title: Interaction between GPIbalpha and FcgammaIIA receptor in human platelets.
abstract: Glycoprotein (GP) Ib (alpha and beta) in platelets forms a noncovalent hetero-oligomeric complex with GPIX and GPV and serves as a receptor for von Willebrand factor (vWF), which mediates the initial adhesion of platelets to the subendothelium after vascular damage and also plays a role in thrombin-induced platelet activation. We investigated the interaction between GPIbalpha and FcgammaIIA receptor using a yeast two-hybrid system and mutagenesis, and we identified residues R542G543R544 in GPIbalpha and D298D299D300 in FcgammaIIA receptor as the primary interaction sites. These results further confirmed the interaction between GPIbalpha and FcgammaIIA receptor and support the hypothesis that the signal transduction of GPIb-IX-V that leads to platelet activation may be partially mediated through FcgammaIIA receptor.
authors.affiliation: Vascular Biology Division, Maryland Research Laboratories, Rockville, MD 20850, USA. bings@mrl.oapi.com
authors.forename: B
authors.initials: B
authors.lastname: Sun
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: J i
authors.initials: Ji
authors.lastname: Kambayashi
mesh_terms: D015703:Antigens, CD / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D001792:Blood Platelets / Q000502:physiology; D006801:Humans; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017452:Receptors, IgG / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D015703:Antigens, CD; C080568:Fc gamma receptor IIA; D010446:Peptide Fragments; D019038:Platelet Glycoprotein GPIb-IX Complex; D017452:Receptors, IgG