Put3 Positively Regulates Proline Utilization in Candida albicans

Area of Science:

• Microbiology
• Molecular Biology
• Yeast Genetics

Background:

• Proline assimilation pathway in Saccharomyces cerevisiae is regulated by Put3 transcription factor.
• Candida albicans is an opportunistic pathogen with orthologous genes to S. cerevisiae, but functional differences exist.

Purpose of the Study:

• To investigate the role of Put3 transcription factor in Candida albicans proline metabolism.
• To compare the function of CaPut3 with its S. cerevisiae ortholog (ScPut3).

Main Methods:

• Phenotypic studies
• Transcription profiling
• Chromatin immunoprecipitation with microarray technology (ChIP-chip)

Main Results:

• Candida albicans utilizes proline as a nitrogen, carbon, or dual source, unlike S. cerevisiae.
• CaPut3 is essential for proline catabolism in C. albicans.
• CaPut3 directly binds to the CaPUT1 promoter and upregulates PUT1 and PUT2.
• CaPut3 directs proline degradation independently of nitrogen availability, unlike ScPut3.

Conclusions:

• The Put3 transcription factor plays a conserved role in proline catabolism in both S. cerevisiae and C. albicans.
• CaPut3's ability to utilize proline freely contributes to C. albicans' success as a pathogen.