Heterotrimeric G-Protein Signalers and RGSs in Aspergillus fumigatus

Abstract

The heterotrimeric G-protein (G-protein) signaling pathway is one of the most important signaling pathways that transmit external signals into the inside of the cell, triggering appropriate biological responses. The external signals are sensed by various G-protein-coupled receptors (GPCRs) and transmitted into G-proteins consisting of the α, β, and γ subunits. Regulators of G-protein signaling (RGSs) are the key controllers of G-protein signaling pathways. GPCRs, G-proteins, and RGSs are the primary upstream components of the G-protein signaling pathway, and they are highly conserved in most filamentous fungi, playing diverse roles in biological processes. Recent studies characterized the G-protein signaling components in the opportunistic pathogenic fungus Aspergillus fumigatus. In this review, we have summarized the characteristics and functions of GPCRs, G-proteins, and RGSs, and their regulatory roles in governing fungal growth, asexual development, germination, stress tolerance, and virulence in A. fumigatus.

Characterization of a G protein α subunit encoded gene from the dimorphic fungus-Tremella fuciformis

“…T. fuciformis, an edible jelly mushroom, has the capacity to perform this type of morphogenesis (Zhu et al 2016). It has been demonstrated that G proteins are key regulators of this morphological transition in many dimorphic fungi (Park et al 2020). However, G proteins and their functions that are involved in T. fuciformis have been little known.…”

Functional analysis of seven regulators of G protein signaling (RGSs) in the nematode-trapping fungus Arthrobotrys oligospora

“…AoFlbA was significantly downregulated compared to 0 h (4.4-, 5.2-, and 8.2-fold at 12, 24, and 36 h, respectively), especially in the later infection stage (Figure 1c). Meanwhile, AoRgsA, AoRgsB, and AoRgsB2-2 were also downregulated at three time points (12,24, and 36 h). In contrast, AoRgsB2-3 and AoRgsC were significantly upregulated at 12, 24, and 36 h. Specifically, AoRgsB2-3 increased by 2.8-3.0 fold at 12, 24, and 36 h, respectively.…”

“…The GPA activity accelerates GTP hydrolysis at the Gα subunit, thereby limiting the intensity and duration of G protein activation and inactivating or terminating downstream signals [ 10 , 11 ]. GPCRs, G proteins, and RGSs are the key components of G protein signaling and highly conserved in most filamentous fungi [ 1 , 12 ].…”

“…Since the first RGS was found in Saccharomyces cerevisiae [ 13 ], numerous proteins with similar structure and function to RGS have been identified in yeast and filamentous fungi [ 12 , 14 ]. Four RGSs, Sst2, Rgs2, Rax1, and Mdm1, were identified in S. cerevisiae , and Sst2 serves as the principal regulator of mating pheromone signaling [ 2 , 13 ].…”

“…Fusarium graminearum ); they are involved in the regulation of vegetative growth, spore morphogenesis, pathogenicity, and toxin synthesis to varying degrees [ 14 ]. Likewise, six RGSs involved in the regulation of fungal growth, asexual development, germination, stress tolerance, and virulence have been identified in A. fumigatus [ 12 ]. Among these RGSs, FgFlbA is the most important member and has a significant effect on growth, conidiation, toxin synthesis, and virulence [ 14 , 17 ].…”