@article{SauerJuranekMarksetal.2019, author = {Sauer, Markus and Juranek, Stefan A. and Marks, James and De Magis, Alessio and Kazemier, Hinke G and Hilbig, Daniel and Benhalevy, Daniel and Wang, Xiantao and Hafner, Markus and Paeschke, Katrin}, title = {DHX36 prevents the accumulation of translationally inactive mRNAs with G4-structures in untranslated regions}, series = {Nature Communications}, volume = {10}, journal = {Nature Communications}, number = {2421}, doi = {10.1038/s41467-019-10432-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227486}, pages = {1-15}, year = {2019}, abstract = {Translation efficiency can be affected by mRNA stability and secondary structures, including G-quadruplex structures (G4s). The highly conserved DEAH-box helicase DHX36/RHAU resolves G4s on DNA and RNA in vitro, however a systems-wide analysis of DHX36 targets and function is lacking. We map globally DHX36 binding to RNA in human cell lines and find it preferentially interacting with G-rich and G4-forming sequences on more than 4500 mRNAs. While DHX36 knockout (KO) results in a significant increase in target mRNA abundance, ribosome occupancy and protein output from these targets decrease, suggesting that they were rendered translationally incompetent. Considering that DHX36 targets, harboring G4s, preferentially localize in stress granules, and that DHX36 KO results in increased SG formation and protein kinase R (PKR/EIF2AK2) phosphorylation, we speculate that DHX36 is involved in resolution of rG4 induced cellular stress.}, language = {en} } @article{WagnerKunzChowdhuryetal.2019, author = {Wagner, Fabienne and Kunz, Tobias C. and Chowdhury, Suvagata R. and Thiede, Bernd and Fraunholz, Martin and Eger, Debora and Kozjak-Pavlovic, Vera}, title = {Armadillo repeat-containing protein 1 is a dual localization protein associated with mitochondrial intermembrane space bridging complex}, series = {PLoS ONE}, volume = {14}, journal = {PLoS ONE}, number = {10}, doi = {10.1371/journal.pone.0218303}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202670}, pages = {e0218303}, year = {2019}, abstract = {Cristae architecture is important for the function of mitochondria, the organelles that play the central role in many cellular processes. The mitochondrial contact site and cristae organizing system (MICOS) together with the sorting and assembly machinery (SAM) forms the mitochondrial intermembrane space bridging complex (MIB), a large protein complex present in mammalian mitochondria that partakes in the formation and maintenance of cristae. We report here a new subunit of the mammalian MICOS/MIB complex, an armadillo repeat-containing protein 1 (ArmC1). ArmC1 localizes both to cytosol and mitochondria, where it associates with the outer mitochondrial membrane through its carboxy-terminus. ArmC1 interacts with other constituents of the MICOS/MIB complex and its amounts are reduced upon MICOS/MIB complex depletion. Mitochondria lacking ArmC1 do not show defects in cristae structure, respiration or protein content, but appear fragmented and with reduced motility. ArmC1 represents therefore a peripheral MICOS/MIB component that appears to play a role in mitochondrial distribution in the cell.}, language = {en} } @article{KehrbergerHolzschuh2019, author = {Kehrberger, Sandra and Holzschuh, Andrea}, title = {Warmer temperatures advance flowering in a spring plant more strongly than emergence of two solitary spring bee species}, series = {PLoS ONE}, volume = {14}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0218824}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201165}, pages = {e0218824}, year = {2019}, abstract = {Climate warming has the potential to disrupt plant-pollinator interactions or to increase competition of co-flowering plants for pollinators, due to species-specific phenological responses to temperature. However, studies focusing on the effect of temperature on solitary bee emergence and the flowering onset of their food plants under natural conditions are still rare. We studied the effect of temperature on the phenology of the two spring bees Osmia cornuta and Osmia bicornis, by placing bee cocoons on eleven grasslands differing in mean site temperature. On seven grasslands, we additionally studied the effect of temperature on the phenology of the red-list plant Pulsatilla vulgaris, which was the first flowering plant, and of