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Zhang, D.

Publications and source records attributed to Zhang, D..

At least 487 records · Page 27Linked to original sources

iCn3D, a Web-based 3D Viewer for the Visualization of Biomolecular Structure and Sequence Annotation

SummaryiCn3D (l-see-in-3D) is a web-based 3D molecular structure viewer implemented in JavaScript. It invites users to explore sequence-structure relationships by displaying 3D structures, protein and nucleotide sequences, and biological annotations such as protein domains, Single Nucleotide Variations, functional sites, molecular contacts, as well as user defined features. Customized and user-annotated displays can be shared with colleagues or publishers via a simple URL, or embedded in web pages as live 3D displays. iCn3D is unique in its ability to simultaneously show 3D structure, 2D molecular networks and interactions, and 1D protein and nucleotide sequences through an integrated sequence/annotation browser. Arbitrary molecular features can be selected in any of the 1D/2D/3D windows as sets of molecules or residues, utilizing flexible user interfaces. These selections are synchronized dynamically in all displays. They can, for example, be shown as tracks in the 1D sequence/annotation browser with simultaneous 3D representations. They can be saved and reused throughout a single user session, or exported for subsequent sessions and further external analysis. iCn3D is rich in structural analysis and visualization features and has a built-in user interface that supports both command line- and menu-driven operation. Session commands can be saved, replayed and shared. iCn3D can display superimposed structures obtained from NCBFs VAST+ structural alignment resource, for comparative analysis of tertiary or quaternary structure. iCn3D can also display electron density maps for crystal structures and export files for 3D printing. The following example URL exemplifies some of the 1D/2D/3D representations: https://www.ncbi.nlm.nih.gov/Structure/icn3d/full.html?mmdbid=1TUP&showanno=1&show2d=1&showsets=1.\n\nAvailability and implementationiCn3D is freely available to the public. Its source code is available at https://github.com/ncbi/icn3d.

bioinformatics↗

PhyloSuite: an integrated and scalable desktop platform for streamlined molecular sequence data management and evolutionary phylogenetics studies

Multi-gene and genomic datasets have become commonplace in the field of phylogenetics, but many of the existing tools are not designed for such datasets, which makes the analysis time-consuming and tedious. We therefore present PhyloSuite, a user-friendly workflow desktop platform dedicated to streamlining molecular sequence data management and evolutionary phylogenetics studies. It employs a plugin-based system that integrates a number of useful phylogenetic and bioinformatic tools, thereby streamlining the entire procedure, from data acquisition to phylogenetic tree annotation, with the following features: (i) point-and-click and drag-and-drop graphical user interface, (ii) a workspace to manage and organize molecular sequence data and results of analyses, (iii) GenBank entries extraction and comparative statistics, (iv) a phylogenetic workflow with batch processing capability, (v) elaborate bioinformatic analysis for mitochondrial genomes. The aim of PhyloSuite is to enable researchers to spend more time playing with scientific questions, instead of wasting it on conducting standard analyses. The compiled binary of PhyloSuite is available under the GPL license at https://github.com/dongzhang0725/PhyloSuite/releases, implemented in Python and runs on Windows, Mac OSX and Linux.

bioinformatics↗

The rice G protein γ subunit qPE9-1 positively regulates grain-filling process by interacting with abscisic acid and auxin

The rice genome contains a single G (RGA1) and G{beta} (RGB1) and five G{gamma} subunits. Recent genetic studies have shown that DEP1/qPE9-1, an atypical putative G{gamma} protein, is responsible for dense and erect panicles, but the biochemical and molecular mechanisms underlying control of grain size are not well understood. Here, we report that plants carrying qPE9-1 have more endosperm cells per grain than plants contain the qpe9-1 allele. The qPE9-1 line has a higher rate and longer period of starch accumulation than the qpe9-1 line. Additionally, the expression of several key genes encoding enzymes catalyzing sucrose metabolism and starch biosynthesis is higher in the qPE9-1 line than in the qpe9-1 line, especially from the mid to late grain-filling stage. Grains of the qPE9-1 line also have higher contents of two phytohormones, ABA and IAA. Exogenous application of ABA or IAA enhanced starch accumulation and the expression of genes encoding grain-filling-related enzymes in the grains of qPE9-1, whereas only IAA produced these effects in qpe9-1. Based on these results, we conclude that qPE9-1 promotes endosperm cell proliferation and positively regulates starch accumulation largely through ABA and IAA, which enhance the expression of genes encoding starch biosynthesis during the late grain-filling stage.

