| Autor: |
Fitzgerald, Lawrence W, Iyer, Geeta, Conklin, Deborah S, Krause, Carol M, Marshall, Anne, Patterson, John P, Tran, David P, Jonak, Gerald J, Hartig, Paul R |
| Zdroj: |
Neuropsychopharmacology; August 1999, Vol. 21 Issue: Supplement 1 p82S-90S, 9p |
| Abstrakt: |
RNA encoding the rat serotonin 5-HT2Creceptor undergoes editing whereby one to four adenosines are converted to inosines. This conversion can change up to three codons out of a stretch of five in the second intracellular loop of the receptor. RNA editing of the rat 5-HT2Creceptor that changes all three codons was shown previously to alter intracellular signaling by 5-HT without changing its receptor-binding affinity. We analyzed 5-HT2Creceptor editing in human brain and hypothalamic RNA samples and confirmed that all four adenosine editing sites observed in rat were also present in human samples. Additionally, we identified a novel editing site in the middle edited codon that extends the repertoire of 5-HT2Creceptors by six additional protein isoforms. We observed that editing reduces both the binding affinity and functional potency of agonists for recombinant human 5-HT2Creceptor isoforms. This effect on binding affinity was proportional to the agonist's intrinsic activity, with full agonists most affected, and antagonists showing no effect. These data suggest that RNA editing may alter coupling energetics within the ternary complex, thereby altering agonist binding affinities, G protein coupling, and functional responses. RNA editing may thus provide a novel mechanism for regulating 5-HT synaptic signaling and plasticity.Neuropsychopharmacology (1999) 21 82S–90S.10.1016/S0893-133X(99)00004-4 |
| Databáze: |
Supplemental Index |
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