| Autor: |
A, Schootemeijer, G, van Willigen, H, van der Vuurst, L G, Tertoolen, S W, De Laat, J W, Akkerman |
| Rok vydání: |
1997 |
| Předmět: |
|
| Zdroj: |
Thrombosis and haemostasis. 77(1) |
| ISSN: |
0340-6245 |
| Popis: |
The migration of integrins to sites of cell-cell and cell-matrix contact is thought to be important for adhesion strengthening. We studied the lateral diffusion of integrin alpha IIb beta 3 (glycoprotein IIb/IIIa) in the plasma membrane of a cultured human megakaryocyte by fluorescence recovery after photobleaching of FITC-labelled monovalent Fab fragments directed against the beta 3 subunit. The diffusion of beta 3 on the unstimulated megakaryocyte showed a lateral diffusion coefficient (D) of 0.37 x 10(-9) cm2/s and a mobile fraction of about 50%. Stimulation with ADP (20 microM) or alpha-thrombin (10 U/ml) at 22 degrees C induced transient decreases in both parameters reducing D to 0.21 x 10(-9) cm2/s and the mobile fraction to about 25%. The fall in D was observed within 1 min after stimulation but the fall in mobile fraction showed a lag phase of 5 min. The lag phase was absent in the presence of Calpain I inhibitor, where-as cytochalasin D completely abolished the decreased in mobile fraction. The data are compatible with the concept that cell activation induces anchorage of 50% of the mobile alpha IIb beta 3 (25% of the whole population of receptor) to the cytoplasmic actin filaments, although, as discussed, other rationals are not ruled out. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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