True Arrestins and Arrestin-Fold Proteins: A Structure-Based Appraisal - Progress in Molecular Biology and Translational Science - page 18

and RGP1 isoforms as well as arrestin-related trafficking adaptors or ADCs, but true
arrestins are missing. Functionally, members of the arrestin clan have generally a scaf-
folding role in various membrane protein trafficking events. Despite their similar struc-
ture, the mechanism of cargo recognition and internalization and the nature of
recruited partners differ for the different members. Based on the recent literature, true
arrestins (visual and b-arrestins), ARRDCs, and yeast ARTS are the closest from a func-
tional point of view.
ABBREVIATIONS
7TM seven-transmembrane spanning
ADC amoebal arrestin domain-containing protein
ARRDC arrestin domain-containing protein
ART arrestin-related trafficking adaptor
BAR Bin/amphyphisin/rvs
CI-MPR cation-independent mannose-6-phosphate receptor
DSCR3 Down syndrome critical region gene 3
ESCRT endosomal sorting complex required for transport
GARP Golgi-associated retrograde protein
GEF guanylate nucleotide exchange factor
GPCR G-protein-coupled receptor
GRK G-protein-coupled receptor kinase
InsP 6 nositol hexakisphosphate
PM plasma membrane
RGP1 retrograde Golgi transport protein
SNX sorting nexin
TGN trans-Golgi network
TXNIP thioredoxin-interacting protein
VDUP vitamin D3-upregulated protein
VPS vacuolar protein sorting
1. INTRODUCTION
Visual/ b -arrestins are scaffolding proteins regulatingG-protein-coupled
receptor (GPCR)-dependent signaling. They are folded almost exclusively
as 20 b -strands plus a single a -helix organized as pseudosymmetrical N- and
C-domains. 1-8
Recently, other proteins involved in trafficking and distantly related to
arrestins on the basis of their sequence (about 10% identity) have been
modeled (arrestin domain-containing proteins (ARRDCs), arrestin-related
trafficking adaptors (ARTs), DSCR3) 9,10 or crystallized (vacuolar protein