573 research outputs found

    Wnt evolution and function shuffling in liberal and conservative chordate genomes

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    Background What impact gene loss has on the evolution of developmental processes, and how function shuffling has affected retained genes driving essential biological processes, remain open questions in the fields of genome evolution and EvoDevo. To investigate these problems, we have analyzed the evolution of the Wnt ligand repertoire in the chordate phylum as a case study. Results We conduct an exhaustive survey of Wnt genes in genomic databases, identifying 156 Wnt genes in 13 non-vertebrate chordates. This represents the most complete Wnt gene catalog of the chordate subphyla and has allowed us to resolve previous ambiguities about the orthology of many Wnt genes, including the identification of WntA for the first time in chordates. Moreover, we create the first complete expression atlas for the Wnt family during amphioxus development, providing a useful resource to investigate the evolution of Wnt expression throughout the radiation of chordates. Conclusions Our data underscore extraordinary genomic stasis in cephalochordates, which contrasts with the liberal and dynamic evolutionary patterns of gene loss and duplication in urochordate genomes. Our analysis has allowed us to infer ancestral Wnt functions shared among all chordates, several cases of function shuffling among Wnt paralogs, as well as unique expression domains for Wnt genes that likely reflect functional innovations in each chordate lineage. Finally, we propose a potential relationship between the evolution of WntA and the evolution of the mouth in chordates

    Mapping the H2 resistance effective against Globodera pallida pathotype Pa1 in tetraploid potato

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    This work was supported by the Rural & Environment Science & Analytical Services Division of the Scottish Government, the BBSRC, through the joint projects CRF/2009/SCRI/SOP 0929, BB/L008025/1 and BB/K018299/1. Additional funding was obtained through the James Hutton Institute SEEDCORN initiative, AHDB Potato, the Perry Foundation and The Felix Cobbold Trust. Amanpreet Kaur was supported by the Commonwealth Scholarship Commission through a Commonwealth split-site Ph.D. grant.Key message: The nematode resistance gene H2 was mapped to the distal end of chromosome 5 in tetraploid potato. The H2 resistance gene, introduced into cultivated potatoes from the wild diploid species Solanum multidissectum, confers a high level of resistance to the Pa1 pathotype of the potato cyst nematode Globodera pallida. A cross between tetraploid H2-containing breeding clone P55/7 and susceptible potato variety Picasso yielded an F1 population that segregated approximately 1:1 for the resistance phenotype, which is consistent with a single dominant gene in a simplex configuration. Using genome reduction methodologies RenSeq and GenSeq, the segregating F1 population enabled the genetic characterisation of the resistance through a bulked segregant analysis. A diagnostic RenSeq analysis of the parents confirmed that the resistance in P55/7 cannot be explained by previously characterised resistance genes. Only the variety Picasso contained functionally characterised disease resistance genes Rpi-R1, Rpi-R3a, Rpi-R3b variant, Gpa2 and Rx, which was independently confirmed through effector vacuum infiltration assays. RenSeq and GenSeq independently identified sequence polymorphisms linked to the H2 resistance on the top end of potato chromosome 5. Allele-specific KASP markers further defined the locus containing the H2 gene to a 4.7 Mb interval on the distal short arm of potato chromosome 5 and to positions that correspond to 1.4 MB and 6.1 MB in the potato reference genome.Publisher PDFPeer reviewe

    An inter-subunit protein-peptide interface that stabilizes the specific activity and oligomerization of the AAA+ chaperone Reptin

