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1.
New Phytol ; 219(2): 697-713, 2018 07.
Article in English | MEDLINE | ID: mdl-29726613

ABSTRACT

Cyst nematodes deliver effector proteins into host cells to manipulate cellular processes and establish a metabolically hyperactive feeding site. The novel 30D08 effector protein is produced in the dorsal gland of parasitic juveniles, but its function has remained unknown. We demonstrate that expression of 30D08 contributes to nematode parasitism, the protein is packaged into secretory granules and it is targeted to the plant nucleus where it interacts with SMU2 (homolog of suppressor of mec-8 and unc-52 2), an auxiliary spliceosomal protein. We show that SMU2 is expressed in feeding sites and an smu2 mutant is less susceptible to nematode infection. In Arabidopsis expressing 30D08 under the SMU2 promoter, several genes were found to be alternatively spliced and the most abundant functional classes represented among differentially expressed genes were involved in RNA processing, transcription and binding, as well as in development, and hormone and secondary metabolism, representing key cellular processes known to be important for feeding site formation. In conclusion, we demonstrated that the 30D08 effector is secreted from the nematode and targeted to the plant nucleus where its interaction with a host auxiliary spliceosomal protein may alter the pre-mRNA splicing and expression of a subset of genes important for feeding site formation.


Subject(s)
Arabidopsis/genetics , Arabidopsis/parasitology , Cell Nucleus/metabolism , Feeding Behavior , Gene Expression Regulation, Plant , Helminth Proteins/metabolism , Host-Parasite Interactions/genetics , Tylenchoidea/metabolism , Alternative Splicing/genetics , Amino Acid Sequence , Animals , Genes, Plant , Helminth Proteins/chemistry , Life Cycle Stages , Nuclear Localization Signals , Parasites/metabolism , Plant Cells/metabolism , Plant Leaves/metabolism , Plant Roots/growth & development , Plant Roots/metabolism , Plant Roots/parasitology , Promoter Regions, Genetic/genetics , Protein Binding , RNA Interference , Seedlings/metabolism , Tylenchoidea/growth & development , Up-Regulation
2.
Redox Biol ; 8: 11-7, 2016 08.
Article in English | MEDLINE | ID: mdl-26722839

ABSTRACT

AIMS: Increased production of reactive oxygen species (ROS) in mitochondria, play an important role in the cardiovascular system. Furthermore, oxidative metabolism of mitochondria comprised of biophoton emissions, are linked to ROS and oxidative stress. In this review we investigated the association between the ability of ClearViewTM system (ClearView) to indicate the presence or absence of cardiovascular disease through mitochondria respiration as depicted through biophotonic emission. METHODS AND RESULTS: One hundred and ninety-five out of the three hundred and fifty-three human subjects enrolled in this prospective, single site study had at least one cardiovascular related diagnosis. Measurements with ClearView consisted of scanning all 10 fingers twice. Images were captured through the ClearView software and analyzed to produce a scale that indicates the presence or absence of cardiovascular disease. The association of ClearView's ability to indicate the presence or absence of cardiovascular disease with a physician's diagnosis was assessed using odds ratios (OR) and area under ROC curve (AUC). Adjusting for age, OR of ClearView measurements conducted with capacitive barrier was 3.44 (95%CI: 2.13, 5.55) and the OR without the capacitive barrier was 2.15 (95%CI: 1.42, 3.23). The OR in men were 5.91 (95%CI: 2.35, 14.85) and 2.88 (95%CI: 1.38, 6.01), adjusting for age and corresponding to with and without capacitive barrier. The OR in women were 3.50 (95%CI: 1.86, 6.59) and 2.09 (95%CI: 1.20, 3.64) with and without capacitive barrier. AUCs for measurements with capacitive barrier were >0.90. CONCLUSION: ClearView detected the presence or absence of cardiovascular disease independent of other conditions.


Subject(s)
Absorptiometry, Photon/methods , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/metabolism , Cell Respiration , Mitochondria, Heart/metabolism , Photons , Area Under Curve , Cardiovascular Diseases/etiology , Cardiovascular Diseases/physiopathology , Case-Control Studies , Comorbidity , Female , Humans , Male , Odds Ratio , Oxidation-Reduction , Oxidative Stress , Reactive Oxygen Species/metabolism
3.
Plant Physiol ; 166(3): 1162-76, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25192697

