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aedes aegypti uses rna interference in defense against sindbis virus infection.rna interference (rnai) is an important anti-viral defense mechanism. the aedes aegypti genome encodes rnai component orthologs, however, most populations of this mosquito are readily infected by, and subsequently transmit flaviviruses and alphaviruses. the goal of this study was to use ae. aegypti as a model system to determine how the mosquito's anti-viral rnai pathway interacts with recombinant sindbis virus (sinv; family togaviridae, genus alphavirus).200818366655
an essential role for pick1 in nmda receptor-dependent bidirectional synaptic plasticity.pick1 is a calcium-sensing, pdz domain-containing protein that interacts with glur2 and glur3 ampa receptor (ampar) subunits and regulates their trafficking. although pick1 has been principally implicated in long-term depression (ltd), pick1 overexpression in ca1 pyramidal neurons causes a camk- and pkc-dependent potentiation of ampar-mediated transmission and an increase in synaptic glur2-lacking ampars, mechanisms associated with nmda receptor (nmdar)-dependent long-term potentiation (ltp). he ...200818367088
a virus-encoded cell-cell fusion machine dependent on surrogate adhesins.the reovirus fusion-associated small transmembrane (fast) proteins function as virus-encoded cellular fusogens, mediating efficient cell-cell rather than virus-cell membrane fusion. with ectodomains of only approximately 20-40 residues, it is unclear how such diminutive viral fusion proteins mediate the initial stages (i.e. membrane contact and close membrane apposition) of the fusion reaction that precede actual membrane merger. we now show that the fast proteins lack specific receptor-binding ...200818369467
detection and analysis of protein isgylation.isg15 is a ubiquitin-like modifi er that is conjugated to target proteins by a sequential reaction catalyzed by e1/e2/e3 enzymes (protein isgylation). isg15 and protein isgylation are upregulated by interferon stimuli. isg15 functions as an antiviral protein against sindbis virus and hiv-1, but the molecular mechanism remains unknown. here we describe in detail methods for detecting and analyzing protein isgylation. the methods consist of plasmid transfection and affi nity purifi cation of isgyl ...200818373255
characterization of oligophrenin-1, a rhogap lost in patients affected with mental retardation: lentiviral injection in organotypic brain slice cultures.mutations in regulators and effectors of the rho gtpases underlie various forms of mental retardation (mr). among them, oligophrenin-1 (ophn1), which encodes a rho-gtpase activating protein, was one of the first rho-linked mr genes identified. upon characterization of ophn1 in hippocampal brain slices, we obtained evidence for the requirement of ophn1 in dendritic spine morphogenesis and neuronal function of ca1 pyramidal neurons. organotypic hippocampal brain slice cultures are commonly used as ...200818374170
the hiv-1 envelope glycoprotein gp120 features four heparan sulfate binding domains, including the co-receptor binding site.it is well established that the human immunodeficiency virus-1 envelope glycoprotein surface unit, gp120, binds to cell-associated heparan sulfate (hs). virus infectivity is increased by such interaction, and a variety of soluble polyanions efficiently neutralize immunodeficiency virus-1 in vitro. this interaction has been mainly attributed to the gp120 v3 loop. however, although evidence suggested that this particular domain does not fully recapitulate the binding activity of the protein, the a ...200818378683
diagnostics of pogosta disease: antigenic properties and evaluation of sindbis virus igm and igg enzyme immunoassays.sindbis virus (sinv) is a mosquito-borne causative agent of a fever-rash arthritis, pogosta disease, as verified recently by virus isolation from acutely ill patients. pogosta disease occurs annually, but it emerges as unique epidemics every 7 years in finland; over 10,000 patient samples have been analyzed for sinv antibodies, with over 2000 diagnosed acute sinv infections. however, the performance of these serological tests with a large number of samples has not been described before. the aim ...200818380591
different effect of proteasome inhibition on vesicular stomatitis virus and poliovirus replication.proteasome activity is an important part of viral replication. in this study, we examined the effect of proteasome inhibitors on the replication of vesicular stomatitis virus (vsv) and poliovirus. we found that the proteasome inhibitors significantly suppressed vsv protein synthesis, virus accumulation, and protected infected cells from toxic effect of vsv replication. in contrast, poliovirus replication was delayed, but not diminished in the presence of the proteasome inhibitors mg132 and borte ...200818382670
roles of lef-4 and ptp/bvp rna triphosphatases in processing of baculovirus late mrnas.the baculovirus autographa californica nucleopolyhedrovirus encodes two proteins with rna triphosphatase activity. late expression factor lef-4, which is an essential gene, is a component of the rna polymerase and also encodes the rna capping enzyme guanylyltransferase. ptp/bvp is also an rna triphosphatase, but is not essential for viral replication, possibly because its activity is redundant to that of lef-4. to elucidate the role of these proteins in mrna cap formation, a mutant virus that la ...200818385232
cleavage of group 1 coronavirus spike proteins: how furin cleavage is traded off against heparan sulfate binding upon cell culture adaptation.a longstanding enigmatic feature of the group 1 coronaviruses is the uncleaved phenotype of their spike protein, an exceptional property among class i fusion proteins. here, however, we show that some group 1 coronavirus spike proteins carry a furin enzyme recognition motif and can actually be cleaved, as demonstrated for a feline coronavirus. interestingly, this feature can be lost during cell culture adaptation by a single mutation in the cleavage motif; this, however, preserves a heparan sulf ...200818400867
selective ablation of proliferating astrocytes does not affect disease outcome in either acute or chronic models of motor neuron degeneration.astrocytes play important roles in normal cns function; however, following traumatic injury or during neurodegeneration, astrocytes undergo changes in morphology, gene expression and cellular function known as reactive astrogliosis, a process that may also include cell proliferation. at present, the role of astrocyte proliferation is not understood in disease etiology of neurodegenerative diseases such as amyotrophic lateral sclerosis (als), a fatal motor neuron disorder that is characterized by ...200818410928
stable synaptic retention of serine-880-phosphorylated glur2 in hippocampal neurons.phosphorylation of s880 within the glur2 c-terminus has been reported to promote endocytosis of ampa receptors (ampars) by preventing glur2 interaction with the putative synaptic anchoring proteins grip and abp. it is not yet established however, whether s880 phosphorylation induces removal of ampars from synaptic sites, and the trafficking of phosphorylated glur2 subunits with surface and endocytosed glur2 has not been directly compared within the same intact neurons. here we show that phosphor ...200818417360