plant biology↗

Genetic variation within genes associated with mitochondrial function is significantly associated with later age at onset of Parkinson disease and contributes to disease risk

Mitochondrial dysfunction has been implicated in the aetiology of monogenic Parkinsons disease (PD). Yet the role that mitochondrial processes play in the most common form of the disease; sporadic PD, is yet to be fully established. Here we comprehensively assessed the role of mitochondrial function associated genes in sporadic PD by leveraging improvements in the scale and analysis of PD GWAS data with recent advances in our understanding of the genetics of mitochondrial disease. First, we identified that a proportion of the \"missing heritability\" of the PD can be explained by common variation within genes implicated in mitochondrial disease (primary gene list) and mitochondrial function (secondary gene list). Next we calculated a mitochondrial-specific polygenic risk score (PRS) and showed that cumulative small effect variants within both our primary and secondary gene lists are significantly associated with increased PD risk. Most significantly we further report that the PRS of the secondary mitochondrial gene list was significantly associated with later age at onset. Finally, to identify possible functional genomic associations we implemented Mendelian randomisation, which showed that 14 of these mitochondrial function associated genes showed functional consequence associated with PD risk. Further analysis suggested that the 14 identified genes are not only involved in mitophagy but implicate new mitochondrial processes. Our data suggests that therapeutics targeting mitochondrial bioenergetics and proteostasis pathways distinct from mitophagy could be beneficial to treating the early stage of PD.

genetics↗

CSTDB: A Crop Stress-tolerance Gene and Protein Database Integrated by Convolutional Neural Networks

Numerous studies have shown that many genes and proteins in plants are involved in the regulation of plant resistance to abiotic and biotic stresses. The researches on the stress tolerance of crops are also the focus of many researchers. To provides a reliable platform for collecting and retrieving genetic and protein information related to stress tolerance found in crops, we constructed CSTDB(Crops Stress-tolerance Database), an integrated database that includes stress-tolerance genes and proteins for many crop species. The database was developed based on convolutional neural network technology. It is a web-accessible database that contains detailed information on the stress-tolerance genes and proteins of major crop species. Currently, the database records four major crops containing 1,371 abiotic stress-tolerance genes or proteins, and 207 genes or proteins associated with biotic stress. Each gene and protein has detailed functional information and sequence information, such as stress types, Genbank ID, Pubmed ID, Protein ID, 3D model picture and FASTA files. As a user-friendly browsing tool, this database provides search functions, BALST functions and file download functions. CSTDB can be a valuable resource, which is designed to meet the broad needs of researchers working on crops stress-tolerance experiments. Database URL: http://pcsb.ahau.edu.cn:8080/CSTDB

bioinformatics↗

Genome structure and evolution of Antirrhnum majus L.

Snapdragon (Antirrhinum majus L.), a member of Plantaginaceae, is an important model for plant genetics and molecular studies on plant growth and development, transposon biology and self-incompatibility. Here we report a high-quality genome assembly of A. majus cultivated JI7 (A. majus cv.JI7) of a 510 Mb with 37,714 annotated protein-coding genes. The scaffolds covering 97.12% of the assembled genome were anchored on 8 chromosomes. Comparative and evolutionary analyses revealed that Plantaginaceae and Solanaceae diverged from their most recent ancestor around 62 million years ago (MYA). We also revealed the genetic architectures associated with complex traits such as flower asymmetry and self-incompatibility including a unique TCP duplication around 46-49 MYA and a near complete{psi} S-locus of ca.2 Mb. The genome sequence obtained in this study not only provides the first genome sequenced from Plantaginaceae but also bring the popular plant model system of Antirrhinum into a genomic age.

