102 research outputs found

    Advice for journalists covering Covid-19: Welsh NHS confederation

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    The outbreak of COVID-19 is placing an unprecedented strain on health services in Wales and across the world. At the same time, coverage of the outbreak is essential, and there is a great demand from media organisations and their audiences to receive information about the outbreak and its frontline. This can put additional pressures on health care organisations and staff and may in certain cases interfere with their operations in dealing with the outbreak. This document has been prepared by Professor Karin Wahl-Jorgensen, Cardiff University, to support the work of the Welsh NHS Confederation. It draws on input from leading academics, journalists and PR practitioners (full list of contributors on p. 9). The document provides a number of suggestions for media organisations designed to facilitate coverage in and around healthcare facilities in Wales. The experts involved in preparing this document are independent from the NHS, and the document does not reflect official NHS policy. Here is a summary of our advice: 1. Responsible, detailed, and accurate reporting of COVID-19 is an essential public service. 2. Use credible experts as sources and be wary of unverified rumour 3. News organisations should use pooled materials whenever possible. 4. If looking for information verification, check other sources first before contacting NHS. 5. Ensure compliance with procedures for risk assessment and consent. 6. Enforce social distancing and ensure safe use of equipment. 7. Ensure risk assessments have been carried out prior to hospital visits and face-toface interactions with NHS staff. 8. Obtain consent from anyone interviewed or filmed. 9. When making requests for interviews or information, be specific about who you need to speak to, and where, what and how the information will be used

    The mitosis and neurodevelopment proteins NDE1 and NDEL1 form dimers, tetramers and polymers with a folded-back structure in solution

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    Paralogs NDE1 (nuclear distribution element 1) and NDEL1 (NDE-like 1) are essential for mitosis and neurodevelopment. Both proteins are predicted to have similar structures, based upon high sequence similarity, and they co-complex in mammalian cells. X-ray diffraction studies and homology modeling suggest that their N-terminal regions (residues 8–167) adopt continuous, extended α-helical coiled-coil structures, but no experimentally derived information on the structure of their C-terminal regions or the architecture of the full-length proteins is available. In the case of NDE1, no biophysical data exists. Here we characterize the structural architecture of both full-length proteins utilizing negative stain electron microscopy along with our established paradigm of chemical cross-linking followed by tryptic digestion, mass spectrometry, and database searching, which we enhance using isotope labeling for mixed NDE1-NDEL1. We determined that full-length NDE1 forms needle-like dimers and tetramers in solution, similar to crystal structures of NDEL1, as well as chain-like end-to-end polymers. The C-terminal domain of each protein, required for interaction with key protein partners dynein and DISC1 (disrupted-in-schizophrenia 1), includes a predicted disordered region that allows a bent back structure. This facilitates interaction of the C-terminal region with the N-terminal coiled-coil domain and is in agreement with previous results showing N- and C-terminal regions of NDEL1 and NDE1 cooperating in dynein interaction. It sheds light on recently identified mutations in the NDE1 gene that cause truncation of the encoded protein. Additionally, analysis of mixed NDE1-NDEL1 complexes demonstrates that NDE1 and NDEL1 can interact directly

    Drosophila Neurotrophins Reveal a Common Mechanism for Nervous System Formation

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    Neurotrophic interactions occur in Drosophila, but to date, no neurotrophic factor had been found. Neurotrophins are the main vertebrate secreted signalling molecules that link nervous system structure and function: they regulate neuronal survival, targeting, synaptic plasticity, memory and cognition. We have identified a neurotrophic factor in flies, Drosophila Neurotrophin (DNT1), structurally related to all known neurotrophins and highly conserved in insects.By investigating with genetics the consequences of removing DNT1 or adding it in excess, we show that DNT1 maintains neuronal survival, as more neurons die in DNT1 mutants and expression of DNT1 rescues naturally occurring cell death, and it enables targeting by motor neurons. We show that Spa¨ tzle and a further fly neurotrophin superfamily member, DNT2, also have neurotrophic functions in flies. Our findings imply that most likely a neurotrophin was present in the common ancestor of all bilateral organisms, giving rise to invertebrate and vertebrate neurotrophins through gene or whole-genome duplications. This work provides a missing link between aspects of neuronal function in flies and vertebrates, and it opens the opportunity to use Drosophila to investigate further aspects of neurotrophin function and to model related diseases

    A SOS3 homologue maps to HvNax4, a barley locus controlling an environmentally sensitive Na+ exclusion trait

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    Genes that enable crops to limit Na+ accumulation in shoot tissues represent potential sources of salinity tolerance for breeding. In barley, the HvNax4 locus lowered shoot Na+ content by between 12% and 59% (g−1 DW), or not at all, depending on the growth conditions in hydroponics and a range of soil types, indicating a strong influence of environment on expression. HvNax4 was fine-mapped on the long arm of barley chromosome 1H. Corresponding intervals of ∼200 kb, containing a total of 34 predicted genes, were defined in the sequenced rice and Brachypodium genomes. HvCBL4, a close barley homologue of the SOS3 salinity tolerance gene of Arabidopsis, co-segregated with HvNax4. No difference in HvCBL4 mRNA expression was detected between the mapping parents. However, genomic and cDNA sequences of the HvCBL4 alleles were obtained, revealing a single Ala111Thr amino acid substitution difference in the encoded proteins. The known crystal structure of SOS3 was used as a template to obtain molecular models of the barley proteins, resulting in structures very similar to that of SOS3. The position in SOS3 corresponding to the barley substitution does not participate directly in Ca2+ binding, post-translational modifications or interaction with the SOS2 signalling partner. However, Thr111 but not Ala111 forms a predicted hydrogen bond with a neighbouring α-helix, which has potential implications for the overall structure and function of the barley protein. HvCBL4 therefore represents a candidate for HvNax4 that warrants further investigation

