Structural studies of BK and JC Polyomavirus interactions with their receptors

BK- und JC-Polyomaviren sind doppelsträngig, zirkuläre DNA-Viren mit einem ikosaedrischen Kapsid, das hauptsächlich aus Pentameren des VP1-Proteins besteht. Diese opportunistischen Viren können unter immunsuppressiven Bedingungen reaktiviert werden und verursachen hauptsächlich BKPyV-assoziierte Nephropathie bei Nierentransplantationen oder progressive multifokale Leukoenzephalopathie im Falle einer JCPyV-Reaktivierung. Diese Arbeit konzentriert sich auf die Untersuchung der Interaktionen zwischen dem Virus und seinen Wirtsrezeptoren. Das erste Projekt zielt darauf ab, zu verstehen, wie Mutationen im VP1-Protein, die bei Empfängern von Nierentransplantaten während einer persistierenden BKPyV-Infektion häufig auftreten, die Struktur und den Tropismus des Virus beeinflussen. Durch funktionelle und strukturelle Studien konnten wir zwei unterschiedliche Funktionsmuster aufzeigen. Die N-Q-Variante verliert durch die Mutation der Aminosäure 69 die Fähigkeit, mit Sialinsäure zu interagieren, was darauf hindeutet, dass ein anderer Rezeptor verwendet wird, um die Infektion dieser Variante in 293TT-Zellen zu unterstützen. Andererseits weist die VQQ-Variante einen Loop-Switch auf, der durch Mutationen der Aminosäuren 72 und 73 verursacht wird, was uns zu der Annahme veranlasst, dass diese Variante die Interaktion mit dem unbekannten Rezeptor verliert und somit ihre schwache Infektiosität in 293TT-Zellen erklärt. Obwohl diese Variante ein breiteres Gangliosid-Bindungsprofil aufweist, infiziert sie nicht über die Ganglioside. Es wurden weitere Varianten untersucht, die ebenfalls unterschiedliche Gangliosid-Bindungsprofile und strukturelle Veränderungen aufweisen. Das zweite Projekt dieser Arbeit zielt ebenfalls auf die Untersuchung des Tropismus und der Struktur ab, in diesem Fall jedoch der verschiedenen Genotypen von BKPyV. Funktionelle Tests haben gezeigt, dass gI, II und III für die Infektion stark von Sialinsäuren abhängig sind, während 50 % der Infektion bei gIV verbleiben, was auch in diesem Fall darauf hindeutet, dass ein anderer Rezeptor für die Infektion verwendet wird. Die Strukturstudie des gIV-VP1-Pentamers ergab keine wesentlichen strukturellen Unterschiede im Vergleich zur gI-Struktur. Das dritte Projekt konzentrierte sich auf die Charakterisierung der Interaktion zwischen JCPyV und einem seiner Eintrittsrezeptoren: dem Serotoninrezeptor 5HTRB. JCPyV VP1- Pentamere und VLPs wurden exprimiert und gereinigt, ebenso wie 5HT2RB. Ziel war es, durch SPR-Messungen herauszufinden, ob das Virus nur über ein Pentamer mit dem Rezeptor interagiert oder die Schnittstelle mehrerer Pentamere benötigt. Die SPR-Messungen waren jedoch nicht schlüssig

The potential of role play in undergraduate psychology training

This paper reports on the use of role-play as a scenario-based learning approach in the teaching of counselling skills, client assessment and diagnostic interviewing within psychological training. While role-play is not a new technique in teaching such skills, its use is generally reserved for the training of higher level students. This paper explores the use of role-play for undergraduate training, its usefulness and how ambiguity and uncertainty can be incorporated into scripts for more effective training. Through a process of constructivist learning, students arrive at meaning between each other in how they approach even improvised role scripts

Small RNA Diversity in Plants and its Impact in Development

MicroRNAs are a class of non-coding RNAs involved in post-transcriptional control of gene expression, either via degradation or translational inhibition of target mRNAs. Both experimental and computational approaches have been used to identify miRNAs and their target genes. In plants, deep sequencing methods have recently allowed the analysis of small RNA diversity in different species and/or mutants. Most sequencing efforts have been concentrated on the identification of miRNAs and their mRNA targets have been predicted based on complementarity criteria. The recent demonstration that certain plant miRNAs could act partly via inhibition of protein translation certainly opens new fields of analysis for plant miRNA function on a broader group of targets. The roles of conserved miRNAs on target mRNA stability have been analysed in different species and defined common mechanisms in development and stress responses. In contrast, much less is known about expression patterns or functions of non-conserved miRNAs. In this review, we focus on the comparative analyses of plant small RNA diversity and the action of si/miRNAs in post-transcriptional regulation of some key genes involved in root development

The potential of role-play in undergraduate psychology training / Marie Caltabiano … [et al.]

This paper reports on the use of role-play as a scenario-based learning approach in the teaching of counselling skills, client assessment and diagnostic interviewing within psychological training. While role-play is not a new technique in teaching such skills, its use is generally reserved for the training of higher level students. This paper explores the use of role-play for undergraduate training, its usefulness and how ambiguity and uncertainty can be incorporated into scripts for more effective training. Through a process of constructivist learning, students arrive at meaning between each other in how they approach even improvised role scripts

Cyclodipeptide synthases, a family of class-I aminoacyl-tRNA synthetase-like enzymes involved in non-ribosomal peptide synthesis

Cyclodipeptide synthases (CDPSs) belong to a newly defined family of enzymes that use aminoacyl-tRNAs (aa-tRNAs) as substrates to synthesize the two peptide bonds of various cyclodipeptides, which are the precursors of many natural products with noteworthy biological activities. Here, we describe the crystal structure of AlbC, a CDPS from Streptomyces noursei. The AlbC structure consists of a monomer containing a Rossmann-fold domain. Strikingly, it is highly similar to the catalytic domain of class-I aminoacyl-tRNA synthetases (aaRSs), especially class-Ic TyrRSs and TrpRSs. AlbC contains a deep pocket, highly conserved among CDPSs. Site-directed mutagenesis studies indicate that this pocket accommodates the aminoacyl moiety of the aa-tRNA substrate in a way similar to that used by TyrRSs to recognize their tyrosine substrates. These studies also suggest that the tRNA moiety of the aa-tRNA interacts with AlbC via at least one patch of basic residues, which is conserved among CDPSs but not present in class-Ic aaRSs. AlbC catalyses its two-substrate reaction via a ping-pong mechanism with a covalent intermediate in which l-Phe is shown to be transferred from Phe-tRNAPhe to an active serine. These findings provide insight into the molecular bases of the interactions between CDPSs and their aa-tRNAs substrates, and the catalytic mechanism used by CDPSs to achieve the non-ribosomal synthesis of cyclodipeptides

Monitoring Black Sea environmental changes from space: New products for altimetry, ocean colour and salinity. Potentialities and requirements for a dedicated in-situ observing system

21 pages, 13 figures, 2 tables, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2022.998970/full#supplementary-material.-- Data availability statement: The datasets generated for this study can be found on the web interface (http://www.eo4sibs.uliege.be/) and on Zenodo under data doi: 10.5281/zenodo.6397223 with a full documentation that include Products User Manuals (PUM) and Algorithm Theoretical Basis Document (ATBD). All these products are distributed in netCDF files Grégoire et al. (2022). SMOS SSS and CDM products are also available at https://bec.icm.csic.es/bec-ftp-service/In this paper, satellite products developed during the Earth Observation for Science and Innovation in the Black Sea (EO4SIBS) ESA project are presented. Ocean colour, sea level anomaly and sea surface salinity datasets are produced for the last decade and validated with regional in-situ observations. New data processing is tested to appropriately tackle the Black Sea’s particular configuration and geophysical characteristics. For altimetry, the full rate (20Hz) altimeter measurements from Cryosat-2 and Sentinel-3A are processed to deliver a 5Hz along-track product. This product is combined with existing 1Hz product to produce gridded datasets for the sea level anomaly, mean dynamic topography, geostrophic currents. This new set of altimetry gridded products offers a better definition of the main Black Sea current, a more accurate reconstruction and characterization of eddies structure, in particular, in coastal areas, and improves the observable wavelength by a factor of 1.6. The EO4SIBS sea surface salinity from SMOS is the first satellite product for salinity in the Black Sea. Specific data treatments are applied to remedy the issue of land-sea and radio frequency interference contamination and to adapt the dielectric constant model to the low salinity and cold waters of the Black Sea. The quality of the SMOS products is assessed and shows a significant improvement from Level-2 to Level -3 and Level-4 products. Level-4 products accuracy is 0.4-0.6 psu, a comparable value to that in the Mediterranean Sea. On average SMOS sea surface salinity is lower than salinity measured by Argo floats, with a larger error in the eastern basin. The adequacy of SMOS SSS to reproduce the spatial characteristics of the Black Sea surface salinity and, in particular, plume patterns is analyzed. For ocean colour, chlorophyll-a, turbidity and suspended particulate materials are proposed using regional calibrated algorithms and satellite data provided by OLCI sensor onboard Sentinel-3 mission. The seasonal cycle of ocean colour products is described and a water classification scheme is proposed. The development of these three types of products has suffered from important in-situ data gaps that hinder a sound calibration of the algorithms and a proper assessment of the datasets quality. We propose recommendations for improving the in-situ observing system that will support the development of satellite productsThis work has been carried out as part of the European Space Agency contract Earth Observation data For Science and Innovations in the Black Sea (EO4SIBS, ESA contract n° 4000127237/19/I-EF). MG received fundings from the Copernicus Marine Service (CMEMS), the European Union’s Horizon 2020 BRIDGE-BS project under grant agreement No. 101000240 and by the Project CE2COAST funded by ANR(FR), BELSPO (BE), FCT (PT), IZM (LV), MI (IE), MIUR (IT), Rannis (IS), and RCN (NO) through the 2019 “Joint Transnational Call on Next Generation Climate Science in Europe for Oceans” initiated by JPI Climate and JPI Oceans. The research on SMOS SSS has been also supported in part by the Spanish R&D project INTERACT (PID2020-114623RB-C31), which is funded by MCIN/AEI/10.13039/501100011033, funding from the Spanish government through the “Severo Ochoa Centre of Excellence” accreditation (CEX2019-000928-S) and the CSIC Thematic Interdisciplinary Platform TeledetectPeer reviewe

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe