Structural Basis of the Allosteric Inhibition of Human ABCG2 by Nanobodies.

Autor: Irobalieva RN; Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland., Manolaridis I; Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland., Jackson SM; Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland., Ni D; Laboratory of Biological Electron Microscopy (LBEM), Institute of Physics, School of Basic Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Dept. of Fund. Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland., Pardon E; Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium., Stahlberg H; Laboratory of Biological Electron Microscopy (LBEM), Institute of Physics, School of Basic Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Dept. of Fund. Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland., Steyaert J; Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium., Locher KP; Institute of Molecular Biology and Biophysics, ETH Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland. Electronic address: locher@mol.biol.ethz.ch.
Jazyk: angličtina
Zdroj: Journal of molecular biology [J Mol Biol] 2023 Oct 01; Vol. 435 (19), pp. 168234. Date of Electronic Publication: 2023 Aug 18.
DOI: 10.1016/j.jmb.2023.168234
Abstrakt: ABCG2 is an ATP-binding cassette transporter that exports a wide range of xenobiotic compounds and has been recognized as a contributing factor for multidrug resistance in cancer cells. Substrate and inhibitor interactions with ABCG2 have been extensively studied and small molecule inhibitors have been developed that prevent the export of anticancer drugs from tumor cells. Here, we explore the potential for inhibitors that target sites other than the substrate binding pocket of ABCG2. We developed novel nanobodies against ABCG2 and used functional analyses to select three inhibitory nanobodies (Nb8, Nb17 and Nb96) for structural studies by single particle cryo-electron microscopy. Our results showed that these nanobodies allosterically bind to different regions of the nucleotide binding domains. Two copies of Nb8 bind to the apex of the NBDs preventing them from fully closing. Nb17 binds near the two-fold axis of the transporter and interacts with both NBDs. Nb96 binds to the side of the NBD and immobilizes a region connected to key motifs involved in ATP binding and hydrolysis. All three nanobodies prevent the transporter from undergoing conformational changes required for substrate transport. These findings advance our understanding of the molecular basis of modulation of ABCG2 by external binders, which may contribute to the development of a new generation of inhibitors. Furthermore, this is the first example of modulation of human multidrug resistance transporters by nanobodies.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: