Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| daphnia magna and xenopus laevis as in vivo models to probe toxicity and uptake of quantum dots functionalized with gh625. | the use of quantum dots (qds) for nanomedicine is hampered by their potential toxicologic effects and difficulties with delivery into the cell interior. we accomplished an in vivo study exploiting daphnia magna and xenopus laevis to evaluate both toxicity and uptake of qds coated with the membranotropic peptide gh625 derived from the glycoprotein h of herpes simplex virus and widely used for drug delivery studies. we evaluated and compared the effects of qds and gh625-qds on the survival, uptake ... | 2017 | 28435254 |
| in situ microprobe single-cell capillary electrophoresis mass spectrometry: metabolic reorganization in single differentiating cells in the live vertebrate (xenopus laevis) embryo. | knowledge of single-cell metabolism would provide a powerful look into cell activity changes as cells differentiate to all the tissues of the vertebrate embryo. however, single-cell mass spectrometry technologies have not yet been made compatible with complex three-dimensional changes and rapidly decreasing cell sizes during early development of the embryo. here, we bridge this technological gap by integrating capillary microsampling, microscale metabolite extraction, and capillary electrophores ... | 2017 | 28434226 |
| endocrine disruption by environmental gestagens in amphibians - a short review supported by new in vitro data using gonads of xenopus laevis. | endocrine disruption caused by various anthropogenic compounds is of persisting concern, especially for aquatic wildlife, because surface waters are the main sink of these so-called endocrine disruptors (ed). in the past, research focused on (anti)estrogenic, (anti)androgenic, and (anti)thyroidal substances, affecting primarily reproduction and development in vertebrates; however, other endocrine systems might be also targeted by ed. environmental gestagens, including natural progestogens (e.g. ... | 2017 | 28431277 |
| frizzled 3 acts upstream of alcam during embryonic eye development. | formation of a functional eye during vertebrate embryogenesis requires different processes such as cell differentiation, cell migration, cell-cell interactions as well as intracellular signalling processes. it was previously shown that the non-canonical wnt receptor frizzled 3 (fzd3) is required for proper eye formation, however, the underlying mechanism is poorly understood. here we demonstrate that loss of fzd3 induces severe malformations of the developing eye and that this defect is phenocop ... | 2017 | 28427856 |
| xenopus egg extract: a powerful tool to study genome maintenance mechanisms. | dna repair pathways are crucial to maintain the integrity of our genome and prevent genetic diseases such as cancer. there are many different types of dna damage and specific dna repair mechanisms have evolved to deal with these lesions. in addition to these repair pathways there is an extensive signaling network that regulates processes important for repair, such as cell cycle control and transcription. despite extensive research, dna damage repair and signaling are not fully understood. in vit ... | 2017 | 28427716 |
| characterization of microtubule buckling in living cells. | microtubules are filamentous biopolymers involved in essential biological processes. they form key structures in eukaryotic cells, and thus it is very important to determine the mechanisms involved in the formation and maintenance of the microtubule network. microtubule bucklings are transient and localized events commonly observed in living cells and characterized by a fast bending and its posterior relaxation. active forces provided by molecular motors have been indicated as responsible for mo ... | 2017 | 28424847 |
| use of xenopus frogs to study renal development/repair. | the xenopus genus includes several members of aquatic frogs native to africa but is perhaps best known for the species xenopus laevis and xenopus tropicalis. these species were popularized as model organisms from as early as the 1800s and have been instrumental in expanding several biological fields including cell biology, environmental toxicology, regenerative biology, and developmental biology. in fact, much of what we know about the formation and maturation of the vertebrate renal system has ... | 2017 | 28409343 |
| asymmetries in cell division, cell size, and furrowing in the xenopus laevis embryo. | asymmetric cell divisions produce two daughter cells with distinct fate. during embryogenesis, this mechanism is fundamental to build tissues and organs because it generates cell diversity. in adults, it remains crucial to maintain stem cells. the enthusiasm for asymmetric cell division is not only motivated by the beauty of the mechanism and the fundamental questions it raises, but has also very pragmatic reasons. indeed, misregulation of asymmetric cell divisions is believed to have dramatic c ... | 2017 | 28409308 |
| asymmetric localization and distribution of factors determining cell fate during early development of xenopus laevis. | asymmetric division is a property of eukaryotic cells that is fundamental to the formation of higher life forms. despite its importance, the mechanism behind it remains elusive. asymmetry in the cell is induced by polarization of cell fate determinants that become unevenly distributed among progeny cells. so far dozens of determinants have been identified. xenopus laevis is an ideal system to study asymmetric cell division during early development, because of the huge size of its oocytes and ear ... | 2017 | 28409307 |
| chromosomal passenger complex hydrodynamics suggests chaperoning of the inactive state by nucleoplasmin/nucleophosmin. | the chromosomal passenger complex (cpc) is a conserved, essential regulator of cell division. as such, significant anti-cancer drug development efforts have been focused on targeting it, most notably by inhibiting its aurkb kinase subunit. the cpc is activated by aurkb-catalyzed autophosphorylation on multiple subunits, but how this regulates cpc interactions with other mitotic proteins remains unclear. we investigated the hydrodynamic behavior of the cpc in xenopus laevis egg cytosol using sucr ... | 2017 | 28404751 |
| masculinization-related genes and cell-mass structures during early gonadal differentiation in the african clawed frog xenopus laevis. | the african clawed frog xenopus laevis has a female heterogametic zz/zw-type sex-determining system. we previously discovered a w-linked female sex-determining gene dm-w that is involved in ovary formation, probably through the up-regulation of the estrogen synthesis genes cyp19a1 and foxl2. we also reported that a unique "mass-in-line structure", which disappears from zz gonads during early testicular development, might serve as the basis for ovary differentiation in zw gonads. however, the mol ... | 2017 | 28397603 |
| pattern of neurogenesis and identification of neuronal progenitor subtypes during pallial development in xenopus laevis. | the complexity of the pallium during evolution has increased dramatically in many different respects. the highest level of complexity is found in mammals, where most of the pallium (cortex) shows a layered organization and neurons are generated during development following an inside-out order, a sequence not observed in other amniotes (birds and reptiles). species-differences may be related to major neurogenetic events, from the neural progenitors that divide and produce all pallial cells. in ma ... | 2017 | 28396626 |
