Schematic representation of an interleukin-4Rα/GP Ib-IX receptor.

The platelet GP Ib-IX receptor complex is composed of the disulfide-linked α- and β-subunits of GP Ib and noncovalently associated GP IX. A coding sequence was generated replacing most of the GP Ibα extracytoplasmic sequence (residues 1-472) with the extracytoplasmic domain (residues 1-198) of the interleukin-4 receptor α chain (IL-4Rα). Studies are presented characterizing the phenotypic consequences of the IL-4Rα/GP Ibα subunit in heterologous cells and in a murine model of the Bernard-Soulier syndrome.