ABSTRACT

With an optimized expression cassette consisting of the soybean (Glycine max) native promoter modified for enhanced expression driving a chimeric gene coding for the soybean native amino-terminal 86 amino acids fused to an insensitive shuffled variant of maize (Zea mays) 4-hydroxyphenylpyruvate dioxygenase (HPPD), we achieved field tolerance in transgenic soybean plants to the HPPD-inhibiting herbicides mesotrione, isoxaflutole, and tembotrione. Directed evolution of maize HPPD was accomplished by progressively incorporating amino acids from naturally occurring diversity and novel substitutions identified by saturation mutagenesis, combined at random through shuffling. Localization of heterologously expressed HPPD mimicked that of the native enzyme, which was shown to be dually targeted to chloroplasts and the cytosol. Analysis of the native soybean HPPD gene revealed two transcription start sites, leading to transcripts encoding two HPPD polypeptides. The N-terminal region of the longer encoded peptide directs proteins to the chloroplast, while the short form remains in the cytosol. In contrast, maize HPPD was found almost exclusively in chloroplasts. Evolved HPPD enzymes showed insensitivity to five inhibitor herbicides. In 2013 field trials, transgenic soybean events made with optimized promoter and HPPD variant expression cassettes were tested with three herbicides and showed tolerance to four times the labeled rates of mesotrione and isoxaflutole and two times the labeled rates of tembotrione.


Subject(s)
4-Hydroxyphenylpyruvate Dioxygenase/antagonists & inhibitors , Glycine max/enzymology , Herbicides/pharmacology , 4-Hydroxyphenylpyruvate Dioxygenase/genetics , 4-Hydroxyphenylpyruvate Dioxygenase/metabolism , Amino Acid Sequence , Cyclohexanones/chemistry , Cyclohexanones/pharmacology , Gene Expression , Herbicides/chemistry , Isoxazoles , Molecular Sequence Data , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified , Sequence Alignment , Glycine max/drug effects , Glycine max/genetics
4.
Plant Mol Biol ; 67(3): 215-29, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18311542

ABSTRACT

Cytokinins (CKs) are plant hormones that regulate a large number of processes associated with plant growth and development such as induction of stomata opening, delayed senescence, suppression of auxin-induced apical dominance, signaling of nitrogen availability, differentiation of plastids and control of sink strength. In maize, CKs are thought to play an important role in establishing seed size and increasing seed set under normal and unfavorable environmental conditions therefore influencing yield. In recent years, the discovery of isopentenyl transferase (IPT) genes in plants has shed light on the CK biosynthesis pathway in plants. In an effort to increase our understanding of the role played by CKs in maize development and sink-strength, we identified several putative IPT genes using a bioinformatics approach. We focused our attention on one gene in particular, ZmIPT2, because of its strong expression in developing kernels. The expression of the gene and its product overlays the change in CK levels in developing kernels suggesting a major role in CK biosynthesis for kernel development. We demonstrate that at 8-10 days after pollination (DAP) the endosperm and especially the basal transfer cell layer (BETL) is a major site of ZmIPT2 expression, and that this expression persists in the BETL and the developing embryo into later kernel development stages. We show that ectopic expression of ZmIPT2 in calli and in planta created phenotypes consistent with CK overproduction. We also show that ZmIPT2 preferentially uses ADP and ATP over AMP as the substrates for dimethylallyl diphosphate (DMAPP) IPT activity. The expression pattern of ZmIPT2 in the BETL, endosperm and embryo during kernel development will be discussed with an emphasis on the suggested role of CKs in determining sink-strength and grain production in crop plants.


Subject(s)
Alkyl and Aryl Transferases/genetics , Zea mays/genetics , Amino Acid Sequence , Arabidopsis/enzymology , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Binding Sites , Conserved Sequence , Cytokinins/genetics , Gene Amplification , Molecular Sequence Data , Multigene Family , Phylogeny , Plant Leaves/enzymology , Plant Proteins/genetics , Polymerase Chain Reaction , Restriction Mapping , Zea mays/enzymology
5.
Nat Mater ; 2(3): 196-200, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12612679

ABSTRACT

Because of their extraordinary electronic and mechanical properties, carbon nanotubes have great potential as materials for applications ranging from molecular electronics to ultrasensitive biosensors. Biological molecules interacting with carbon nanotubes provide them with specific chemical handles that would make several of these applications possible. Here we use phage display to identify peptides with selective affinity for carbon nanotubes. Binding specificity has been confirmed by demonstrating direct attachment of nanotubes to phage and free peptides immobilized on microspheres. Consensus binding sequences show a motif rich in histidine and tryptophan, at specific locations. Our analysis of peptide conformations shows that the binding sequence is flexible and folds into a structure matching the geometry of carbon nanotubes. The hydrophobic structure of the peptide chains suggests that they act as symmetric detergents.


Subject(s)
Nanotubes, Carbon/metabolism , Peptides/chemical synthesis , Microspheres , Peptide Library , Peptides/metabolism , Protein Conformation
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