CD48

The gene for CD48 is located in chromosome 1q23 and contains four exons, each exon encoding one of the four domains of CD48: signal peptide, variable (V) domain, constant 2 (C2) domain and the glycophosphatidylinositol anchor (GPI anchor). The cDNA sequence of 1137 nucleotides encodes a 243 amino acid polypeptide of about 45 kDa. It consists of a 26 amino acid signal peptide, 194 amino acids of mature CD48 (V and C2 domains) and the C-terminal 23 amino acid segment comprising the GPI anchor. The GPI linkage of CD48 to the cell surface is through serine residue 220. Approximately 35-40% of the total molecular weight is attributed to the carbohydrate side chains. == Interactions ==

CD48 was found to have a very low affinity for CD2 with dissociation constant (K_{D}) K_{D} = 8 μM which is about 5 - 10 times stronger than for CD2. == Function ==

Cell distribution CD48 is expressed on all peripheral blood lymphocytes (PBL) including T cells, B cells, NK cells and thymocytes. It is also found on the surface of activated T cells, mast cells, monocytes and granulocytes. CD48 interaction with CD2 has been shown to promote lipid raft formation, T cell activation and the formation of caveolae for macrophages through cell signal transduction via GPI moieties. ==Clinical significance==

CD48 is being investigated amongst other markers in research on inflammation markers and therapies for HIV/AIDS. Heterozygous germline mutation in a patient was associated with a recurrent inflammatory syndrome resembling hemophagocytic lymphohistiocytosis. == See also ==