[1] These receptors were originally identified by their ability to bind N-formyl peptides such as N-formylmethionine produced by the degradation of either bacterial or host cells.
[5] The close phylogenetic relation of signaling in chemotaxis and olfaction was recently proved by detection formyl peptide receptor like proteins as a distinct family of vomeronasal organ chemosensors in mice.
Since these oligopeptides were produced by bacteria or synthetic analogs of such products, it was suggested that the N-formyl oligopeptides are important chemotatic factors and their receptors are important chemotactic factor receptors that act respectively as signaling and signal-recognizing elements to initiate inflammation responses in order to defend against bacterial invasion.
Two receptors where thereafter discovered and named FPR1 and FPR2 based on the similarity of their genes' predicted amino acid sequence to that of FPR rather than on any ability to bind or be activated by the formyl oligopeptides.
These three receptors have been renamed as FPR1, FPR2, and FPR3 and found to have very different specificities for the formyl oligopeptides and very different functions that include initiating inflammatory responses to N-formyl peptides released not only by bacteria but also a multiplicity of elements released by host tissues; dampening and resolving inflammatory responses; and perhaps contributing to the development of certain neurological cancers and an array of neurological diseases Amyloid-based diseases.