ジャーナル: Nat Commun / 年: 2025 タイトル: Structural basis for the transport and regulation mechanism of the multidrug resistance-associated protein 2. 著者: Eriko Koide / Harlan L Pietz / Jean Beltran / Jue Chen / 要旨: Multidrug resistance-associated protein 2 (MRP2) is an ATP-powered exporter important for maintaining liver homeostasis and a potential contributor to chemotherapeutic resistance. Using cryogenic ...Multidrug resistance-associated protein 2 (MRP2) is an ATP-powered exporter important for maintaining liver homeostasis and a potential contributor to chemotherapeutic resistance. Using cryogenic electron microscopy (cryo-EM), we determine the structures of human MRP2 in three conformational states: an autoinhibited state, a substrate-bound pre-translocation state, and an ATP-bound post-translocation state. In the autoinhibited state, the cytosolic regulatory (R) domain plugs into the transmembrane substrate-binding site and extends into the cytosol to form a composite ATP-binding site at the surface of nucleotide-binding domain 2. Substrate displaces the R domain, permitting conformational changes necessary for transport. These observations suggest that the R domain functions as a selectivity gauge, where only at sufficiently high concentrations can the substrate effectively initiate transport. Comparative structural analyzes of MRP2 bound to various substrates, as determined in this study and others, reveal how MRP2 recognizes a diverse array of compounds, supporting its role in multidrug resistance.
全体 : MRP2(E1462Q) in inward-facing, R-domain engaged conformation
全体
名称: MRP2(E1462Q) in inward-facing, R-domain engaged conformation
要素
細胞: MRP2(E1462Q) in inward-facing, R-domain engaged conformation
タンパク質・ペプチド: ATP-binding cassette sub-family C member 2
リガンド: ADENOSINE-5'-TRIPHOSPHATE
リガンド: MAGNESIUM ION
リガンド: UNKNOWN LIGAND
リガンド: CHOLESTEROL
-
超分子 #1: MRP2(E1462Q) in inward-facing, R-domain engaged conformation
超分子
名称: MRP2(E1462Q) in inward-facing, R-domain engaged conformation タイプ: cell / ID: 1 / 親要素: 0 / 含まれる分子: #1 詳細: detergent-solubilized MRP2(E1462Q) bound to ATP and magnesium. Lipids and cholesterols were also identified bound to the protein.