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characterizing channelrhodopsin channel properties via two-electrode voltage clamp and kinetic modeling.two-electrode voltage clamp (tevc) is a preferred electrophysiological technique used to study gating kinetics and ion selectivity of light-activated channelrhodopsins (chrs). the method uses two intracellular microelectrodes to hold, or clamp, the membrane potential at a specific value and measure the flow of ions across the plasma membrane. here, we describe the use of tevc and a simple solution exchange protocol to measure cation selectivity and analyze gating kinetics of the c1c2 chimera exp ...202132865738
epigenetic control of myeloid cells behavior by histone deacetylase activity (hdac) during tissue and organ regeneration in xenopus laevis.in the present work we have focused on the histone deacetylase (hdac) control of myeloid cells behavior during xenopus tail regeneration. here we show that myeloid differentiation is crucial to modulate the regenerative ability of xenopus tadpoles in a hdac activity-dependent fashion. hdac activity inhibition during the first wave of myeloid differentiation disrupted myeloid cells dynamics in the regenerative bud as well the mrna expression pattern of myeloid markers, such as lurp, mpox, spib an ...202132858087
clearance of activity-evoked k+ transients and associated glia cell swelling occur independently of aqp4: a study with an isoform-selective aqp4 inhibitor.the mammalian brain consists of 80% water, which is continuously shifted between different compartments and cellular structures by mechanisms that are, to a large extent, unresolved. aquaporin 4 (aqp4) is abundantly expressed in glia and ependymal cells of the mammalian brain and has been proposed to act as a gatekeeper for brain water dynamics, predominantly based on studies utilizing aqp4-deficient mice. however, these mice have a range of secondary effects due to the gene deletion. an efficie ...202132506554
xenopus deep cell aggregates: a 3d tissue model for mesenchymal-to-epithelial transition.mesenchymal-to-epithelial transition (met) describes the ability of loosely associated migratory cells to form a more adherent sheet-like assembly of cells. met is a conserved motif occurring throughout organogenesis and plays a key role in regeneration and cancer metastasis, and is the first step in producing induced pluripotent stem cells (ipscs). to resolve fundamental biological questions about met, its relation to epithelial-to-mesenchymal transition, and to explore met's role in tissue ass ...202132939727
evolution of the endothelin pathway drove neural crest cell diversification.neural crest cells (nccs) are migratory, multipotent embryonic cells that are unique to vertebrates and form an array of clade-defining adult features. the evolution of nccs has been linked to various genomic events, including the evolution of new gene-regulatory networks1,2, the de novo evolution of genes3 and the proliferation of paralogous genes during genome-wide duplication events4. however, conclusive functional evidence linking new and/or duplicated genes to ncc evolution is lacking. endo ...202032939088
establishing embryonic territories in the context of wnt signaling.this review highlights the work that my research group has been developing, together with international collaborators, during the last decade. since we were able to establish xenopus laevis experimental model in brazil we have been focused on understanding early embryonic patterns regarding neural induction and axes establishment. in this context, wnt pathway appears as a major player and has been much explored by us and other research groups. here we chose to review three published works that w ...202032930371
a collision coupling model governs the activation of neuronal girk1/2 channels by muscarinic-2 receptors.the g protein-activated inwardly rectifying k+-channel (girk) modulates heart rate and neuronal excitability. following g-protein coupled receptor (gpcr)-mediated activation of heterotrimeric g proteins (gαβγ), opening of the channel is obtained by direct binding of gβγ subunits. interestingly, girks are solely activated by gβγ subunits released from gαi/o-coupled gpcrs, despite the fact that all receptor types, for instance gαq-coupled, are also able to provide gβγ subunits. it is proposed that ...202032903404
lethal and teratogenic impacts of imazapyr, diquat dibromide, and glufosinate ammonium herbicide formulations using frog embryo teratogenesis assay-xenopus (fetax).globally, amphibians are experiencing widespread abnormalities and population declines. one potential contributor to these challenges is the use of pesticides, particularly aquatic herbicides applied to aquatic habitats inhabited by amphibians. critical issues of concern are the potential toxicity and teratogenicity of these herbicides towards amphibians. using the fetax protocol, three globally used formulations, including diquat dibromide (midstream), glufosinate ammonium (basta), and imazapyr ...202032901337
maximizing crispr/cas9 phenotype penetrance applying predictive modeling of editing outcomes in xenopus and zebrafish embryos.crispr/cas9 genome editing has revolutionized functional genomics in vertebrates. however, crispr/cas9 edited f0 animals too often demonstrate variable phenotypic penetrance due to the mosaic nature of editing outcomes after double strand break (dsb) repair. even with high efficiency levels of genome editing, phenotypes may be obscured by proportional presence of in-frame mutations that still produce functional protein. recently, studies in cell culture systems have shown that the nature of cris ...202032887910
tetrapeptide ac-haee-nh2 protects α4β2 nachr from inhibition by aβ.the cholinergic deficit in alzheimer's disease (ad) may arise from selective loss of cholinergic neurons caused by the binding of aβ peptide to nicotinic acetylcholine receptors (nachrs). thus, compounds preventing such an interaction are needed to address the cholinergic dysfunction. recent findings suggest that the 11evhh14 site in aβ peptide mediates its interaction with α4β2 nachr. this site contains several charged amino acid residues, hence we hypothesized that the formation of aβ-α4β2 nac ...202032872553
embryonic epidermal lectins in three amphibian species, rana ornativentris, bufo japonicus formosus, and cynops pyrrhogaster.intelectins (itlns) are secretory lectins found in several chordate species that recognize carbohydrates on the bacterial cell surface depending on ca2+ . in newly hatched larvae of rana ornativentris (r. orn), bufo japonicus formosus (b. jpn), and cynops pyrrhogaster (c. pyr), an anti-itln monoclonal antibody (mab) labeled a subset of epidermal cells in whole-mount immunocytochemical assays. in western blot analyses, the mab identified protein bands at approximately 33-37 kda in the larval extr ...202032729712
human cationic amino acid transporters are not affected by direct nitros(yl)ation.a direct inhibiting effect of no on the function of cat-1 and -2a has been postulated to occur via nitrosylation of cysteine residues in the transporters. neither the no donor snap nor a mixture of sin-1 and spermine nonoate, that generates the strong nitrosating agent n2o3, reduced cat-mediated l-arginine transport. direct nitros(yl)ation does either not occur in cats or does not affect their transport function. a regulatory effect of no or nitrosating agents on cat-mediated transport under phy ...202032008093