co-flowering plants with later flowering. With a warming of 0.1°C, the abundance-weighted mean emergence of O. cornuta males advanced by 0.4 days. Females of both species did not shift their emergence. Warmer temperatures advanced the abundance-weighted mean flowering of P. vulgaris by 1.3 days per 0.1°C increase, but did not shift flowering onset of co-flowering plants. Competition for pollinators between P. vulgaris and co-flowering plants does not increase within the studied temperature range. We demonstrate that temperature advances plant flowering more strongly than bee emergence suggesting an increased risk of pollinator limitation for the first flowers of P. vulgaris.}, language = {en} } @article{AkhoonGuptaTiwarietal.2019, author = {Akhoon, Bashir A. and Gupta, Shishir K. and Tiwari, Sudeep and Rathor, Laxmi and Pant, Aakanksha and Singh, Nivedita and Gupta, Shailendra K. and Dandekar, Thomas and Pandey, Rakesh}, title = {C. elegans protein interaction network analysis probes RNAi validated pro-longevity effect of nhr-6, a human homolog of tumor suppressor Nr4a1}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-51649-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202666}, pages = {15711}, year = {2019}, abstract = {Protein-protein interaction (PPI) studies are gaining momentum these days due to the plethora of various high-throughput experimental methods available for detecting PPIs. Proteins create complexes and networks by functioning in harmony with other proteins and here in silico network biology hold the promise to reveal new functionality of genes as it is very difficult and laborious to carry out experimental high-throughput genetic screens in living organisms. We demonstrate this approach by computationally screening C. elegans conserved homologs of already reported human tumor suppressor and aging associated genes. We select by this nhr-6, vab-3 and gst-23 as predicted longevity genes for RNAi screen. The RNAi results demonstrated the pro-longevity effect of these genes. Nuclear hormone receptor nhr-6 RNAi inhibition resulted in a C. elegans phenotype of 23.46\% lifespan reduction. Moreover, we show that nhr-6 regulates oxidative stress resistance in worms and does not affect the feeding behavior of worms. These findings imply the potential of nhr-6 as a common therapeutic target for aging and cancer ailments, stressing the power of in silico PPI network analysis coupled with RNAi screens to describe gene function.}, language = {en} } @article{ReuterJaeckelsKneitzetal.2019, author = {Reuter, Isabel and J{\"a}ckels, Jana and Kneitz, Susanne and Kuper, Jochen and Lesch, Klaus-Peter and Lillesaar, Christina}, title = {Fgf3 is crucial for the generation of monoaminergic cerebrospinal fluid contacting cells in zebrafish}, series = {Biology Open}, volume = {8}, journal = {Biology Open}, doi = {10.1242/bio.040683}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200749}, pages = {bio040683}, year = {2019}, abstract = {In most vertebrates, including zebrafish, the hypothalamic serotonergic cerebrospinal fluid-contacting (CSF-c) cells constitute a prominent population. In contrast to the hindbrain serotonergic neurons, little is known about the development and function of these cells. Here, we identify fibroblast growth factor (Fgf)3 as the main Fgf ligand controlling the ontogeny of serotonergic CSF-c cells. We show that fgf3 positively regulates the number of serotonergic CSF-c cells, as well as a subset of dopaminergic and neuroendocrine cells in the posterior hypothalamus via control of proliferation and cell survival. Further, expression of the ETS-domain transcription factor etv5b is downregulated after fgf3 impairment. Previous findings identified etv5b as critical for the proliferation of serotonergic progenitors in the hypothalamus, and therefore we now suggest that Fgf3 acts via etv5b during early development to ultimately control the number of mature serotonergic CSF-c cells. Moreover, our analysis of the developing hypothalamic transcriptome shows that the expression of fgf3 is upregulated upon fgf3 loss-of-function, suggesting activation of a self-compensatory mechanism. Together, these results highlight Fgf3 in a novel context as part of a signalling pathway of critical importance for hypothalamic development.