genomics↗

Genetic variability in response to Aβ deposition influences Alzheimer’s risk

Genetic analysis of late-onset Alzheimers disease risk has previously identified a network of largely microglial genes that form a transcriptional network. In transgenic mouse models of amyloid deposition we have previously shown that the expression of many of the mouse orthologs of these genes are co-ordinately up-regulated by amyloid deposition. Here we investigate whether systematic analysis of other members of this mouse amyloid-responsive network predicts other Alzheimers risk loci. This statistical comparison of the mouse amyloid-response network with Alzheimers disease genome-wide association studies identifies 5 other genetic risk loci for the disease (OAS1, CXCL10, LAPTM5, ITGAM and LILRB4). This work suggests that genetic variability in the microglial response to amyloid deposition is a major determinant for Alzheimers risk.\n\nOne Sentence SummaryIdentification of 5 new risk loci for Alzheimers by statistical comparison of mouse A{beta} microglial response with gene-based SNPs from human GWAS

neuroscience↗

Multimodal interferometric imaging of nanoscale structure and macromolecular motion uncovers UV induced cellular paroxysm

We present a multimodal label-free interferometric imaging platform for measuring intracellular nanoscale structure and macromolecular dynamics in living cells with a sensitivity to macromolecules as small as 20nm and millisecond temporal resolution. We validate this system by pairing experimental measurements of nanosphere phantoms with a novel interferometric theory. Applying this system in vitro, we explore changes in higher-order chromatin structure and dynamics that occur due to cellular fixation, stem cell differentiation, and ultraviolet (UV) light irradiation. Finally, we discover a new phenomenon, cellular paroxysm, a near-instantaneous, synchronous burst of motion that occurs early in the process of UV induced cell death. Given this platforms ability to obtain nanoscale sensitive, millisecond resolved information within live cells without concerns of photobleaching, it has the potential to answer a broad range of critical biological questions about macromolecular behavior in live cells, particularly about the relationship between cellular structure and function.

biophysics↗

Metabolic engineering of Escherichia coli for de novo biosynthesis of vitamin B12

The only known source of vitamin B12 (adenosylcobalamin) is from bacteria and archaea, and the only unknown step in its biosynthesis is the production of the intermediate adenosylcobinamide phosphate. Here, using genetic and metabolic engineering, we generated an Escherichia coli strain that produces vitamin B12 via an engineered de novo aerobic biosynthetic pathway. Excitingly, the BluE and CobC enzymes from Rhodobacter capsulatus transform L-threonine into (R)-1-Amino-2-propanol O-2-Phosphate, which is then condensed with adenosylcobyric acid to yield adenosylcobinamide phosphate by either CobD from the aeroic R. capsulatus or CbiB from the anerobic Salmonella typhimurium. These findings suggest that the biosynthetic steps from co(II)byrinic acid a,c-diamide to adocobalamin are the same in both the aerobic and anaerobic pathways. Finally, we increased the vitamin B12 yield of a recombinant E. coli strain by more than [~]250-fold to 307.00 {micro}g/g DCW via metabolic engineering and optimization of fermentation conditions. Beyond our scientific insights about the aerobic and anaerobic pathways and our demonstration of E. coli as a microbial biosynthetic platform for vitamin B12 production, our study offers an encouraging example of how the several dozen proteins of a complex biosynthetic pathway can be transferred between organisms to facilitate industrial production.

synthetic biology↗

Transcriptional regulation of voltage-gated sodium channels contributes to GM-CSF induced pain

Granolocyte-macrophage colony stimulating factor (GM-CSF) induces production of granulocyte and macrophage populations from the hematopoietic progenitor cells; it is one of the most common growth factors in the blood. GM-CSF is also involved in bone cancer pain development by regulating tumor-nerve interactions, remodeling of peripheral nerves and sensitization of damage-sensing (nociceptive) nerves. However, the precise mechanism for GM-CSF-dependent pain is unclear. In this study, we found that GM-CSF is highly expressed in human malignant osteosarcoma. Rats implanted with bone cancer cells develop mechanical and thermal hyperalgesia but antagonizing GM-CSF in these animals significantly reduced such hypersensitivity. Nociceptor-specific voltage gated Na+ channels Nav1.7, Nav1.8 and Nav1.9 were found to be selectively up-regulated in rat DRG neurons treated with GM-CSF, which resulted in enhanced excitability. GM-CSF activated the Jak2 and Stat3 signaling pathway which promoted the transcription of Nav1.7-1.9 in DRG neurons. Accordingly targeted knocking down either Nav1.7-1.9 or Jak2/Stat3 in DRG neurons alleviated the hyperalgesia in rats. Our findings describe a new bone cancer pain mechanism and provide a new insight into the physiological and pathological functions of GM-CSF.

