Regulation of G-protein-coupled receptor activity by Rab GTPases

The regulation of G-protein-coupled receptor (GPCR) activity involves a diversity of vesicular transport processes. Receptor desensitization and resensitization are intimately connected with membrane trafficking events such as endocytosis, intracellular sorting, transport to lysosomes, and recycling to the plasma membrane. Ras-related GTPases of the rab family are known to regulate these processes, including a subset of rab proteins that are specific for endosomes and lysosomes. While much study has been given to endocytic rabs using standard models such as transferrin receptors, less is known about how rabs regulate signal-transducing receptors. This article reviews recent work concerning rab GTPases and their regulation of GPCR activity via membrane transport mechanisms.