Anti-Proteinase-activated Receptor-4 (extracellular)-FITC

 

Anti-Proteinase-activated Receptor-4 (extracellular)-FITC

Product#:

APR-034-F

Sizes:

50 µl

Host:

Rabbit.

Epitope:

Peptide (C)HLRGQRWPFGEAA(S)R corresponding to amino acid residues 136-150 of human PAR-4 (Accession  Q96RI0 ). Cys 149 was replaced with Ser.

Putative epitope location:

Extracellular, 1ST loop.

Homology:

Rat, mouse - identical.   Label: Fuorescein isothiocyanate (FITC).

Applications:

Flow Cytometry:

.

Flow cytometry analysis of PAR-4 expression in live intact HL-60 (human promyelocytic leukemia) cell line. Black line: Unstained HL-60 cells Green line: HL-60 cells + Anti-PAR-4 (extracellular)-FITC antibody (#APR-034-F)

HL-60 cells were induced to differentiate into a mature neutrophil-like phenotype by incubation with dimethyl sulfoxide (DMSO) (1.25%) for three days. The neutrophil phenotype was confirmed by staining the cells with Anti-CD11b-PE antibody. Double staining with Anti-PAR-4 (extracellular)-FITC antibody (#APR-034-F), (1:40) shows that most differentiated cells express both markers (upper right panel).

Proteinase-activated receptor 4 (PAR-4) 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 proteinase 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 proteinases. Hence, PAR-4 is activated by both thrombin and trypsin whereas PAR-1 and PAR-3 are activated only by thrombin and PAR-2 is activated only by trypsin.^1-3 PAR-4 can be also cleaved and activated by other proteinases such as cathepsin G.

 

The intracellular signaling mechanisms mediated by PAR-4 activation are not completely elucidated but they involve calcium mobilization downstream of phospholipase Cb through the Gaq pathway.^1-3

 

Tissue distribution of PAR-4 is very broad with the highest expression levels found in lung, testis, pancreas and small intestine. In addition, PAR-4 expression was observed in platelets, megakaryocytes and leukocytes. Studies with platelets derived form PAR-4 knockout mice have established an essential role for PAR-4 in thrombin-induced platelet activation.

PAR-4 is likely involved in other physiological functions such as regulation of gastrointestinal motility and regulation of vascular endothelial cell function.^1-3

 

Alomone Labs is pleased to offer a highly specific antibody directed against an epitope at the 1^st extracellular loop of the human proteinase-activated receptor-4. Anti- Proteinase-activated Receptor-4 (extracellular) antibody (#APR-034) can be used in Western blot, immunohistochemical, immunocytochemical, and flow cytometry applications and has been tested in human and rat samples.

 

Alomone Labs is pleased to offer a new version of the Anti-Proteinase-activated Receptor-4 (extracellular) antibody (#APR-034) directly conjugated to fluorescein isothiocyanate (FITC). The Anti-Proteinase-activated Receptor-4 (extracellular)-FITC antibody (#APR-034-F) can be used for immunofluorescent applications such as direct flow cytometry and recognizes PAR-4 from human, rat and mouse samples.