title: Mitochondrial Complex I Is a Global Regulator of Secondary Metabolism, Virulence and Azole Sensitivity in Fungi.
abstract: Recent estimates of the global burden of fungal disease suggest that that their incidence has been drastically underestimated and that mortality may rival that of malaria or tuberculosis. Azoles are the principal class of antifungal drug and the only available oral treatment for fungal disease. Recent occurrence and increase in azole resistance is a major concern worldwide. Known azole resistance mechanisms include over-expression of efflux pumps and mutation of the gene encoding the target protein cyp51a, however, for one of the most important fungal pathogens of humans, Aspergillus fumigatus, much of the observed azole resistance does not appear to involve such mechanisms. Here we present evidence that azole resistance in A. fumigatus can arise through mutation of components of mitochondrial complex I. Gene deletions of the 29.9KD subunit of this complex are azole resistant, less virulent and exhibit dysregulation of secondary metabolite gene clusters in a manner analogous to deletion mutants of the secondary metabolism regulator, LaeA. Additionally we observe that a mutation leading to an E180D amino acid change in the 29.9 KD subunit is strongly associated with clinical azole resistant A. fumigatus isolates. Evidence presented in this paper suggests that complex I may play a role in the hypoxic response and that one possible mechanism for cell death during azole treatment is a dysfunctional hypoxic response that may be restored by dysregulation of complex I. Both deletion of the 29.9 KD subunit of complex I and azole treatment alone profoundly change expression of gene clusters involved in secondary metabolism and immunotoxin production raising potential concerns about long term azole therapy.
authors.affiliation: Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom.
authors.forename: Mike
authors.initials: M
authors.lastname: Bromley
authors.affiliation: Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom.
authors.forename: Anna
authors.initials: A
authors.lastname: Johns
authors.affiliation: National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom.
authors.forename: Emma
authors.initials: E
authors.lastname: Davies
authors.affiliation: Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom.
authors.forename: Marcin
authors.initials: M
authors.lastname: Fraczek
authors.affiliation: Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Mabey Gilsenan
authors.affiliation: The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom.
authors.forename: Natalya
authors.initials: N
authors.lastname: Kurbatova
authors.affiliation: The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom.
authors.forename: Maria
authors.initials: M
authors.lastname: Keays
authors.affiliation: The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom.
authors.forename: Misha
authors.initials: M
authors.lastname: Kapushesky
authors.affiliation: Centro Nacional de Analisis Genomico, Parc Cientific de Barcelona, Baldiri Reixac, 4, PCB - Tower I, 08028 Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Gut
authors.affiliation: Centro Nacional de Analisis Genomico, Parc Cientific de Barcelona, Baldiri Reixac, 4, PCB - Tower I, 08028 Barcelona, Spain.
authors.forename: Ivo
authors.initials: I
authors.lastname: Gut
authors.affiliation: National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom.
authors.forename: David W
authors.initials: DW
authors.lastname: Denning
authors.affiliation: Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom.|National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Bowyer
mesh_terms: D000935:Antifungal Agents / Q000627:therapeutic use; D001228:Aspergillosis / Q000188:drug therapy* / Q000235:genetics / Q000382:microbiology; D001232:Aspergillus fumigatus / Q000187:drug effects / Q000472:pathogenicity; D001393:Azoles / Q000627:therapeutic use; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D025141:Drug Resistance, Fungal / Q000235:genetics*; D042967:Electron Transport Complex I / Q000187:drug effects / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D008826:Microbial Sensitivity Tests; D008928:Mitochondria / Q000187:drug effects / Q000235:genetics*; D009154:Mutation; D064210:Secondary Metabolism / Q000187:drug effects
chemical_list: D000935:Antifungal Agents; D001393:Azoles; D005656:Fungal Proteins; D003577:Cytochrome P-450 Enzyme System; C465526:cytochrome P-450 CYP51A, Aspergillus; D042967:Electron Transport Complex I