| monna, a potent and selective blocker for transmembrane protein with unknown function 16/anoctamin-1. | transmembrane protein with unknown function 16/anoctamin-1 (ano1) is a protein widely expressed in mammalian tissues, and it has the properties of the classic calcium-activated chloride channel (cacc). this protein has been implicated in numerous major physiological functions. however, the lack of effective and selective blockers has hindered a detailed study of the physiological functions of this channel. in this study, we have developed a potent and selective blocker for endogenous ano1 in xen ... | 2013 | 23997117 |
| a nuclear f-actin scaffold stabilizes ribonucleoprotein droplets against gravity in large cells. | the size of a typical eukaryotic cell is of the order of ∼10 μm. however, some cell types grow to very large sizes, including oocytes (immature eggs) of organisms from humans to starfish. for example, oocytes of the frog xenopus laevis grow to a diameter ≥1 mm. they have a correspondingly large nucleus (germinal vesicle) of ∼450 μm in diameter, which is similar to smaller somatic nuclei, but contains a significantly higher concentration of actin. the form and structure of this nuclear actin rema ... | 2013 | 23995731 |
| d-amino acid oxidase and presence of d-proline in xenopus laevis. | we purified d-amino acid oxidase (ec 1.4.3.3, dao) from xenopus laevis tadpoles. the optimal temperature and ph for enzyme activity were 35-40 °c and 8.3-9.0, respectively, depending on the substrate amino acids available to the enzyme; the highest activity was observed with d-proline followed by d-phenylalanine. activity was significantly inhibited by p-hydroxymercuribenzoate, but only moderately by p-chloromercuribenzoate or benzoate. enzyme activity was increased until the final tadpole stage ... | 2013 | 23994361 |
| propofol modulation of α1 glycine receptors does not require a structural transition at adjacent subunits that is crucial to agonist-induced activation. | pentameric glycine receptors (glyrs) couple agonist binding to activation of an intrinsic ion channel. substitution of the r271 residue impairs agonist-induced activation and is associated with the human disease hyperekplexia. on the basis of a homology model of the α1 glyr, we substituted residues in the vicinity of r271 with cysteines, generating r271c, q226c, and d284c single-mutant glyrs and r271c/q226c and r271c/d284c double-mutant glyrs. we then examined the impact of interactions between ... | 2013 | 23992940 |
| [follicular cells of the amphibian ovary: origin, structure, and functions]. | formation of the follicular envelopes surrounding oocytes in the developing ovary and their subsequent morphological differentiation go hand-in-hand with succession of the steroidogenesis stages, arrest of meiosis and its maintenance, establishment of the conditions necessary for vitellogenesis, oocyte growth, and maturation. metabolites are exchanged via gap junctions and receptor-mediated transport through the perioocytic space. the ion transport in follicular cells (fcs) regulates the plasma ... | 2016 | 25434201 |
| control of dna replication by the nucleus/cytoplasm ratio in xenopus. | the nucleus/cytoplasm (n/c) ratio controls s phase dynamics in many biological systems, most notably the abrupt remodeling of the cell cycle that occurs at the midblastula transition in early xenopus laevis embryos. after an initial series of rapid cleavage cycles consisting only of s and m phases, a critical n/c ratio is reached, which causes a sharp increase in the length of s phase as the cell cycle is reconfigured to resemble somatic cell cycles. how the n/c ratio determines the length of s ... | 2013 | 23986447 |
| attenuation of bone morphogenetic protein signaling during amphibian limb development results in the generation of stage-specific defects. | the vertebrate limb is one of the most intensively studied organs in the field of developmental biology. limb development in tetrapod vertebrates is highly conserved and dependent on the interaction of several important molecular pathways. the bone morphogenetic protein (bmp) signaling cascade is one of these pathways and has been shown to be crucial for several aspects of limb development. here, we have used a xenopus laevis transgenic line, in which expression of the inhibitor noggin is under ... | 2013 | 23981117 |
| xmap215 activity sets spindle length by controlling the total mass of spindle microtubules. | metaphase spindles are microtubule-based structures that use a multitude of proteins to modulate their morphology and function. today, we understand many details of microtubule assembly, the role of microtubule-associated proteins, and the action of molecular motors. ultimately, the challenge remains to understand how the collective behaviour of these nanometre-scale processes gives rise to a properly sized spindle on the micrometre scale. by systematically engineering the enzymatic activity of ... | 2013 | 23974040 |
| physiological concentrations of zinc reduce taurine-activated glyr responses to drugs of abuse. | taurine is an endogenous ligand acting on glycine receptors in many brain regions, including the hippocampus, prefrontal cortex, and nucleus accumbens (nacc). these areas also contain low concentrations of zinc, which is known to potentiate glycine receptor responses. despite an increasing awareness of the role of the glycine receptor in the rewarding properties of drugs of abuse, the possible interactions of these compounds with zinc has not been thoroughly addressed. two-electrode voltage-clam ... | 2013 | 23973295 |
| comparative studies of apoptosis in xenopus laevis and mouse thymoma cell lines. | with the use of in vitro methods and cell lines, functional aspects of apoptosis in the xenopus laevis b3/b7 and mouse el4 thymoma cell lines are revealed. moreover, by using information gleaned from digital imaging and immunocytochemistry, changes in locations of key proteins implicated in apoptotic anti-cancer responses, e.g. p53 and mdm2, are shown. suggestions are offered as to what these results might mean with respect to the evolutionary conservation of the function and structure of these ... | 2013 | 23971701 |
| expression profiling of intestinal tissues implicates tissue-specific genes and pathways essential for thyroid hormone-induced adult stem cell development. | the study of the epithelium during development in the vertebrate intestine touches upon many contemporary aspects of biology: to name a few, the formation of the adult stem cells (ascs) essential for the life-long self-renewal and the balance of stem cell activity for renewal vs cancer development. although extensive analyses have been carried out on the property and functions of the adult intestinal stem cells in mammals, little is known about their formation during development due to the diffi ... | 2013 | 23970787 |
| molecular crowding drives active pin1 into nonspecific complexes with endogenous proteins prior to substrate recognition. | proteins and nucleic acids maintain the crowded interior of a living cell and can reach concentrations in the order of 200-400 g/l which affects the physicochemical parameters of the environment, such as viscosity and hydrodynamic as well as nonspecific strong repulsive and weak attractive interactions. dynamics, structure, and activity of macromolecules were demonstrated to be affected by these parameters. however, it remains controversially debated, which of these factors are the dominant caus ... | 2013 | 23968199 |
