ABSTRACT
G-protein coupled receptors (GPCRs) can form biologically relevant dimers and oligomers, which are important to regulate receptor function. They have specific signal transduction pathways, thus mediating a series of physiological and pathological processes, such as cardiovascular regulation, energy metabolism, etc. GPCR dimers become one of the new drug targets, attracting increasing attention. Traditionally, the research on GPCR dimers have been performed on a population " ensemble average" level. However, the main problem is that there may be valuable information hidden in this " noise". Single molecule technology has unprecedented spatial and temporal resolution, which can directly display the internal state, trajectory of GPCR dimers and the changes with time and surrounding environment. It helps to further analyze the key role and drug targets of GPCR dimers. Here, we review single-molecule techniques (such as total internal reflection fluorescence microscopy, stimulated emis-sion loss microscopy and ground state depletion microscopy, etc.) that have been applied to GPCR dimers.