Recombinant Mouse DNAM-1/CD226 Fc Chimera Protein, CF

DNAX accessory molecule-1 (DNAM-1), also known as CD226, is a 65 kDa type I transmembrane glycoprotein that belongs to the immunoglobulin superfamily (1). Mature mouse DNAM has a 236 amino acid (aa) extracellular domain (ECD) that contains two Ig-like C2-set domains, and possesses a 58 aa cytoplasmic region that contains motifs for binding PDZ domains and band 4.1 family proteins (1, 2). Within the ECD, mouse DNAM-1 shares 52% and 86% aa sequence identity with human and rat DNAM-1, respectively. Additional cDNA transcripts of mouse DNAM-1 may give rise to secreted or transmembrane isoforms with ECD deletions. DNAM-1 is expressed on several lymphoid and myeloid cell types and interacts with CD155/PVR and Nectin-2/CD112 (2-4). Ligation of DNAM-1 promotes the activation of NK cells, CD8⁺ T cells, and mast cells (3-7), induces dendritic cell maturation, initiates megakaryocyte and activated platelet adhesion to vascular endothelial cells, and stimulates monocyte extravasation; conversely, it inhibits the formation of osteoclasts (8-11). Platelet-endothelium interactions that are mediated by DNAM-1 enable the metastasis of tumor cells to the lung (12). On activated, but not resting NK, T, and mast cells, the cis association of DNAM-1 with CD18 contributes to tyrosine and serine phosphorylation of DNAM-1 during activation (7, 10, 13-15).