Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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| genetics, morphology, advertisement calls, and historical records distinguish six new polyploid species of african clawed frog (xenopus, pipidae) from west and central africa. | african clawed frogs, genus xenopus, are extraordinary among vertebrates in the diversity of their polyploid species and the high number of independent polyploidization events that occurred during their diversification. here we update current understanding of the evolutionary history of this group and describe six new species from west and central sub-saharan africa, including four tetraploids and two dodecaploids. we provide information on molecular variation, morphology, karyotypes, vocalizati ... | 2015 | 26672747 |
| hepatocystin is essential for trpm7 function during early embryogenesis. | mutations in protein kinase c substrate 80k-h (prkcsh), which encodes for an 80 kda protein named hepatocystin (80k-h, prkcsh), gives rise to polycystic liver disease (pcld). hepatocystin functions as the noncatalytic beta subunit of glucosidase ii, an endoplasmic reticulum (er)-resident enzyme involved in processing and quality control of newly synthesized glycoproteins. patients harboring heterozygous germline mutations in prkcsh are thought to develop renal cysts as a result of somatic loss o ... | 2015 | 26671672 |
| nearly 1000 protein identifications from 50 ng of xenopus laevis zygote homogenate using online sample preparation on a strong cation exchange monolith based microreactor coupled with capillary zone electrophoresis. | a sulfonate-silica hybrid strong cation exchange monolith microreactor was synthesized and coupled to a linear polyacrylamide coated capillary for online sample preparation and capillary zone electrophoresis-tandem mass spectrometry (cze-ms/ms) bottom-up proteomic analysis. the protein sample was loaded onto the microreactor in an acidic buffer. after online reduction, alkylation, and digestion with trypsin, the digests were eluted with 200 mm ammonium bicarbonate at ph 8.2 for cze-ms/ms analysi ... | 2016 | 26670623 |
| perturbation of critical prolines in gloeobacter violaceus ligand-gated ion channel (glic) supports conserved gating motions among cys-loop receptors. | gloeobacter violaceus ligand-gated ion channel (glic) has served as a valuable structural and functional model for the eukaryotic cys-loop receptor superfamily. in cys-loop and other receptors, we have previously demonstrated the crucial roles played by several conserved prolines. here we explore the role of prolines in the gating transitions of glic. as conventional substitutions at some positions resulted in nonfunctional proteins, we used in vivo non-canonical amino acid mutagenesis to determ ... | 2015 | 26668320 |
| regulation of the na+,cl- coupled creatine transporter creat (slc6a8) by the janus kinase jak3. | the creatine transporter creat (slc6a8), a na+,cl- coupled transporter is expressed in diverse tissues including the brain. genetic defects of slc6a8 result in mental retardation with seizures. the present study explored the regulation of creat by janus kinase jak3, which is expressed in a variety of tissues including the brain and participates in the regulation of cell survival and differentiation of neuronal precursor cells. | 2015 | 26666525 |
| up-regulation of voltage gated k+ channels kv1.3 and kv1.5 by protein kinase pkb/akt. | the voltage gated k+ channels kv1.3 and kv1.5 contribute to the orchestration of cell proliferation. kinases participating in the regulation of cell proliferation include protein kinase b (pkb/akt). the present study thus explored whether pkb/akt modifies the abundance and function of kv1.3 and kv1.5. | 2015 | 26666245 |
| identification of a stelar-localized transport protein that facilitates root-to-shoot transfer of chloride in arabidopsis. | under saline conditions, higher plants restrict the accumulation of chloride ions (cl(-)) in the shoot by regulating their transfer from the root symplast into the xylem-associated apoplast. to identify molecular mechanisms underpinning this phenomenon, we undertook a transcriptional screen of salt stressed arabidopsis (arabidopsis thaliana) roots. microarrays, quantitative rt-pcr, and promoter-gus fusions identified a candidate gene involved in cl(-) xylem loading from the nitrate transporter 1 ... | 2016 | 26662602 |
| tob1 is expressed in developing and adult gonads and is associated with the p-body marker, dcp2. | tob1 is a member of the btg/tob family of proteins with established antiproliferative function. in danio rerio and xenopus laevis, the tob1 gene is expressed from the one-cell stage through to early gastrula stages, followed in later development by discrete expression in many tissues including the notochord and somites. in both mouse and human, tob1 is expressed in many adult tissues including the testis and ovary; however, the specific cell types are unknown. we examine tob1 gene expression in ... | 2016 | 26662055 |
| pou5f3.2-induced proliferative state of embryonic cells during gastrulation of xenopus laevis embryo. | pou class v (pou-v) transcription factors play the important role in maintenance of pluripotency and cell differentiation. pou5f3.2 (oct25), one of xenopus pou-v transcription factors, shows the zygotic expression prior to gastrulation. in order to know the molecular mechanism of pou5f3.2 expression at gastrula stage, we examined a responsiveness of pou5f3.2 to nodal signaling. animal cap assay demonstrated that xnr2 activates the gene expression of pou5f3.2. in comparative analysis of the 5'-fl ... | 2015 | 26660397 |
| the polarity protein inturned links nphp4 to daam1 to control the subapical actin network in multiciliated cells. | motile cilia polarization requires intracellular anchorage to the cytoskeleton; however, the molecular machinery that supports this process remains elusive. we report that inturned plays a central role in coordinating the interaction between cilia-associated proteins and actin-nucleation factors. we observed that knockdown of nphp4 in multiciliated cells of the xenopus laevis epidermis compromised ciliogenesis and directional fluid flow. depletion of nphp4 disrupted the subapical actin layer. co ... | 2015 | 26644512 |
| evaluation of presurgical skin preparation agents in african clawed frogs (xenopus laevis). | despite the routine collection of oocytes from african clawed frogs (xenopus laevis) for use in research, few studies have evaluated methods for preparing their skin for surgery. we evaluated 3 skin preparatory agents by examining their antibacterial efficacy and the gross and microscopic appearance of xenopus skin after exposure. frogs (n = 14) were sedated and treated (contact time, 10 min) with 0.9% sterile nacl on one-half of the ventrum and with 0.5% povidone-iodine or 0.75% chlorhexidine o ... | 2015 | 26632790 |
| expression pattern of bcar3, a downstream target of gata2, and its binding partner, bcar1, during xenopus development. | primitive hematopoiesis generates red blood cells that deliver oxygen to the developing embryo. mesodermal cells commit to a primitive blood cell fate during gastrulation and, in order to do so the mesoderm must receive non-cell autonomous signals transmitted from other germ layers. in xenopus, the transcription factor gata2 functions in ectodermal cells to generate or transmit the non-cell autonomous signals. here we have identified breast cancer antiestrogen resistance 3 (bcar3) as a gene that ... | 2016 | 26631802 |
