TY - JOUR A1 - Shao, Yi-Ming A1 - Ma, Xiaohua A1 - Paira, Priyankar A1 - Tan, Aaron A1 - Herr, Deron Raymond A1 - Lim, Kah Leong A1 - Ng, Chee Hoe A1 - Venkatesan, Gopalakrishnan A1 - Klotz, Karl-Norbert A1 - Federico, Stephanie A1 - Spalluto, Giampiero A1 - Cheong, Siew Lee A1 - Chen, Yu Zong A1 - Pastorin, Giorgia T1 - Discovery of indolylpiperazinylpyrimidines with dual-target profiles at adenosine A2A and dopamine D2 receptors for Parkinson's disease treatment JF - PLoS ONE N2 - Parkinson’s disease (PD) is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in the substantia nigra of the human brain, leading to depletion of dopamine production. Dopamine replacement therapy remains the mainstay for attenuation of PD symptoms. Nonetheless, the potential benefit of current pharmacotherapies is mostly limited by adverse side effects, such as drug-induced dyskinesia, motor fluctuations and psychosis. Non-dopaminergic receptors, such as human A2A adenosine receptors, have emerged as important therapeutic targets in potentiating therapeutic effects and reducing the unwanted side effects. In this study, new chemical entities targeting both human A2A adenosine receptor and dopamine D2 receptor were designed and evaluated. Two computational methods, namely support vector machine (SVM) models and Tanimoto similarity-based clustering analysis, were integrated for the identification of compounds containing indole-piperazine-pyrimidine (IPP) scaffold. Subsequent synthesis and testing resulted in compounds 5 and 6, which acted as human A2A adenosine receptor binders in the radioligand competition assay (Ki = 8.7–11.2 μM) as well as human dopamine D2 receptor binders in the artificial cell membrane assay (EC50 = 22.5–40.2 μM). Moreover, compound 5 showed improvement in movement and mitigation of the loss of dopaminergic neurons in Drosophila models of PD. Furthermore, in vitro toxicity studies on compounds 5 and 6 did not reveal any mutagenicity (up to 100 μM), hepatotoxicity (up to 30 μM) or cardiotoxicity (up to 30 μM). Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-237766 VL - 13 ER - TY - JOUR A1 - del Olmo Toledo, Valentina A1 - Puccinelli, Robert A1 - Fordyce, Polly M. A1 - Pérez, J. Christian T1 - Diversification of DNA binding specificities enabled SREBP transcription regulators to expand the repertoire of cellular functions that they govern in fungi JF - PLoS Genetics N2 - The Sterol Regulatory Element Binding Proteins (SREBPs) are basic-helix-loop-helix transcription regulators that control the expression of sterol biosynthesis genes in higher eukaryotes and some fungi. Surprisingly, SREBPs do not regulate sterol biosynthesis in the ascomycete yeasts (Saccharomycotina) as this role was handed off to an unrelated transcription regulator in this clade. The SREBPs, nonetheless, expanded in fungi such as the ascomycete yeasts Candida spp., raising questions about their role and evolution in these organisms. Here we report that the fungal SREBPs diversified their DNA binding preferences concomitantly with an expansion in function. We establish that several branches of fungal SREBPs preferentially bind non-palindromic DNA sequences, in contrast to the palindromic DNA motifs recognized by most basic-helix-loop-helix proteins (including SREBPs) in higher eukaryotes. Reconstruction and biochemical characterization of the likely ancestor protein suggest that an intrinsic DNA binding promiscuity in the family was resolved by alternative mechanisms in different branches of fungal SREBPs. Furthermore, we show that two SREBPs in the human commensal yeast Candida albicans drive a transcriptional cascade that inhibits a morphological switch under anaerobic conditions. Preventing this morphological transition enhances C. albicans colonization of the mammalian intestine, the fungus’ natural niche. Thus, our results illustrate how diversification in DNA binding preferences enabled the functional expansion of a family of eukaryotic transcription regulators. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228983 VL - 14 ER - TY - JOUR A1 - Lu, Yuan A1 - Boswell, Mikki A1 - Boswell, William A1 - Kneitz, Susanne A1 - Klotz, Barbara A1 - Savage, Markita A1 - Salinas, Raquel A1 - Marks, Rebacca A1 - Regneri, Janine A1 - Postlethwait, John A1 - Warren, Wesley C. A1 - Schartl, Manfred A1 - Walter, Ronald T1 - Gene expression variation and parental allele inheritance in a Xiphophorus interspecies hybridization model JF - PLoS Genetics N2 - Understanding the genetic mechanisms underlying segregation of phenotypic variation through successive generations is important for understanding physiological changes and disease risk. Tracing the etiology of variation in gene expression enables identification of genetic interactions, and may uncover molecular mechanisms leading to the phenotypic expression of a trait, especially when utilizing model organisms that have well-defined genetic lineages. There are a plethora of studies that describe relationships between gene