Evidence for two functionally different fibrinogen receptors on hemopoietic cells: The glycoprotein IIb–IIIa and the mitogenic fibrinogen receptor
✍ Scribed by Jean-Pierre Levesque; Antoinette Hatzfeld; Gilbert Hudry-Clergeon; George D. Wilner; Jacques Hatzfeld
- Publisher
- John Wiley and Sons
- Year
- 1987
- Tongue
- English
- Volume
- 132
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
We have previously established that the mitogenic effect of fibrinogen on hemopoietic cell lines Raji and JM is mediated via a specific receptor (Levesque, J.-P. et al.: Proc. Natl. Acad. Sci. USA 83:6494-6498, 1986). In this study, we have further characterized the fibrinogen domain involved in the binding to the mitogenic receptor. This binding was not inhibited either by a monoclonal antibody against the C-terminal sequence of the fibrinogen gamma chains or by synthetic peptides containing the Arg-Gly-Asp sequence. Such inhibition is specific of the platelet fibrinogen receptor, the glycoprotein IIb-IIIa complex. Fragments containing the fibrinogen D domain were the only plasmin degradation products of fibrinogen which were mitogenic. These fragments acted via direct binding on the mitogenic receptor with a Kd of 2.24 X 10(-6) M. This value was similar to the KI value of unlabeled fragments D (2.47 X 10(-6) M). Our results suggest the presence of two different functional types of fibrinogen receptors: the glycoprotein IIb-IIIa receptor responsible both for platelet aggregation and leukocyte adhesion and killing, and the mitogenic receptor involved in proliferation control of hemopoietic cells.