}, language = {en} } @article{KunzGoetzSaueretal.2019, author = {Kunz, Tobias C. and G{\"o}tz, Ralph and Sauer, Markus and Rudel, Thomas}, title = {Detection of chlamydia developmental forms and secreted effectors by expansion microscopy}, series = {Frontiers in Cellular and Infection Microbiology}, volume = {9}, journal = {Frontiers in Cellular and Infection Microbiology}, number = {276}, issn = {2235-2988}, doi = {10.3389/fcimb.2019.00276}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195716}, year = {2019}, abstract = {Expansion microscopy (ExM) is a novel tool to improve the resolution of fluorescence-based microscopy that has not yet been used to visualize intracellular pathogens. Here we show the expansion of the intracellular pathogen Chlamydia trachomatis, enabling to differentiate its two distinct forms, catabolic active reticulate bodies (RB) and infectious elementary bodies (EB), on a conventional confocal microscope. We show that ExM enables the possibility to precisely locate chlamydial effector proteins, such as CPAF or Cdu1, within and outside of the chlamydial inclusion. Thus, we claim that ExM offers the possibility to address a broad range of questions and may be useful for further research on various intracellular pathogens.}, language = {en} } @article{GoosDejungWehmanetal.2019, author = {Goos, Carina and Dejung, Mario and Wehman, Ann M. and M-Natus, Elisabeth and Schmidt, Johannes and Sunter, Jack and Engstler, Markus and Butter, Falk and Kramer, Susanne}, title = {Trypanosomes can initiate nuclear export co-transcriptionally}, series = {Nucleic Acids Research}, volume = {47}, journal = {Nucleic Acids Research}, number = {1}, doi = {10.1093/nar/gky1136}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177709}, pages = {266-282}, year = {2019}, abstract = {The nuclear envelope serves as important messenger RNA (mRNA) surveillance system. In yeast and human, several control systems act in parallel to prevent nuclear export of unprocessed mRNAs. Trypanosomes lack homologues to most of the involved proteins and their nuclear mRNA metabolism is non-conventional exemplified by polycistronic transcription and mRNA processing by trans-splicing. We here visualized nuclear export in trypanosomes by intra- and intermolecular multi-colour single molecule FISH. We found that, in striking contrast to other eukaryotes, the initiation of nuclear export requires neither the completion of transcription nor splicing. Nevertheless, we show that unspliced mRNAs are mostly prevented from reaching the nucleus-distant cytoplasm and instead accumulate at the nuclear periphery in cytoplasmic nuclear periphery granules (NPGs). Further characterization of NPGs by electron microscopy and proteomics revealed that the granules are located at the cytoplasmic site of the nuclear pores and contain most cytoplasmic RNA-binding proteins but none of the major translation initiation factors, consistent with a function in preventing faulty mRNAs from reaching translation. Our data indicate that trypanosomes regulate the completion of nuclear export, rather than the initiation. Nuclear export control remains poorly understood, in any organism, and the described way of control may not be restricted to trypanosomes.}, language = {en} } @article{GebertSteffanDewenterMorettoetal.2019, author = {Gebert, Friederike and Steffan-Dewenter, Ingolf and Moretto, Philippe and Peters, Marcell K.}, title = {Climate rather than dung resources predict dung beetle abundance and diversity along elevational and land use gradients on Mt. Kilimanjaro}, series = {Journal of Biogeography}, volume = {47}, journal = {Journal of Biogeography}, number = {2}, doi = {10.1111/jbi.13710}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204701}, pages = {371 -- 381}, year = {2019}, abstract = {Aim: While elevational gradients in species richness constitute some of the best depicted patterns in ecology, there is a large uncertainty concerning the role of food resource availability for the establishment of diversity gradients in insects. Here, we analysed the importance of climate, area, land use and food resources for determining diversity gradients of dung beetles along extensive elevation and land use gradients on Mt. Kilimanjaro, Tanzania. Location: Mt. Kilimanjaro, Tanzania. Taxon: Scarabaeidae (Coleoptera). Methods: Dung beetles were recorded with baited pitfall traps at 66 study plots along a 3.6 km elevational gradient. In order to quantify food resources