@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} } @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} }