a new role for ns polyprotein cleavage in sindbis virus replication.one of the distinguishing features of the alphaviruses is a sequential processing of the nonstructural polyproteins p1234 and p123. in the early stages of the infection, the complex of p123+nsp4 forms the primary replication complexes (rcs) that function in negative-strand rna synthesis. the following processing steps make nsp1+p23+nsp4, and later nsp1+nsp2+nsp3+nsp4. the latter mature complex is active in positive-strand rna synthesis but can no longer produce negative strands. however, the reg ...200818417571
sindbis virus conformational changes induced by a neutralizing anti-e1 monoclonal antibody.a rare sindbis virus anti-e1 neutralizing monoclonal antibody, sin-33, was investigated to determine the mechanism of in vitro neutralization. a cryoelectron microscopic reconstruction of sindbis virus (svhr) neutralized with fab from sin-33 (fab-33) revealed conformational changes on the surface of the virion at a resolution of 24 a. fab-33 was found to bind e1 in less than 1:1 molar ratios, as shown by the absence of fab density in the reconstruction and stoichiometric measurements using radio ...200818417595
semliki forest virus and sindbis virus vectors.semliki forest virus (sfv) and sindbis virus (sin) are two, positive-strand rna viruses of the alphavirus genus. vectors for both have been developed to express high levels of foreign genes in vitro and in vivo. basic protocol 1 describes the preparation of packaged sfv and sin replicons by co-electroporation of helper and vector rna into baby hamster kidney (bhk)-21 cells. basic protocol 2 describes the activation of packaged sfv replicons with a-chymotrypsin. basic protocol 3 provides a method ...200218428324
alphaviruses: semliki forest virus and sindbis virus vectors for gene transfer into neurons.alphaviral vectors based on semliki forest virus and sindbis virus infect many host cell types, causing rapid and high-level transgene expression. compared to other viruses used to infect cns cell and tissue preparations, semliki forest virus and sindbis virus exhibit an outstanding preference for neurons rather than glial cells. high-titer vector generation typically requires biosafety level 1 or 2 containment and occurs in less than 2 days. wild-type vectors are cytotoxic, permitting short-ter ...200718428656
development of robust antiviral assays for profiling compounds against a panel of positive-strand rna viruses using atp/luminescence readout.the development of antiviral assays using an atp/luminescence-based readout to profile antiviral compounds against the positive-strand rna viruses: yellow fever virus (yfv), west nile virus (wnv), sindbis virus, and coxsackie b virus, representing three virus families, is described. this assay readout is based upon the bioluminescent measurement of atp in metabolically active cells. antiviral efficacy was determined by measuring the atp level in cells that were protected from the viral cytopathi ...200818433887
the ring domain of ciap1 mediates the degradation of ring-bearing inhibitor of apoptosis proteins by distinct pathways.the inhibitor of apoptosis proteins (iaps) are key repressors of apoptosis. several iap proteins contain a ring domain that functions as an e3 ubiquitin ligase involved in the ubiquitin-proteasome pathway. here we investigated the interplay of ubiquitin-proteasome pathway and ring-mediated iap turnover. we found that the card-ring domain of ciap1 (ciap1-cr) is capable of down-regulating protein levels of ring-bearing iaps such as ciap1, ciap2, xiap, and livin, while sparing naip and survivin, wh ...200818434593
gamma-retroviral vectors enveloped with an antibody and an engineered fusogenic protein achieved antigen-specific targeting.development of methods to engineer gamma-retroviral vectors capable of transducing target cells in a cell-specific manner could impact the future of the clinical application of gene therapy as well as the understanding of the biology of transfer gene vectors. two molecular events are critical for controlling the entry of gamma-retroviral vectors to target cells: binding to cell-surface receptors and the subsequent fusion of viral vector membrane and cellular membrane. in this report, we evaluate ...200818435481
usutu virus sequences in culex pipiens (diptera: culicidae), spain. 200818439389
differential mechanisms of complement-mediated neutralization of the closely related paramyxoviruses simian virus 5 and mumps virus.the complement system is an important component of the innate immune response to virus infection. the role of human complement pathways in the in vitro neutralization of three closely related paramyxoviruses, simian virus 5 (sv5), mumps virus (muv) and human parainfluenza virus type 2 (hpiv2) was investigated. sera from ten donors showed high levels of neutralization against hpiv2 that was largely complement-independent, whereas nine of ten donor sera were found to neutralize sv5 and muv only in ...200818440578
development of a new noncytopathic semliki forest virus vector providing high expression levels and stability.alphavirus vectors express high levels of recombinant proteins in mammalian cells, but their cytopathic nature makes this expression transient. in order to generate a semliki forest virus (sfv) noncytopathic vector we introduced mutations previously described to turn sindbis virus noncytopathic into a conserved position in an sfv vector expressing lacz. interestingly, mutant p718t in replicase nsp2 subunit was able to replicate in only a small percentage of bhk cells, producing beta-gal-expressi ...200818442838
post-imaging fiducial markers aid in the orientation determination of complexes with mixed or unknown symmetry.during the entry process many icosahedral viruses must adopt a lower-order symmetry or incur a symmetry mismatch to release their genome through a single site. a membrane model system in which poliovirus was bound to receptor-decorated liposomes was used to pioneer techniques that studied the break in the symmetry of the initial attachment complex by cryo-electron microscopy. novel methods involving a fiducial marker for the membrane contact point were developed to objectively determine the symm ...200818442921
cholesterol effectively blocks entry of flavivirus.japanese encephalitis virus (jev) and dengue virus serotype 2 (den-2) are enveloped flaviviruses that enter cells through receptor-mediated endocytosis and low ph-triggered membrane fusion and then replicate in intracellular membrane structures. lipid rafts, cholesterol-enriched lipid-ordered membrane domains, are platforms for a variety of cellular functions. in this study, we found that disruption of lipid raft formation by cholesterol depletion with methyl-beta-cyclodextrin or cholesterol che ...200818448543
bac-mediated transgenic expression of fluorescent autophagic protein beclin 1 reveals a role for beclin 1 in lymphocyte development.beclin 1/atg6 is an essential component of the evolutionary conserved ptdins(3)-kinase (vps34) protein complex that regulates macroautophagy (autophagy) in eukaryotic cells and also interacts with antiapoptotic bcl-2 family members, bcl-2, and bcl-x(l). to elucidate the physiological function of beclin 1, we generated transgenic mice producing a green fluorescent beclin 1 protein (beclin 1-gfp) under beclin 1 endogenous regulation. the beclin 1-gfp transgene is functional because it completely r ...200818451870
protein kinase m zeta regulation of na/k atpase: a persistent neuroprotective mechanism of ischemic preconditioning in hippocampal slice cultures.in ischemic preconditioning, a sublethal ischemic insult protects neurons from subsequent ischemia. in organotypic hippocampal slice cultures a sublethal 5-minute hypoxia-hypoglycemia treatment prevented neuronal loss after a 10-minute experimental ischemic (ei) treatment of hypoxia-hypoglycemia. whereas preconditioning protected against ei given 24 h later, it did not protect when ei was given 2 h later, suggesting a slow development of neuroprotection. this model identified two regulators of i ...200818455703
