Phosphatidylinositol 4,5-bisphosphate and Arf6-regulated membrane traffic

Citation
Fd. Brown et al., Phosphatidylinositol 4,5-bisphosphate and Arf6-regulated membrane traffic, J CELL BIOL, 154(5), 2001, pp. 1007-1017
Citations number
47
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
0021-9525 → ACNP
Volume
154
Issue
5
Year of publication
2001
Pages
1007 - 1017
Database
ISI
SICI code
0021-9525(20010903)154:5<1007:P4AAMT>2.0.ZU;2-0
Abstract
ADP ribosylation factor (Arf) 6 regulates the movement of membrane between the plasma membrane (PM) and a nonclathrin-derived endosomal compartment an d activates phosphatidylinositol 4-phosphate 5-kinase (PIP 5-kinase), an en zyme that generates phosphatidylinositol 4,5-bisphosphate (PIP2). Here, we show that PIP2 visualized by expressing a fusion protein of the pleckstrin homology domain from PLC delta and green fluorescent protein (PH-GFP), colo calized with Arf6 at the PM and on tubular endosomal structures. Activation of Arf6 by expression of its exchange factor EFA6 stimulated protrusion fo rmation, the uptake of PM into macropinosomes enriched in PIP2, and recycli ng of this membrane back to the PM. By contrast, expression of Arf6 Q67L, a GTP hydrolysis-resistant mutant, induced the formation of PIP2 positive ac tin-coated vacuoles that were unable to recycle membrane back to the PM. PM proteins, such as beta1-integrin, plakoglobin, and major histocompatibilit y complex class I, that normally traffic through the Arf6 endosomal compart ment became trapped in this vacuolar compartment. Overexpression of human P IP 5-kinase a mimicked the effects seen with Arf6 Q67L. These results demon strate that PIP 5-kinase activity and PIP2 turnover controlled by activatio n and inactivation of Arf6 is critical for trafficking through the Arf6 PM- endosomal recycling pathway.