Document Detail


Regulated and constitutive activation of specific signalling pathways by the human S1P5 receptor.
MedLine Citation:
PMID:  12569073     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1 We tested the hypothesis, whether G Protein-coupled receptors (GPCRs) may differentially regulate specific signalling pathways by constitutive and agonist-induced activation using the human sphingosine 1-phosphate receptor S1P(5) as a model. 2 S1P(5) receptor-expressing HEK293 cells exhibited a high degree of basal activity for both inhibition of adenylyl cyclase and extracellular signal regulated kinase (ERK) when cultured in serum, which contains high levels of sphingosine 1-phosphate (S1P). However, basal activity was independent of the presence of S1P: (i) constitutive activity remained when cells were cultured in delipidated serum, (ii) addition of S1P to delipidated serum did not increase basal S1P(5) receptor signalling. 3 Conversely, constitutive inhibition of forskolin-stimulated adenylyl cyclase was further enhanced by S1P in S1P(5)-HEK293 cells. 4 Transfection of several mammalian cell lines (CHO-K1, HEK293, NIH-3T3, RH7777) with the S1P(5) receptor induced cell rounding, which was more pronounced in the presence of S1P-containing serum. Rounded cell morphology did not correlate with apoptotic cell death, but led to detachment of cells. 5 Cell surface ELISA assays showed that a fraction of plasma membrane S1P(5) receptors were dose-dependently internalized with S1P. 6 These data reveal that intrinsic inhibition of unstimulated adenylyl cyclase or ERK activity by the S1P(5) receptor is insensitive to ligand modulation. Conversely, effects on forskolin-stimulated adenylyl cyclase, cell morphology and internalization can be further augmented with S1P. Our results suggest that different signal transduction pathways are not equally activated through constitutively active GPCRs with promiscuous signalling characteristics.
Authors:
Anke Niedernberg; Andree Blaukat; Torsten Schöneberg; Evi Kostenis
Related Documents :
9409733 - Identification of cdnas encoding two g protein-coupled receptors for lysosphingolipids.
19423373 - Toward the three-dimensional structure and lysophosphatidic acid binding characteristic...
17936613 - Contribution of estrogen receptors alpha and beta to the effects of estradiol in the br...
Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  British journal of pharmacology     Volume:  138     ISSN:  0007-1188     ISO Abbreviation:  Br. J. Pharmacol.     Publication Date:  2003 Feb 
Date Detail:
Created Date:  2003-02-05     Completed Date:  2003-10-14     Revised Date:  2010-09-14    
Medline Journal Info:
Nlm Unique ID:  7502536     Medline TA:  Br J Pharmacol     Country:  England    
Other Details:
Languages:  eng     Pagination:  481-93     Citation Subset:  IM    
Affiliation:
Disease group Cardiovascular Diseases, Aventis Pharma, Building H825, 65926 Frankfurt, Germany.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Apoptosis
Caspases / metabolism
Cell Line
Cell Size
Cloning, Molecular
Cricetinae
Cyclic AMP / metabolism
Dose-Response Relationship, Drug
Forskolin / administration & dosage,  pharmacology
Green Fluorescent Proteins
Humans
Luminescent Proteins / genetics
Mice
Mitogen-Activated Protein Kinases / metabolism
Receptors, Cell Surface / genetics,  metabolism*
Receptors, G-Protein-Coupled*
Receptors, Lysophospholipid
Recombinant Fusion Proteins / metabolism
Signal Transduction*
Subcellular Fractions / metabolism
Transfection
Chemical
Reg. No./Substance:
0/Luminescent Proteins; 0/Receptors, Cell Surface; 0/Receptors, G-Protein-Coupled; 0/Receptors, Lysophospholipid; 0/Recombinant Fusion Proteins; 147336-22-9/Green Fluorescent Proteins; 60-92-4/Cyclic AMP; 66428-89-5/Forskolin; EC 2.7.11.24/Mitogen-Activated Protein Kinases; EC 3.4.22.-/Caspases
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Heterogeneity of presynaptic muscarinic receptors mediating inhibition of sympathetic transmitter re...
Next Document:  Attenuation of acute and chronic effects of morphine by the imidazoline receptor ligand 2-(2-benzofu...