Team "Serotonin and Physiopathologies"
par- 4 mai 2011
Project leader : Franck Vandermoere
Staff : Samah Karaki, Elisabeth Cassier, Nathalie Galéotti, Philippe Marin
Eric Reiter (INRA-University of Tours)
The objective of this program is to identify phosphoproteomes generated upon 5-HT receptor activation by various ligand subclasses by means of quantitative phosphoproteomic approaches combining SILAC (Stable Isotope Labelling of Aminoacids in Cell Cultures) and double enrichment of phosphopeptides by Hydrophilic Interaction LIquid Chromatography (HILIC) and metal affinity chromatography using TiO2 beads, followed by their analysis by nano-LC-FT-MS/MS (using a LTQ-Orbitrap-XL) and their identification using the MaxQuant (Max Plank Institute of Biochemistry, http://www.maxquant.org/) software. Our goal is to identify novel G protein-independent signalling mechanisms engaged by 5-HT receptors or pathways selectively initiated by sub categories of receptor ligands. Our previous studies of phosphoproteomes generated by several neurotrophic factors revealed the power of such phosphoproteomic screens to identify previously uncharacterized signalling mechanisms engaged by these compounds.
Principle of the quantitative phosphoproteomic approach used to decipher 5-HT receptor-associated phosphoproteomes
Our objectives are :
To compare phosphoproteomes generated by hallucinogenic (e.g. LSD and the phenethylamine DOI) and non-hallucinogenic (e.g. lisuride and ergotamine) agonists of 5-HT2A receptors. We hypothesize that both agonist categories engage distinct signalling pathways that might account for their distinct behavioural responses. We aim at identifying phosphorylation events selectively induced by hallucinogens, which are potential molecular substrates of their psychoactive effects.
To characterize G protein-independent signalling pathways engaged by 5-HT4 receptors (Src-dependent pathway) and 5-HT2C receptors (b-arrestin-dependent pathway).
To identify new phosphorylation sites on selected 5-HT signalling effectors, purified by affinity, using quantitative phosphoproteomics
Publications related to the project :
Delcourt N, Thouvenot E, Chanrion B, Galeotti N, Jouin P, Bockaert J, Marin P (2007) PACAP type I receptor transactivation is essential for IGF-1 receptor signalling and antiapoptotic activity in neurons. EMBO J 26:1542-1551.
Delcourt N, Bockaert J, Marin P (2007) GPCR-jacking : from a new route in RTK signalling to a new concept in GPCR activation. Trends Pharmacol Sci 28:602-607