| antennal-expressed ammonium transporters in the malaria vector mosquito anopheles gambiae. | the principal afrotropical malaria vector mosquito, anopheles gambiae remains a significant threat to human health. in this anthropophagic species, females detect and respond to a range of human-derived volatile kairomones such as ammonia, lactic acid, and other carboxylic acids in their quest for blood meals. while the molecular underpinnings of mosquito olfaction and host seeking are becoming better understood, many questions remain unanswered. in this study, we have identified and characteriz ... | 2014 | 25360676 |
| ltr retroelements are intrinsic components of transcriptional networks in frogs. | ltr retroelements (ltr res) constitute a major group of transposable elements widely distributed in eukaryotic genomes. through their own mechanism of retrotranscription ltr res enrich the genomic landscape by providing genetic variability, thus contributing to genome structure and organization. nonetheless, transcriptomic activity of ltr res still remains an obscure domain within cell, developmental, and organism biology. | 2014 | 25056159 |
| current perspectives on the use of alternative species in human health and ecological hazard assessments. | traditional animal toxicity tests can be time and resource intensive, thereby limiting the number of chemicals that can be comprehensively tested for potential hazards to humans and/or to the environment. | 2013 | 23771518 |
| determination of alkali-sensing parts of the insulin receptor-related receptor using the bioinformatic approach. | irr (insulin receptor-related receptor) is a receptor tyrosine kinase belonging to the insulin receptor family, which also includes insulin receptor and igf-ir receptor. we have previously shown that irr is activated by extracellular fluid with ph > 7.9 and regulates excess alkali excretion in the body. we performed a bioinformatic analysis of the ph-sensitive potential of all three members of the insulin receptor family of various animal species (from frog to man) and their chimeras with swappi ... | 0 | 26085948 |
| molecular phylogeny of pseudocapillaroides xenopi (moravec et cosgrov 1982) and development of a quantitative pcr assay for its detection in aquarium sediment. | we used high-fidelity pcr to amplify a portion of the small ribosomal subunit (18s rrna) of pseudocapillaroides xenopi, a nematode that parasitizes the skin of xenopus laevis. the 1113-bp amplicon was cloned, sequenced, and aligned with sequences from 22 other nematodes in the order trichocephalida; caenorhabditis elegans was used as the outgroup. maximum-likelihood and bayesian inference phylogenetic analyses clustered p. xenopi in a clade containing only members of the genus capillaria. our an ... | 0 | 25650974 |
| agr genes, missing in amniotes, are involved in the body appendages regeneration in frog tadpoles. | previous studies have shown that agr genes, which encode thioredoxin domain-containing secreted proteins, play a critical role in limb regeneration in salamanders. to determine the evolutionary conservation of agr function, it is important to examine whether agrs play a similar role in species with a different type of regeneration. here, we refined the phylogeny of agrs, revealing three subfamilies: ag1, agr2 and agr3. importantly, we established that ag1 was lost in higher vertebrates, which co ... | 0 | 23412115 |
| follicle online: an integrated database of follicle assembly, development and ovulation. | folliculogenesis is an important part of ovarian function as it provides the oocytes for female reproductive life. characterizing genes/proteins involved in folliculogenesis is fundamental for understanding the mechanisms associated with this biological function and to cure the diseases associated with folliculogenesis. a large number of genes/proteins associated with folliculogenesis have been identified from different species. however, no dedicated public resource is currently available for fo ... | 2015 | 25931457 |
| zar1 represses translation in xenopus oocytes and binds to the tcs in maternal mrnas with different characteristics than zar2. | maternal mrnas are translationally regulated during early development. zar1 and its closely related homolog, zar2, are both crucial in early development. xenopus laevis zygote arrest 2 (zar2) binds to the translational control sequence (tcs) in maternal mrnas and regulates translation. the molecular mechanism of zar1 has not been described. here we report similarities and differences between xenopus zar1 and zar2. analysis of zar sequences in vertebrates revealed two zar family members with cons ... | 2013 | 23827238 |
| the ph sensitivity of aqp0 channels in tetraploid and diploid teleosts. | water homeostasis and the structural integrity of the vertebrate lens is partially mediated by aqp0 channels. emerging evidence indicates that external ph may be involved in channel gating. here we show that a tetraploid teleost, the atlantic salmon, retains 4 aqp0 genes (aqp0a1, -0a2, -0b1, and -0b2), which are highly, but not exclusively, expressed in the lens. functional characterization reveals that, although each paralog permeates water efficiently, the permeability is respectively shifted ... | 2015 | 25667219 |
| distinct features of cap binding by eif4e1b proteins. | eif4e1b, closely related to the canonical translation initiation factor 4e (eif4e1a), cap-binding protein is highly expressed in mouse, xenopus and zebrafish oocytes. we have previously characterized eif4e1b as a component of the cpeb mrnp translation repressor complex along with the eif4e-binding protein 4e-transporter, the xp54/ddx6 rna helicase and additional rna-binding proteins. eif4e1b exhibited only very weak interactions with m(7)gtp-sepharose and, rather than binding eif4g, interacted w ... | 2014 | 25463438 |
| adaptive evolutionary paths from uv reception to sensing violet light by epistatic interactions. | ultraviolet (uv) reception is useful for such basic behaviors as mate choice, foraging, predator avoidance, communication, and navigation, whereas violet reception improves visual resolution and subtle contrast detection. uv and violet reception are mediated by the short wavelength-sensitive (sws1) pigments that absorb light maximally (λmax) at ~360 nm and ~395 to 440 nm, respectively. because of strong nonadditive (epistatic) interactions among amino acid changes in the pigments, the adaptive e ... | 2015 | 26601250 |
| direct recording of trans-plasma membrane electron currents mediated by a member of the cytochrome b561 family of soybean. | trans-plasma membrane electron transfer is achieved by b-type cytochromes of different families, and plays a fundamental role in diverse cellular processes involving two interacting redox couples that are physically separated by a phospholipid bilayer, such as iron uptake and redox signaling. despite their importance, no direct recordings of trans-plasma membrane electron currents have been described in plants. in this work, we provide robust electrophysiological evidence of trans-plasma membran ... | 2015 | 26282237 |
| the xenopus alcohol dehydrogenase gene family: characterization and comparative analysis incorporating amphibian and reptilian genomes. | the alcohol dehydrogenase (adh) gene family uniquely illustrates the concept of enzymogenesis. in vertebrates, tandem duplications gave rise to a multiplicity of forms that have been classified in eight enzyme classes, according to primary structure and function. some of these classes appear to be exclusive of particular organisms, such as the frog adh8, a unique nadp+-dependent adh enzyme. this work describes the adh system of xenopus, as a model organism, and explores the first amphibian and r ... | 2014 | 24649825 |