| signals governing the trafficking and mistrafficking of a ciliary gpcr, rhodopsin. | rhodopsin is a cilia-specific gpcr essential for vision. rhodopsin mislocalization is associated with blinding diseases called retinal ciliopathies. the mechanism by which rhodopsin mislocalizes in rod photoreceptor neurons is not well understood. therefore, we investigated the roles of trafficking signals in rhodopsin mislocalization. rhodopsin and its truncation mutants were fused to a photoconvertible fluorescent protein, dendra2, and expressed in xenopus laevis rod photoreceptors. photoconve ... | 2013 | 23966685 |
| coarse architecture of the transient receptor potential vanilloid 1 (trpv1) ion channel determined by fluorescence resonance energy transfer. | the transient receptor potential vanilloid 1 ion channel is responsible for the perception of high temperatures and low extracellular ph, and it is also involved in the response to some pungent compounds. importantly, it is also associated with the perception of pain and noxious stimuli. here, we attempt to discern the molecular organization and location of the n and c termini of the transient receptor potential vanilloid 1 ion channel by measuring fret between genetically attached enhanced yell ... | 2013 | 23965996 |
| menthol inhibits 5-ht3 receptor-mediated currents. | the effects of alcohol monoterpene menthol, a major active ingredient of the peppermint plant, were tested on the function of human 5-hydroxytryptamine type 3 (5-ht3) receptors expressed in xenopus laevis oocytes. 5-ht (1 μm)-evoked currents recorded by two-electrode voltage-clamp technique were reversibly inhibited by menthol in a concentration-dependent (ic50 = 163 μm) manner. the effects of menthol developed gradually, reaching a steady-state level within 10-15 minutes and did not involve g-p ... | 2013 | 23965380 |
| [the obtaining and analysis of physiological activity of secreted proteins of noggin family]. | we have developed methods for producing recombinant proteins of noggin family (noggin1 and noggin2 of the xenopus laevis frog) that can interact with bmp factors of tgf-beta superfamily. the genetic constructs which allow one to effectively obtain noggin1 and noggin2 from synthetic mrna microinjected into xenopus laevis early embryos, as well as in the prokaryotic expression system, were generated. the obtained proteins contain three myc-tag epitopes on their n-terminus. this allow one to compar ... | 2013 | 23964527 |
| conformational changes represent the rate-limiting step in the transport cycle of maize sucrose transporter1. | proton-driven suc transporters allow phloem cells of higher plants to accumulate suc to more than 1 m, which is up to ~1000-fold higher than in the surrounding extracellular space. the carrier protein can accomplish this task only because proton and suc transport are tightly coupled. this study provides insights into this coupling by resolving the first step in the transport cycle of the suc transporter sut1 from maize (zea mays). voltage clamp fluorometry measurements combining electrophysiolog ... | 2013 | 23964025 |
| unliganded thyroid hormone receptor regulates metamorphic timing via the recruitment of histone deacetylase complexes. | anuran metamorphosis involves a complex series of tissue transformations that change an aquatic tadpole to a terrestrial frog and resembles the postembryonic perinatal period in mammals. thyroid hormone (th) plays a causative role in amphibian metamorphosis and its effect is mediated by th receptors (trs). molecular analyses during xenopus development have shown that unliganded tr recruits histone deacetylase (hdac)-containing n-cor/smrt complexes and causes histone deacetylation at target genes ... | 2013 | 23962846 |
| differential modulation of brain nicotinic acetylcholine receptor function by cytisine, varenicline, and two novel bispidine compounds: emergent properties of a hybrid molecule. | partial agonist therapies for the treatment of nicotine addiction and dependence depend on both agonistic and antagonistic effects of the ligands, and side effects associated with other nachrs greatly limit the efficacy of nicotinic partial agonists. we evaluated the in vitro pharmacological properties of four partial agonists, two current smoking cessation drugs, varenicline and cytisine, and two novel bispidine compounds, bpc and bmsp, by using defined nachr subtypes expressed in xenopus laevi ... | 2013 | 23959137 |
| dehydration mediated microrna response in the african clawed frog xenopus laevis. | exposure to various environmental stresses induces metabolic rate depression in many animal species, an adaptation that conserves energy until the environment is again conducive to normal life. the african clawed frog, xenopus laevis, is periodically subjected to arid summers in south africa, and utilizes entry into the hypometabolic state of estivation as a mechanism of long term survival. during estivation, frogs must typically deal with substantial dehydration as their ponds dry out and x. la ... | 2013 | 23958654 |
| vestibular lesion-induced developmental plasticity in spinal locomotor networks during xenopus laevis metamorphosis. | during frog metamorphosis, the vestibular sensory system remains unchanged, while spinal motor networks undergo a massive restructuring associated with the transition from the larval to adult biomechanical system. we investigated in xenopus laevis the impact of a pre- (tadpole stage) or post-metamorphosis (juvenile stage) unilateral labyrinthectomy (ul) on young adult swimming performance and underlying spinal locomotor circuitry. the acute disruptive effects on locomotion were similar in both t ... | 2013 | 23951071 |
| nonclassical mhc class i-dependent invariant t cells are evolutionarily conserved and prominent from early development in amphibians. | human and murine mhc nonclassical class ib-restricted invariant t (it) cell subsets, such as invariant natural killer t cells (inkt) and mucosal-associated invariant t cells, have specialized functions early in immune responses, especially in modulating subsequent adaptive immune responses. here, we characterize a prominent it population in the amphibian xenopus laevis and show the requirement of the class ib molecule, xenopus nonclassical gene 10, in its differentiation and function. using xeno ... | 2013 | 23940320 |
| the severe autosomal dominant retinitis pigmentosa rhodopsin mutant ter349glu mislocalizes and induces rapid rod cell death. | mutations in the rhodopsin gene cause approximately one-tenth of retinitis pigmentosa cases worldwide, and most result in endoplasmic reticulum retention and apoptosis. other rhodopsin mutations cause receptor mislocalization, diminished/constitutive activity, or faulty protein-protein interactions. the purpose of this study was to test for mechanisms by which the autosomal dominant rhodopsin mutation ter349glu causes an early, rapid retinal degeneration in patients. the mutation adds an additio ... | 2013 | 23940033 |
| expression and functional characterization of xhmg-at-hook genes in xenopus laevis. | high mobility group a proteins (hmga1 and hmga2) are architectural nuclear factors involved in development, cell differentiation, and cancer formation and progression. here we report the cloning, developmental expression and functional analysis of a new multi-at-hook factor in xenopus laevis (xhmg-at-hook) that exists in three different isoforms. xhmg-at-hook1 and 3 isoforms, but not isoform 2, are expressed throughout the entire development of xenopus, both in the maternal and zygotic phase. lo ... | 2013 | 23936116 |
| crucial residue involved in l-lactate recognition by human monocarboxylate transporter 4 (hmct4). | monocarboxylate transporters (mcts) transport monocarboxylates such as lactate, pyruvate and ketone bodies. these transporters are very attractive therapeutic targets in cancer. elucidations of the functions and structures of mcts is necessary for the development of effective medicine which targeting these proteins. however, in comparison with mct1, there is little information on location of the function moiety of mct4 and which constituent amino acids govern the transport function of mct4. the ... | 2013 | 23935841 |