structural basis of the fanconi anemia-associated mutations within the fanca and fancg complex.monoubiquitination of the fanconi anemia complementation group d2 (fancd2) protein by the fa core ubiquitin ligase complex is the central event in the fa pathway. fanca and fancg play major roles in the nuclear localization of the fa core complex. mutations of these two genes are the most frequently observed genetic alterations in fa patients, and most point mutations in fanca are clustered in the c-terminal domain (ctd). to understand the basis of the fa-associated fanca mutations, we determine ...202032002546
tectal crfr1 receptor involvement in avoidance and approach behaviors in the south african clawed frog, xenopus laevis.animals in the wild must balance food intake with vigilance for predators in order to survive. the optic tectum plays an important role in the integration of external (predators) and internal (energy status) cues related to predator defense and prey capture. however, the role of neuromodulators involved in tectal sensorimotor processing is poorly studied. recently we showed that tectal crfr1 receptor activation decreases food intake in the south african clawed frog, xenopus laevis, suggesting th ...202032001211
cav2.1 c-terminal fragments produced in xenopus laevis oocytes do not modify the channel expression and functional properties.the sequence and genomic organization of the cacna1a gene that encodes the cav2.1 subunit of both p and q-type ca2+ channels are well conserved in mammals. in human, rat and mouse cacna1a, the use of an alternative acceptor site at the exon 46-47 boundary results in the expression of a long cav2.1 splice variant. in transfected cells, the long isoform of human cav2.1 produces a c-terminal fragment, but it is not known whether this fragment affects cav2.1 expression or functional properties. here ...202031981388
subcellular localization of the tff peptides xp1 and xp4 in the xenopus laevis gastric/esophageal mucosa: different secretion modes reflecting diverse protective functions.the tff peptides xp1 and xp4 from xenopus laevis are orthologs of tff1 and tff2, respectively. xp1 is secreted as a monomer from gastric surface mucous cells and is generally not associated with mucins, whereas xp4 is a typical secretory peptide from esophageal goblet cells, and gastric mucous neck and antral gland cells tightly associated as a lectin with the ortholog of mucin muc6. both tff peptides have diverse protective functions, xp1 as a scavenger for reactive oxygen species preventing ox ...202031979419
expression of α3β2β4 nicotinic acetylcholine receptors by rat adrenal chromaffin cells determined using novel conopeptide antagonists.adrenal chromaffin cells release neurotransmitters in response to stress and may be involved in conditions such as post-traumatic stress and anxiety disorders. neurotransmitter release is triggered, in part, by activation of nicotinic acetylcholine receptors (nachrs). however, despite decades of use as a model system for studying exocytosis, the nachr subtypes involved have not been pharmacologically identified. quantitative real-time pcr of rat adrenal medulla revealed an abundance of mrnas for ...202031967330
hydrogen sulfide impairs meiosis resumption in xenopuslaevis oocytes.the role of hydrogen sulfide (h2s) is addressed in xenopuslaevis oocytes. three enzymes involved in h2s metabolism, cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase, were detected in prophase i and metaphase ii-arrested oocytes and drove an acceleration of oocyte meiosis resumption when inhibited. moreover, meiosis resumption is associated with a significant decrease in endogenous h2s. on another hand, a dose-dependent inhibition was obtained using the h2 ...202031963573
convergent extension in the amphibian, xenopus laevis.this review is a comprehensive analysis of the cell biology and biomechanics of convergent extension in xenopus.202031959291
biochemical reconstitution of branching microtubule nucleation.microtubules are nucleated from specific locations at precise times in the cell cycle. however, the factors that constitute these microtubule nucleation pathways and their mode of action still need to be identified. using purified xenopus laevis proteins we biochemically reconstitute branching microtubule nucleation, which is critical for chromosome segregation. we found that besides the microtubule nucleator gamma-tubulin ring complex (γ-turc), the branching effectors augmin and tpx2 are requir ...202031933480
developmental and lethal effects of glyphosate and a glyphosate-based product on xenopus laevis embryos and tadpoles.effects of pure glyphosate and a glyphosate-based product were evaluated comparatively using two embryonic development stages of xenopus laevis as model system. when pure glyphosate was applied in ph adjusted media, lethal or developmental effects were not observed at concentrations up to 500 mg l-1. the 96 h lc50 values for the commercial herbicide, in contrast, were 32.1 and 35.1 mg active ingredient l-1 for embryos and tadpoles, respectively. since pure glyphosate has no effect on the selecte ...202031932905
reciprocal matched filtering in the inner ear of the african clawed frog (xenopus laevis).anurans (frogs and toads) are the most vocal amphibians. in most species, only males produce advertisement calls for defending territories and attracting mates. female vocalizations are the exceptions among frogs, however in the african clawed frog (xenopus laevis) both males and females produce distinct vocalizations. the matched filter hypothesis predicts a correspondence between peripheral auditory tuning of receivers and properties of species-specific acoustic signals, but few studies have a ...202031907715
xenopus embryos show a compensatory response following perturbation of the notch signaling pathway.as an essential feature of development, robustness ensures that embryos attain a consistent phenotype despite genetic and environmental variation. the growing number of examples demonstrating that embryos can mount a compensatory response to germline mutations in key developmental genes has heightened interest in the phenomenon of embryonic robustness. while considerable progress has been made in elucidating genetic compensation in response to germline mutations, the diversity, mechanisms, and l ...202031899211
generation, coordination, and evolution of neural circuits for vocal communication.in many species, vocal communication is essential for coordinating social behaviors including courtship, mating, parenting, rivalry, and alarm signaling. effective communication requires accurate production, detection, and classification of signals, as well as selection of socially appropriate responses. understanding how signals are generated and how acoustic signals are perceived is key to understanding the neurobiology of social behaviors. here we review our long-standing research program foc ...202031896561
genome-wide analysis identifies cis-acting elements regulating mrna polyadenylation and translation during vertebrate oocyte maturation.most cells change patterns of gene expression through transcriptional regulation. in contrast, oocytes are transcriptionally silent and regulate mrna poly(a) tail length to control protein production. however, the genome-wide relationship of poly(a) tail changes to mrna translation during vertebrate oocyte maturation is not known. we used tail-seq and polyribosome analysis to measure poly(a) tail and translational changes during oocyte maturation in xenopus laevis we identified large-scale poly( ...202031896558