| the mgcracgap sxip motif tethers centralspindlin to microtubule plus ends in xenopus laevis. | centralspindlin, a complex of the kinesin-6-family member mklp1 and mgcracgap (also known as kif23 and racgap1, respectively), is required for cytokinesis and cell-cell junctions. during anaphase, centralspindlin accumulates at overlapping central spindle microtubules and directs contractile ring formation by recruiting the gef ect2 to the cell equator to activate rhoa. we found that mgcracgap localized to the plus ends of equatorial astral microtubules during cytokinesis in xenopus laevis embry ... | 2017 | 28389580 |
| clinical and genetic spectrum of bartter syndrome type 3. | bartter syndrome type 3 is a clinically heterogeneous hereditary salt-losing tubulopathy caused by mutations of the chloride voltage-gated channel kb gene (clcnkb), which encodes the clc-kb chloride channel involved in nacl reabsorption in the renal tubule. to study phenotype/genotype correlations, we performed genetic analyses by direct sequencing and multiplex ligation-dependent probe amplification and retrospectively analyzed medical charts for 115 patients with clcnkb mutations. functional a ... | 2017 | 28381550 |
| a dominant mutation in nuclear receptor interacting protein 1 causes urinary tract malformations via dysregulation of retinoic acid signaling. | congenital anomalies of the kidney and urinary tract (cakut) are the most common cause of ckd in the first three decades of life. however, for most patients with cakut, the causative mutation remains unknown. we identified a kindred with an autosomal dominant form of cakut. by whole-exome sequencing, we identified a heterozygous truncating mutation (c.279delg, p.trp93fs*) of the nuclear receptor interacting protein 1 gene (nrip1) in all seven affected members. nrip1 encodes a nuclear receptor tr ... | 2017 | 28381549 |
| multiple origins of embryonic and tadpole myeloid cells in xenopus laevis. | rabbit anti-serum against a myeloid-cell-specific peroxidase (mpo) of xenopus laevis was generated to identify myeloid cells in adult and larval animals. smears of blood samples from adult hematopoietic organs were co-stained with mpo and with xl-2, a mouse monoclonal antibody against a leukocyte common antigen. lymphocytes found in the thymus and spleen were xl-2+mpo- and granulocytes found in peripheral blood cells and the spleen were xl-2+mpo+, indicating that double-staining with these two a ... | 2017 | 28374149 |
| upregulation of matrix metalloproteinase triggers transdifferentiation of retinal pigmented epithelial cells in xenopus laevis: a link between inflammatory response and regeneration. | in adult xenopus eyes, when the whole retina is removed, retinal pigmented epithelial (rpe) cells become activated to be retinal stem cells and regenerate the whole retina. in the present study, using a tissue culture model, it was examined whether upregulation of matrix metalloproteinases (mmps) triggers retinal regeneration. soon after retinal removal, xmmp9 and xmmp18 were strongly upregulated in the tissues of the rpe and the choroid. in the culture, mmp expression in the rpe cells correspon ... | 2017 | 28371543 |
| population-specific resequencing associates the atp-binding cassette subfamily c member 4 gene with gout in new zealand māori and pacific men. | there is no evidence for a genetic association between organic anion transporters 1-3 (slc22a6, slc22a7, and slc22a8) and multidrug resistance protein 4 (mrp4; encoded by abcc4) with the levels of serum urate or gout. the māori and pacific (polynesian) population of new zealand has the highest prevalence of gout worldwide. the aim of this study was to determine whether any polynesian population-specific genetic variants in slc22a6-8 and abcc4 are associated with gout. | 2017 | 28371506 |
| interaction and developmental activation of two neuroendocrine systems that regulate light-mediated skin pigmentation. | lower vertebrates use rapid light-regulated changes in skin colour for camouflage (background adaptation) or during circadian variation in irradiance levels. two neuroendocrine systems, the eye/alpha-melanocyte-stimulating hormone (α-msh) and the pineal complex/melatonin circuits, regulate the process through their respective dispersion and aggregation of pigment granules (melanosomes) in skin melanophores. during development, xenopus laevis tadpoles raised on a black background or in the dark p ... | 2017 | 28371026 |
| cul-2lrr-1 and ubxn-3 drive replisome disassembly during dna replication termination and mitosis. | replisome disassembly is the final step of dna replication in eukaryotes, involving the ubiquitylation and cdc48-dependent dissolution of the cmg helicase (cdc45-mcm-gins). using caenorhabditis elegans early embryos and xenopus laevis egg extracts, we show that the e3 ligase cul-2lrr-1 associates with the replisome and drives ubiquitylation and disassembly of cmg, together with the cdc-48 cofactors ufd-1 and npl-4. removal of cmg from chromatin in frog egg extracts requires cul2 neddylation, and ... | 2017 | 28368371 |
| xenopus metamorphosis as a model to study thyroid hormone receptor function during vertebrate developmental transitions. | a hormone-dependent developmental transition from aquatic to terrestrial existence occurs in all tetrapod vertebrates, such as birth, hatching, and metamorphosis. thyroid hormones (th) and their receptors (trs) are key players in the tissue transformations comprising vertebrate developmental transitions. the african clawed frog, xenopus, is a premier model for the role of trs in developmental transitions because of the numerous and dramatic th-dependent tissue transformations during metamorphosi ... | 2017 | 28363743 |
| asymmetrically reduced expression of hand1 homeologs involving a single nucleotide substitution in a cis-regulatory element. | during vertebrate evolution, whole genome duplications resulted in a number of duplicated genes, some of which eventually changed their expression patterns and/or levels via alteration of cis-regulatory sequences. however, the initial process involved in such cis-regulatory changes remains unclear. therefore, we investigated this process by analyzing the duplicated hand1 genes of xenopus laevis (hand1.l and hand1.s), which were generated by allotetraploidization 17-18 million years ago, and comp ... | 2017 | 28359808 |
| the heterochronic gene lin28 regulates amphibian metamorphosis through disturbance of thyroid hormone function. | metamorphosis is a classic example of developmental transition, which involves important morphological and physiological changes that prepare the organism for the adult life. it has been very well established that amphibian metamorphosis is mainly controlled by thyroid hormone (th). here, we show that the heterochronic gene lin28 is downregulated during xenopus laevis metamorphosis. lin28 overexpression before activation of th signaling delays metamorphosis and inhibits the expression of th targ ... | 2017 | 28359807 |
| paxillin and embryonic polyadenylation binding protein (epabp) engage to regulate androgen-dependent xenopus laevis oocyte maturation - a model of kinase-dependent regulation of protein expression. | steroid-triggered xenopus laevis oocyte maturation is an elegant physiologic model of nongenomic steroid signaling, as it proceeds completely independent of transcription. we previously demonstrated that androgens are the main physiologic stimulator of oocyte maturation in xenopus oocytes, and that the adaptor protein paxillin plays a crucial role in mediating this process through a positive feedback loop in which paxillin first enhances mos protein translation, ensued by erk2 activation and erk ... | 2017 | 28359799 |
