Fermi surface of the filled-skutterudite superconductor LaRu4P12: A clue to the origin of the metal-insulator transition in PrRu4P12

We report the de Haas-van Alphen (dHvA) effect and magnetoresistance in the filled-skutterudite superconductor LaRu4P12, which is a reference material of PrRu4P12 that exhibits a metal-insulator (M-I) transition at T_MI~60 K. The observed dHvA branches for the main Fermi surface (FS) are well explained by the band-structure calculation, using the full potential linearized augmented-plane-wave method with the local-density approximation, suggesting a nesting instability with q =(1,0,0) in the main multiply connected FS as expected also in PrRu4P12. Observed cyclotron effective masses of (2.6-11.8)m_0, which are roughly twice the calculated masses, indicate the large mass enhancement even in the La-skutterudites. Comparing the FS between LaRu4P12 and PrRu4P12, an essential role of c-f hybridization cooperating with the FS nesting in driving the the M-I transition in PrRu4P12 has been clarified.Comment: Appeared in Physical Review

The possible functions of duplicated ets (GGAA) motifs located near transcription start sites of various human genes

Transcription is one of the most fundamental nuclear functions and is an enzyme complex-mediated reaction that converts DNA sequences into mRNA. Analyzing DNA sequences of 5′-flanking regions of several human genes that respond to 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in HL-60 cells, we have identified that the ets (GGAA) motifs are duplicated, overlapped, or clustered within a 500-bp distance from the most 5′-upstream region of the cDNA. Multiple protein factors including Ets family proteins are known to recognize and bind to the GGAA containing sequences. In addition, it has been reported that the ets motifs play important roles in regulation of various promoters. Here, we propose a molecular mechanism, defined by the presence of duplication and multiplication of the GGAA motifs, that is responsible for the initiation of transcription of several genes and for the recruitment of binding proteins to the transcription start site (TSS) of TATA-less promoters

Evolutionary Instability of Symbiotic Function in Bradyrhizobium japonicum

Bacterial mutualists are often acquired from the environment by eukaryotic hosts. However, both theory and empirical work suggest that this bacterial lifestyle is evolutionarily unstable. Bacterial evolution outside of the host is predicted to favor traits that promote an independent lifestyle in the environment at a cost to symbiotic function. Consistent with these predictions, environmentally-acquired bacterial mutualists often lose symbiotic function over evolutionary time. Here, we investigate the evolutionary erosion of symbiotic traits in Bradyrhizobium japonicum, a nodulating root symbiont of legumes. Building on a previous published phylogeny we infer loss events of nodulation capability in a natural population of Bradyrhizobium, potentially driven by mutation or deletion of symbiosis loci. Subsequently, we experimentally evolved representative strains from the symbiont population under host-free in vitro conditions to examine potential drivers of these loss events. Among Bradyrhizobium genotypes that evolved significant increases in fitness in vitro, two exhibited reduced symbiotic quality, but no experimentally evolved strain lost nodulation capability or evolved any fixed changes at six sequenced loci. Our results are consistent with trade-offs between symbiotic quality and fitness in a host free environment. However, the drivers of loss-of-nodulation events in natural Bradyrhizobium populations remain unknown

The Transcription Factor YY1 Is a Substrate for Polo-Like Kinase 1 at the G2/M Transition of the Cell Cycle

Yin-Yang 1 (YY1) is an essential multifunctional zinc-finger protein. It has been shown over the past two decades to be a critical regulator of a vast array of biological processes, including development, cell proliferation and differentiation, DNA repair, and apoptosis. YY1 exerts its functions primarily as a transcription factor that can activate or repress gene expression, dependent on its spatial and temporal context. YY1 regulates a large number of genes involved in cell cycle transitions, many of which are oncogenes and tumor-suppressor genes. YY1 itself has been classified as an oncogene and was found to be upregulated in many cancer types. Unfortunately, our knowledge of what regulates YY1 is very minimal. Although YY1 has been shown to be a phosphoprotein, no kinase has ever been identified for the phosphorylation of YY1. Polo-like kinase 1 (Plk1) has emerged in the past few years as a major cell cycle regulator, particularly for cell division. Plk1 has been shown to play important roles in the G/M transition into mitosis and for the proper execution of cytokinesis, processes that YY1 has been shown to regulate also. Here, we present evidence that Plk1 directly phosphorylates YY1 in vitro and in vivo at threonine 39 in the activation domain. We show that this phosphorylation is cell cycle regulated and peaks at G2/M. This is the first report identifying a kinase for which YY1 is a substrate