phosphorylation influences water and ion channel function of atpip2;1.the phosphorylation state of two serine residues within the c-terminal domain of atpip2;1 (s280, s283) regulates its plasma membrane localization in response to salt and osmotic stress. here, we investigated whether the phosphorylation state of s280 and s283 also influence atpip2;1 facilitated water and cation transport. a series of single and double s280 and s283 phosphomimic and phosphonull atpip2;1 mutants were tested in heterologous systems. in xenopus laevis oocytes, phosphomimic mutants at ...202032678928
predation threats for a 24-h period activated the extension of axons in the brains of xenopus tadpoles.the threat of predation is a driving force in the evolution of animals. we have previously reported that xenopus laevis enhanced their tail muscles and increased their swimming speeds in the presence of japanese larval salamander predators. herein, we investigated the induced gene expression changes in the brains of tadpoles under the threat of predation using 3'-tag digital gene expression profiling. we found that many muscle genes were expressed after 24 h of exposure to predation. ingenuity p ...202032678123
electrophysiological effects of non-vitamin k antagonist oral anticoagulants on atrial repolarizing potassium channels.non-vitamin k antagonist oral anticoagulants (noacs) are widely used in the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (af). the efficacy of noacs has been attributed in part to pleiotropic effects that are mediated through effects on thrombin, factor xa, and their respective receptors. direct pharmacological effects of noacs and cardiac ion channels have not been addressed to date. we hypothesized that the favourable clinical outcome of noac use ...202032676673
functional and regulatory characterization of three amts in maize roots.maize grows in nitrate-dominated dryland soils, but shortly upon localized dressing of nitrogen fertilizers, ammonium is retained as a noticeable form of nitrogen source available to roots. thus in addition to nitrate, the absorption of ammonium can be an important strategy that promotes rapid plant growth at strong nitrogen demanding stages. the present study reports the functional characterization of three root-expressed ammonium transporters (amts), aiming at finding out functional and regula ...202032676086
mechanosensitivity is an essential component of phototransduction in vertebrate rods.photoreceptors are specialized cells devoted to the transduction of the incoming visual signals. rods are able also to shed from their tip old disks and to synthesize at the base of the outer segment (os) new disks. by combining electrophysiology, optical tweezers (ots), and biochemistry, we investigate mechanosensitivity in the rods of xenopus laevis, and we show that 1) mechanosensitive channels (mscs), transient receptor potential canonical 1 (trpc1), and piezo1 are present in rod inner segme ...202032667916
role of taalmt1 malate-gaba transporter in alkaline ph tolerance of wheat.malate exudation through wheat (triticum aestivum l) aluminium-activated malate transporter 1 (taalmt1) confers al3+ tolerance at low ph, but is also activated by alkaline ph, and is regulated by and facilitates significant transport of gamma-aminobutyric acid (gaba, a zwitterionic buffer). therefore, taalmt1 may facilitate acidification of an alkaline rhizosphere by promoting exudation of both malate and gaba. here, the performance of wheat near isogenic lines et8 (al+3 -tolerant, high taalmt1 ...202032666573
slc12a2 variants cause a neurodevelopmental disorder or cochleovestibular defect.the slc12 gene family consists of slc12a1-slc12a9, encoding electroneutral cation-coupled chloride co-transporters. scl12a2 has been shown to play a role in corticogenesis and therefore represents a strong candidate neurodevelopmental disorder gene. through trio exome sequencing we identified de novo mutations in slc12a2 in six children with neurodevelopmental disorders. all had developmental delay or intellectual disability ranging from mild to severe. two had sensorineural deafness. we also id ...202032658972
oxidized glutathione increases delta-subunit expressing epithelial sodium channel activity in xenopus laevis oocytes.epithelial sodium channels (enac) are heterotrimeric structures, made up of α, β, and γ subunits, and play an important role in maintaining fluid homeostasis. when δ-enac subunits are expressed in place of (or in addition to) the α-enac subunit alongside β- and γ- subunits, fundamental changes in the biophysical properties of enac can be observed. using human enac crna constructs and the xenopas laevis oocyte expression system, we show that oxidized glutathione (gssg) differently effects αβγ-ena ...202032656545
mambalgin-2 induces cell cycle arrest and apoptosis in glioma cells via interaction with asic1a.gliomas are fast growing and highly invasive brain tumors, characterized by tumor microenvironment acidification that drives glioma cell growth and migration. channels containing acid-sensing ion channel 1a subunit (asic1a) mediate amiloride-sensitive cation influx in late stage glioma cells, but not in normal astrocytes. thus, selective targeting of asic1a can be a perspective strategy for glioma treatment. here, asic1a expression in u251 mg and a172 glioma cells, but not in normal astrocytes, ...202032650495
transcriptomic analysis identifies early cellular and molecular events by which estrogen disrupts testis differentiation and causes feminization in xenopus laevis.extensive studies have shown that estrogenic endocrine-disrupting chemicals (edcs) can disrupt testis differentiation and even cause feminization in vertebrates. however, little is known about the mechanisms by which estrogenic edcs disrupt testis differentiation. here, we employed xenopus laevis, a model amphibian species sensitive to estrogenic edcs, to explore the molecular and cellular events by which 17β-estradiol (e2) disrupts testis differentiation and causes feminization. following water ...202032645606
altered glutaminase 1 activity during neurulation and its potential implications in neural tube defects.the neurulation process is regulated by a large amount of genetic and environmental factors that determine the establishment, folding, and fusion of the neural plate to form the neural tube, which develops into the main structure of the central nervous system. a recently described factor involved in this process is glutamate. through nmda ionotropic receptor, glutamate modifies intracellular ca2+ dynamics allowing the oriented cell migration and proliferation, essentials processes in neurulation ...202032636743
the histone h3-h4 tetramer is a copper reductase enzyme.eukaryotic histone h3-h4 tetramers contain a putative copper (cu2+) binding site at the h3-h3' dimerization interface with unknown function. the coincident emergence of eukaryotes with global oxygenation, which challenged cellular copper utilization, raised the possibility that histones may function in cellular copper homeostasis. we report that the recombinant xenopus laevis h3-h4 tetramer is an oxidoreductase enzyme that binds cu2+ and catalyzes its reduction to cu1+ in vitro. loss- and gain-o ...202032631887
heterologous expression of concatenated nicotinic ach receptors: pros and cons of subunit concatenation and recommendations for construct designs.concatenation of cys-loop receptor subunits is a commonly used technique to ensure experimental control of receptor assembly. however, we recently demonstrated that widely used constructs did not lead to the expression of uniform pools of ternary and more complex receptors. the aim was therefore to identify viable strategies for designing concatenated constructs that would allow strict control of resultant receptor pools.202032627170
