Subcellular Organization of GPCR Signaling

Area of Science:

• Cellular Biology
• Molecular Pharmacology
• Signal Transduction

Background:

• G protein-coupled receptors (GPCRs) are crucial signal transducers involved in diverse physiological processes.
• GPCRs exhibit dynamic and isoform-specific membrane trafficking, influencing their signaling potential.
• Subcellular localization of GPCRs impacts their ability to initiate or regulate cellular signaling pathways.

Purpose of the Study:

• To review emerging insights into the subcellular organization of GPCR function in mammalian cells.
• To focus on signaling mediated by heterotrimeric G proteins and β-arrestins.
• To highlight GPCR signaling from multiple membrane compartments beyond the plasma membrane.

Main Methods:

• Review of recent scientific literature and evidence.
• Focus on studies investigating GPCR localization and signaling.
• Analysis of G protein and β-arrestin-mediated signaling pathways.

Main Results:

• GPCR-mediated G protein activation occurs not only at the plasma membrane (PM) but also at endosomes and Golgi membranes.
• β-arrestin-dependent signaling can be initiated from the PM.
• β-arrestin trafficking to clathrin-coated pits (CCPs) mediates PM signaling after GPCR activation and ligand dissociation.

Conclusions:

• GPCR signaling is spatially organized and occurs from multiple intracellular membrane locations.
• The subcellular location of GPCRs dictates the specific signaling outcomes mediated by G proteins and β-arrestins.
• Understanding GPCR trafficking and localization is critical for comprehending their diverse cellular functions.