Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| laboratory and field evaluation of predator odors as repellents for kiore (rattus exulans) and ship rats (r. rattus). | predator odors may serve to stop rats from entering conservation areas or to decrease predation, food consumption, and other damage by rats in areas tainted with predator odor. we compared the efficacy of real predator odors and synthetic odors (derived from the urine and feces of carnivores) as rat repellents with real herbivore odors as controls in a y maze. we tested six predator odors: cat (felis catus) urine and feces, mongoose (herpestes auropunctatus) feces, n-propylthietane, s-methyl, me ... | 2001 | 11471938 |
| endothelial exposure to hypoxia induces egr-1 expression involving pkcalpha-mediated ras/raf-1/erk1/2 pathway. | hypoxia induces endothelial dysfunction that results in a series of cardiovascular injuries. early growth response-1 (egr-1) has been indicated as a common theme in vascular injury. here we demonstrates that in bovine aortic endothelial cells (ecs) subjected to hypoxia (po(2) approximately 23 mmhg), rapidly increased egr-1 mrna expression which peaked within 30 min and decreased afterwards. treatment of ecs with pd98059, a specific inhibitor to mitogen-activated protein kinase (mapk/erk), inhibi ... | 2001 | 11473356 |
| assessment of in vitro fertility of deer spermatozoa by heterologous ivf with zona-free bovine oocytes. | we have previously shown that the in vitro development of deer embryos differed according to the ivf conditions. the aim of the study was to use heterologous ivf with zona-free matured bovine oocytes to assess the in vitro fertility of 3 samples of deer semen (2 ejaculates from sika deer (cervus nippon) and 1 pool of epididymal spermatozoa from red deer (cervus elaphus)). the frozen/thawed semen samples were selected on percoll gradient and resuspended in tyrode modified medium supplemented with ... | 2001 | 11480618 |
| oscillation in the activities of mek/erk1/2 during cardiopulmonary bypass in pigs. | because cardiopulmonary bypass (cpb) is associated with edema and vasoreactive dysfunction and erk1/2 pathway is involved in vascular contractility and permeability, a time course study was performed to monitor mek/erk1/2/elk-1 activities during cpb. | 2001 | 11490347 |
| inhibition of p38 mitogen activated protein kinase increases lipopolysaccharide induced inhibition of apoptosis in neutrophils by activating extracellular signal-regulated kinase. | prolonged polymorphonuclear neutrophil (pmn) survival has been implicated in tissue injury after sepsis. previously we reported that lipopolysaccharide (lps) inhibits pmn apoptosis via the activation of the extracellular signal-regulated kinase (erk). conversely, the p38 mitogen activated protein kinase (mapk) pathway is involved in the spontaneous apoptosis of pmns. the interaction between these 2 pathways and their ability to regulate apoptosis during sepsis remain largely undefined. we hypoth ... | 2001 | 11490356 |
| spred is a sprouty-related suppressor of ras signalling. | cellular proliferation, and differentiation of cells in response to extracellular signals, are controlled by the signal transduction pathway of ras, raf and map (mitogen-activated protein) kinase. the mechanisms that regulate this pathway are not well known. here we describe two structurally similar tyrosine kinase substrates, spred-1 and spred-2. these two proteins contain a cysteine-rich domain related to sprouty (the spr domain) at the carboxy terminus. in drosophila, sprouty inhibits the sig ... | 2001 | 11493923 |
| involvement of mitogen-activated protein kinase pathways in staphylococcus aureus invasion of normal osteoblasts. | staphylococcus aureus invades osteoblasts and can persist in the intracellular environment. the present study examined the role of osteoblast mitogen-activated protein kinase (mapk) pathways in bacterial invasion. s. aureus infection of normal human and mouse osteoblasts resulted in an increase in the phosphorylation of the extracellular signal-regulated protein kinases (erk 1 and 2). this stimulation of erk 1 and 2 correlated with the time course of s. aureus invasion, and bacterial adherence i ... | 2001 | 11500391 |
| erk2- and p90(rsk2)-dependent pathways regulate the ccaat/enhancer-binding protein-beta interaction with serum response factor. | the serum response element (sre) of the c-fos promoter is a convergence point for mitogenic signaling pathways. several transcription factors regulate sre, including serum response factor (srf), ternary complex factors, and ccaat/enhancer-binding protein-beta (c/ebpbeta). c/ebpbeta can interact with both srf and the ternary complex factor family member elk-1, but only in response to activated ras. transactivation of the sre by c/ebpbeta is also greatly stimulated by ras. the ras effectors that s ... | 2001 | 11500490 |
| health protocol for translocation of free-ranging elk. | when considering an elk (cervus elaphus) restoration program, wildlife managers must evaluate the positive and negative elements of translocation. we prepared this protocol to give an overview of health considerations associated with translocation of elk, with an emphasis on movement of free-ranging elk from western north america to the southeastern usa. we evaluated infectious agents and ectoparasites reported in elk from two perspectives. first, we made a qualitative estimate of the ability of ... | 2001 | 11504216 |
| experimental infection of nontarget species of rodents and birds with brucella abortus strain rb51 vaccine. | the brucella abortus vaccine strain rb51 (srb51) is being considered for use in the management of bnucellosis in wild bison (bison bison) and elk (cervus elaphus) populations in the greater yellowstone area (usa). evaluation of the vaccines safety in non-target species was considered necessary prior to field use. between june 1998 and december 1999, ground squirrels (spermophilus richardsonii, n = 21), deer mice (peromyscus maniculatus, n = 14), prairie voles (microtus ochrogaster, n = 21), and ... | 2001 | 11504226 |
| safety of brucella abortus strain rb51 in deer mice. | brucella abortus strain rb51 is an approved brucellosis vaccine for use in cattle that may have potential as an oral vaccine for use in elk (cervus elaphus) and/or bison (bison bison). this study was designed to determine effects of strain rb51 on deer mice (peromyscus maniculatus), a nontarget species that could have access to treated baits in a field situation. in february 1994, 90 mice were orally dosed or intraperitoneally injected with 1 x 10(8) colony forming units strain rb51 and 77 contr ... | 2001 | 11504238 |
| the descended larynx is not uniquely human. | morphological modifications of vocal anatomy are widespread among vertebrates, and the investigation of the physiological mechanisms and adaptive functions of such variants is an important focus of research into the evolution of communication. the "descended larynx" of adult humans has traditionally been considered unique to our species, representing an adaptation for articulate speech, and debate concerning the position of the larynx in extinct hominids assumes that a lowered larynx is diagnost ... | 2001 | 11506679 |
| mechanisms of inhibition of the ras-map kinase signaling pathway in 30.7b ras 12 cells by tea polyphenols (-)-epigallocatechin-3-gallate and theaflavin-3,3'-digallate. | our previous study showed that tea polyphenols inhibited map kinase and ap-1 activities in mouse epidermal jb6 cells and the corresponding h-ras-transformed cell line 30.7b ras 12. the present study investigated the mechanisms of this inhibition. the cells were incubated with (-)-epigallocatechin-3-gallate (egcg) or theaflavin-3,3'-digallate (tfdig) (20 mm) for different times, and the cell lysate was analyzed by immunoblotting. egcg treatment decreased the levels of phospho-erk1/2 and -mek1/2 t ... | 2001 | 11511526 |
