Recombinant Mouse CXCL16 (Histidine-tagged) Protein

CXC chemokine ligand 16 (CXCL16) is a type I membrane protein containing a non-ELR motif-containing CXC chemokine domain in its extracellular region. Together with Fractalkine (CX3CL1), CXCL16 constitute the only two transmembrane chemokines within the superfamily. Mouse CXCL16 cDNA encodes a 246 amino acid (aa) precursor protein with a putative 26 aa residue signal peptide, an 88 aa residue chemokine domain, an 87 aa residue mucin-like spacer region, a 22 aa residue transmembrane domain, and a 23 aa residue cytoplasmic tail with a potential tyrosine phosphorylation and SH2 protein-binding site. Mouse and human CXCL16 share 49% overall aa identity and 70% similarity in the chemokine domains. Mouse CXCL16 is produced by dendritic cells in lymphoid organ T cell zones and by cells in the splenic red pulp both as membrane-bound and soluble forms. Based on northern blot analysis, CXCL16 is also expressed in some nonlymphoid tissues such as lung, small intestine and kidney. The functional receptor for CXCL16 has been identified as CXCR6 (also known as Bonzo, STRL33 or TYMSTR), a receptor previously shown to be a co-receptor for HIV entry. CXCL16 has also been independently cloned and named SRPSOX (scavenger receptor that binds phosphatidylserine and oxidized lipoprotein). It was shown to be a specific receptor for OxLDL but not LDL or acetyl-LDL (1 - 3).