early-diverged eukaryote trypanosoma: Topics by WorldWideScience.org

Visual Genome-Wide RNAi Screening to Identify Human Host Factors Required for Trypanosoma cruzi Infection

No abstract prepared.

2008-10-15

Two tandemly linked identical genes code for the glycosomal glyceraldehyde-phosphate dehydrogenase in Trypanosoma brucei.

The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy...Full Text Available

Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase does not conform to the 'hotspot' topogenic signal model.

Trypanosoma brucei contains two isoenzymes for glyceraldehyde-phosphate dehydrogenase (GAPDH); one enzyme resides in a microbody-like organelle, the glycosome, the other one is found in the cytosol....Full Text Available

1986-05-01

The region encompassing the procyclic acidic repetitive protein (PARP) gene promoter plays a role in plasmid DNA replication in Trypanosoma brucei.

The genes which encode glycosomal glyceraldehyde-phosphate dehydrogenase (gGAPDH) of Trypanosoma cruzi are arranged as a tandemly repeated pair on a single chromosome and are identical at the level...Full Text Available

1990-09-01

Testing the Efficacy of a Multi-Component DNA-Prime/DNA-Boost Vaccine against Trypanosoma cruzi Infection in Dogs

We have previously reported the construction and characterization of an autonomously replicating plasmid in Trypanosoma brucei. In this plasmid the procyclic acidic repetitive protein (PARP) gene promoter...Full Text Available

1994-10-11

In vitro growth inhibition of bloodstream forms of Trypanosoma brucei and Trypanosoma congolense by iron chelators

BackgroundTrypanosoma cruzi, the etiologic agent of Chagas Disease, is a major vector borne health problem in Latin America and an emerging...Full Text Available

In vitro assay for curative activity in blood of mice infected with Trypanosoma musculi.

African trypanosomes exert significant morbidity and mortality in man and livestock. Only a few drugs are available for the treatment of trypanosome infections and therefore, the development of new...Full Text Available

Characterization of antibodies mediating protection and cure of Trypanosoma musculi infection in mice.

An in vitro assay for curative antibody present in plasma of mice cured of Trypanosoma musculi is described. The assay involves the addition of plasma to a sample of infected blood, followed by hourly...Full Text Available

1986-08-01

Aspirin Treatment of Mice Infected with Trypanosoma cruzi and Implications for the Pathogenesis of Chagas Disease

Plasma samples were collected from mice infected with Trypanosoma musculi at different times postinfection and administered to naive recipient mice either before or during T. musculi infection. The...Full Text Available

1985-06-01

The COG database: an updated version includes eukaryotes

Chagas disease, caused by infection with Trypanosoma cruzi, is an important cause of cardiovascular disease. It is increasingly clear that parasite-derived prostaglandins potently modulate...Full Text Available

Eukaryotic Diversity in an Anaerobic Aquifer Polluted with Landfill Leachate?

BackgroundThe availability of multiple, essentially complete genome sequences of prokaryotes and eukaryotes spurred both the demand and the opportunity for the construction of an...Full Text Available

Identification of Contractile Vacuole Proteins in Trypanosoma cruzi

Eukaryotes may influence pollutant degradation processes in groundwater ecosystems by activities such as predation on bacteria and recycling of nutrients. Culture-independent community profiling and...Full Text Available

2008-07-01

Molecular, functional and structural properties of the prolyl oligopeptidase of Trypanosoma cruzi (POP Tc80), which is required for parasite entry into mammalian cells

Contractile vacuole complexes are critical components of cell volume regulation and have been shown to have other functional roles in several free-living protists....Full Text Available

The mode and tempo of genome size evolution in eukaryotes

We have demonstrated that the 80 kDa POP Tc80 (prolyl oligopeptidase of Trypanosoma cruzi) is involved in the process of cell invasion, since specific inhibitors block parasite...Full Text Available

2005-05-15

Rab protein evolution and the history of the eukaryotic endomembrane system

Eukaryotic genome size varies over five orders of magnitude; however, the distribution is strongly skewed toward small values. Genome size is highly correlated to a number of phenotypic traits, suggesting...Full Text Available

2007-05-01

Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae

Spectacular increases in the quantity of sequence data genome have facilitated major advances in eukaryotic comparative genomics. By exploiting homology with classical model organisms, this makes possible...Full Text Available

2010-10-01

British Library Electronic Table of Contents (United Kingdom)

Ethnobotanical and chemotaxonomical studies for antiparasitic activity of Colombian Annonaceae were carried out. In vitro antiprotozoal activity of 36 extracts obtained from six different species was determined against promastigotes of three Leishmania species, epimastigotes of Trypanosoma cruzi and both chloroquine sensitive (F32) and resistant (W2) Plasmodium falciparum. Cytotoxic activity was evaluated in U-937 cells. Active extracts were selected according their selectivity index (SI). Extracts from Annona muricata, Rollinia exsucca, Rollinia pittieri and Xylopia aromatica were active against Leishmania spp. and Trypanosoma cruzi showing IC50 values lower than 25mg/ml. Hexane extract from Rollinia pittieri leaves was the most selective against Trypanosoma cruzi and Leishmania spp. (IS=...

2007-01-01

Ellman's-reagent-mediated regeneration of trypanothione in situ: substrate-economical microplate and time-dependent inhibition assays for trypanothione reductase.

EXTINCTION OF EXPERIMENTAL TRIATOMA INFESTANS POPULATIONS FOLLOWING CONTINUOUS EXPOSURE TO DOGS WEARING DELTAMETHRIN-TREATED COLLARS

Trypanothione reductase (TryR) is a key enzyme involved in the oxidative stress management of the Trypanosoma and Leishmania parasites, which helps to maintain an intracellular reducing environment...Full Text Available

2003-02-01

Biochemical analysis of PIFTC3, the Trypanosoma brucei ortholog of nematode DYF-13, reveals interactions with established and putative intraflagellar transport components

Dogs are domestic reservoir hosts of Trypanosoma cruzi, the etiological agent of Chagas disease. We evaluated the effect of deltamethrin-treated dog collars (DTDCs) over time...Full Text Available

2006-05-01

1 2 3 4

Towards a Synthetic Chloroplast

DYF-13, originally identified in C. elegans within a collection of dye-filling chemosensory mutants, is one of several proteins that have been classified as putatively involved...Full Text Available

2010-10-01

Plasticity in patterns of histone modifications and chromosomal proteins in Drosophila heterochromatin

BackgroundThe evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria,...Full Text Available

Building the Perfect Parasite: Cell Division in Apicomplexa

Eukaryotic genomes are packaged in two basic forms, euchromatin and heterochromatin. We have examined the composition and organization of Drosophila melanogaster heterochromatin in...Full Text Available

2011-02-01

Mitochondrial NADH:ubiquinone oxidoreductase (complex I) in eukaryotes: A highly conserved subunit composition highlighted by mining of protein databases

Apicomplexans are pathogens responsible for malaria, toxoplasmosis, and crytposporidiosis in humans, and a wide range of livestock diseases. These unicellular eukaryotes are stealthy invaders, sheltering...Full Text Available

2007-06-01

British Library Electronic Table of Contents (United Kingdom)

Complex I (NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain. Compared to its bacterial counterpart which encompasses 14-17 subunits, mitochondrial complex I has almost tripled its subunit composition during evolution of eukaryotes, by recruitment of so-called accessory subunits, part of them being specific to distinct evolutionary lineages. The increasing availability of numerous broadly sampled eukaryotic genomes now enables the reconstruction of the evolutionary history of this large protein complex. Here, a combination of profile-based sequence comparisons and basic structural properties analyses at the protein level enabled to pinpoint homology relationships between complex I subunits from fungi, mammals or green plants, previously identified...

2011-01-01

Transposable elements are enriched within or in close proximity to xenobiotic-metabolizing cytochrome P450 genes

Translation Elongation Factor 1A Facilitates the Assembly of the Tombusvirus Replicase and Stimulates Minus-Strand Synthesis

BackgroundTransposons, i.e. transposable elements (TEs), are the major internal spontaneous mutation agents for the variability of eukaryotic genomes. To address the general issue...Full Text Available

The fission yeast gene pmt1+ encodes a DNA methyltransferase homologue.

Replication of plus-strand RNA viruses depends on host factors that are recruited into viral replicase complexes. Previous studies showed that eukaryotic translation elongation factor (eEF1A) is one...Full Text Available

2010-11-01

The chromosomal association/dissociation of the chromatin insulator protein Cp190 of Drosophila melanogaster is mediated by the BTB/POZ domain and two acidic regions

DNA methylation of cytosine residues is a widespread phenomenon and has been implicated in a number of biological processes in both prokaryotes and eukaryotes. This methylation occurs at the 5-position...Full Text Available

1995-01-25

TassDB2 - A comprehensive database of subtle alternative splicing events

BackgroundChromatin insulators or boundary elements are a class of functional elements in the eukaryotic genome. They regulate gene transcription by interfering with promoter-enhancer...Full Text Available

Structural and Functional Insights into Saccharomyces cerevisiae Tpa1, a Putative Prolylhydroxylase Influencing Translation Termination and Transcription*

BackgroundSubtle alternative splicing events involving tandem splice sites separated by a short (2-12 nucleotides) distance are frequent and evolutionarily widespread in eukaryotes,...Full Text Available

ReplicationDomain: a visualization tool and comparative database for genome-wide replication timing data

Efficiency of translation termination relies on the specific recognition of the three stop codons by the eukaryotic translation termination factor eRF1. To date only a few proteins are known to be involved...Full Text Available

2010-10-01

PtdIns 3-Kinase Orchestrates Autophagosome Formation in Yeast

BackgroundEukaryotic DNA replication is regulated at the level of large chromosomal domains (0.5–5 megabases in mammals) within which replicons are activated relatively synchronously....Full Text Available

Pseudomonas aeruginosa-Candida albicans Interactions: Localization and Fungal Toxicity of a Phenazine Derivative?

Eukaryotic cells can massively transport their own cytoplasmic contents into a lytic compartment, the vacuole/lysosome, for recycling through a conserved system called autophagy. The key process in...Full Text Available

2011-01-01

Proteasomal chymotrypsin-like peptidase activity is required for essential functions of human monocyte-derived dendritic cells

Phenazines are redox-active small molecules that play significant roles in the interactions between pseudomonads and diverse eukaryotes, including fungi. When Pseudomonas aeruginosa...Full Text Available

2009-01-01

Primary structure and regulation of vegetative specific genes of Dictyostelium discoideum.

The ubiquitin–proteasome pathway is the principal system for extralysosomal protein degradation in eukaryotic cells, and is essential for the regulation and maintenance of basic cellular processes,...Full Text Available

2007-01-01

Overexpression of human virus surface glycoprotein precursors induces cytosolic unfolded protein response in Saccharomyces cerevisiae

We have examined the expression and structure of several genes belonging to two classes of vegetative specific genes of the simple eukaryote, Dictyostelium discoideum. In amebae grown on bacteria, deactivation...Full Text Available

1989-12-11

Mutagenic and cytotoxic activity of doxorubicin and daunorubicin derivatives on prokaryotic and eukaryotic cells.

BackgroundThe expression of human virus surface proteins, as well as other mammalian glycoproteins, is much more efficient in cells of higher eukaryotes rather than yeasts. The limitations...Full Text Available

Membrane nanotubes induced by aqueous phase separation and stabilized by spontaneous curvature

The mutagenic and cytotoxic activity of two newly synthesized doxorubicin derivatives and of one daunorubicin derivative were studied in V79 Chinese hamster cells and bacteria (Salmonella typhimurium...Full Text Available

1984-07-01

Lessons in Signaling and Tumorigenesis from Polyomavirus Middle T Antigen

Tubular membrane structures are widespread in eukaryotic cells, but the mechanisms underlying their formation and stability are not well understood. Previous work has focused on tube extrusion from...Full Text Available

2011-03-22

Large-scale Analysis of Thermo-stable, Mammalian Proteins Provides Insights into the Intrinsically Disordered Proteome

Summary: The small DNA tumor viruses have provided a very long-lived source of insights into many aspects of the life cycle of eukaryotic cells. In recent years, the emphasis has been on cancer-related...Full Text Available

2009-09-01

1 2 3 4

Improving the Arabidopsis genome annotation using maximal transcript alignment assemblies

Intrinsically disordered proteins are predicted to be highly abundant and play broad biological roles in eukaryotic cells. In particular, by virtue of their structural malleability and propensity...Full Text Available

2009-01-01

Identification of cell cycle-related regulatory motifs using a kernel canonical correlation analysis

The spliced alignment of expressed sequence data to genomic sequence has proven a key tool in the comprehensive annotation of genes in eukaryotic genomes. A novel algorithm was developed to assemble...Full Text Available

2003-10-01

Human Pol II promoter recognition based on primary sequences and free energy of dinucleotides

BackgroundGene regulation is a key mechanism in higher eukaryotic cellular processes. One of the major challenges in gene regulation studies is to identify regulators affecting the...Full Text Available

Genomes are covered with ubiquitous 11 bp periodic patterns, the "class A flexible patterns"

BackgroundPromoter region plays an important role in determining where the transcription of a particular gene should be initiated. Computational prediction of eukaryotic Pol II promoter...Full Text Available

Genome-wide profiling of forum domains in Drosophila melanogaster

BackgroundThe genomes of prokaryotes and lower eukaryotes display a very strong 11 bp periodic bias in the distribution of their nucleotides. This bias is present throughout a given...Full Text Available

