scholarly journals Molecular Analysis of CPRα, a MATα-Specific Pheromone Receptor Gene of Cryptococcus neoformans

2002 ◽  
Vol 1 (3) ◽  
pp. 432-439 ◽  
Author(s):  
Seyung Chung ◽  
Marvin Karos ◽  
Yun C. Chang ◽  
Jan Lukszo ◽  
Brian L. Wickes ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
G Protein ◽  
Sequence Similarity ◽  
Receptor Gene ◽  
Environmental Cues ◽  
Wild Type ◽  
High Sequence Similarity ◽  
Pheromone Receptor ◽  
Mating Efficiency ◽  
G Protein Coupled

ABSTRACT The putative Cryptococcus neoformans pheromone receptor gene CPRα was isolated and studied for its role in mating and filamentation. CPRα is MATα specific and located adjacent to STE12α at the MATα locus. It encodes a protein which possesses high sequence similarity to the seven-transmembrane class of G-protein-coupled pheromone receptors reported for other basidiomycetous fungi. Strains containing a deletion of the CPRα gene exhibited drastic reductions in mating efficiency but were not completely sterile. Δcprα cells displayed wild-type mating efficiency when reconstituted with the wild-type CPRα gene. Hyphal production on filament agar was not affected in the Δcprα strain, indicating no significant role for CPRα in sensing environmental cues during haploid fruiting. The wild-type MATα CPRα strain produced abundant hyphae in response to synthetic MATa pheromone; however, the hyphal response to pheromone by Δcprα cells was significantly reduced. Exposure of wild-type cells to synthetic MATa pheromone for 2 h induced MFα pheromone expression, whereas unexposed cells showed only basal levels of the MFα transcript. The Δcprα cells, however, exhibited only basal levels of MFα message with or without pheromone exposure, suggesting that CPRα and MFα are components of the same signaling pathway.

scholarly journals Importance of a Developmentally Regulated Pheromone Receptor of Cryptococcus neoformans for Virulence

2003 ◽  
Vol 71 (9) ◽  
pp. 4953-4960 ◽  
Author(s):  
Yun C. Chang ◽  
Georgina F. Miller ◽  
K. J. Kwon-Chung
Keyword(s):  
Cryptococcus Neoformans ◽  
Transmembrane Domain ◽  
Etiologic Agent ◽  
Specific Gene ◽  
Wild Type ◽  
Developmentally Regulated ◽  
Pheromone Receptor ◽  
Solid Media ◽  
Mating Efficiency ◽  
Survival And Growth

ABSTRACT Cryptococcus neoformans is the etiologic agent of cryptococcosis. Two mating types exist in this fungus, MATα and MAT a. The CPR a gene of C. neoformans is a MAT a strain-specific gene and encodes a putative seven-transmembrane domain pheromone receptor. Unlike the other reported fungal pheromone receptors, CPR a shows functional diversity. Deletion of CPR a drastically affects mating efficiency but does not abolish mating. CPR a expression is developmentally regulated and is not affected by deletion of the transcriptional regulator STE12 a. The expression of CPR a is markedly increased by shifting cultures from liquid to solid media. CPR a also plays a significant role in virulence. Δcpr a cells produce smaller capsules in the brains of mice than the wild-type cells, and the mice infected with Δcpr a survive significantly longer than those receiving the wild-type strain. Our results suggest that the MAT a pheromone receptor of C. neoformans is not only required for mating but also important for survival and growth of the fungus in host tissue.

scholarly journals Mutations in a gene encoding the alpha subunit of a Saccharomyces cerevisiae G protein indicate a role in mating pheromone signaling.

1988 ◽  
Vol 8 (6) ◽  
pp. 2484-2493 ◽  
Author(s):  
K Y Jahng ◽  
J Ferguson ◽  
S I Reed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
G Protein ◽  
Genomic Library ◽  
Negative Impact ◽  
Receptor Gene ◽  
Temperature Sensitive ◽  
Specific Cell ◽  
Protein Activity ◽  
Mating Pheromone ◽  
Pheromone Receptor

Mutations which allowed conjugation by Saccharomyces cerevisiae cells lacking a mating pheromone receptor gene were selected. One of the genes defined by such mutations was isolated from a yeast genomic library by complementation of a temperature-sensitive mutation and is identical to the gene GPA1 (also known as SCG1), recently shown to be highly homologous to genes encoding the alpha subunits of mammalian G proteins. Physiological analysis of temperature-sensitive gpa1 mutations suggests that the encoded G protein is involved in signaling in response to mating pheromones. Mutational disruption of G-protein activity causes cell-cycle arrest in G1, deposition of mating-specific cell surface agglutinins, and induction of pheromone-specific mRNAs, all of which are responses to pheromone in wild-type cells. In addition, mutants can conjugate without the benefit of mating pheromone or pheromone receptor. A model is presented where the activated G protein has a negative impact on a constitutive signal which normally keeps the pheromone response repressed.

