TY - GEN A1 - Riedelsberger, Janin A1 - Dreyer, Ingo A1 - Gonzalez, Wendy T1 - Outward rectification of voltage-gated K+ channels evolved at least twice in life history T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Voltage-gated potassium (K+) channels are present in all living systems. Despite high structural similarities in the transmembrane domains (TMD), this K+ channel type segregates into at least two main functional categories-hyperpolarization-activated, inward-rectifying (Kin) and depolarization-activated, outward-rectifying (Kout) channels. Voltage-gated K+ channels sense the membrane voltage via a voltage-sensing domain that is connected to the conduction pathway of the channel. It has been shown that the voltage-sensing mechanism is the same in Kin and Kout channels, but its performance results in opposite pore conformations. It is not known how the different coupling of voltage-sensor and pore is implemented. Here, we studied sequence and structural data of voltage-gated K+ channels from animals and plants with emphasis on the property of opposite rectification. We identified structural hotspots that alone allow already the distinction between Kin and Kout channels. Among them is a loop between TMD S5 and the pore that is very short in animal Kout, longer in plant and animal Kin and the longest in plant Kout channels. In combination with further structural and phylogenetic analyses this finding suggests that outward-rectification evolved twice and independently in the animal and plant kingdom. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 521 KW - multiple sequence alignment KW - potassium channel KW - Arabidopsis thaliana KW - inward rectification KW - pacemaker channels KW - S4-S5 linker KW - sensor KW - expression KW - mechanism KW - activation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-409594 SN - 1866-8372 IS - 521 ER - TY - JOUR A1 - Powali, Debarchan A1 - Sharma, Shubham A1 - Mandal, Riddhi A1 - Mitra, Supriyo T1 - A reappraisal of the 2005 Kashmir (M-w 7.6) earthquake and its aftershocks BT - seismotectonics of NW Himalaya JF - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth N2 - We study the source properties of the 2005 Kashmir earthquake and its aftershocks to unravel the seismotectonics of the NW Himalayan syntaxis. The mainshock and larger aftershocks have been simultaneously relocated using phase data. We use back-projection of high-frequency energy from multiple teleseismic arrays to model the spatio-temporal evolution of the mainshock rupture. Our analysis reveal a bilateral rupture, which initially propagated SE and then NW of the epicenter, with an average rupture velocity of similar to 2 km s(-1). The area of maximum energy release is parallel to and bound by the surface rupture. Incorporating rupture propagation and velocity, we model the mainshock as a line source using P- and SH-waveform inversion. Our result confirms that the mainshock occurred on a NE dipping (similar to 35 degrees) fault plane, with centroid depth of similar to 10 km. Integrated source time function show that majority of the energy was released in the first similar to 20 s, and was confined above the hypocenter. From waveform inverted fault dimension and seismic moment, we argue that the mainshock had an additional similar to 25 km blind rupture beyond the NW Himalayan syntaxis. Combining this with findings from previous studies, we conjecture that the blind rupture propagated NW of the syntaxis underneath a weak detachment overlain by infra-Cambrian salt layer, and terminated in a wedge thrust. All moderate-to-large aftershocks, NW of the mainshock rupture, are concentrated at the edge of the blind rupture termination. Source modeling of these aftershocks reveal thrust mechanism with centroid depths of 2-10 km, and fault planes oriented subparallel to the mainshock rupture. To study the influence of mainshock rupture on aftershock occurrence, we compute Coulomb failure stress on aftershock faults. All these aftershocks lie in the positive Coulomb stress change region. This suggest that the aftershocks have been triggered by either co-seismic or post-seismic slip on the mainshock fault. KW - Kashmir earthquake KW - Aftershocks KW - High frequency back-projection KW - Source KW - mechanism KW - Coulomb failure stress KW - Seismo-tectonics Y1 - 2020 U6 - https://doi.org/10.1016/j.tecto.2020.228501 SN - 0040-1951 SN - 1879-3266 VL - 789 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Meyer, Sebastian T. A1 - Ebeling, Anne A1 - Eisenhauer, Nico A1 - Hertzog, Lionel A1 - Hillebrand, Helmut A1 - Milcu, Alexandru A1 - Pompe, Sven A1 - Abbas, Maike A1 - Bessler, Holger A1 - Buchmann, Nina A1 - De Luca, Enrica A1 - Engels, Christof A1 - Fischer, Markus A1 - Gleixner, Gerd A1 - Hudewenz, Anika A1 - Klein, Alexandra-Maria A1 - de Kroon, Hans A1 - Leimer, Sophia A1 - Loranger, Hannah A1 - Mommer, Liesje A1 - Oelmann, Yvonne A1 - Ravenek, Janneke M. A1 - Roscher, Christiane A1 - Rottstock, Tanja A1 - Scherber, Christoph A1 - Scherer-Lorenzen, Michael A1 - Scheu, Stefan A1 - Schmid, Bernhard A1 - Schulze, Ernst-Detlef A1 - Staudler, Andrea A1 - Strecker, Tanja A1 - Temperton, Vicky A1 - Tscharntke, Teja A1 - Vogel, Anja A1 - Voigt, Winfried A1 - Weigelt, Alexandra A1 - Wilcke, Wolfgang A1 - Weisser, Wolfgang W. T1 - Effects of biodiversity strengthen over time as ecosystem functioning declines at low and increases at high biodiversity JF - Ecosphere : the magazine of the International