| muscle-invasive transitional cell carcinoma of the urinary bladder: a population-based study of patterns of care and prognostic factors. | population-based cancer registries can permit the study of the survivorship of all patients with a particular diagnosis regardless of patterns of referral and practice within a specific geographic distribution. the purpose of this study is to describe the patterns of care, outcome, and prognostic factors for bladder cancer in the northern region of the province of alberta, canada, between 1984 and 1993. | 2001 | 11516847 |
| lipopolysaccharide activation of the mek-erk1/2 pathway in human monocytic cells mediates tissue factor and tumor necrosis factor alpha expression by inducing elk-1 phosphorylation and egr-1 expression. | lipopolysaccharide (lps) induces human monocytes to express many proinflammatory mediators, including the procoagulant molecule tissue factor (tf) and the cytokine tumor necrosis factor alpha (tnf-alpha). the tf and tnf-alpha genes are regulated by various transcription factors, including nuclear factor (nf)-kappab/rel proteins and egr-1. in this study, the role of the mek-erk1/2 mitogen-activated protein kinase (mapk) pathway in lps induction of tf and tnf-alpha gene expression in human monocyt ... | 2001 | 11520792 |
| activation of extracellular signal-regulated kinase and c-jun-nh(2)-terminal kinase but not p38 mitogen-activated protein kinases is required for rrr-alpha-tocopheryl succinate-induced apoptosis of human breast cancer cells. | rrr-alpha-tocopherol succinate (vitamin e succinate, ves) is a potent, selective apoptotic agent for cancer cells but not normal cells. ves has been shown to inhibit the growth of a wide variety of tumor cells in cell culture and animal models. studies addressing mechanisms of action of ves-induced apoptosis have identified transforming growth factor-beta, fas/cd95-apo-1, and mitogen-activated protein kinase (mapk) signaling pathway involvement. here we show that mapks, the extracellular signal- ... | 2001 | 11522656 |
| enhancement of epidermal growth factor signaling and activation of src kinase by gangliosides. | in a recent study, inhibition of cellular ganglioside synthesis blocked growth factor-induced fibroblast proliferation. conversely, enrichment of cell membrane gangliosides by ganglioside preincubation enhanced growth factor-elicited cell proliferation. in the absence of serum and growth factors, neunacalpha2-3galbeta1-3galnacbeta1-4(neunacalpha2-3)galbeta1-4glcbeta1-1cer (g(d1a)) acted like a growth factor when cells were pretreated with the ganglioside, stimulating proliferation of normal huma ... | 2001 | 11535585 |
| keratinocyte growth factor activates p38 mapk to induce stress fibre formation in human prostate du145 cells. | fgf7/keratinocyte growth factor (kgf) regulates the differentiation and development of the prostate epithelium, while over-expression of fgf8 and fgf1 are implicated in carcinogenesis of the prostate. we tested the hypothesis that different members of the fgf family function through different signalling molecules. in prostate du145 cells, both fgf1 and fgf2 activated erk1/2 potently and p38 moderately. kgf was however most efficient in inducing p38 activities but had no effect on erk1/2 function ... | 2001 | 11536048 |
| functional analysis of the conserved domains of a rice knox homeodomain protein, osh15. | the rice knox protein osh15 consists of four conserved domains: the meinox domain, which can be divided into two subdomains (knox1 and knox2); the gse domain; the elk domain; and the homeodomain (hd). to investigate the function of each domain, we generated 10 truncated proteins with deletions in the conserved domains and four proteins with mutations in the conserved amino acids in the hd. transgenic analysis suggested that knox2 and hd are essential for inducing the abnormal phenotype and that ... | 2001 | 11549765 |
| molecular evolution of growth hormone (gh) in cetartiodactyla: cloning and characterization of the gene encoding gh from a primitive ruminant, the chevrotain (tragulus javanicus). | in mammals the sequence of pituitary growth hormone (gh) is generally strongly conserved, indicating a slow basal rate of molecular evolution. however, on two occasions, during the evolution of primates and that of cetartiodactyls, the rate of evolution has increased dramatically (25 to 50-fold) so that the sequences of human and ruminant ghs differ markedly from those of other mammalian ghs. to define further the burst of gh evolution that occurred in cetartiodactyls, the gh gene of the chevrot ... | 2001 | 11551118 |
| delta 9-tetrahydrocannabinol-induced mapk/erk and elk-1 activation in vivo depends on dopaminergic transmission. | it is now well established that central effects of delta 9-tetrahydrocannabinol (thc), the main psychoactive component of marijuana, are mediated by cb1 cannabinoid receptors. however, intraneuronal signalling pathways activated in vivo by thc remain poorly understood. we show that acute administration of thc induces a progressive and transient activation (i.e. phosphorylation) of the mitogen activated protein kinase/extracellular signal-regulated kinase (mapk/erk) in the dorsal striatum and the ... | 2001 | 11553284 |
| functional components of basic fibroblast growth factor signaling that inhibit lung elastin gene expression. | previously, we have demonstrated that basic fibroblast growth factor (bfgf) decreases elastin gene transcription in confluent rat lung fibroblasts via the binding of a fra-1-c-jun heterodimer to an activator protein-1-camp response element in the distal region of the elastin promoter. in the present study, we show that bfgf activates the mitogen-activated protein kinase extracellular signal-regulated kinase 1/2, resulting in the translocation of phosphorylated extracellular signal-regulated kina ... | 2001 | 11557580 |
| alpha-synuclein affects the mapk pathway and accelerates cell death. | insoluble alpha-synuclein accumulates in parkinson's disease, diffuse lewy body disease, and multiple system atrophy. however, the relationship between its accumulation and pathogenesis is still unclear. recently, we reported that overexpression of alpha-synuclein affects elk-1 phosphorylation in cultured cells, which is mainly performed by mitogen-activated protein kinases (mapks). we further examined the relationship between mapk signaling and the effects of alpha-synuclein expression on ecdys ... | 2001 | 11560921 |
| net-targeted mutant mice develop a vascular phenotype and up-regulate egr-1. | the ternary complex factors (tcfs) net, elk-1 and sap-1 regulate immediate early genes through serum response elements (sres) in vitro, but, surprisingly, their in vivo roles are unknown. net is a repressor that is expressed in sites of vasculogenesis during mouse development. we have made gene-targeted mice that express a hypomorphic mutant of net, net delta, which lacks the ets dna-binding domain. strikingly, homozygous mutant mice develop a vascular defect and up-regulate an immediate early g ... | 2001 | 11566878 |
| lack of elk-1 phosphorylation and dysregulation of the extracellular regulated kinase signaling pathway in senescent human fibroblast. | replicative senescence is characterized by numerous phenotypic alterations including the loss of proliferative capacity in response to mitogens and numerous changes in gene expression including impaired serum inducibility of the immediate-early genes c-fos and erg-1. transcription of c-fos in response to mitogens depends on the activation of a multiprotein complex formed on the c-fos serum response element (sre), which includes the transcription factors srf (serum response factor) and tcf (terna ... | 2001 | 11570821 |
