Author, as appears in the article.: Javier Capilla; Fabio Gsaller; Peter Hortschansky; Takanori Furukawa; Paul D. Carr; Bharat Rash; Christoph Müller; Franz Bracher; Paul Bowyer; Hubertus Haas; Axel A. Brakhage; Michael J. Bromley
Department: Ciències Mèdiques Bàsiques
URV's Author/s: CAPILLA LUQUE, JAVIER
Keywords: cell extract pyrrole derivative CCAAT binding factor
Abstract: Azole drugs selectively target fungal sterol biosynthesis and are critical to our antifungal therapeutic arsenal. However, resistance to this class of drugs, particularly in the major human mould pathogen Aspergillus fumigatus, is emerging and reaching levels that have prompted some to suggest that there is a realistic probability that they will be lost for clinical use. The dominating class of pan-azole resistant isolates is characterized by the presence of a tandem repeat of at least 34 bases (TR34) within the promoter of cyp51A, the gene encoding the azole drug target sterol C14-demethylase. Here we demonstrate that the repeat sequence in TR34 is bound by both the sterol regulatory element binding protein (SREBP) SrbA, and the CCAAT binding complex (CBC). We show that the CBC acts complementary to SrbA as a negative regulator of ergosterol biosynthesis and show that lack of CBC activity results in increased sterol levels via transcriptional derepression of multiple ergosterol biosynthetic genes including those coding for HMG-CoA-synthase, HMG-CoA-reductase and sterol C14-demethylase. In agreement with these findings, inactivation of the CBC increased tolerance to different classes of drugs targeting ergosterol biosynthesis including the azoles, allylamines (terbinafine) and statins (simvastatin). We reveal that a clinically relevant mutation in HapE (P88L) significantly impairs the binding affinity of the CBC to its target site. We identify that the mechanism underpinning TR34 driven overexpression of cyp51A results from duplication of SrbA but not CBC binding sites and show that deletion of the 34 mer results in lack of cyp51A expression and increased azole susceptibility similar to a cyp51A null mutant. Finally we show that strains lacking a functional CBC are severely attenuated for pathogenicity in a pulmonary and systemic model of aspergillosis.
Research group: Unitat de Micologia i Microbiologia Ambiental
Thematic Areas: Health sciences Ciencias de la salud Ciències de la salut
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 1553-7366
Author identifier: N/D; N/D; N/D; N/D; N/D; N/D; N/D; N/D; N/D; N/D; N/D; N/D
Record's date: 2016-09-20
Last page: 22p
Journal volume: 12
Papper version: info:eu-repo/semantics/publishedVersion
Link to the original source: https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1005775
Article's DOI: 10.1371/journal.ppat.1005775
Entity: Universitat Rovira i Virgili
Journal publication year: 2016
First page: Art.num. e1005775
Publication Type: Article Artículo Article
Repositori URV