Regulation of Post-Golgi Traffic of G Protein-Coupled Receptors - GPCR Signalling Complexes: Synthesis, Assembly, Trafficking and Specificity - page 80

Chapter 5
Regulation of Post-Golgi Traffic
of G Protein-Coupled Receptors

Guangyu Wu

Contents
5.1 Cell-Surface Transport of Nascent G Protein-Coupled Receptors (GPCRs).................. 84

5.2 Sorting Signals for Vesicle-Mediated Post-Golgi Transport........................................... 85

5.3 Regulation of Post-Golgi Traffic of GPCRs by Specific Motifs

and Possible Mechanisms............................................................................................... 86

5.3.1 The LL Motif and Its Interaction with Rab8 GTPase in Post-Golgi

Transport of b 2 -AR ............................................................................................. 86

5.3.2 The C-Terminal Tails and ARF1 GTPase in Post-Golgi

Transport of GPCRs ........................................................................................... 88

5.3.3 The VxPx Motif and Its Interaction with ARF4 GTPase in Post-Golgi

Transport of Rhodopsin...................................................................................... 88

5.3.4 The Acidic Motifs and Their Interaction with the p24 Family

Proteins in the Post-Golgi Transport of GPCRs................................................. 89

5.3.5 The YS Motif in Post-Golgi Traffic of a 2 -AR ................................................... 90

5.4 Concluding Remarks....................................................................................................... 91

References ................................................................................................................................ 91

Abstract Anterograde trafficking of newly synthesized G protein-coupled receptors
(GPCRs) from the endoplasmic reticulum to the cell surface represents a crucial
checkpoint in controlling the amount of the functional receptors at the cell surface
and the strength of signaling initiated by the receptors. In contrast to the extensively
studied, well-understood endocytic and recycling pathways, the molecular mecha-
nisms underlying the cell-surface targeting of the receptors remain poorly defined.
In this chapter, I will discuss current advances in understanding post-Golgi transport
of GPCRs by focusing on specific motifs or sequences that may function as sorting
signals regulating export from the Golgi and subsequent transport to the plasma
membrane of GPCRs.