scholarly journals GPR11, a Putative Seven-Transmembrane G Protein-Coupled Receptor, Controls Zoospore Development and Virulence of Phytophthora sojae

2009 ◽  
Vol 9 (2) ◽  
pp. 242-250 ◽  
Author(s):  
Yonglin Wang ◽  
Aining Li ◽  
Xiaoli Wang ◽  
Xin Zhang ◽  
Wei Zhao ◽  
...  

ABSTRACT G protein-coupled receptors (GPCRs) represent a large receptor family involved in a broad spectrum of cell signaling. To understand signaling mechanisms mediated by GPCRs in Phytophthora sojae, we identified and characterized the PsGPR11 gene, which encodes a putative seven-transmembrane GPCR. An expression analysis revealed that PsGPR11 was differentially expressed during asexual development. The highest expression level occurred in zoospores and was upregulated during early infection. PsGPR11-deficienct transformants were obtained by gene silencing strategies. Silenced transformants exhibited no differences in hyphal growth or morphology, sporangium production or size, or mating behavior. However, the release of zoospores from sporangia was severely impaired in the silenced transformants, and about 50% of the sporangia did not completely release their zoospores. Zoospore encystment and germination were also impaired, and zoospores of the transformants lost their pathogenicity to soybean. In addition, no interaction was observed between PsGPR11 and PsGPA1 with a conventional yeast two-hybrid assay, and the transcriptional levels of some genes which were identified as being negatively regulated by PsGPA1 were not clearly altered in PsGPR11-silenced mutants. These results suggest that PsGPR11-mediated signaling controls P. sojae zoospore development and virulence through the pathways independent of G protein.

Parasitology ◽  
2019 ◽  
Vol 147 (8) ◽  
pp. 865-872 ◽  
Author(s):  
Oliver Weth ◽  
Simone Haeberlein ◽  
Martin Haimann ◽  
Yinjie Zhang ◽  
Christoph G. Grevelding

AbstractSchistosomiasis is an acute and chronic disease caused by parasitic worms of the genus Schistosoma. Treatment is solely dependent on praziquantel. In the face of the worldwide dimension, projects have been initiated to develop new chemotherapies. Due to their proven druggability, G protein-coupled receptors (GPCRs) are promising targets for anthelmintics. However, to identify candidate receptors, a deeper understanding of GPCR signalling in schistosome biology is essential. Comparative transcriptomics of paired and unpaired worms and their gonads revealed 59 differentially regulated GPCR-coding genes putatively involved in neuronal processes. In general, the diversity among GPCRs and their integral membrane topology make it difficult to characterize and deorphanize these receptors. To overcome existing limitations, we performed a pilot approach and utilized the innovative Membrane-Anchored Ligand And Receptor yeast two-hybrid system (MALAR-Y2H) to associate potential neuropeptide ligands with their cognate receptors. Here, we demonstrated the ability to express full-length GPCRs of Schistosoma mansoni in a heterologous yeast-based system. Additionally, we localized GPCRs and chimeras of neuropeptides fused to the WBP1 transmembrane domain of yeast to the plasma membrane of yeast cells. Reporter gene assays indicated ligand-receptor binding, which allowed us to identify certain neuropeptides as potential ligands for two GPCRs, which had been found before to be differentially expressed in schistosomes in a pairing-dependent manner. Thus, the MALAR-Y2H system appears suitable to unravel schistosome GPCR–ligand interactions. Besides its relevance for understanding schistosome biology, identifying and characterizing GPCR–ligand interaction will also contribute to applied research aspects.


2004 ◽  
Vol 32 (5) ◽  
pp. 878-880 ◽  
Author(s):  
G. Milligan ◽  
H. Murdoch ◽  
E. Kellett ◽  
J.H. White ◽  
G.-J. Feng

A substantial number of G-protein-coupled receptor-interacting proteins have been identified initially by the use of yeast two-hybrid screens. Using the C-terminal tail of both opioid receptors and the melanin concentrating hormone receptor-1 as bait, the actin and intermediate filament-binding protein periplakin was isolated. In each case, the site of interaction is within helix VIII of the receptor and periplakin limits agonist-mediated G-protein activation potentially by competing with G-protein for this region of the receptor.