arbovirus evolution in vivo is constrained by host alternation.the intrinsic plasticity of rna viruses can facilitate host range changes that lead to epidemics. however, evolutionary processes promoting cross-species transfers are poorly defined, especially for arthropod-borne viruses (arboviruses). in theory, cross species transfers by arboviruses may be constrained by their alternating infection of disparate hosts, where optimal replication in one host involves a fitness tradeoff for the other. accordingly, freeing arboviruses from alternate replication v ...200818458341
intra-peritoneal injection of polyclonal anti-interferon alpha antibodies cross the blood brain barrier and neutralize interferon alpha.the central nervous system (cns) is known to be an immunologically privileged organ in the body largely because the blood brain barrier (bbb) prevents the flow of large molecules, proteins, and cells from crossing into the cns from the periphery. these restrictive properties of the bbb have made it difficult to treat cns diseases. in this study, mice were infected intracranially (i.c.) with sindbis virus (sv) and then treated either i.c. or intraperitoneally (i.p.) with neutralizing antibodies a ...200818461447
fundamental issues in mosquito surveillance for arboviral transmission.marked spatiotemporal variabilities in mosquito infection of arboviruses, exemplified by the transmission of west nile virus (wnv) in america, require adaptive strategies for mosquito sampling, pool screening and data analyses. currently there is a lack of reliable and consistent measures of risk exposure, which may compromise comparison of surveillance data. based on quantitative reasoning, we critically examined fundamental issues regarding mosquito sampling design and estimation of transmissi ...200818466940
inhibition of alphavirus infection in cell culture and in mice with antisense morpholino oligomers.the genus alphavirus contains members that threaten human health, both as natural pathogens and as potential biological weapons. peptide-conjugated phosphorodiamidate morpholino oligomers (ppmo) enter cells readily and can inhibit viral replication through sequence-specific steric blockade of viral rna. sindbis virus (sinv) has low pathogenicity in humans and is regularly utilized as a model alphavirus. ppmo targeting the 5'-terminal and aug translation start site regions of the sinv genome bloc ...200818468653
molecular mechanisms of antibody-mediated neutralisation of flavivirus infection.flaviviruses are a group of positive-stranded rna viruses that cause a spectrum of severe illnesses globally in more than 50 million individuals each year. while effective vaccines exist for three members of this group (yellow fever, japanese encephalitis, and tick-borne encephalitis viruses), safe and effective vaccines for several other flaviviruses of clinical importance, including west nile and dengue viruses, remain in development. an effective humoral immune response is critical for protec ...200818471342
properties of non-structural protein 1 of semliki forest virus and its interference with virus replication.semliki forest virus (sfv) non-structural protein 1 (nsp1) is a major component of the virus replicase complex. it has previously been studied in cells infected with virus or using transient or stable expression systems. to extend these studies, tetracycline-inducible stable cell lines expressing sfv nsp1 or its palmitoylation-negative mutant (nsp16d) were constructed. the levels of protein expression and the subcellular localization of nsp1 in induced cells were similar to those in virus-infect ...200818474562
a five-amino-acid deletion of the eastern equine encephalitis virus capsid protein attenuates replication in mammalian systems but not in mosquito cells.eastern equine encephalitis virus (eeev) is a human and veterinary pathogen that causes sporadic cases of fatal neurological disease. we previously demonstrated that the capsid protein of eeev is a potent inhibitor of host cell gene expression and that this function maps to the amino terminus of the protein. we now identify amino acids 55 to 75, within the n terminus of the capsid, as critical for the inhibition of host cell gene expression. an analysis of stable eeev replicons expressing mutant ...200818480443
efficient trans-encapsidation of hepatitis c virus rnas into infectious virus-like particles.recently, complete replication of hepatitis c virus (hcv) in tissue culture was established using the jfh1 isolate. to analyze determinants of hcv genome packaging and virion assembly, we developed a system that supports particle production based on trans-packaging of subgenomic viral rnas. using jfh1 helper viruses, we show that subgenomic jfh1 replicons lacking the entire core to ns2 coding region are efficiently encapsidated into infectious virus-like particles. similarly, chimeric helper vir ...200818480457
visualization of targeted transduction by engineered lentiviral vectors.we have reported a method to target lentiviral vectors to specific cell types. this method requires the incorporation of two distinct molecules on the viral vector surface: one is an antibody that renders the targeting specificity for the engineered vector, and the other is a fusogenic protein that allows the engineered vector to enter the target cell. however, the molecular mechanism that controls the targeted infection needs to be defined. in this report, we tracked the individual lentiviral p ...200818480844
alphavirus production is inhibited in neurofibromin 1-deficient cells through activated ras signalling.virus-host interactions essential for alphavirus pathogenesis are poorly understood. to address this shortcoming, we coupled retrovirus insertional mutagenesis and a cell survival selection strategy to generate clonal cell lines broadly resistant to sindbis virus (sinv) and other alphaviruses. resistant cells had significantly impaired sinv production relative to wild-type (wt) cells, although virus binding and fusion events were similar in both sets of cells. analysis of the retroviral integrat ...200818485440
leishmania braziliensis infection induces dendritic cell activation, isg15 transcription, and the generation of protective immune responses.leishmania (viannia) braziliensis is the causative agent of cutaneous and mucosal leishmaniasis in south america, and the latter is a severe and disfiguring form of the disease. our understanding of how l. braziliensis parasites interact with dendritic cells (dcs) is limited, partially due to the difficulty in generating axenic amastigotes. in this study, we successfully generated axenic amastigotes of l. braziliensis and used them to test the hypothesis that l. braziliensis infection efficientl ...200818490754
role for conserved residues of sindbis virus nonstructural protein 2 methyltransferase-like domain in regulation of minus-strand synthesis and development of cytopathic infection.the plus-strand rna genome of sindbis virus (sinv) encodes four nonstructural proteins (nsp1 to nsp4) that are involved in the replication of the viral rna. the approximately 800-amino-acid nsp2 consists of an n-terminal domain with nucleoside triphosphatase and helicase activities and a c-terminal protease domain. recently, the structure determined for venezuelan equine encephalitis virus nsp2 indicated the presence of a previously unrecognized methyltransferase (mtase)-like domain within the c ...200818495773
the autophagy-related protein beclin 1 shows reduced expression in early alzheimer disease and regulates amyloid beta accumulation in mice.autophagy is the principal cellular pathway for degradation of long-lived proteins and organelles and regulates cell fate in response to stress. recently, autophagy has been implicated in neurodegeneration, but whether it is detrimental or protective remains unclear. here we report that beclin 1, a protein with a key role in autophagy, was decreased in affected brain regions of patients with alzheimer disease (ad) early in the disease process. heterozygous deletion of beclin 1 (becn1) in mice de ...200818497889
critical role of cdk5 and polo-like kinase 2 in homeostatic synaptic plasticity during elevated activity.homeostatic plasticity keeps neuronal spiking output within an optimal range in the face of chronically altered levels of network activity. little is known about the underlying molecular mechanisms, particularly in response to elevated activity. we report that, in hippocampal neurons experiencing heightened activity, the activity-inducible protein kinase polo-like kinase 2 (plk2, also known as snk) was required for synaptic scaling-a principal mechanism underlying homeostatic plasticity. synapti ...200818498738
west nile virus infection of drosophila melanogaster induces a protective rnai response.to determine if west nile virus (wnv) infection of insect cells induces a protective rnai response, drosophila melanogaster s2 and aedes albopictus c6/36 cells were infected with wnv, and the production of wnv-homologous small rnas was assayed as an indicator of rnai induction. a distinct population of approximately 25 nt wnv-homologous small rnas was detected in infected s2 cells but not c6/36 cells. rnai knockdown of argonaute 2 in s2 cells resulted in slightly increased susceptibility to wnv ...200818501400
ires-dependent replication of venezuelan equine encephalitis virus makes it highly attenuated and incapable of replicating in mosquito cells.the development of infectious cdna for different alphaviruses opened an opportunity to explore their attenuation by extensively modifying the viral genomes, an approach that might minimize or exclude the reversion to the wild-type, pathogenic phenotype. moreover, the genomes of such alphaviruses can be engineered to contain rna elements that would be functional only in cells of vertebrate, but not insect, origin. in the present study, we developed a recombinant veev that is more attenuated than ...200818501401
autophagy and viral neurovirulence.as terminally differentiated vital cells, neurons may be specialized to fight viral infections without undergoing cellular self-destruction. the cellular lysosomal degradation pathway, autophagy, is emerging as one such mechanism of neuronal antiviral defence. autophagy has diverse physiological functions, such as cellular adaptation to stress, routine organelle and protein turnover, and innate immunity against intracellular pathogens, including viruses. most of the in vivo evidence for an antiv ...200818503639
preclinical safety and biodistribution of sindbis virus measles dna vaccines administered as a single dose or followed by live attenuated measles vaccine in a heterologous prime-boost regimen.measles still causes considerable morbidity and mortality among infants and young children in developing countries. to develop a new public health tool to reduce this burden, we designed two sindbis virus replicon vaccines encoding measles virus (mv) hemagglutinin (h) and fusion (f) proteins (pmsin-h and pmsinhfdu). our goal is to administer the vaccines to young infants at 6 and 10 weeks of age to prime the immune system to safely and effectively respond to subsequent immunization at age approx ...200818507515
synthesis of genomic and subgenomic rna in mosquito cells infected with two sindbis virus nsp4 mutants: influence of intracellular nucleoside triphosphate concentrations.cells infected with sindbis virus (sv) make two positive-strand rnas, a genomic-length rna (g) rna and a subgenomic (sg) rna. in cells infected with svstd, and in general in cells infected with wt alphaviruses, more sg rna is made than g rna. how the balance between synthesis of g rna and sg rna is regulated is not known. svpzf and svcpc are nsp4 mutants of sv which, in mosquito cells, make more g rna than sg rna. when low concentrations of pyrazofurin (inhibits the synthesis of utp and ctp) wer ...200818508899
induction of broad cd4+ and cd8+ t-cell responses and cross-neutralizing antibodies against hepatitis c virus by vaccination with th1-adjuvanted polypeptides followed by defective alphaviral particles expressing envelope glycoproteins gpe1 and gpe2 and nonstructural proteins 3, 4, and 5.broad, multispecific cd4(+) and cd8(+) t-cell responses to the hepatitis c virus (hcv), as well as virus-cross-neutralizing antibodies, are associated with recovery from acute infection and may also be associated in chronic hcv patients with a favorable response to antiviral treatment. in order to recapitulate all of these responses in an ideal vaccine regimen, we have explored the use of recombinant hcv polypeptides combined with various th1-type adjuvants and replication-defective alphaviral p ...200818508900
zic2 regulates retinal ganglion cell axon avoidance of ephrinb2 through inducing expression of the guidance receptor ephb1.the navigation of retinal axons to ipsilateral and contralateral targets in the brain depends on the decision to cross or avoid the midline at the optic chiasm, a critical guidance maneuver that establishes the binocular visual pathway. previous work has identified a specific guidance receptor, ephb1, that mediates the repulsion of uncrossed axons away from its ligand, ephrinb2, at the optic chiasm midline (williams et al., 2003), and a transcription factor zic2, that, like ephb1, is required fo ...200818524895
silencing the genes for dopa decarboxylase or dopachrome conversion enzyme reduces melanization of foreign targets in anopheles gambiae.the production of melanin is a complex biochemical process in which several enzymes may play a role. although phenoloxidase and serine proteases are clearly key components, the activity of other enzymes, including dopa decarboxylase and dopachrome conversion enzyme may also be required. we tested the effect of knockdown of gene expression for these two enzymes on melanization of abiotic targets in the mosquito, anopheles gambiae. knockdown of dopa decarboxylase and dopachrome conversion enzyme r ...200818534885
mouse hepatitis virus type 2 enters cells through a clathrin-mediated endocytic pathway independent of eps15.it has recently been shown that cell entry of mouse hepatitis virus type 2 (mhv-2) is mediated through endocytosis (z. qiu et al., j. virol. 80:5768-5776, 2006). however, the molecular mechanism underlying mhv-2 entry is not known. here we employed multiple chemical and molecular approaches to determine the molecular pathways for mhv-2 entry. our results showed that mhv-2 gene expression and infectivity were significantly inhibited when cells were treated with chemical and physiologic blockers o ...200818550663
mouse hepatitis coronavirus rna replication depends on gbf1-mediated arf1 activation.coronaviruses induce in infected cells the formation of double membrane vesicles, which are the sites of rna replication. not much is known about the formation of these vesicles, although recent observations indicate an important role for the endoplasmic reticulum in the formation of the mouse hepatitis coronavirus (mhv) replication complexes (rcs). we now show that mhv replication is sensitive to brefeldin a (bfa). consistently, expression of a dominant-negative mutant of arf1, known to mimic t ...200818551169