scholarly journals Rescue of defective G protein–coupled receptor function in vivo by intermolecular cooperation

2010 ◽  
Vol 107 (5) ◽  
pp. 2319-2324 ◽  
Author(s):  
Adolfo Rivero-Müller ◽  
Yen-Yin Chou ◽  
Inhae Ji ◽  
Svetlana Lajic ◽  
Aylin C. Hanyaloglu ◽  
...  
Keyword(s):  
G Protein ◽  
G Protein Coupled Receptors ◽  
Luteinizing Hormone Receptor ◽  
Wild Type ◽  
Gpcr Signaling ◽  
Physiological Relevance ◽  
Biosynthesis Activation ◽  
Mutant Receptors ◽  
G Protein Coupled

G protein–coupled receptors (GPCRs) are ubiquitous mediators of signaling of hormones, neurotransmitters, and sensing. The old dogma is that a one ligand/one receptor complex constitutes the functional unit of GPCR signaling. However, there is mounting evidence that some GPCRs form dimers or oligomers during their biosynthesis, activation, inactivation, and/or internalization. This evidence has been obtained exclusively from cell culture experiments, and proof for the physiological significance of GPCR di/oligomerization in vivo is still missing. Using the mouse luteinizing hormone receptor (LHR) as a model GPCR, we demonstrate that transgenic mice coexpressing binding-deficient and signaling-deficient forms of LHR can reestablish normal LH actions through intermolecular functional complementation of the mutant receptors in the absence of functional wild-type receptors. These results provide compelling in vivo evidence for the physiological relevance of intermolecular cooperation in GPCR signaling.

Abstract 213: Rapid Activation of G-Protein Coupled Estrogen Receptor 1 Protects the Heart Against Ischemia-Reperfusion Injury by Inhibiting the mPTP Opening via PKC/AKT/ERK/GSK-3b Pathways

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Jean Chrisostome Bopassa ◽  
Rong Lu ◽  
Harpreet Singh ◽  
Netanel F Zilberstein ◽  
Bjorn Olde ◽  
...  
Keyword(s):  
Infarct Size ◽  
G Protein ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Wild Type ◽  
Mptp Opening ◽  
Estrogen Effects ◽  
Estrogen Effect ◽  
Rapid Activation ◽  
G Protein Coupled

Introduction: Estrogen effect can be mediated by three receptors: Classical estrogen receptors: alpha (ERa) and beta (ERb), and recently identified G protein-coupled estrogen receptor1 (GPER1). Hypothesis: We investigated the role of ERa, ERb and GPER1 in mediating rapid estrogen-induced cardioprotection in male mice hearts subjected to ischemia/reperfusion using wild type (WT) and gene specific knockout animals. Methods: Isolated hearts from wild type (WT: C57BL/6NCrL), ERa-/-, ERb-/- and GPER1-/- were perfused using Langendorff apparatus with Krebs Henseleit buffer (control) or with the addition of estrogen (40 nM). Hearts were subjected to 18 min global ischemia followed by 60 min reperfusion. Cardiac function was recorded during the entire experiment and myocardial infarct size measured by TTC staining at the end of the reperfusion. Mitochondria calcium retention capacity (CRC) required to induce the mitochondrial permeability transition pore (mPTP) opening was assessed after 10 min reperfusion. Protein levels were measured by Western Blot in whole heart lysates after 5 min treatment just before ischemia, and after 10 min reperfusion. LY294002, U0126 and Chelerythrin-Cl were used as inhibitor of PI-3K/Akt, MAPK/ERK and PKC translocation, respectively. Results: In WT, ERa-/- and ERb-/-, estrogen treatment significantly improved cardiac functional recovery, reduced infarct size and improved mitochondrial CRC. However, estrogen effects were completely absent in GPER1-/-. Estrogen treatment during 5 min before ischemia induced up-regulation of Akt, GSK-3b, and ERK1/2 phosphorylation in WT mouse as compared with control but not in GPER1-/-. However, after 10 min reperfusion estrogen effect was still oserved on GSK-3b, but not on Akt and ERK1/2. Chelerythrin-Cl prevented estrogen-induced cardioprotection effect and U126 abolished estrogen effect on mitochondrial CRC while LY294002 could not prevent estrogen effect on GSK-3b observed in WT. P<0.05 and n=3-6. Conclusion: Rapid activation of GPER1 induces cardioprotection effect against ischemia/reperfusion injury. Estrogen effects through GPER1 are associated with phosphorylation of Akt, GSK-3b and ERK1/2, translocation of PKC, and inhibition of the mPTP opening.

