The role of fungal G protein-coupled receptors in interspecies cell-cell communication

Fungi occupy a wide range of ecological niches in which they compete or associate with other organisms through the perception of external signals and appropriate cellular responses. Fungal G protein-coupled receptors (GPCRs) are seven-transmembrane domain proteins that mediate the perception of extracellular cues. Despite their critical importance, the majority of fungal GPCRs are currently orphan receptors with unknown ligands and functions. In this review, we summarize the current knowledge on the role of fungal GPCRs in the perception of non-self signals and address persistent inconsistencies in the literature regarding fungal GPCR classification. We propose a refined system that differentiates between characterized, proposed, and uncharacterized GPCRs. Finally, we discuss how synthetic biology tools and experimental work in the native fungal organisms can elucidate the physiological role of fungal GPCRs during interspecies cell-cell communication.