This article describes a study using time-resolved cryo-electron microscopy to visualize the dynamic signaling processes of the human neurotensin receptor type 1 (NTSR1). The researchers captured the receptor in complex with various G-protein subtypes, revealing how the intracellular surface of the receptor reshapes itself to accommodate different partners. By analyzing over 20 intermediate states, the authors identified a non-canonical (NC) coupling state that allows for faster G-protein dissociation compared to the standard canonical orientation. The study further details the structural transitions triggered by GDP and GTP, including the specific movement of the α5 helix and the closure of the α-helical domain. Ultimately, these findings provide a comprehensive structural framework for understanding GPCR signaling promiscuity and the mechanics of G-protein activation.

References:

• Kobayashi K, Kawakami K, Matsui T E, et al. The dynamic basis of G-protein recognition and activation by a GPCR[J]. Nature, 2026: 1-10.