SEARCH · PubMed Health

Results for “Coprinus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMed2004

Flutolanil and carboxin resistance in Coprinus cinereus conferred by a mutation in the cytochrome b560 subunit of succinate dehydrogenase complex (Complex II).

A gene that confers resistance to the systemic fungicide flutolanil was isolated from a mutant strain of the basidiomycete Coprinus cinereus. The flutolanil resistance gene was mapped to a chromosome of approximately 3.2 Mb, and a chromosome-specific cosmid library was constructed. Two cosmid clones that were able to transform a wild-type, flutolanil-sensitive, strain of C. cinereus to resistance were isolated from the library. Analysis of a subclone containing the resistance gene revealed the presence of the sdhC gene, which encodes the cytochrome b560 subunit of the succinate dehydrogenase (SDH) complex (Complex II) in the mitochondrial membrane. Comparison between the sdhC gene of a wild-type strain and that of a mutant strain revealed a single point mutation, which results in the replacement of Asn by Lys at position 80. Measurements of succinate-cytochrome c reductase activity in the transformants with mutant sdhC gene(s) suggest that flutolanil resistance of the fungus is caused by a decrease in the affinity of the SDH complex for flutolanil. This sdhC mutation also conferred cross-resistance against another systemic fungicide, carboxin, an anilide that is structurally related to flutolanil. In other organisms carboxin resistance mutations have been found in the genes sdhB and sdhD, but this is the first demonstration that a mutation in sdhC can also confer resistance. The mutant gene cloned in this work can be utilized as a dominant selectable marker in gene manipulation experiments in C. cinereus.

Amino Acid Sequence↗

PubMed1997

A physical assay for meiotic recombination in Coprinus cinereus.

We have used the polymerase chain reaction (PCR) method to monitor meiotic recombination in the basidiomycete Coprinus cinereus. We used DNA-mediated transformation to recover strains with modifications of the trp1 locus. The modifications were designed to introduce unique PCR priming sites separated by a homologous 2.4 kb region in which crossing over could occur. We showed that exchange occurred in this region at the frequency expected for a typical region of this genome (2.4 kb should correspond to a genetic length of 0.08 cM). We also detected products resulting from crossing over in DNAs extracted from cells in meiotic prophase. The assay should be useful for monitoring exchange in mutants that cannot complete meiosis.

Blotting, Southern↗

PubMed1997

Restriction enzyme-mediated DNA integration in Coprinus cinereus.

Restriction enzyme-mediated DNA integration (REMI) has recently received attention as a new technique for the generation of mutants by transformation in fungi. Here we analyse this method in the basidiomycete Coprinus cinereus using the homologous pabI gene as a selectable marker and the restriction enzymes BamHI, EcoRI and PstI. Addition of restriction enzymes to transformation mixtures results in an earlier appearance of transformants and influences transformation rates in an enzyme- and concentration-dependent manner. Low concentrations of restriction enzyme result in increased numbers of transformation rates decrease with higher enzyme concentrations. If protoplasts are made from cells stored in the cold, the transformation rates drop drastically even in the presence of low amounts of enzyme. In several transformants, plasmid integration directly correlated with the action of restriction enzyme at random chromosomal restriction sites. In some cases, restriction enzymes appear to reduce the number of integration events per transformant. Simultaneously, mutation rates can be enhanced due to the presence of restriction enzymes. Although restriction enzymes clearly promote plasmid integration into the host genome they also have cytotoxic and possibly mutagenic effects that result from processes other than plasmid integration. In consequence, for any given enzyme used in REMI mutagenesis, the enzyme concentration that gives the highest number of transformants must be defined experimentally. Such optimal transformation conditions should give the highest probability of obtaining mutations caused by a single restriction enzyme-mediated integration of the selection marker.

Blotting, Southern↗

PubMed1976

Effect of cyclic AMP on glycogen phosphorylase in Coprinus macrorhizus.

Glycogen phosphorylase (1,4-alpha-D-glucan:orthophosphate alpha-glucosyltransfase, EC 2.4.1.1) activity was found in mycelial extracts of Coprinus macrorhizus concurrently with decrease of glycogen content in mycelial cells. Incubation of the enzyme sample with cyclic AMP and ATP leads to a 3-fold activation of the glucogen phosphorylase activity. Activation of the enzyme partially purified through Sepharose 6B required a cellular fraction containing cyclic AMP-dependent protein kinase.