Author(s):  
Gabriele Stephan ◽  
Niklas Ravn-Boess ◽  
Dimitris G Placantonakis

Abstract Members of the adhesion family of G protein-coupled receptors (GPCRs) have received attention for their roles in health and disease, including cancer. Over the past decade, several members of the family have been implicated in the pathogenesis of glioblastoma. Here, we discuss the basic biology of adhesion GPCRs and review in detail specific members of the receptor family with known functions in glioblastoma. Finally, we discuss the potential use of adhesion GPCRs as novel treatment targets in neuro-oncology.


mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Aílton Pereira da Costa Filho ◽  
Guilherme Thomaz Pereira Brancini ◽  
Patrícia Alves de Castro ◽  
Clara Valero ◽  
Jaire Alves Ferreira Filho ◽  
...  

ABSTRACT G-protein coupled receptors (GPCRs) are extracellular signaling receptors that sense environmental cues. Fungi sense their environment primarily through GPCR-mediated signaling pathways, which, in turn, regulate fungal development, metabolism, virulence, and mycotoxin biosynthesis. Aspergillus fumigatus is an important human pathogen that causes aspergillosis, a heterogeneous group of diseases that present a wide range of clinical manifestations. Here, we investigate in detail the role of the GPCRs GprM and GprJ in growth and gene expression. GprM and GprJ are important for melanin production and the regulation of the cell wall integrity (CWI) pathway. Overexpression of gprM and gprJ causes a 20 and 50% reduction in growth rate compared to the wild-type (WT) strain and increases sensitivity to cell wall-damaging agents. Phosphorylation of the CWI protein kinase MpkA is increased in the ΔgprM and ΔgprJ strains and decreased in the overexpression mutants compared to the WT strain. Furthermore, differences in cell wall polysaccharide concentrations and organization were observed in these strains. Transcriptome sequencing suggests that GprM and GprJ negatively regulate genes encoding secondary metabolites (SMs). Mass spectrometry analysis confirmed that the production of fumagillin, pyripyropene, fumigaclavine C, fumiquinazoline, and fumitremorgin is reduced in the ΔgprM and ΔgprJ strains, at least partially through the activation of MpkA. Overexpression of grpM also resulted in the regulation of many transcription factors, with AsgA predicted to function downstream of GprM and MpkA signaling. Finally, we show that the ΔgprM and ΔgprJ mutants are reduced in virulence in the Galleria mellonella insect model of invasive aspergillosis. IMPORTANCE A. fumigatus is the main etiological agent of invasive pulmonary aspergillosis, a life-threatening fungal disease that occurs in severely immunocompromised humans. Withstanding the host environment is essential for A. fumigatus virulence, and sensing of extracellular cues occurs primarily through G-protein coupled receptors (GPCRs) that activate signal transduction pathways, which, in turn, regulate fungal development, metabolism, virulence, and mycotoxin biosynthesis. The A. fumigatus genome encodes 15 putative classical GPCRs, with only three having been functionally characterized to date. In this work, we show that the two GPCRs GprM and GprJ regulate the phosphorylation of the mitogen-activated protein kinase MpkA and thus control the regulation of the cell wall integrity pathway. GprM and GprJ are also involved in the regulation of the production of the secondary metabolites fumagillin, pyripyropene, fumigaclavine C, fumiquinazoline, melanin, and fumitremorgin, and this regulation partially occurs through the activation of MpkA. Furthermore, GprM and GprJ are important for virulence in the insect model Galleria mellonella. This work therefore functionally characterizes two GPCRs and shows how they regulate several intracellular pathways that have been shown to be crucial for A. fumigatus virulence.


mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Katharyn J. Affeldt ◽  
Joseph Carrig ◽  
Meareg Amare ◽  
Nancy P. Keller