| the nucleic acid-binding domain and translational repression activity of a xenopus terminal uridylyl transferase. | terminal uridylyl transferases (tuts) catalyze the addition of uridines to the 3' ends of rnas and are implicated in the regulation of both messenger rnas and micrornas. to better understand how tuts add uridines to rnas, we focused on a putative tut from xenopus laevis, xtut7. we determined that xtut7 catalyzed the addition of uridines to rnas. mutational analysis revealed that a truncated xtut7 enzyme, which contained solely the nucleotidyl transferase and poly(a) polymerase-associated domains ... | 2013 | 23709223 |
| functional expression of human α9* nicotinic acetylcholine receptors in x. laevis oocytes is dependent on the α9 subunit 5' utr. | nicotinic acetylcholine receptors (nachrs) containing the α9 subunit are expressed in a wide variety of non-neuronal tissues ranging from immune cells to breast carcinomas. the α9 subunit is able to assemble into a functional homomeric nachr and also co-assemble with the α10 subunit into functional heteromeric nachrs. despite the increasing awareness of the important roles of this subunit in vertebrates, the study of human α9-containing nachrs has been severely limited by difficulties in its exp ... | 2013 | 23717646 |
| cloning, sequencing and phylogenetic analysis of the small gtpase gene cdc-42 from ancylostoma caninum. | cdc-42 is a member of the rho gtpase subfamily that is involved in many signaling pathways, including mitosis, cell polarity, cell migration and cytoskeleton remodeling. here, we present the first characterization of a full-length cdna encoding the small gtpase cdc-42, designated as accdc-42, isolated from the parasitic nematode ancylostoma caninum. the encoded protein contains 191 amino acid residues with a predicted molecular weight of 21 kda and displays a high level of identity with the rho- ... | 2012 | 23000556 |
| the cholinomimetic morantel as an open channel blocker of the ascaris suum acr-16 nachr. | nematode parasite infections pose a significant threat in human and veterinary medicine. at least a third of the world's population is at risk from nematode parasite infections. these infections not only cause health problems, but also cause loss of livestock production and hence, economic losses. anthelmintic drugs are the mainstay by which control of nematode parasite infections is achieved. many of the currently available anthelmintics act on nicotinic acetylcholine receptors (nachrs). howeve ... | 2016 | 27995347 |
| nicotinic acetylcholine receptors: a comparison of the nachrs of caenorhabditis elegans and parasitic nematodes. | nicotinic acetylcholine receptors (nachrs) play a key role in the normal physiology of nematodes and provide an established target site for anthelmintics. the free-living nematode, caenorhabditis elegans, has a large number of nachr subunit genes in its genome and so provides an experimental model for testing novel anthelmintics which act at these sites. however, many parasitic nematodes lack specific genes present in c. elegans, and so care is required in extrapolating from studies using c. ele ... | 2013 | 23500392 |
| acr-26: a novel nicotinic receptor subunit of parasitic nematodes. | nematode nicotinic acetylcholine receptors are the targets for many effective anthelmintics, including those recently introduced into the market. we have identified a novel nicotinic receptor subunit sequence, acr-26, that is expressed in all the animal parasitic nematodes we examined from clades iii, iv and v, but is not present in the genomes of trichinella spiralis, caenorhabditis elegans, pristionchus pacificus and meloidogyne spp. in ascaris suum, acr-26 is expressed on muscle cells isolate ... | 2012 | 22387572 |
| aspergillus glaucus aquaglyceroporin gene glpf confers high osmosis tolerance in heterologous organisms. | aquaglyceroporins (glpfs) that transport glycerol along with water and other uncharged solutes are involved in osmoregulation in myriad species. fungal species form a large group of eukaryotic organisms, and their glpfs may be diverse, exhibiting various activities. however, few filamentous fungal glpfs have been biologically investigated. here, a glpf gene from the halophilic fungus aspergillus glaucus (agglpf) was verified to be a channel of water or glycerol in xenopus laevis oocytes and was ... | 2015 | 26209670 |
| an isoprenylation and palmitoylation motif promotes intraluminal vesicle delivery of proteins in cells from distant species. | the c-terminal ends of small gtpases contain hypervariable sequences which may be posttranslationally modified by defined lipid moieties. the diverse structural motifs generated direct proteins towards specific cellular membranes or organelles. however, knowledge on the factors that determine these selective associations is limited. here we show, using advanced microscopy, that the isoprenylation and palmitoylation motif of human rhob (-cincckvl) targets chimeric proteins to intraluminal vesicle ... | 2014 | 25207810 |
| effects of transgenic cry1ca rice on the development of xenopus laevis. | in fields of genetically modified, insect-resistant rice expressing bacillus thuringiensis (bt) proteins, frogs are exposed to bt cry proteins by consuming both target and non-target insects, and through their highly permeable skin. in the present study, we assessed the potential risk posed by transgenic cry1ca rice (t1c-19) on the development of a frog species by adding purified cry1ca protein or t1c-19 rice straw into the rearing water of xenopus laevis tadpoles, and by feeding x. laevis frogl ... | 2015 | 26695426 |
| effects of amphibian phylogeny, climate and human impact on the occurrence of the amphibian-killing chytrid fungus. | chytridiomycosis, due to the fungus batrachochytrium dendrobatidis (bd), has been associated with the alarming decline and extinction crisis of amphibians worldwide. because conservation programs are implemented locally, it is essential to understand how the complex interactions among host species, climate and human activities contribute to bd occurrence at regional scales. using weighted phylogenetic regressions and model selection, we investigated geographic patterns of bd occurrence along a l ... | 2017 | 28055125 |
| xenopus laevis and emerging amphibian pathogens in chile. | amphibians face an extinction crisis with no precedence. two emerging infectious diseases, ranaviral disease caused by viruses within the genus ranavirus and chytridiomycosis due to batrachochytrium dendrobatidis (bd), have been linked with amphibian mass mortalities and population declines in many regions of the globe. the african clawed frog (xenopus laevis) has been indicated as a vector for the spread of these pathogens. since the 1970s, this species has been invasive in central chile. we co ... | 2016 | 27682604 |
| chytrid fungus infections in laboratory and introduced xenopus laevis populations: assessing the risks for u.k. native amphibians. | the chytrid fungus batrachochytrium dendrobatidis (bd) is notorious amongst current conservation biology challenges, responsible for mass mortality and extinction of amphibian species. world trade in amphibians is implicated in global dissemination. exports of south african xenopus laevis have led to establishment of this invasive species on four continents. bd naturally infects this host in africa and now occurs in several introduced populations. however, no previous studies have investigated t ... | 2015 | 25843959 |
| inhibition of local immune responses by the frog-killing fungus batrachochytrium dendrobatidis. | amphibians are suffering unprecedented global declines. a leading cause is the infectious disease chytridiomycosis caused by the chytrid fungus batrachochytrium dendrobatidis. chytridiomycosis is a skin disease which disrupts transport of essential ions leading to death. soluble factors produced by b. dendrobatidis impair amphibian and mammalian lymphocytes in vitro, but previous studies have not shown the effects of these inhibitory factors in vivo. to demonstrate in vivo inhibition of immunity ... | 2014 | 25156734 |