for the dung beetle community in form of mammal defecation rates, we assessed mammalian diversity and biomass with camera traps. Using a multi-model inference framework and path analysis, we tested the direct and indirect links between climate, area, land use and mammal defecation rates on the species richness and abundance of dung beetles. Results: We found that the species richness of dung beetles declined exponentially with increasing elevation. Human land use diminished the species richness of functional groups exhibiting complex behaviour but did not have a significant influence on total species richness. Path analysis suggested that climate, in particular temperature and to a lesser degree precipitation, were the most important predictors of dung beetle species richness while mammal defecation rate was not supported as a predictor variable. Main conclusions: Along broad climatic gradients, dung beetle diversity is mainly limited by climatic factors rather than by food resources. Our study points to a predominant role of temperature-driven processes for the maintenance and origination of species diversity of ectothermic organisms, which will consequently be subject to ongoing climatic changes.}, language = {en} } @article{RequierPailletLarocheetal.2019, author = {Requier, Fabrice and Paillet, Yoan and Laroche, Fabienne and Rutschmann, Benjamin and Zhang, Jie and Lombardi, Fabio and Svoboda, Miroslav and Steffan-Dewenter, Ingolf}, title = {Contribution of European forests to safeguard wild honeybee populations}, series = {Conservation Letters}, volume = {13}, journal = {Conservation Letters}, number = {2}, doi = {10.1111/conl.12693}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204407}, pages = {e12693}, year = {2019}, abstract = {Abstract Recent studies reveal the use of tree cavities by wild honeybee colonies in European forests. This highlights the conservation potential of forests for a highly threatened component of the native entomofauna in Europe, but currently no estimate of potential wild honeybee population sizes exists. Here, we analyzed the tree cavity densities of 106 forest areas across Europe and inferred an expected population size of wild honeybees. Both forest and management types affected the density of tree cavities. Accordingly, we estimated that more than 80,000 wild honeybee colonies could be sustained in European forests. As expected, potential conservation hotspots were identified in unmanaged forests, and, surprisingly, also in other large forest areas across Europe. Our results contribute to the EU policy strategy to halt pollinator declines and reveal the potential of forest areas for the conservation of so far neglected wild honeybee populations in Europe.}, language = {en} } @article{PattschullWalzGruendletal.2019, author = {Pattschull, Grit and Walz, Susanne and Gr{\"u}ndl, Marco and Schwab, Melissa and R{\"u}hl, Eva and Baluapuri, Apoorva and Cindric-Vranesic, Anita and Kneitz, Susanne and Wolf, Elmar and Ade, Carsten P. and Rosenwald, Andreas and von Eyss, Bj{\"o}rn and Gaubatz, Stefan}, title = {The Myb-MuvB complex is required for YAP-dependent transcription of mitotic genes}, series = {Cell Reports}, volume = {27}, journal = {Cell Reports}, number = {12}, doi = {10.1016/j.celrep.2019.05.071}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202039}, pages = {3533-3546}, year = {2019}, abstract = {YAP and TAZ, downstream effectors of the Hippo pathway, are important regulators of proliferation. Here, we show that the ability of YAP to activate mitotic gene expression is dependent on the Myb-MuvB (MMB) complex, a master regulator of genes expressed in the G2/M phase of the cell cycle. By carrying out genome-wide expression and binding analyses, we found that YAP promotes binding of the MMB subunit B-MYB to the promoters of mitotic target genes. YAP binds to B-MYB and stimulates B-MYB chromatin association through distal enhancer elements that interact with MMB-regulated promoters through chromatin looping. The cooperation between YAP and B-MYB is critical for YAP-mediated entry into mitosis. Furthermore, the expression of genes coactivated by YAP and B-MYB is associated with poor survival of cancer patients. Our findings provide a molecular mechanism by which YAP and MMB regulate mitotic gene expression and suggest a link between two cancer-relevant signaling pathways.}, language = {en} }