Ecology University KW - biodiversity ecosystem functioning (BEF) KW - ecosystem processes KW - grassland KW - mechanism KW - plant productivity KW - plant species richness KW - temporal effects KW - trophic interactions Y1 - 2016 U6 - https://doi.org/10.1002/ecs2.1619 SN - 2150-8925 VL - 7 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Mai-Linde, Yasemin A1 - Linker, Torsten T1 - Radical clock probes to determine carbohydrate radical stabilities JF - Organic letters N2 - Carbohydrate radical stabilities in the 1- and 2-position have been determined by a radical clock approach, starting from cyclopropanated sugars with xanthates as precursors. Various hexoses and pentoses afforded 1-deoxy sugars as main products, indicating that anomeric radicals are more stable than radicals in the 2-position. An additional influence of the configurations on radical stabilities has been observed. Our results should be interesting for the understanding of 1,2-radical rearrangements in carbohydrate chemistry and offer an easy access to deoxy-vinyl sugars. KW - stereoselective-synthesis KW - convenient synthesis KW - chemistry KW - cyclopropanation KW - mechanism KW - glycals KW - beta-(acyloxy)alkylrear KW - rangement KW - sugars Y1 - 2020 U6 - https://doi.org/10.1021/acs.orglett.0c00111 SN - 1523-7060 SN - 1523-7052 VL - 22 IS - 4 SP - 1525 EP - 1529 PB - American Chemical Society CY - Washington ER - TY - GEN A1 - Hoffmann, Mathias A1 - Schulz-Hanke, Maximilian A1 - Alba, Juana Garcia A1 - Jurisch, Nicole A1 - Hagemann, Ulrike A1 - Sachs, Torsten A1 - Sommer, Michael A1 - Augustin, Jürgen T1 - A simple calculation algorithm to separate high-resolution CH4 flux measurements into ebullition- and diffusion-derived components T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - Processes driving the production, transformation and transport of methane (CH4) in wetland ecosystems are highly complex. We present a simple calculation algorithm to separate open-water CH4 fluxes measured with automatic chambers into diffusion- and ebullition-derived components. This helps to reveal underlying dynamics, to identify potential environmental drivers and, thus, to calculate reliable CH4 emission estimates. The flux separation is based on identification of ebullition-related sudden concentration changes during single measurements. Therefore, a variable ebullition filter is applied, using the lower and upper quartile and the interquartile range (IQR). Automation of data processing is achieved by using an established R script, adjusted for the purpose of CH4 flux calculation. The algorithm was validated by performing a laboratory experiment and tested using flux measurement data (July to September 2013) from a former fen grassland site, which converted into a shallow lake as a result of rewetting. Ebullition and diffusion contributed equally (46 and 55 %) to total CH4 emissions, which is comparable to ratios given in the literature. Moreover, the separation algorithm revealed a concealed shift in the diurnal trend of diffusive fluxes throughout the measurement period. The water temperature gradient was identified as one of the major drivers of diffusive CH4 emissions, whereas no significant driver was found in the case of erratic CH4 ebullition events. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 604 KW - water methane emissions KW - chamber system KW - CO2 KW - lake KW - fen KW - exchange KW - mechanism KW - turbulence KW - transport KW - reservior Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-416659 SN - 1866-8372 IS - 604 SP - 109 EP - 118 ER - TY - GEN A1 - Hess, Anne-Katrin A1 - Saffert, Paul A1 - Liebeton, Klaus A1 - Ignatova, Zoya T1 - Optimization of translation profiles enhances protein expression and solubility T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - mRNA is translated with a non-uniform speed that actively coordinates co-translational folding of protein domains. Using structure-based homology we identified the structural domains in epoxide hydrolases (EHs) and introduced slow-translating codons to delineate the translation of single domains. These changes in translation speed dramatically improved the solubility of two EHs of metagenomic origin in Escherichia coli. Conversely, the importance of transient attenuation for the folding, and consequently solubility, of EH was evidenced with a member of the EH family from Agrobacterium radiobacter, which partitions in the soluble fraction when expressed in E. coli. Synonymous substitutions of codons shaping the slow-transiting regions to fast-translating codons render this protein insoluble. Furthermore, we show that low protein yield can be enhanced by decreasing the free folding energy of the initial 5'-coding region, which can disrupt mRNA secondary structure and enhance ribosomal loading. This study provides direct experimental evidence that mRNA is not a mere messenger for translation of codons into amino acids but bears an additional layer of information for folding, solubility and expression level of the encoded protein. Furthermore, it provides a general frame on how to modulate and fine-tune gene expression of a target protein. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 518 KW - transfer-RNA genes KW - codon usage KW - Escherichia coli KW - Epoxide hydrolases KW - messenger-RNA KW - sequence KW - elongation KW - Ribosome KW - mechanism KW - Membrane Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-409574 SN - 1866-8372 IS - 518 ER -