article published yes Wei Ying author Yaowei Wang author Hong Wei author Yongming Luo author Qian Ma author Heyuan Zhu author Hilde Janssens author Nemanja Vukašinović author Miroslav Kvasnica author Johan M. Winne author Yongxiang Gao author Shutang Tan author 2DE75584-F248-11E8-B48F-1D18A9856A870000-0002-0471-8285 Jiří Friml author 4159519E-F248-11E8-B48F-1D18A9856A870000-0002-8302-7596 Xin Liu author Eugenia Russinova author Linfeng Sun author JiFr department 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. American Association for the Advancement of Science2024 eng 1095-9203 38513023 00125295520002810.1126/science.adj4591 3836689eadj4591 Ying, W., Wang, Y., Wei, H., Luo, Y., Ma, Q., Zhu, H., … Sun, L. (2024). Structure and function of the Arabidopsis ABC transporter ABCB19 in brassinosteroid export. <i>Science</i>. American Association for the Advancement of Science. <a href="https://doi.org/10.1126/science.adj4591">https://doi.org/10.1126/science.adj4591</a> W. Ying <i>et al.</i>, “Structure and function of the Arabidopsis ABC transporter ABCB19 in brassinosteroid export,” <i>Science</i>, vol. 383, no. 6689. American Association for the Advancement of Science, p. eadj4591, 2024. Ying W, Wang Y, Wei H, et al. Structure and function of the Arabidopsis ABC transporter ABCB19 in brassinosteroid export. <i>Science</i>. 2024;383(6689):eadj4591. doi:<a href="https://doi.org/10.1126/science.adj4591">10.1126/science.adj4591</a> Ying, Wei, Yaowei Wang, Hong Wei, Yongming Luo, Qian Ma, Heyuan Zhu, Hilde Janssens, et al. “Structure and Function of the Arabidopsis ABC Transporter ABCB19 in Brassinosteroid Export.” <i>Science</i>. American Association for the Advancement of Science, 2024. <a href="https://doi.org/10.1126/science.adj4591">https://doi.org/10.1126/science.adj4591</a>. Ying, Wei, et al. “Structure and Function of the Arabidopsis ABC Transporter ABCB19 in Brassinosteroid Export.” <i>Science</i>, vol. 383, no. 6689, American Association for the Advancement of Science, 2024, p. eadj4591, doi:<a href="https://doi.org/10.1126/science.adj4591">10.1126/science.adj4591</a>. W. Ying, Y. Wang, H. Wei, Y. Luo, Q. Ma, H. Zhu, H. Janssens, N. Vukašinović, M. Kvasnica, J.M. Winne, Y. Gao, S. Tan, J. Friml, X. Liu, E. Russinova, L. Sun, Science 383 (2024) eadj4591. Ying W, Wang Y, Wei H, Luo Y, Ma Q, Zhu H, Janssens H, Vukašinović N, Kvasnica M, Winne JM, Gao Y, Tan S, Friml J, Liu X, Russinova E, Sun L. 2024. Structure and function of the Arabidopsis ABC transporter ABCB19 in brassinosteroid export. Science. 383(6689), eadj4591. 152512024-03-31T22:01:12Z2025-09-04T13:19:48Z