    Components of Coated Vesicles and Nuclear Pore Complexes Share a Common Molecular Architecture

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    Numerous features distinguish prokaryotes from eukaryotes, chief among which are the distinctive internal membrane systems of eukaryotic cells. These membrane systems form elaborate compartments and vesicular trafficking pathways, and sequester the chromatin within the nuclear envelope. The nuclear pore complex is the portal that specifically mediates macromolecular trafficking across the nuclear envelope. Although it is generally understood that these internal membrane systems evolved from specialized invaginations of the prokaryotic plasma membrane, it is not clear how the nuclear pore complex could have evolved from organisms with no analogous transport system. Here we use computational and biochemical methods to perform a structural analysis of the seven proteins comprising the yNup84/vNup107–160 subcomplex, a core building block of the nuclear pore complex. Our analysis indicates that all seven proteins contain either a β-propeller fold, an α-solenoid fold, or a distinctive arrangement of both, revealing close similarities between the structures comprising the yNup84/vNup107–160 subcomplex and those comprising the major types of vesicle coating complexes that maintain vesicular trafficking pathways. These similarities suggest a common evolutionary origin for nuclear pore complexes and coated vesicles in an early membrane-curving module that led to the formation of the internal membrane systems in modern eukaryotes

    The Overlap of Small Molecule and Protein Binding Sites within Families of Protein Structures

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    Protein–protein interactions are challenging targets for modulation by small molecules. Here, we propose an approach that harnesses the increasing structural coverage of protein complexes to identify small molecules that may target protein interactions. Specifically, we identify ligand and protein binding sites that overlap upon alignment of homologous proteins. Of the 2,619 protein structure families observed to bind proteins, 1,028 also bind small molecules (250–1000 Da), and 197 exhibit a statistically significant (p<0.01) overlap between ligand and protein binding positions. These “bi-functional positions”, which bind both ligands and proteins, are particularly enriched in tyrosine and tryptophan residues, similar to “energetic hotspots” described previously, and are significantly less conserved than mono-functional and solvent exposed positions. Homology transfer identifies ligands whose binding sites overlap at least 20% of the protein interface for 35% of domain–domain and 45% of domain–peptide mediated interactions. The analysis recovered known small-molecule modulators of protein interactions as well as predicted new interaction targets based on the sequence similarity of ligand binding sites. We illustrate the predictive utility of the method by suggesting structural mechanisms for the effects of sanglifehrin A on HIV virion production, bepridil on the cellular entry of anthrax edema factor, and fusicoccin on vertebrate developmental pathways. The results, available at http://pibase.janelia.org, represent a comprehensive collection of structurally characterized modulators of protein interactions, and suggest that homologous structures are a useful resource for the rational design of interaction modulators

    Advice for journalists covering Covid-19: Welsh NHS confederation

    Get PDF
    The outbreak of COVID-19 is placing an unprecedented strain on health services in Wales and across the world. At the same time, coverage of the outbreak is essential, and there is a great demand from media organisations and their audiences to receive information about the outbreak and its frontline. This can put additional pressures on health care organisations and staff and may in certain cases interfere with their operations in dealing with the outbreak. This document has been prepared by Professor Karin Wahl-Jorgensen, Cardiff University, to support the work of the Welsh NHS Confederation. It draws on input from leading academics, journalists and PR practitioners (full list of contributors on p. 9). The document provides a number of suggestions for media organisations designed to facilitate coverage in and around healthcare facilities in Wales. The experts involved in preparing this document are independent from the NHS, and the document does not reflect official NHS policy. Here is a summary of our advice: 1. Responsible, detailed, and accurate reporting of COVID-19 is an essential public service. 2. Use credible experts as sources and be wary of unverified rumour 3. News organisations should use pooled materials whenever possible. 4. If looking for information verification, check other sources first before contacting NHS. 5. Ensure compliance with procedures for risk assessment and consent. 6. Enforce social distancing and ensure safe use of equipment. 7. Ensure risk assessments have been carried out prior to hospital visits and face-toface interactions with NHS staff. 8. Obtain consent from anyone interviewed or filmed. 9. When making requests for interviews or information, be specific about who you need to speak to, and where, what and how the information will be used

    The Interaction Properties of the Human Rab GTPase Family – A Comparative Analysis Reveals Determinants of Molecular Binding Selectivity

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    Rab GTPases constitute the largest subfamily of the Ras protein superfamily. Rab proteins regulate organelle biogenesis and transport, and display distinct binding preferences for effector and activator proteins, many of which have not been elucidated yet. The underlying molecular recognition motifs, binding partner preferences and selectivities are not well understood.Comparative analysis of the amino acid sequences and the three-dimensional electrostatic and hydrophobic molecular interaction fields of 62 human Rab proteins revealed a wide range of binding properties with large differences between some Rab proteins. This analysis assists the functional annotation of Rab proteins 12, 14, 26, 37 and 41 and provided an explanation for the shared function of Rab3 and 27. Rab7a and 7b have very different electrostatic potentials, indicating that they may bind to different effector proteins and thus, exert different functions. The subfamily V Rab GTPases which are associated with endosome differ subtly in the interaction properties of their switch regions, and this may explain exchange factor specificity and exchange kinetics.We have analysed conservation of sequence and of molecular interaction fields to cluster and annotate the human Rab proteins. The analysis of three dimensional molecular interaction fields provides detailed insight that is not available from a sequence-based approach alone. Based on our results, we predict novel functions for some Rab proteins and provide insights into their divergent functions and the determinants of their binding partner selectivity
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