@article{ReynoldsCliffeFoerstneretal.2014, author = {Reynolds, David and Cliffe, Laura and F{\"o}rstner, Konrad U. and Hon, Chung-Chau and Siegel, T. Nicolai and Sabatini, Robert}, title = {Regulation of transcription termination by glucosylated hydroxymethyluracil, base J, in Leishmania major and Trypanosoma brucei}, series = {Nucleic Acids Research}, volume = {42}, journal = {Nucleic Acids Research}, number = {15}, doi = {10.1093/nar/gku714}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117863}, pages = {9717-9729}, year = {2014}, abstract = {Base J, beta-d-glucosyl-hydroxymethyluracil, is an epigenetic modification of thymine in the nuclear DNA of flagellated protozoa of the order Kinetoplastida. J is enriched at sites involved in RNA polymerase ( RNAP) II initiation and termination. Reduction of J in Leishmania tarentolae via growth in BrdU resulted in cell death and indicated a role of J in the regulation of RNAP II termination. To further explore J function in RNAP II termination among kinetoplastids and avoid indirect effects associated with BrdU toxicity and genetic deletions, we inhibited J synthesis in Leishmania major and Trypanosoma brucei using DMOG. Reduction of J in L. major resulted in genome-wide defects in transcription termination at the end of polycistronic gene clusters and the generation of antisense RNAs, without cell death. In contrast, loss of J in T. brucei did not lead to genome-wide termination defects; however, the loss of J at specific sites within polycistronic gene clusters led to altered transcription termination and increased expression of downstream genes. Thus, J regulation of RNAP II transcription termination genome-wide is restricted to Leishmania spp., while in T. brucei it regulates termination and gene expression at specific sites within polycistronic gene clusters.}, language = {en} } @article{BerghoffKonzerManketal.2013, author = {Berghoff, Bork A. and Konzer, Anne and Mank, Nils N. and Looso, Mario and Rische, Tom and F{\"o}rstner, Konrad U. and Kr{\"u}ger, Marcus and Klug, Gabriele}, title = {Integrative "Omics"-Approach Discovers Dynamic and Regulatory Features of Bacterial Stress Responses}, series = {PLOS Genetics}, volume = {9}, journal = {PLOS Genetics}, number = {6}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1003576}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127587}, pages = {e1003576}, year = {2013}, abstract = {Bacteria constantly face stress conditions and therefore mount specific responses to ensure adaptation and survival. Stress responses were believed to be predominantly regulated at the transcriptional level. In the phototrophic bacterium Rhodobacter sphaeroides the response to singlet oxygen is initiated by alternative sigma factors. Further adaptive mechanisms include post-transcriptional and post-translational events, which have to be considered to gain a deeper understanding of how sophisticated regulation networks operate. To address this issue, we integrated three layers of regulation: (1) total mRNA levels at different time-points revealed dynamics of the transcriptome, (2) mRNAs in polysome fractions reported on translational regulation (translatome), and (3) SILAC-based mass spectrometry was used to quantify protein abundances (proteome). The singlet oxygen stress response exhibited highly dynamic features regarding short-term effects and late adaptation, which could in part be assigned to the sigma factors RpoE and RpoH2 generating distinct expression kinetics of corresponding regulons. The occurrence of polar expression patterns of genes within stress-inducible operons pointed to an alternative of dynamic fine-tuning upon stress. In addition to transcriptional activation, we observed significant induction of genes at the post-transcriptional level (translatome), which identified new putative regulators and assigned genes of quorum sensing to the singlet oxygen stress response. Intriguingly, the SILAC approach explored the stress-dependent decline of photosynthetic proteins, but also identified 19 new open reading frames, which were partly validated by RNA-seq. We propose that comparative approaches as presented here will help to create multi-layered expression maps on the system level ("expressome"). Finally, intense mass spectrometry combined with RNA-seq might be the future tool of choice to re-annotate genomes in various organisms and will help to understand how they adapt to alternating conditions.}, language = {en} }