Purity
>95%, by SDS-PAGE under reducing conditions and visualized by silver stain
Endotoxin Level
<0.10 EU per 1 μg of the protein by the LAL method.
Activity
Measured by the ability of the immobilized protein to support the adhesion of HeLa human cervical epithelial carcinoma cells. The ED 50 for this effect is 0.25-1.0 μg/mL.
Source
Mouse myeloma cell line, NS0-derived Gln22-His163, with a C-terminal 6-His tag
Accession #
N-terminal Sequence
AnalysisNo results obtained: Gln22 predicted, sequencing might be blocked
Predicted Molecular Mass
16.3 kDa
SDS-PAGE
28-33 kDa, reducing conditions
2664-LR |
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Formulation Lyophilized from a 0.2 μm filtered solution in PBS. | ||
Reconstitution Reconstitute at 300 μg/mL in PBS. | ||
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | ||
Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
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Background: LAIR1
LAIR1 (leukocyte-associated Ig-like receptor-1, designated CD305) is an approximately 40 kDa type I transmembrane inhibitory glycoprotein belonging to the Ig superfamily (1-4). LAIR1 is a collagen-binding protein that is expressed in a differentiation- and activation-dependent manner on most immune cells, including T, B, NK and dendritic cells (DC), monocytes, CD34+ hematopoietic progenitors, most thymocytes, and selected granulocyte populations (2-7). Mature human LAIR1 is a 266 amino acid (aa) type I transmembrane protein that includes a 144 aa extracellular domain (ECD) with one collagen-binding C2-type Ig-like domain, and a 101 aa cytoplasmic domain with two ITIM motifs (2, 3, 8, 9). Of four potential human LAIR1 splice variants, LAIR1b has a 17 aa deletion within the ECD, but outside the Ig domain. LAIR1c differs from LAIR1b by one aa. LAIR1d has a 78 aa cytoplasmic truncation and lacks ITIM motifs. Human LAIR1 ECD shares<45% aa sequence identity with mouse, rat, bovine or canine LAIR1 ECD, but all are functional orthologs. Humans, but not rodents, also express the 152 aa secreted protein LAIR2, which shares 83% aa sequence identity with the LAIR1 ECD up to aa 140 and can block LAIR1 collagen binding (1, 2). A soluble form of LAIR1 found in plasma and urine also binds collagen (10). Adhesion of LAIR1 to collagens in the extracellular matrix, transmembrane collagens expressed by tumor cells, or antibody-mediated crosslinking of LAIR1, inhibits signals relayed by ITAM-bearing receptors and some cytokine-mediated signals (6-8, 13). Processes that are inhibited include B and T cell receptor-mediated activation, NK and T cell‑mediated cytotoxicity, and basophil degranulation (1-4, 8). LAIR1 is reduced or absent on chronic lymphocytic leukemia (CLL) B cells, and some B and DC cells in systemic lupus erythematosus (SLE). Its under‑expression potentially enhances CLL proliferation and SLE immune responses (7, 11, 12).
References:
Meyaard, L. (2008) J. Leukoc. Biol. 83:799.
Meyaard, L. et al. (1997) Immunity 7:283.
Lebbink, R.J. et al. (2004) J. Immunol. 172:5535.
Ouyang, W. et al. (2003) Biochem. Biophys. Res. Commun. 310:1236.
Verbrugge, A. et al. (2006) J. Leukoc. Biol. 79:828.
Lebbink, R.J. et al. (2006) J. Exp. Med. 203:1419.
Bonaccorsi, I. et al. (2010) PLoS ONE 5:e15080.
Tang, X. et al. (2009) J. Immunol. 182:5446.
Brondijk, T.H.C. et al. (2010) Blood 115:1364.
Olde Nordkamp, M.J. et al. (2011) Arthritis Rheum. 63:3749.
Poggi, A. et al. (2008) Leukemia 22:980.
Colombo, B.M. et al. (2012) PLoS ONE 7:e31903.
Rygiel, T.P. et al. (2011) Mol. Immunol. 49(1-2):402.
Long Name:
Leukocyte-associated Ig-like Receptor 1
Entrez Gene IDs:
3903 (Human)
Alternate Names:
CD305 antigen; CD305; CD305leukocyte-associated Ig-like receptor 1; hLAIR1; LAIR1; LAIR-1; leukocyte-associated immunoglobulin-like receptor 1
