G-protein-coupled receptors（GPCRs） are G-protein-coupled heptaspanning-membrane receptors.This group has thousands of members and is one of the important drug targets,accounting for 40%-50%of the drugs currently on the market.In the last decade,there has been a substantial re-evaluation of the assumption that GPCRs exist primarily as monomeric polypeptides, with support increasing for a model in which GPCRs can exist as homo- or hetero- dimers or even high-order oligomers.GPCRs dimers are hot research topics.Recent reports suggest that homo- or hetero- dimers exhibit ＂specific＂ functional properties which are distinct from monomeric receptors,involving agonist recognition,signaling,trafficking,and so on.Meanwhile,the occurrence of dimers with different pharmacological and signaling properties opens a completely new field in the search for novel drug targets useful to combat a variety of diseases and with potentially fewer side effects.In this paper,we will mainly review their specific structures and signal transduction,which help us reach for the high-hanging fruits in GPCRs drug discovery.