High-Content, High-Throughput Analysis of Cell Cycle Perturbations Induced by the HSP90 Inhibitor XL888

BACKGROUND: Many proteins that are dysregulated or mutated in cancer cells rely on the molecular chaperone HSP90 for their proper folding and activity, which has led to considerable interest in HSP90 as a cancer drug target. The diverse array of HSP90 client proteins encompasses oncogenic drivers, cell cycle components, and a variety of regulatory factors, so inhibition of HSP90 perturbs multiple cellular processes, including mitogenic signaling and cell cycle control. Although many reports have investigated HSP90 inhibition in the context of the cell cycle, no large-scale studies have examined potential correlations between cell genotype and the cell cycle phenotypes of HSP90 inhibition. METHODOLOGY/PRINCIPAL FINDINGS: To address this question, we developed a novel high-content, high-throughput cell cycle assay and profiled the effects of two distinct small molecule HSP90 inhibitors (XL888 and 17-AAG [17-allylamino-17-demethoxygeldanamycin]) in a large, genetically diverse panel of cancer cell lines. The cell cycle phenotypes of both inhibitors were strikingly similar and fell into three classes: accumulation in M-phase, G2-phase, or G1-phase. Accumulation in M-phase was the most prominent phenotype and notably, was also correlated with TP53 mutant status. We additionally observed unexpected complexity in the response of the cell cycle-associated client PLK1 to HSP90 inhibition, and we suggest that inhibitor-induced PLK1 depletion may contribute to the striking metaphase arrest phenotype seen in many of the M-arrested cell lines. CONCLUSIONS/SIGNIFICANCE: Our analysis of the cell cycle phenotypes induced by HSP90 inhibition in 25 cancer cell lines revealed that the phenotypic response was highly dependent on cellular genotype as well as on the concentration of HSP90 inhibitor and the time of treatment. M-phase arrest correlated with the presence of TP53 mutations, while G2 or G1 arrest was more commonly seen in cells bearing wt TP53. We draw upon previous literature to suggest an integrated model that accounts for these varying observations

New carboalkoxybis(triphenylphosphine)palladium(II) cationic complexes: Synthesis, characterization, reactivity and role in the catalytic hydrocarboalkoxylation of ethene. X-ray structure of trans-[Pd(COOMe)(TsO)(PPh3)2]·2CHCl3

The cationic complexes trans-[Pd(COOR)(H2O)(PPh3)2](TsO) have been synthesised by reacting cis-[Pd(H2O)2(PPh3)2](TsO)2·2H2O with CO in ROH (R = Me and Et), practically under room conditions, or by methathetical exchange of trans-[Pd(COOMe)Cl(PPh3)2] with Ag(TsO) (R = n-Pr, iso-Pr, n-Bu, iso-Bu, sec-Bu). They have been characterised by IR, 1H NMR and 31P NMR spectroscopies. The X-ray investigation of trans-[Pd(COOMe)(TsO)(PPh3)2] reveals that the palladium center is surrounded in a virtually square planar environment realized by two PPh3 trans to each other, the carbon atom of the carbomethoxy ligand and an oxygen atom of the p-toluensulfonate anion, with two crystallization molecules of CHCl3. The Pd–O–S angle, 151.9 (3)°, is very wide, probably due to the interaction of one CHCl3 molecule with the complex inner core. The carbomethoxy derivatives react with R′OH yielding the corresponding R′ carboalkoxy derivative (R′ = Et, n-Pr and iso-Pr); ethene does not insert into the Pd–COOMe bond; decarbomethoxylation occurs when treated with TsOH/H2O in MeOH at 50 °C. All the carboalkoxy are precursors for the catalytic carboalkoxylation of ethene if used in combination of PPh3 and TsOH, better in the presence of some water. Experimental evidences are more in favor of the so-called “hydride” mechanism rather than the “carbomethoxy” mechanism

