Cryo-EM structure of the rhodopsin-G alpha i-beta gamma complex reveals binding of the rhodopsin C-terminal tail to the g beta subunit

Autor: Tsai, Ching-Ju, Marino, Jacopo, Adaixo, Ricardo, Pamulal, Filip, Muehle, Jonas, Maeda, Shoji, Flock, Tilman, Taylorn, Nicholas M. I., Mohammed, Inayatulla, Matile, Hugues, Dawson, Roger J. P., Deupi, Xavier, Stahlberg, Henning, Schertler, Gebhard
Popis: One of the largest membrane protein families in eukaryotes are G protein-coupled receptors (GPCRs). GPCRs modulate cell physiology by activating diverse intracellular transducers, prominently heterotrimeric G proteins. The recent surge in structural data has expanded our understanding of GPCR-mediated signal transduction. However, many aspects, including the existence of transient interactions, remain elusive. We present the cryo-EM structure of the light-sensitive GPCR rhodopsin in complex with heterotrimeric Gi. Our density map reveals the receptor C-terminal tail bound to the G beta subunit of the G protein, providing a structural foundation for the role of the C-terminal tail in GPCR signaling, and of G beta as scaffold for recruiting G alpha subunits and G protein-receptor kinases. By comparing available complexes, we found a small set of common anchoring points that are G protein-subtype specific. Taken together, our structure and analysis provide new structural basis for the molecular events of the GPCR signaling pathway.
Databáze: OpenAIRE