Download MendeleyStructural insights into brassinosteroid export mediated by the Arabidopsis ABC transporter ABCB1.
Wei, H., Zhu, H., Ying, W., Janssens, H., Kvasnica, M., Winne, J.M., Gao, Y., Friml, J., Ma, Q., Tan, S., Liu, X., Russinova, E., Sun, L.(2025) Plant Commun 6: 101181-101181
- PubMed: 39497419
- DOI: https://doi.org/10.1016/j.xplc.2024.101181
- Primary Citation of Related Structures:
8ZPX, 8ZPZ, 8ZQ4 - PubMed Abstract:
Brassinosteroids (BRs) are steroidal phytohormones indispensable for plant growth, development, and responses to environmental stresses. The export of bioactive BRs to the apoplast is essential for BR signaling initiation, which requires binding of a BR molecule to the extracellular domains of the plasma membrane-localized receptor complex. We have previously shown that the Arabidopsis thaliana ATP-binding cassette (ABC) transporter ABCB19 functions as a BR exporter and, together with its close homolog ABCB1, positively regulates BR signaling. Here, we demonstrate that ABCB1 is another BR transporter. The ATP hydrolysis activity of ABCB1 can be stimulated by bioactive BRs, and its transport activity was confirmed in proteoliposomes and protoplasts. Structures of ABCB1 were determined in substrate-unbound (apo), brassinolide (BL)-bound, and ATP plus BL-bound states. In the BL-bound structure, BL is bound to the hydrophobic cavity formed by the transmembrane domain and triggers local conformational changes. Together, our data provide additional insights into ABC transporter-mediated BR export.
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Physical Sciences at the Microscale, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.
Organizational Affiliation:
