149 research outputs found

    Discursive power in the global political economy of agriculture and food: the case of the Bayer-Monsanto merger

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    Several mergers of big and powerful companies have led to a concentration in the global seed and agrochemical market to currently four big players. Public concerns about consequences for food security, the environment, or innovation in the market arose over this. Thus, the mergers were met with broad opposition, mainly from civil society, when they were announced. The companies, on the other hand, tried to reach the merger at as little cost and with as little interference as possible. During such struggles, different forms of power exerted by different actors are at play and influence the outcome. So far, very little research has examined the discursive power relations in the agrichemical merger context. This study explores what role discursive power relations in Europe played in the specific example of the Bayer-Monsanto merger. A critical discourse analysis (Fairclough) is conducted on press releases from both the merger opponents and the two merger companies, Bayer and Monsanto. Discourses and frames are identified and extracted, and their power is defined through reflection on prevalent social practices and norms. The study concludes that the discursive power relations played a relatively marginal role in the outcome of the Bayer- Monsanto merger itself. For different reasons, the opponents did not manage to discursively trigger the necessary social change and action required to achieve a change in the currently existing agrochem merger regulations in Europe. However, there are strong indications that the discursive practices of the opponents will influence the agrochem market in Europe in the longer term.M-I

    Molecular cloning and expression of subunit 9 of the 26S proteasome

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    AbstractSeven peptides from subunit 9 (S9) of the human 26S proteasome were sequenced and this information was used to clone a HeLa cDNA that encodes the 46 kDa subunit. Rabbit polyclonal antisera were made against a ubiquitin fusion protein containing 12 amino acids from S9 and against a full-length S9 expressed in E. coli. Western blot analysis showed that the S9-specific antibodies bound the 26S proteasome and its regulatory complex separated on non-denaturing gels. In SDS-PAGE samples of the two complexes, the S9-specific antibodies bound a single 46 kDa subunit. Thus, a cDNA encoding a novel 26S protease subunit has been isolated, sequenced, and expressed.©1997 Federation of European Biochemical Societies

    Pyridine nucleotide cycle: studies in Escherichia coli and the human cell line D98/AH2

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    Journal ArticleDifferent metabolic steps comprise the pyridine nucleotide cycles in Escherichia coli and in the human cell line HeLa D98/AH2. An analysis of the "P-labeling patterns in vivo reveals that in E. coli, pyrophosphate bond cleavage of intracellular NAD predominates, while in the human cell line, cleavage of the nicotinamide ribose bond predominates

    Peptide sequencing identifies MSS1, a modulator of HIV Tat-mediated transactivation, as subunit 7 of the 26 S protease

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    AbstractSubunit 7 is an integral component of the human erythrocyte 26 S protease. Peptide sequence analysis reveals that 22 amino acids from the N-terminus of subunit 7 correspond exactly to the N-terminus of MSS1, a modulator of HIV gene expression. Additional internal peptides from subunit 7 obtained by CNBr cleavage also match 100% with the deduced amino acid sequence of MSS1. Based on the fact that directly sequenced peptides from subunit 7 are identical to more than 12% of the hypothetical translation product of MSS1, and the fact that the molecular weight of subunit 7 (49 kDa) corresponds to the predicted molecular weight of MSS1 (48,633 Da), we conclude that subunit 7 is MSS1

    KEKE motifs Proposed roles in protein—protein association and presentation of peptides by MHC Class I receptors

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    AbstractA stretch of 28 ‘alternating’ lysine (K) and glutamate (E) residues is found in an activator of the multicatalytic protease. Such ‘KEKE sequences’ are also present in subunits of the multicatalytic protease, in subunits of the 26S protease and in a variety of chaperonins. We propose that KEKE regions promote association between protein complexes. Furthermore, they may contribute to the selection of peptides presented on MHC Class I receptors

    Energiesparen in Bürgerhand

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    ENERGIESPAREN IN BÜRGERHAND Energiesparen in Bürgerhand / Blömer, Sebastian (Rights reserved) ( -

    Molecular and immunophenotypic characterization of SMARCB1 (INI1) - deficient intrathoracic Neoplasms

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    The switch/sucrose-non-fermenting (SWI/SNF) complex is an ATP-dependent chromatin remodeling complex that plays important roles in DNA repair, transcription and cell differentiation. This complex consists of multiple subunits and is of particular interest in thoracic malignancies due to frequent subunit alteration of SMARCA4 (BRG1). Much less is known about SMARCB1 (INI1) deficient intrathoracic neoplasms, which are rare, often misclassified and understudied. In a retrospective analysis of 1479 intrathoracic malignant neoplasms using immunohistochemistry for INI1 (SMARCB1) on tissue micro arrays (TMA) and a search through our hospital sarcoma database, we identified in total nine intrathoracic, INI1 deficient cases (n = 9). We characterized these cases further by additional immunohistochemistry, broad targeted genomic analysis, methylation profiling and correlated them with clinical and radiological data. This showed that genomic SMARCB1 together with tumor suppressor alterations drive tumorigenesis in some of these cases, rather than epigenetic changes such as DNA methylation. A proper diagnostic classification, however, remains challenging. Intrathoracic tumors with loss or alteration of SMARCB1 (INI1) are highly aggressive and remain often underdiagnosed due to their rarity, which leads to false diagnostic interpretations. A better understanding of these tumors and proper diagnosis is important for better patient care as clinical trials and more targeted therapeutic options are emerging

    Potential Immunocompetence of Proteolytic Fragments Produced by Proteasomes before Evolution of the Vertebrate Immune System

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    To generate peptides for presentation by major histocompatibility complex (MHC) class I molecules to T lymphocytes, the immune system of vertebrates has recruited the proteasomes, phylogenetically ancient multicatalytic high molecular weight endoproteases. We have previously shown that many of the proteolytic fragments generated by vertebrate proteasomes have structural features in common with peptides eluted from MHC class I molecules, suggesting that many MHC class I ligands are direct products of proteasomal proteolysis. Here, we report that the processing of polypeptides by proteasomes is conserved in evolution, not only among vertebrate species, but including invertebrate eukaryotes such as insects and yeast. Unexpectedly, we found that several high copy ligands of MHC class I molecules, in particular, self-ligands, are major products in digests of source polypeptides by invertebrate proteasomes. Moreover, many major dual cleavage peptides produced by invertebrate proteasomes have the length and the NH2 and COOH termini preferred by MHC class I. Thus, the ability of proteasomes to generate potentially immunocompetent peptides evolved well before the vertebrate immune system. We demonstrate with polypeptide substrates that interferon γ induction in vivo or addition of recombinant proteasome activator 28α in vitro alters proteasomal proteolysis in such a way that the generation of peptides with the structural features of MHC class I ligands is optimized. However, these changes are quantitative and do not confer qualitatively novel characteristics to proteasomal proteolysis. The data suggest that proteasomes may have influenced the evolution of MHC class I molecules
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