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    The work was supported by: the Czech Science Foundation 16-20860S (PM, LH) and 16-07321S (BV, TH), the project MEYS – NPS I – LO1413, and MH CZ - DRO (MMCI, 00209805); the BBSRC RASOR consortium (BB/C511599/1; United Kingdom); Cancer Research UK (C21383/A6950); The International Centre for Cancer Vaccine Science project carried out within the International Research Agendas programme of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund; A*STAR, Singapore and NSCC, Singapore.Reptin is a member of the AAA+ superfamily whose members can exist in equilibrium between monomeric apo forms and ligand bound hexamers. Inter-subunit protein-protein interfaces that stabilize Reptin in its oligomeric state are not well-defined. A self-peptide binding assay identified a protein-peptide interface mapping to an inter-subunit “rim” of the hexamer bridged by Tyrosine-340. A Y340A mutation reduced ADP-dependent oligomer formation using a gel filtration assay, suggesting that Y340 forms a dominant oligomer stabilizing side chain. The monomeric ReptinY340A mutant protein exhibited increased activity to its partner protein AGR2 in an ELISA assay, further suggesting that hexamer formation can preclude certain protein interactions. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) demonstrated that the Y340A mutation attenuated deuterium suppression of Reptin in this motif in the presence of ligand. By contrast, the tyrosine motif of Reptin interacts with a shallower pocket in the hetero-oligomeric structure containing Pontin and HDX-MS revealed no obvious role of the Y340 side chain in stabilizing the Reptin-Pontin oligomer. Molecular dynamic simulations (MDS) rationalized how the Y340A mutation impacts upon a normally stabilizing inter-subunit amino acid contact. MDS also revealed how the D299N mutation can, by contrast, remove oligomer de-stabilizing contacts. These data suggest that the Reptin interactome can be regulated by a ligand dependent equilibrium between monomeric and hexameric forms through a hydrophobic inter-subunit protein-protein interaction motif bridged by Tyrosine-340. Significance Discovering dynamic protein-protein interactions is a fundamental aim of research in the life sciences. An emerging view of protein-protein interactions in higher eukaryotes is that they are driven by small linear polypeptide sequences; the linear motif. We report on the use of linear-peptide motif screens to discover a relatively high affinity peptide-protein interaction for the AAA+ and pro-oncogenic protein Reptin. This peptide interaction site was shown to form a ‘hot-spot’ protein-protein interaction site, and validated to be important for ligand-induced oligomerization of the Reptin protein. These biochemical data provide a foundation to understand how single point mutations in Reptin can impact on its oligomerization and protein-protein interaction landscape.PostprintPeer reviewe

    Revealing the Mechanism for Covalent Inhibition of Glycoside Hydrolases by Carbasugars at an Atomic Level

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    Mechanism-based glycoside hydrolase inhibitors are carbohydrate analogs that mimic the natural substrate’s structure. Their covalent bond formation with the glycoside hydrolase makes these compounds excellent tools for chemical biology and potential drug candidates. Here we report the synthesis of cyclohexene-based α-galactopyranoside mimics and the kinetic and structural characterization of their inhibitory activity toward an α-galactosidase from Thermotoga maritima (TmGalA). By solving the structures of several enzyme-bound species during mechanism-based covalent inhibition of TmGalA, we show that the Michaelis complexes for intact inhibitor and product have half-chair (2H3) conformations for the cyclohexene fragment, while the covalently linked intermediate adopts a flattened half-chair (2H3) conformation. Hybrid QM/MM calculations confirm the structural and electronic properties of the enzyme-bound species and provide insight into key interactions in the enzyme-active site. These insights should stimulate the design of mechanism-based glycoside hydrolase inhibitors with tailored chemical properties

    Distance measurement of a noncovalently bound Y@C82 pair with double electron electron resonance spectroscopy

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    Paramagnetic endohedral fullerenes with long spin coherence times, such as N@C60 and Y@C82, are being explored as potential spin quantum bits (qubits). Their use for quantum information processing requires a way to hold them in fixed spatial arrangements. Here we report the synthesis of a porphyrinbased two-site receptor 1, offering a rigid structure that binds spin-active fullerenes (Y@C82) at a center-to-center distance of 5.0 nm, predicted from molecular simulations. The spin-spin dipolar coupling was measured with the pulsed EPR spectroscopy technique of double electron electron resonance (DEER) and analysed to give a distance of 4.87 nm with a small distribution of distances

    Voice Therapy For Transgender People

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    Transrodne osobe su osobe koje osjećaju nesklad između roda s kojim se poistovjećuju i spola u kojem su se rodili. Transrodnost je ĆĄirok pojam i obuhvaća čitav spektar rodno nenormativnih identiteta. Dva glavna obrasca tranzicije prema drugom spolu, odnosno rodu su: Male-to-Female (MtF) i Female-to-Male (FtM). Transrodne osobe navode da ih njihov glas često “izdaje”, odnosno otkriva njihov bioloĆĄki rod te predstavlja posljednju prepreku u potpuno uĆŸivljavanje u novu rodnu ulogu. Bez obzira na to, često nisu svjesni da se zbog glasa mogu obratiti logopedu. Cilj ovog preglednog rada je dati uvid u poremećaje glasa kod transrodnih osoba, odnosno opisati logopedsku procjenu te terapijske postupke, a sve u svrhu boljeg razumijevanja potreba ovih osoba.Transgender individuals are people who feel an incongruity between their self-identified gender and their birth gender. Transgenderism is a broad term and includes a spectrum of gender-nonconforming identities. The two main patterns of gender transition are Male-to-Female (MtF) and Female-to-Male (FtM).Transgender people often think their voice “betrays” them, i.e. it reveals their biological gender and represents the last obstacle to the individual’s full enjoyment of his/her new gender role. Regardless of this, many transgender individuals are not aware of the fact that they can go to speech and language pathologists (SLP) for therapy. The aim of this review article is to provide insight into the voice disorders of transgender people, i.e. to describe the assessment process and therapy protocols in hope of gaining a better understanding of the needs of this population