| differential thyroid hormone sensitivity of fast cycling progenitors in the neurogenic niches of tadpoles and juvenile frogs. | adult neurogenesis occurs in neural stem cell (nsc) niches where slow cycling stem cells give rise to faster cycling progenitors. in the adult mouse nsc niche thyroid hormone, t3, and its receptor trα act as a neurogenic switch promoting progenitor cell cycle completion and neuronal differentiation. little is known about whether and how t3 controls proliferation of differentially cycling cells during xenopus neurogenesis. to address this question, we first used sox3 as a marker of stem cell and ... | 2016 | 26628040 |
| the differential effects of resveratrol and trans-ε-viniferin on the gaba-induced current in gabaa receptor subtypes expressed in xenopus laevis oocytes. | the natural products resveratrol and trans-ε-viniferin have been reported to have many beneficial effects, which include the enhancement of cognition and memory. there have been no studies which have reported the effects of these compounds on the different gabaa receptor subtypes and this study aimed to address this. | 2015 | 26626239 |
| functional characterization of a novel class of morantel-sensitive acetylcholine receptors in nematodes. | acetylcholine receptors are pentameric ligand-gated channels involved in excitatory neuro-transmission in both vertebrates and invertebrates. in nematodes, they represent major targets for cholinergic agonist or antagonist anthelmintic drugs. despite the large diversity of acetylcholine-receptor subunit genes present in nematodes, only a few receptor subtypes have been characterized so far. interestingly, parasitic nematodes affecting human or animal health possess two closely related members of ... | 2015 | 26625142 |
| analysis of neural progenitors from embryogenesis to juvenile adult in xenopus laevis reveals biphasic neurogenesis and continuous lengthening of the cell cycle. | xenopus laevis is a prominent model system for studying neural development, but our understanding of the long-term temporal dynamics of neurogenesis remains incomplete. here, we present the first continuous description of neurogenesis in x. laevis, covering the entire period of development from the specification of neural ectoderm during gastrulation to juvenile frog. we have used molecular markers to identify progenitors and neurons, short-term bromodeoxyuridine (brdu) incorporation to map the ... | 2015 | 26621828 |
| on the origin of vertebrate somites. | somites, blocks of mesoderm tissue located on either side of the neural tube in the developing vertebrate embryo, are derived from mesenchymal cells in the presomitic mesoderm (psm) and are a defining characteristic of vertebrates. in vertebrates, the somite segmental boundary is determined by notch signalling and the antagonistic relationship of the downstream targets of notch, lfng, and delta1 in the anterior psm. the presence of somites in the basal chordate amphioxus (branchiostoma floridae) ... | 2015 | 26613046 |
| correction: integrin α5β1 function is regulated by xgipc/kermit2 mediated endocytosis during xenopus laevis gastrulation. | 2015 | 26605543 | |
| involvement of slit-robo signaling in the development of the posterior commissure and concomitant swimming behavior in xenopus laevis. | during vertebrate development, the central nervous system (cns) has stereotyped neuronal tracts (scaffolds) that include longitudinal and commissural axonal bundles, such as the medial longitudinal fascicle or the posterior commissure (pc). as these early tracts appear to guide later-developing neurons, they are thought to provide the basic framework of vertebrate neuronal circuitry. the proper construction of these neuronal circuits is thought to be a crucial step for eliciting coordinated beha ... | 2015 | 26605073 |
| adaptive evolutionary paths from uv reception to sensing violet light by epistatic interactions. | ultraviolet (uv) reception is useful for such basic behaviors as mate choice, foraging, predator avoidance, communication, and navigation, whereas violet reception improves visual resolution and subtle contrast detection. uv and violet reception are mediated by the short wavelength-sensitive (sws1) pigments that absorb light maximally (λmax) at ~360 nm and ~395 to 440 nm, respectively. because of strong nonadditive (epistatic) interactions among amino acid changes in the pigments, the adaptive e ... | 2015 | 26601250 |
| involvement of the l-type amino acid transporter lat2 in the transport of 3,3'-diiodothyronine across the plasma membrane. | thyroid hormones are transported across cell membranes by transmembrane transporter proteins, for example by members of the monocarboxylate transporter (mct) and the l-type amino acid transporter (lat) families. lats consist of a light chain (e.g. lat2) and a heavy chain (cd98), which is essential for their cell surface expression and functionality. the specificity of lat2 for thyroid hormones and their metabolites and its role in their transport was not fully clear. this fact motivated us to es ... | 2015 | 26601072 |
| integrated assessment of biochemical markers in premetamorphic tadpoles of three amphibian species exposed to glyphosate- and methidathion-based pesticides in single and combination forms. | in this study, we evaluated the toxic effects of a glyphosate-based herbicide (gbh) and a methidathion-based insecticide (mbi), individually and in combination, on premetamorphic tadpoles of three anuran species: pelophylax ridibundus, xenopus laevis, and bufotes viridis. based on the determined 96-h lc50 values of each species, the effects of a series of sublethal concentrations of single pesticides and their mixtures after 96-h exposure and also the time-related effects of a high sublethal con ... | 2016 | 26595308 |
| the prototoxin lypd6b modulates heteromeric α3β4-containing nicotinic acetylcholine receptors, but not α7 homomers. | prototoxins are a diverse family of membrane-tethered molecules expressed in the nervous system that modulate nicotinic cholinergic signaling, but their functions and specificity have yet to be completely explored. we tested the selectivity and efficacy of leukocyte antigen, plaur (plasminogen activator, urokinase receptor) domain-containing (lypd)-6b on α3β4-, α3α5β4-, and α7-containing nicotinic acetylcholine receptors (nachrs). to constrain stoichiometry, fusion proteins encoding concatemers ... | 2016 | 26586467 |
| effect of n-glycosylation on the transport activity of the peptide transporter pept1. | the intestinal peptide transporter pept1 provides bulk quantities of amino acids to epithelial cells. pept1 is a high-capacity and low-affinity solute carrier of the slc15 family found in apical membranes of enterocytes in small intestine and distal colon. surprisingly, murine pept1 (mpept1) has an apparent molecular mass of ∼95 kda in the small intestine but ∼105 kda in the large intestine. here we describe studies on mpept1 protein glycosylation and how glycans affect transport function. putat ... | 2016 | 26585416 |
| rna-seq and microarray analysis of the xenopus inner ear transcriptome discloses orthologous omim(®) genes for hereditary disorders of hearing and balance. | auditory and vestibular disorders are prevalent sensory disabilities caused by genetic and environmental (noise, trauma, chemicals) factors that often damage mechanosensory hair cells of the inner ear. development of treatments for inner ear disorders of hearing and balance relies on the use of animal models such as fish, amphibians, reptiles, birds, and non-human mammals. here, we aimed to augment the utility of the genus xenopus for uncovering genetic mechanisms essential for the maintenance o ... | 2015 | 26582541 |
