Two members of a distinct subfamily of 5-hydroxytryptamine receptors differentially expressed in rat brain

Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3452-6. doi: 10.1073/pnas.90.8.3452.

Abstract

We report two serotonin (5-hydroxytryptamine, 5-HT) receptors, MR22 and REC17, that belong to the G-protein-associated receptor superfamily. MR22 and REC17 are 371 and 357 amino acids long, respectively, as deduced from nucleotide sequence and share 68% mutual amino acid identity and 30-35% identity with known catecholamine and 5-HT receptors. Saturable binding of 125I-labeled (+)-lysergic acid diethylamide to transiently expressed MR22 in COS-M6 cells was inhibited by ergotamine > methiothepin > 5-carboxamidotryptamine > 5-HT. For REC17, the rank of potency was ergotamine > 5-carboxamidotryptamine > methiothepin > methysergide > 5-HT. Both were insensitive to 5-HT1A, 5-HT1D or 5-HT2 serotonergic ligands [8-hydroxy-2-(di-n-propylamino)tetralin, sumatriptan, and 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane]. The mRNAs encoding MR22 were detected in the CA1 region of hippocampus, the medial habenula, and raphe nuclei. In contrast, mRNAs encoding REC17 were found throughout the rat central nervous system. We propose that REC17 and MR22, designated as 5-HT5 alpha and 5-HT5 beta, represent a distinct subfamily of 5-HT receptors.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Brain / physiology*
  • Cell Line
  • Cloning, Molecular / methods
  • GTP-Binding Proteins / genetics
  • HeLa Cells
  • Humans
  • Hypothalamus / physiology
  • Molecular Sequence Data
  • Multigene Family*
  • Oligodeoxyribonucleotides
  • Poly A / genetics
  • Poly A / isolation & purification
  • Polymerase Chain Reaction / methods
  • RNA / genetics
  • RNA / isolation & purification
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Receptors, Serotonin / biosynthesis
  • Receptors, Serotonin / genetics*
  • Receptors, Serotonin / metabolism
  • Transfection

Substances

  • MR22 receptor
  • Oligodeoxyribonucleotides
  • REC17 receptor
  • RNA, Messenger
  • Receptors, Serotonin
  • Poly A
  • RNA
  • GTP-Binding Proteins

Associated data

  • GENBANK/L10072
  • GENBANK/L10073