Expression and Characterization of the Mycobacterium tuberculosis Serine/Threonine Protein Kinase PknB

Forum domains are stretches of chromosomal DNA that are excised from eukaryotic chromosomes during their spontaneous non-random fragmentation. Most forum domains are 50–200 kb in length....Full Text Available

2011-05-01

Evolution of macromolecular import pathways in mitochondria, hydrogenosomes and mitosomes

PknB is a member of the newly discovered eukaryotic-like protein serine/threonine kinase (PSTK) family of proteins. The pknB gene was cloned and expressed in Escherichia coli....Full Text Available

1999-11-01

Acetylation of Histones and Transcription-Related Factors

All eukaryotes require mitochondria for survival and growth. The origin of mitochondria can be traced down to a single endosymbiotic event between two probably prokaryotic organisms. Subsequent evolution...Full Text Available

2010-03-12

A small RNA promotes siderophore production through transcriptional and metabolic remodeling

The state of chromatin (the packaging of DNA in eukaryotes) has long been recognized to have major effects on levels of gene expression, and numerous chromatin-altering strategies—including...Full Text Available

2000-06-01

A profusion of upstream open reading frame mechanisms in polyamine-responsive translational regulation

Siderophores are essential factors for iron (Fe) acquisition in bacteria during colonization and infection of eukaryotic hosts, which restrain iron access through iron-binding protein, such as lactoferrin...Full Text Available

2010-08-24

Genetic and expression analysis of cattle identifies candidate genes in pathways responding to Trypanosoma congolense infection.

In many eukaryotic mRNAs one or more short ‘upstream’ open reading frames, uORFs, precede the initiator of the main coding sequence. Upstream ORFs are functionally diverse as illustrated...Full Text Available

2010-01-01

The unique hypusine modification of eIF5A promotes islet ? cell inflammation and dysfunction in mice

African bovine trypanosomiasis caused by Trypanosoma sp., is a major constraint on cattle productivity in sub-Saharan Africa. Some African Bos taurus breeds are highly tolerant of infection, but the potentially more productive Bos indicus zebu breeds are much more susceptible. Zebu cattle are well adapted for plowing and haulage, and increasing their tolerance of trypanosomiasis could have a major impact on crop cultivation as well as dairy and beef production. We used three strategies to obtain short lists of candidate genes within QTL that were previously shown to regulate response to infection. We analyzed the transcriptomes of trypanotolerant N'Dama and susceptible Boran cattle after infection with Trypanosoma congolense. We sequenced EST libraries from these two breeds to identify polymorphisms that might underlie previously identified quantitative trait loci (QTL), and we assessed QTL regions and candidate loci for evidence of selective ...

2011-05-18

The YTH Domain Is a Novel RNA Binding Domain*

In both type 1 and type 2 diabetes, pancreatic islet dysfunction results in part from cytokine-mediated inflammation. The ubiquitous eukaryotic translation initiation factor 5A (eIF5A), which is the...Full Text Available

2010-06-01

Structure, Function, and Evolution of Rice Centromeres

The YTH (YT521-B homology) domain was identified by sequence comparison and is found in 174 different proteins expressed in eukaryotes. It is characterized by 14 invariant residues within an α-helix/β-sheet...Full Text Available

2010-05-07

Sequence analysis of two alleles reveals that intra-and intergenic recombination played a role in the evolution of the radish fertility restorer (Rfo)

The centromere is the most characteristic landmark of eukaryotic chromosomes. Centromeres function as the site for kinetochore assembly and spindle attachment, allowing for the faithful pairing and segregation of sister chromatids during cell division. Characterization of centromeric DNA is not only essential to understand the structure and organization of plant genomes, but it is also a critical step in the development of plant artificial chromosomes. The centromeres of most model eukaryotic species, consist predominantly of long arrays of satellite DNA. Determining the precise DNA boundary of a centromere has proven to be a difficult task in multicellular eukaryotes. We have successfully cloned and sequenced the centromere of rice chromosome 8 (Cen8), representing the first fully sequenced centromere from any multicellular eukaryotes. The functional core of Cen8 spans ~800 kb of DNA, which was ...

2010-02-04

Selective control of amino acid metabolism by the GCN2 eIF2 kinase pathway in Saccharomyces cerevisiae

BackgroundLand plant genomes contain multiple members of a eukaryote-specific gene family encoding proteins with pentatricopeptide repeat (PPR) motifs. Some PPR proteins were shown...Full Text Available

Plasmids for the cloning and expression of full-length double-stranded cDNAs under control of the SV40 early or late gene promoter.