neuroscience↗

Single-cell RNA-seq reveals dynamic transcriptome profiling in human early neural differentiation

BackgroundInvestigating cell fate decision and subpopulation specification in the context of the neural lineage is fundamental to understanding neurogenesis and neurodegenerative diseases. The differentiation process of neural-tube-like rosettes in vitro is representative of neural tube structures, which are composed of radially organized, columnar epithelial cells and give rise to functional neural cells. However, the underlying regulatory network of cell fate commitment during early neural differentiation remains elusive.\n\nResultsIn this study, we investigated the genome-wide transcriptome profile of single cells from six consecutive reprogramming and neural differentiation time points and identified cellular subpopulations present at each differentiation stage. Based on the inferred reconstructed trajectory and the characteristics of subpopulations contributing the most towards commitment to the central nervous system (CNS) lineage at each stage during differentiation, we identified putative novel transcription factors in regulating neural differentiation. In addition, we dissected the dynamics of chromatin accessibility at the neural differentiation stages and revealed active c/s-regulatory elements for transcription factors known to have a key role in neural differentiation as well as for those that we suggest are also involved. Further, communication network analysis demonstrated that cellular interactions most frequently occurred among embryoid body (EB) stage and each cell subpopulation possessed a distinctive spectrum of ligands and receptors associated with neural differentiation which could reflect the identity of each subpopulation.\n\nConclusionsOur study provides a comprehensive and integrative study of the transcriptomics and epigenetics of human early neural differentiation, which paves the way for a deeper understanding of the regulatory mechanisms driving the differentiation of the neural lineage.

developmental biology↗

CRISPR-bind: a simple, custom CRISPR/dCas9-mediated labeling of genomic DNA for mapping in nanochannel arrays

Bionano genome mapping is a robust optical mapping technology used for de novo construction of whole genomes using ultra-long DNA molecules, able to efficiently interrogate genomic structural variation. It is also used for functional analysis such as epigenetic analysis and DNA replication mapping and kinetics. Genomic labeling for genome mapping is currently specified by a single strand nicking restriction enzyme followed by fluorophore incorporation by nick-translation (NLRS), or by a direct label and stain (DLS) chemistry which conjugates a fluorophore directly to an enzyme-defined recognition site. Although these methods are efficient and produce high quality whole genome mapping data, they are limited by the number of available enzymes--and thus the number of recognition sequences--to choose from. The ability to label other sequences can provide higher definition in the data and may be used for countless additional applications. Previously, custom labeling was accomplished via the nick-translation approach using CRISPR-Cas9, leveraging Cas9 mutant D10A which has one of its cleavage sites deactivated, thus effectively converting the CRISPR-Cas9 complex into a nickase with customizable target sequences. Here we have improved upon this approach by using dCas9, a nuclease-deficient double knockout Cas9 with no cutting activity, to directly label DNA with a fluorescent CRISPR-dCas9 complex (CRISPR-bind). Unlike labeling with CRISPR-Cas9 D10A nickase, in which nicking, labeling, and repair by ligation, all occur as separate steps, the new assay has the advantage of labeling DNA in one step, since the CRISPR-dCas9 complex itself is fluorescent and remains bound during imaging. CRISPR-bind can be added directly to a sample that has already been labeled using DLS or NLRS, thus overlaying additional information onto the same molecules. Using the dCas9 protein assembled with custom target crRNA and fluorescently labeled tracrRNA, we demonstrate rapid labeling of repetitive DUF1220 elements. We also combine NLRS-based whole genome mapping with CRISPR-bind labeling targeting Alu loci. This rapid, convenient, non-damaging, and cost-effective technology is a valuable tool for custom labeling of any CRISPR-Cas9 amenable target sequence.

genomics↗

Genome-wide CNV study and functional evaluation identified CTDSPL as tumour suppressor gene for cervical cancer

