8 research outputs found

    Sequencing of \u3ci\u3eAspergillus nidulans\u3c/i\u3e and comparative analysis with \u3ci\u3eA. fumigatus\u3c/i\u3e and \u3ci\u3eA. oryzae\u3c/i\u3e

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    The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso, and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation. Document includes all supplementary information (820 pages). Supplementary files are also attached below as Related files. THERE IS NO SUPPLEMENTARY FILE #7. PDF file size (with supplementary files included) is 10 Mbytes. An optimized version of the ARTICLE ONLY is attached as a Related File and is 1.9 Mbytes

    Sequencing of \u3ci\u3eAspergillus nidulans\u3c/i\u3e and comparative analysis with \u3ci\u3eA. fumigatus\u3c/i\u3e and \u3ci\u3eA. oryzae\u3c/i\u3e

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    The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso, and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation. Document includes all supplementary information (820 pages). Supplementary files are also attached below as Related files. THERE IS NO SUPPLEMENTARY FILE #7. PDF file size (with supplementary files included) is 10 Mbytes. An optimized version of the ARTICLE ONLY is attached as a Related File and is 1.9 Mbytes

    Prognostic DNA methylation markers for sporadic colorectal cancer: a systematic review

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    Background Biomarkers that can predict the prognosis of colorectal cancer (CRC) patients and that can stratify high-risk early stage patients from low-risk early stage patients are urgently needed for better management of CRC. During the last decades, a large variety of prognostic DNA methylation markers has been published in the literature. However, to date, none of these markers are used in clinical practice. Methods To obtain an overview of the number of published prognostic methylation markers for CRC, the number of markers that was validated independently, and the current level of evidence (LoE), we conducted a systematic review of PubMed, EMBASE, and MEDLINE. In addition, we scored studies based on the REMARK guidelines that were established in order to attain more transparency and complete reporting of prognostic biomarker studies. Eighty-three studies reporting on 123 methylation markers fulfilled the study entry criteria and were scored according to REMARK. Results Sixty-three studies investigated single methylation markers, whereas 20 studies reported combinations of methylation markers. We observed substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology. The median (range) REMARK score for the studies was 10.7 points (4.5 to 17.5) out of a maximum of 20 possible points. The median REMARK score was lower in studies, which reported a p value below 0.05 versus those, which did not (p = 0.005). A borderline statistically significant association was observed between the reported p value of the survival analysis and the size of the study population (p = 0.051). Only 23 out of 123 markers (17%) were investigated in two or more study series. For 12 markers, and two multimarker panels, consistent results were reported in two or more study series. For four markers, the current LoE is level II, for all other markers, the LoE is lower. Conclusion This systematic review reflects that adequate reporting according to REMARK and validation of prognostic methylation markers is absent in the majority of CRC methylation marker studies. However, this systematic review provides a comprehensive overview of published prognostic methylation markers for CRC and highlights the most promising markers that have been published in the last two decades

    CsnA abhängige Entwicklung und Aminosäurebiosynthese im filamentösen Pilz <i>Aspergillus nidulans</i>.