| characterization of monocarboxylate transporter 6: expression in human intestine and transport of the antidiabetic drug nateglinide. | monocarboxylate transporter (mct) 6, encoded by slc16a5, is a member of the monocarboxylate transporter family. nateglinide, an oral hypoglycemic agent, quickly reaches the maximal serum concentration after its premeal administration. although the functional existence of uptake systems for nateglinide in the intestine has been demonstrated, these transport systems have not yet been identified at the molecular level. the aim of this study was to demonstrate the localization of mct6 in the human s ... | 2013 | 23935065 |
| development: scaling to size by protease inhibition. | the dorsal half of bisected xenopus laevis embryos can regenerate a well-proportioned organism on a smaller scale. a new study indicates that the removal of ventral tissue generates a steeper chordin gradient by reducing sizzled, a secreted inhibitor of tolloid chordinases. | 2013 | 23928082 |
| enhanced hsp30 and hsp70 accumulation in xenopus cells subjected to concurrent sodium arsenite and cadmium chloride stress. | heat shock proteins (hsps) are molecular chaperones that aid in protein folding, translocation and in preventing stress-induced protein aggregation. the present study examined the effect of simultaneous sodium arsenite and cadmium chloride treatment on the pattern of hsp30 and hsp70 accumulation in a6 kidney epithelial cells of the frog, xenopus laevis. immunoblot analysis revealed that hsp30 and hsp70 accumulation in concurrent stressor treatments were significantly higher than the sum of hsp30 ... | 2013 | 23919948 |
| blastocoel-spanning filopodia in cleavage-stage xenopus laevis: potential roles in morphogen distribution and detection. | in the frog xenopus laevis, dorsal-ventral axis specification involves cytoskeleton-dependent transport of localized transcripts and proteins during the first cell cycle, and activation of the canonical wnt pathway to locally stabilize translated beta-catenin which, by as early as the 32-cell stage, commits nuclei in prospective dorsal lineages to the subsequent expression of dorsal target genes. maternal ligands important for activating this dorsal-specific signaling pathway are thought to inte ... | 2013 | 23916849 |
| titration of four replication factors is essential for the xenopus laevis midblastula transition. | the rapid, reductive early divisions of many metazoan embryos are followed by the midblastula transition (mbt), during which the cell cycle elongates and zygotic transcription begins. it has been proposed that the increasing nuclear to cytoplasmic (n/c) ratio is critical for controlling the events of the mbt. we show that four dna replication factors--cut5, recq4, treslin, and drf1--are limiting for replication initiation at increasing n/c ratios in vitro and in vivo in xenopus laevis. the level ... | 2013 | 23907533 |
| effects of perfluorooctanesulfonate and perfluorobutanesulfonate on the growth and sexual development of xenopus laevis. | perfluorobutanesulfonate (pfbs), as a substitute for perfluorooctanesulfonate (pfos), is widespread in the environment and biotic samples as well as pfos. to investigate effects of pfos and pfbs on the growth and sexual development of amphibians, we exposed xenopus laevis tadpoles at a series of concentrations of pfos and pfbs (0.1; 1; 100; 1,000 μg/l) as well as 17-beta-estradiol (e2, 100 ng/l) and 5 alpha-androstan-17-beta-ol-3-one (dht, 100 ng/l) from stage 46/47 to 2 months postmetamorphosis ... | 2013 | 23907449 |
| the phosphoinositide sensitivity of the k(v) channel family. | recently, we screened several kv channels for possible dependence on plasma membrane phosphatidylinositol 4,5-bisphosphate (pi(4,5)p 2). the channels were expressed in tsa-201 cells and the pi(4,5)p 2 was depleted by several manipulations in whole-cell experiments with parallel measurements of channel activity. in contrast to reports on excised-patches using xenopus laevis oocytes, we found only kv 7, but none of the other tested kv channels, to be strongly dependent on pi(4,5)p 2. we now have e ... | 2017 | 23907203 |
| bulk electroporation of retinal ganglion cells in live xenopus tadpoles. | individual neurons in the developing nervous system of xenopus laevis can be visualized by the targeted delivery of a fluorophore. the fluorophore can be delivered as a fluorescent dye or dna that encodes a fluorescent protein. local iontophoresis is a method that works well for transfer of fluorescent dye to retinal ganglion cells (rgcs) in the eye, but it does not give a high yield for delivery of dna. this is largely because the degree of pigmentation of the eyes, even in albino strains, make ... | 2013 | 23906915 |
| dye labeling retinal ganglion cell axons in live xenopus tadpoles. | individual neurons in the developing nervous system can be visualized by the targeted delivery of a fluorophore. in this article, we describe a method for introducing a fluorescent dye via iontophoresis into retinal ganglion cell (rgc) axons in albino xenopus laevis tadpoles. iontophoresis is the enhanced permeation of molecules across biological membranes under the influence of an electrical field. lipophilic dyes such as dii are well suited to this method--being insoluble in the aqueous enviro ... | 2013 | 23906914 |
| ontogenesis of the extra-bulbar olfactory pathway in xenopus laevis. | although the development, anatomy, and physiology of the vertebrate olfactory system are fairly well understood, there is still no clear definition of the terminal nerve complex acknowledged by all. among the most debated matters is whether or not the extrabulbar projections found in anamniotes should or should not be considered part of the terminal nerve complex. in this context, we investigated the early development of the extrabulbar pathway in xenopus larvae from placodal differentiation to ... | 2013 | 23904212 |
| an externally accessible linker region in the sodium-coupled phosphate transporter pit-1 (slc20a1) is important for transport function. | members of the slc20 cotransporter family (pit-1, pit-2) are ubiquitously expressed in mammalian tissue and are thought to perform housekeeping functions for intracellular pi homeostasis as well as being implicated in vascular calcification and renal pi reabsorption. the aims of this study were to investigate the topology of a linker region in pit-1 between the predicted 2(nd) and 3(rd) transmembrane domains and to investigate the functional consequences of cysteine substitutions in this region. | 2013 | 23899881 |
| neurotoxic unc-8 mutants encode constitutively active deg/enac channels that are blocked by divalent cations. | ion channels of the deg/enac family can induce neurodegeneration under conditions in which they become hyperactivated. the caenorhabditis elegans deg/enac channel mec-4(d) encodes a mutant channel with a substitution in the pore domain that causes swelling and death of the six touch neurons in which it is expressed. dominant mutations in the c. elegans deg/enac channel subunit unc-8 result in uncoordinated movement. here we show that this unc-8 movement defect is correlated with the selective de ... | 2013 | 23898007 |
