Arf Proteins and Their Regulators: At the Interface Between Membrane Lipids and the Protein Trafficking Machinery - Ras Superfamily Small G Proteins: Biology and Mechanisms 2 - page 150

Table 8.1 Arf effectors
Effector Arf Location Arf interacting region

Coat complexes
COPI

Arf1 Golgi, ERGIC ʳ -COP ʲ -COP

Arfs 4, 5 Golgi, ERGIC ND

AP1/clathrin Arfs 1, 3 TGN, endosomes ʳ -AP-1, ʲ -AP-1

GGA1, 2, 3/clathrin Arfs 1, 3 TGN, endosomes GAT domain

AP3 Arfs 1, 3 Endosomes, TGN Endosomes, TGN

AP4 Arfs 1, 3 TGN ʵ -AP-4, -AP-4 (also binds

GDP-bound form)

ʼ

Lipid-modifying enzymes
FAPP1, FAPP2 Arf1 trans -Golgi PH domain

CERT Arf1 trans -Golgi PH domain

OSBP Arf1 trans -Golgi PH domain

PI 4 kinase Arf1 trans -Golgi trans -Golgi

PI4P-5 kinase Arfs1-6 PM (Arf6) PM (Arf6)

Phospholipase D Arfs1-6 PM (Arf6) PM (Arf6)

Tethers
GMAP-210 Arf1 cis -Golgi C-terminal GRAB domain

Golgin160 Arf1 Golgi N-terminus

Exocyst Arf6 PM Sec10

G protein regulators
ARHGAP21 Arf1, 6 Golgi, PM PH domain, C-terminal helix

Cytohesin/Arno Arf6, Arl4 PM PH domain

Scaffolding proteins
JIP3, JIP4

Arf6 Endosomes, intercellular

bridge

Leucine zipper domain (LZII)

FIP3, FIP4 Arfs 5, 6 Recycling endosomes,

midbody

CC

Nm23-H1 Arf6 PM, cell junctions ND

Arfaptin1, arfaptin2 Arf1 Golgi, TGN BAR domain

Cargo
Rhodopsin Arf4 TGN VxPx targeting motif
AP adaptor protein, BAR Bin/Amphiphysin/Rvs, CC coiled-coil, COP coatomer protein, ER
endoplasmic reticulum, ERGIC ER-Golgi intermediate compartment, GAT GGA (Golgi-localized,
ʳ -adaptin homologous, ADP-ribosylation factor-binding protein) and TOM1 homologous, GRAB

GRIP (golgin-97/RabBP2 /Imh1p/p230)-related Arf binding, PM plasma membrane, TGN trans -

Golgi network; ND, not determined

α

eukaryotic cells (Dacks and Field 2007 ). Intriguingly, the last eukaryotic common
ancestor (LECA) likely possessed only one Arf family member, in contrast to
having already nearly 20 Rab proteins (Koumandou et al. 2013 ). However, multiple
Arf GEFs and GAPs existed in this ancient eukaryotic ancestor, supporting the idea
that a key feature of Arf function is a single Arf protein participating in multiple
GEF and GAP regulatory complexes (Koumandou et al. 2013 ; Schlacht et al. 2013 ).
This feature is conserved in modern organisms, for example, in humans, which have
only 5 Arf proteins, yet at least 15 GEFs and 31 GAPs. Perhaps a clue as to the