Biosynthesis and processing of platelet GPIIb-IIIa in human megakaryocytes

Biosynthesis and Processing of Platelet GPIIb-IIIa in Human Megal ryocytes

Platelet membrane glycoprotein IIb-IIIa forms a calcium-dependent heterodimer and constitutes the fibrinogen receptor on stimulated platelets. GPIIb is a two-chain protein containing disulfide-linked ~t and 13 subunits. GPIIIa is a single chain protein. These proteins are synthesized in the bone marrow by megakaryocytes, but the study of their synthesis has been hampered by the difficulty in ob...

Density of Platelet GPIIb-IIIa and Bleeding Severity in Iranian Patients with Glanzmann’s Thrombasthenia

Biosynthesis and assembly of platelet GPIIb-IIIa in human megakaryocytes: evidence that assembly between pro-GPIIb and GPIIIa is a prerequisite for expression of the complex on the cell surface.

The platelet membrane glycoproteins GPIIb and GPIIIa form a calcium-dependent heterodimer that functions as a receptor for adhesive proteins on stimulated platelets. In this study, we have investigated the kinetics of the assembly reaction that result in GPIIb-IIIa dimerization. Pulse-chase experiments analysis performed on human megakaryocytes obtained from liquid cultures of chronic myelogeno...

Quantitation of human in vitro megakaryocytopoiesis by radioimmunoassay.

The isolation and characterization of human megakaryocyte growth factors has been hampered because evaluation of megakaryocyte growth in semisolid medium requires both lengthy incubation and visual quantitation. In addition, colony formation requires cell division, while most regulation of platelet production may involve individual, nonproliferating differentiating megakaryocytes. We have devel...

Flow cytometric analysis of normal human megakaryocytes.

Megakaryocytes from normal routine human bone marrow aspirates were analyzed by flow cytometry for size, fine cell structure and granularity, membrane expression of glycoprotein (GP) IIb/IIIa and ploidy. Marrow cells were initially enriched for megakaryocytes by a Percoll density gradient and megakaryocytes were labeled with a fluoresceinated monoclonal antibody directed to the GPIIb/IIIa compl...