Deletion of the Candida albicans G-protein-coupled receptor, encoded by orf19.1944 and its allele orf19.9499, produces mutants defective in filamentous growth

2004 ◽  
Vol 50 (12) ◽  
pp. 1081-1085 ◽  
Author(s):  
Quentin L Sciascia ◽  
Patrick A Sullivan ◽  
Peter C Farley
Keyword(s):  
Candida Albicans ◽  
G Protein ◽  
Transmembrane Domain ◽  
Single Copy ◽  
Filamentous Growth ◽  
Homozygous Deletion ◽  
Tube Formation ◽  
G Protein Coupled Receptor ◽  
Environmental Signals ◽  
G Protein Coupled

Filamentous growth of Candida albicans occurs in response to a variety of environmental signals. The C. albicans gene orf19.1944 and its allele orf19.9499 are identical and are predicted to encode an 823-residue, 7-transmembrane-domain protein that has all the expected features of a G-protein-coupled receptor. The protein is 20.9% identical to the Saccharomyces cerevisiae Gpr1p receptor that signals both glucose availability and nitrogen limitation. Deletion of both copies of the gene in C. albicans abolished filamentation by colonies embedded in rich media (YPS, YPGal, and YPGlu), whereas mutants carrying a single copy of the gene were indistinguishable from the parental strain under these conditions. On medium containing low concentrations of ammonia (SLAD and SLAM media), surface colonies of both the homozygous deletion mutants and the mutants carrying a single copy of the gene were defective in filamentation. Serum-induced germ tube formation was unaffected by deletion of this gene, as was filamentation of the mutants growing on the surface of solid Spider medium at 37 °C or embedded in solid Spider medium at 25 °C. The protein encoded by orf19.1944 and orf19.9499 has a role in filamentation by both surface and embedded colonies, presumably as a sensor of environmental cues.Key words: Candida albicans, G-protein-coupled receptor, orf19.1944, embedded agar, filamentation.

Effects ofN- andC-terminal addition of oligolysines or native loop residues on the biophysical properties of transmembrane domain peptides from a G-protein coupled receptor

2006 ◽  
Vol 12 (12) ◽  
pp. 808-822 ◽  
Author(s):  
Patricia Cano-Sanchez ◽  
Beatrice Severino ◽  
V. V. Sureshbabu ◽  
Joe Russo ◽  
Tatsuya Inui ◽  
...  
Keyword(s):  
G Protein ◽  
Transmembrane Domain ◽  
Biophysical Properties ◽  
G Protein Coupled Receptor ◽  
G Protein Coupled

scholarly journals Expression and biophysical analysis of two double-transmembrane domain-containing fragments from a yeast G protein-coupled receptor

Biopolymers ◽  
2008 ◽  
Vol 90 (2) ◽  
pp. 117-130 ◽  
Author(s):  
Leah S. Cohen ◽  
Boris Arshava ◽  
Racha Estephan ◽  
Jacqueline Englander ◽  
Heejung Kim ◽  
...  
Keyword(s):  
G Protein ◽  
Transmembrane Domain ◽  
G Protein Coupled Receptor ◽  
Biophysical Analysis ◽  
G Protein Coupled

Carbon source induced yeast-to-hypha transition in Candida albicans is dependent on the presence of amino acids and on the G-protein-coupled receptor Gpr1

2005 ◽  
Vol 33 (1) ◽  
pp. 291-293 ◽  
Author(s):  
M.M. Maidan ◽  
J.M. Thevelein ◽  
P. Van Dijck
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Candida Albicans ◽  
Carbon Source ◽  
G Protein ◽  
High Glucose ◽  
Glucose Concentration ◽  
G Protein Coupled Receptor ◽  
Hypha Formation ◽  
G Protein Coupled

Yeast-to-hypha transition in Candida albicans can be induced by a wide variety of factors, including specific nutrients. We have started to investigate the mechanism by which some of these nutrients may be sensed. The G-protein-coupled receptor Gpr1 is required for yeast-to-hypha transition on various solid hypha-inducing media. Recently we have shown induction of Gpr1 internalization by specific amino acids, e.g. methionine. This suggests a possible role for methionine as a ligand of CaGpr1. Here we show that there is a big variation in methionine-induced hypha formation depending on the type of carbon source present in the medium. In addition high glucose concentrations repress hypha formation whereas a concentration of 0.1%, which mimics the glucose concentration present in the bloodstream, results in maximal hypha formation. Hence, it remains unclear whether Gpr1 senses sugars, as in Saccharomyces cerevisiae, or specific amino acids like methionine.

scholarly journals G-protein-coupled receptor 30 mediates the effects of estrogen on endothelial cell tube formation in vitro

2017 ◽  
Vol 39 (6) ◽  
pp. 1461-1467 ◽  
Author(s):  
Liyuan Zhou ◽  
Hong Chen ◽  
Xun Mao ◽  
Hongbo Qi ◽  
Philip N. Baker ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
G Protein ◽  
Tube Formation ◽  
G Protein Coupled Receptor ◽  
G Protein Coupled

scholarly journals The Chain Length Dependence of Helix Formation of the Second Transmembrane Domain of a G Protein-coupled Receptor ofSaccharomycescerevisiae