| prevalence of batrachochytrium dendrobatidis in xenopus collected in africa (1871-2000) and in california (2001-2010). | international trade of the invasive south african clawed frog (xenopus laevis), a subclinical carrier of the fungal pathogen batrachochytrium dendrobatis (bd) has been proposed as a major means of introduction of bd into naïve, susceptible amphibian populations. the historical presence of bd in the indigenous african population of xenopus is well documented. however, there are no reports documenting the presence of bd in wild xenopus populations in the us, particularly in california where introd ... | 2013 | 23691097 |
| germ tube mediated invasion of batrachochytrium dendrobatidis in amphibian skin is host dependent. | batrachochytrium dendrobatidis (bd) is the causative agent of chytridiomycosis, a fungal skin disease in amphibians and driver of worldwide amphibian declines.we focussed on the early stages of infection by bd in 3 amphibian species with a differential susceptibility to chytridiomycosis. skin explants of alytes muletensis, litoria caerulea and xenopus leavis were exposed to bd in an ussing chamber for 3 to 5 days. early interactions of bd with amphibian skin were observed using light microscopy ... | 2012 | 22911798 |
| batrachochytrium dendrobatidis zoospore secretions rapidly disturb intercellular junctions in frog skin. | global amphibian declines are in part driven by the chytrid fungus batrachochytrium dendrobatidis, causing superficial dermatomycosis with epidermal hyperplasia and hyperkeratosis in infected amphibians. the susceptibility to chytridiomycosis and the severity of epidermal lesions in amphibians with chytridiomycosis are not consistent across species or even among individuals. severe infections cause death of the animal most likely through disturbance of ion homeostasis. the mechanism by which thi ... | 2012 | 22903040 |
| proton-dependent glutamine uptake by aphid bacteriocyte amino acid transporter apglnt1. | aphids house large populations of the gammaproteobacterial symbiont buchnera aphidicola in specialized bacteriocyte cells. the combined biosynthetic capability of the holobiont (acyrthosiphon pisum and buchnera) is sufficient for biosynthesis of all twenty protein coding amino acids, including amino acids that animals alone cannot synthesize; and that are present at low concentrations in a. pisum's plant phloem sap diet. collaborative holobiont amino acid biosynthesis depends on glutamine import ... | 2015 | 26028424 |
| the hymenochirins: a family of host-defense peptides from the congo dwarf clawed frog hymenochirus boettgeri (pipidae). | skin secretions of frogs from the subfamily xenopodinae (xenopus+silurana) within the family pipidae are a rich source of antimicrobial peptides with therapeutic potential but species from the sister taxon hymenochirus in the subfamily pipinae (hymenochirus+pseudhymenochirus+pipa) have not been investigated. peptidomic analysis of norepinephrine-stimulated skin secretions from two distinct populations of the congo dwarf clawed frog hymenochirus boettgeri (tornier, 1896) has led to identification ... | 2012 | 22497805 |
| ultrastructure of the spermatozoon of the diphyllobothriidean cestode cephalochlamys namaquensis (cohn, 1906). | this contribution provides the first ultrastructural and cytochemical data on the mature spermatozoon of a diphyllobothriidean cestode belonging to the family cephalochlamydidae. the mature spermatozoon of cephalochlamys namaquensis (cohn, 1906), a parasite of the african clawed frog, xenopus laevis (daudin, 1802), from southern california, usa, has been examined using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for glycogen. ... | 2012 | 22576853 |
| identification, immunolocalization, and immunological characterization of nitric oxide synthase-interacting protein from clonorchis sinensis. | recently, accumulating evidences indicate that nitric oxide (no) is a potent mediator with diverse roles in regulating cellular functions, signaling pathways, and variety of pathological processes. in the present study, using data from the published genomic for clonorchis sinensis (c. sinensis), we investigated a gene encoding nitric oxide synthase-interacting protein (nosip) of c. sinensis. recombinant csnosip (rcsnosip) was expressed and purified from escherichia coli bl21. the open reading fr ... | 2014 | 24604383 |
| proteome-wide dataset supporting the study of ancient metazoan macromolecular complexes. | our analysis examines the conservation of multiprotein complexes among metazoa through use of high resolution biochemical fractionation and precision mass spectrometry applied to soluble cell extracts from 5 representative model organisms caenorhabditis elegans, drosophila melanogaster, mus musculus, strongylocentrotus purpuratus, and homo sapiens. the interaction network obtained from the data was validated globally in 4 distant species (xenopus laevis, nematostella vectensis, dictyostelium dis ... | 2016 | 26870755 |
| proteome compression via protein domain compositions. | in this paper, we study domain compositions of proteins via compression of whole proteins in an organism for the sake of obtaining the entropy that the individual contains. we suppose that a protein is a multiset of domains. since gene duplication and fusion have occurred through evolutionary processes, the same domains and the same compositions of domains appear in multiple proteins, which enables us to compress a proteome by using references to proteins for duplicated and fused proteins. such ... | 2014 | 24486717 |
| functional characterization of a novel aquaporin from dictyostelium discoideum amoebae implies a unique gating mechanism. | the social amoeba dictyostelium discoideum is a widely used model organism for studying basic functions of protozoan and metazoan cells, such as osmoregulation and cell motility. there is evidence from other species that cellular water channels, aquaporins (aqp), are central to both processes. yet, data on d. discoideum aqps is almost absent. despite cloning of two putative d. discoideum aqps, waca, and aqpa, water permeability has not been shown. further, waca and aqpa are expressed at the late ... | 2012 | 22262860 |
| high-throughput screening with the eimeria tenella cdc2-related kinase2/cyclin complex etcrk2/etcyc3a. | the poultry disease coccidiosis, caused by infection with eimeria spp. apicomplexan parasites, is responsible for enormous economic losses to the global poultry industry. the rapid increase of resistance to therapeutic agents, as well as the expense of vaccination with live attenuated vaccines, requires the development of new effective treatments for coccidiosis. because of their key regulatory function in the eukaryotic cell cycle, cyclin-dependent kinases (cdks) are prominent drug targets. the ... | 2012 | 22723289 |
| an inducible amphipathic helix within the intrinsically disordered c-terminus is not required for protein biosynthesis, trafficking, or garp2 interaction, but can participate in membrane curvature generation by peripherin-2/rds. | peripherin-2/rds is required for biogenesis of vertebrate photoreceptor outer segment organelles. its localization at the high curvature rim domains of outer segment disk membranes suggests that it may act to shape these structures; however, the molecular function of this protein is not yet resolved. here, we apply biochemical, biophysical, and imaging techniques, to elucidate the role(s) played by the protein's intrinsically disordered c-terminal domain, and an incipient amphipathic α-helix con ... | 2017 | 28325841 |