| peptides derived from pro-growth hormone-releasing hormone activate p38 mitogen-activated protein kinase in gh3 pituitary cells. | posttranslational processing of the pro-growth hormone-releasing hormone (proghrh) peptide can result in the formation of at least two peptide products: ghrh and the c-terminal peptide, ghrh-related peptide (ghrh-rp). while cyclic adenosine monophosphate transduces many of the actions of ghrh, other pathways also have been implicated in its actions. the aims of this study were to examine and characterize the activation of mitogen-activated protein kinase (mapk) pathways by ghrh, and ghrh-rp in p ... | 2001 | 11572318 |
| high glucose-enhanced mesangial cell extracellular signal-regulated protein kinase activation and alpha1(iv) collagen expression in response to endothelin-1: role of specific protein kinase c isozymes. | high glucose (hg) stimulates glomerular mesangial cell (mc) expression of extracellular matrix, a process involving protein kinase c (pkc) isozymes and enhanced signaling by autocrine peptides such as endothelin-1 (et-1). the purpose of this study was to identify the specific pkc isozymes mediating the effects of hg on mc extracellular signal-regulated protein kinase (erk1/2) signaling and alpha1(iv) collagen expression in response to et-1. hg (30 mmol/l for 72 h) enhanced et-1-stimulated alpha1 ... | 2001 | 11574422 |
| disabled-2 mediates c-fos suppression and the cell growth regulatory activity of retinoic acid in embryonic carcinoma cells. | f9 embryonic stem cell-like teratocarcinoma cells are widely used to study early embryonic development and cell differentiation. the cells can be induced by retinoic acid to undergo endodermal differentiation. the retinoic acid-induced differentiation accompanies cell growth suppression, and thus, f9 cells are also often used as a model for analysis of retinoic acid biological activity. we have recently shown that mapk activation and c-fos expression are uncoupled in f9 cells upon retinoic acid- ... | 2001 | 11577091 |
| glial cell-derived neurotrophic factor (gdnf)-induced migration and signal transduction in corneal epithelial cells. | to identify signal-transduction pathways induced by glial cell-derived neurotrophic factor (gdnf) in corneal epithelial cells and to characterize its effect on cell migration. | 2001 | 11581189 |
| constitutive activation of extracellular signal-regulated kinase 2 by synergistic point mutations. | constitutively active mutant forms of signaling enzymes provide insight into mechanisms of activation as well as useful molecular tools for probing downstream targets. in this study, point mutations in erk2 at conserved residues l73p and s151d were identified that individually led to 8-12-fold increased specific activity and in combination reached 50-fold, indicating synergistic interactions between these residues. examination by mass spectrometry, phosphatase sensitivity, and western blotting r ... | 2001 | 11591711 |
| potent inhibition of nfat activation and t cell cytokine production by novel low molecular weight pyrazole compounds. | nfat (nuclear factor of activated t cell) proteins are expressed in most immune system cells and regulate the transcription of cytokine genes critical for the immune response. the activity of nfat proteins is tightly regulated by the ca(2+)/calmodulin-dependent protein phosphatase 2b/calcineurin (can). dephosphorylation of nfat by can is required for nfat nuclear localization. current immunosuppressive drugs such as cyclosporin a and fk506 block can activity thus inhibiting nuclear translocation ... | 2001 | 11592964 |
| creutzfeldt-jakob disease in unusually young patients who consumed venison. | creutzfeldt-jakob disease (cjd) in humans and chronic wasting disease (cwd) in deer and elk occur in the united states. recent reports of 3 unusually young patients with cjd who regularly consumed deer or elk meat created concern about the possible zoonotic transmission of cwd. | 2001 | 11594928 |
| oestrogen receptor beta is not present in the pilosebaceous unit of red deer skin during the non-breeding season. | androgens and oestrogens both have roles in skin physiology. recently a second oestrogen receptor (erbeta) has been identified in androgen-dependent tissues. the red deer grows a breeding season, androgen-dependent mane when plasma testosterone rises; this is replaced with small neck hairs during the non-breeding season. in non-breeding season deer skin, erbeta was localised to the blood vessels and arrector pili muscle, but in contrast to human skin, not in the pilosebaceous unit or epidermis. ... | 2000 | 11595814 |
| differential expression of active, phosphorylation-dependent map kinases, mapk/erk, sapk/jnk and p38, and specific transcription factor substrates following quinolinic acid excitotoxicity in the rat. | excitotoxicity is considered a major cell death inductor in neurodegeneration. yet mechanisms involved in cell death and cell survival following excitotoxic insults are poorly understood. expression of active, phosphorylation-dependent mitogen-activated extracellular signal-regulated kinases (mapk/erks), stress activated c-jun n-terminal kinases (sapk/jnks) and p38 kinases, as well as their putative active specific transcriptional factor substrates creb, elk-1, atf-2, c-myc and c-jun, have been ... | 2001 | 11597764 |
| group i metabotropic glutamate receptor activation increases phosphorylation of camp response element-binding protein, elk-1, and extracellular signal-regulated kinases in rat dorsal striatum. | cyclic amp response element-binding protein (creb) is a major transcriptional activator at the calcium and camp response-element (cacre). phosphorylated (p)creb facilitates gene expression in striatal neurons. elk-1 is another transcriptional regulator at the serum response element in the upstream promoter region of the cacre. elk-1 is phosphorylated by extracellular signal-regulated kinases (erk) and may also contribute to the regulation of gene expression. to evaluate putative roles of group i ... | 2001 | 11597767 |
| heparin and heparan sulfate inhibit extracellular signal-regulated kinase activation and myocardial cell hypertrophy induced by endothelin-1. | heparan sulfate (hs) is one of the components of extracellular matrix and a potent anti-growth factor in various cells. heparin has a similar structure to hs and is demonstrated to inhibit myocardial cell hypertrophy. we examined the intracellular signal mechanisms linking to the inhibitory effects of heparin and hs on endothelin-1 (et-1)-induced hypertrophy in cultured rat neonatal myocardial cells (mcs). heparin inhibited et-1-induced c-fos mrna expression. heparin and hs inhibited et-1-induce ... | 2001 | 11599124 |
| direct action of melatonin in human granulosa-luteal cells. | the direct involvement of melatonin in modulation of ovarian steroidogenesis, the high levels of melatonin found in human follicular fluid, and the presence of melatonin binding sites in the ovary led us to hypothesize that melatonin acts as a modulator of ovarian function. in contrast to the hypothalamus and pituitary, the mechanism of melatonin action at the level of the ovary is still poorly understood. in the present study, we investigated the gene expression of the two different forms of me ... | 2001 | 11600542 |
| experimental ehrlichia phagocytophila infection in red deer (cervus elaphus). | 2001 | 11601517 | |
| activation of raf/erk1/2 map kinase pathway is involved in gm-csf-induced proliferation and survival but not in erythropoietin-induced differentiation of tf-1 cells. | the involvement of mapk pathways in differentiation, proliferation and survival was investigated by comparing epo and gm-csf signalling in human factor-dependent myeloerythroid tf-1 cells with abnormal epo-r. gm-csf withdrawal induced cell-cycle arrest and apoptosis accompanied by increased caspase-3 activity, dna degradation and reduced expression of the antiapoptotic bcl-2 and bcl-xl proteins. readministration of gm-csf but not epo reversed these processes and induced proliferation. the gm-csf ... | 2001 | 11602185 |