| pkc-mediated phosphorylation of nuclear lamins at a single serine residue regulates interphase nuclear size in xenopus and mammalian cells. | how nuclear size is regulated is a fundamental cell-biological question with relevance to cancers, which often exhibit enlarged nuclei. we previously reported that conventional protein kinase c (cpkc) contributes to nuclear size reductions that occur during early xenopus development. here we report that pkc-mediated phosphorylation of lamin b3 (lb3) contributes to this mechanism of nuclear size regulation. by mapping pkc phosphorylation sites on lb3 and testing the effects of phosphomutants in x ... | 2017 | 28356420 |
| spemann organizer transcriptome induction by early beta-catenin, wnt, nodal, and siamois signals in xenopus laevis. | the earliest event in xenopus development is the dorsal accumulation of nuclear β-catenin under the influence of cytoplasmic determinants displaced by fertilization. in this study, a genome-wide approach was used to examine transcription of the 43,673 genes annotated in the xenopus laevis genome under a variety of conditions that inhibit or promote formation of the spemann organizer signaling center. loss of function of β-catenin with antisense morpholinos reproducibly reduced the expression of ... | 2017 | 28348214 |
| osptr7 (osnpf8.1), a putative peptide transporter in rice, is involved in dimethylarsenate accumulation in rice grain. | rice (oryza sativa) is a major dietary source of arsenic (as) for the population consuming rice as their staple food. rice grain contains both inorganic as and methylated as species, especially dimethyarsinate (dma). dma is highly mobile in long-distance translocation in plants, but the underlying mechanism remains unknown. in the present study, we showed that osptr7 (osnpf8.1), a putative peptide transporter in rice, was permeable to dma in xenopus laevis oocytes. transient expression of the os ... | 2017 | 28340032 |
| glycans in the intestinal peptide transporter pept1 contribute to function and protect from proteolysis. | despite the fact that many membrane proteins carry extracellular glycans, little is known about whether the glycan chains also affect protein function. we recently demonstrated that the proton-coupled oligopeptide transporter 1 (pept1) in the intestine is glycosylated at six asparagine residues (n50, n406, n439, n510, n515, and n532). mutagenesis-induced disruption of the individual n-glycosylation site n50, which is highly conserved among mammals, was detected to significantly enhance the pept1 ... | 2017 | 28336547 |
| the modulation of two motor behaviors by persistent sodium currents in xenopus laevis tadpoles. | persistent sodium currents (inap) are common in neuronal circuitries and have been implicated in several diseases, such as amyotrophic lateral sclerosis (als) and epilepsy. however, the role of inap in the regulation of specific behaviors is still poorly understood. in this study we have characterized inap and investigated its role in the swimming and struggling behavior of xenopus tadpoles. inap was identified in three groups of neurons, namely, sensory rohon-beard neurons (rb neurons), descend ... | 2017 | 28331009 |
| actomyosin-generated tension on cadherin is similar between dividing and non-dividing epithelial cells in early xenopus laevis embryos. | epithelia represent a unique situation where polarized cells must maintain sufficiently strong cell-cell contacts to guarantee the epithelial integrity indispensable for barrier functions. nevertheless, epithelia must also keep sufficient plasticity which is crucial during development and morphogenesis. adherens junctions and mechanical forces produced by the actomyosin cytoskeleton are major players for epithelial integrity maintenance and plasticity regulations. to understand how the epitheliu ... | 2017 | 28327558 |
| direct regulation of histidine ammonia-lyase 2 gene by thyroid hormone in the developing adult intestinal stem cells. | most vertebrate organs use adult stem cells to maintain homeostasis and ensure proper repair when damaged. how such organ-specific stem cells are formed during vertebrate development is largely unexplored. we have been using the thyroid hormone (t3)-dependent amphibian metamorphosis to address this issue. early studies in xenopus laevis have shown that intestinal remodeling involves complete degeneration of the larval epithelium and de novo formation of adult stem cells through dedifferentiation ... | 2017 | 28323994 |
| sall1 and sall4 repress pou5f3 family expression to allow neural patterning, differentiation, and morphogenesis in xenopus laevis. | the embryonic precursor of the vertebrate central nervous system, the neural plate, is patterned along the anterior-posterior axis and shaped by morphogenetic movements early in development. we previously identified the genes sall1 and sall4, known regulators of pluripotency in other contexts, as transcriptional targets of developmental signaling pathways that regulate neural development. here, we demonstrate that these two genes are required for induction of posterior neural fates, the cell sha ... | 2017 | 28322736 |
| teratogenic hazard of bpei-coated silver nanoparticles to xenopus laevis. | silver nanoparticles (agnps) are among the most exploited antimicrobial agents and are used in many consumer products. size and surface reactivity are critical physico-chemical properties responsible for nps toxicity, and surface coatings, often used to functionalize or stabilize agnps, can influence their toxic profile and biocompatibility. in the current study the developmental toxicity of (1) negatively charged citrate-coated agnps (cit-agnps), (2) positively charged branched polyethylenimine ... | 2017 | 28318347 |
| jak-stat pathway activation in response to spinal cord injury in regenerative and non-regenerative stages of xenopus laevis. | xenopus laevis tadpoles can regenerate the spinal cord after injury but this capability is lost during metamorphosis. comparative studies between pre-metamorphic and metamorphic xenopus stages can aid towards understanding the molecular mechanisms of spinal cord regeneration. analysis of a previous transcriptome-wide study suggests that, in response to injury, the jak-stat pathway is differentially activated in regenerative and non-regenerative stages. we characterized the activation of the jak- ... | 2017 | 28316792 |
| a cellular mechanism for inverse effectiveness in multisensory integration. | to build a coherent view of the external world, an organism needs to integrate multiple types of sensory information from different sources, a process known as multisensory integration (msi). previously, we showed that the temporal dependence of msi in the optic tectum of xenopus laevis tadpoles is mediated by the network dynamics of the recruitment of local inhibition by sensory input (felch et al., 2016). this was one of the first cellular-level mechanisms described for msi. here, we expand th ... | 2017 | 28315524 |
| novel short antimicrobial peptide isolated from xenopus laevis skin. | a rich source of bioactive peptides, including a large number of antimicrobial peptides, has been found in amphibian skin. in this study, a novel short antimicrobial peptide was purified from xenopus laevis skin and characterised through reversed-phase high-performance liquid chromatography, edman degradation and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. the peptide was composed of six amino acids with a sequence of dedlde and thus named x. laevis antibacteria ... | 2017 | 28299865 |
