45 research outputs found

    Calcium regulation of the human mitochondrial ATP-Mg/Pi carrier SLC25A24 uses a locking pin mechanism

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    Mitochondrial ATP-Mg/Pi carriers import adenine nucleotides into the mitochondrial matrix and export phosphate to the cytosol. They are calcium-regulated to control the size of the matrix adenine nucleotide pool in response to cellular energetic demands. They consist of three domains: an N-terminal regulatory domain containing four calcium-binding EF-hands, a linker loop domain with an amphipathic α-helix and a C-terminal mitochondrial carrier domain for the transport of substrates. Here, we use thermostability assays to demonstrate that the carrier is regulated by calcium via a locking pin mechanism involving the amphipathic α-helix. When calcium levels in the intermembrane space are high, the N-terminus of the amphipathic α-helix is bound to a cleft in the regulatory domain, leading to substrate transport by the carrier domain. When calcium levels drop, the cleft closes, and the amphipathic α-helix is released to bind to the carrier domain via its C-terminus, locking the carrier in an inhibited state

    A broad distribution of the alternative oxidase in microsporidian parasites

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    Microsporidia are a group of obligate intracellular parasitic eukaryotes that were considered to be amitochondriate until the recent discovery of highly reduced mitochondrial organelles called mitosomes. Analysis of the complete genome of Encephalitozoon cuniculi revealed a highly reduced set of proteins in the organelle, mostly related to the assembly of ironsulphur clusters. Oxidative phosphorylation and the Krebs cycle proteins were absent, in keeping with the notion that the microsporidia and their mitosomes are anaerobic, as is the case for other mitosome bearing eukaryotes, such as Giardia. Here we provide evidence opening the possibility that mitosomes in a number of microsporidian lineages are not completely anaerobic. Specifically, we have identified and characterized a gene encoding the alternative oxidase (AOX), a typically mitochondrial terminal oxidase in eukaryotes, in the genomes of several distantly related microsporidian species, even though this gene is absent from the complete genome of E. cuniculi. In order to confirm that these genes encode functional proteins, AOX genes from both A. locustae and T. hominis were over-expressed in E. coli and AOX activity measured spectrophotometrically using ubiquinol-1 (UQ-1) as substrate. Both A. locustae and T. hominis AOX proteins reduced UQ-1 in a cyanide and antimycin-resistant manner that was sensitive to ascofuranone, a potent inhibitor of the trypanosomal AOX. The physiological role of AOX microsporidia may be to reoxidise reducing equivalents produced by glycolysis, in a manner comparable to that observed in trypanosome

    Conservation genetics of the annual hemiparasitic plant Melampyrum sylvaticum (Orobanchaceae) in the UK and Scandinavia

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    Melampyrum sylvaticum is an endangered annual hemiparasitic plant that is found in only 19 small and isolated populations in the United Kingdom (UK). To evaluate the genetic consequences of this patchy distribution we compared levels of diversity, inbreeding and differentiation from ten populations from the UK with eight relatively large populations from Sweden and Norway where the species is more continuously distributed. We demonstrate that in both the UK and Scandinavia, the species is highly inbreeding (global F IS = 0.899). Levels of population differentiation were high (F’ST = 0.892) and significantly higher amongst UK populations (F’ST = 0.949) than Scandinavian populations (F’ST = 0.762; P < 0.01). The isolated populations in the UK have, on average, lower genetic diversity (allelic richness, proportion of loci that are polymorphic, gene diversity) than Scandinavian populations, and this diversity difference is associated with the smaller census size and population area of UK populations. From a conservation perspective, the naturally inbreeding nature of the species may buffer the species against immediate effects of inbreeding depression, but the markedly lower levels of genetic diversity in UK populations may represent a genetic constraint to evolutionary change. In addition, the high levels of population differentiation suggest that gene flow among populations will not be effective at replenishing lost variation. We thus recommend supporting in situ conservation management with ex situ populations and human-mediated seed dispersal among selected populations in the UK