| [xenopus laevis peroxiredoxins: gene expression during development and characterization of the enzymes]. | reactive oxygen species (ros) are produced via catabolic and anabolic processes during normal embryonic development, and ros content in the cell is maintained at a certain level. peroxiredoxins are a family of selenium-independent peroxidases and play a key role in maintaining redox homeostasis of the cell. in addition to regulating the ros level, peroxiredoxins are involved in intracellular and intercellular signaling, cell differentiation, and tissue development. the time course of peroxiredox ... | 2016 | 27239855 |
| identification and characterization of a novel intelectin in the digestive tract of xenopus laevis. | the intelectin (intl) family is a group of secretory lectins in chordates that serve multiple functions, including innate immunity, through ca(2+)-dependent recognition of carbohydrate chains. although six intl family lectins have so far been reported in xenopus laevis, none have been identified in the intestine. using a monoclonal antibody to the xenopus embryonic epidermal lectin (xeel or intl-1), i identified cross-reactive proteins in the intestines. the proteins were purified by affinity ch ... | 2016 | 26855011 |
| differential effects of the recombinant toxin pntx4(5-5) from the spider phoneutria nigriventer on mammalian and insect sodium channels. | the toxin pntx4(5-5) from the spider phoneutria nigriventer is extremely toxic/lethal to insects but has no macroscopic behavioral effects observed in mice after intracerebral injection. nevertheless, it was demonstrated that it inhibits the n-methyl-d-aspartate (nmda) - subtype of glutamate receptors of cultured rat hippocampal neurons. pntx4(5-5) has 63% identity to pntx4(6-1), another insecticidal toxin from p. nigriventer, which can slow down the sodium current inactivation in insect central ... | 2016 | 26747232 |
| recombinant expression and characterization of α-conotoxin lvia in escherichia coli. | α-conotoxin lvia is derived from conus lividus, native to hainan, and is the most selective inhibitor of α3β2 nicotinic acetylcholine receptors (nachrs) known to date. in this study, an efficient approach for the production of recombinant α-conotoxin lvia is described. tandem repeats of a lvia gene fragment were constructed and fused with a ksi gene and a his₆ tag in a escherichia coli (e. coli) expression vector pet-31b(+). the recombinant plasmids were transformed into e. coli and were found t ... | 2016 | 26742048 |
| investigations of the synergistic enhancement of antimicrobial activity in mixtures of magainin 2 and pgla. | magainins are antimicrobial peptides isolated from the african clawed frog xenopus laevis. they interact with bacterial membranes where they cause channel formation and membrane disruption. when added as a cocktail magainin 2 and pgla are considerably more efficient when compared to the corresponding amounts of individual components. in order to investigate this synergistic interaction of pgla and magainin a number of magainin variants have been prepared and investigated in biological and biophy ... | 2016 | 26099623 |
| using supported bilayers to study the spatiotemporal organization of membrane-bound proteins. | cell division in prokaryotes and eukaryotes is commonly initiated by the well-controlled binding of proteins to the cytoplasmic side of the cell membrane. however, a precise characterization of the spatiotemporal dynamics of membrane-bound proteins is often difficult to achieve in vivo. here, we present protocols for the use of supported lipid bilayers to rebuild the cytokinetic machineries of cells with greatly different dimensions: the bacterium escherichia coli and eggs of the vertebrate xeno ... | 2015 | 25997350 |
| remyelination by resident oligodendrocyte precursor cells in a xenopus laevis inducible model of demyelination. | we have generated a xenopus laevis transgenic line, mbp-gfp-ntr, allowing conditional ablation of myelin-forming oligodendrocytes. in this transgenic line the transgene is driven by the proximal portion of the myelin basic protein regulatory sequence, specific to mature oligodendrocytes. the transgene protein is formed by the green fluorescent protein reporter fused to the escherichia coli nitroreductase (ntr) selection enzyme. the ntr enzyme converts the innocuous prodrug metronidazole (mtz) to ... | 2015 | 25896276 |
| the influence of electromagnetic pollution on living organisms: historical trends and forecasting changes. | current technologies have become a source of omnipresent electromagnetic pollution from generated electromagnetic fields and resulting electromagnetic radiation. in many cases this pollution is much stronger than any natural sources of electromagnetic fields or radiation. the harm caused by this pollution is still open to question since there is no clear and definitive evidence of its negative influence on humans. this is despite the fact that extremely low frequency electromagnetic fields were ... | 2015 | 25811025 |
| host-defense peptides from skin secretions of fraser's clawed frog xenopus fraseri (pipidae): further insight into the evolutionary history of the xenopodinae. | peptidomic analysis of norepinephrine-stimulated skin secretions of the tetraploid frog xenopus fraseri boulenger, 1905 (pipidae) led to identification of 13 host-defense peptides. the primary structures of the peptides demonstrate that they belong to the magainin (3 peptides), peptide glycine-leucine-amide, pgla (4 peptides), and xenopsin-precursor fragment, xpf (2 peptides) families, first identified in xenopus laevis, together with caerulein precursor fragment-related peptides, cpf-rp (4 pept ... | 2014 | 25463057 |
| [optimization of coding sequences and expression of antimicrobial peptide magainin ii in escherichia coli and pichia pastoris]. | the antimicrobial peptide magainin ii is expressed in the skin of the african clawed frog, xenopus laevis, and exhibits a broad spectrum of antimicrobial activity as well as tumoricidal properties at low concentrations. in addition, magaininii plays a synergistic role during antimicrobial and tumoricidal processes with another antimicrobial peptide pgla that is also expressed in xenopus laevis. the optimized cdna sequence of magainin ii and magainin ii-pgla hybrid peptide according to e. coli or ... | 2014 | 25195251 |
| magainin 2 induces bacterial cell death showing apoptotic properties. | magainin 2 is pore-forming antimicrobial peptide on lipid matrix of bacterial membrane, secreted from the skin of the african clawed frog xenopus laevis. the aim of this study was to investigate a new concept for antibacterial mechanisms called bacterial apoptosis-like cell death. we examined the morphological changes induced by magainin 2 in escherichia coli, regarding apoptosis. specifically, phosphatidylserine externalization from the inner to outer membrane surface was detected by annexin v ... | 2014 | 25023640 |
| isolation and characterization of xenopus soluble epoxide hydrolase. | soluble epoxide hydrolase (seh) contributes to cell growth, but the contribution of seh to embryonic development is not well understood. in this study, xenopus seh cdna was isolated from embryos of xenopus laevis. the xenopus seh was expressed in escherichia coli and was purified. the epoxide hydrolase and phosphatase activities of purified seh were investigated. the xenopus seh did not show phosphatase activity toward 4-methylumbelliferyl phosphate or several lysophosphatidic acids although it ... | 2014 | 24681163 |