expression and genotype, however, the idea that global variations in gene expression are also controlled by genotype remains novel. Despite the identification of loci that control gene expression variation, the global understanding of how genome constitution affects trait variability is unknown. To study this question, we utilized Xiphophorus fish of different, but tractable genetic backgrounds (inbred, F1 interspecies hybrids, and backcross hybrid progeny), and measured each individual’s gene expression concurrent with the degrees of inter-individual expression variation. We found, (a) F1 interspecies hybrids exhibited less variability than inbred animals, indicting gene expression variation is not affected by the fraction of heterozygous loci within an individual genome, and (b), that mixing genotypes in backcross populations led to higher levels of gene expression variability, supporting the idea that expression variability is caused by heterogeneity of genotypes of cis or trans loci. In conclusion, heterogeneity of genotype, introduced by inheritance of different alleles, accounts for the largest effects on global phenotypical variability. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-237318 VL - 14 ER - TY - JOUR A1 - El Mouali, Youssef A1 - Gaviria-Cantin, Tania A1 - Sánchez-Romero, María Antonia A1 - Gibert, Marta A1 - Westermann, Alexander J. A1 - Vogel, Jörg A1 - Balsalobre, Carlos T1 - CRP-cAMP mediates silencing of Salmonella virulence at the post-transcriptional level JF - PLoS Genetics N2 - Invasion of epithelial cells by Salmonella enterica requires expression of genes located in the pathogenicity island I (SPI-1). The expression of SPI-1 genes is very tightly regulated and activated only under specific conditions. Most studies have focused on the regulatory pathways that induce SPI-1 expression. Here, we describe a new regulatory circuit involving CRP-cAMP, a widely established metabolic regulator, in silencing of SPI-1 genes under non-permissive conditions. In CRP-cAMP-deficient strains we detected a strong upregulation of SPI-1 genes in the mid-logarithmic growth phase. Genetic analyses revealed that CRP-cAMP modulates the level of HilD, the master regulator of Salmonella invasion. This regulation occurs at the post-transcriptional level and requires the presence of a newly identified regulatory motif within the hilD 3’UTR. We further demonstrate that in Salmonella the Hfq-dependent sRNA Spot 42 is under the transcriptional repression of CRP-cAMP and, when this transcriptional repression is relieved, Spot 42 exerts a positive effect on hilD expression. In vivo and in vitro assays indicate that Spot 42 targets, through its unstructured region III, the 3’UTR of the hilD transcript. Together, our results highlight the biological relevance of the hilD 3’UTR as a hub for post-transcriptional control of Salmonella invasion gene expression. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226614 VL - 14 ER - TY - JOUR A1 - Wheeler, Nicole E. A1 - Gardner, Paul P. A1 - Barquist, Lars T1 - Machine learning identifies signatures of host adaptation in the bacterial pathogen Salmonella enterica JF - PLoS Genetics N2 - Emerging pathogens are a major threat to public health, however understanding how pathogens adapt to new niches remains a challenge. New methods are urgently required to provide functional insights into pathogens from the massive genomic data sets now being generated from routine pathogen surveillance for epidemiological purposes. Here, we measure the burden of atypical mutations in protein coding genes across independently evolved Salmonella enterica lineages, and use these as input to train a random forest classifier to identify strains associated with extraintestinal disease. Members of the species fall along a continuum, from pathovars which cause gastrointestinal infection and low mortality, associated with a broad host-range, to those that cause invasive infection and high mortality, associated with a narrowed host range. Our random forest classifier learned to perfectly discriminate long-established gastrointestinal and invasive serovars of Salmonella. Additionally, it was able to discriminate recently emerged Salmonella Enteritidis and Typhimurium lineages associated with invasive disease in immunocompromised populations in sub-Saharan Africa, and within-host adaptation to invasive infection. We dissect the architecture of the model to identify the genes that were most informative of phenotype, revealing a common theme of degradation of metabolic pathways in extraintestinal lineages. This approach accurately identifies patterns of gene degradation and diversifying selection specific to invasive serovars that have been captured by more labour-intensive investigations, but can be readily scaled to larger analyses. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233662 VL - 14 ER - TY - JOUR A1 - Toepfer, Franziska A1 - Wolf, Reinhard A1 - Heisenberg, Martin T1 - Multi-stability with ambiguous visual stimuli in Drosophila orientation behavior JF - PLoS Biology N2 - It is widely accepted for humans and higher animals that vision is an active process in which the organism interprets the stimulus. To find out whether this also holds for lower animals, we designed an ambiguous motion stimulus, which serves as something like a multi-stable perception paradigm in Drosophila behavior. Confronted with a uniform panoramic texture in a closed-loop situation in stationary flight, the flies adjust their yaw torque to stabilize their virtual self-rotation. To make the visual input ambiguous, we added a second texture. Both textures got a rotatory bias to move into opposite directions at a constant relative angular velocity. The results indicate that the fly now had three possible frames of reference for self-rotation: either of the two motion components as well as the integrated motion vector of the two. In this ambiguous stimulus situation, the flies generated a continuous sequence of behaviors, each one adjusted to one or another of the three references. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228976 VL - 16 ER - TY - JOUR A1 - Banas, Bernhard A1 - Steubl, Dominik A1 - Renders, Lutz A1 - Chittka, Dominik A1 - Banas, Miriam C. A1 - Wekerle, Thomas A1 - Koch, Martina A1 - Witzke, Oliver A1 - Mühlfeld, Anja A1 - Sommerer, Claudia A1 - Habicht, Antje A1 - Hugo, Christian A1 - Hünig, Thomas A1 - Lindemann, Monika A1 - Schmidt, Traudel A1 - Rascle, Anne A1 - Barabas, Sascha A1 - Deml, Ludwig A1 - Wagner, Ralf A1 - Krämer, Bernhard K. A1 - Krüger, Bernd T1 - Clinical validation of a novel enzyme-linked immunosorbent spot assay-based in vitro diagnostic assay to monitor cytomegalovirus-specific cell-mediated immunity in kidney transplant recipients: a multicenter, longitudinal, prospective, observational study JF - Transplant International N2 - Impaired cytomegalovirus (CMV)-specific cell-mediated immunity (CMV-CMI) is a major cause of CMV reactivation and associated complications in solid-organ transplantation. Reliably assessing CMV-CMI is desirable to individually adjust antiviral and immunosuppressive therapy. This study aimed to evaluate the suitability of T-Track® CMV, a novel IFN-γ ELISpot assay based on the stimulation of peripheral blood mononuclear cells with pp65 and IE-I CMV proteins, to monitor CMV-CMI following kidney transplantation. A prospective longitudinal multicenter study was conducted in 86 intermediate-risk renal transplant recipients. CMV-CMI, CMV viral load, and clinical complications were monitored over 6 months post-transplantation. Ninety-five percent and 88–92% ELISpot assays were positive pre- and post-transplantation, respectively. CMV-specific response was reduced following immunosuppressive treatment and increased in patients with graft rejection, indicating the ability of the ELISpot assay to monitor patients' immunosuppressive state. Interestingly, median pp65-specific response was ninefold higher in patients with self-clearing viral load compared to antivirally treated patients prior to first viral load detection (P < 0.001), suggesting that reactivity to pp65 represents a potential immunocompetence marker. Altogether, T-Track® CMV is a highly sensitive IFN-γ ELISpot assay, suitable for the immunomonitoring of CMV-seropositive renal transplant recipients, and with a potential use for the risk assessment of CMV-related clinical complications (ClinicalTrials.gov Identifier: NCT02083042). KW - CMV-specific cell-mediated immunity KW - cytomegalovirus KW - IFN‐γ ELISpot KW - immunomonitoring KW - in vitro diagnostic KW - kidney or renal transplantation Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-221468 VL - 31 ER - TY - JOUR A1 - Graus, Dorothea A1 - Konrad, Kai R. A1 - Bemm, Felix A1 - Nebioglu, Meliha Görkem Patir A1 - Lorey, Christian A1 - Duscha, Kerstin A1 - Güthoff, Tilman A1 - Herrmann, Johannes A1 - Ferjani, Ali A1 - Cuin, Tracey Ann A1 - Roelfsema, M. Rob G. A1 - Schumacher, Karin A1 - Neuhaus, H. Ekkehard A1 - Marten, Irene A1 - Hedrich, Rainer T1 - High V-PPase activity is beneficial under high salt loads, but detrimental without salinity JF - New Phytologist N2 - The membrane-bound proton-pumping pyrophosphatase (V-PPase), together with the V-type H+-ATPase, generates the proton motive force that drives vacuolar membrane solute transport. Transgenic plants constitutively overexpressing V-PPases were shown to have improved salinity tolerance, but the relative impact of increasing PPi hydrolysis and proton-pumping functions has yet to be dissected. For a better understanding of the molecular processes underlying V-PPase-dependent salt tolerance, we transiently overexpressed the pyrophosphate-driven proton pump (NbVHP) in Nicotiana benthamiana leaves and studied its functional properties in relation to salt treatment by primarily using patch-clamp, impalement electrodes and pH imaging. NbVHP overexpression led to higher vacuolar proton currents and vacuolar acidification. After 3 d in salt-untreated