scholarly journals Botrytis cinerea G Protein β Subunit Bcgb1 Controls Growth, Development and Virulence by Regulating cAMP Signaling and MAPK Signaling

2021 ◽  
Vol 7 (6) ◽  
pp. 431
Author(s):  
Jiejing Tang ◽  
Mingde Wu ◽  
Jing Zhang ◽  
Guoqing Li ◽  
Long Yang
Keyword(s):  
Botrytis Cinerea ◽  
G Protein ◽  
Map Kinases ◽  
Gray Mold ◽  
Mapk Signaling ◽  
Camp Signaling ◽  
Phytopathogenic Fungus ◽  
Intracellular Camp ◽  
Β Subunit ◽  
Oxidative Stresses

Botrytis cinerea is a necrotrophic phytopathogenic fungus that causes gray mold disease in many crops. To better understand the role of G protein signaling in the development and virulence of this fungus, the G protein β subunit gene Bcgb1 was knocked out in this study. The ΔBcgb1 mutants showed reduced mycelial growth rate, but increased aerial hyphae and mycelial biomass, lack of conidiation, failed to form sclerotia, increased resistance to cell wall and oxidative stresses, delayed formation of infection cushions, and decreased virulence. Deletion of Bcgb1 resulted in a significant reduction in the expression of several genes involved in cAMP signaling, and caused a notable increase in intracellular cAMP levels, suggesting that G protein β subunit Bcgb1 plays an important role in cAMP signaling. Furthermore, phosphorylation levels of MAP kinases (Bmp1 and Bmp3) were increased in the ΔBcgb1 mutants. Yeast two-hybrid assays showed that Bcgb1 interacts with MAPK (Bmp1 and Bmp3) cascade proteins (BcSte11, BcBck1, BcMkk1, and BcSte50), and the Bmp1-regulated gene Bcgas2 was up-regulated in the ΔBcgb1 mutant. These results indicated that Gβ protein Bcgb1 is involved in the MAPK signaling pathway in B. cinerea. In summary, our results revealed that Gβ protein Bcgb1 controls development and virulence through both the cAMP and MAPK (Bmp1 and Bmp3) signaling pathways in B. cinerea.

scholarly journals Epigenetic control of pheromone MAPK signaling determines sexual fecundity inCandida albicans

2017 ◽  
Vol 114 (52) ◽  
pp. 13780-13785 ◽  
Author(s):  
Christine M. Scaduto ◽  
Shail Kabrawala ◽  
Gregory J. Thomson ◽  
William Scheving ◽  
Andy Ly ◽  
...  
Keyword(s):  
Candida Albicans ◽  
G Protein ◽  
Map Kinases ◽  
Mapk Pathway ◽  
Cell Types ◽  
Mapk Signaling ◽  
Toggle Switch ◽  
Β Subunit ◽  
Epigenetic Control ◽  
Incandida Albicans

Several pathogenicCandidaspecies are capable of heritable and reversible switching between two epigenetic states, “white” and “opaque.” InCandida albicans, white cells are essentially sterile, whereas opaque cells are mating-proficient. Here, we interrogate the mechanism by which the white-opaque switch regulates sexual fecundity and identify four genes in the pheromone MAPK pathway that are expressed at significantly higher levels in opaque cells than in white cells. These genes encode the β subunit of the G-protein complex (STE4), the pheromone MAPK scaffold (CST5), and the two terminal MAP kinases (CEK1/CEK2). To define the contribution of each factor to mating,C. albicanswhite cells were reverse-engineered to express elevated, opaque-like levels of these factors, either singly or in combination. We show that white cells co-overexpressingSTE4,CST5, andCEK2undergo mating four orders of magnitude more efficiently than control white cells and at a frequency approaching that of opaque cells. Moreover, engineered white cells recapitulate the transcriptional and morphological responses of opaque cells to pheromone. These results therefore reveal multiple bottlenecks in pheromone MAPK signaling in white cells and that alleviation of these bottlenecks enables efficient mating by these “sterile” cell types. Taken together, our findings establish that differential expression of several MAPK factors underlies the epigenetic control of mating inC. albicans. We also discuss how fitness advantages could have driven the evolution of a toggle switch to regulate sexual reproduction in pathogenicCandidaspecies.

scholarly journals The Pathogenic TSH β-subunit Variant C105Vfs114X Causes a Modified Signaling Profile at TSHR

2019 ◽  
Vol 20 (22) ◽  
pp. 5564 ◽  
Author(s):  
Kalveram ◽  
Kleinau ◽  
Szymańska ◽  
Scheerer ◽  
Rivero-Müller ◽  
...  
Keyword(s):  
Functional Characterization ◽  
3D Structure ◽  
Mapk Signaling ◽  
Thyroid Stimulating Hormone ◽  
Mitogen Activated Protein Kinase ◽  
Hek293 Cells ◽  
Camp Signaling ◽  
Β Subunit ◽  
Severe Phenotype ◽  
Patient Mutation

