GARP, Recombinant Mouse (Glycoprotein A Repetitions Predominant, GARP Protein, Garpin, D11S833E, Leu

Leucinerich repeat protein 32 (LRRC32), also known as GARP (glycoprotein A repetitions predominant), is an 80kD type I transmembrane glycoprotein (1). Mature mouse LRRC32 consists of a 608 amino acid (aa) extracellular domain (ECD) that contains 22 leucinerich, repeats, a 21 aa transmembrane segment, and a 14 aa cytoplasmic domain (2 4). Within the ECD, mouse LRRC32 shares 80 and 94% aa sequence identity with human and rat LRRC32, respectively. LRRC32 is widely expressed during embryogenesis and on adult platelets (4, 5)., Among 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 TGFb latency associated peptide (LAP) and tethers latent TGFb on the surface of activated Treg cells (9, 10). The presentation of TGFb on Tregs contributes to their ability to suppress naïve T cell proliferation (11). Source: Recombinant corresponding to Ser62-Thr209 mouse Leucinerich expressed in E. coli. Molecular Weight: ~17.1kD, Biological Activity: Measured in a cell proliferation assay using 4MBr­5 monkey epithelial cells. Rubin, J.S. et al. (1989) Proc. Natl. Acad. Sci. USA 86:802. The ED50 for this effect is typically 20-120 ng/ml. Endotoxin Level: <1EU/ug (LAL method), Storage and Stability: Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile buffer. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.