2002 ◽  
Vol 277 (17) ◽  
pp. 14483-14492 ◽  
Author(s):  
Fa-Xiang Ding ◽  
David Schreiber ◽  
Nathan C. VerBerkmoes ◽  
Jeffrey M. Becker ◽  
Fred Naider
Keyword(s):  
G Protein ◽  
Chain Length ◽  
Transmembrane Domain ◽  
G Protein Coupled Receptor ◽  
Length Dependence ◽  
Helix Formation ◽  
G Protein Coupled

scholarly journals Gpr1, a Putative G-Protein-Coupled Receptor, Regulates Morphogenesis and Hypha Formation in the Pathogenic Fungus Candida albicans

2004 ◽  
Vol 3 (4) ◽  
pp. 919-931 ◽  
Author(s):  
Takuya Miwa ◽  
Yukinobu Takagi ◽  
Makiko Shinozaki ◽  
Cheol-Won Yun ◽  
Wiley A. Schell ◽  
...  
Keyword(s):  
Candida Albicans ◽  
G Protein ◽  
Pathogenic Fungus ◽  
Glucose Sensing ◽  
Dependent Manner ◽  
G Protein Coupled Receptor ◽  
Epistasis Analysis ◽  
Hypha Formation ◽  
Mutant Strains ◽  
G Protein Coupled

ABSTRACT In response to various extracellular signals, the morphology of the human fungal pathogen Candida albicans switches from yeast to hypha form. Here, we report that GPR1 encoding a putative G-protein-coupled receptor and GPA2 encoding a Gα subunit are required for hypha formation and morphogenesis in C. albicans. Mutants lacking Gpr1 (gpr1/gpr1) or Gpa2 (gpa2/gpa2) are defective in hypha formation and morphogenesis on solid hypha-inducing media. These phenotypic defects in solid cultures are suppressed by exogenously added dibutyryl-cyclic AMP (dibutyryl-cAMP). Biochemical studies also reveal that GPR1 and GPA2 are required for a glucose-dependent increase in cellular cAMP. An epistasis analysis indicates that Gpr1 functions upstream of Gpa2 in the same signaling pathway, and a two-hybrid assay reveals that the carboxyl-terminal tail of Gpr1 interacts with Gpa2. Moreover, expression levels of HWP1 and ECE1, which are cAMP-dependent hypha-specific genes, are reduced in both mutant strains. These findings support a model that Gpr1, as well as Gpa2, regulates hypha formation and morphogenesis in a cAMP-dependent manner. In contrast, GPR1 and GPA2 are not required for hypha formation in liquid fetal bovine serum (FBS) medium. Furthermore, the gpr1 and the gpa2 mutant strains are fully virulent in a mouse infection. These findings suggest that Gpr1 and Gpa2 are involved in the glucose-sensing machinery that regulates morphogenesis and hypha formation in solid media via a cAMP-dependent mechanism, but they are not required for hypha formation in liquid medium or during invasive candidiasis.

scholarly journals Evidence for Osteocalcin Binding and Activation of GPRC6A in β-Cells

Endocrinology ◽  
2016 ◽  
Vol 157 (5) ◽  
pp. 1866-1880 ◽  
Author(s):  
Min Pi ◽  
Karan Kapoor ◽  
Ruisong Ye ◽  
Satoru Kenneth Nishimoto ◽  
Jeremy C. Smith ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
G Protein ◽  
Computational Models ◽  
Transmembrane Domain ◽  
Structural Basis ◽  
G Protein Coupled Receptor ◽  
Β Cells ◽  
Β Cell ◽  
Cell Functions ◽  
G Protein Coupled

Abstract The possibility that G protein-coupled receptor family C member A (GPRC6A) is the osteocalcin (Ocn)-sensing G protein-coupled receptor that directly regulates pancreatic β-cell functions is controversial. In the current study, we found that Ocn and an Ocn-derived C-terminal hexapeptide directly activate GPRC6A-dependent ERK signaling in vitro. Computational models probe the structural basis of Ocn binding to GPRC6A and predict that the C-terminal hexapeptide docks to the extracellular side of the transmembrane domain of GPRC6A. Consistent with the modeling, mutations in the computationally identified binding pocket of GPRC6A reduced Ocn and C-terminal hexapeptide activation of this receptor. In addition, selective deletion of Gprc6a in β-cells (Gprc6aβ-cell-cko) by crossing Gprc6aflox/flox mice with Ins2-Cre mice resulted in reduced pancreatic weight, islet number, insulin protein content, and insulin message expression. Both islet size and β-cell proliferation were reduced in Gprc6aβ-cell-cko compared with control mice. Gprc6aβ-cell-cko exhibited abnormal glucose tolerance, but normal insulin sensitivity. Islets isolated from Gprc6aβ-cell-cko mice showed reduced insulin simulation index in response to Ocn. These data establish the structural basis for Ocn direct activation of GPRC6A and confirm a role for GPRC6A in regulating β-cell proliferation and insulin secretion.

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