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SWItch/sucrose non-fermenting (SWI/SNF) complexes are a family of chromatin remodelers that are conserved across eukaryotes. Mutations in subunits of SWI/SNF cause a multitude of different developmental disorders in humans, most of which have no current treatment options. Here, we identify an alanine-to-valine-causing mutation in the SWI/SNF subunit snfc-5 (SMARCB1 in humans) that prevents embryonic lethality in Caenorhabditis elegans nematodes harboring a loss-of-function mutation in the SWI/SNF subunit swsn-1 (SMARCC1/2 in humans). Furthermore, we found that the combination of this specific mutation in snfc-5 and a loss-of-function mutation in either of the E3 ubiquitin ligases ubr-5 (UBR5 in humans) or hecd-1 (HECTD1 in humans) can restore development to adulthood in swsn-1 loss-of-function mutants that otherwise die as embryos. Using these mutant models, we established a set of 335 genes that are dysregulated in SWI/SNF mutants that arrest their development embryonically but exhibit near wild-type levels of expression in the presence of suppressor mutations that prevent embryonic lethality, suggesting that SWI/SNF promotes development by regulating some subset of these 335 genes. In addition, we show that SWI/SNF protein levels are reduced in swsn-1; snfc-5 double mutants and partly restored to wild-type levels in swsn-1; snfc-5; ubr-5 triple mutants, consistent with a model in which UBR-5 regulates SWI/SNF levels by tagging the complex for proteasomal degradation. Our findings establish a link between two E3 ubiquitin ligases and SWI/SNF function and suggest that UBR5 and HECTD1 could be potential therapeutic targets for the many developmental disorders caused by missense mutations in SWI/SNF subunits.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Humanos , Caenorhabditis elegans/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Ubiquitinas/metabolismoRESUMO
Inherited epigenetic information has been observed to regulate a variety of complex organismal phenotypes across diverse taxa of life. This continually expanding body of literature suggests that epigenetic inheritance plays a significant, and potentially fundamental, role in inheritance. Despite the important role these types of effects play in biology, the molecular mediators of this non-genetic transmission of information are just now beginning to be deciphered. Here we provide an intellectual framework for interpreting these findings and how they can interact with each other. We also define the different types of mechanisms that have been found to mediate epigenetic inheritance and to regulate whether epigenetic information persists for one or many generations. The field of epigenetic inheritance is entering an exciting phase, in which we are beginning to understand the mechanisms by which non-genetic information is transmitted to, and deciphered by, subsequent generations to maintain essential environmental information without permanently altering the genetic code. A more complete understanding of how and when epigenetic inheritance occurs will advance our understanding of numerous different aspects of biology ranging from how organisms cope with changing environments to human pathologies influenced by a parent's environment.
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Epigênese Genética , Hereditariedade , Metilação de DNA/genética , Epigênese Genética/genética , Epigenômica , Padrões de Herança/genética , FenótipoRESUMO
INTRODUCTION: The purpose of this study was to examine the feasibility of adapting and translating an evidence-based occupational therapist-delivered program shown to be effective in the community to residential aged care (RAC). The program aims to improve quality of care and quality of life for people living with dementia and the wellbeing of the family care partner. METHODS: This study took place in a not-for-profit RAC home in Adelaide, South Australia. Mixed methods, specifically questionnaires, activity logs, focus group, and one-on-one interviews were used to evaluate the feasibility of the program implementation. Staff working in the participating home, occupational therapists trained to deliver the program, and residents and their family carer partners were included. Quantitative data were analysed using proportions, means, and standard deviations. Qualitative data were analysed using a thematic approach. CONSUMER AND COMMUNITY INVOLVEMENT: This study was conducted together with a consumer (person living with dementia) and a carer representative (family member of someone residing in RAC). These representatives provided input towards the study design, interpretation of study data, discussion of results, and recommendations for future consideration. RESULTS: Small changes to the program improved feasibility and acceptability for delivery in RAC. While the care home staff required added support during implementation, the intervention therapists felt that the program could be delivered in this setting. Family