Formyl peptide receptor 1 (IPR027345)

Short name: Formyl_pep_1_rcpt

Overlapping homologous superfamilies


Family relationships


Formyl peptide receptors (FPR) are members of the rhodopsin-like G-protein coupled receptor family and are involved in chemotaxis [PMID: 17084101, PMID: 19498085]. They were originally identified by their ability to bind N-formyl peptides (typified by fMet-Leu-Phe (fMLP)), produced by the degradation of either bacterial or host cells [PMID: 12401407, PMID: 16684671] but subsequent ligands have been discovered, containing many microbial agonists derived from both bacteria and viruses [PMID: 16365159, PMID: 17084101].

FPRs were initially found on leukocytes, but they are expressed in other cells, for example, immature dendritic cells, platelets, microglial cells, astrocytes, fibroblasts and platelets [PMID: 16365159, PMID: 17084101]. FPRs are expressed at high levels on polymorphonuclear and mononuclear phagocytes. Formyl peptide receptors are not only involved in mediating immune cell response to infection, but also act to suppress the immune system under certain conditions [PMID: 11369647]. The main responses elicited upon ligation of formylated peptides, are those of morphological polarization, locomotion, production of reactive-oxygen species and release of proteolytic enzymes [PMID: 17084101]. There are three formyl peptide receptor subtypes, FPR1, FPR2 and FPR3 [PMID: 23160941, PMID: 19498085]. The sequence similarity between FPR1 and FPR2 is high (69%), and although there is a large sequence similarity also between FPR2 and FPR3 (83%), FPR3 can not bind formylated peptides [PMID: 17084101, PMID: 19498085].

This entry represents formyl peptide receptor 1 (FPR1, also known as fMet-Leu-Phe receptor) which plays an important role for host defence. This is shown in mice that are devoid of receptor expression, are unable to respond to an infection by Listeria monocytogenes [PMID: 9989980]. The interaction between formyl-methionyl-leucyl phenylalanine (fMLF) and FPR1 triggers a cascade of multiple second messengers through the activation of phospholipase C, phospholipase D and phospholipase A2. This signalling cascade culminates in cell chemotaxis [PMID: 1093163], phagocytosis [PMID: 7734243], production of proinflammatory mediators [PMID: 18458054] and activation of transcription factors [PMID: 9065470]. The characterisation of FPR1 function has focused on cells involved in brain function and disease and research indicates that FPR1 is expressed in highly malignant human glioma cells, and is thought to be responsible for mediating motility, growth and angiogenesis of the glioblastoma [PMID: 15928303, PMID: 19233142]. The number of ligands for FPRs is immense, and includes many microbial agonists derived from both bacteria and viruses [PMID: 16365159, PMID: 17084101]. However, unlike FPR2 and FPR3, ligands for FPR1 include endogenous substances, such as annexin AI peptide (Ac9-25) [PMID: 15951351], and allergens, such as the house mite allergen [PMID: 17559171].

GO terms

Biological Process

GO:0007186 G-protein coupled receptor signaling pathway

Molecular Function

GO:0004982 N-formyl peptide receptor activity

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.