Adenosine Triphosphate↗

PubMed1991

Signal transduction in Coprinus congregatus: evidence for the involvement of G proteins in blue light photomorphogenesis.

This paper reports the presence of several G proteins and light-sensitive GTP-binding proteins in the fungus Coprinus congregatus, a filamentous eukaryote. (Mono)ADP-ribosylation experiments with crude membranes in the presence of the (poly)ADP-ribosyltransferase inhibitor, 3-amino-benzamide, resulted in the detection of a cholera toxin substrate of 52 kDa and two pertussis toxin substrates, 33 and 39 kDa. Two-dimensional polyacrylamide gel analysis of GTP-binding proteins exposed in vivo to [35S]-labeled guanosine 5'-[gamma-thio]-triphosphate in the presence or absence of light demonstrated light enhanced analog binding. These results support the concept of the involvement of G proteins in phototransduction in C. congregatus.

Cell Membrane↗

PubMed1994

Three-dimensional structure of a recombinant peroxidase from Coprinus cinereus at 2.6 A resolution.

The structure of a recombinant peroxidase from the ink cap, Coprinus cinereus, CiP, is reported to 2.6 A resolution and refined to a R-value of 18.1%. The structure was solved by molecular replacement using the coordinates from a newly published ligninase structure. LiP. CiP crystallizes in space group P2(1)2(1)2(1) with two independent molecules in the asymmetric unit related by the vector 0.29b + 0.5c. The two CiP molecules are structurally identical; each contains two Ca2+ ions in positions equivalent to those found in the LiP structure. Two N-acetylglucosamines and one mannose residue were fitted into the density adjacent to two of the three predicted glycosylation sites. The refinement also included 40 and 41 water molecules, respectively, in the two CiP molecules. The structure of CiP displays a folding very similar to that of LiP. The active sites are almost identical in the LiP and CiP structures. CiP has a much larger opening to the active site than LiP.

Binding Sites↗

PubMed1975

[Modification of the high frequency of reversion of the nicotonic-2 mutant of Coprinus radiatus. II. Polymorphism of strains with low frequencies of reversion (author's transl)].

The nic2 mutation of Coprinus radiatus is unstable at meiosis. Strains derived from the initial mutant can be divided intto two classes: the "neutral genomes" which all revert at meiosis with different frequencies but in an autonomous way; and the "aggressive genomes", which inhibit the reversion of neutral genomes, present a large polymorphism in their own reversion and lose their aggressiveness at meiosis, becoming neutral genomes. The characteristics and the relationships of these two strains are presented in this paper.

Agaricales↗

PubMed1977

Mutational synergism between p-fluorophenylalanine and UV in Coprinus lagopus.

Previous studies have shown that the amino acid analogue p-fluorophenylalanine (PFP) is mutagenic to Coprinus lagopus due to its incorporation into proteins [32]. Spontaneous mutations, PFP and UV mutagenesis and PFP/UV synergism have been studied in a UV resistant strain and in two complementing UV sensitive mutant strains. By comparison to the UV resistant strain, one UV sensitive strain shows normal spontaneous mutations, 1.4% PFP-induced mutations and 50-fold UV mutagenesis. The second UV sensitive strain has 19-fold spontaneous mutation frequency, 8% PFP induced mutations and slightly elevated UV mutagenesis. In all 3 strains the PFP/UV synergism is comparable (4--5 times the arithmetic expected). The results indicate that PFP mutagenesis is due to the incorporation of PFP into enzymes normally functioning in the organism but which also participate in UV repair mechanisms. A model is proposed for UV repair which is based on a PFP sensitive excision repair system of at least two enzymes, and alternative "error proof" pathway which is not suscetible to PFP and an "error prone" pathway which is responsible for UV mutagenesis and is susceptible to PFP as shown by the PFP/UV synergism. Because PFP is given before UV treatment, this implies a UV inducible cofactor and a PFP sensitive enzyme which only functions after UV activation.

Agaricales↗

PubMed1989

Properties of genetic instability during the vegetative growth of Coprinus radiatus.

