Overexpression of TUF1 restores respiratory growth and fluconazole sensitivity to a Cryptococcus neoformans vad1Delta mutant.
The yeast-like fungus Cryptococcus neoformans favours respiration as a mechanism of energy production, and thus depends heavily on mitochondrial function. Previous studies of a C. neoformans vad1Delta mutant revealed reduced expression of the mitochondrial elongation factor TUF1 and defects in glycerol utilization, consistent with mitochondrial dysfunction. In this study, we found that in trans expression of TUF1 in the vad1Delta mutant suppressed the mitochondrial defects, including growth on respiration-dependent carbon sources and fluconazole resistance, associated with VAD1 deletion. Tetracycline, an inhibitor of mitochondrial translation, was found to confer resistance to fluconazole in the wild-type and vad1Delta mutant, whereas the fluconazole susceptibility of the TUF1-overexpressing strain was unaffected by tetracycline treatment. In the presence of fluconazole, the vad1Delta mutant exhibited increased activation of the global transcriptional regulator Sre1. TUF1 overexpression failed to alter cleavage of Sre1 in response to fluconazole in the vad1Delta mutant, suggesting that TUF1 repression in the vad1Delta mutant is distal to Sre1, or that it occurs through an independent pathway.
Panepinto
John C
JC
Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, State University of New York at Buffalo, Buffalo, NY, USA.
Misener
Amanda L
AL
Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, State University of New York at Buffalo, Buffalo, NY, USA.
Oliver
Brian G
BG
Seattle Biomedical Research Institute, Seattle, WA, USA.
Hu
Guowu
G
Section of Infectious Diseases, University of Illinois at Chicago, Chicago, IL, USA.
Park
Yoon Dong
YD
Section of Infectious Diseases, University of Illinois at Chicago, Chicago, IL, USA.
Shin
Soowan
S
Section of Infectious Diseases, University of Illinois at Chicago, Chicago, IL, USA.
White
Theodore C
TC
Seattle Biomedical Research Institute, Seattle, WA, USA.
Williamson
Peter R
PR
Section of Translational Mycology, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.|Section of Infectious Diseases, University of Illinois at Chicago, Chicago, IL, USA.
D000935:Antifungal Agents / Q000494:pharmacology*; D003455:Cryptococcus neoformans / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D025141:Drug Resistance, Fungal; D015725:Fluconazole / Q000494:pharmacology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism*; D012331:RNA, Fungal / Q000235:genetics
D000935:Antifungal Agents; D005656:Fungal Proteins; D024101:Mitochondrial Proteins; D010445:Peptide Elongation Factors; D012331:RNA, Fungal; D015725:Fluconazole