| when size matters: transient receptor potential vanilloid 4 channel as a volume-sensor rather than an osmo-sensor. | mammalian cells are frequently exposed to stressors causing volume changes. the transient receptor potential vanilloid 4 (trpv4) channel translates osmotic stress into ion flux. the molecular mechanism coupling osmolarity to trpv4 activation remains elusive. trpv4 responds to isosmolar cell swelling and osmolarity translated via different aquaporins. trpv4 functions as a volume-sensing ion channel irrespective of the origin of the cell swelling. | 2017 | 28295351 |
| functional organization of vestibulo-ocular responses in abducens motoneurons. | vestibulo-ocular reflexes (vors) are the dominating contributors to gaze stabilization in all vertebrates. during horizontal head movements, abducens motoneurons form the final element of the reflex arc that integrates visuovestibular inputs into temporally precise motor commands for the lateral rectus eye muscle. here, we studied a possible differentiation of abducens motoneurons into subtypes by evaluating their morphology, discharge properties, and synaptic pharmacology in semi-intact in vitr ... | 2017 | 28292832 |
| transcriptomic insights into genetic diversity of protein-coding genes in x. laevis. | we characterize the genetic diversity of xenopus laevis strains using rna-seq data and allele-specific analysis. this data provides a catalogue of coding variation, which can be used for improving the genomic sequence, as well as for better sequence alignment, probe design, and proteomic analysis. in addition, we paint a broad picture of the genetic landscape of the species by functionally annotating different classes of mutations with a well-established prediction tool (polyphen-2). further, we ... | 2017 | 28283406 |
| persistent fibrosis, hypertrophy and sarcomere disorganisation after endoscopy-guided heart resection in adult xenopus. | models of cardiac repair are needed to understand mechanisms underlying failure to regenerate in human cardiac tissue. such studies are currently dominated by the use of zebrafish and mice. remarkably, it is between these two evolutionary separated species that the adult cardiac regenerative capacity is thought to be lost, but causes of this difference remain largely unknown. amphibians, evolutionary positioned between these two models, are of particular interest to help fill this lack of knowle ... | 2017 | 28278282 |
| reversal of ddk-mediated mcm phosphorylation by rif1-pp1 regulates replication initiation and replisome stability independently of atr/chk1. | dbf4-dependent kinases (ddks) are required for the initiation of dna replication, their essential targets being the mcm2-7 proteins. we show that, in xenopus laevis egg extracts and human cells, hyper-phosphorylation of dna-bound mcm4, but not phosphorylation of mcm2, correlates with dna replication. these phosphorylations are differentially affected by the ddk inhibitors pha-767491 and xl413. we show that ddk-dependent mcm phosphorylation is reversed by protein phosphatase 1 (pp1) targeted to c ... | 2017 | 28273463 |
| moving or being moved: that makes a difference. | during head/body movements, gaze stability is ensured by transformation of motion-related sensory signals into respective motor commands. passively induced motion in all vertebrates including amphibians evokes a robust vestibulo-ocular reflex, suggesting an equally important role of this motor reaction during actively induced motion. however, during self-induced movements including locomotion, motor efference copies offer a convenient additional substrate for counteracting retinal image displace ... | 2017 | 28271408 |
| structural analysis of the role of tpx2 in branching microtubule nucleation. | the mitotic spindle consists of microtubules (mts), which are nucleated by the γ-tubulin ring complex (γ-turc). how the γ-turc gets activated at the right time and location remains elusive. recently, it was uncovered that mts nucleate from preexisting mts within the mitotic spindle, which requires the protein tpx2, but the mechanism basis for tpx2 action is unknown. here, we investigate the role of tpx2 in branching mt nucleation. we establish the domain organization of xenopus laevis tpx2 and d ... | 2017 | 28264915 |
| gadolinium released by the linear gadolinium-based contrast-agent gd-dtpa decreases the activity of human epithelial na+ channels (enacs). | gadolinium-based-contrast-agents (gbcas) are used for magnetic-resonance-imaging and associated with renal and cardiovascular adverse reactions caused by released gd3+ ions. gd3+ is also a modulator of mechano-gated ion channels, including the epithelial na+ channel (enac) that is expressed in kidney epithelium and the vasculature. enac is important for salt-/water homeostasis and blood pressure regulation and a likely target of released gd3+ from gbcas causing the above-mentioned adverse reacti ... | 2017 | 28257815 |
| folate receptor 1 is necessary for neural plate cell apical constriction during xenopus neural tube formation. | folate supplementation prevents up to 70% of neural tube defects (ntds), which result from a failure of neural tube closure during embryogenesis. the elucidation of the mechanisms underlying folate action has been challenging. this study introduces xenopus laevis as a model to determine the cellular and molecular mechanisms involved in folate action during neural tube formation. we show that knockdown of folate receptor 1 (folr1; also known as frα) impairs neural tube formation and leads to ntds ... | 2017 | 28255006 |
| optimization of the t3-induced xenopus metamorphosis assay for detecting thyroid hormone signaling disruption of chemicals. | t3-induced xenopus metamorphosis is an ideal model for detecting thyroid hormone (th) signaling disruption of chemicals. to optimize the t3-induced xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for t3 induction. xenopus laevis at stage 52 were exposed to series of concentrations of t3 (0.31-2.5nmol/l) for 6days. by comparing morphological changes induced by t3 ... | 2017 | 28254053 |
| role of cdc6 during oogenesis and early embryo development in mouse and xenopus laevis. | cdc6 is an important player in cell cycle regulation. it is involved in the regulation of both s-phase and m-phase. its role during oogenesis is crucial for repression of the s-phase between the first and the second meiotic m-phases, and it also regulates, via cdk1 inhibition, the m-phase entry and exit. this is of special importance for the reactivation of the major m-phase-regulating kinase cdk1 (cyclin-dependent kinase 1) in oocytes entering metaphase ii of meiosis and in embryo cleavage divi ... | 2017 | 28247050 |
| kv3.1/kv3.2 channel positive modulators enable faster activating kinetics and increase firing frequency in fast-spiking gabaergic interneurons. | due to their fast kinetic properties, kv3.1 voltage gated potassium channels are important in setting and controlling firing frequency in neurons and pivotal in generating high frequency firing of interneurons. pharmacological activation of kv3.1 channels may possess therapeutic potential for treatment of epilepsy, hearing disorders, schizophrenia and cognitive impairments. here we thoroughly investigate the selectivity and positive modulation of the two small molecules, ex15 and re01, on kv3 ch ... | 2017 | 28242439 |
| the capz interacting protein rcsd1 is required for cardiogenesis downstream of wnt11a in xenopus laevis. | wnt proteins are critical for embryonic cardiogenesis and cardiomyogenesis by regulating different intracellular signalling pathways. whereas canonical wnt/β-catenin signalling is required for mesoderm induction and proliferation of cardiac progenitor cells, β-catenin independent, non-canonical wnt signalling regulates cardiac specification and terminal differentiation. although the diverse cardiac malformations associated with the loss of non-canonical wnt11 in mice such as outflow tract (oft) ... | 2017 | 28237811 |