care partners of residents with dementia felt that the program may be better suited if provided upon entry to RAC or in early stages of dementia. CONCLUSION: Adapting a community-based dementia care program to RAC can be safe and feasible. Program adaptations are necessary for feasibility. Further adaptations and evaluations of associated outcomes (related to residents with dementia and their family care partners) are needed to assess the program effectiveness in larger scale. PLAIN LANGUAGE SUMMARY: Spending quality time with family members in residential aged care is important. However, many struggle to know what to say or do when visiting a family member who lives with dementia. Programs that teach families about how to communicate with people living with dementia, how to support them to take part in important everyday living activities, or how to understand why changes in behaviours may occur have not been available in residential aged care. This paper describes how we adapted one such evidence-based program from community to residential aged care settings. We consulted with people living with dementia, carers, and families and found that the program could also be valuable in this care setting. Residential aged care staff described how the program is very different to what is usually available in residential aged care, but they were optimistic that with the right support, it could be a valuable way to support residents with dementia and their families. Family members of residents with dementia and therapists delivering the program felt that residents in early stages of living in residential aged care and/or early stages of dementia could benefit the most from these programs. We found that including family members in the intervention process can be useful and empowering for families and residents. Future work should also focus on involving other staff members caring for residents in the process. Communication between staff and families is the key for program delivery and success and treating each person as an individual.
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The eMouseAtlas resource is an online database of 3D digital models of mouse development, an ontology of mouse embryo anatomy and a gene-expression database with about 30K spatially mapped gene-expression patterns. It is closely linked with the MGI/GXD database at the Jackson Laboratory and holds links to almost all available image-based gene-expression data for the mouse embryo. In this resource article we describe the novel web-based tools we have developed for 3D visualisation of embryo anatomy and gene expression. We show how mapping of gene expression data onto spatial models delivers a framework for capturing gene expression that enhances our understanding of development, and we review the exploratory tools utilised by the EMAGE gene expression database as a means of defining co-expression of in situ hybridisation, immunohistochemistry, and lacZ-omic expression patterns. We report on recent developments of the eHistology atlas and our use of web-services to support embedding of the online 'The Atlas of Mouse Development' in the context of other resources such as the DMDD mouse phenotype database. In addition, we discuss new developments including a cellular-resolution placental atlas, third-party atlas models, clonal analysis data and a new interactive eLearning resource for developmental processes.
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Atlas como Assunto , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário , Anatomia Artística , Animais , Regulação da Expressão Gênica no Desenvolvimento , Internet , CamundongosRESUMO
EMAGE (http://www.emouseatlas.org/emage/) is a freely available database of in situ gene expression patterns that allows users to perform online queries of mouse developmental gene expression. EMAGE is unique in providing both text-based descriptions of gene expression plus spatial maps of gene expression patterns. This mapping allows spatial queries to be accomplished alongside more traditional text-based queries. Here, we describe our recent progress in spatial mapping and data integration. EMAGE has developed a method of spatially mapping 3D embryo images captured using optical projection tomography, and through the use of an IIP3D viewer allows users to view arbitrary sections of raw and mapped 3D image data in the context of a web browser. EMAGE now includes enhancer data, and we have spatially mapped images from a comprehensive screen of transgenic reporter mice that detail the expression of mouse non-coding genomic DNA fragments with enhancer activity. We have integrated the eMouseAtlas anatomical atlas and the EMAGE database so that a user of the atlas can query the EMAGE database easily. In addition, we have extended the atlas framework to enable EMAGE to spatially cross-index EMBRYS whole mount in situ hybridization data. We additionally report on recent developments to the EMAGE web interface, including new query and analysis capabilities.
