Hydrophobically stabilized open state for the lateral gate of the Sec translocon

The Sec translocon is a central component of cellular pathways for protein translocation and membrane integration. Using both atomistic and coarse-grained molecular simulations, we investigate the conformational landscape of the translocon and explore the role of peptide substrates in the regulation of the translocation and integration pathways. Inclusion of a hydrophobic peptide substrate in the translocon stabilizes the opening of the lateral gate for membrane integration, whereas a hydrophilic peptide substrate favors the closed lateral gate conformation. The relative orientation of the plug moiety and a peptide substrate within the translocon channel is similarly dependent on whether the substrate is hydrophobic or hydrophilic in character, and the energetics of the translocon lateral gate opening in the presence of a peptide substrate is governed by the energetics of the peptide interface with the membrane. Implications of these results for the regulation of Sec-mediated pathways for protein translocation vs. membrane integration are discussed

Green transformations in Vietnam's energy sector

Vietnam has experienced rapid economic growth over the past few decades, as well as growing environmental pressures. The country is therefore pursuing strategies for green transformations, which are the processes of restructuring to bring economies and societies within the planetary boundaries. This article addresses the opportunities, barriers, and trade‐offs for green transformations in Vietnam's energy sector and examines them from an energy justice perspective. The article draws on in‐depths expert interviews with representatives from government agencies, private firms, academic institutions, and multilateral institutions in Vietnam. The article finds that Vietnam is undergoing efforts to move away from business as usual by promoting renewable energy and energy efficiency, as well as aligning energy and climate plans with national development priorities such as energy security and economic growth. Yet there is a need for more coordinated, integrated approaches and policies that span across the 3 areas that address green transformations in Vietnam: green growth, sustainable development, and climate change. Finally, although key actors seem to be aware and may be critical of major trade‐offs such as land grabs for energy projects, the impacts on affected people need to be better understood and mitigated

Monitoring of total copper contents in organically and conventionally managed soils. Part 4: – Total contents in German pomiculture soils

Die Auswirkungen dauerhafter Anwendung kupferhaltiger Fungizide auf die Nachhaltigkeit der Bodengüte sind im Rahmen der Europäischen Wirkstoffzulassung Gegenstand eines EU-weiten Programms zur Erfassung der Kupfer­gehalte im Boden geworden. 1613 Einzelproben wurden aus den Bodenhorizonten 0–5 und 5–20 cm von Baumobstlagen an 40 ökologisch und 12 konventionell bewirtschafteten Standorten unter den Aspekten einer möglichst repräsentativen Erfassung der Belastungsverteilung entnommen. Das Erhebungs­ergebnis soll als Grundlage für die Auswahl gebietstypischer Anbausituationen dienen, die in Verbindung mit einer spezifischen Expositionsermittlung die Erfassung der Wirkungsausprägung an empfindlichen Indikator­arten der jeweiligen Regenwurmzönosen ermöglicht. Auf der Basis von Gesamtgehalten wird die Belastungssituation und -verteilung auf Prüfflächen und Referenzflächen in deutschen Baumobstbaugebieten als Minimal-, Mittel- und Maximalwert sowie für verschiedene Perzentile dargestellt. Darüber hinaus werden aus der Bewirtschaftungshistorie resultierende Schwermetallein­träge quantifiziert und Belastungsunterschiede zwischen Obstbaumreihen und Fahrgassen diskutiert. Bei der Belastungserhebung konnte durch Verknüpfung von Daten zur Bewirtschaftungsgeschichte mit vorhandenen Flächenbelastungen in Verbindung mit beispielhaft für das Anbaugebiet Niederelbe ermittelten Kupferaufwandmengen im Zeitraum 1960 bis 2010 nachgewiesen werden, dass diese Belastungen aus den Jahren 1960 bis etwa 1995 resultieren, wo noch zwischen 10 und 13 kg Reinkupfer pro Jahr und Hektar zur Schaderregerbekämpfung im Baumobstbau angewandt wurden. Welche Anteile von diesen ‚gealterten’ Kupfergesamtgehalten bioverfügbar sind und damit auf die Bodenzönose wirken, wird derzeit untersucht. Anhand der in der Vorbeprobung erhobenen Daten zur Belastungssituation, Standortbeschreibung und Bewirtschaftungsdauer werden 2 bis 3 Baumobstlagen vorgeschlagen, die sich für eine biologische Statuserhebung zu Auswirkungen auf die Regenwurmzönose eignen.    Implications of long-term usage of copper fungicides on sustainable soil quality have been described for a long time, and according to the regulation of active substances, are objective of a survey on copper contents in agricultural soils in several EU member countries. 1613 single samples from the soil horizon 0–5 and 5–20 cm were taken from 40 organically and 12 conventionally managed pomiculture sites trying to make reference to all aspects relevant for a representative assessment of copper loads. The result of that survey is intended to enable the selection of site-typical types of cultivation being the prerequisite of an assessment of effects to the earthworm coenosis in combination with a refined exposure analysis. On the basis of total contents, the copper load and their distribution on test and reference fields of German pomiculture cultivation sites is presented including the minimum, maximum and mean value as well as percentiles. Additionally, the heavy metal content in general was determined and differences in copper contents between tree row and driving lines were identified. Comparing managing history and current management, it is obvious that load peaks result from copper applications between 1960 to 1995, when between 10 to 13 kg copper per ha and year were applied to control plant diseases. The evaluation of bio available copper, resulting from aged total copper contents, is not yet completely finished. By means of data, generated in preliminary samplings concerning load situation, site description and duration of management, 2–3 pomiculture sites are suggested being appropriate to assess the recent situation of soil quality in terms of responses on a population level.   &nbsp