hyperisgylation of old world monkey isg15 in human cells.isg15 is an ubiquitin-like protein, highly induced by type i interferons. upon the cooperative activity of specific ubiquitinating enzymes, isg15 can be conjugated to its substrates. increasing evidence points to a role for protein isgylation in anti-viral and anti-tumoral defense.200818560560
a mouse-passaged dengue virus strain with reduced affinity for heparan sulfate causes severe disease in mice by establishing increased systemic viral loads.the four serotypes of dengue virus (denv1 to denv4) cause extensive morbidity and mortality. a major obstacle to studying disease pathogenesis and developing therapies has been the lack of a small-animal model. we previously reported isolation of a denv2 strain, obtained by passaging a clinical isolate between mosquito cells and mice, that caused severe denv disease in mice and contained multiple mutations, including many in domain ii of the envelope (e) protein. here, we describe a recombinant ...200818562532
substrate-binding sites of ubr1, the ubiquitin ligase of the n-end rule pathway.substrates of a ubiquitin-dependent proteolytic system called the n-end rule pathway include proteins with destabilizing n-terminal residues. n-recognins, the pathway's ubiquitin ligases, contain three substrate-binding sites. the type-1 site is specific for basic n-terminal residues (arg, lys, and his). the type-2 site is specific for bulky hydrophobic n-terminal residues (trp, phe, tyr, leu, and ile). we show here that the type-1/2 sites of ubr1, the sole n-recognin of the yeast saccharomyces ...200818566452
the cell biology of autophagy in metazoans: a developing story.the cell biological phenomenon of autophagy (or ;self-eating') has attracted increasing attention in recent years. in this review, we first address the cell biological functions of autophagy, and then discuss recent insights into the role of autophagy in animal development, particularly in c. elegans, drosophila and mouse. work in these and other model systems has also provided evidence for the involvement of autophagy in disease processes, such as neurodegeneration, tumorigenesis, pathogenic in ...200818567846
a paramyxovirus-vectored intranasal vaccine against ebola virus is immunogenic in vector-immune animals.ebola virus (ebov) causes outbreaks of a highly lethal hemorrhagic fever in humans. the virus can be transmitted by direct contact as well as by aerosol and is considered a potential bioweapon. because direct immunization of the respiratory tract should be particularly effective against infection of mucosal surfaces, we previously developed an intranasal vaccine based on replication-competent human parainfluenza virus type 3 (hpiv3) expressing ebov glycoprotein gp (hpiv3/ebogp) and showed that i ...200818570964
age and gender related differences in human parotid gland gene expression.the present study evaluated differences in gene expression associated with age and gender in the human parotid gland.200818571147
deficiency of a potential 3p21.3 tumor suppressor gene ube1l (uba7) does not accelerate lung cancer development in k-rasla2 mice.genetic lesions in chromosomal region 3p21.3 marks one of the earliest events in human lung cancer development. it is hypothesized that one or more tumor suppressor genes reside in this region. identification and characterization of these genes are important for the understanding of lung cancer initiation. ube1l (uba7) is a long-suspected 3p21.3 residing tumor suppressor gene. it encodes the key enzyme that activates isgylation, a novel, ubiquitination-like, post-translational protein modificati ...200918571763
targeted cell entry of lentiviral vectors.retargeting of lentiviral vector entry to cell types of interest is a key factor in improving the safety and efficacy of gene transfer. in this study we show that the retargetable envelope glycoproteins of measles virus (mv), namely, the hemagglutinin (h) responsible for receptor recognition and the fusion protein (f), can pseudotype human immunodeficiency virus 1 (hiv-1) vectors when their cytoplasmic tails are truncated. we then pseudotyped hiv-1 vectors with mv glycoproteins displaying on h e ...200818578012
activity-induced polo-like kinase 2 is required for homeostatic plasticity of hippocampal neurons during epileptiform activity.homeostatic plasticity mechanisms stabilize the activity of a neuron or neuronal circuit during prolonged periods of increased network activity and have been proposed to function in the prevention of epilepsy. how homeostatic plasticity is achieved at the molecular level during hyperactivity states in general, and during epileptiform activity in particular, is unclear. using organotypic hippocampal slice cultures as a model system, we found that the protein kinase polo-like kinase 2 (plk2) was i ...200818579731
alphavirus replicon particles acting as adjuvants promote cd8+ t cell responses to co-delivered antigen.alphavirus replicon particles induce strong antibody and cd8+ t cell responses to expressed antigens in numerous experimental systems. we have recently demonstrated that venezuelan equine encephalitis virus replicon particles (vrp) possess adjuvant activity for systemic and mucosal antibody responses. in this report, we demonstrate that vrp induced an increased and balanced serum igg subtype response to co-delivered antigen, with simultaneous induction of antigen-specific igg1 and igg2a antibodi ...200818582997
[isolation of influenza virus a (orthomyxoviridae, influenza a virus), dhori virus (orthomyxoviridae, thogotovirus), and newcastle's disease virus (paromyxoviridae, avulavirus) on the malyi zhemchuzhnyi island in the north-western area of the caspian sea].the paper presents the results of the 2003 and 2006 environmental virological monitoring surveys on the malyi zhemchuzhnyi island where a large breeding colony of sea gull (laridae) is located. in the past several years, expansion of cormorants (phalacrocorax carbo) has enhanced the intensity of populational interactions. the investigators isolated 13 strains of influenza a virus (orthomyxoviridae, influenza a virus) subtype h13n1 (from sea gulls (n = 4), cormorants (n = 9) 1 strain of dhori vir ...200818590134
targeting lentiviral vectors to antigen-specific immunoglobulins.gene transfer into b cells by lentivectors can provide an alternative approach to managing b lymphocyte malignancies and autoreactive b cell-mediated autoimmune diseases. these pathogenic b cell populations can be distinguished by their surface expression of monospecific immunoglobulin. development of a novel vector system to deliver genes to these specific b cells could improve the safety and efficacy of gene therapy. we have developed an efficient method to target lentivectors to monospecific ...200818590376
the dynamic envelope of a fusion class ii virus. e3 domain of glycoprotein e2 precursor in semliki forest virus provides a unique contact with the fusion protein e1.in alphaviruses, here represented by semliki forest virus, infection requires an acid-responsive spike configuration to facilitate membrane fusion. the creation of this relies on the chaperone function of glycoprotein e2 precursor (p62) and its maturation cleavage into the small external e3 and the membrane-anchored e2 glycoproteins. to reveal how the e3 domain of p62 exerts its control of spike functions, we determine the structure of a p62 cleavage-impaired mutant virus particle (sql) by elect ...200818596032
preferential cytolysis of peripheral memory cd4+ t cells by in vitro x4-tropic human immunodeficiency virus type 1 infection before the completion of reverse transcription.cd4+ t-cell depletion is the hallmark of aids pathogenesis. multiple mechanisms may contribute to the death of productively infected cd4+ t cells and innocent-bystander cells. in this study, we characterize a novel mechanism in which human immunodeficiency virus type 1 (hiv-1) infection preferentially depletes peripheral memory cd4+ t cells before the completion of reverse transcription. using a recombinant hiv-1 carrying the green fluorescent protein reporter gene, we demonstrate that memory cd ...200818596085
molecular defects caused by temperature-sensitive mutations in semliki forest virus nsp1.alphavirus replicase protein nsp1 has multiple functions during viral rna synthesis. it catalyzes methyltransferase and guanylyltransferase activities needed in viral mrna capping, attaches the viral replication complex to cytoplasmic membranes, and is required for minus-strand rna synthesis. two temperature-sensitive (ts) mutations in semliki forest virus (sfv) were previously identified within nsp1: ts10 (e529d) and ts14 (d119n). recombinant viruses containing these individual mutations reprod ...200818596091
survival of enveloped and non-enveloped viruses on surfaces compared with other micro-organisms and impact of suboptimal disinfectant exposure.survival of enveloped and non-enveloped viruses was compared with that of bacteria, yeasts and mycobacteria when dried on the surface of polyvinyl chloride test carriers in the presence or absence of an organic matrix. the efficacy of glutaraldehyde and accelerated hydrogen peroxide (ahp) disinfectants was evaluated. reovirus, a non-enveloped virus, persisted and had a rf of 2 after 30 days whereas enterococcus faecalis had an rf of 4 over the same time period. the other test organisms (sindbis ...200818602193
vaccinia virus e3 protein prevents the antiviral action of isg15.the ubiquitin-like modifier isg15 is one of the most predominant proteins induced by type i interferons (ifn). in this study, murine embryo fibroblast (mefs) and mice lacking the gene were used to demonstrate a novel role of isg15 as a host defense molecule against vaccinia virus (vacv) infection. in mefs, the growth of replication competent western reserve (wr) vacv strain was affected by the absence of isg15, but in addition, virus lacking e3 protein (vvdeltae3l) that is unable to grow in isg1 ...200818604270
the aedes aegypti toll pathway controls dengue virus infection.aedes aegypti, the mosquito vector of dengue viruses, utilizes its innate immune system to ward off a variety of pathogens, some of which can cause disease in humans. to date, the features of insects' innate immune defenses against viruses have mainly been studied in the fruit fly drosophila melanogaster, which appears to utilize different immune pathways against different types of viruses, in addition to an rna interference-based defense system. we have used the recently released whole-genome s ...200818604274
nitrosylation of isg15 prevents the disulfide bond-mediated dimerization of isg15 and contributes to effective isgylation.the expression of the ubiquitin-like molecule isg15 (ucrp) and protein modification by isg15 (isgylation) are strongly activated by interferon, genotoxic stress, and pathogen infection, suggesting that isg15 plays an important role in innate immune responses. inducible nitric-oxide synthase (inos) is induced by the similar stimuli as isg15 and enhances the production of nitric oxide (no), a pleiotropic free radical with antipathogen activity. here, we report that cysteine residues (cys-76 and -1 ...200818606809
ubiquitination is required for effective replication of coxsackievirus b3.protein ubiquitination and/or degradation by the ubiquitin/proteasome system (ups) have been recognized as critical mechanisms in the regulation of numerous essential cellular functions. the importance of the ups in viral pathogenesis has become increasingly apparent. using murine cardiomyocytes, we have previously demonstrated that the ups plays a key role in the replication of coxsackievirus b3 (cvb3), an important human pathogen associated with various diseases. to further elucidate the under ...200818612413
enhanced interferon production from chick embryo cells aged in in vitro.the plaque-forming efficiency of sindbis virus decreased as much as 1000-fold, and plaque size was diminished markedly, when tested on chick embryo cell monolayers aged in vitro. the plaquing efficiency and plaque size of newcastle disease virus was unaffected. the reaction(s) associated with aging in vitro which lead to lowered plaquing efficiency are slowed considerably when cell monolayers are: (1) established in simpson-hirst medium rather than standard growth medium; (2) held at 31 degrees ...196718614054
replication of sindbis virus. iii. an electron microscopic study of virus maturation using the surface replica technique.we have examined surface replicas of chick embryo cells infected with sindbis virus. in some cells the virus buds over extensive areas of the cell surface, although there are areas where budding virus is clustered and other regions almost devoid of budding figures. in other cells, virus budding occurs primarily or exclusively at the periphery of the monolayer cells. budding in these cells often occurs in long processes extending from the cell, which have widths from one to several virion diamete ...197318620201
density-dependent competitive suppression of sylvatic dengue virus by endemic dengue virus in cultured mosquito cells.mosquito-borne dengue viruses are maintained in two discrete transmission cycles: a sylvatic cycle between nonhuman primates and sylvatic aedes mosquitoes, and an endemic cycle between humans and peridomestic aedes (primarily ae. aegypti and ae. albopictus). most sylvatic strains are genetically distinct from endemic strains, and human infections with sylvatic strains have been detected only rarely. interestingly, sylvatic strains replicate as well as endemic strains in ae. aegypti and experimen ...200818620509
evidence for interferon production and its correlation with yf 17dd vaccine virus yields in primary chick embryo cells.early experiments have resulted in the establishment of an efficient methodology for the production of a yellow fever vaccine in chicken embryo fibroblasts (cef) using the 17dd virus strain [freire, m.s., mann, g.f., marchevsky, r.s., yamamura, a.m., almeida, l.f., jabor, a.v., malachias, j.m., coutinho, e.s., galler, r., 2005. production of yellow fever 17dd vaccine virus in primary culture of chicken embryo fibroblasts: yields, thermo and genetic stability, attenuation and immunogenicity. vacc ...200818621087
host restriction factors blocking retroviral replication.retroviruses are highly successful intracellular parasites, and as such they are found in nearly all branches of life. some are relatively benign, but many are highly pathogenic and can cause either acute or chronic diseases. therefore, there is tremendous selective pressure on the host to prevent retroviral replication, and for this reason cells have evolved a variety of restriction factors that act to inhibit or block the viruses. this review is a survey of the best-characterized restriction f ...200818624631
analysis of venezuelan equine encephalitis replicon particles packaged in different coats.the venezuelan equine encephalitis (vee) virus replicon system was used to produce virus-like replicon particles (vrp) packaged with a number of different vee-derived glycoprotein (gp) coats. the gp coat is believed to be responsible for the cellular tropism noted for vrp and it is possible that different vee gp coats may have different affinities for cells. we examined vrp packaged in four different vee gp coats for their ability to infect cells in vitro and to induce both humoral and cellular ...200818628938
