Recombinant Mouse CRACC/SLAMF7 Protein, CF

CD2-like receptor activating cytotoxic cells (CRACC), also known as CS1, novel Ly9, SLAMF7, and CD319, is a 66 kDa type I transmembrane glycoprotein in the SLAM subgroup of the CD2 family (1). Mature mouse CRACC consists of a 202 amino acid (aa) extracellular domain (ECD) with one Ig-like V-set domain and one Ig-like C2-set domain, a 21 aa transmembrane segment, and an 88 aa cytoplasmic domain with two immunoreceptor tyrosine-based switch motifs ITSMs (2, 3). Within the ECD, mouse CRACC shares 53% aa sequence identity with human CRACC. It shares 19% - 35% aa sequence identity with comparable regions of other mouse SLAM proteins including 2B4, BLAME, CD2F-10, CD84, CD229, NTB-A, and SLAM/CD150. Additional isoforms of mouse CRACC are distinguished by deletions and/or substitutions in their cytoplasmic domains. CRACC is expressed on the surface of NK cells, CD8⁺ T cells, activated B cells, and mature dendritic cells (4, 5). It interacts homophilically to induce NK, CTL, and B cell activation (4 - 7). In human NK cells, activated CRACC transmits signals following association with the adaptor protein EAT-2 (8).