• Purity

  >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

• Endotoxin Level

  <0.01 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. When Recombinant Human LRRC32/GARP is immobilized at 5 μg/mL (100 μL/well) Recombinant Human Latent TGF‑ beta 1 (Catalog # ) binds with an apparent K    _d <30 nM.  

• Source

  Chinese Hamster Ovary cell line, CHO-derived Met1-Asn627, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Ala18

• Predicted Molecular Mass

  67.0 kDa (monomer)

• SDS-PAGE

  70-80 kDa, reducing conditions

Background: LRRC32/GARP

Leucine-rich repeat protein 32 (LRRC32), also known as GARP (glycoprotein A repetitions predominant), is an 80 kDa type I transmembrane glycoprotein (1). Mature human LRRC32 consists of a 608 amino acid (aa) extracellular domain (ECD) that contains 22 leucine‑rich repeats, a 21 aa transmembrane segment, and a 14 aa cytoplasmic domain (2, 3). Within the ECD, human LRRC32 shares approximately 80% aa sequence identity with mouse and rat LRRC32. LRRC32 is widely expressed during embryogenesis and on adult platelets (4, 5). Human LRRC32 is identified as a lineage specific key receptor for human T cells. It is selectively expressed on activated FOXP3+ regulatory T cells (Treg) (6-10). LRRC32 expression promotes the acquisition of a Treg phenotype including reduced cellular proliferation, reduced cytokine secretion, and the capacity to suppress the proliferation of naïve T cells (6 ‑ 8). LRRC32 binds directly to the TGF-beta latency associated peptide (LAP) and tethers latent TGF-beta on the surface of activated Treg cells (9, 10). The presentation of TGF-beta on Tregs contributes to their ability to suppress naïve T cell proliferation (11).

• References:

1. Battaglia, M. and M.G. Roncarolo (2009) Eur. J. Immunol. 39:3296.

2. Ollendorff, V. et al. (1994) Cell Growth Differ. 5:213.

3. Bella, J. et al. (2008) Cell Mol Life Sci. 65:2307.

4. Roubin, R. et al. (1996) Int. J. Dev. Biol. 40:545.

5. Macaulay, I.C. et al. (2007) Blood 109:3260.

6. Wang, R. et al. (2008) PloS ONE 3:e2705.

7. Wang, R. et al. (2009) Proc. Natl. Acad. Sci. 106:13439.

8. Probst-Kepper, M. et al. (2009) J. Cell. Mol. Med. 13:3343.

9. Tran, D.Q. et al. (2009) Proc. Natl. Acad. Sci. 106:13445.

10. Stockis, J. et al. (2009) Eur. J. Immunol. 39:3315.

11. Vignali, D.A. et al. (2008) Nat. Rev. Immunol. 8:523.

• Long Name:

  Leucine-rich Repeat Containing 32/Glycoprotein A Repetitions Predominant

• Entrez Gene IDs:

  2615 (Human); 434215 (Mouse)

• Alternate Names:

  D11S833E; D11S833Eleucine-rich repeat-containing protein 32; GARP; GARPGarpin; Garpin; Glycoprotein A repetitions predominantgarpin; leucine rich repeat containing 32; LRRC32