| β subunits functionally differentiate human kv4.3 potassium channel splice variants. | the human ventricular cardiomyocyte transient outward k+ current (ito) mediates the initial phase of myocyte repolarization and its disruption is implicated in brugada syndrome and heart failure (hf). human cardiac ito is generated primarily by two kv4.3 splice variants (kv4.3l and kv4.3s, diverging only by a c-terminal, s6-proximal, 19-residue stretch unique to kv4.3l), which are differentially remodeled in hf, but considered functionally alike at baseline. kv4.3 is regulated in human heart by ... | 2017 | 28228734 |
| xenopus laevis kif18a is a highly processive kinesin required for meiotic spindle integrity. | the assembly and functionality of the mitotic spindle depends on the coordinated activities of microtubule-associated motor proteins of the dynein and kinesin superfamily. our current understanding of the function of motor proteins is significantly shaped by studies using xenopus laevis egg extract as its open structure allows complex experimental manipulations hardly feasible in other model systems. yet, the kinesin-8 orthologue of human kif18a has not been described in xenopus laevis so far. h ... | 2017 | 28228376 |
| acute and chronic outcomes of gas-bubble disease in a colony of african clawed frogs (xenopus laevis). | gas-bubble disease occurs in aquatic species that are exposed to water that is supersaturated with gases. in february 2007, municipal water supersaturated with gas was inadvertently pumped into the vivarium's aquatic housing systems and affected approximately 450 adult female xenopus laevis. the inflow of supersaturated water was stopped immediately, the holding tanks aggressively aerated, and all experimental manipulations and feeding ceased. within the first 6 h after the event, morbidity appr ... | 2017 | 28222834 |
| systematic variation of the benzenesulfonamide part of the glun2a selective nmda receptor antagonist tcn-201. | glun2a subunit containing n-methyl-d-aspartate receptors (nmdars) are highly involved in various physiological processes in the central nervous system, but also in some diseases, such as anxiety, depression and schizophrenia. however, the role of glun2a subunit containing nmdars in pathological processes is not exactly elucidated. in order to obtain potent and selective inhibitors of glun2a subunit containing nmdars, the selective negative allosteric modulator 2 was systematically modified at th ... | 2017 | 28222314 |
| heteromeric slick/slack k+ channels show graded sensitivity to cell volume changes. | slick and slack high-conductance k+ channels are found in the cns, kidneys, pancreas, among other organs, where they play an important role in cell excitability as well as in ion transport processes. they are both activated by na+ and cl- but show a differential regulation by cell volume changes. slick has been shown to be regulated by cell volume changes, whereas slack is insensitive. α-subunits of these channels form homomeric as well as heteromeric channels. it is the aim of this work to expl ... | 2017 | 28222129 |
| motor neurons tune premotor activity in a vertebrate central pattern generator. | central patterns generators (cpgs) are neural circuits that drive rhythmic motor output without sensory feedback. vertebrate cpgs are generally believed to operate in a top-down manner in which premotor interneurons activate motor neurons that in turn drive muscles. in contrast, the frog (xenopus laevis) vocal cpg contains a functionally unexplored neuronal projection from the motor nucleus to the premotor nucleus, indicating a recurrent pathway that may contribute to rhythm generation. in this ... | 2017 | 28219984 |
| a mutation in the g-protein gene gnb2 causes familial sinus node and atrioventricular conduction dysfunction. | familial sinus node and atrioventricular conduction dysfunction is a rare disorder that leads to paroxysmal dizziness, fatigue, and syncope because of a temporarily or permanently reduced heart rate. to date, only a few genes for familial sinus and atrioventricular conduction dysfunction are known, and the majority of cases remain pathogenically unresolved. | 2017 | 28219978 |
| disrupting effects of azocyclotin to the hypothalamo-pituitary-gonadal axis and reproduction of xenopus laevis. | over the past few decades, the hazards associated with the extensive use of organictin compounds have become an issue of extreme concern, while at present the effects of these substances on amphibians remain poorly understood. in the present study, we chose azocyclotin, one of common use acaricides in china. we focused on sexual development and steroidogenesis disrupting effects of azocyclotin in the xenopus laevis. tadpoles were exposed to azocyclotin (0.05 and 0.5μg/l) for long-term (4 months) ... | 2017 | 28213302 |
| the microtubule plus-end-tracking protein tacc3 promotes persistent axon outgrowth and mediates responses to axon guidance signals during development. | formation of precise neuronal connections requires proper axon guidance. microtubules (mts) of the growth cone provide a critical driving force during navigation of the growing ends of axons. pioneer mts and their plus-end tracking proteins (+tips) are thought to play integrative roles during this navigation. tacc3 is a + tip that we have previously implicated in regulating mt dynamics within axons. however, the role of tacc3 in axon guidance has not been previously explored. | 2017 | 28202041 |
| dynamic properties of calcium-activated chloride currents in xenopus laevis oocytes. | chloride is the most abundant permeable anion in the cell, and numerous studies in the last two decades highlight the great importance and broad physiological role of chloride currents mediated anion transport. they participate in a multiplicity of key processes, as for instance, the regulation of electrical excitability, apoptosis, cell cycle, epithelial secretion and neuronal excitability. in addition, dysfunction of cl- channels is involved in a variety of human diseases such as epilepsy, ost ... | 2017 | 28198817 |
| strong signal increase in sted fluorescence microscopy by imaging regions of subdiffraction extent. | photobleaching remains a limiting factor in superresolution fluorescence microscopy. this is particularly true for stimulated emission depletion (sted) and reversible saturable/switchable optical fluorescence transitions (resolft) microscopy, where adjacent fluorescent molecules are distinguished by sequentially turning them off (or on) using a pattern of light formed as a doughnut or a standing wave. in sample regions where the pattern intensity reaches or exceeds a certain threshold, the molec ... | 2017 | 28193881 |
| bile acids potentiate proton-activated currents in xenopus laevis oocytes expressing human acid-sensing ion channel (asic1a). | acid-sensing ion channels (asics) are nonvoltage-gated sodium channels transiently activated by extracellular protons and belong to the epithelial sodium channel (enac)/degenerin (deg) family of ion channels. bile acids have been shown to activate two members of this family, the bile acid-sensitive ion channel (basic) and enac. to investigate whether bile acids also modulate asic function, human asic1a was heterologously expressed in xenopus laevis oocytes. exposing oocytes to tauro-conjugated c ... | 2017 | 28193786 |
| filaggrin has evolved from an "s100 fused-type protein" (sftp) gene present in a common ancestor of amphibians and mammals. | the expression of filaggrin in differentiated keratinocytes and the association of filaggrin mutations with ichthyosis vulgaris and atopic dermatitis suggest that this prototypical member of the s100 fused-type protein (sftp) family plays a key role in the epidermal barrier to the environment. here, we report that sftp genes are present not only in amniotes but also in amphibians. four sftps are expressed in the skin of the frog xenopus laevis. the results of this study indicate that filaggrin h ... | 2017 | 28191671 |
