The many roles of sulfur in the fungal–host interaction

Abstract

Sulfur is an essential macronutrient for life, and consequently, all living organisms must acquire it from external sources to thrive and grow. Sulfur is a constituent of a multitude of crucial molecules, such as the S-containing proteinogenic amino acids cysteine and methionine; cofactors and prosthetic groups, such as coenzyme-A and iron–sulfur (Fe–S) clusters; and other essential organic molecules, such as glutathione or S-adenosylmethionine. Additionally, sulfur in cysteine thiols is an active redox group that plays paramount roles in protein stability, enzyme catalysis, and redox homeostasis. Furthermore, H₂S is gaining more attention as a crucial signaling molecule that influences metabolism and physiological functions. Given its importance, it is not surprising that sulfur plays key roles in the host–pathogen interaction. However, in contrast to its well-recognized involvement in the plant–pathogen interaction, the specific contributions of sulfur to the human–fungal interaction are much less understood. In this short review, I highlight some of the most important known mechanisms and propose directions for further research.