| [seasonal adaptation of general metabolism and energy metabolism in the elk alces alces from pechora taiga]. | 2001 | 11605439 | |
| activation of mu-opioid receptor induces expression of c-fos and junb via mitogen-activated protein kinase cascade. | opioid-induced long-term functional alterations of the nervous system, such as tolerance, addiction, and dependence, conceivably involve changes in gene expression. the authors have previously reported that opioid receptors are functionally coupled to extracellular signal-regulated kinase, a class of the mitogen-activated protein kinase. to address whether activation of the opioid receptor induces changes in gene expression through the activation of extracellular signal-regulated kinase, the aut ... | 2001 | 11605942 |
| oncogenic levels of mitogen-activated protein kinase (mapk) signaling of the dinucleotide kras2 mutations g12f and gg12-13vc. | we previously reported the occurrence of novel dinucleotide mutations of the k-ras gene (kras2) in 2% of pancreatic tumors sampled, but it remained unknown whether these were functional mutations that convert the proto-oncogene to an oncogene, or unselected mutations that might inactivate protein function. in the current study, the functionality of these rare mutations was quantitated via a mitogen-activated protein kinase (mapk) pathway-specific transactivational reporter system. pathway activa ... | 2001 | 11668624 |
| development of a homogeneous map kinase reporter gene screen for the identification of agonists and antagonists at the cxcr1 chemokine receptor. | agonist activity at g protein-coupled receptors (gpcrs) that regulate heterotrimeric g proteins of the galpha(i/o) or galpha(q) families has been shown to result in activation of the mitogen-activated protein (map) kinase cascade. to facilitate compound screening for these classes of gpcr, we have developed a reporter gene that detects the activation of the ternary complex transcription factor sap1a following map kinase activation. in contrast to other reporter gene assays for galpha(i/o)-couple ... | 2001 | 11679162 |
| group i metabotropic glutamate receptors control phosphorylation of creb, elk-1 and erk via a camkii-dependent pathway in rat striatum. | in vivo activation of group i metabotropic glutamate receptors (mglurs) upregulates phosphorylation of cyclic amp response element-binding protein (creb), elk-1 and extracellular signal-regulated kinases (erk) in striatal neurons. to evaluate putative roles of ca2+/calmodulin-dependent protein kinase ii (camkii) in creb, elk-1 and erk phosphorylation, the camkii inhibitor, kn62, was infused simultaneously with the group i mglur agonist, 3,5-dihydroxyphenylglycine (dhpg), into the rat dorsal stri ... | 2001 | 11682144 |
| pten does not modulate glut4 translocation in rat adipose cells under physiological conditions. | pten is a 3'-inositol lipid phosphatase that dephosphorylates products of pi 3-kinase. since pi 3-kinase is required for many metabolic actions of insulin, we investigated the role of pten in insulin-stimulated translocation of glut4. in control rat adipose cells, we observed a approximately 2-fold increase in cell surface glut4 upon maximal insulin stimulation. overexpression of wild-type pten abolished this response to insulin. translocation of glut4 in cells overexpressing pten mutants withou ... | 2001 | 11689011 |
| onchocercosis in red deer (cervus elaphus) from spain. | onchocercosis, caused by onchocerca flexuosa, was observed in red deer (cervus elaphus) from spain for the first time. adult specimens of p. flexuosa were found in nodules in subcutaneous tissues in 42 of 125 (33%) red deer between october 1994 and september 1995; intensity of infection +/- sd was 3.93 +/- 5.26 nodules per infected host. a clear seasonal pattern in the distribution of nodules was observed, with higher values of prevalence and intensity in fall and winter in contrast to spring an ... | 2001 | 11695405 |
| enhancement of survival by lpa via erk1/erk2 and pi 3-kinase/akt pathways in a murine hepatocyte cell line. | first published september 5, 2001; 10.1152/ajpcell.00077.2001.-protective mechanisms for lysophosphatidic acid (lpa) against cell death caused by clostridium difficile toxin, or tumor necrosis factor-alpha (tnf-alpha) plus d-galactosamine, were investigated in a murine hepatocyte cell line aml12 expressing edg2 lpa receptor. in these models of hepatocellular injury, lpa prevented hepatocyte damage, suppressed apoptosis, and enhanced cell survival in a dose-dependent fashion. the protective effec ... | 2001 | 11698260 |
| stimulation of endothelin b receptors in astrocytes induces camp response element-binding protein phosphorylation and c-fos expression via multiple mitogen-activated protein kinase signaling pathways. | the vasoconstrictor peptide endothelin (et-1) exerts its physiological and pathological effects via activation of et(a) and et(b) receptor (et-r) subtypes. in this study, we demonstrate that both et-r subtypes are highly expressed in rat astrocytes in vivo, indicating that these cells are potential targets of the biological effects of et-1 in the brain. in cultured cortical astrocytes, both et-r subtypes are expressed, and selective stimulation of et(b)-r with et-1 induces phosphorylation of cam ... | 2001 | 11698596 |
| activation of elk-1, an ets transcription factor, by glucose and egf treatment of insulinoma cells. | elk-1, a member of the ternary complex factor family of ets domain proteins that bind serum response elements, is activated by phosphorylation in a cell-specific manner in response to growth factors and other agents. the purpose of the current study was to determine whether elk-1 activation contributes to glucose-/depolarization-induced ca(2+)-dependent induction of immediate early response genes in pancreatic islet beta-cells. the results of experiments in insulinoma (min6) cells demonstrated t ... | 2001 | 11701445 |
| no direct mitogenic effect of sex hormones on antlerogenic cells detected in vitro. | deer pedicles, antecedents of antlers, develop from a specialized periosteum (antlerogenic periosteum) which overlies the lateral crest of the deer frontal bone. the initiation of pedicle growth is triggered by androgen hormones. thus far, it is not known whether pedicle initiation is caused by direct stimulation of androgen hormones on the antlerogenic periosteum or whether some intermediate mechanisms are necessary. the present study took an in vitro approach to investigate whether sex hormone ... | 2001 | 11703073 |
| biological activity of re-1 silencing transcription factor (rest) towards distinct transcriptional activators. | the zinc finger protein re-1 silencing transcription factor (rest) is a transcriptional repressor that represses neuronal genes in non-neuronal tissues. we have analyzed the ability of rest and the rest mutants, restdeltan and restdeltac lacking either the n-terminal or c-terminal repression domains of rest, to inhibit transcription mediated by distinct transcriptional activator proteins. for this purpose we have designed an activator specific assay where transcription is activated as a result o ... | 2001 | 11703459 |