    The genome of the yellow potato cyst nematode, Globodera rostochiensis, reveals insights into the basis of parasitism and virulence

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    BACKGROUND: The yellow potato cyst nematode, Globodera rostochiensis, is a devastating plant pathogen of global economic importance. This biotrophic parasite secretes effectors from pharyngeal glands, some of which were acquired by horizontal gene transfer, to manipulate host processes and promote parasitism. G. rostochiensis is classified into pathotypes with different plant resistance-breaking phenotypes. RESULTS: We generate a high quality genome assembly for G. rostochiensis pathotype Ro1, identify putative effectors and horizontal gene transfer events, map gene expression through the life cycle focusing on key parasitic transitions and sequence the genomes of eight populations including four additional pathotypes to identify variation. Horizontal gene transfer contributes 3.5 % of the predicted genes, of which approximately 8.5 % are deployed as effectors. Over one-third of all effector genes are clustered in 21 putative ‘effector islands’ in the genome. We identify a dorsal gland promoter element motif (termed DOG Box) present upstream in representatives from 26 out of 28 dorsal gland effector families, and predict a putative effector superset associated with this motif. We validate gland cell expression in two novel genes by in situ hybridisation and catalogue dorsal gland promoter element-containing effectors from available cyst nematode genomes. Comparison of effector diversity between pathotypes highlights correlation with plant resistance-breaking. CONCLUSIONS: These G. rostochiensis genome resources will facilitate major advances in understanding nematode plant-parasitism. Dorsal gland promoter element-containing effectors are at the front line of the evolutionary arms race between plant and parasite and the ability to predict gland cell expression a priori promises rapid advances in understanding their roles and mechanisms of action.SE-vdA is supported by BBSRC grant BB/M014207/1. Sequencing was funded by BBSRC grant BB/F000642/1 to the University of Leeds and grant BB/F00334X/1 to the Wellcome Trust Sanger Institute). DRL was supported by a fellowship from The James Hutton Institute and the School of Biological Sciences, University of Edinburgh. GK was supported by a BBSRC PhD studentship. The James Hutton Institute receives funding from the Scottish Government. JAC and NEH are supported by the Wellcome Trust through its core funding of the Wellcome Trust Sanger Institute (grant 098051). This work was also supported by funding from the Canadian Safety and Security Program, project number CRTI09_462RD

    A DHODH inhibitor increases p53 synthesis and enhances tumor cell killing by p53 degradation blockage

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    ML, CD, IvL, GP, TM, SD, MS, APF, CT, DL, MAH, KL and SL: project grants from the Swedish Research Council, the Swedish Cancer Society and the Swedish Childhood Cancer Foundation. MHi and JC: Cancer Research UK (C8/A6613). MC, EP and WE: Wellcome Trust (073915). MN and BV: projects MEYS-NPS-LO1413 and GACR P206/12/G151. EMC, MP, MMS, ZF and PG: Norwegian Cancer Society (182735, 732200) and Helse Vest (911884, 911789). RB and SC: NIH (R01 CA95684), the Leukemia and Lymphoma Society and the Waxman Foundation. NW, AH, Ad’H: Cancer Research UK (C21383/A6950) and Engineering and Physical Sciences Research Council Doctoral Training Program. JL and YZ: Cancer Research UK (C240/A15751). MH and BW: SARomics Biostructures ABUY, KF: DDDP SciLife, Sweden. LJ, MHa, RS and A-LG: CBCS, Sweden. VP: SciLife fellowship. AT: Breast Cancer Research Scotland.The development of non-genotoxic therapies that activate wild-type p53 in tumors is of great interest since the discovery of p53 as a tumor suppressor. Here we report the identification of over 100 small-molecules activating p53 in cells. We elucidate the mechanism of action of a chiral tetrahydroindazole (HZ00), and through target deconvolution, we deduce that its active enantiomer (R)-HZ00, inhibits dihydroorotate dehydrogenase (DHODH). The chiral specificity of HZ05, a more potent analog, is revealed by the crystal structure of the (R)-HZ05/DHODH complex. Twelve other DHODH inhibitor chemotypes are detailed among the p53 activators, which identifies DHODH as a frequent target for structurally diverse compounds. We observe that HZ compounds accumulate cancer cells in S-phase, increase p53 synthesis, and synergize with an inhibitor of p53 degradation to reduce tumor growth in vivo. We, therefore, propose a strategy to promote cancer cell killing by p53 instead of its reversible cell cycle arresting effect.Publisher PDFPeer reviewe
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