Candida albicans is the leading fungal pathogen of humans, causing life-threatening infection in immunocompromised individuals. Treatment of candidiasis is hampered by the limited number of antifungal drugs. The triazoles are the largest class of antifungal drugs in clinical use. They inhibit lanosterol 14-demethylase (Erg11). The therapeutic efficacy of triazoles is compromised by the emergence of drug resistant strains. C. albicans can acquire triazole resistance by multiple distinct mechanisms, including mechanisms to cope with drug-induced cellular stresses. Upc2, a transcriptional regulator of ergosterol biosynthesis pathway genes, is critical for resistance to triazoles. We find that Cph2 is also a regulator of ergosterol biosynthesis and misregulation of Cph2 leads to altered drug sensitivity. How Upc2 and Cph2 are regulated in C. albicans is unclear. Here we propose to use chemical approaches to dissect regulatory mechanisms for Cph2 and Upc2.
Aim 1 identifies small molecules that target transcriptional regulation of ergosterol homeostasis.
Aim 2 identifies protein targets of selected hit compounds in C. albicans by chemical genomics approaches.
Aim 3 will be target verification and functional characterization in C. albicans. Identification of smal molecules and their targets will lead to the discovery of novel pathways and mechanisms that control ergosterol homeostasis and triazole resistance.

Public Health Relevance

Candida has emerged as a significant human pathogen, causing life-threatening infection in immunocompromised individuals. Treatment of candidiasis is hampered by the limited number of antifungal drugs and the emergence of drug resistance. Development of novel combinatory drug therapy will help fight against Candida infections and lower the level of drug toxicity to people.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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Special Emphasis Panel (ZAI1-LG-M (J2))
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Duncan, Rory A
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University of California Irvine
Schools of Medicine
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Yu, Clinton; Kandur, Wynne; Kao, Athit et al. (2014) Developing new isotope-coded mass spectrometry-cleavable cross-linkers for elucidating protein structures. Anal Chem 86:2099-106
Lu, Yang; Su, Chang; Unoje, Ohimai et al. (2014) Quorum sensing controls hyphal initiation in Candida albicans through Ubr1-mediated protein degradation. Proc Natl Acad Sci U S A 111:1975-80
Lu, Yang; Su, Chang; Liu, Haoping (2014) Candida albicans hyphal initiation and elongation. Trends Microbiol 22:707-14
Lu, Yang; Su, Chang; Solis, Norma V et al. (2013) Synergistic regulation of hyphal elongation by hypoxia, CO(2), and nutrient conditions controls the virulence of Candida albicans. Cell Host Microbe 14:499-509
Su, Chang; Lu, Yang; Liu, Haoping (2013) Reduced TOR signaling sustains hyphal development in Candida albicans by lowering Hog1 basal activity. Mol Biol Cell 24:385-97
Stevenson, John S; Liu, Haoping (2013) Nucleosome assembly factors CAF-1 and HIR modulate epigenetic switching frequencies in an H3K56 acetylation-associated manner in Candida albicans. Eukaryot Cell 12:591-603