| radicicol suppresses transformation and restores tropomyosin-2 expression in both ras- and mek-transformed cells without inhibiting the raf/mek/erk signaling cascade. | the antibiotic radicicol suppresses transformation in a variety of transformed cells. the antineoplastic effects of the drug have been attributed to the degradation of raf and the inactivation of the ras/raf/mitogen-activated protein kinase kinase (mek)/extracellular signal-regulated kinase (erk) signaling cascade. here we demonstrate that radicicol induces cell spreading, suppresses anchorage-independent cell growth, and increases the expression of the high-molecular weight tropomyosin isoform ... | 2001 | 11714635 |
| hiv nef increases t cell erk map kinase activity. | the human immunodeficiency regulatory protein nef enhances viral replication and is central to viral pathogenesis. although nef has displayed a capacity to associate with a diverse assortment of cellular molecules and to increase t cell activity, the biochemical activity of nef in t cells remains poorly defined. in this report we examine the bioactivity of nef in primary cd4 t cells and, in particular, focus on the biochemical pathways known to be central to t cell activity. the extracellular si ... | 2002 | 11726657 |
| studies on the inhibition of tumor cell growth and microtubule assembly by 3-hydroxy-4-[(e)-(2-furyl)methylidene]methyl-3-cyclopentene-1,2-dione, an intensively coloured maillard reaction product. | very recently, 3-hydroxy-4-[(e)-(2-furyl)methylidene]methyl-3-cyclopentene-1,2-dione (1) has been successfully identified as an intensively coloured maillard product formed from glucose and l-proline upon thermal food processing. using a biomimetic synthetic strategy, reference material of compound 1 was prepared and purified, and then used to study its effect on the growth of human tumor cells. compound 1 was found to potently inhibit the growth of human tumor cells in vitro. using a reporter g ... | 2002 | 11731031 |
| ctgf/hcs24 induces chondrocyte differentiation through a p38 mitogen-activated protein kinase (p38mapk), and proliferation through a p44/42 mapk/extracellular-signal regulated kinase (erk). | connective tissue growth factor/hypertrophic chondrocyte specific gene product 24 (ctgf/hcs24) promotes proliferation and differentiation of chondrocytes in culture. we investigated the roles of two major types of mitogen activated protein kinase (mapk) in the promotion of proliferation and differentiation by ctgf/hcs24. here we report the effects of the mapkk/mek 1/2 inhibitor, pd098059, and p38 mapk inhibitor, sb203580, in a human chondrosarcoma-derived chondrocytic cell line (hcs-2/8) and rab ... | 2001 | 11732999 |
| ngf signaling from clathrin-coated vesicles: evidence that signaling endosomes serve as a platform for the ras-mapk pathway. | the target-derived neurotrophic factor "nerve growth factor" (ngf) signals through trka to promote the survival, differentiation, and maintenance of neurons. how the ngf signal in axon terminals is conveyed to the cell body is unknown. the "signaling endosome hypothesis" envisions that ngf-trka complexes are internalized at the axon terminal and retrogradely transported to the cell body. following ngf treatment, we found that clathrin-coated vesicles contained ngf bound to trka together with act ... | 2001 | 11738027 |
| bacterial peptidoglycan-induced tnf-alpha transcription is mediated through the transcription factors egr-1, elk-1, and nf-kappab. | bacteria and their ubiquitous cell wall component peptidoglycan (pgn) activate the innate immune system of the host and induce the release of inflammatory molecules. tnf-alpha is one of the highest induced cytokines in macrophages stimulated with pgn; however, the regulation of tnf-alpha expression in pgn-activated cells is poorly understood. this study was done to identify some of the transcription factors that regulate the expression of the tnf-alpha gene in macrophages stimulated with pgn. ou ... | 2001 | 11739517 |
| acidic extracellular ph induces vascular endothelial growth factor (vegf) in human glioblastoma cells via erk1/2 mapk signaling pathway: mechanism of low ph-induced vegf. | overexpression of vascular endothelial growth factor (vegf) is associated with disease progression in human glioblastomas. we recently showed that vegf promoter activity is inversely correlated with tumor extracellular ph (ph(o)) in vivo in the human glioma (u87 mg) xenografts. here we show that substitution of the neutral culture medium (ph 7.3) with acidic ph medium (ph 6.6) up-regulates vegf mrna and protein production in human glioblastoma cells as reflected by northern blot analysis and enz ... | 2002 | 11741977 |
| isolation and characterization of a drosophila homologue of mitogen-activated protein kinase phosphatase-3 which has a high substrate specificity towards extracellular-signal-regulated kinase. | a partial c-terminal cdna sequence of a novel drosophila mitogen-activated protein kinase phosphatase (mkp), designated dmkp-3, was identified from an epitope expressed sequence tag database, and the missing n-terminal cdna fragment was cloned from a drosophila cdna library. dmkp-3 is a protein of 411 amino acids, with a calculated molecular mass of 45.8 kda; the deduced amino acid sequence is most similar to that of mammalian mkp-3. recombinant dmkp-3 produced in escherichia coli retained intri ... | 2002 | 11742539 |
| felodipine inhibits nuclear translocation of p42/44 mitogen-activated protein kinase and human smooth muscle cell growth. | smooth muscle cell (smc) proliferation contributes to vascular structural changes in cardiovascular disease. ca(2+) antagonists exert antiproliferative effects and may also be clinically beneficial in the patients. however, the underlying mechanisms of action remain elusive. activation of mitogen-activated protein kinases (mapk), in particular p42/44mapk plays a central role in cell proliferation. we hypothesise that ca(2+) antagonists inhibit cell proliferation by interfering with the p42/44map ... | 2002 | 11744032 |
| creb and elk-1 phosphorylation by metabotropic glutamate receptors in striatal neurons (review). | metabotropic glutamate receptors (mglurs) are implicated in the regulation of diverse neuronal plasticity and neuropathological processes in the central nervous system. activation of mglurs couples glutamatergic signals to second messengers in a subtype-specific manner: activation of group i mglurs upregulates ca2+ cascades, while group ii/iii downregulates the adenylate cyclase and camp cascades. dominant presynaptic inhibitory actions of group ii/iii mglurs on the glutamate release, extensive ... | 2002 | 11744988 |
| gamma synuclein: subcellular localization in neuronal and non-neuronal cells and effect on signal transduction. | synucleins are small, highly conserved proteins in vertebrates, especially abundant in neurons and typically enriched in presynaptic terminals. alpha-synuclein protein and a fragment of it, called nac, have been found in association with pathological lesions of neurodegenerative diseases. recently, mutations in a alpha-synuclein gene have been reported in families susceptible to an inherited form of parkinson's diseases. in addition, alpha-synuclein has been implicated in the pathophysiology of ... | 2001 | 11746666 |
| biotransformation of flobufen enantiomers in ruminant hepatocytes and subcellular fractions. | flobufen (f), a new antiinflammatory drug, has one chiral and one prochiral center in its structure. reduction of rac-f, the principal biotransformation pathway, leads to the formation of four diastereoisomers of 4-dihydroflobufen (dhf). f was chosen as a model substrate for interspecies comparison of activity, stereospecificity, and stereoselectivity of biotransformation enzymes in fallow bucks, red deer stags, and roe bucks in vitro. formation of f metabolites was examined in hepatocyte suspen ... | 2001 | 11746816 |