| the expression of talen before fertilization provides a rapid knock-out phenotype in xenopus laevis founder embryos. | recent advances in genome editing using programmable nucleases have revolutionized gene targeting in various organisms. successful gene knock-out has been shown in xenopus, a widely used model organism, although a system enabling less mosaic knock-out in founder embryos (f0) needs to be explored in order to judge phenotypes in the f0 generation. here, we injected modified highly active transcription activator-like effector nuclease (talen) mrna to oocytes at the germinal vesicle (gv) stage, foll ... | 2015 | 26580070 |
| oshkt2;2/1-mediated na(+) influx over k(+) uptake in roots potentially increases toxic na(+) accumulation in a salt-tolerant landrace of rice nona bokra upon salinity stress. | hkt transporters are na(+)-permeable membrane proteins, which mediate na(+) and k(+) homeostasis in k(+)-depleted and saline environments in plants. class ii hkt transporters, a distinct subgroup found predominantly in monocots, are known to mediate na(+)-k(+) co-transport in principle. here we report features of ion transport functions of no-oshkt2;2/1, a class ii transporter identified in a salt tolerant landrace of indica rice, nona bokra. we profiled no-oshkt2;2/1 expression in organs of non ... | 2016 | 26578190 |
| molecular cloning and expression of a gaba receptor subunit from the crayfish procambarus clarkii. | molecular cloning has introduced an unexpected, large diversity of neurotransmitter hetero- oligomeric receptors. extensive research on the molecular structure of the γ-aminobutyric acid receptor (gabar) has been of great significance for understanding how the nervous system works in both vertebrates and invertebrates. however, only two examples of functional homo-oligomeric gaba-activated cl(-) channels have been reported. in the vertebrate retina, the gabaρ1 subunit of various species forms ho ... | 2016 | 26577600 |
| sex differences and endocrine regulation of auditory-evoked, neural responses in african clawed frogs (xenopus). | mating depends on the accurate detection of signals that convey species identity and reproductive state. in african clawed frogs, xenopus, this information is conveyed by vocal signals that differ in temporal patterns and spectral features between sexes and across species. we characterized spectral sensitivity using auditory-evoked potentials (aeps), commonly known as the auditory brainstem response, in males and females of four xenopus species. in female x. amieti, x. petersii, and x. laevis, p ... | 2016 | 26572136 |
| identification of an inhibitory alcohol binding site in gabaa ρ1 receptors. | alcohols inhibit γ-aminobutyric acid type a ρ1 receptor function. after introducing mutations in several positions of the second transmembrane helix in ρ1, we studied the effects of ethanol and hexanol on gaba responses using two-electrode voltage clamp electrophysiology in xenopus laevis oocytes. the 6' mutations produced the following effects on ethanol and hexanol responses: small increase or no change (t6'm), increased inhibition (t6'v), and small potentiation (t6'y and t6'f). the 5' mutatio ... | 2016 | 26571107 |
| quantification of x. laevis vitellogenin by liquid chromatography tandem mass spectrometry. | over the last several decades, there has been an increase in public awareness and regulatory activity in regard to the presence of emerging contaminants in the environment that may have the potential to interact with the endocrine system of exposed wildlife. alterations in vitellogenin (vtg), a high density yolk precursor protein, can indicate endocrine activity in oviparous species, including many fish and amphibians. while various methodologies and experiments have been performed to characteri ... | 2016 | 26562177 |
| distinctive effects of nicotinic receptor intracellular-loop mutations associated with nocturnal frontal lobe epilepsy. | previously characterized nicotinic acetylcholine receptor (nachr) autosomal dominant nocturnal frontal lobe epilepsy (adnfle)-associated mutations are found in α2, α4 and β2 subunit transmembrane (tm) domains. they predominantly increase ach potency and, for β2-subunit mutants, increase macroscopic currents. two recently-identified mutations, α4(r336h) and β2(v337g), located in the intracellular cytoplasmic loop (c2) have been associated with non-familial nfle. effects of these mutations on α4β2 ... | 2016 | 26561946 |
| alternative splice variant of the thiazide-sensitive nacl cotransporter: a novel player in renal salt handling. | the thiazide-sensitive nacl cotransporter (ncc) is an important pharmacological target in the treatment of hypertension. the human slc12a3 gene, encoding ncc, gives rise to three isoforms. only the third isoform has been extensively investigated. the aim of the present study was, therefore, to establish the abundance and localization of the almost identical isoforms 1 and 2 (ncc1/2) in the human kidney and to determine their functional properties and regulation in physiological conditions. immun ... | 2016 | 26561651 |
| identification of micrornas and microrna targets in xenopus gastrulae: the role of mir-26 in the regulation of smad1. | micrornas (mirnas) are known to play diverse roles in the regulation of vertebrate development. to investigate mirna-target mrna relationships in embryonic development, we have carried out small-rna sequencing to identify mirnas expressed in the early gastrula of xenopus laevis. we identify a total of 180 mirnas, and we have identified the locations of the mirna precursor sequences in the x. laevis genome. of these mirnas, 141 represent mirs previously identified in xenopus tropicalis. alignment ... | 2016 | 26548531 |
| using in vivo imaging to measure rna mobility in xenopus laevis oocytes. | rna localization in the xenopus oocyte is responsible for the establishment of polarity during oogenesis as well as the specification of germ layers during embryogenesis. however, the inability to monitor mrna localization in live vertebrate oocytes has posed a major barrier to understanding the mechanisms driving directional transport. here we describe a method for imaging ms2 tagged rna in live xenopus oocytes to study the dynamics of rna localization. we also focus on methods for implementing ... | 2016 | 26546269 |
| sulfate and thiosulfate inhibit oxalate transport via a dprestin (slc26a6)-dependent mechanism in an insect model of calcium oxalate nephrolithiasis. | nephrolithiasis is one of the most common urinary tract disorders, with the majority of kidney stones composed of calcium oxalate (caox). given its prevalence (us occurrence 10%), it is still poorly understood, lacking progress in identifying new therapies because of its complex etiology. drosophila melanogaster (fruitfly) is a recently developed model of caox nephrolithiasis. effects of sulfate and thiosulfate on crystal formation were investigated using the drosophila model, as well as electro ... | 2016 | 26538444 |
| sex-specific response to hypoxia in a reduced brainstem preparation from xenopus laevis. | respiratory reflexes and tolerance to hypoxia show significant sexual dimorphism. however, the data supporting this notion originates exclusively from mammals. to determine whether this concept is limited to this group of vertebrates, we examined the sex-specific response to acute hypoxia in an adult reduced brainstem preparation from xenopus laevis. within the first 5min of exposure to hypoxic acsf (98% n2/2% co2), recordings of respiratory-related activity show a stronger increase in fictive b ... | 2016 | 26528898 |
