Elevation of intracellular cAMP levels by dominant active heterotrimeric G protein alpha subunits ScGP-A and ScGP-C in homobasidiomycete, Schizophyllum commune. (1/173)

In many fungi, the heterotrimeric G protein alpha subunits, and/or small G protein (RAS) control intracellular cAMP levels. But it is not clear which types of G proteins modulate cAMP levels in homobasidiomycete (mushrooms). To explain the mechanism, we expressed dominant active RAS (a homolog of S. cerevisiae RAS1) in homobasidiomycete Schizophyllum commune and compared the cAMP levels in the transformed clones with those of clones expressing dominant active heterotrimeric G protein alpha subunits ScGP-A, B, and C. The results demonstrated that the dominant active ScGP-A and C elevated the intracellular cAMP levels. In contrast, the dominant active S. commune RAS gene did not affect the cAMP levels, even though colony growth and formation of fruiting bodies were apparently repressed. These data suggest that the heterotrimeric G protein alpha subunits are involved in the mechanism of cAMP regulation, and that RAS modulates another signal-transduction pathway regulating cell growth and differentiation.  (+info)

Quantitative determination of bitter principles in specimens of Ganoderma lucidum using high-performance liquid chromatography and its application to the evaluation of ganoderma products. (2/173)

For quantitative determination of 19 triterpene constituents, including six ganoderma alcohols (1-6) and 13 ganoderma acids (7-19), in the products of Ganoderma lucidum, an analytical system was developed using high-performance liquid chromatography with an ODS column. The mobile phase was a linear gradient of 1% AcOH/H(2)O-CH(3)CN and 2% AcOH/H(2)O-CH(3)CN, and the elution profile was monitored at 243 and 250 nm for ganoderma alcohols and acids, respectively. The relative standard deviations of this method were less than 2.35% and 2.18% (n=5) for intraday and interday assays, and the recoveries were 90.9-100.8% and 93.4-103.9% for constituents of alcohol and acid groups, respectively. This system was applied to a quantitative determination of the constituents in 10 different products of G. lucidum: six usual umbrella forms of the fruiting bodies, three antlered forms of the fruiting bodies and spores, and eight specimens from the same G. lucidum strain, which was parasitized on logs from different plants or different fungus beds. The analytical results indicated that the quantity and composition of these triterpenes differed appreciably among various specimens, but the relative ratio of the alcohols and acids was not significantly different when the same strain of G. lucidum was used.  (+info)

Expansion of the Candida tanzawaensis yeast clade: 16 novel Candida species from basidiocarp-feeding beetles. (3/173)

A major clade of new yeast taxa from the digestive tract of basidiocarp-feeding beetles is recognized based on rRNA gene sequence analyses. Almost 30 % of 650 gut isolates formed a statistically well-supported clade that included Candida tanzawaensis. The yeasts in the clade were isolated from 11 families of beetles, of which Tenebrionidae and Erotylidae were most commonly sampled. Repeated isolation of certain yeasts from the same beetle species at different times and places indicated strong host associations. Sexual reproduction was never observed in the yeasts. Based on comparisons of small- and large-subunit rRNA gene sequences and morphological and physiological traits, the yeasts were placed in Candida ambrosiae and in 16 other undescribed taxa. In this report, the novel species in the genus Candida are described and their relationships with other taxa in the Saccharomycetes are discussed. The novel species and their type strains are as follows: Candida guaymorum (NRRL Y-27568(T)=CBS 9823(T)), Candida bokatorum (NRRL Y-27571(T)=CBS 9824(T)), Candida kunorum (NRRL Y-27580(T)=CBS 9825(T)), Candida terraborum (NRRL Y-27573(T)=CBS 9826(T)), Candida emberorum (NRRL Y-27606(T)=CBS 9827(T)), Candida wounanorum (NRRL Y-27574(T)=CBS 9828(T)), Candida yuchorum (NRRL Y-27569(T)=CBS 9829(T)), Candida chickasaworum (NRRL Y-27566(T)=CBS 9830(T)), Candida choctaworum (NRRL Y-27584(T)=CBS 9831(T)), Candida bolitotheri (NRRL Y-27587(T)=CBS 9832(T)), Candida atakaporum (NRRL Y-27570(T)=CBS 9833(T)), Candida panamericana (NRRL Y-27567(T)=CBS 9834(T)), Candida bribrorum (NRRL Y-27572(T)=CBS 9835(T)), Candida maxii (NRRL Y-27588(T)=CBS 9836(T)), Candida anneliseae (NRRL Y-27563(T)=CBS 9837(T)) and Candida taliae (NRRL Y-27589(T)=CBS 9838(T)).  (+info)

The ornithine cycle enzyme arginase from Agaricus bisporus and its role in urea accumulation in fruit bodies. (4/173)