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Bases de Dados Genéticas , Embrião de Mamíferos/metabolismo , Expressão Gênica , Camundongos/genética , Animais , Gráficos por Computador , Imageamento Tridimensional , Internet , Camundongos/embriologia , Camundongos/metabolismo , Modelos Animais , Tomografia/métodosRESUMO
Bacterial cell surfaces are commonly decorated with a layer formed from multiple copies of adhesin proteins whose binding interactions initiate colonization and infection processes. In this study, we investigate the physical deformability of the UspA1 adhesin protein from Moraxella catarrhalis, a causative agent of middle-ear infections in humans. UspA1 binds a range of extracellular proteins including fibronectin, and the epithelial cellular receptor carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). Electron microscopy indicates that unliganded UspA1 is densely packed at, and extends about 800 Å from, the Moraxella surface. Using a modified atomic force microscope, we show that the adhesive properties and thickness of the UspA1 layer at the cell surface varies on addition of either fibronectin or CEACAM1. This in situ analysis is then correlated with the molecular structure of UspA1. To provide an overall model for UspA1, we have determined crystal structures for two N-terminal fragments which are then combined with a previous structure of the CEACAM1-binding site. We show that the UspA1-fibronectin complex is formed between UspA1 head region and the 13th type-III domain of fibronectin and, using X-ray scattering, that the complex involves an angular association between these two proteins. In combination with a previous study, which showed that the CEACAM1-UspA1 complex is distinctively bent in solution, we correlate these observations on isolated fragments of UspA1 with its in situ response on the cell surface. This study therefore provides a rare direct demonstration of protein conformational change at the cell surface.
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Adesinas Bacterianas/metabolismo , Antígenos CD/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Moléculas de Adesão Celular/metabolismo , Fibronectinas/metabolismo , Mecanotransdução Celular , Moraxella catarrhalis/metabolismo , Adesinas Bacterianas/ultraestrutura , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/ultraestrutura , Membrana Celular/metabolismo , Humanos , Microscopia de Força Atômica , Modelos Moleculares , Moraxella catarrhalis/ultraestrutura , Ligação Proteica , Espalhamento a Baixo Ângulo , Difração de Raios XRESUMO
The parental environment of C. elegans can have lasting effects on progeny development and immunity. Vitamin B12 exposure in C. elegans has been shown to accelerate development and protect against pathogenic bacteria. Here, we show that parental exposure to dietary vitamin B12 or vitamin B12-producing bacteria results in offspring with accelerated growth that persists for a single generation. During infection with the microsporidian Nematocida parisii, the offspring of worms fed vitamin B12 diets have better reproductive fitness but similar infection levels, suggesting increased tolerance to microsporidian infection. Vitamin B12-induced intergenerational growth acceleration and N. parisii tolerance is dependent upon the methionine biosynthesis pathway. Offspring from vitamin B12-exposed parents are protected from pathogenic Pseudomonas vranovensis and this protection is mediated through methionine biosynthesis and propionyl-CoA breakdown pathways. Our results show how parental microbial diet impacts progeny development through the transfer of vitamin B12 which results in accelerated growth and pathogen tolerance.
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The gut microbiome has been proposed to influence many aspects of animal development and physiology. However, both the specific bacterial species and the molecular mechanisms by which bacteria exert these effects are unknown in most cases. Here, we established a high throughput screening platform using the model animal Caenorhabditis elegans for identifying bacterial species and mechanisms that influence animal development and physiology. From our initial screens we found that many Bacillus species can restore normal animal development to insulin signaling mutant animals that otherwise do not develop to adulthood. To determine how Bacilli influence animal development we screened a complete non-essential gene knockout library of Bacillus subtilis for mutants that no longer restored development to adulthood. We found the Bacillus gene speB is required for animal development. In the absence of speB, B. subtilis produces excess N1-aminopropylagmatine. This polyamine is taken up by animal intestinal cells via the polyamine transporter CATP-5. When this molecule is taken up in sufficient quantities it inhibits animal mitochondrial function and causes diverse species of animals to arrest their development. To our knowledge, these are the first observations that B. subtilis can produce N1-aminopropylagmatine and that polyamines produced by intestinal microbiome species can antagonize animal development and mitochondrial function. Given that Bacilli species are regularly isolated from animal intestinal microbiomes, including from humans, we propose that altered polyamine production from intestinal Bacilli is likely to also influence animal development and metabolism in other species and potentially even contribute developmental and metabolic pathologies in humans. In addition, our findings demonstrate that C. elegans can be used as a model animal to conduct high throughput screens for bacterial species and bioactive molecules that alter animal physiology.