| mitogen-activated protein kinase is required for bryostatin 1-induced differentiation of the human acute lymphoblastic leukemia cell line reh. | bryostatin 1 (bryo 1) is known to induce the differentiation and cell cycle arrest of human lymphoid leukemia cells in vitro. the extracellular signal-regulated kinase (erk), originally identified as a participant in mitogenic signaling, has recently been implicated in the signaling of cellular differentiation. to examine the role of the erk/mitogen-activated protein (map) kinase pathway in b-lymphoid cell differentiation of the reh acute lymphoblastic leukemia cell line, the effects of bryo 1 o ... | 2001 | 11751459 |
| a mutant arabidopsis heterotrimeric g-protein beta subunit affects leaf, flower, and fruit development. | a genetic screen was performed to find new mutants with an erecta (er) phenotype and to identify genes that may function with er, a receptor-like kinase. these mutants were named elk (for erecta-like) and were placed into five complementation groups. we positionally cloned elk4 and determined that it encodes agb1, a putative heterotrimeric g-protein beta subunit. therefore, elk4 was renamed agb1. agb1-1 plants express similar fruit phenotypes, as seen in er plants, but differ from er in that the ... | 2001 | 11752377 |
| mapping the receptor site for ergtoxin, a specific blocker of erg channels. | we show here that ergtoxin (ergtx) is a bona fide, specific blocker of the human ether-a-go-go-related gene (herg) channels. it does not affect the function of either m-eag or m-elk channels. a chimeric construction containing a segment of the p-region of m-eag channel inserted into the herg channel drastically diminished or completely abolished the inhibitory effect of ergtx, whereas chimeras of the p-region of herg channel into m-eag channels recovered the inhibitory effect. from the p-region ... | 2002 | 11755529 |
| selective in vivo inhibition of mitogen-activated protein kinase activation using cell-permeable peptides. | the extracellular signal-regulated kinase (erk), a member of the mitogen-activated protein kinases (mapks), is essential for cellular proliferation and differentiation, and thus there exists great interest to develop specific and selective inhibitors of this enzyme. whereas small molecule inhibitors pd098095 and u0126 have been used to study mapk/erk kinase (mek), their target selectivity has been questioned recently. the cross-reactivity of atp-directed inhibitors with other protein kinases pro ... | 2002 | 11756441 |
| a retrospective study of neonatal mortality in farmed elk. | despite the increasing importance of the canadian elk industry, the veterinary literature concerning diseases of elk is sparse, in particular for the neonatal period. this study summarizes necropsy findings in 111 farmed elk calves, up to 30 days of age, submitted to the diagnostic laboratory of the western college of veterinary medicine over a 9-year period (990 to 1998). causes of mortality fit into 3 categories: infectious disease, noninfectious disease, and undetermined. organisms causing di ... | 2001 | 11769617 |
| comparison of analgesic techniques for antler removal in wapiti. | the purpose of this research was to compare the effectiveness of ring block anesthesia (la) and electroanesthesia (a) for antler removal in elk given a long-acting tranquilizer to remove stress from restraint. thirty-two male wapiti were given 1 mg/kg body weight of zuclopenthixol acetate; the next day, they were restrained in a hydraulic chute, provided with electroanesthesia or a lidocaine ring block, and had their antlers removed. behavioral response to antler removal was scored. significantl ... | 2001 | 11769618 |
| linkage of rapid estrogen action to mapk activation by eralpha-shc association and shc pathway activation. | e2 rapidly activates mapk in breast cancer cells, and the mechanism for this effect has not been fully identified. since growth factor-induced mapk activation involves signaling via the adapter protein shc (src-homology and collagen homology) and its association with membrane receptors, we hypothesized that breast cancer cells utilize similar signaling mechanisms in response to e2. in the present study, we demonstrated that e2 rapidly induced shc phosphorylation and shc-grb2 (growth factor recep ... | 2002 | 11773443 |
| at1 receptor mutant lacking heterotrimeric g protein coupling activates the src-ras-erk pathway without nuclear translocation of erks. | angiotensin ii (ang ii) type 1 receptors (at1rs) activate tyrosine kinases, including src. whether or not tyrosine kinase activation by at1r occurs independently of heterotrimeric g protein coupling and, if so, the cellular function of such a mechanism are unknown. to address these questions, we used an at1ar intracellular second loop mutant, which lacks heterotrimeric g protein coupling (at1a-i2m). surprisingly, ang ii-induced src activation was preserved in at1a-i2m, which was not attenuated b ... | 2002 | 11777928 |
| specificity determinants in mapk signaling to transcription factors. | one critical component in determining the specificity, fidelity, and efficiency of mapk substrate phosphorylation is the presence of distinct docking domains in the substrate proteins. these docking domains are found in a range of substrates, including the transcription factors myocyte enhancer factor-2a and sap-1. however, the sequences of these motifs differ, as does their targeting preferences by mapks, with sap-1 being targeted by both the erk and p38 isoforms, whereas myocyte enhancer facto ... | 2002 | 11786537 |
| identification of the critical features of a small peptide inhibitor of jnk activity. | the c-jun n-terminal kinases (jnks) are a subfamily of the mitogen-activated protein kinases (mapks). although progress in evaluating the functions of other mapks has been facilitated by the characterization of specific inhibitors, no jnk-directed inhibitor is commercially available. we have identified a 21-amino acid peptide inhibitor of activated jnks, based on amino acids 143-163 of the jnk-binding domain (jbd) of the jnk scaffolding protein, jnk-interacting protein-1 (jip-1). this peptide, i ... | 2002 | 11790767 |
| a distinct class of dominant negative ras mutants: cytosolic gtp-bound ras effector domain mutants that inhibit ras signaling and transformation and enhance cell adhesion. | cytosolic gtp-bound ras has been shown to act as a dominant negative (dn) inhibitor of ras by sequestering raf in non-productive cytosolic complexes. nevertheless, this distinct class of dn mutants has been neither well characterized nor extensively used to analyze ras signaling. in contrast, dn ras17n, which functions by blocking ras guanine nucleotide exchange factors, has been well characterized and is widely used. cytosolic gtp-bound ras mutants could be used to inhibit particular ras effect ... | 2002 | 11799108 |
| a preliminary study of the genetic diversity of xinjiang tarim red deer (cervus elaphus yarkandensis) using the microsatellite dna method. | to evaluate the genetic diversity of the xinjiang tarim red deer (cervus elaphus yarkandensis) population, we analyzed the frequencies of microsatellite alleles. samples were collected from 3 isolated populations in xaya, lopnur and qarqan of xinjiang. although 10 microsatellite loci were examined, alleles of 133 to 190 base-pairs were detected for only 3 loci: bm5004, bm4208 and bm888. the average observed multilocus heterozygosity was 0.08 +/- 0.04 for the xaya, 0 for the lopnur, and 0.17 +/- ... | 2001 | 11799907 |
| gnrh regulates early growth response protein 1 transcription through multiple promoter elements. | pulsatile secretion of gnrh is the major regulator of gonadotropin (lh, fsh) gene expression and secretion. recently, gnrh has been shown to rapidly stimulate the expression of early growth response protein-1 (egr-1), a transcription factor that is essential for lhbeta gene expression in the pituitary. in this study, we examined the regulatory elements and signal transduction pathways by which gnrh regulates egr-1 transcription. deletion analysis of the murine egr-1 promoter identified two regio ... | 2002 | 11818496 |