relationship between oxygen consumption and neuronal activity in a defined neural circuit.neuronal computations related to sensory and motor activity along with the maintenance of spike discharge, synaptic transmission, and associated housekeeping are energetically demanding. the most efficient metabolic process to provide large amounts of energy equivalents is oxidative phosphorylation and thus dependent on o2 consumption. therefore, o2 levels in the brain are a critical parameter that influences neuronal function. measurements of o2 consumption have been used to estimate the cost o ...202032615976
comprehensive imaging of sensory-evoked activity of entire neurons within the awake developing brain using ultrafast aod-based random-access two-photon microscopy.determining how neurons transform synaptic input and encode information in action potential (ap) firing output is required for understanding dendritic integration, neural transforms and encoding. limitations in the speed of imaging 3d volumes of brain encompassing complex dendritic arbors in vivo using conventional galvanometer mirror-based laser-scanning microscopy has hampered fully capturing fluorescent sensors of activity throughout an individual neuron's entire complement of synaptic inputs ...202032612514
cofactor-enabled functional expression of fruit fly, honeybee, and bumblebee nicotinic receptors reveals picomolar neonicotinoid actions.the difficulty of achieving robust functional expression of insect nicotinic acetylcholine receptors (nachrs) has hampered our understanding of these important molecular targets of globally deployed neonicotinoid insecticides at a time when concerns have grown regarding the toxicity of this chemotype to insect pollinators. we show that thioredoxin-related transmembrane protein 3 (tmx3) is essential to enable robust expression in xenopus laevis oocytes of honeybee (apis mellifera) and bumblebee ( ...202032611810
disabled-2: a positive regulator of the early differentiation of myoblasts.dab2 is an adaptor protein and a tumor suppressor. our previous study has found that dab2 was expressed in early differentiating skeletal muscles in mouse embryos. in this study, we determined the role of dab2 in the skeletal muscle differentiation using c2c12 myoblasts in vitro and xenopus laevis embryos in vivo. the expression of dab2 was increased in c2c12 myoblasts during the formation of myotubes in vitro. knockdown of dab2 expression in c2c12 myoblasts resulted in a reduction of myotube fo ...202032607799
comparing the effect of triadimefon and its metabolite on male and female xenopus laevis: obstructed growth and gonad morphology.amphibians are the most endangered class of vertebrates. in this study, xenopus laevis frogs were exposed to 0, 1 and 10 mg/l of triadimefon or triadimenol. after 14 or 28 days of exposure, high levels of triadimefon or triadimenol obstructed the growth of frogs. however, low levels of triadimefon induced the growth of females after the longer period of exposure. we also found that the antioxidant enzyme activity and ldh levels in males were higher than those in females after 28-days exposure. i ...202032603964
the histone chaperone fact induces cas9 multi-turnover behavior and modifies genome manipulation in human cells.cas9 is a prokaryotic rna-guided dna endonuclease that binds substrates tightly in vitro but turns over rapidly when used to manipulate genomes in eukaryotic cells. little is known about the factors responsible for dislodging cas9 or how they influence genome engineering. unbiased detection through proximity labeling of transient protein interactions in cell-free xenopus laevis egg extract identified the dimeric histone chaperone facilitates chromatin transcription (fact) as an interactor of sub ...202032603710
active forces shape the metaphase spindle through a mechanical instability.the metaphase spindle is a dynamic structure orchestrating chromosome segregation during cell division. recently, soft matter approaches have shown that the spindle behaves as an active liquid crystal. still, it remains unclear how active force generation contributes to its characteristic spindle-like shape. here we combine theory and experiments to show that molecular motor-driven forces shape the structure through a barreling-type instability. we test our physical model by titrating dynein act ...202032601228
a turripeptide from polystira nobilis venom inhibits human α3β2 and α7 nicotinic acetylcholine receptors.almost all marine snails within superfamily conoidea produce venoms containing numerous neuroactive peptides. most toxins characterized from members of this superfamily are produced by species belonging to family conidae. these toxins (conotoxins) affect diverse membrane proteins, such as voltage- and ligand-gated ion channels, including nicotinic acetylcholine receptors (nachrs). family turridae has been considerably less studied than their conidae counterpart and, therefore, turrid toxins (tur ...202032592834
organizing the oocyte: rna localization meets phase separation.rna localization is a key biological strategy for organizing the cytoplasm and generating both cellular and developmental polarity. during rna localization, rnas are targeted asymmetrically to specific subcellular destinations, resulting in spatially and temporally restricted gene expression through local protein synthesis. first discovered in oocytes and embryos, rna localization is now recognized as a significant regulatory strategy for diverse rnas, both coding and non-coding, in a wide range ...202032591084
contribution of monocarboxylate transporter 6 to the pharmacokinetics and pharmacodynamics of bumetanide in mice.bumetanide, a sulfamyl loop diuretic, is used for the treatment of edema in association with congestive heart failure. being a polar, anionic compound at physiologic ph, bumetanide uptake and efflux into different tissues is largely transporter-mediated. of note, organic anion transporters (slc22a) have been extensively studied in terms of their importance in transporting bumetanide to its primary site of action in the kidney. the contribution of one of the less-studied bumetanide transporters, ...202032587098
functional analysis of the osnpf4.5 nitrate transporter reveals a conserved mycorrhizal pathway of nitrogen acquisition in plants.low availability of nitrogen (n) is often a major limiting factor to crop yield in most nutrient-poor soils. arbuscular mycorrhizal (am) fungi are beneficial symbionts of most land plants that enhance plant nutrient uptake, particularly of phosphate. a growing number of reports point to the substantially increased n accumulation in many mycorrhizal plants; however, the contribution of am symbiosis to plant n nutrition and the mechanisms underlying the am-mediated n acquisition are still in the e ...202032586957
acute toxicity of fluazinam to aquatic organisms and its bioaccumulation in brachydanio rerio.fluazinam (fzn) is a dinitroaniline fungicide. to evaluate the environmental risk of fzn in aquatic environments and ascertain the potential danger to typical aquatic organisms in china, the acute toxicity of fzn to representative aquatic organisms, including brachydanio rerio, chlorella vulgaris beij., daphnia magna straus, and xenopus laevis, was measured, and its bioaccumulation properties in brachydanio rerio were further investigated. the results showed that the acute toxicity of fzn to bra ...202032583109