| gremlin1 induces anterior-posterior limb bifurcations in developing xenopus limbs but does not enhance limb regeneration. | gremlin1 (grem1) has been previously identified as being significantly up-regulated during regeneration of xenopus laevis limbs. grem1 is an antagonist of bone morphogenetic proteins (bmps) with a known role in limb development in amniotes. it forms part of a self-regulating feedback loop linking epithelial (fgf) and mesenchymal (shh) signalling centres, thereby controlling outgrowth, anterior posterior and proximal distal patterning. spatiotemporal regulation of the same genes in developing and ... | 2015 | 26527308 |
| affinity of the heparin binding motif of noggin1 to heparan sulfate and its visualization in the embryonic tissues. | heparin binding motifs were found in many secreted proteins and it was suggested that they are responsible for retardation of the protein diffusion within the intercellular space due to the binding to heparan sulfate proteoglycanes (hspg). here we used synthetic fitc labeled heparin binding motif (hbm peptide) of the xenopus laevis secreted bmp inhibitor noggin1 to study its diffusion along the surface of the heparin beads by frap method. as a result, we have found out that diffusivity of hbm-la ... | 2015 | 26525852 |
| [role of monocarboxylate transporter in statin-induced cytotoxicity]. | although exercise and drug therapy are important to prevent progression of arteriosclerotic disease, exercise leads to an increase in muscular disorder induced by hmg-coa reductase inhibitors (statins). elucidation of this mechanism is needed to prevent the occurrence of muscular disorders. since exercise induces expression of monocarboxylate transporter (mct) 4, we focused on the association between mct4 function and statin-induced muscle injury. first, we examined the transport of l-lactate vi ... | 2015 | 26521871 |
| monitoring smad activity in vivo using the xenopus model system. | the embryo of the african clawed frog xenopus laevis plays a central role in the field of cell and developmental biology. one of the strengths of xenopus as model system lies in the high degree of conservation between amphibians and mammals in the molecular mechanisms controlling tissue patterning and differentiation. as such, many signaling cascades were first investigated in frog embryos and then confirmed in mouse and/or human cells. the tgf-β signaling cascade greatly benefited from this mod ... | 2016 | 26520129 |
| alternatively spliced isoforms of kv10.1 potassium channels modulate channel properties and can activate cyclin-dependent kinase in xenopus oocytes. | kv10.1 is a voltage-gated potassium channel expressed selectively in the mammalian brain but also aberrantly in cancer cells. in this study we identified short splice variants of kv10.1 resulting from exon-skipping events (e65 and e70) in human brain and cancer cell lines. the presence of the variants was confirmed by northern blot and rnase protection assays. both variants completely lacked the transmembrane domains of the channel and produced cytoplasmic proteins without channel function. in a ... | 2015 | 26518875 |
| novel reporter for faithful monitoring of erk2 dynamics in living cells and model organisms. | uncoupling of erk1/2 phosphorylation from subcellular localization is essential towards the understanding of molecular mechanisms that control erk1/2-mediated cell-fate decision. erk1/2 non-catalytic functions and discoveries of new specific anchors responsible of the subcellular compartmentalization of erk1/2 signaling pathway have been proposed as regulation mechanisms for which dynamic monitoring of erk1/2 localization is necessary. however, studying the spatiotemporal features of erk2, for i ... | 2015 | 26517832 |
| application of local gene induction by infrared laser-mediated microscope and temperature stimulator to amphibian regeneration study. | urodele amphibians (newts and salamanders) and anuran amphibians (frogs) are excellent research models to reveal mechanisms of three-dimensional organ regeneration since they have exceptionally high regenerative capacity among tetrapods. however, the difficulty in manipulating gene expression in cells in a spatially restricted manner has so far hindered elucidation of the molecular mechanisms of organ regeneration in amphibians. recently, local heat shock by laser irradiation has enabled local g ... | 2015 | 26510480 |
| distribution of single wall carbon nanotubes in the xenopus laevis embryo after microinjection. | single wall carbon nanotubes (swcnts) are advanced materials with the potential for a myriad of diverse applications, including biological technologies and large-scale usage with the potential for environmental impacts. swcnts have been exposed to developing organisms to determine their effects on embryogenesis, and results have been inconsistent arising, in part, from differing material quality, dispersion status, material size, impurity from catalysts and stability. for this study, we utilized ... | 2016 | 26510384 |
| identification and bioinformatics analyses of the basic helix-loop-helix transcription factors in xenopus laevis. | xenopus laevis is a long established model organism for developmental, behavioral and neurological studies. herein, an updated genome-wide survey was conducted using the ongoing genome project of xenopus laevis and 106 non-redundant basic helix-loop-helix (bhlh) genes were identified in the xenopus laevis genome databases. gene ontology (go) enrichment statistics showed 51 significant go annotations of biological processes and molecular functions and 5 significant kegg pathways and a number of x ... | 2015 | 26506645 |
| up-regulation of intestinal phosphate transporter napi-iib (slc34a2) by the kinases spak and osr1. | spak (sps1-related proline/alanine-rich kinase) and osr1 (oxidative stress-responsive kinase 1), kinases controlled by wnk (with-no-k[lys] kinase), are powerful regulators of cellular ion transport and blood pressure. observations in gene-targeted mice disclosed an impact of spak/osr1 on phosphate metabolism. the present study thus tested whether spak and/or osr1 contributes to the regulation of the intestinal na(+)-coupled phosphate co-transporter napi-iib (slc34a2). | 2015 | 26506223 |
| a database of microrna expression patterns in xenopus laevis. | micrornas (mirnas) are short, non-coding rnas around 22 nucleotides long. they inhibit gene expression either by translational repression or by causing the degradation of the mrnas they bind to. many are highly conserved amongst diverse organisms and have restricted spatio-temporal expression patterns during embryonic development where they are thought to be involved in generating accuracy of developmental timing and in supporting cell fate decisions and tissue identity. we determined the expres ... | 2015 | 26506012 |
| verapamil-sensitive transport of quinacrine and methylene blue via the plasmodium falciparum chloroquine resistance transporter reduces the parasite's susceptibility to these tricyclic drugs. | it is becoming increasingly apparent that certain mutations in the plasmodium falciparum chloroquine resistance transporter (pfcrt) alter the parasite's susceptibility to diverse compounds. here we investigated the interaction of pfcrt with 3 tricyclic compounds that have been used to treat malaria (quinacrine [qc] and methylene blue [mb]) or to study p. falciparum (acridine orange [ao]). | 2016 | 26503982 |
| dose-dependent early life stage toxicities in xenopus laevis exposed in ovo to selenium. | selenium (se) is a developmental toxicant in oviparous vertebrates. the adverse reproductive effects of se toxicity have been predominantly investigated in fishes and birds with only a few studies focusing on amphibians. the objective of this study was to determine tissue-based toxicity thresholds for early life stage se toxicities in xenopus laevis as a consequence of in ovo exposure through maternal transfer of dietary se. following a 68-day dietary exposure to food augmented with l-selenometh ... | 2015 | 26501870 |