| regulation of the erk2-elk1 signaling pathway and megakaryocytic differentiation of bcr-abl(+) k562 leukemic cells by gab2. | in the blast crisis phase of chronic myelogenous leukemia (cml), bcr-abl(+) myeloblasts fail to undergo terminal maturation. the extracellular signal-regulated kinase (erk) mitogen-activated protein (map) kinase has been shown to mediate terminal differentiation of myeloid cells. interestingly, bcr-abl(+) cml cell lines established from blast crisis were found to have low erk map kinase activity. in this study, we analyzed the role of the gab2 docking protein in regulation of the erk map kinase ... | 2002 | 11830491 |
| sex differences in emigration and mortality affect optimal management of deer populations. | populations of red deer that are limited by food, like those of many other ungulates, commonly include more females than males. we assessed the contribution of variation in sex- and age-specific rates of mortality and emigration to density-dependent changes in the adult sex ratio, using long-term observations and demographic experiments involving the red deer population on rum, scotland. we incorporated these effects in a stochastic model of local populations under different management regimes t ... | 2002 | 11832944 |
| nitric oxide-induced programmed cell death in human neuroblastoma cells is accompanied by the synthesis of egr-1, a zinc finger transcription factor. | nitric oxide (no) is cytotoxic for human sh-sy5y neuroblastoma cells. while nuclear condensation was visible in cells treated with nitric oxide donors, we observed that the plasma membrane remained intact, indicating that no induced apoptotic cell death. we analyzed the no-induced apoptotic signaling cascade in sh-sy5y cells and observed a striking increase in early growth response (egr)-1 promoter activity as a result of no-induced cell death. likewise, we detected an activation of the transcri ... | 2002 | 11835312 |
| the regulatory effect of erk1/2 signal pathway on production of tnfalpha induced by lps in mice kupffer cells. | to study the rule of erk1/2 activity and regulative effect of erk1/2 pathway on the production of pro-inflammatory cytokine tnfalpha in mice kupffer cells (mkc) induced by lps, and to exploring novel methods to prevent and treat clinical patients of endotoxemia. | 2001 | 11835717 |
| antibodies to granulocytic ehrlichia in moose, red deer, and roe deer in norway. | serum samples from 104 moose (alces alces), 124 red deer (cervus elaphus) and 114 roe deer (capreolus capreolus), collected from different counties in southern norway from 1994 to 2000, were analysed by an indirect immunofluorescent antibody staining method for antibodies to ehrlichia equi. the overall seroprevalences for granulocytic ehrlichia spp. in moose, red deer, and roe deer from ixodes ricinus infested counties were 43%, 55%, and 96%, respectively. antibody prevalence was significantly h ... | 2002 | 11838199 |
| brucella abortus strain rb51 vaccination in elk. i. efficacy of reduced dosage. | bovine brucellosis is a serious zoonotic disease affecting some populations of rocky mountain elk (cervus elaphus nelsoni) and bison (bison bison) in the greater yellowstone area, usa. the fear that elk and/or bison may spread brucella abortus to livestock has prompted efforts to reduce or eliminate the disease in wildlife. brucella abortus strain rb51 (rb51) vaccine has recently been approved for use in cattle. unlike strain 19 vaccine, rb51 does not cause false positive reactions on standard b ... | 2002 | 11838212 |
| brucella abortus strain rb51 vaccination in elk. ii. failure of high dosage to prevent abortion. | brucella abortus strain rb51 is used as a vaccine because it induces antibodies that do not react on standard serologic tests for brucellosis allowing differentiation between vaccination and infection. strain rb51 was evaluated in captive elk (cervus elaphus) to determine if vaccination protected against abortion following experimental challenge. thirty elk were vaccinated intramuscularly with 1.0 x 10(10) colony-forming units (cfu) of strain rb51 in march 1998. fourteen of these were given a bo ... | 2002 | 11838225 |
| explaining stasis: microevolutionary studies in natural populations. | microevolution, defined as a change in the genetic constitution of a population over time, is considered to be of commonplace occurrence in nature. its ubiquity can be inferred from the observation that quantitative genetic divergence among populations usually exceeds that to be expected due to genetic drift alone, and from numerous observations and experiments consistent with local adaptation. experimental manipulations in natural populations have provided evidence that rapid evolutionary respo ... | 2001 | 11838766 |
| the activity of the extracellular signal-regulated kinase 2 is regulated by differential phosphorylation in the activation loop. | the mitogen-activated protein kinases (map kinases) play a central role in signaling pathways initiated by extracellular stimuli such as growth factors, cytokines, and various forms of environmental stress. full activation of the map kinases requires dual phosphorylation of the thr and tyr residues in the txy motif of the activation loop by map kinase kinases. interestingly, down-regulation of map kinase activity can be initiated by multiple ser/thr phosphatases, tyr-specific phosphatases, and d ... | 2002 | 11839761 |
| development of in vitro embryo production systems for red deer (cervus elaphus). part 1. effect of epithelial oviductal monolayers and heparin on in vitro sperm motility and penetration of in vitro matured oocytes. | in vitro fertilisation (ivf) protocols for red deer have yielded low fertilisation rates, with no embryo development beyond the eight-cell stage when heparin was used as the in vitro capacitation agent. as this low fertilisation rate may result from reduced motility, the present study investigated the use of red deer oviduct epithelial cell monolayers (coem) and conditioned medium (cm) from the monolayers to maintain red deer sperm motility in vitro. a second experiment compared the fertilisabil ... | 2002 | 11841907 |
| development of in vitro embryo production systems for red deer (cervus elaphus). part 2. the timing of in vitro nuclear oocyte maturation. | the time course of in vitro red deer nuclear oocyte maturation was determined. ovaries were obtained at slaughter and oocytes were aspirated from follicles greater than 2mm in diameter. oocytes with compact cumulus cells were matured in 50 microl microdrops (10 per drop) under mineral oil containing tcm 199 supplemented with 0.33 mm pyruvate, 10 microg lh and fsh, 1 microg oestradiol and 10% foetal bovine serum. oocytes were matured at 39 degrees c and 5% co(2) in air. at 3h intervals (0-27 h) o ... | 2002 | 11841908 |
| development of in vitro embryo production systems for red deer (cervus elaphus). part 3. in vitro fertilisation using sheep serum as a capacitating agent and the subsequent birth of calves. | the following experiments investigated the use of sheep serum (ss) as a capacitating agent for red deer (cervus elaphus) sperm during in vitro fertilisation. red deer oocytes were collected at slaughter and matured in vitro for 24h in tcm-199 supplemented with 10% foetal calf serum, 10 microg ml(-1) fsh and lh, and 1microg ml(-1) of oestradiol. fertilisation medium was ivf-sof modified to contain 5mm ca(2+) and no glucose. experiment 1 investigated the addition of heparin, bsa (8 mg ml(-1)) or 2 ... | 2002 | 11841909 |
