Recent advances in understanding the fungal G-protein-coupled receptors

ABSTRACT

Abstract@#Transmission of extracellular signal across the plasma membrane into the cells of organisms is impossible without cell surface receptors. One of the most broadly studied receptor is the G-protein coupled receptor. This receptor is coupled with heterotrimeric G proteins with α, β and γ subunits that perceives external stimuli and transduces the signal into the cell for suitable physiological and biochemical responses. They have also been reported as potential receptors to sense light and fatty acids, but their exact mechanism remains unclear in fungi. Signalling and regulation via G proteins has been extensively studied in various models including pathogenic fungi. Fungal GPCRs are broadly required in fungal defence stimulation, vegetative growth, and pathogenicity mechanism. This review aims to highlight the research in fungal GPCRs including classification, physiological roles, mechanisms of action and signalling in GPCR function. Through fungal genome sequencing, mammalian GPCRs have been identified apart from fungal-specific GPCRs which adds another dimension to the classification. The deorphanisation of unclassified fungal GPCRs is necessary to further understand their role in fungi. While the mechanism of action has been well documented in mammals, the glucose and pheromone sensing are the only two well mapped systems in yeast. However, we are yet to ascertain if there are any additional mechanisms of signalling at work in fungi. Further we endeavour to compare and contrast between the eukaryotic GPCRs in various aspects of functionality. Through the information derived we hope to determine the gaps in knowledge and by so doing determine the future directions of GPCR research in fungi.