Abstract
HEK293 cells expressing wild-type CXCR2 recruit PH-Akt-GFP to the leading edge of the cell in response to chemokine. However, in cells expressing mutant CXCR2 defective in AP-2 and HIP binding, i.e. with a mutation in the LLKIL motif, PH-Akt-GFP does not localize to the leading edge in response to ligand. Inhibition of Akt/PKB by transfection of HEK 293 cells with a dominant negative (kinase defective) Akt/PKB inhibits CXCR2 mediated chemotaxis. FRET analysis reveals that membrane-bound activated Cdc42 and Rac1 localize to the leading edge of cells expressing wild-type CXCR2 receptor, but not in cells expressing mutant CXCR2. By contrast, when the activation of Cdc42 and Rac1 are monitored by affinity precipitation assay, cells expressing either wild-type or LLKIL mutant receptors show equivalent ligand induction. Altogether, these data suggest that restricted localized activation of Akt/PKB, Rac1 and Cdc42 is crucial for chemotactic responses and that events mediated by the LLKIL motif are crucial for chemotaxis.
Original language | English (US) |
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Pages (from-to) | 5489-5496 |
Number of pages | 8 |
Journal | Journal of Cell Science |
Volume | 117 |
Issue number | 23 |
DOIs | |
State | Published - Nov 1 2004 |
Externally published | Yes |
Keywords
- AP-2
- CXCR2
- Chemotaxis
- FRET
- Internalization
- PH-Akt-GFP
ASJC Scopus subject areas
- Cell Biology