Small GTPase regulation of GPCR anterograde trafficking

Regulation of post-Golgi traffic of G protein-coupled receptors

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 mechanisms 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.

Regulated GPCR trafficking to the plasma membrane: general issues and the CCR5 chemokine receptor example

The regulated export of nascent G protein coupled receptors (GPCRs) from intracellular stores is an emerging concept with important implications in cell biology and pharmacology. This phenomenon requires a complex network of interactions between GPCRs with either chaperones and escort proteins or gatekeepers, which are respectively involved in the progression of GPCRs along the biosynthetic pathway to the plasma membrane or in their retention in intracellular compartments. The regulated export of GPCRs is also controlled by external stimuli and might represent an adaptive mechanism to specific physiological constraints, such as the sustained activation of the CCR5 chemokine receptor in the context of chemotaxis.