G protein-coupled receptors (GPCR) are so named because of their regulation
of an intracellular heterotrimeric complex made up of Ga, and Gbg subunits.
Ligand binding to receptor stimulates the well-described exchange of GDP for
GTP by Ga. This activity lies at the apex of numerous signaling cascades induced
by a range of different stimuli including light, odorants, amino acids, nucleotides,
lipids, and peptides/proteins. GPCRs make up the largest family of integral
membrane proteins and account for approximately 5% of all genes found in the
human genome.1 Clinically, approximately 45% of modern drugs target GPCRs,
underscoring the importance of having quality research tools to study their
functions.2 R&D Systems continues to expand its selection of products for
GPCR research to include reagents for at least 20 chemokine receptors, as well
as other GPCRs in key areas of biological Science (Table 1).
| Table 1. G Protein-related Products |
| GPCR |
Antibodies |
Proteins |
Primers |
mRNA Quantitation Kits |
| APJ |
H |
|
|
|
| CD97 |
H |
H |
|
|
| D6 |
H |
|
|
|
| ChemR23 |
H |
|
|
|
Chemokine Receptors
(CCR,CXCR,CX3,CR,XCR)a |
H,M |
|
H,M,R |
H |
| EDG-1 |
H |
|
|
|
| FPRL1/LXA4R |
H |
|
|
|
| Frizzled-1 through 9b |
H,M |
H,M |
|
|
| GABA-B-R2 |
H |
|
|
|
| HCR/CRAM-A/B |
H |
|
|
|
| HM74A/GPR109A |
H |
|
|
|
| Leukotriene B4R1 |
H |
|
|
|
| Key: H-Human, M-Mouse, R-Rat |
a. For a complete listing of chemokine receptor products please see our website at www.RnDSystems.com/go/Chemokines.
b. For a complete listing of frizzled receptor products please see our website at www.RnDSystems.com/go/Wnt. |
One example, FPRL1/LXA4R, is a GPCR with homology to the formyl peptide receptor
(FPR1) and is activated by formyl-methionyl-leucyl-phenylalanine (fMLP). However,
FPRL1/LXA4R binds fMLP with only low affinity (Kd ~5 μM). 3 In contrast,
lipoxin A4 (LXA4), a bioactive eicosanoid, has been identified to be the most
potent endogenous ligand of FPRL1/LXA4R with a Kd about 3 orders of magnitude
higher than that of fMLP. FPRL1/LXA4R mediates the anti-inflammatory effects
of LXA4, and stable LXA4 analogs, to modulate leukocyte trafficking and promote
the resolution of inflammation.4,5 The receptor is also thought to mediate
the actions of pro-inflammatory mediators associated with human diseases, including
amyloidosis, Alzheimer’s disease, prion disease, and HIV. 6
R&D Systems now offers a monoclonal antibody specific for the G protein-coupled
receptor FPRL1/LXA4R (Catalog # MAB3479; Figure 1).
References
- Takeda, S. et al. (2002) FEBS Lett. 520:97.
- Drews, J. (2000) Science 287:1960.
- Fiore, S. & C.N. Serhan (1995) Biochemistry 34:16678.
- Fiore, S. et al. (1994) J. Exp. Med. 180:253.
- Takano, T. et al. (1997) J. Exp. Med. 185:1693.
- Le, Y. et al. (2002) Trends Immunol. 23:541.
|