differential cholesterol binding by class ii fusion proteins determines membrane fusion properties.the class ii fusion proteins of the alphaviruses and flaviviruses mediate virus infection by driving the fusion of the virus membrane with that of the cell. these fusion proteins are triggered by low ph, and their structures are strikingly similar in both the prefusion dimer and the postfusion homotrimer conformations. here we have compared cholesterol interactions during membrane fusion by these two groups of viruses. using cholesterol-depleted insect cells, we showed that fusion and infection ...200818632857
bluetongue virus: dissection of the polymerase complex.bluetongue is a vector-borne viral disease of ruminants that is endemic in tropical and subtropical countries. since 1998 the virus has also appeared in europe. partly due to the seriousness of the disease, bluetongue virus (btv), a member of genus orbivirus within the family reoviridae, has been a subject of intense molecular study for the last three decades and is now one of the best understood viruses at the molecular and structural levels. btv is a complex non-enveloped virus with seven stru ...200818632949
cd8+ t lymphocytes control murine cytomegalovirus replication in the central nervous system of newborn animals.human cmv infection of the neonatal cns results in long-term neurologic sequelae. to define the pathogenesis of fetal human cmv cns infections, we investigated mechanisms of virus clearance from the cns of neonatal balb/c mice infected with murine cmv (mcmv). virus titers peaked in the cns between postnatal days 10-14 and infectious virus was undetectable by postnatal day 21. congruent with virus clearance was the recruitment of cd8(+) t cells into the cns. depletion of cd8(+) t cells resulted i ...200818641350
sv(lm21), a mutant of sindbis virus able to grow in aedes albopictus cells in the absence of methionine, shows increased sensitivity to s-adenosylhomocysteine hydrolase inhibitors such as neplanocin a.inhibition of s-adenosylhomocysteine (adohcy) hydrolase by compounds such as neplanocin a (npa) leads to the build-up of adohcy and the inhibition of methyltransferase enzymes. whether assayed by efficiency of plaquing or virus yield, svlm21, a mutant of sindbis virus resistant to methionine deprivation, was more sensitive to npa than was the standard virus (svstd) from which it was derived. for example, whereas 10 microg npa/ml depressed the yield of svlm21 by more than 30-fold, the yield of sv ...198818644581
activity of the small modified amino acid alpha-hydroxy glycineamide on in vitro and in vivo human immunodeficiency virus type 1 capsid assembly and infectivity.upon maturation of the human immunodeficiency virus type 1 (hiv-1) virion, proteolytic cleavage of the gag precursor protein by the viral protease is followed by morphological changes of the capsid protein p24, which will ultimately transform the virus core from an immature spherical to a mature conical structure. virion infectivity is critically dependent on the optimal semistability of the capsid cone structure. we have reported earlier that glycineamide (g-nh(2)), when added to the culture me ...200818644965
molecular engineering of viral gene delivery vehicles.viruses can be engineered to efficiently deliver exogenous genes, but their natural gene delivery properties often fail to meet human therapeutic needs. therefore, engineering viral vectors with new properties, including enhanced targeting abilities and resistance to immune responses, is a growing area of research. this review discusses protein engineering approaches to generate viral vectors with novel gene delivery capabilities. rational design of viral vectors has yielded successful advances ...200818647114
protein kinase a mediates activity-dependent kv4.2 channel trafficking.the a-type potassium channel subunit kv4.2 influences hippocampal function through regulation of dendritic excitability, and changes in kv4.2 surface expression alter synaptic plasticity. recent data from our laboratory demonstrate that egfp (enhanced green fluorescent protein)-tagged kv4.2 channels located in dendritic spines are internalized in an activity-dependent manner after synaptic stimulation and during chemically induced long-term potentiation. however, the molecular trigger for kv4.2 ...200818650329
effector cd4+ t-cell involvement in clearance of infectious herpes simplex virus type 1 from sensory ganglia and spinal cords.in primary infection, cd8(+) t cells are important for clearance of infectious herpes simplex virus (hsv) from sensory ganglia. in this study, evidence of cd4(+) t-cell-mediated clearance of infectious hsv type 1 (hsv-1) from neural tissues was also detected. in immunocompetent mice, hsv-specific cd4(+) t cells were present in sensory ganglia and spinal cords coincident with hsv-1 clearance from these sites and remained detectable at least 8 months postinfection. neural cd4(+) t cells isolated a ...200818667492
murine coronavirus mouse hepatitis virus is recognized by mda5 and induces type i interferon in brain macrophages/microglia.the coronavirus mouse hepatitis virus (mhv) induces a minimal type i interferon (ifn) response in several cell types in vitro despite the fact that the type i ifn response is important in protecting the mouse from infection in vivo. when infected with mhv, mice deficient in ifn-associated receptor expression (ifnar(-/-)) became moribund by 48 h postinfection. mhv also replicated to higher titers and exhibited a more broad tissue tropism in these mice, which lack a type i ifn response. interestin ...200818667505
kv4 accessory protein dppx (dpp6) is a critical regulator of membrane excitability in hippocampal ca1 pyramidal neurons.a-type k+ currents have unique kinetic and voltage-dependent properties that allow them to finely tune synaptic integration, action potential (ap) shape and firing patterns. in hippocampal ca1 pyramidal neurons, kv4 channels make up the majority of the somatodendritic a-type current. studies in heterologous expression systems have shown that kv4 channels interact with transmembrane dipeptidyl-peptidase-like proteins (dppls) to regulate the surface trafficking and biophysical properties of kv4 ch ...200818667548
ras signaling mechanisms underlying impaired glur1-dependent plasticity associated with fragile x syndrome.fragile x syndrome, caused by the loss of fmr1 gene function and loss of fragile x mental retardation protein (fmrp), is the most commonly inherited form of mental retardation. the syndrome is characterized by associative learning deficits, reduced risk of cancer, dendritic spine dysmorphogenesis, and facial dysmorphism. however, the molecular mechanism that links loss of function of fmr1 to the learning disability remains unclear. here, we report an examination of small gtpase ras signaling and ...200818667617
the capsid-coding region hairpin element (chp) is a critical determinant of dengue virus and west nile virus rna synthesis.dengue virus (denv) and west nile virus (wnv) are members of the flavivirus genus of positive-strand rna viruses. rna sequences and structures, primarily in the untranslated regions, have been shown to modulate flaviviral gene expression and genome replication. previously, we demonstrated that a structure in the denv coding region (chp) enhances translation start codon selection and is required for viral replication. here we further characterize the role of the chp in the denv life cycle. we dem ...200818676000