We have investigated copy number variations (CNVs) in relation to cervical cancer by analyzing 731,422 single-nucleotide polymorphisms (SNPs) in 1,034 cervical cancer cases and 3,948 controls, followed by replication in 1,396 cases and 1,057 controls. We found that a 6367bp deletion in intron 1 of the CTD small phosphatase like gene (CTDSPL) was associated with 2.54-fold increased risk of cervical cancer (odds ratio =2.54, 95% confidence interval =2.08-3.12, P=2.0x10-19). This CNV is one of the strongest genetic risk variants identified so far for cervical cancer. The deletion removes the binding sites of zinc finger protein 263, binding protein 2 and interferon regulatory factor 1, and hence downregulates the transcription of CTDSPL. HeLa cells expressing CTDSPL showed a significant decrease in colony-forming ability. Compared with control groups, mice injected with HeLa cells expressing CTDSPL exhibited a significant reduction in tumour volume. Furthermore, CTDSPL-depleted immortalized End1/E6E7 could form tumours in NOD-SCID mice.

cancer biology↗

The key lethal effect existed in the antibacterial behavior of short, medium, and long chain fatty acid monoglycerides on Escherichia coli

Monoglyceride is an amphiphilic molecule with promising antimicrobial activity for bacteria; however, the key lethal effect in its antibacterial behavior was still unknown. In the study, monobutyrate (MB), monolaurate (ML), monomyristate (MM) were selected to represent the short, medium, and long chain monoglycerides to compare their inhibitory effect against Escherichia coli, and a new dose-dependent inhibitory mechanism was proposed by the key lethal effect. The minimal inhibitory concentration and antibacterial curve showed a huge diversity existed in biology activity of MB, ML and MM. The results in scanning electron microscopy and flow cytometry assay indicated that the interference level of MB on cell membrane was obviously weaker than that of ML and MM, while the latter two had similar performance in increasing cell permeability at low doses. The results presented in UV-Vis spectroscopy, cell cycle and biomacromolecules synthesis inhibition assay showed that the cell cycle of Escherichia coli was obviously affected by three monoglycerides at doses near MIC, which was therefore regarded as the key lethal effect. The reason for the better biological activity of MM than ML was the stronger interference ability on bacterial cell cycle. In addition, an expanded antibacterial mode was raised that cell permeability increase at low doses was antimicrobial basis, cell cycle arrest at medium doses played the key lethal effect, and cell lysis at high doses was the result of combined action.

microbiology↗

The identification of critical lethal action in antimicrobial mechanism of glycerol monomyristate against foodborne pathogens

Glycerol monomyristate (GMM) is a promising antimicrobial substance due to its broad antibacterial spectrum: however, the critical lethal action in its antimicrobial mechanism for foodborne pathogens remains unclear. In the present study, the inhibitory activities of GMM on Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) were compared, and its membrane and intracellular action mechanism was investigated. The results showed that the susceptibility of E. coli to GMM was the highest, followed by S. aureus, and C. albicans being the poorest. Using flow cytometry, the GMM dose causing above 50% permeability ratio on E. coli was lower than that on S. aureus. The images from scanning electron microscope revealed no doses difference existed between the two strains when the obvious cell damage occurred. Furthermore, cell cycle and multiple fluorescent staining assays showed only the cell division of E. coli and S. aureus, excluding that of C. albicans, was obviously affected at 1/4 MIC and 1/2 MIC, indicating that the DNA interfere and subsequent cell division inhibition was likely to be the critical lethal action with doses near MIC, which can also explain the poor sensitivity of C. albicans.\n\nImportanceFoodborne pathogens, as a common source of biological pollution in the food industry, can cause millions of food poisoning incidents each year, which poses great risks to consumers health and safety. The use of monoglyceride as an edible surfactant to inhibit the growth of food-borne microorganisms has been a long time, but the relevant antibacterial mechanism is too broad to accurately grasp its key lethal effect and its action doses, which not only affects the antibacterial efficiency, but also may result in the abnormalities of food flavor when adding at overdoses. The significance of the study is to identify the key lethal effect and its action doses, which will greatly enhance the understanding of the response mechanism of different types of foodborne pathogens to monoglycerides, and provide a more reasonable reference for differential control and treatment of different gastrointestinal infections when combined with antibiotics in clinical.

