A conserved juxtamembrane motif in plant NFR5 receptors is essential for root nodule symbiosis

• 成果类型: Article
• 署名作者: Hansen, Simon Boje; Luu, Thi Bich; Gysel, Kira; Lironi, Damiano; Jensen, Ingeborg Bitsch; Tsitsikli, Magdalini; Birkefeldt, Thea Gramkov; Trgovcevic, Alen; Stougaard, Jens; Radutoiu, Simona; Andersena, Kasper Rojkjaer
• 署名单位: Aarhus University; University of Freiburg
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10416
• DOI: 10.1073/pnas.2405671121
• 发表日期: 2024-11-12
• 关键词: structural basis; innate immunity; protein-kinase; activation; signal; bak1; complex; phosphorylation; perception; regulator

摘要

Establishment of root nodule symbiosis is initiated by the perception of bacterial Nod factor ligands by the plant LysM receptor kinases NFR1 and NFR5. Receptor signaling initiating the symbiotic pathway depends on the kinase activity of NFR1, while the signaling mechanism of the catalytically inactive NFR5 pseudokinase is unknown. Here, we present the crystal structure of the signaling- competent Lotus japonicus NFR5 intracellular domain, comprising the juxtamembrane region and pseudokinase domain. The juxtamembrane region is structurally well defined and forms two alpha- helices, alpha A and alpha A ', which contain an exposed hydrophobic motif. We demonstrate that this juxtamembrane motif promotes NFR5-NFR5 and NFR1-NFR5 interactions and is essential for symbiotic signaling. Conservation analysis reveals that the juxtamembrane motif is present throughout NFR5- type receptors and is required for symbiosis signaling from barley RLK10, suggesting a conserved and broader function for this motif in plant-microbe symbioses.