scholarly journals Heterotrimeric G-Protein Signalers and RGSs in Aspergillus fumigatus

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 902
Author(s):  
Hee-Soo Park ◽  
Min-Ju Kim ◽  
Jae-Hyuk Yu ◽  
Kwang-Soo Shin

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.

2016 ◽  
Vol 48 (7) ◽  
pp. 429-445 ◽  
Author(s):  
Taketsugu Hama ◽  
Frank Park

Autosomal dominant polycystic kidney disease (ADPKD) is a signalopathy of renal tubular epithelial cells caused by naturally occurring mutations in two distinct genes, polycystic kidney disease 1 ( PKD1) and 2 ( PKD2). Genetic variants in PKD1, which encodes the polycystin-1 (PC-1) protein, remain the predominant factor associated with the pathogenesis of nearly two-thirds of all patients diagnosed with PKD. Although the relationship between defective PC-1 with renal cystic disease initiation and progression remains to be fully elucidated, there are numerous clinical studies that have focused upon the control of effector systems involving heterotrimeric G protein regulation. A major regulator in the activation state of heterotrimeric G proteins are G protein-coupled receptors (GPCRs), which are defined by their seven transmembrane-spanning regions. PC-1 has been considered to function as an unconventional GPCR, but the mechanisms by which PC-1 controls signal processing, magnitude, or trafficking through heterotrimeric G proteins remains to be fully known. The diversity of heterotrimeric G protein signaling in PKD is further complicated by the presence of non-GPCR proteins in the membrane or cytoplasm that also modulate the functional state of heterotrimeric G proteins within the cell. Moreover, PC-1 abnormalities promote changes in hormonal systems that ultimately interact with distinct GPCRs in the kidney to potentially amplify or antagonize signaling output from PC-1. This review will focus upon the canonical and noncanonical signaling pathways that have been described in PKD with specific emphasis on which heterotrimeric G proteins are involved in the pathological reorganization of the tubular epithelial cell architecture to exacerbate renal cystogenic pathways.


1999 ◽  
Vol 79 ◽  
pp. 152
Author(s):  
Aya Takesono ◽  
Mary J. Cismowski ◽  
Catalina Ribas ◽  
Michael Bernard ◽  
Peter Chung ◽  
...  

1999 ◽  
Vol 274 (47) ◽  
pp. 33202-33205 ◽  
Author(s):  
Aya Takesono ◽  
Mary J. Cismowski ◽  
Catalina Ribas ◽  
Michael Bernard ◽  
Peter Chung ◽  
...  

2019 ◽  
Vol 20 (22) ◽  
pp. 5628 ◽  
Author(s):  
Hnin Phyu Lwin ◽  
Yong-Ho Choi ◽  
Min-Woo Lee ◽  
Jae-Hyuk Yu ◽  
Kwang-Soo Shin

The regulator of G-protein signaling (RGS) proteins play an important role in upstream control of heterotrimeric G-protein signaling pathways. In the genome of the human opportunistic pathogenic fungus Aspergillus fumigatus, six RGS protein-encoding genes are present. To characterize the rgsA gene predicted to encode a protein with an RGS domain, we generated an rgsA null mutant and observed the phenotypes of the mutant. The deletion (Δ) of rgsA resulted in increased radial growth and enhanced asexual sporulation in both solid and liquid culture conditions. Accordingly, transcripts levels of the key asexual developmental regulators abaA, brlA, and wetA are elevated in the ΔrgsA mutant. Moreover, ΔrgsA resulted in elevated spore germination rates in the absence of a carbon source. The activity of cAMP-dependent protein kinase A (PKA) and mRNA levels of genes encoding PKA signaling elements are elevated by ΔrgsA. In addition, mRNA levels of genes associated with stress-response signaling increased with the lack of rgsA, and the ΔrgsA spores showed enhanced tolerance against oxidative stressors. Comparative transcriptomic analyses revealed that the ΔrgsA mutant showed higher mRNA levels of gliotoxin (GT) biosynthetic genes. Accordingly, the rgsA null mutant exhibited increased production of GT and elevated virulence in the mouse. Conversely, the majority of genes encoding glucan degrading enzymes were down-regulated by ΔrgsA, and endoglucanase activities were reduced. In summary, RgsA plays multiple roles, governing growth, development, stress responses, virulence, and external polymer degradation—likely by attenuating PKA signaling.


2015 ◽  
Vol 169 (1) ◽  
pp. 512-529 ◽  
Author(s):  
David Chakravorty ◽  
Timothy E. Gookin ◽  
Matthew J. Milner ◽  
Yunqing Yu ◽  
Sarah M. Assmann

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