Gene silencing by RNA Interference in the white rot fungus Phanerochaete chrysosporium.

The effectiveness of RNA interference (RNAi) is demonstrated in the lignin-degrading fungus Phanerochaete chrysosporium. The manganese-containing superoxide dismutase gene (MnSOD1) was used as the target for RNAi. The plasmid constructed for gene silencing contained a transcriptional unit for hairpin RNA expression.

Characterization of the PON1 active site using modeling simulation, in relation to PON1 lactonase activity.

Paraoxonase1 (PON1) is a HDL bound enzyme and many of the anti-atherogenic properties of HDL are attributed to PON1. The enzyme precise mechanism of protective action and its endogenous substrate remain elusive. PON1 hydrolyzes organophosphates, arylesters and lactones, whereas the lactones activity is assumed as the physio/pathological one.

A mutation analysis of the phenylalanine hydroxylase (PAH) gene in the Israeli population.

Hyperphenylalaninemia (HPA) is a group of diseases characterized by a persistent elevation of phenylalanine levels in tissues and biological fluids. The most frequent form is phenylalanine hydroxylase deficiency, causing phenylketonuria (PKU). Among 159 Israeli patients (Jews, Muslim and Christian Arabs and Druze) with HPA, in whom at least one of the mutations was characterized, a total of 43 different mutations were detected, including seven novel ones.

Overexpression of mutated forms of aspartate kinase and cystathionine gamma-synthase in tobacco leaves resulted in the high accumulation of methionine and threonine.

Methionine and threonine are two essential amino acids, the levels of which limit the nutritional quality of plants. Both amino acids diverge from the same branch of the aspartate family biosynthesis pathway; therefore, their biosynthesis pathways compete for the same carbon/amino substrate. To further elucidate the regulation of methionine biosynthesis and seek ways of increasing the levels of these two amino acids, we crossed transgenic tobacco plants overexpressing the bacterial feedback-insensitive aspartate kinase (bAK), containing a significantly higher threonine level, with plants overexpressing Arabidopsis cystathionine gamma-synthase (AtCGS), the first unique enzyme of methionine biosynthesis.

Fungal metabolites modulating NF-kappaB activity: an approach to cancer therapy and chemoprevention (review).

Fighting cancer is considered one of the most important areas of research in medicine and immunology. Due to the ability of cancer cells to mutate and become resistant to available drugs, new scientific approaches, focused on molecular mechanisms of carcinogenesis, are needed. A new direction in cancer treatment has arisen, devoted to the adjuvant use of natural bioactive compounds in conventional chemotherapy.

Antioxidant activity, polyphenol content, and related compounds in different fruit juices and homogenates prepared from 29 different pomegranate accessions.

Pomegranate juice is well known for its health beneficial compounds, which can be attributed to its high level of antioxidant activity and total polyphenol content. Our objective was to study the relationships between antioxidant activity, total polyphenol content, total anthocyanins content, and the levels of four major hydrolyzable tannins in four different juices/homogenates prepared from different sections of the fruit. To this end, 29 different accessions were tested.

Characterization of oxidative stress in blood from diabetic vs. hypercholesterolaemic patients, using a novel synthesized marker.

In the present study, we extend our novel concept of designing and using exogenous markers for the characterization of oxidative stress (OS) and OS-associated diseases. The aim was to use such a synthetic compound as a tool for studying OS in blood from diabetic and hypercholesterolaemic (Hc) patients. The marker used N-linoleoyl tyrosine (LT) was constructed from tyrosine and linoleic acid (LA); both components are known to be easily oxidized upon exposure to different types of reactive oxygen/nitrogen species (ROS/RNS), and to generate specific oxidized products, depending on the type of oxidants present in vivo.

Lysine enhances methionine content by modulating the expression of S-adenosylmethionine synthase.

Lysine and methionine are two essential amino acids whose levels affect the nutritional quality of cereals and legume plants. Both amino acids are synthesized through the aspartate family biosynthesis pathway. Within this family, lysine and methionine are produced by two different branches, the lysine branch and the threonine-methionine branch, which compete for the same carbon/amino substrate.

Oxysterols, cholesterol homeostasis, and Alzheimer disease.

Aberrant cholesterol metabolism has been implicated in Alzheimer disease (AD) and other neurological disorders. Oxysterols and other cholesterol oxidation products are effective ligands of liver X activated receptor (LXR) nuclear receptors, major regulators of genes subserving cholesterol homeostasis. LXR receptors act as molecular sensors of cellular cholesterol concentrations and effectors of tissue cholesterol reduction.

Enhanced substituted resorcinol hydrophobicity augments tyrosinase inhibition potency.

The objective of the present study was to investigate to what extent the addition of hydrophobic residues to a 2,4-resorcinol derivative would contribute to their tyrosinase inhibitory potency. Hence, 3-(2,4-dihydroxyphenyl)propionic acid, isolated from Ficus carica, was transformed into esters, and the relationship between the structure of these esters to their mushroom tyrosinase inhibition activity was explored. The enzyme crystallographic structure, published recently (Matoba, Y.

Enhanced levels of methionine and cysteine in transgenic alfalfa (Medicago sativa L.) plants over-expressing the Arabidopsis cystathionine gamma-synthase gene.

With the aim of increasing the methionine level in alfalfa (Medicago sativa L.) and thus improving its nutritional quality, we produced transgenic alfalfa plants that expressed the Arabidopsis cystathionine gamma-synthase (AtCGS), the enzyme that controls the synthesis of the first intermediate metabolite in the methionine pathway. The AtCGS cDNA was driven by the Arabidopsis rubisco small subunit promoter to obtain expression in leaves.

An in vivo internal deletion in the N-terminus region of Arabidopsis cystathionine gamma-synthase results in CGS expression that is insensitive to methionine.

Cystathionine gamma-synthase (CGS), the first enzyme of methionine biosynthesis in higher plants, plays an important role in the biosynthesis pathway and in regulating methionine metabolism in plant cells. In response to methionine, the expression of this enzyme is regulated via amino acid sequences located in its N-terminal. Here, using reverse transcription PCR and ribonuclease protection analysis, we demonstrate that, in addition to the full-length CGS transcript, a deleted form exists in Arabidopsis.

Induction of antitumor immunity by CTL epitopes genetically linked to membrane-anchored beta2-microglobulin.

Level and persistence of antigenic peptides presented by APCs on MHC class I (MHC-I) molecules influence the magnitude and quality of the ensuing CTL response. We recently demonstrated the unique immunological properties conferred on APCs by expressing beta2-microglobulin (beta2m) as an integral membrane protein. In this study, we explored membrane-anchored beta2m as a platform for cancer vaccines using as a model MO5, an OVA-expressing mouse B16 melanoma.

Transgenic tobacco plants overexpressing the Met25 gene of Saccharomyces cerevisiae exhibit enhanced levels of cysteine and glutathione and increased tolerance to oxidative stress.

The cysteine biosynthesis pathway differs between plants and the yeast Saccharomyces cerevisiae. The yeast MET25 gene encoded to O-acetylhomoserine sulfhydrylase (AHS) catalyzed the reaction that form homocysteine, which later can be converted into cystiene. In vitro studies show that this enzyme possesses also the activity of O-acetyl(thiol)lyase (OASTL) that catalyzes synthesis of cysteine in plants.

The expression level of threonine synthase and cystathionine-gamma-synthase is influenced by the level of both threonine and methionine in Arabidopsis plants.

The biosynthesis pathways of the essential amino acids methionine and threonine diverge from O-phosphohomoserine, an intermediate metabolite in the aspartate family of amino acids. Thus, the enzymes cystathionine-gamma-synthase (CGS) in the methionine pathway and threonine synthase (TS), the last enzyme in the threonine pathway, compete for this common substrate. To study this branching point, we overexpressed TS in sense and antisense orientation in Arabidopsis plants with the aim to study its effect on the level of threonine but more importantly on the methionine content.

Soluble methionine enhances accumulation of a 15 kDa zein, a methionine-rich storage protein, in transgenic alfalfa but not in transgenic tobacco plants.

With the general aim of elevating the content of the essential amino acid methionine in vegetative tissues of plants, alfalfa (Medicago sativa L.) and tobacco plants, as well as BY2 tobacco suspension cells, were transformed with a beta-zein::3HA gene under the 35S promoter of cauliflower mosaic virus encoding a rumen-stable methionine-rich storage protein of 15 kDa zein. To examine whether soluble methionine content limited the accumulation of the 15 kDa zein::3HA, methionine was first added to the growth medium of the different transgenic plants and the level of the alien protein was determined.

The association of common SNPs and haplotypes in the CETP and MDR1 genes with lipids response to fluvastatin in familial hypercholesterolemia.