| mechanisms of amphibian macrophage development: characterization of the xenopus laevis colony-stimulating factor-1 receptor. | macrophage-lineage cells are indispensable to vertebrate homeostasis and immunity. in turn, macrophage development is largely regulated through colony-stimulating factor-1 (csf1) binding to its cognate receptor (csf1r). to study amphibian monopoiesis, we identified and characterized the x. laevis csf1r cdna transcript. quantitative analysis revealed that csf1r tissue gene expression increased with x. laevis development, with greatest transcript levels detected in the adult lung, spleen and liver ... | 2014 | 26154317 |
| role of the hypoxia response pathway in lens formation during embryonic development of xenopus laevis. | the ring finger ubiquitin ligase seven in absentia homolog 2 (siah2) was identified in the r7 photoreceptor cells of drosophila melanogaster, and it regulates the stability of prolyl hydroxylase domains (phds), with a concomitant effect on hif-1α availability in the hypoxia response pathway. we previously reported that the hypoxia response pathway contributes to eye development during the embryonic development of xenopus laevis. in this paper, the role of siah2-mediated hypoxia response pathway ... | 2013 | 24282676 |
| molecular cloning, expression, bioinformatics analysis, and bioactivity of tnfsf13 (april) in the south african clawed frog (xenopus laevi): a new model to study immunological diseases. | tnfsf13 is one of the tumor necrosis factor (tnf) superfamily members that plays important roles in immune homeostasis and proliferation or apoptosis of certain tumor cell lines. this report describes the development of xenopus laevis tnfsf13 as a model to study its important role in relation to immunological diseases. in brief, tnfsf13 from xenopus laevis (designated xltnfsf13) was first amplified by rt-pcr and rapid amplification of cdna end (race) techniques. bioinformatics analyses revealed ... | 2013 | 23829578 |
| [cloning and bioinformatic analysis of tagln2 cdna of bufo japonicus formosus]. | to study the bioactive polypeptides included in bufo skin and its secretions the plasmid skin cdna library of adult japanese toad bufo japonicus formosus was prepared. the psd64tr has been used as the vector and the cloning sites are xho i and ecor i. to screen cdnas encoding bioactive components, the plasmid cdna library was transformed into e. coli dh5 competent cells, and positive colonies were screened by colony pcr (polymerase chain reaction). the suspension of a single colony in lb medium ... | 2013 | 23672022 |
| three-dimensional model for the human cl-/hco3- exchanger, ae1, by homology to the e. coli clc protein. | ae1 mediates electroneutral 1:1 exchange of bicarbonate for chloride across the plasma membrane of erythrocytes and type a cells of the renal collecting duct. no high-resolution structure is available for the ae1 membrane domain, which alone is required for its transport activity. a recent electron microscopy structure of the ae1 membrane domain was proposed to have a similar protein fold to clc chloride channels. we developed a three-dimensional homology model of the ae1 membrane domain, using ... | 2013 | 23583773 |
| bacterial lipopolysaccharides stimulate production of xcl1, a calcium-dependent lipopolysaccharide-binding serum lectin, in xenopus laevis. | xenopus laevis serum lectin xcl1 is a newly identified molecule of the xcgl (or x-lectin) family, a unique group of ca(2+)-dependent lectins that have a fibrinogen-like domain. the xcl1 protein was purified from lipopolysaccharide (lps)-stimulated frog sera by sequential affinity chromatography on heparin-acrylic beads and galactose-sepharose. xcl1 comprises multiple oligomeric proteins consisting of 37-kda subunit polypeptides, as revealed by sodium dodecyl sulfate-polyacrylamide electrophoresi ... | 2013 | 23454582 |
| characterization of the molecular structure, expression and bioactivity of the tnfsf13b (baff) gene of the south african clawed frog, xenopus laevis. | b cell activating factor (baff), a member of the tumor necrosis factor family, is critical to b cell survival, proliferation, maturation, and immunoglobulin secretion and to t cell activation. in the present study, the full-length cdna of baff from the south african clawed frog (xenopus laevis, designated xlbaff) was cloned using rapid amplification of cdna ends (race) techniques and rt-pcr. the full-length cdna of xlbaff consists of 1204 bases including an open reading frame (orf) of 801 nucleo ... | 2013 | 23428910 |
| recombinant expression and purification of the antimicrobial peptide magainin-2. | magainin-2 (mag2) is a polycationic antimicrobial peptide isolated from the skin of the african clawed frog xenopus laevis. it has a wide spectrum of antimicrobial activities against gram-positive and gram-negative bacteria, fungi, and induces osmotic lysis of protozoa. mag2 also possesses antiviral and antitumoral properties. these activities make this peptide a promising candidate for therapeutic applications. recombinant expression systems are necessary for the affordable production of large ... | 2013 | 23125137 |
| live imaging of targeted cell ablation in xenopus: a new model to study demyelination and repair. | live imaging studies of the processes of demyelination and remyelination have so far been technically limited in mammals. we have thus generated a xenopus laevis transgenic line allowing live imaging and conditional ablation of myelinating oligodendrocytes throughout the cns. in these transgenic pmbp-egfp-ntr tadpoles the myelin basic protein (mbp) regulatory sequences, specific to mature oligodendrocytes, are used to drive expression of an egfp (enhanced green fluorescent protein) reporter fuse ... | 2012 | 22973012 |
| immune roles of amphibian (xenopus laevis) tadpole granulocytes during frog virus 3 ranavirus infections. | infections by frog virus 3 (fv3) and other ranaviruses (rvs) are contributing to the amphibian declines, while the mechanisms controlling anuran tadpole susceptibility and adult frog resistance to rvs, including the roles of polymorphonuclear granulocytes (pmns) during anti-fv3 responses, remain largely unknown. since amphibian kidneys represent an important fv3 target, the inability of amphibian (xenopus laevis) tadpoles to mount effective kidney inflammatory responses to fv3 is thought to cont ... | 2017 | 28238879 |
| amphibian (xenopus laevis) tadpoles and adult frogs mount distinct interferon responses to the frog virus 3 ranavirus. | infections of amphibians by frog virus 3 (fv3) and other ranavirus genus members are significantly contributing to the amphibian declines, yet much remains unknown regarding amphibian antiviral immunity. notably, amphibians represent an important step in the evolution of antiviral interferon (ifn) cytokines as they are amongst the first vertebrates to possess both type i and type iii ifns. accordingly, we examined the roles of type i and iii ifns in the skin of fv3-challenged amphibian xenopus l ... | 2017 | 28081430 |
| long term effects of carbaryl exposure on antiviral immune responses in xenopus laevis. | water pollutants associated with agriculture may contribute to the increased prevalence of infectious diseases caused by ranaviruses. we have established the amphibian xenopus laevis and the ranavirus frog virus 3 (fv3) as a reliable experimental platform for evaluating the effects of common waterborne pollutants, such as the insecticide carbaryl. following 3 weeks of exposure to 10 ppb carbaryl, x. laevis tadpoles exhibited a marked increase in mortality and accelerated development. exposure at ... | 2017 | 27988452 |
| frog virus 3 dissemination in the brain of tadpoles, but not in adult xenopus, involves blood brain barrier dysfunction. | while increasing evidence points to a key role of monocytes in amphibian host defenses, monocytes are also thought to be important in the dissemination and persistent infection caused by ranavirus. however, little is known about the fate of infected macrophages or if ranavirus exploits immune privileged organs, such as the brain, in order to establish a reservoir. the amphibian xenopus laevis and frog virus 3 (fv3) were established as an experimental platform for investigating in vivo whether ra ... | 2016 | 26931458 |
