Biology Reference
In-Depth Information
10
Regulation and Function of the
Small GTP-binding Protein ARF6
in Membrane Dynamics
Thierry Dubois, Emma Colucci-Guyon,
Florence Niedergang, Magali Prigent
and
Philippe Chavrier
ADP-ribosylation factor 6 (ARF6) is the most divergent member of the ARF
subgroup of Ras-related small GTP-binding proteins. ARF6 activation, i.e.,
GTP-loading, occurs at the plasma membrane and is catalysed by Sec7
domain-containing guanine nucleotide exchange factors belonging to the
EFA6 and ARNO families. In its active GTP-bound state, ARF6 regulates
internalization of membrane components via the endocytic pathway and
controls membrane recycling to regions of plasma membrane and cortical
actin cytoskeleton remodelling. Recently, several partners of GTP-bound
ARF6 have been identified that mediate ARF6 function in plasma membrane
organization.
ADP-ribosylation factors (ARFs) form a group of six, small (20-kDa) GTP-
binding proteins related to Ras. ARF1 is localized to the Golgi complex
where it regulates the recruitment of coat proteins during the formation of
transport vesicles (Chavrier and Goud, 1999). Available information
regarding ARF3 and ARF5, although limited, points toward a similar role
for these proteins in maintaining the secretory pathway (Moss and Vaughan,
