Recombinant Human Natural Killer Cell Receptor 2B4/SLAMF4/CD244 (C-6His)

Source: Human Cells. MW :23.1kD. Recombinant Human Natural Killer Cell Receptor 2B4 is produced by our Mammalian expression system and the target gene encoding Cys22-Arg221 is expressed with a 6His tag at the C-terminus. Natural killer cell receptor 2B4 is a type I transmembrane glycoprotein in the SLAM subgroup of the CD2 protein family.2B4 interacts with CD48, while other SLAM family proteins interact homophilically. Three additional splice variants of human 2B4 have deletions of the short region between the Ig-like domains, the second Ig-like domain, or a portion of the cytoplasmic tail.2B4 is expressed on all NK cells, gamma delta T cells, monocytes, some CD4+ and CD8+ T cells, and some dendritic cells. CD48 mediates 2B4+ cell interactions with nearly all hematopoietic cell types, including cells of the same type. 2B4/CD48 signaling cooperates with other receptor systems to either promote or inhibit NK and CD8+ T cell activation. The inhibitory activities are distinct from those of MHC I restricted inhibitory NK cell receptors. Ligation of 2B4 with antibodies or CD48 constructs can either directly trigger inhibitory signaling or disrupt an inhibitory interaction, leading to cellular activation. The inhibitory effect is associated with the long form of 2B4, while the activation is associated with the short form. 2B4 can also induce signaling through CD48. Protein function: Heterophilic receptor of the signaling lymphocytic activation molecule (SLAM) family, its ligand is CD48. SLAM receptors triggered by homo- or heterotypic cell-cell interactions are modulating the activation and differentiation of a wide variety of immune cells and thus are involved in the regulation and interconnection of both innate and adaptive immune response. Activities are controlled by presence or absence of small cytoplasmic adapter proteins, SH2D1A/SAP and/or SH2D1B/EAT-2. Acts as activating natural killer (NK) cell receptor (PubMed:10359122, PubMed:8376943, PubMed:11714776). Activating function implicates association with SH2D1A and FYN (PubMed:15713798). Downstreaming signaling involves predominantly VAV1, and, to a lesser degree, INPP5D/SHIP1 and CBL. Signal attenuation in the absence of SH2D1A is proposed to be dependent on INPP5D and to a lesser extent PTPN6/SHP-1 and PTPN11/SHP-2 (PubMed:10934222, PubMed:15713798). Stimulates NK cell cytotoxicity, production of IFN-gamma and granule exocytosis (PubMed:8376943, PubMed:11714776). Optimal expansion and activation of NK cells seems to be dependent on the engagement of CD244 with CD48 expressed on neighboring NK cells. Acts as costimulator in NK activation by enhancing signals by other NK receptors such as NCR3 and NCR1 (PubMed:10741393). At early stages of NK cell differentiation may function as an inhibitory receptor possibly ensuring the self- tolerance of developing NK cells (PubMed:11917118). Involved in the regulation of CD8(+) T-cell proliferation, expression on activated T-cells and binding to CD488 provides costimulatory-like function for neighboring T-cells. Inhibits inflammatory responses in dendritic cells (DCs). [The UniProt Consortium]