| peptidomic analysis of skin secretions provides insight into the taxonomic status of the african clawed frogs xenopus victorianus and xenopus laevis sudanensis (pipidae). | peptidomic analysis was used to compare the distribution of host-defense peptides in norepinephrine-stimulated skin secretions from xenopus victorianusahl, 1924 (also described as the subspecies x. laevis victorianus) and xenopus laevis sudanensisperret, 1966 with the previously determined distributions in xenopus laevis (daudin, 1802) and xenopus petersii bocage, 1895. peptides belonging to the magainin, peptide glycine-leucine-amide (pgla), and caerulein precursor fragment (cpf) families were ... | 2013 | 23896465 |
| the structure and development of xenopus laevis cornea. | the african clawed frog, xenopus laevis, is a widely used model organism for tissue development. we have followed the process of corneal development closely in xenopus and examined the corneal ultrastructure at each stage during its formation. xenopus cornea development starts at stage 25 from a simple embryonic epidermis overlying the developing optic vesicle. after detachment of the lens placode which takes place around stage 30, cranial neural crest cells start to invade the space between the ... | 2013 | 23896054 |
| bcstx3 is a founder of a novel sea anemone toxin family of potassium channel blocker. | sea anemone venoms have become a rich source of peptide toxins which are invaluable tools for studying the structure and functions of ion channels. in this work, bcstx3, a toxin found in the venom of a bunodosoma caissarum (population captured at the saint peter and saint paul archipelago, brazil) was purified and biochemically and pharmacologically characterized. the pharmacological effects were studied on 12 different subtypes of voltage-gated potassium channels (k(v)1.1-k(v)1.6; k(v)2.1; k(v) ... | 2013 | 23895459 |
| xepac protein and ip3/ca2+ pathway implication during xenopus laevis vitellogenesis. | the objective of this study was to elucidate the signalling pathways initiated by camp once inside the xenopus laevis oocyte, where it triggers and maintains vitellogenin endocytic uptake. our results showed the presence of xepac transcripts at all stages of oogenesis and we demonstrated that a camp analogue that exclusively activates xepac, 8-cpt, was able to rescue the endocytic activity in oocytes with uncoupled gap junctions. inhibition experiments for the ip3/ca2+ signalling pathway showed ... | 2015 | 23890344 |
| single blastomere expression profiling of xenopus laevis embryos of 8 to 32-cells reveals developmental asymmetry. | we have measured the expression of 41 maternal mrnas in individual blastomeres collected from the 8 to 32-cell xenopus laevis embryos to determine when and how asymmetry in the body plan is introduced. we demonstrate that the asymmetry along the animal-vegetal axis in the oocyte is transferred to the daughter cells during early cell divisions. all studied mrnas are distributed evenly among the set of animal as well as vegetal blastomeres. we find no asymmetry in mrna levels that might be ascribe ... | 2013 | 23880666 |
| the retinal pigment epithelium: an important player of retinal disorders and regeneration. | the retinal pigment epithelium (rpe) is a partner of the neural retina and is indispensable for vision. in humans, proliferation and transformation (cell-type switching) of rpe cells after a traumatic injury of the neural retina causes a retinal disorder leading to loss of vision. in contrast, in certain adult amphibians such as xenopus laevis and the newt, a similar process in rpe cells leads to regeneration of the entire retina. in this review, on the basis of accumulating evidence in basic bi ... | 2014 | 23880527 |
| sox4 and sox11 function during xenopus laevis eye development. | soxc genes are involved in many developmental processes such as cardiac, lymphoid, and bone development. the soxc gene family is represented by sox4, sox11, and sox12. loss of either sox4 or sox11 function is lethal during mouse embryogenesis. here, we demonstrate that sox4 and sox11 are strongly expressed in the developing eye, heart as well as brain in xenopus laevis. morpholino oligonucleotide mediated knock-down approaches in anterior neural tissue revealed that interference with either sox4 ... | 2013 | 23874955 |
| interrogating transcriptional regulatory sequences in tol2-mediated xenopus transgenics. | identifying gene regulatory elements and their target genes in vertebrates remains a significant challenge. it is now recognized that transcriptional regulatory sequences are critical in orchestrating dynamic controls of tissue-specific gene expression during vertebrate development and in adult tissues, and that these elements can be positioned at great distances in relation to the promoters of the genes they control. while significant progress has been made in mapping dna binding regions by com ... | 2013 | 23874664 |
| germes is involved in translocation of germ plasm during development of xenopus primordial germ cells. | germes mrna and protein are components of the germ plasm in xenopus laevis. previously, based on phenotypic observations of tailbud embryos expressing intact and mutant germes, it was suggested that germes is involved in the organization of germ plasm (berekelya et al., 2007). recently, to observe the germ plasm in a living embryo, we generated transgenic xenopus expressing egfp fused with a mitochondrial targeting signal, because germ plasm is enriched with mitochondria (taguchi et al., 2012). ... | 2013 | 23873375 |
| melanocortin mc(4) receptor-mediated feeding and grooming in rodents. | decades ago it was recognized that the pharmacological profile of melanocortin ligands that stimulated grooming behavior in rats was strikingly similar to that of xenopus laevis melanophore pigment dispersion. after cloning of the melanocortin mc1 receptor, expressed in melanocytes, and the melanocortin mc4 receptor, expressed mainly in brain, the pharmacological profiles of these receptors appeared to be very similar and it was demonstrated that these receptors mediate melanocortin-induced pigm ... | 2013 | 23872405 |
| when size does matter: organelle size influences the properties of transport mediated by molecular motors. | organelle transport is driven by the action of molecular motors. in this work, we studied the dynamics of organelles of different sizes with the aim of understanding the complex relation between organelle motion and microenvironment. | 2013 | 23872153 |
| differential expression and novel permeability properties of three aquaporin 8 paralogs from seawater-challenged atlantic salmon smolts. | aquaporins may facilitate transepithelial water absorption in the intestine of seawater (sw)-acclimated fish. here we have characterized three full-length aqp8 paralogs from atlantic salmon (salmo salar). bayesian inference revealed that each paralog is a representative of the three major classes of aqp8aa, aqp8ab and aqp8b genes found in other teleosts. the permeability properties were studied by heterologous expression in xenopus laevis oocytes, and the expression levels examined by qpcr, immu ... | 2013 | 23868847 |
| mitotic trigger waves and the spatial coordination of the xenopus cell cycle. | despite the large size of the xenopus laevis egg (approximately 1.2 mm diameter), a fertilized egg rapidly proceeds through mitosis in a spatially coordinated fashion. mitosis is initiated by a bistable system of regulatory proteins centred on cdk1 (refs 1, 2), raising the possibility that this spatial coordination could be achieved through trigger waves of cdk1 activity. using an extract system that performs cell cycles in vitro, here we show that mitosis does spread through xenopus cytoplasm v ... | 2013 | 23863935 |
