Cloning and expression of a human serotonin 5-HT4 receptor cDNA

J Neurochem. 1997 Nov;69(5):1810-9. doi: 10.1046/j.1471-4159.1997.69051810.x.


Using a combination of library screening and nested PCR based on a partial human serotonin 5-HT4 receptor sequence, we have cloned the complete coding region for a human 5-HT4 receptor. The sequence shows extensive similarity to the published porcine 5-HT4A and rat 5-HT4L receptor cDNA; however, in comparison with the latter, we find an open reading frame corresponding to only 388 amino acids instead of 406 amino acids. This difference is due to a frame shift caused by an additional cytosine found in the human sequence after position 1,154. Moreover, we also found the same additional cytosine in the rat 5-HT4 sequence. We confirmed the occurrence of the sequence by examining this part of the sequence in genomic DNA of 10 human volunteers and in rat genomic DNA. Based on a part of the genomic 5-HT4 receptor sequence that was identified in the cloning process, there seem to be at least two possible splice sites in the coding region of the gene. The human 5-HT4 receptor, transiently expressed in COS-7 cells, showed radioligand binding properties similar to 5-HT4 receptors in guinea pig striatal tissue. [3H]GR 113808 revealed K(D) values of 0.15 +/- 0.01 nM for the human receptor and 0.3 +/- 0.1 nM in the guinea pig tissue. Binding constants were determined for four investigated 5-HT4 antagonists and three agonists, and appropriate binding inhibition constants were found in each case. Stimulation of transfected COS-7 cells with 5-HT4-specific agonists caused an increase in cyclic AMP levels.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding, Competitive
  • Brain / metabolism*
  • COS Cells
  • Cell Membrane / metabolism
  • Cloning, Molecular
  • Cytosine
  • DNA Primers
  • Frameshift Mutation
  • Guinea Pigs
  • Humans
  • Indoles / metabolism
  • Kinetics
  • Molecular Sequence Data
  • Open Reading Frames
  • Polymerase Chain Reaction
  • Rats
  • Receptors, Serotonin / biosynthesis*
  • Receptors, Serotonin / chemistry
  • Receptors, Serotonin / genetics*
  • Receptors, Serotonin, 5-HT4
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Serotonin Antagonists / metabolism
  • Sulfonamides / metabolism
  • Swine
  • Transfection


  • DNA Primers
  • Indoles
  • Receptors, Serotonin
  • Recombinant Proteins
  • Serotonin Antagonists
  • Sulfonamides
  • Receptors, Serotonin, 5-HT4
  • Cytosine
  • GR 113808