Structure and function of the Arabidopsis ABC transporter ABCB19 in brassinosteroid export

• 成果类型: Article
• 署名作者: Ying, Wei; Wang, Yaowei; Wei, Hong; Luo, Yongming; Ma, Qian; Zhu, Heyuan; Janssens, Hilde; Vukasinovic, Nemanja; Kvasnica, Miroslav; Winne, Johan M.; Gao, Yongxiang; Tan, Shutang; Friml, Jiri; Liu, Xin; Russinova, Eugenia; Sun, Linfeng
• 署名单位: Chinese Academy of Sciences; University of Science & Technology of China, CAS; Ghent University; Flanders Institute for Biotechnology (VIB); Ghent University; Czech Academy of Sciences; Institute of Experimental Botany of the Czech Academy of Sciences; Institute of Science & Technology - Austria
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-11221
• DOI: 10.1126/science.adj4591
• 发表日期: 2024-03-22
• 关键词: auxin transport; p-glycoprotein; cryo-em; twisted dwarf1; kinase; interacts; efflux; root; expression; binding

摘要

Brassinosteroids are steroidal phytohormones that regulate plant development and physiology, including adaptation to environmental stresses. Brassinosteroids are synthesized in the cell interior but bind receptors at the cell surface, necessitating a yet to be identified export mechanism. Here, we show that a member of the ATP-binding cassette (ABC) transporter superfamily, ABCB19, functions as a brassinosteroid exporter. We present its structure in both the substrate-unbound and the brassinosteroid-bound states. Bioactive brassinosteroids are potent activators of ABCB19 ATP hydrolysis activity, and transport assays showed that ABCB19 transports brassinosteroids. In Arabidopsis thaliana, ABCB19 and its close homolog, ABCB1, positively regulate brassinosteroid responses. Our results uncover an elusive export mechanism for bioactive brassinosteroids that is tightly coordinated with brassinosteroid signaling.