    Understanding acute ankle ligamentous sprain injury in sports

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    This paper summarizes the current understanding on acute ankle sprain injury, which is the most common acute sport trauma, accounting for about 14% of all sport-related injuries. Among, 80% are ligamentous sprains caused by explosive inversion or supination. The injury motion often happens at the subtalar joint and tears the anterior talofibular ligament (ATFL) which possesses the lowest ultimate load among the lateral ligaments at the ankle. For extrinsic risk factors to ankle sprain injury, prescribing orthosis decreases the risk while increased exercise intensity in soccer raises the risk. For intrinsic factors, a foot size with increased width, an increased ankle eversion to inversion strength, plantarflexion strength and ratio between dorsiflexion and plantarflexion strength, and limb dominance could increase the ankle sprain injury risk. Players with a previous sprain history, players wearing shoes with air cells, players who do not stretch before exercising, players with inferior single leg balance, and overweight players are 4.9, 4.3, 2.6, 2.4 and 3.9 times more likely to sustain an ankle sprain injury. The aetiology of most ankle sprain injuries is incorrect foot positioning at landing – a medially-deviated vertical ground reaction force causes an explosive supination or inversion moment at the subtalar joint in a short time (about 50 ms). Another aetiology is the delayed reaction time of the peroneal muscles at the lateral aspect of the ankle (60–90 ms). The failure supination or inversion torque is about 41–45 Nm to cause ligamentous rupture in simulated spraining tests on cadaver. A previous case report revealed that the ankle joint reached 48 degrees inversion and 10 degrees internal rotation during an accidental grade I ankle ligamentous sprain injury during a dynamic cutting trial in laboratory. Diagnosis techniques and grading systems vary, but the management of ankle ligamentous sprain injury is mainly conservative. Immobilization should not be used as it results in joint stiffness, muscle atrophy and loss of proprioception. Traditional Chinese medicine such as herbs, massage and acupuncture were well applied in China in managing sports injuries, and was reported to be effective in relieving pain, reducing swelling and edema, and restoring normal ankle function. Finally, the best practice of sports medicine would be to prevent the injury. Different previous approaches, including designing prophylactice devices, introducing functional interventions, as well as change of games rules were highlighted. This paper allows the readers to catch up with the previous researches on ankle sprain injury, and facilitate the future research idea on sport-related ankle sprain injury

    Virologie / Bakteriologie / Mykologie

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    141 - Effizienz von Kaliumhypochlorit zur Inaktivierung ausgewĂ€hlter pilzlicher, bakterieller und viraler PflanzenkrankheitserregerEfficancy of Potassium Hypochlorite (KClO) to inactivate selected plant pathogenic fungi, bacteria and virusesMarlon-Hans RodrĂ­guez, Martina Bandte, Gerhard Fischer, Carmen BĂŒttner142 - Eignung von elektrolytisch generiertem Kaliumhypochlorit zur Inaktivierung von Pflanzenviren in rezirkulierender NĂ€hrlösungen im GewĂ€chshausanbau 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 BĂŒttner143 - Ultrafiltration und Ultrazentrifugation zur Konzentrierung von Pflanzenviren in NĂ€hrlösungUltrafiltration and ultracentrifugation as tools to concentrate plant viruses in nutrient solutionJanina Vincenz, Martina Bandte, Carmen BĂŒttner144 - Reinigung doppelstrĂ€ngiger 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 KieselsĂ€ureapplikation Virus infizierter GurkenkulturenSabine Holz, Grzegorz Bartoszewski , Michael Kube, Carmen BĂŒttner146 - 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 BĂŒttner147 - 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 ĂŒber die PopulationsdiversitĂ€t?A. Rumbou, S. von Bargen, M. Rott, R. Jalkanen, C. BĂŒttner148 - 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 DiversitĂ€t 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 BĂŒttner, Jenny Robel, Hans-Peter MĂŒhlbach, Susanne von Bargen, Carmen BĂŒttner151 - 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 BĂŒttner152 - VollstĂ€ndige Genomsequenz eines Carrot virus S Isolates aus Meerfenchel aus SpanienW. Menzel, P. Menzel, S. Winter153 - Nachweis und vollstĂ€ndige 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 verĂ€ndern das Dufststoffbouquet ihres pflanzlichen LebensraumsPlant volatile emission is affected by phytoplasma infectionMargit Rid, Kai Lukat, Svenja Hoferer, JĂŒrgen Gross159 - Ist das Wurzelbild ein Sortierungsmerkmal fĂŒr 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 ÎČ-Caryophyllen als Lockstoff fĂŒr die Apfeltriebsucht ĂŒbertragende Blattsaugerart Cacopsylla pictaThe impact of ÎČ-caryophyllene as attractant for the Apple Proliferation transmitting insect Cacopsylla pictaConstanze Mesca, Svenja Hoferer, JĂŒrgen 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 GĂ€rber163 - 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 BrĂ€ndle164 - Welkekrankheit an Euonymus japonicaWilt disease on Euonymus japonicaUlrike Brielmaier-Liebetanz, Roswitha Ulrich, Stefan Wagner, Sabine Werres165 - Taxonomische Analyse der mikrobiellen Gemeinschaft von ZuckerrĂŒben 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 PĂŒhler, Andreas SchlĂŒter, 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 BartholomĂ€us, Mark Varrelman

    Expression and Purification of Membrane Proteins in Saccharomyces cerevisiae.

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    Saccharomyces cerevisiae is one of the most popular expression systems for eukaryotic membrane proteins. Here, we describe protocols for the expression and purification of mitochondrial membrane proteins developed in our laboratory during the last 15 years. To optimize their expression in a functional form, different promoter systems as well as codon-optimization and complementation strategies were established. Purification approaches were developed which remove the membrane protein from the affinity column by specific proteolytic cleavage rather than by elution. This strategy has several important advantages, most notably improving the purity of the sample, as contaminants stay bound to the column, thus eliminating the need for a secondary purification step, such as size exclusion chromatography. This strategy also avoids dilution of the sample, which would occur as a consequence of elution, precluding the need for concentration steps, and thus preventing detergent concentration
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