In Coprinus radiatus, a mutation at the Nic-2 locus unstable at meiosis has been previously described. Further studies have now shown that this mutation is also unstable, although with lower frequency, during vegetative growth. This 'vegetative instability', which is thermosensitive, is not a random process but an aggregative process, perhaps depending on the physiological state of the mycelium.

Agaricales↗

PubMed1989

Self-fructification associated with genetic instability in Coprinus radiatus.

In the basidiomycete Coprinus radiatus, crosses gave rise with a high frequency to 2 types of self-fructifying progeny. The first type showed monokaryotic fruiting due to the occurrence of a mutation associated with the B1 incompatibility factor. The second type showed fruiting due to the presence of the 2 parental genomes in the original spore. Mutability and abnormal development of the life cycle are responsible for self-fructification. These features occurred in progeny of related strains harbouring a genetic instability located at the Nic-2 locus. High mutability, disturbance of the development of the life cycle and genetic instability are traits which resemble hybrid dysgenesis in Drosophila and meiotic dysgenesis in Phycomyces.

Agaricales↗

PubMed1996

Morphometric analysis of cell size patterning involved in gravitropic curvature of the stipe of Coprinus cinereus.

During gravitropic bending of the stipe of Coprinus cinereus the majority of elongation occurred in the apical region of the lower surface of the stipe, although some elongation was seen throughout the stipe. The final rate of elongation was similar at both the upper and lower stipe surfaces but the lower surface achieved this rate first (close to the reaction time 25 min), whilst the upper surface of the stipe only attained its final elongation rate after a period of acceleration of 150 min. Detailed morphometric analysis of cell size patterning in transverse sections revealed no significant differences in cross sectional area, spatial or proportional distribution of different cell types between the upper and lower regions of the gravitropic bend. Measurements of longitudinal cell size revealed significant differences in compartment size between the lower and upper region. Hyphal compartments of lower regions of the bend were on average four to five times longer than those of the upper region.

Cell Size↗

PubMed1990

Purification and characterization of an ubiquitin-immuno-reactive protein localized in the cap of young basidiocarp in the basidiomycete Coprinus cinereus.

The ubiquitin-immuno-reactive protein with a molecular weight of 27,800 daltons, which is mainly present in the cap of young basidiocarp, was purified from the basidiomycete Coprinus cinereus. The molecular weight of the native protein was approximately 55,000 as determined by gel filtration chromatography. The isoelectric point of the protein was 4.4. The amino-terminal sequence of the protein was also determined.

Amino Acid Sequence↗

PubMed1981

Control of adenosine 3',5'-monophosphate level and protein phosphorylation by depolarizing agents in Coprinus macrorhizus.

The treatment of mycelial cells with membrane-active antibiotics, uncouplers of oxidative phosphorylation and KCl leads to a transient increase in adenosine 3',-5'-monophosphate (cyclic AMP) levels in Coprinus macrorhizus. The maximal values and duration of increase in the cyclic AMP level depended on the kind and amount of these drugs. The treatment with these drugs simultaneously resulted in a rapid increase in the phosphorylation of three cellular proteins. The levels and time course of phosphorylation of these proteins were paralleled with the increase of cyclic AMP level in response to the drugs used. Thus, the treatment of these drugs causes the transient increase of cyclic AMP level and cyclic AMP stimulates the phosphorylation of particular proteins by activating protein kinases.

Agaricales↗

PubMed1988

Ammonium ions and glutamine inhibit sporulation of Coprinus cinereus basidia assayed in vitro.

Basidia of Coprinus cinereus (Schaeff.:Fr) S. F. Gray are committed to their developmental pathway, continuing through meiosis and sporulation even when excised from their parental fruit body. A technique is described which permits this in vitro differentiation to be used as a rapid, small-scale bioassay for chemicals which interfere with these morphogenetic processes. Of a range of compounds tested, only ammonium and glutamine, and some structural analogues, were able to inhibit basidium differentiation. Growth was not inhibited; instead the differentiation inhibitors caused vegetative hyphal tips to grow out from regions of the basidial apparatus expected to be in active growth during sporulation. Depending on the stage reached at the time of exposure to the inhibitors, vegetative hyphal tips emerged from the four apical sites for sterigmata, from the tips of sterigmata, from partially formed or abnormal spores, and from the basal regions of the basidium from which paraphyses would be expected to arise. The experiments show that ammonium ions and glutamine halt meiocyte differentiation. Reports of similar effects in other organisms, animals and plants as well as fungi, may imply that sporulation events are generally sensitive to ammonium inhibition.