BackgroundWhen eukaryotic cells are deprived of amino acids, uncharged tRNAs accumulate and activate the conserved GCN2 protein kinase. Activated Gcn2p up-regulates the general amino...Full Text Available

Intracellular activity of the peptide antibiotic NZ2114: studies with Staphylococcus aureus and human THP-1 monocytes, and comparison with daptomycin and vancomycin

Okayama and Berg (1) have recently described a technique for the high efficiency cloning of full-length dscDNAs. We have constructed eukaryotic expression vectors compatible both with this technique...Full Text Available

1983-10-25

DEFF Research Database (Denmark)

Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism.

2010-01-01

Genome-wide analysis of N¹-methyl-adenosine modification in human tRNAs

GNOM-LIKE1/ERMO1 and SEC24a/ERMO2 Are Required for Maintenance of Endoplasmic Reticulum Morphology in Arabidopsis thaliana[W

The N¹-methyl-Adenosine (m¹A58) modification at the conserved nucleotide 58 in the TΨC loop is present in most eukaryotic tRNAs. In yeast, m¹A58 modification...Full Text Available

2010-07-01

1 2 3 4

Experimental bovine trypanosomiasis. Changes in serum immunoglobulins, complement and complement components in infected animals.

The endoplasmic reticulum (ER) is composed of tubules, sheets, and three-way junctions, resulting in a highly conserved polygonal network in all eukaryotes. The molecular mechanisms responsible for...Full Text Available

2009-11-01

Topoisomerases of kinetoplastid parasites: why so fascinating?

In three calves experimentally infected with Trypanosoma congolense the amounts of IgG1 and IgG2 were little changed and similar to those of normal animals. IgM increased in amount early in the infection and the amount of the increase appeared related to the parasite burden. The amounts of IgA and IgE were both much decreased and this also appeared related to the numbers of parasites in the blood. There was a decrease in the amounts of total haemolytic complement and complement components C1, C1q and C3 in the infected calves. Furthermore the amounts of properdin fluctuated with the cyclical changes in numbers of T. congolense parasites in the individual calves. No significant change in the amount of C8 was observed. It is considered that activation of both the alternative and the classical complement pathways occurs in trypanosome infected animals but that neither pathway goes to its terminal stages.

1978-11-01

British Library Electronic Table of Contents (United Kingdom)

Summary DNA topoisomerases are the key enzymes involved in carrying out high precision DNA transactions inside the cells. However, they are detrimental to the cell when a wide variety of topoisomerase-targeted drugs generate cytotoxic lesions by trapping the enzymes in covalent complexes on the DNA. The discovery of unusual heterodimeric topoisomerase I in kinetoplastid family added a new twist in topoisomerase research related to evolution, functional conservation and their preferential sensitivity to Camptothecin. On the other hand, structural and mechanistic studies on kinetoplastid topoisomerase II delineate some distinguishing features that differentiate the parasitic enzyme from its prokaryotic and eukaryotic counterparts. This review summarizes the recent advances in research in kin...

2006-01-01

Structural Insights into the Interaction of the Evolutionarily Conserved ZPR1 Domain Tandem with Eukaryotic EF1A, Receptors, and SMN Complexes

Nucleomorph Ribosomal DNA and Telomere Dynamics in Chlorarachniophyte Algae

Eukaryotic genomes encode a zinc finger protein (ZPR1) with tandem ZPR1 domains. In response to growth stimuli, ZPR1 assembles into complexes with eukaryotic translation elongation factor 1A (eEF1A) and the survival motor neurons protein. To gain insight into the structural mechanisms underlying the essential function of ZPR1 in diverse organisms, we determined the crystal structure of a ZPR1 domain tandem and characterized the interaction with eEF1A. The ZPR1 domain consists of an elongation initiation factor 2-like zinc finger and a double-stranded {beta} helix with a helical hairpin insertion. ZPR1 binds preferentially to GDP-bound eEF1A but does not directly influence the kinetics of nucleotide exchange or GTP hydrolysis. However, ZPR1 efficiently displaces the exchange factor eEF1B from preformed nucleotide-free complexes, suggesting that it may function as a negative regulator of eEF1A activation. Structure-based mutational and ...

2007-01-01

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT. Chlorarachniophytes are enigmatic marine unicellular algae that acquired photosynthesis by secondary endosymbiosis. Chlorarachniophytes are unusual in that the nucleus of the engulfed algal cell (a green alga) persists in a miniaturized form, termed a nucleomorph. The nucleomorph genome of the model chlorarachniophyte, Bigelowiella natans CCMP621, is 373 kilobase pairs (kbp) in size, the smallest nuclear genome characterized to date. The B. natans nucleomorph genome is composed of three chromosomes, each with canonical eukaryotic telomeres and sub telomeric ribosomal DNA (rDNA) operons transcribed away from the chromosome end. Here we present the complete rDNA operon and telomeric region from the nucleomorph genome of Lotharella oceanica CCMP622, a newly characterized chlorarachn...

2010-01-01

Morphologie des cellules de levure et la reproduction sexuelle - Apercu general et quelques considerations

British Library Electronic Table of Contents (United Kingdom)

Over the decades, basic research in life sciences has profited greatly from the study of the small unicellular fungal species Saccharomyces cerevisiae. This yeast turned out to be key for the identification and understanding of molecular mechanisms that underlay the basic functions of all eukaryotic cells. These include, but are not limited to, the regulatory mechanisms behind cellular reproduction (cell cycle control), cellular morphogenesis (cell polarity, cytoskeleton and membrane trafficking) and the management of cellular information (chromosome biology, transcription and translation). Rapid access to genomic information of many yeast species, combined with bioinformatics analyses, provide information on the evolutionary history of yeasts and the molecular ancestry of their constituen...

2011-01-01

Crystal structure of the human centromeric nucleosome containing CENP-A

British Library Electronic Table of Contents (United Kingdom)

In eukaryotes, accurate chromosome segregation during mitosis and meiosis is coordinated by kinetochores, which are unique chromosomal sites for microtubule attachment. Centromeres specify the kinetochore formation sites on individual chromosomes, and are epigenetically marked by the assembly of nucleosomes containing the centromere-specific histone H3 variant, CENP-A. Although the underlying mechanism is unclear, centromere inheritance is probably dictated by the architecture of the centromeric nucleosome. Here we report the crystal structure of the human centromeric nucleosome containing CENP-A and its cognate ?-satellite DNA derivative (147 base pairs). In the human CENP-A nucleosome, the DNA is wrapped around the histone octamer, consisting of two each of histones H2A, H2B, H4 and CENP...

2011-01-01

BzpF is a CREB-like transcription factor that regulates spore maturation and stability in Dictyostelium

British Library Electronic Table of Contents (United Kingdom)

The cAMP response element-binding protein (CREB) is a highly conserved transcription factor that integrates signaling through the cAMP-dependent protein kinase A (PKA) in many eukaryotes. PKA plays a critical role in Dictyostelium development but no CREB homologue has been identified in this system. Here we show that Dictyostelium utilizes a CREB-like protein, BzpF, to integrate PKA signaling during late development. bzpF^- mutants produce compromised spores, which are extremely unstable and germination defective. Previously, we have found that BzpF binds the canonical CRE motif in vitro. In this paper, we determined the DNA binding specificity of BzpF using protein binding microarray (PBM) and showed that the motif with the highest specificity is a CRE-like sequence. BzpF is necessary to ...

2011-01-01

A PAC containing the human mitochondrial DNA polymerase gamma gene (POLG) maps to chromosome 15q25

The effect of substrate modification on microbial growth on surfaces

The human mitochondrial DNA (mtDNA) is a closed circular, 16,569-bp double-stranded DNA, encoding 13 genes whose protein products are subunits of the oxidative phosphorylation system required for synthesis of most of the ATP consumed by eukaryotic cells. Point mutations of the mtDNA that cause multi-tissue, loss-of-energy syndromes, called mitochondrial encephalomyopathies (e.g., MERRF and MELAS), have been identified. In addition, large-scale deletions of the human mtDNA have been identified and are the molecular bases for the neonatal and adolescent onset loss-of-energy syndromes Pearson and Kearns-Sayer, respectively. 5 refs., 1 fig.

1997-03-01

Expression of bacterial luciferase in eukaryotic cells

The principle aim of the program was to produce a novel, non-leaching antimicrobial surface for commercial development and future use in the liquid food packaging industry. Antimicrobial surfaces which exist presently have been produced to combat the growth of prokaryotic organisms and usually function as slow release systems. A system which could inhibit eukaryotic growth without contaminating the surrounding 'environment' with the inhibitor was considered of great commercial importance. The remit of this study was concerned with creating a surface which could control the growth of eukaryotic organisms found in fruit juice with particular interest in the yeast, Saccharomyces cerevisiae. Putative antimicrobial surfaces were created by the chemical modification of the test substrate polymers; nylon and ethylvinyl alcohol (EVOH). Surfaces were chemically modified by the covalent coupling of antimicrobial agents known to be ...