| nonclassical mhc-restricted invariant vα6 t cells are critical for efficient early innate antiviral immunity in the amphibian xenopus laevis. | nonclassical mhc class ib-restricted invariant t (it) cell subsets are attracting interest because of their potential to regulate immune responses against various pathogens. the biological relevance and evolutionary conservation of it cells have recently been strengthened by the identification of it cells (invariant vα6 [ivα6]) restricted by the nonclassical mhc class ib molecule xnc10 in the amphibian xenopus laevis. these ivα6 t cells are functionally similar to mammalian cd1d-restricted invar ... | 2015 | 26062996 |
| prominent amphibian (xenopus laevis) tadpole type iii interferon response to the frog virus 3 ranavirus. | ranaviruses (iridoviridae) are posing an increasing threat to amphibian populations, with anuran tadpoles being particularly susceptible to these viral infections. moreover, amphibians are the most basal phylogenetic class of vertebrates known to possess both type i and type iii interferon (ifn)-mediated immunity. moreover, little is known regarding the respective roles of the ifn mediators in amphibian antiviral defenses. accordingly, we transcriptionally and functionally compared the amphibian ... | 2015 | 25717104 |
| inflammation-induced reactivation of the ranavirus frog virus 3 in asymptomatic xenopus laevis. | natural infections of ectothermic vertebrates by ranaviruses (rv, family iridoviridae) are rapidly increasing, with an alarming expansion of rv tropism and resulting die-offs of numerous animal populations. notably, infection studies of the amphibian xenopus laevis with the ranavirus frog virus 3 (fv3) have revealed that although the adult frog immune system is efficient at controlling rv infections, residual quiescent virus can be detected in mononuclear phagocytes of otherwise asymptomatic ani ... | 2014 | 25390636 |
| negative effects of low dose atrazine exposure on the development of effective immunity to fv3 in xenopus laevis. | the recent dramatic increase of the prevalence and range of amphibian host species and populations infected by ranaviruses such as frog virus 3 (fv3) raises concerns about the efficacies of amphibian antiviral immunity. in this context, the potential negative effects of water contaminants such as the herbicide atrazine, at environmentally relevant levels, on host antiviral immunity remains unclear. here we describe the use of the amphibian xenopus laevis as an ecotoxicology platform to elucidate ... | 2014 | 24984115 |
| the amphibian (xenopus laevis) type i interferon response to frog virus 3: new insight into ranavirus pathogenicity. | the increasing prevalence of ranavirus (rv; iridoviridae) infections of wild and commercially maintained aquatic species is raising considerable concerns. while xenopus laevis is the leading model for studies of immunity to rv, amphibian antiviral interferon (ifn) responses remain largely uncharacterized. accordingly, an x. laevis type i interferon was identified, the expression of the gene for this ifn was examined in rv (frog virus 3 [fv3])-infected tadpoles and adult frogs by quantitative pcr ... | 2014 | 24623410 |
| immune evasion strategies of ranaviruses and innate immune responses to these emerging pathogens. | ranaviruses (rv, iridoviridae) are large double-stranded dna viruses that infect fish, amphibians and reptiles. for ecological and commercial reasons, considerable attention has been drawn to the increasing prevalence of ranaviral infections of wild populations and in aquacultural settings. importantly, rvs appear to be capable of crossing species barriers of numerous poikilotherms, suggesting that these pathogens possess a broad host range and potent immune evasion mechanisms. indeed, while som ... | 2012 | 22852041 |
| susceptibility of xenopus laevis tadpoles to infection by the ranavirus frog-virus 3 correlates with a reduced and delayed innate immune response in comparison with adult frogs. | xenopus laevis adults mount effective immune responses to ranavirus frog virus 3 (fv3) infections and clear the pathogen within 2-3 weeks. in contrast, most tadpoles cannot clear fv3 and succumb to infections within a month. while larval susceptibility has been attributed to ineffective adaptive immunity, the contribution of innate immune components has not been addressed. accordingly, we performed a comprehensive gene expression analysis on fv3-infected tadpoles and adults. in comparison to adu ... | 2012 | 22819836 |
| a molecular characterization of the agonist binding site of a nematode cys-loop gaba receptor. | cys-loop gaba receptors represent important targets for human chemotherapeutics and insecticides and are potential targets for novel anthelmintics (nematicides). however, compared with insect and mammalian receptors, little is known regarding the pharmacological characteristics of nematode cys-loop gaba receptors. here we have investigated the agonist binding site of the cys-loop gaba receptor unc-49 (hco-unc-49) from the parasitic nematode haemonchus contortus. | 2015 | 25850584 |
| comparative pharmacology of flatworm and roundworm glutamate-gated chloride channels: implications for potential anthelmintics. | pharmacological targeting of glutamate-gated chloride channels (glucls) is a potent anthelmintic strategy, evidenced by macrocyclic lactones that eliminate numerous roundworm infections by activating roundworm glucls. given the recent identification of flatworm glucls and the urgent need for drugs against schistosomiasis, flatworm glucls should be evaluated as potential anthelmintic targets. this study sought to identify agonists or modulators of one such glucl, smglucl-2 from the parasitic flat ... | 2014 | 25516835 |
| opposing effects of the anesthetic propofol at pentameric ligand-gated ion channels mediated by a common site. | propofol is an intravenous general anesthetic that alters neuronal excitability by modulating agonist responses of pentameric ligand-gated ion channels (plgics). evidence suggests that propofol enhancement of anion-selective plgics is mediated by a binding site between adjacent subunits, whereas propofol inhibition of cation-selective plgics occurs via a binding site contained within helices m1-m4 of individual subunits. we considered this idea by testing propofol modulation of homomeric human g ... | 2014 | 24501356 |
| acr-23 encodes a monepantel-sensitive channel in caenorhabditis elegans. | monepantel is a member of the recently identified class of anthelmintics known as the amino-acetonitrile derivatives (aads). monepantel controls all major gastro-intestinal nematodes in sheep including those that are resistant to the classical anthelmintics. previous studies have shown that the caenorhabditis elegans acr-23 and the haemonchus contortus hco-mptl-1 genes may be prominent targets of monepantel. with this discovery it became possible to investigate the mode of action of monepantel i ... | 2013 | 23950710 |
| selective effect of the anthelmintic bephenium on haemonchus contortus levamisole-sensitive acetylcholine receptors. | acetylcholine receptors (achrs) are pentameric ligand-gated ion channels involved in the neurotransmission of both vertebrates and invertebrates. a number of anthelmintic compounds like levamisole and pyrantel target the achrs of nematodes producing spastic paralysis of the worms. the muscle achrs of nematode parasites fall into three pharmacological classes that are preferentially activated by the cholinergic agonists levamisole (l-type), nicotine (n-type) and bephenium (b-type), respectively. ... | 2012 | 22526556 |
