Native and cloned 5-HT(3A)(S) receptors are anchored to F-actin in clonal cells and neurons

• Published in: Molecular and cellular neuroscience 2002-05, Vol.20 (1), p.110-124
• Main Authors: Emerit, Michel B, Doucet, Edith, Darmon, Michèle, Hamon, Michel
• Format: Article
• Language: English
• Subjects: Actins - metabolism; Animals; Binding Sites - drug effects; Binding Sites - physiology; Bridged Bicyclo Compounds, Heterocyclic - pharmacology; Cell Membrane - metabolism; Central Nervous System - cytology; Central Nervous System - metabolism; CHO Cells; Clone Cells - cytology; Clone Cells - metabolism; Cloning, Molecular; COS Cells; Cricetinae; Culture Media, Serum-Free - pharmacology; Cytoskeleton - metabolism; Fetus; Gene Expression Regulation - physiology; Hippocampus - cytology; Hippocampus - metabolism; Macromolecular Substances; Molecular Conformation; Neurons - cytology; Neurons - metabolism; Polymers - metabolism; Rats; Receptors, Serotonin - drug effects; Receptors, Serotonin - genetics; Receptors, Serotonin - metabolism; Receptors, Serotonin, 5-HT3; Synaptic Transmission - genetics; Thiazoles - pharmacology; Thiazolidines; Transfection
• ISSN: 1044-7431

Using selective antibodies to visualize the short isoform of the 5-HT(3A) receptor, we report here that both native and cloned 5-HT(3A)(S) receptors formed clusters associated with F-actin in all cell types studied. NG 108-15 cells expressing native 5-HT(3A)(S) receptors, COS-7 cells transiently expressing 5-HT(3A)(S) subunits, and CHO cells stably transfected with a plasmid encoding the 5-HT(3A)(S) sequence all exhibited similar surface receptor topology with 5-HT(3A)(S) receptor cluster accumulation in F-actin-rich lamellipodia and microspikes. Colocalization and coclustering of 5-HT(3A)(S) subunits and F-actin were also observed in transfected hippocampal neurons. Treatment of the neurons with latrunculin-A, a compound altering F-actin polymerization, demonstrated that 5-HT(3A)(S) receptor cluster size and topology were dependent on F-actin integrity. These results suggest that the anchoring of 5-HT(3A)(S) receptor clusters to the cytoskeletal network probably plays a key role in the physiological regulation of the receptor topology and dynamics, as is the case for other members of the 4-TMD ion channel receptor family.