@article{BlaettnerDasPaprotkaetal.2016, author = {Bl{\"a}ttner, Sebastian and Das, Sudip and Paprotka, Kerstin and Eilers, Ursula and Krischke, Markus and Kretschmer, Dorothee and Remmele, Christian W. and Dittrich, Marcus and M{\"u}ller, Tobias and Schuelein-Voelk, Christina and Hertlein, Tobias and Mueller, Martin J. and Huettel, Bruno and Reinhardt, Richard and Ohlsen, Knut and Rudel, Thomas and Fraunholz, Martin J.}, title = {Staphylococcus aureus Exploits a Non-ribosomal Cyclic Dipeptide to Modulate Survival within Epithelial Cells and Phagocytes}, series = {PLoS Pathogens}, volume = {12}, journal = {PLoS Pathogens}, number = {9}, doi = {10.1371/journal.ppat.1005857}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-180380}, year = {2016}, abstract = {Community-acquired (CA) Staphylococcus aureus cause various diseases even in healthy individuals. Enhanced virulence of CA-strains is partly attributed to increased production of toxins such as phenol-soluble modulins (PSM). The pathogen is internalized efficiently by mammalian host cells and intracellular S. aureus has recently been shown to contribute to disease. Upon internalization, cytotoxic S. aureus strains can disrupt phagosomal membranes and kill host cells in a PSM-dependent manner. However, PSM are not sufficient for these processes. Here we screened for factors required for intracellular S. aureus virulence. We infected escape reporter host cells with strains from an established transposon mutant library and detected phagosomal escape rates using automated microscopy. We thereby, among other factors, identified a non-ribosomal peptide synthetase (NRPS) to be required for efficient phagosomal escape and intracellular survival of S. aureus as well as induction of host cell death. By genetic complementation as well as supplementation with the synthetic NRPS product, the cyclic dipeptide phevalin, wild-type phenotypes were restored. We further demonstrate that the NRPS is contributing to virulence in a mouse pneumonia model. Together, our data illustrate a hitherto unrecognized function of the S. aureus NRPS and its dipeptide product during S. aureus infection.}, language = {en} } @article{WalperWeisteMuelleretal.2016, author = {Walper, Elisabeth and Weiste, Christoph and Mueller, Martin J. and Hamberg, Mats and Dr{\"o}ge-Laser, Wolfgang}, title = {Screen Identifying Arabidopsis Transcription Factors Involved in the Response to 9-Lipoxygenase-Derived Oxylipins}, series = {PLoS One}, volume = {11}, journal = {PLoS One}, number = {4}, doi = {10.1371/journal.pone.0153216}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146857}, pages = {e0153216}, year = {2016}, abstract = {13-Lipoxygenase-derived oxylipins, such as jasmonates act as potent signaling molecules in plants. Although experimental evidence supports the impact of oxylipins generated by the 9-Lipoxygenase (9-LOX) pathway in root development and pathogen defense, their signaling function in plants remains largely elusive. Based on the root growth inhibiting properties of the 9-LOX-oxylipin 9-HOT (9-hydroxy-10,12,15-octadecatrienoic acid), we established a screening approach aiming at identifying transcription factors (TFs) involved in signaling and/or metabolism of this oxylipin. Making use of the AtTORF-Ex (Arabidopsis thaliana Transcription Factor Open Reading Frame Expression) collection of plant lines overexpressing TF genes, we screened for those TFs which restore root growth on 9-HOT. Out of 6,000 lines, eight TFs were recovered at least three times and were therefore selected for detailed analysis. Overexpression of the basic leucine Zipper (bZIP) TF TGA5 and its target, the monoxygenase CYP81D11 reduced the effect of added 9-HOT, presumably due to activation of a detoxification pathway. The highly related ETHYLENE RESPONSE FACTORs ERF106 and ERF107 induce a broad detoxification response towards 9-LOX-oxylipins and xenobiotic compounds. From a set of 18 related group S-bZIP factors isolated in the screen, bZIP11 is known to participate in auxin-mediated root growth and may connect oxylipins to root meristem function. The TF candidates isolated in this screen provide starting points for further attempts to dissect putative signaling pathways involving 9-LOX-derived oxylipins.}, language = {en} } @article{SegererHadamekZundleretal.2016, author = {Segerer, Gabriela and Hadamek, Kerstin and Zundler, Matthias and Fekete, Agnes and Seifried, Annegrit and Mueller, Martin J. and Koentgen, Frank and Gessler, Manfred and Jeanclos, Elisabeth and Gohla, Antje}, title = {An essential developmental function for murine phosphoglycolate phosphatase in safeguarding cell proliferation}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, doi = {10.1038/srep35160}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181094}, year = {2016}, abstract = {Mammalian phosphoglycolate phosphatase (PGP) is thought to target phosphoglycolate, a 2-deoxyribose fragment derived from the repair of oxidative DNA lesions. However, the physiological role of this activity and the biological function of the DNA damage product phosphoglycolate is unknown. We now show that knockin replacement of murine Pgp with its phosphatase-inactive Pgp\(^{D34N}\) mutant is embryonically lethal due to intrauterine growth arrest and developmental delay in midgestation. PGP inactivation attenuated triosephosphate isomerase activity, increased triglyceride levels at the expense of the cellular phosphatidylcholine content, and inhibited cell proliferation. These effects were prevented under hypoxic conditions or by blocking phosphoglycolate release from damaged DNA. Thus, PGP is essential to sustain cell proliferation in the presence of oxygen. Collectively, our findings reveal a previously unknown mechanism coupling a DNA damage repair product to the control of intermediary metabolism and cell proliferation.}, language = {en} }