Methionine is required for cAMP-PKA-mediated morphogenesis and virulence of Candida albicans

Area of Science:

• Mycology
• Infectious Diseases
• Molecular Biology

Background:

• Candida albicans is a significant human fungal pathogen responsible for various infections.
• The yeast-to-hyphae transition is a critical virulence factor for C. albicans.
• Environmental cues, such as methionine, can trigger this morphogenetic switch.

Purpose of the Study:

• To investigate the role of methionine permease Mup1 in C. albicans morphogenesis and virulence.
• To elucidate the metabolic pathway downstream of methionine influencing hyphal development.
• To explore the connection between methionine metabolism and the cAMP-PKA signaling pathway.

Main Methods:

• Investigated the function of Mup1 in methionine-induced morphogenesis and virulence using genetic approaches.
• Analyzed the role of S-adenosyl methionine (SAM) conversion and decarboxylation by Spe2.
• Assessed the impact of inhibiting Mup1 and Spe2 on biofilm formation, macrophage survival, and systemic infection in mice.
• Measured cAMP production in response to methionine in Mup1 and Spe2 mutants.

Main Results:

• Mup1 is essential for methionine-induced morphogenesis, biofilm formation, macrophage survival, and virulence.
• Methionine-induced morphogenesis requires conversion to S-adenosyl methionine (SAM) and decarboxylation by Spe2.
• Inhibition of Spe2 impairs morphogenesis and delays systemic virulence in mice.
• Both Mup1 and Spe2 are crucial for methionine-induced cAMP production, linking amino acid metabolism to the cAMP-PKA pathway.

Conclusions:

• Methionine transport and metabolism, mediated by Mup1 and Spe2, are critical for C. albicans virulence.
• The pathway involving SAM decarboxylation and polyamine biosynthesis connects methionine to the cAMP-PKA pathway.
• Targeting amino acid transport and metabolism pathways could represent a novel therapeutic strategy to prevent C. albicans infections.