electromechanical coupling of the kv1.1 voltage-gated k+ channel is fine-tuned by the simplest amino acid residue in the s4-s5 linker.investigating the shaker-related k+ channel kv1.1, the dysfunction of which is responsible for episodic ataxia 1 (ea1), at the functional and molecular level provides valuable understandings on normal channel dynamics, structural correlates underlying voltage-gating, and disease-causing mechanisms. most studies focused on apparently functional amino acid residues composing voltage-gated k+ channels, neglecting the simplest ones. glycine at position 311 of kv1.1 is highly conserved both evolution ...202032577860
polo-like kinase 1 (plk1) is a positive regulator of dna replication in the xenopus in vitro system.polo-like kinase 1 (plk1) is a cell cycle kinase essential for mitosis progression, but also important for checkpoint recovery and adaptation in response to dna damage and replication stress. however, although plk1 is expressed in s phase, little is known about its function during unperturbed dna replication. using xenopus laevis egg extracts, mimicking early embryonic replication, we demonstrate that plk1 is simultaneously recruited to chromatin with pre-replication proteins where it accumulate ...202032573322
molecular regulation of α3β4 nicotinic acetylcholine receptors by lupeol in cardiovascular system.cardiovascular disease (cvd) occurs globally and has a high mortality rate. the highest risk factor for developing cvd is high blood pressure. currently, natural products are emerging for the treatment of hypertension to avoid the side effects of drugs. among existing natural products, lupeol is known to be effective against hypertension in animal experiments. however, there exists no study regarding the molecular physiological evidence against the effects of lupeol. consequently, we investigate ...202032570692
three host plant volatiles, hexanal, lauric acid, and tetradecane, are detected by an antenna-biased expressed odorant receptor 27 in the dark black chafer holotrichia parallela.insects rely on olfaction to locate their host plants by antennae in complex chemical environments. odorant receptor (or) genes are thought to play a crucial role in the process. ors function together with odorant coreceptors to determine the specificity and sensitivity of olfactory reception. the dark black chafer, holotrichia parallela motschulsky (coleoptera: scarabaeidae), is a destructive underground pest. to understand the molecular basis of h. parallela olfactory reception, an olfactory-b ...202032551589
chemical and voltage gating of gap junction channels expressed in xenopus oocytes.in most tissues, cells in contact with each other directly intercommunicate via cell-to-cell channels aggregated at gap junctions. direct cell-to-cell communication provides a fundamental mechanism for coordinating many cellular functions in mature and developing organs, as it enables free exchange of small cytosolic molecules. gap junction channels are regulated by a chemical gating mechanism sensitive to cytosolic calcium concentration [ca2+]i in the nanomolar range mediated by ca2+-activated ...202032548808
investigating the impact of the phosphorylation status of tyrosine residues within the tacc domain of tacc3 on microtubule behavior during axon growth and guidance.axon guidance is a critical process in forming the connections between a neuron and its target. the growth cone steers the growing axon toward the appropriate direction by integrating extracellular guidance cues and initiating intracellular signal transduction pathways downstream of these cues. the growth cone generates these responses by remodeling its cytoskeletal components. regulation of microtubule dynamics within the growth cone is important for making guidance decisions. tacc3, as a micro ...202032543081
the transition state and regulation of γ-turc-mediated microtubule nucleation revealed by single molecule microscopy.determining how microtubules (mts) are nucleated is essential for understanding how the cytoskeleton assembles. while the mt nucleator, γ-tubulin ring complex (γ-turc) has been identified, precisely how γ-turc nucleates a mt remains poorly understood. here, we developed a single molecule assay to directly visualize nucleation of a mt from purified xenopus laevis γ-turc. we reveal a high γ-/αβ-tubulin affinity, which facilitates assembly of a mt from γ-turc. whereas spontaneous nucleation require ...202032538784
functional characterization of the arabidopsis ammonium transporter atamt1;3 with the emphasis on structural determinants of substrate binding and permeation properties.atamt1;3 is a major contributor to high-affinity ammonium uptake in arabidopsis roots. using a stable electrophysiological recording strategy, we demonstrate in xenopus laevis oocytes that atamt1;3 functions as a typical high-affinity nh4+ uniporter independent of protons and ca2+. the findings that atamt1;3 transports methylammonium (mea+, a chemical analog of nh4+) with extremely low affinity (km in the range of 2.9-6.1 mm) led to investigate the mechanisms underlying substrate binding. homolo ...202032528489
hcn2 channel-induced rescue of brain teratogenesis via local and long-range bioelectric repair.embryonic exposure to the teratogen nicotine results in brain defects, by disrupting endogenous spatial pre patterns necessary for normal brain size and patterning. extending prior work in xenopus laevis that showed that misexpression of ion channels can rescue morphogenesis, we demonstrate and characterize a novel aspect of developmental bioelectricity: channel-dependent repair signals propagate long-range across the embryo. we show that distal hcn2 channel misexpression and distal transplants ...202032528251
xela ds2 and xela vs2: two novel skin epithelial-like cell lines from adult african clawed frog (xenopus laevis) and their response to an extracellular viral dsrna analogue.the skin epithelial layer acts as an important immunological barrier against pathogens and is capable of recognizing and responding to pathogen-associated molecular patterns (pamps) in human and mouse models. although presumed, it is unknown whether amphibian skin epithelial cells exhibit the ability to respond to pamps such as viral double-stranded rna (dsrna). to address this, two cell lines from the dorsal skin (xela ds2) and ventral skin (xela vs2) of the african clawed frog (xenopus laevis) ...202032526291
monoterpenes differently regulate acid-sensitive and mechano-gated k2p channels.potassium k2p ("leak") channels conduct current across the entire physiological voltage range and carry leak or "background" currents that are, in part, time- and voltage-independent. the activity of k2p channels affects numerous physiological processes, such as cardiac function, pain perception, depression, neuroprotection, and cancer development. we have recently established that, when expressed in xenopus laevis oocytes, k2p2.1 (trek-1) channels are activated by several monoterpenes (mts). he ...202032508645
the influence of long-term cadmium exposure on the male advertisement call of xenopus laevis.cadmium (cd) is a non-essential environmental endocrine-disrupting compound found in water and a potential threat to aquatic habitats. cd has been shown to have various short-term effects on aquatic animals; however, evidence for long-term effects of cd on vocal communications in amphibians is lacking. to better understand the long-term effects of low-dose cd on acoustic communication in amphibians, male xenopus laevis individuals were treated with low cd concentrations (0.1, 1, and 10 μg/l) via ...202031889288
