2B4/CD244 Extracellular Domain (human, recombinant)

2B4, also known as CD244, is a cell surface receptor and a member of the signaling lymphocytic activation molecule (SLAM) receptor family (SLAMF).{54463} It is comprised of an extracellular domain containing immunoglobulin (Ig) variable-like (IgV) and Ig constant 2-like (IgC2) motifs and several glycosylation sites, a membrane-spanning region, and a cytoplasmic domain containing serine, tyrosine, and threonine phosphorylation sites.{54464} It is expressed on natural killer (NK) cells, certain T cells, monocytes, basophils, and eosinophils. 2B4 has an activating role when the adapter protein SLAM-associated protein (SAP) is present and bound to intracellular tyrosine-based switch motifs (ITSM) on the cytoplasmic domain.{54463} When SAP is absent, SHP-1, SHP-2, SHIP-1, or CsK are able to bind, which leads to inhibitory signaling. 2B4 has cis- and trans-interactions with the cell surface receptor CD48 during the initiation and continuation of allergic reactions. It has a complex role in cancer, with male, but not female, CD244-/- mice rejecting tumor cells in a xenograft model, however, its role is primarily inhibitory in tumor-associated immune cells.{54464} The expression of CD244 is decreased in NK cells from patients with multiple myeloma or systemic lupus erythematosus (SLE).{54463} 2B4 is associated with X-linked lymphoproliferative disease (XLPD), which is characterized by a mutation in SAP that prevents it from binding to 2B4.{54465} Cayman’s 2B4/CD244 Extracellular Domain (human, recombinant) protein can be used for ELISA. This protein consists of 211 amino acids, has a calculated molecular weight of 23.8 kDa, and a predicted N-terminus of Cys22 after signal peptide cleavage. By SDS-PAGE, under reducing conditions, the apparent molecular mass of the protein is approximately 45-50 kDa due to glycosylation.