| quantitative analysis of filament branch orientation in listeria actin comet tails. | several bacterial and viral pathogens hijack the host actin cytoskeleton machinery to facilitate spread and infection. in particular, listeria uses arp2/3-mediated actin filament nucleation at the bacterial surface to generate a branched network that will help propel the bacteria. however, the mechanism of force generation remains elusive due to the lack of high-resolution three-dimensional structural data on the spatial organization of the actin mother and daughter (i.e., branch) filaments with ... | 2016 | 26497103 |
| odorant receptor-based discovery of natural repellents of human lice. | the body louse, pediculus humanus humanus, is an obligate blood-feeding ectoparasite and an important insect vector that mediates the transmission of diseases to humans. the analysis of the body louse genome revealed a drastic reduction of the chemosensory gene repertoires when compared to other insects, suggesting specific olfactory adaptations to host specialization and permanent parasitic lifestyle. here, we present for the first time functional evidence for the role of odorant receptors (ors ... | 2015 | 26494014 |
| rhodopsin forms nanodomains in rod outer segment disc membranes of the cold-blooded xenopus laevis. | rhodopsin forms nanoscale domains (i.e., nanodomains) in rod outer segment disc membranes from mammalian species. it is unclear whether rhodopsin arranges in a similar manner in amphibian species, which are often used as a model system to investigate the function of rhodopsin and the structure of photoreceptor cells. moreover, since samples are routinely prepared at low temperatures, it is unclear whether lipid phase separation effects in the membrane promote the observed nanodomain organization ... | 2015 | 26492040 |
| corrigendum: fertilization competence of the egg-coating envelope is regulated by direct interaction of dicalcin and gp41, the xenopus laevis zp3. | 2015 | 26488680 | |
| in vivo study of dynamics and stability of dendritic spines on olfactory bulb interneurons in xenopus laevis tadpoles. | dendritic spines undergo continuous remodeling during development of the nervous system. their stability is essential for maintaining a functional neuronal circuit. spine dynamics and stability of cortical excitatory pyramidal neurons have been explored extensively in mammalian animal models. however, little is known about spiny interneurons in non-mammalian vertebrate models. in the present study, neuronal morphology was visualized by single-cell electroporation. spiny neurons were surveyed in ... | 2015 | 26485435 |
| the hydroxyl side chain of a highly conserved serine residue is required for cation selectivity and substrate transport in the glial glutamate transporter glt-1/slc1a2. | glutamate transporters maintain synaptic concentration of the excitatory neurotransmitter below neurotoxic levels. their transport cycle consists of cotransport of glutamate with three sodium ions and one proton, followed by countertransport of potassium. structural studies proposed that a highly conserved serine located in the binding pocket of the homologous gltph coordinates l-aspartate as well as the sodium ion na1. to experimentally validate these findings, we generated and characterized se ... | 2015 | 26483543 |
| functional characterization of a transition metal ion transporter, oszip6 from rice (oryza sativa l.). | micronutrients are important for the growth and development of plants, which deploy families of transporters for their uptake and distribution. we have functionally characterized a novel transition metal ion transporter from rice, oszip6 (oryza sativa zinc regulated transporter, iron regulated transporter-like protein 6). the transporter was found to be transcriptionally activated in shoot and root tissues in response to deficiency in fe(2+), zn(2+) and mn(2+). oszip6 was expressed in xenopus la ... | 2015 | 26476396 |
| cell cycle control in the early embryonic development of aquatic animal species. | the cell cycle is integrated with many aspects of embryonic development. not only is proper control over the pace of cell proliferation important, but also the timing of cell cycle progression is coordinated with transcription, cell migration, and cell differentiation. due to the ease with which the embryos of aquatic organisms can be observed and manipulated, they have been a popular choice for embryologists throughout history. in the cell cycle field, aquatic organisms have been extremely impo ... | 2015 | 26475527 |
| effects of dietary exposure of polycyclic musk hhcb on the metamorphosis of xenopus laevis. | the compound 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[γ]-2-benzopyrane (hhcb; galaxolide, chemical abstracts service number 1222-05-5) is a synthetic musk used extensively as a fragrance in many consumer products and classified as an emerging pollutant. the ecotoxicological information available for hhcb addresses exposure via water, but this compound is frequently adsorbed into particulate matter. the goal of the present study was to assess the effects of dietary exposure to seve ... | 2016 | 26472276 |
| catalytic activity of human carbonic anhydrase isoform ix is displayed both extra- and intracellularly. | most carbonic anhydrases catalyse the reversible conversion of carbon dioxide to protons and bicarbonate, either as soluble cytosolic enzymes, in or at intracellular organelles, or at the extracellular face of the cell membrane as membrane-anchored proteins. carbonic anhydrase isoform ix (ca ix), a membrane-bound enzyme with catalytic activity at the extracellular membrane surface, has come to prominence in recent years because of its association with hypoxic tissue, particularly tumours, often ... | 2016 | 26470855 |
| bumetanide derivatives aqb007 and aqb011 selectively block the aquaporin-1 ion channel conductance and slow cancer cell migration. | aquaporins (aqps) in the major intrinsic family of proteins mediate fluxes of water and other small solutes across cell membranes. aqp1 is a water channel, and under permissive conditions, a nonselective cation channel gated by cgmp. in addition to mediating fluid transport, aqp1 expression facilitates rapid cell migration in cell types including colon cancers and glioblastoma. work here defines new pharmacological derivatives of bumetanide that selectively inhibit the ion channel, but not the w ... | 2016 | 26467039 |
| phosphorylation of rs1 (rsc1a1) steers inhibition of different exocytotic pathways for glucose transporter sglt1 and nucleoside transporter cnt1, and an rs1-derived peptide inhibits glucose absorption. | cellular uptake adapts rapidly to physiologic demands by changing transporter abundance in the plasma membrane. the human gene rsc1a1 codes for a 67-kda protein named rs1 that has been shown to induce downregulation of the sodium-d-glucose cotransporter 1 (sglt1) and of the concentrative nucleoside transporter 1 (cnt1) in the plasma membrane by blocking exocytosis at the golgi. injecting rs1 fragments into xenopus laevis oocytes expressing sglt1 or cnt1 and measuring the expressed uptake of α-me ... | 2016 | 26464324 |
| a curcumin analog, go-y078, effectively inhibits angiogenesis through actin disorganization. | the inhibition of angiogenesis is a theoretically ideal chemotherapy for cancer, but there remains room for improvement. most inhibitors of angiogenesis approved to date target vascular endothelial growth factors (vegfs); however, vegfs are only one of the many classes of participant in tumor angiogenesis. because tumor angiogenesis is orchestrated by many components, including growth factors, signal transducers, and effectors, its regulation exhibits redundancy. curcumin can associate with many ... | 2016 | 26459768 |
