DNA polymerase of a basidiomycete fungus, Coprinus cinereus.
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ABSTRACT:
SUBMITTER: Lowe D
PROVIDER: S-EPMC1162695 | biostudies-other | 1981 Mar
REPOSITORIES: biostudies-other
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Project description:Coprinus cinereus has two main types of mycelia, the asexual monokaryon and the sexual dikaryon, formed by fusion of compatible monokaryons. Syngamy (plasmogamy) and karyogamy are spatially and temporally separated, which is typical for basidiomycetous fungi. This property of the dikaryon enables an easy exchange of nuclear partners in further dikaryotic-monokaryotic and dikaryotic-dikaryotic mycelial fusions. Fruiting bodies normally develop on the dikaryon, and the cytological process of fruiting-body development has been described in its principles. Within the specialized basidia, present within the gills of the fruiting bodies, karyogamy occurs in a synchronized manner. It is directly followed by meiosis and by the production of the meiotic basidiospores. The synchrony of karyogamy and meiosis has made the fungus a classical object to study meiotic cytology and recombination. Several genes involved in these processes have been identified. Both monokaryons and dikaryons can form multicellular resting bodies (sclerotia) and different types of mitotic spores, the small uninucleate aerial oidia, and, within submerged mycelium, the large thick-walled chlamydospores. The decision about whether a structure will be formed is made on the basis of environmental signals (light, temperature, humidity, and nutrients). Of the intrinsic factors that control development, the products of the two mating type loci are most important. Mutant complementation and PCR approaches identified further genes which possibly link the two mating-type pathways with each other and with nutritional regulation, for example with the cAMP signaling pathway. Among genes specifically expressed within the fruiting body are those for two galectins, beta-galactoside binding lectins that probably act in hyphal aggregation. These genes serve as molecular markers to study development in wild-type and mutant strains. The isolation of genes for potential non-DNA methyltransferases, needed for tissue formation within the fruiting body, promises the discovery of new signaling pathways, possibly involving secondary fungal metabolites.
| S-EPMC98996 | biostudies-literature
Project description:Coprinopsis cinerea exhibits synchronised meiosis in the gill tissue of the fungus, which is 75% meiotic. The mushroom develops from a dikaryon, which contains two separate nuclei. These nucleifuse in the basidia (karyogamy). After karyogamy, the nuclei enter an extended meiotic prophase, in which pahcytene occurs at 6 hours post karyogamy (K+6). The tetrads produced by the second meiotic division are present 12 hours after karyogamy (K+12). To examine a comprehensive timecourse of meiosis in this organism, we took samples over a 15-hour period, 3 hours apart: K-3, K, K+3, K+6, K+9, K+12. Keywords: time course
2010-02-01 | GSE13731 | GEO
Project description:A laccase from Coprinus cinereus is active at alkaline pH, an essential property for some potential applications. We cloned and sequenced three laccase genes (lcc1, lcc2, and lcc3) from the ink cap basidiomycete C. cinereus. The lcc1 gene contained 7 introns, while both lcc2 and lcc3 contained 13 introns. The predicted mature proteins (Lcc1 to Lcc3) are 58 to 80% identical at the amino acid level. The predicted Lcc1 contains a 23-amino-acid C-terminal extension rich in arginine and lysine, suggesting that C-terminal processing may occur during its biosynthesis. We expressed the Lcc1 protein in Aspergillus oryzae and purified it. The Lcc1 protein as expressed in A. oryzae has an apparent molecular mass of 66 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and absorption maxima at 278 and 614 nm. Based on the N-terminal protein sequence of the laccase, a 4-residue propeptide was processed during the maturation of the enzyme. The dioxygen specificity of the laccase showed an apparent K(m) of 21 +/- 2 microM and a catalytic constant of 200 +/- 10 min(-1) for O(2) with 2, 2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) as the reducing substrate at pH 5.5. Lcc1 from A. oryzae may be useful in industrial applications. This is the first report of a basidiomycete laccase whose biosynthesis involves both N-terminal and C-terminal processing.
| S-EPMC91665 | biostudies-literature
Project description:Mating compatibility in C. cinerea is controlled by two loci, A and B. Following fusion of undifferentiated hyphal cells, a complex program is initiated which results in the maintenance of one nucleus from each parent in every cell (the dikaryon). We identified downstream targets of the A locus (A on), the B locus (B on), and both loci (Aon Bon) using strains in which the two pathways are activated separately, and a dikaryotic strain. keywords: Cell type comparison
2010-06-21 | GSE20628 | GEO
Project description:Coprinopsis cinerea exhibits synchronised meiosis in the gill tissue of the fungus, which is 75% meiotic. The mushroom develops from a dikaryon, which contains two separate nuclei. These nucleifuse in the basidia (karyogamy). After karyogamy, the nuclei enter an extended meiotic prophase, in which pahcytene occurs at 6 hours post karyogamy (K+6). The tetrads produced by the second meiotic division are present 12 hours after karyogamy (K+12). To examine a comprehensive timecourse of meiosis in this organism, we took samples over a 15-hour period, 3 hours apart: K-3, K, K+3, K+6, K+9, K+12. Keywords: time course Four biological replicate samples of each timepoint were taken. Labelled cDNA was hybridized to arrays in a 2 channel reaction. The reference sample was a mixture of timepoint samples.
