A proposed bovine neuropeptide Y (NPY) receptor cDNA clone, or its human homologue, confers neither NPY binding sites nor NPY responsiveness on transfected cells

Regul Pept. 1993 Sep 22;47(3):247-58. doi: 10.1016/0167-0115(93)90392-l.


Receptors with seven transmembrane domains (7TM) constitute a large family of structurally and functionally related proteins which respond to various types of ligands. We describe here the cloning and expression of a human 7TM receptor, denoted hFB22 (human Fetal Brain 22), which is the homologue (92% amino acid identity) of a bovine receptor (LCR1) reported by others to bind neuropeptide Y (NPY) with a pharmacological profile of the Y3 receptor subtype. However, upon expression in COS1 (confirmed by Northern analysis), COS7 or CHO-K1 cells, the hFB22 receptor did not confer specific 125I-Bolton-Hunter-NPY, 3H-propionyl-NPY or 125I-peptide YY (PYY) binding sites, in either intact cells or in membrane preparations. Similarly, cells transfected with the corresponding bovine clone (LCR1) did not show specific NPY/PYY binding exceeding that resulting from endogenous binding sites; mock-transfected COS7 cells, used frequently for heterologous expression of receptors, were found to have endogenous specific 125I-NPY binding sites (Bmax = 112 fmol/mg protein; Kd = 0.25 nM). Moreover, the hFB22 transfected cells, when compared to control transfected cells, did not display de novo NPY- or PYY-induced second messenger responses, i.e., (1) inhibition of forskolin-stimulated cAMP accumulation or (2) 45Ca2+ influx. The presence of hFB22 mRNA was detected in several human neuroblastoma cell lines, none of which was found to express Y3-like NPY binding sites. hFB22 displays 39% amino acid sequence identity (in the transmembrane regions) to the human interleukin-8 receptor, and 32-36% amino acid identity to the human receptors of angiotensin II, bradykinin, and n-formylpeptide, but only 23% amino acid identity to the previously described human NPY/PYY receptor of the Y1 receptor subtype. Our results show that hFB22 and LCR1 do not encode NPY receptors, and their true ligand(s) remains to be identified.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Cattle
  • Cell Line
  • Cloning, Molecular
  • Cyclic AMP / metabolism
  • DNA, Complementary / genetics
  • DNA, Complementary / metabolism*
  • Humans
  • Molecular Sequence Data
  • Neuropeptide Y / pharmacology*
  • Polymerase Chain Reaction
  • Receptors, Neuropeptide Y / genetics
  • Receptors, Neuropeptide Y / metabolism*
  • Sequence Alignment
  • Sequence Homology, Nucleic Acid
  • Transfection


  • DNA, Complementary
  • Neuropeptide Y
  • Receptors, Neuropeptide Y
  • Cyclic AMP

Associated data

  • GENBANK/L01639