Selective coupling of the human anaphylatoxin C5a receptor and alpha 16 in human kidney 293 cells.

The peptide C5a which is generated during the complement cascade is an important chemotactic factor involved in the inflammatory response. The C5a receptor (C5aR) primary sequence suggests that it has a serpentine structure of seven transmembrane domains which is typical of classical G-protein-coupled receptors. To investigate the signal transduction mechanism of C5a we transiently expressed the C5aR in combination with different G-protein alpha subunits in human kidney 293 cells and measured the PLC activity induced upon C5a stimulation. Cotransfection of C5aR and alpha 16 stimulated PLC while cotransfection of C5aR with either alpha q or alpha i2 did not.