In search of the authentic nation: landscape and national identity in Canada and Switzerland

While the study of nationalism and national identity has flourished in the last decade, little attention has been devoted to the conditions under which natural environments acquire significance in definitions of nationhood. This article examines the identity-forming role of landscape depictions in two polyethnic nation-states: Canada and Switzerland. Two types of geographical national identity are identified. The first – what we call the ‘nationalisation of nature’– portrays zarticular landscapes as expressions of national authenticity. The second pattern – what we refer to as the ‘naturalisation of the nation’– rests upon a notion of geographical determinism that depicts specific landscapes as forces capable of determining national identity. The authors offer two reasons why the second pattern came to prevail in the cases under consideration: (1) the affinity between wild landscape and the Romantic ideal of pure, rugged nature, and (2) a divergence between the nationalist ideal of ethnic homogeneity and the polyethnic composition of the two societies under consideration

SecA-Mediated Protein Translocation through the SecYEG Channel

In bacteria, the Sec translocase mediates the translocation of proteins into and across the cytoplasmic membrane. It consists of a protein conducting channel SecYEG, the ATP-dependent motor SecA, and the accessory SecDF complex. Here we discuss the function and structure of the Sec translocase

SecA, a remarkable nanomachine

Biological cells harbor a variety of molecular machines that carry out mechanical work at the nanoscale. One of these nanomachines is the bacterial motor protein SecA which translocates secretory proteins through the protein-conducting membrane channel SecYEG. SecA converts chemically stored energy in the form of ATP into a mechanical force to drive polypeptide transport through SecYEG and across the cytoplasmic membrane. In order to accommodate a translocating polypeptide chain and to release transmembrane segments of membrane proteins into the lipid bilayer, SecYEG needs to open its central channel and the lateral gate. Recent crystal structures provide a detailed insight into the rearrangements required for channel opening. Here, we review our current understanding of the mode of operation of the SecA motor protein in concert with the dynamic SecYEG channel. We conclude with a new model for SecA-mediated protein translocation that unifies previous conflicting data

Crosstalk between different family members: IL27 recapitulates IFNγ responses in HCC cells, but is inhibited by IL6-type cytokines

