Cloning and characterization of a novel beta integrin-related cDNA coding for the protein TIED ("ten beta integrin EGF-like repeat domains") that maps to chromosome band 13q33: A divergent stand-alone integrin stalk structure

Herein we describe the cDNA sequence of a novel human gene, ITGBL1, encodin g a beta integrin-related protein termed TIED [for ten beta integrin epider mal growth factor (EGF)-like repeat domains]. Overlapping cDNA clones from fetal lung, HUVEC, and osteoblast cDNA libraries encode a sequence comprisi ng a typical signal peptide, followed by a hydrophilic 471-amino-acid domai n containing 10 tandem EGF-like repeats strikingly similar to those found i n the cysteine-rich "stalk-like" structure of integrin beta subunits, The E GF-like repeats of TIED and beta integrins are unique in that they alternat e in homology and possess two additional cysteines (eight in total) whose p ositions differ from those in the other eight-cysteine EGF-like domains of laminin, fibrillin, and the latent TGF-beta binding proteins. TIED mRNA tra nscripts of 2.8 kb were detected in aorta, thymus, and osteogenic sarcoma c ells. The ITGBL1 gene was mapped to human chromosome 13, band 13q33. We sug gest that ITGBL1 may be linked in some way with the evolution of the integr in beta subunits. (C) 1999 Academic Press.