1) Background: Central congenital hypothyroidism (CCH) is a rare endocrine disorder that can be caused by mutations in the β-subunit of thyrotropin (TSHB). The TSHB mutation C105Vfs114X leads to isolated thyroid-stimulating-hormone-(TSH)-deficiency and results in a severe phenotype. The aim of this study was to gain more insight into the underlying molecular mechanism and the functional effects of this mutation based on two assumptions: a) the three-dimensional (3D) structure of TSH should be modified with the C105V substitution, and/or b) whether the C-terminal modifications lead to signaling differences. 2) Methods: wild-type (WT) and different mutants of hTSH were generated in human embryonic kidney 293 cells (HEK293 cells) and TSH preparations were used to stimulate thyrotropin receptor (TSHR) stably transfected into follicular thyroid cancer cells (FTC133-TSHR cells) and transiently transfected into HEK293 cells. Functional characterization was performed by determination of Gs, mitogen activated protein kinase (MAPK) and Gq/11 activation. 3) Results: The patient mutation C105Vfs114X and further designed TSH mutants diminished cyclic adenosine monophosphate (cAMP) signaling activity. Surprisingly, MAPK signaling for all mutants was comparable to WT, while none of the mutants induced PLC activation. 4) Conclusion: We characterized the patient mutation C105Vfs114X concerning different signaling pathways. We identified a strong decrease of cAMP signaling induction and speculate that this could, in combination with diverse signaling regarding the other pathways, accounting for the patient’s severe phenotype.

Cloning and Analyzing of G-protein β-Subunit Gene in Rhizoctonia solani Causing Soybean Sharp Eyespot

2009 ◽  
Vol 35 (2) ◽  
pp. 370-374
Author(s):  
Bing-Tian MA ◽  
Guang-Lin QU ◽  
Wen-Juan HUANG ◽  
Yu-Fan LIN ◽  
Shi-Gui LI
Keyword(s):  
Rhizoctonia Solani ◽  
G Protein ◽  
Β Subunit ◽  
Subunit Gene ◽  
Sharp Eyespot

scholarly journals Cyclophilin BcCyp2 Regulates Infection-Related Development to Facilitate Virulence of the Gray Mold Fungus Botrytis cinerea

2021 ◽  
Vol 22 (4) ◽  
pp. 1694
Author(s):  
Jiao Sun ◽  
Chen-Hao Sun ◽  
Hao-Wu Chang ◽  
Song Yang ◽  
Yue Liu ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Gray Mold ◽  
Gene Encoding ◽  
Histone 3 ◽  
Mold Fungus ◽  
Related Development ◽  
Hyphal Morphology ◽  
Cellular Components

Cyclophilin (Cyp) and Ca2+/calcineurin proteins are cellular components related to fungal morphogenesis and virulence; however, their roles in mediating the pathogenesis of Botrytis cinerea, the causative agent of gray mold on over 1000 plant species, remain largely unexplored. Here, we show that disruption of cyclophilin gene BcCYP2 did not impair the pathogen mycelial growth, osmotic and oxidative stress adaptation as well as cell wall integrity, but delayed conidial germination and germling development, altered conidial and sclerotial morphology, reduced infection cushion (IC) formation, sclerotial production and virulence. Exogenous cyclic adenosine monophosphate (cAMP) rescued the deficiency of IC formation of the ∆Bccyp2 mutants, and exogenous cyclosporine A (CsA), an inhibitor targeting cyclophilins, altered hyphal morphology and prevented host-cell penetration in the BcCYP2 harboring strains. Moreover, calcineurin-dependent (CND) genes are differentially expressed in strains losing BcCYP2 in the presence of CsA, suggesting that BcCyp2 functions in the upstream of cAMP- and Ca2+/calcineurin-dependent signaling pathways. Interestingly, during IC formation, expression of BcCYP2 is downregulated in a mutant losing BcJAR1, a gene encoding histone 3 lysine 4 (H3K4) demethylase that regulates fungal development and pathogenesis, in B. cinerea, implying that BcCyp2 functions under the control of BcJar1. Collectively, our findings provide new insights into cyclophilins mediating the pathogenesis of B. cinerea and potential targets for drug intervention for fungal diseases.

scholarly journals Characterization of Postharvest Fungicide-Resistant Botrytis cinerea Isolates From Commercially Stored Apple Fruit