downregulation of protein disulfide isomerase in sepsis and its role in tumor necrosis factor-alpha release.protein disulfide isomerase (pdi) is an important factor for the protein modification step in the post-translational event. pdi plays an essential role in cell survival under various stress conditions. it has been reported that pdi can serve as a negative regulator of nuclear factor-kappa-b (nf-kappab) and that it can inhibit lipopolysaccharide (lps)-induced proinflammatory cytokine production in macrophages. thus, pdi may be an intracellular anti-inflammatory molecule. although we have previous ...200818680601
oncolytic vaccinia virus: from bedside to benchtop and back.the field of oncolytic viral therapy has undergone a major shift in focus in the last few years. less research has been directed at making incremental improvements in original vectors based mainly on strains of adenovirus and hsv; instead a variety of different viral strains have been suggested as potential backbones for future oncolytic viruses (including newcastle disease virus, reovirus, vesicular stomatitis virus, polio virus, retrovirus, sindbis virus, picornavirus, mumps and measles virus) ...200818683104
different types of nsp3-containing protein complexes in sindbis virus-infected cells.alphaviruses represent a serious public health threat and cause a wide variety of diseases, ranging from severe encephalitis, which can result in death or neurological sequelae, to mild infection, characterized by fever, skin rashes, and arthritis. in the infected cells, alphaviruses express only four nonstructural proteins, which function in the synthesis of virus-specific rnas and in modification of the intracellular environment. the results of our study suggest that sindbis virus (sinv) infec ...200818684830
the requirement of reactive oxygen intermediates for lymphocytic choriomeningitis virus binding and growth.multiple viruses induce reactive oxygen intermediate (roi) generation during infection that plays an important role in growth. we have examined the importance of roi during lymphocytic choriomeningitis virus (lcmv) infection of immortalized bhk-21 cells and murine peritoneal macrophages. within 15 min of virus addition, intracellular roi levels increased. to examine the contribution of roi to lcmv infection, cells were pretreated with antioxidant prior to virus addition. antioxidant treatment in ...200818691729
chimeric alphavirus vaccine candidates for chikungunya.chikungunya virus (chikv) is an emerging alphavirus that has caused major epidemics in india and islands off the east coast of africa since 2005. importations into europe and the americas, including one that led to epidemic transmission in italy during 2007, underscore the risk of endemic establishment elsewhere. because there is no licensed human vaccine, and an attenuated investigational new drug product developed by the u.s. army causes mild arthritis in some vaccinees, we developed chimeric ...200818692107
trafficking and intracellular atpase activity of human ecto-nucleotidase ntpdase3 and the effect of er-targeted ntpdase3 on protein folding.ecto-nucleoside triphosphate diphosphohydrolases, ntpdase1 (cd39) and ntpdase3, are integral plasma membrane proteins that hydrolyze extracellular nucleotides, thereby modulating the function of purinergic receptors. during processing in the secretory pathway, the active sites of ecto-nucleotidases are located in the lumen of vesicular compartments, thus raising the question whether the ecto-nucleotidases affect the atp-dependent processes in these compartments, including protein folding in the ...200818693757
pathogenic role of natural killer t and natural killer cells in acetaminophen-induced liver injury in mice is dependent on the presence of dimethyl sulfoxide.dimethyl sulfoxide (dmso) is commonly used in biological studies to dissolve drugs and enzyme inhibitors with low solubility. although dmso is generally thought of as being relatively inert, it can induce biological effects that are often overlooked. an example that highlights this potential problem is found in a recent report demonstrating a pathogenic role for natural killer t (nkt) and natural killer (nk) cells in acetaminophen-induced liver injury (aili) in c57bl/6 mice in which dmso was use ...200818712839
a duplex real-time reverse transcriptase polymerase chain reaction assay for the detection of st. louis encephalitis and eastern equine encephalitis viruses.a duplex taqman real-time reverse transcriptase polymerase chain reaction (pcr) assay was developed for the detection of st. louis encephalitis virus (slev) and eastern equine encephalitis virus (eeev), for use in human and vector surveillance. the respective targets selected for the assay were the conserved ns5 and e1 genes of the 2 viruses. because of the insufficient number of ns5 sequences from slev strains in the genbank database, we determined the sequence of an approximately 1-kb region f ...200818715737
regulation of postsynaptic rapgap spar by polo-like kinase 2 and the scfbeta-trcp ubiquitin ligase in hippocampal neurons.the ubiquitin-proteasome pathway (upp) regulates synaptic function, but little is known about specific upp targets and mechanisms in mammalian synapses. we report here that the scf(beta-trcp) complex, a multisubunit e3 ubiquitin ligase, targets the postsynaptic spine-associated rap gtpase activating protein (spar) for degradation in neurons. spar degradation by scf(beta-trcp) depended on the activity-inducible protein kinase polo-like kinase 2 (plk2). in the presence of plk2, spar physically ass ...200818723513
cre-dependent expression of multiple transgenes in isolated neurons of the adult forebrain.transgenic mice with mosaic, golgi-staining-like expression of enhanced green fluorescent protein (egfp) have been very useful in studying the dynamics of neuronal structure and function. in order to further investigate the molecular events regulating structural plasticity, it would be useful to express multiple proteins in the same sparse neurons, allowing co-expression of functional proteins or co-labeling of subcellular compartments with other fluorescent proteins. however, it has been diffic ...200818725976
[serological monitoring of arbovirus infections in the estuary of the kuban river (the 2006-2007 data)].solid-phase enzyme immunoassay, neutralization test, and the hemagglutination-inhibition test were used to study the sera from human beings (152 samples), agricultural animals (n = 77), hares (n = 3), and wild birds (n = 69), collected in 2006-2007 in the kuban river estuary (temryuk district, krasnodar territory). there were specific antibodies against viruses of west nile (wh), tick-borne encephalitis (tbe) (flaviviridae, flavivirus), sindbis (togaviridae, alphavirus), the antigenic complex of ...200818756814
sindbis virus vectors elicit hemagglutinin-specific humoral and cellular immune responses and offer a dose-sparing strategy for vaccination.we report here on the use of a sindbis virus-based dna-launch rna replicon vector (psin-ha) that expresses influenza hemagglutinin (ha) as an immunogen. immunization of mice with psin-ha generated anti-ha antibody and ctl responses and resulted in lower lung viral titers after influenza challenge when compared to controls. importantly, immunization with a low dose of psin-ha mediated significantly reduced lung viral titers following challenge at 43 weeks after the final immunization. in contrast ...200818761047
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