T-Cell Activation Antigen, Increased Late Expression (TACTILE)

Sequence analysis predicted that the 569-amino acid TACTILE protein is a member of the immunoglobulin superfamily. TACTILE contains a signal peptide; an extracellular region with 15 N-linked glycosylation sites and a 132-residue stretch rich in serine, threonine, and proline, a characteristic of domains with extensive O-linked glycosylation; a transmembrane domain; and a 45-amino acid cytoplasmic domain.Immunoprecipitation and immunoblot analyses showed that both recombinant and native TACTILE proteins are expressed as 160-kD proteins under reducing conditions. Northern blot analysis revealed expression of a major 4.4- and a minor 2.4-kb TACTILE transcript in cell lines that also express the TACTILE protein.