Virologie / Bakteriologie / Mykologie

141 - Effizienz von Kaliumhypochlorit zur Inaktivierung ausgewählter pilzlicher, bakterieller und viraler PflanzenkrankheitserregerEfficancy of Potassium Hypochlorite (KClO) to inactivate selected plant pathogenic fungi, bacteria and virusesMarlon-Hans Rodríguez, Martina Bandte, Gerhard Fischer, Carmen Büttner142 - Eignung von elektrolytisch generiertem Kaliumhypochlorit zur Inaktivierung von Pflanzenviren in rezirkulierender Nährlösungen im Gewächshausanbau von TomatenAbility of electrolysed produced Potassium Hypochlorite (KClO) to inactivate plant viruses in recirculating nutrient solutions in greenhouse production of tomatosJanine Paulke, Martina Bandte, Carmen Büttner143 - Ultrafiltration und Ultrazentrifugation zur Konzentrierung von Pflanzenviren in NährlösungUltrafiltration and ultracentrifugation as tools to concentrate plant viruses in nutrient solutionJanina Vincenz, Martina Bandte, Carmen Büttner144 - Reinigung doppelsträngiger RNA in Verbindung mit Hochdurchsatzsequenzierung als Werkzeug zum Nachweis von RNA Viren in PflanzenThe combination of double-stranded RNA isolation and deep sequencing as an unspecific diagnostic tool to assess the presence of RNA viruses in plantsTill Lesker, Paul Rentz, Edgar Maiss145 - Impact of silica supplementation on virus infected cucumber culturesRolle der Kieselsäureapplikation Virus infizierter GurkenkulturenSabine Holz, Grzegorz Bartoszewski , Michael Kube, Carmen Büttner146 - Untersuchungen zum Auftreten des Arabis mosaic virus in Birken aus Rovaniemi (Finnland) mit Virus-spezifischen SymptomenInvestigations on the occurence of Arabis mosaic virus in birches from Rovaniemi (Finland) with virus-specific symptomsRichard Pauwels, Markus Rott, Susanne von Bargen, Carmen Büttner147 - Cherry leaf roll virus in Betula spp. in Finland: what do we know about its population diversity?Cherry leaf roll virus in Birken-Arten in Finnland: Was wissen wir über die Populationsdiversität?A. Rumbou, S. von Bargen, M. Rott, R. Jalkanen, C. Büttner148 - Viruserkrankungen im WeinbauViroses in viticultureHenriette Gruber, Patricia Bohnert, Christiane Rieger149 - Molecular analysis of Tobacco rattle virus isolates from potatoes in various parts of GermanyKerstin Lindner, Renate Koenig150 - Detektion und Diversität des European mountain ash ringspot-associated virus (EMARaV) in Ebereschen (Sorbus aucuparia L.) in NorwegenDetection and variability of European mountain ash ringspot-associated virus (EMARaV) in Sorbus aucuparia L. in NorwayTheresa Büttner, Jenny Robel, Hans-Peter Mühlbach, Susanne von Bargen, Carmen Büttner151 - Charakterisierung des European mountain ash ringspot-associated virus (EMARaV) in Mehlbeerenarten (Sorbus spp.)Characterization of the European mountain ash ringspot-associated virus (EMARaV) in whitebeam species (Sorbus spp.)Luisa Dieckmann, Jenny Robel, Susanne von Bargen, Carmen Büttner152 - Vollständige Genomsequenz eines Carrot virus S Isolates aus Meerfenchel aus SpanienW. Menzel, P. Menzel, S. Winter153 - Nachweis und vollständige Sequenzierung eines Carla- und eines Potex-virus aus Epiphyullum spec.Detection and complete sequence of a Carla- and Potexvirus in Epiphyllum spec.Edgar Maiss, Paul Rentz, Annette Hohe, Rosa Herbst154 - Analysis of mixed populations of latent viruses of apple and rubbery wood disease of apple using new generation sequencingAnalyse von Mischpopulationen latenter Apfelviren und der Gummiholzkrankheit an Apfel mittels HochdurchsatzsequenzierungVladimir Jakovljevic, Patricia Otten, Jonathon Blake, Wilhelm Jelkmann155 - Experiments on transmission of viroids under glass and longevity of viroid RNA in detached leaves under different storage conditionsThi Thu Vo, Heinz-Wilhelm Dehne, Stephan Winter, Joachim Hamacher156 - Phytoplasmen in Schleswig-HolsteinPhytoplasmas in the state of Schleswig-HolsteinG. Henkel, C. Willmer, M. Wunderlich, B. Golecki157 . Phytoplasmen verändern das Dufststoffbouquet ihres pflanzlichen LebensraumsPlant volatile emission is affected by phytoplasma infectionMargit Rid, Kai Lukat, Svenja Hoferer, Jürgen Gross159 - Ist das Wurzelbild ein Sortierungsmerkmal für durch Candidatus Phytoplasma pyri verursachten Birnenverfall?Is the root file a sorting feature for Pear decline caused by Canditatus Phytoplama pyri?Georg Henkel, Claudia Willmer, Bernd Kaland, Bettina Golecki160 - Die Bedeutung von β-Caryophyllen als Lockstoff für die Apfeltriebsucht übertragende Blattsaugerart Cacopsylla pictaThe impact of β-caryophyllene as attractant for the Apple Proliferation transmitting insect Cacopsylla pictaConstanze Mesca, Svenja Hoferer, Jürgen Gross161 - Echte Mehltauarten an Beet- und BalkonpflanzenSpecies of powdery mildews on bedding plantsUlrike Brielmaier-Liebetanz162 - Echter Mehltau an Petersilie – Untersuchungen zum WirtspflanzenspektrumPowdery Mildew of Parsley – studies on the host rangePeggy Marx, Ute Gärber163 - Falscher Mehltau an Petersilie – Untersuchungen zum Wirtspflanzenspektrum und molekularbiologische CharakterisierungDowny mildew of parsley – studies on the host range and molecular characterizationGabriele Leinhos, Hermann-Josef Krauthausen, Frank Brändle164 - Welkekrankheit an Euonymus japonicaWilt disease on Euonymus japonicaUlrike Brielmaier-Liebetanz, Roswitha Ulrich, Stefan Wagner, Sabine Werres165 - Taxonomische Analyse der mikrobiellen Gemeinschaft von Zuckerrüben unter unterschiedlichen Lagerbedingungen mittels Hochdurchsatz-Amplikonsequenzierung von unterschiedlichen MarkergenenTaxonomic analysis of the microbial community in stored sugar beets using highthroughput sequencing of different marker genesSebastian Liebe, Daniel Wibberg, Anika Winkler, Alfred Pühler, Andreas Schlüter, Mark Varrelmann166 - Molecular characterization of a novel mycovirus found in Rhizoctonia solani AG 2-2IIIBMolekulare Charakterisierung eines neuen Mycovirus aus Rhizoctonia solani AG 2-2 IIIBAnika Bartholomäus, Mark Varrelman