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During maturation oocytes undergo a recently discovered mitochondrial proteome remodeling event in flies1, frogs1, and humans2. This oocyte mitochondrial remodeling, which includes substantial changes in electron transport chain (ETC) subunit abundance1,2, is regulated by maternal insulin signaling1. Why oocytes undergo mitochondrial remodeling is unknown, with some speculating that it might be an evolutionarily conserved mechanism to protect oocytes from genotoxic damage by reactive oxygen species (ROS)2. In Caenorhabditis elegans, we previously found that maternal exposure to osmotic stress drives a 50-fold increase in offspring survival in response to future osmotic stress3. Like mitochondrial remodeling, we found that this intergenerational adaptation is also regulated by insulin signaling to oocytes3. Here, we used proteomics and genetic manipulations to show that insulin signaling to oocytes regulates offspring's ability to adapt to future stress via a mechanism that depends on ETC composition in maternal oocytes. Specifically, we found that maternally expressed mutant alleles of nduf-7 (complex I subunit) or isp-1 (complex III subunit) altered offspring's response to osmotic stress at hatching independently of offspring genotype. Furthermore, we found that expressing wild-type isp-1 in germ cells (oocytes) was sufficient to restore offspring's normal response to osmotic stress. Chemical mutagenesis screens revealed that maternal ETC composition regulates offspring's response to stress by altering AMP kinase function in offspring which in turn regulates both ATP and glycerol metabolism in response to continued osmotic stress. To our knowledge, these data are the first to show that proper oocyte ETC composition is required to link a mother's environment to adaptive changes in offspring metabolism. The data also raise the possibility that the reason diverse animals exhibit insulin regulated remodeling of oocyte mitochondria is to tailor offspring metabolism to best match the environment of their mother.
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Impaired motivational drive is a key feature of depression. Chronic stress is a known antecedent to the development of depression in humans and depressive-like states in animals. Whilst there is a clear relationship between stress and motivational drive, the mechanisms underpinning this association remain unclear. One hypothesis is that the endocrine system, via corticotropin-releasing hormone (CRH) in the paraventricular nucleus of the hypothalamus (PVN; PVNCRH), initiates a hormonal cascade resulting in glucocorticoid release, and that excessive glucocorticoids change brain circuit function to produce depression-related symptoms. Another mostly unexplored hypothesis is that the direct activity of PVNCRH neurons and their input to other stress- and reward-related brain regions drives these behaviors. To further understand the direct involvement of PVNCRH neurons in motivation, we used optogenetic stimulation to activate these neurons 1 h/day for 5 consecutive days and showed increased acute stress-related behaviors and long-lasting deficits in the motivational drive for sucrose. This was associated with increased Fos-protein expression in the lateral hypothalamus (LH). Direct stimulation of the PVNCRH inputs in the LH produced a similar pattern of effects on sucrose motivation. Together, these data suggest that PVNCRH neuronal activity may be directly responsible for changes in motivational drive and that these behavioral changes may, in part, be driven by PVNCRH synaptic projections to the LH.