| zebrafish transgenic constructs label specific neurons in xenopus laevis spinal cord and identify frog v0v spinal neurons. | a correctly functioning spinal cord is crucial for locomotion and communication between body and brain but there are fundamental gaps in our knowledge of how spinal neuronal circuitry is established and functions. to understand the genetic program that regulates specification and functions of this circuitry, we need to connect neuronal molecular phenotypes with physiological analyses. studies using xenopus laevis tadpoles have increased our understanding of spinal cord neuronal physiology and fu ... | 2017 | 28188691 |
| identification of a mammalian silicon transporter. | silicon (si) has long been known to play a major physiological and structural role in certain organisms, including diatoms, sponges, and many higher plants, leading to the recent identification of multiple proteins responsible for si transport in a range of algal and plant species. in mammals, despite several convincing studies suggesting that silicon is an important factor in bone development and connective tissue health, there is a critical lack of understanding about the biochemical pathways ... | 2017 | 28179233 |
| pax2/pax8-defined subdomains and the occurrence of apoptosis in the posterior placodal area of mice. | the present work aims to improve our understanding of the causes and functions of apoptosis during the morphogenesis of epibranchial placodes in mice. schematic maps helped to compare the spatiotemporal sequence of apoptotic events with the protein expression patterns of general (six1) and specific placodal markers (pax2, pax8). our findings challenge the view that, in mammals, all three epibranchial placodes spring from the original posterior placodal area (ppa) of presomite or early somite emb ... | 2017 | 28160066 |
| capillary electrophoresis coupled to negative mode electrospray ionization-mass spectrometry using an electrokinetically-pumped nanospray interface with primary amines grafted to the interior of a glass emitter. | we demonstrate an electrokinetically pumped sheath flow nanospray interface for capillary electrophoresis coupled to negative mode electrospray mass spectrometry. in this interface, application of an electric field generates electro-osmotic flow at the interior of a glass emitter that is pulled to a 10-20µm inner diameter orifice. electro-osmotic flow pumps liquid around the distal tip of the separation capillary, ensheathing analyte into the electrospray electrolyte. in negative ion mode, negat ... | 2017 | 28153293 |
| mir-182 regulates slit2-mediated axon guidance by modulating the local translation of a specific mrna. | during brain wiring, cue-induced axon behaviors such as directional steering and branching are aided by localized mrna translation. different guidance cues elicit translation of subsets of mrnas that differentially regulate the cytoskeleton, yet little is understood about how specific mrnas are selected for translation. micrornas (mirnas) are critical translational regulators that act through a sequence-specific mechanism. here, we investigate the local role of mirnas in mrna-specific translatio ... | 2017 | 28147273 |
| pharmacological characterization of the excitatory 'cys-loop' gaba receptor family in caenorhabditis elegans. | ionotropic gaba receptors are evolutionarily conserved proteins that mediate cellular and network inhibition in both vertebrates and invertebrates. a unique class of excitatory gaba receptors has been identified in several nematode species. despite well-characterized functions in caenorhabditis elegans, little is known about the pharmacology of the excitatory gaba receptors exp-1 and lgc-35. using a panel of compounds that differentially activate and modulate ionotropic gaba receptors, we invest ... | 2017 | 28146602 |
| extracellular ca2+ is required for fertilization in the african clawed frog, xenopus laevis. | the necessity of extracellular ca2+ for fertilization and early embryonic development in the african clawed frog, xenopus laevis, is controversial. ca2+ entry into x. laevis sperm is reportedly required for the acrosome reaction, yet fertilization and embryonic development have been documented to occur in high concentrations of the ca2+ chelator bapta. here we sought to resolve this controversy. | 2017 | 28114360 |
| molecular features of the l-type amino acid transporter 2 determine different import and export profiles for thyroid hormones and amino acids. | the l-type amino acid transporter 2 (lat2) imports amino acids (aa) and also certain thyroid hormones (th), e.g. 3,3'-t2 and t3, but not rt3 and t4. we utilized lat2 mutations (y130a, n133s, f242w) that increase 3,3'-t2 import and focus here on import and export capacity for aa, t4, t3, bch and derivatives thereof to delineate molecular features. transport studies and analysis of competitive inhibition of import by radiolabelled th and aa were performed in xenopus laevis oocytes. only y130a, a p ... | 2017 | 28108384 |
| diclofenac can exhibit estrogenic modes of action in male xenopus laevis, and affects the hypothalamus-pituitary-gonad axis and mating vocalizations. | diclofenac (dcf) is a non-steroidal analgesic and antiphlogistic. due to its tremendous use, dcf can be found in the environment, especially in sewage, but also surface waters, ground and drinking water. previous studies indicated that dcf can modulate the reproductive physiology of fish by altering the expression of important key enzymes of the hypothalamus-pituitary-gonad-axis (hpg-axis) and might act as an estrogenic endocrine disrupting chemical (edc). other studies, however, demonstrated th ... | 2017 | 28107717 |
| the nedd4 binding protein 3 is required for anterior neural development in xenopus laevis. | the fezzin family member nedd4-binding protein 3 (n4bp3) is known to regulate axonal and dendritic branching. here, we show that n4bp3 is expressed in the neural tissue of the early xenopus laevis embryo including the eye, the brain and neural crest cells. knockdown of n4bp3 in the xenopus anterior neural tissue results in severe developmental impairment of the eye, the brain and neural crest derived cranial cartilage structures. moreover, we demonstrate that n4bp3 depletion leads to a significa ... | 2017 | 28104388 |
| spinal cord regeneration in xenopus laevis. | here we present a protocol for the husbandry of xenopus laevis tadpoles and froglets, and procedures to study spinal cord regeneration. this includes methods to induce spinal cord injury (sci); dna and morpholino electroporation for genetic studies; in vivo imaging for cell analysis; a swimming test to measure functional recovery; and a convenient model for screening for new compounds that promote neural regeneration. these protocols establish x. laevis as a unique model organism for understandi ... | 2017 | 28102835 |
| automated mitotic spindle tracking suggests a link between spindle dynamics, spindle orientation, and anaphase onset in epithelial cells. | proper spindle positioning at anaphase onset is essential for normal tissue organization and function. here we develop automated spindle-tracking software and apply it to characterize mitotic spindle dynamics in the xenopus laevis embryonic epithelium. we find that metaphase spindles first undergo a sustained rotation that brings them on-axis with their final orientation. this sustained rotation is followed by a set of striking stereotyped rotational oscillations that bring the spindle into near ... | 2017 | 28100633 |