ABSTRACTG protein-coupled receptors (GPCRs) are transmembrane receptors that relay signals from the external environment inside the cell, allowing an organism to adapt to its surroundings. They are known to detect a vast array of ligands, including sugars, amino acids, pheromone peptides, nitrogen sources, oxylipins, and light. Despite their prevalence in fungal genomes, very little is known about the functions of filamentous fungal GPCRs. Here we present the first full-genome assessment of fungal GPCRs through characterization of null mutants of all 15 GPCRs encoded by the aflatoxin-producing fungusAspergillus flavus. All strains were assessed for growth, development, ability to produce aflatoxin, and response to carbon sources, nitrogen sources, stress agents, and lipids. Most GPCR mutants were aberrant in one or more response processes, possibly indicative of cross talk in downstream signaling pathways. Interestingly, the biological defects of the mutants did not correspond with assignment to established GPCR classes; this is likely due to the paucity of data for characterized fungal GPCRs. Many of the GPCR transcripts were differentially regulated under various conditions as well. The data presented here provide an extensive overview of the full set of GPCRs encoded byA. flavusand provide a framework for analysis in other fungal species.IMPORTANCEAspergillus flavusis an opportunistic pathogen of crops and animals, including humans, and it produces a carcinogenic toxin called aflatoxin. Because of this,A. flavusaccounts for food shortages and economic losses in addition to sickness and death. Effective means of combating this pathogen are needed to mitigate its deleterious effects. G protein-coupled receptors (GPCRs) are often used as therapeutic targets due to their signal specificity, and it is estimated that half of all drugs target GPCRs. In fungi such asA. flavus, GPCRs are likely necessary for sensing the changes in the environment, including food sources, developmental signals, stress agents, and signals from other organisms. Therefore, elucidating their functions inA. flavuscould identify ideal receptors against which to develop antagonists.


2019 ◽  
Vol 87 (4) ◽  
Author(s):  
Alexandra Anderson ◽  
Yee Lian Chew ◽  
William Schafer ◽  
Rachel McMullan

ABSTRACT G protein-coupled receptors contribute to host defense across the animal kingdom, transducing many signals involved in both vertebrate and invertebrate immune responses. While it has become well established that the nematode worm Caenorhabditis elegans triggers innate immune responses following infection with numerous bacterial, fungal, and viral pathogens, the mechanisms by which C. elegans recognizes these pathogens have remained somewhat more elusive. C. elegans G protein-coupled receptors have been implicated in recognizing pathogen-associated damage and activating downstream host immune responses. Here we identify and characterize a novel G protein-coupled receptor required to regulate the C. elegans response to infection with Microbacterium nematophilum. We show that this receptor, which we designate pathogen clearance-defective receptor 1 (PCDR-1), is required for efficient pathogen clearance following infection. PCDR-1 acts upstream of multiple G proteins, including the C. elegans Gαq ortholog, EGL-30, in rectal epithelial cells to promote pathogen clearance via a novel mechanism.


2019 ◽  
Vol 1456 (1) ◽  
pp. 5-25 ◽  
Author(s):  
Rory K. Morgan ◽  
Garret R. Anderson ◽  
Demet Araç ◽  
Gabriela Aust ◽  
Nariman Balenga ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Alessandra de Felice ◽  
Simone Aureli ◽  
Vittorio Limongelli

G protein-coupled receptors (GPCRs) are the largest human membrane receptor family regulating a wide range of cell signaling. For this reason, GPCRs are highly desirable drug targets, with approximately 40% of prescribed medicines targeting a member of this receptor family. The structural homology of GPCRs and the broad spectrum of applications of GPCR-acting drugs suggest an investigation of the cross-activity of a drug toward different GPCR receptors with the aim of rationalizing drug side effects, designing more selective and less toxic compounds, and possibly proposing off-label therapeutic applications. Herein, we present an original in silico approach named “Computational Profiling for GPCRs” (CPG), which is able to represent, in a one-dimensional (1D) string, the physico-chemical properties of a ligand–GPCR binding interaction and, through a tailored alignment algorithm, repurpose the ligand for a different GPCR. We show three case studies where docking calculations and pharmacological data confirm the drug repurposing findings obtained through CPG on 5-hydroxytryptamine receptor 2B, beta-2 adrenergic receptor, and M2 muscarinic acetylcholine receptor. The CPG code is released as a user-friendly graphical user interface with numerous options that make CPG a powerful tool to assist the drug design of GPCR ligands.


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