Synaptic multiprotein complexes associated with 5-HT(2C) receptors: a proteomic approach.
Membrane-bound receptors such as tyrosine kinases and ionotropic receptors are associated with large protein networks structured by protein-protein interactions involving multidomain proteins. Although these networks have emerged as a general mechanism of cellular signalling, much less is known about the protein complexes associated with G-protein-coupled receptors (GPCRs). Using a proteomic approach based on peptide affinity chromatography followed by mass spectrometry and immunoblotting, we have identified 15 proteins that interact with the C- terminal tail of the 5-hydroxytryptamine 2C (5-HT(2C)) receptor, a GPCR. These proteins include several synaptic multidomain proteins containing one or several PDZ domains (PSD95 and the proteins of the tripartite complex Veli3-CASK-Mint1), proteins of the actin/spectrin cytoskeleton and signalling proteins. Coimmunoprecipitation experiments showed that 5-HT(2C) receptors interact with PSD95 and the Veli3-CASK-Mint1 complex in vivo. Electron microscopy also indicated a synaptic enrichment of Veli3 and 5-HT(2C) receptors and their colocalization in microvilli of choroidal cells. These results indicate that the 5-HT(2C) receptor is associated with protein networks that are important for its synaptic localization and its coupling to the signalling machinery.
Bécamel
Carine
C
CNRS UPR9023, CCIPE 141 rue de la Cardonille, F-34094 Montpellier Cedex 05, France.
Alonso
Gérard
G
Galéotti
Nathalie
N
Demey
Emmanuelle
E
Jouin
Patrick
P
Ullmer
Christoph
C
Dumuis
Aline
A
Bockaert
Joël
J
Marin
Philippe
P
D000595:Amino Acid Sequence; D000818:Animals; D002831:Choroid Plexus / Q000502:physiology; D015180:Electrophoresis, Gel, Two-Dimensional; D019204:GTP-Binding Proteins / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry; D020543:Proteome; D044405:Receptor, Serotonin, 5-HT2C; D011985:Receptors, Serotonin / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013569:Synapses / Q000378:metabolism*; D014162:Transfection
D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D020543:Proteome; D044405:Receptor, Serotonin, 5-HT2C; D011985:Receptors, Serotonin; D019204:GTP-Binding Proteins