1998-07-01

International Nuclear Information System (INIS)

Expression of Bacterial luciferase enzyme (lux) in mammalian cells would be a powerful bioreporter protein system for in vivo imaging because eukaryotic luciferases need expensive substrates. However, only a few efforts have been made to express bacterial luciferase enzyme in mammalian cells. As the result of this, we attempted to construct bicistronic vector including two bacterial luciferase genes (LuxA and LuxB) for assessing the potential to be visualized in vitro or in vivo by optical imaging system after transfection to mammalian cells. We designed and synthesized luxA and luxB genes from Photorhabdus Luminescens. To co-express both luxA and luxB genes from a single promoter, we cloned as a bicistronic transcript fused with an internal ribosomal entry site (IRES). This bicistronic transcript was transfected by Superfect to HEK 293T cell line. We also transfected lux A and lux B vector to HEK 293T cells separately. To evaluate gene expression, n-decanal and ...

2005-11-18

ATP-dependent partitioning of the DNA template into supercoiled domains by Escherichia coli UvrAB

International Nuclear Information System (INIS)

The helicase action of the Escherichia coli UvrAB complex on a covalently closed circular DNA template was monitored using bacterial DNA topoisomerase I, which specifically removes negative supercoils. In the presence of E. coli DNA topoisomerase I and ATP, the UvrAB complex gradually introduced positive supercoils into the input relaxed plasmid DNA template. Positive supercoils were not produced when E. coli DNA topoisomerase I was replaced by eukaryotic DNA topoisomerase I or when both E. coli and eukaryotic DNA topoisomerases I were added simultaneously. These results suggest that like other DNA helix-tracking processes, the ATP-dependent action of the UvrAM complex on duplex DNA simultaneously generates both positive and negative supercoils, which are not constrained by protein binding but are torsionally strained. The supercoiling activity of UvrAB on UV-damaged DNA was also studied using UV-damaged plasmid DNA and a mutant UvrA protein ...

T-2 mycotoxin inhibits mitochondrial protein synthesis

Metal Coupled Folding of Cys2His2 Zinc-Finger

The authors investigated the effect of T-2 toxin on rat liver mitochondrial protein synthesis. Isolated rat liver mitochondria were supplemented with an S-100 supernatant from rat liver and an external ATP-generating system. An in-vitro assay employing cycloheximide, and inhibitor of cytoplasmic protein synthesis, and chloramphenicol, and inhibitor of mitochondrial protein synthesis, to distinguish mitochondrial protein synthesis from the cytoplasmic process. Amino acid incorporation into mitochondria was dependent on the concentration of mitochondria and was inhibited by chloramphenicol. The rate of uptake of tritium leucine into mitochondrial protein was unaffected by the addition of T-2 toxin and was not a rate-limiting step in incorporation. However, 0.02 micrograms/ml of T-2 toxin decreased the rate of protein synthesis inhibition correlated with the amount of T-2 toxin taken up by the mitochondria. While T-2 toxin is known to inhibit eukaryotic protein ...

1988-01-01

CERN Document Server

Zinc-fingers, which widely exist in eukaryotic cell and play crucial roles in life processes, depend on the binding of zinc ion for their proper folding. To computationally study the zinc coupled folding of the zinc-fingers, charge transfer and metal induced protonation/deprotonation effects have to be considered. Here, by attempting to implicitly account for such effects in classical molecular dynamics and performing intensive simulations with explicit solvent for the peptides with and without zinc binding, we investigate the folding of the Cys2His2 type zinc-finger motif and the coupling between the peptide folding and zinc binding. We find that zinc ion not only stabilizes the native structure, but also participates in the whole folding process. It binds to the peptide at early stage of folding, and directs or modulates the folding and stabilizations of the component beta-hairpin and alpha-helix. Such a crucial role of zinc binding is mediated by the packing of ...

2008-01-01

Genetical approach to oxygen toxicity. [Saccharomyces cerevisiae

Cotton plants expressing CYP6AE14 double-stranded RNA show enhanced resistance to bollworms

The role of intermediate products of dioxygen reduction in cytotoxic effects ascribed to oxygen molecules was studied in vivo using various yeast mutants with changed response to oxygen stress. It has been documented that superoxide radical exerts its deleterious effects on yeast cells directly and the role of other oxygen species derived from it is hardly detectable. Yeast Saccharomyces cerevisiae, however, cannot be considered as a typical eukaryotic organism due to its inability of synthesizing polyunsaturated fatty acids (pufa). These fatty acids are known as main target molecules during oxidative stress and their peroxidation leads to cytotoxic effects. As fatty acid content could be easily manipulated in yeast, this organism was used to evaluate the contribution of pufa peroxidation process to the cytotoxic effects of oxygen. Results obtained show, that yeast cells containing linolenic acid as the main constituent of phospholipids are hypersensitive to oxygen ...