| mras gtpase is a novel stemness marker that impacts mouse embryonic stem cell plasticity and xenopus embryonic cell fate. | pluripotent mouse embryonic stem cells (mescs), maintained in the presence of the leukemia inhibitory factor (lif) cytokine, provide a powerful model with which to study pluripotency and differentiation programs. extensive microarray studies on cultured cells have led to the identification of three lif signatures. here we focus on muscle ras oncogene homolog (mras), which is a small gtpase of the ras family encoded within the pluri gene cluster. to characterise the effects of mras on cell plurip ... | 2013 | 23863483 |
| chromatin dynamics at the htert promoter during transcriptional activation and repression by c-myc and mnt in xenopus leavis oocytes. | the transcription factors c-myc and mnt regulate gene expression through dimerization with max and binding to e-boxes in target genes. while c-myc activates gene expression via recruitment of histone modifying complexes, mnt acts as a transcriptional repressor. here, we used the xenopus leavis oocyte system to address the effect of c-myc and mnt on transcription and chromatin remodeling over the e-box region in the human telomerase reverse transcriptase (htert) promoter. as expected we found ele ... | 2013 | 23860446 |
| rna-binding protein vg1rbp regulates terminal arbor formation but not long-range axon navigation in the developing visual system. | local synthesis of β-actin is required for attractive turning responses to guidance cues of growth cones in vitro but its functional role in axon guidance in vivo is poorly understood. the transport and translation of β-actin mrna is regulated by the rna-binding protein, vg1rbp (zipcode-binding protein-1). to examine whether vg1rbp plays a role in axon navigation in vivo, we disrupted vg1rbp function in embryonic xenopus laevis retinal ganglion cells by expressing a dominant-negative vg1rbp and ... | 2014 | 23853158 |
| production of xenopus tropicalis egg extracts to identify microtubule-associated rnas. | many organisms localize mrnas to specific subcellular destinations to spatially and temporally control gene expression. recent studies have demonstrated that the majority of the transcriptome is localized to a nonrandom position in cells and embryos. one approach to identify localized mrnas is to biochemically purify a cellular structure of interest and to identify all associated transcripts. using recently developed high-throughput sequencing technologies it is now straightforward to identify a ... | 2013 | 23851481 |
| evidence and uptake routes for zinc oxide nanoparticles through the gastrointestinal barrier in xenopus laevis. | the developmental toxicity of nanostructured materials, as well as their impact on the biological barriers, represents a crucial aspect to be assessed in a nanosafety policy framework. nanosized metal oxides have been demonstrated to affect xenopus laevis embryonic development, with nzno specifically targeting the digestive system. to study the mechanisms of the nzno-induced intestinal lesions, we tested two different nominally sized zno nanoparticles (nps) at effective concentrations. advanced ... | 2014 | 23848496 |
| cargo transport by cytoplasmic dynein can center embryonic centrosomes. | to complete meiosis ii in animal cells, the male dna material needs to meet the female dna material contained in the female pronucleus at the egg center, but it is not known how the male pronucleus, deposited by the sperm at the periphery of the cell, finds the cell center in large eggs. pronucleus centering is an active process that appears to involve microtubules and molecular motors. for small and medium-sized cells, the force required to move the centrosome can arise from either microtubule ... | 2013 | 23840877 |
| transport of xanthurenic acid by rat/human organic anion transporters oat1 and oat3. | kynurenic acid, a tryptophan metabolite, is involved in psychiatric disease. our laboratory previously described its transport by rat/human organic anion transporters roat1, hoat1, roat3 and hoat3, which are involved in drug disposition. in this study, we performed an uptake experiment using xenopus laevis oocytes to examine the transport of xanthurenic acid, a tryptophan catabolite and kynurenic acid analog, by various transporters. all the transporters tested stimulated the uptake of xanthuren ... | 2013 | 23832370 |
| a novel method for induction of pairing in xenopus by addition of steroids into the water. | the african clawed frog, xenopus laevis, is widely used in biological studies. ovulation of xenopus is normally induced by the injection of human chorionic gonadotropin (hcg) into the dorsal lymph sac of fully-grown female frogs. previously, we reported a novel method for inducing xenopus ovulation by adding a mixture of steroids into the surrounding water. in the present study, we demonstrate how to induce reproductive behavior in male frogs using the same methodology. the types and concentrati ... | 2013 | 23829209 |
| functional properties of a newly cloned fish ortholog of the neutral amino acid transporter b0at1 (slc6a19). | the functional properties of an ortholog of the b(0)at1 (slc6a19) amino acid transporter, cloned from the intestine of the sea bass dicentrachus labrax, were investigated. the two-electrode voltage-clamp technique was applied to xenopus laevis oocytes heterologously expressing the transporter in order to measure the currents associated with the transport process in different conditions. in particular the substrate specificity, the ionic requirements, and possible effects of ph were examined. amo ... | 2013 | 23827520 |
| in vivo endocrine disruption assessment of wastewater treatment plant effluents with small organisms. | surface water receives a variety of micro-pollutants that could alter aquatic organisms' reproduction and development. it is known that a few nanograms per litre of these compounds can induce endocrine-disrupting effects in aquatic species. many compounds are released daily in wastewater, and identifying the compounds responsible for inducing such disruption is difficult. methods using biological analysis are therefore an alternative to chemical analysis, as the endocrine disruption potential of ... | 2013 | 23823564 |
| homoeologous chromosomes of xenopus laevis are highly conserved after whole-genome duplication. | it has been suggested that whole-genome duplication (wgd) occurred twice during the evolutionary process of vertebrates around 450 and 500 million years ago, which contributed to an increase in the genomic and phenotypic complexities of vertebrates. however, little is still known about the evolutionary process of homoeologous chromosomes after wgd because many duplicate genes have been lost. therefore, xenopus laevis (2n=36) and xenopus (silurana) tropicalis (2n=20) are good animal models for st ... | 2013 | 23820579 |
| the centriolar satellite protein ssx2ip promotes centrosome maturation. | meiotic maturation in vertebrate oocytes is an excellent model system for microtubule reorganization during m-phase spindle assembly. here, we surveyed changes in the pattern of microtubule-interacting proteins upon xenopus laevis oocyte maturation by quantitative proteomics. we identified the synovial sarcoma x breakpoint protein (ssx2ip) as a novel spindle protein. using x. laevis egg extracts, we show that ssx2ip accumulated at spindle poles in a dynein-dependent manner and interacted with th ... | 2013 | 23816619 |
| transmembrane water-flux through slc4a11: a route defective in genetic corneal diseases. | three genetic corneal dystrophies [congenital hereditary endothelial dystrophy type 2 (ched2), harboyan syndrome and fuchs endothelial corneal dystrophy] arise from mutations of the slc4a11 gene, which cause blindness from fluid accumulation in the corneal stroma. selective transmembrane water conductance controls cell size, renal fluid reabsorption and cell division. all known water-channelling proteins belong to the major intrinsic protein family, exemplified by aquaporins (aqps). here we iden ... | 2013 | 23813972 |
