Research summary

Techniques:

(1) Using co-immunoprecipitation, various adaptations of fluorescent resonance energy transfer (FRET and BRET), proximity ligation assay (PLA) techniques to identify GPCR homodimers and heterodimer 

(2) GPCR monomer-homodimer-oligomer interconversion by monitoring receptor dynamically on cells using total internal reflection fluorescence microscopy, resonance energy transfer, and proximity biotinylation.

(3) Identification of phosphorylation sites on GPCR by mass spectrometry.

(4) Using interference peptides and MALDI-TOF mass spectrometry to confirm GPCR homodimers and heterodimers, and explore the dimer interfaces.

(5) The XCELLigence RTCA system to measure migration, invasion and proliferation.

Selected publications:

• 1, Bai B, Chen X, Zhang R, Wang X, Jiang Y, Li D, Wang Z, Chen J. Dual-agonist occupancy of orexin receptor 1 and cholecystokinin A receptor heterodimers decreases G-protein-dependent signaling and migration in the human colon cancer cell line HT-29. Biochim Biophys Acta Molecular Cell Research. 2017 Jul;1864(7):1153-1164.

• 2, Cai X, Bai B, Zhang R, Wang C, Chen J. Apelin receptor homodimer-oligomers revealed by single-molecule imaging and novel G protein-dependent signaling. Sci Rep. 2017 Jan 16;7:40335. doi: 10.1038/srep40335. 

• 3, Chen J, Zhang R, Chen X, Wang C, Cai X, Liu H, Jiang Y, Liu C, Bai B. Heterodimerization of human orexin receptor 1 and kappa opioid receptor promotes protein kinase A/cAMP-response element binding protein signaling via a Gαs-mediated mechanism. Cell Signal. 2015 Jul;27(7):1426-38. 

• 4, Chen X, Bai B, Tian Y, Du H, Chen J. Identification of serine 348 on the apelin receptor as a novel regulatory phosphorylation site in apelin-13-induced G protein-independent biased signaling. J Biol Chem. 2014 Nov 7;289(45):31173-87.