several phosphate transport processes are present in vascular smooth muscle cells.we have studied inorganic phosphate (pi) handling in rat aortic vascular smooth muscle cells (vsmc) using 32p-radiotracer assays. our results have revealed a complex set of mechanisms consisting of 1) well-known pit1/pit2-mediated sodium-dependent pi transport; 2) slc20-unrelated sodium-dependent pi transport that is sensitive to the stilbene derivatives 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (dids) and 4-acetamido-4-isothiocyanostilbene-2,2-disulfonate (sits); 3) a sodium-independe ...202031886722
distinct m6a methylome profiles in poly(a) rna from xenopus laevis testis and that treated with atrazine.recent discovery of reversible n6-methyladenosine (m6a) methylation on messenger rna (mrna) and mapping of m6a methylomes in mammals, plant and yeast revealed potential regulatory functions of this rna modification. however, the role of the m6a methylomes in amphibious is still poorly understood. here, we examined the m6a transcriptome-wide profile in testis tissues of xenopus laevis (x. laevis) with and without treatment with 100 μg/l atrazine (az) through m6a sequencing analysis using the late ...202031877456
transformation of receptor tyrosine kinases into glutamate receptors and photoreceptors.receptor tyrosine kinases (rtks) are key regulators of cellular functions in metazoans. in vertebrates, rtks are mostly activated by polypeptides but are not naturally sensitive to amino acids or light. taking inspiration from venus kinase receptors (vkrs), an atypical family of rtks found in nature, we have transformed the human insulin (hir) and hepatocyte growth factor receptor (hmet) into glutamate receptors by replacing their extracellular binding domains with the ligand-binding domain of m ...202031872568
modeling ocular lens disease in xenopus.ocular lens clouding is termed as cataract, which depending on the onset, is classified as congenital or age-related. developing new cataract treatments requires new models. thus far, xenopus embryos have not been evaluated as a system for studying cataract.202031872467
bupropion inhibits serotonin type 3ab heteromeric channels at clinically relevant concentrations.bupropion, a food and drug administration-approved antidepressant and smoking cessation aid, blocks dopamine and norepinephrine reuptake transporters and noncompetitively inhibits nicotinic acetylcholine and serotonin (5-ht) type 3a receptors (5-ht3ars). 5-ht3 receptors are pentameric ligand-gated ion channels that regulate synaptic activity in the central and peripheral nervous system, presynaptically and postsynaptically. in the present study, we examined and compared the effect of bupropion a ...202031871303
the γ-hydroxybutyric acid (ghb) analogue ncs-382 is a substrate for both monocarboxylate transporters subtypes 1 and 4.the small-molecule ligand (e)-2-(5-hydroxy-5,7,8,9-tetrahydro-6h-benzo[7]annulen-6-ylidene)acetic acid (ncs-382) is an analogue of γ-hydroxybutyric acid (ghb) and is widely used for probing the brain-specific ghb high-affinity binding sites. to reach these, brain uptake is imperative, and it is therefore important to understand the molecular mechanisms of ncs-382 transport in order to direct in vivo studies. in this study, we hypothesized that ncs-382 is a substrate for the monocarboxylate trans ...202031866563
applying tensile and compressive force to xenopus animal cap tissue.over many years, the xenopus laevis embryo has provided a powerful model system to investigate how mechanical forces regulate cellular function. here, we describe a system to apply reproducible tensile and compressive force to x. laevis animal cap tissue explants and to simultaneously assess cellular behavior using live confocal imaging.202031857437
insights into the assembly and activation of the microtubule nucleator γ-turc.microtubules are dynamic polymers of α- and β-tubulin and have crucial roles in cell signalling, cell migration, intracellular transport and chromosome segregation1. they assemble de novo from αβ-tubulin dimers in an essential process termed microtubule nucleation. complexes that contain the protein γ-tubulin serve as structural templates for the microtubule nucleation reaction2. in vertebrates, microtubules are nucleated by the 2.2-megadalton γ-tubulin ring complex (γ-turc), which comprises γ-t ...202031856152
organ-specific requirements for thyroid hormone receptor ensure temporal coordination of tissue-specific transformations and completion of xenopus metamorphosis.background: thyroid hormone (triiodothyronine [t3]) is essential for the development throughout vertebrates. anuran metamorphosis mimics mammalian postembryonic development, a period around birth when plasma t3 level peaks and many organs/tissues mature into their adult forms. compared with the uterus-enclosed mammalian embryos, tadpoles can be easily manipulated to study the roles of t3 and t3 receptors (trs) in tissue remodeling and adult organ development. we and others have previously knocke ...202031854240
bringing immersive science to undergraduate laboratory courses using crispr gene knockouts in frogs and butterflies.the use of crispr/cas9 for gene editing offers new opportunities for biology students to perform genuine research exploring the gene-to-phenotype relationship. it is important to introduce the next generation of scientists, health practitioners and other members of society to the technical and ethical aspects of gene editing. here, we share our experience leading hands-on undergraduate laboratory classes, where students formulate hypotheses regarding the roles of candidate genes involved in deve ...202032034043
annexin a3 is necessary for parallel artery-vein alignment in the mouse retina.annexin a3 (anxa3) is a member of the calcium-regulated, cell membrane-binding family of annexin proteins. we previously confirmed that anxa3 is expressed in the endothelial lineage in vertebrates and that loss of anxa3 in xenopus laevis leads to embryonic blood vessel defects. however, the biological function of anxa3 in mammals is completely unknown. in order to investigate anxa3 vascular function in mammals, we generated an endothelial cell-specific anxa3 conditional knockout mouse model (anx ...202032020697
active emigration from climate change-caused seawater intrusion into freshwater habitats.ecological risk assessment associated with seawater intrusions has been supported on the determination of lethal/sublethal effects following standard protocols that force exposure neglecting the ability of mobile organisms to spatially avoid salinized environments. thus, this work aimed at assessing active emigration from climate change-caused seawater intrusion into freshwater habitats. to specific objectives were delineated: first, to compute median 12-h avoidance conductivities (ac50,12h) for ...202031883492
heparan sulfate proteoglycans regulate bmp signalling during neural crest induction.bone morphogenetic protein (bmp) signalling is key to many developmental processes, including early regionalisation of the ectoderm. the neural crest is induced here by a combination of bmp and wnt signals from nearby tissues with many secreted factors contributing to its initial specification at the neural plate border. gremlin 1 (grem1) is a secreted bmp antagonist expressed in the neural crest in xenopus laevis but its function here is unknown. as well as binding bmps, grem1 has been shown to ...202031883440
