Regulation of G protein-coupled receptor trafficking.

G protein-coupled receptors (GPCRs) mediate cellular responses to diverse extracellular stimuli to play a vital role in the control of physiology and behaviour. GPCR trafficking is of fundamental importance for the regulation of GPCRs signaling. In this mini review, we will discuss some of the recent findings on the mechanisms that regulate GPCR trafficking, which include (i) large dense-core vesicle (LDCV)-associated GPCR delivery which could be a general cell biological mechanism for rapid modulation of membrane receptors in response to certain stimuli; (ii) lateral diffusion of GPCRs in the plasma membrane for rapid change of the number of neurotransmitter receptors during synaptic plasticity and (iii) constitutive internalization of GPCRs, that contributes to receptor resensitization and distribution, including axonal polarization.