| the xenopus tropicalis orthologue of trpv3 is heat sensitive. | thermosensitive members of the transient receptor potential (trp) family of ion channels (thermal trp channels) play a crucial role in mammalian temperature sensing. orthologues of these channels are present in lower vertebrates and, remarkably, some thermal trp orthologues from different species appear to mediate opposing responses to temperature. for example, whereas the mammalian trpv3 channel is activated by heat, frog trpv3 is reportedly activated by cold. intrigued by the potential implica ... | 2015 | 26458875 |
| the scd6/lsm14 protein xrapb has properties different from rap55 in selecting mrna for early translation or intracellular distribution in xenopus oocytes. | oocytes accumulate mrnas in the form of maternal ribonucleoprotein (rnp) particles, the protein components of which determine the location and stability of individual mrnas prior to translation. scd6/lsm14 proteins, typified by rap55, function in a wide range of eukaryotes in repressing translation and relocating mrnps to processing bodies and stress granules. in xenopus laevis, the rap55 orthologue xrapa fulfils these functions. here we describe the properties of a variant of xrapa, xrapb, whic ... | 2015 | 26455898 |
| rho kinase is required to prevent retinal axons from entering the contralateral optic nerve. | to grow out to contact target neurons an axon uses its distal tip, the growth cone, as a sensor of molecular cues that help the axon make appropriate guidance decisions at a series of choice points along the journey. in the developing visual system, the axons of the output cells of the retina, the retinal ganglion cells (rgcs), cross the brain midline at the optic chiasm. shortly after, they grow past the brain entry point of the optic nerve arising from the contralateral eye, and extend dorso-c ... | 2015 | 26455469 |
| ca(2+)-bk channel clusters in olfactory receptor neurons and their role in odour coding. | olfactory receptor neurons (orns) have high-voltage-gated ca(2+) channels whose physiological impact has remained enigmatic since the voltage-gated conductances in this cell type were first described in the 1980s. here we show that in orn somata of xenopus laevis tadpoles these channels are clustered and co-expressed with large-conductance potassium (bk) channels. we found approximately five clusters per orn and twelve ca(2+) channels per cluster. the action potential-triggered activation of bk ... | 2015 | 26452167 |
| serotonergic regulation of melanocyte conversion: a bioelectrically regulated network for stochastic all-or-none hyperpigmentation. | experimentally induced depolarization of resting membrane potential in "instructor cells" in xenopus laevis embryos causes hyperpigmentation in an all-or-none fashion in some tadpoles due to excess proliferation and migration of melanocytes. we showed that this stochastic process involved serotonin signaling, adenosine 3',5'-monophosphate (camp), and the transcription factors camp response element-binding protein (creb), sox10, and slug. transcriptional microarray analysis of embryos taken at st ... | 2015 | 26443706 |
| putting it all on pigmentation: heuristics of a bold and stochastic cell fate decision. | gradients of transmembrane potential coordinate cell-fate decisions and patterning during embryogenesis and wound-healing. bioelectrical signaling may also be more important for adult pathologies than currently recognized. in this issue of science signaling, lobikin et al. describe a role for bioelectric signals during the development of xenopus leavis embryos to instruct an organism-level response reminiscent of neoplastic progression in melanoma. | 2015 | 26443702 |
| dual processing of sulfated steroids in the olfactory system of an anuran amphibian. | chemical communication is widespread in amphibians, but if compared to later diverging tetrapods the available functional data is limited. the existing information on the vomeronasal system of anurans is particularly sparse. amphibians represent a transitional stage in the evolution of the olfactory system. most species have anatomically separated main and vomeronasal systems, but recent studies have shown that in anurans their molecular separation is still underway. sulfated steroids function a ... | 2015 | 26441543 |
| xenopus borealis as an alternative source of oocytes for biophysical and pharmacological studies of neuronal ion channels. | for the past 30 years, oocytes from xenopus laevis have been extensively used to express and characterise ion channels in an easily controlled environment. here we report the first use of oocytes from the closely related species xenopus borealis as an alternative expression system for neuronal ion channels. using the two-electrode voltage-clamp technique, we show that a wide variety of voltage- and ligand-gated ion channels have the same channel properties and pharmacological profiles when expre ... | 2015 | 26440210 |
| xenopus laevis as a model to identify translation impairment. | protein synthesis is a fundamental process to gene expression impacting diverse biological processes notably adaptation to environmental conditions. the initiation step, which involves the assembly of the ribosomal subunits at the mrna initiation codon, involved initiation factor including eif4g1. defects in this rate limiting step of translation are linked to diverse disorders. to study the potential consequences of such deregulations, xenopus laevis oocytes constitute an attractive model with ... | 2015 | 26437037 |
| the phytosiderophore efflux transporter tom2 is involved in metal transport in rice. | iron is an essential metal element for all living organisms. graminaceous plants produce and secrete mugineic acid family phytosiderophores from their roots to acquire iron in the soil. phytosiderophores chelate and solubilize insoluble iron hydroxide in the soil. subsequently, plants take up iron-phytosiderophore complexes through specific transporters on the root cell membrane. phytosiderophores are also thought to be important for the internal transport of various transition metals, including ... | 2015 | 26432636 |
| tebuconazole disrupts steroidogenesis in xenopus laevis. | a 27-day controlled exposure study of adult male african clawed frogs (xenopus laevis) was conducted to examine the mechanism by which tebuconazole may disrupt steroidogenesis. the fungicide was measured by lc-ms/ms in tank water and in target tissues (adipose, kidney, liver, and brain), and we observed tissue-specific bioconcentration with bcf up to 238. up to 10 different steroid hormones were quantified in gonads using lc-ms/ms and in plasma using gc-ms/ms and a radioimmunoassay was performed ... | 2015 | 26432166 |
| extinction of an introduced warm-climate alien species, xenopus laevis, by extreme weather events. | invasive, non-native species represent a major threat to biodiversity worldwide. the african amphibian xenopus laevis is widely regarded as an invasive species and a threat to local faunas. populations originating at the western cape, south africa, have been introduced on four continents, mostly in areas with a similar mediterranean climate. some introduced populations are also established in cooler environments where persistence for many decades suggests a capacity for long-term adaptation. in ... | 2017 | 26430383 |