| scaling of pattern formations and morphogen gradients. | the concentration gradient of morphogens provides positional information for an embryo and plays a pivotal role in pattern formation of tissues during the developmental processes. morphogen-dependent pattern formations show robustness despite various perturbations. although tissues usually grow and dynamically change their size during histogenesis, proper patterns are formed without the influence of size variations. furthermore, even when the blastula embryo of xenopus laevis is bisected into do ... | 2017 | 28097650 |
| high-throughput analysis reveals novel maternal germline rnas crucial for primordial germ cell preservation and proper migration. | during oogenesis, hundreds of maternal rnas are selectively localized to the animal or vegetal pole, including determinants of somatic and germline fates. although microarray analysis has identified localized determinants, it is not comprehensive and is limited to known transcripts. here, we utilized high-throughput rna-sequencing analysis to comprehensively interrogate animal and vegetal pole rnas in the fully grown xenopus laevis oocyte. we identified 411 (198 annotated) and 27 (15 annotated) ... | 2017 | 28096217 |
| xenopus as a model for studies in mechanical stress and cell division. | we exist in a physical world, and cells within biological tissues must respond appropriately to both environmental forces and forces generated within the tissue to ensure normal development and homeostasis. cell division is required for normal tissue growth and maintenance, but both the direction and rate of cell division must be tightly controlled to avoid diseases of over-proliferation such as cancer. recent studies have shown that mechanical cues can cause mitotic entry and orient the mitotic ... | 2017 | 28095623 |
| tools for live imaging of active rho gtpases in xenopus. | rho family gtpases are signaling molecules that orchestrate cytoskeletal dynamics in a variety of cellular processes. because they effect localized changes to the cytoskeleton only in their active (gtp-bound) conformation, the ability to monitor the active state of rho gtpases in space and time is critical for understanding their function. here, we summarize popular tools used for live imaging of active rho gtpases, outlining advantages and drawbacks of these approaches. additionally, we highlig ... | 2017 | 28095620 |
| xenopus egg extract to study regulation of genome-wide and locus-specific dna replication. | faithful dna replication, coupled with accurate repair of dna damage, is essential to maintain genome stability and relies on different dna metabolism genes. many of these genes are involved in the assembly of replication origins, in the coordination of dna repair to protect replication forks progression in the presence of dna damage and in the replication of repetitive chromatin regions. some dna metabolism genes are essential in higher eukaryotes, suggesting the existence of specialized mechan ... | 2017 | 28095613 |
| xenopus laevis as a model system to study cytoskeletal dynamics during axon pathfinding. | the model system, xenopus laevis, has been used in innumerable research studies and has contributed to the understanding of multiple cytoskeletal components, including actin, microtubules, and neurofilaments, during axon pathfinding. xenopus developmental stages have been widely characterized, and the xenopus genome has been sequenced, allowing gene expression modifications through exogenous molecules. xenopus cell cultures are ideal for long periods of live imaging because they are easily obtai ... | 2017 | 28095612 |
| quantifying the relative contributions of different solute carriers to aggregate substrate transport. | determining the contributions of different transporter species to overall cellular transport is fundamental for understanding the physiological regulation of solutes. we calculated the relative activities of solute carrier (slc) transporters using the michaelis-menten equation and global fitting to estimate the normalized maximum transport rate for each transporter (vmax). data input were the normalized measured uptake of the essential neutral amino acid (aa) l-leucine (leu) from concentration-d ... | 2017 | 28091567 |
| high variability of expression profiles of homeologous genes for wnt, hh, notch, and hippo signaling pathways in xenopus laevis. | cell signaling pathways, such as wnt, hedgehog (hh), notch, and hippo, are essential for embryogenesis, organogenesis, and tissue homeostasis. in this study, we analyzed 415 genes involved in these pathways in the allotetraploid frog, xenopus laevis. most genes are retained in two subgenomes called l and s (193 homeologous gene pairs and 29 singletons). this conservation rate of homeologs is much higher than that of all genes in the x. laevis genome (86.9% vs 60.2%). among singletons, 24 genes a ... | 2017 | 28089430 |
| reassessment of glut7 and glut9 as putative fructose and glucose transporters. | although increased dietary fructose consumption is associated with metabolic impairments, the mechanisms and regulation of intestinal fructose absorption are poorly understood. glut5 is considered to be the main intestinal fructose transporter. other glut family members, such as glut7 and glut9 are also expressed in the intestine and were shown to transport fructose and glucose. a conserved isoleucine-containing motif (nxi) was proposed to be essential for fructose transport capacity of glut7 an ... | 2017 | 28083649 |
| calpain-mediated proteolysis of talin and fak regulates adhesion dynamics necessary for axon guidance. | guidance of axons to their proper synaptic target sites requires spatially and temporally precise modulation of biochemical signals within growth cones. ionic calcium (ca2+) is an essential signal for axon guidance that mediates opposing effects on growth cone motility. the diverse effects of ca2+ arise from the precise localization of ca2+ signals into microdomains containing specific ca2+ effectors. for example, differences in the mechanical and chemical composition of the underlying substrata ... | 2017 | 28069919 |
| de novo mutations in smchd1 cause bosma arhinia microphthalmia syndrome and abrogate nasal development. | bosma arhinia microphthalmia syndrome (bams) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. we report here that missense mutations in the epigenetic regulator smchd1 mapping to the extended atpase domain of the encoded protein cause bams in all 14 cases studied. all mutations were de novo where parental dna was available. biochemical tests and in vivo assays in xenopus laevis embryos suggest that these mutations may behav ... | 2017 | 28067911 |
| mefloquine inhibits voltage dependent nav1.4 channel by overlapping the local anaesthetic binding site. | mefloquine constitutes a multitarget antimalaric that inhibits cation currents. however, the effect and the binding site of this compound on na+ channels is unknown. to address the mechanism of action of mefloquine, we employed two-electrode voltage clamp recordings on xenopus laevis oocytes, site-directed mutagenesis of the rat na+ channel, and a combined in silico approach using molecular dynamics and docking protocols. we found that mefloquine: i) inhibited nav1.4 currents (ic50 =60μm), ii) s ... | 2017 | 28057491 |