Biallelic C1QBP Mutations Cause Severe Neonatal-, Childhood-, or Later-Onset Cardiomyopathy Associated with Combined Respiratory-Chain Deficiencies

Complement component 1 Q subcomponent-binding protein (C1QBP; also known as p32) is a multi-compartmental protein whose precise function remains unknown. It is an evolutionary conserved multifunctional protein localized primarily in the mitochondrial matrix and has roles in inflammation and infection processes, mitochondrial ribosome biogenesis, and regulation of apoptosis and nuclear transcription. It has an N-terminal mitochondrial targeting peptide that is proteolytically processed after import into the mitochondrial matrix, where it forms a homotrimeric complex organized in a doughnut-shaped structure. Although C1QBP has been reported to exert pleiotropic effects on many cellular processes, we report here four individuals from unrelated families where biallelic mutations in C1QBP cause a defect in mitochondrial energy metabolism. Infants presented with cardiomyopathy accompanied by multisystemic involvement (liver, kidney, and brain), and children and adults presented with myopathy and progressive external ophthalmoplegia. Multiple mitochondrial respiratory-chain defects, associated with the accumulation of multiple deletions of mitochondrial DNA in the later-onset myopathic cases, were identified in all affected individuals. Steady-state C1QBP levels were decreased in all individuals’ samples, leading to combined respiratory-chain enzyme deficiency of complexes I, III, and IV. C1qbp−/− mouse embryonic fibroblasts (MEFs) resembled the human disease phenotype by showing multiple defects in oxidative phosphorylation (OXPHOS). Complementation with wild-type, but not mutagenized, C1qbp restored OXPHOS protein levels and mitochondrial enzyme activities in C1qbp−/− MEFs. C1QBP deficiency represents an important mitochondrial disorder associated with a clinical spectrum ranging from infantile lactic acidosis to childhood (cardio)myopathy and late-onset progressive external ophthalmoplegia