Cloning and functional expression of a human neuroendocrine vasoactive intestinal peptide receptor.

Vasoactive intestinal peptide (VIP) is a potent mediator of gastrointestinal, nervous, pulmonary, vascular and immune functions. A cDNA was obtained from human HT29 intestinal epithelial cells and found to encode a 457 amino acid, 52 kDa VIP receptor. Transfection of the cDNA into COS-7 cells and 293 cells resulted in expression of specific saturable binding of VIP with a Kd of 0.8 nM, and induction of increases in intracellular cAMP by VIP with an EC50 of 1 nM. The human VIP receptor is homologous to other G protein-coupled receptors of the secretin-parathyroid hormone receptor family. A 2.8 kb transcript was detected in human lung, HT29 cells and Raji B-lymphoblasts with weaker expression in human brain, heart, kidney, liver and placenta.