An extensive survey of higher fungi revealed that members of the family Agaricaceae, including Agaricus bisporus, accumulate substantial amounts of urea in their fruit bodies. An important role of the ornithine cycle enzymes in urea accumulation has been proposed. In this work, we present the cloning and sequencing of the arginase gene and its promoter region from A. bisporus. A PCR-probe based on fungal arginase was used to identify the A. bisporus arginase gene from a cDNA library. The arginase cDNA encodes a 311-aa protein which is most likely expressed in the cytosol. Expression of the cDNA in Escherichia coli was established as a His-tagged fusion protein. The arginase gene was used as a molecular marker to study expression and regulation during sporophore formation and postharvest development. The expression of the arginase gene was significantly up-regulated from developmental stage 3 onwards for all the tissues studied. A maximum of expression was reached at stage 6 for both stipe and cap tissue. In postharvest stages 5, 6 and 7 the level of expression observed was similar to normal growth stages 5, 6 and 7. A good correlation was found between arginase expression and urea content of stipe, velum, gills, cap and peel tissue. For all tissues the urea content decreased over the first four stages of development. From stage 4 onwards urea accumulated again except for stipe tissue where no significant changes were observed. The same trend was also observed for postharvest development, but the observed increase of urea in postharvest tissues was much higher.  (+info)

Comparative effect of the fungicide Prochloraz-Mn on Agaricus bisporus vegetative-mycelium and fruit-body cell walls. (5/173)

Fungicides to control mycopathogens of commercial Agaricus bisporus, a mushroom cultivated for human consumption, are a major field of study, since these chemicals are toxic to both the host and its fungal parasites. The fungicide Prochloraz-Mn, used at its LD50 for A. bisporus, partially inhibited protein biosynthesis in the vegetative mycelial cell walls of this mushroom and caused significant changes in cell-wall polysaccharide structure, as deduced by methylation analysis and gas liquid chromatography-mass spectrometry (GLC-MS). Furthermore, the aggregated mycelial walls showed distinct alterations in their overall chemical composition following the administration of Prochloraz-Mn at the LD50 and the LD50 x1000. As expected, GLC-MS studies indicated that the latter dose caused more appreciable differences in polysaccharide structure. The decrease in mushroom crop yields obtained from industrial cultures treated with Prochloraz-Mn to control V. fungicola infection depended on the dose of the fungicide employed, whereas fruit-body morphology was only slightly affected at the highest Prochloraz-Mn concentration used.  (+info)

Pregnane-type steroids from the inedible mushroom Thelephora terrestris. (6/173)

Chromatographic fractionation of the methanol extract of fruiting bodies of the inedible Japanese mushroom Thelephora terrestris (Thelephoraceae) has led to the isolation and characterization of two unusual new pregnane-type steroids, 2beta,3alpha-dihydroxypregna-4,7,16-trien-12,20-dione (2) and 1alpha,2beta,3alpha-trihydroxypregna-4,7,16-trien-12,20-dione (3) named terresterones A and B (2, 3), as well as the previously known compound stizophyllin, now assigned as 2beta,3alpha,12beta-trihydroxypregna-4,7,16-trien-20-one (1). Elucidation of their structures and the revision of the stereochemical assignment of stizophyllin were achieved by means of extensive 1D and 2D NMR, UV, CD, IR, MS and molecular modeling experiments. This paper presents the first report on the isolation of true pregnane-type steroids from the Fungi kingdom.  (+info)

A Hydrophobin of the chestnut blight fungus, Cryphonectria parasitica, is required for stromal pustule eruption. (7/173)

Hydrophobins are abundant small hydrophobic proteins that are present on the surfaces of many filamentous fungi. The chestnut blight pathogen Cryphonectria parasitica was shown to produce a class II hydrophobin, cryparin. Cryparin is the most abundant protein produced by this fungus when grown in liquid culture. When the fungus is growing on chestnut trees, cryparin is found only in the fungal fruiting body walls. Deletion of the gene encoding cryparin resulted in a culture phenotype typical of hydrophobin deletion mutants of other fungi, i.e., easily wettable (nonhydrophobic) hyphae. When grown on the natural substrate of the fungus, however, cryparin-null mutation strains were unable to normally produce its fungal fruiting bodies. Although the stromal pustules showed normal development initially, they were unable to erupt through the bark of the tree. The hydrophobin cryparin thus plays an essential role in the fitness of this important plant pathogen by facilitating the eruption of the fungal fruiting bodies through the bark of its host tree.  (+info)

Aldose reductase inhibitors from the fruiting bodies of Ganoderma applanatum. (8/173)

The isolation and characterization of rat lens aldose reductase (RLAR) inhibitors from the fruiting bodies of Ganoderma applanatum were conducted. Among the extracts and fractions from G. applanatum tested, the MeOH extract and EtOAc fraction were found to exhibit potent RLAR inhibition in vitro, their IC50 being 1.7 and 0.8 microg/ml, respectively. From the active EtOAc fraction, seven compounds with diverse structural moieties were isolated and identified as D-mannitol (1), 2-methoxyfatty acids (2), cerebrosides (3), daucosterol (4), 2,5-dihydroxyacetophenone (5), 2,5-dihydroxybenzoic acid (6), and protocatechualdehyde (7). Among them, protocatechualdehyde (7) was found to be the most potent RLAR inhibitor (IC50=0.7 microg/ml), and may be useful for the prevention and/or treatment of diabetic complications.  (+info)