Biogenesis of the vitronectin receptor in human endothelial cell: evidence that the vitronectin receptor and GPIIb-IIIa are synthesized by a common mechanism.

摘要: Human endothelial cells express a membrane glycoprotein alpha beta heterodimer similar to the human platelet IIb-IIIa complex (GPIIb-IIIa). This noncovalently associated is vitronectin receptor (VNR). These two receptors belong cytoadhesin family and share same subunit. They different recognition specificities: GPIIb-IIIa for fibrinogen, fibronectin, von Willebrand factor (vWF), whereas VNR vitronectin, possibly fibrinogen vWF. We analyzed biosynthesis of cell VNR. Our data show that two-chain protein which biosynthesized as single-chain precursor: pro-VNR alpha. Pro-VNR forms with beta, this association occurs prior Golgi- mediated processing oligosaccharide side chains. Mature glycosylated by not fully processed chains because it remains endoglycosidase H (endo H) sensitive, even when expressed on surface. characteristic appears common feature members family. results indicate although are in cells, their expression controlled mechanisms, providing further support concept constitutes distinct group adhesion receptors.