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Hormônio Adrenocorticotrópico , Hormônio Liberador da Corticotropina , Animais , Humanos , Motivação , Hormônios Liberadores de Hormônios Hipofisários , Optogenética , Hipotálamo , Glucocorticoides , Neurônios , SacaroseRESUMO
MOTIVATION: Sources of neuroscience data in Drosophila are diverse and disparate making integrated search and retrieval difficult. A major obstacle to this is the lack of a comprehensive and logically structured anatomical framework and an intuitive interface. RESULTS: We present an online resource that provides a convenient way to study and query fly brain anatomy, expression and genetic data. We extended the newly developed BrainName nomenclature for the adult fly brain into a logically structured ontology that relates a comprehensive set of published neuron classes to the brain regions they innervate. The Virtual Fly Brain interface allows users to explore the structure of the Drosophila brain by browsing 3D images of a brain with subregions displayed as coloured overlays. An integrated query mechanism allows complex searches of underlying anatomy, cells, expression and other data from community databases. AVAILABILITY: Virtual Fly Brain is freely available online at www.virtualflybrain.org CONTACT: jda@inf.ed.ac.uk.
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Bases de Dados Factuais , Drosophila/anatomia & histologia , Drosophila/fisiologia , Software , Animais , Encéfalo/anatomia & histologia , Encéfalo/metabolismo , Mapeamento Encefálico , Internet , NeurociênciasRESUMO
The hereditary stomatocytoses are a series of dominantly inherited hemolytic anemias in which the permeability of the erythrocyte membrane to monovalent cations is pathologically increased. The causative mutations for some forms of hereditary stomatocytosis have been found in the transporter protein genes, RHAG and SLC4A1. Glucose transporter 1 (glut1) deficiency syndromes (glut1DSs) result from mutations in SLC2A1, encoding glut1. Glut1 is the main glucose transporter in the mammalian blood-brain barrier, and glut1DSs are manifested by an array of neurologic symptoms. We have previously reported 2 cases of stomatin-deficient cryohydrocytosis (sdCHC), a rare form of stomatocytosis associated with a cold-induced cation leak, hemolytic anemia, and hepatosplenomegaly but also with cataracts, seizures, mental retardation, and movement disorder. We now show that sdCHC is associated with mutations in SLC2A1 that cause both loss of glucose transport and a cation leak, as shown by expression studies in Xenopus oocytes. On the basis of a 3-dimensional model of glut1, we propose potential mechanisms underlying the phenotypes of the 2 mutations found. We investigated the loss of stomatin during erythropoiesis and find this occurs during reticulocyte maturation and involves endocytosis. The molecular basis of the glut1DS, paroxysmal exercise-induced dyskinesia, and sdCHC phenotypes are compared and discussed.
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Transportador de Glucose Tipo 1/deficiência , Transportador de Glucose Tipo 1/genética , Hiperpotassemia/congênito , Proteínas de Membrana/deficiência , Mutação , Sequência de Aminoácidos , Animais , Catarata/sangue , Catarata/genética , Desoxiglucose/metabolismo , Eritrócitos/metabolismo , Feminino , Transportador de Glucose Tipo 1/sangue , Transportador de Glucose Tipo 1/química , Humanos , Hiperpotassemia/sangue , Hiperpotassemia/genética , Hiperpotassemia/metabolismo , Técnicas In Vitro , Transporte de Íons , Proteínas de Membrana/sangue , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Mutantes/sangue , Proteínas Mutantes/química , Proteínas Mutantes/genética , Oócitos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia Estrutural de Proteína , Síndrome , Xenopus laevisRESUMO
Mutations in the human erythroid Krüppel-like factor (EKLF) can lead to either anemia or the benign InLu phenotype. To elucidate the relationship between these mutations and the differing phenotypes, we prepared recombinant forms of wild-type and 5 mutant EKLF proteins and quantitated their binding affinity to a range of EKLF-regulated genes. Missense mutants (R328H, R328L, and R331G) from persons with InLu phenotype did not bind DNA. Hence, as with the heterozygous loss of function nonsense (L127X, S270X, and K292X) and frameshift (P190Lfs and R319Efs) EKLF mutations, monoallelic loss of EKLF does not result in haploinsufficiency at all loci. In contrast, K332Q has a slightly reduced DNA binding affinity (â¼ 2-fold) for all promoters examined but exhibits a phenotype only in a compound heterozygote with a nonfunctional allele. E325K also has a reduced, but significant, binding affinity, particularly for the ß-globin gene but results in a disease phenotype even with the wild-type allele expressed, although not as a classic dominant-negative mutant. E325K protein may therefore actively interfere with EKLF-dependent processes by destabilizing transcription complexes, providing a rational explanation for the severity of the disease phenotype. Our study highlights the critical role of residues within the second EKLF zinc finger domain.
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Doença/genética , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/fisiologia , Regiões Promotoras Genéticas , Sequência de Aminoácidos , Sítios de Ligação/genética , Células Cultivadas , Humanos , Fatores de Transcrição Kruppel-Like/química , Modelos Biológicos , Modelos Moleculares , Dados de Sequência Molecular , Mutação/fisiologia , Fenótipo , Regiões Promotoras Genéticas/genética , Regiões Promotoras Genéticas/fisiologia , Homologia de Sequência de Aminoácidos , Índice de Gravidade de Doença , Especificidade por Substrato/genética , Ativação Transcricional , Dedos de Zinco/genéticaRESUMO
BACKGROUND: Large-scale volumetric biomedical image data of three or more dimensions are a significant challenge for distributed browsing and visualisation. Many images now exceed 10GB which for most users is too large to handle in terms of computer RAM and network bandwidth. This is aggravated when users need to access tens or hundreds of such images from an archive. Here we solve the problem for 2D section views through archive data delivering compressed tiled images enabling users to browse through very-large volume data in the context of a standard web-browser. The system provides an interactive visualisation for grey-level and colour 3D images including multiple image layers and spatial-data overlay. RESULTS: The standard Internet Imaging Protocol (IIP) has been extended to enable arbitrary 2D sectioning of 3D data as well a multi-layered images and indexed overlays. The extended protocol is termed IIP3D and we have implemented a matching server to deliver the protocol and a series of Ajax/Javascript client codes that will run in an Internet browser. We have tested the server software on a low-cost linux-based server for image volumes up to 135GB and 64 simultaneous users. The section views are delivered with response times independent of scale and orientation. The exemplar client provided multi-layer image views with user-controlled colour-filtering and overlays. CONCLUSIONS: Interactive browsing of arbitrary sections through large biomedical-image volumes is made possible by use of an extended internet protocol and efficient server-based image tiling. The tools open the possibility of enabling fast access to large image archives without the requirement of whole image download and client computers with very large memory configurations. The system was demonstrated using a range of medical and biomedical image data extending up to 135GB for a single image volume.
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Imageamento Tridimensional/métodos , Software , Sistemas Computacionais , Computadores , Compressão de Dados , Humanos , Internet , Interface Usuário-ComputadorRESUMO
CYP164 family P450 enzymes are found in only a subset of mycobacteria and include CYP164A1, which is the sole P450 found in Mycobacterium leprae, the causative agent of leprosy. This has previously led to interest in this enzyme as a potential drug target. Here we describe the first crystal structure of a CYP164 enzyme, CYP164A2 from Mycobacterium smegmatis. CYP164A2 has a distinctive, enlarged hydrophobic active site that extends above the porphyrin ring toward the access channels. Unusually, we find that CYP164A2 can simultaneously bind two econazole molecules in different regions of the enlarged active site and is accompanied by the rearrangement and ordering of the BC loop. The primary location is through a classic interaction of the azole group with the porphyrin iron. The second econazole molecule is bound to a unique site and is linked to a tetracoordinated metal ion complexed to one of the heme carboxylates and to the side chains of His 105 and His 364. All of these features are preserved in the closely homologous M. leprae CYP164A1. The computational docking of azole compounds to a homology model of CYP164A1 suggests that these compounds will form effective inhibitors and is supported by the correlation of parallel docking with experimental binding studies of CYP164A2. The binding of econazole to CYP164A2 occurs primarily through the high-spin "open" conformation of the enzyme (K(d) [dissociation constant] of 0.1 µM), with binding to the low-spin "closed" form being significantly hindered (K(d) of 338 µM). These studies support previous suggestions that azole derivatives may provide an effective strategy to improve the treatment of leprosy.
