@article{AmichSchaffererHaasetal.2013,
  author    = {Amich, Jorge and Schafferer, Lukas and Haas, Hubertus and Krappmann, Sven},
  title     = {Regulation of Sulphur Assimilation Is Essential for Virulence and Affects Iron Homeostasis of the Human-Pathogenic Mould Aspergillus fumigatus},
  series = {PLoS Pathogens},
  volume    = {9},
  journal   = {PLoS Pathogens},
  number    = {8},
  doi       = {10.1371/journal.ppat.1003573},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130372},
  pages     = {e1003573},
  year      = {2013},
  abstract  = {Abstract Sulphur is an essential element that all pathogens have to absorb from their surroundings in order to grow inside their infected host. Despite its importance, the relevance of sulphur assimilation in fungal virulence is largely unexplored. Here we report a role of the bZIP transcription factor MetR in sulphur assimilation and virulence of the human pathogen Aspergillus fumigatus. The MetR regulator is essential for growth on a variety of sulphur sources; remarkably, it is fundamental for assimilation of inorganic S-sources but dispensable for utilization of methionine. Accordingly, it strongly supports expression of genes directly related to inorganic sulphur assimilation but not of genes connected to methionine metabolism. On a broader scale, MetR orchestrates the comprehensive transcriptional adaptation to sulphur-starving conditions as demonstrated by digital gene expression analysis. Surprisingly, A. fumigatus is able to utilize volatile sulphur compounds produced by its methionine catabolism, a process that has not been described before and that is MetR-dependent. The A. fumigatus MetR transcriptional activator is important for virulence in both leukopenic mice and an alternative mini-host model of aspergillosis, as it was essential for the development of pulmonary aspergillosis and supported the systemic dissemination of the fungus. MetR action under sulphur-starving conditions is further required for proper iron regulation, which links regulation of sulphur metabolism to iron homeostasis and demonstrates an unprecedented regulatory crosstalk. Taken together, this study provides evidence that regulation of sulphur assimilation is not only crucial for A. fumigatus virulence but also affects the balance of iron in this prime opportunistic pathogen. Author Summary Invasive pulmonary aspergillosis (IPA) is a life-threatening disease that affects primarily immunosuppressed patients. During the last decades the incidence of this disease that is accompanied by high mortality rates has increased. Since opportunistic pathogenic fungi, unlike other pathogens, do not express specific virulence factors, it is becoming more and more clear that the elucidation of fungal metabolism is an essential task to understand fungal pathogenicity and to identify novel antifungal targets. In this work we report genetic inactivation of the sulphur transcription regulator MetR in Aspergillus fumigatus and subsequent study of the resulting phenotypes and transcriptional deregulation of the mutant. Here we show that regulation of sulphur assimilation is an essential process for the manifestation of IPA. Moreover, a regulatory connection between sulphur metabolism and iron homeostasis, a further essential virulence determinant of A. fumigatus, is demonstrated in this study for the first time. A deeper knowledge of sulphur metabolism holds the promise of increasing our understanding of fungal virulence and might lead to improved antifungal therapy.},
  language  = {en}
}
@article{GaubatzEsterlechnerReichertetal.2013,
  author    = {Gaubatz, Stefan and Esterlechner, Jasmina and Reichert, Nina and Iltzsche, Fabian and Krause, Michael and Finkernagel, Florian},
  title     = {LIN9, a Subunit of the DREAM Complex, Regulates Mitotic Gene Expression and Proliferation of Embryonic Stem Cells},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0062882},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96922},
  year      = {2013},
  abstract  = {The DREAM complex plays an important role in regulation of gene expression during the cell cycle. We have previously shown that the DREAM subunit LIN9 is required for early embryonic development and for the maintenance of the inner cell mass in vitro. In this study we examined the effect of knocking down LIN9 on ESCs. We demonstrate that depletion of LIN9 alters the cell cycle distribution of ESCs and results in an accumulation of cells in G2 and M and in an increase of polyploid cells. Genome-wide expression studies showed that the depletion of LIN9 results in downregulation of mitotic genes and in upregulation of differentiation-specific genes. ChIP-on chip experiments showed that mitotic genes are direct targets of LIN9 while lineage specific markers are regulated indirectly. Importantly, depletion of LIN9 does not alter the expression of pluripotency markers SOX2, OCT4 and Nanog and LIN9 depleted ESCs retain alkaline phosphatase activity. We conclude that LIN9 is essential for proliferation and genome stability of ESCs by activating genes with important functions in mitosis and cytokinesis.},
  language  = {en}
}
@article{KimGrimmigGrimmetal.2013,
  author    = {Kim, Mia and Grimmig, Tanja and Grimm, Martin and Lazariotou, Maria and Meier, Eva and Rosenwald, Andreas and Tsaur, Igor and Blaheta, Roman and Heemann, Uwe and Germer, Christoph-Thomas and Waaga-Gasser, Ana Maria and Gasser, Martin},
  title     = {Expression of Foxp3 in Colorectal Cancer but Not in Treg Cells Correlates with Disease Progression in Patients with Colorectal Cancer},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {1},
  doi       = {10.1371/journal.pone.0053630},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130340},
  pages     = {e53630},
  year      = {2013},
  abstract  = {Background Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA. Hypothesis Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing. Methods To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression. Results Applying our algorithm to the data, 9\% of the genes were assigned as AS, while only 3\% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry. Conclusions PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.},
  language  = {en}
}
@article{RiedelMofoloAvotaetal.2013,
  author    = {Riedel, Alice and Mofolo, Boitumelo and Avota, Elita and Schneider-Schaulies, Sibylle and Meintjes, Ayton and Mulder, Nicola and Kneitz, Susanne},
  title     = {Accumulation of Splice Variants and Transcripts in Response to PI3K Inhibition in T Cells},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {2},
  doi       = {10.1371/journal.pone.0050695},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130335},
  pages     = {e50695},
  year      = {2013},
  abstract  = {Background Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA. Hypothesis Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing. Methods To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression. Results Applying our algorithm to the data, 9\% of the genes were assigned as AS, while only 3\% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry. Conclusions PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.},
  language  = {en}
}