title: Platelet GPIb-IX-V-dependent signaling.
abstract: Although the signaling pathways related to GPIb-IX-V have not been fully elucidated, an accumulating body of evidence suggests that phospholipase C (PLC)gamma2 activation, subsequent Ca++ release and oscillations constitute an essential signal transduction pathway related to GPIb-IX-V. Src family kinases are required for PLCgamma2 activation, while FcR gamma-chain/Fc gammaRIIA may be dispensable for PLCgamma2 activation. Although PI-3K serves to potentiate various signaling events culminating in alpha(IIb)beta3 activation, PI-3K activity may be dispensable for Src-PLCgamma2 activation in GPIb-IX-V-mediated signaling. Glycosphingolipid-enriched microdomains (GEMs) appear to provide platforms for the signal transduction pathway related to GIb-IX-V, as the interaction between GPIb-IX-V and Src or PLCgamma2 tyrosine phosphorylation occurs exclusively in GEMs.
authors.affiliation: Department of Laboratory Medicine, University of Yamanashi, Nakakoma, Yamanashi, Japan. yozaki@yamanashi.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Ozaki
authors.forename: N
authors.initials: N
authors.lastname: Asazuma
authors.forename: K
authors.initials: K
authors.lastname: Suzuki-Inoue
authors.forename: M C
authors.initials: MC
authors.lastname: Berndt
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000737:chemistry; D001792:Blood Platelets / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D006028:Glycosphingolipids / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D021962:Membrane Microdomains / Q000737:chemistry; D008954:Models, Biological; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*; D017452:Receptors, IgG / Q000737:chemistry / Q000378:metabolism; D015398:Signal Transduction; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism
chemical_list: D015703:Antigens, CD; C080568:Fc gamma receptor IIA; D006028:Glycosphingolipids; D019038:Platelet Glycoprotein GPIb-IX Complex; D017452:Receptors, IgG; D014443:Tyrosine; D019869:Phosphatidylinositol 3-Kinases; D006152:Cyclic GMP; D002118:Calcium