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PI-3-kinase-dependent membrane recruitment of centaurin-α2 is essential for its effect on ARF6-mediated actin cytoskeleton reorganisation
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| Zeitschriftentitel: | Journal of Cell Science |
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| Personen und Körperschaften: | , , |
| In: | Journal of Cell Science, 120, 2007, 5, S. 792-801 |
| Format: | E-Article |
| Sprache: | Englisch |
| veröffentlicht: |
The Company of Biologists
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| Schlagwörter: |
| Zusammenfassung: | <jats:p>GTPase activating proteins (GAPs) of the centaurin family regulate the actin cytoskeleton and vesicle trafficking through inactivation of the ADP-ribosylation factor (ARF) family of small GTP-binding proteins. We report the functional characterisation of centaurin-α2, which is structurally related to the centaurin-α1 ARF6 GAP. centaurin-α2 contains an N-terminal GAP domain followed by two pleckstrin homology (PH) domains (N-PH and C-PH). In vitro, GFP-centaurin-α2 specifically binds the phosphatidylinositol (PI) 3-kinase lipid products, PI 3,4-P2 and PI 3,4,5-P3 (PIP3), through its C-terminal PH domain. In agreement with this observation, GFP-centaurin-α2 was recruited to the plasma membrane from the cytosol in EGF-stimulated cells in a PI-3-kinase-dependent manner. Moreover, the C-PH domain is sufficient and necessary for membrane recruitment of centaurin-α2. centaurin-α2 shows sustained kinetics of PI-3-kinase-mediated membrane recruitment in EGF-stimulated cells, owing to its binding to PI 3,4-P2. centaurin-α2 prevents ARF6 translocation to, and cortical actin formation at, the plasma membrane, which are phenotypic indications for ARF6 activation in EGF-stimulated cells. Moreover, the constitutively active mutant of ARF6 reverses the effect of centaurin-α2 on cortical actin formation. The membrane targeted centaurin-α2 is constitutively active. Together, these studies indicate that centaurin-α2 is recruited in a sustained manner to the plasma membrane through binding to PI 3,4-P2 and thereby regulates actin reorganisation via ARF6.</jats:p> |
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| Umfang: | 792-801 |
| ISSN: |
1477-9137
0021-9533 |
| DOI: | 10.1242/jcs.03373 |