Serotonin 2C receptor (5-HT2CR) mRNA editing-induced down-regulation of 5-HT2CR function in Xenopus oocytes: the significance of site C editing.

Serotonin 2C receptor (5-HT2CR) mRNA receives editing at 5 nucleotide positions (sites A-E) located in the sequence encoding the second intracellular loop of 5-HT2CR. 5-HT2CR mRNA without editing and with editing at sites AB, ABD, ABC, ABCD, and C are translated to 6 isoforms of 5-HT2CR: INI(non-edited), VNI(AB), VNV(ABD), VSI(ABC), VSV(ABCD), and ISI(C), respectively. In this study, we investigated electrophysiologically the ability of these isoforms to couple with the G protein/phospholipase C (PLC) system using Xenopus oocytes injected with edited 5-HT2CR RNAs and muscarinic M(1) receptor (M1R) RNA.