Decoding the structural basis of ligand recognition and biased signaling in the motilin receptor.

IF 7.5 1区生物学 Q1 CELL BIOLOGY

Cell reports Pub Date : 2025-03-25 Epub Date: 2025-02-22 DOI:10.1016/j.celrep.2025.115329

Chongzhao You, Mengting Jiang, Tianyu Gao, Zining Zhu, Xinheng He, Youwei Xu, Yuan Gao, Yi Jiang, H Eric Xu

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引用次数: 0

Abstract

The motilin receptor (MTLR) is a key target for treating gastrointestinal (GI) disorders like gastroparesis, yet developing effective agonists remains challenging due to drug tolerance and signaling bias. We present cryoelectron microscopy (cryo-EM) structures of MTLR bound to azithromycin, a macrolide antibiotic, and DS-3801b, a non-macrolide agonist. Distinct ligand recognition mechanisms are revealed, with azithromycin binding deeply within the orthosteric pocket and DS-3801b adopting a special clamp-like conformation stabilized by a water molecule. We also highlight the critical role of extracellular loop 2 (ECL2) in ligand specificity and signaling pathway activation, affecting both G-protein and β-arrestin signaling. Additionally, the "D^2.60R^2.63S^3.28" motif and interactions around transmembranes 6/7 (TM6/7) are identified as key drivers of signaling selectivity. These findings offer insights into the structural dynamics of MTLR, laying the groundwork for the rational design of next-generation GI prokinetic drugs with enhanced efficacy and safety.

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来源期刊

Cell reports CELL BIOLOGY-

CiteScore

13.80

自引率

1.10%

发文量

1305

审稿时长

77 days

期刊介绍： Cell Reports publishes high-quality research across the life sciences and focuses on new biological insight as its primary criterion for publication. The journal offers three primary article types: Reports, which are shorter single-point articles, research articles, which are longer and provide deeper mechanistic insights, and resources, which highlight significant technical advances or major informational datasets that contribute to biological advances. Reviews covering recent literature in emerging and active fields are also accepted. The Cell Reports Portfolio includes gold open-access journals that cover life, medical, and physical sciences, and its mission is to make cutting-edge research and methodologies available to a wide readership. The journal's professional in-house editors work closely with authors, reviewers, and the scientific advisory board, which consists of current and future leaders in their respective fields. The advisory board guides the scope, content, and quality of the journal, but editorial decisions are independently made by the in-house scientific editors of Cell Reports.