148 research outputs found

    Ethologic and Economic Examination of Aviary Housing for Commercial Laying Flocks

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    The authors report that the results of their research indicate that appropriate housing is necessary for intensively kept hens and that the housing has to correspond to the vital needs and natures of the animals

    IEX-1 directly interferes with RelA/p65 dependent transactivation and regulation of apoptosis

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    The early response gene IEX-1 plays a complex role in the regulation of apoptosis. Depending on the cellular context and the apoptotic stimulus, IEX-1 is capable to either enhance or suppress apoptosis. To further dissect the molecular mechanisms involved in the modulation of apoptosis by IEX-1, we analysed the molecular crosstalk between IEX-1 and the NF-kappa B pathway. Using GST-pulldown assays, a direct interaction of IEX-1 with the C-terminal region of the subunit RelA/p65 harbouring the transactivation domain of the NF-kappa B transcription factor was shown. This interaction negatively regulates RelA/p65 dependent transactivation as shown by GAL4-and luciferase assay and was confirmed for the endogenous proteins by co-immunoprecipitation experiments. Using deletion constructs, we were able to map the C-terminal region of IEX-1 as the critical determinant of the interaction with RelA/p65. We could further show, that IEX-1 mediated NF-kappa B inhibition accounts for the reduced expression of the anti-apoptotic NF-kappa B target genes Bc1-2, Bcl-xL, cIAP1 and cIAP2, thereby sensitizing cells for apoptotic stimuli. Finally, ChIP-assays revealed that IEX-1 associates with the promoter of these genes. Altogether, our findings suggest a critical role of IEX-1 in the NF-kappa B dependent regulation of apoptotic responses. (C) 2007 Elsevier B.V All rights reserved

    Cytochrome oxidase subunit VI of Trypanosoma brucei is imported without a cleaved presequence and is developmentally regulated at both RNA and protein levels

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    Mitochondrial respiration in the African trypanosome undergoes dramatic developmental stage regulation. This requires co-ordinated control of components encoded by both the nuclear genome and the kinetoplast, the unusual mitochondrial genome of these parasites. As a model for understanding the co-ordination of these genomes, we have examined the regulation and mitochondrial import of a nuclear-encoded component of the cytochrome oxidase complex, cytochrome oxidase subunit VI (COXVI). By generating transgenic trypanosomes expressing intact or mutant forms of this protein, we demonstrate that COXVI is not imported using a conventional cleaved presequence and show that sequences at the N-terminus of the protein are necessary for correct mitochondrial sorting. Analyses of endogenous and transgenic COXVI mRNA and protein expression in parasites undergoing developmental stage differentiation demonstrates a temporal order of control involving regulation in the abundance of, first, mRNA and then protein. This represents the first dissection of the regulation and import of a nuclear-encoded protein into the cytochrome oxidase complex in these organisms, which were among the earliest eukaryotes to possess a mitochondrion

    The alimentary impact of the hemp seed

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    Hemp seed and hemp seed oil can supply us with many important substances. Their essential fatty acid compositions are favourable, but they may contain non-psychotropic cannabinoids. Emerging data show that these components can influence the health status of the population beneficially. Some data also showed trace amounts of tetrahydrocannabinol in seed oils, the main psychotropic cannabinoid that is contraindicated.Our aim was to examine cannabinoids and fatty acid composition as well as metal and non-metal element compositions in products, like hemp seed oil and chopped hemp seed capsule.The cannabinoids were separated by thin layer chromatography. Fatty acid composition was determined with gas chromatography, and elements (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Si, Sn, Sr, V, and Zn) were measured by inductively coupled plasma optical emission spectrometric method. Selenium was determined with polarographic analyser.Cannabinoids were not detectable by thin layer chromatography, so hemp seed oil, as well as the capsule, have no psychotropic adverse effect. Our data showed that hemp seed contains essential fatty acids close to the recommended ratio. The B and Se concentrations of the oils and the P concentration of the capsule are also relevant

    Disruption of AP1S1, Causing a Novel Neurocutaneous Syndrome, Perturbs Development of the Skin and Spinal Cord

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    Adaptor protein (AP) complexes regulate clathrin-coated vesicle assembly, protein cargo sorting, and vesicular trafficking between organelles in eukaryotic cells. Because disruption of the various subunits of the AP complexes is embryonic lethal in the majority of cases, characterization of their function in vivo is still lacking. Here, we describe the first mutation in the human AP1S1 gene, encoding the small subunit Οƒ1A of the AP-1 complex. This founder splice mutation, which leads to a premature stop codon, was found in four families with a unique syndrome characterized by mental retardation, enteropathy, deafness, peripheral neuropathy, ichthyosis, and keratodermia (MEDNIK). To validate the pathogenic effect of the mutation, we knocked down Ap1s1 expression in zebrafish using selective antisens morpholino oligonucleotides (AMO). The knockdown phenotype consisted of perturbation in skin formation, reduced pigmentation, and severe motility deficits due to impaired neural network development. Both neural and skin defects were rescued by co-injection of AMO with wild-type (WT) human AP1S1 mRNA, but not by co-injecting the truncated form of AP1S1, consistent with a loss-of-function effect of this mutation. Together, these results confirm AP1S1 as the gene responsible for MEDNIK syndrome and demonstrate a critical role of AP1S1 in development of the skin and spinal cord