| cell segregation, mixing, and tissue pattern in the spinal cord of the xenopus laevis neurula. | during xenopus laevis neurulation, neural ectodermal cells of the spinal cord are patterned at the same time that they intercalate mediolaterally and radially, moving within and between two cell layers. curious if these rearrangements disrupt early cell identities, we lineage-traced cells in each layer from neural plate stages to the closed neural tube, and used in situ hybridization to assay gene expression in the moving cells. | 2013 | 23813905 |
| the melanocyte photosensory system in the human skin. | the pigment cells form the largest population of neural crest cells to migrate into the epidermis and hair follicle along each dermatomic area from the neural folds. the melanopsin system responsible for photoentrainment, was isolated from the photosensitive dermal melanophores of frogs xenopus laevis responding to light. melanocytes form a photoresponsive network which reads the environmental seasonal variations in the light cycles in the same manner. the present work was undertaken to study th ... | 2013 | 23807911 |
| preparation of developing xenopus muscle for sarcomeric protein localization by high-resolution imaging. | mutations in several sarcomeric proteins have been linked to various human myopathies. therefore, having an in vivo developmental model available that develops quickly and efficiently is key for investigators to elucidate the critical steps, components and signaling pathways involved in building a myofibril; this is the pivotal foundation for deciphering disease mechanisms as well as the development of myopathy-related therapeutics. although striated muscle cell culture studies have been extreme ... | 2014 | 23806641 |
| anks6 is a central component of a nephronophthisis module linking nek8 to invs and nphp3. | nephronophthisis is an autosomal recessive cystic kidney disease that leads to renal failure in childhood or adolescence. most nphp gene products form molecular networks. here we identify anks6 as a new nphp family member that connects nek8 (nphp9) to invs (nphp2) and nphp3. we show that anks6 localizes to the proximal cilium and confirm its role in renal development through knockdown experiments in zebrafish and xenopus laevis. we also identify six families with anks6 mutations affected by neph ... | 2013 | 23793029 |
| thermal mechanisms of millimeter wave stimulation of excitable cells. | interactions between millimeter waves (mmws) and biological systems have received increasing attention due to the growing use of mmw radiation in technologies ranging from experimental medical devices to telecommunications and airport security. studies have shown that mmw exposure alters cellular function, especially in neurons and muscles. however, the biophysical mechanisms underlying such effects are still poorly understood. due to the high aqueous absorbance of mmw, thermal mechanisms are li ... | 2013 | 23790370 |
| crystal structure of a human iκb kinase β asymmetric dimer. | phosphorylation of inhibitor of nuclear transcription factor κb (iκb) by iκb kinase (ikk) triggers the degradation of iκb and migration of cytoplasmic κb to the nucleus where it promotes the transcription of its target genes. activation of ikk is achieved by phosphorylation of its main subunit, ikkβ, at the activation loop sites. here, we report the 2.8 å resolution crystal structure of human ikkβ (hikkβ), which is partially phosphorylated and bound to the staurosporine analog k252a. the hikkβ p ... | 2013 | 23792959 |
| rna-seq in the tetraploid xenopus laevis enables genome-wide insight in a classic developmental biology model organism. | advances in sequencing technology have significantly advanced the landscape of developmental biology research. the dissection of genetic networks in model and non-model organisms has been greatly enhanced with high-throughput sequencing technologies. rna-seq has revolutionized the ability to perform developmental biology research in organisms without a published genome sequence. here, we describe a protocol for developmental biologists to perform rna-seq on dissected tissue or whole embryos. we ... | 2014 | 23792920 |
| characterization of the mouse clc-k1/barttin chloride channel. | several cl(-) channels have been described in the native renal tubule, but their correspondence with clc-k1 and clc-k2 channels (orthologs of human clc-ka and clc-kb), which play a major role in transcellular cl(-) absorption in the kidney, has yet to be established. this is partly because investigation of heterologous expression has involved rat or human clc-k models, whereas characterization of the native renal tubule has been done in mice. here, we investigate the electrophysiological propert ... | 2013 | 23791703 |
| high efficiency talens enable f0 functional analysis by targeted gene disruption in xenopus laevis embryos. | recently, gene editing with transcription activator-like effector nucleases (talens) has been used in the life sciences. talens can be easily customized to recognize a specific dna sequence and efficiently introduce double-strand breaks at the targeted genomic locus. subsequent non-homologous end-joining repair leads to targeted gene disruption by base insertion, deletion, or both. here, to readily evaluate the efficacy of talens in xenopus laevis embryos, we performed the targeted gene disrupti ... | 2013 | 23789092 |
| depletion of uhrf1 inhibits chromosomal dna replication in xenopus egg extracts. | uhrf1 (ubiquitin-like, containing phd and ring finger domains 1) has a well-established role in epigenetic regulation through the recognition of various histone marks and interaction with chromatin-modifying proteins. however, its function in regulating cell cycle progression remains poorly understood and has been largely attributed to a role in transcriptional regulation. in this study we have used xenopus laevis egg extracts to analyse uhrf1 function in dna replication in the absence of transc ... | 2013 | 23788677 |
| rna-binding protein hermes/rbpms inversely affects synapse density and axon arbor formation in retinal ganglion cells in vivo. | the rna-binding protein hermes [rna-binding protein with multiple splicing (rbpms)] is expressed exclusively in retinal ganglion cells (rgcs) in the cns, but its function in these cells is not known. here we show that hermes protein translocates in granules from rgc bodies down the growing axons. hermes loss of function in both xenopus laevis and zebrafish embryos leads to a significant reduction in retinal axon arbor complexity in the optic tectum, and expression of a dominant acting mutant her ... | 2013 | 23785151 |
| intranuclear dna density affects chromosome condensation in metazoans. | chromosome condensation is critical for accurate inheritance of genetic information. the degree of condensation, which is reflected in the size of the condensed chromosomes during mitosis, is not constant. it is differentially regulated in embryonic and somatic cells. in addition to the developmentally programmed regulation of chromosome condensation, there may be adaptive regulation based on spatial parameters such as genomic length or cell size. we propose that chromosome condensation is affec ... | 2013 | 23783035 |
| differential role of pten phosphatase in chemotactic growth cone guidance. | negatively targeting the tumor suppressor and phosphoinositide phosphatase pten (phosphatase and tensin homologue) promotes axon regrowth after injury. how pten functions in axon guidance has remained unknown. here we report the differential role of pten in chemotactic guidance of axonal growth cones. down-regulating pten expression in xenopus laevis spinal neurons selectively abolished growth cone chemorepulsion but permitted chemoattraction. these findings persisted during camp-dependent switc ... | 2013 | 23775074 |
