Structure of an endosomal signaling GPCR-G protein-beta-arrestin megacomplex.Nguyen, A.H., Thomsen, A.R.B., Cahill 3rd, T.J., Huang, R., Huang, L.Y., Marcink, T., Clarke, O.B., Heissel, S., Masoudi, A., Ben-Hail, D., Samaan, F., Dandey, V.P., Tan, Y.Z., Hong, C., Mahoney, J.P., Triest, S., Little 4th, J., Chen, X., Sunahara, R., Steyaert, J., Molina, H., Yu, Z., des Georges, A., Lefkowitz, R.J.
(2019) Nat Struct Mol Biol 26: 1123-1131
- PubMed: 31740855
- DOI: 10.1038/s41594-019-0330-y
- Structures With Same Primary Citation
- PubMed Abstract:
Classically, G-protein-coupled receptors (GPCRs) are thought to activate G protein from the plasma membrane and are subsequently desensitized by β-arrestin (β-arr). However, some GPCRs continue to signal through G protein from internalized compartmen ...
Classically, G-protein-coupled receptors (GPCRs) are thought to activate G protein from the plasma membrane and are subsequently desensitized by β-arrestin (β-arr). However, some GPCRs continue to signal through G protein from internalized compartments, mediated by a GPCR-G protein-β-arr 'megaplex'. Nevertheless, the molecular architecture of the megaplex remains unknown. Here, we present its cryo-electron microscopy structure, which shows simultaneous engagement of human G protein and bovine β-arr to the core and phosphorylated tail, respectively, of a single active human chimeric β 2 -adrenergic receptor with the C-terminal tail of the arginine vasopressin type 2 receptor (β 2 V 2 R). All three components adopt their canonical active conformations, suggesting that a single megaplex GPCR is capable of simultaneously activating G protein and β-arr. Our findings provide a structural basis for GPCR-mediated sustained internalized G protein signaling.
Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC, USA. firstname.lastname@example.org.