68 research outputs found
Gender Equality und Rechtsstaatlichkeit in der EU : Die polnische Justizreform
Rechtsstaatlichkeit und gender equality sind in der Europäischen Union (EU) in Artikel 2 des Vertrages von Lissabon (EUV) als Grundwerte der Union verankert. Jüngst wurde die Auszahlung von EU-Mitteln in der Richtlinie 2020/2092 an die Einhaltung der Rechtsstaatlichkeit gekoppelt. Im Rahmen der umstrittenen Justizreform in Polen leitete die Europäische Kommission zudem erstmalig ein Rechtsstaatlichkeitsverfahren nach Arti-kel 7 EUV ein, um die Werte der EU zu schützen. Doch das darin gewährte Gleichstellungsgebot stößt an seine Grenzen, wo Kompetenzen zwischen den Mitgliedstaaten und der Union aufgeteilt sind und der Zugang zur Po-litikgestaltung betroffen ist. Letzterer ist für die stetige Neudefinition von Geschlecht von Bedeutung. Dies wird am Beispiel des Gender-Quality-Akti-vismus und der aktuellen Justizreform in Polen deutlich. Die in diesem Zu-sammenhang erfolgten Entscheidungen des Gerichtshofes der EU können nur punktuell eingreifen, sind jedoch kein Garant für eine nachhaltige poli-tische und gesellschaftliche Berücksichtigung von gender equalit
Gender Equality und Rechtsstaatlichkeit in der EU
Rechtsstaatlichkeit und gender equality sind in der Europäischen Union (EU) in Artikel 2 des Vertrages von Lissabon (EUV) als Grundwerte der Union verankert. Jüngst wurde die Auszahlung von EU-Mitteln in der Richtlinie 2020/2092 an die Einhaltung der Rechtsstaatlichkeit gekoppelt. Im Rahmen der umstrittenen Justizreform in Polen leitete die Europäische Kommission zudem erstmalig ein Rechtsstaatlichkeitsverfahren nach Artikel 7 EUV ein, um die Werte der EU zu schützen. Doch das darin gewährte Gleichstellungsgebot stößt an seine Grenzen, wo Kompetenzen zwischen den Mitgliedstaaten und der Union aufgeteilt sind und der Zugang zur Politikgestaltung betroffen ist. Letzterer ist für die stetige Neudefinition von Geschlecht von Bedeutung. Dies wird am Beispiel des Gender-Quality-Aktivismus und der aktuellen Justizreform in Polen deutlich. Die in diesem Zusammenhang erfolgten Entscheidungen des Gerichtshofes der EU können nur punktuell eingreifen, sind jedoch kein Garant für eine nachhaltige politische und gesellschaftliche Berücksichtigung von gender equality
Quantitative expression analysis of selected transcription factors in pavement, basal and trichome cells of mature leaves from Arabidopsis thaliana
Gene expression levels of several transcription factors from Arabidopsis thaliana that were described previously to be involved in leaf development and trichome formation were analysed in trichome, basal and pavement cells of mature leaves. Single cell samples of these three cells types were collected by glass micro-capillaries. Real-time reverse transcription (RT)-PCR was used to analyse expression patterns of the following transcription factors: MYB23, MYB55, AtHB1, FILAMENTOUS FLOWER (FIL)/YABBY1 (YAB1), TRIPTYCHON (TRY) and CAPRICE (CPC). A difference in the expression patterns of TRY and CPC was revealed. Contrary to the CPC expression pattern, no transcripts of TRY could be detected in pavement cells. FIL/YAB1 was exclusively expressed in trichome cells. AtHB1 was highly expressed throughout all three cell types. MYB55 was higher expressed in basal cells than in trichome and pavement cells. MYB23 showed a pattern of low expression in pavement cells, medium in basal cells and high expression in trichomes. Expression patterns obtained by single cell sampling and real-time RT-PCR were compared to promoter GUS fusions of the selected transcription factors. Therefore, we regenerated two transgenic Arabidopsis lines that expressed the GUS reporter gene under control of the promoters of MYB55 and YAB1. In conclusion, despite their function in leaf morphogenesis, all six transcription factors were detected in mature leaves. Furthermore, single cell sampling and promoter GUS staining patterns demonstrated the predominant presence of MYB55 in basal cells as compared to pavement cells and trichomes
Site-Directed Mutagenesis of IRX9, IRX9L and IRX14 Proteins Involved in Xylan Biosynthesis:Glycosyltransferase Activity Is Not Required for IRX9 Function in Arabidopsis
Xylans constitute the main non-cellulosic polysaccharide in the secondary cell walls of plants. Several genes predicted to encode glycosyltransferases are required for the synthesis of the xylan backbone even though it is a homopolymer consisting entirely of β-1,4-linked xylose residues. The putative glycosyltransferases IRX9, IRX14, and IRX10 (or the paralogs IRX9L, IRX14L, and IRX10L) are required for xylan backbone synthesis in Arabidopsis. To investigate the function of IRX9, IRX9L, and IRX14, we identified amino acid residues known to be essential for catalytic function in homologous mammalian proteins and generated modified cDNA clones encoding proteins where these residues would be mutated. The mutated gene constructs were used to transform wild-type Arabidopsis plants and the irx9 and irx14 mutants, which are deficient in xylan synthesis. The ability of the mutated proteins to complement