41 research outputs found

    Grundlagen und quantitative Beschreibung der Schaedigungsmechanismen in der Superlegierung MAR-M247

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    Available from TIB Hannover: F95B626+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

    Proteome analysis of the effects of all-trans retinoic acid on human germ cell tumor cell lines

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    We analysed the effects of all-trans retinoic acid (ATRA) on proliferation and changes in the global proteome of the nullipotent human embryonal carcinoma cell line 2102Ep and the pluripotent cell line NTERA2 cl.D1 (NT2). Differentially expressed proteins were assessed by 2D-PAGE and mass spectrometry, followed by verification and analysis of protein modifications of proteins of the retinoid pathway. We established a proteome map of the germ cell tumor (GCT) cell line NT2 showing neuronal differentiation under ATRA treatment for 7days. Using bioinformatic analyses, we identified functional groups of altered proteins and potentially involved pathways, of which changes to the organization of the cytoskeleton and anti-apoptotic effects were the most prominent. Changes observed in the expression of factors involved in the retinoid pathway under ATRA, namely an upregulation of CRBP and CRABP2, were also reflected in GCT tissues of different histologies, providing further insight into factors involved in the differentiation of these pluripotent tumors. BIOLOGICAL SIGNIFICANCE: Treatment of NT2 germ cell tumor cells with all-trans retinoic acid (ATRA) is a model to investigate differentiation. We analysed differentially expressed proteins by 2D-PAGE and mass spectrometry and provide a proteome map of NT2 cells under 7days of ATRA. By bioinformatic analyses, functional groups of proteins and involved pathways like changes to the cytoskeleton and anti-apoptotic effects were identified. Factors involved in the retinoid pathway, in particular upregulation of CRBP, CRABP1 and CRABP2, also showed differential expression in tumors with different histological subtypes, which provides insight into gene regulation under induced and spontaneous differentiation in germ cell tumors

    Systems-Level Analysis of Nitrogen Starvation-Induced Modifications of Carbon Metabolism in a Chlamydomonas reinhardtii Starchless Mutant

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    To understand the molecular basis underlying increased triacylglycerol (TAG) accumulation in starchless (sta) Chlamydomonas reinhardtii mutants, we undertook comparative time-course transcriptomics of strains CC-4348 (sta6 mutant), CC-4349, a cell wall–deficient (cw) strain purported to represent the parental STA6 strain, and three independent STA6 strains generated by complementation of sta6 (CC-4565/STA6-C2, CC-4566/STA6-C4, and CC-4567/STA6-C6) in the context of N deprivation. Despite N starvation–induced dramatic remodeling of the transcriptome, there were relatively few differences (5 × 10(2)) observed between sta6 and STA6, the most dramatic of which were increased abundance of transcripts encoding key regulated or rate-limiting steps in central carbon metabolism, specifically isocitrate lyase, malate synthase, transaldolase, fructose bisphosphatase and phosphoenolpyruvate carboxykinase (encoded by ICL1, MAS1, TAL1, FBP1, and PCK1 respectively), suggestive of increased carbon movement toward hexose-phosphate in sta6 by upregulation of the glyoxylate pathway and gluconeogenesis. Enzyme assays validated the increase in isocitrate lyase and malate synthase activities. Targeted metabolite analysis indicated increased succinate, malate, and Glc-6-P and decreased Fru-1,6-bisphosphate, illustrating the effect of these changes. Comparisons of independent data sets in multiple strains allowed the delineation of a sequence of events in the global N starvation response in C. reinhardtii, starting within minutes with the upregulation of alternative N assimilation routes and carbohydrate synthesis and subsequently a more gradual upregulation of genes encoding enzymes of TAG synthesis. Finally, genome resequencing analysis indicated that (1) the deletion in sta6 extends into the neighboring gene encoding respiratory burst oxidase, and (2) a commonly used STA6 strain (CC-4349) as well as the sequenced reference (CC-503) are not congenic with respect to sta6 (CC-4348), underscoring the importance of using complemented strains for more rigorous assignment of phenotype to genotype
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