Candida albicans is one of the most frequently isolated fungal pathogens of humans. It can undergo reversible morphogenetic transitions between budding yeast, pseudohyphal, and hyphal growth forms. Its unique ability to switch from yeast to hyphal growth in response to various host and environmental signals is essential to its pathogenicity. Many hypha-specific genes encode virulence factors. Hyphal development is regulated by multiple signal transduction pathways. Among them, the cAMP-dependent protein kinase A (PKA) pathway is a major regulator of morphogenesis and virulence. Despite its importance, the molecular mechanism for how the cAMP-PKA pathway activates the hyphal transcriptional program is still not known. We find cAMP- PKA dependent down-regulation of the major repressor of hyphal morphogenesis, Nrg1, correlates with the initiation of the hyphal transcriptional program. Sustained hyphal transcription requires Hda1 being recruited to the promoters of hypha-specific genes, where it leads to changes in promoter chromatin. We propose to determine the mechanisms and regulators for cAMP-PKA dependent Nrg1 down-regulation upon hyphal induction in Aim 1.
Aim 2 defines host factor(s) and C. albicans pathways for the promoter recruitment of Hda1 and its importance in invasive candidiasis.
Aim 3 studies functions and regulation of Cph2. A combined approach using molecular genetics, cell biology and biochemistry will be taken in our studies. This work will provide us with a better understanding of how C. albicans integrates various signals to control growth and development, and how it survives and grows in various host environments.
Candida has emerged as a significant human pathogen. It causes common mucosal manifestations such as oropharyngeal thrush and vaginitis. In hospitalized patients, disseminated candidiasis is the fourth most common infection (outpacing all gram- negative species) and carries a mortality rate in excess of 30%. Development of the next generation of antifungal agents will require a further understanding of the biology of Candida.
|Lu, Yang; Su, Chang; Liu, Haoping (2014) Candida albicans hyphal initiation and elongation. Trends Microbiol 22:707-14|
|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|
|Wang, Allen; Raniga, Prashna Pala; Lane, Shelley et al. (2009) Hyphal chain formation in Candida albicans: Cdc28-Hgc1 phosphorylation of Efg1 represses cell separation genes. Mol Cell Biol 29:4406-16|
|Lu, Yang; Su, Chang; Mao, Xuming et al. (2008) Efg1-mediated recruitment of NuA4 to promoters is required for hypha-specific Swi/Snf binding and activation in Candida albicans. Mol Biol Cell 19:4260-72|
|Wang, Allen; Lane, Shelley; Tian, Zhen et al. (2007) Temporal and spatial control of HGC1 expression results in Hgc1 localization to the apical cells of hyphae in Candida albicans. Eukaryot Cell 6:253-61|
|Cao, Fang; Lane, Shelley; Raniga, Prashna Pala et al. (2006) The Flo8 transcription factor is essential for hyphal development and virulence in Candida albicans. Mol Biol Cell 17:295-307|
|Mao, Xuming; Cao, Fang; Nie, Xinyi et al. (2006) The Swi/Snf chromatin remodeling complex is essential for hyphal development in Candida albicans. FEBS Lett 580:2615-22|
|Chou, Song; Lane, Shelley; Liu, Haoping (2006) Regulation of mating and filamentation genes by two distinct Ste12 complexes in Saccharomyces cerevisiae. Mol Cell Biol 26:4794-805|
|Huang, Guanghua; Wang, Huafeng; Chou, Song et al. (2006) Bistable expression of WOR1, a master regulator of white-opaque switching in Candida albicans. Proc Natl Acad Sci U S A 103:12813-8|
|Chou, Song; Huang, Lan; Liu, Haoping (2004) Fus3-regulated Tec1 degradation through SCFCdc4 determines MAPK signaling specificity during mating in yeast. Cell 119:981-90|
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