Study of the essentiality of the Aspergillus fumigatustriA gene, encoding RNA triphosphatase, using the heterokaryon rescue technique and the conditional gene expression driven by the alcA and niiA promoters. Fungal genetics and biology : FG & B [Fungal Genet Biol] Journal article | | Title | Study of the essentiality of the Aspergillus fumigatustriA gene, encoding RNA triphosphatase, using the heterokaryon rescue technique and the conditional gene expression driven by the alcA and niiA promoters. | | Author(s) | Monteiro MC, Lucas JR | | Institution | Departamento de Microbiología y Parasitología. Facultad de Farmacia. Campus Universitario. Universidad de Alcalá, Ctra. Madrid-Barcelona Km 33, Alcalá de Henares ES-28871. Madrid. Spain. | | Source | Fungal Genet Biol 2009 Oct 30. | | Abstract | The identification of essential genes represents a critical step in the discovery of novel therapeutic targets in A. fumigatus. Structural analyses of the Saccharomyces cerevisiae RNA triphosphatase pointed out this enzyme as an attractive therapeutic target for fungal infections. In addition, demonstration of the essentiality of the S. cerevisiae RNA triphosphatase encoding gene enhanced the value of this potential therapeutic target. Nevertheless, consideration of a fungal RNA triphophatase as an ideal therapeutic target needs confirmation of the essentiality of the respective gene in a fungal pathogen. In this work, we analyzed the essentiality of the A. fumigatus triA gene, encoding RNA triphosphatase, by conditional gene expression and heterokaryon deletion. Using the conditional gene expression driven by the alcA promoter (alcA(P)), we found that TriA depletion causes morphological abnormalities that result in a very strong growth inhibition. Nevertheless, since a strict terminal phenotype was not observed, the essentiality of the triA gene could not be ensured. Accordingly, the essentiality of this gene was analyzed by the heterokaryon rescue technique. Results obtained unequivocally demonstrated the essentiality of the A. fumigatus triA gene, indicating the suitability of the RNA triphosphatase as an ideal therapeutic target to treat A. fumigatus infections. Besides, a second conditional gene expression system, based on the niiA promoter (niiA(P)), was utilized in this work. Although the niiA(P)-mediated repression of triA was less severe than that driven by the alcA(P), a strong growth inhibition was also found in niiA(P)-triA strains. Finally, E-tests performed to determine whether triA down-regulated cells became more sensitive to antifungals suggest a synergic effect between amphotericin B and another antifungal inhibiting the A. fumigatus RNA triphosphatase activity. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19883779 |
|
|
| |
Advertise on this site.
| | |
|