microbiology↗

Variation at the TRIM11 locus modifies Progressive Supranuclear Palsy phenotype

ObjectiveThe basis for clinical variation related to underlying Progressive Supranuclear Palsy (PSP) pathology is unknown. We performed a genome wide association study (GWAS) to identify genetic determinants of PSP phenotype.\n\nMethodsTwo independent pathological and clinically diagnosed PSP cohorts were genotyped and phenotyped to create Richardsons syndrome (RS) and non-RS groups. We carried out separate logistic regression GWAS to compare RS and non-RS groups and then combined datasets to carry out a whole cohort analysis (RS=367, non-RS=130). We validated our findings in a third cohort by referring to data from 100 deeply phenotyped cases from a recent GWAS. We assessed the expression/co-expression patterns of our identified genes and used our data to carry out gene-based association testing.\n\nResultsOur lead single nucleotide polymorphism (SNP), rs564309, showed an association signal in both cohorts, reaching genome wide significance in our whole cohort analysis - OR 5.5 (3.2-10.0), p-value 1.7x10-9. rs564309 is an intronic variant of the tripartite motif-containing protein 11 (TRIM11) gene, a component of the ubiquitin proteasome system (UPS). In our third cohort, minor allele frequencies of surrogate SNPs in high linkage disequilibrium with rs564309 replicated our findings. Gene based association testing confirmed an association signal at TRIM11. We found that TRIM11 is predominantly expressed neuronally, in the cerebellum and basal ganglia.\n\nInterpretationOur study suggests that the TRIM11 locus is a genetic modifier of PSP phenotype and potentially adds further evidence for the UPS having a key role in tau pathology, therefore representing a target for disease modifying therapies.

neuroscience↗

Autophagy determines osimertinib resistance through regulation of stem cell-like properties in EGFR-mutant lung cancer

Drug resistance to Osimertinib, a 3rd-generation EGFR-TKI is inevitable. Autophagy plays a contradictory role in resistance of 1st and 2nd generation EGFR-TKI, and its significance in osimertinib resistance is much less clear. We therefore investigated whether autophagy determines osimertinib resistance. First, osimertinib induced autophagy to a much greater extent than that of gefitinib, and autophagy inhibition further increased osimertinib efficacy. Next, enhanced autophagy was found in osimertinib resistant cells and autophagy inhibition partially reversed osimertinib resistance. Enhanced stem-cell like properties were found in resistant cells, and siRNA-knock down of SOX2 or ALDH1A1reversed osimertinib resistance. Of note, autophagy inhibition or siRNA-knock down of Beclin-1 decreased expression of SOX2 and ALDH1A1 and stem-cell like properties. Next, autophagy inhibition and osimertinib in combination effectively blocked tumor growth in xenografts, which was associated with decreased autophagy and stem cell-like properties in vivo. Finally, enhanced autophagy was found in lung cancer patients with resistance to osimertinib. In conclusion, the current study delineates a previously unknown function of autophagy in determining osimertinib resistance through promoting stem-cell like properties.

cancer biology↗

Localization and protein-protein interaction of protein kinase CK2 suggest a chaperone-like activity is integral to its function in M. oryzae.

Magnaporthe oryzae (Mo) is a model pathogen causing rice blast resulting in yield and economic losses world-wide. CK2 is a constitutively active, serine/threonine kinase in eukaryotes, having a wide array of known substrates and involved in many cellular processes. We investigated the localization and role of MoCK2 during growth and infection. BLAST search for MoCK2 components and targeted deletion of subunits was combined with protein-GFP fusions to investigate localization. We found one CKa and two CKb subunits of the CK2 holoenzyme. Deletion of the catalytic subunit CKa was not possible and might indicate that such deletions are lethal. The CKb subunits could be deleted but they were both necessary for normal growth and pathogenicity. Localization studies showed that the CK2 holoenzyme needed to be intact for normal localization at septal pores and at appressorium penetration pores. Nuclear localization of CKa was however not dependent on the intact CK2 holoenzyme. In appressoria, CK2 formed a large ring perpendicular to the penetration pore and the ring formation was dependent on the presence of all CK2 subunits. The effects on growth and pathogenicity of deletion of the b subunits combined with the localization indicate that CK2 can have important regulatory functions not only in the nucleus/nucleolus but also at fungal specific structures as septa and appressorial pores.

cell biology↗