the mutants was investigated by measuring growth, determining cell wall composition, and microscopic analysis of stem cross-sections of the transgenic plants. The six different mutated versions of IRX9 and IRX9-L were all able to complement the irx9 mutant phenotype, indicating that residues known to be essential for glycosyltransferases function in homologous proteins are not essential for the biological function of IRX9/IRX9L. Two out of three mutated IRX14 complemented the irx14 mutant, including a mutant in the predicted catalytic amino acid. A IRX14 protein mutated in the substrate-binding DxD motif did not complement the irx14 mutant. Thus, substrate binding is important for IRX14 function but catalytic activity may not be essential for the function of the protein. The data indicate that IRX9/IRX9L have an essential structural function, most likely by interacting with the IRX10/IRX10L proteins, but do not have an essential catalytic function. Most likely IRX14 also has primarily a structural role, but it cannot be excluded that the protein has an important enzymatic activity
Conserved Glu-47 and Lys-50 residues are critical for UDP-N-acetylglucosamine/UMP antiport activity of the mouse Golgi-associated transporter Slc35a3
Nucleotide sugar transporters (NSTs) regulate the flux of activated sugars from the cytosol into the lumen of the Golgi apparatus where glycosyltransferases use them for the modification of proteins, lipids, and proteoglycans. It has been well established that NSTs are antiporters that exchange nucleotide sugars with the respective nucleoside monophosphate. Nevertheless, information about the molecular basis of ligand recognition and transport is scarce. Here, using topology predictors, cysteine-scanning mutagenesis, expression of GFP-tagged protein variants, and phenotypic complementation of the yeast strain Kl3, we identified residues involved in the activity of a mouse UDP-GlcNAc transporter, murine solute carrier family 35 member A3 (mSLC35A3). We specifically focused on the putative transmembrane helix 2 (TMH2) and observed that cells expressing E47C or K50C SLC35A3 variants had lower levels of GlcNAc-containing glycoconjugates than WT cells, indicating impaired UDP-GlcNAc transport activity of these two variants. A conservative substitution analysis revealed that single or double substitutions of Glu-47 and Lys-50 does not restore GlcNAc glycoconjugates. Analysis of mSLC35A3 and its genetic variants reconstituted into proteoliposomes disclosed that i) all variants act as UDP-GlcNAc/UMP antiporters; ii) conservative substitutions (E47D, E47Q, K50R or K50H) impair UDP-GlcNAc uptake; and iii) substitutions of Glu-47 and Lys-50 dramatically alter kinetic parameters, consistent with a critical role of these two residues in mSLC35A3 function. A bioinformatics analysis revealed that a EXXK motif in TMH2 is highly conserved across SLC35 A subfamily members, and a 3D-homology model predicted that Glu-47 and Lys-50 are facing the central cavity of the proteinFil: Toscanini, MarÃa Agustina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de NanobiotecnologÃa. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de NanobiotecnologÃa; ArgentinaFil: Favarolo, Maria Belen. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas; ArgentinaFil: Gonzalez Flecha, Francisco Luis. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas; ArgentinaFil: Ebert, Berit. University of Melbourne; AustraliaFil: Rautengarten, Carsten. University of Melbourne; AustraliaFil: Bredeston, Luis MarÃa. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Instituto de QuÃmica y FÃsico-QuÃmica Biológicas; Argentin
An Integrative Approach to the Identification of Arabidopsis and Rice Genes Involved in Xylan and Secondary Wall Development
Xylans constitute the major non-cellulosic component of plant biomass. Xylan biosynthesis is particularly pronounced in cells with secondary walls, implying that the synthesis network consists of a set of highly expressed genes in such cells. To improve the understanding of xylan biosynthesis, we performed a comparative analysis of co-expression networks between Arabidopsis and rice as reference species with different wall types. Many co-expressed genes were represented by orthologs in both species, which implies common biological features, while some gene families were only found in one of the species, and therefore likely to be related to differences in their cell walls. To predict the subcellular location of the identified proteins, we developed a new method, PFANTOM (plant protein family information-based predictor for endomembrane), which was shown to perform better for proteins in the endomembrane system than other available prediction methods. Based on the combined approach of co-expression and predicted cellular localization, we propose a model for Arabidopsis and rice xylan synthesis in the Golgi apparatus and signaling from plasma membrane to nucleus for secondary cell wall differentiation. As an experimental validation of the model, we show that an Arabidopsis mutant in the PGSIP1 gene encoding one of the Golgi localized candidate proteins has a highly decreased content of glucuronic acid in secondary cell walls and substantially reduced xylan glucuronosyltransferase activity
