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

ABSTRACT: ADP-ribosylation factor (Arf) 6 regulates the movement of membrane between the plasma membrane (PM) and a nonclathrin-derived endosomal compartment and activates phosphatidylinositol 4-phosphate 5-kinase (PIP 5-kinase), an enzyme that generates phosphatidylinositol 4,5-bisphosphate (PIP2). Here, we show that PIP2 visualized by expressing a fusion protein of the pleckstrin homology domain from PLCdelta and green fluorescent protein (PH-GFP), colocalized with Arf6 at the PM and on tubular endosomal structures. Activation of Arf6 by expression of its exchange factor EFA6 stimulated protrusion formation, the uptake of PM into macropinosomes enriched in PIP2, and recycling of this membrane back to the PM. By contrast, expression of Arf6 Q67L, a GTP hydrolysis-resistant mutant, induced the forma

SUBMITTER: Brown FD 

PROVIDER: S-EPMC2196179 | biostudies-literature | 2001 Sep

REPOSITORIES: biostudies-literature