Serotonin Receptor cDNA Cloned From Lymnaea stagnalis

• Published in: Proceedings of the National Academy of Sciences - PNAS 1993-01, Vol.90 (1), p.11-15
• Main Authors: Sugamori, Kim S., Sunahara, Roger K., Guan, Hong-Chang, Andrew G. M. Bulloch, Tensen, Cees P., Seeman, Philip, Niznik, Hyman B., Hubert H. M. Van Tol
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Animals; Base Sequence; Binding, Competitive; Biochemistry; Biological and medical sciences; Blotting, Northern; cDNA; Cell receptors; Cell structures and functions; Central nervous system; Cloning, Molecular; Complementary DNA; COS cells; Deoxyribonucleic acid; DNA; DNA - genetics; Drosophila; Freshwater; freshwater molluscs; Fundamental and applied biological sciences. Psychology; genes; Humans; Lymnaea - genetics; Lymnaea - metabolism; Lymnaea stagnalis; Messenger RNA; Molecular and cellular biology; Molecular Sequence Data; molecular structure; Mollusks; Monoamines receptors (catecholamine, serotonine, histamine, acetylcholine); neurotransmitters; nucleotide sequence; Oligodeoxyribonucleotides; Pharmacology; Phylogeny; Poly A - genetics; Poly A - isolation & purification; Polymerase Chain Reaction; predictions; Receptors; Receptors, Serotonin - genetics; Receptors, Serotonin - metabolism; Recombinant Proteins - metabolism; RNA, Messenger - genetics; RNA, Messenger - isolation & purification; Sequence Homology, Amino Acid; serotonin; Serotonin receptors; Transfection
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.90.1.11

Serotonin (5-HT) is a major neurotransmitter that influences various behaviors, neuronal plasticity, learning, and memory in molluscs. Although the physiology of 5-HT transmission in molluscs is well studied, little is known about the pharmacology and diversity of the 5-HT receptor system. Based on the high homology of genes coding for guanine nucleotide-binding protein (G protein)-coupled receptors, we have cloned a gene for the Lymnaea stagnalis 5-HT (5HTlym) receptor. The putative receptor protein, 509 amino acids long, has highest homology with the Drosophila 5-HT receptors and mammalian 5HT1receptors. As revealed by RNA blot-hybridization analysis, two mRNA species of 2.3 and 3.2 kb are detected in the central nervous system of Lymnaea. Transient expression of 5HTlym in COS-7 cells showed saturable [3H]lysergic acid diethylamide binding with an estimated dissociation constant of 0.9 nM. The 5HTlym receptor exhibited a mixed 5HT-like pharmacology that cannot be precisely categorized with existing mammalian classification nomenclature. However, the 5HTlym receptor does display some characteristics that have been attributed to the putative mammalian vascular 5HT1-like receptor.