| gene methylation in gastric cancer. | gastric cancer is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide. over 70% of new cases and deaths occur in developing countries. in the early years of the molecular biology revolution, cancer research mainly focuses on genetic alterations, including gastric cancer. epigenetic mechanisms are essential for normal development and maintenance of tissue-specific gene expression patterns in mammals. disruption of epigenetic processes can lea ... | 2013 | 23669186 |
| hepatitis e virus orf3 is a functional ion channel required for release of infectious particles. | hepatitis e virus (hev) is the leading cause of enterically transmitted viral hepatitis globally. of hev's three orfs, the function of orf3 has remained elusive. here, we demonstrate that via homophilic interactions orf3 forms multimeric complexes associated with intracellular endoplasmic reticulum (er)-derived membranes. hev orf3 shares several structural features with class i viroporins, and the function of hev orf3 can be maintained by replacing it with the well-characterized viroporin influe ... | 2017 | 28096411 |
| the 5' untranslated region of the human t-cell lymphotropic virus type 1 mrna enables cap-independent translation initiation. | the human t-cell leukemia virus type 1 (htlv-1) is a complex human retrovirus that causes adult t cell leukemia and of htlv-associated myelopathy/tropical spastic paraparesis. the mrna of some complex retroviruses, including the human and simian immunodeficiency viruses (hiv and siv), can initiate translation using a canonical cap-dependent mechanism or through an internal ribosome entry site (ires). in this study, we present strong evidence showing that like hiv-1 and siv, the 5'-untranslated r ... | 2014 | 24623421 |
| channel-mediated lactic acid transport: a novel function for aquaglyceroporins in bacteria. | mips (major intrinsic proteins), also known as aquaporins, are membrane proteins that channel water and/or uncharged solutes across membranes in all kingdoms of life. considering the enormous number of different bacteria on earth, functional information on bacterial mips is scarce. in the present study, six mips [glpf1 (glycerol facilitator 1)-glpf6] were identified in the genome of the gram-positive lactic acid bacterium lactobacillus plantarum. heterologous expression in xenopus laevis oocytes ... | 2013 | 23799297 |
| site directed mutagenesis of stsut1 reveals target amino acids of regulation and stability. | plant sucrose transporters (suts) are functional as sucrose-proton-cotransporters with an optimal transport activity in the acidic ph range. recently, the ph optimum of the solanum tuberosum sucrose transporter stsut1 was experimentally determined to range at an unexpectedly low ph of 3 or even below. various research groups have confirmed these surprising findings independently and in different organisms. here we provide further experimental evidence for a ph optimum at physiological extrema. s ... | 2013 | 23954800 |
| lizip3 is a cellular zinc transporter that mediates the tightly regulated import of zinc in leishmania infantum parasites. | cellular zinc homeostasis ensures that the intracellular concentration of this element is kept within limits that enable its participation in critical physiological processes without exerting toxic effects. we report here the identification and characterization of the first mediator of zinc homeostasis in leishmania infantum, lizip3, a member of the zip family of divalent metal-ion transporters. the zinc transporter activity of lizip3 was first disclosed by its capacity to rescue the growth of s ... | 2015 | 25644708 |
| complete genome sequence of the frog pathogen mycobacterium ulcerans ecovar liflandii. | in 2004, a previously undiscovered mycobacterium resembling mycobacterium ulcerans (the agent of buruli ulcer) was reported in an outbreak of a lethal mycobacteriosis in a laboratory colony of the african clawed frog xenopus tropicalis. this mycobacterium makes mycolactone and is one of several strains of m. ulcerans-like mycolactone-producing mycobacteria recovered from ectotherms around the world. here, we describe the complete 6,399,543-bp genome of this frog pathogen (previously unofficially ... | 2013 | 23204453 |
| teratogenic effects of organic extracts from the pearl river sediments on xenopus laevis embryos. | toxicity of organic extracts from the pearl river sediments was investigated with xenopus laevis embryos. the effects of sediment organic extracts on the mortality, body length and malformation of x. laevis embryos were tested by the frog embryo teratogenesis assay-xenopus (fetax). the 96-h lc₅₀ values for x. laevis embryos ranged from 62 to 137 g/l (g extracted sediment per l), and the toxicity effect on body length of larvae was not significant under 20 g/l. however, the teratogenic effects pr ... | 2014 | 24361698 |
| mimicking the intramolecular hydrogen bond: synthesis, biological evaluation, and molecular modeling of benzoxazines and quinazolines as potential antimalarial agents. | the intramolecular hydrogen bond formed between a protonated amine and a neighboring h-bond acceptor group in the side chain of amodiaquine and isoquine is thought to play an important role in their antimalarial activities. here we describe isoquine-based compounds in which the intramolecular h-bond is mimicked by a methylene linker. the antimalarial activities of the resulting benzoxazines, their isosteric tetrahydroquinazoline derivatives, and febrifugine-based 1,3-quinazolin-4-ones were exami ... | 2012 | 23145816 |
| the malaria parasite's lactate transporter pffnt is the target of antiplasmodial compounds identified in whole cell phenotypic screens. | in this study the 'malaria box' chemical library comprising 400 compounds with antiplasmodial activity was screened for compounds that perturb the internal ph of the malaria parasite, plasmodium falciparum. fifteen compounds induced an acidification of the parasite cytosol. two of these did so by inhibiting the parasite's formate nitrite transporter (pffnt), which mediates the h+-coupled efflux from the parasite of lactate generated by glycolysis. both compounds were shown to inhibit lactate tra ... | 2017 | 28178359 |
| verapamil-sensitive transport of quinacrine and methylene blue via the plasmodium falciparum chloroquine resistance transporter reduces the parasite's susceptibility to these tricyclic drugs. | it is becoming increasingly apparent that certain mutations in the plasmodium falciparum chloroquine resistance transporter (pfcrt) alter the parasite's susceptibility to diverse compounds. here we investigated the interaction of pfcrt with 3 tricyclic compounds that have been used to treat malaria (quinacrine [qc] and methylene blue [mb]) or to study p. falciparum (acridine orange [ao]). | 2016 | 26503982 |
| a lactate and formate transporter in the intraerythrocytic malaria parasite, plasmodium falciparum. | the intraerythrocytic malaria parasite relies primarily on glycolysis to fuel its rapid growth and reproduction. the major byproduct of this metabolism, lactic acid, is extruded into the external medium. in this study, we show that the human malaria parasite plasmodium falciparum expresses at its surface a member of the microbial formate-nitrite transporter family (pffnt), which, when expressed in xenopus laevis oocytes, transports both formate and lactate. the transport characteristics of pffnt ... | 2015 | 25823844 |
| erythrocyte lysis and xenopus laevis oocyte rupture by recombinant plasmodium falciparum hemolysin iii. | malaria kills more than 1 million people per year worldwide, with severe malaria anemia accounting for the majority of the deaths. malaria anemia is multifactorial in etiology, including infected erythrocyte destruction and decrease in erythrocyte production, as well as destruction or clearance of noninfected erythrocytes. we identified a panspecies plasmodium hemolysin type iii related to bacterial hemolysins. the identification of a hemolysin iii homologue in plasmodium suggests a potential ro ... | 2014 | 25148832 |