| mctp2 is a dosage-sensitive gene required for cardiac outflow tract development. | coarctation of the aorta (coa) and hypoplastic left heart syndrome (hlhs) have been reported in rare individuals with large terminal deletions of chromosome 15q26. however, no single gene important for left ventricular outflow tract (lvot) development has been identified in this region. using array-comparative genomic hybridization, we identified two half-siblings with coa with a 2.2 mb deletion on 15q26.2, inherited from their mother, who was mosaic for this deletion. this interval contains an ... | 2013 | 23773997 |
| proteomic analysis of early reprogramming events in murine somatic cells incubated with xenopus laevis oocyte extracts demonstrates network associations with induced pluripotency markers. | the reprogramming of somatic cells into a pluripotent/embryonic-like state holds great potential for regenerative medicine, bypassing ethical issues associated with embryonic stem cells (escs). numerous methods, including somatic cell nuclear transfer (scnt), fusion to pluripotent cells, the use of cell extracts, and expression of transcription factors, have been used to reprogram cells into es-like cells [termed induced pluripotent stem cells (ipscs)]. this study investigated early events in th ... | 2013 | 23768116 |
| imaging of xenopus laevis oocyte plasma membrane in physiological-like conditions by atomic force microscopy. | xenopus laevis oocytes are an interesting model for the study of many developmental mechanisms because of their dimensions and the ease with which they can be manipulated. in addition, they are widely employed systems for the expression and functional study of heterologous proteins, which can be expressed with high efficiency on their plasma membrane. here we applied atomic force microscopy (afm) to the study of the plasma membrane of x. laevis oocytes. in particular, we developed and optimized ... | 2013 | 23745574 |
| aqf026 is a pharmacologic agonist of the water channel aquaporin-1. | aquaporin-1 (aqp1) facilitates the osmotic transport of water across the capillary endothelium, among other cell types, and thereby has a substantial role in ultrafiltration during peritoneal dialysis. at present, pharmacologic agents that enhance aqp1-mediated water transport, which would be expected to increase the efficiency of peritoneal dialysis, are not available. here, we describe aqf026, an aquaporin agonist that is a chemical derivative of the arylsulfonamide compound furosemide. in the ... | 2013 | 23744886 |
| two recombinant α-like scorpion toxins from mesobuthus eupeus with differential affinity toward insect and mammalian na(+) channels. | α-scorpion toxins are modulators of voltage-gated na(+) channels (navs), which bind to the receptor site 3 to inhibit the fast inactivation of the channels. meunatxα-12 and meunatxα-13 are two new α-scorpion toxin-like peptides identified by cdna cloning from the scorpion mesobuthus eupeus with unknown functions. here, we report their recombinant production, oxidative refolding, structural and functional features. by in vitro renaturation from bacterial inclusion bodies and further purification ... | 2013 | 23743216 |
| retinoic acid-activated ndrg1a represses wnt/β-catenin signaling to allow xenopus pancreas, oesophagus, stomach, and duodenum specification. | how cells integrate multiple patterning signals to achieve early endoderm regionalization remains largely unknown. between gastrulation and neurulation, retinoic acid (ra) signaling is required, while wnt/β-catenin signaling has to be repressed for the specification of the pancreas, oesophagus, stomach, and duodenum primordia in xenopus embryos. in attempt to screen for ra regulated genes in xenopus endoderm, we identified a direct ra target gene, n-myc downstream regulated gene 1a (ndrg1a) that ... | 2013 | 23741453 |
| the nuclear f-actin interactome of xenopus oocytes reveals an actin-bundling kinesin that is essential for meiotic cytokinesis. | nuclei of xenopus laevis oocytes grow 100 000-fold larger in volume than a typical somatic nucleus and require an unusual intranuclear f-actin scaffold for mechanical stability. we now developed a method for mapping f-actin interactomes and identified a comprehensive set of f-actin binders from the oocyte nuclei. unexpectedly, the most prominent interactor was a novel kinesin termed nabkin (nuclear and meiotic actin-bundling kinesin). nabkin not only binds microtubules but also f-actin structure ... | 2013 | 23727888 |
| the proteomic profile of stichodactyla duerdeni secretion reveals the presence of a novel o-linked glycopeptide. | sea anemones represent one of the emerging groups of interest concerning venomous animals in toxinology and the goal of the present work was the prospection, and the structural and functional characterization of the compounds present in the secretion of the sea anemone stichodactyla duerdeni from brazilian coast. we used a combination of offline rpc-maldi-tof and online nano-rpc-esi-ltq-orbitrap proteomic techniques as well as functional bioassays. the mucus was milked by electric stimulation an ... | 2013 | 23727489 |
| potassium-chloride cotransporter 3 interacts with vav2 to synchronize the cell volume decrease response with cell protrusion dynamics. | loss-of-function of the potassium-chloride cotransporter 3 (kcc3) causes hereditary motor and sensory neuropathy with agenesis of the corpus callosum (hmsn/acc), a severe neurodegenerative disease associated with defective midline crossing of commissural axons in the brain. conversely, kcc3 over-expression in breast, ovarian and cervical cancer is associated with enhanced tumor cell malignancy and invasiveness. we identified a highly conserved proline-rich sequence within the c-terminus of the c ... | 2013 | 23724134 |
| fshd muscular dystrophy region gene 1 binds suv4-20h1 histone methyltransferase and impairs myogenesis. | facioscapulohumeral muscular dystrophy (fshd) is an autosomal dominant myopathy with a strong epigenetic component. it is associated with deletion of a macrosatellite repeat leading to over-expression of the nearby genes. among them, we focused on fshd region gene 1 (frg1) since its over-expression in mice, xenopus laevis and caenorhabditis elegans, leads to muscular dystrophy-like defects, suggesting that frg1 plays a relevant role in muscle biology. here we show that, when over-expressed, frg1 ... | 2013 | 23720823 |
| 2-aminoethoxydiphenyl borate activates the mechanically gated human kcnk channels kcnk 2 (trek-1), kcnk 4 (traak), and kcnk 10 (trek-2). | two-pore domain k(+) (kcnk, k2p) channels underlie the "leak" (background) potassium conductance in many types of excitable cells. they oppose membrane depolarization and cell excitability. these channels have been reported to be modulated by several physical and chemical stimuli. the compound 2-aminoethoxydiphenyl borate (2-apb) was originally described as an inhibitor of ip3-induced ca(2+) release but has been shown to act as either a blocker or an activator for several ion channels. here, we ... | 2013 | 23720627 |
| the polarization of the g-protein activated potassium channel girk5 to the vegetal pole of xenopus laevis oocytes is driven by a di-leucine motif. | the g protein-coupled inwardly-rectifying potassium channels (known as girk or kir3) form functional heterotetramers gated by g-βγ subunits. girk channels participate in heart rate modulation and neuronal postsynaptic inhibition in mammals. in xenopus laevis oocytes, girk5 is a functional homomultimer. previously, we found that phosphorylation of a tyrosine (y16) at its n-terminus downregulates the surface expression of girk5. in this work, we elucidated the subcellular localization and traffick ... | 2013 | 23717539 |
