cDNA cloning and functional expression of a human monocyte chemoattractant protein 1 receptor.

A novel human G-protein-coupled seven-transmembrane-type receptor gene, 24-1, has been cloned from THP-1 cells. The 24-1 was 56% and 34% identical to the macrophage inflammatory protein-1 alpha (MIP-1 alpha) receptor and the interleukin-8 (IL-8) receptors at the amino acid level, respectively. To examine the ligand specificity of the receptor, we have established a stable transfectant of this gene with human kidney 293 cells. Monocyte chemoattractant protein-1 (MCP-1) induced a rapid increase of Ca++ influx in the 24-1-transfectant, while other C-C chemokines tested did not. This indicates that the 24-1 encodes the human MCP-1 receptor.