| concentration-dependent effects of nuclear lamins on nuclear size in xenopus and mammalian cells. | a fundamental question in cell biology concerns the regulation of organelle size. while nuclear size is exquisitely controlled in different cell types, inappropriate nuclear enlargement is used to diagnose and stage cancer. clarifying the functional significance of nuclear size necessitates an understanding of the mechanisms and proteins that control nuclear size. one structural component implicated in the regulation of nuclear morphology is the nuclear lamina, a meshwork of intermediate lamin f ... | 2015 | 26429910 |
| biochemical and hematologic reference intervals for aged xenopus laevis in a research colony. | xenopus laevis, the african clawed frog, is commonly used in developmental and toxicology research studies. little information is available on aged x. laevis; however, with the complete mapping of the genome and the availability of transgenic animal models, the number of aged animals in research colonies is increasing. the goals of this study were to obtain biochemical and hematologic parameters to establish reference intervals for aged x. laevis and to compare results with those from young adul ... | 2015 | 26424243 |
| dicalcin, a zona pellucida protein that regulates fertilization competence of the egg coat in xenopus laevis. | fertilization is a highly coordinated process whereby sperm interact with the egg-coating envelope (called the zona pellucida, zp) in a taxon-restricted manner, fertilization triggers the resumption of the cell cycle of the egg, ultimately leading to generation of a new organism that contains hereditary information of the parents. the complete sperm-zp interaction comprises sperm recognition of the zp, the acrosome reaction, penetration of the zp, and fusion with the egg. recent evidence suggest ... | 2015 | 26420688 |
| exposure to 3,3',5-triiodothyronine affects histone and rna polymerase ii modifications, but not dna methylation status, in the regulatory region of the xenopus laevis thyroid hormone receptor βα gene. | thyroid hormones (ths) play a critical role in amphibian metamorphosis, during which the th receptor (tr) gene, thrb, is upregulated in a tissue-specific manner. the xenopus laevis thrb gene has 3 th response elements (tres) in the 5' flanking regulatory region and 1 tre in the exon b region, around which cpg sites are highly distributed. to clarify whether exposure to 3,3',5-triiodothyronine (t3) affects histone and rna polymerase ii (rnapii) modifications and the level of dna methylation in th ... | 2015 | 26417689 |
| low concentrations of metal mixture exposures have adverse effects on selected biomarkers of xenopus laevis tadpoles. | polluted ecosystems may contain mixtures of metals, such that the combinations of metals, even in low concentrations, may cause adverse effects. in the present study, we focused on toxic effects of mixtures of selected metals, the lc50 values, and also their safety limit in aquatic systems imposed by the european legislation using a model organism. xenopus laevis tadpoles were used as test organisms. they were exposed to metals or their combinations due to 96-h lc50 values. glutathione s-transfe ... | 2015 | 26415005 |
| joint effects of pesticides and ultraviolet-b radiation on amphibian larvae. | a combination of multiple stressors may be linked to global amphibian declines. of these, pesticides and uvb radiation co-exposures were examined on the african clawed frog (xenopus laevis) to provide information that may be useful for amphibian conservation. the independent action model and inferential statistics were used to examine interactions between pesticides (malathion, endosulfan, α-cypermethrin, or chlorothalonil) and environmentally relevant uvb exposures. uvb radiation alone caused 3 ... | 2015 | 26412264 |
| the role of flexible loops in folding, trafficking and activity of equilibrative nucleoside transporters. | equilibrative nucleoside transporters (ents) are integral membrane proteins, which reside in plasma membranes of all eukaryotic cells and mediate thermodynamically downhill transport of nucleosides. this process is essential for nucleoside recycling, and also plays a key role in terminating adenosine-mediated cellular signaling. furthermore, ents mediate the uptake of many drugs, including anticancer and antiviral nucleoside analogues. the structure and mechanism, by which ents catalyze trans-me ... | 2015 | 26406980 |
| xenopus limb bud morphogenesis. | xenopus laevis, the south african clawed frog, is a well-established model organism for the study of developmental biology and regeneration due to its many advantages for both classical and molecular studies of patterning and morphogenesis. while contemporary studies of limb development tend to focus on models developed from the study of chicken and mouse embryos, there are also many classical studies of limb development in frogs. these include both fate and specification maps, that, due to thei ... | 2016 | 26404044 |
| isoform-specific phosphorylation-dependent regulation of connexin hemichannels. | connexins form gap junction channels made up of two connexons (hemichannels) from adjacent cells. unopposed hemichannels may open toward the extracellular space upon stimulation by, e.g., removal of divalent cations from the extracellular solution and allow isoform-specific transmembrane flux of fluorescent dyes and physiologically relevant molecules, such as atp and ions. connexin (cx)43 and cx30 are the major astrocytic connexins. protein kinase c (pkc) regulates cx43 in its cell-cell gap junc ... | 2015 | 26400258 |
| proteomics of xenopus development. | modern mass spectrometry-based methods provide an exciting opportunity to characterize protein expression in the developing embryo. we have employed an isotopic labeling technology to quantify the expression dynamics of nearly 6000 proteins across six stages of development in xenopus laevis from the single stage zygote through the mid-blastula transition and the onset of organogenesis. approximately 40% of the proteins show significant changes in expression across the development stages. the exp ... | 2016 | 26396253 |
| involvement of vat-1 in phosphatidylserine transfer from the endoplasmic reticulum to mitochondria. | mitochondria receive phosphatidylserine (ps) from the endoplasmic reticulum (er), but how ps is moved from the er to mitochondria is unclear. current models postulate a physical link between the organelles, but no involvement of cytosolic proteins. here, we have reconstituted ps transport from the er to mitochondria in vitro using xenopus egg components. transport is independent of er proteins, but is dependent on a cytosolic factor that has a preferential affinity for ps. crosslinking with a ph ... | 2015 | 26394711 |
| the xenopus orfeome: a resource that enables functional genomics. | functional characterisation of proteins and large-scale, systems-level studies are enabled by extensive sets of cloned open reading frames (orfs) in an easily-accessible format that enables many different applications. here we report the release of the first stage of the xenopus orfeome, which contains 8673 orfs from the xenopus gene collection (xgc) for xenopus laevis, cloned into a gateway® donor vector enabling rapid in-frame transfer of the orfs to expression vectors. this resource represent ... | 2015 | 26391338 |
| histone h3 lysine 9 trimethylation is required for suppressing the expression of an embryonically activated retrotransposon in xenopus laevis. | transposable elements in the genome are generally silenced in differentiated somatic cells. however, increasing evidence indicates that some of them are actively transcribed in early embryos and the proper regulation of retrotransposon expression is essential for normal development. although their developmentally regulated expression has been shown, the mechanisms controlling retrotransposon expression in early embryos are still not well understood. here, we observe a dynamic expression pattern ... | 2015 | 26387861 |