Agaricales↗

PubMed1992

Kinetics of stem gravitropism in Coprinus cinereus: determination of presentation time and "dosage-response" relationships using clinostats.

The sensitivity to gravitational stimulation of excised stems of the mushroom fruit body of Coprinus cinereus was determined using clinostat rotation to remove partially-stimulated stems from the normal unidirectional gravitational field. For the strain and conditions tested, the presentation time (the minimum time of stimulation required to elicit a gravitropic reaction) was determined to be 9.6 min. This is the first time the presentation time has been determined for a fungal gravitropic response. Constructional details are given of the clinostats employed in the research and their further use is discussed.

Coprinus↗

PubMed1989

Molecular characterization of TRP1, a gene coding for tryptophan synthetase in the basidiomycete Coprinus cinereus.

We utilized a cloned gene (TRP5) encoding tryptophan synthetase (TSase) from Saccharomyces cerevisiae to identify and clone the corresponding gene (TRP1) from the basidiomycete Coprinus cinereus. The primary nucleotide (nt) sequence of this gene was determined and compared to sequences from other filamentous fungi, as well as to other genes coding for TSase. A transformation assay was used to demonstrate that 321 nt, which do not include CAAT or TATAAA elements and precede the translation initiation codon, are sufficient for expression in a variety of chromosomal locations. The coding region (2584 nt) is interrupted at nine positions, and putative splicing signals (5'-GTRNGT...YAG-3') are present in each case. The predicted translation product contains 702 amino acids (aa) and is very similar to other TSases, except in the region of aa 257-296 that connects the alpha and beta functional domains. Both the number and the identity of the aa differ in this region between C. cinereus. S. cerevisiae, and Neurospora crassa. Comparison of exon boundaries in the C. cinereus sequence to the three-dimensional structure of Salmonella typhimurium TSase indicates that there is no simple correlation between exons and major functional domains in this protein.

Agaricales↗

PubMed1993

Nucleotide sequence of a ras gene from the basidiomycete Coprinus cinereus.

The basidiomycete Lentinus edodes (Le.) ras gene (or its cDNA clone) [Hori et al., Gene 105 (1991) 91-96] was utilized to identify and clone the corresponding gene (Cc.ras)-containing genomic fragment from the basidiomycete, Coprinus cinereus. Cc.ras encodes 215 amino acids (aa) interrupted by six small introns. The deduced Cc.RAS protein exhibits significant homology (84.7% identical) to the Le.RAS protein (217 aa) in size and aa sequence.

Amino Acid Sequence↗

PubMed1994

Comparison of two b1 alleles from within the A mating-type of the basidiomycete Coprinus cinereus.

We cloned and sequenced the b1 specificity gene, b1-2, from the A43 mating-type locus of the basidiomycete Coprinus cinereus, to compare its molecular structure to a previously published allele. The b1-2 gene was identified and isolated using a transformation assay for A-activity. The nucleotide (nt) sequence was determined and compared to the published sequence for the b1 specificity gene of the A42 mating-type locus. Both genes map to the same physical location within the A mating-type locus and conserved structural organization is observed at both the genomic and the protein level. Sequence alignments show that the two alleles share 73% overall nt sequence identity for the open reading frames (ORFs) and 68% overall amino acid (aa) sequence identity for the deduced polypeptides. Allowing for conservative substitutions, the overall aa sequence similarity is 79%. Comparison of the deduced aa sequences reveals several conserved structural motifs, including a DNA-binding homeodomain, putative bipartite nuclear localization signal sequences, and four predicted dimerization motifs. Regions rich in Pro and hydroxylated aa (Ser and Thr) are also common to both alleles. Sequence similarity varies greatly along the length of the gene at both the nt and aa levels. In general, similarity increases progressively from the N- to the C-terminal end with variable patterns of similarity observed for individual exons and the predicted motifs they encode. The low sequence similarity observed in the N terminus suggests that variability in this region may be involved in non-self recognition. Differing levels of positional and compositional constraint are apparent for different functional domains.

Alleles↗