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    Die Familie der Aspergillen ist eine sehr heterogene Gruppe filamentöser Pilze. Aspergillus nidulans ist ein wichtiger eukaryotischer Modellorganismus für Metabolismus- und Entwicklungsstudien. Aspergillus oryzae ist von großer biotechnologischer Bedeutung in der asiatischen Lebensmittelindustrie, wohingegen der opportunistische humanpathogene Pilz A. fumigatus von wachsender medizinischer Bedeutung ist. Diese Arbeit konzentriert sich auf das COP9 Signalosom, einen essentiellen, eukaryontischen Entwicklungsregulator und die generelle Kontrolle der Aminosäurebiosynthese (gc). Die generelle Kontrolle regelt die zelluläre Antwort auf Aminosäuremangel. Beide Netzwerke sind von der Bäckerhefe bis zum Menschen hoch konserviert.Das COP9 Signalosom ist ein Multiproteinkomplex, dessen wichtigste zugehörige enzymatische Aktivitäten aus Kinase- und De-ubiquitinierungsaktivitäten und einer intrinsischen Deneddylaseaktivität bestehen. Diese Arbeit untersucht die Relevanz der ersten Untereinheit des COP9 Signalosoms CsnA anhand der Expression von verkürzten Proteinvarianten. csnA Deletionsmutanten weisen diverse pleiotrophe Phänotypen auf. Die Expression von verkürzten CsnA Peptiden ermöglichte es, die Funktionen des COP9 Signalosoms von Aktivitäten des CsnA Proteins zu trennen. Der CsnA C-Terminus ist wichtig für die Aufrechterhaltung des Komplexzusammenhalts und der COP9 Aktivitäten. Der CsnA N-Terminus hingegen scheint eine wichtige Rolle in der Regulation der Ausbildung von Lufthyphen zu spielen. Im Zuge der manuellen Annotation der Genome der Pilze A. nidulans, A. fumigatus und A. oryzae wurden grundlegende Gene der generellen Kontrolle der Aminosäurebiosynthese (cpc) im Vergleich zu niederen und höheren Eukaryonten untersucht. Die Resultate der Untersuchung zeigen, daß die grundlegenden Mechanismen der cpc der filamentösen Pilze eher denen der Hefen ähneln und etwas weniger komplex als bei höheren Organismen sind. Die externen und internen Sensoren und die Aufnahmesysteme für Aminosäuren hingegen scheinen eher denen höherer Eukaryonten zu ähneln als denen einzelliger Hefen. Die Ergebnisse weisen darauf hin, daß die Aufnahme- und Sensorsysteme für Aminosäuren einen Einfluß auf das Wachstum und die Entwicklung der Pilze haben könnten, wie man sie aus Säugersystemen kennt.Die Untersuchung des Transports des zentralen Transkriptionsfaktors der cpc CpcA in den Zellkern wurde in S. cerevisiae und A. nidulans untersucht. Für einen effizienten Transport in den Nukleus ist das Kernlokalisierungssignal von CpcA notwendig. In der Bäckerhefe wurden zwei Importine Srp1p und Kap95p identifiziert, die essentiell für den Kerntransport von CpcA sind. Diese wurden auch hoch konserviert in in silico Untersuchungen in den Aspergillengenomen wiedergefunden. Die hypothetischen Aspergillenproteine SrpA und KapA könnten auch in Aspergillus notwendig für den Kerntransport von CpcA sein

    Regulation of the acuF Gene, Encoding Phosphoenolpyruvate Carboxykinase in the Filamentous Fungus Aspergillus nidulans

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    Phosphoenolpyruvate carboxykinase (PEPCK) is a key enzyme required for gluconeogenesis when microorganisms grow on carbon sources metabolized via the tricarboxylic acid (TCA) cycle. Aspergillus nidulans acuF mutants isolated by their inability to use acetate as a carbon source specifically lack PEPCK. The acuF gene has been cloned and shown to encode a protein with high similarity to PEPCK from bacteria, plants, and fungi. The regulation of acuF expression has been studied by Northern blotting and by the construction of lacZ fusion reporters. Induction by acetate is abolished in mutants unable to metabolize acetate via the TCA cycle, and induction by amino acids metabolized via 2-oxoglutarate is lost in mutants unable to form 2-oxoglutarate. Induction by acetate and proline is not additive, consistent with a single mechanism of induction. Malate and succinate result in induction, and it is proposed that PEPCK is controlled by a novel mechanism of induction by a TCA cycle intermediate or derivative, thereby allowing gluconeogenesis to occur during growth on any carbon source metabolized via the TCA cycle. It has been shown that the facB gene, which mediates acetate induction of enzymes specifically required for acetate utilization, is not directly involved in PEPCK induction. This is in contrast to Saccharomyces cerevisiae, where Cat8p and Sip4p, homologs of FacB, regulate PEPCK as well as the expression of other genes necessary for growth on nonfermentable carbon sources in response to the carbon source present. This difference in the control of gluconeogenesis reflects the ability of A. nidulans and other filamentous fungi to use a wide variety of carbon sources in comparison with S. cerevisiae. The acuF gene was also found to be subject to activation by the CCAAT binding protein AnCF, a protein homologous to the S. cerevisiae Hap complex and the mammalian NFY complex

    An eight-subunit COP9 signalosome with an intact JAMM motif is required for fungal fruit body formation

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    Fruit body formation in filamentous fungi is a complex and yet hardly understood process. We show here that protein turnover control is crucial for Aspergillus nidulans development. Deletion of genes encoding COP9 signalosome (CSN) subunits 1, 2, 4, or 5 resulted in identical blocks in fruit body formation. The CSN multiprotein complex controls ubiquitin-dependent protein degradation in eukaryotes. Six CSN subunits interacted in a yeast two-hybrid analysis, and the complete eight-subunit CSN was recruited by a functional tandem affinity purification tag fusion of subunit 5 (CsnE). The tagged CsnE was unable to recruit any CSN subunit in a strain deleted for subunit 1 or subunit 4. Mutations in the JAMM metalloprotease core of CsnE resulted in mutant phenotypes identical to those of csn deletion strains. We propose that a correctly assembled CSN including a functional JAMM links protein turnover to fungal sexual development

    Sequencing of Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae

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    International audienceThe aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation
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