title: Identification and localization of a skeletal muscle secrotonin 5-HT2A receptor coupled to the Jak/STAT pathway.
abstract: The neurotransmitter serotonin mediates a wide variety of peripheral and central physiological effects through the binding to multiple receptor subtypes (Wilkinson, L. O., and Dourish, C. T. (1991) in Serotonin Receptor Subtypes: Basic and Clinical Aspects (Peroutka, S. J., ed) Vol. 15, pp.147-210, Wiley-Liss, New York). Among them, serotonin 5-HT2A receptors are known to activate the phospholipase C-beta second messenger pathway (Peroutka, S. J. (1995) Trends Neurosci. 18, 68-69). We identified and localized in rat skeletal muscle myoblasts a functional serotonin 5-HT2A receptor. This receptor was detected on the plasma membrane, in myoblasts, and at the level of T-tubules in contracting myotubes. Binding of serotonin to its receptor increases the expression of genes involved in myogenic differentiation. Unexpectedly, the 5-HT2A receptor is able to activate another signaling pathway; it triggers a rapid and transient tyrosine phosphorylation of Jak2 kinase in response to serotonin. Jak2 auto-phosphorylation is followed by the tyrosine phosphorylation of STAT3 (signal transducers and activators of transcription) and its translocation into the nucleus. We also find that the 5-HT2A receptor and STAT3 co-precipitate with Jak2, indicating that they are physically associated. We conclude that the serotonin 5-HT2A receptor identified in skeletal muscle myoblasts is able to activate the intracellular phosphorylation pathway used by cytokines. The presence of serotonin receptors in T-tubules suggests a role for serotonin in excitation-contraction coupling and (or) an effect in skeletal muscle fiber repairing.
authors.affiliation: Centre de Recherches sur l'Endocrinologie Moléculaire et le Développement, CNRS, UPR 1511, 9, rue Jules Hetzel, 92 190 Meudon, France. gdeniau@infobiogen.fr
authors.forename: I
authors.initials: I
authors.lastname: Guillet-Deniau
authors.forename: A F
authors.initials: AF
authors.lastname: Burnol
authors.forename: J
authors.initials: J
authors.lastname: Girard
mesh_terms: D000818:Animals; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005333:Fetus; D051272:Glucose Transporter Type 1; D051273:Glucose Transporter Type 2; D053614:Janus Kinase 2; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000096:biosynthesis; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018008:Myogenin / Q000096:biosynthesis; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D051381:Rats; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D050796:STAT3 Transcription Factor; D012701:Serotonin / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D004268:DNA-Binding Proteins; D051272:Glucose Transporter Type 1; D051273:Glucose Transporter Type 2; D009004:Monosaccharide Transport Proteins; C503803:Myog protein, rat; D018008:Myogenin; D011518:Proto-Oncogene Proteins; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat; D015534:Trans-Activators; D012701:Serotonin; D011505:Protein-Tyrosine Kinases; C507927:Jak2 protein, rat; D053614:Janus Kinase 2