Objective: To examine whether genetic polymorphisms in the cholesteryl-ester transfer protein (CETP) and the P-glycoprotein drug transporter (MDR1), are associated with variable lipid response to fluvastatin.

Methods: Lipid levels were determined in a compliance-monitored clinical study at baseline and following 20 weeks of treatment with 40 mg dose of fluvastatin in 76 FH patients. CETP and MDR1 SNP genotyping was performed and linear regression was used to examine the associations between common SNPs and haplotypes and lipid response.

HIV-1 neutralization by chimeric CD4-CG10 polypeptides fused to human IgG1.

The envelope glycoprotein of HIV-1 is the principal target for entry inhibitors. The use of soluble CD4 has been found to be impractical as most clinical isolates are resistant to neutralization at feasible concentrations. CG10 is one of a small group of monoclonal antibodies specific to CD4-induced epitopes, which are structurally associated with the chemokine receptor-binding site and are capable of blocking the interaction of gp120 with its obligatory co-receptor.

Membrane-anchored beta 2-microglobulin stabilizes a highly receptive state of MHC class I molecules.

The magnitude of response elicited by CTL-inducing vaccines correlates with the density of MHC class I (MHC-I)-peptide complexes formed on the APC membrane. The MHC-I L chain, beta2-microglobulin (beta2m), governs complex stability. We reasoned that genetically converting beta2m into an integral membrane protein should exert a marked stabilizing effect on the resulting MHC-I molecules and enhance vaccine efficacy.

A new method for measuring scouring efficiency of natural fibers based on the cellulose-binding domain-beta-glucuronidase fused protein.

Cellulose-binding domains (CBDs) are characterized by their ability to strongly bind to different forms of cellulose. This study examined the use of a recombinant CBD fused to the reporter enzyme beta-glucuronidase (CBD-GUS) to determine the extent of removal of the water-repellent waxy component of cotton fiber cuticles following hydrolytic treatment, i.e.

In-cell generation of antibody single-chain Fv transcripts by targeted RNA trans-splicing.

The humoral immune response propels the production of a diversified pool of antibodies with high affinity and selectivity for the eliciting antigen. Their isolation entails either B-cell cloning or the linking of authentic pairs of variable region genes encoding them. We hypothesized that targeted RNA trans-splicing (TS) inside the B-cell nucleus could be harnessed as a novel means to link both variable region genes and reconstitute genuine immune B-cell specificities.

Reactive oxygen species and induction of lignin peroxidase in Phanerochaete chrysosporium.

We studied oxidative stress in lignin peroxidase (LIP)-producing cultures (cultures flushed with pure O(2)) of Phanerochaete chrysosporium by comparing levels of reactive oxygen species (ROS), cumulative oxidative damage, and antioxidant enzymes with those found in non-LIP-producing cultures (cultures grown with free exchange of atmospheric air [control cultures]). A significant increase in the intracellular peroxide concentration and the degree of oxidative damage to macromolecules, e.g.

Cloning of European eel (Anguilla anguilla) FSH-beta subunit, and expression of FSH-beta and LH-beta in males and females after sex determination.

The European eel (Anguilla anguilla) is a catadromic teleost species with a complex life cycle, both in sea and freshwater environments. The sex determination phase of gonadal development occurs in a freshwater environment. Polymorphism occurs in increasing rates with respect to gender.

The effect of under- and overexpressed CoEXG1-encoded exoglucanase secreted by Candida oleophila on the biocontrol of Penicillium digitatum.

The yeast, Candida oleophila, is acknowledged for its biocontrol activity against postharvest moulds. However, the mechanism of this activity is not fully understood. One of the conjectured modes of action is associated with extracellular lytic enzymes, such as beta-exoglucanase.

In vivo analysis of various substrates utilized by cystathionine gamma-synthase and O-acetylhomoserine sulfhydrylase in methionine biosynthesis.

To gain insight into the evolution of the methionine biosynthesis pathway, in vivo complementation tests were performed. The substrate specificity of three enzymes that intrinsically use different homoserine-esterified substrates and have different sulfur assimilation pathways was examined: two cystathionine gamma-synthases (the Escherichia coli enzyme that naturally utilizes O-succinylhomoserine [OSH]) and the Arabidopsis thaliana enzyme that naturally exploits O-phosphohomoserine [OPH]. Both of these act through the transsulfuration pathway.