Candida albicans is the most common fungal pathogen of humans, and causes infections that range from oral and vaginal candidiasis to life-threatening candidemia and invasive disease. Our broad objectives are to identify pathogen virulence mechanisms, prospective drug targets, and drug resistance mechanisms through large-scale analysis of C. albicans gene function. With the C. albicans genomic sequence, it is now possible to define the spectrum of gene function through analysis of strains that are defective in each gene. There has been no publicly available large-scale analysis of C. albicans gene function to date because C. albicans genetic analysis is cumbersome. We have developed a method that streamlines C. albicans gene disruption. A pilot set of 253 transposon-generated insertions into C. albicans ORFs has been used to identify new genes that govern pathogenicity and antifungal drug resistance. In addition, our results suggest that 36 of the genes are essential, and may be prospective drug targets. Our findings illustrate that genetic determinants of virulence and viability may be identified efficiently and cost-effectively through genetic analysis in C. albicans, rather than by inference from model yeasts that are seldom pathogens. We propose to expand the analysis through creation of a large set of cloned, sequenced C. albicans orf::Tn7-UAU1 insertion plasmids, construction of C. albicans orf::Tn7-UAU1/orf::Tn7-URA3 viable insertion homozygotes, and screening among the strains for alterations of phenotypes associated with pathogenicity, including filamentation, biofilm formation, antifungal drug resistance, host-cell interaction, and cell surface properties. Definition of the genes that govern these processes will lead to mechanistic insight, to candidate genes for mechanistic analysis, to therapeutic targets for pharmacological exploitation, and to rapid tests for the potential of an infecting strain to develop drug resistance.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
7R01AI057804-06
Application #
7738060
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Program Officer
Duncan, Rory A
Project Start
2004-03-01
Project End
2011-02-28
Budget Start
2008-12-01
Budget End
2011-02-28
Support Year
6
Fiscal Year
2008
Total Cost
$506,261
Indirect Cost
Name
Carnegie-Mellon University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
052184116
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Blankenship, Jill R; Cheng, Shaoji; Woolford, Carol A et al. (2014) Mutational analysis of essential septins reveals a role for septin-mediated signaling in filamentation. Eukaryot Cell 13:1403-10
Vasicek, Erin M; Berkow, Elizabeth L; Bruno, Vincent M et al. (2014) Disruption of the transcriptional regulator Cas5 results in enhanced killing of Candida albicans by Fluconazole. Antimicrob Agents Chemother 58:6807-18
Thevissen, Karin; de Mello Tavares, Patricia; Xu, Deming et al. (2012) The plant defensin RsAFP2 induces cell wall stress, septin mislocalization and accumulation of ceramides in Candida albicans. Mol Microbiol 84:166-80
Argimon, Silvia; Fanning, Saranna; Blankenship, Jill R et al. (2011) Interaction between the Candida albicans high-osmolarity glycerol (HOG) pathway and the response to human beta-defensins 2 and 3. Eukaryot Cell 10:272-5
Morrow, Michael W; Janke, Megan R; Lund, Kyle et al. (2011) The Candida albicans Kar2 protein is essential and functions during the translocation of proteins into the endoplasmic reticulum. Curr Genet 57:25-37
Bishop, Andrew C; Sun, Tao; Johnson, Mitchell E et al. (2011) Robust utilization of phospholipase-generated metabolites, glycerophosphodiesters, by Candida albicans: role of the CaGit1 permease. Eukaryot Cell 10:1618-27
Blankenship, Jill R; Fanning, Saranna; Hamaker, Jessica J et al. (2010) An extensive circuitry for cell wall regulation in Candida albicans. PLoS Pathog 6:e1000752
Park, Hyunsook; Liu, Yaoping; Solis, Norma et al. (2009) Transcriptional responses of candida albicans to epithelial and endothelial cells. Eukaryot Cell 8:1498-510
Chamilos, Georgios; Nobile, Clarissa J; Bruno, Vincent M et al. (2009) Candida albicans Cas5, a regulator of cell wall integrity, is required for virulence in murine and toll mutant fly models. J Infect Dis 200:152-7
Rauceo, Jason M; Blankenship, Jill R; Fanning, Saranna et al. (2008) Regulation of the Candida albicans cell wall damage response by transcription factor Sko1 and PAS kinase Psk1. Mol Biol Cell 19:2741-51

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