Abstract
The small GTP-binding protein ADP-ribosylation factor 6 (Arf6) is involved in plasma membrane/endosomes trafficking. However, precisely how the activation of Arf6 regulates vesicular transport is still unclear. Here, we show that, in vitro, recombinant Arf6GTP recruits purified clathrin-adaptor complex AP-2 (but not AP-1) onto phospholipid liposomes in the absence of phosphoinositides. We also show that phosphoinositides and Arf6 tightly cooperate to translocate AP-2 to the membrane. In vivo, Arf6GTP (but not Arf6GDP) was found associated to AP-2. The expression of the GTP-locked mutant of Arf6 leads to the plasma membrane redistribution of AP-2 in Arf6GTP-enriched areas. Finally, we demonstrated that the expression of the GTP-locked mutant of Arf6 inhibits transferrin receptor internalization without affecting its recycling. Altogether, our results demonstrated that Arf6GTP interacts specifically with AP-2 and promotes its membrane recruitment. These findings strongly suggest that Arf6 plays a major role in clathrin-mediated endocytosis by directly controlling the assembly of the AP-2/clathrin coat.
Highlights
The ADP-ribosylation factor (Arf)1 family, which includes six isoforms, regulates vesicular trafficking [1]
We show that phosphoinositides and ADP-ribosylation factor 6 (Arf6) tightly cooperate to translocate AP-2 to the membrane
MyrArf6GTP Recruits the AP-2 Complex onto Phospholipid Liposomes—By analogy with Arf1, which interacts with AP-1, -3, and -4, we studied the possibility that Arf6 recruits AP-2 to the lipid membrane
Summary
The ADP-ribosylation factor (Arf)1 family, which includes six isoforms, regulates vesicular trafficking [1]. The small GTP-binding protein ADP-ribosylation factor 6 (Arf6) is involved in plasma membrane/endosomes trafficking. The expression of the GTP-locked mutant of Arf6 leads to the plasma membrane redistribution of AP-2 in Arf6GTP-enriched areas.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have