- Peptide (C)NFSPWTNDPKERIN, corresponding to amino acid residues 179-192 of human FPR1 (Accession P21462). 2nd extracellular loop.
- Western blot analysis of human HL-60 promyelocytic leukemia (lanes 1 and 5), human THP-1 acute monocytic leukemia (lanes 2 and 6), human T-84 colorectal carcinoma (lanes 3 and 7) and human U-87 MG glioblastoma (lanes 4 and 8) cell lysates:1-4. Anti-Human FPR1 (extracellular) Antibody (#AFR-001), (1:200).
5-8. Anti-Human FPR1 (extracellular) Antibody, preincubated with Human FPR1 (extracellular) Blocking Peptide (#BLP-FR001).
- Cell surface detection of FPR1 by indirect flow cytometry in live intact human THP-1 monocytic leukemia cells:___ Cells.
___ Cells + goat-anti-rabbit-FITC.
___ Cells + Anti-Human FPR1 (extracellular) Antibody (#AFR-001), (2.5μg) + goat-anti-rabbit-FITC.
- The blocking peptide in not suitable for this application.
Chemotactic factors from both Gram-positive and Gram-negative bacteria are short peptides with N-formyl methionine at the N-terminus (extensively reviewed in reference 1). These peptides are released from bacteria during infection and activate formyl peptide receptors (FPR), members of the G-protein coupled receptor (GPCR) superfamily. In humans, the FPR family consists mainly of three receptors, FPR1, FPR2/ALX (formerly FPRL1), and FPR3 (formerly FPRL2) which all couple to the Gi subtype of G-proteins and ultimately lead to the activation of phospholipase C and intracellular Ca2+ increase1,2.
FPRL1, or FPR2/ALX as it is commonly called, is a seven transmembrane protein like all GPCRs. This receptor was originally cloned by screening a HL60 neutrophil cDNA library with a FPR1 cDNA probe3. FPR2/ALX shares 69% identity with FPR1 and despite its high homology, it displays relatively low affinity for fmlf, the most potent N-formyl peptide released by bacteria3.
FPR1 was originally found in neutrophils and later found to be distributed in myeloid and non-myeloid cells as is the case for FPR2/ALX and FPR3 (FPR3 though is not expressed in neutrophils). FPR1 is also expressed in multiple organs and tissues including epithelial cells in organs with secretory functions, endocrine cells, liver hepathocytes, smooth muscle cells and endothelial cells, brain spinal cord and both motor and sensory neurons4. FPR2/ALX has a similar tissue distribution to that of FPR1.
While N-formyl peptides were the first peptides found to activate these receptors, the ligand diversity for FPR has proven to be quite broad and demonstrates to be both pro- and anti-inflammatory. They include peptidic ligands originating from bacterial and viral sources (including HIV), endogenous ligands such as chemokines and annexins, short peptides associated with inflammation and infection. Indeed, peptides from Herpes, Ebola and coronavirus 229E are ligands of FPR11.
Species reactivity key:
Anti-Human FPR1 (extracellular) Antibody (#AFR-001) is a highly specific antibody directed against an epitope of the human N-formyl peptide receptor 1. The antibody can be used in western blot and indirect live cell flow cytometry applications. It has been designed to recognize FPR1 from human samples only.
- Anti-Human FPR1 (extracellular)-ATTO Fluor-488 Antibody (#AFR-001-AG).
This ATTO-conjugated antibody can be used to detect FPR1 in live cell flow cytometry.