2010-01-31 | E-GEOD-13731 | biostudies-arrayexpress
Project description:Mating compatibility in C. cinerea is controlled by two loci, A and B. Following fusion of undifferentiated hyphal cells, a complex program is initiated which results in the maintenance of one nucleus from each parent in every cell (the dikaryon). We identified downstream targets of the A locus (A on), the B locus (B on), and both loci (Aon Bon) using strains in which the two pathways are activated separately, and a dikaryotic strain. keywords: Cell type comparison Four biological replicate samples of each experimental strain were taken. Labelled cDNA was hybridized to arrays in a 2 channel reaction. The reference sample was an unmated monokaryotic strain.
2010-06-21 | E-GEOD-20628 | biostudies-arrayexpress
Project description:Mushrooms, such as Coprinus cinereus, possess large families of pheromones and G-protein-coupled receptors that are sequestered at the B mating-type locus and whose function is to confer vast numbers of different mating types. This ability results from complex patterns of cognate and noncognate pheromone/receptor pairings, which potentially offer a unique insight into the molecular interaction between receptor and ligand. In this study we have identified many more members of these families by molecular analysis of strains collected worldwide. There are three groups of genes at each B locus. We have identified two alleles of group 1, five alleles of group 2, and seven alleles of group 3, encoding in total 14 different receptors and 29 different pheromones. The specificity of many newly identified alleles was determined by transformation analysis. One striking finding was that receptors fall into groups based on sequence homology but these do not correspond to the groups defined by position, indicating that complex evolutionary processes gave rise to the B loci. While additional allelic versions may occur in nature, the number of B specificities possible by combination of the alleles that we describe is 70, close to previous estimates based on population analysis.
| S-EPMC1451185 | biostudies-literature
Project description:Cancer cell line bioassay-guided separation of an ethyl acetate extract prepared from a plant-associated fungus, Coprinus cinereus, led to the isolation of three new sesquiterpenes, coprinastatin 1 (1), coprinol (2), and the epimer (4a), of the known sesquiterpene triol (4b). The previously described sesquiterpene 3 and oxazolinone 5 were also isolated. The structure and relative configuration of coprinastatin 1 (1) were determined by HRMS and by 1D- and 2D-NMR spectroscopic analyses. The structure of terpene 2 was elucidated by single-crystal X-ray diffraction experiments. The remaining structures were similarly determined, structure 3 by spectroscopic analyses and both 4a and 5 by X-ray crystal structure determination. Coprinastatin 1 (1) was found to inhibit growth of the murine P388 lymphocytic leukemia cell line and the pathogenic bacterium Neisseria gonorrhoeae.
| S-EPMC2846224 | biostudies-literature
Project description:Sesquiterpene synthases catalyze with different catalytic fidelity the cyclization of farnesyl pyrophosphate (FPP) into hundreds of known compounds with diverse structures and stereochemistries. Two sesquiterpene synthases, Cop4 and Cop6, were previously isolated from Coprinus cinereus as part of a fungal genome survey. This study investigates the reaction mechanism and catalytic fidelity of the two enzymes. Cyclization of all-trans-FPP ((E,E)-FPP) was compared to the cyclization of the cis-trans isomer of FPP ((Z,E)-FPP) as a surrogate for the secondary cisoid neryl cation intermediate generated by sesquiterpene synthases, which are capable of isomerizing the C2--C3 pi bond of all-trans-FPP. Cop6 is a "high-fidelity" alpha-cuprenene synthase that retains its fidelity under various conditions tested. Cop4 is a catalytically promiscuous enzyme that cyclizes (E,E)-FPP into multiple products, including (-)-germacrene D and cubebol. Changing the pH of the reaction drastically alters the fidelity of Cop4 and makes it a highly selective enzyme. Cyclization of (Z,E)-FPP by Cop4 and Cop6 yields products that are very different from those obtained with (E,E)-FPP. Conversion of (E,E)-FPP proceeds via a (6R)-beta-bisabolyl carbocation in the case of Cop6 and an (E,E)-germacradienyl carbocation in the case of Cop4. However, (Z,E)-FPP is cyclized via a (6S)-beta-bisabolene carbocation by both enzymes. Structural modeling suggests that differences in the active site and the loop that covers the active site of the two enzymes might explain their different catalytic fidelities.
| S-EPMC2873112 | biostudies-literature
Project description:The mushroom Coprinopsis cinerea is a classic experimental model for multicellular development in fungi because it grows on defined media, completes its life cycle in 2 weeks, produces some 10(8) synchronized meiocytes, and can be manipulated at all stages in development by mutation and transformation. The 37-megabase genome of C. cinerea was sequenced and assembled into 13 chromosomes. Meiotic recombination rates vary greatly along the chromosomes, and retrotransposons are absent in large regions of the genome with low levels of meiotic recombination. Single-copy genes with identifiable orthologs in other basidiomycetes are predominant in low-recombination regions of the chromosome. In contrast, paralogous multicopy genes are found in the highly recombining regions, including a large family of protein kinases (FunK1) unique to multicellular fungi. Analyses of P450 and hydrophobin gene families confirmed that local gene duplications drive the expansions of paralogous copies and the expansions occur in independent lineages of Agaricomycotina fungi. Gene-expression patterns from microarrays were used to dissect the transcriptional program of dikaryon formation (mating). Several members of the FunK1 kinase family are differentially regulated during sexual morphogenesis, and coordinate regulation of adjacent duplications is rare. The genomes of C. cinerea and Laccaria bicolor, a symbiotic basidiomycete, share extensive regions of synteny. The largest syntenic blocks occur in regions with low meiotic recombination rates, no transposable elements, and tight gene spacing, where orthologous single-copy genes are overrepresented. The chromosome assembly of C. cinerea is an essential resource in understanding the evolution of multicellularity in the fungi.
| S-EPMC2900686 | biostudies-literature