Structural and functional investigation of ABC transporter STE6-2p from Pichia pastoris reveals unexpected interaction with sterol molecules

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are multidomain transmembrane proteins, which facilitate the transport of various substances across cell membranes using energy derived from ATP hydrolysis. They are important drug targets since they mediate decreased drug susceptibility during pharmacological treatments. For the methylotrophic yeast Pichia pastoris, a model organism that is a widely used host for protein expression, the role and function of its ABC transporters is unexplored. In this work, we investigated the Pichia ABC-B transporter STE6-2p. Functional investigations revealed that STE6-2p is capable of transporting rhodamines in vivo and is active in the presence of verapamil and triazoles in vitro. A phylogenetic analysis displays homology among multidrug resistance (MDR) transporters from pathogenic fungi to human ABC-B transporters. Further, we present high-resolution single-particle electron cryomicroscopy structures of an ABC transporter from P. pastoris in the apo conformation (3.1 Å) and in complex with verapamil and adenylyl imidodiphosphate (AMP-PNP) (3.2 Å). An unknown density between transmembrane helices 4, 5, and 6 in both structures suggests the presence of a sterol-binding site of unknown function

Conceptions of the Catastrophe. Discourses on the Past before the Rise of Holocaust Memory

Analysis of early-ypost war institutinonal discourses on the recent past

Association of kidney function with effectiveness of procalcitonin-guided antibiotic treatment:A patient-level meta-analysis from randomized controlled trials

Patients with impaired kidney function have a significantly slower decrease of procalcitonin (PCT) levels during infection. Our aim was to study PCT-guided antibiotic stewardship and clinical outcomes in patients with impairments of kidney function as assessed by creatinine levels measured upon hospital admission. We pooled and analyzed individual data from 15 randomized controlled trials who were randomly assigned to receive antibiotic therapy based on a PCT-algorithms or based on standard of care. We stratified patients on the initial glomerular filtration rate (GFR, ml/min/1.73 m2) in three groups (GFR >90 [chronic kidney disease; CKD 1], GFR 15-89 [CKD 2-4] and GFR0.05). This individual patient data meta-analysis confirms that the use of PCT in patients with impaired kidney function, as assessed by admission creatinine levels, is associated with shorter antibiotic courses and lower mortality rates

Simulation of Channel Segregation During Directional Solidification of In—75 wt pct Ga. Qualitative Comparison with In Situ Observations

International audienceFreckles are common defects in industrial casting. They result from thermosolutal convection due to buoyancy forces generated from density variations in the liquid. The present paper proposes a numerical analysis for the formation of channel segregation using the three-dimensional (3D) cellular automaton (CA)—finite element (FE) model. The model integrates kinetics laws for the nucleation and growth of a microstructure with the solution of the conservation equations for the casting, while introducing an intermediate modeling scale for a direct representation of the envelope of the dendritic grains. Directional solidification of a cuboid cell is studied. Its geometry, the alloy chosen as well as the process parameters are inspired from experimental observations recently reported in the literature. Snapshots of the convective pattern, the solute distribution, and the morphology of the growth front are qualitatively compared. Similitudes are found when considering the coupled 3D CAFE simulations. Limitations of the model to reach direct simulation of the experiments are discussed

Invasive Plant Suppresses the Growth of Native Tree Seedlings by Disrupting Belowground Mutualisms

The impact of exotic species on native organisms is widely acknowledged, but poorly understood. Very few studies have empirically investigated how invading plants may alter delicate ecological interactions among resident species in the invaded range. We present novel evidence that antifungal phytochemistry of the invasive plant, Alliaria petiolata, a European invader of North American forests, suppresses native plant growth by disrupting mutualistic associations between native canopy tree seedlings and belowground arbuscular mycorrhizal fungi. Our results elucidate an indirect mechanism by which invasive plants can impact native flora, and may help explain how this plant successfully invades relatively undisturbed forest habitat

A Daphnane Diterpenoid Isolated from Wikstroemia polyantha Induces an Inflammatory Response and Modulates miRNA Activity

MicroRNAs (miRNAs) are endogenously expressed single-stranded ∼21–23 nucleotide RNAs that inhibit gene expression post-transcriptionally by binding imperfectly to elements usually within the 3′untranslated region (3′UTR) of mRNAs. Small interfering RNAs (siRNAs) mediate site-specific cleavage by binding with perfect complementarity to RNA. Here, a cell-based miRNA reporter system was developed to screen for compounds from marine and plant extracts that inhibit miRNA or siRNA activity. The daphnane diterpenoid genkwanine M (GENK) isolated from the plant Wikstroemia polyantha induces an early inflammatory response and can moderately inhibit miR-122 activity in the liver Huh-7 cell line. GENK does not alter miR-122 levels nor does it directly inhibit siRNA activity in an in vitro cleavage assay. Finally, we demonstrate that GENK can inhibit HCV infection in Huh-7 cells. In summary, the development of the cell-based miRNA sensor system should prove useful in identifying compounds that affect miRNA/siRNA activity

The Global Financial Crisis and a New Capitalism?

The 2008 global financial crisis was the consequence of the process (1) of financialization, or the creation of massive fictitious financial wealth, that began in the 1980s,; and (2) the hegemony of a reactionary ideology-namely, neoliberalism-based on self-regulated and efficient markets. Although laissez-faire capitalism is intrinsically unstable, the lessons of the 1929 stock market crash of 1929 and the Great Depression of the 1930s were transformed into theories and institutions or regulations that led to the '30 glorious years of capitalism' (1948-77) and that could have helped avoid a financial crisis as profound as the present one. But it did not, because a coalition of rentiers and 'financists' achieved hegemony and, while deregulating the existing financial operations, refused to regulate the financial innovations that made these markets even riskier. Neoclassical economics played the role of a meta-ideology as it legitimized, mathematically and 'scientifically,' neoliberal ideology and deregulation. From this crisis a new democratic capitalist system will emerge, though its character is difficult to predict. It will not be financialized, but the glory years' tendencies toward a global and knowledge-based capitalism in which professionals have more say than rentier capitalists, as well as the tendency to improve democracy by making it more social and participative, will be resumed

Going underground: Resort to terrorism in mass mobilization dissident campaigns

© The Author(s) 2018. When and why do groups participating in mass dissent choose to initiate terrorist campaigns? I argue that groups involved in civil wars and mass civil resistance might face similar organizational pressures, which encourage the initiation of terrorism due to higher tactical effectiveness. Internal organizational pressure might depend on leaders’ expectations of a decline in followers’ commitment with protracted use of mass tactics. This is likely to motivate leaders to initiate terrorist campaigns to secure organizational survival. External organizational pressures might depend on increasing dissident campaigns’ fragmentation. This intensifies competition making leaders more likely to initiate terrorism so as to establish themselves at the forefront of their movements. The findings provide empirical support consistent with my claims and indicate no significant difference between civil wars and mass civil resistance movements with regards to these effects. Contrary to the common idea that the use of conventional violence should entail a higher willingness to engage in illegal violence against non-combatants, this finding suggests that conflict dynamics affect the decision to initiate terrorism and that terrorist campaigns have a coherent strategic logic across different types of mass dissent.Economic and Social Research Council (1511095