The <i>Arabidopsis</i> Golgi-localized GDP-L-fucose transporter is required for plant development
Indexación: Web of Science.Nucleotide sugar transport across Golgi membranes is essential for the luminal biosynthesis of glycan structures. Here we identify GDP-fucose transporter 1 (GFT1), an Arabidopsis nucleotide sugar transporter that translocates GDP-L-fucose into the Golgi lumen. Using proteo-liposome-based transport assays, we show that GFT preferentially transports GDP-L-fucose over other nucleotide sugars in vitro, while GFT1-silenced plants are almost devoid of L-fucose in cell wall-derived xyloglucan and rhamnogalacturonan II. Furthermore, these lines display reduced L-fucose content in N-glycan structures accompanied by severe developmental growth defects. We conclude that GFT1 is the major nucleotide sugar transporter for import of GDP-L-fucose into the Golgi and is required for proper plant growth and development.http://www.nature.com/articles/ncomms1211
The elaborate route for UDP-arabinose delivery into the Golgi of plants
Indexación: Scopus.In plants, L-Arabinose (Ara) is a key component of cell wall polymers, glycoproteins, as well as flavonoids, and signaling peptides. Whereas the majority of Ara found in plant glycans occurs as a furanose ring (Araf), the activated precursor has a pyranose ring configuration (UDP-Arap). The biosynthesis of UDP-Arap mainly occurs via the epimerization of UDP-xylose (UDP-Xyl) in the Golgi lumen. Given that the predominant Ara form found in plants is Araf, UDP-Arap must exit the Golgi to be interconverted into UDPAraf by UDP-Ara mutases that are located outside on the cytosolic surface of the Golgi. Subsequently, UDP-Araf must be transported back into the lumen. This step is vital because glycosyltransferases, the enzymes mediating the glycosylation reactions, are located within the Golgi lumen, and UDP-Arap, synthesized within the Golgi, is not their preferred substrate. Thus, the transport of UDP-Araf into the Golgi is a prerequisite. Although this step is critical for cell wall biosynthesis and the glycosylation of proteins and signaling peptides, the identification of these transporters has remained elusive. In this study, we present data demonstrating the identification and characterization of a family of Golgilocalized UDP-Araf transporters in Arabidopsis. The application of a proteoliposome-based transport assay revealed that four members of the nucleotide sugar transporter (NST) family can efficiently transport UDP-Araf in vitro. Subsequent analysis of mutant lines affected in the function of these NSTs confirmed their role as UDP-Araf transporters in vivo.http://www.pnas.org/content/114/16/4261.ful
Vascular CXCR4 Expression – a Novel Antiangiogenic Target in Gastric Cancer?
BACKGROUND:
G-protein-coupled receptors (GPCRs) are prime candidates for novel cancer prevention and treatment strategies. We searched for differentially expressed GPCRs in node positive gastric carcinomas.
METHODOLOGY/PRINCIPAL FINDINGS:
Differential expression of GPCRs in three node positive vs. three node negative intestinal type gastric carcinomas was analyzed by gene array technology. The candidate genes CXCL12 and its receptor CXCR4 were validated by real-time reverse-transcription polymerase chain reaction in an independent set of 37 gastric carcinomas. Translation was studied by immunohistochemistry in 347 gastric carcinomas using tissue microarrays as well as in 61 matching lymph node metastases. Protein expression was correlated with clinicopathological patient characteristics and survival. 52 GPCRs and GPCR-related genes were up- or down-regulated in node positive gastric cancer, including CXCL12. Differential expression of CXCL12 was confirmed by RT-PCR and correlated with local tumour growth. CXCL12 immunopositivity was negatively associated with distant metastases and tumour grade. Only 17% of gastric carcinomas showed CXCR4 immunopositive tumour cells, which was associated with higher local tumour extent. 29% of gastric carcinomas showed CXCR4 positive tumour microvessels. Vascular CXCR4 expression was significantly associated with higher local tumour extent as well as higher UICC-stages. When expressing both, CXCL12 in tumour cells and CXCR4 in tumour microvessels, these tumours also were highly significantly associated with higher T- and UICC-stages. Three lymph node metastases revealed vascular CXCR4 expression while tumour cells completely lacked CXCR4 in all cases. The expression of CXCL12 and CXCR4 had no impact on patient survival.
CONCLUSIONS/SIGNIFICANCE:
Our results substantiate the significance of GPCRs on the biology of gastric carcinomas and provide evidence that the CXCL12-CXCR4 pathway might be a novel promising antiangiogenic target for the treatment of gastric carcinomas
Identification and characterization of a golgi-localized UDP-Xylose transporter family from Arabidopsis
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