| crystal structure of a ternary sap-1/srf/c-fos sre dna complex. | combinatorial dna binding by proteins for promoter-specific gene activation is a common mode of dna regulation in eukaryotic organisms, and occurs at the promoter of the c-fos proto-oncogene. the c-fos promoter contains a serum response element (sre) that mediates ternary complex formation with the ets proteins sap-1 or elk-1 and the mads-box protein, serum response factor (srf). here, we report the crystal structure of a ternary sap-1/srf/c-fos sre dna complex containing the minimal dna-binding ... | 2001 | 11846562 |
| nonradioactive assay of flag-tagged mapk using anti-flag antibody-coated multiwell plates. | we have developed a rapid, sensitive, and quantitative 96-well microplate-based nonradioactive immunoprecipitation/kinase assay to evaluate mitogen-activated protein kinase (mapk) activity. three quantitative nonradioactive imunoprecipitation/kinase assays of mapk were demonstrated on a 96-well microplate coated with anti-flag m2 antibody (anti-flag m2 plate): (i) the capture of phosphorylated flag-tagged mapk fusion protein (flag-mapk) from phorbol esters-stimulated, flag-mapk-transfected cos-7 ... | 2002 | 11848420 |
| downregulation of c-fos gene transcription in cells transformed by e1a and cha-ras oncogenes: a role of sustained activation of map/erk kinase cascade and of inactive chromatin structure at c-fos promoter. | ref cells transformed by oncogenes e1a and cha-ras reveal high and constitutive dna-binding activity of ap-1 factor lacking in c-fos protein. consistently, the transcription of c-fos gene has been found to be downregulated. to elucidate the mechanisms of c-fos downregulation in e1a+cha-ras transformants, we studied the levels of activity of erk, jnk/sapk and p38 kinases and phosphorylation state of elk-1 transcription factor involved in regulation of c-fos gene. using two approaches, western blo ... | 2002 | 11850800 |
| ecdysone-inducible expression of oncogenic ha-ras in nih 3t3 cells leads to transient nuclear localization of activated extracellular signal-regulated kinase regulated by mitogen-activated protein kinase phosphatase-1. | the ras family of gtp-binding proteins are key transducers of extracellular signals, particularly through the mitogen-activated protein kinase (mapk) pathway. constitutively active forms of ras are found in a variety of tumours, suggesting an important role for this pathway in cancer. here we report that initial cellular exposure to oncogenic ras chronically activated the mapk pathway in the cytoplasm, but transiently activated the same pathway in the nucleus. nuclear-activated extracellular sig ... | 2002 | 11853538 |
| immunodiagnosis of experimental parelaphostrongylus tenuis infection in elk. | elk infected with the meningeal worm, parelaphostrongylus tenuis (protostrongylidae), do not consistently excrete larvae in feces, making the current method of diagnosing live animals using the baermann fecal technique unreliable. serological diagnosis could prove more useful in diagnosing field-infected animals but depends on the identification and availability of good quality antigen. to mimic field infections, 2 elk were inoculated with 6 infective l3 larvae of p. tenuis, and another 2 with 2 ... | 2002 | 11858642 |
| [role of the tcf phosphorylation state and the chromatin structure in the negative transcription regulation of the c-fos proto-oncogene in e1a + c-ha-ras transformed cells]. | as compared with normal rat embryo fibroblasts (ref), c-fos transcription is suppressed in ref transformed with the e1a and cha-ras complementing oncogenes. negative regulation of the fos promoter is due to the serum-responsive element (sre) constantly bound with the serum response factor (srf) and with the ternary complex factor (tcf), which form the srf/srf/tcf complex. possible mechanisms of the c-fos suppression were studied, including changes in the tcf content and phosphorylation and repla ... | 2002 | 11862715 |
| inhibition of mek1,2/erk mitogenic pathway by estrogen with antiproliferative properties in rat aortic smooth muscle cells. | proliferation and migration of vascular smooth muscle cells (vsmcs) are believed to contribute significantly to intimal thickening in atheroscleosis, restenosis, and venous bypass graft disease. estrogen inhibits proliferation and migration of vsmcs. however, antiproliferative mechanisms of estrogen were not well elucidated yet. in this study, we investigated the antiproliferative effect of estrogen to determine whether the transduction signals and protooncogenes were affected in rat aortic smoo ... | 2002 | 11867267 |
| hepatitis c virus core protein induces cell proliferation and activates erk, jnk, and p38 map kinases together with the map kinase phosphatase mkp-1 in a hepg2 tet-off cell line. | hepatitis c virus (hcv) core protein is a multifunctional protein interacting with cellular and viral proteins and promoters. a tetracycline-regulated system was used to generate a hepg2 tet-off cell line allowing regulated expression of a full-length (191 aa) and an n(c)-truncated core protein (160 aa). in this system hcv core protein expression activates extracellular signal-regulated kinase (erk), c-jun n-terminal kinase (jnk), and p38 mitogen-activated protein (map) kinase, induces map kinas ... | 2002 | 11878930 |
| a phylogenetic comparison of red deer and wapiti using mitochondrial dna. | a phylogeny was constructed for red deer/wapiti (cervus elaphus) subspecies using sequence data from the control region of mitochondrial dna (mtdna). the tree was rooted using cervus nippon (sika deer), cervus albirostris (thorold's white-lipped deer), and several odocoileinae species. a division between the mtdna haplotypes of red deer (european) and wapiti (asian/north american) corresponds to subspecies found on opposite sides of the himalayan mountains and gobi, which suggests wapiti should ... | 2002 | 11884159 |
| troglitazone activates p21cip/waf1 through the erk pathway in hct15 human colorectal cancer cells. | in this study, we identified a new mechanism for the anti-proliferation of hct15 colorectal cancer cells by troglitazone (tro). treating hct15 cells with 20 microm of tro transiently increased extracellular signal regulated kinase (erk) activity within 15 min, and this subsequently induced p21cip/waf1 cell cycle regulator and localized in the nucleus. raf-1 modification and mek activation also occurred after tro treatment, and elk-1-dependent trans-reporter gene expression was concomitantly indu ... | 2002 | 11888673 |
| long-term depression in the adult hippocampus in vivo involves activation of extracellular signal-regulated kinase and phosphorylation of elk-1. | protein kinase cascades likely play a critical role in the signaling events that underlie synaptic plasticity and memory. the extracellular signal-regulated kinase (erk) cascade is suited well for such a role because its targets include regulators of gene expression. here we report that the erk cascade is recruited during long-term depression (ltd) of synaptic strength in area ca1 of the adult hippocampus in vivo and selectively impacts on phosphorylation of the nuclear transcription factor elk- ... | 2002 | 11896145 |
| active, phosphorylation-dependent map kinases, mapk/erk, sapk/jnk and p38, and specific transcription factor substrates are differentially expressed following systemic administration of kainic acid to the adult rat. | excitotoxicity is considered a major cell death inductor in neurodegeneration. yet the mechanisms involved in cell death and cell survival following excitotoxic insults are poorly understood. expression of active, phosphorylation-dependent mitogen-activated extracellular signal-regulated kinases (mapk/erks), stress-activated c-jun n-terminal kinases (sapk/jnks) and p38 kinases, as well as their putative active, phosphorylation-dependent specific transcriptional factor substrates creb, elk-1, atf ... | 2002 | 11904760 |