    Basolateral Sorting of Syntaxin 4 Is Dependent on Its N-terminal Domain and the AP1B Clathrin Adaptor, and Required for the Epithelial Cell Polarity

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    Generation of epithelial cell polarity requires mechanisms to sort plasma membrane proteins to the apical and basolateral domains. Sorting involves incorporation into specific vesicular carriers and subsequent fusion to the correct target membranes mediated by specific SNARE proteins. In polarized epithelial cells, the SNARE protein syntaxin 4 localizes exclusively to the basolateral plasma membrane and plays an important role in basolateral trafficking pathways. However, the mechanism of basolateral targeting of syntaxin 4 itself has remained poorly understood. Here we show that newly synthesized syntaxin 4 is directly targeted to the basolateral plasma membrane in polarized Madin-Darby canine kidney (MDCK) cells. Basolateral targeting depends on a signal that is centered around residues 24–29 in the N-terminal domain of syntaxin 4. Furthermore, basolateral targeting of syntaxin 4 is dependent on the epithelial cell-specific clathrin adaptor AP1B. Disruption of the basolateral targeting signal of syntaxin 4 leads to non-polarized delivery to both the apical and basolateral surface, as well as partial intercellular retention in the trans-Golgi network. Importantly, disruption of the basolateral targeting signal of syntaxin 4 leads to the inability of MDCK cells to establish a polarized morphology which suggests that restriction of syntaxin 4 to the basolateral domain is required for epithelial cell polarity

    JPN Guidelines for the management of acute pancreatitis: treatment of gallstone-induced acute pancreatitis

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    Gallstones, along with alcohol, are one of the primary etiological factors of acute pancreatitis, and knowledge of the etiology as well as the diagnosis and management of gallstones, is crucial for managing acute pancreatitis. Because of this, evidence regarding the management of gallstone-induced pancreatitis in Japan was collected, and recommendation levels were established by comparing current clinical practices with optimal clinical practices. The JPN Guidelines for managing gallstone-induced acute pancreatitis recommend two procedures: (1) an urgent endoscopic procedure should be performed in patients in whom biliary duct obstruction is suspected and in patients complicated by cholangitis (Recommendation A); and (2) after the attack of gallstone pancreatitis has subsided, a laparoscopic cholecystectomy should be performed during the same hospital stay (Recommendation B)

    Structural Disorder Provides Increased Adaptability for Vesicle Trafficking Pathways

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    Vesicle trafficking systems play essential roles in the communication between the organelles of eukaryotic cells and also between cells and their environment. Endocytosis and the late secretory route are mediated by clathrin-coated vesicles, while the COat Protein I and II (COPI and COPII) routes stand for the bidirectional traffic between the ER and the Golgi apparatus. Despite similar fundamental organizations, the molecular machinery, functions, and evolutionary characteristics of the three systems are very different. In this work, we compiled the basic functional protein groups of the three main routes for human and yeast and analyzed them from the structural disorder perspective. We found similar overall disorder content in yeast and human proteins, confirming the well-conserved nature of these systems. Most functional groups contain highly disordered proteins, supporting the general importance of structural disorder in these routes, although some of them seem to heavily rely on disorder, while others do not. Interestingly, the clathrin system is significantly more disordered (,23%) than the other two, COPI (,9%) and COPII (,8%). We show that this structural phenomenon enhances the inherent plasticity and increased evolutionary adaptability of the clathrin system, which distinguishes it from the other two routes. Since multi-functionality (moonlighting) is indicative of both plasticity and adaptability, we studied its prevalence in vesicle trafficking proteins and correlated it with structural disorder. Clathrin adaptors have the highest capability for moonlighting while also comprising the most highly disordered members. The ability to acquire tissue specific functions was also used to approach adaptability: clathrin route genes have the most tissue specific exons encoding for protein segments enriched in structural disorder and interaction sites. Overall, our results confirm the general importance of structural disorder in vesicle trafficking and suggest major roles for this structural property in shaping the differences of evolutionary adaptability in the three routes

    HIV-1 Nef Targets MHC-I and CD4 for Degradation Via a Final Common Ξ²-COP–Dependent Pathway in T Cells

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    To facilitate viral infection and spread, HIV-1 Nef disrupts the surface expression of the viral receptor (CD4) and molecules capable of presenting HIV antigens to the immune system (MHC-I). To accomplish this, Nef binds to the cytoplasmic tails of both molecules and then, by mechanisms that are not well understood, disrupts the trafficking of each molecule in different ways. Specifically, Nef promotes CD4 internalization after it has been transported to the cell surface, whereas Nef uses the clathrin adaptor, AP-1, to disrupt normal transport of MHC-I from the TGN to the cell surface. Despite these differences in initial intracellular trafficking, we demonstrate that MHC-I and CD4 are ultimately found in the same Rab7+ vesicles and are both targeted for degradation via the activity of the Nef-interacting protein, Ξ²-COP. Moreover, we demonstrate that Nef contains two separable Ξ²-COP binding sites. One site, an arginine (RXR) motif in the N-terminal Ξ± helical domain of Nef, is necessary for maximal MHC-I degradation. The second site, composed of a di-acidic motif located in the C-terminal loop domain of Nef, is needed for efficient CD4 degradation. The requirement for redundant motifs with distinct roles supports a model in which Nef exists in multiple conformational states that allow access to different motifs, depending upon which cellular target is bound by Nef
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