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Antifúngicos/metabolismo , Proteínas de Bactérias/química , Sistema Enzimático do Citocromo P-450/química , Econazol/metabolismo , Hanseníase/tratamento farmacológico , Mycobacterium leprae , Antifúngicos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Domínio Catalítico , Sequência Conservada , Cristalografia por Raios X , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Econazol/farmacologia , Heme/metabolismo , Histidina/metabolismo , Humanos , Ferro/metabolismo , Cinética , Hanseníase/microbiologia , Modelos Moleculares , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium leprae/efeitos dos fármacos , Mycobacterium leprae/enzimologia , Mycobacterium smegmatis/química , Mycobacterium smegmatis/enzimologia , Porfirinas/metabolismo , Ligação Proteica , Estrutura Secundária de ProteínaRESUMO
Moraxella catarrhalis is a ubiquitous human-specific bacterium commonly associated with upper and lower respiratory tract infections, including otitis media, sinusitis and chronic obstructive pulmonary disease. The bacterium uses an autotransporter protein UspA1 to target an important human cellular receptor carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). Using X-ray crystallography, we show that the CEACAM1 receptor-binding region of UspA1 unusually consists of an extended, rod-like left-handed trimeric coiled-coil. Mutagenesis and binding studies of UspA1 and the N-domain of CEACAM1 have been used to delineate the interacting surfaces between ligand and receptor and guide assembly of the complex. However, solution scattering, molecular modelling and electron microscopy analyses all indicate that significant bending of the UspA1 coiled-coil stalk also occurs. This explains how UspA1 can engage CEACAM1 at a site far distant from its head group, permitting closer proximity of the respective cell surfaces during infection.
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Adesinas Bacterianas/metabolismo , Antígenos CD/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Moléculas de Adesão Celular/metabolismo , Adesinas Bacterianas/química , Antígenos CD/química , Proteínas da Membrana Bacteriana Externa/química , Sítios de Ligação , Moléculas de Adesão Celular/química , Dicroísmo Circular , Cristalografia por Raios X , Humanos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Ligação Proteica , Estrutura Secundária de Proteína , Receptores de Superfície Celular , TermodinâmicaRESUMO
eMouseAtlas (www.emouseatlas.org) is a comprehensive online resource to visualise mouse development and investigate gene expression in the mouse embryo. We have recently deployed a completely redesigned Mouse Anatomy Atlas website (www.emouseatlas.org/emap/ema) that allows users to view 3D embryo reconstructions, delineated anatomy, and high-resolution histological sections. A new feature of the website is the IIP3D web tool that allows a user to view arbitrary sections of 3D embryo reconstructions using a web browser. This feature provides interactive access to very high-volume 3D images via a tiled pan-and-zoom style interface and circumvents the need to download large image files for visualisation. eMouseAtlas additionally includes EMAGE (Edinburgh Mouse Atlas of Gene Expression) (www.emouseatlas.org/emage), a freely available, curated online database of in situ gene expression patterns, where gene expression domains extracted from raw data images are spatially mapped into atlas embryo models. In this way, EMAGE introduces a spatial dimension to transcriptome data and allows exploration of the spatial similarity between gene expression patterns. New features of the EMAGE interface allow complex queries to be built, and users can view and compare multiple gene expression patterns. EMAGE now includes mapping of 3D gene expression domains captured using the imaging technique optical projection tomography. 3D mapping uses WlzWarp, an open-source software tool developed by eMouseAtlas.
