Abstract
We report the novel observation that engagement of beta 2 integrins on human neutrophils is accompanied by increased levels of the small GTPases Rap1 and Rap2 in a membrane-enriched fraction and a concomitant decrease of these proteins in a granule-enriched fraction. In parallel, we observed a similar time-dependent decrease of gelatinase B (a marker of specific and gelatinase B-containing granules) but not myeloperoxidase (a marker of azurophil granules) in the granule fraction, and release of lactoferrin (a marker of specific granules) in the extracellular medium. Furthermore, inhibition of Src tyrosine kinases, or phosphoinositide 3-kinase with PP1 or LY294002, respectively, blocked 02 integrin-induced degranulation and the redistribution of Rap1 and Rap2 to a membrane-enriched fraction. Consequently, the 02 integrin-dependent exocytosis of specific and gelatinase B-containing granules occurs via a Src tyrosine kinase/phosphoinositide 3-kinase signaling pathway and is responsible for the translocation of Rap1 and Rap2 to the plasma membrane in human neutrophils. (C) 2008 Elsevier Inc. All rights reserved.
Original language | English |
---|---|
Pages (from-to) | 642-646 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 376 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2008 |
Subject classification (UKÄ)
- Biological Sciences
Free keywords
- Signal transduction
- beta 2 Integrins
- Human neutrophils
- Degranulation
- Rap GTPases