1986-01-01

British Library Electronic Table of Contents (United Kingdom)

RNA interference (RNAi) plays an important role in regulating gene expression in eukaryotes. Previously, we generated Arabidopsis and tobacco plants expressing double-stranded RNA (dsRNA) targeting a cotton bollworm (Helicoverpa armigera) P450 gene, CYP6AE14. Bollworms fed on transgenic dsCYP6AE14 plants showed suppressed CYP6AE14 expression and reduced growth on gossypol-containing diet (Mao et?al., in Nat Biotechnol 25: 1307?1313, 2007). Here we report generation and analysis of dsRNA-expressing cotton (Gossypium hirsutum) plants. Bollworm larvae reared on T2 plants of the ds6-3 line exhibited drastically retarded growth, and the transgenic plants were less damaged by bollworms than the control. Quantitative reverse-transcription polymerase chain reaction (RT-PCR) showed that the CYP6AE1...

2011-01-01

The ATG1/ATG13 Protein Kinase Complex Is Both a Regulator and a Target of Autophagic Recycling in Arabidopsis.

Genomic analysis of the symbiotic marine crenarchaeon, Cenarchaeumsymbiosum

Autophagy is an intracellular recycling route in eukaryotes whereby organelles and cytoplasm are sequestered in vesicles, which are subsequently delivered to the vacuole for breakdown. The process is induced by various nutrient-responsive signaling cascades converging on the Autophagy-Related1 (ATG1)/ATG13 kinase complex. Here, we describe the ATG1/13 complex in Arabidopsis thaliana and show that it is both a regulator and a target of autophagy. Plants missing ATG13 are hypersensitive to nutrient limitations and senesce prematurely similar to mutants lacking other components of the ATG system. Synthesis of the ATG12-ATG5 and ATG8-phosphatidylethanolamine adducts, which are essential for autophagy, still occurs in ATG13-deficient plants, but the biogenesis of ATG8-decorated autophagic bodies does not, indicating that the complex regulates downstream events required for autophagosome enclosure and/or vacuolar delivery. Surprisingly, levels of the ATG1a and ATG13a ...

2011-10-01

Genome analysis of F. nucleatum sub spp vincentii and its comparison with the genome of F. nucleatum ATCC 25586.

Crenarchaea are ubiquitous and abundant microbial constituents of soils, sediments, lakes and ocean waters, yet relatively little is known about their fundamental evolutionary, ecological, and physiological properties. To better describe the ubiquitous nonthermophilic Crenarchaea, we analyzed the genome sequence of one representative, the uncultivated sponge symbiont, Cenarchaeum symbiosum. C. symbiosum genotypes coinhabiting the same host partitioned into two dominant populations, corresponding to previously described a- and b-type ribosomal RNA variants. Although synthetic, overlapping a- and b-type ribotypes harbored significant genetic variability. A single tiling path comprising the dominant a-type genotype was assembled, and used to explore the biological properties of C. symbiosum and its planktonic relatives. Out of a total of 2,066 predicted open reading frames, 36% were more highly conserved with other Archaea. The remainder partitioned between bacteria (18%), ...

2006-06-24

Local chromatin structure of heterochromatin regulates repeatedDNA stability, nucleolus structure, and genome integrity

We present the draft genome sequence and its analysis for Fusobacterium nucleatum sub spp. vincentii (FNV), and compare that genome with F. nucleatum ATCC 25586 (FN). A total of 441 FNV open reading frames (ORFs) with no orthologs in FN have been identified. Of these, 118 ORFs have no known function and are unique to FNV, whereas 323 ORFs have functional orthologs in other organisms. In addition to the excretion of butyrate, H2S and ammonia-like FN, FNV has the additional capability to excrete lactate and aminobutyrate. Unlike FN, FNV is likely to incorporate galactopyranose, galacturonate, and sialic acid into its O-antigen. It appears to transport ferrous iron by an anaerobic ferrous transporter. Genes for eukaryotic type serine/threonine kinase and phosphatase, transpeptidase E-transglycosylase Pbp1A are found in FNV but not in FN. Unique ABC transporters, cryptic phages, and three types of restriction-modification systems have been identified in FNV. ORFs for ...

2003-06-01