Lymphocyte Antigen 6D (LY6D)

A monoclonal antibody termed E48 recognizes a 20-kD glycoprotein present in desmosomal intercellular adhesions of keratinocytes and in squamous carcinoma cells.E48 gene contains 3 exons separated by 2 small introns. In contrast, other Ly6 genes, such as CD59, have 4 exons. Promoter and reporter analyses identified numerous SP1 sites in the E48 promoter region.The deduced 128-amino acid protein is homologous to the mouse ThB antigen and other members of the Ly6 family of GPI-anchored proteins. It contains a signal peptide, 2 theoretical phosphorylation sites, and 3 putative myristoylation sites. Northern blot analysis revealed expression of a 0.8-kb E48 transcript in squamous cell carcinoma cell lines and squamous epithelial tissue; expression was not detected on mononuclear cells.