Integrin Beta Like Protein 1 (ITGbL1)

By screening an EST cDNA database for sequence homology with integrins, Berg et al. (1999) identified overlapping partial-length cDNA clones from human osteoclastoma, fetal lung, and umbilical vein endothelial cDNA libraries. A subsequent screening identified a potential full-length clone from an osteoblast cell cDNA library. The novel cDNA clone was found to encode a 494-amino acid protein, which the authors designated TIED. The sequence comprised a typical signal peptide, followed by a hydrophilic 471-amino acid domain containing 10 tandem EGF-like repeats strikingly similar to those found in the cysteine-rich 'stalk-like' structure of integrin-beta subunits. Northern blot analysis revealed a single RNA transcript of approximately 2.8 kb. TIED was widely expressed in many tissues, but readily detectable only in aorta.