Recombinant Human PEAR1 Protein, CF

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human PEAR1 Protein, CF Summary

• Details of Functionality: Measured by its binding ability in a functional ELISA. Recombinant Human PEAR1 (Catalog # 4527-PR) binds Recombinant Human Fc epsilon RI alpha (Catalog # 6678-FC) with an ED₅₀ of 0.0400-0.340 µg/mL.
• Source: Chinese Hamster Ovary cell line, CHO-derived human PEAR1 protein
  Leu21-Ser754 with a C-terminal 6-His tag
• Accession #: NP_001073940
• N-terminal Sequence: Leu21
• Protein/Peptide Type: Recombinant Proteins
• Gene: PEAR1
• Purity: >90%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Endotoxin Note: <0.01 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 78.3 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 120-130 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS.
• Purity: >90%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Reconstitution Instructions: Reconstitute at 200 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human PEAR1 Protein, CF

• Jedi
• PEAR1
• platelet endothelial aggregation receptor 1

Background

Platelet endothelial aggregation receptor 1 (PEAR1) is a 150 kDa type I transmembrane protein and member of the MEGF family of proteins (1). Human PEAR1 is synthesized as a 1037 amino acid (aa) precursor that contains a 20 aa signal sequence, a 735 aa extracellular domain (ECD), a 21 aa transmembrane region, and a 261 aa cytoplasmic region (SwissProt # Q5VY43). The ECD consists of 15 EGF-like repeats that vary in length from 39 to 42 aa and contain a consensus sequence of CX_1-2GX₂GX_2-4CX₃CX_1-3CX_1-2GX_1-2CX₄GX₁CX₁CX₂GX₂GX₂C (1). The consensus repeat contains six conserved glycine residues and eight conserved cysteine residues, suggesting four disulfide-bonded cysteine pairs in each EGF repeat (1). Within the ECD, there are also five potential sites for N-linked glycosylation. The cytoplasmic region contains five potential Src homology 3-binding, proline-rich domains (1). Mature human PEAR1 is 84% aa identical to mature mouse PEAR1.  PEAR1 is most highly expressed in platelets and endothelial cells (1). High affinity immunoglobulin E receptor subunit  alpha (Fc epsilon R1 alpha ) has been identified as an activating platelet endothelium aggregation receptor 1 (PEAR1) ligand. The signaling enhances and stabilizes platelet aggregates, which leads to tyrosine-phosphorylation of PEAR1 (2). Phosphorylation of PEAR1 is inhibited by the alpha _IIb beta ₃ antagonist eptifibatide, thus demonstrating that PEAR1 tyrosine phosphorylation is dependent on surface contacts between activated platelets (1). PEAR1 can be phosphorylated in an alpha _IIb beta ₃ integrin-dependent manner on tyrosine (Tyr925) and serine residues (Ser593 and Ser1029) and, potentially, at Tyr804, Tyr943, and Tyr979 (1). Sushi, von Willebrand factor type A, EFG and pentraxin domain containing 1 (SVEP1) has also been identified as a high affinity ligand for PEAR1 and this interaction promotes disease associated AKT/mTOR signaling in vascular cells and platelets (3). Inherited PEAR1 variations that alter expression or function of the platelet signaling molecule could modify agonist-induced aggregation in native platelets (3). In addition, a genetic variant in PEAR1 could be an important determinant of residual platelet function during aspirin treatment, because the COX1/thromboxane A2 pathway will be strongly inhibited by aspirin, and maximal aggregation will then be dependent on other secondary signaling pathways (4).

1. Nanda, N. et al. (2005) J. Biol. Chem. 280:24680.
2. Sun, Y. et al. (2015) Mol Cell Proteomics. 14(5): 1265-1274
3. Elenbaas, J. et al. (2023) Nat Commun. 14: 850
4. Herrera-Galeano, J.E. et al. (2008) Arterioscler. Thromb. Vasc. Biol. 28:1484.

Publications for PEAR1 (4527-PR)(2)

Publications using 4527-PR

• Kauskot A, Di Michele M, Loyen S, Freson K, Verhamme P, Hoylaerts MF A novel mechanism of sustained platelet αIIbβ3 activation via PEAR1. Blood, 2012-02-27;119(17):4056-65. 2012-02-27 [PMID: 22371881] (Bioassay, Human)
• Faraday N, Yanek LR, Yang XP, Mathias R, Herrera-Galeano JE, Suktitipat B, Qayyum R, Johnson AD, Chen MH, Tofler GH, Ruczinski I, Friedman AD, Gylfason A, Thorsteinsdottir U, Bray PF, O'Donnell CJ, Becker DM, Becker LC Identification of a specific intronic PEAR1 gene variant associated with greater platelet aggregability and protein expression. Blood, 2011-07-26;118(12):3367-75. 2011-07-26 [PMID: 21791418] (ELISA (Standard))

Bioinformatics

• Gene Symbol: PEAR1
• Uniprot:
  • NP_001073940()