d-glucuronolactone attenuates para-xylene-induced defects in neuronal development and plasticity in xenopus tectum in vivo.xylene and its derivatives are known to be neurotoxic to the central nervous system of animals. our previous work has shown that para-xylene (px) can cause an increase in apoptotic cells and abnormal avoidance behavior in xenopus laevis. however, the mechanism underlying the impact of px on neuronal structural and functional plasticity is less clear. here, we examined the effects of px on neuronal development and plasticity in the developing optic tectum. we found that huc/d-positive neurons wer ...202031811891
analysis of clcnkb mutations at dimer-interface, calcium-binding site, and pore reveals a variety of functional alterations in clc-kb channel leading to bartter syndrome.pathological missense mutations in clcnkb gene give a wide spectrum of clinical phenotypes in bartter syndrome type iii patients. molecular analysis of the mutated clc-kb channels can be helpful to classify the mutations according to their functional alteration. we investigated the functional consequences of nine mutations in the clcnkb gene causing bartter syndrome. we first established that all tested mutations lead to decreased clc-kb currents. combining electrophysiological and biochemical m ...202031803959
role of trka signaling during tadpole tail regeneration and early embryonic development in xenopus laevis.neurotrophic signaling regulates neural cell behaviors in development and physiology, although its role in regeneration has not been fully investigated. here, we examined the role of neurotrophic signaling in xenopus laevis tadpole tail regeneration. after the tadpole tails were amputated, the expression of neurotrophin ligand family genes, especially ngf and bdnf, was up-regulated as regeneration proceeded. moreover, notochordal expression of the ngf receptor gene trka, but not that of other ne ...202031788928
studying in vivo retinal progenitor cell proliferation in xenopus laevis.the efficient generation and maintenance of retinal progenitor cells (rpcs) are key goals needed for developing strategies for productive eye repair. although vertebrate eye development and retinogenesis are well characterized, the mechanisms that can initiate rpc proliferation following injury-induced regrowth and repair remain unknown. this is partly because endogenous rpc proliferation typically occurs during embryogenesis while studies of retinal regeneration have largely utilized adult (or ...202031786778
molecular characterization of the orphan transporter slc16a9, an extracellular ph- and na+-sensitive creatine transporter.human monocarboxylate transporters (hmcts) mediate the transport of monocarboxylates across plasma membranes. one such transporter, hmct9, has been shown to be related to serum uric acid levels and the risk of renal overload gout. however, the functional characteristics of hmct9 remain unknown. the aim of this study was to investigate the expression and localization of hmct9 using a xenopus laevis oocyte heterologous expression system and characterize its transport properties. kinetic analysis o ...202031784090
a glimpse of the peptide profile presentation by xenopus laevis mhc class i: crystal structure of pxela-uaa reveals a distinct peptide-binding groove.the african clawed frog, xenopus laevis, is a model species for amphibians. before metamorphosis, tadpoles do not efficiently express the single classical mhc class i (mhc-i) molecule xela-uaa, but after metamorphosis, adults express this molecule in abundance. to elucidate the ag-presenting mechanism of xela-uaa, in this study, the xela-uaa structure complex (pxela-uaag) bound with a peptide from a synthetic random peptide library was determined. the amino acid homology between the xela-uaa and ...202031776204
endoplasmic reticulum transmembrane protein tmtc3 contributes to o-mannosylation of e-cadherin, cellular adherence, and embryonic gastrulation.protein glycosylation plays essential roles in protein structure, stability, and activity such as cell adhesion. the cadherin superfamily of adhesion molecules carry o-linked mannose glycans at conserved sites and it was recently demonstrated that the transmembrane and tetratricopeptide repeat-containing proteins 1-4 (tmtc1-4) gene products contribute to the addition of these o-linked mannoses. here, biochemical, cell biological, and organismal analysis was used to determine that tmtc3 supports ...202031851597
desensitization of nmda channels requires ligand binding to both glun1 and glun2 subunits to constrict the pore beside the activation gate.n-methyl-d-aspartate (nmda) receptor channels are activated by glutamate (or nmda) and glycine. the channels also undergo desensitization, which denotes decreased channel availability, after prolonged exposure to the activating ligands. glycine apparently has a paradoxical negative effect on desensitization, as the increase in ambient glycine in concentrations required for channel activation would increase sustained nmda receptor currents. we hypothesized that this classical "glycine-dependent d ...202031821563
apple almt9 requires a conserved c-terminal domain for malate transport underlying fruit acidity.malate accumulation in the vacuole largely determines apple (malus domestica) fruit acidity, and low fruit acidity is strongly associated with truncation of ma1, an ortholog of aluminum-activated malate transporter9 (almt9) in arabidopsis (arabidopsis thaliana). a mutation at base 1,455 in the open reading frame of ma1 leads to a premature stop codon that truncates the protein by 84 amino acids at its c-terminal end. here, we report that both the full-length protein, ma1, and its naturally occur ...202031772076
effect of triadimefon and its metabolite on adult amphibians xenopus laevis.the decrease in the population of amphibians all over the world has raised concerns. adult x. laevis frogs were exposed to 0, 1 and 10 mg/l triadimefon and triadimenol. after 14 or 28 days exposure, we collected male and female specimens to study swimming activity, lactic dehydrogenase (ldh) and antioxidant enzyme activity in blood samples, histopathology of liver and thyroid tissue, thyroid hormone levels and thyroid hormone-related gene expression levels in brains. our results showed that tria ...202031743868
ligand binding characteristics of the ku80 von willebrand domain.the n-terminal von willebrand domain of ku80 supports interactions with a ku binding motif (kbm) that has been identified in at least three other dna repair proteins: the non-homologous end joining (nhej) scaffold aplf, the modulator of retrovirus infection, mri, and the werner syndrome protein (wrn). a second, more recently identified ku binding motif present in xlf and several other proteins (kbmx) has also been reported to interact with this domain. the isolated ku80 von willebrand antigen do ...202031733588
tomato roots have a functional silicon influx transporter but not a functional silicon efflux transporter.silicon (si) accumulation in shoots differs greatly with plant species, but the molecular mechanisms for this interspecific difference are unknown. here, we isolated homologous genes of rice si influx (sllsi1) and efflux (sllsi2) transporter genes in tomato (solanum lycopersicum l.) and functionally characterized these genes. sllsi1 showed transport activity for si when expressed in both rice lsi1 mutant and xenopus laevis oocytes. sllsi1 was constitutively expressed in the roots. immunostaining ...202031724184