| eomesodermin-at dawn of cell fate decisions during early embryogenesis. | proteins of the large family of t-box transcription factors are implicated in a broad spectrum of developmental processes. loss-of-function mutations of t-box(tbx) factors frequently cause severe embryonic phenotypes, often resulting from defects in cell fate specification and lineage differentiation. this review summarizes current knowledge on the functions of the t-box transcription factor eomesodermin (eomes) from postfertilization development until gastrulation stages of vertebrate embryos. ... | 2017 | 28057273 |
| mutations in gabrb3: from febrile seizures to epileptic encephalopathies. | to examine the role of mutations in gabrb3 encoding the β3 subunit of the gabaa receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. | 2017 | 28053010 |
| global decay of mrna is a hallmark of apoptosis in aging xenopus eggs. | cytoplasmic mrnas are specifically degraded in somatic cells as a part of early apoptotic response. however, no reports have been presented so far concerning mrna fate in apoptotic gametes. in the present study, we analyzed the content of various cytoplasmic mrnas in aging oocytes and eggs of the african clawed frog, xenopus laevis. to circumvent large gene expression variation among the individual oocytes and eggs, single-cell monitoring of transcript levels has been implemented, using multiple ... | 2017 | 28045588 |
| molecular cloning and functional expression of the k+ channel kv7.1 and the regulatory subunit kcne1 from equine myocardium. | the voltage-gated k+-channel kv7.1 and the subunit kcne1, encoded by the kcnq1 and kcne1 genes, respectively, are responsible for termination of the cardiac action potential. in humans, mutations in these genes can predispose patients to arrhythmias and sudden cardiac death (scd). | 2017 | 28917093 |
| organ culture of the xenopus tadpole intestine. | during xenopus metamorphosis, most tadpole organs remodel from the larval to adult form to prepare for adaptation to terrestrial life. organ culture serves as an important tool for studying larval-to-adult organ remodeling independent of the effects of other parts of the body. here, i introduce a protocol for organ culture in vitro using the xenopus laevis tadpole intestine before metamorphic climax. during culture in the absence of exogenous 3,3',5-triiodo-l-thyronine (t3), the most potent natu ... | 2017 | 28912375 |
| collagen-embedded tumor transplantations in xenopus laevis tadpoles. | the xenopus laevis tadpole provides a valuable model for studying tumorigenesis and tumor immunity by intravital real-time microscopy. using well-characterized thymic lymphoid tumor lines (15/0 and ff-2) that are transplantable into their compatible hosts (lg-15 isogenic clones and the f inbred strain, respectively), a system of semisolid tumor engraftment has been designed. because these lymphoid tumor cell lines are not adherent and grow in suspension, they are first immobilized in a matrix of ... | 2017 | 28912374 |
| expression profile of rrbp1 genes during embryonic development and in adult tissues of xenopus laevis. | recent studies suggest that ribosome-binding protein 1 (rrbp1) is involved in multiple diseases such as tumorigenesis and cardiomyopathies. however, its function during embryonic development remains largely unknown. we searched xenopus laevis database with human rrbp1 protein sequence and identified two cdna sequences encoding xenopus orthologs of rrbp1 including rrbp1a (nm_001089623) and rrbp1b (nm_001092468). both genes were firstly detected at blastula stage 8 with weak signals in animal hemi ... | 2017 | 28034797 |
| visual experience dependent regulation of neuronal structure and function by histone deacetylase 1 in developing xenopus tectum in vivo. | histone deacetylase 1 (hdac1) is thought to play pivotal roles in neurogenesis and neurodegeneration. however, the role of hdac1 in neuronal growth and structural plasticity in the developing brain in vivo remains unclear. here, we show that in the optic tectum of xenopus laevis, hdac1 knockdown dramatically decreased the frequency of ampar-mediated synaptic currents and increased the frequency of gabaar-mediated currents, whereas hdac1 overexpression significantly decreased the frequency of gab ... | 2017 | 28033671 |
| the amino acid transporter, slc1a3, is plasma membrane-localised in adipocytes and its activity is insensitive to insulin. | the hormone insulin coordinates the catabolism of nutrients by protein phosphorylation. phosphoproteomic analysis identified insulin-responsive phosphorylation of the glu/asp transporter slc1a3/eaat1 in adipocytes. the role of slc1a3 in adipocytes is not well-understood. we show that slc1a3 is localised to the plasma membrane and the major regulator of acidic amino acid uptake in adipocytes. however, its localisation and activity were unaffected by insulin or mutation of the insulin-regulated ph ... | 2017 | 28032905 |
| human neuronal calcium sensor-1 protein avoids histidine residues to decrease ph sensitivity. | ph is highly regulated in mammalian central nervous systems. neuronal calcium sensor-1 (ncs-1) can interact with numerous target proteins. compared to that in the ncs-1 protein of caenorhabditis elegans, evolution has avoided the placement of histidine residues at positions 102 and 83 in the ncs-1 protein of humans and xenopus laevis, possibly to decrease the conformational sensitivity to ph gradients in synaptic processes. we used all-atom molecular dynamics simulations to investigate the effec ... | 2017 | 28030949 |
| ape2 zf-grf facilitates 3'-5' resection of dna damage following oxidative stress. | the xenopus laevis ape2 (apurinic/apyrimidinic endonuclease 2) nuclease participates in 3'-5' nucleolytic resection of oxidative dna damage and activation of the atr-chk1 dna damage response (ddr) pathway via ill-defined mechanisms. here we report that ape2 resection activity is regulated by dna interactions in its zf-grf domain, a region sharing high homology with ddr proteins topoisomerase 3α (top3α) and neil3 (nei-like dna glycosylase 3), as well as transcription and rna regulatory proteins, ... | 2017 | 28028224 |
| pfkfb4 control of akt signaling is essential for premigratory and migratory neural crest formation. | neural crest (nc) specification comprises an early phase, initiating immature nc progenitors formation at neural plate stage, and a later phase at neural fold stage, resulting in a functional premigratory nc that is able to delaminate and migrate. we found that the nc gene regulatory network triggers upregulation of pfkfb4 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4) during this late specification phase. as shown in previous studies, pfkfb4 controls akt signaling in gastrulas and gly ... | 2017 | 29038306 |
| sonic hedgehog antagonists reduce size and alter patterning of the frog inner ear. | sonic hedgehog (shh) signaling plays a major role in vertebrate development, from regulation of proliferation to the patterning of various organs. in amniotes, shh affects dorsoventral patterning in the inner ear but affects anteroposterior patterning in teleost ears. it remains unknown how altered function of shh relates to morphogenetic changes that coincide with the evolution of limbs and novel auditory organs in the ear. in this study, we used the tetrapod, xenopus laevis, to test how increa ... | 2017 | 29030893 |
| evolution of vocal patterns: tuning hindbrain circuits during species divergence. | the neural circuits underlying divergent courtship behaviors of closely related species provide a framework for insight into the evolution of motor patterns. in frogs, male advertisement calls serve as unique species identifiers and females prefer conspecific to heterospecific calls. advertisement calls of three relatively recently (∼8.5 mya) diverged species - xenopus laevis, x. petersii and x. victorianus - include rapid trains of sound pulses (fast trills). we show that while fast trills are ... | 2017 | 28011819 |