Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
1,662
result(s) for
"Ng, James"
Sort by:
Systemic and Phloem‐Specific Protein Targeting by High Affinity Nanobodies Expressed From a Plant RNA Virus Vector
The emergence of nanobodies (Nbs) has kindled an avid interest for their use in genetic engineering and plant biotechnology. In planta expression of Nbs has relied on either stable or transient transformation approaches that are lengthy and cannot support systemic expression, respectively. In addition, there is no precedence for studies on tissue‐specific expression of Nbs. To address these issues, viral vectors could be used as an alternative, but this has not been shown. Here, this proof‐of‐concept study establishes a platform to demonstrate the phloem‐specific targeting of proteins by Nbs expressed from a citrus tristeza virus‐based vector. The vector facilitates anti‐green fluorescent protein (GFP) Nb production within the phloem of transgenic Nicotiana benthamiana plants expressing a GFP‐fused endoplasmic reticulum‐targeting peptide and that of a microtubule marker line expressing GFP‐fused α‐tubulin 6. The interaction between anti‐GFP Nb and the GFP‐tagged peptide/protein is corroborated by both pull‐down assays and fluorescence resonance energy transfer‐fluorescence lifetime imaging microscopy (FRET‐FLIM) measurements. This proof‐of‐concept platform—including validation of Nb–antigen interaction in the phloem by FRET‐FLIM analysis, which has not been described in the literature—is novel for exploring Nb‐mediated functions applicable to targeting or identifying phloem proteins and those co‐opted into the virus infection process. This proof‐of‐concept study, with validation by pull‐down assays and FRET‐FLIM measurements, establishes a platform for targeting proteins in the phloem by nanobodies expressed from a viral vector.
Journal Article
Baxter turns down his buzz : a story for little kids about ADHD
\"A high-energy rabbit that must learn to control his activity level and impulsiveness. Baxter's uncle Barnaby guides Baxter through the steps necessary to 'turn down his buzz.' Techniques such as mindfulness, progressive relaxation, and visualization are employed\"-- Provided by publisher.
Book
virus capsid component mediates virion retention and transmission by its insect vector
Numerous pathogens of humans, animals, and plants are transmitted by specific arthropod vectors. However, understanding the mechanisms governing these pathogen–vector interactions is hampered, in part, by the lack of easy-to-use analytical tools. We investigated whitefly transmission of Lettuce infectious yellows virus (LIYV) by using a unique immunofluorescent localization approach in which we fed virions or recombinant virus capsid components to whiteflies, followed by feeding them antibodies to the virions or capsid components, respectively. Fluorescent signals, indicating the retention of virions, were localized in the anterior foregut or cibarium of a whitefly vector biotype but not within those of a whitefly nonvector biotype. Retention of virions in these locations strongly corresponded with the whitefly vector transmission of LIYV. When four recombinant LIYV capsid components were individually fed to whitefly vectors, significantly more whiteflies retained the recombinant minor coat protein (CPm). As demonstrated previously and in the present study, whitefly vectors failed to transmit virions preincubated with anti-CPm antibodies but transmitted virions preincubated with antibodies recognizing the major coat protein (CP). Correspondingly, the number of insects that specifically retained virions preincubated with anti-CPm antibodies were significantly reduced compared with those that specifically retained virions preincubated with anti-CP antibodies. Notably, a transmission-defective CPm mutant was deficient in specific virion retention, whereas the CPm-restored virus showed WT levels of specific virion retention and transmission. These data provide strong evidence that transmission of LIYV is determined by a CPm-mediated virion retention mechanism in the anterior foregut or cibarium of whitefly vectors.
Journal Article
The secret of Ashona
With a romance brewing between him and Bethany, the discovery that his brother and sister are secretly king and queen of the Fairy world, plus the Stain brothers growing more and more underhanded, fourteen-year-old Erec is not in the right state of mind for his next two tasks.
Book
Split green fluorescent protein as a tool to study infection with a plant pathogen, Cauliflower mosaic virus
The split GFP technique is based on the auto-assembly of GFP when two polypeptides-GFP1-10 (residues 1-214; the detector) and GFP11 (residues 215-230; the tag)-both non-fluorescing on their own, associate spontaneously to form a fluorescent molecule. We evaluated this technique for its efficacy in contributing to the characterization of Cauliflower mosaic virus (CaMV) infection. A recombinant CaMV with GFP11 fused to the viral protein P6 (a key player in CaMV infection and major constituent of viral factory inclusions that arise during infection) was constructed and used to inoculate transgenic Arabidopsis thaliana expressing GFP1-10. The mutant virus (CaMV 11P6) was infectious, aphid-transmissible and the insertion was stable over many passages. Symptoms on infected plants were delayed and milder. Viral protein accumulation, especially of recombinant 11P6, was greatly decreased, impeding its detection early in infection. Nonetheless, spread of infection from the inoculated leaf to other leaves was followed by whole plant imaging. Infected cells displayed in real time confocal laser scanning microscopy fluorescence in wild type-looking virus factories. Thus, it allowed for the first time to track a CaMV protein in vivo in the context of an authentic infection. 11P6 was immunoprecipitated with anti-GFP nanobodies, presenting a new application for the split GFP system in protein-protein interaction assays and pro-teomics. Taken together, split GFP can be an attractive alternative to using the entire GFP for protein tagging.