the flavor enhancer maltol increases pigment aggregation in dermal and neural melanophores in xenopus laevis tadpoles.melanophores are pigmented cells that change the distribution of melanosomes, enabling animals to appear lighter or darker for camouflage, thermoregulation, and protection from ultraviolet radiation. a complex series of hormonal and neural mechanisms regulates melanophore pigment distribution, making these dynamic cells a valuable tool to screen toxicants as they rapidly respond to changes in the environment. we found that maltol, a naturally occurring flavor enhancer and fragrance agent, induce ...202031721268
iron nanoparticle bio-interactions evaluated in xenopus laevis embryos, a model for studying the safety of ingested nanoparticles.iron nanoparticles (nps) have been proposed as a tool in very different fields such as environmental remediation and biomedical applications, including food fortification against iron deficiency, even if there is still concern about their safety. here, we propose xenopus laevis embryos as a suitable model to investigate the toxicity and the bio-interactions at the intestinal barrier of fe3o4 and zerovalent iron (zvi) nps compared to fe(ii) and (iii) salts in the 5 to 100 mg fe/l concentration ra ...202031718350
toward decoding bioelectric events in xenopus embryogenesis: new methodology for tracking interplay between calcium and resting potentials in vivo.although chemical signaling during embryogenesis is readily addressed by a plethora of available techniques, the developmental functions of ionic signaling are still poorly understood. it is increasingly realized that bioelectric events in nonneural cells are critical for pattern regulation, but their study has been hampered by difficulties in monitoring and manipulating them in vivo. recent developments in visualizing electrical signaling dynamics in the field of neuroscience have facilitated f ...202031711960
arabidopsis pic30 encodes a major facilitator superfamily transporter responsible for the uptake of picolinate herbicides.picloram is an auxinic herbicide that is widely used for controlling broad leaf weeds. however, its mechanism of transport into plants is poorly understood. in a genetic screen for picloram resistance, we identified three arabidopsis mutant alleles of pic30 (picloram resistant30) that are specifically resistant to picolinates, but not to other auxins. pic30 is a previously uncharacterized gene that encodes a major facilitator superfamily (mfs) transporter. similar to most members of mfs, pic30 c ...202031710151
serotonin and mucxs release by small secretory cells depend on xpod, a ssc specific marker gene.mucus secretion and ciliary motility are hallmarks for muco-ciliary epithelia (mce). both, mammalian airways as well as the less complex epidermis of xenopus embryos show cilia-driven mucus flow to protect the organism against harmful effects by exogenous pathogens or pollutants. four cell types set up the epidermal mce in xenopus. multi-ciliated cells (mccs) generate an anterior to posterior flow of mucus. ion secreting cells (iscs) are characterized by the expression of ion transporters, presu ...202031705622
the hkt transporter hvhkt1;5 negatively regulates salt tolerance.maintaining low intracellular na+ concentrations is an essential physiological strategy in salt stress tolerance in most cereal crops. here, we characterized a member of the high-affinity k+ transporter (hkt) family in barley (hordeum vulgare), hvhkt1;5, which negatively regulates salt tolerance and has different functions from its homology in other cereal crops. hvhkt1;5 encodes a plasma membrane protein localized to root stele cells, particularly in xylem parenchyma cells adjacent to the xylem ...202031690708
simple method to characterize the ciliary proteome of multiciliated cells.motile cilia of multiciliated epithelial cells have important roles in animal development and cell homeostasis. although several studies have identified and reported proteins localized in this complex organelle and the related immotile primary cilia from various cell types, it is still challenging to isolate high quantities of ciliary proteins for proteomic analysis. in this study, african clawed frog (xenopus laevis) embryos, which have many multiciliated cells in the epidermis, were treated wi ...202031689115
complement c1q subunit molecules from xenopus laevis possess conserved function in c1q-immunoglobulin interaction.complement component 1q (c1q), together with c1r and c1s to form c1, recognize and bind immune complex to initiate the classical complement pathway. in this study, c1q subunit molecules (xlc1qa, xlc1qb, xlc1qc) were cloned and analyzed from xenopus laevis (x. laevis). the open reading frame (orf) of xlc1qa is 819 bp of nucleotide sequence encoding 272 amino acids, the orf of xlc1qb is 711 bp encoding 236 aa, and the xlc1qc is consists of 732 bp encoding 243 aa. the deduced amino acid sequences c ...202031678076
identification and characterization of the atlantic salmon peptide transporter 1a.peptide transporter 1 (pept1) mediates the uptake of dietary di-/tripeptides in vertebrates. however, in teleost fish gut, more than one pept1-type transporter might operate, because of teleost-specific whole gen(om)e duplication event(s) that occurred during evolution. here, we describe a novel teleost di-/tripeptide transporter, i.e., the atlantic salmon (salmo salar) peptide transporter 1a [pept1a; or solute carrier family 15 member 1a (slc15a1a)], which is a paralog (77% similarity and 64% i ...202031664857
extracellular lysine 38 plays a crucial role in ph-dependent transport via human monocarboxylate transporter 1.human monocarboxylate transporters (hmcts) are expressed in many tissues and mediate the transport of various substrates across the plasma membrane. among hmcts, hmct1-4 cotransport h+ with monocarboxylates such as pyruvate and l-lactate, implying that these proteins recognize both substrate and h+. however, the mechanism of translocation, and particularly that of hmct1 ph-dependent transport, remains largely unknown. this study aimed at identifying residues involved in the ph dependence of hmct ...202031593685
cytosolic gaba inhibits anion transport by wheat almt1.anion transport by aluminium-activated malate transporter (almt) proteins is negatively regulated by gamma-aminobutyric acid (gaba), which increases in concentration during stress. here, the interaction between gaba and wheat (triticum aestivum, ta) taalmt1 heterologously-expressed in xenopus laevis oocytes was investigated. gaba inhibited anion transport by taalmt1 in membrane patches from the cytosolic, not extracellular membrane face, via a reduction in open probability (npopen ), not an inhi ...202031591723
morpholino studies in xenopus brain development.antisense morpholino oligonucleotides (mos) have become a valuable method to knockdown protein levels, to block with mrna splicing and to interfere with mirna function. mos are widely used to alter gene expression in development of xenopus and zebrafish, where they are typically injected into the fertilized egg or blastomeres. here we present methods to use electroporation to target delivery of mos to the central nervous system of xenopus laevis or xenopus tropicalis tadpoles. briefly, mo electr ...202031552666
odontomas in frogs.odontomas are variably differentiated, hamartoma-like proliferations of odontogenic epithelium, pulp ectomesenchyme (odontoblasts), and dental matrix. frogs are polyphyodont and homodont. their teeth also differ from mammals in that they are restricted to the upper jaw in adults and lack a periodontal ligament and cementum, attaching directly to the underlying bone. odontomas were identified in an african clawed frog (xenopus laevis), a false tomato frog (dyscophus guineti), and a tomato frog of ...202031551010
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