conditions, V-PPase-overexpressing leaves showed a drop in photosynthetic capacity, plasma membrane depolarization and eventual leaf necrosis. Salt, however, rescued NbVHP-hyperactive cells from cell death. Furthermore, a salt-induced rise in V-PPase but not of V-ATPase pump currents was detected in nontransformed plants. The results indicate that under normal growth conditions, plants need to regulate the V-PPase pump activity to avoid hyperactivity and its negative feedback on cell viability. Nonetheless, V-PPase proton pump function becomes increasingly important under salt stress for generating the pH gradient necessary for vacuolar proton-coupled Na+ sequestration. KW - cell death KW - plasma membrane voltage KW - proton pump currents KW - salt KW - vacuolar pH KW - vacuolar proton-ATPase (V-ATPase) KW - vacuolar proton-pyrophosphatase (V-PPase) Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227553 VL - 219 ER - TY - JOUR A1 - Voss, Lena J. A1 - McAdam, Scott A. M. A1 - Knoblauch, Michael A1 - Rathje, Jan M. A1 - Brodribb, Tim A1 - Hedrich, Rainer A1 - Roelfsema, M. Rob G. T1 - Guard cells in fern stomata are connected by plasmodesmata, but control cytosolic Ca2+ levels autonomously JF - New Phytologist N2 - Recent studies have revealed that some responses of fern stomata to environmental signals differ from those of their relatives in seed plants. However, it is unknown whether the biophysical properties of guard cells differ fundamentally between species of both clades. Intracellular micro-electrodes and the fluorescent Ca2+ reporter FURA2 were used to study voltage-dependent cation channels and Ca2+ signals in guard cells of the ferns Polypodium vulgare and Asplenium scolopendrium. Voltage clamp experiments with fern guard cells revealed similar properties of voltage-dependent K+ channels as found in seed plants. However, fluorescent dyes moved within the fern stomata, from one guard cell to the other, which does not occur in most seed plants. Despite the presence of plasmodesmata, which interconnect fern guard cells, Ca2+ signals could be elicited in each of the cells individually. Based on the common properties of voltage-dependent channels in ferns and seed plants, it is likely that these key transport proteins are conserved in vascular plants. However, the symplastic connections between fern guard cells in mature stomata indicate that the biophysical mechanisms that control stomatal movements differ between ferns and seed plants. KW - calcium signals KW - ferns KW - guard cell KW - plasmodesmata KW - potassium channels KW - seed plants KW - stomata Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233247 VL - 219 ER - TY - JOUR A1 - Shih, Po-Yuan A1 - Chou, Shu-Jen A1 - Müller, Caroline A1 - Halkier, Barbara Ann A1 - Deeken, Rosalia A1 - Lai, Erh-Min T1 - Differential roles of glucosinolates and camalexin at different stages of Agrobacterium-mediated transformation JF - Molecular Plant Pathology N2 - Agrobacterium tumefaciens is the causal agent of crown gall disease in a wide range of plants via a unique interkingdom DNA transfer from bacterial cells into the plant genome. Agrobacterium tumefaciens is capable of transferring its T-DNA into different plant parts at different developmental stages for transient and stable transformation. However, the plant genes and mechanisms involved in these transformation processes are not well understood. We used Arabidopsis thaliana Col-0 seedlings to reveal the gene expression profiles at early time points during Agrobacterium infection. Common and differentially expressed genes were found in shoots and roots. A gene ontology analysis showed that the glucosinolate (GS) biosynthesis pathway was an enriched common response. Strikingly, several genes involved in indole glucosinolate (iGS) modification and the camalexin biosynthesis pathway were up-regulated, whereas genes in aliphatic glucosinolate (aGS) biosynthesis were generally down-regulated, on Agrobacterium infection. Thus, we evaluated the impacts of GSs and camalexin during different stages of Agrobacterium-mediated transformation combining Arabidopsis mutant studies, metabolite profiling and exogenous applications of various GS hydrolysis products or camalexin. The results suggest that the iGS hydrolysis pathway plays an inhibitory role on transformation efficiency in Arabidopsis seedlings at the early infection stage. Later in the Agrobacterium infection process, the accumulation of camalexin is a key factor inhibiting tumour development on Arabidopsis inflorescence stalks. In conclusion, this study reveals the differential roles of GSs and camalexin at different stages of Agrobacterium-mediated transformation and provides new insights into crown gall disease control and improvement of plant transformation. KW - Agrobacterium-mediated transformation KW - Agrobac-terium tumefaciens KW - camalexin KW - crown gall KW - glucosinolates KW - plant defence KW - transcriptome Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-237883 VL - 19 ER -