What do ARF proteins do?

The ADP-ribosylation factor (ARF) small GTPases regulate vesicular traffic and organelle structure by recruiting coat proteins, regulating phospholipid metabolism and modulating the structure of actin at membrane surfaces.

What proteins are responsible for activating ARF?

The five ARF proteins in humans, ARF1, ARF3, ARF4, ARF5, and ARF6, are ubiquitously expressed. Studies to date have focused mainly on ARF1 at the Golgi and ARF6 at the plasma membrane, but ARF3, ARF4 and ARF5 are also present on Golgi membranes (Fig.

What does ARF 1 do?

ARF6 primarily engages in the regulation of endocytic trafficking and cytoskeleton remodeling, whereas ARF1 recruits different sets of coat proteins to form distinct transport vesicles that control protein transport at different intracellular organelles (Palacios, Price, Schweitzer, Collard, & D’Souza-Schorey, 2001; …

What is ARF in cells?

ADP-ribosylation factor (Arf) GTPases are a subfamily of the Ras superfamily of small GTPases. Arf proteins perform diverse and critical functions in fundamental cellular processes like membrane trafficking, lipid modification, cytokinesis and cell adhesion.

What are the roles of ARF like proteins?

Members of the ADP-ribosylation factor (ARF) family of guanine-nucleotide-binding (G) proteins, including the ARF-like (ARL) proteins and SAR1, regulate membrane traffic and organelle structure by recruiting cargo-sorting coat proteins, modulating membrane lipid composition, and interacting with regulators of other G proteins.

How does ARF1 play a role in membrane traffic?

ARF1 also regulates the formation of clathrin-coated vesicles at the trans -Golgi network by promoting the recruitment of adaptor-protein complexes AP-1, AP-3, AP-4, and the GGAs from the cytosol onto membranes. ARF1 activation has been shown to stimulate the assembly of spectrin and the actin cytoskeleton on Golgi membranes.

What does ARF1 do in the Golgi membrane?

ARF1 activation has been shown to stimulate the assembly of spectrin and the actin cytoskeleton on Golgi membranes. Nucleotide exchange on ARF is regulated by the Sec7-domain-containing GEFs.

How does GTP affect the targeting of ARF1?

Membrane lipid composition and temporal aspects of vesicle budding can affect the targeting of ARF1 to Golgi membranes. GTP hydrolysis on ARF1 is required for the dissociation of coat proteins from transport vesicles, and is mediated by a family of ARF GAPs.