| chlorpheniramine analogues reverse chloroquine resistance in plasmodium falciparum by inhibiting pfcrt. | the emergence and spread of malaria parasites that are resistant to chloroquine (cq) has been a disaster for world health. the antihistamine chlorpheniramine (cp) partially resensitizes cq-resistant (cqr) parasites to cq but possesses little intrinsic antiplasmodial activity. mutations in the parasite's cq resistance transporter (pfcrt) confer resistance to cq by enabling the protein to transport the drug away from its site of action, and it is thought that resistance-reversers such as cp exert ... | 2014 | 24900883 |
| diverse mutational pathways converge on saturable chloroquine transport via the malaria parasite's chloroquine resistance transporter. | mutations in the chloroquine resistance transporter (pfcrt) are the primary determinant of chloroquine (cq) resistance in the malaria parasite plasmodium falciparum. a number of distinct pfcrt haplotypes, containing between 4 and 10 mutations, have given rise to cq resistance in different parts of the world. here we present a detailed molecular analysis of the number of mutations (and the order of addition) required to confer cq transport activity upon the pfcrt as well as a kinetic characteriza ... | 2014 | 24728833 |
| quinine dimers are potent inhibitors of the plasmodium falciparum chloroquine resistance transporter and are active against quinoline-resistant p. falciparum. | chloroquine (cq) resistance in the human malaria parasite plasmodium falciparum is primarily conferred by mutations in the "chloroquine resistance transporter" (pfcrt). the resistance-conferring form of pfcrt (pfcrt(cqr)) mediates cq resistance by effluxing the drug from the parasite's digestive vacuole, the acidic compartment in which cq exerts its antiplasmodial effect. pfcrt(cqr) can also decrease the parasite's susceptibility to other quinoline drugs, including the current antimalarials quin ... | 2014 | 24369685 |
| studying epigenetic dna modifications in undergraduate laboratories using complementary bioinformatic and molecular approaches. | epigenetic inheritance is the inheritance of genetic information that is not based on dna sequence alone. one type of epigenetic information that has come to the forefront in the last few years is modified dna bases. the most common modified dna base in nature is 5-methylcytosine. herein, we describe a laboratory experiment that combines bioinformatic and molecular approaches to study the presence and abundance of 5-methylcytosine in different organisms. students were originally provided with th ... | 2013 | 24022990 |
| glutathione transport: a new role for pfcrt in chloroquine resistance. | chloroquine (cq) kills plasmodium falciparum by binding heme, preventing its detoxification to hemozoin in the digestive vacuole (dv) of the parasite. cq resistance (cqr) is associated with mutations in the dv membrane protein p. falciparum chloroquine resistance transporter (pfcrt), mediating the leakage of cq from the dv. however, additional factors are thought to contribute to the resistance phenotype. this study tested the hypothesis that there is a link between glutathione (gsh) and cqr. | 2013 | 23256874 |
| malaria parasite type 4 equilibrative nucleoside transporters (ent4) are purine transporters with distinct substrate specificity. | malaria, caused by plasmodia parasites, affects hundreds of millions of people. as purine auxotrophs, plasmodia use transporters to import host purines for subsequent metabolism by the purine salvage pathway. thus purine transporters are attractive drug targets. all sequenced plasmodia genomes encode four ents (equilibrative nucleoside transporters). during the pathogenic intraerythrocytic stages, ent1 is a major route of purine nucleoside/nucleobase transport. another plasma membrane purine tra ... | 2012 | 22670848 |
| saquinavir inhibits the malaria parasite's chloroquine resistance transporter. | the antiretroviral protease inhibitors (apis) ritonavir, saquinavir, and lopinavir, used to treat hiv infection, inhibit the growth of plasmodium falciparum at clinically relevant concentrations. moreover, it has been reported that these apis potentiate the activity of chloroquine (cq) against this parasite in vitro. the mechanism underlying this effect is not understood, but the degree of chemosensitization varies between the different apis and, with the exception of ritonavir, appears to be de ... | 2012 | 22354298 |
| the morphology and attachment of protopolystoma xenopodis (monogenea: polystomatidae) infecting the african clawed frog xenopus laevis. | the african clawed frog xenopus laevis (anura: pipidae) is host to more than 25 parasite genera encompassing most of the parasitic invertebrate groups. protopolystoma xenopodis price, 1943 (monogenea: polystomatidae) is one of two monogeneans infecting x. laevis. this study focussed on the external morphology of different developmental stages using scanning electron microscopy, histology and light microscopy. eggs are released continuously and are washed out when the frog urinates. after success ... | 2014 | 24823278 |
| acquired immunity protects against helminth infection in a natural host population: long-term field and laboratory evidence. | long-term records of parasite infection are rare for individuals in wild host populations. this study, on an introduced population of xenopus laevis in wales, demonstrates powerful control by acquired immunity of the monogenean, protopolystoma xenopodis. field evidence was based on a 10 year dataset for 619 individually-marked hosts screened at each capture for patent (egg-producing) infection. the adult parasite population occurred predominantly in juvenile hosts. invasion began rapidly 'post-b ... | 2012 | 22906507 |
| phylogenetic analysis and positive-selection site detecting of vascular endothelial growth factor family in vertebrates. | vascular endothelial growth factor (vegf), known to play an important role in vascular homeostasis, vascular integrity and angiogenesis, is little known about the evolutionary relationship of its five members especially the role of gene duplication and natural selection in the evolution of the vegf family. in this study, seventy-five full-length cdna sequences from 33 vertebrate species were extracted from the ncbi's genbank, uniprot protein database and the ensembl database. by phylogenetic ana ... | 2014 | 24200960 |
| atnpf2.5 modulates chloride (cl(-)) efflux from roots of arabidopsis thaliana. | the accumulation of high concentrations of chloride (cl(-)) in leaves can adversely affect plant growth. when comparing different varieties of the same cl(-) sensitive plant species those that exclude relatively more cl(-) from their shoots tend to perform better under saline conditions; however, the molecular mechanisms involved in maintaining low shoot cl(-) remain largely undefined. recently, it was shown that the nrt1/ptr family 2.4 protein (npf2.4) loads cl(-) into the root xylem, which aff ... | 2016 | 28111585 |
| aquaglyceroporins are the entry pathway of boric acid in trypanosoma brucei. | the boron element possesses a range of different effects on living beings. it is essential to beneficial at low concentrations, but toxic at excessive concentrations. recently, some boron-based compounds have been identified as promising molecules against trypanosoma brucei, the causative agent of sleeping sickness. however, until now, the boron metabolism and its access route into the parasite remained elusive. the present study addressed the permeability of t. brucei aquaglyceroporins (tbaqps) ... | 2017 | 28087364 |