# Structural dynamics of the plant hormone receptor ETR1 in a native‐like membrane environment

## TL;DR

This study reveals how the plant hormone receptor ETR1 moves and functions in a realistic membrane environment using advanced NMR techniques.

## Contribution

The study provides the first evidence of metal-triggered long-range allosteric signaling in a plant hormone receptor.

## Key findings

- ETR1 shows high internal dynamics with regions decoupled from the transmembrane domain.
- Cu(I) stabilizes ETR1 dynamics, suggesting a role in signal transmission.
- Nanodisc-based strategies enable high-resolution structural analysis of membrane proteins in plant signaling.

## Abstract

Ethylene (C2H4) regulates plant processes, such as germination, fruit ripening, and stress responses, impacting nutrition and food quality. The membrane‐bound receptor ETR1 from Arabidopsis thaliana is a model for ethylene signaling, but both full‐length and the soluble cytoplasmic domain have resisted crystallization. We present high‐resolution NMR spectra of full‐length ETR1 reconstituted in lipid nanodiscs, overcoming limitations and enhancing sample uniformity. ETR1 shows high internal dynamics with regions decoupled from the transmembrane domain, possibly explaining past crystallization failures and reflecting functional flexibility. Introduction of Cu(I), an essential cofactor for ethylene binding, stiffened receptor dynamics, suggesting a stabilizing role in signal transmission. This work demonstrates nanodisc‐based strategies as powerful tools for resolving membrane protein structures in plant signaling.

The present study unveils the structural and signaling dynamics of ETR1, a key plant ethylene receptor. Using an optimized nanodisc system and solution NMR, we captured full‐length ETR1 in a native‐like membrane environment. Our findings reveal dynamic domain uncoupling and Cu(I)‐induced rigidification, providing the first evidence of metal‐triggered long‐range allosteric signaling in a plant hormone receptor.