| Autor: |
A E Butler-Zimrin, R A Heidenreich, Saul Surrey, Elias Schwartz, Robin Eisman, Joel S. Bennett, Mortimer Poncz, Gaston Vilaire |
| Rok vydání: |
1987 |
| Předmět: |
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| Zdroj: |
XIth International Congress on Thrombosis and Haemostasis. |
| ISSN: |
2567-689X |
| DOI: |
10.1055/s-0038-1643961 |
| Popis: |
The platelet membrane GPIIb/GPIIIa complex on activated platelets contains receptors for fibrinogen, von Willebrand factor, and fibronectin. GPIIb and GPIlia also appear to be members of a family of membrane receptors involved in cell-cell and cell-matrix interactions. To study the structure of GPIIb and GPIIIa, we have constructed an expression library in the vector lambda gtll using mRNA from the HEL cell line and screened it with polyclonal antibody against each platelet protein. HEL cells constitutively express proteins similar to platelet GPIIb and GPIIIa. A 3.2kb GPIIb cDNA clone was identified that encodes for all 1008 amino acids of GPIIb including the known N-terminal amino acids of the α Cand βsubunits. This confirms that GPIIb is synthesized as a single chain polypeptide that is cleaved into two disulfide-linked subunits posttranslation. Analysis of the amino acid sequence revealed a major C-terminal transmembrane domain in the βsubunit, two potential transmembrane domains near the N-terminus of the αsubunit, and four possible N-linked glycosylation sites. Approximately 30% amino acid identity was found between GPIIb and the available amino acid sequences for the larger chains of the fibronectin and vitronectin receptors. Initial sequence analysis of a 3.8kb cDNA for GPIIIa included the known N-terminal amino acids of the platelet protein. Northern blot analysis was performed using HEL cell total RNA. The GPIIb cDNA hybridized to a 4.1kb mRNA while the GPIIIa cDNA hybridized to a 5.8kb mRNA. This indicates that the two cDNAs do not cross-hybridize and suggests that GPIIb and GPIIIa are encoded by separate genes. The availability of these cDNA for GPIIb and GPIIIa will facilitate study of the structure and function of the proteins and will aid in clarifying their relationship to other adhesive protein receptors. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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