Journal Article
Baxter and Danny stand up to bullying
Buford Blue Jay's bullying drives Baxter and Danny to an open field, where they meet Queen Beth of the Bees who calms them and guides them in helping their friends.
Book
A balance between vector survival and virus transmission is achieved through JAK/STAT signaling inhibition by a plant virus
Viruses pose a great threat to animal and plant health worldwide, with many being dependent on insect vectors for transmission between hosts. While the virus–host arms race has been well established, how viruses and insect vectors adapt to each other remains poorly understood. Begomoviruses comprise the largest genus of plantinfecting DNA viruses and are exclusively transmitted by the whitefly Bemisia tabaci. Here, we show that the vector Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway plays an important role in mediating the adaptation between the begomovirus tomato yellow leaf curl virus (TYLCV) and whiteflies. We found that the JAK/STAT pathway in B. tabaci functions as an antiviral mechanism against TYLCV infection in whiteflies as evidenced by the increase in viral DNA and coat protein (CP) levels after inhibiting JAK/STAT signaling. Two STAT-activated effector genes, BtCD109-2 and BtCD109-3, mediate this anti-TYLCV activity. To counteract this vector immunity, TYLCV has evolved strategies that impair the whitefly JAK/STAT pathway. Infection of TYLCV is associated with a reduction of JAK/STAT pathway activity in whiteflies. Moreover, TYLCV CP binds to STAT and blocks its nuclear translocation, thus, abrogating the STAT-dependent transactivation of target genes. We further show that inhibition of the whitefly JAK/STAT pathway facilitates TYLCV transmission but reduces whitefly survival and fecundity, indicating that this JAK/STAT-dependent TYLCV–whitefly interaction plays an important role in keeping a balance between whitefly fitness and TYLCV transmission. This study reveals a mechanism of plant virus–insect vector coadaptation in relation to vector survival and virus transmission.
Journal Article
Danny and the blue cloud : coping with childhood depression
\"Danny the bear has a blue cloud of depression hanging over his head; he gets help with his blue cloud from Barnaby the rabbit\"-- Provided by publisher.
Book
Comparative analysis identifies amino acids critical for citrus tristeza virus (T36CA) encoded proteins involved in suppression of RNA silencing and differential systemic infection in two plant species
Complementary (c)DNA clones corresponding to the full‐length genome of T36CA (a Californian isolate of Citrus tristeza virus with the T36 genotype), which shares 99.1% identity with that of T36FL (a T36 isolate from Florida), were made into a vector system to express the green fluorescent protein (GFP). Agroinfiltration of two prototype T36CA‐based vectors (pT36CA) to Nicotiana benthamiana plants resulted in local but not systemic GFP expression/viral infection. This contrasted with agroinfiltration of the T36FL‐based vector (pT36FL), which resulted in both local and systemic GFP expression/viral infection. A prototype T36CA systemically infected RNA silencing‐defective N. benthamiana lines, demonstrating that a genetic basis for its defective systemic infection was RNA silencing. We evaluated the in planta bioactivity of chimeric pT36CA‐pT36FL constructs and the results suggested that nucleotide variants in several open reading frames of the prototype T36CA could be responsible for its defective systemic infection. A single amino acid substitution in each of two silencing suppressors, p20 (S107G) and p25 (G36D), of prototype T36CA facilitated its systemic infectivity in N. benthamiana (albeit with reduced titre relative to that of T36FL) but not in Citrus macrophylla plants. Enhanced virus accumulation and, remarkably, robust systemic infection of T36CA in N. benthamiana and C. macrophylla plants, respectively, required two additional amino acid substitutions engineered in p65 (N118S and S158L), a putative closterovirus movement protein. The availability of pT36CA provides a unique opportunity for comparative analysis to identify viral coding and noncoding nucleotides or sequences involved in functions that are vital for in planta infection. Differential bioactivity of citrus tristeza virus (CTV), T36CA, in two plant hosts is delineated by specific amino acid residues in two viral suppressors of RNA silencing and a putative CTV movement protein.
Journal Article