female ticks. Whereby a number of transcripts were upregulated during early feeding, presumably for feeding site establishment and then during late feeding, 52% of these were downregulated, indicating that transcripts were required at specific feeding stages. This suggested that secretory proteins are under stringent transcriptional regulation that fine-tunes their expression in salivary glands during feeding. No open

  2. Hypoxic-induced stress protein expression in rat cardiac myocytes

    International Nuclear Information System (INIS)

    Howard, G.; Geoghegan, T.E.

    1986-01-01

    Mammalian stress proteins can be induced in cells and tissues exposed to a variety of conditions including hyperthermia and diminished O 2 supply. The authors have previously shown that the expression of three stress proteins (71, 85, and 95 kDa) was induced in cardiac tissue from mice exposed to hypoxic conditions. The expression of mRNAs coding for the 85 and 95 kDa proteins increase with time of exposure to hypoxia, while the mRNA coding for the 71 kDa protein is transiently induced. The authors extended these studies to investigate the expression of stress proteins in isolated rat cardiac myocytes. Freshly prepared myocytes were exposed to control, hypoxic, anoxic, or heat-shock environments for up to 16 h. The proteins were then labeled for 6 hours with [ 35 S]methionine. Analysis of the solubilized proteins by SDS-PAGE and autoradiography showed that there was a 6-fold increase in synthesis of the 85 kDa protein upon exposure to hypoxia but not heat-shock conditions. The 71 kDa protein was present at high levels in both control and treated myocyte protein preparations, and presumably had been induced during the isolation procedure. Total RNA isolated from intact rat heart and isolated myocytes was compared by cell-free translation analysis and showed induction of RNAs coding for several stress proteins in the myocyte preparation. The induced proteins at 85 and 95 kDa have molecular weights similar to reported cell stress and/or glucose-regulated proteins

  3. Protein expression of Myt272-3 recombinant clone and in silico ...

    African Journals Online (AJOL)

    Purpose: To investigate the expression of Myt272-3 recombinant protein and also to predict a possible protein vaccine candidate against Mycobacterium tuberculosis. Methods: Myt272-3 protein was expressed in pET30a+-Myt272-3 clone. The purity of the protein was determined using Dynabeads® His-Tag Isolation ...

  4. [Eukaryotic expression of Leptospira interrogans lipL32/1-ompL1/1 fusion gene encoding genus-specific protein antigens and the immunoreactivity of expression products].

    Science.gov (United States)

    Yan, Jie; Zhao, Shou-feng; Mao, Ya-fei; Ruan, Ping; Luo, Yi-hui; Li, Shu-ping; Li, Li-wei

    2005-01-01

    To construct the eukaryotic expression system of L.interrogans lipL32/1-ompL1/1 fusion gene and to identify the immunoreactivity of expression products. PCR with linking primer was used to construct the fusion gene lipL32/1-ompL1/1. The P.pastoris eukaryotic expression system of the fusion gene, pPIC9K-lipL32/1-ompL1/1-P. pastorisGS115, was constructed after the fusion gene was cloned and sequenced. Colony with phenotype His(+)Mut(+) was isolated by using MD and MM plates and His(+) Mut(+) transformant with high resistance to G418 was screened out by using YPD plate. Using lysate of His(+) Mut(+) colony with high copies of the target gene digested with yeast lyase as the template and 5'AOX1 and 3'AOX1 as the primers, the target fusion gene in chromosome DNA of the constructed P. pastoris engineering strain was detected by PCR. Methanol in BMMY medium was used to induce the target recombinant protein rLipL32/1-rOmpL1/1 expression. rLipL32/1-rOmpL1/1 in the medium supernatant was extracted by using ammonium sulfate precipitation and Ni-NTA affinity chromatography. Output and immunoreactivity of rLipL32/1-rOmpL1/1 were measured by SDS-PAGE and Western blot methods, respectively. Amplification fragments of the obtained fusion gene lipL32/1-ompL1/1 was 1794 bp in size. The homogeneity of nucleotide and putative amino acid seque