Comparison of the proteome profiles of Entamoeba histolytica and its close but non-pathogenic relative Entamoeba dispar.

The microaerophilic protist Entamoeba histolytica is a source of considerable morbidity and mortality in many countries of the world by acting as a causative agent of amoebic dysentery and liver abscess. Its close relative, Entamoeba dispar, also colonises the human colon but is non-pathogenic. In the present study, we wanted to assess if the close relatedness of these two organisms could be used to identify virulence factors in E.

Molecular and immunological characterization of the glycosylated orange allergen Cit s 1.

The IgE of sera from patients with a history of allergy to oranges (Citrus sinensis) binds a number of proteins in orange extract, including Cit s 1, a germin-like protein. In the present study, we have analyzed its immunological cross-reactivity and its molecular nature. Sera from many of the patients examined recognize a range of glycoproteins and neoglycoconjugates containing beta1,2-xylose and core alpha1,3-fucose on their N-glycans.

Historical demography of brown trout (Salmo trutta) in the Adriatic drainage including the putative S. letnica endemic to Lake Ohrid.

We explore the historical demography of the Adriatic lineage of brown trout and more explicitly the colonization and phylogenetic placement of Ohrid trout, based on variation at 12 microsatellite loci and the mtDNA control region. All Adriatic basin haplotypes reside in derived positions in a network that represents the entire lineage. The central presumably most ancestral haplotype in this network is restricted to the Iberian Peninsula, where it is very common, supporting a Western Mediterranean origin for the lineage.

Neurocognitive aging: prior memories hinder new hippocampal encoding.

Normal aging is often accompanied by impairments in forming new memories, and studies of aging rodents have revealed structural and functional changes to the hippocampus that might point to the mechanisms behind such memory loss. In this article, we synthesize recent neurobiological and neurophysiological findings into a model of the information-processing circuit of the aging hippocampus. The key point of the model is that small concurrent changes during aging strengthen the auto-associative network of the CA3 subregion at the cost of processing new information coming in from the entorhinal cortex.

Towards abolition of immunogenic structures in insect cells: characterization of a honey-bee (Apis mellifera) multi-gene family reveals both an allergy-related core alpha1,3-fucosyltransferase and the first insect Lewis-histo-blood-group-related antigen-synthesizing enzyme.

Glycoproteins from honey-bee (Apis mellifera), such as phospholipase A2 and hyaluronidase, are well-known major bee-venom allergens. They carry N-linked oligosaccharide structures with two types of alpha1,3-fucosylation: the modification by alpha1,3-fucose of the innermost core GlcNAc, which constitutes an epitope recognized by IgE from some bee-venom-allergic patients, and an antennal Lewis-like GalNAcbeta1,4(Fucalpha1,3)GlcNAc moiety. We now report the cloning and expression of two cDNAs encoding the relevant active alpha1,3-FucTs (alpha1,3-fucosyltransferases).

Comparative characterisation of recombinant invertebrate and vertebrate peptide O-Xylosyltransferases.

Chondroitin and heparan sulphates have key functions in animal development and their synthesis is initiated by the action of UDP-alpha-D-xylose:proteoglycan core protein beta-D-xylosyltransferase (EC 2.4.2.

Individual differences in neurocognitive aging of the medial temporal lobe.

A wide spectrum of outcomes in the cognitive effects of aging is routinely observed in studies of the elderly. Individual differences in neurocognitive aging are also a characteristic of other species, such as rodents and non-human primates. In particular, investigations at behavioral, brain systems, cellular and molecular levels of analysis have provided much information on the basis for individual differences in neurocognitive aging among healthy outbred rats.

A deletion in the golgi alpha-mannosidase II gene of Caenorhabditis elegans results in unexpected non-wild-type N-glycan structures.

The processing of N-linked oligosaccharides by alpha-mannosidases in the endoplasmic reticulum and Golgi is a process conserved in plants and animals. After the transfer of a GlcNAc residue to Asn-bound Man(5)GlcNAc(2) by N-acetylglucosaminyltransferase I, an alpha-mannosidase (EC 3.2.

Reconstitution in vitro of the GDP-fucose biosynthetic pathways of Caenorhabditis elegans and Drosophila melanogaster.

The deoxyhexose sugar fucose has an important fine-tuning role in regulating the functions of glycoconjugates in disease and development in mammals. The two genetic model organisms Caenorhabditis elegans and Drosophila melanogaster also express a range of fucosylated glycans, and the nematode particularly has a number of novel forms. For the synthesis of such glycans, the formation of GDP-fucose, which is generated from GDP-mannose in three steps catalysed by two enzymes, is required.

Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) genes expressed during infection of cotton (Gossypium hirsutum)dagger.

SUMMARY We sought to identify Fusarium oxysporum f. sp. vasinfectum (Fov) genes that may be associated with pathogenicity.

Urease-induced alkalinization of extracellular pH and its antitumor activity in human breast and lung cancers.

Jack bean urease catalyzes the decomposition of urea into ammonia, which in turn increases the pH of the surrounding medium. Based on these two properties, we have investigated the antitumor effects of urease in vitro and in vivo on human lung and breast cancer cell lines either by the enzyme itself or in combination with other chemotherapeutic drugs. First, through the generation of toxic ammonia, urease exerted direct cytotoxicity on A549 and MDA-MB-231 tumor cells with LC50 of 0.

Influenza, 1918.

