Compared to FPR1 and FPR2, FPR3 is highly phosphorylated (a signal for receptor inactivation and internalization) and more localized to small intracellular vesicles.

[7][8] The FPR3 gene was cloned and named based on the similarity of the amino acid sequence which it encodes to that encoded by the gene for FPR1 (see formyl peptide receptor 1 for details)[9][10][11][12][13][14][15][16] The studies indicated that FPR3 is composed of 352 amino acids and its gene, similar to FPR1, has an intronless open reading frames which encodes a protein with the 7 transmembrane structure of G protein coupled receptors; FPR3 has 69% and 72% amino acid sequence identities with FPR1.

However, fMMYALF, a N-formyl hexapeptide derived from the mitochondrial protein, NADH dehydrogenase subunit 6, is a weak agonist for FPR3 but >100-fold more potent in stimulating FPR1 and FPR2.

[25] F2L is a naturally occurring acylated peptide derived from the N-terminal sequence of heme-binding protein 1 by cathepsin D cleavage that potently stimulates chemotaxis through FPR3 in monocytes and monocyte-derived dendritic cells.

[8] Similar to FPR2 (see FPR2 section), FPR3 is activated by humanin and thereby may be involved in inhibiting the inflammation occurring in and perhaps contributing to Alzheimer's disease.