Gianna Cecchetto

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In Aspergillus nidulans, loss-of-function mutations in the uapA and azgA genes, encoding the major uric acid-xanthine and hypoxanthine-adenine-guanine permeases, respectively, result in impaired utilization of these purines as sole nitrogen sources. The residual growth of the mutant strains is due to the activity of a broad specificity purine permease. We(More)
The PrnA transcriptional activator of Aspergillus nidulans binds as a dimer to CCGG-N-CCGG inverted repeats and to CCGG-6/7N-CCGG direct repeats. The binding specificity of the PrnA Zn cluster differs from that of the Gal4p/Ppr1p/UaY/Put3p group of proteins. Chimeras with UaY, a protein that strictly recognizes a CGG-6N-CCG motif, show that the recognition(More)
In this article we study the cellular expression of UapA and AzgA, the two major purine transporters of Aspergillus nidulans, by constructing strains expressing, from their native promoters, fully functional fluorescent (UapA-sGFP, AzgA-sGFP) or immunological (UapA-His) chimeric transporters. Epifluorescence microscopy and immunodetection showed that under(More)
The azgA gene of Aspergillus nidulans encodes a hypoxanthine-adenine-guanine transporter. It has been cloned by a novel transposon methodology. The null phenotype of azgA was defined by a number of mutations, including a large deletion. In mycelia, the azgA gene is, like other genes of purine catabolism, induced by uric acid and repressed by ammonium. Its(More)
Aspergillus nidulans possesses three well-characterized purine transporters encoded by the genes uapA, uapC and azgA. Expression of these genes in mycelium is induced by purines and repressed by ammonium or glutamine through the action of the pathway-specific UaY regulator and the general GATA factor AreA respectively. Here, we describe the regulation of(More)
Molybdenum-containing enzymes of the hydroxylase class (such as xanthine dehydrogenase, aldehyde oxidase and nicotinate dehydrogenase) require a terminal sulphur atom attached to the molybdenum to hydroxylate their specific substrates. The transulphurylation reaction is carried out in Drosophila melanogaster by the product of the ma-I gene. In Aspergillus(More)
The ascomycete fungusAspergillus nidulans can utilize purines (adenine, guanine, hypoxanthine, xanthine, and uric acid) as sole nitrogen sources [1]. The expression of most structural genes involved in the pathway of purine uptake and catabolism is subject to uric acid induction, mediated by the product of the positive regulatory geneuaY, and to nitrogen(More)
UaY is the specific ZnII(2)Cys(6) transcriptional activator of the purine utilisation pathway in Aspergillus nidulans. Previous work has determined the consensus binding sequence by EMSA and foot-printing. We determine here that it binds as a dimer to its cognate CGG-N(6)-CCG sites. We identify the uaY109 mutation, which has been shown to affect(More)
In this work, the antimicrobial activity of extracts of wood rotting higher Basidiomycetes mushrooms isolated from Eucalyptus plantations in Uruguay was studied using bacterial and fungal phytopathogens as targets. Fifty-one extracts from mycelia and growth broth were prepared from higher Basidiomycetes mushrooms, from which eight extracts (from Ganoderma(More)
Purine transporters as substrate entry points in organisms, are involved in a number of cellular processes such as nitrogen source uptake, energy metabolism and synthesis of nucleic acids. In this study, two nucleobase transporter genes (phZ, phU) from Phanerochaete chrysosporium were cloned, identified, and functionally characterized. Our results show that(More)