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Atlas como Assunto , Camundongos/genética , Transcriptoma , AnimaisRESUMO
Annexins are a large family of intracellular phospholipid-binding proteins, yet several extracellular roles have been identified. Specifically, annexin A2, found in a heterotetrameric complex with S100A10, not only serves as a key extracellular binding partner for pathogens and host proteins alike, but also can be shed or secreted. We reported previously that soluble annexin A2 tetramer (A2t) activates human monocyte-derived macrophages (MDM), resulting in secretion of inflammatory mediators and enhanced phagocytosis. Although a receptor for A2t has been cloned from bone marrow stromal cells, data contained in this study demonstrate that it is dispensable for A2t-dependent activation of MDM. Furthermore, A2t activates wild-type murine bone marrow-derived macrophages, whereas macrophages from myeloid differentiation factor 88-deficient mice display a blunted response, suggesting a role for Toll-like receptor (TLR) signaling. Small interfering RNA knockdown of TLR4 in human MDM reduced the response to A2t, blocking antibodies against TLR4 (but not TLR2) blocked activation altogether, and bone marrow-derived macrophages from TLR4(-/-) mice were refractory to A2t. These data demonstrate that the modulation of macrophage function by A2t is mediated through TLR4, suggesting a previously unknown, but important role for this stress-sensitive protein in the detection of danger to the host, whether from injury or invasion.
Assuntos
Anexina A2/fisiologia , Ativação de Macrófagos/genética , Macrófagos/metabolismo , Receptor 4 Toll-Like/fisiologia , Animais , Anexina A2/metabolismo , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células Cultivadas , Feminino , Humanos , Inflamação/genética , Inflamação/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Ativação de Macrófagos/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Fator 88 de Diferenciação Mieloide/fisiologia , Multimerização Proteica/fisiologia , RNA Interferente Pequeno/farmacologia , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismoRESUMO
EMAGE (http://www.emouseatlas.org/emage) is a freely available online database of in situ gene expression patterns in the developing mouse embryo. Gene expression domains from raw images are extracted and integrated spatially into a set of standard 3D virtual mouse embryos at different stages of development, which allows data interrogation by spatial methods. An anatomy ontology is also used to describe sites of expression, which allows data to be queried using text-based methods. Here, we describe recent enhancements to EMAGE including: the release of a completely re-designed website, which offers integration of many different search functions in HTML web pages, improved user feedback and the ability to find similar expression patterns at the click of a button; back-end refactoring from an object oriented to relational architecture, allowing associated SQL access; and the provision of further access by standard formatted URLs and a Java API. We have also increased data coverage by sourcing from a greater selection of journals and developed automated methods for spatial data annotation that are being applied to spatially incorporate the genome-wide (approximately 19,000 gene) 'EURExpress' dataset into EMAGE.
Assuntos
Biologia Computacional/métodos , Bases de Dados Genéticas , Bases de Dados de Ácidos Nucleicos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Expressão Gênica , Acesso à Informação , Animais , Automação , Biologia Computacional/tendências , Desenvolvimento Embrionário/genética , Armazenamento e Recuperação da Informação/métodos , Internet , Camundongos , Linguagens de Programação , SoftwareRESUMO
Spirituality continues to exert a strong influence in people's lives both in work and beyond. However, given that spirituality is often non-formalized and personal, we continue to know little about how moral reasoning is strategized. In this paper, we examine how Buddhist leader-practitioners interpret and operationalize a process of self-decentralization based upon Buddhist emptiness theory as a form of moral reasoning. We find that Buddhist leader-practitioners share a common understanding of a self-decentralized identity and operationalize self-decentralization through two practices in Buddhist philosophy-skillful means and the middle way-to foreground social outcomes. However, we also find that practitioners face tensions and challenges in moral reasoning relates to agency-the 're-centering' of the self as an enlightened self and the use of karmic reasoning to justify (un)ethical behavior-and contextual constraints that lead to feelings of vulnerability and exclusion. We present a model that elaborates these processes and invite further research that examines novel approaches and dynamic interpretations of the self in moral reasoning.