| the cloning of a frog. | it is relatively unusual for the nobel prize in physiology or medicine to be made, to a large extent, on the basis of a single author paper, published over 50 years ago, for work carried out by a graduate student. this was largely true of a paper published in 1962 in the journal development (called at that time the journal of embryology and experimental morphology). the main subject of that paper was the production of normal tadpoles from the nuclei of intestinal epithelium cells of xenopus laev ... | 2013 | 23715536 |
| the hypoxia factor hif-1α controls neural crest chemotaxis and epithelial to mesenchymal transition. | one of the most important mechanisms that promotes metastasis is the stabilization of hif-1 (hypoxia-inducible transcription factor 1). we decided to test whether hif-1α also was required for early embryonic development. we focused our attention on the development of the neural crest, a highly migratory embryonic cell population whose behavior has been likened to cancer metastasis. inhibition of hif-1α by antisense morpholinos in xenopus laevis or zebrafish embryos led to complete inhibition of ... | 2013 | 23712262 |
| differential muscle regulatory factor gene expression between larval and adult myogenesis in the frog xenopus laevis: adult myogenic cell-specific myf5 upregulation and its relation to the notochord suppression of adult muscle differentiation. | during xenopus laevis metamorphosis, larval-to-adult muscle conversion depends on the differential responses of adult and larval myogenic cells to thyroid hormone. essential differences in cell growth, differentiation, and hormone-dependent life-or-death fate have been reported between cultured larval (tail) and adult (hindlimb) myogenic cells. a previous study revealed that tail notochord cells suppress terminal differentiation in adult (but not larval) myogenic cells. however, little is known ... | 2013 | 23708921 |
| novel clcnkb mutations causing bartter syndrome affect channel surface expression. | mutations in the clcnkb gene encoding the clc-kb cl(-) channel cause bartter syndrome, which is a salt-losing renal tubulopathy. here, we investigate the functional consequences of seven mutations. when expressed in xenopus laevis oocytes, four mutants carried no current (c.736g>c, p.gly246arg; c.1271g>a, p.gly424glu; c.1313g>a, p.arg438his; c.1316t>c, p.leu439pro), whereas others displayed a 30%-60% reduction in conductance as compared with wild-type clc-kb (c.242t>c, p.leu81pro; c.274c>t, p.ar ... | 2013 | 23703872 |
| chemical activation of rarβ induces post-embryonically bilateral limb duplication during xenopus limb regeneration. | the anuran amphibian xenopus laevis can regenerate its limbs for a limited time during the larval stage, while limbs are still developing. using this regeneration model, we evaluated the proximo-distal blastema cell identity when endogenous retinoids were increased by cyp26 inhibition or when rar-specific agonists altered ra signaling. simultaneous proximo-distal and antero-posterior limb duplications were generated, and the rar-specific agonist can modify blastema identity after amputation, bec ... | 2013 | 23703360 |
| functional modulation of the glutamate transporter variant glt1b by the pdz domain protein pick1. | the dominant glutamate transporter isoform in the mammalian brain, glt1, exists as at least three splice variants, glt1a, glt1b, and glt1c. glt1b interacts with the scaffold protein pick1 (protein interacting with kinase c1), which is implicated in glutamatergic neurotransmission via its regulatory effect on trafficking of ampa-type glutamate receptors. the 11 extreme c-terminal residues specific for the glt1b variant are essential for its specific interaction with the pick1 pdz domain, but a fu ... | 2013 | 23697999 |
| ifasp: combining isobaric mass tagging with filter-aided sample preparation. | careful, clean and controlled preparation of samples for mass spectrometry proteomics is crucial to obtain reproducible and reliable data. this is especially important when carrying out quantitative proteomics by chemical isobaric labeling (aka tandem mass tagging), since the differentially labeled samples are combined quite late during the sample processing. addressing this need for robust and reliable sample processing for quantitative proteomics, we describe here ifasp, a simple protocol for ... | 2013 | 23692318 |
| lethal and sublethal effects of three insecticides on two developmental stages of xenopus laevis and comparison with other amphibians. | it has been suggested that xenopus laevis is less sensitive than other amphibians to some chemicals, and therefore, that the frog embryo teratogenesis assay-xenopus (fetax) may have limited use in risk assessments for other amphibians. however, comparisons are based mostly on results of fetax, which emphasizes embryos. larval x. laevis may be more sensitive to chemicals than embryos and may serve as a better life stage in risk assessments. the present study was conducted to determine the lethal ... | 2013 | 23686650 |
| the cytoskeletal protein zyxin inhibits shh signaling during the cns patterning in xenopus laevis through interaction with the transcription factor gli1. | zyxin is a cytoskeletal protein that controls cell movements by regulating actin filaments assembly, but it can also modulate gene expression owing to its interactions with the proteins involved in signaling cascades. therefore, identification of proteins that interact with zyxin in embryonic cells is a promising way to unravel mechanisms responsible for coupling of two major components of embryogenesis: morphogenetic movements and cell differentiation. now we show that in xenopus laevis embryos ... | 2013 | 23685334 |
| xenopus laevis nucleotide binding protein 1 (xnubp1) is important for convergent extension movements and controls ciliogenesis via regulation of the actin cytoskeleton. | nucleotide binding protein 1 (nubp1) is a highly conserved phosphate loop (p-loop) atpase involved in diverse processes including iron-sulfur protein assembly, centrosome duplication and lung development. here, we report the cloning, expression and functional characterization of xenopus laevis nubp1. we show that xnubp1 is expressed maternally, displays elevated expression in neural tissues and is required for convergent extension movements and neural tube closure. in addition, xnubp1knockdown l ... | 2013 | 23685253 |
| reactive oxygen species and anti-oxidant defenses in tail of tadpoles, xenopus laevis. | tail regression in tadpoles is one of the most spectacular events in anuran metamorphosis. reactive oxygen species and oxidative stress play an important role during this process. presently, the cell- and tissue-specific localization of antioxidant enzymes such as superoxide dismutase (sod) and catalase as well as neuronal and inducible nitric oxide synthase isoforms (nnos and inos) responsible for production of nitric oxide (no) were carried out during different stages of metamorphosis in tail ... | 2013 | 23684737 |
| built for rowing: frog muscle is tuned to limb morphology to power swimming. | rowing is demanding, in part, because drag on the oars increases as the square of their speed. hence, as muscles shorten faster, their force capacity falls, whereas drag rises. how do frogs resolve this dilemma to swim rapidly? we predicted that shortening velocity cannot exceed a terminal velocity where muscle and fluid torques balance. this terminal velocity, which is below vmax, depends on gear ratio (gr = outlever/inlever) and webbed foot area. perhaps such properties of swimmers are 'tuned' ... | 2013 | 23676897 |