2017 ◽  
Vol 107 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Wayne M. Jurick ◽  
Otilia Macarisin ◽  
Verneta L. Gaskins ◽  
Eunhee Park ◽  
Jiujiang Yu ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Gray Mold ◽  
Apple Fruit ◽  
Sublethal Dose ◽  
Long Term Storage ◽  
Pose Control ◽  
First Time

Botrytis cinerea causes gray mold and is an economically important postharvest pathogen of fruit, vegetables, and ornamentals. Fludioxonil-sensitive B. cinerea isolates were collected in 2011 and 2013 from commercial storage in Pennsylvania. Eight isolates had values for effective concentrations for inhibiting 50% of mycelial growth of 0.0004 to 0.0038 μg/ml for fludioxonil and were dual resistant to pyrimethanil and thiabendazole. Resistance was generated in vitro, following exposure to a sublethal dose of fludioxonil, in seven of eight dual-resistant B. cinerea isolates. Three vigorously growing B. cinerea isolates with multiresistance to postharvest fungicides were further characterized and found to be osmosensitive and retained resistance in the absence of selection pressure. A representative multiresistant B. cinerea strain caused decay on apple fruit treated with postharvest fungicides, which confirmed the in vitro results. The R632I mutation in the Mrr1 gene, associated with fludioxonil resistance in B. cinerea, was not detected in multipostharvest fungicide-resistant B. cinerea isolates, suggesting that the fungus may be using additional mechanisms to mediate resistance. Results from this study show for the first time that B. cinerea with dual resistance to pyrimethanil and thiabendazole can also rapidly develop resistance to fludioxonil, which may pose control challenges in the packinghouse environment and during long-term storage.

scholarly journals Imaging of persistent cAMP signaling by internalized G protein-coupled receptors

2010 ◽  
Vol 45 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Davide Calebiro ◽  
Viacheslav O Nikolaev ◽  
Martin J Lohse
Keyword(s):  
G Protein ◽  
Intracellular Signaling ◽  
Current Model ◽  
Living Cells ◽  
G Protein Coupled Receptors ◽  
Membrane Receptors ◽  
Optical Methods ◽  
Camp Signaling ◽  
Gpcr Signaling ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) are the largest family of plasma membrane receptors. They mediate the effects of several endogenous cues and serve as important pharmacological targets. Although many biochemical events involved in GPCR signaling have been characterized in great detail, little is known about their spatiotemporal dynamics in living cells. The recent advent of optical methods based on fluorescent resonance energy transfer allows, for the first time, to directly monitor GPCR signaling in living cells. Utilizing these methods, it has been recently possible to show that the receptors for two protein/peptide hormones, the TSH and the parathyroid hormone, continue signaling to cAMP after their internalization into endosomes. This type of intracellular signaling is persistent and apparently triggers specific cellular outcomes. Here, we review these recent data and explain the optical methods used for such studies. Based on these findings, we propose a revision of the current model of the GPCR–cAMP signaling pathway to accommodate receptor signaling at endosomes.

scholarly journals Intracellular Loop 2 Peptides of the Human 5HT1a Receptor are Differential Activators of Gi

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Brian Hall ◽  
Carley Squires ◽  
Keith K. Parker
Keyword(s):  
G Protein ◽  
Pharmacological Intervention ◽  
Intracellular Camp ◽  
Intracellular Loop ◽  
Peptide Mimics ◽  
G Protein Coupling ◽  
5Ht1a Receptor ◽  
Protein Coupling ◽  
Loop Region ◽  
Loop 2

Peptide mimics of intracellular loop 2 (ic2) of the human 5HT1a receptor have been studied with respect to their ability to inhibit agonist binding via interference with receptor-G-protein coupling. These peptides give shallow concentration-effect relationships. Additionally, these peptides have been studied with respect to their ability to trigger the signal transduction system of this Gi-coupled receptor. Two signaling parameters have been quantified: concentration of intracellular cAMP and changes in incorporation into the G protein of a stable analog of GTP. In both cases, peptide mimics near midloop of ic2 actually show agonist activity with efficacy falling off toward both loop termini near TM 3 and TM 4. Previous results have suggested that the loop region near the TM3/ic2 interface is primarily responsible for receptor-G-protein coupling, while the current result emphasizes the mid-ic2 loop region's ability to activate the G protein following initial coupling. A limited number of peptides from the receptor's TM5/ic3 loop vicinity were also studied regarding agonist inhibition and G-protein activation. These peptides provide additional evidence that the human 5HT1a receptor, TM5/ic3 loop region, is involved in both coupling and activation actions. Overall, these results provide further information about potential pharmacological intervention and drug development with respect to the human 5HT1a receptor/G-protein system. Finally, the structural evidence generated here provides testable models pending crystallization and X-ray analysis of the receptor.

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