Interleukin-27 (IL27) is a type-I-cytokine of the IL6/IL12 family predominantly secreted by activated macrophages and dendritic cells. In the liver, IL27 expression was observed to be upregulated in patients with hepatitis B, and sera of hepatocellular carcinoma (HCC) patients contain significantly elevated levels of IL27 compared to healthy controls or patients with hepatitis and/or liver cirrhosis. In this study, we show that IL27 induces STAT1 and STAT3 phosphorylation in 5 HCC lines and 3 different types of non-transformed liver cells. We were especially interested in the relevance of the IL27-induced STAT3 activation in liver cells. Thus, we compared the IL27 responses with those induced by IFNγ (STAT1-dominated response) or IL6-type cytokines (IL6, hyper-IL6 (hy-IL6) or OSM) (STAT3-dominated response) by microarray analysis and find that in HCC cells, IL27 induces an IFNγ-like, STAT1-dependent transcriptional response, but we do not find an effective STAT3-dependent response. Validation experiments corroborate the finding from the microarray evaluation. Interestingly, the availability of STAT1 seems critical in the shaping of the IL27 response, as the siRNA knock-down of STAT1 revealed the ability of IL27 to induce the acute-phase protein γ-fibrinogen, a typical IL6 family characteristic. Moreover, we describe a crosstalk between the signaling of IL6-type cytokines and IL27: responses to the gp130-engaging cytokine IL27 (but not those to IFNs) can be inhibited by IL6-type cytokine pre-stimulation, likely by a SOCS3-mediated mechanism. Thus, IL27 recapitulates IFNγ responses in liver cells, but differs from IFNγ by its sensitivity to SOCS3 inhibition

Pre- and syn-eruptive degassing and crystallisation processes of the 2010 and 2006 eruptions of Merapi volcano, Indonesia

The 2010 eruption of Merapi (VEI 4) was the volcano’s largest since 1872. In contrast to the prolonged and effusive dome-forming eruptions typical of Merapi’s recent activity, the 2010 eruption began explosively, before a new dome was rapidly emplaced. This new dome was subsequently destroyed by explosions, generating pyroclastic density currents (PDCs), predominantly consisting of dark coloured, dense blocks of basaltic andesite dome lava. A shift towards open-vent conditions in the later stages of the eruption culminated in multiple explosions and the generation of PDCs with conspicuous grey scoria and white pumice clasts resulting from sub-plinian convective column collapse. This paper presents geochemical data for melt inclusions and their clinopyroxene hosts extracted from dense dome lava, grey scoria and white pumice generated during the peak of the 2010 eruption. These are compared with clinopyroxene-hosted melt inclusions from scoriaceous dome fragments from the prolonged dome-forming 2006 eruption, to elucidate any relationship between pre-eruptive degassing and crystallisation processes and eruptive style. Secondary ion mass spectrometry analysis of volatiles (H2O, CO2) and light lithophile elements (Li, B, Be) is augmented by electron microprobe analysis of major elements and volatiles (Cl, S, F) in melt inclusions and groundmass glass. Geobarometric analysis shows that the clinopyroxene phenocrysts crystallised at depths of up to 20 km, with the greatest calculated depths associated with phenocrysts from the white pumice. Based on their volatile contents, melt inclusions have re-equilibrated during shallower storage and/or ascent, at depths of ~0.6–9.7 km, where the Merapi magma system is interpreted to be highly interconnected and not formed of discrete magma reservoirs. Melt inclusions enriched in Li show uniform “buffered” Cl concentrations, indicating the presence of an exsolved brine phase. Boron-enriched inclusions also support the presence of a brine phase, which helped to stabilise B in the melt. Calculations based on S concentrations in melt inclusions and groundmass glass require a degassing melt volume of 0.36 km3 in order to produce the mass of SO2 emitted during the 2010 eruption. This volume is approximately an order of magnitude higher than the erupted magma (DRE) volume. The transition between the contrasting eruptive styles in 2010 and 2006 is linked to changes in magmatic flux and changes in degassing style, with the explosive activity in 2010 driven by an influx of deep magma, which overwhelmed the shallower magma system and ascended rapidly, accompanied by closed-system degassing

Sejarah Filsafat India

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