The worst recorded influenza outbreak took place in 1918, when my uncle, Dr Jules S Martin, was a young doctor in the Royal Army Medical Corps in Mozambique. This letter from his commanding officer gives an insight into the horror of the experience

The Drosophila fused lobes gene encodes an N-acetylglucosaminidase involved in N-glycan processing.

Most processed, e.g. fucosylated, N-glycans on insect glycoproteins terminate in mannose, yet the relevant modifying enzymes require the prior action of N-acetylglucosaminyltransferase I.

Modulation of neural carbohydrate epitope expression in Drosophila melanogaster cells.

Neural pathways in invertebrates are often tracked using anti-horseradish peroxidase, a cross-reaction due to the presence of core alpha1,3-fucosylated N-glycans. In order to investigate the molecular basis of this epitope in a cellular context, we compared two Drosophila melanogaster cell lines: the S2 and the neuronal-like BG2-c6 cell lines. As shown by mass spectrometric and chromatographic analyses, only the BG2-c6 cell line expresses alpha1,3/alpha1,6-difucosylated N-glycans, a result that correlates with anti-horseradish peroxidase binding.

Definition of immunogenic carbohydrate epitopes.

Carbohydrates are known as sources of immunological cross-reactivity of allergenic significance. In celery and in cypress pollen, the major allergens Api g 5 and Cup a 1 are recognised by antisera raised against anti-horseradish peroxidase and by patients' IgE which apparently bind carbohydrate epitopes; mass spectrometric analysis of the tryptic peptides and of their N-glycans showed the presence of oligosaccharides carrying both xylose and core alpha1,3-fucose residues. Core alpha1,3-fucose residues are also a feature of invertebrates: genetic and biochemical studies on the fruitfly Drosophila melanogaster, the parasitic trematode Schistosoma mansoni and the nematode worm Caenorhabditis elegans indicate that these organisms possess core alpha1,3-fucosyltransferases.

The transcription factor ATAF2 represses the expression of pathogenesis-related genes in Arabidopsis.

ATAF2, a member of the plant-specific NAC-domain transcription factor family, is highly induced in leaves at a wound site and is responsive to the wound-related phytohormones methyl jasmonate and salicylic acid, but not to abscisic acid. Overexpression of ATAF2 leads to an increased biomass and yellowing of the leaves, but there is no obvious phenotype in two independent ATAF2 T-DNA insertion lines. At the transcriptome level, ATAF2 overexpression resulted in repression of a number of pathogenesis-related proteins.

Age-associated alterations of hippocampal place cells are subregion specific.

Aging is associated with spatial memory impairments and with deficient encoding of information by the hippocampus. In young adult rats, recent studies on the firing properties of hippocampal neurons have emphasized the importance of the CA3 subregion in the rapid encoding of new spatial information. Here, we compared the spatial firing patterns of CA1 and CA3 neurons in aged memory-impaired rats with those of young rats as they explored familiar and novel environments.

Entamoeba histolytica: analysis of the trophozoite proteome by two-dimensional polyacrylamide gel electrophoresis.

The Entamoeba histolytica genome project carried out at TIGR and the Sanger Institute has produced a near-complete set of deduced open reading frame sequences. These data provide strong support for the identification of signals from proteomic analyses such as two-dimensional electrophoresis by protein sequencing and/or mass spectrometric methods. To carry out an initial investigation of the E.

Microarray analysis reveals vegetative molecular phenotypes of Arabidopsis flowering-time mutants.

The transition to flowering occurs at the shoot apex; however, most of the characterized genes that affect the timing of floral induction are expressed throughout the plant. To further our understanding of these genes and the flowering process, the vegetative molecular phenotypes of 16 Arabidopsis mutants associated with the major flowering initiation pathways were assayed using a 13,000 clone microarray under two different conditions that affect flowering. All mutants showed at least one change in gene expression other than the mutant flowering gene.

Place cells of aged rats in two visually identical compartments.

Aged rats perform poorly on spatial learning tasks, a cognitive impairment which has been linked to the failure of hippocampal networks to fully encode changes in the external environment [Barnes CA, Suster MS, Shen J, McNaughton BL. Multistability of cognitive maps in the hippocampus of old rats. Nature 1997;388(6639):272-5; Wilson IA, Ikonen S, Gureviciene I, McMahan RW, Gallagher M, Eichenbaum H, et al.

A genetic and structural analysis of the N-glycosylation capabilities.

The recent draft sequencing of the rice (Oryza sativa) genome has enabled a genetic analysis of the glycosylation capabilities of an agroeconomically important group of plants, the monocotyledons. In this study, we have not only identified genes putatively encoding enzymes involved in N-glycosylation, but have examined by MALDI-TOF MS the structures of the N-glycans of rice and other monocotyledons (maize, wheat and dates; Zea mays, Triticum aestivum and Phoenix dactylifera); these data show that within the plant kingdom the types of N-glycans found are very similar between monocotyledons, dicotyledons and gymnosperms. Subsequently, we constructed expression vectors for the key enzymes forming plant-typical structures in rice, N-acetylglucosaminyltransferase I (GlcNAc-TI; EC 2.

Spatial and temporal analysis of the local response to wounding in Arabidopsis leaves.

We studied the local response to wounding in Arabidopsis thaliana leaves using a two-step microarray analysis. A microarray containing 3500 cDNA clones was first screened to enrich for genes affected by wounding in the immediate vicinity of the wound (4 h post wounding). 359 non-redundant putative wound responsive genes were then spotted on a smaller wound-response array for detailed analysis of spatial expression (local, adjacent and systemic), timing of expression (0.