| incorporation of non-canonical amino acids. | in this chapter we discuss the strengths, caveats and technical considerations of three approaches for reprogramming the chemical composition of selected amino acids within a membrane protein. in vivo nonsense suppression in the xenopus laevis oocyte, evolved orthogonal trna and aminoacyl-trna synthetase pairs and protein ligation for biochemical production of semisynthetic proteins have been used successfully for ion channel and receptor studies. the level of difficulty for the application of e ... | 2015 | 26381943 |
| grapevine and arabidopsis cation-chloride cotransporters localize to the golgi and trans-golgi network and indirectly influence long-distance ion transport and plant salt tolerance. | plant cation-chloride cotransporters (cccs) have been implicated in conferring salt tolerance. they are predicted to improve shoot salt exclusion by directly catalyzing the retrieval of sodium (na(+)) and chloride (cl(-)) ions from the root xylem. we investigated whether grapevine (vitis vinifera [vvi]) ccc has a role in salt tolerance by cloning and functionally characterizing the gene from the cultivar cabernet sauvignon. amino acid sequence analysis revealed that vviccc shares a high degree o ... | 2015 | 26378102 |
| molecular cloning and functional expression of the equine k+ channel kv11.1 (ether à go-go-related/kcnh2 gene) and the regulatory subunit kcne2 from equine myocardium. | the kcnh2 and kcne2 genes encode the cardiac voltage-gated k+ channel kv11.1 and its auxiliary β subunit kcne2. kv11.1 is critical for repolarization of the cardiac action potential. in humans, mutations or drug therapy affecting the kv11.1 channel are associated with prolongation of the qt intervals on the ecg and increased risk of ventricular tachyarrhythmia and sudden cardiac death--conditions known as congenital or acquired long qt syndrome (lqts), respectively. in horses, sudden, unexplaine ... | 2015 | 26376488 |
| identification of a vxp targeting signal in the flagellar na+ /k+ -atpase. | na(+) /k(+) -atpase (nka) participates in setting electrochemical gradients, cardiotonic steroid signaling and cellular adhesion. distinct isoforms of nka are found in different tissues and subcellular localization patterns. for example, nka α1 is widely expressed, nka α3 is enriched in neurons and nka α4 is a testes-specific isoform found in sperm flagella. in some tissues, ankyrin, a key component of the membrane cytoskeleton, can regulate the trafficking of nka. in the retina, nka and ankyrin ... | 2015 | 26373354 |
| gata2 regulates wnt signaling to promote primitive red blood cell fate. | primitive erythropoiesis is regulated in a non cell-autonomous fashion across evolution from frogs to mammals. in xenopus laevis, signals from the overlying ectoderm are required to induce the mesoderm to adopt an erythroid fate. previous studies in our lab identified the transcription factor gata2 as a key regulator of this ectodermal signal. to identify gata2 target genes in the ectoderm required for red blood cell formation in the mesoderm, we used microarray analysis to compare gene expressi ... | 2015 | 26365900 |
| cdc174, a novel component of the exon junction complex whose mutation underlies a syndrome of hypotonia and psychomotor developmental delay. | siblings of non-consanguineous jewish-ethiopian ancestry presented with congenital axial hypotonia, weakness of the abducens nerve, psychomotor developmental delay with brain ventriculomegaly, variable thinning of corpus callosum and cardiac septal defects. homozygosity mapping identified a single disease-associated locus of 3.5 mb on chromosome 3. studies of a bedouin consanguineous kindred affected with a similar recessive phenotype identified a single disease-associated 18 mb homozygosity loc ... | 2015 | 26358778 |
| role of n-glycosylation in renal betaine transport. | the osmolyte and folding chaperone betaine is transported by the renal na(+)-coupled gaba (γ-aminobutyric acid) symporter bgt-1 (betaine/gaba transporter 1), a member of the slc6 (solute carrier 6) family. under hypertonic conditions, the transcription, translation and plasma membrane (pm) insertion of bgt-1 in kidney cells are significantly increased, resulting in elevated betaine and gaba transport. re-establishing isotonicity involves pm depletion of bgt-1. the molecular mechanism of the regu ... | 2015 | 26348906 |
| kinetochore function is controlled by a phospho-dependent coexpansion of inner and outer components. | it is widely accepted that the kinetochore is built on cenp-a-marked centromeric chromatin in a hierarchical order from inner to outer kinetochore. recruitment of many kinetochore proteins depends on microtubule attachment status, but it remains unclear how their assembly/disassembly is orchestrated. applying 3d structured illumination microscopy to xenopus laevis egg extracts, here we reveal that in the absence of microtubule attachment, proteins responsible for lateral attachment and spindle c ... | 2015 | 26347137 |
| a zinc(ii) photocage based on a decarboxylation metal ion release mechanism for investigating homeostasis and biological signaling. | metal ion signaling in biology has been studied extensively with ortho-nitrobenzyl photocages; however, the low quantum yields and other optical properties are not ideal for these applications. we describe the synthesis and characterization of ntadecage, the first member in a new class of zn(2+) photocages that utilizes a light-driven decarboxylation reaction in the metal ion release mechanism. ntadecage binds zn(2+) with sub-pm affinity using a modified nitrilotriacetate chelator and exhibits a ... | 2015 | 26346802 |
| nf2/merlin is required for the axial pattern formation in the xenopus laevis embryo. | the nf2 gene product merlin is a ferm-domain protein possessing a broad tumor-suppressing function. nf2/merlin has been implicated in regulating multiple signaling pathways critical for cell growth and survival. however, it remains unknown whether nf2/merlin regulates wnt/β-catenin signaling during vertebrate embryogenesis. here we demonstrate that nf2/merlin is required for body pattern formation in the xenopus laevis embryo. depletion of the maternal nf2/merlin enhances organizer gene expressi ... | 2015 | 26344136 |
| histone h2b gene cloning, with implication for its function during nuclear shaping in the chinese mitten crab, eriocheir sinensis. | spermatogenesis in animals is the process by which male spermatogonia develop into mature spermatozoa. in most taxa, the process involves changes in the basic proteins associated with dna. somatic-type histones are partially or totally replaced by transition proteins, which in turn are replaced by protamines producing compact packaging of the genome. sperm chromatin in the chinese mitten crab (eriocheir sinensis) has a noncompacted loosely arranged organization. however, its formation during spe ... | 2016 | 26343795 |
| phosphorylation at serine 52 and 635 does not alter the transport properties of glucosinolate transporter atgtr1. | little is known about how plants regulate transporters of defense compounds. in a. thaliana, glucosinolates are transported between tissues by npf2.10 (atgtr1) and npf2.11 (atgtr2). mining of the phosphat4.0 database showed two cytosol exposed phosphorylation sites for atgtr1 and one membrane-buried phosphorylation site for atgtr2. in this study, we investigate whether mutation of the two potential regulatory sites of atgtr1 affected transport of glucosinolates in xenopus oocytes. characterizati ... | 2016 | 26340317 |