scholarly journals Melatonin promotes sleep by activating the BK channel in C. elegans

2020 ◽  
Vol 117 (40) ◽  
pp. 25128-25137
Author(s):  
Longgang Niu ◽  
Yan Li ◽  
Pengyu Zong ◽  
Ping Liu ◽  
Yuan Shui ◽  
...  
Keyword(s):  
G Protein ◽  
Neurotransmitter Release ◽  
Expression System ◽  
Molecular Target ◽  
Bk Channel ◽  
G Protein Coupled Receptors ◽  
Wild Type ◽  
Heterologous Expression System ◽  
C Elegans ◽  
G Protein Coupled

Melatonin (Mel) promotes sleep through G protein-coupled receptors. However, the downstream molecular target(s) is unknown. We identified the Caenorhabditis elegans BK channel SLO-1 as a molecular target of the Mel receptor PCDR-1-. Knockout of pcdr-1, slo-1, or homt-1 (a gene required for Mel synthesis) causes substantially increased neurotransmitter release and shortened sleep duration, and these effects are nonadditive in double knockouts. Exogenous Mel inhibits neurotransmitter release and promotes sleep in wild-type (WT) but not pcdr-1 and slo-1 mutants. In a heterologous expression system, Mel activates the human BK channel (hSlo1) in a membrane-delimited manner in the presence of the Mel receptor MT1 but not MT2. A peptide acting to release free Gβγ also activates hSlo1 in a MT1-dependent and membrane-delimited manner, whereas a Gβλ inhibitor abolishes the stimulating effect of Mel. Our results suggest that Mel promotes sleep by activating the BK channel through a specific Mel receptor and Gβλ.

A cloning strategy for G-protein-coupled hormone receptors: the ovine beta 1-adrenergic receptor

1995 ◽  
Vol 7 (3) ◽  
pp. 521 ◽  
Author(s):  
JF Padbury ◽  
YT Tseng ◽  
JA Waschek
Keyword(s):  
G Protein ◽  
Sequence Homology ◽  
Hormone Receptors ◽  
Genomic Library ◽  
Receptor Gene ◽  
G Protein Coupled Receptors ◽  
Transcriptional Level ◽  
Fetal Life ◽  
Single Clone ◽  
G Protein Coupled

Regulation of beta 1-adrenergic receptors is unusual in developing animals. For example, glucocorticoid-and thyroid hormone-responsiveness for several genes is seen in animals treated during fetal life but beta 1-responsiveness is not seen until after birth. In order to investigate this at the transcriptional level, the ovine beta 1 receptor gene was cloned from a sheep genomic library. An approach using high-stringency screening with cDNA probes and oligonucleotides from regions of human and rat genes conserved but unique to the beta 1 receptor but not to other seven transmembrane, G-protein-coupled receptors. Over 800,000 clones were screened from which 40-50 positive clones were identified by each of the probes. There was, however, only a single clone which was recognized by each of the probes. A 5-kb insert was subcloned and shown to contain sequences which hybridized to each of the probes. Using the restriction map of the rat beta 1 receptor, a 1.0-kb Pst1 internal fragment was further subcloned for sequence identification. Confirmation of this fragment as the ovine beta 1 receptor was based on homology of the beta 1 receptor from other species and tissue distribution of mRNA. Nucleotide sequence homology was 93% with the human beta 1 receptor and 84% with rat. Amino acid sequence homology was > 75% and approached 100% in the transmembrane regions. The approach described represents a practical approach to cloning and identification of hormone receptors from the highly homologous members of the seven-transmembrane, G-protein-coupled receptors.

DNA sequences of RAPD fragments in artiodactyls

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 456-458 ◽  
Author(s):  
Silja Kostia ◽  
Jukka Palo ◽  
Sirkka-Liisa Varvio
Keyword(s):  
Dna Sequences ◽  
Sequence Similarity ◽  
Receptor Gene ◽  
Chromosome 2 ◽  
High Sequence Similarity ◽  
Microsatellite Repeats ◽  
Rapd Profile ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

A bovine RAPD profile, generated by a 10-mer primer, was analysed by sequencing the major fragments. Three of four different fragments showed homologies to previously characterized mammalian sequences. One was 61–66% identical to LINE sequences and another was 78.5% identical to a human chromosome 2 sequence tagged site. The third fragment was 93.1% identical to the human type 2 inositol 1,4,5-trisphosphate receptor gene. This fragment had counterparts in white-tailed deer and reindeer; fragments of slightly different size in these species showed high sequence similarity and the size differences were due to varying numbers of dinucleotide microsatellite repeats inside the fragment. Key words : RAPD, artiodactyls, sequence similarity, microsatellites, type 2 inositol 1,4,5-trisphosphate receptor.

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