Anti-Human Protease-Activated

Anti-Human Protease-Activated Receptor-1 (extracellular)-FITC

PAR-1, Thrombin receptor, Coagulation factor II receptor, F2R
Cat #: APR-031-F
Sizes: 50 µl
Source: Rabbit
Type: Polyclonal
Applications: FC
May also work in: IC, LCI
Reactivity: H

Anti-Human Protease-Activated Receptor-1 (extracellular)-FITCApplication key:

CBE- Cell-based ELISA, FC- Flow cytometry, IC- Immunocytochemistry, IE- Indirect ELISA, IFC- Indirect flow cytometry, IH- Immunohistochemistry, IP- Immunoprecipitation, LCI- Live cell imaging, N- Neutralization, WB- Western blot

Species reactivity key:

H- Human, M- Mouse, R- Rat

Anti-Human Protease-Activated Receptor-1 (extracellular) (#APR-031) is a highly specific antibody directed against an epitope of the human protein. The antibody can be used in western blot, immunohistochemistry, immunocytochemistry, and live cell flow cytometry applications. It has been designed to recognize PAR-1 from human samples.

Alomone Labs is pleased to offer a new version of this antibody that is directly conjugated to fluorescein isothiocyanate (FITC). Anti-Human Protease-Activated Receptor-1 (extracellular)-FITC antibody (#APR-031-F) can be used in immunofluorescent applications such as direct live cell flow cytometry.

• Applications
• Specifications
• Scientific Background
• Related Products

Direct flow cytometry

Direct flow cytometry of live intact human MEG-01 megakaryoblastic leukemia cells:
^___ Cells.
^___ Cells + rabbit IgG isotype control-FITC
^___ Cells + Anti-Human Protease-Activated Receptor-1 (extracellular)-FITC antibody (APR-031-F), (5 µg).
Immunogen
Peptide (C)KNESGLTEYRLVSINK, corresponding to amino acid residues 61-76 of human PAR-1 (Accession P25116). Extracellular, N terminal.

HomologyMonkey - identical.
PurityAffinity purified on immobilized antigen.
FormulationLyophilized powder. Resuspended antibody contains phosphate buffered saline (PBS), pH 7.4, 1% BSA, 0.05% NaN₃.
SpecificityWon’t recognize PAR-1 from mouse and rat samples.
LabelFluorescein isothiocyanate (FITC).
Standard quality control of each lotWestern blot analysis (unlabeled antibody, #APR-031), and direct flow cytometry (labeled antibody).
Peptide confirmationConfirmed by amino acid analysis and mass spectrometry.
Storage before reconstitutionThe antibody ships as a lyophilized powder at room temperature. Upon arrival, it should be stored at -20°C.
Reconstitution50 μl double distilled water (DDW).
Antibody concentration after reconstitution1 mg/ml.
Storage after reconstitutionThe reconstituted solution can be stored at 4°C, protected from the light, for up to 1 week. For longer periods, small aliquots should be stored at -20°C. Avoid multiple freezing and thawing. Centrifuge all antibody preparations before use (10000 × g 5 min).
Control antigen storage before reconstitutionLyophilized powder can be stored intact at room temperature for 2 weeks. For longer periods, it should be stored at -20°C.
Control antigen reconstitution100 µl double distilled water (DDW).
Control antigen storage after reconstitution-20ºC.
Preadsorption Control1 μg peptide per 1 μg antibody.
Scientific background

Protease-activated receptor 1 (PAR-1) belongs to a family of four G protein-coupled receptors (PAR-1 - 4) that are activated as a result of proteolytic cleavage by certain serine proteases, hence their name. In this novel modality of activation, a specific protease cleaves the PAR receptor within a defined sequence in its extracellular N-terminal domain. This results in the creation of a new N-terminal tethered ligand, which subsequently binds to a site in the second extracellular loop of the same receptor. This binding results in the coupling of the receptor to G proteins and in the activation of several signal transduction pathways.^1-3

Different PARs are activated by different proteases. Hence, PAR-1 is activated by thrombin (and is in fact also known as the thrombin receptor), as are PAR-3 and PAR-4, while PAR-2 is activated by trypsin.^1-3 PAR-1 can be also cleaved and activated by other proteases such as plasmin, Factor Xa, cathepsin G, and others.

The intramolecular nature of PAR activation and the continuous presence of the tethered ligand that cannot diffuse away imply the existence of several mechanisms for the rapid termination of PAR signaling. Indeed, following receptor activation, there is rapid phosphorylation of the C-terminal end of the receptor, followed by receptor internalization and degradation. In addition, several proteases can cleave away the tethered ligand, thereby “disarming” the PAR.^1-3

PAR-1 signals through several G proteins including Gα_q, Gα_i, and Gα_12/13, resulting in the activation of several transduction pathways including intracellular Ca²⁺ mobilization, Rho and Rac signaling, and MAPK activation.^1-3

PAR-1 is expressed in several cell types including platelets, leukocytes, vascular endothelial cells, gastrointestinal epithelial cells, myocytes, and neurons. The best studied physiological function of PAR-1 is its involvement in the coagulation cascade. Thrombin, the preeminent ligand of PAR-1, activates the receptor on the surface of platelets, hence inducing platelet aggregation, granular secretion, and procoagulant activity. PAR-1 also plays a crucial role in vascular ontogenesis. Accordingly, PAR-1 knockout mice show bleeding at multiple sites and usually die at mid-gestation.^1-3

PAR-1 also plays important roles in tumor growth and metastasis. PAR-1 is upregulated in several human cancers as are several proteases such as plasmin and matrix metalloproteases (MMPs) that act as PAR-1 ligands, thereby creating an autocrine loop. PAR-1 activation in cancer cells transmits mitogenic signals through the activation of the erk1/2 pathway and is involved in tumor spread via its pro-angiogenic activity.⁴

References

1. MacFarlane, S.R. et al. (2001) Pharmacol. Rev. 53, 245.
2. Hollenberg, M.D. et al. (2002) Pharmacol. Rev. 54, 203.
3. Ossovskaya, V.S. et al. (2004) Physiol. Rev. 84, 579.
4. Arora, P. et al. (2007) J. Cell Sci. 120, 921.