Multiple functions of DOA1 in Candida albicans

Area of Science:

• Microbiology
• Molecular Biology
• Fungal Pathogenesis

Background:

• The human-pathogenic fungus Candida albicans requires regulation of virulence factors.
• Ubiquitin-dependent protein degradation is a key cellular process.
• Orthologs of DOA1 in other organisms, like Saccharomyces cerevisiae, are involved in protein degradation.

Purpose of the Study:

• To identify and characterize regulators of virulence in Candida albicans.
• To investigate the function of a novel gene, CaDOA1, similar to known protein degradation and signaling proteins.
• To explore the role of CaDOA1 in Candida albicans cellular processes and morphology.

Main Methods:

• Gene identification and sequence analysis.
• Gene disruption and phenotypic analysis of mutants (colony morphology, temperature sensitivity, enzyme secretion, compound sensitivity).
• Transcriptional profiling of gene-disrupted mutants.

Main Results:

• CaDOA1, containing WD-repeats and a functional mellitin-like sequence, is expressed under all conditions.
• Disruption of CaDOA1 leads to altered colony morphology, temperature sensitivity, reduced enzyme secretion, and hypersensitivity to various compounds.
• Deltadoa1 mutants exhibit a striking switch to filamentous growth (pseudohyphae and true hyphae) under yeast-promoting conditions.
• Upregulation of ubiquitin-mediated proteolysis genes (e.g., CDC48, UBI4) was observed in Deltadoa1 mutants.
• CaDOA1 shares functions with its S. cerevisiae orthologue but also possesses unique roles in C. albicans.

Conclusions:

• CaDOA1 is involved in ubiquitin-mediated proteolysis in Candida albicans.
• CaDOA1 plays a significant role in regulating fungal morphology, including the yeast-to-hyphal transition.
• Ubiquitin-mediated proteolysis is a critical pathway for controlling morphology in Candida albicans.
• CaDOA1 represents a potential target for understanding and manipulating C. albicans virulence.