title: The glycoprotein Ib-IX-V complex is a platelet counterreceptor for P-selectin.
abstract: We have identified platelet glycoprotein (GP) Ibalpha as a counterreceptor for P-selectin. GP Ibalpha is a component of the GP Ib-IX-V complex, which mediates platelet adhesion to subendothelium at sites of injury. Cells expressing P-selectin adhered to immobilized GP Ibalpha, and GP Ibalpha-expressing cells adhered to and rolled on P-selectin and on histamine-stimulated endothelium in a P-selectin-dependent manner. In like manner, platelets rolled on activated endothelium, a phenomenon inhibited by antibodies to both P-selectin and GP Ibalpha. Unlike the P-selectin interaction with its leukocyte ligand, PSGL-1 (P-selectin glycoprotein ligand 1), the interaction with GP Ibalpha required neither calcium nor carbohydrate core-2 branching or alpha(1,3)-fucosylation. The interaction was inhibited by sulfated proteoglycans and by antibodies against GP Ibalpha, including one directed at a tyrosine-sulfated region of the polypeptide. Thus, the GP Ib-IX-V complex mediates platelet attachment to both subendothelium and activated endothelium.
authors.affiliation: Department of Medicine, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Romo
authors.forename: J F
authors.initials: JF
authors.lastname: Dong
authors.forename: A J
authors.initials: AJ
authors.lastname: Schade
authors.forename: E E
authors.initials: EE
authors.lastname: Gardiner
authors.forename: G S
authors.initials: GS
authors.lastname: Kansas
authors.forename: C Q
authors.initials: CQ
authors.lastname: Li
authors.forename: L V
authors.initials: LV
authors.lastname: McIntire
authors.forename: M C
authors.initials: MC
authors.lastname: Berndt
authors.forename: J A
authors.initials: JA
authors.lastname: López
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000378:metabolism* / Q000473:pathology; D016466:CHO Cells; D006224:Cricetinae; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008024:Ligands; D008562:Membrane Glycoproteins / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism*; D010973:Platelet Adhesiveness; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*
chemical_list: D008024:Ligands; D008562:Membrane Glycoproteins; D019007:P-Selectin; C084882:P-selectin ligand protein; D019038:Platelet Glycoprotein GPIb-IX Complex