Search results for "Cell Wall"
showing 10 items of 226 documents
Cloning of a cDNA fragment encoding part of the protein moiety of the 58-kDa fibrinogen-binding mannoprotein of Candida albicans
2006
Immunoscreening of a Candida albicans expression library with antibodies against the 58 kDa fibrinogen-binding mannoprotein (mp58) of the fungus resulted in the isolation of clones encoding the protein moiety of this molecule. Sequence of the 0.9 kb cDNA of one of the clones selected for further analysis, revealed an open reading frame coding for 292 amino acids, which displays sequence similarity to proteins belonging to a family of immunodominant antigens of Aspergillus spp. The gene corresponding to this cDNA was named FBP1 (fibrinogen-binding protein). These results represent the first report on the identification of C. albicans genes encoding surface receptors for host proteins.
The Implication of Xyloglucan Endotransglucosylase/Hydrolase (XTHs) in Tomato Fruit Infection by Penicillium expansum Link. A
2007
In general, cell wall-degrading enzymes produced by plant pathogenic fungi are considered important pathogenicity factors. In this work, we evaluate the implication of xyloglucan endotransglucosylase/ hydrolase (XTHs), a potential hemicellulosic repairing enzyme, in the infection mechanism process by the fungus. This study investigated the SIXTHS expresion and xyloglucan endotransglucosylase (XET) activity during infection of two tomato fruit cultivars by Penicillium expansum Link. A. In infected fruits, XET specific activity decreased drastically after long infection periods, 24 and 48 h for Canario and Money Maker tomato fruits, respectively. Real Time RT-PCR of eleven SIXTHS also showed …
Isolation and characterization of anavirulent Candida albicansyeast monomorphic mutant
2003
Mutagenesis of Candida albicans strain ATCC 26555 with N-methyl-nitro-N-nitrosoguanidine followed by plating on solid yeast nitrogen base-N-acetylglucosamine medium at 37 degrees C yielded colony morphology variants that were characterized as forming smooth colonies, in contrast to the rough colonies formed by the parental strain. One yeast monomorphic mutant, CAL4, was studied in detail. Strain CAL4 is defective in filamentous growth, unable to form hyphae or pseudohyphae in vivo and in vitro. These filamentous structures are not elicited by commonly used external stimuli such as serum. The mutant had no obvious alterations in its mannan, glucan or chitin content. The total quantity of non…
Metal ion adsorption by phomopsis sp. Biomaterial in laboratory experiments and real Wastewater Treatments
2005
An insoluble material of polysaccharidic nature has been obtained by thermal alkali treatment of the filamentous fungus Phomopsis sp. FT-IR spectrum of the resulting material as well as its nitrogen content suggest that chitosan and glucans are the main components of the biomaterial. Information on Lewis base sites has also been obtained and used as a guideline in the evaluation of the complexing ability against a number of metal ions in aqueous media at pH in the range 4--6. Results indicate that after 24h contact time, up to 870 micromol/g of lead, 390 micromol/g of copper, 230 micromol/g of cadmium, 150 micromol/g of zinc and 110 micromol/g of nickel ions are adsorbed into the material. …
Combined omics approaches reveal distinct responses between light and heavy rare earth elements in Saccharomyces cerevisiae
2022
International audience; The rapid development of green energy sources and new medical technologies contributes to the increased exploitation of rare earth elements (REEs). They can be subdivided into light (LREEs) and heavy (HREEs) REEs. Mining, industrial processing, and end-use practices of REEs has led to elevated environmental concentrations and raises concerns about their toxicity to organisms and their impact on ecosystems. REE toxicity has been reported, but its precise underlying molecular effects have not been well described. Here, transcriptomic and proteomic approaches were combined to decipher the molecular responses of the model organism Saccharomyces cerevisiae to La (LREE) an…
The Loss of Structural Integrity in Damaged Spruce Needles from Locations Exposed to Air Pollution I. Mesophyll and Central Cylinder
1990
In connection with the new type of forest damage, the individual disease situation of two-year-old spruce (Picea abies) needles was analyzed histopathologically in forest areas exposed to different levels of O3-, SO2- and NO3- pollution. Early damage results from losses of chlorophyll in the mesophyll cells. The bleaching is more intensive towards the apex in severely damaged needles. The cytoplasm is aggregated at the cell wall and the chloroplasts show definite structural damage as well. The mesophyll cells below the epidermis, or the cells adjacent to the vascular bundle sheath, appear to be particularly susceptible. Collapsed cells (bone cells), which increase in number with damage, can…
An ethoxylated surfactant enhances the penetration of the sulfated laminarin through leaf cuticle and stomata, leading to increased induced resistanc…
2016
International audience; Some β-1,3-glucans and particularly sulfated laminarin (PS3) are known as resistance inducers (RIs) in grapevine against the downy mildew. However, their efficacy in vineyard is still often too low, which might be caused by a limited penetration through the leaf cuticle following spray application. We used (14) C-sucrose uptake experiments with grapevine leaves in order to select a surfactant as saccharide penetration enhancer. Our results showed that though sucrose foliar uptake was low, it was strongly enhanced by Dehscofix CO125 (DE), a highly ethoxylated surfactant. Fluorescent saccharides were then produced and laser scanning microscopy was used to analyze their…
Yeast Cell Wall Glycoproteins
1991
In higher cells, glycoproteins play a variety of functions as surface receptors, cell-cell mediators, carriers of enzyme activities, components of the extracellular matrix, etc. In most glycoproteins, the protein moiety will be the functional part whereas the carbohydrate moiety would contribute to the attainment of an adequate tertiary structure, modify the glycoprotein molecule making it more resistant to degradation, and facilitate its secretion.
Cell Wall and Secreted Proteins ofCandida albicans: Identification, Function, and Expression
1998
SUMMARYThe cell wall is essential to nearly every aspect of the biology and pathogenicity of Candida albicans. Although it was intially considered an almost inert cellular structure that protected the protoplast against osmotic offense, more recent studies have demonstrated that it is a dynamic organelle. The major components of the cell wall are glucan and chitin, which are associated with structural rigidity, and mannoproteins. The protein component, including both mannoprotein and nonmannoproteins, comprises some 40 or more moieties. Wall proteins may differ in their expression, secretion, or topological location within the wall structure. Proteins may be modified by glycosylation (prima…
Changes in the cell wall glycoprotein composition of Candida albicans associated to the inhibition of germ tube formation by EDTA.
1994
Hyphal development in Candida albicans was blocked by EDTA. This effect was not due to a general growth inhibition since the chelator did not affect protein and DNA synthesis. Recovery of mycelial growth was observed when EDTA-grown cells were incubated at 37 degrees C in EDTA-free medium. High-molecular-weight mannoproteins (HMWM) that are mycelium-specific wall components, and particularly a 260-kDa species (HMWM-260), were absent in the wall of cells grown under germination conditions in the presence of EDTA. Synthesis of the HMWM-260 species was not inhibited but its incorporation (secretion) into the wall structure seemed to be blocked in EDTA-treated cells.